Genome characterization of a novel binary toxin-positive strain of Clostridium difficile and comparison with the epidemic 027 and 078 strains.

PubMed

Peng, Zhong; Liu, Sidi; Meng, Xiujuan; Liang, Wan; Xu, Zhuofei; Tang, Biao; Wang, Yuanguo; Duan, Juping; Fu, Chenchao; Wu, Bin; Wu, Anhua; Li, Chunhui

2017-01-01

Clostridium difficile is an anaerobic Gram-positive spore-forming gut pathogen that causes antibiotic-associated diarrhea worldwide. A small number of C. difficile strains express the binary toxin (CDT), which is generally found in C. difficile 027 (ST1) and/or 078 (ST11) in clinic. However, we isolated a binary toxin-positive non-027, non-078 C. difficile LC693 that is associated with severe diarrhea in China. The genotype of this strain was determined as ST201. To understand the pathogenesis-basis of C. difficile ST201, the strain LC693 was chosen for whole genome sequencing, and its genome sequence was analyzed together with the other two ST201 strains VL-0104 and VL-0391 and compared to the epidemic 027/ST1 and 078/ST11 strains. The project finally generated an estimated genome size of approximately 4.07 Mbp for strain LC693. Genome size of the three ST201 strains ranged from 4.07 to 4.16 Mb, with an average GC content between 28.5 and 28.9%. Phylogenetic analysis demonstrated that the ST201 strains belonged to clade 3. The ST201 genomes contained more than 40 antibiotic resistance genes and 15 of them were predicted to be associated with vancomycin-resistance. The ST201 strains contained a larger PaLoc with a Tn6218 element inserted than the 027/ST1 and 078/ST11 strains, and encoded a truncated TcdC. In addition, the ST201 strains contained intact binary toxin coding and regulation genes which are highly homologous to the 027/ST1 strain. Genome comparison of the ST201 strains with the epidemic 027 and 078 strain identified 641 genes specific for C. difficile ST201, and a number of them were predicted as fitness and virulence associated genes. The presence of those genes also contributes to the pathogenesis of the ST201 strains. In this study, the genomic characterization of three binary toxin-positive C. difficile ST201 strains in clade 3 was discussed and compared to the genomes of the epidemic 027 and the 078 strains. Our analysis identified a number fitness and virulence associated genes/loci in the ST201 genomes that contribute to the pathogenesis of C. difficile ST201.

Function of the CRISPR-Cas System of the Human Pathogen Clostridium difficile

PubMed Central

Boudry, Pierre; Semenova, Ekaterina; Monot, Marc; Datsenko, Kirill A.; Lopatina, Anna; Sekulovic, Ognjen; Ospina-Bedoya, Maicol; Fortier, Louis-Charles; Severinov, Konstantin; Dupuy, Bruno

2015-01-01

ABSTRACT Clostridium difficile is the cause of most frequently occurring nosocomial diarrhea worldwide. As an enteropathogen, C. difficile must be exposed to multiple exogenous genetic elements in bacteriophage-rich gut communities. CRISPR (clustered regularly interspaced short palindromic repeats)-Cas (CRISPR-associated) systems allow bacteria to adapt to foreign genetic invaders. Our recent data revealed active expression and processing of CRISPR RNAs from multiple type I-B CRISPR arrays in C. difficile reference strain 630. Here, we demonstrate active expression of CRISPR arrays in strain R20291, an epidemic C. difficile strain. Through genome sequencing and host range analysis of several new C. difficile phages and plasmid conjugation experiments, we provide evidence of defensive function of the CRISPR-Cas system in both C. difficile strains. We further demonstrate that C. difficile Cas proteins are capable of interference in a heterologous host, Escherichia coli. These data set the stage for mechanistic and physiological analyses of CRISPR-Cas-mediated interactions of important global human pathogen with its genetic parasites. PMID:26330515

Variations in Virulence and Molecular Biology among Emerging Strains of Clostridium difficile

PubMed Central

Hunt, Jonathan J.

2013-01-01

SUMMARY Clostridium difficile is a Gram-positive, spore-forming organism which infects and colonizes the large intestine, produces potent toxins, triggers inflammation, and causes significant systemic complications. Treating C. difficile infection (CDI) has always been difficult, because the disease is both caused and resolved by antibiotic treatment. For three and a half decades, C. difficile has presented a treatment challenge to clinicians, and the situation took a turn for the worse about 10 years ago. An increase in epidemic outbreaks related to CDI was first noticed around 2003, and these outbreaks correlated with a sudden increase in the mortality rate of this illness. Further studies discovered that these changes in CDI epidemiology were associated with the rapid emergence of hypervirulent strains of C. difficile, now collectively referred to as NAP1/BI/027 strains. The discovery of new epidemic strains of C. difficile has provided a unique opportunity for retrospective and prospective studies that have sought to understand how these strains have essentially replaced more historical strains as a major cause of CDI. Moreover, detailed studies on the pathogenesis of NAP1/BI/027 strains are leading to new hypotheses on how this emerging strain causes severe disease and is more commonly associated with epidemics. In this review, we provide an overview of CDI, discuss critical mechanisms of C. difficile virulence, and explain how differences in virulence-associated factors between historical and newly emerging strains might explain the hypervirulence exhibited by this pathogen during the past decade. PMID:24296572

Clostridium difficile and Clostridium perfringens from wild carnivore species in Brazil.

PubMed

Silva, Rodrigo Otávio Silveira; D'Elia, Mirella Lauria; Tostes Teixeira, Erika Procópio; Pereira, Pedro Lúcio Lithg; de Magalhães Soares, Danielle Ferreira; Cavalcanti, Álvaro Roberto; Kocuvan, Aleksander; Rupnik, Maja; Santos, André Luiz Quagliatto; Junior, Carlos Augusto Oliveira; Lobato, Francisco Carlos Faria

2014-08-01

Despite some case reports, the importance of Clostridium perfringens and Clostridium difficile for wild carnivores remains unclear. Thus, the objective of this study was to identify C. perfringens and C. difficile strains in stool samples from wild carnivore species in Brazil. A total of 34 stool samples were collected and subjected to C. perfringens and C. difficile isolation. Suggestive colonies of C. perfringens were then analyzed for genes encoding the major C. perfringens toxins (alpha, beta, epsilon and iota) and the beta-2 toxin (cpb2), enterotoxin (cpe) and NetB (netb) genes. C. difficile strains were analyzed by multiplex-PCR for toxins A (tcdA) and B (tcdB) and a binary toxin gene (cdtB) and also submitted to a PCR ribotyping. Unthawed aliquots of samples positive for C. difficile isolation were subjected to the detection of A/B toxins by a cytotoxicity assay (CTA). C. perfringens was isolated from 26 samples (76.5%), all of which were genotyped as type A. The netb gene was not detected, whereas the cpb2 and cpe genes were found in nine and three C. perfringens strains, respectively. C. difficile was isolated from two (5.9%) samples. A non-toxigenic strain was recovered from a non-diarrheic maned wolf (Chrysocyon brachyurus). Conversely, a toxigenic strain was found in the sample of a diarrheic ocelot (Leopardus pardallis); an unthawed stool sample was also positive for A/B toxins by CTA, indicating a diagnosis of C. difficile-associated diarrhea in this animal. The present work suggests that wild carnivore species could carry C. difficile strains and that they could be susceptible to C. difficile infection. Copyright © 2014 Elsevier Ltd. All rights reserved.

Association of healthcare exposure with acquisition of different Clostridium difficile strain types in patients with recurrent infection or colonization after clinical resolution of initial infection.

PubMed

Thabit, A K; Housman, S T; Burnham, C D; Nicolau, D P

2016-02-01

Following the resolution of an episode of Clostridium difficile infection (CDI), the factors associated with acquisition of different C. difficile strain types in patients with recurrent infection or persistent colonization have not been evaluated. To explore factors with potential correlation with acquisition of different C. difficile strain types in patients clinically cured of CDI through long-term follow-up across the continuum of care. Polymerase chain reaction ribotyping was performed on C. difficile isolates recovered at baseline and follow-up (days 19-38) from stool samples of patients successfully treated for CDI, and those who had recurrence and/or colonization following symptom resolution. Chart review was conducted to determine factors associated with acquisition of a different C. difficile ribotype. Of 25 patients initially cured of CDI, five had a recurrence and eight were colonized at follow-up. Patients did not differ with regard to age, sex, and whether the initial infection was with the BI/NAP1/027 strain. Ribotyping revealed that two out of five patients had recurrence attributed to a different strain type. Three of the colonized patients demonstrated strain switching compared with five patients who carried the same baseline strain. All patients (both infected and colonized) with different C. difficile ribotypes were exposed to the healthcare system. Exposure to antibiotics and proton pump inhibitors were not related to strain switching. Exposure to healthcare, but not to antibiotics or proton pump inhibitors, was consistently associated with recurrence or colonization with a different C. difficile ribotype. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Epidemic Clostridium difficile Strains Demonstrate Increased Competitive Fitness Compared to Nonepidemic Isolates

PubMed Central

Robinson, Catherine D.; Auchtung, Jennifer M.; Collins, James

2014-01-01

Clostridium difficile infection is the most common cause of severe cases of antibiotic-associated diarrhea (AAD) and is a significant health burden. Recent increases in the rate of C. difficile infection have paralleled the emergence of a specific phylogenetic clade of C. difficile strains (ribotype 027; North American pulsed-field electrophoresis 1 [NAP1]; restriction endonuclease analysis [REA] group BI). Initial reports indicated that ribotype 027 strains were associated with increased morbidity and mortality and might be hypervirulent. Although subsequent work has raised some doubt as to whether ribotype 027 strains are hypervirulent, the strains are considered epidemic isolates that have caused severe outbreaks across the globe. We hypothesized that one factor that could lead to the increased prevalence of ribotype 027 strains would be if these strains had increased competitive fitness compared to strains of other ribotypes. We developed a moderate-throughput in vitro model of C. difficile infection and used it to test competition between four ribotype 027 clinical isolates and clinical isolates of four other ribotypes (001, 002, 014, and 053). We found that ribotype 027 strains outcompeted the strains of other ribotypes. A similar competitive advantage was observed when two ribotype pairs were competed in a mouse model of C. difficile infection. Based upon these results, we conclude that one possible mechanism through which ribotype 027 strains have caused outbreaks worldwide is their increased ability to compete in the presence of a complex microbiota. PMID:24733099

Multiplex PCR Targeting tpi (Triose Phosphate Isomerase), tcdA (Toxin A), and tcdB (Toxin B) Genes for Toxigenic Culture of Clostridium difficile

PubMed Central

Lemee, Ludovic; Dhalluin, Anne; Testelin, Sabrina; Mattrat, Marie-Andre; Maillard, Karine; Lemeland, Jean-François; Pons, Jean-Louis

2004-01-01

A multiplex PCR toxigenic culture approach was designed for simultaneous identification and toxigenic type characterization of Clostridium difficile isolates. Three pairs of primers were designed for the amplification of (i) a species-specific internal fragment of the tpi (triose phosphate isomerase) gene, (ii) an internal fragment of the tcdB (toxin B) gene, and (iii) an internal fragment of the tcdA (toxin A) gene allowing distinction between toxin A-positive, toxin B-positive (A+B+) strains and toxin A-negative, toxin B-positive (A−B+) variant strains. The reliability of the multiplex PCR was established by using a panel of 72 C. difficile strains including A+B+, A−B−, and A−B+ toxigenic types and 11 other Clostridium species type strains. The multiplex PCR assay was then included in a toxigenic culture approach for the detection, identification, and toxigenic type characterization of C. difficile in 1,343 consecutive human and animal stool samples. Overall, 111 (15.4%) of 721 human samples were positive for C. difficile; 67 (60.4%) of these samples contained A+B+ toxigenic isolates, and none of them contained A−B+ variant strains. Fifty (8%) of 622 animal samples contained C. difficile strains, which were toxigenic in 27 (54%) cases, including 1 A−B+ variant isolate. Eighty of the 721 human stool samples (37 positive and 43 negative for C. difficile culture) were comparatively tested by Premier Toxins A&B (Meridian Bioscience) and Triage C. difficile Panel (Biosite) immunoassays, the results of which were found concordant with toxigenic culture for 82.5 and 92.5% of the samples, respectively. The multiplex PCR toxigenic culture scheme described here allows combined diagnosis and toxigenic type characterization for human and animal C. difficile intestinal infections. PMID:15583303

Genomic and expression analysis of the vanG-like gene cluster of Clostridium difficile.

PubMed

Peltier, Johann; Courtin, Pascal; El Meouche, Imane; Catel-Ferreira, Manuella; Chapot-Chartier, Marie-Pierre; Lemée, Ludovic; Pons, Jean-Louis

2013-07-01

Primary antibiotic treatment of Clostridium difficile intestinal diseases requires metronidazole or vancomycin therapy. A cluster of genes homologous to enterococcal glycopeptides resistance vanG genes was found in the genome of C. difficile 630, although this strain remains sensitive to vancomycin. This vanG-like gene cluster was found to consist of five ORFs: the regulatory region consisting of vanR and vanS and the effector region consisting of vanG, vanXY and vanT. We found that 57 out of 83 C. difficile strains, representative of the main lineages of the species, harbour this vanG-like cluster. The cluster is expressed as an operon and, when present, is found at the same genomic location in all strains. The vanG, vanXY and vanT homologues in C. difficile 630 are co-transcribed and expressed to a low level throughout the growth phases in the absence of vancomycin. Conversely, the expression of these genes is strongly induced in the presence of subinhibitory concentrations of vancomycin, indicating that the vanG-like operon is functional at the transcriptional level in C. difficile. Hydrophilic interaction liquid chromatography (HILIC-HPLC) and MS analysis of cytoplasmic peptidoglycan precursors of C. difficile 630 grown without vancomycin revealed the exclusive presence of a UDP-MurNAc-pentapeptide with an alanine at the C terminus. UDP-MurNAc-pentapeptide [d-Ala] was also the only peptidoglycan precursor detected in C. difficile grown in the presence of vancomycin, corroborating the lack of vancomycin resistance. Peptidoglycan structures of a vanG-like mutant strain and of a strain lacking the vanG-like cluster did not differ from the C. difficile 630 strain, indicating that the vanG-like cluster also has no impact on cell-wall composition.

Presence of the epidemic North American Pulsed Field type 1 Clostridium difficile strain in hospitalized children.

PubMed

Toltzis, Philip; Kim, Jason; Dul, Michael; Zoltanski, Joan; Smathers, Sarah; Zaoutis, Theoklis

2009-04-01

A hypervirulent strain of Clostridium difficile-labeled North American Pulsed Field type 1 causes severe disease in adults. To determine the prevalence of NAP1 C. difficile in children, organisms from consecutive C. difficile toxin-positive stool samples at 2 children's hospitals microbiology laboratories were characterized. We found that 19.4% of these samples were NAP1.

Effect of tcdR Mutation on Sporulation in the Epidemic Clostridium difficile Strain R20291.

PubMed

Girinathan, Brintha P; Monot, Marc; Boyle, Daniel; McAllister, Kathleen N; Sorg, Joseph A; Dupuy, Bruno; Govind, Revathi

2017-01-01

Clostridium difficile is an important nosocomial pathogen and the leading cause of hospital-acquired diarrhea. Antibiotic use is the primary risk factor for the development of C. difficile -associated disease because it disrupts normally protective gut flora and enables C. difficile to colonize the colon. C. difficile damages host tissue by secreting toxins and disseminates by forming spores. The toxin-encoding genes, tcdA and tcdB , are part of a pathogenicity locus, which also includes the tcdR gene that codes for TcdR, an alternate sigma factor that initiates transcription of tcdA and tcdB genes. We created a tcdR mutant in epidemic-type C. difficile strain R20291 in an attempt to identify the global role of tcdR . A site-directed mutation in tcdR affected both toxin production and sporulation in C. difficile R20291. Spores of the tcdR mutant were more heat sensitive than the wild type (WT). Nearly 3-fold more taurocholate was needed to germinate spores from the tcdR mutant than to germinate the spores prepared from the WT strain. Transmission electron microscopic analysis of the spores also revealed a weakly assembled exosporium on the tcdR mutant spores. Accordingly, comparative transcriptome analysis showed many differentially expressed sporulation genes in the tcdR mutant compared to the WT strain. These data suggest that regulatory networks of toxin production and sporulation in C. difficile strain R20291 a re linked with each other. IMPORTANCE C. difficile infects thousands of hospitalized patients every year, causing significant morbidity and mortality. C. difficile spores play a pivotal role in the transmission of the pathogen in the hospital environment. During infection, the spores germinate, and the vegetative bacterial cells produce toxins that damage host tissue. Thus, sporulation and toxin production are two important traits of C. difficile . In this study, we showed that a mutation in tcdR , the toxin gene regulator, affects both toxin production and sporulation in epidemic-type C. difficile strain R20291.

Effect of tcdR Mutation on Sporulation in the Epidemic Clostridium difficile Strain R20291

PubMed Central

Girinathan, Brintha P.; Monot, Marc; Boyle, Daniel; McAllister, Kathleen N.; Dupuy, Bruno

2017-01-01

ABSTRACT Clostridium difficile is an important nosocomial pathogen and the leading cause of hospital-acquired diarrhea. Antibiotic use is the primary risk factor for the development of C. difficile-associated disease because it disrupts normally protective gut flora and enables C. difficile to colonize the colon. C. difficile damages host tissue by secreting toxins and disseminates by forming spores. The toxin-encoding genes, tcdA and tcdB, are part of a pathogenicity locus, which also includes the tcdR gene that codes for TcdR, an alternate sigma factor that initiates transcription of tcdA and tcdB genes. We created a tcdR mutant in epidemic-type C. difficile strain R20291 in an attempt to identify the global role of tcdR. A site-directed mutation in tcdR affected both toxin production and sporulation in C. difficile R20291. Spores of the tcdR mutant were more heat sensitive than the wild type (WT). Nearly 3-fold more taurocholate was needed to germinate spores from the tcdR mutant than to germinate the spores prepared from the WT strain. Transmission electron microscopic analysis of the spores also revealed a weakly assembled exosporium on the tcdR mutant spores. Accordingly, comparative transcriptome analysis showed many differentially expressed sporulation genes in the tcdR mutant compared to the WT strain. These data suggest that regulatory networks of toxin production and sporulation in C. difficile strain R20291 are linked with each other. IMPORTANCE C. difficile infects thousands of hospitalized patients every year, causing significant morbidity and mortality. C. difficile spores play a pivotal role in the transmission of the pathogen in the hospital environment. During infection, the spores germinate, and the vegetative bacterial cells produce toxins that damage host tissue. Thus, sporulation and toxin production are two important traits of C. difficile. In this study, we showed that a mutation in tcdR, the toxin gene regulator, affects both toxin production and sporulation in epidemic-type C. difficile strain R20291. PMID:28217744

Impacts of infection with different toxigenic Clostridium difficile strains on faecal microbiota in children

NASA Astrophysics Data System (ADS)

Ling, Zongxin; Liu, Xia; Jia, Xiaoyun; Cheng, Yiwen; Luo, Yueqiu; Yuan, Li; Wang, Yuezhu; Zhao, Chunna; Guo, Shu; Li, Lanjuan; Xu, Xiwei; Xiang, Charlie

2014-12-01

Increasing evidence suggests that altered intestinal microbial composition and function result in an increased risk of Clostridium difficile-associated diarrhoea (CDAD); however, the specific changes of intestinal microbiota in children suffering from CDAD and their associations with C. difficile strain toxigenicity are poorly understood. High-throughput pyrosequencing showed that reduced faecal bacterial diversity and dramatic shifts of microbial composition were found in children with CDAD. The Firmicutes/Bacteroidetes ratio was increased significantly in patients with CDAD, which indicated that dysbiosis of faecal microbiota was closely associated with CDAD. C. difficile infection resulted in an increase in lactate-producing phylotypes, with a corresponding decrease in butyrate-producing bacteria. The decrease in butyrate and lactate buildup impaired intestinal colonisation resistance, which increased the susceptibility to C. difficile colonisation. Strains of C. difficile which were positive for both toxin A and toxin B reduced faecal bacterial diversity to a greater degree than strains that were only toxin B-positive, and were associated with unusually abundant Enterococcus, which implies that the C. difficile toxins have different impacts on the faecal microbiota of children. Greater understanding of the relationships between disruption of the normal faecal microbiota and colonisation with C. difficile that produces different toxins might lead to improved treatment.

Recognition of Clostridium difficile PCR-ribotypes 001, 027 and 126/078 using an extended MALDI-TOF MS system.

PubMed

Reil, M; Erhard, M; Kuijper, E J; Kist, M; Zaiss, H; Witte, W; Gruber, H; Borgmann, S

2011-11-01

During the last decade, Clostridium difficile infection (CDI) increased markedly inside as well as outside of hospitals. In association with the occurrence of new hypervirulent C. difficile strains, CDI became more important. Until now typing of C. difficile strains has been enabled by PCR-ribotyping. However, this method is restricted to specialized laboratories combined with high maintenance cost. Therefore, we tested MALDI-TOF mass spectrometry for typing of C. difficile to provide a fast method for surveillance of CDI. Using a standard set of 25 different C. difficile PCR ribotypes a database was made by different mass spectra recorded in the SARAMIS software (AnagnosTec, Zossen, Germany). The database was validated with 355 C. difficile strains belonging to 29 different PCR ribotypes collected prospectively from all submitted feces samples in 2009. The most frequent PCR ribotypes were type 001 (70%), 027 (4.8%) and 078/126 (4.7%). All three types were recognized by MALDI-TOF MS. We conclude that an extended MALDI-TOF system was capable to recognize specific markers for ribotypes 001, 027 and 078/126 allowing an effective identification of these strains.

Cellular Uptake and Mode-of-Action of Clostridium difficile Toxins.

PubMed

Papatheodorou, Panagiotis; Barth, Holger; Minton, Nigel; Aktories, Klaus

2018-01-01

Research on the human gut pathogen Clostridium difficile and its toxins has gained much attention, particularly as a consequence of the increasing threat to human health presented by emerging hypervirulent strains. Toxin A (TcdA) and B (TcdB) are the two major virulence determinants of C. difficile. Both are single-chain proteins with a similar multidomain architecture. Certain hypervirulent C. difficile strains also produce a third toxin, namely binary toxin CDT (Clostridium difficile transferase). As C. difficile toxins are the causative agents of C. difficile-associated diseases (CDAD), such as antibiotics-associated diarrhea and pseudomembranous colitis, considerable efforts have been expended to unravel their molecular mode-of-action and the cellular mechanisms responsible for their uptake. Notably, a high proportion of studies on C. difficile toxins were performed in European laboratories. In this chapter we will highlight important recent advances in C. difficile toxins research.

Evolutionary clade affects resistance of Clostridium difficile spores to Cold Atmospheric Plasma

NASA Astrophysics Data System (ADS)

Connor, Mairéad; Flynn, Padrig B.; Fairley, Derek J.; Marks, Nikki; Manesiotis, Panagiotis; Graham, William G.; Gilmore, Brendan F.; McGrath, John W.

2017-02-01

Clostridium difficile is a spore forming bacterium and the leading cause of colitis and antibiotic associated diarrhoea in the developed world. Spores produced by C. difficile are robust and can remain viable for months, leading to prolonged healthcare-associated outbreaks with high mortality. Exposure of C. difficile spores to a novel, non-thermal atmospheric pressure gas plasma was assessed. Factors affecting sporicidal efficacy, including percentage of oxygen in the helium carrier gas admixture, and the effect on spores from different strains representing the five evolutionary C. difficile clades was investigated. Strains from different clades displayed varying resistance to cold plasma. Strain R20291, representing the globally epidemic ribotype 027 type, was the most resistant. However all tested strains displayed a ~3 log reduction in viable spore counts after plasma treatment for 5 minutes. Inactivation of a ribotype 078 strain, the most prevalent clinical type seen in Northern Ireland, was further assessed with respect to surface decontamination, pH, and hydrogen peroxide concentration. Environmental factors affected plasma activity, with dry spores without the presence of organic matter being most susceptible. This study demonstrates that cold atmospheric plasma can effectively inactivate C. difficile spores, and highlights factors that can affect sporicidal activity.

PCR ribotyping and arbitrarily primed PCR for typing strains of Clostridium difficile from a Polish maternity hospital.

PubMed

Martirosian, G; Kuipers, S; Verbrugh, H; van Belkum, A; Meisel-Mikolajczyk, F

1995-08-01

Detection of the source of Clostridium difficile strains is of importance for the control of the nosocomial spread of this microorganism. For this purpose, vaginal and rectal swabs from 183 mothers, duplicate fecal samples (taken on days 1 and 4 after birth) from 183 neonates, and 94 environmental samples were cultured for C. difficile. The microorganism was never detected in the meconium obtained on day 1 after birth. On the other hand, an incidence of 17% C. difficile positivity was noted in the fecal samples obtained on day 4 after birth. Forty-two percent of the 31 colonized neonates had been delivered with complications. The bacteria were never encountered in the rectal swabs of the mothers, and C. difficile was identified in only one vaginal swab. In contrast, 13% of the environmental samples were positive for C. difficile. No major difference was encountered between patient and environmental isolates with respect to toxigenicity (58 to 65% toxigenic isolates). All strains were subsequently typed by PCR amplification of the 16S-23S ribosomal intergenic spacer regions and by arbitrarily primed PCR (AP-PCR) with different primers and combinations thereof. All environmental isolates and 11 of 31 neonatal strains were of a single type. The vaginal strain was unique, and among the maternity ward- and neonate-related isolates, only two additional AP-PCR types were identified. When a collection of C. difficile strains from patients hospitalized in other institutions and suffering from antibiotic-associated diarrhea or pseudomembranous colitis was analyzed in a similar manner, it appeared that the strain from the maternity ward was unique. The other strain commonly encountered among the neonates was also identified frequently among the isolates from patients with antibiotic-associated diarrhea or pseudomembranous colitis, indicating its general occurrence. On the basis of both epidemiological studies and PCR-mediated genotyping, it was shown that the environment and not the birth canal is the major source of C. difficile acquisition by neonates in this maternity hospital setting. Furthermore, AP-PCR appears to be a fast and useful method for epidemiologically relevant typing of C. difficile isolates.

Molecular characteristics of Clostridium difficile strains from patients with a first recurrence more than 8 weeks after the primary infection.

PubMed

Chen, Yijian; Rashid, Mamun Ur; Huang, Haihui; Fang, Hong; Nord, Carl Erik; Wang, Minggui; Weintraub, Andrej

2017-08-01

Nearly all published studies of recurrent Clostridium difficile infections (CDI) report recurrent CDI within 8 weeks after the primary infection. This study explored the molecular characteristics of C. difficile isolates from the first recurrent CDI more than 8 weeks after the primary infection. Consecutive hospitalized patients with a recurrent CDI more than 8 weeks after a primary infection were enrolled prospectively from January 2008 to February 2011. All C. difficile isolates of the primary and recurrent infections were collected and subjected to polymerase chain reaction ribotyping and antimicrobial susceptibility testing. There were 62 cases of CDI in this study, which included 32 cases (51.6%) of recurrence due to the same ribotype of C. difficile, 26 (41.9%) cases due to a different ribotype, and four (6.5%) cases with 2-4 recurrences due to the same or different strains. One hundred and forty C. difficile isolates were obtained, which included 62 primary CDI isolates and 78 recurrent isolates. Ribotype 020 was the most common C. difficile strain in primary and recurrent infections. Ribotype 001 accounted for 15.4% (10/78) of recurrent infections and 3.2% (2/62) of primary infections (p = 0.0447). The minimum inhibitory concentration at 90% (MIC 90 ) values of linezolid, moxifloxacin, and clindamycin against type 001 strains were much higher, compared to the three other common ribotypes. Recurrent CDI more than 8 weeks after a primary infection can be caused by the same or different C. difficile ribotype at similar percentages. Ribotype 001 C. difficile strains, which have a lower susceptibility to antimicrobials, were isolated more frequently in patients with a recurrent CDI. Copyright © 2015. Published by Elsevier B.V.

Genome Sequence of Vibrio cholerae Strain O1 Ogawa El Tor, Isolated in Mexico, 2013

PubMed Central

Hernández-Monroy, Irma; López-Martínez, Irma; Ortiz-Alcántara, Joanna; González-Durán, Elizabeth; Ruiz-Matus, Cuitláhuac; Kuri-Morales, Pablo; Ramírez-González, José Ernesto

2014-01-01

We present the draft genome sequence of Vibrio cholerae InDRE 3140 recovered in 2013 during a cholera outbreak in Mexico. The genome showed the Vibrio 7th pandemic islands VSP1 and VSP2, the pathogenic islands VPI-1 and VPI-2, the integrative and conjugative element SXT/R391 (ICE-SXT), and both prophages CTXφ and RS1φ. PMID:25359919

Presence of Clostridium difficile in poultry and poultry meat in Egypt.

PubMed

Abdel-Glil, Mostafa Y; Thomas, Prasad; Schmoock, Gernot; Abou-El-Azm, Kamel; Wieler, Lothar H; Neubauer, Heinrich; Seyboldt, Christian

2018-06-01

C. difficile has been recognized as a potential zoonotic agent encouraging investigations of C. difficile prevalence and ribotypes in animals. Here we report the prevalence and diversity of Egyptian C. difficile in I) samples from healthy poultry (n = 50), II) samples from diseased poultry (n = 54), and III) poultry meat (n = 150). Thirteen isolates were obtained from seven healthy and five diseased animals, but no C. difficile was cultured from poultry meat. The isolated C. difficile strains belonged to 3 different PCR-ribotypes (039/2, 205 and 001/FLI01). The detection of strains related to RT 001 known for its ability to cause disease in humans makes poultry a potential reservoir for pathogenic C. difficile. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Inducible Expression of spo0A as a Universal Tool for Studying Sporulation in Clostridium difficile.

PubMed

Dembek, Marcin; Willing, Stephanie E; Hong, Huynh A; Hosseini, Siamand; Salgado, Paula S; Cutting, Simon M

2017-01-01

Clostridium difficile remains a leading nosocomial pathogen, putting considerable strain on the healthcare system. The ability to form endospores, highly resistant to environmental insults, is key to its persistence and transmission. However, important differences exist between the sporulation pathways of C. difficile and the model Gram-positive organism Bacillus subtilis . Amongst the challenges in studying sporulation in C. difficile is the relatively poor levels of sporulation and high heterogeneity in the sporulation process. To overcome these limitations we placed P tet regulatory elements upstream of the master regulator of sporulation, spo0A , generating a new strain that can be artificially induced to sporulate by addition of anhydrotetracycline (ATc). We demonstrate that this strain is asporogenous in the absence of ATc, and that ATc can be used to drive faster and more efficient sporulation. Induction of Spo0A is titratable and this can be used in the study of the spo0A regulon both in vitro and in vivo , as demonstrated using a mouse model of C. difficile infection (CDI). Insights into differences between the sporulation pathways in B. subtilis and C. difficile gained by study of the inducible strain are discussed, further highlighting the universal interest of this tool. The P tet -spo0A strain provides a useful background in which to generate mutations in genes involved in sporulation, therefore providing an exciting new tool to unravel key aspects of sporulation in C. difficile.

Inducible Expression of spo0A as a Universal Tool for Studying Sporulation in Clostridium difficile

PubMed Central

Dembek, Marcin; Willing, Stephanie E.; Hong, Huynh A.; Hosseini, Siamand; Salgado, Paula S.; Cutting, Simon M.

2017-01-01

Clostridium difficile remains a leading nosocomial pathogen, putting considerable strain on the healthcare system. The ability to form endospores, highly resistant to environmental insults, is key to its persistence and transmission. However, important differences exist between the sporulation pathways of C. difficile and the model Gram-positive organism Bacillus subtilis. Amongst the challenges in studying sporulation in C. difficile is the relatively poor levels of sporulation and high heterogeneity in the sporulation process. To overcome these limitations we placed Ptet regulatory elements upstream of the master regulator of sporulation, spo0A, generating a new strain that can be artificially induced to sporulate by addition of anhydrotetracycline (ATc). We demonstrate that this strain is asporogenous in the absence of ATc, and that ATc can be used to drive faster and more efficient sporulation. Induction of Spo0A is titratable and this can be used in the study of the spo0A regulon both in vitro and in vivo, as demonstrated using a mouse model of C. difficile infection (CDI). Insights into differences between the sporulation pathways in B. subtilis and C. difficile gained by study of the inducible strain are discussed, further highlighting the universal interest of this tool. The Ptet-spo0A strain provides a useful background in which to generate mutations in genes involved in sporulation, therefore providing an exciting new tool to unravel key aspects of sporulation in C. difficile. PMID:28983286

Isolation of various genotypes of Clostridium difficile from patients and the environment in an oncology ward.

PubMed

Cohen, S H; Tang, Y J; Muenzer, J; Gumerlock, P H; Silva, J

1997-05-01

The epidemiology of Clostridium difficile-associated diarrhea (CDAD) is not well defined in nonepidemic situations because precise biotyping techniques have only recently become available. Arbitrarily primed polymerase chain reaction (AP-PCR) was used to determine strain identity of C. difficile isolates recovered on our oncology ward, at an incidence rate of 0.84%. Twenty-one strains of C. difficile, which were grouped into 18 different AP-PCR types, were isolated from patients' specimens. Forty-two C. difficile isolates recovered from the environment (33 toxigenic and 9 nontoxigenic) represented 9 different AP-PCR types. The most commonly found type, a toxigenic strain accounting for 29% of the environmental isolates, was widespread throughout the ward. None of the environmental types were found among the isolates from patients. Three patients' isolates were of the same AP-PCR type, and two of these patients had occupied neighboring rooms at the same time. The diversity of C. difficile isotypes suggests that endemic nosocomial CDAD is not necessarily clonally spread.

Carriage of Clostridium difficile by Wild Urban Norway Rats (Rattus norvegicus) and Black Rats (Rattus rattus)

PubMed Central

Patrick, David M.; Mak, Sunny; Jardine, Claire M.; Tang, Patrick; Weese, J. Scott

2014-01-01

Clostridium difficile is an important cause of enteric infections in humans. Recently, concerns have been raised regarding whether animals could be a source of C. difficile spores. Although colonization has been identified in a number of domestic species, the ability of commensal pests to serve as a reservoir for C. difficile has not been well investigated. The objective of this study was to determine whether urban rats (Rattus spp.) from Vancouver, Canada, carry C. difficile. Clostridium difficile was isolated from the colon contents of trapped rats and was characterized using ribotyping, toxinotyping, and toxin gene identification. Generalized linear mixed models and spatial analysis were used to characterize the ecology of C. difficile in rats. Clostridium difficile was isolated from 95 of 724 (13.1%) rats, although prevalence differed from 0% to 46.7% among city blocks. The odds of being C. difficile positive decreased with increasing weight (odds ratio [OR], 0.67; 95% confidence interval [CI], 0.53 to 0.87), suggesting that carriage is more common in younger animals. The strains isolated included 9 ribotypes that matched recognized international designations, 5 identified by our laboratory in previous studies, and 21 “novel” ribotypes. Some strains were clustered geographically; however, the majority were dispersed throughout the study area, supporting environmental sources of exposure and widespread environmental contamination with a variety of C. difficile strains. Given that urban rats are the source of a number of other pathogens responsible for human morbidity and mortality, the potential for rats to be a source of C. difficile for humans deserves further consideration. PMID:24317079

Carriage of Clostridium difficile by wild urban Norway rats (Rattus norvegicus) and black rats (Rattus rattus).

PubMed

Himsworth, Chelsea G; Patrick, David M; Mak, Sunny; Jardine, Claire M; Tang, Patrick; Weese, J Scott

2014-02-01

Clostridium difficile is an important cause of enteric infections in humans. Recently, concerns have been raised regarding whether animals could be a source of C. difficile spores. Although colonization has been identified in a number of domestic species, the ability of commensal pests to serve as a reservoir for C. difficile has not been well investigated. The objective of this study was to determine whether urban rats (Rattus spp.) from Vancouver, Canada, carry C. difficile. Clostridium difficile was isolated from the colon contents of trapped rats and was characterized using ribotyping, toxinotyping, and toxin gene identification. Generalized linear mixed models and spatial analysis were used to characterize the ecology of C. difficile in rats. Clostridium difficile was isolated from 95 of 724 (13.1%) rats, although prevalence differed from 0% to 46.7% among city blocks. The odds of being C. difficile positive decreased with increasing weight (odds ratio [OR], 0.67; 95% confidence interval [CI], 0.53 to 0.87), suggesting that carriage is more common in younger animals. The strains isolated included 9 ribotypes that matched recognized international designations, 5 identified by our laboratory in previous studies, and 21 "novel" ribotypes. Some strains were clustered geographically; however, the majority were dispersed throughout the study area, supporting environmental sources of exposure and widespread environmental contamination with a variety of C. difficile strains. Given that urban rats are the source of a number of other pathogens responsible for human morbidity and mortality, the potential for rats to be a source of C. difficile for humans deserves further consideration.

Sequence Similarity of Clostridium difficile Strains by Analysis of Conserved Genes and Genome Content Is Reflected by Their Ribotype Affiliation

PubMed Central

Kurka, Hedwig; Ehrenreich, Armin; Ludwig, Wolfgang; Monot, Marc; Rupnik, Maja; Barbut, Frederic; Indra, Alexander; Dupuy, Bruno; Liebl, Wolfgang

2014-01-01

PCR-ribotyping is a broadly used method for the classification of isolates of Clostridium difficile, an emerging intestinal pathogen, causing infections with increased disease severity and incidence in several European and North American countries. We have now carried out clustering analysis with selected genes of numerous C. difficile strains as well as gene content comparisons of their genomes in order to broaden our view of the relatedness of strains assigned to different ribotypes. We analyzed the genomic content of 48 C. difficile strains representing 21 different ribotypes. The calculation of distance matrix-based dendrograms using the neighbor joining method for 14 conserved genes (standard phylogenetic marker genes) from the genomes of the C. difficile strains demonstrated that the genes from strains with the same ribotype generally clustered together. Further, certain ribotypes always clustered together and formed ribotype groups, i.e. ribotypes 078, 033 and 126, as well as ribotypes 002 and 017, indicating their relatedness. Comparisons of the gene contents of the genomes of ribotypes that clustered according to the conserved gene analysis revealed that the number of common genes of the ribotypes belonging to each of these three ribotype groups were very similar for the 078/033/126 group (at most 69 specific genes between the different strains with the same ribotype) but less similar for the 002/017 group (86 genes difference). It appears that the ribotype is indicative not only of a specific pattern of the amplified 16S–23S rRNA intergenic spacer but also reflects specific differences in the nucleotide sequences of the conserved genes studied here. It can be anticipated that the sequence deviations of more genes of C. difficile strains are correlated with their PCR-ribotype. In conclusion, the results of this study corroborate and extend the concept of clonal C. difficile lineages, which correlate with ribotypes affiliation. PMID:24482682

In vitro activity of cadazolid against clinically relevant Clostridium difficile isolates and in an in vitro gut model of C. difficile infection.

PubMed

Chilton, C H; Crowther, G S; Baines, S D; Todhunter, S L; Freeman, J; Locher, H H; Athanasiou, A; Wilcox, M H

2014-03-01

We investigated the in vitro activity of cadazolid against 100 Clostridium difficile isolates and its efficacy in a simulated human gut model of C. difficile infection (CDI). MICs of cadazolid, metronidazole, vancomycin, moxifloxacin and linezolid were determined using agar incorporation for 100 C. difficile isolates, including 30 epidemic strains (ribotypes 027, 106 and 001) with reduced metronidazole susceptibility, 2 linezolid-resistant isolates and 2 moxifloxacin-resistant isolates. We evaluated the efficacy of two cadazolid dosing regimens (250 versus 750 mg/L twice daily for 7 days) to treat simulated CDI. Microflora populations, C. difficile total viable counts and spores, cytotoxin titres, possible emergence of cadazolid, linezolid or quinolone resistance, and antimicrobial concentrations were monitored throughout. Cadazolid was active against all (including linezolid- and moxifloxacin-resistant) C. difficile strains (MIC90 0.125, range 0.03-0.25 mg/L). The cadazolid geometric mean MIC was 152-fold, 16-fold, 9-fold and 7-fold lower than those of moxifloxacin, linezolid, metronidazole and vancomycin, respectively. Both cadazolid dosing regimens rapidly reduced C. difficile viable counts and cytotoxin with no evidence of recurrence. Cadazolid levels persisted at 50-100-fold supra-MIC for 14 days post-dosing. Cadazolid inhibition of enumerated gut microflora was limited, with the exception of bifidobacteria; Bacteroides fragilis group and Lactobacillus spp. counts were unaffected. There was no evidence for selection of strains resistant to cadazolid, quinolones or linezolid. Cadazolid activity was greater than other tested antimicrobials against 100 C. difficile strains. Cadazolid effectively treated simulated CDI in a gut model, with limited impact on the enumerated gut microflora and no signs of recurrence or emergence of resistance within the experimental timeframe.

Diagnosis of Clostridium difficile Infection: an Ongoing Conundrum for Clinicians and for Clinical Laboratories

PubMed Central

Carroll, Karen C.

2013-01-01

SUMMARY Clostridium difficile is a formidable nosocomial and community-acquired pathogen, causing clinical presentations ranging from asymptomatic colonization to self-limiting diarrhea to toxic megacolon and fulminant colitis. Since the early 2000s, the incidence of C. difficile disease has increased dramatically, and this is thought to be due to the emergence of new strain types. For many years, the mainstay of C. difficile disease diagnosis was enzyme immunoassays for detection of the C. difficile toxin(s), although it is now generally accepted that these assays lack sensitivity. A number of molecular assays are commercially available for the detection of C. difficile. This review covers the history and biology of C. difficile and provides an in-depth discussion of the laboratory methods used for the diagnosis of C. difficile infection (CDI). In addition, strain typing methods for C. difficile and the evolving epidemiology of colonization and infection with this organism are discussed. Finally, considerations for diagnosing C. difficile disease in special patient populations, such as children, oncology patients, transplant patients, and patients with inflammatory bowel disease, are described. As detection of C. difficile in clinical specimens does not always equate with disease, the diagnosis of C. difficile infection continues to be a challenge for both laboratories and clinicians. PMID:23824374

Prevalence of Clostridium difficile in raw beef, cow, sheep, goat, camel and buffalo meat in Iran.

PubMed

Rahimi, Ebrahim; Jalali, Mohammad; Weese, J Scott

2014-02-05

Clostridium difficile has been shown to be a nosocomial pathogen associated with diarrhoea and pseudomembranous colitis in hospitalised patients and the infection is believed to be acquired nosocomially. Recent studies have shown the occurrence of C. difficile in food animals which may act as a source of infection to humans.The aim of this study was to determine the occurrence of C. difficile in retail raw beef, cow, sheep, goat, camel and buffalo meat in Iran. From April to October 2012, a total of 660 raw meat samples from beef, cow, sheep, goat, camel and buffalo were purchased from 49 butcheries in Isfahan and Khuzestan provinces, Iran, and were evaluated for the presence of C. difficile using a method including selective enrichment in C. difficile broth, subsequent alcohol shock-treatment and plating onto C. difficile selective medium. C. difficile isolates were tested for the presence of toxin genes and were typed using PCR ribotyping. In this study, 13 of 660 meat samples (2%) were contaminated with C. difficile. The highest prevalence of C. difficile was found in buffalo meat (9%), followed by goat meat (3.3%), beef meat (1.7%), cow (0.94%) and sheep meat (0.9%). Seven of the 13C. difficile strains (53.9%) were positive for tcdA, tcdB and cdtB toxin genes and were classified as ribotype 078. Four strains (30.8%) were positive tcdA, and tcdB, and one strain (7.7%) was possessed only tcdB. The remaining isolate was non-toxigenic. Susceptibilities of 13C. difficile isolates were determined for 11 antimicrobial drugs using the disk diffusion assay. Resistance to clindamycin, gentamycin, and nalidixic acid was the most common finding. To our knowledge, the present study is the first report of the isolation of C. difficile from raw buffalo meat. This study indicates the potential importance of food, including buffalo meat, as a source of transmission of C. difficile to humans.

Chemical and Stress Resistances of Clostridium difficile Spores and Vegetative Cells

PubMed Central

Edwards, Adrianne N.; Karim, Samiha T.; Pascual, Ricardo A.; Jowhar, Lina M.; Anderson, Sarah E.; McBride, Shonna M.

2016-01-01

Clostridium difficile is a Gram-positive, sporogenic and anaerobic bacterium that causes a potentially fatal colitis. C. difficile enters the body as dormant spores that germinate in the colon to form vegetative cells that secrete toxins and cause the symptoms of infection. During transit through the intestine, some vegetative cells transform into spores, which are more resistant to killing by environmental insults than the vegetative cells. Understanding the inherent resistance properties of the vegetative and spore forms of C. difficile is imperative for the development of methods to target and destroy the bacterium. The objective of this study was to define the chemical and environmental resistance properties of C. difficile vegetative cells and spores. We examined vegetative cell and spore tolerances of three C. difficile strains, including 630Δerm, a 012 ribotype and a derivative of a past epidemic strain; R20291, a 027 ribotype and current epidemic strain; and 5325, a clinical isolate that is a 078 ribotype. All isolates were tested for tolerance to ethanol, oxygen, hydrogen peroxide, butanol, chloroform, heat and sodium hypochlorite (household bleach). Our results indicate that 630Δerm vegetative cells (630 spo0A) are more resistant to oxidative stress than those of R20291 (R20291 spo0A) and 5325 (5325 spo0A). In addition, 5325 spo0A vegetative cells exhibited greater resistance to organic solvents. In contrast, 630Δerm spores were more sensitive than R20291 or 5325 spores to butanol. Spores from all three strains exhibited high levels of resistance to ethanol, hydrogen peroxide, chloroform and heat, although R20291 spores were more resistant to temperatures in the range of 60–75°C. Finally, household bleach served as the only chemical reagent tested that consistently reduced C. difficile vegetative cells and spores of all tested strains. These findings establish conditions that result in vegetative cell and spore elimination and illustrate the resistance of C. difficile to common decontamination methods. These results further demonstrate that the vegetative cells and spores of various C. difficile strains have different resistance properties that may impact decontamination of surfaces and hands. PMID:27833595

Proteomic analysis of a NAP1 Clostridium difficile clinical isolate resistant to metronidazole.

PubMed

Chong, Patrick M; Lynch, Tarah; McCorrister, Stuart; Kibsey, Pamela; Miller, Mark; Gravel, Denise; Westmacott, Garrett R; Mulvey, Michael R

2014-01-01

Clostridium difficile is an anaerobic, Gram-positive bacterium that has been implicated as the leading cause of antibiotic-associated diarrhea. Metronidazole is currently the first-line treatment for mild to moderate C. difficile infections. Our laboratory isolated a strain of C. difficile with a stable resistance phenotype to metronidazole. A shotgun proteomics approach was used to compare differences in the proteomes of metronidazole-resistant and -susceptible isolates. NAP1 C. difficile strains CD26A54_R (Met-resistant), CD26A54_S (reduced- susceptibility), and VLOO13 (Met-susceptible) were grown to mid-log phase, and spiked with metronidazole at concentrations 2 doubling dilutions below the MIC. Peptides from each sample were labeled with iTRAQ and subjected to 2D-LC-MS/MS analysis. In the absence of metronidazole, higher expression was observed of some proteins in C. difficile strains CD26A54_S and CD26A54_R that may be involved with reduced susceptibility or resistance to metronidazole, including DNA repair proteins, putative nitroreductases, and the ferric uptake regulator (Fur). After treatment with metronidazole, moderate increases were seen in the expression of stress-related proteins in all strains. A moderate increase was also observed in the expression of the DNA repair protein RecA in CD26A54_R. This study provided an in-depth proteomic analysis of a stable, metronidazole-resistant C. difficile isolate. The results suggested that a multi-factorial response may be associated with high level metronidazole-resistance in C. difficile, including the possible roles of altered iron metabolism and/or DNA repair.

Typing Clostridium difficile strains based on tandem repeat sequences

PubMed Central

2009-01-01

Background Genotyping of epidemic Clostridium difficile strains is necessary to track their emergence and spread. Portability of genotyping data is desirable to facilitate inter-laboratory comparisons and epidemiological studies. Results This report presents results from a systematic screen for variation in repetitive DNA in the genome of C. difficile. We describe two tandem repeat loci, designated 'TR6' and 'TR10', which display extensive sequence variation that may be useful for sequence-based strain typing. Based on an investigation of 154 C. difficile isolates comprising 75 ribotypes, tandem repeat sequencing demonstrated excellent concordance with widely used PCR ribotyping and equal discriminatory power. Moreover, tandem repeat sequences enabled the reconstruction of the isolates' largely clonal population structure and evolutionary history. Conclusion We conclude that sequence analysis of the two repetitive loci introduced here may be highly useful for routine typing of C. difficile. Tandem repeat sequence typing resolves phylogenetic diversity to a level equivalent to PCR ribotypes. DNA sequences may be stored in databases accessible over the internet, obviating the need for the exchange of reference strains. PMID:19133124

Use of matrix-assisted laser desorption ionization-time of flight mass spectrometry to identify MLST clade 4 Clostridium difficile isolates.

PubMed

Cheng, Jing-Wei; Liu, Chang; Kudinha, Timothy; Xiao, Meng; Yu, Shu-Ying; Yang, Chun-Xia; Wei, Ming; Liang, Guo-Wei; Shao, Dong-Hua; Kong, Fanrong; Tong, Zhao-Hui; Xu, Ying-Chun

2018-04-26

Clostridium difficile is the leading cause of health care-associated infections. Previous studies suggest that C. difficile MLST clade 4 strains with higher drug resistance rates constitute the major clone spreading in China. Thus development of a rapid and accurate typing method for these strains is needed to monitor the epidemiology of this clone and to guide clinical treatment. A total of 160 non-duplicate C. difficile isolates recovered from three large teaching hospitals in Beijing were studied. All the 41 clade 4 C. difficile isolates clustered together on the PCA dendrogram. Spectra peak statistics revealed that five markers (2691.43Da, 2704.91Da, 2711.93Da, 3247.27Da and 3290.76Da) can easily and reliably distinguish between clade 4 and non-clade 4 isolates, with area under the curve (AUC) values of 0.991, 0.997, 0.973, 1 and 1, respectively. In conclusion, MALDI-TOF MS is a very simple and accurate method for identifying C. difficile MLST clade 4 strains. Copyright © 2018 Elsevier Inc. All rights reserved.

A Modified R-Type Bacteriocin Specifically Targeting Clostridium difficile Prevents Colonization of Mice without Affecting Gut Microbiota Diversity

PubMed Central

Gebhart, Dana; Lok, Stephen; Clare, Simon; Tomas, Myreen; Stares, Mark; Scholl, Dean; Donskey, Curtis J.; Lawley, Trevor D.

2015-01-01

ABSTRACT Clostridium difficile is a leading cause of nosocomial infections worldwide and has become an urgent public health threat requiring immediate attention. Epidemic lineages of the BI/NAP1/027 strain type have emerged and spread through health care systems across the globe over the past decade. Limiting person-to-person transmission and eradicating C. difficile, especially the BI/NAP1/027 strain type, from health care facilities are difficult due to the abundant shedding of spores that are impervious to most interventions. Effective prophylaxis for C. difficile infection (CDI) is lacking. We have genetically modified a contractile R-type bacteriocin (“diffocin”) from C. difficile strain CD4 to kill BI/NAP1/027-type strains for this purpose. The natural receptor binding protein (RBP) responsible for diffocin targeting was replaced with a newly discovered RBP identified within a prophage of a BI/NAP1/027-type target strain by genome mining. The resulting modified diffocins (a.k.a. Avidocin-CDs), Av-CD291.1 and Av-CD291.2, were stable and killed all 16 tested BI/NAP1/027-type strains. Av-CD291.2 administered in drinking water survived passage through the mouse gastrointestinal (GI) tract, did not detectably alter the mouse gut microbiota or disrupt natural colonization resistance to C. difficile or the vancomycin-resistant Enterococcus faecium (VREF), and prevented antibiotic-induced colonization of mice inoculated with BI/NAP1/027-type spores. Given the high incidence and virulence of the pathogen, preventing colonization by BI/NAP1/027-type strains and limiting their transmission could significantly reduce the occurrence of the most severe CDIs. This modified diffocin represents a prototype of an Avidocin-CD platform capable of producing targetable, precision anti-C. difficile agents that can prevent and potentially treat CDIs without disrupting protective indigenous microbiota. PMID:25805733

Genome Sequence of Vibrio cholerae Strain O1 Ogawa El Tor, Isolated in Mexico, 2013.

PubMed

Díaz-Quiñonez, José Alberto; Hernández-Monroy, Irma; López-Martínez, Irma; Ortiz-Alcántara, Joanna; González-Durán, Elizabeth; Ruiz-Matus, Cuitláhuac; Kuri-Morales, Pablo; Ramírez-González, José Ernesto

2014-10-30

We present the draft genome sequence of Vibrio cholerae InDRE 3140 recovered in 2013 during a cholera outbreak in Mexico. The genome showed the Vibrio 7th pandemic islands VSP1 and VSP2, the pathogenic islands VPI-1 and VPI-2, the integrative and conjugative element SXT/R391 (ICE-SXT), and both prophages CTXφ and RS1φ. Copyright © 2014 Díaz-Quiñonez et al.

The Ecology and Pathobiology of Clostridium difficile Infections: An Interdisciplinary Challenge

PubMed Central

Dubberke, Erik R.; Haslam, David B.; Lanzas, Cristina; Bobo, Linda D.; Burnham, Carey-Ann D.; Gröhn, Yrjö T.; Tarr, Phillip I.

2013-01-01

Summary Clostridium difficile is a well recognized pathogen of humans and animals. Although C. difficile was first identified over 70 years ago, much remains unknown in regards to the primary source of human acquisition and its pathobiology. These deficits in our knowledge have been intensified by dramatic increases in both the frequency and severity of disease in humans over the last decade. The changes in C. difficile epidemiology might be due to the emergence of a hypervirulent stain of C. difficile, aging of the population, altered risk of developing infection with newer medications, and/or increased exposure to C. difficile outside of hospitals. In recent years there have been numerous reports documenting C. difficile contamination of various foods, and reports of similarities between strains that infect animals and strains that infect humans as well. The purposes of this review are to highlight the many challenges to diagnosing, treating, and preventing C. difficile infection in humans, and to stress that collaboration between human and veterinary researchers is needed to control this pathogen. PMID:21223531

Proteomic Analysis of a NAP1 Clostridium difficile Clinical Isolate Resistant to Metronidazole

PubMed Central

Chong, Patrick M.; Lynch, Tarah; McCorrister, Stuart; Kibsey, Pamela; Miller, Mark; Gravel, Denise; Westmacott, Garrett R.; Mulvey, Michael R.

2014-01-01

Background Clostridium difficile is an anaerobic, Gram-positive bacterium that has been implicated as the leading cause of antibiotic-associated diarrhea. Metronidazole is currently the first-line treatment for mild to moderate C. difficile infections. Our laboratory isolated a strain of C. difficile with a stable resistance phenotype to metronidazole. A shotgun proteomics approach was used to compare differences in the proteomes of metronidazole-resistant and -susceptible isolates. Methodology/Principal Findings NAP1 C. difficile strains CD26A54_R (Met-resistant), CD26A54_S (reduced- susceptibility), and VLOO13 (Met-susceptible) were grown to mid-log phase, and spiked with metronidazole at concentrations 2 doubling dilutions below the MIC. Peptides from each sample were labeled with iTRAQ and subjected to 2D-LC-MS/MS analysis. In the absence of metronidazole, higher expression was observed of some proteins in C. difficile strains CD26A54_S and CD26A54_R that may be involved with reduced susceptibility or resistance to metronidazole, including DNA repair proteins, putative nitroreductases, and the ferric uptake regulator (Fur). After treatment with metronidazole, moderate increases were seen in the expression of stress-related proteins in all strains. A moderate increase was also observed in the expression of the DNA repair protein RecA in CD26A54_R. Conclusions/Significance This study provided an in-depth proteomic analysis of a stable, metronidazole-resistant C. difficile isolate. The results suggested that a multi-factorial response may be associated with high level metronidazole-resistance in C. difficile, including the possible roles of altered iron metabolism and/or DNA repair. PMID:24400070

Mutations associated with reduced surotomycin susceptibility in Clostridium difficile and Enterococcus species.

PubMed

Adams, Hannah M; Li, Xiang; Mascio, Carmela; Chesnel, Laurent; Palmer, Kelli L

2015-07-01

Clostridium difficile infection (CDI) is an urgent public health concern causing considerable clinical and economic burdens. CDI can be treated with antibiotics, but recurrence of the disease following successful treatment of the initial episode often occurs. Surotomycin is a rapidly bactericidal cyclic lipopeptide antibiotic that is in clinical trials for CDI treatment and that has demonstrated superiority over vancomycin in preventing CDI relapse. Surotomycin is a structural analogue of the membrane-active antibiotic daptomycin. Previously, we utilized in vitro serial passage experiments to derive C. difficile strains with reduced surotomycin susceptibilities. The parent strains used included ATCC 700057 and clinical isolates from the restriction endonuclease analysis (REA) groups BI and K. Serial passage experiments were also performed with vancomycin-resistant and vancomycin-susceptible Enterococcus faecium and Enterococcus faecalis. The goal of this study is to identify mutations associated with reduced surotomycin susceptibility in C. difficile and enterococci. Illumina sequence data generated for the parent strains and serial passage isolates were compared. We identified nonsynonymous mutations in genes coding for cardiolipin synthase in C. difficile ATCC 700057, enoyl-(acyl carrier protein) reductase II (FabK) and cell division protein FtsH2 in C. difficile REA type BI, and a PadR family transcriptional regulator in C. difficile REA type K. Among the 4 enterococcal strain pairs, 20 mutations were identified, and those mutations overlap those associated with daptomycin resistance. These data give insight into the mechanism of action of surotomycin against C. difficile, possible mechanisms for resistance emergence during clinical use, and the potential impacts of surotomycin therapy on intestinal enterococci. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Comparison of Clostridium difficile Ribotypes Circulating in Australian Hospitals and Communities.

PubMed

Furuya-Kanamori, Luis; Riley, Thomas V; Paterson, David L; Foster, Niki F; Huber, Charlotte A; Hong, Stacey; Harris-Brown, Tiffany; Robson, Jenny; Clements, Archie C A

2017-01-01

Clostridium difficile infection (CDI) is becoming less exclusively a health care-associated CDI (HA-CDI). The incidence of community-associated CDI (CA-CDI) has increased over the past few decades. It has been postulated that asymptomatic toxigenic C. difficile (TCD)-colonized patients may play a role in the transfer of C. difficile between the hospital setting and the community. Thus, to investigate the relatedness of C. difficile across the hospital and community settings, we compared the characteristics of symptomatic and asymptomatic host patients and the pathogens from these patients in these two settings over a 3-year period. Two studies were simultaneously conducted; the first study enrolled symptomatic CDI patients from two tertiary care hospitals and the community in two Australian states, while the second study enrolled asymptomatic TCD-colonized patients from the same tertiary care hospitals. A total of 324 patients (96 with HA-CDI, 152 with CA-CDI, and 76 colonized with TCD) were enrolled. The predominant C. difficile ribotypes isolated in the hospital setting corresponded with those isolated in the community, as it was found that for 79% of the C. difficile isolates from hospitals, an isolate with a matching ribotype was isolated in the community, suggesting that transmission between these two settings is occurring. The toxigenic C. difficile strains causing symptomatic infection were similar to those causing asymptomatic infection, and patients exposed to antimicrobials prior to admission were more likely to develop a symptomatic infection (odds ratio, 2.94; 95% confidence interval, 1.20 to 7.14). Our findings suggest that the development of CDI symptoms in a setting without establishment of hospital epidemics with binary toxin-producing C. difficile strains may be driven mainly by host susceptibility and exposure to antimicrobials, rather than by C. difficile strain characteristics. Copyright © 2016 American Society for Microbiology.

A case of multiple recurrence of Clostridium difficile infection with severe hematochezia in an immunocompromised host.

PubMed

Zhang, Xuewu; Chen, Yunbo; Gu, Silan; Zheng, Beiwen; Lv, Tao; Lou, Yinjun; Jin, Jie

2016-12-01

Clostridium difficile infection (CDI) is increasing in incidence and severity. Clinically, diarrhea frequently occurs, but severe hematochezia is rarely seen with CDI. We describe here a hematopoietic stem cell transplantation (HSCT) recipient who experienced life-threatening gastrointestinal bleeding due to severe CDI. Subsequent stool surveillance and molecular typing observed the patient who had two episodes of recurrence with a new strain of C. difficile distinct from the initial infection. We analyze C. difficile strains obtained from the patient, and also discuss the diagnosis and treatment of this case. Copyright © 2016 Elsevier Ltd. All rights reserved.

Novel High-Molecular-Weight, R-Type Bacteriocins of Clostridium difficile

PubMed Central

Gebhart, Dana; Williams, Steven R.; Bishop-Lilly, Kimberly A.; Govoni, Gregory R.; Willner, Kristin M.; Butani, Amy; Sozhamannan, Shanmuga; Martin, David; Fortier, Louis-Charles

2012-01-01

Clostridium difficile causes one of the leading nosocomial infections in developed countries, and therapeutic choices are limited. Some strains of C. difficile produce phage tail-like particles upon induction of the SOS response. These particles have bactericidal activity against other C. difficile strains and can therefore be classified as bacteriocins, similar to the R-type pyocins of Pseudomonas aeruginosa. These R-type bacteriocin particles, which have been purified from different strains, each have a different C. difficile-killing spectrum, with no one bacteriocin killing all C. difficile isolates tested. We have identified the genetic locus of these “diffocins” (open reading frames 1359 to 1376) and have found them to be common among the species. The entire diffocin genetic locus of more than 20 kb was cloned and expressed in Bacillus subtilis, and this resulted in production of bactericidal particles. One of the interesting features of these particles is a very large structural protein of ∼200 kDa, the product of gene 1374. This large protein determines the killing spectrum of the particles and is likely the receptor-binding protein. Diffocins may provide an alternate bactericidal agent to prevent or treat infections and to decolonize individuals who are asymptomatic carriers. PMID:22984261

A modified R-type bacteriocin specifically targeting Clostridium difficile prevents colonization of mice without affecting gut microbiota diversity.

PubMed

Gebhart, Dana; Lok, Stephen; Clare, Simon; Tomas, Myreen; Stares, Mark; Scholl, Dean; Donskey, Curtis J; Lawley, Trevor D; Govoni, Gregory R

2015-03-24

Clostridium difficile is a leading cause of nosocomial infections worldwide and has become an urgent public health threat requiring immediate attention. Epidemic lineages of the BI/NAP1/027 strain type have emerged and spread through health care systems across the globe over the past decade. Limiting person-to-person transmission and eradicating C. difficile, especially the BI/NAP1/027 strain type, from health care facilities are difficult due to the abundant shedding of spores that are impervious to most interventions. Effective prophylaxis for C. difficile infection (CDI) is lacking. We have genetically modified a contractile R-type bacteriocin ("diffocin") from C. difficile strain CD4 to kill BI/NAP1/027-type strains for this purpose. The natural receptor binding protein (RBP) responsible for diffocin targeting was replaced with a newly discovered RBP identified within a prophage of a BI/NAP1/027-type target strain by genome mining. The resulting modified diffocins (a.k.a. Avidocin-CDs), Av-CD291.1 and Av-CD291.2, were stable and killed all 16 tested BI/NAP1/027-type strains. Av-CD291.2 administered in drinking water survived passage through the mouse gastrointestinal (GI) tract, did not detectably alter the mouse gut microbiota or disrupt natural colonization resistance to C. difficile or the vancomycin-resistant Enterococcus faecium (VREF), and prevented antibiotic-induced colonization of mice inoculated with BI/NAP1/027-type spores. Given the high incidence and virulence of the pathogen, preventing colonization by BI/NAP1/027-type strains and limiting their transmission could significantly reduce the occurrence of the most severe CDIs. This modified diffocin represents a prototype of an Avidocin-CD platform capable of producing targetable, precision anti-C. difficile agents that can prevent and potentially treat CDIs without disrupting protective indigenous microbiota. Treatment and prevention strategies for bacterial diseases rely heavily on traditional antibiotics, which impose strong selection for resistance and disrupt protective microbiota. One consequence has been an upsurge of opportunistic pathogens, such as Clostridium difficile, that exploit antibiotic-induced disruptions in gut microbiota to proliferate and cause life-threatening diseases. We have developed alternative agents that utilize contractile bactericidal protein complexes (R-type bacteriocins) to kill specific C. difficile pathogens. Efficacy in a preclinical animal study indicates these molecules warrant further development as potential prophylactic agents to prevent C. difficile infections in humans. Since these agents do not detectably alter the indigenous gut microbiota or colonization resistance in mice, we believe they will be safe to administer as a prophylactic to block transmission in high-risk environments without rendering patients susceptible to enteric infection after cessation of treatment. Copyright © 2015 Gebhart et al.

As Clear as Mud? Determining the Diversity and Prevalence of Prophages in the Draft Genomes of Estuarine Isolates of Clostridium difficile.

PubMed

Hargreaves, Katherine R; Otieno, James R; Thanki, Anisha; Blades, Matthew J; Millard, Andrew D; Browne, Hilary P; Lawley, Trevor D; Clokie, Martha R J

2015-05-27

The bacterium Clostridium difficile is a significant cause of nosocomial infections worldwide. The pathogenic success of this organism can be attributed to its flexible genome which is characterized by the exchange of mobile genetic elements, and by ongoing genome evolution. Despite its pathogenic status, C. difficile can also be carried asymptomatically, and has been isolated from natural environments such as water and sediments where multiple strain types (ribotypes) are found in close proximity. These include ribotypes which are associated with disease, as well as those that are less commonly isolated from patients. Little is known about the genomic content of strains in such reservoirs in the natural environment. In this study, draft genomes have been generated for 13 C. difficile isolates from estuarine sediments including clinically relevant and environmental associated types. To identify the genetic diversity within this strain collection, whole-genome comparisons were performed using the assemblies. The strains are highly genetically diverse with regards to the C. difficile "mobilome," which includes transposons and prophage elements. We identified a novel transposon-like element in two R078 isolates. Multiple, related and unrelated, prophages were detected in isolates across ribotype groups, including two novel prophage elements and those related to the transducing phage φC2. The susceptibility of these isolates to lytic phage infection was tested using a panel of characterized phages found from the same locality. In conclusion, estuarine sediments are a source of genetically diverse C. difficile strains with a complex network of prophages, which could contribute to the emergence of new strains in clinics. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

As Clear as Mud? Determining the Diversity and Prevalence of Prophages in the Draft Genomes of Estuarine Isolates of Clostridium difficile

PubMed Central

Hargreaves, Katherine R.; Otieno, James R.; Thanki, Anisha; Blades, Matthew J.; Millard, Andrew D.; Browne, Hilary P.; Lawley, Trevor D.; Clokie, Martha R.J.

2015-01-01

The bacterium Clostridium difficile is a significant cause of nosocomial infections worldwide. The pathogenic success of this organism can be attributed to its flexible genome which is characterized by the exchange of mobile genetic elements, and by ongoing genome evolution. Despite its pathogenic status, C. difficile can also be carried asymptomatically, and has been isolated from natural environments such as water and sediments where multiple strain types (ribotypes) are found in close proximity. These include ribotypes which are associated with disease, as well as those that are less commonly isolated from patients. Little is known about the genomic content of strains in such reservoirs in the natural environment. In this study, draft genomes have been generated for 13 C. difficile isolates from estuarine sediments including clinically relevant and environmental associated types. To identify the genetic diversity within this strain collection, whole-genome comparisons were performed using the assemblies. The strains are highly genetically diverse with regards to the C. difficile “mobilome,” which includes transposons and prophage elements. We identified a novel transposon-like element in two R078 isolates. Multiple, related and unrelated, prophages were detected in isolates across ribotype groups, including two novel prophage elements and those related to the transducing phage φC2. The susceptibility of these isolates to lytic phage infection was tested using a panel of characterized phages found from the same locality. In conclusion, estuarine sediments are a source of genetically diverse C. difficile strains with a complex network of prophages, which could contribute to the emergence of new strains in clinics. PMID:26019165

Predominance and high antibiotic resistance of the emerging Clostridium difficile genotypes NAPCR1 and NAP9 in a Costa Rican hospital over a 2-year period without outbreaks.

PubMed

López-Ureña, Diana; Quesada-Gómez, Carlos; Montoya-Ramírez, Mónica; del Mar Gamboa-Coronado, María; Somogyi, Teresita; Rodríguez, César; Rodríguez-Cavallini, Evelyn

2016-05-11

Clostridium difficile is the major causative agent of nosocomial antibiotic-associated diarrhea. In a 2009 outbreak of C. difficile-associated diarrhea that was recorded in a major Costa Rican hospital, the hypervirulent NAP1 strain (45%) predominated together with a local genotype variant (NAPCR1, 31%). Both strains were fluoroquinolone-resistant and the NAPCR1 genotype, in addition, was resistant to clindamycin and rifampicin. We now report on the genotypes and antibiotic susceptibilities of 68 C. difficile isolates from a major Costa Rican hospital over a 2-year period without outbreaks. In contrast to our previous findings, no NAP1 strains were detected, and for the first time in a Costa Rican hospital, a significant fraction of the isolates were NAP9 strains (n=14, 21%). The local NAPCR1 genotype remained prevalent (n=18, 26%) and coexisted with 14 strains (21%) of classic hospital NAP types (NAP2, NAP4, and NAP6), eight new genotypes (12%), four environmental strains classified as NAP10 or NAP11 (6%), three strains without NAP designation (4%) and seven non-toxigenic strains (10%). All 68 strains were resistant to ciprofloxacin, 88% were resistant to clindamycin and 50% were resistant to moxifloxacin and rifampicin. Metronidazole and vancomycin susceptibilities were universal. The NAPCR1 and NAP9 strains, which have been associated with more severe clinical infections, were more resistant to antibiotics than the other strains. Altogether, our results confirm that the epidemiology of C. difficile infection is dynamic and that A(-)B(+) strains from the NAP9 type are on the rise not only in the developed world. Moreover, our results reveal that the local NAPCR1 strains still circulate in the country without causing outbreaks but with equally high antibiotic-resistance rates and levels.

Abundant and diverse clustered regularly interspaced short palindromic repeat spacers in Clostridium difficile strains and prophages target multiple phage types within this pathogen.

PubMed

Hargreaves, Katherine R; Flores, Cesar O; Lawley, Trevor D; Clokie, Martha R J

2014-08-26

Clostridium difficile is an important human-pathogenic bacterium causing antibiotic-associated nosocomial infections worldwide. Mobile genetic elements and bacteriophages have helped shape C. difficile genome evolution. In many bacteria, phage infection may be controlled by a form of bacterial immunity called the clustered regularly interspaced short palindromic repeats/CRISPR-associated (CRISPR/Cas) system. This uses acquired short nucleotide sequences (spacers) to target homologous sequences (protospacers) in phage genomes. C. difficile carries multiple CRISPR arrays, and in this paper we examine the relationships between the host- and phage-carried elements of the system. We detected multiple matches between spacers and regions in 31 C. difficile phage and prophage genomes. A subset of the spacers was located in prophage-carried CRISPR arrays. The CRISPR spacer profiles generated suggest that related phages would have similar host ranges. Furthermore, we show that C. difficile strains of the same ribotype could either have similar or divergent CRISPR contents. Both synonymous and nonsynonymous mutations in the protospacer sequences were identified, as well as differences in the protospacer adjacent motif (PAM), which could explain how phages escape this system. This paper illustrates how the distribution and diversity of CRISPR spacers in C. difficile, and its prophages, could modulate phage predation for this pathogen and impact upon its evolution and pathogenicity. Clostridium difficile is a significant bacterial human pathogen which undergoes continual genome evolution, resulting in the emergence of new virulent strains. Phages are major facilitators of genome evolution in other bacterial species, and we use sequence analysis-based approaches in order to examine whether the CRISPR/Cas system could control these interactions across divergent C. difficile strains. The presence of spacer sequences in prophages that are homologous to phage genomes raises an extra level of complexity in this predator-prey microbial system. Our results demonstrate that the impact of phage infection in this system is widespread and that the CRISPR/Cas system is likely to be an important aspect of the evolutionary dynamics in C. difficile. Copyright © 2014 Hargreaves et al.

CodY-Dependent Regulation of Sporulation in Clostridium difficile.

PubMed

Nawrocki, Kathryn L; Edwards, Adrianne N; Daou, Nadine; Bouillaut, Laurent; McBride, Shonna M

2016-08-01

Clostridium difficile must form a spore to survive outside the gastrointestinal tract. The factors that trigger sporulation in C. difficile remain poorly understood. Previous studies have suggested that a link exists between nutritional status and sporulation initiation in C. difficile In this study, we investigated the impact of the global nutritional regulator CodY on sporulation in C. difficile strains from the historical 012 ribotype and the current epidemic 027 ribotype. Sporulation frequencies were increased in both backgrounds, demonstrating that CodY represses sporulation in C. difficile The 027 codY mutant exhibited a greater increase in spore formation than the 012 codY mutant. To determine the role of CodY in the observed sporulation phenotypes, we examined several factors that are known to influence sporulation in C. difficile Using transcriptional reporter fusions and quantitative reverse transcription-PCR (qRT-PCR) analysis, we found that two loci associated with the initiation of sporulation, opp and sinR, are regulated by CodY. The data demonstrate that CodY is a repressor of sporulation in C. difficile and that the impact of CodY on sporulation and expression of specific genes is significantly influenced by the strain background. These results suggest that the variability of CodY-dependent regulation is an important contributor to virulence and sporulation in current epidemic isolates. This report provides further evidence that nutritional state, virulence, and sporulation are linked in C. difficile This study sought to examine the relationship between nutrition and sporulation in C. difficile by examining the global nutritional regulator CodY. CodY is a known virulence and nutritional regulator of C. difficile, but its role in sporulation was unknown. Here, we demonstrate that CodY is a negative regulator of sporulation in two different ribotypes of C. difficile We also demonstrate that CodY regulates known effectors of sporulation, Opp and SinR. These results support the idea that nutrient limitation is a trigger for sporulation in C. difficile and that the response to nutrient limitation is coordinated by CodY. Additionally, we demonstrate that CodY has an altered role in sporulation regulation for some strains. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

CodY-Dependent Regulation of Sporulation in Clostridium difficile

PubMed Central

Nawrocki, Kathryn L.; Edwards, Adrianne N.; Daou, Nadine; Bouillaut, Laurent

2016-01-01

ABSTRACT Clostridium difficile must form a spore to survive outside the gastrointestinal tract. The factors that trigger sporulation in C. difficile remain poorly understood. Previous studies have suggested that a link exists between nutritional status and sporulation initiation in C. difficile. In this study, we investigated the impact of the global nutritional regulator CodY on sporulation in C. difficile strains from the historical 012 ribotype and the current epidemic 027 ribotype. Sporulation frequencies were increased in both backgrounds, demonstrating that CodY represses sporulation in C. difficile. The 027 codY mutant exhibited a greater increase in spore formation than the 012 codY mutant. To determine the role of CodY in the observed sporulation phenotypes, we examined several factors that are known to influence sporulation in C. difficile. Using transcriptional reporter fusions and quantitative reverse transcription-PCR (qRT-PCR) analysis, we found that two loci associated with the initiation of sporulation, opp and sinR, are regulated by CodY. The data demonstrate that CodY is a repressor of sporulation in C. difficile and that the impact of CodY on sporulation and expression of specific genes is significantly influenced by the strain background. These results suggest that the variability of CodY-dependent regulation is an important contributor to virulence and sporulation in current epidemic isolates. This report provides further evidence that nutritional state, virulence, and sporulation are linked in C. difficile. IMPORTANCE This study sought to examine the relationship between nutrition and sporulation in C. difficile by examining the global nutritional regulator CodY. CodY is a known virulence and nutritional regulator of C. difficile, but its role in sporulation was unknown. Here, we demonstrate that CodY is a negative regulator of sporulation in two different ribotypes of C. difficile. We also demonstrate that CodY regulates known effectors of sporulation, Opp and SinR. These results support the idea that nutrient limitation is a trigger for sporulation in C. difficile and that the response to nutrient limitation is coordinated by CodY. Additionally, we demonstrate that CodY has an altered role in sporulation regulation for some strains. PMID:27246573

Preventing clostridium difficile infection in the intensive care unit.

PubMed

Zilberberg, Marya D; Shorr, Andrew F

2013-01-01

Clostridium difficile is a formidable problem in the twenty-first century. Because of injudicious use of antibiotics, the emergence of the hypervirulent epidemic strain of this organism has been difficult to contain. The NAP1/BI/027 strain causes more-severe disease than other widely prevalent strains and affects patients who were not traditionally thought to be at risk for Clostridium difficile infection. Critically ill patients remain at high risk for this pathogen, and preventive measures, such as meticulous contact precautions, hand hygiene, environmental disinfection, and, most importantly, antibiotic stewardship, are the cornerstones of mitigation in the intensive care unit. Copyright © 2013 Elsevier Inc. All rights reserved.

Evaluation of a commercial latex test for Clostridium difficile for reactivity with C. difficile and cross-reactions with other bacteria.

PubMed Central

Miles, B L; Siders, J A; Allen, S D

1988-01-01

Seventy-eight species of bacteria (739 isolates) were tested for reactivity with a commercial latex test for Clostridium difficile. All noncytotoxic as well as cytotoxic strains of C. difficile reacted positively. Immuno-specific cross-reactions were found only with C. sporogenes, proteolytic C. botulinum, and Peptostreptococcus anaerobius. PMID:3235677

Recent advances in the understanding of antibiotic resistance in Clostridium difficile infection

PubMed Central

2016-01-01

Clostridium difficile epidemiology has changed in recent years, with the emergence of highly virulent types associated with severe infections, high rates of recurrences and mortality. Antibiotic resistance plays an important role in driving these epidemiological changes and the emergence of new types. While clindamycin resistance was driving historical endemic types, new types are associated with resistance to fluoroquinolones. Furthermore, resistance to multiple antibiotics is a common feature of the newly emergent strains and, in general, of many epidemic isolates. A reduced susceptibility to antibiotics used for C. difficile infection (CDI) treatment, in particular to metronidazole, has recently been described in several studies. Furthermore, an increased number of strains show resistance to rifamycins, used for the treatment of relapsing CDI. Several mechanisms of resistance have been identified in C. difficile, including acquisition of genetic elements and alterations of the antibiotic target sites. The C. difficile genome contains a plethora of mobile genetic elements, many of them involved in antibiotic resistance. Transfer of genetic elements among C. difficile strains or between C. difficile and other bacterial species can occur through different mechanisms that facilitate their spread. Investigations of the fitness cost in C. difficile indicate that both genetic elements and mutations in the molecular targets of antibiotics can be maintained regardless of the burden imposed on fitness, suggesting that resistances may persist in the C. difficile population also in absence of antibiotic selective pressure. The rapid evolution of antibiotic resistance and its composite nature complicate strategies in the treatment and prevention of CDI. The rapid identification of new phenotypic and genotypic traits, the implementation of effective antimicrobial stewardship and infection control programs, and the development of alternative therapies are needed to prevent and contain the spread of resistance and to ensure an efficacious therapy for CDI. PMID:26862400

Crystal structures of two nitroreductases from hypervirulent Clostridium difficile and functionally related interactions with the antibiotic metronidazole

PubMed Central

Wang, Bing; Powell, Samantha M.; Hessami, Neda; Najar, Fares Z.; Thomas, Leonard M.; Karr, Elizabeth A.; West, Ann H.; Richter-Addo, George B.

2016-01-01

Nitroreductases (NRs) are flavin mononucleotide (FMN)-dependent enzymes that catalyze the biotransformation of organic nitro compounds (RNO2; R = alkyl, aryl) to the nitroso RN=O, hydroxylamino RNHOH, or amine RNH2 derivatives. Metronidazole (Mtz) is a nitro-containing antibiotic that is commonly prescribed for lower-gut infections caused by the anaerobic bacterium Clostridium difficile. C. difficile infections rank number one among hospital acquired infections, and can result in diarrhea, severe colitis, or even death. Although NRs have been implicated in Mtz resistance of C. difficile, no NRs have been characterized from the hypervirulent R20291 strain of C. difficile. We report the first expression, purification, and three-dimensional X-ray crystal structures of two NRs from the C. difficile R20291 strain. The X-ray crystal structures of the two NRs were solved to 2.1 Å resolution. Their homodimeric structures exhibit the classic NR α+β fold, with each protomer binding one FMN cofactor near the dimer interface. Functional assays demonstrate that these two NRs metabolize Mtz with associated re-oxidation of the proteins. Importantly, these results represent the first isolation and characterization of NRs from the hypervirulent R20291 strain of relevance to organic RNO2 (e.g., Mtz) metabolism. PMID:27623089

Clostridium difficile: a problem of concern in developed countries and still a mystery in Latin America.

PubMed

Balassiano, I T; Yates, E A; Domingues, R M C P; Ferreira, E O

2012-02-01

Clostridium difficile-associated disease (CDAD) is caused by a spore-forming bacterium and can result in highly variable disease, ranging from mild diarrhoea to severe clinical manifestations. Infections are most commonly seen in hospital settings and are often associated with on-going antibiotic therapy. Incidences of CDAD have shown a sustained increase worldwide over the last ten years and a hypervirulent C. difficile strain, PCR ribotype 027/REA type BI/North American pulsed-field (NAP) type 1 (027/BI/NAP-1), has caused outbreaks in North America and Europe. In contrast, only a few reports of cases in Latin America have been published and the hypervirulent strain 027/BI/NAP-1 has, so far, only been reported in Costa Rica. The potential worldwide spread of this infection calls for epidemiological studies to characterize currently circulating strains and also highlights the need for increased awareness and vigilance among healthcare professionals in currently unaffected areas, such as Latin America. This review attempts to summarize reports of C. difficile infection worldwide, especially in Latin America, and aims to provide an introduction to the problems associated with this pathogen for those countries that might face outbreaks of epidemic strains of C. difficile for the first time in the near future.

75 FR 53310 - Proposed Data Collections Submitted for Public Comment and Recommendations

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-31

.... Proposed Project Clostridium difficile Infection (CDI) Surveillance--New--National Center for Emerging and... Brief Description Steady increases in the rate and severity of Clostridium difficile infection (CDI... description of the molecular characteristics of C. difficile strains and the epidemiology of this infection...

Survey of Clostridium difficile in retail seafood in College Station, Texas

USDA-ARS?s Scientific Manuscript database

The incidence and severity of disease associated with toxigenic Clostridium difficile have increased in hospitals in North America with the emergence of newer, more virulent strains. Toxigenic C. difficile has been isolated from food animals and retail meat with potential implications of transfer t...

Rifaximin-resistant Clostridium difficile strains isolated from symptomatic patients.

PubMed

Reigadas, E; Muñoz-Pacheco, P; Vázquez-Cuesta, S; Alcalá, L; Marín, M; Martin, A; Bouza, E

2017-12-01

Rifaximin has been proposed as an alternative treatment for specific cases of Clostridium difficile infection (CDI) and intestinal decontamination. Rifaximin-resistant C. difficile has occasionally been reported. Antibiotic susceptibility testing relies on anaerobic agar dilution (reference method), which is cumbersome and not routinely used. There is no commercial test for detection of resistance to rifaximin. To assess resistance to rifaximin by C. difficile and to evaluate the correlation between the results of the rifampicin E-test and susceptibility to rifaximin. We compared the in vitro susceptibility of clinical CDI isolates to rifaximin over a 6-month period using the agar dilution method with susceptibility to rifampicin using the E-test. All isolates were characterized using PCR-ribotyping. Clinical data were recorded prospectively. We recovered 276 consecutive C. difficile isolates and found that 32.2% of episodes were caused by rifaximin-resistant strains. The MICs for rifaximin ranged from <0.0009-256 mg/L, with a geometric mean (GM) of 0.256 mg/L, an MIC 50/90 of 0.015/>256 mg/L. Rifaximin and rifampicin MICs were comparable, and all strains classed as resistant by agar dilution were correctly classified as resistant by E-test. The most common ribotypes were 001 (37.2%), 078/126 (14.3%), and 014 (12.0%). Ribotype 001 exhibited the highest MICs for rifaximin. Resistance to rifaximin was common; resistance rates were higher in ribotype 001 strains. Susceptibility to rifaximin determined by agar dilution correlated with susceptibility to rifampicin determined using the E-test, including rifaximin-resistant strains. Our results suggest that the rifampicin E-test is a valid method for the prediction of rifaximin-resistant C. difficile. Copyright © 2017 Elsevier Ltd. All rights reserved.

The impact of horizontal gene transfer on the biology of Clostridium difficile.

PubMed

Roberts, Adam P; Allan, Elaine; Mullany, Peter

2014-01-01

Clostridium difficile infection (CDI) is now recognised as the main cause of healthcare associated diarrhoea. Over the recent years there has been a change in the epidemiology of CDI with certain related strains dominating infection. These strains have been termed hyper-virulent and have successfully spread across the globe. Many C. difficile strains have had their genomes completely sequenced allowing researchers to build up a very detailed picture of the contribution of horizontal gene transfer to the adaptive potential, through the acquisition of mobile DNA, of this organism. Here, we review and discuss the contribution of mobile genetic elements to the biology of this clinically important pathogen. © 2014 Elsevier Ltd All rights reserved.

DETECTION, RIBOTYPING AND ANTIMICROBIAL RESISTANCE PROPERTIES OF CLOSTRIDIUM DIFFICILE STRAINS ISOLATED FROM THE CASES OF DIARRHEA.

PubMed

Kouzegaran, Samaneh; Ganjifard, Mahmood; Tanha, Amir Saber

2016-10-01

Clostridium difficile is the most prevalent cause of antibiotic-associated infectious diarrhea al-around the world. Prevalence of virulent and resistant strains of Clostridium difficile is increasing now a day. The present investigation was carried out to study the prevalence, ribotyping and antibiotic resistance pattern of C. difficile isolated from diarrheic and non-diarrheic pediatrics. Four-hundred stool specimens were collected from the diarrheic and non-diarrheic pediatrics hospitalized due to the diseases other than diarrhea. Samples were cultured and their positive results were subjected to disk diffusion and PCR-based ribotyping. Thirty-five out of 400 (8.75%) samples were positive for C. difficile . Prevalence of C. difficile in diarrheic and non-diarrheic pediatrics were 11.25% and 4.16%, respectively. Male had the higher prevalence of bacteria than female ( P < 0.05). eight to twelve months old pediatrics were the most commonly infected group. R27 (14.28%), R1 (10.71%), R12 (7.14%), R13 (7.14%) and R18 (7.14%) were most commonly detected ribotypes. There were no positive results for studied ribotypes in non-diarrheic pediatrics. C. difficile strains had the highest levels of resistance against tetracycline (71.42%), erythromycin (57.14%), moxifloxacin (48.57%), metronidazole (28.57%) and clindamycin (22.85%) antibiotics. Prescription of antibiotics in diarrheic pediatrics, males and also 8-12 months old pediatrics should be done in a regular and cautious manner.

Characterization of a Stable, Metronidazole-Resistant Clostridium difficile Clinical Isolate

PubMed Central

Lynch, Tarah; Chong, Patrick; Zhang, Jason; Hizon, Romeo; Du, Tim; Graham, Morag R.; Beniac, Daniel R.; Booth, Timothy F.; Kibsey, Pamela; Miller, Mark; Gravel, Denise; Mulvey, Michael R.

2013-01-01

Background Clostridium difficile are Gram-positive, spore forming anaerobic bacteria that are the leading cause of healthcare-associated diarrhea, usually associated with antibiotic usage. Metronidazole is currently the first-line treatment for mild to moderate C. difficile diarrhea however recurrence occurs at rates of 15–35%. There are few reports of C. difficile metronidazole resistance in the literature, and when observed, the phenotype has been transient and lost after storage or exposure of the bacteria to freeze/thaw cycles. Owing to the unstable nature of the resistance phenotype in the laboratory, clinical significance and understanding of the resistance mechanisms is lacking. Methodology/Principal Findings Genotypic and phenotypic characterization was performed on a metronidazole resistant clinical isolate of C. difficile. Whole-genome sequencing was used to identify potential genetic contributions to the phenotypic variation observed with molecular and bacteriological techniques. Phenotypic observations of the metronidazole resistant strain revealed aberrant growth in broth and elongated cell morphology relative to a metronidazole-susceptible, wild type NAP1 strain. Comparative genomic analysis revealed single nucleotide polymorphism (SNP) level variation within genes affecting core metabolic pathways such as electron transport, iron utilization and energy production. Conclusions/Significance This is the first characterization of stable, metronidazole resistance in a C. difficile isolate. The study provides an in-depth genomic and phenotypic analysis of this strain and provides a foundation for future studies to elucidate mechanisms conferring metronidazole resistance in C. difficile that have not been previously described. PMID:23349739

Clostridium difficile infection

PubMed Central

Smits, Wiep Klaas; Lyras, Dena; Lacy, D. Borden; Wilcox, Mark H.; Kuijper, Ed J.

2017-01-01

Infection of the colon with the Gram-positive bacterium Clostridium difficile is potentially life threatening, especially in elderly people and in patients who have dysbiosis of the gut microbiota following antimicrobial drug exposure. C. difficile is the leading cause of health-care-associated infective diarrhoea. The life cycle of C. difficile is influenced by antimicrobial agents, the host immune system, and the host microbiota and its associated metabolites. The primary mediators of inflammation in C. difficile infection (CDI) are large clostridial toxins, toxin A (TcdA) and toxin B (TcdB), and, in some bacterial strains, the binary toxin CDT. The toxins trigger a complex cascade of host cellular responses to cause diarrhoea, inflammation and tissue necrosis — the major symptoms of CDI. The factors responsible for the epidemic of some C. difficile strains are poorly understood. Recurrent infections are common and can be debilitating. Toxin detection for diagnosis is important for accurate epidemiological study, and for optimal management and prevention strategies. Infections are commonly treated with specific antimicrobial agents, but faecal microbiota transplants have shown promise for recurrent infections. Future biotherapies for C. difficile infections are likely to involve defined combinations of key gut microbiota. PMID:27158839

Clostridium difficile associated infection, diarrhea and colitis

PubMed Central

Hookman, Perry; Barkin, Jamie S

2009-01-01

A new, hypervirulent strain of Clostridium difficile, called NAP1/BI/027, has been implicated in C. difficile outbreaks associated with increased morbidity and mortality since the early 2000s. The epidemic strain is resistant to fluoroquinolones in vitro, which was infrequent prior to 2001. The name of this strain reflects its characteristics, demonstrated by different typing methods: pulsed-field gel electrophoresis (NAP1), restriction endonuclease analysis (BI) and polymerase chain reaction (027). In 2004 and 2005, the US Centers for Disease Control and Prevention (CDC) emphasized that the risk of C. difficile-associated diarrhea (CDAD) is increased, not only by the usual factors, including antibiotic exposure, but also gastrointestinal surgery/manipulation, prolonged length of stay in a healthcare setting, serious underlying illness, immune-compromising conditions, and aging. Patients on proton pump inhibitors (PPIs) have an elevated risk, as do peripartum women and heart transplant recipients. Before 2002, toxic megacolon in C. difficile-associated colitis (CDAC), was rare, but its incidence has increased dramatically. Up to two-thirds of hospitalized patients may be infected with C. difficile. Asymptomatic carriers admitted to healthcare facilities can transmit the organism to other susceptible patients, thereby becoming vectors. Fulminant colitis is reported more frequently during outbreaks of C. difficile infection in patients with inflammatory bowel disease (IBD). C. difficile infection with IBD carries a higher mortality than without underlying IBD. This article reviews the latest information on C. difficile infection, including presentation, vulnerable hosts and choice of antibiotics, alternative therapies, and probiotics and immunotherapy. We review contact precautions for patients with known or suspected C. difficile-associated disease. Healthcare institutions require accurate and rapid diagnosis for early detection of possible outbreaks, to initiate specific therapy and implement effective control measures. A comprehensive C. difficile infection control management rapid response team (RRT) is recommended for each health care facility. A communication network between RRTs is recommended, in coordination with each country’s department of health. Our aim is to convey a comprehensive source of information and to guide healthcare professionals in the difficult decisions that they face when caring for these oftentimes very ill patients. PMID:19340897

Is there a relationship between the presence of the binary toxin genes in Clostridium difficile strains and the severity of C. difficile infection (CDI)?

PubMed

Berry, C E; Davies, K A; Owens, D W; Wilcox, M H

2017-12-01

Some strains of Clostridium difficile produce a binary toxin, in addition to the main C. difficile virulence factors (toxins A and B). There have been conflicting reports regarding the role of binary toxin and its relationship to the severity of C. difficile infection (CDI). Samples, isolates and clinical data were collected as part of a prospective multicentre diagnostic study. Clostridium difficile isolates (n = 1259) were tested by polymerase chain reaction (PCR) assay to detect binary toxin genes cdtA and cdtB. The PCR binary toxin gene results were compared with clinical severity and outcome data, including 30-day all-cause mortality. The 1259 isolates corresponded to 1083 different patients (October 2010 to September 2011). The prevalence of binary toxin positive strains was significantly higher in faecal samples with detectable toxin A/B than in those without toxin but that were positive by cytotoxigenic culture (26.3% vs. 10.3%, p < 0.001). The presence of binary toxin correlated moderately with markers of CDI severity (white cell count, serum albumin concentration and serum creatinine concentration). However, the risk ratio for all-cause mortality was 1.68 for binary toxin positive patients and patients were significantly less likely to survive if they had CDI caused by a binary toxin gene positive strain, even after adjusting for age (p < 0.001). The presence of binary toxin genes does not predict the clinical severity of CDI, but it is significantly associated with the risk of all-cause mortality.

Protection of hamsters against Clostridium difficile ileocaecitis by prior colonisation with non-pathogenic strains.

PubMed

Borriello, S P; Barclay, F E

1985-06-01

Prior colonisation of clindamycin-treated hamsters with non-toxigenic strains of C. difficile protected them from subsequent colonisation with a toxigenic pathogenic strain. In total, 13 of 18 'protected' hamsters survived for up to 27 days whereas all 27 animals challenged with the toxigenic strain alone died within 48 h. Protection was not evident if a heat-killed suspension was used or if the colonising non-toxigenic strain was first removed with vancomycin. No antitoxic activity could be detected in the faeces of animals colonised with the non-toxigenic strains. Other species of clostridia did not protect against the lethal effects of subsequent exposure to the toxigenic strain. Conversely, non-toxigenic strains would not protect the animals from the lethal effects of a different clostridial pathogen, C. spiroforme. In most cases, even in the protected animals, the toxigenic strain eventually became dominant and caused disease, with translocation across the gut wall occurring early in the disease process. It was also shown that a non-toxigenic strain of C. difficile can adhere to gut mucosa. It is proposed that the protection afforded by the non-toxigenic strains may be due to competition for ecological niches.

Lactobacillus delbrueckii ssp. bulgaricus B-30892 can inhibit cytotoxic effects and adhesion of pathogenic Clostridium difficile to Caco-2 cells

PubMed Central

Banerjee, Pratik; Merkel, Glenn J; Bhunia, Arun K

2009-01-01

Background Probiotic microorganisms are receiving increasing interest for use in the prevention, treatment, or dietary management of certain diseases, including antibiotic-associated diarrhea (AAD). Clostridium difficile is the most common cause of AAD and the resulting C. difficile – mediated infection (CDI), is potentially deadly. C. difficile associated diarrhea (CDAD) is manifested by severe inflammation and colitis, mostly due to the release of two exotoxins by C. difficile causing destruction of epithelial cells in the intestine. The aim of this study was to determine the effect of probiotic bacteria Lactobacillus delbrueckii ssp. bulgaricus B-30892 (LDB B-30892) on C. difficile-mediated cytotoxicity using Caco-2 cells as a model. Methods Experiments were carried out to test if the cytotoxicity induced by C. difficile-conditioned-medium on Caco-2 cells can be altered by cell-free supernatant (CFS) from LDB B-30892 in different dilutions (1:2 to 1:2048). In a similar experimental setup, comparative evaluations of other probiotic strains were made by contrasting the results from these strains with the results from LDB B-30892, specifically the ability to affect C. difficile induced cytotoxicity on Caco-2 monolayers. Adhesion assays followed by quantitative analysis by Giemsa staining were conducted to test if the CFSs from LDB B-30892 and other probiotic test strains have the capability to alter the adhesion of C. difficile to the Caco-2 monolayer. Experiments were also performed to evaluate if LDB B-30892 or its released components have any bactericidal effect on C. difficile. Results and discussion Co-culturing of LDB B-30892 with C. difficile inhibited the C. difficile-mediated cytotoxicity on Caco-2 cells. When CFS from LDB B-30892-C. difficile co-culture was administered (up to a dilution of 1:16) on Caco-2 monolayer, there were no signs of cytotoxicity. When CFS from separately grown LDB B-30892 was mixed with the cell-free toxin preparation (CFT) of separately cultured C. difficile, the LDB B-30892 CFS was inhibitory to C. difficile CFT-mediated cytotoxicity at a ratio of 1:8 (LDB B-30892 CFS:C. difficile CFT). We failed to find any similar inhibition of C. difficile-mediated cytotoxicity when other probiotic organisms were tested in parallel to LDB B-30892. Our data of cytotoxicity experiments suggest that LDB B-30892 releases one or more bioactive component(s) into the CFS, which neutralizes the cytotoxicity induced by C. difficile, probably by inactivating its toxin(s). Our data also indicate that CFS from LDB B-30892 reduced the adhesion of C. difficile by 81%, which is significantly (P <0.01) higher than all other probiotic organisms tested in this study. Conclusion This study reveals the very first findings that Lactobacillus delbrueckii ssp. bulgaricus B-30892 (LDB B-30892) can eliminate C. difficile-mediated cytotoxicity, using Caco-2 cells as a model. The study also demonstrates that LDB B-30892 can reduce the colonization of C. difficile cells in colorectal cells. More study is warranted to elucidate the specific mechanism of action of such reduction of cytotoxicity and colonization. PMID:19397787

Clostridium difficile infection: Early history, diagnosis and molecular strain typing methods.

PubMed

Rodriguez, C; Van Broeck, J; Taminiau, B; Delmée, M; Daube, G

2016-08-01

Recognised as the leading cause of nosocomial antibiotic-associated diarrhoea, the incidence of Clostridium difficile infection (CDI) remains high despite efforts to improve prevention and reduce the spread of the bacterium in healthcare settings. In the last decade, many studies have focused on the epidemiology and rapid diagnosis of CDI. In addition, different typing methods have been developed for epidemiological studies. This review explores the history of C. difficile and the current scope of the infection. The variety of available laboratory tests for CDI diagnosis and strain typing methods are also examined. Copyright © 2016 Elsevier Ltd. All rights reserved.

Surface-layer (S-layer) of human and animal Clostridium difficile strains and their behaviour in adherence to epithelial cells and intestinal colonization.

PubMed

Spigaglia, Patrizia; Barketi-Klai, Amira; Collignon, Anne; Mastrantonio, Paola; Barbanti, Fabrizio; Rupnik, Maja; Janezic, Sandra; Kansau, Imad

2013-09-01

Clostridium difficile is a frequent cause of severe, recurrent post-antibiotic diarrhoea and pseudomembranous colitis. The surface layer (S-layer) is the predominant outer surface component of C. difficile which is involved in pathogen-host interactions critical to pathogenesis. In this study, we characterized the S-layer protein A (SlpA) of animal and human strains belonging to different PCR-ribotypes (PR) and compared the in vitro adherence and in vivo colonization properties of strains showing different SlpA variants. Since each SlpA variant has been recently associated with an S-layer cassette, we were able to deduce the cassette for each of our strains. In this study, an identity of 99-100 % was found among the SlpA of isolates belonging to PR 012, 014/020, 045 and 078. One exception was the SlpA of a poultry isolate, PR 014/020, which showed 99 % identity with that of strain 0160, another PR 014/020 which contains an S-layer cassette 6. Interestingly, this cassette has also been found in a PR 018 strain, an emerging virulent type currently predominant in Italy. Five other SlpA variants (v014/020a-e) were identified in strains PR 014/020. In vitro adherence assays and in vivo colonization experiments were performed on five PR 014/020 strains: human 1064 (v014/020e), human 4684/08 (v014/020b), human IT1106 (v078a), poultry P30 (v014/020d) and poultry PB90 (v014/020b) strains. Adhesion assays indicate that C. difficile strains vary in their capacity to adhere to cells in culture and that adhesion seems to be independent of the SlpA variant. Colonization properties were assessed in vivo using a dixenic mouse model of colonization. The kinetics of faecal shedding and caecal colonization were similar when human 4684/08 (v014/020b) strain was compared with human 1064 (v014/020e) and poultry PB90 (v014/020b) strain. In contrast, poultry P30 (v014/020d) strain outcompeted both human 4684/08 (v014/020b) and IT1106 (v078a) strains and its adherence to caeca at day 7 was significantly higher. The peculiar characteristics of C. difficile P30 seem to advantage it in colonizing the intestinal mice niche, increasing its ability to compete and adapt. The results obtained underline the need of an increased attention to the genetic evolution of C. difficile to prevent and limit the consequences of the emergence of increasingly virulent strains.

Different Antibiotic Resistance and Sporulation Properties within Multiclonal Clostridium difficile PCR Ribotypes 078, 126, and 033 in a Single Calf Farm

PubMed Central

Zidaric, Valerija; Pardon, Bart; dos Vultos, Tiago; Deprez, Piet; Brouwer, Michael Sebastiaan Maria; Roberts, Adam P.; Henriques, Adriano O.

2012-01-01

Clostridium difficile strains were sampled periodically from 50 animals at a single veal calf farm over a period of 6 months. At arrival, 10% of animals were C. difficile positive, and the peak incidence was determined to occur at the age of 18 days (16%). The prevalence then decreased, and at slaughter, C. difficile could not be isolated. Six different PCR ribotypes were detected, and strains within a single PCR ribotype could be differentiated further by pulsed-field gel electrophoresis (PFGE). The PCR ribotype diversity was high up to the animal age of 18 days, but at later sampling points, PCR ribotype 078 and the highly related PCR ribotype 126 predominated. Resistance to tetracycline, doxycycline, and erythromycin was detected, while all strains were susceptible to amoxicillin and metronidazole. Multiple variations of the resistance gene tet(M) were present at the same sampling point, and these changed over time. We have shown that PCR ribotypes often associated with cattle (ribotypes 078, 126, and 033) were not clonal but differed in PFGE type, sporulation properties, antibiotic sensitivities, and tetracycline resistance determinants, suggesting that multiple strains of the same PCR ribotype infected the calves and that calves were likely to be infected prior to arrival at the farm. Importantly, strains isolated at later time points were more likely to be resistant to tetracycline and erythromycin and showed higher early sporulation efficiencies in vitro, suggesting that these two properties converge to promote the persistence of C. difficile in the environment or in hosts. PMID:23001653

Risk factors for Clostridium difficile infection in a hepatology ward.

PubMed

Vanjak, Dominique; Girault, Guillaume; Branger, Catherine; Rufat, Pierre; Valla, Dominique-Charles; Fantin, Bruno

2007-02-01

During 2001, Clostridium difficile infection was observed in 23 patients hospitalized in a hepatology ward (attack rate, 0.9%). Since strain typing ruled out a clonal dissemination, we performed a case-control study. In addition to antibiotic use as a risk factor, the C. difficile infection rate was higher among patients with autoimmune hepatitis (P<.01).

Genome-Based Comparison of Clostridioides difficile: Average Amino Acid Identity Analysis of Core Genomes.

PubMed

Cabal, Adriana; Jun, Se-Ran; Jenjaroenpun, Piroon; Wanchai, Visanu; Nookaew, Intawat; Wongsurawat, Thidathip; Burgess, Mary J; Kothari, Atul; Wassenaar, Trudy M; Ussery, David W

2018-02-14

Infections due to Clostridioides difficile (previously known as Clostridium difficile) are a major problem in hospitals, where cases can be caused by community-acquired strains as well as by nosocomial spread. Whole genome sequences from clinical samples contain a lot of information but that needs to be analyzed and compared in such a way that the outcome is useful for clinicians or epidemiologists. Here, we compare 663 public available complete genome sequences of C. difficile using average amino acid identity (AAI) scores. This analysis revealed that most of these genomes (640, 96.5%) clearly belong to the same species, while the remaining 23 genomes produce four distinct clusters within the Clostridioides genus. The main C. difficile cluster can be further divided into sub-clusters, depending on the chosen cutoff. We demonstrate that MLST, either based on partial or full gene-length, results in biased estimates of genetic differences and does not capture the true degree of similarity or differences of complete genomes. Presence of genes coding for C. difficile toxins A and B (ToxA/B), as well as the binary C. difficile toxin (CDT), was deduced from their unique PfamA domain architectures. Out of the 663 C. difficile genomes, 535 (80.7%) contained at least one copy of ToxA or ToxB, while these genes were missing from 128 genomes. Although some clusters were enriched for toxin presence, these genes are variably present in a given genetic background. The CDT genes were found in 191 genomes, which were restricted to a few clusters only, and only one cluster lacked the toxin A/B genes consistently. A total of 310 genomes contained ToxA/B without CDT (47%). Further, published metagenomic data from stools were used to assess the presence of C. difficile sequences in blinded cases of C. difficile infection (CDI) and controls, to test if metagenomic analysis is sensitive enough to detect the pathogen, and to establish strain relationships between cases from the same hospital. We conclude that metagenomics can contribute to the identification of CDI and can assist in characterization of the most probable causative strain in CDI patients.

Clostridium difficile infection in the twenty-first century

PubMed Central

Ghose, Chandrabali

2013-01-01

Clostridium difficile is a spore-forming gram-positive bacillus, and the leading cause of antibiotic-associated nosocomial diarrhea and colitis in the industrialized world. With the emergence of a hypervirulent strain of C. difficile (BI/NAP1/027), the epidemiology of C. difficile infection has rapidly changed in the last decade. C. difficile infection, once thought to be an easy to treat bacterial infection, has evolved into an epidemic that is associated with a high rate of mortality, causing disease in patients thought to be low-risk. In this review, we discuss the changing face of C .difficile infection and the novel treatment and prevention strategies needed to halt this ever growing epidemic. PMID:26038491

CRISPR Diversity and Microevolution in Clostridium difficile

PubMed Central

Andersen, Joakim M.; Shoup, Madelyn; Robinson, Cathy; Britton, Robert; Olsen, Katharina E.P.; Barrangou, Rodolphe

2016-01-01

Abstract Virulent strains of Clostridium difficile have become a global health problem associated with morbidity and mortality. Traditional typing methods do not provide ideal resolution to track outbreak strains, ascertain genetic diversity between isolates, or monitor the phylogeny of this species on a global basis. Here, we investigate the occurrence and diversity of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated genes (cas) in C. difficile to assess the potential of CRISPR-based phylogeny and high-resolution genotyping. A single Type-IB CRISPR-Cas system was identified in 217 analyzed genomes with cas gene clusters present at conserved chromosomal locations, suggesting vertical evolution of the system, assessing a total of 1,865 CRISPR arrays. The CRISPR arrays, markedly enriched (8.5 arrays/genome) compared with other species, occur both at conserved and variable locations across strains, and thus provide a basis for typing based on locus occurrence and spacer polymorphism. Clustering of strains by array composition correlated with sequence type (ST) analysis. Spacer content and polymorphism within conserved CRISPR arrays revealed phylogenetic relationship across clades and within ST. Spacer polymorphisms of conserved arrays were instrumental for differentiating closely related strains, e.g., ST1/RT027/B1 strains and pathogenicity locus encoding ST3/RT001 strains. CRISPR spacers showed sequence similarity to phage sequences, which is consistent with the native role of CRISPR-Cas as adaptive immune systems in bacteria. Overall, CRISPR-Cas sequences constitute a valuable basis for genotyping of C. difficile isolates, provide insights into the micro-evolutionary events that occur between closely related strains, and reflect the evolutionary trajectory of these genomes. PMID:27576538

MALDI-TOF MS is more accurate than VITEK II ANC card and API Rapid ID 32 A system for the identification of Clostridium species.

PubMed

Kim, Young Jin; Kim, Si Hyun; Park, Hyun-Jung; Park, Hae-Geun; Park, Dongchul; Song, Sae Am; Lee, Hee Joo; Yong, Dongeun; Choi, Jun Yong; Kook, Joong-Ki; Kim, Hye Ran; Shin, Jeong Hwan

2016-08-01

All 50 Clostridium difficile strains were definitely identified by Vitek2 system, Rapid ID 32A system, and MALDI-TOF. For 18 non-difficile Clostridium strains, the identification results were correct in 0, 2, and 17 strains by Vitek2, Rapid ID 32A, and MALDI-TOF, respectively. MALDI-TOF could be used as the primary tool for identification of Clostridium species. Copyright © 2016 Elsevier Ltd. All rights reserved.

Macro and micro diversity of Clostridium difficile isolates from diverse sources and geographical locations.

PubMed

Stabler, Richard A; Dawson, Lisa F; Valiente, Esmeralda; Cairns, Michelle D; Martin, Melissa J; Donahue, Elizabeth H; Riley, Thomas V; Songer, J Glenn; Kuijper, Ed J; Dingle, Kate E; Wren, Brendan W

2012-01-01

Clostridium difficile has emerged rapidly as the leading cause of antibiotic-associated diarrheal disease, with the temporal and geographical appearance of dominant PCR ribotypes such as 017, 027 and 078. Despite this continued threat, we have a poor understanding of how or why particular variants emerge and the sources of strains that dominate different human populations. We have undertaken a breadth genotyping study using multilocus sequence typing (MLST) analysis of 385 C. difficile strains from diverse sources by host (human, animal and food), geographical locations (North America, Europe and Australia) and PCR ribotypes. Results identified 18 novel sequence types (STs) and 3 new allele sequences and confirmed the presence of five distinct clonal lineages generally associated with outbreaks of C. difficile infection in humans. Strains of animal and food origin were found of both ST-1 and ST-11 that are frequently associated with human disease. An in depth MLST analysis of the evolutionary distant ST-11/PCR ribotype 078 clonal lineage revealed that ST-11 can be found in alternative but closely related PCR ribotypes and PCR ribotype 078 alleles contain mutations generating novel STs. PCR ribotype 027 and 017 lineages may consist of two divergent subclades. Furthermore evidence of microdiversity was present within the heterogeneous clade 1. This study helps to define the evolutionary origin of dominant C. difficile lineages and demonstrates that C. difficile is continuing to evolve in concert with human activity.

Ursodeoxycholic Acid Inhibits Clostridium difficile Spore Germination and Vegetative Growth, and Prevents the Recurrence of Ileal Pouchitis Associated With the Infection.

PubMed

Weingarden, Alexa R; Chen, Chi; Zhang, Ningning; Graiziger, Carolyn T; Dosa, Peter I; Steer, Clifford J; Shaughnessy, Megan K; Johnson, James R; Sadowsky, Michael J; Khoruts, Alexander

2016-09-01

To test whether ursodeoxycholic acid (UDCA) is inhibitory to Clostridium difficile and can be used in the treatment of C. difficile-associated ileal pouchitis. The restoration of secondary bile metabolism may be the key mechanism for fecal microbiota transplantation (FMT) in treating recurrent C. difficile infections (RCDI). Therefore, it is possible that exogenous administration of inhibitory bile acids may be used directly as nonantibiotic therapeutics for this indication. The need for such a treatment alternative is especially significant in patients with refractory C. difficile-associated pouchitis, where the efficacy of FMT may be limited. We measured the ability of UDCA to suppress the germination and the vegetative growth of 11 clinical isolate strains of C. difficile from patients treated with FMT for RCDI. In addition, we used oral UDCA to treat a patient with RCDI pouchitis that proved refractory to multiple antibiotic treatments and FMT. UDCA was found to be inhibitory to the germination and the vegetative growth of all C. difficile strains tested. Fecal concentrations of UDCA from the patient with RCDI pouchitis exceeded levels necessary to inhibit the germination and the growth of C. difficile in vitro. The patient has remained infection free for over 10 months after the initiation of UDCA. UDCA can be considered as a therapeutic option in patients with C. difficile-associated pouchitis. Further studies need to be conducted to define the optimal dose and duration of such a treatment. In addition, bile acid derivatives inhibitory to C. difficile that are able to achieve high intracolonic concentrations may be developed as therapeutics for RCDI colitis.

Evaluation of the Cepheid® Xpert®C. difficile binary toxin (BT) diagnostic assay.

PubMed

McGovern, Alan M; Androga, Grace O; Moono, Peter; Collins, Deirdre A; Foster, Niki F; Chang, Barbara J; Riley, Thomas V

2018-06-01

Strains of Clostridium difficile producing only binary toxin (CDT) are found commonly in animals but not humans. However, human diagnostic tests rarely look for CDT. The Cepheid Xpert C. difficile BT assay detects CDT with equal sensitivity (≥92%) in human and animal faecal samples. Copyright © 2018 Elsevier Ltd. All rights reserved.

Impact and Time Course of Clostridium difficile Colonization in Very Low Birth Weight Infants.

PubMed

Pichler, Karin; Bausenhardt, Benjamin; Huhulescu, Steliana; Lindtner, Claudia; Indra, Alexander; Allerberger, Franz; Berger, Angelika

2018-06-12

Clostridium difficile is a gram-positive, anaerobic spore-forming, toxin-producing bacillus, which is one of the most common causes for health care-associated infections. High colonization rates in clinically asymptomatic neonates and infants have been described, although most studies go back to the early 1980 and 1990s, and were carried out in term and late preterm infants. The aim of our study was to determine both the impact and time course of C. difficile colonization in a cohort of very low birth weight infants (VLBWI) in an era of PCR-based technologies for diagnosis. Stool samples of VLBWI were analyzed for the presence of C. difficile strains in regular intervals during the hospital stay by PCR ribotyping. Analysis was continued throughout the first 2 years of life. A 32% C. difficile colonization rate during the first 2 years of life and an in-hospital colonization rate of 8% was found in a cohort of 190 VLBWI. C. difficile colonization occurred mainly in the first 6 months of life, which was similar to term neonates. In-hospital colonization accounted for only a small percentage of cases with no detection of hypervirulent strains. Also, C. difficile colonization was not related to an adverse outcome in this VLBWI cohort. Oral lactoferrin of bovine origin and treatment with piperacillin/tazobactam were negatively correlated with C. difficile colonization in our study. C. difficile colonization in our cohort of VLBWI was significantly lower than has been described in the literature and was not related to an adverse outcome. © 2018 S. Karger AG, Basel.

Infection of hamsters with historical and epidemic BI types of Clostridium difficile.

PubMed

Razaq, Nadia; Sambol, Susan; Nagaro, Kristin; Zukowski, Walter; Cheknis, Adam; Johnson, Stuart; Gerding, Dale N

2007-12-15

North American and European hospitals have reported outbreaks of Clostridium difficile-associated disease with unexpectedly high mortality caused by a newly recognized group of C. difficile strains, group BI. Our objective was to compare, in hamsters, the virulence of a historical nonepidemic BI type, BI1, with that of 2 recent epidemic BI types, BI6 and BI17, and with that of 2 standard toxigenic strains, K14 and 630. For each strain, 10 hamsters were given 1 dose of clindamycin, followed 5 days later with 100 C. difficile spores administered by gastric inoculation. Outcomes were recorded. The hamster model demonstrated variations in mean times from inoculation to death (for BI6, 40 h; for BI1, 48 h; for K14, 49 h; for BI17, 69 h; for 630, 102 h; for BI6, BI1, and K14 vs. 630, P< .01; for BI17 vs. 630, P< .05) and from colonization to death (for BI1, 7 h; for BI17, 13 h; for BI6, 16 h; for K14, 17 h; for 630, 52 h; for BI1, BI17, BI6, and K14 vs. 630, P< .01). Group BI strains were not more rapidly fatal than the standard toxinotype 0 strain K14 but were more rapidly fatal than the standard toxinotype 0 strain 630. BI6, the most common BI type in our collection, was particularly virulent in hamsters, consistently causing death within 48 h of inoculation.

Non-toxigenic environmental Vibrio cholerae O1 strain from Haiti provides evidence of pre-pandemic cholera in Hispaniola.

PubMed

Azarian, Taj; Ali, Afsar; Johnson, Judith A; Jubair, Mohammad; Cella, Eleonora; Ciccozzi, Massimo; Nolan, David J; Farmerie, William; Rashid, Mohammad H; Sinha-Ray, Shrestha; Alam, Meer T; Morris, J Glenn; Salemi, Marco

2016-10-27

Vibrio cholerae is ubiquitous in aquatic environments, with environmental toxigenic V. cholerae O1 strains serving as a source for recurrent cholera epidemics and pandemic disease. However, a number of questions remain about long-term survival and evolution of V. cholerae strains within these aquatic environmental reservoirs. Through monitoring of the Haitian aquatic environment following the 2010 cholera epidemic, we isolated two novel non-toxigenic (ctxA/B-negative) Vibrio cholerae O1. These two isolates underwent whole-genome sequencing and were investigated through comparative genomics and Bayesian coalescent analysis. These isolates cluster in the evolutionary tree with strains responsible for clinical cholera, possessing genomic components of 6 th and 7 th pandemic lineages, and diverge from "modern" cholera strains around 1548 C.E. [95% HPD: 1532-1555]. Vibrio Pathogenicity Island (VPI)-1 was present; however, SXT/R391-family ICE and VPI-2 were absent. Rugose phenotype conversion and vibriophage resistance evidenced adaption for persistence in aquatic environments. The identification of V. cholerae O1 strains in the Haitian environment, which predate the first reported cholera pandemic in 1817, broadens our understanding of the history of pandemics. It also raises the possibility that these and similar environmental strains could acquire virulence genes from the 2010 Haitian epidemic clone, including the cholera toxin producing CTXϕ.

Abundant and Diverse Clustered Regularly Interspaced Short Palindromic Repeat Spacers in Clostridium difficile Strains and Prophages Target Multiple Phage Types within This Pathogen

PubMed Central

Hargreaves, Katherine R.; Flores, Cesar O.; Lawley, Trevor D.

2014-01-01

ABSTRACT Clostridium difficile is an important human-pathogenic bacterium causing antibiotic-associated nosocomial infections worldwide. Mobile genetic elements and bacteriophages have helped shape C. difficile genome evolution. In many bacteria, phage infection may be controlled by a form of bacterial immunity called the clustered regularly interspaced short palindromic repeats/CRISPR-associated (CRISPR/Cas) system. This uses acquired short nucleotide sequences (spacers) to target homologous sequences (protospacers) in phage genomes. C. difficile carries multiple CRISPR arrays, and in this paper we examine the relationships between the host- and phage-carried elements of the system. We detected multiple matches between spacers and regions in 31 C. difficile phage and prophage genomes. A subset of the spacers was located in prophage-carried CRISPR arrays. The CRISPR spacer profiles generated suggest that related phages would have similar host ranges. Furthermore, we show that C. difficile strains of the same ribotype could either have similar or divergent CRISPR contents. Both synonymous and nonsynonymous mutations in the protospacer sequences were identified, as well as differences in the protospacer adjacent motif (PAM), which could explain how phages escape this system. This paper illustrates how the distribution and diversity of CRISPR spacers in C. difficile, and its prophages, could modulate phage predation for this pathogen and impact upon its evolution and pathogenicity. PMID:25161187

Clostridium difficile binary toxin CDT

PubMed Central

Gerding, Dale N; Johnson, Stuart; Rupnik, Maja; Aktories, Klaus

2014-01-01

Binary toxin (CDT) is frequently observed in Clostridium difficile strains associated with increased severity of C. difficile infection (CDI). CDT belongs to the family of binary ADP-ribosylating toxins consisting of two separate toxin components: CDTa, the enzymatic ADP-ribosyltransferase which modifies actin, and CDTb which binds to host cells and translocates CDTa into the cytosol. CDTb is activated by serine proteases and binds to lipolysis stimulated lipoprotein receptor. ADP-ribosylation induces depolymerization of the actin cytoskeleton. Toxin-induced actin depolymerization also produces microtubule-based membrane protrusions which form a network on epithelial cells and increase bacterial adherence. Multiple clinical studies indicate an association between binary toxin genes in C. difficile and increased 30-d CDI mortality independent of PCR ribotype. Further studies including measures of binary toxin in stool, analyses of CDI mortality caused by CDT-producing strains, and examination of the relationship of CDT expression to TcdA and TcdB toxin variants and PCR ribotypes are needed. PMID:24253566

Contamination of ready-to-eat raw vegetables with Clostridium difficile in France.

PubMed

Eckert, Catherine; Burghoffer, Béatrice; Barbut, Frédéric

2013-09-01

The presence of Clostridium difficile in food like shellfish, vegetables and meat has been reported in several publications during the past few years. The objective of this study was to assess the prevalence of ready-to-eat raw vegetables contaminated with C. difficile in France. One hundred and four ready-to-eat salads and vegetables were studied. Toxigenic C. difficile strains were isolated in three samples (2.9 %): two ready-to-eat salads (one heart of lettuce and one lamb's lettuce salad) and one portion of pea sprouts. The strains belonged to three different PCR ribotypes: 001, 014/020/077 and 015. The detection thresholds for vegetative cells and spores cells varied between 1 and 3 c.f.u. in 20 g salad and between 6 and 15 c.f.u. in 20 g salad, respectively, for the method employed.

Clostridium difficile Infection Among US Emergency Department Patients With Diarrhea and No Vomiting.

PubMed

Abrahamian, Fredrick M; Talan, David A; Krishnadasan, Anusha; Citron, Diane M; Paulick, Ashley L; Anderson, Lydia J; Goldstein, Ellie J C; Moran, Gregory J

2017-07-01

The incidence of Clostridium difficile infection has increased and has been observed among persons from the community who have not been exposed to antibiotics or health care settings. Our aims are to determine prevalence of C difficile infection among emergency department (ED) patients with diarrhea and the prevalence among patients without traditional risk factors. We conducted a prospective observational study of patients aged 2 years or older with diarrhea (≥3 episodes/24 hours) and no vomiting in 10 US EDs (2010 to 2013). We confirmed C difficile infection by positive stool culture result and toxin assay. C difficile infection risk factors were antibiotic use or overnight health care stay in the previous 3 months or previous C difficile infection. We typed strains with pulsed-field gel electrophoresis. Of 422 participants, median age was 46 years (range 2 to 94 years), with median illness duration of 3.0 days and 43.4% having greater than or equal to 10 episodes of diarrhea during the previous 24 hours. At least one risk factor for C difficile infection was present in 40.8% of participants; 25.9% were receiving antibiotics, 26.9% had health care stay within the previous 3 months, and 3.3% had previous C difficile infection. Forty-three participants (10.2%) had C difficile infection; among these, 24 (55.8%) received antibiotics and 19 (44.2%) had health care exposure; 17 of 43 (39.5%) lacked any risk factor. Among participants without risk factors, C difficile infection prevalence was 6.9%. The most commonly identified North American pulsed-field gel electrophoresis (NAP) strains were NAP type 1 (23.3%) and NAP type 4 (16.3%). Among mostly adults presenting to US EDs with diarrhea and no vomiting, C difficile infection accounted for approximately 10%. More than one third of patients with C difficile infection lacked traditional risk factors for the disease. Among participants without traditional risk factors, prevalence of C difficile infection was approximately 7%. Copyright © 2016 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

Clostridium difficile ribotypes in humans and animals in Brazil

PubMed Central

Silva, Rodrigo Otávio Silveira; Rupnik, Maja; Diniz, Amanda Nádia; Vilela, Eduardo Garcia; Lobato, Francisco Carlos Faria

2015-01-01

Clostridium difficile is an emerging enteropathogen responsible for pseudomembranous colitis in humans and diarrhoea in several domestic and wild animal species. Despite its known importance, there are few studies aboutC. difficile polymerase chain reaction (PCR) ribotypes in Brazil and the actual knowledge is restricted to studies on human isolates. The aim of the study was therefore to compare C. difficileribotypes isolated from humans and animals in Brazil. Seventy-six C. difficile strains isolated from humans (n = 25), dogs (n = 23), piglets (n = 12), foals (n = 7), calves (n = 7), one cat, and one manned wolf were distributed into 24 different PCR ribotypes. Among toxigenic strains, PCR ribotypes 014/020 and 106 were the most common, accounting for 14 (18.4%) and eight (10.5%) samples, respectively. Fourteen different PCR ribotypes were detected among human isolates, nine of them have also been identified in at least one animal species. PCR ribotype 027 was not detected, whereas 078 were found only in foals. This data suggests a high diversity of PCR ribotypes in humans and animals in Brazil and support the discussion of C. difficile as a zoonotic pathogen. PMID:26676318

Highly Divergent Clostridium difficile Strains Isolated from the Environment

PubMed Central

Janezic, Sandra; Potocnik, Mojca; Zidaric, Valerija; Rupnik, Maja

2016-01-01

Clostridium difficile is one of the most important human and animal pathogens. However, the bacterium is ubiquitous and can be isolated from various sources. Here we report the prevalence and characterization of C. difficile in less studied environmental samples, puddle water (n = 104) and soil (n = 79). C. difficile was detected in 14.4% of puddle water and in 36.7% of soil samples. Environmental strains displayed antimicrobial resistance patterns comparable to already published data of human and animal isolates. A total of 480 isolates were grouped into 34 different PCR ribotypes. More than half of these (52.9%; 18 of 34) were already described in humans or animals. However, 14 PCR ribotypes were new in our PCR ribotype library and all but one were non-toxigenic. The multilocus sequence analysis of these new PCR ribotypes revealed that non-toxigenic environmental isolates are phylogenetically distinct and belong to three highly divergent clades, two of which have not been described before. Our data suggest that environment is a potential reservoir of genetically diverse population of C. difficile. PMID:27880843

CRISPR Diversity and Microevolution in Clostridium difficile.

PubMed

Andersen, Joakim M; Shoup, Madelyn; Robinson, Cathy; Britton, Robert; Olsen, Katharina E P; Barrangou, Rodolphe

2016-09-19

Virulent strains of Clostridium difficile have become a global health problem associated with morbidity and mortality. Traditional typing methods do not provide ideal resolution to track outbreak strains, ascertain genetic diversity between isolates, or monitor the phylogeny of this species on a global basis. Here, we investigate the occurrence and diversity of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated genes (cas) in C. difficile to assess the potential of CRISPR-based phylogeny and high-resolution genotyping. A single Type-IB CRISPR-Cas system was identified in 217 analyzed genomes with cas gene clusters present at conserved chromosomal locations, suggesting vertical evolution of the system, assessing a total of 1,865 CRISPR arrays. The CRISPR arrays, markedly enriched (8.5 arrays/genome) compared with other species, occur both at conserved and variable locations across strains, and thus provide a basis for typing based on locus occurrence and spacer polymorphism. Clustering of strains by array composition correlated with sequence type (ST) analysis. Spacer content and polymorphism within conserved CRISPR arrays revealed phylogenetic relationship across clades and within ST. Spacer polymorphisms of conserved arrays were instrumental for differentiating closely related strains, e.g., ST1/RT027/B1 strains and pathogenicity locus encoding ST3/RT001 strains. CRISPR spacers showed sequence similarity to phage sequences, which is consistent with the native role of CRISPR-Cas as adaptive immune systems in bacteria. Overall, CRISPR-Cas sequences constitute a valuable basis for genotyping of C. difficile isolates, provide insights into the micro-evolutionary events that occur between closely related strains, and reflect the evolutionary trajectory of these genomes. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Fourteen-Genome Comparison Identifies DNA Markers for Severe-Disease-Associated Strains of Clostridium difficile▿†

PubMed Central

Forgetta, Vincenzo; Oughton, Matthew T.; Marquis, Pascale; Brukner, Ivan; Blanchette, Ruth; Haub, Kevin; Magrini, Vince; Mardis, Elaine R.; Gerding, Dale N.; Loo, Vivian G.; Miller, Mark A.; Mulvey, Michael R.; Rupnik, Maja; Dascal, Andre; Dewar, Ken

2011-01-01

Clostridium difficile is a common cause of infectious diarrhea in hospitalized patients. A severe and increased incidence of C. difficile infection (CDI) is associated predominantly with the NAP1 strain; however, the existence of other severe-disease-associated (SDA) strains and the extensive genetic diversity across C. difficile complicate reliable detection and diagnosis. Comparative genome analysis of 14 sequenced genomes, including those of a subset of NAP1 isolates, allowed the assessment of genetic diversity within and between strain types to identify DNA markers that are associated with severe disease. Comparative genome analysis of 14 isolates, including five publicly available strains, revealed that C. difficile has a core genome of 3.4 Mb, comprising ∼3,000 genes. Analysis of the core genome identified candidate DNA markers that were subsequently evaluated using a multistrain panel of 177 isolates, representing more than 50 pulsovars and 8 toxinotypes. A subset of 117 isolates from the panel had associated patient data that allowed assessment of an association between the DNA markers and severe CDI. We identified 20 candidate DNA markers for species-wide detection and 10,683 single nucleotide polymorphisms (SNPs) associated with the predominant SDA strain (NAP1). A species-wide detection candidate marker, the sspA gene, was found to be the same across 177 sequenced isolates and lacked significant similarity to those of other species. Candidate SNPs in genes CD1269 and CD1265 were found to associate more closely with disease severity than currently used diagnostic markers, as they were also present in the toxin A-negative and B-positive (A-B+) strain types. The genetic markers identified illustrate the potential of comparative genomics for the discovery of diagnostic DNA-based targets that are species specific or associated with multiple SDA strains. PMID:21508155

Motility and Flagellar Glycosylation in Clostridium difficile▿ †

PubMed Central

Twine, Susan M.; Reid, Christopher W.; Aubry, Annie; McMullin, David R.; Fulton, Kelly M.; Austin, John; Logan, Susan M.

2009-01-01

In this study, intact flagellin proteins were purified from strains of Clostridium difficile and analyzed using quadrupole time of flight and linear ion trap mass spectrometers. Top-down studies showed the flagellin proteins to have a mass greater than that predicted from the corresponding gene sequence. These top-down studies revealed marker ions characteristic of glycan modifications. Additionally, diversity in the observed masses of glycan modifications was seen between strains. Electron transfer dissociation mass spectrometry was used to demonstrate that the glycan was attached to the flagellin protein backbone in O linkage via a HexNAc residue in all strains examined. Bioinformatic analysis of C. difficile genomes revealed diversity with respect to glycan biosynthesis gene content within the flagellar biosynthesis locus, likely reflected by the observed flagellar glycan diversity. In C. difficile strain 630, insertional inactivation of a glycosyltransferase gene (CD0240) present in all sequenced genomes resulted in an inability to produce flagellar filaments at the cell surface and only minor amounts of unmodified flagellin protein. PMID:19749038

Isolation of Clostridium difficile from dogs with digestive disorders, including stable metronidazole-resistant strains.

PubMed

Orden, Cristina; Blanco, Jose L; Álvarez-Pérez, Sergio; Garcia-Sancho, Mercedes; Rodriguez-Franco, Fernando; Sainz, Angel; Villaescusa, Alejandra; Harmanus, Celine; Kuijper, Ed; Garcia, Marta E

2017-02-01

The prevalence of Clostridium difficile in 107 dogs with diverse digestive disorders attended in a Spanish veterinary teaching hospital was assessed. The microorganism was isolated from 13 dogs (12.1%) of different disease groups. Isolates belonged to PCR ribotypes 078, 106, 154 and 430 (all of them toxigenic) and 110 (non-toxigenic), and were resistant to several antimicrobial drugs. Notably, seven isolates obtained from different dogs displayed stable resistance to metronidazole. The results of this study provide further evidence that dogs can act as a reservoir of C. difficile strains of epidemic ribotypes with resistance to multiple antibiotics. Copyright © 2016 Elsevier Ltd. All rights reserved.

Activity of a dry mist hydrogen peroxide system against environmental Clostridium difficile contamination in elderly care wards.

PubMed

Shapey, S; Machin, K; Levi, K; Boswell, T C

2008-10-01

Clostridium difficile causes serious healthcare-associated infections. Infection control is difficult, due in part to environmental contamination with C. difficile spores. These spores are relatively resistant to cleaning and disinfection. The activity of a dry mist hydrogen peroxide decontamination system (Sterinis) against environmental C. difficile contamination was assessed in three elderly care wards. Initial sampling for C. difficile was performed in 16 rooms across a variety of wards and specialties, using Brazier's CCEY (cycloserine-cefoxitin-egg yolk) agar. Ten rooms for elderly patients (eight isolation and two sluice rooms) were then resampled following dry mist hydrogen peroxide decontamination. Representative isolates of C. difficile were typed by polymerase chain reaction ribotyping. C. difficile was recovered from 3%, 11% and 26% of samples from low, medium and high risk rooms, respectively. In 10 high risk elderly care rooms, 24% (48/203) of samples were positive for C. difficile, with a mean of 6.8 colony-forming units (cfu) per 10 samples prior to hydrogen peroxide decontamination. Ribotyping identified the presence of the three main UK epidemic strains (ribotypes 001, 027 and 106) and four rooms contained mixed strains. After a single cycle of hydrogen peroxide decontamination, only 3% (7/203) of samples were positive (P<0.001), with a mean of 0.4 cfu per 10 samples ( approximately 94% reduction). The Sterinis hydrogen peroxide system significantly reduced the extent of environmental contamination with C. difficile in these elderly care rooms. This relatively quick and user-friendly technology might be a more reliable method of terminally disinfecting isolation rooms, following detergent cleaning, compared to the manual application of other disinfectants.

Isolation of recombinant antibodies directed against surface proteins of Clostridium difficile.

PubMed

Shirvan, Ali Nazari; Aitken, Robert

2016-01-01

Clostridium difficile has emerged as an increasingly important nosocomial pathogen and the prime causative agent of antibiotic-associated diarrhoea and pseudomembranous colitis in humans. In addition to toxins A and B, immunological studies using antisera from patients infected with C. difficile have shown that a number of other bacterial factors contribute to the pathogenesis, including surface proteins, which are responsible for adhesion, motility and other interactions with the human host. In this study, various clostridial targets, including FliC, FliD and cell wall protein 66, were expressed and purified. Phage antibody display yielded a large panel of specific recombinant antibodies, which were expressed, purified and characterised. Reactions of the recombinant antibodies with their targets were detected by enzyme-linked immunosorbent assay; and Western blotting suggested that linear rather than conformational epitopes were recognised. Binding of the recombinant antibodies to surface-layer proteins and their components showed strain specificity, with good recognition of proteins from C. difficile 630. However, no reaction was observed for strain R20291-a representative of the 027 ribotype. Binding of the recombinant antibodies to C. difficile M120 extracts indicated that a component of a surface-layer protein of this strain might possess immunoglobulin-binding activities. The recombinant antibodies against FliC and FliD proteins were able to inhibit bacterial motility. Copyright © 2016. Published by Elsevier Editora Ltda.

Clostridium difficile Drug Pipeline: Challenges in Discovery and Development of New Agents

PubMed Central

2015-01-01

In the past decade Clostridium difficile has become a bacterial pathogen of global significance. Epidemic strains have spread throughout hospitals, while community acquired infections and other sources ensure a constant inoculation of spores into hospitals. In response to the increasing medical burden, a new C. difficile antibiotic, fidaxomicin, was approved in 2011 for the treatment of C. difficile-associated diarrhea. Rudimentary fecal transplants are also being trialed as effective treatments. Despite these advances, therapies that are more effective against C. difficile spores and less damaging to the resident gastrointestinal microbiome and that reduce recurrent disease are still desperately needed. However, bringing a new treatment for C. difficile infection to market involves particular challenges. This review covers the current drug discovery pipeline, including both small molecule and biologic therapies, and highlights the challenges associated with in vitro and in vivo models of C. difficile infection for drug screening and lead optimization. PMID:25760275

Clostridium difficile infection: molecular pathogenesis and novel therapeutics

PubMed Central

Rineh, Ardeshir; Kelso, Michael J; Vatansever, Fatma; Tegos, George P; Hamblin, Michael R

2015-01-01

The Gram-positive anaerobic bacterium Clostridium difficile produces toxins A and B, which can cause a spectrum of diseases from pseudomembranous colitis to C. difficile-associated diarrhea. A limited number of C. difficile strains also produce a binary toxin that exhibits ADP ribosyltransferase activity. Here, the structure and the mechanism of action of these toxins as well as their role in disease are reviewed. Nosocomial C. difficile infection is often contracted in hospital when patients treated with antibiotics suffer a disturbance in normal gut microflora. C. difficile spores can persist on dry, inanimate surface for months. Metronidazole and oral vancomycin are clinically used for treatment of C. difficile infection but clinical failure and concern about promotion of resistance are motivating the search for novel non-antibiotic therapeutics. Methods for controlling both toxins and spores, replacing gut microflora by probiotics or fecal transplant, and killing bacteria in the anaerobic gut by photodynamic therapy are discussed. PMID:24410618

Presence of Clostridium difficile in pig faecal samples and wild animal species associated with pig farms.

PubMed

Andrés-Lasheras, S; Bolea, R; Mainar-Jaime, R C; Kuijper, E; Sevilla, E; Martín-Burriel, I; Chirino-Trejo, M

2017-02-01

To determine the presence of Clostridium difficile on fattening pig farms in north-eastern Spain. Twenty-seven farms were sampled. Pools of pig faecal samples (n = 210), samples of intestinal content from common farm pest species (n = 95) and environment-related samples (n = 93) were collected. Isolates were tested for toxin genes of C. difficile, and typed by PCR-ribotyping and toxinotyping. The minimal inhibitory concentrations of six antimicrobial agents were determined using Etest. Thirty-four isolates were obtained from 12 farms, and 30 (88·2%) had toxin genes. Seven ribotypes were identified. Ribotype 078 and its variant 126 were predominant (52·9%). The same ribotypes were isolated from different animal species on the same farm. None of the isolates were resistant to metronidazole or vancomycin. Clostridium difficile was common within the pig farm environment. Most of the positive samples came from pest species or were pest-related environmental samples. Pest species were colonized with toxigenic and antimicrobial-resistant C. difficile strains of the same ribotypes that are found in humans and pigs. Rodents and pigeons may transmit toxigenic and antimicrobial-resistant C. difficile strains that are of the same ribotypes as those occuring in humans. © 2016 The Society for Applied Microbiology.

Detection of a cfr(B) Variant in German Enterococcus faecium Clinical Isolates and the Impact on Linezolid Resistance in Enterococcus spp.

PubMed

Bender, Jennifer K; Fleige, Carola; Klare, Ingo; Fiedler, Stefan; Mischnik, Alexander; Mutters, Nico T; Dingle, Kate E; Werner, Guido

2016-01-01

The National Reference Centre for Staphylococci and Enterococci in Germany has received an increasing number of clinical linezolid-resistant E. faecium isolates in recent years. Five isolates harbored a cfr(B) variant gene locus the product of which is capable of conferring linezolid resistance. The cfr(B)-like methyltransferase gene was also detected in Clostridium difficile. Antimicrobial susceptibility was determined for cfr(B)-positive and linezolid-resistant E. faecium isolates and two isogenic C. difficile strains. All strains were subjected to whole genome sequencing and analyzed with respect to mutations in the 23S rDNA, rplC, rplD and rplV genes and integration sites of the cfr(B) variant locus. To evaluate methyltransferase function, the cfr(B) variant of Enterococcus and Clostridium was expressed in both E. coli and Enterococcus spp. Ribosomal target site mutations were detected in E. faecium strains but absent in clostridia. Sequencing revealed 99.9% identity between cfr(B) of Enterococcus and cfr of Clostridium. The methyltransferase gene is encoded by transposon Tn6218 which was present in C. difficile Ox3196, truncated in some E. faecium and absent in C. difficile Ox3206. The latter finding explains the lack of linezolid and chloramphenicol resistance in C. difficile Ox3206 and demonstrates for the first time a direct correlation of elevated linezolid MICs in C. difficile upon cfr acquisition. Tn6218 insertion sites revealed novel target loci for integration, both within the bacterial chromosome and as an integral part of plasmids. Importantly, the very first plasmid-association of a cfr(B) variant was observed. Although we failed to measure cfr(B)-mediated resistance in transformed laboratory strains the occurrence of the multidrug resistance gene cfr on putatively highly mobile and/or extrachromosomal DNA in clinical isolates is worrisome with respect to dissemination of antibiotic resistances.

Detection of a cfr(B) Variant in German Enterococcus faecium Clinical Isolates and the Impact on Linezolid Resistance in Enterococcus spp.

PubMed Central

Fleige, Carola; Klare, Ingo; Fiedler, Stefan; Mischnik, Alexander; Mutters, Nico T.; Dingle, Kate E.; Werner, Guido

2016-01-01

The National Reference Centre for Staphylococci and Enterococci in Germany has received an increasing number of clinical linezolid-resistant E. faecium isolates in recent years. Five isolates harbored a cfr(B) variant gene locus the product of which is capable of conferring linezolid resistance. The cfr(B)-like methyltransferase gene was also detected in Clostridium difficile. Antimicrobial susceptibility was determined for cfr(B)-positive and linezolid-resistant E. faecium isolates and two isogenic C. difficile strains. All strains were subjected to whole genome sequencing and analyzed with respect to mutations in the 23S rDNA, rplC, rplD and rplV genes and integration sites of the cfr(B) variant locus. To evaluate methyltransferase function, the cfr(B) variant of Enterococcus and Clostridium was expressed in both E. coli and Enterococcus spp. Ribosomal target site mutations were detected in E. faecium strains but absent in clostridia. Sequencing revealed 99.9% identity between cfr(B) of Enterococcus and cfr of Clostridium. The methyltransferase gene is encoded by transposon Tn6218 which was present in C. difficile Ox3196, truncated in some E. faecium and absent in C. difficile Ox3206. The latter finding explains the lack of linezolid and chloramphenicol resistance in C. difficile Ox3206 and demonstrates for the first time a direct correlation of elevated linezolid MICs in C. difficile upon cfr acquisition. Tn6218 insertion sites revealed novel target loci for integration, both within the bacterial chromosome and as an integral part of plasmids. Importantly, the very first plasmid-association of a cfr(B) variant was observed. Although we failed to measure cfr(B)-mediated resistance in transformed laboratory strains the occurrence of the multidrug resistance gene cfr on putatively highly mobile and/or extrachromosomal DNA in clinical isolates is worrisome with respect to dissemination of antibiotic resistances. PMID:27893790

Prevalence and Duration of Asymptomatic Clostridium difficile Carriage among Healthy Subjects in Pittsburgh, Pennsylvania

PubMed Central

Galdys, Alison L.; Nelson, Jemma S.; Shutt, Kathleen A.; Schlackman, Jessica L.; Pakstis, Diana L.; Pasculle, A. William; Marsh, Jane W.; Harrison, Lee H.

2014-01-01

Previous studies suggested that 7 to 15% of healthy adults are colonized with toxigenic Clostridium difficile. To investigate the epidemiology, genetic diversity, and duration of C. difficile colonization in asymptomatic persons, we recruited healthy adults from the general population in Allegheny County, Pennsylvania. Participants provided epidemiological and dietary intake data and submitted stool specimens. The presence of C. difficile in stool specimens was determined by anaerobic culture. Stool specimens yielding C. difficile underwent nucleic acid testing of the tcdA gene segment with a commercial assay; tcdC genotyping was performed on C. difficile isolates. Subjects positive for C. difficile by toxigenic anaerobic culture were asked to submit additional specimens. One hundred six (81%) of 130 subjects submitted specimens, and 7 (6.6%) of those subjects were colonized with C. difficile. Seven distinct tcdC genotypes were observed among the 7 C. difficile-colonized individuals, including tcdC genotype 20, which has been found in uncooked ground pork in this region. Two (33%) out of 6 C. difficile-colonized subjects who submitted additional specimens tested positive for identical C. difficile strains on successive occasions, 1 month apart. The prevalence of C. difficile carriage in this healthy cohort is concordant with prior estimates. C. difficile-colonized individuals may be important reservoirs for C. difficile and may falsely test positive for infections due to C. difficile when evaluated for community-acquired diarrhea caused by other enteric pathogens. PMID:24759727

Pharmacodynamic studies of vancomycin, metronidazole and fusidic acid against Clostridium difficile.

PubMed

Odenholt, Inga; Walder, Mats; Wullt, Marlene

2007-01-01

Pharmacodynamic studies of antibiotics have attracted great interest in recent years. However, studies on the pharmacodynamics of different antibiotics against Clostridium difficile are scarce. The postantibiotic effects (PAE) and the postantibiotic sub-minimum inhibitory concentration (MIC) effects (PA SME) of vancomycin, metronidazole and fusidic acid were investigated by viable counts against three different strains of C. difficile. The killing rate and extent of the three antibiotics against the same strains were also studied by adding 2, 4, 8, 16 and 32x MIC of the three antibiotics, respectively. Metronidazole exerted a very rapid bactericidal effect at concentrations of 8x MIC and above against all three strains investigated. Vancomycin gave overall less kill in comparison to metronidazole and was bacteriostatic against two of the three strains. Fusidic acid exerted a concentration-dependent killing against two of the strains. Vancomycin exerted short PAEs and PA SMEs against all three strains. Significantly longer PAEs and PA SMEs were noted for fusidic acid. Metronidazole gave similar short PAEs like vancomycin but longer PA SMEs were noted against two of the investigated strains. Metronidazole exerted the most prominent bactericidal effect greater than fusidic acid and greater than vancomycin. Fusidic acid gave overall the longest PAEs and PA SMEs greater than metronidazole and greater than vancomycin. Copyright 2007 S. Karger AG, Basel.

Genomic study of the Type IVC secretion system in Clostridium difficile: understanding C. difficile evolution via horizontal gene transfer.

PubMed

Zhang, Wen; Cheng, Ying; Du, Pengcheng; Zhang, Yuanyuan; Jia, Hongbing; Li, Xianping; Wang, Jing; Han, Na; Qiang, Yujun; Chen, Chen; Lu, Jinxing

2017-01-01

Clostridium difficile, the etiological agent of Clostridium difficile infection (CDI), is a gram-positive, spore-forming bacillus that is responsible for ∼20% of antibiotic-related cases of diarrhea and nearly all cases of pseudomembranous colitis. Previous data have shown that a substantial proportion (11%) of the C. difficile genome consists of mobile genetic elements, including seven conjugative transposons. However, the mechanism underlying the formation of a mosaic genome in C. difficile is unknown. The type-IV secretion system (T4SS) is the only secretion system known to transfer DNA segments among bacteria. We searched genome databases to identify a candidate T4SS in C. difficile that could transfer DNA among different C. difficile strains. All T4SS gene clusters in C. difficile are located within genomic islands (GIs), which have variable lengths and structures and are all conjugative transposons. During the horizontal-transfer process of T4SS GIs within the C. difficile population, the excision sites were altered, resulting in different short-tandem repeat sequences among the T4SS GIs, as well as different chromosomal insertion sites and additional regions in the GIs.

Genome-Based Infection Tracking Reveals Dynamics of Clostridium difficile Transmission and Disease Recurrence.

PubMed

Kumar, Nitin; Miyajima, Fabio; He, Miao; Roberts, Paul; Swale, Andrew; Ellison, Louise; Pickard, Derek; Smith, Godfrey; Molyneux, Rebecca; Dougan, Gordon; Parkhill, Julian; Wren, Brendan W; Parry, Christopher M; Pirmohamed, Munir; Lawley, Trevor D

2016-03-15

Accurate tracking of Clostridium difficile transmission within healthcare settings is key to its containment but is hindered by the lack of discriminatory power of standard genotyping methods. We describe a whole-genome phylogenetic-based method to track the transmission of individual clones in infected hospital patients from the epidemic C. difficile 027/ST1 lineage, and to distinguish between the 2 causes of recurrent disease, relapse (same strain), or reinfection (different strain). We monitored patients with C. difficile infection in a UK hospital over a 2-year period. We performed whole-genome sequencing and phylogenetic analysis of 108 strains isolated from symptomatic patients. High-resolution phylogeny was integrated with in-hospital transfers and contact data to create an infection network linking individual patients and specific hospital wards. Epidemic C. difficile 027/ST1 caused the majority of infections during our sampling period. Integration of whole-genome single nucleotide polymorphism (SNP) phylogenetic analysis, which accurately discriminated between 27 distinct SNP genotypes, with patient movement and contact data identified 32 plausible transmission events, including ward-based contamination (66%) or direct donor-recipient contact (34%). Highly contagious donors were identified who contributed to the persistence of clones within distinct hospital wards and the spread of clones between wards, especially in areas of intense turnover. Recurrent cases were identified between 4 and 26 weeks, highlighting the limitation of the standard <8-week cutoff used for patient diagnosis and management. Genome-based infection tracking to monitor the persistence and spread of C. difficile within healthcare facilities could inform infection control and patient management. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America.

Strong antimicrobial activity of xanthohumol and other derivatives from hops (Humulus lupulus L.) on gut anaerobic bacteria.

PubMed

Cermak, Pavel; Olsovska, Jana; Mikyska, Alexandr; Dusek, Martin; Kadleckova, Zuzana; Vanicek, Jiri; Nyc, Otakar; Sigler, Karel; Bostikova, Vanda; Bostik, Pavel

2017-11-01

Anaerobic bacteria, such as Bacteroides fragilis or Clostridium perfringens, are part of indigenous human flora. However, Clostridium difficile represents also an important causative agent of nosocomial infectious antibiotic-associated diarrhoea. Treatment of C. difficile infection is problematic, making it imperative to search for new compounds with antimicrobial properties. Hops (Humulus lupulus L.) contain substances with antibacterial properties. We tested antimicrobial activity of purified hop constituents humulone, lupulone and xanthohumol against anaerobic bacteria. The antimicrobial activity was established against B. fragilis, C. perfringens and C. difficile strains according to standard testing protocols (CLSI, EUCAST), and the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBC) were calculated. All C. difficile strains were toxigenic and clinically relevant, as they were isolated from patients with diarrhoea. Strongest antimicrobial effects were observed with xanthohumol showing MIC and MBC values of 15-107 μg/mL, which are close to those of conventional antibiotics in the strains of bacteria with increased resistance. Slightly higher MIC and MBC values were obtained with lupulone followed by higher values of humulone. Our study, thus, shows a potential of purified hop compounds, especially xanthohumol, as alternatives for treatment of infections caused by select anaerobic bacteria, namely nosocomial diarrhoea caused by resistant strains. © 2017 APMIS. Published by John Wiley & Sons Ltd.

Immunization with Bacillus Spores Expressing Toxin A Peptide Repeats Protects against Infection with Clostridium difficile Strains Producing Toxins A and B ▿ †

PubMed Central

Permpoonpattana, Patima; Hong, Huynh A.; Phetcharaburanin, Jutarop; Huang, Jen-Min; Cook, Jenny; Fairweather, Neil F.; Cutting, Simon M.

2011-01-01

Clostridium difficile is a leading cause of nosocomial infection in the developed world. Two toxins, A and B, produced by most strains of C. difficile are implicated as virulence factors, yet only recently has the requirement of these for infection been investigated by genetic manipulation. Current vaccine strategies are focused mostly on parenteral delivery of toxoids. In this work, we have used bacterial spores (Bacillus subtilis) as a delivery vehicle to evaluate the carboxy-terminal repeat domains of toxins A and B as protective antigens. Our findings are important and show that oral immunization of the repeat domain of toxin A is sufficient to confer protection in a hamster model of infection designed to closely mimic the human course of infection. Importantly, neutralizing antibodies to the toxin A repeat domain were shown to be cross-reactive with the analogous domain of toxin B and, being of high avidity, provided protection against challenge with a C. difficile strain producing toxins A and B (A+B+). Thus, although many strains produce both toxins, antibodies to only toxin A can mediate protection. Animals vaccinated with recombinant spores were fully able to survive reinfection, a property that is particularly important for a disease with which patients are prone to relapse. We show that mucosal immunization, not parenteral delivery, is required to generate secretory IgA and that production of these neutralizing polymeric antibodies correlates with protection. This work demonstrates that an effective vaccine against C. difficile can be designed around two attributes, mucosal delivery and the repeat domain of toxin A. PMID:21482682

Clostridium difficile infection: epidemiology, diagnosis and understanding transmission.

PubMed

Martin, Jessica S H; Monaghan, Tanya M; Wilcox, Mark H

2016-04-01

Clostridium difficile infection (CDI) continues to affect patients in hospitals and communities worldwide. The spectrum of clinical disease ranges from mild diarrhoea to toxic megacolon, colonic perforation and death. However, this bacterium might also be carried asymptomatically in the gut, potentially leading to 'silent' onward transmission. Modern technologies, such as whole-genome sequencing and multi-locus variable-number tandem-repeat analysis, are helping to track C. difficile transmission across health-care facilities, countries and continents, offering the potential to illuminate previously under-recognized sources of infection. These typing strategies have also demonstrated heterogeneity in terms of CDI incidence and strain types reflecting different stages of epidemic spread. However, comparison of CDI epidemiology, particularly between countries, is challenging due to wide-ranging approaches to sampling and testing. Diagnostic strategies for C. difficile are complicated both by the wide range of bacterial targets and tests available and the need to differentiate between toxin-producing and non-toxigenic strains. Multistep diagnostic algorithms have been recommended to improve sensitivity and specificity. In this Review, we describe the latest advances in the understanding of C. difficile epidemiology, transmission and diagnosis, and discuss the effect of these developments on the clinical management of CDI.

Clostridium difficile Genotypes in Piglet Populations in Germany

PubMed Central

Neubauer, Heinrich; Schmoock, Gernot; Baier, Sylvia; Harlizius, Jürgen; Nienhoff, Hendrik; Brase, Katja; Zimmermann, Stefan; Seyboldt, Christian

2013-01-01

Clostridium difficile was isolated from 147 of 201 (73%) rectal swabs of piglets from 15 farms of Lower Saxony and North Rhine-Westphalia. In 14 farms, 14 to 100% (mean, 78%) of the animals tested were culture positive. The rate of isolation was 68% postpartum, increased to 94% in animals 2 to 14 days of age, and declined to 0% for animals 49 days of age and older. There was no link between isolation and antibiotic treatment or diarrhea of piglets. Strains were assigned to 10 PCR ribotypes, and up to 4 PCR ribotypes were found to be present at the same time on a farm. The closely related PCR ribotypes 078 (55%) and 126 (20%) were most frequently recovered and were present in 13 of the 14 positive farms. The comparison of multilocus VNTR (variable number of tandem repeats) analysis (MLVA) data from this study and previously published data on human, porcine, and bovine PCR ribotype 078 isolates from 5 European countries revealed genetic differences between strains of different geographic origin and confirmed the relatedness of human and porcine C. difficile isolates. This study demonstrated that the human-pathogenic PCR ribotypes 078 and 126 are predominant in piglets in Germany. The results suggest that presence of C. difficile is correlated with animal age but not with antibiotic treatment or clinical disease. MLVA indicated that strains of the same geographical origin are often genetically related and corroborated the hypothesis of a close epidemiological connection between human and porcine C. difficile isolates. PMID:24025903

Clinical Severity of Clostridium difficile PCR Ribotype 027: A Case-Case Study

PubMed Central

Morgan, Oliver W.; Rodrigues, Boaventura; Elston, Tony; Verlander, Neville Q.; Brown, Derek F. J.; Brazier, Jonathan; Reacher, Mark

2008-01-01

Background Clostridium difficile is a leading infectious cause of health care associated diarrhoea. Several industrialised countries have reported increased C. difficile infections and outbreaks, which have been attributed to the emergent PCR ribotype 027 strain. Methods and Findings We conducted a case-case study to compare severity of C. difficile disease for patients with 027 versus non-027 ribotypes. We retrospectively collected clinical information about 123/136 patients with C. difficile infections admitted to hospitals in the East of England region in 2006 and from whom stool isolates were cultured and ribotyped as part of an earlier national survey. We defined severe C. difficile disease as having one or more of shock, paralytic ileus, pseudo membranous colitis or toxic megacolon. Patient median age was 83 years old (range 3 to 98, interquartile range 75 to 89), 86% were prescribed antibiotics in the eight weeks before illness onset, 41% had ribotype 027 and 30-day all cause mortality during hospital admission was 21%. Severe disease occurred in 24% (95%CI 13% to 37%) and 17% (95%CI 9% to 27%) of patients with PCR ribotype 027 and non-027 ribotypes respectively. In a multivariable model, ribotype 027 was not associated with severe disease after adjusting for sex, discharge from hospital prior to 60 days of current admission, gastroenteritis on admission, number of initiator antibiotics for C. difficile disease, and hospital where the patient was admitted. Conclusions Our study found no evidence to support previous assertions that ribotype 027 is more virulent than other PCR ribotypes. This finding raises questions about the contribution of this strain to the recent increase in C. difficile disease throughout North America and Europe. PMID:18350149

Clinical severity of Clostridium difficile PCR ribotype 027: a case-case study.

PubMed

Morgan, Oliver W; Rodrigues, Boaventura; Elston, Tony; Verlander, Neville Q; Brown, Derek F J; Brazier, Jonathan; Reacher, Mark

2008-03-19

Clostridium difficile is a leading infectious cause of health care associated diarrhoea. Several industrialised countries have reported increased C. difficile infections and outbreaks, which have been attributed to the emergent PCR ribotype 027 strain. We conducted a case-case study to compare severity of C. difficile disease for patients with 027 versus non-027 ribotypes. We retrospectively collected clinical information about 123/136 patients with C. difficile infections admitted to hospitals in the East of England region in 2006 and from whom stool isolates were cultured and ribotyped as part of an earlier national survey. We defined severe C. difficile disease as having one or more of shock, paralytic ileus, pseudo membranous colitis or toxic megacolon. Patient median age was 83 years old (range 3 to 98, interquartile range 75 to 89), 86% were prescribed antibiotics in the eight weeks before illness onset, 41% had ribotype 027 and 30-day all cause mortality during hospital admission was 21%. Severe disease occurred in 24% (95%CI 13% to 37%) and 17% (95%CI 9% to 27%) of patients with PCR ribotype 027 and non-027 ribotypes respectively. In a multivariable model, ribotype 027 was not associated with severe disease after adjusting for sex, discharge from hospital prior to 60 days of current admission, gastroenteritis on admission, number of initiator antibiotics for C. difficile disease, and hospital where the patient was admitted. Our study found no evidence to support previous assertions that ribotype 027 is more virulent than other PCR ribotypes. This finding raises questions about the contribution of this strain to the recent increase in C. difficile disease throughout North America and Europe.

Prevalence and Characterization of a Binary Toxin (Actin-Specific ADP-Ribosyltransferase) from Clostridium difficile

PubMed Central

Gonçalves, Carina; Decré, Dominique; Barbut, Frédéric; Burghoffer, Béatrice; Petit, Jean-Claude

2004-01-01

In addition to the two large clostridial cytotoxins (TcdA and TcdB), some strains of Clostridium difficile also produce an actin-specific ADP-ribosyltransferase, called binary toxin CDT. We used a PCR method and Southern blotting for the detection of genes encoding the enzymatic (CDTa) and binding (CDTb) components of the binary toxin in 369 strains isolated from patients with suspected C. difficile-associated diarrhea or colitis. Twenty-two strains (a prevalence of 6%) harbored both genes. When binary toxin production was assessed by Western blotting, 19 of the 22 strains reacted with antisera against the iota toxin of C. perfringens (anti-Ia and anti-Ib). Additionally, binary toxin activity, detected by the ADP-ribosyltransferase assay, was present in only 17 of the 22 strains. Subsequently, all 22 binary toxin-positive strains were tested for the production of toxins TcdA and TcdB, toxinotyped, and characterized by serogrouping, PCR ribotyping, arbitrarily primed PCR, and pulsed-field gel electrophoresis. All binary toxin-positive strains also produced TcdB and/or TcdA. However, they had significant changes in the tcdA and tcdB genes and belonged to variant toxinotypes III, IV, V, VII, IX, and XIII. We could differentiate 16 profiles by using typing methods, indicating that most of the binary toxin-positive strains were unrelated. PMID:15131151

A New Type of Toxin A-Negative, Toxin B-Positive Clostridium difficile Strain Lacking a Complete tcdA Gene

PubMed Central

Marín, Mercedes; Martín, Adoración; Rupnik, Maja

2014-01-01

Toxins A and B are the main virulence factors of Clostridium difficile and are the targets for molecular diagnostic tests. Here, we describe a new toxin A-negative, toxin B-positive, binary toxin CDT (Clostridium difficile transferase)-negative (A− B+ CDT−) toxinotype (XXXII) characterized by a variant type of pathogenicity locus (PaLoc) without tcdA and with atypical organization of the PaLoc integration site. PMID:25428159

Clostridium difficile Infection in Production Animals and Avian Species: A Review.

PubMed

Moono, Peter; Foster, Niki F; Hampson, David J; Knight, Daniel R; Bloomfield, Lauren E; Riley, Thomas V

2016-12-01

Clostridium difficile is the leading cause of antibiotic-associated diarrhea and colitis in hospitalized humans. Recently, C. difficile infection (CDI) has been increasingly recognized as a cause of neonatal enteritis in food animals such as pigs, resulting in stunted growth, delays in weaning, and mortality, as well as colitis in large birds such as ostriches. C. difficile is a strictly anaerobic spore-forming bacterium, which produces two toxins A (TcdA) and B (TcdB) as its main virulence factors. The majority of strains isolated from animals produce an additional binary toxin (C. difficile transferase) that is associated with increased virulence. C. difficile is ubiquitous in the environment and has a wide host range. This review summarizes the epidemiology, clinical presentations, risk factors, and laboratory diagnosis of CDI in animals. Increased awareness by veterinarians and animal owners of the significance of clinical disease caused by C. difficile in livestock and avians is needed. Finally, this review provides an overview on methods for controlling environmental contamination and potential therapeutics available.

The role of toxins in Clostridium difficile infection.

PubMed

Chandrasekaran, Ramyavardhanee; Lacy, D Borden

2017-11-01

Clostridium difficile is a bacterial pathogen that is the leading cause of nosocomial antibiotic-associated diarrhea and pseudomembranous colitis worldwide. The incidence, severity, mortality and healthcare costs associated with C. difficile infection (CDI) are rising, making C. difficile a major threat to public health. Traditional treatments for CDI involve use of antibiotics such as metronidazole and vancomycin, but disease recurrence occurs in about 30% of patients, highlighting the need for new therapies. The pathogenesis of C. difficile is primarily mediated by the actions of two large clostridial glucosylating toxins, toxin A (TcdA) and toxin B (TcdB). Some strains produce a third toxin, the binary toxin C. difficile transferase, which can also contribute to C. difficile virulence and disease. These toxins act on the colonic epithelium and immune cells and induce a complex cascade of cellular events that result in fluid secretion, inflammation and tissue damage, which are the hallmark features of the disease. In this review, we summarize our current understanding of the structure and mechanism of action of the C. difficile toxins and their role in disease. Published by Oxford University Press on behalf of FEMS 2017.

The incidence of Clostridioides difficile and Clostridium perfringens netF-positive strains in diarrheic dogs.

PubMed

Diniz, Amanda Nadia; Coura, Fernanda Morcatti; Rupnik, Maja; Adams, Vicki; Stent, Thomas L; Rood, Julian I; de Oliveira, Carlos Augusto; Lobato, Francisco Carlos Faria; Silva, Rodrigo Otávio Silveira

2018-02-01

The aim of this study was to examine the incidence of Clostridioides (previously Clostridium) difficile and Clostridium perfringens in the feces of diarrheic and non-diarrheic dogs. Also, the presence of other common canine enteropathogens was examined. Toxigenic C. difficile and C. perfringens positive for the NetF-encoding gene (netF) were detected in 11 (11.9%) and seven (7.6%) diarrheic dogs, respectively. Three dogs were diagnosed simultaneously with toxigenic C. difficile and netF-positive C. perfringens. Among other enteropathogens, Giardia sp. was the most common agent detected in dogs positive for toxigenic C. difficile or netF-positive C. perfringens. The results suggest that C. difficile and C. perfringens occur more frequently as a primary cause of diarrhea. Copyright © 2017 Elsevier Ltd. All rights reserved.

Clostridium difficile infection among immunocompromised patients in Rio de Janeiro, Brazil and detection of moxifloxacin resistance in a ribotype 014 strain.

PubMed

Secco, Danielle Angst; Balassiano, Ilana Teruszkin; Boente, Renata Ferreira; Miranda, Karla Rodrigues; Brazier, Jon; Hall, Val; dos Santos-Filho, Joaquim; Lobo, Leandro Araujo; Nouér, Simone Aranha; Domingues, Regina Maria Cavalcanti Pilotto

2014-08-01

Clostridium difficile is a Gram-positive spore forming anaerobic bacterium, often associated with nosocomial diarrhea and pseudomembranous colitis. The acquisition of this organism occurs primarily in hospitals through accidental ingestion of spores, and its establishment and proliferation in the colon results from the removal of members of the normal intestinal flora during or after antibiotic therapy. In this study, stool samples from patients admitted to the University Hospital Clementino Fraga Filho (HUCCF/UFRJ) were screened for C. difficile toxins with an ELISA test and cultured with standard techniques for C. difficile isolation. A total of 74 stool samples were collected from patients undergoing antibiotic therapy between August 2009 and November 2010, only two (2.7%) were positive in the ELISA test and culture. A third isolate was obtained from a negative ELISA test sample. All cases of CDI were identified in patients with acute lymphoid or myeloid leukemia. Genotypic and phenotypic characterization showed that all strains carried toxins A and B genes, and belonged to PCR-ribotypes 014, 043 and 046. The isolated strains were sensitive to metronidazole and vancomycin, and resistant to ciprofloxacin and levofloxacin. Resistance to moxifloxacin, was present in the strain from PCR-ribotype 014, that showed an amino acid substitution in gyrB gene (Asp 426 → Asn). This is the first time that this mutation in a PCR-ribotype 014 strain has been described in Brazil. Copyright © 2014 Elsevier Ltd. All rights reserved.

Clostridium difficile chimeric toxin receptor binding domain vaccine induced protection against different strains in active and passive challenge models.

PubMed

Tian, Jing-Hui; Glenn, Gregory; Flyer, David; Zhou, Bin; Liu, Ye; Sullivan, Eddie; Wu, Hua; Cummings, James F; Elllingsworth, Larry; Smith, Gale

2017-07-24

Clostridium difficile is the number one cause of nosocomial antibiotic-associated diarrhea in developed countries. Historically, pathogenesis was attributed two homologous glucosylating toxins, toxin-A (TcdA) and toxin-B (TcdB). Over the past decade, however, highly virulent epidemic strains of C. difficile (B1/NAP1/027) have emerged and are linked to an increase in morbidity and mortality. Increased virulence is attributed to multiple factors including: increased production of A- and B-toxins; production of binary toxin (CDT); and the emergence of more toxic TcdB variants (TcdB (027) ). TcdB (027) is more cytotoxicity to cells; causes greater tissue damage and toxicity in animals; and is antigenically distinct from historical TcdB (TcdB (003) ). Broadly protective vaccines and therapeutic antibody strategies, therefore, may target TcdA, TcdB variants and CDT. To facilitate the generation of multivalent toxin-based C. difficile vaccines and therapeutic antibodies, we have generated fusion proteins constructed from the receptor binding domains (RBD) of TcdA, TcdB (003) , TcdB (027) and CDT. Herein, we describe the development of a trivalent toxin (T-toxin) vaccine (CDTb/TcdB (003) /TcdA) and quadravalent toxin (Q-toxin) vaccine (CDTb/TcB (003) /TcdA/TcdB (027) ) fusion proteins that retain the protective toxin neutralizing epitopes. Active immunization of mice or hamsters with T-toxin or Q-toxin fusion protein vaccines elicited the generation of toxin neutralizing antibodies to each of the toxins. Hamsters immunized with the Q-toxin vaccine were broadly protected against spore challenge with historical C. difficile 630 (toxinotype 0/ribotype 003) and epidemic NAP1 (toxinotype III/ribotype 027) strains. Fully human polyclonal antitoxin IgG was produced by immunization of transgenic bovine with these fusion proteins. In passive transfer studies, mice were protected against lethal toxin challenge. Hamsters treated with human antitoxin IgG were completely protected when challenged with historical or epidemic strains of C. difficile. The use of chimeric fusion proteins is an attractive approach to producing multivalent antitoxin vaccines and therapeutic polyclonal antibodies for prevention and treatment of C. difficile infections (CDI). Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Clostridium difficile colonization in preoperative colorectal cancer patients

PubMed Central

Lv, Yinxiang; Huang, Chen; Sheng, Qinsong; Zhao, Peng; Ye, Julian; Jiang, Weiqin; Liu, Lulu; Song, Xiaojun; Tong, Zhou; Chen, Wenbin; Lin, Jianjiang; Tang, Yi-Wei; Jin, Dazhi; Fang, Weijia

2017-01-01

The entire process of Clostridium difficile colonization to infection develops in large intestine. However, the real colonization pattern of C. difficile in preoperative colorectal cancer patients has not been studied. In this study, 33 C. difficile strains (16.1%) were isolated from stool samples of 205 preoperative colorectal cancer patients. C. difficile colonization rates in lymph node metastasis patients (22.3%) were significantly higher than lymph node negative patients (10.8%) (OR=2.314, 95%CI=1.023-5.235, P =0.025). Meanwhile, patients positive for stool occult blood had lower C. difficile colonization rates than negative patients (11.5% vs. 24.0%, OR=0.300, 95%CI=0.131-0.685, P =0.019). A total of 16 sequence types were revealed by multilocus sequence typing. Minimum spanning tree and time-space cluster analysis indicated that all C. difficile isolates were epidemiologically unrelated. Antibiotic susceptibility testing showed all isolates were susceptible to vancomycin and metronidazole. The results suggested that the prevalence of C. difficile colonization is high in preoperative colorectal cancer patients, and the colonization is not acquired in the hospital. Since lymph node metastasis colorectal cancer patients inevitably require adjuvant chemotherapy and C. difficile infection may halt the ongoing treatment, the call for sustained monitoring of C. difficile in those patients is apparently urgent. PMID:28060753

Clostridium difficile colonization in preoperative colorectal cancer patients.

PubMed

Zheng, Yi; Luo, Yun; Lv, Yinxiang; Huang, Chen; Sheng, Qinsong; Zhao, Peng; Ye, Julian; Jiang, Weiqin; Liu, Lulu; Song, Xiaojun; Tong, Zhou; Chen, Wenbin; Lin, Jianjiang; Tang, Yi-Wei; Jin, Dazhi; Fang, Weijia

2017-02-14

The entire process of Clostridium difficile colonization to infection develops in large intestine. However, the real colonization pattern of C. difficile in preoperative colorectal cancer patients has not been studied. In this study, 33 C. difficile strains (16.1%) were isolated from stool samples of 205 preoperative colorectal cancer patients. C. difficile colonization rates in lymph node metastasis patients (22.3%) were significantly higher than lymph node negative patients (10.8%) (OR=2.314, 95%CI=1.023-5.235, P =0.025). Meanwhile, patients positive for stool occult blood had lower C. difficile colonization rates than negative patients (11.5% vs. 24.0%, OR=0.300, 95%CI=0.131-0.685, P =0.019). A total of 16 sequence types were revealed by multilocus sequence typing. Minimum spanning tree and time-space cluster analysis indicated that all C. difficile isolates were epidemiologically unrelated. Antibiotic susceptibility testing showed all isolates were susceptible to vancomycin and metronidazole. The results suggested that the prevalence of C. difficile colonization is high in preoperative colorectal cancer patients, and the colonization is not acquired in the hospital. Since lymph node metastasis colorectal cancer patients inevitably require adjuvant chemotherapy and C. difficile infection may halt the ongoing treatment, the call for sustained monitoring of C. difficile in those patients is apparently urgent.

Prevention and treatment of Clostridium difficile associated diarrhea by reconstitution of the microbiota.

PubMed

Eliakim-Raz, Noa; Bishara, Jihad

2018-05-21

This review summarizes the latest advances in treating and preventing Clostridium difficile infection (CDI), the most common infectious disease cause of nosocomial diarrhea in adults in developed countries. As customary antibiotic therapies against C. difficile, metronidazole and vancomycin, are broad spectrum, they affect greatly the gut microbiota, which result in very high recurrence rates. Therefore, new strategies are researched intensively. New therapies focus on limiting further destruction of the gut microbiota or restoring the microbiota to its pre-destructed state. These include new antibiotics, such as fidaxomicin, which demonstrates reduced CDI recurrences, among other new drugs, biotherapeutic strategies, mainly fecal microbiota transplantation but also competitive inhibition with non-toxigenic strains of C. difficile, and finally, monoclonal antibodies against C. difficile toxins which offer protection against recurrences.

Pomegranate extract exhibits in vitro activity against Clostridium difficile.

PubMed

Finegold, Sydney M; Summanen, Paula H; Corbett, Karen; Downes, Julia; Henning, Susanne M; Li, Zhaoping

2014-10-01

To determine the possible utility of pomegranate extract in the management or prevention of Clostridium difficile infections or colonization. The activity of pomegranate was tested against 29 clinical C. difficile isolates using the Clinical and Laboratory Standards Institute-approved agar dilution technique. Total phenolics content of the pomegranate extract was determined by Folin-Ciocalteau colorimetric method and final concentrations of 6.25 to 400 μg/mL gallic acid equivalent were achieved in the agar. All strains had MICs at 12.5 to 25 mg/mL gallic acid equivalent range. Our results suggest antimicrobial in vitro activity for pomegranate extract against toxigenic C. difficile. Pomegranate extract may be a useful contributor to the management and prevention of C. difficile disease or colonization. Copyright © 2014 Elsevier Inc. All rights reserved.

Multihospital Outbreak of Clostridium difficile Infection, Cleveland, Ohio, USA

PubMed Central

Jump, Robin L.P.; Riggs, Michelle M.; Sethi, Ajay K.; Pultz, Michael J.; Ellis-Reid, Tracie; Riebel, William; Gerding, Dale N.; Salata, Robert A.

2010-01-01

To determine whether a multihospital Clostridium difficile outbreak was associated with epidemic strains and whether use of particular fluoroquinolones was associated with increased infection rates, we cultured feces from C. difficile–infected patients. Use of fluoroquionolones with enhanced antianaerobic activity was not associated with increased infection rates. PMID:20409374

Progress in the Discovery of Treatments for C. difficile Infection: A Clinical and Medicinal Chemistry Review

PubMed Central

Tsutsumi, Lissa S.; Owusu, Yaw B.; Hurdle, Julian G.; Sun, Dianqing

2014-01-01

Clostridium difficile is an anaerobic, Gram-positive pathogen that causes C. difficile infection, which results in significant morbidity and mortality. The incidence of C. difficile infection in developed countries has become increasingly high due to the emergence of newer epidemic strains, a growing elderly population, extensive use of broad spectrum antibiotics, and limited therapies for this diarrheal disease. Because treatment options currently available for C. difficile infection have some drawbacks, including cost, promotion of resistance, and selectivity problems, new agents are urgently needed to address these challenges. This review article focuses on two parts: the first part summarizes current clinical treatment strategies and agents under clinical development for C. difficile infection; the second part reviews newly reported anti-difficile agents that have been evaluated or reevaluated in the last five years and are in the early stages of drug discovery and development. Antibiotics are divided into natural product inspired and synthetic small molecule compounds that may have the potential to be more efficacious than currently approved treatments. This includes potency, selectivity, reduced cytotoxicity, and novel modes of action to prevent resistance. PMID:24236721

Clostridium difficile infection

PubMed Central

Vedantam, Gayatri; Clark, Andrew; Chu, Michele; McQuade, Rebecca; Mallozzi, Michael; Viswanathan, V. K.

2012-01-01

Clostridium difficile infection is the leading cause of antibiotic- and healthcare-associated diarrhea, and its containment and treatment imposes a significant financial burden, estimated to be over $3 billion in the USA alone. Since the year 2000, CDI epidemics/outbreaks have occurred in North America, Europe and Asia. These outbreaks have been variously associated with, or attributed to, the emergence of Clostridium difficile strains with increased virulence, an increase in resistance to commonly used antimicrobials such as the fluoroquinolones, or host susceptibilities, including the use of gastric acid suppressants, to name a few. Efforts to elucidate C. difficile pathogenic mechanisms have been hampered by a lack of molecular tools, manipulatable animal models, and genetic intractability of clinical C. difficile isolates. However, in the past 5 y, painstaking efforts have resulted in the unraveling of multiple C. difficile virulence-associated pathways and mechanisms. We have recently reviewed the disease, its associated risk factors, transmission and interventions (Viswanathan, Gut Microbes 2010). This article summarizes genetics, non-toxin virulence factors, and host-cell biology associated with C. difficile pathogenesis as of 2011, and highlights those findings/factors that may be of interest as future intervention targets. PMID:22555464

The Role of Rho GTPases in Toxicity of Clostridium difficile Toxins

PubMed Central

Chen, Shuyi; Sun, Chunli; Wang, Haiying; Wang, Jufang

2015-01-01

Clostridium difficile (C. difficile) is the main cause of antibiotic-associated diarrhea prevailing in hospital settings. In the past decade, the morbidity and mortality of C. difficile infection (CDI) has increased significantly due to the emergence of hypervirulent strains. Toxin A (TcdA) and toxin B (TcdB), the two exotoxins of C. difficile, are the major virulence factors of CDI. The common mode of action of TcdA and TcdB is elicited by specific glucosylation of Rho-GTPase proteins in the host cytosol using UDP-glucose as a co-substrate, resulting in the inactivation of Rho proteins. Rho proteins are the key members in many biological processes and signaling pathways, inactivation of which leads to cytopathic and cytotoxic effects and immune responses of the host cells. It is supposed that Rho GTPases play an important role in the toxicity of C. difficile toxins. This review focuses on recent progresses in the understanding of functional consequences of Rho GTPases glucosylation induced by C. difficile toxins and the role of Rho GTPases in the toxicity of TcdA and TcdB. PMID:26633511

Probiotics for the Primary and Secondary Prevention of C. difficile Infections: A Meta-analysis and Systematic Review

PubMed Central

McFarland, Lynne V.

2015-01-01

Clostridium difficile infections are a global clinical concern and are one of the leading causes of nosocomial outbreaks. Preventing these infections has benefited from multidisciplinary infection control strategies and new antibiotics, but the problem persists. Probiotics are effective in preventing antibiotic-associated diarrhea and may also be a beneficial strategy for C. difficile infections, but randomized controlled trials are scarce. This meta-analysis pools 21 randomized, controlled trials for primary prevention of C. difficile infections (CDI) and four trials for secondary prevention of C. difficile recurrences and assesses the efficacy of specific probiotic strains. Four probiotics significantly improved primary CDI prevention: (Saccharomyces boulardii, Lactobacillus casei DN114001, a mixture of L. acidophilus and Bifidobacterium bifidum, and a mixture of L. acidophilus, L. casei and L. rhamnosus). None of the tested probiotics significantly improved secondary prevention of CDI. More confirmatory randomized trials are needed to establish if probiotics are useful for preventing C. difficile infections. PMID:27025619

Genetic diversity of environmental Vibrio cholerae O1 strains isolated in Northern Vietnam.

PubMed

Takemura, Taichiro; Murase, Kazunori; Maruyama, Fumito; Tran, Thi Luong; Ota, Atsushi; Nakagawa, Ichiro; Nguyen, Dong Tu; Ngo, Tu Cuong; Nguyen, Thi Hang; Tokizawa, Asako; Morita, Masatomo; Ohnishi, Makoto; Nguyen, Binh Minh; Yamashiro, Tetsu

2017-10-01

Cholera epidemics have been recorded periodically in Vietnam during the seventh cholera pandemic. Since cholera is a water-borne disease, systematic monitoring of environmental waters for Vibrio cholerae presence is important for predicting and preventing cholera epidemics. We conducted monitoring, isolation, and genetic characterization of V. cholerae strains in Nam Dinh province of Northern Vietnam from Jul 2013 to Feb 2015. In this study, four V. cholerae O1 strains were detected and isolated from 110 analyzed water samples (3.6%); however, none of them carried the cholera toxin gene, ctxA, in their genomes. Whole genome sequencing and phylogenetic analysis revealed that the four O1 isolates were separated into two independent clusters, and one of them diverged from a common ancestor with pandemic strains. The analysis of pathogenicity islands (CTX prophage, VPI-I, VPI-II, VSP-I, and VSP-II) indicated that one strain (VNND_2014Jun_6SS) harbored an unknown prophage-like sequence with high homology to vibriophage KSF-1 phi and VCY phi, identified from Bangladesh and the USA, respectively, while the other three strains carried tcpA gene with a distinct sequence demonstrating a separate clonal lineage. These results suggest that the aquatic environment can harbor highly divergent V. cholera strains and serve as a reservoir for multiple V. cholerae virulence-associated genes which may be exchanged via mobile genetic elements. Therefore, continuous monitoring and genetic characterization of V. cholerae strains in the environment should contribute to the early detection of the sources of infection and prevention of cholera outbreaks as well as to understanding the natural ecology and evolution of V. cholerae. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

High-resolution melting analysis of the single nucleotide polymorphism hot-spot region in the rpoB gene as an indicator of reduced susceptibility to rifaximin in Clostridium difficile.

PubMed

Pecavar, Verena; Blaschitz, Marion; Hufnagl, Peter; Zeinzinger, Josef; Fiedler, Anita; Allerberger, Franz; Maass, Matthias; Indra, Alexander

2012-06-01

Clostridium difficile, a Gram-positive, spore-forming, anaerobic bacterium, is the main causative agent of hospital-acquired diarrhoea worldwide. In addition to metronidazole and vancomycin, rifaximin, a rifamycin derivative, is a promising antibiotic for the treatment of recurring C. difficile infections (CDI). However, exposure of C. difficile to this antibiotic has led to the development of rifaximin-resistance due to point mutations in the β-subunit of the RNA polymerase (rpoB) gene. In the present study, 348 C. difficile strains with known PCR-ribotypes were investigated for respective single nucleotide polymorphisms (SNPs) within the proposed rpoB hot-spot region by using high-resolution melting (HRM) analysis. This method allows the detection of SNPs by comparing the altered melting behaviour of dsDNA with that of wild-type DNA. Discrimination between wild-type and mutant strains was enhanced by creating heteroduplexes by mixing sample DNA with wild-type DNA, leading to characteristic melting curve shapes from samples containing SNPs in the respective rpoB section. In the present study, we were able to identify 16 different rpoB sequence-types (ST) by sequencing analysis of a 325 bp fragment. The 16 PCR STs displayed a total of 24 different SNPs. Fifteen of these 24 SNPs were located within the proposed 151 bp SNP hot-spot region, resulting in 11 different HRM curve profiles (CP). Eleven SNPs (seven of which were within the proposed hot-spot region) led to amino acid substitutions associated with reduced susceptibility to rifaximin and 13 SNPs (eight of which were within the hot-spot region) were synonymous. This investigation clearly demonstrates that HRM analysis of the proposed SNP hot-spot region in the rpoB gene of C. difficile is a fast and cost-effective method for the identification of C. difficile samples with reduced susceptibility to rifaximin and even allows simultaneous SNP subtyping of the respective C. difficile isolates.

Sporulation properties and antimicrobial susceptibility in endemic and rare Clostridium difficile PCR ribotypes.

PubMed

Zidaric, Valerija; Rupnik, Maja

2016-06-01

Increased sporulation and antibiotic resistance have been proposed to be associated with certain Clostridium difficile epidemic strains such as PCR ribotype 027. In this study we examined these properties in another widespread PCR ribotype, 014/020, in comparison to prevalent PCR ribotype 002 and a group of rarely represented PCR ribotypes. Highest sporulation was observed in 014/020 strains at 24 h, while after 72 h PCR ribotype 002 and rare PCR ribotypes formed higher total number of spores. PCR ribotype 014/020 strains exhibited slightly higher resistance to tested antimicrobials, followed by group of rare PCR ribotypes and less common PCR ribotype 002. Neither sporulation properties nor antibiotic resistance clearly differed in endemic and rare strains. Copyright © 2016 Elsevier Ltd. All rights reserved.

Production of a complete binary toxin (actin-specific ADP-ribosyltransferase) by Clostridium difficile CD196.

PubMed

Perelle, S; Gibert, M; Bourlioux, P; Corthier, G; Popoff, M R

1997-04-01

A Clostridium difficile isolate was found to produce an actin-specific ADP-ribosyltransferase (CDT) homologous to the enzymatic components of Clostridium perfringens iota toxin and Clostridium spiroforme toxin (M. R. Popoff, E. J. Rubin, D. M. Gill, and P. Boquet, Infect. Immun. 56:2299-2306, 1988). The CDT locus from C. difficile CD196 was cloned and sequenced. It contained two genes (cdtA and cdtB) which display organizations and sequences similar to those of the iota toxin gene. The deduced enzymatic (CDTa) and binding (CDTb) components have 81 and 84% identity, respectively, with the corresponding components of iota toxin. CDTa and CDTb induced actin cytoskeleton alterations similar to those caused by other clostridial binary toxins. The lower level of production of binary toxin by CD196 than of iota toxin by C. perfringens was related to a lower transcript level, possibly due to a promoter region different from that of iota toxin genes. The cdtA and cdtB genes have been detected in 3 of 24 clinical isolates examined, and cdtB alone was found in 2 additional strains. One strain (in addition to CD196) was shown by Western blotting to produce CDTa and CDTb. These results indicate that some C. difficile strains synthesize a binary toxin that could be an additional virulence factor.

Production of a complete binary toxin (actin-specific ADP-ribosyltransferase) by Clostridium difficile CD196.

PubMed Central

Perelle, S; Gibert, M; Bourlioux, P; Corthier, G; Popoff, M R

1997-01-01

A Clostridium difficile isolate was found to produce an actin-specific ADP-ribosyltransferase (CDT) homologous to the enzymatic components of Clostridium perfringens iota toxin and Clostridium spiroforme toxin (M. R. Popoff, E. J. Rubin, D. M. Gill, and P. Boquet, Infect. Immun. 56:2299-2306, 1988). The CDT locus from C. difficile CD196 was cloned and sequenced. It contained two genes (cdtA and cdtB) which display organizations and sequences similar to those of the iota toxin gene. The deduced enzymatic (CDTa) and binding (CDTb) components have 81 and 84% identity, respectively, with the corresponding components of iota toxin. CDTa and CDTb induced actin cytoskeleton alterations similar to those caused by other clostridial binary toxins. The lower level of production of binary toxin by CD196 than of iota toxin by C. perfringens was related to a lower transcript level, possibly due to a promoter region different from that of iota toxin genes. The cdtA and cdtB genes have been detected in 3 of 24 clinical isolates examined, and cdtB alone was found in 2 additional strains. One strain (in addition to CD196) was shown by Western blotting to produce CDTa and CDTb. These results indicate that some C. difficile strains synthesize a binary toxin that could be an additional virulence factor. PMID:9119480

Investigation of a cluster of Clostridium difficile infections in a pediatric oncology setting.

PubMed

Dantes, Raymund; Epson, Erin E; Dominguez, Samuel R; Dolan, Susan; Wang, Frank; Hurst, Amanda; Parker, Sarah K; Johnston, Helen; West, Kelly; Anderson, Lydia; Rasheed, James K; Moulton-Meissner, Heather; Noble-Wang, Judith; Limbago, Brandi; Dowell, Elaine; Hilden, Joanne M; Guh, Alice; Pollack, Lori A; Gould, Carolyn V

2016-02-01

We investigated an increase in Clostridium difficile infection (CDI) among pediatric oncology patients. CDI cases were defined as first C difficile positive stool tests between December 1, 2010, and September 6, 2012, in pediatric oncology patients receiving inpatient or outpatient care at a single hospital. A case-control study was performed to identify CDI risk factors, infection prevention and antimicrobial prescribing practices were assessed, and environmental sampling was conducted. Available isolates were strain-typed by pulsed-field gel electrophoresis. An increase in hospital-onset CDI cases was observed from June-August 2012. Independent risk factors for CDI included hospitalization in the bone marrow transplant ward and exposure to computerized tomography scanning or cefepime in the prior 12 weeks. Cefepime use increased beginning in late 2011, reflecting a practice change for patients with neutropenic fever. There were 13 distinct strain types among 22 available isolates. Hospital-onset CDI rates decreased to near-baseline levels with enhanced infection prevention measures, including environmental cleaning and prolonged contact isolation. C difficile strain diversity associated with a cluster of CDI among pediatric oncology patients suggests a need for greater understanding of modes and sources of transmission and strategies to reduce patient susceptibility to CDI. Further research is needed on the risk of CDI with cefepime and its use as primary empirical treatment for neutropenic fever. Published by Elsevier Inc.

Antipathogenic activity of probiotics against Salmonella Typhimurium and Clostridium difficile in anaerobic batch culture systems: is it due to synergies in probiotic mixtures or the specificity of single strains?

PubMed

Tejero-Sariñena, Sandra; Barlow, Janine; Costabile, Adele; Gibson, Glenn R; Rowland, Ian

2013-12-01

Probiotics are currently being investigated for prevention of infections caused by enteric pathogens. The aim of this in vitro study was to evaluate the influence of three single probiotics: Lactobacillus casei NCIMB 30185 (PXN 37), Lactobacillus acidophilus NCIMB 30184 (PXN 35), Bifidobacterium breve NCIMB 30180 (PXN 25) and a probiotic mixture containing the above strains plus twelve other strains belonging to the Lactobacillus, Bifidobacterium, Lactococcus, Streptococcus and Bacillus genera on the survival of Salmonella Typhimurium and Clostridium difficile using pH-controlled anaerobic batch cultures containing mixed faecal bacteria. Changes in relevant bacterial groups and effects of probiotic addition on survival of the two pathogens were assessed over 24 h. Quantitative analysis of bacterial populations revealed that there was a significant increase in lactobacilli and/or bifidobacteria numbers, depending on probiotic addition, compared with the control (no added probiotic). There was also a significant reduction in S. Typhimurium and C. difficile numbers in the presence of certain probiotics compared with controls. Of the probiotic treatments, two single strains namely L. casei NCIMB 30185 (PXN 37), and B. breve NCIMB 30180 (PXN 25) were the most potent in reducing the numbers of S. Typhimurium and C. difficile. In addition, the supplementation with probiotics into the systems influenced some fermentations parameters. Acetate was found in the largest concentrations in all vessels and lactate and formate were generally detected in higher amounts in vessels with probiotic addition compared to controls. Copyright © 2013 Elsevier Ltd. All rights reserved.

Binary toxin and its clinical importance in Clostridium difficile infection, Belgium.

PubMed

Pilate, T; Verhaegen, J; Van Ranst, M; Saegeman, V

2016-11-01

Binary toxin-producing Clostridium difficile strains such as ribotypes 027 and 078 have been associated with increased Clostridium difficile infection (CDI) severity. Our objective was to investigate the association between presence of the binary toxin gene and CDI severity and recurrence. We performed a laboratory-based retrospective study including patients between January 2013 and March 2015 whose fecal samples were analyzed by polymerase chain reaction (PCR) for the presence of the genes for toxin B and binary toxin and a deletion in the tcdC gene, specific for ribotype 027. Clinical and epidemiological characteristics were compared between 33 binary toxin-positive CDI patients and 33 binary toxin-negative CDI patients. Subsequently, the characteristics of 66 CDI patients were compared to those of 66 diarrhea patients who were carriers of non-toxigenic C. difficile strains. Fifty-nine of 1034 (5.7 %) fecal samples analyzed by PCR were binary toxin-positive, belonging to 33 different patients. No samples were positive for ribotype 027. Binary toxin-positive CDI patients did not differ from binary toxin-negative CDI patients in terms of disease recurrence, morbidity, or mortality, except for a higher peripheral leukocytosis in the binary toxin-positive group (16.30 × 10 9 /L vs. 11.65 × 10 9 /L; p = 0.02). The second part of our study showed that CDI patients had more severe disease, but not a higher 30-day mortality rate than diarrhea patients with a non-toxicogenic C. difficile strain. In our setting with a low prevalence of ribotype 027, the presence of the binary toxin gene is not associated with poor outcome.

[Characteristics of Clostridium difficile infection in a high complexity hospital and report of the circulation of the NAP1/027 hypervirulent strain in Colombia].

PubMed

Gualtero, Sandra Milena; Abril, Lina Alejandra; Camelo, Nathalia; Sanchez, Susi Daniela; Davila, Fabián Antonio; Arias, Gerson; Silva, Edwin; Bustos, Ingrid Gissel; Josa, Diego Fernando; Torres, Isabel Cristina; Zambrano, Luis Carlos; Pareja, María José

2017-12-01

Clostridium difficile is the main pathogen related to healthcare-associated diarrhea and it is the cause of 20 to 30% of diarrhea cases caused by antibiotics. In Colombia and Latin America, the knowledge about the epidemiological behavior of this infection is limited. To describe the characteristics of a series of patients with C. difficile infection. We performed a descriptive case series study of patients with C. difficile infection hospitalized in the Fundación Clínica Shaio from January, 2012, to November, 2015. We analyzed 36 patients. The average age was 65 years. The risk factors associated with the infection were: previous use of antibiotics (94.4%), prior hospitalization in the last three months (66.7%) and use of proton pump inhibitors (50%). The most common comorbidities were chronic kidney disease (41.7%) and diabetes mellitus (30.6%). The most frequent symptoms were more than three loose stools per day (97.1%) and abdominal pain (42.9%). According to the severity of the disease, 44.4% of cases were classified as mild to moderate, 38.9% as severe, and 11.1% as complicated or severe. The detection of the toxin by PCR (GeneXpert) was the most common diagnostic procedure (63.8%). Global mortality during hospitalization was 8%. We identified four strains with serotype NAP1/027 and nine samples positive for binary toxin. Clostridium difficile infection should be suspected in patients with diarrhea and traditional risk factors associated with this disease. We report the circulation of the hypervirulent strain serotype NAP1/027 in Colombia, which should be countered with epidemiological surveillance and a prompt diagnosis.

Clostridium perfringens and C. difficile in parvovirus-positive dogs.

PubMed

Silva, Rodrigo Otávio Silveira; Dorella, Fernanda Alves; Figueiredo, Henrique Cesar Pereira; Costa, Érica Azevedo; Pelicia, Vanessa; Ribeiro, Bruna Letícia Devidé; Ribeiro, Marcio Garcia; Paes, Antonio Carlos; Megid, Jane; Lobato, Francisco Carlos Faria

2017-12-01

The aim of this study was to investigate Clostridium difficile and Clostridium perfringens in 82 diarrheic dogs positive for canine parvovirus type 2 (CPV). Enterotoxigenic C. perfringens type A was isolated from three (3.6%) dogs. One (1.2%) strain was also positive for NetE- and NetF-encoding genes, which are commonly associated with diarrhea in dogs. Toxigenic C. difficile was isolated from one animal (1.2%), which was also positive for A/B toxins. The present study identified C. difficile and C. perfringens infection in CPV-positive dogs. Further studies are necessary to clarify if clostridial infections may predispose or potentiate CPV-infection in dogs or vice versa. Copyright © 2017 Elsevier Ltd. All rights reserved.

A review of the economics of treating Clostridium difficile infection.

PubMed

Mergenhagen, Kari A; Wojciechowski, Amy L; Paladino, Joseph A

2014-07-01

Clostridium difficile infection (CDI) is a costly result of antibiotic use, responsible for an estimated 14,000 deaths annually in the USA according to the Centers for Disease Control and Prevention. Annual costs attributable to CDI are in excess of $US 1 billion. This review summarizes appropriate utilization of prevention and treatment methods for CDI that have the potential to reduce the economic and humanistic costs of the disease. Some cost-effective strategies to prevent CDI include screening and isolation of hospital admissions based on C. difficile carriage to reduce transmission in the inpatient setting, and probiotics, which are potentially efficacious in preventing CDI in the appropriate patient population. The most extensively studied agents for treatment of CDI are metronidazole, vancomycin, and fidaxomicin. Most economic comparisons between metronidazole and vancomycin favor vancomycin, especially with the emergence of metronidazole-resistant C. difficile strains. Metronidazole can only be recommended for mild disease. Moderate to severe CDI should be treated with vancomycin, preferably the compounded oral solution, which provides the most cost-effective therapeutic option. Fidaxomicin offers a clinically effective and potentially cost-effective alternative for treating moderate CDI in patients who do not have the NAP1/BI/027 strain of C. difficile. Probiotics and fecal microbiota transplant have variable efficacy and the US FDA does not currently regulate the content; the potential economic advantages of these treatment modalities are currently unknown.

In Vitro and In Vivo Activities of Nitazoxanide against Clostridium difficile

PubMed Central

McVay, Catherine S.; Rolfe, Rial D.

2000-01-01

We have used the hamster model of antibiotic-induced Clostridium difficile intestinal disease to evaluate nitazoxanide (NTZ), a nitrothiazole benzamide antimicrobial agent. The following in vitro and in vivo activities of NTZ in the adult hamster were examined and compared to those of metronidazole and vancomycin: (i) MICs and minimum bactericidal concentrations (MBCs) against C. difficile, (ii) toxicity, (iii) ability to prevent C. difficile-associated ileocecitis, and (iv) propensity to induce C. difficile-associated ileocecitis. The MICs and MBCs of NTZ against 15 toxigenic strains of C. difficile were comparable to those of vancomycin or metronidazole. C. difficile-associated ileocecitis was induced with oral clindamycin and toxigenic C. difficile in a group of 60 hamsters. Subgroups of 10 hamsters were given six daily intragastric treatments of NTZ (15, 7.5, and 3.0 mg/100 g of body weight [gbw]), metronidazole (15 mg/100 gbw), vancomycin (5 mg/100 gbw), or saline (1 ml/100 gbw). Animals receiving saline died 3 days post-C. difficile challenge. During the treatment period, NTZ (≥7.5 mg/100 gbw), like metronidazole and vancomycin, prevented outward manifestations of clindamycin-induced C. difficile intestinal disease. Six of ten hamsters on a scheduled dose of 3.0 mg of NTZ/100 gbw survived for the complete treatment period. Of these surviving animals, all but three died of C. difficile disease by between 3 and 12 days following discontinuation of antibiotic therapy. Another group of hamsters received six similar daily doses of the three antibiotics, followed by an inoculation with toxigenic C. difficile. All of the NTZ-treated animals survived the 15-day postinfection period. Upon necropsy, all hamsters appeared normal: there were no gross signs of toxicity or C. difficile intestinal disease, nor was C. difficile detected in the cultures of the ceca of these animals. By contrast, vancomycin and metronidazole treatment induced fatal C. difficile intestinal disease in 20 and 70% of recipients, respectively. PMID:10952564

High prevalence of Clostridium difficile on retail root vegetables, Western Australia.

PubMed

Lim, S C; Foster, N F; Elliott, B; Riley, T V

2018-02-01

The incidence of community-associated Clostridium difficile infection (CA-CDI) in Australia has increased since mid-2011. With reports of clinically important C. difficile strains being isolated from retail foods in Europe and North America, a foodborne source of C. difficile in cases of CA-CDI is a possibility. This study represents the first to investigate the prevalence and genotypes of C. difficile in Australian retail vegetables. A total of 300 root vegetables grown in Western Australia (WA) were collected from retail stores and farmers' markets. Three vegetables of the same kind bought from the same store/market were treated as one sample. Selective enrichment culture, toxin profiling and PCR ribotyping were performed. Clostridium difficile was isolated from 30% (30/100) of pooled vegetable samples, 55·6% of organic potatoes, 50% of nonorganic potatoes, 22·2% of organic beetroots, 5·6% of organic onions and 5·3% of organic carrots. Over half (51·2%, 22/43) the isolates were toxigenic. Many of the ribotypes of C. difficile isolated were common among human and Australian animals. Clostridium difficile could be found commonly on retail root vegetables of WA. This may be potential sources for CA-CDI. This study enhances knowledge of possible sources of C. difficile in the Australian community, outside the hospital setting. © 2017 The Society for Applied Microbiology.

Genome Sequence Analysis of Vibrio cholerae clinical isolates from 2013 in Mexico reveals the presence of the strain responsible for the 2010 Haiti outbreak.

PubMed

Díaz-Quiñonez, José Alberto

2017-01-01

La primera semana de septiembre de 2013, el Sistema Nacional de Vigilancia Epidemiológica identificó dos casos de cólera en Ciudad de México. Los cultivos de ambas muestras se confirmaron como Vibrio cholerae serogrupo O1, serotipo Ogawa, biotipo El Tor. Los análisis iniciales por electroforesis por campos pulsados y por reacción en cadena de la polimerasa indicaron que ambas cepas eran similares, pero diferentes de las previamente reportadas en México. La semana siguiente se identificaron cuatro casos más en una comunidad del Estado de Hidalgo, ubicada a 121 kilómetros al noreste de Ciudad de México. Posteriormente se inició un brote de cólera en la región de La Huasteca. Los análisis genómicos de cuatro cepas obtenidas en este estudio confirmaron la presencia de las islas de patogenicidad VPI -1 y VPI-2, VSP-1 y VSP-2, y del elemento integrador SXT. La estructura genómica de los cuatro aislamientos fue similar a la de V. cholerae cepa 2010 EL-1786, identificada durante la epidemia en Haití en 2010. Este estudio pone de manifiesto que la epidemiología molecular es una herramienta muy poderosa para vigilar, prevenir y controlar enfermedades de importancia en salud pública en México. The first week of September 2013, the National Epidemiological Surveillance System identified two cases of cholera in Mexico City. The cultures of both samples were confirmed as Vibrio cholerae serogroup O1, serotype Ogawa, biotype El Tor. Initial analyses by pulsed-field gel electrophoresis and by polymerase chain reaction-amplification of the virulence genes, suggested that both strains were similar, but different from those previously reported in Mexico. The following week, four more cases were identified in a community in the state of Hidalgo, located 121 km northeast of Mexico City. Thereafter a cholera outbreak started in the region of La Huasteca. Genomic analyses of the strains obtained in this study confirmed the presence of pathogenicity islands VPI-1 and VPI-2, VSP-1 and VSP-2, and of the integrative element SXT. The genomic structure of the 4 isolates was similar to that of V. cholerae strain 2010 EL-1786, identified during the epidemic in Haiti in 2010. This study shows that molecular epidemiology is a very powerful tool to monitor, prevent and control diseases of public health importance in Mexico. Copyright: © 2017 SecretarÍa de Salud.

Community Environmental Contamination of Toxigenic Clostridium difficile

PubMed Central

Alam, M Jahangir; Walk, Seth T.; Endres, Bradley T.; Basseres, Eugenie; Khaleduzzaman, Mohammed; Amadio, Jonathan; Musick, William L.; Christensen, Jennifer L.; Kuo, Julie; Atmar, Robert L.

2017-01-01

Abstract Background. Clostridium difficile infection is often considered to result from recent acquisition of a C difficile isolate in a healthcare setting. However, C difficile spores can persist for long periods of time, suggesting a potentially large community environmental reservoir. The objectives of this study were to assess community environmental contamination of toxigenic C difficile and to assess strain distribution in environmental versus clinical isolates. Methods. From 2013 to 2015, we collected community environmental swabs from homes and public areas in Houston, Texas to assess C difficile contamination. All positive isolates were tested for C difficile toxins A and B, ribotyped, and compared with clinical C difficile isolates obtained from hospitalized patients in Houston healthcare settings. Results. A total of 2538 environmental samples were collected over the study period. These included samples obtained from homes (n = 1079), parks (n = 491), chain stores (n = 225), fast food restaurants (n = 123), other commercial stores (n = 172), and hospitals (n = 448). Overall, 418 environmental isolates grew toxigenic C difficile (16.5%; P < .001) most commonly from parks (24.6%), followed by homes (17.1%), hospitals (16.5%), commercial stores (8.1%), chain stores (7.6%), and fast food restaurants (6.5%). A similar distribution of ribotypes was observed between clinical and environmental isolates with the exception that ribotype 027 was more common in clinical isolates compared with environmental isolates (P < .001). Conclusions. We identified a high prevalence of toxigenic C difficile from community environs that were similar ribotypes to clinical isolates. These findings suggest that interventions beyond isolation of symptomatic patients should be targeted for prevention of C difficile infection. PMID:28480289

Strain Types and Antimicrobial Resistance Patterns of Clostridium difficile Isolates from the United States, 2011 to 2013

PubMed Central

Goering, Richard V.; Whitmore, Joseph D.; Lynn, Ashley N. W.; Persing, David H.; Tenover, Fred C.

2014-01-01

We determined the PCR ribotypes and antimicrobial susceptibility patterns of 508 toxigenic Clostridium difficile isolates collected between 2011 and 2013 from 32 U.S. hospitals. Of the 29 PCR ribotypes identified, the 027 strain type was the most common (28.1%), although the rates varied by geographic region. Ribotype 014/020 isolates appear to be emerging. Clindamycin and moxifloxacin resistances (36.8% and 35.8%, respectively) were the most frequent resistance phenotypes observed. Reduced susceptibility to vancomycin was observed in 39.1% of 027 isolates. PMID:24752264

Clostridium difficile carbohydrates: glucan in spores, PSII common antigen in cells, immunogenicity of PSII in swine and synthesis of a dual C. difficile-ETEC conjugate vaccine.

PubMed

Bertolo, Lisa; Boncheff, Alexander G; Ma, Zuchao; Chen, Yu-Han; Wakeford, Terra; Friendship, Robert M; Rosseau, Joyce; Weese, J Scott; Chu, Michele; Mallozzi, Michael; Vedantam, Gayatri; Monteiro, Mario A

2012-06-01

Clostridium difficile is responsible for severe diarrhea in humans that may cause death. Spores are the infectious form of C. difficile, which germinate into toxin-producing vegetative cells in response to bile acids. Recently, we discovered that C. difficile cells possess three complex polysaccharides (PSs), named PSI, PSII, and PSIII, in which PSI was only associated with a hypervirulent ribotype 027 strain, PSII was hypothesized to be a common antigen, and PSIII was a water-insoluble polymer. Here, we show that (i) C. difficile spores contain, at least in part, a D-glucan, (ii) PSI is not a ribotype 027-unique antigen, (iii) common antigen PSII may in part be present as a low molecular weight lipoteichoic acid, (iv) selective hydrolysis of PSII yields single PSII repeat units, (v) the glycosyl diester-phosphate linkage affords high flexibility to PSII, and (vi) that PSII is immunogenic in sows. Also, with the intent of creating a dual anti-diarrheal vaccine against C. difficile and enterotoxin Escherichia coli (ETEC) infections in humans, we describe the conjugation of PSII to the ETEC-associated LTB enterotoxin. Copyright © 2012 Elsevier Ltd. All rights reserved.

Comparative in vitro activities of LFF571 against Clostridium difficile and 630 other intestinal strains of aerobic and anaerobic bacteria.

PubMed

Citron, Diane M; Tyrrell, Kerin L; Merriam, C Vreni; Goldstein, Ellie J C

2012-05-01

The in vitro activities of LFF571, a novel analog of GE2270A that inhibits bacterial growth by binding with high affinity for protein synthesis elongation factor Tu, fidaxomicin, and 10 other antimicrobial agents were determined against 50 strains of Clostridium difficile and 630 other anaerobic and aerobic organisms of intestinal origin. LFF571 possesses potent activity against C. difficile and most other Gram-positive anaerobes (MIC(90), ≤ 0.25 μg/ml), with the exception of bifidobacteria and lactobacilli. The MIC(90)s for aerobes, including enterococci, Staphylococcus aureus (as well as methicillin-resistant S. aureus [MRSA] isolates), Streptococcus pyogenes, and other streptococci were 0.06, 0.125, 2, and 8 μg/ml, respectively. Comparatively, fidaxomicin showed variable activity against Gram-positive organisms: MIC(90)s against C. difficile, Clostridium perfringens, and Bifidobacterium spp. were 0.5, ≤ 0.015, and 0.125 μg/ml, respectively, but >32 μg/ml against Clostridium ramosum and Clostridium innocuum. MIC(90) for S. pyogenes and other streptococci was 16 and >32 μg/ml, respectively. LFF571 and fidaxomicin were generally less active against Gram-negative anaerobes.

Convergent Loss of ABC Transporter Genes From Clostridioides difficile Genomes Is Associated With Impaired Tyrosine Uptake and p-Cresol Production.

PubMed

Steglich, Matthias; Hofmann, Julia D; Helmecke, Julia; Sikorski, Johannes; Spröer, Cathrin; Riedel, Thomas; Bunk, Boyke; Overmann, Jörg; Neumann-Schaal, Meina; Nübel, Ulrich

2018-01-01

We report the frequent, convergent loss of two genes encoding the substrate-binding protein and the ATP-binding protein of an ATP-binding cassette (ABC) transporter from the genomes of unrelated Clostridioides difficile strains. This specific genomic deletion was strongly associated with the reduced uptake of tyrosine and phenylalanine and production of derived Stickland fermentation products, including p -cresol, suggesting that the affected ABC transporter had been responsible for the import of aromatic amino acids. In contrast, the transporter gene loss did not measurably affect bacterial growth or production of enterotoxins. Phylogenomic analysis of publically available genome sequences indicated that this transporter gene deletion had occurred multiple times in diverse clonal lineages of C. difficile , with a particularly high prevalence in ribotype 027 isolates, where 48 of 195 genomes (25%) were affected. The transporter gene deletion likely was facilitated by the repetitive structure of its genomic location. While at least some of the observed transporter gene deletions are likely to have occurred during the natural life cycle of C. difficile , we also provide evidence for the emergence of this mutation during long-term laboratory cultivation of reference strain R20291.

Convergent Loss of ABC Transporter Genes From Clostridioides difficile Genomes Is Associated With Impaired Tyrosine Uptake and p-Cresol Production

PubMed Central

Steglich, Matthias; Hofmann, Julia D.; Helmecke, Julia; Sikorski, Johannes; Spröer, Cathrin; Riedel, Thomas; Bunk, Boyke; Overmann, Jörg; Neumann-Schaal, Meina; Nübel, Ulrich

2018-01-01

We report the frequent, convergent loss of two genes encoding the substrate-binding protein and the ATP-binding protein of an ATP-binding cassette (ABC) transporter from the genomes of unrelated Clostridioides difficile strains. This specific genomic deletion was strongly associated with the reduced uptake of tyrosine and phenylalanine and production of derived Stickland fermentation products, including p-cresol, suggesting that the affected ABC transporter had been responsible for the import of aromatic amino acids. In contrast, the transporter gene loss did not measurably affect bacterial growth or production of enterotoxins. Phylogenomic analysis of publically available genome sequences indicated that this transporter gene deletion had occurred multiple times in diverse clonal lineages of C. difficile, with a particularly high prevalence in ribotype 027 isolates, where 48 of 195 genomes (25%) were affected. The transporter gene deletion likely was facilitated by the repetitive structure of its genomic location. While at least some of the observed transporter gene deletions are likely to have occurred during the natural life cycle of C. difficile, we also provide evidence for the emergence of this mutation during long-term laboratory cultivation of reference strain R20291. PMID:29867812

First clinical and microbiological characterization of Clostridium difficile infection in a Croatian University Hospital.

PubMed

Novak, Anita; Spigaglia, Patrizia; Barbanti, Fabrizio; Goic-Barisic, Ivana; Tonkic, Marija

2014-12-01

Clinical background and molecular epidemiology of Clostridium difficile infection (CDI) in the University Hospital Centre Split were investigated from January 2010 to December 2011. In total, 54 patients with first episode of CDI were consecutively included in the study based on the positive EIA test specific for A and B toxins. Demographic and clinical data were prospectively analyzed from medical records. CDI incidence rate was 0.6 per 10,000 patient-days. Thirty six cases (70.6%) were healthcare-associated, twelve cases (23.5%) were community-associated and three (5.9%) were indeterminate. Six patients (11.7%) had suffered one or more recurrences and 37 patients (72.5%) showed severe CDI. Prior therapy with third generation cephalosporin was significantly associated with severe CDI (P<0.021). Fifty four toxigenic C. difficile strains were isolated and 50 of them were available for PCR-ribotyping. Sixteen different PCR-ribotypes were identified. The most prevalent were PCR-ribotype 001 (27.8%) and 014/020 (24.1%). Twenty three strains were resistant to at least one of the antibiotics tested. Among resistant strains, three (13.0%)--all PCR-ribotype 001--were multi-resistant. Resistance to fluoroquinolones was significantly higher in strains that caused infection after previous use of fluoroquinolones (P=0.04). Copyright © 2014 Elsevier Ltd. All rights reserved.

Clostridium difficile Toxins A and B: Insights into Pathogenic Properties and Extraintestinal Effects

PubMed Central

Di Bella, Stefano; Ascenzi, Paolo; Siarakas, Steven; Petrosillo, Nicola; di Masi, Alessandra

2016-01-01

Clostridium difficile infection (CDI) has significant clinical impact especially on the elderly and/or immunocompromised patients. The pathogenicity of Clostridium difficile is mainly mediated by two exotoxins: toxin A (TcdA) and toxin B (TcdB). These toxins primarily disrupt the cytoskeletal structure and the tight junctions of target cells causing cell rounding and ultimately cell death. Detectable C. difficile toxemia is strongly associated with fulminant disease. However, besides the well-known intestinal damage, recent animal and in vitro studies have suggested a more far-reaching role for these toxins activity including cardiac, renal, and neurologic impairment. The creation of C. difficile strains with mutations in the genes encoding toxin A and B indicate that toxin B plays a major role in overall CDI pathogenesis. Novel insights, such as the role of a regulator protein (TcdE) on toxin production and binding interactions between albumin and C. difficile toxins, have recently been discovered and will be described. Our review focuses on the toxin-mediated pathogenic processes of CDI with an emphasis on recent studies. PMID:27153087

Survey of Clostridium difficile in retail seafood in College Station, Texas.

PubMed

Norman, Keri N; Harvey, Roger B; Andrews, Kathleen; Hume, Michael E; Callaway, Todd R; Anderson, Robin C; Nisbet, David J

2014-01-01

The incidence and severity of disease associated with toxigenic Clostridium difficile have increased in hospitals in North America with the emergence of newer, more virulent strains. Toxigenic C. difficile has been isolated from food animals and retail meat with potential implications of transfer to humans. The objective of the present study was to investigate the prevalence of C. difficile in retail seafood from grocery stores in College Station, Texas. C. difficile was found in 4.5% (3/67) of shellfish and finfish samples. The positive samples included one each from fresh mussel, frozen salmon and frozen shrimp. The mussel and salmon isolates were characterized as toxinotype V and pulsed-field gel electrophoresis (PFGE) type-NAP7. The shrimp isolate was identified as toxinotype XII, but had an unknown PFGE type. Susceptibilities to 11 antimicrobial agents were identical for the mussel and salmon isolates and were sensitive to eight of 11 antimicrobials (including ampicillin) and intermediate to clindamycin. However, the shrimp isolate was resistant to clindamycin and ampicillin. This study demonstrates that seafood, like other food commodities, can be contaminated by C. difficile.

Clostridium difficile virulence factors: Insights into an anaerobic spore-forming pathogen.

PubMed

Awad, Milena M; Johanesen, Priscilla A; Carter, Glen P; Rose, Edward; Lyras, Dena

2014-01-01

The worldwide emergence of epidemic strains of Clostridium difficile linked to increased disease severity and mortality has resulted in greater research efforts toward determining the virulence factors and pathogenesis mechanisms used by this organism to cause disease. C. difficile is an opportunist pathogen that employs many factors to infect and damage the host, often with devastating consequences. This review will focus on the role of the 2 major virulence factors, toxin A (TcdA) and toxin B (TcdB), as well as the role of other putative virulence factors, such as binary toxin, in C. difficile-mediated infection. Consideration is given to the importance of spores in both the initiation of disease and disease recurrence and also to the role that surface proteins play in host interactions.

Clostridium difficile virulence factors: Insights into an anaerobic spore-forming pathogen

PubMed Central

Awad, Milena M; Johanesen, Priscilla A; Carter, Glen P; Rose, Edward; Lyras, Dena

2014-01-01

The worldwide emergence of epidemic strains of Clostridium difficile linked to increased disease severity and mortality has resulted in greater research efforts toward determining the virulence factors and pathogenesis mechanisms used by this organism to cause disease. C. difficile is an opportunist pathogen that employs many factors to infect and damage the host, often with devastating consequences. This review will focus on the role of the 2 major virulence factors, toxin A (TcdA) and toxin B (TcdB), as well as the role of other putative virulence factors, such as binary toxin, in C. difficile-mediated infection. Consideration is given to the importance of spores in both the initiation of disease and disease recurrence and also to the role that surface proteins play in host interactions. PMID:25483328

Breakthrough Clostridium difficile Infection in Cirrhotic Patients Receiving Rifaximin.

PubMed

Reigadas, Elena; Alcalá, Luis; Gómez, Javier; Marín, Mercedes; Martin, Adoración; Onori, Raffaella; Muñoz, Patricia; Bouza, Emilio

2018-03-19

Patients with cirrhosis are at high risk of Clostridium difficile infection (CDI). Rifaximin is commonly used in cirrhotic patients as prophylaxis for hepatic encephalopathy (HE). Several studies have demonstrated the efficacy of rifaximin in the treatment of CDI; however, resistance to rifaximin has also been reported. Few studies have assessed the risk of developing CDI in cirrhotic patients receiving rifaximin. Our objective was to assess the incidence and characteristics of CDI in patients with cirrhosis, especially in those who received rifaximin. We assessed the incidence and clinical characteristics of CDI in cirrhotic patients over a 6-year period in our hospital. Medical charts were retrospectively reviewed. Ribotyping and antimicrobial susceptibility testing of all strains against rifaximin were performed. A total of 388 cirrhotic patients were included, of whom 127 patients had at least 1 episode of diarrhea in which a sample was sent to the laboratory. CDI was detected in 46 patients. Fourteen patients (30.4%) were receiving rifaximin as prophylaxis for HE. The main ribotypes detected were 001 (30.4%), followed by 014 (19.6%). Resistance to rifaximin was 34.1% overall, and 84.6% in patients who had received rifaximin. Multivariate analysis showed that rifamycin therapy and ribotype 001 were significant risk factors for having a rifaximin-resistant C. difficile strain. A high percentage of CDI cases were detected in cirrhotic patients receiving rifaximin, mostly owing to selection of rifaximin-resistant C. difficile strains. Clinicians should be aware of the risk of CDI in cirrhotic patients, even in those receiving rifaximin.

Correlation between fecal calprotectin levels, disease severity and the hypervirulent ribotype 027 strain in patients with Clostridium difficile infection.

PubMed

Peretz, Avi; Tkhawkho, Linda; Pastukh, Nina; Brodsky, Diana; Halevi, Chen Namimi; Nitzan, Orna

2016-06-22

Clostridium difficile is the most common infectious etiology of nosocomial diarrhea. Fecal calprotectin (fc) is a sensitive marker of intestinal inflammation, found to be associated with enteric bacterial infections and inflammatory bowel disease. We evaluated fc levels using a Chemiluminescent immunoassay method, in hospitalized patients with C. difficile infection (CDI) diagnosed by molecular stool examination and assessed correlation with virulent ribotype 027 strain infection, antibiotic susceptibility by gradient Etest strip performed on C. difficile colonies and clinical and laboratory measures of disease severity. Statistical analysis was performed for correlation of fc levels with clinical and laboratory parameters, disease severity and patient outcomes. Overall 29 patients with CDI were admitted at the Poria medical center in northern Israel, during June 2014-May 2015. Resistance to metronidazole was found in 3 (10.3 %) isolates and to vancomycin in 5 (17.2 %) isolates. Regarding patient outcomes, within 30 days of CDI diagnosis, recurrence of disease occurred in 10 (34.5 %) patients and 2 patients (6.9 %) died. Seven (24.1 %) isolates were C. difficile ribotype 027. Mean fc level was 331.4 μg/g (21-932). Higher fc levels were found in patients with C. difficile ribotype 027 (p < 0.0005). Fc levels were also correlated with elevated peripheral blood white cell count (p = 0.0007). A trend for higher fc levels was found in patients with a higher clostridium severity score index (p = 0.0633). No correlation was found between fecal calprotectin levels and age, sex, functional status, community versus hospital acquired CDI, antibiotic susceptibility, fever, and creatinine levels. Our study highlights the fact that fc has a potential role as a biomarker of disease severity and binary toxin producing ribotype associated disease.

Subtyping of Clostridium difficile PCR ribotypes 591, 106 and 002, the dominant strain types circulating in Medellin, Colombia.

PubMed

Salazar, Clara Lina; Reyes, Catalina; Cienfuegos-Gallet, Astrid Vanessa; Best, Emma; Atehortua, Santiago; Sierra, Patricia; Correa, Margarita M; Fawley, Warren N; Paredes-Sabja, Daniel; Wilcox, Mark; Gonzalez, Angel

2018-01-01

We aimed to achieve a higher typing resolution within the three dominant Clostridium difficile ribotypes (591,106 and 002) circulating in Colombia. A total of 50 C. difficile isolates we had previously typed by PCR-ribotyping, representing the major three ribotypes circulating in Colombia, were analyzed. Twenty-seven isolates of ribotype 591, 12 of ribotype 106 and 11 of ribotype 002 were subtyped by multiple locus variable-number tandem-repeat analysis (MLVA). The presence of the PaLoc genes (tcdA/tcdB), toxin production in culture and antimicrobial susceptibility were also determined. From the total C. difficile ribotypes analyzed, 20 isolates (74%) of ribotype 591, nine (75%) of ribotype 106 and five (45.5%) of ribotype 002 were recovered from patients with Clostridium difficile infection (CDI). MLVA allowed us to recognize four and two different clonal complexes for ribotypes 591 and 002, respectively, having a summed tandem-repeat difference (STRD) <2, whereas none of the ribotype 106 isolates were grouped in a cluster or clonal complex having a STRD >10. Six ribotype 591 and three ribotype 002 isolates belonging to a defined clonal complex were isolated on the same week in two different hospitals. All ribotypes harbored either tcdA+/tcdB+ or tcdA-/tcdB+ PaLoc genes. Moreover, 94% of the isolates were positive for toxin in culture. All isolates were susceptible to vancomycin and metronidazole, while 75% to 100% of the isolates were resistant to clindamycin, and less than 14.8% of ribotype 591 isolates were resistant to moxifloxacina. No significant differences were found among ribotypes with respect to demographic and clinical patients' data; however, our results demonstrated a high molecular heterogeneity of C. difficile strains circulating in Colombia.

Subtyping of Clostridium difficile PCR ribotypes 591, 106 and 002, the dominant strain types circulating in Medellin, Colombia

PubMed Central

Salazar, Clara Lina; Reyes, Catalina; Cienfuegos-Gallet, Astrid Vanessa; Best, Emma; Atehortua, Santiago; Sierra, Patricia; Correa, Margarita M.; Fawley, Warren N.; Paredes-Sabja, Daniel; Wilcox, Mark

2018-01-01

We aimed to achieve a higher typing resolution within the three dominant Clostridium difficile ribotypes (591,106 and 002) circulating in Colombia. A total of 50 C. difficile isolates we had previously typed by PCR-ribotyping, representing the major three ribotypes circulating in Colombia, were analyzed. Twenty-seven isolates of ribotype 591, 12 of ribotype 106 and 11 of ribotype 002 were subtyped by multiple locus variable-number tandem-repeat analysis (MLVA). The presence of the PaLoc genes (tcdA/tcdB), toxin production in culture and antimicrobial susceptibility were also determined. From the total C. difficile ribotypes analyzed, 20 isolates (74%) of ribotype 591, nine (75%) of ribotype 106 and five (45.5%) of ribotype 002 were recovered from patients with Clostridium difficile infection (CDI). MLVA allowed us to recognize four and two different clonal complexes for ribotypes 591 and 002, respectively, having a summed tandem-repeat difference (STRD) <2, whereas none of the ribotype 106 isolates were grouped in a cluster or clonal complex having a STRD >10. Six ribotype 591 and three ribotype 002 isolates belonging to a defined clonal complex were isolated on the same week in two different hospitals. All ribotypes harbored either tcdA+/tcdB+ or tcdA-/tcdB+ PaLoc genes. Moreover, 94% of the isolates were positive for toxin in culture. All isolates were susceptible to vancomycin and metronidazole, while 75% to 100% of the isolates were resistant to clindamycin, and less than 14.8% of ribotype 591 isolates were resistant to moxifloxacina. No significant differences were found among ribotypes with respect to demographic and clinical patients’ data; however, our results demonstrated a high molecular heterogeneity of C. difficile strains circulating in Colombia. PMID:29649308

Evaluation of a chromogenic culture medium for isolation of Clostridium difficile within 24 hours.

PubMed

Perry, John D; Asir, Kerry; Halimi, Diane; Orenga, Sylvain; Dale, Joanne; Payne, Michelle; Carlton, Ruth; Evans, Jim; Gould, F Kate

2010-11-01

Rapid and effective methods for the isolation of Clostridium difficile from stool samples are desirable to obtain isolates for typing or to facilitate accurate diagnosis of C. difficile-associated diarrhea. We report on the evaluation of a prototype chromogenic medium (ID C. difficile prototype [IDCd]) for isolation of C. difficile. The chromogenic medium was compared using (i) 368 untreated stool samples that were also inoculated onto CLO medium, (ii) 339 stool samples that were subjected to alcohol shock and also inoculated onto five distinct selective agars, and (iii) standardized suspensions of 10 C. difficile ribotypes (untreated and alcohol treated) that were also inoculated onto five distinct selective agars. Two hundred thirty-six isolates of C. difficile were recovered from 368 untreated stool samples, and all but 1 of these strains (99.6%) were recovered on IDCd within 24 h, whereas 74.6% of isolates were recovered on CLO medium after 48 h. Of 339 alcohol-treated stool samples cultured onto IDCd and five other selective agars, C. difficile was recovered from 218 samples using a combination of all media. The use of IDCd allowed recovery of 96.3% of isolates within 24 h, whereas 51 to 83% of isolates were recovered within 24 h using the five other media. Finally, when they were challenged with pure cultures, all 10 ribotypes of C. difficile generated higher colony counts on IDCd irrespective of alcohol pretreatment or duration of incubation. We conclude that IDCd is an effective medium for isolation of C. difficile from stool samples within 24 h.

Evaluation of a Chromogenic Culture Medium for Isolation of Clostridium difficile within 24 Hours ▿

PubMed Central

Perry, John D.; Asir, Kerry; Halimi, Diane; Orenga, Sylvain; Dale, Joanne; Payne, Michelle; Carlton, Ruth; Evans, Jim; Gould, F. Kate

2010-01-01

Rapid and effective methods for the isolation of Clostridium difficile from stool samples are desirable to obtain isolates for typing or to facilitate accurate diagnosis of C. difficile-associated diarrhea. We report on the evaluation of a prototype chromogenic medium (ID C. difficile prototype [IDCd]) for isolation of C. difficile. The chromogenic medium was compared using (i) 368 untreated stool samples that were also inoculated onto CLO medium, (ii) 339 stool samples that were subjected to alcohol shock and also inoculated onto five distinct selective agars, and (iii) standardized suspensions of 10 C. difficile ribotypes (untreated and alcohol treated) that were also inoculated onto five distinct selective agars. Two hundred thirty-six isolates of C. difficile were recovered from 368 untreated stool samples, and all but 1 of these strains (99.6%) were recovered on IDCd within 24 h, whereas 74.6% of isolates were recovered on CLO medium after 48 h. Of 339 alcohol-treated stool samples cultured onto IDCd and five other selective agars, C. difficile was recovered from 218 samples using a combination of all media. The use of IDCd allowed recovery of 96.3% of isolates within 24 h, whereas 51 to 83% of isolates were recovered within 24 h using the five other media. Finally, when they were challenged with pure cultures, all 10 ribotypes of C. difficile generated higher colony counts on IDCd irrespective of alcohol pretreatment or duration of incubation. We conclude that IDCd is an effective medium for isolation of C. difficile from stool samples within 24 h. PMID:20739493

Clostridium difficile as a cause of healthcare-associated diarrhoea among children in Auckland, New Zealand: clinical and molecular epidemiology.

PubMed

Sathyendran, V; McAuliffe, G N; Swager, T; Freeman, J T; Taylor, S L; Roberts, S A

2014-10-01

We aimed to determine the incidence of Clostridium difficile infection (CDI), the molecular epidemiology of circulating C. difficile strains and risk factors for CDI among hospitalised children in the Auckland region. A cross-sectional study was undertaken of hospitalised children <15 years of age in two hospitals investigated for healthcare-associated diarrhoea between November 2011 and June 2012. Stool specimens were analysed for the presence of C. difficile using a two-step testing algorithm including polymerase chain reaction (PCR). C. difficile was cultured and PCR ribotyping performed. Demographic data, illness characteristics and risk factors were compared between children with and without CDI. Non-duplicate stool specimens were collected from 320 children with a median age of 1.2 years (range 3 days to 15 years). Forty-six patients (14 %) tested met the definition for CDI. The overall incidence of CDI was 2.0 per 10,000 bed days. The percentage of positive tests among neonates was only 2.6 %. PCR ribotyping showed a range of strains, with ribotype 014 being the most common. Significant risk factors for CDI were treatment with proton pump inhibitors [risk ratio (RR) 1.74, 95 % confidence interval (CI) 1.09-5.59; p = 0.002], presence of underlying malignancy (RR 2.71, 95 % CI 1.65-4.62; p = 0.001), receiving chemotherapy (RR 2.70, 95 % CI 1.41-4.83; p = 0.003) and exposure to antibiotics (RR 1.17, 95 % CI 0.99-1.17; p = 0.03). C. difficile is an important cause of healthcare-associated diarrhoea in this paediatric population. The notion that neonatal populations will always have high rates of colonisation with C. difficile may not be correct. Several risk factors associated with CDI among adults were also found to be significant.

Clostridium difficile phages: still difficult?

PubMed Central

Hargreaves, Katherine R.; Clokie, Martha R. J.

2014-01-01

Phages that infect Clostridium difficile were first isolated for typing purposes in the 1980s, but their use was short lived. However, the rise of C. difficile epidemics over the last decade has triggered a resurgence of interest in using phages to combat this pathogen. Phage therapy is an attractive treatment option for C. difficile infection, however, developing suitable phages is challenging. In this review we summarize the difficulties faced by researchers in this field, and we discuss the solutions and strategies used for the development of C. difficile phages for use as novel therapeutics. Epidemiological data has highlighted the diversity and distribution of C. difficile, and shown that novel strains continue to emerge in clinical settings. In parallel with epidemiological studies, advances in molecular biology have bolstered our understanding of C. difficile biology, and our knowledge of phage–host interactions in other bacterial species. These three fields of biology have therefore paved the way for future work on C. difficile phages to progress and develop. Benefits of using C. difficile phages as therapeutic agents include the fact that they have highly specific interactions with their bacterial hosts. Studies also show that they can reduce bacterial numbers in both in vitro and in vivo systems. Genetic analysis has revealed the genomic diversity among these phages and provided an insight into their taxonomy and evolution. No strictly virulent C. difficile phages have been reported and this contributes to the difficulties with their therapeutic exploitation. Although treatment approaches using the phage-encoded endolysin protein have been explored, the benefits of using “whole-phages” are such that they remain a major research focus. Whilst we don’t envisage working with C. difficile phages will be problem-free, sufficient study should inform future strategies to facilitate their development to combat this problematic pathogen. PMID:24808893

Laboratory diagnosis of Clostridium difficile infection: Comparison of Techlab C. diff Quik Chek Complete, Xpert C. difficile, and multistep algorithmic approach.

PubMed

Seo, Ja Young; Jeong, Ji Hun; Kim, Kyung Hee; Ahn, Jeong-Yeal; Park, Pil-Whan; Seo, Yiel-Hea

2017-11-01

Clostridium difficile is a major pathogen responsible for nosocomial infectious diarrhea. We explored optimal laboratory strategies for diagnosis of C. difficile infection (CDI) in our clinical settings, a 1400-bed tertiary care hospital. Using 191 fresh stool samples from adult patients, we evaluated the performance of Xpert C. difficile (Xpert CD), C. diff Quik Chek Complete (which simultaneously detects glutamate dehydrogenase [GDH] and C. difficile toxins [CDT]), toxigenic culture, and a two-step algorithm composed of GDH/CDT as a screening test and Xpert CD as a confirmatory test. Clostridium difficile was detected in 35 samples (18.3%), and all isolates were toxigenic strains. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value of each assay for detecting CDI were as follows: Quik Chek Complete CDT (45.7%, 100%, 100%, 89.1%), Quik Chek Complete GDH (97.1%, 99.4%, 97.1%, 99.4%), Xpert CD (94.3%, 100%, 100%, 98.7%), and toxigenic culture (91.4%, 100%, 100%, 98.1%). A two-step algorithm performed identically with Xpert CD assay. Our data showed that most C. difficile isolates from adult patients were toxigenic. We demonstrated that a two-step algorithm based on GDH/CDT assay followed by Xpert CD assay as a confirmatory test was rapid, reliable, and cost effective for diagnosis of CDI in an adult patient setting with high prevalence of toxigenic C. difficile. © 2017 Wiley Periodicals, Inc.

Toxigenic Clostridium difficile colonization among hospitalised adults; risk factors and impact on survival.

PubMed

Behar, Laura; Chadwick, David; Dunne, Angela; Jones, Christopher I; Proctor, Claire; Rajkumar, Chakravarthi; Sharratt, Paula; Stanley, Philip; Whiley, Angela; Wilks, Mark; Llewelyn, Martin J

2017-07-01

To establish risk factors for Clostridium difficile colonization among hospitalized patients in England. Patients admitted to elderly medicine wards at three acute hospitals in England were recruited to a prospective observational study. Participants were asked to provide a stool sample as soon as possible after enrolment and then weekly during their hospital stay. Samples were cultured for C. difficile before ribotyping and toxin detection by PCR. A multivariable logistic regression model of risk factors for C. difficile colonization was fitted from univariable risk factors significant at the p < 0.05 level. 410/727 participants submitted ≥1 stool sample and 40 (9.8%) carried toxigenic C. difficile in the first sample taken. Ribotype 106 was identified three times and seven other ribotypes twice. No ribotype 027 strains were identified. Independent predictors of colonization were previous C. difficile infection (OR 4.53 (95% C.I. 1.33-15.48) and malnutrition (MUST score ≥2) (OR 3.29 (95% C.I. 1.47-7.35)). Although C. difficile colonised patients experienced higher 90-day mortality, colonization was not an independent risk for death. In a non-epidemic setting patients who have previously had CDI and have a MUST score of ≥2 are at increased risk of C. difficile colonization and could be targeted for active surveillance to prevent C. difficile transmission. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Fecal Microbiome Among Nursing Home Residents with Advanced Dementia and Clostridium difficile.

PubMed

Araos, Rafael; Andreatos, Nikolaos; Ugalde, Juan; Mitchell, Susan; Mylonakis, Eleftherios; D'Agata, Erika M C

2018-06-01

Patients colonized with toxinogenic strains of Clostridium difficile have an increased risk of subsequent infection. Given the potential role of the gut microbiome in increasing the risk of C. difficile colonization, we assessed the diversity and composition of the gut microbiota among long-term care facility (LTCF) residents with advanced dementia colonized with C. difficile. Retrospective analysis of rectal samples collected during a prospective observational study. Thirty-five nursing homes in Boston, Massachusetts. Eighty-seven LTCF residents with advanced dementia. Operational taxonomic units were identified using 16S rRNA sequencing. Samples positive for C. difficile were matched to negative controls in a 1:3 ratio and assessed for differences in alpha diversity, beta diversity, and differentially abundant features. Clostridium difficile sequence variants were identified among 7/87 (8.04%) residents. No patient had evidence of C. difficile infection. Demographic characteristics and antimicrobial exposure were similar between the seven cases and 21 controls. The overall biodiversity among cases and controls was reduced with a median Shannon index of 3.2 (interquartile range 2.7-3.9), with no statistically significant differences between groups. The bacterial community structure was significantly different among residents with C. difficile colonization versus those without and included a predominance of Akkermansia spp., Dermabacter spp., Romboutsia spp., Meiothermus spp., Peptoclostridium spp., and Ruminococcaceae UGC 009. LTCF residents with advanced dementia have substantial dysbiosis of their gut microbiome. Specific taxa characterized C. difficile colonization status.

Genome Sequence of Clostridium paraputrificum 373-A1 Isolated in Chile from a Patient Infected with Clostridium difficile

PubMed Central

Guerrero-Araya, Enzo; Plaza-Garrido, Angela; Díaz-Yañez, Fernando; Pizaro-Guajardo, Marjorie; Valenzuela, Sandro L.; Meneses, Claudio; Gil, Fernando

2016-01-01

Clostridium paraputrificum is a gut microbiota member reported in several cases of bacteremia and coinfections. So far, only one genome sequence of a C. paraputrificum (AGR2156) isolate is available. Here, we present the draft genome of C. paraputrificum strain 373-A1, isolated from stools from a patient with C. difficile infection. PMID:27811092

Rapid change of fecal microbiome and disappearance of Clostridium difficile in a colonized infant after transition from breast milk to cow milk.

PubMed

Davis, Manli Y; Zhang, Husen; Brannan, Lera E; Carman, Robert J; Boone, James H

2016-10-07

Clostridium difficile is the most common known cause of antibiotic-associated diarrhea. Upon the disturbance of gut microbiota by antibiotics, C. difficile establishes growth and releases toxins A and B, which cause tissue damage in the host. The symptoms of C. difficile infection disease range from mild diarrhea to pseudomembranous colitis and toxic megacolon. Interestingly, 10-50 % of infants are asymptomatic carriers of C. difficile. This longitudinal study of the C. difficile colonization in an infant revealed the dynamics of C. difficile presence in gut microbiota. Fifty fecal samples, collected weekly between 5.5 and 17 months of age from a female infant who was an asymptomatic carrier of C. difficile, were analyzed by 16S rRNA gene sequencing. Colonization switching between toxigenic and non-toxigenic C. difficile strains as well as more than 100,000-fold fluctuations of C. difficile counts were observed. C. difficile toxins were detected during the testing period in some infant stool samples, but the infant never had diarrhea. Although fecal microbiota was stable during breast feeding, a dramatic and permanent change of microbiota composition was observed within 5 days of the transition from human milk to cow milk. A rapid decline and eventual disappearance of C. difficile coincided with weaning at 12.5 months. An increase in the relative abundance of Bacteroides spp., Blautia spp., Parabacteroides spp., Coprococcus spp., Ruminococcus spp., and Oscillospira spp. and a decrease of Bifidobacterium spp., Lactobacillus spp., Escherichia spp., and Clostridium spp. were observed during weaning. The change in microbiome composition was accompanied by a gradual increase of fecal pH from 5.5 to 7. The bacterial groups that are less abundant in early infancy, and that increase in relative abundance after weaning, likely are responsible for the expulsion of C. difficile.

Effectiveness of screening hospital admissions to detect asymptomatic carriers of Clostridium difficile: a modeling evaluation.

PubMed

Lanzas, Cristina; Dubberke, Erik R

2014-08-01

Both asymptomatic and symptomatic Clostridium difficile carriers contribute to new colonizations and infections within a hospital, but current control strategies focus only on preventing transmission from symptomatic carriers. Our objective was to evaluate the potential effectiveness of methods targeting asymptomatic carriers to control C. difficile colonization and infection (CDI) rates in a hospital ward: screening patients at admission to detect asymptomatic C. difficile carriers and placing positive patients into contact precautions. We developed an agent-based transmission model for C. difficile that incorporates screening and contact precautions for asymptomatic carriers in a hospital ward. We simulated scenarios that vary according to screening test characteristics, colonization prevalence, and type of strain present at admission. In our baseline scenario, on average, 42% of CDI cases were community-onset cases. Within the hospital-onset (HO) cases, approximately half were patients admitted as asymptomatic carriers who became symptomatic in the ward. On average, testing for asymptomatic carriers reduced the number of new colonizations and HO-CDI cases by 40%-50% and 10%-25%, respectively, compared with the baseline scenario. Test sensitivity, turnaround time, colonization prevalence at admission, and strain type had significant effects on testing efficacy. Testing for asymptomatic carriers at admission may reduce both the number of new colonizations and HO-CDI cases. Additional reductions could be achieved by preventing disease in patients who are admitted as asymptomatic carriers and developed CDI during the hospital stay.

Clostridium difficile in retail meat and processing plants in Texas.

PubMed

Harvey, Roger B; Norman, Keri N; Andrews, Kathleen; Norby, Bo; Hume, Michael E; Scanlan, Charles M; Hardin, Margaret D; Scott, Harvey M

2011-07-01

The incidence and severity of disease associated with toxigenic Clostridium difficile have increased in hospitals in North America from the emergence of newer, more virulent strains. Toxigenic C. difficile has been isolated from food animals and retail meat with potential implications of transfer to human beings. The objective of the present study was to determine the prevalence of C. difficile in pork from sausage manufacturing plants and retail meat in Texas. Twenty-three C. difficile isolates were detected from 243 meat samples (9.5%) from 3 sausage-manufacturing plants and 5 retail meat outlets from 2004 to 2009. Twenty-two isolates were positive for toxins A, B, and binary toxin, and were characterized as toxinotype V, PFGE type-NAP7, or "NAP7-variant." Susceptibilities to 11 antimicrobial agents in the current study were similar to those reported previously for toxinotype V isolates, although the results suggested somewhat reduced resistance than reported for other meat, animal, or human clinical toxinotype V isolates.

Comparative Genome Analysis and Global Phylogeny of the Toxin Variant Clostridium difficile PCR Ribotype 017 Reveals the Evolution of Two Independent Sublineages

PubMed Central

Cairns, M. D.; Preston, M. D.; Hall, C. L.; Gerding, D. N.; Hawkey, P. M.; Kato, H.; Kim, H.; Kuijper, E. J.; Lawley, T. D.; Pituch, H.; Reid, S.; Kullin, B.; Riley, T. V.; Solomon, K.; Tsai, P. J.; Weese, J. S.

2016-01-01

ABSTRACT The diarrheal pathogen Clostridium difficile consists of at least six distinct evolutionary lineages. The RT017 lineage is anomalous, as strains only express toxin B, compared to strains from other lineages that produce toxins A and B and, occasionally, binary toxin. Historically, RT017 initially was reported in Asia but now has been reported worldwide. We used whole-genome sequencing and phylogenetic analysis to investigate the patterns of global spread and population structure of 277 RT017 isolates from animal and human origins from six continents, isolated between 1990 and 2013. We reveal two distinct evenly split sublineages (SL1 and SL2) of C. difficile RT017 that contain multiple independent clonal expansions. All 24 animal isolates were contained within SL1 along with human isolates, suggesting potential transmission between animals and humans. Genetic analyses revealed an overrepresentation of antibiotic resistance genes. Phylogeographic analyses show a North American origin for RT017, as has been found for the recently emerged epidemic RT027 lineage. Despite having only one toxin, RT017 strains have evolved in parallel from at least two independent sources and can readily transmit between continents. PMID:28031436

A multicentre randomised controlled trial evaluating lactobacilli and bifidobacteria in the prevention of antibiotic-associated diarrhoea in older people admitted to hospital: the PLACIDE study protocol

PubMed Central

2012-01-01

Background Antibiotic associated diarrhoea complicates 5–39% of courses of antibiotic treatment. Major risk factors are increased age and admission to hospital. Of particular importance is C. difficile associated diarrhoea which occurs in about 4% of antibiotic courses and may result in severe illness, death and high healthcare costs. The emergence of the more virulent 027 strain of C. difficile has further heightened concerns. Probiotics may prevent antibiotic associated diarrhoea by several mechanisms including colonization resistance through maintaining a healthy gut flora. Methods This study aims to test the hypothesis that administration of a probiotic comprising two strains of lactobacilli and two strains of bifidobacteria alongside antibiotic treatment prevents antibiotic associated diarrhoea. We have designed a prospective, parallel group trial where people aged 65 years or more admitted to hospital and receiving one or more antibiotics are randomly allocated to receive either one capsule of the probiotic or a matching placebo daily for 21 days. The primary outcomes are the frequency of antibiotic associated and C. difficile diarrhoea during 8–12 weeks follow-up. To directly inform routine clinical practice, we will recruit a sufficient number of patients to demonstrate a 50% reduction in the frequency of C. difficile diarrhoea with a power of 80%. To maximize the generalizability of our findings and in view of the well-established safety record of probiotics, we will recruit a broad range of medical and surgical in-patients from two different health regions within the UK. Discussion Antibiotic associated diarrhoea constitutes a significant health burden. In particular, current measures to prevent and control C. difficile diarrhoea are expensive and disrupt clinical care. This trial may have considerable significance for the prevention of antibiotic associated diarrhoea in hospitals. Trial registration International Standard Randomised Controlled Trial Number Register ISRCTN70017204. PMID:22559011

Household Transmission of Clostridium difficile to Family Members and Domestic Pets.

PubMed

Loo, Vivian G; Brassard, Paul; Miller, Mark A

2016-11-01

OBJECTIVE To determine the risk of Clostridium difficile transmission from index cases with C. difficile infection (CDI) to their household contacts and domestic pets. DESIGN A prospective study from April 2011 to June 2013. SETTING Patients with CDI from Canadian tertiary care centers. PARTICIPANTS Patients with CDI, their household human contacts, and pets. METHODS Epidemiologic information and stool or rectal swabs were collected from participants at enrollment and monthly for up to 4 months. Pulsed-field gel electrophoresis (PFGE) was performed on C. difficile isolates. Probable transmission was defined as the conversion of a C. difficile culture-negative contact to C. difficile culture-positive contact with a PFGE pattern indistinguishable or closely related to the index case. Possible transmission was defined as a contact with a positive C. difficile culture at baseline with a strain indistinguishable or closely related to the index case. RESULTS A total of 51 patients with CDI participated in this study; 67 human contacts and 15 pet contacts were included. Overall, 9 human contacts (13.4%) were C. difficile culture positive; 1 contact (1.5%) developed CDI; and 8 contacts were asymptomatic. Of 67 human contacts, probable transmission occurred in 1 human contact (1.5%) and possible transmission occurred in 5 human contacts (7.5%). Of 15 pet contacts, probable transmission occurred in 3 (20%) and possible transmission occurred in 1 (6.7%). CONCLUSIONS There was a high proportion of C. difficile culture positivity at 13.4% among human contacts and asymptomatic carriage of domestic pets reached 26.7%. These results suggest that household transmission of C. difficile may be a source of community-associated cases. Infect Control Hosp Epidemiol 2016;1-7.

Inactivation of Clostridium difficile in sewage sludge by anaerobic thermophilic digestion.

PubMed

Xu, Changyun; Salsali, Hamidreza; Weese, Scott; Warriner, Keith

2016-01-01

There has been an increase in community-associated Clostridium difficile infections with biosolids derived from wastewater treatment being identified as one potential source. The current study evaluated the efficacy of thermophilic digestion in decreasing levels of C. difficile ribotype 078 associated with sewage sludge. Five isolates of C. difficile 078 were introduced (final density of 5 log CFU/g) into digested sludge and subjected to anaerobic digestion at mesophilic (36 or 42 °C) or thermophilic (55 °C) temperatures for up to 60 days. It was found that mesophilic digestion at 36 °C did not result in a significant reduction in C. difficile spore levels. In contrast, thermophilic sludge digestion reduced endospore levels at a rate of 0.19-2.68 log CFU/day, depending on the strain tested. The mechanism of lethality was indirect - by stimulating germination then inactivating the resultant vegetative cells. Acidification of sludge by adding acetic acid (6 g/L) inhibited the germination of spores regardless of the sludge digestion temperature. In conclusion, thermophilic digestion can be applied to reduce C. difficile in biosolids, thereby reducing the environmental burden of the enteric pathogen.

Antimicrobial activity of natural products against Clostridium difficile in vitro.

PubMed

Roshan, N; Riley, T V; Hammer, K A

2017-05-10

To investigate the antimicrobial activity of various natural products against Clostridium difficile in vitro. The antibacterial activity of 20 natural products was determined by the agar well diffusion and broth microdilution assays against four C. difficile strains, three comparator organisms and four gastrointestinal commensal organisms. Of the raw natural products, garlic juice had the highest activity. The most active processed products were peppermint oil and the four pure compounds trans-cinnamaldehyde, allicin, menthol and zingerone. Furthermore, Bacteroides species had similar susceptibility to C. difficile to most natural products; however, Lactobacillus casei was less susceptible. The combined effect of natural products with vancomycin or metronidazole was determined using the conventional checkerboard titration method and the fractional inhibitory concentration index was calculated. The results showed a possible synergism between trans-cinnamaldehyde and vancomycin and partial synergy between trans-cinnamaldehyde and metronidazole. The study indicates a range of antimicrobial activity of natural products against C. difficile and suggests that they may be useful as alternative or complementary treatments for C. difficile infection (CDI), particularly as most are able to be given orally. This study encourages further investigation of natural products for treatment of CDI. © 2017 The Society for Applied Microbiology.

Mucosal Antibodies to the C Terminus of Toxin A Prevent Colonization of Clostridium difficile

PubMed Central

Hong, Huynh A.; Hitri, Krisztina; Hosseini, Siamand; Kotowicz, Natalia; Bryan, Donna; Mawas, Fatme; Wilkinson, Anthony J.; van Broekhoven, Annie; Kearsey, Jonathan

2017-01-01

ABSTRACT Mucosal immunity is considered important for protection against Clostridium difficile infection (CDI). We show that in hamsters immunized with Bacillus subtilis spores expressing a carboxy-terminal segment (TcdA26–39) of C. difficile toxin A, no colonization occurs in protected animals when challenged with C. difficile strain 630. In contrast, animals immunized with toxoids showed no protection and remained fully colonized. Along with neutralizing toxins, antibodies to TcdA26–39 (but not to toxoids), whether raised to the recombinant protein or to TcdA26–39 expressed on the B. subtilis spore surface, cross-react with a number of seemingly unrelated proteins expressed on the vegetative cell surface or spore coat of C. difficile. These include two dehydrogenases, AdhE1 and LdhA, as well as the CdeC protein that is present on the spore. Anti-TcdA26–39 mucosal antibodies obtained following immunization with recombinant B. subtilis spores were able to reduce the adhesion of C. difficile to mucus-producing intestinal cells. This cross-reaction is intriguing yet important since it illustrates the importance of mucosal immunity for complete protection against CDI. PMID:28167669

The roles of host and pathogen factors and the innate immune response in the pathogenesis of Clostridium difficile infection

PubMed Central

Sun, Xingmin; Hirota, Simon A.

2014-01-01

Clostridium difficile (C. difficile) is the most common cause of nosocomial antibiotic-associated diarrhea and the etiologic agent of pseudomembranous colitis. The clinical manifestation of Clostridium difficile infection (CDI) is highly variable, from asymptomatic carriage, to mild self-limiting diarrhea, to the more severe pseudomembranous colitis. Furthermore, in extreme cases, colonic inflammation and tissue damage can lead to toxic megacolon, a condition requiring surgical intervention. C. difficile expresses two key virulence factors; the exotoxins, toxin A (TcdA) and toxin B (TcdB), which are glucosyltransferases that target host-cell monomeric GTPases. In addition, some hypervirulent strains produce a third toxin, binary toxin or C. difficile transferase (CDT), which may contribute to the pathogenesis of CDI. More recently, other factors such as surface layer proteins (SLPs) and flagellin have also been linked to the inflammatory responses observed in CDI. Although the adaptive immune response can influence the severity of CDI, the innate immune responses to C. difficile and its toxins play crucial roles in CDI onset, progression, and overall prognosis. Despite this, the innate immune responses in CDI have drawn relatively little attention from clinical researchers. Targeting these responses may prove useful clinically as adjuvant therapies, especially in refractory and/or recurrent CDI. This review will focus on recent advances in our understanding of how C. difficile and its toxins modulate innate immune responses that contribute to CDI pathogenesis. PMID:25242213

DNA microarray-based PCR ribotyping of Clostridium difficile.

PubMed

Schneeberg, Alexander; Ehricht, Ralf; Slickers, Peter; Baier, Vico; Neubauer, Heinrich; Zimmermann, Stefan; Rabold, Denise; Lübke-Becker, Antina; Seyboldt, Christian

2015-02-01

This study presents a DNA microarray-based assay for fast and simple PCR ribotyping of Clostridium difficile strains. Hybridization probes were designed to query the modularly structured intergenic spacer region (ISR), which is also the template for conventional and PCR ribotyping with subsequent capillary gel electrophoresis (seq-PCR) ribotyping. The probes were derived from sequences available in GenBank as well as from theoretical ISR module combinations. A database of reference hybridization patterns was set up from a collection of 142 well-characterized C. difficile isolates representing 48 seq-PCR ribotypes. The reference hybridization patterns calculated by the arithmetic mean were compared using a similarity matrix analysis. The 48 investigated seq-PCR ribotypes revealed 27 array profiles that were clearly distinguishable. The most frequent human-pathogenic ribotypes 001, 014/020, 027, and 078/126 were discriminated by the microarray. C. difficile strains related to 078/126 (033, 045/FLI01, 078, 126, 126/FLI01, 413, 413/FLI01, 598, 620, 652, and 660) and 014/020 (014, 020, and 449) showed similar hybridization patterns, confirming their genetic relatedness, which was previously reported. A panel of 50 C. difficile field isolates was tested by seq-PCR ribotyping and the DNA microarray-based assay in parallel. Taking into account that the current version of the microarray does not discriminate some closely related seq-PCR ribotypes, all isolates were typed correctly. Moreover, seq-PCR ribotypes without reference profiles available in the database (ribotype 009 and 5 new types) were correctly recognized as new ribotypes, confirming the performance and expansion potential of the microarray. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Prevalence of Clostridium difficile toxinotypes in infected patients at a tertiary care center in Lebanon.

PubMed

Moukhaiber, Romy; Araj, George F; Kissoyan, Kohar Annie B; Cheaito, Katia A; Matar, Ghassan M

2015-07-30

Due to the increase in the incidence of Clostridium difficile associated diseases at a tertiary care center in Lebanon, this study was undertaken to determine the prevalent C. difficile toxinotypes. The immunocard method was used to test for toxins A and B in 88 collected stool samples, followed with API 20A to confirm for C. difficile. PCR amplification of the triose phosphate isomerase (tpi) gene, the toxin encoding genes tcdA, and tcdB, followed by toxinotyping, were performed on recovered isolates and stool specimens. Out of the 88 stool samples obtained, 30 (65.2%) were Immunocard positive, culture and or tpi positive for C. difficile. Of the 30 isolates, 4 were PCR negative for the tcdA and tcdB genes (A-B-), and 26 were PCR positive for the tcdA and / or tcdB genes with 4 being A+B+, 1 A+B-, and 21 A-B+. The results of toxinotyping showed that 2 isolates belonged to toxinotype 0, 4 to toxinotype XI, 2 to toxinotype XII, 1 to toxinotype XVI, 1(A+B-) and twenty (A-B+) designated as toxinotype 0-like. C. difficile was detected in 65.2% of patients' stools with prevalence of toxinotype 0-like. Identification of toxinotypes of C. difficile is important to determine the virulence potential of strains and control their spread.

[Prevalence of Clostridium difficile infection in hospitalized patients with diarrhea: results of a French prospective multicenter bi-annual point prevalence study].

PubMed

Barbut, Frédéric; Ramé, Laetitia; Petit, Amandine; Suzon, Laina; de Chevigny, Alix; Eckert, Catherine

2015-04-01

Clostridium difficile infections represent the major cause of healthcare-associated diarrhea. The objective of the study was to determine the incidence of C. difficile infection (CDI) in 2012 and to assess the under-estimation of the disease in France. Seventy healthcare facilities participated in a prospective point prevalence study. Each laboratory was requested to send all the diarrheal stool samples from hospitalized patients during 2 days (one in December 2012 and one in July 2013) to the National Reference Laboratory (NRL) for C. difficile, irrespective of a medical request for C. difficile. At the NRL, stool samples were analyzed using the Quik Chek Complete assay (Alere). Positive samples for glutamate deshydrogenase or toxins were confirmed by the toxigenic culture. Results obtained by the NRL were then compared to those given by each healthcare facility. Incidence of CDI in 2012 was provided by each healthcare facility through a specific questionnaire. Mean incidence of CDI reported in 2012 by the HCF was 3.6 ± 2.9 per 10,000 patient-days; the incidence was positively correlated to the density testing (defined by the number of tests per 10,000 patient-days), which varied across the HCF (median 29.0 per 10,000 patient-days, IQR 19-50). During the bi-annual point prevalence survey, 651 stool samples were included and 90 were positive for C. difficile in culture. The overall prevalence of patients infected by a toxigenic C. difficile strain was 9.7% (63/651) and the prevalence of patients colonized by a non-toxigenic strain was 4.2% (27/651). Among the 65 cases of CDI detected by the NRL, 35 (55.6%) were missed by the participating HCF because of a lack of sensitivity of the methods used for the diagnosis (16/63, 25.4%) or because of a lack of clinical suspicion (19/63, 30.2%). The incidence of CDI in 2012 has increased in France compared to that of 2009 but is still underestimated because of a lack of clinical suspicion or a lack of sensitivity of methods used for toxin detection. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Diversity of Clostridium difficile PCR ribotypes in Europe: results from the European, multicentre, prospective, biannual, point-prevalence study of Clostridium difficile infection in hospitalised patients with diarrhoea (EUCLID), 2012 and 2013.

PubMed

Davies, Kerrie A; Ashwin, Helen; Longshaw, Christopher M; Burns, David A; Davis, Georgina L; Wilcox, Mark H

2016-07-21

Clostridium difficile infection (CDI) is the major cause of infective diarrhoea in healthcare environments. As part of the European, multicentre, prospective, biannual, point-prevalence study of Clostridium difficile infection in hospitalised patients with diarrhoea (EUCLID), the largest C. difficile epidemiological study of its type, PCR ribotype distribution of C. difficile isolates in Europe was investigated. PCR ribotyping was performed on 1,196 C. difficile isolates from diarrhoeal samples sent to the European coordinating laboratory in 2012-13 and 2013 (from two sampling days) by 482 participating hospitals from 19 European countries. A total of 125 ribotypes were identified, of which ribotypes 027 (19%, n =222), 001/072 (11%, n = 134) and 014/020 (10%, n = 119) were the most prevalent. Distinct regional patterns of ribotype distribution were noted. Of 596 isolates from patients with toxin-positive stools (CDI cases), ribotype 027 accounted for 22% (32/144) of infections in cases aged from 18 to less than 65 years, but the prevalence decreased in those aged ≥ 65 years (14% (59/412)) and further decreased in those aged ≥ 81 years (9% (18/195)). The prevalence of ribotype 027 and 176, but not other epidemic strains, was inversely proportional to overall ribotype diversity (R(2) = 0.717). This study highlights an increased diversity of C. difficile ribotypes across Europe compared with previous studies, with considerable intercountry variation in ribotype distribution. Continuous surveillance programmes are necessary to monitor the changing epidemiology of C. difficile. This article is copyright of The Authors, 2016.

The zoonotic potential of Clostridium difficile from small companion animals and their owners.

PubMed

Rabold, Denise; Espelage, Werner; Abu Sin, Muna; Eckmanns, Tim; Schneeberg, Alexander; Neubauer, Heinrich; Möbius, Nadine; Hille, Katja; Wieler, Lothar H; Seyboldt, Christian; Lübke-Becker, Antina

2018-01-01

Clostridium difficile infections (CDI) in humans range from asymptomatic carriage to life-threatening intestinal disease. Findings on C. difficile in various animal species and an overlap in ribotypes (RTs) suggest potential zoonotic transmission. However, the impact of animals for human CDI remains unclear. In a large-scale survey we collected 1,447 fecal samples to determine the occurrence of C. difficile in small companion animals (dogs and cats) and their owners and to assess potential epidemiological links within the community. The Germany-wide survey was conducted from July 2012-August 2013. PCR ribotyping, Multilocus VNTR Analysis (MLVA) and PCR detection of toxin genes were used to characterize isolated C. difficile strains. A database was defined and logistic regression used to identify putative factors associated with fecal shedding of C. difficile. In total, 1,418 samples met the inclusion criteria. The isolation rates for small companion animals and their owners within the community were similarly low with 3.0% (25/840) and 2.9% (17/578), respectively. PCR ribotyping revealed eight and twelve different RTs in animals and humans, respectively, whereas three RTs were isolated in both, humans and animals. RT 014/0, a well-known human hospital-associated lineage, was predominantly detected in animal samples. Moreover, the potentially highly pathogenic RTs 027 and 078 were isolated from dogs. Even though, C. difficile did not occur simultaneously in animals and humans sharing the same household. The results of the epidemiological analysis of factors associated with fecal shedding of C. difficile support the hypothesis of a zoonotic potential. Molecular characterization and epidemiological analysis revealed that the zoonotic risk for C. difficile associated with dogs and cats within the community is low but cannot be excluded.

Change in Quality of Life with Velopharyngeal Insufficiency Surgery

PubMed Central

Skirko, Jonathan R.; Weaver, Edward M.; Perkins, Jonathan A.; Kinter, Sara; Eblen, Linda; Martina, Julie; Sie, Kathleen C.Y.

2018-01-01

Objective 1) Define the minimal clinically important difference (MCID) of the Velopharyngeal Insufficiency (VPI) Effects on Life Outcomes (VELO) instrument, and 2) test for change in quality of life after VPI surgery. Study Design Prospective observational cohort. Setting VPI clinic at a tertiary pediatric medical center. Subjects and Methods Children with VPI and their parents completed the VELO instrument (higher score is better quality of life) at enrollment and then underwent VPI surgery (Furlow palatoplasty or sphincter pharyngoplasty, n=32), other treatments (obturator or oronasal fistula repair, n=7), or no treatment (n=18). They completed the VELO instrument again and an instrument of global rating of change in quality of life at one year. MCID was anchored to the global change instrument scores corresponding to “a little” or “somewhat” better. Within-group (paired t-test) and between-group (Student’s t-test) changes in VELO were tested for the VPI surgery and no treatment groups. The association between treatment group and VELO change was tested with multivariate linear regression, adjusting for confounders. Results Follow up was obtained on 37/57 (65%) of patients. The mean (SD) VELO change scores corresponding to the MCID anchor was 15 (13). The VELO score improved significantly more in the VPI surgery group (change 22 [15]), p<0.001) than in the no-treatment group (change 9 [12], p=0.04), after adjusting for confounders (p=0.007 between groups). Conclusion VPI surgery using the Furlow palatoplasty or sphincter pharyngoplasty improves VPI specific quality-of-life, and the improvement is clinically important. PMID:26124262

A Delphi survey on diagnosis and management of stress velopharyngeal insufficiency in wind musicians.

PubMed

Evans, Alison; Driscoll, Tim; Ackermann, Bronwen

2014-10-01

The aim of this study was to identify current trends in clinical assessment and management of stress velopharyngeal insufficiency (VPI) in wind musicians. This was an online two-round Delphi survey of health practitioners familiar with assessing and treating musicians with stress VPI. Fourteen specialists (seven otolaryngologists and seven speech-language pathologists) from four countries participated in the Delphi survey. From the first round questionnaire, 32 items were identified as being causes, assessment tools, diagnostic indicators, and treatment methods for stress VPI. The second round questionnaire revealed that prolonged exposure to high intra-oral pressures was important in determining the cause of stress VPI. The most important assessment tools for stress VPI were case history and nasendoscopy. The most important indicator for stress VPI was self-reported symptoms. There was no clear agreement identified on the management methods for stress VPI for musicians. However, the trend followed by most of the survey participants was a combination of conservative management approaches (including rest or watch and wait, speech-language pathology intervention, velopharyngeal muscle training, and changes to the instrument or reed), and then, if symptoms persist, to use injection pharyngoplasty or pharyngeal flap. This survey demonstrates that no standard management protocol currently exists for musicians diagnosed with stress VPI, but provides current trends in the assessment and management which can be used in future guidelines for health professionals who treat wind musicians.

Clostridium difficile in retail baskets, trolleys, conveyor belts, and plastic bags in Saudi Arabia.

PubMed

Alqumber, Mohammed A

2014-10-01

To determine Clostridium difficile (C. difficile) prevalence on retail surfaces and shoppers plastic bags. From 20 June to 10 August 2011, in a cross-sectional epidemiological study, 17 supermarkets from 2 cities, Albaha and Altaif, Saudi Arabia were sampled. A total of 800 samples, which comprised 200 samples per surveyed surface, were studied. These included baskets, trolleys, conveyer belts, and outgoing shoppers' plastic bags. Clostridium difficile strains were isolated. The isolates were characterized using ribotyping and  polymerase chain reaction for the detection of toxin A (tcdA), toxin B (tcdB), binary toxin (cdtB), and toxin C (tcdC) genes. Susceptibility to antibiotics was determined on a Muller-Hinton agar with 5% sheep blood agar using E-tests. Overall, the C. difficile prevalence on sampled surfaces was 0.75%. The highest prevalence was found on retail baskets and trolleys, followed by plastic bags. A total of 5 different ribotypes were identified. Alterations in tcdC were detected in ribotype 027 and BT1. All the identified isolates were susceptible to vancomycin, but resistant to levofloxacin. In this study, C. difficile was present at a rate of 0.75% on supermarket surfaces. Spore disinfection of implicated surfaces may be necessary to control any community-acquired infections caused by this pathogen. 

Control of Clostridium difficile Physiopathology in Response to Cysteine Availability

PubMed Central

Dubois, Thomas; Dancer-Thibonnier, Marie; Monot, Marc; Hamiot, Audrey; Bouillaut, Laurent; Soutourina, Olga; Martin-Verstraete, Isabelle

2016-01-01

The pathogenicity of Clostridium difficile is linked to its ability to produce two toxins: TcdA and TcdB. The level of toxin synthesis is influenced by environmental signals, such as phosphotransferase system (PTS) sugars, biotin, and amino acids, especially cysteine. To understand the molecular mechanisms of cysteine-dependent repression of toxin production, we reconstructed the sulfur metabolism pathways of C. difficile strain 630 in silico and validated some of them by testing C. difficile growth in the presence of various sulfur sources. High levels of sulfide and pyruvate were produced in the presence of 10 mM cysteine, indicating that cysteine is actively catabolized by cysteine desulfhydrases. Using a transcriptomic approach, we analyzed cysteine-dependent control of gene expression and showed that cysteine modulates the expression of genes involved in cysteine metabolism, amino acid biosynthesis, fermentation, energy metabolism, iron acquisition, and the stress response. Additionally, a sigma factor (SigL) and global regulators (CcpA, CodY, and Fur) were tested to elucidate their roles in the cysteine-dependent regulation of toxin production. Among these regulators, only sigL inactivation resulted in the derepression of toxin gene expression in the presence of cysteine. Interestingly, the sigL mutant produced less pyruvate and H2S than the wild-type strain. Unlike cysteine, the addition of 10 mM pyruvate to the medium for a short time during the growth of the wild-type and sigL mutant strains reduced expression of the toxin genes, indicating that cysteine-dependent repression of toxin production is mainly due to the accumulation of cysteine by-products during growth. Finally, we showed that the effect of pyruvate on toxin gene expression is mediated at least in part by the two-component system CD2602-CD2601. PMID:27297391

Pathogenicity Island Cross Talk Mediated by Recombination Directionality Factors Facilitates Excision from the Chromosome.

PubMed

Carpenter, Megan R; Rozovsky, Sharon; Boyd, E Fidelma

2015-12-14

Pathogenicity islands (PAIs) are mobile integrated genetic elements (MIGEs) that contain a diverse range of virulence factors and are essential in the evolution of pathogenic bacteria. PAIs are widespread among bacteria and integrate into the host genome, commonly at a tRNA locus, via integrase-mediated site-specific recombination. The excision of PAIs is the first step in the horizontal transfer of these elements and is not well understood. In this study, we examined the role of recombination directionality factors (RDFs) and their relationship with integrases in the excision of two PAIs essential for Vibrio cholerae host colonization: Vibrio pathogenicity island 1 (VPI-1) and VPI-2. VPI-1 does not contain an RDF, which allowed us to answer the question of whether RDFs are an absolute requirement for excision. We found that an RDF was required for efficient excision of VPI-2 but not VPI-1 and that RDFs can induce excision of both islands. Expression data revealed that the RDFs act as transcriptional repressors to both VPI-1- and VPI-2-encoded integrases. We demonstrated that the RDFs Vibrio excision factor A (VefA) and VefB bind at the attachment sites (overlapping the int promoter region) of VPI-1 and VPI-2, thus supporting this mode of integrase repression. In addition, V. cholerae RDFs are promiscuous due to their dual functions of promoting excision of both VPI-1 and VPI-2 and acting as negative transcriptional regulators of the integrases. This is the first demonstration of cross talk between PAIs mediated via RDFs which reveals the complex interactions that occur between separately acquired MIGEs. Deciphering the mechanisms of pathogenicity island excision is necessary for understanding the evolution and spread of these elements to their nonpathogenic counterparts. Such mechanistic insight would assist in predicting the mobility of uncharacterized genetic elements. This study identified extensive RDF-mediated cross talk between two nonhomologous VPIs and demonstrated the dual functionality of RDF proteins: (i) inducing PAI excision and (ii) acting as transcriptional regulators. Findings from this study may be implicated in determining the mobilome contribution of other bacteria with multiple MIGEs. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

In vitro production of Clostridium difficile spores for use in the efficacy evaluation of disinfectants: a precollaborative investigation.

PubMed

Hasan, Jafrul A; Japal, Knoxley M; Christensen, Erick R; Samalot-Freire, Luisa C

2011-01-01

Clostridium difficile is a strict anaerobic spore-forming bacterium, and an increasingly common nosocomial pathogen. The U.S. Environmental Protection Agency (EPA) is responsible for the registration of disinfectants, including products designed to treat environmental surfaces contaminated with spores of C. difficile. Product efficacy data are required for registration; however, there is a lack of methodology for generating high-quality spore suspensions for evaluating product performance. As such, a study was carried out to select a suitable C. difficile strain and to develop a stand-alone method to prepare a spore suspension that meets specific criteria necessary for quantitative testing of disinfectants. The criteria are: (1) a spore titer of > 8 log10/mL, (2) > or = 90% spores to vegetative cells, and (3) resistance of spores (determined by viability) to 2.5 M hydrochloric acid (HCl). Several strains of C. difficile (toxigenic and nontoxigenic) were grown on various media (solid and liquid) for varying lengths of time to determine the best combination of incubation conditions and media to optimize spore production and quality. Once the spore production procedure was optimized, a toxigenic strain of C. difficile [American Type Culture Collection (ATCC) 43598] was selected for use in trials to verify repeatability from one production run to the next. The spore suspension was initiated by spreading vegetative cells of C. difficile (ATCC 43598) on CDC anaerobic 5% sheep blood agar plates and incubating for 7-10 days at 36 +/- 1 degrees C under anaerobic conditions. Spores were harvested when > or = 90% of the cells converted to spores as determined by observation using phase-contrast microscopy. The spores were washed three times with saline-Tween-80, resuspended in cold deionized water, heated to 70 degrees C for 10 min, evaluated microscopically for quality, and enumerated on cycloserine-cefoxitin-fructose agar containing horse blood and taurocholate. The spore suspension was used to inoculate brushed stainless steel carriers (1 cm in diameter) with and without a soil load in accordance with the Standard Quantitative Carrier Disk Test Method (ASTM E-2197-02) to determine carrier load. Once it was determined that > 6 log10 spores/carrier could be recovered, spores were evaluated for resistance to HCI. The sporulation method presented in this report is simple and repeatable and results in spore suspension of high titer (> 8 log10/mL) and quality (> or = 90% spores to vegetative cells) that met acid resistance criteria (spores were resistant to 2.5 M HCI for 10 min). In addition, recovery from brushed stainless steel carriers with and without soil load was > 6 log10 spores/carrier. A 6 log10 performance standard was set forth in the EPA's interim guidance for generating data to support a label claim for effectiveness against C. difficile spores on hard, nonporous surfaces. This precollaborative investigation successfully demonstrated the use of a methodology for in vitro production of C. difficile spores (ATCC 43598) necessary for conducting efficacy tests. A proposal will be submitted to the AOAC INTERNATIONAL Methods Committee on Antimicrobial Efficacy Testing for a collaborative study; see Appendix.

Dietary trehalose enhances virulence of epidemic Clostridium difficile.

PubMed

Collins, J; Robinson, C; Danhof, H; Knetsch, C W; van Leeuwen, H C; Lawley, T D; Auchtung, J M; Britton, R A

2018-01-18

Clostridium difficile disease has recently increased to become a dominant nosocomial pathogen in North America and Europe, although little is known about what has driven this emergence. Here we show that two epidemic ribotypes (RT027 and RT078) have acquired unique mechanisms to metabolize low concentrations of the disaccharide trehalose. RT027 strains contain a single point mutation in the trehalose repressor that increases the sensitivity of this ribotype to trehalose by more than 500-fold. Furthermore, dietary trehalose increases the virulence of a RT027 strain in a mouse model of infection. RT078 strains acquired a cluster of four genes involved in trehalose metabolism, including a PTS permease that is both necessary and sufficient for growth on low concentrations of trehalose. We propose that the implementation of trehalose as a food additive into the human diet, shortly before the emergence of these two epidemic lineages, helped select for their emergence and contributed to hypervirulence.

Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2 (Bio-K+): Characterization, Manufacture, Mechanisms of Action, and Quality Control of a Specific Probiotic Combination for Primary Prevention of Clostridium difficile Infection.

PubMed

Auclair, Julie; Frappier, Martin; Millette, Mathieu

2015-05-15

A specific probiotic formulation composed of Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2 (Bio-K+) has been marketed in North America since 1996. The strains and the commercial products have been evaluated for safety, identity, gastrointestinal survival, and stability throughout shelf life. The capacity of both the fermented beverages and the capsules to reduce incidences of antibiotic-associated diarrhea and Clostridium difficile infection (CDI) has been demonstrated in human clinical trials. Individual strains and the finished products have shown antimicrobial activity against C. difficile and toxin A/B neutralization capacity in vitro. The use of this specific probiotic formulation as part of a bundle of preventive measures to control CDI in healthcare settings is discussed. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Genetics of Cleft Palate and Velopharyngeal Insufficiency

PubMed Central

Sweeney, Walter M.; Lanier, Steve T.; Purnell, Chad A.; Gosain, Arun K.

2015-01-01

Velopharyngeal insufficiency (VPI) can occur in the setting of an unrepaired or repaired cleft lip and palate. The rate of VPI has been documented as high as 33% in some studies with higher rates of recurrences following surgery associated with genetic syndromes such as 22q11.2 deletions. The primary cause of VPI in these groups is still identified as the anatomic abnormalities of the velum. In this review, the anatomy and physiology of the velum are discussed along with genetic mutations associated with VPI. PMID:27617110

Preparation of Syndiotactic Poly(vinyl alcohol)/Poly(vinyl pivalate/vinyl acetate) Microspheres with Radiopacity Using Suspension Copolymerization and Saponification

NASA Astrophysics Data System (ADS)

Seok Lyoo, Won; Wook Cha, Jin; Young Kwak, Kun; Jae Lee, Young; Yong Jeon, Han; Sik Chung, Yong; Kyun Noh, Seok

2010-06-01

To prepare Poly(vinyl pivalate/vinyl acetate) [P(VPi/VAc)] microspheres with radiopacity, the suspension copolymerization approach in the presence of aqueous radiopaque nanoparticles was used. After, The P(VPi/VAc) microspheres with radiopacity were saponified in heterogeneous system, and then P(VPi/VAc) microspheres without aggregates were converted to s-PVA/P(VPi/VAc) microspheres of skin/core structure through the heterogeneous surface saponification. Radiopacity of microspheres was confirmed with Computed tomography (CT).

Role of Glycosyltransferases Modifying Type B Flagellin of Emerging Hypervirulent Clostridium difficile Lineages and Their Impact on Motility and Biofilm Formation*

PubMed Central

Valiente, Esmeralda; Bouché, Laura; Hitchen, Paul; Faulds-Pain, Alexandra; Songane, Mario; Dawson, Lisa F.; Donahue, Elizabeth; Stabler, Richard A.; Panico, Maria; Morris, Howard R.; Bajaj-Elliott, Mona; Logan, Susan M.; Dell, Anne; Wren, Brendan W.

2016-01-01

Clostridium difficile is the principal cause of nosocomial infectious diarrhea worldwide. The pathogen modifies its flagellin with either a type A or type B O-linked glycosylation system, which has a contributory role in pathogenesis. We study the functional role of glycosyltransferases modifying type B flagellin in the 023 and 027 hypervirulent C. difficile lineages by mutagenesis of five putative glycosyltransferases and biosynthetic genes. We reveal their roles in the biosynthesis of the flagellin glycan chain and demonstrate that flagellar post-translational modification affects motility and adhesion-related bacterial properties of these strains. We show that the glycosyltransferases 1 and 2 (GT1 and GT2) are responsible for the sequential addition of a GlcNAc and two rhamnoses, respectively, and that GT3 is associated with the incorporation of a novel sulfonated peptidyl-amido sugar moiety whose structure is reported in our accompanying paper (Bouché, L., Panico, M., Hitchen, P., Binet, D., Sastre, F., Faulds-Pain, A., Valiente, E., Vinogradov, E., Aubry, A., Fulton, K., Twine, S., Logan, S. M., Wren, B. W., Dell, A., and Morris, H. R. (2016) J. Biol. Chem. 291, 25439–25449). GT2 is also responsible for methylation of the rhamnoses. Whereas type B modification is not required for flagellar assembly, some mutations that result in truncation or abolition of the glycan reduce bacterial motility and promote autoaggregation and biofilm formation. The complete lack of flagellin modification also significantly reduces adhesion of C. difficile to Caco-2 intestinal epithelial cells but does not affect activation of human TLR5. Our study advances our understanding of the genes involved in flagellar glycosylation and their biological roles in emerging hypervirulent C. difficile strains. PMID:27703012

Metronidazole-triazole conjugates: Activity against Clostridium difficile and parasites

PubMed Central

Jarrad, Angie M.; Karoli, Tomislav; Debnath, Anjan; Tay, Chin Yen; Huang, Johnny X.; Kaeslin, Geraldine; Elliott, Alysha G.; Miyamoto, Yukiko; Ramu, Soumya; Kavanagh, Angela M.; Zuegg, Johannes; Eckmann, Lars; Blaskovich, Mark A.T.; Cooper, Matthew A.

2015-01-01

Metronidazole has been used clinically for over 50 years as an antiparasitic and broad-spectrum antibacterial agent effective against anaerobic bacteria. However resistance to metronidazole in parasites and bacteria has been reported, and improved second-generation metronidazole analogues are needed. The copper catalysed Huigsen azide-alkyne 1,3-dipolar cycloaddition offers a way to efficiently assemble new libraries of metronidazole analogues. Several new metronidazole-triazole conjugates (Mtz-triazoles) have been identified with excellent broad spectrum antimicrobial and antiparasitic activity targeting Clostridium difficile, Entamoeba histolytica and Giardia lamblia. Cross resistance to metronidazole was observed against stable metronidazole resistant C. difficile and G. lamblia strains. However for the most potent Mtz-triazoles, the activity remained in a therapeutically relevant window. PMID:26117821

Burden of Clostridium difficile infection in the United States.

PubMed

Lessa, Fernanda C; Mu, Yi; Bamberg, Wendy M; Beldavs, Zintars G; Dumyati, Ghinwa K; Dunn, John R; Farley, Monica M; Holzbauer, Stacy M; Meek, James I; Phipps, Erin C; Wilson, Lucy E; Winston, Lisa G; Cohen, Jessica A; Limbago, Brandi M; Fridkin, Scott K; Gerding, Dale N; McDonald, L Clifford

2015-02-26

The magnitude and scope of Clostridium difficile infection in the United States continue to evolve. In 2011, we performed active population- and laboratory-based surveillance across 10 geographic areas in the United States to identify cases of C. difficile infection (stool specimens positive for C. difficile on either toxin or molecular assay in residents ≥ 1 year of age). Cases were classified as community-associated or health care-associated. In a sample of cases of C. difficile infection, specimens were cultured and isolates underwent molecular typing. We used regression models to calculate estimates of national incidence and total number of infections, first recurrences, and deaths within 30 days after the diagnosis of C. difficile infection. A total of 15,461 cases of C. difficile infection were identified in the 10 geographic areas; 65.8% were health care-associated, but only 24.2% had onset during hospitalization. After adjustment for predictors of disease incidence, the estimated number of incident C. difficile infections in the United States was 453,000 (95% confidence interval [CI], 397,100 to 508,500). The incidence was estimated to be higher among females (rate ratio, 1.26; 95% CI, 1.25 to 1.27), whites (rate ratio, 1.72; 95% CI, 1.56 to 2.0), and persons 65 years of age or older (rate ratio, 8.65; 95% CI, 8.16 to 9.31). The estimated number of first recurrences of C. difficile infection was 83,000 (95% CI, 57,000 to 108,900), and the estimated number of deaths was 29,300 (95% CI, 16,500 to 42,100). The North American pulsed-field gel electrophoresis type 1 (NAP1) strain was more prevalent among health care-associated infections than among community-associated infections (30.7% vs. 18.8%, P<0.001). C. difficile was responsible for almost half a million infections and was associated with approximately 29,000 deaths in 2011. (Funded by the Centers for Disease Control and Prevention.).

Clostridium difficile colonization and infection in patients with hepatic cirrhosis.

PubMed

Yan, Dong; Chen, Yunbo; Lv, Tao; Huang, Yandi; Yang, Jiezuan; Li, Yongtao; Huang, Jianrong; Li, Lanjuan

2017-10-01

The aim of this study was to investigate the toxigenic Clostridium difficile colonization (CDC, colonization with toxigenic C. difficile but without symptoms) and C. difficile infection (CDI, active C. difficile infection resulting in disease symptoms) in hepatic cirrhosis patients, identify the risk factors of CDC, and determine the correlation between CDC and CDI. The strains of toxigenic C. difficile were isolated from patients with hepatic cirrhosis within 48 h after admission, followed by multilocus sequence typing (MLST). Patients were divided into toxigenic CDC group and noncolonized (NC) group according to the colonization. Logistic regression analysis was performed to analyse the risk factors for the CDC. Besides, the CDI incidence was compared between the two groups. Colonization of toxigenic C. difficile was identified in 104 cases (19.8 %). Eighteen sequence types (STs) were identified, among which ST-3, ST-54, ST-35 and ST-37 were the predominant types. Child-Pugh class C(relative risk, RR, 3.025; 95 % CI: 1.410-6.488), decrease of prothrombin time activity (PTA) (RR 2.180; 95 % CI: 1.368-3.476), decrease of platelet (RR 2.746; 95 % CI: 0.931-8.103) and concurrent hepatic encephalopathy (RR 1.740; 95 % CI: 1.012-2.990) were identified as the risk factors for the hepatic cirrhosis patients with CDC. The CDI incidence in the CDC group was also significantly higher than that of the NC group (26.0 % vs 1.7 %, P<0.001). An carriage rate of 19.8 % was reported in the hepatic cirrhosis patients with C. difficile colonization. Child's class C, decrease of PTA and platelet, and concurrent hepatic encephalopathy were the risk factors for the hepatic cirrhosis patients with C. difficile colonization. Hepatic cirrhosis patients with C. difficile colonization were more susceptible to CDI.

Lactobacillus acidophilus modulates the virulence of Clostridium difficile.

PubMed

Yun, B; Oh, S; Griffiths, M W

2014-01-01

Clostridium difficile is a spore-forming, toxin-producing, anaerobic bacterium that colonizes the human gastrointestinal tract. This pathogen causes antibiotic-associated diarrhea and colitis in animals and humans. Antibiotic-associated diseases may be treated with probiotics, and interest is increasing in such uses of probiotics. This study investigated the effect of Lactobacillus strains on the quorum-sensing signals and toxin production of C. difficile. In addition, an in vivo experiment was designed to assess whether Lactobacillus acidophilus GP1B is able to control C. difficile-associated disease. Autoinducer-2 activity was measured for C. difficile using the Vibrio harveyi coupled bioluminescent assay. Cell extract (10μg/mL) of L. acidophilus GP1B exhibited the highest inhibitory activity among 5 to 40μg/mL cell-extract concentrations. Real-time PCR data indicated decreased transcriptional levels in luxS, tcdA, tcdB, and txeR genes in the presence of 10μg/mL of cell extract of L. acidophilus GP1B. Survival rates at 5d for mice given the pathogen alone with L. acidophilus GP1B cell extract or L. acidophilus GP1B were 10, 70, and 80%, respectively. In addition, the lactic acid-produced L. acidophilus GP1B exhibits an inhibitory effect against the growth of C. difficile. Both the L. acidophilus GP1B and GP1B cell extract have significant antipathogenic effects on C. difficile. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Acoustic analysis of voice in children with cleft palate and velopharyngeal insufficiency.

PubMed

Villafuerte-Gonzalez, Rocio; Valadez-Jimenez, Victor M; Hernandez-Lopez, Xochiquetzal; Ysunza, Pablo Antonio

2015-07-01

Acoustic analysis of voice can provide instrumental data concerning vocal abnormalities. These findings can be used for monitoring clinical course in cases of voice disorders. Cleft palate severely affects the structure of the vocal tract. Hence, voice quality can also be also affected. To study whether the main acoustic parameters of voice, including fundamental frequency, shimmer and jitter are significantly different in patients with a repaired cleft palate, as compared with normal children without speech, language and voice disorders. Fourteen patients with repaired unilateral cleft lip and palate and persistent or residual velopharyngeal insufficiency (VPI) were studied. A control group was assembled with healthy volunteer subjects matched by age and gender. Hypernasality and nasal emission were perceptually assessed in patients with VPI. Size of the gap as assessed by videonasopharyngoscopy was classified in patients with VPI. Acoustic analysis of voice including Fundamental frequency (F0), shimmer and jitter were compared between patients with VPI and control subjects. F0 was significantly higher in male patients as compared with male controls. Shimmer was significantly higher in patients with VPI regardless of gender. Moreover, patients with moderate VPI showed a significantly higher shimmer perturbation, regardless of gender. Although future research regarding voice disorders in patients with VPI is needed, at the present time it seems reasonable to include strategies for voice therapy in the speech and language pathology intervention plan for patients with VPI. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Biomedical applications of stereoregular poly(vinyl alcohol) micro- and nanoparticles

NASA Astrophysics Data System (ADS)

Lyoo, Won Seok; Kim, Joon Ho; Kim, Sam Soo; Ghim, Han Do

2002-11-01

Syndiotactic poly(vinyl alcohol) (PVA)/poly(vinyl pivalate/vinyl acetate) (P(VPi/VAc)) and atactic PVA/PVAc micro- and nanoparticles with skin/core structure have been prepared by heterogeneous saponification of P(VPi/VAc) and PVAc micro- and nanoparticles. Especially, to prepare P(VPi/VAc) and PVAc microparticles having various particle sizes and uniform particle size distribution, vinyl pivalate (VPi)/vinyl acetate (VAc) and VAc were suspension-polymerized using a low-temperature initiator, 2,2"-azobis(2,4-dimethylvaleronitrile). P(VPi/VAc) particles are promising precursor of stereoregular PVA embolic materials which can be introduced through catheters in the management of gastrointestinal bleeders, arteriovenous malformations, hemangiomas, and traumatic rupture of blood vessels. Monodisperse and/or nearly monodisperse P(VPi/VAc) and PVAc microparticles with various particle diameters were obtained by controlling suspension polymerization conditions. Monodisperse P(VPi/VAc) and PVAc microparticles having various particle sizes were partially saponified in the heterogeneous system. PVA/P(VPi/VAc) and PVA/PVAc microparticles having various tacticity and degree of saponification were produced by controlling various polymerization and saponification conditions. The coating of stereoregular PVA micro- and nanoparticles for drug release experiments was conducted with the strepo-avidin-alkaline phosphatase conjugate in variable conditions of pH value, coating buffer, and reaction temperature. Protein-coated syndiotactic PVA micro- and nanoparticles, which does not crosslinking, were more superior to controllability of drug release, durability, and dimensional stability to water and blood than atactic one.

Bioprospecting Deep-Sea Actinobacteria for Novel Anti-infective Natural Products

PubMed Central

Xu, Dongbo; Han, Linna; Li, Chunhui; Cao, Qi; Zhu, Duolong; Barrett, Nolan H.; Harmody, Dedra; Chen, Jing; Zhu, Haining; McCarthy, Peter J.; Sun, Xingmin; Wang, Guojun

2018-01-01

The global prevalence of drug resistance has created an urgent need for the discovery of novel anti-infective drugs. The major source of antibiotics in current clinical practice is terrestrial actinobacteria; the less-exploited deep-sea actinobacteria may serve as an unprecedented source of novel natural products. In this study, we evaluated 50 actinobacteria strains derived from diverse deep water sponges and environmental niches for their anti-microbial activities against a panel of pathogens including Candida albicans, Clostridium difficile, Staphylococcus aureus, and methicillin-resistant S. aureus (MRSA), and Pseudomonas aeruginosa. More than half of the tested strains (27) were identified as active in at least one assay. The rare earth salt lanthanum chloride (LaCl3) was shown to be as an effective elicitor. Among the 27 strains, the anti-microbial activity of 15 were induced or enhanced by the addition of LaCl3. This part of study focused on one strain R818, in which potent antifungal activity was induced by the addition of LaCl3. We found that the LaCl3-activated metabolites in R818 are likely antimycin-type compounds. One of them, compound 1, has been purified. Spectroscopic analyses including HR-MS and 1D NMR indicated that this compound is urauchimycin D. The antifungal activity of compound 1 was confirmed with a minimal inhibitory concentration (MIC) of 25 μg/mL; the purified compound also showed a moderate activity against C. difficile. Additional notable strains are: strain N217 which showed both antifungal and antibacterial (including P. aeruginosa) activities and strain M864 which showed potent activity against C. difficile with an MIC value (0.125 μg/mL) lower than those of vancomycin and metronidazole. Our preliminary studies show that deep-sea actinobacteria is a promising source of anti-infective natural products. PMID:29760684

Sialic Acid Catabolism Confers a Competitive Advantage to Pathogenic Vibrio cholerae in the Mouse Intestine▿

PubMed Central

Almagro-Moreno, Salvador; Boyd, E. Fidelma

2009-01-01

Sialic acids comprise a family of nine-carbon ketosugars that are ubiquitous on mammalian mucous membranes. However, sialic acids have a limited distribution among Bacteria and are confined mainly to pathogenic and commensal species. Vibrio pathogenicity island 2 (VPI-2), a 57-kb region found exclusively among pathogenic strains of Vibrio cholerae, contains a cluster of genes (nan-nag) putatively involved in the scavenging (nanH), transport (dctPQM), and catabolism (nanA, nanE, nanK, and nagA) of sialic acid. The capacity to utilize sialic acid as a carbon and energy source might confer an advantage to V. cholerae in the mucus-rich environment of the gut, where sialic acid availability is extensive. In this study, we show that V. cholerae can utilize sialic acid as a sole carbon source. We demonstrate that the genes involved in the utilization of sialic acid are located within the nan-nag region of VPI-2 by complementation of Escherichia coli mutants and gene knockouts in V. cholerae N16961. We show that nanH, dctP, nanA, and nanK are highly expressed in V. cholerae grown on sialic acid. By using the infant mouse model of infection, we show that V. cholerae ΔnanA strain SAM1776 is defective in early intestinal colonization stages. In addition, SAM1776 shows a decrease in the competitive index in colonization-competition assays comparing the mutant strain with both O1 El Tor and classical strains. Our data indicate an important relationship between the catabolism of sialic acid and bacterial pathogenesis, stressing the relevance of the utilization of the resources found in the host's environment. PMID:19564383

Sialic acid catabolism confers a competitive advantage to pathogenic vibrio cholerae in the mouse intestine.

PubMed

Almagro-Moreno, Salvador; Boyd, E Fidelma

2009-09-01

Sialic acids comprise a family of nine-carbon ketosugars that are ubiquitous on mammalian mucous membranes. However, sialic acids have a limited distribution among Bacteria and are confined mainly to pathogenic and commensal species. Vibrio pathogenicity island 2 (VPI-2), a 57-kb region found exclusively among pathogenic strains of Vibrio cholerae, contains a cluster of genes (nan-nag) putatively involved in the scavenging (nanH), transport (dctPQM), and catabolism (nanA, nanE, nanK, and nagA) of sialic acid. The capacity to utilize sialic acid as a carbon and energy source might confer an advantage to V. cholerae in the mucus-rich environment of the gut, where sialic acid availability is extensive. In this study, we show that V. cholerae can utilize sialic acid as a sole carbon source. We demonstrate that the genes involved in the utilization of sialic acid are located within the nan-nag region of VPI-2 by complementation of Escherichia coli mutants and gene knockouts in V. cholerae N16961. We show that nanH, dctP, nanA, and nanK are highly expressed in V. cholerae grown on sialic acid. By using the infant mouse model of infection, we show that V. cholerae DeltananA strain SAM1776 is defective in early intestinal colonization stages. In addition, SAM1776 shows a decrease in the competitive index in colonization-competition assays comparing the mutant strain with both O1 El Tor and classical strains. Our data indicate an important relationship between the catabolism of sialic acid and bacterial pathogenesis, stressing the relevance of the utilization of the resources found in the host's environment.

Advances in the Microbiome: Applications to Clostridium difficile Infection

PubMed Central

Culligan, Eamonn P.; Sleator, Roy D.

2016-01-01

Clostridium difficile is a major cause of morbidity and mortality worldwide, causing over 400,000 infections and approximately 29,000 deaths in the United States alone each year. C. difficile is the most common cause of nosocomial diarrhoea in the developed world, and, in recent years, the emergence of hyper-virulent (mainly ribotypes 027 and 078, sometimes characterised by increased toxin production), epidemic strains and an increase in the number of community-acquired infections has caused further concern. Antibiotic therapy with metronidazole, vancomycin or fidaxomicin is the primary treatment for C. difficile infection (CDI). However, CDI is unique, in that, antibiotic use is also a major risk factor for acquiring CDI or recurrent CDI due to disruption of the normal gut microbiota. Therefore, there is an urgent need for alternative, non-antibiotic therapeutics to treat or prevent CDI. Here, we review a number of such potential treatments which have emerged from advances in the field of microbiome research. PMID:27657145

Epidemiology, Diagnosis, and Management of Clostridium difficile Infection in Patients with Inflammatory Bowel Disease

PubMed Central

Rao, Krishna; Higgins, Peter D. R.

2016-01-01

Clostridium difficile infection (CDI) is a major source of morbidity and mortality for the US healthcare system, and frequently complicates the course of inflammatory bowel disease (IBD). Patients with IBD are more likely to be colonized with C. difficile and develop active infection than the general population. They are also more likely to have severe CDI and develop subsequent complications such as IBD flare, colectomy, or death. Even after successful initial treatment and recovery, recurrent CDI is common. Management of CDI in IBD is fraught with diagnostic and therapeutic challenges, since the clinical presentations of CDI and IBD flare have considerable overlap. Fecal microbiota transplantation can be successful in curing recurrent CDI when other treatments have failed, but may also trigger IBD flare and this warrants caution. New, experimental treatments including vaccines, monoclonal antibodies, and non-toxigenic strains of C. difficile offer promise but are not yet available for clinicians. A better understanding of the complex relationship between the gut microbiota, CDI, and IBD is needed. PMID:27120571

The agr Locus Regulates Virulence and Colonization Genes in Clostridium difficile 027

PubMed Central

Martin, Melissa J.; Clare, Simon; Goulding, David; Faulds-Pain, Alexandra; Barquist, Lars; Browne, Hilary P.; Pettit, Laura; Dougan, Gordon; Lawley, Trevor D.

2013-01-01

The transcriptional regulator AgrA, a member of the LytTR family of proteins, plays a key role in controlling gene expression in some Gram-positive pathogens, including Staphylococcus aureus and Enterococcus faecalis. AgrA is encoded by the agrACDB global regulatory locus, and orthologues are found within the genome of most Clostridium difficile isolates, including the epidemic lineage 027/BI/NAP1. Comparative RNA sequencing of the wild type and otherwise isogenic agrA null mutant derivatives of C. difficile R20291 revealed a network of approximately 75 differentially regulated transcripts at late exponential growth phase, including many genes associated with flagellar assembly and function, such as the major structural subunit, FliC. Other differentially regulated genes include several involved in bis-(3′-5′)-cyclic dimeric GMP (c-di-GMP) synthesis and toxin A expression. C. difficile 027 R20291 agrA mutant derivatives were poorly flagellated and exhibited reduced levels of colonization and relapses in the murine infection model. Thus, the agr locus likely plays a contributory role in the fitness and virulence potential of C. difficile strains in the 027/BI/NAP1 lineage. PMID:23772065

Adaptive Strategies and Pathogenesis of Clostridium difficile from In Vivo Transcriptomics

PubMed Central

Janoir, Claire; Denève, Cécile; Bouttier, Sylvie; Barbut, Frédéric; Hoys, Sandra; Caleechum, Laxmee; Chapetón-Montes, Diana; Pereira, Fátima C.; Henriques, Adriano O.; Collignon, Anne; Monot, Marc

2013-01-01

Clostridium difficile is currently the major cause of nosocomial intestinal diseases associated with antibiotic therapy in adults. In order to improve our knowledge of C. difficile-host interactions, we analyzed the genome-wide temporal expression of C. difficile 630 genes during the first 38 h of mouse colonization to identify genes whose expression is modulated in vivo, suggesting that they may play a role in facilitating the colonization process. In the ceca of the C. difficile-monoassociated mice, 549 genes of the C. difficile genome were differentially expressed compared to their expression during in vitro growth, and they were distributed in several functional categories. Overall, our results emphasize the roles of genes involved in host adaptation. Colonization results in a metabolic shift, with genes responsible for the fermentation as well as several other metabolic pathways being regulated inversely to those involved in carbon metabolism. In addition, several genes involved in stress responses, such as ferrous iron uptake or the response to oxidative stress, were regulated in vivo. Interestingly, many genes encoding conserved hypothetical proteins (CHP) were highly and specifically upregulated in vivo. Moreover, genes for all stages of sporulation were quickly induced in vivo, highlighting the observation that sporulation is central to the persistence of C. difficile in the gut and to its ability to spread in the environment. Finally, we inactivated two genes that were differentially expressed in vivo and evaluated the relative colonization fitness of the wild-type and mutant strains in coinfection experiments. We identified a CHP as a putative colonization factor, supporting the suggestion that the in vivo transcriptomic approach can unravel new C. difficile virulence genes. PMID:23897605

Prevalence of Clostridium difficile infection and colonization in a tertiary hospital and elderly community of North-Eastern Peninsular Malaysia.

PubMed

Zainul, N H; Ma, Z F; Besari, A; Siti Asma, H; Rahman, R A; Collins, D A; Hamid, N; Riley, T V; Lee, Y Y

2017-10-01

Little is known about Clostridium difficile infection (CDI) in Asia. The aims of our study were to explore (i) the prevalence, risk factors and molecular epidemiology of CDI and colonization in a tertiary academic hospital in North-Eastern Peninsular Malaysia; (ii) the rate of carriage of C. difficile among the elderly in the region; (iii) the awareness level of this infection among the hospital staffs and students. For stool samples collected from hospital inpatients with diarrhea (n = 76) and healthy community members (n = 138), C. difficile antigen and toxins were tested by enzyme immunoassay. Stool samples were subsequently analyzed by culture and molecular detection of toxin genes, and PCR ribotyping of isolates. To examine awareness among hospital staff and students, participants were asked to complete a self-administered questionnaire. For the hospital and community studies, the prevalence of non-toxigenic C. difficile colonization was 16% and 2%, respectively. The prevalence of CDI among hospital inpatients with diarrhea was 13%. Out of 22 C. difficile strains from hospital inpatients, the toxigenic ribotypes 043 and 017 were most common (both 14%). In univariate analysis, C. difficile colonization in hospital inpatients was significantly associated with greater duration of hospitalization and use of penicillin (both P < 0·05). Absence of these factors was a possible reason for low colonization in the community. Only 3% of 154 respondents answered all questions correctly in the awareness survey. C. difficile colonization is prevalent in a Malaysian hospital setting but not in the elderly community with little or no contact with hospitals. Awareness of CDI is alarmingly poor.

Pleiotropic roles of Clostridium difficile sin locus

PubMed Central

Ou, Junjun; Dupuy, Bruno

2018-01-01

Clostridium difficile is the primary cause of nosocomial diarrhea and pseudomembranous colitis. It produces dormant spores, which serve as an infectious vehicle responsible for transmission of the disease and persistence of the organism in the environment. In Bacillus subtilis, the sin locus coding SinR (113 aa) and SinI (57 aa) is responsible for sporulation inhibition. In B. subtilis, SinR mainly acts as a repressor of its target genes to control sporulation, biofilm formation, and autolysis. SinI is an inhibitor of SinR, so their interaction determines whether SinR can inhibit its target gene expression. The C. difficile genome carries two sinR homologs in the operon that we named sinR and sinR’, coding for SinR (112 aa) and SinR’ (105 aa), respectively. In this study, we constructed and characterized sin locus mutants in two different C. difficile strains R20291 and JIR8094, to decipher the locus’s role in C. difficile physiology. Transcriptome analysis of the sinRR’ mutants revealed their pleiotropic roles in controlling several pathways including sporulation, toxin production, and motility in C. difficile. Through various genetic and biochemical experiments, we have shown that SinR can regulate transcription of key regulators in these pathways, which includes sigD, spo0A, and codY. We have found that SinR’ acts as an antagonist to SinR by blocking its repressor activity. Using a hamster model, we have also demonstrated that the sin locus is needed for successful C. difficile infection. This study reveals the sin locus as a central link that connects the gene regulatory networks of sporulation, toxin production, and motility; three key pathways that are important for C. difficile pathogenesis. PMID:29529083

Genomic survey of Clostridium difficile reservoirs in the East of England implicates environmental contamination of wastewater treatment plants by clinical lineages.

PubMed

Moradigaravand, Danesh; Gouliouris, Theodore; Ludden, Catherine; Reuter, Sandra; Jamrozy, Dorota; Blane, Beth; Naydenova, Plamena; Judge, Kim; H Aliyu, Sani; F Hadjirin, Nazreen; A Holmes, Mark; Török, Estée; M Brown, Nicholas; Parkhill, Julian; Peacock, Sharon

2018-03-02

There is growing evidence that patients with Clostridiumdifficile-associated diarrhoea often acquire their infecting strain before hospital admission. Wastewater is known to be a potential source of surface water that is contaminated with C. difficile spores. Here, we describe a study that used genome sequencing to compare C. difficile isolated from multiple wastewater treatment plants across the East of England and from patients with clinical disease at a major hospital in the same region. We confirmed that C. difficile from 65 patients were highly diverse and that most cases were not linked to other active cases in the hospital. In total, 186 C. difficile isolates were isolated from effluent water obtained from 18 municipal treatment plants at the point of release into the environment. Whole genome comparisons of clinical and environmental isolates demonstrated highly related populations, and confirmed extensive release of toxigenic C. difficile into surface waters. An analysis based on multilocus sequence types (STs) identified 19 distinct STs in the clinical collection and 38 STs in the wastewater collection, with 13 of 44 STs common to both clinical and wastewater collections. Furthermore, we identified five pairs of highly similar isolates (≤2 SNPs different in the core genome) in clinical and wastewater collections. Strategies to control community acquisition should consider the need for bacterial control of treated wastewater.

Genomic survey of Clostridium difficile reservoirs in the East of England implicates environmental contamination of wastewater treatment plants by clinical lineages

PubMed Central

Moradigaravand, Danesh; Gouliouris, Theodore; Ludden, Catherine; Reuter, Sandra; Jamrozy, Dorota; Blane, Beth; Naydenova, Plamena; Judge, Kim; H. Aliyu, Sani; F. Hadjirin, Nazreen; A. Holmes, Mark; Török, Estée; M. Brown, Nicholas; Parkhill, Julian; Peacock, Sharon

2018-01-01

There is growing evidence that patients with Clostridiumdifficile-associated diarrhoea often acquire their infecting strain before hospital admission. Wastewater is known to be a potential source of surface water that is contaminated with C. difficile spores. Here, we describe a study that used genome sequencing to compare C. difficile isolated from multiple wastewater treatment plants across the East of England and from patients with clinical disease at a major hospital in the same region. We confirmed that C. difficile from 65 patients were highly diverse and that most cases were not linked to other active cases in the hospital. In total, 186 C. difficile isolates were isolated from effluent water obtained from 18 municipal treatment plants at the point of release into the environment. Whole genome comparisons of clinical and environmental isolates demonstrated highly related populations, and confirmed extensive release of toxigenic C. difficile into surface waters. An analysis based on multilocus sequence types (STs) identified 19 distinct STs in the clinical collection and 38 STs in the wastewater collection, with 13 of 44 STs common to both clinical and wastewater collections. Furthermore, we identified five pairs of highly similar isolates (≤2 SNPs different in the core genome) in clinical and wastewater collections. Strategies to control community acquisition should consider the need for bacterial control of treated wastewater. PMID:29498619

Effects of natural products on several stages of the spore cycle of Clostridium difficile in vitro.

PubMed

Roshan, Niloufar; Riley, Thomas V; Hammer, Katherine A

2018-04-19

To investigate the effect of natural products on the spore cycle of C. difficile in vitro. Twenty-two natural products were investigated using four C. difficile strains. Effects on sporulation, determined using microscopy and a conventional spore recovery assay, showed that fresh onion bulb extract (6.3% v v -1 ) and coconut oil (8% v v -1 ) inhibited sporulation in all four isolates by 66-86% and 51-88%, respectively, compared to untreated controls. Fresh ginger rhizome extract (25% v v -1 ) was also inhibitory, although to a lesser extent. Using a standard spore germination and outgrowth assay, germination was unaffected by the 22 products, whereas outgrowth was significantly reduced by artichoke extract (18.8 mg ml -1 ), fresh onion bulb extract (25% v v -1 ), Leptospermum honeys (8% w v -1 ) and allicin (75 mg ml -1 ) (P < 0.01). Sporicidal activity, investigated using a standard plate recovery assay, was minimal. Three of the 22 natural products (13%) showed inhibitory effects on sporulation of C. difficile and six products (27%) reduced vegetative outgrowth of C. difficile. This study shows the potential of natural products to inhibit different stages of C. difficile sporulation and encourages further investigation in this field. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Clostridium difficile: Investigating Transmission Patterns between Infected and Colonized Patients using whole Genome Sequencing.

PubMed

Kong, L Y; Eyre, D W; Corbeil, J; Raymond, F; Walker, A S; Wilcox, M H; Crook, D W; Michaud, S; Toye, B; Frost, E; Dendukuri, N; Schiller, I; Bourgault, A M; Dascal, A; Oughton, M; Longtin, Y; Poirier, L; Brassard, P; Turgeon, N; Gilca, R; Loo, V G

2018-05-28

Whole genome sequencing (WGS) studies can enhance our understanding of the role of patients with asymptomatic Clostridium difficile colonization in transmission. Isolates obtained from patients with Clostridium difficile infection (CDI) and colonization identified in a study conducted during 2006 - 2007 at six Canadian hospitals underwent typing by pulsed-field gel electrophoresis, multilocus sequence typing, and WGS. Isolates from incident CDI cases not in the initial study were also sequenced where possible. Ward movement and typing data were combined to identify plausible donors for each CDI case, as defined by shared time and space within predefined limits. Proportions of plausible donors for CDI cases that were colonized, infected, or both were examined. Five hundred and fifty-four isolates were sequenced successfully, 353 from colonized and 201 from CDI cases. The NAP1/027/ST1 strain was the most common strain, found in 124 (62%) of infected and 92 (26%) of colonized patients. A donor with a plausible ward link was found for 81 CDI cases (40%) using WGS with a threshold of ≤2 single nucleotide variants to determine relatedness. Sixty-five (32%) CDI cases could be linked to both infected and colonized donors. Exclusive linkages to infected and colonized donors were found for 28 (14%) and 12 (6%) CDI cases, respectively. Colonized patients contribute to transmission, but CDI cases are more likely linked to other infected patients than colonized patients in this cohort with high rates of NAP1/027/ST1 strain, highlighting the importance of local prevalence of virulent strains in determining transmission dynamics.

In vitro and in vivo antagonistic activity of new probiotic culture against Clostridium difficile and Clostridium perfringens.

PubMed

Golić, Nataša; Veljović, Katarina; Popović, Nikola; Djokić, Jelena; Strahinić, Ivana; Mrvaljević, Igor; Terzić-Vidojević, Amarela

2017-05-06

Genus Clostridium accompanies more than 200 known species and at least 30 among them are associated with human and animal diseases. At the moment, the treatment of clostridial infections is based on use of antibiotics. However, due to the European ban on the use of antibiotics in livestock production, novel therapeutic strategies for treatment of these hardly curable infections have been evaluated. Hence, in this study the antimicrobial effect of newly designed probiotic culture consisted of natural isolates Lactobacillus helveticus BGRA43, Lactobacillus fermentum BGHI14 and Streptococcus thermophilus BGVLJ1-44 against Clostridium difficile and Clostridium perfringens was analyzed. The probiotic culture showed strong in vitro antimicrobial effect on C. difficile (human clinical isolate). In addition, individual strains and the probiotic combination exhibited immunomodulatory activity. The probiotic combination significantly increased the proliferation of GALT lymphocytes. At the other hand, none of the bacterial treatments (individual strains and the combination) induced the production of proinflammatory cytokines IL-6 and IL-1β by intestinal epithelial cells, Caco-2. Interestingly, Caco-2 cells exposed to the probiotic combination produced significantly elevated amount of TGFβ pointing to potential protecting effect of the probiotic. In addition, the results of field trial on spontaneously infected goats revealed reduction of C. perfringens in goats (below the detection threshold) after the probiotic treatment. The results of this study indicated that the novel probiotic deserves to be further investigated as a promising antimicrobial agent against C. difficile and C. perfringens.

[The study of assessing methods for velopharyngeal function in patients with operated cleft palate

PubMed

Zhang, Z Y; Yuan, W H; Xia, J; Liu, H

1994-03-01

This paper describes the study and quantitative analysis of velopharyngeal function in 103 patients with operated cleft palate using NPF,vedio-camera system and computer.The percentange of semi-circluar and circular closure patterns after surgery was distinct higher in VPI group than in VPC group,but coronary closure pattern was significant lower in VPI group than in VPC group(P<0.05).We compared the results of different operative age by VPI after surgery.The results showed that postoperative RVPI was in direct proportion to operated age.VPI in the group less than 3 years of age.VPI in the group less than 3 years of age was 28.57%,but in the group of over 7 years of age was 96.43%.Both showed significant difference(P<0.01).

Prevalence and risk factors for colonization by Clostridium difficile and extended-spectrum β-lactamase-producing Enterobacteriaceae in rehabilitation clinics in Germany.

PubMed

Arvand, M; Ruscher, C; Bettge-Weller, G; Goltz, M; Pfeifer, Y

2018-01-01

Rehabilitation clinics may vary widely in terms of type of care provided, duration of hospital stay, and case severity. Few data are available on prevalence of Clostridium difficile or extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) colonization in rehabilitation clinics in Germany. This study investigated the frequency of intestinal colonization by these pathogens among patients in rehabilitation clinics of different specialization. In the scope of a point prevalence study, faecal samples and demographic and clinical data were collected in five rehabilitation clinics. Samples were screened for C. difficile and ESBL-E by culture. Isolates were characterized by polymerase chain reaction for C. difficile toxins A and B, for β-lactamase genes, and by molecular typing including pulsed-field gel electrophoresis and PCR-based ribotyping. Of 305 patients screened, 11.1% were colonized by toxigenic C. difficile and 7.5% by ESBL-E. Colonization rates differed markedly between facilities, ranging from 1.6% to 26.3% for C. difficile and from zero to 23.7% for ESBL-E. Prevalence of colonization by C. difficile and ESBL-E was higher in neurological rehabilitation clinics than in clinics with other specialties (P<0.001). Molecular typing revealed six patients from one neurological rehabilitation clinic harbouring a unique C. difficile strain (ribotype 017). CTX-M-15 was the most prevalent ESBL type. We detected several indistinguishable pairs of ESBL-E isolates within some facilities. Significant differences were found in the prevalence of C. difficile and ESBL-E between rehabilitation clinics. Facilities providing specialized medical care for critically ill patients had higher prevalence rates. These results may help to delineate the requirements for infection prevention and control in rehabilitation clinics. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Modification and Evaluation of a Velopharyngeal Insufficiency Quality of Life Instrument

PubMed Central

Skirko, Jonathan R.; Weaver, Edward M; Perkins, Jonathan; Kinter, Sara; Sie, Kathleen C.Y.

2018-01-01

Objective Modify the existing 45-item velopharyngeal insufficiency (VPI) quality of life (QOL) instrument (VPIQL), assess the modified instrument for reliability and provide further validation. There are patient and parent versions of the instrument. Design Validation convenience sample from a previously conducted pilot study. Setting Two academic tertiary referral medical centers. Participants De-identified data were used from 29 subjects with VPI and 29 control subjects age 5–17 years, and parents. Outcome measures Subjects and parents completed VPIQL and a generic pediatric QOL instrument (PedsQL4-0). Data Analysis Twenty-two items were removed from the VPIQL for ceiling effects, floor effects, and redundancy, to produce the modified instrument, VPI Effects on Life Outcomes (VELO) instrument. VELO was tested for internal consistency (Chronbach’s alpha), discriminant validity (paired t-test with control subjects), and concurrent validity (Pearson correlation with the PedsQL4-0). These analyses were also completed for parents. Results The 45-item VPIQL instrument was reduced to the 23-item VELO instrument. The VELO had excellent internal consistency (Chronbach’s alpha 0.96 for parents and 0.95 for VPI subjects). The VELO discriminated well between VPI and control subjects, with mean score (SD) was significantly lower (worse) for VPI subjects (67.6 [23.9]) than for control subjects (97.0 [5.2]) (p<0.0001). The VELO total score was significantly correlated with the PedsQL4.0 (r=0.73) among subjects with VPI. Similar results were seen in parent responses. Conclusions The VELO is a 23-item QOL instrument that was designed to measure and follow QOL in subjects with VPI, with less burden than the original VPIQL. VELO demonstrates internal consistency, disciminant validty, and concurrent validity with the PedsQL4-0. PMID:23069823

Surgical Outcomes for Speech Surgery in 22q11.2 Deletion Syndrome: The Dilemma of Persistent Velopharyngeal Insufficiency After Pharyngeal Flap Operation.

PubMed

Wagner, Ryan D; Wolfswinkel, Erik M; Buchanan, Edward P; Khechoyan, David Y

2017-07-01

The majority of patients with 22q11.2 deletion syndrome suffer from velopharyngeal insufficiency (VPI). Patients with 22q11.2 deletion syndrome (22qDS) commonly present with a large central velopharyngeal gap in the setting of poor velar and pharyngeal wall motion. The posterior pharyngeal flap is considered the most effective technique to treat VPI in this complex patient group. This study aims to critically evaluate success rates of surgical management of VPI in 22qDS patients and discuss options for management of a failed posterior pharyngeal flap (PPF) with persistent VPI. A systematic review was performed through MEDLINE and Scopus to examine the outcomes of PPF surgery to treat VPI in patients with 22qDS. Complications were defined as persistent VPI, hyponasal speech, and obstructive sleep apnea. To demonstrate an approach to management, the authors outline a recent patient with a failed PPF in this patient population at the authors' institution. The authors comprehensively reviewed 58 articles, 13 of which contained relevant information with extractable data. Of the 159 patients with 22qDS who underwent PPF to treat VPI, successful outcomes were reported in 135 patients (80%; range: 0%-100%). Complications were reported in 14% of patients, with need for revision operations in 3%. Surgical management of VPI in patients with 22qDS is challenging, with variable success rates reported in the literature. If unsuccessful, the surgeon faces additional challenges with the revision surgery including a scarred PPF donor site, distorted palatal recipient site, and further medialization of internal carotid arteries. Surgical revision of a failed PPF requires meticulous preoperative planning and technical execution.

Rifaximin disc diffusion test for in vitro susceptibility testing of Clostridium difficile

PubMed Central

Huhulescu, Steliana; Sagel, Ulrich; Fiedler, Anita; Pecavar, Verena; Blaschitz, Marion; Wewalka, Guenther; Allerberger, Franz

2011-01-01

Rifaximin is a rifampicin derivative, poorly absorbed by the gastro-intestinal tract. We studied the in vitro susceptibility to rifamixin of 1082 Clostridium difficile isolates; among these,184 isolates from a strain collection were tested by an in-house rifaximin disc (40 µg) diffusion test, by an in-house rifaximin broth microdilution test, by rifampicin Etest and by rpoB gene sequencing. In the absence of respective CLSI or EUCAST MIC breakpoints for rifaximin and rifampicin against C. difficile we chose MIC ≥32 µg ml−1 as criterion for reduced in vitro susceptibility. To further validate the disc diffusion test 898 consecutive clinical isolates were analysed using the disc diffusion test, the Etest and rpoB gene sequence analysis for all resistant strains. Rifaximin broth microdilution tests of the 184 reference strains yielded rifaximin MICs ranging from 0.001 (n = 1) to ≥1024 µg ml−1 (n = 61); 62 isolates showed a reduced susceptibility (MIC ≥32 µg ml−1). All of these 62 strains showed rpoB gene mutations producing amino acid substitutions; the rifampicin- and rifaximin-susceptible strains showed either a wild-type sequence or silent amino acid substitutions (19 strains). For 11 arbitrarily chosen isolates with rifaximin MICs of >1024 µg ml−1, rifaximin end-point MICs were determined by broth dilution: 4096 µg ml−1 (n = 2), 8192 µg ml−1 (n = 6), 16 384 µg ml−1 (n = 2) and 32 678 µg ml−1 (n = 1). Rifampicin Etests on the 184 C. difficile reference strains yielded MICs ranging from ≤0.002 (n = 117) to ≥32 µg ml−1 (n = 59). Using a 38 mm inhibition zone as breakpoint for reduced susceptibility the use of rifaximin disc diffusion yielded 59 results correlating with those obtained by use of rifaximin broth microdilution in 98.4 % of the 184 strains tested. Rifampicin Etests performed on the 898 clinical isolates revealed that 67 isolates had MICs of ≥32 µg ml−1. There were no discordant results observed among these isolates with reduced susceptibility using an MIC of ≥32 µg ml−1 as breakpoint for reduced rifampicin susceptibility and a <38 mm inhibition zone as breakpoint for reduced rifaximin susceptibility. The prevalence of reduced susceptibility was 7.5 % for all isolates tested. However, for PCR ribotype 027 the prevalence of reduced susceptibility was 26 %. Susceptibility testing in the microbiology laboratory therefore could have an impact on the care and outcome of patients with infection. Our results show that rifaximin – despite its water-insolubility – may be a suitable candidate for disc diffusion testing. PMID:21292853

Vascular endothelial growth factor inhibitor-induced hypertension: from pathophysiology to prevention and treatment based on long-acting nitric oxide donors.

PubMed

Kruzliak, Peter; Novák, Jan; Novák, Miroslav

2014-01-01

Hypertension is the most common adverse effect of the inhibitors of vascular endothelial growth factor (VEGF) pathway-based therapy (VEGF pathway inhibitors therapy, VPI therapy) in cancer patients. VPI includes monoclonal antibodies against VEGF, tyrosine kinase inhibitors, VEGF Traps, and so-called aptamers that may become clinically relevant in the future. All of these substances inhibit the VEGF pathway, which in turn causes a decrease in nitric oxide (NO) and an increase in blood pressure, with the consequent development of hypertension and its final events (e.g., myocardial infarction or stroke). To our knowledge, there is no current study on how to provide an optimal therapy for patients on VPI therapy with hypertension. This review summarizes the roles of VEGF and NO in vessel biology, provides an overview of VPI agents, and suggests a potential treatment procedure for patients with VPI-induced hypertension.

Activity of OPT-80, a novel macrocycle, compared with those of eight other agents against selected anaerobic species.

PubMed

Credito, Kim L; Appelbaum, Peter C

2004-11-01

Agar dilution MIC was used to compare activities of OPT-80, linezolid, vancomycin, teicoplanin, quinupristin/dalfopristin, amoxicillin/clavulanate, imipenem, clindamycin, and metronidazole against 350 gram-positive and -negative anaerobes. OPT-80 was active against gram-positive strains only, especially Clostridium spp. (85 strains tested, including 21 strains of C. difficile), with MICs ranging between

Probiotics in Clostridium difficile infection: reviewing the need for a multistrain probiotic.

PubMed

Hell, M; Bernhofer, C; Stalzer, P; Kern, J M; Claassen, E

2013-03-01

In the past two years an enormous amount of molecular, genetic, metabolomic and mechanistic data on the host-bacterium interaction, a healthy gut microbiota and a possible role for probiotics in Clostridium difficile infection (CDI) has been accumulated. Also, new hypervirulent strains of C. difficile have emerged. Yet, clinical trials in CDI have been less promising than in antibiotic associated diarrhoea in general, with more meta-analysis than primary papers on CDI-clinical-trials. The fact that C. difficile is a spore former, producing at least three different toxins has not yet been incorporated in the rational design of probiotics for (recurrent) CDI. Here we postulate that the plethora of effects of C. difficile and the vast amount of data on the role of commensal gut residents and probiotics point towards a multistrain mixture of probiotics to reduce CDI, but also to limit (nosocomial) transmission and/or endogenous reinfection. On the basis of a retrospective chart review of a series of ten CDI patients where recurrence was expected, all patients on adjunctive probiotic therapy with multistrain cocktail (Ecologic®AAD/OMNiBiOTiC® 10) showed complete clinical resolution. This result, and recent success in faecal transplants in CDI treatment, are supportive for the rational design of multistrain probiotics for CDI.

Efficacy of an Optimised Bacteriophage Cocktail to Clear Clostridium difficile in a Batch Fermentation Model

PubMed Central

Nale, Janet Y.; Redgwell, Tamsin A.; Millard, Andrew; Clokie, Martha R. J.

2018-01-01

Clostridium difficile infection (CDI) is a major cause of infectious diarrhea. Conventional antibiotics are not universally effective for all ribotypes, and can trigger dysbiosis, resistance and recurrent infection. Thus, novel therapeutics are needed to replace and/or supplement the current antibiotics. Here, we describe the activity of an optimised 4-phage cocktail to clear cultures of a clinical ribotype 014/020 strain in fermentation vessels spiked with combined fecal slurries from four healthy volunteers. After 5 h, we observed ~6-log reductions in C. difficile abundance in the prophylaxis regimen and complete C. difficile eradication after 24 h following prophylactic or remedial regimens. Viability assays revealed that commensal enterococci, bifidobacteria, lactobacilli, total anaerobes, and enterobacteria were not affected by either regimens, but a ~2-log increase in the enterobacteria, lactobacilli, and total anaerobe abundance was seen in the phage-only-treated vessel compared to other treatments. The impact of the phage treatments on components of the microbiota was further assayed using metagenomic analysis. Together, our data supports the therapeutic application of our optimised phage cocktail to treat CDI. Also, the increase in specific commensals observed in the phage-treated control could prevent further colonisation of C. difficile, and thus provide protection from infection being able to establish. PMID:29438355

Correlation of [RuCl3(dppb)(VPy)] cytotoxicity with its effects on the cell membranes: an investigation using Langmuir monolayers as membrane models.

PubMed

Sandrino, B; Tominaga, T T; Nobre, T M; Scorsin, L; Wrobel, E C; Fiorin, B C; de Araujo, M P; Caseli, L; Oliveira, O N; Wohnrath, K

2014-09-11

One of the major challenges in drug design is to identify compounds with potential toxicity toward target cells, preferably with molecular-level understanding of their mode of action. In this study, the antitumor property of a ruthenium complex, mer-[RuCl3(dppb)(VPy)] (dppb = 1,4-bis(diphenylphosphine)butane and VPy = 4-vinylpyridine) (RuVPy), was analyzed. Results showed that this compound led to a mortality rate of 50% of HEp-2 cell with 120 ± 10 μmol L(-1), indicating its high toxicity. Then, to prove if its mode of action is associated with its interaction with cell membranes, Langmuir monolayers were used as a membrane model. RuVPy had a strong effect on the surface pressure isotherms, especially on the elastic properties of both the zwitterionic dipalmitoylphosphatidylcholine (DPPC) and the negatively charged dipalmitoylphosphatidylglycerol (DPPG) phospholipids. These data were confirmed by polarization-modulated infrared reflection-absorption spectroscopy (PM-IRRAS). In addition, interactions between the positive group from RuVPy and the phosphate group from the phospholipids were corroborated by density functional theory (DFT) calculations, allowing the determination of the Ru complex orientation at the air-water interface. Although possible contributions from receptors or other cell components cannot be discarded, the results reported here represent evidence for significant effects on the cell membranes which are probably associated with the high toxicity of RuVPy.

Impact of the NAP-1 strain on disease severity, mortality, and recurrence of healthcare-associated Clostridium difficile infection.

PubMed

Bauer, Karri A; Johnston, Jessica E W; Wenzler, Eric; Goff, Debra A; Cook, Charles H; Balada-Llasat, Joan-Miquel; Pancholi, Preeti; Mangino, Julie E

2017-12-01

Studies are conflicting regarding the association of the North American pulsed-field gel electrophoresis type 1 (NAP1) strain in Clostridium difficile infection (CDI) and outcomes. We evaluated the association of NAP1 with healthcare-associated CDI disease severity, mortality, and recurrence at our academic medical center. Healthcare-associated CDI cases were identified from November 1, 2011 through January 31, 2013. Multivariable regression models were used to evaluate the associations of NAP1 with severe disease (based on the Hines VA severity score index), mortality, and recurrence. Among 5424 stool specimens submitted to the Clinical Microbiology Laboratory, 292 (5.4%) were positive for C. difficile by polymerase chain reaction (PCR) on or after hospital day 4; 70 (24%) of these specimens also tested positive for NAP1. During the study period, 247 (85%) patients had non-severe disease and 45 (15%) patients had severe disease. Among patients with non-severe disease, 65 (26%) had NAP1 and among patients with severe disease, 5 (11%) had NAP1. After controlling for potential confounders, NAP1 was not associated with an increased likelihood of severe disease (adjusted odds ratio [aOR] = 0.35; 95% confidence interval [CI], 0.13-0.93), in-hospital mortality (aOR = 1.02; 95% CI, 0.53-1.96), or recurrence (aOR = 1.16, 95% CI, 0.36-3.77). The NAP1 strain did not increase disease severity, mortality, or recurrence in this study, although the incidence of NAP1-positive healthcare associated-CDI was low. The role of strain typing in outcomes and treatment selection in patients with healthcare-associated CDI remains uncertain. Copyright © 2017 Elsevier Ltd. All rights reserved.

Epidemiology of Clostridium difficile-associated disease at University Hospital Basel including molecular characterisation of the isolates 2006-2007.

PubMed

Fenner, L; Frei, R; Gregory, M; Dangel, M; Stranden, A; Widmer, A F

2008-12-01

A prospective study was conducted during a one-year period between 2006 and 2007 to describe the epidemiology of Clostridium difficile-associated disease (CDAD) at University Hospital Basel, Switzerland (UHBS) and to determine phenotypic and genotypic features of C. difficile strains isolated at the Microbiology Laboratory UHBS including strains from regional non-university hospitals. We prospectively identified 78 CDAD cases at UHBS with an incidence of 2.65/1,000 hospitalised patients or 2.3/10,000 patient-days. Sixteen patients (20.5%) were infected with clindamycin-resistant strains of PCR-ribotype 027 during an outbreak at the geriatric hospital. Among 124 single-patient isolates, 28 (22.6%) were resistant to moxifloxacin and 34 (27.4%) were resistant to clindamycin, but all remained susceptible to metronidazole and vancomycin. Of 102 toxigenic isolates, 19 (18.7%) had an 18-bp deletion in the tcdC gene, eight (7.8%) a 39-bp deletion, and one (1.0%) a 54-bp deletion. Genes for binary toxin were present in 27 (21.8%). PCR-ribotype 027 was associated with older age (median age 83.5 vs. 65.5 years, p < 0.0001) and longer duration of hospitalisation before onset of disease (median 15.5 vs. 9 days, p = 0.014) with a trend towards higher crude mortality, more severe disease, and previous use of macrolides compared to ribotype non-027. Overall, severe disease correlated with use of a nasogastric tube and surprisingly shorter duration of hospitalisation before onset of disease. Today, laboratory-based and epidemiological surveillance systems are required to monitor CDAD cases and emergence of new epidemic strains.

Tracking gene expression and oxidative damage of O2-stressed Clostridioides difficile by a multi-omics approach.

PubMed

Neumann-Schaal, Meina; Metzendorf, Nicole G; Troitzsch, Daniel; Nuss, Aaron Mischa; Hofmann, Julia Danielle; Beckstette, Michael; Dersch, Petra; Otto, Andreas; Sievers, Susanne

2018-05-31

Clostridioides difficile is the major pathogen causing diarrhea following antibiotic treatment. It is considered to be a strictly anaerobic bacterium, however, previous studies have shown a certain and strain-dependent oxygen tolerance. In this study, the model strain C. difficile 630Δerm was shifted to micro-aerobiosis and was found to stay growing to the same extent as anaerobically growing cells with only few changes in the metabolite pattern. However, an extensive change in gene expression was determined by RNA-Seq. The most striking adaptation strategies involve a change in the reductive fermentation pathways of the amino acids proline, glycine and leucine. But also a far-reaching restructuring in the carbohydrate metabolism was detected with changes in the phosphotransferase system (PTS) facilitated uptake of sugars and a repression of enzymes of glycolysis and butyrate fermentation. Furthermore, a temporary induction in the synthesis of cofactor riboflavin was detected possibly due to an increased demand for flavin mononucleotid (FMN) and flavin adenine dinucleotide (FAD) in redox reactions. However, biosynthesis of the cofactors thiamin pyrophosphate and cobalamin were repressed deducing oxidation-prone enzymes and intermediates in these pathways. Micro-aerobically shocked cells were characterized by an increased demand for cysteine and a thiol redox proteomics approach revealed a dramatic increase in the oxidative state of cysteine in more than 800 peptides after 15 min of micro-aerobic shock. This provides not only a catalogue of oxidation-prone cysteine residues in the C. difficile proteome but also puts the amino acid cysteine into a key position in the oxidative stress response. Our study suggests that tolerance of C. difficile towards O 2 is based on a complex and far-reaching adjustment of global gene expression which leads to only a slight change in phenotype. Copyright © 2018. Published by Elsevier Ltd.

Clostridium difficile colonization and disease in patients undergoing hematopoietic stem cell transplantation.

PubMed

Bruminhent, Jackrapong; Wang, Zi-Xuan; Hu, Carol; Wagner, John; Sunday, Richard; Bobik, Brent; Hegarty, Sarah; Keith, Scott; Alpdogan, Seyfettin; Carabasi, Matthew; Filicko-O'Hara, Joanne; Flomenberg, Neal; Kasner, Margaret; Outschoorn, Ubaldo Martinez; Weiss, Mark; Flomenberg, Phyllis

2014-09-01

There was an increase in the Clostridium difficile infection (CDI) rate in our bone marrow transplantation unit. To evaluate the role of unit-based transmission, C. difficile screening was performed on adult patients admitted for hematopoietic stem cell transplantation (HSCT) over a 2-year period, and C. difficile isolates were typed. C. difficile testing was performed using a 2-step C. difficile glutamate dehydrogenase antigen plus toxin A/B enzyme immunoassay (EIA) and cytotoxin assay (or molecular toxin assay). Multilocus sequence typing (MLST) was performed on toxin-positive whole stool samples. A retrospective chart review was performed on all patients with a positive toxin assay. Sixteen of 150 patients (10.7%) had toxigenic C. difficile colonization (CDC) on admission. The overall incidence of CDI within 100 days after HSCT was 24.7% (37 of 150). The median time to diagnosis of CDI was 3.5 days after HSCT. In an adjusted logistic regression model, CDC on admission was a significant risk factor for CDI (odds ratio, 68.5; 95% confidence interval, 11.4 to 416.2). MLST on 22 unit patient toxin-positive stool specimens revealed 15 distinct strain types. Further analysis identified at least 1 potential cross-transmission event; some events may have been missed because of incomplete typing from other specimens. Despite aggressive infection control interventions, there was no decline in the number of CDI cases during the study period. These data suggest that prior CDC plays a major role in CDI rates in this high-risk patient population. It remains unclear if CDI was cross-transmitted in the unit. Copyright © 2014 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Defining and Evaluating a Core Genome Multilocus Sequence Typing Scheme for Genome-Wide Typing of Clostridium difficile.

PubMed

Bletz, Stefan; Janezic, Sandra; Harmsen, Dag; Rupnik, Maja; Mellmann, Alexander

2018-06-01

Clostridium difficile , recently renamed Clostridioides difficile , is the most common cause of antibiotic-associated nosocomial gastrointestinal infections worldwide. To differentiate endogenous infections and transmission events, highly discriminatory subtyping is necessary. Today, methods based on whole-genome sequencing data are increasingly used to subtype bacterial pathogens; however, frequently a standardized methodology and typing nomenclature are missing. Here we report a core genome multilocus sequence typing (cgMLST) approach developed for C. difficile Initially, we determined the breadth of the C. difficile population based on all available MLST sequence types with Bayesian inference (BAPS). The resulting BAPS partitions were used in combination with C. difficile clade information to select representative isolates that were subsequently used to define cgMLST target genes. Finally, we evaluated the novel cgMLST scheme with genomes from 3,025 isolates. BAPS grouping ( n = 6 groups) together with the clade information led to a total of 11 representative isolates that were included for cgMLST definition and resulted in 2,270 cgMLST genes that were present in all isolates. Overall, 2,184 to 2,268 cgMLST targets were detected in the genome sequences of 70 outbreak-associated and reference strains, and on average 99.3% cgMLST targets (1,116 to 2,270 targets) were present in 2,954 genomes downloaded from the NCBI database, underlining the representativeness of the cgMLST scheme. Moreover, reanalyzing different cluster scenarios with cgMLST were concordant to published single nucleotide variant analyses. In conclusion, the novel cgMLST is representative for the whole C. difficile population, is highly discriminatory in outbreak situations, and provides a unique nomenclature facilitating interlaboratory exchange. Copyright © 2018 American Society for Microbiology.

Effectiveness of liquid soap vs. chlorhexidine gluconate for the removal of Clostridium difficile from bare hands and gloved hands.

PubMed

Bettin, K; Clabots, C; Mathie, P; Willard, K; Gerding, D N

1994-11-01

To compare liquid soap versus 4% chlorhexidine gluconate in 4% alcohol for the decontamination of bare or gloved hands inoculated with an epidemic strain of Clostridium difficile. C difficile (6.7 log10 colony-forming units [CFU], 47% spores), was seeded onto bare or latex gloved hands of ten volunteers and allowed to dry. Half the volunteers initially washed with soap and half with chlorhexidine, followed by the other agent 1 week later. Cultures were done with Rodac plates at three sites on the hand: finger/thumbtips, the palmar surfaces of the fingers, and the palm. Statistical comparison was by paired Student's t test. On bare hands, soap and chlorhexidine did not differ in residual bacterial counts on the finger/thumbtips (log10 CFU, 2.0 and 2.1, P = NS) and fingers (log10 CFU, 2.4 and 2.5, P = NS). Counts were too high on bare palms to quantitate. On gloved hands, soap was more effective than chlorhexidine on fingers (log10 CFU 1.3 and 1.7, P < .01) and palms (log10 CFU 1.5 and 2.0, P < .01), but not finger/thumbtips (log10 CFU 1.6 with each, P = NS). Residual C difficile counts were lower on gloved hands than bare hands (P < 0.01 to < 0.0001). The two agents did not differ significantly in residual counts of C difficile on bare hands, but on gloved hands residual counts were lower following soap wash than following chlorhexidine wash. These observations support the use of either soap or chlorhexidine as a handwash for removal of C difficile, but efficacy in the prevention of C difficile transmission must be determined by prospective clinical trials.

Activity of OPT-80, a Novel Macrocycle, Compared with Those of Eight Other Agents against Selected Anaerobic Species

PubMed Central

Credito, Kim L.; Appelbaum, Peter C.

2004-01-01

Agar dilution MIC was used to compare activities of OPT-80, linezolid, vancomycin, teicoplanin, quinupristin/dalfopristin, amoxicillin/clavulanate, imipenem, clindamycin, and metronidazole against 350 gram-positive and -negative anaerobes. OPT-80 was active against gram-positive strains only, especially Clostridium spp. (85 strains tested, including 21 strains of C. difficile), with MICs ranging between ≤0.016 and 0.25 μg/ml. PMID:15504874

Information about the Current Strain of Clostridium difficile

MedlinePlus

... rubs may not be as effective against spore-forming bacteria. Contact precautions Environmental cleaning and disinfection strategies. ... Detection of VISA/VRSA S.E.A.R.C.H. Labs Role in the Search and Containment of ...

The Lateral Port Control Pharyngeal Flap: A Thirty-Year Evolution and Followup

PubMed Central

Boutros, Sean; Cutting, Court

2013-01-01

In 1971, Micheal Hogan introduced the Lateral Port Control Pharyngeal Flap (LPCPF) which obtained good results with elimination of VPI. However, there was a high incidence of hyponasality and OSA. We hypothesized that preoperative assessment with videofluoroscopy and nasal endoscopy would enable modification and customization of the LPCPF and result in improvement in the result in both hyponasality and obstructive apnea while still maintaining results in VPI. Thirty consecutive patients underwent customized LPCPF. All patients had preoperative diagnosis of VPI resulting from cleft palate. Patient underwent either videofluoroscopy or nasal endoscopy prior to the planning of surgery. Based on preoperative velar and pharyngeal movement, patients were assigned to wide, medium, or narrow port designs. Patients with significant lateral motion were given wide ports while patients with minimal movement were given narrow ports. There was a 96.66% success rate in the treatment of VPI with one patient with persistent VPI (3.33%). Six patients had mild hyponasality (20 %). Two patients had initial OSA (6.67%), one of which had OSA which lasted longer than six months (3.33%). The modifications of the original flap description have allowed for success in treatment of VPI along with an acceptably low rate of hyponasality and OSA. PMID:23365734

In vitro activities of ramoplanin, teicoplanin, vancomycin, linezolid, bacitracin, and four other antimicrobials against intestinal anaerobic bacteria.

PubMed

Citron, D M; Merriam, C V; Tyrrell, K L; Warren, Y A; Fernandez, H; Goldstein, E J C

2003-07-01

By using an agar dilution method, the in vitro activities of ramoplanin, teicoplanin, vancomycin, linezolid, and five other agents were determined against 300 gram-positive and 54 gram-negative strains of intestinal anaerobes. Ramoplanin was active at or=256 microg/ml. Ramoplanin displays excellent activity against C. difficile and other gram-positive enteric anaerobes, including vancomycin-resistant strains; however, it has poor activity against most gram-negative anaerobes and thus potentially has a lesser effect on the ecological balance of normal fecal flora.

Comparison of seven techniques for typing international epidemic strains of Clostridium difficile: restriction endonuclease analysis, pulsed-field gel electrophoresis, PCR-ribotyping, multilocus sequence typing, multilocus variable-number tandem-repeat analysis, amplified fragment length polymorphism, and surface layer protein A gene sequence typing.

PubMed

Killgore, George; Thompson, Angela; Johnson, Stuart; Brazier, Jon; Kuijper, Ed; Pepin, Jacques; Frost, Eric H; Savelkoul, Paul; Nicholson, Brad; van den Berg, Renate J; Kato, Haru; Sambol, Susan P; Zukowski, Walter; Woods, Christopher; Limbago, Brandi; Gerding, Dale N; McDonald, L Clifford

2008-02-01

Using 42 isolates contributed by laboratories in Canada, The Netherlands, the United Kingdom, and the United States, we compared the results of analyses done with seven Clostridium difficile typing techniques: multilocus variable-number tandem-repeat analysis (MLVA), amplified fragment length polymorphism (AFLP), surface layer protein A gene sequence typing (slpAST), PCR-ribotyping, restriction endonuclease analysis (REA), multilocus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE). We assessed the discriminating ability and typeability of each technique as well as the agreement among techniques in grouping isolates by allele profile A (AP-A) through AP-F, which are defined by toxinotype, the presence of the binary toxin gene, and deletion in the tcdC gene. We found that all isolates were typeable by all techniques and that discrimination index scores for the techniques tested ranged from 0.964 to 0.631 in the following order: MLVA, REA, PFGE, slpAST, PCR-ribotyping, MLST, and AFLP. All the techniques were able to distinguish the current epidemic strain of C. difficile (BI/027/NAP1) from other strains. All of the techniques showed multiple types for AP-A (toxinotype 0, binary toxin negative, and no tcdC gene deletion). REA, slpAST, MLST, and PCR-ribotyping all included AP-B (toxinotype III, binary toxin positive, and an 18-bp deletion in tcdC) in a single group that excluded other APs. PFGE, AFLP, and MLVA grouped two, one, and two different non-AP-B isolates, respectively, with their AP-B isolates. All techniques appear to be capable of detecting outbreak strains, but only REA and MLVA showed sufficient discrimination to distinguish strains from different outbreaks.

The cellular lipids of Romboutsia.

PubMed

Guan, Ziqiang; Chen, Lingli; Gerritsen, Jacoline; Smidt, Hauke; Goldfine, Howard

2016-09-01

We have examined the lipids of three isolates, Romboutsia lituseburensis, Romboutsia ilealis, and Romboutsia sp. strain FRIFI, of the newly described genus Romboutsia by two-dimensional thin-layer chromatography (2D-TLC) and by liquid chromatography/mass spectrometry (LC/MS). We have found three phospholipids, phosphatidylglycerol (PG), cardiolipin and phosphatidic acid in all three species. A fourth phospholipid, lysyl-PG, was found in R. lituseburensis and strain FRIFI. Polyprenyl-phosphates were identified in the lipid extracts of all three species. Three glycolipids, mono-, di- and tri-hexosyldiacylglycerol, were common to all three species. An additional glycolipid, tetrahexosyl-diacylglycerol was identified in strain FRIFI. Acylated trihexosyldiacylglycerol and acyl-tetrahexosydiacylglycerol were also found in R. ilealis and strain FRIFI. Remarkably, no alk-1-enyl ether lipids (plasmalogens) were present in Romboutsia as distinct from bacteria of the related genus Clostridium in which these ether lipids are common. We have compared the lipidome of Romboutsia with that recently described for Clostridium difficile, which has plasmalogens, no lysyl-PG, and no tetrahexosyl-diacylglycerol. According to 16S rRNA gene sequencing, Romboutsia spp. and C. difficile are closely related (>95% sequence identity). Copyright © 2016 Elsevier B.V. All rights reserved.

The Novel Phages phiCD5763 and phiCD2955 Represent Two Groups of Big Plasmidial Siphoviridae Phages of Clostridium difficile.

PubMed

Ramírez-Vargas, Gabriel; Goh, Shan; Rodríguez, César

2018-01-01

Until recently, Clostridium difficile phages were limited to Myoviruses and Siphoviruses of medium genome length (32-57 kb). Here we report the finding of phiCD5763, a Siphovirus with a large extrachromosomal circular genome (132.5 kb, 172 ORFs) and a large capsid (205.6 ± 25.6 nm in diameter) infecting MLST Clade 1 strains of C. difficile . Two subgroups of big phage genomes similar to phiCD5763 were identified in 32 NAP CR1 /RT012/ST-54 C. difficile isolates from Costa Rica and in whole genome sequences (WGS) of 41 C. difficile isolates of Clades 1, 2, 3, and 4 from Canada, USA, UK, Belgium, Iraq, and China. Through comparative genomics we discovered another putative big phage genome in a non-NAP CR1 isolate from Costa Rica, phiCD2955, which represents other big phage genomes found in 130 WGS of MLST Clade 1 and 2 isolates from Canada, USA, Hungary, France, Austria, and UK. phiCD2955 (131.6 kb, 172 ORFs) is related to a previously reported C. difficile phage genome, phiCD211/phiCDIF1296T. Detailed genome analyses of phiCD5763, phiCD2955, phiCD211/phiCDIF1296T, and seven other putative C. difficile big phage genome sequences of 131-136 kb reconstructed from publicly available WGS revealed a modular gene organization and high levels of sequence heterogeneity at several hotspots, suggesting that these genomes correspond to biological entities undergoing recombination. Compared to other C. difficile phages, these big phages have unique predicted terminase, capsid, portal, neck and tail proteins, receptor binding proteins (RBPs), recombinases, resolvases, primases, helicases, ligases, and hypothetical proteins. Moreover, their predicted gene load suggests a complex regulation of both phage and host functions. Overall, our results indicate that the prevalence of C. difficile big bacteriophages is more widespread than realized and open new avenues of research aiming to decipher how these viral elements influence the biology of this emerging pathogen.

Development and Optimization of a High-Throughput Assay To Measure Neutralizing Antibodies against Clostridium difficile Binary Toxin

PubMed Central

Xie, Jinfu; Horton, Melanie; Zorman, Julie; Antonello, Joseph M.; Zhang, Yuhua; Arnold, Beth A.; Secore, Susan; Xoconostle, Rachel; Miezeiewski, Matthew; Wang, Su; Price, Colleen E.; Thiriot, David; Goerke, Aaron; Gentile, Marie-Pierre; Skinner, Julie M.

2014-01-01

Clostridium difficile strains producing binary toxin, in addition to toxin A (TcdA) and toxin B (TcdB), have been associated with more severe disease and increased recurrence of C. difficile infection in recent outbreaks. Binary toxin comprises two subunits (CDTa and CDTb) and catalyzes the ADP-ribosylation of globular actin (G-actin), which leads to the depolymerization of filamentous actin (F-actin) filaments. A robust assay is highly desirable for detecting the cytotoxic effect of the toxin and the presence of neutralizing antibodies in animal and human sera to evaluate vaccine efficacy. We describe here the optimization, using design-of-experiment (DOE) methodology, of a high-throughput assay to measure the toxin potency and neutralizing antibodies (NAb) against binary toxin. Vero cells were chosen from a panel of cells screened for sensitivity and specificity. We have successfully optimized the CDTa-to-CDTb molar ratio, toxin concentration, cell-seeding density, and sera-toxin preincubation time in the NAb assay using DOE methodology. This assay is robust, produces linear results across serial dilutions of hyperimmune serum, and can be used to quantify neutralizing antibodies in sera from hamsters and monkeys immunized with C. difficile binary toxin-containing vaccines. The assay will be useful for C. difficile diagnosis, for epidemiology studies, and for selecting and optimizing vaccine candidates. PMID:24623624

Prognostic significance of visceral pleural invasion in the forthcoming (seventh) edition of TNM classification for lung cancer.

PubMed

Shim, Hyo Sup; Park, In Kyu; Lee, Chang Young; Chung, Kyung Young

2009-08-01

The next revision to the TNM classification for lung cancer (the seventh edition) is scheduled to be released in 2009. However, the definition of visceral pleural invasion (VPI), which is a non-size-based T2 descriptor, still lacks in detail, and its validation is not included. We analyzed 1046 cases of non-small cell lung cancer (NSCLC) with T1, T2, or T3 diseases from 1990 to 2005, and subclassified into p0-p3 according to the degrees of pleural invasion. Survival analyses were performed using Kaplan-Meier method. Then, all patients were subdivided into nine groups according to tumor size and pleural invasion, and we compared survival differences, primarily focusing on T2a and T2b diseases according to the seventh edition. There was no survival difference between patients with p1 and p2, thus we regarded p1 or p2 as VPI. There was survival difference between two groups, which are expected to be classified as T2b. The behavior of tumors larger than 5cm but 7cm or less with VPI was similar to T3 tumors. VPI is a poor prognostic factor of NSCLC, and the penetration through the elastic layer of the visceral pleura regardless of its exposure on the pleural surface (pl and p2) should be defined as VPI. This study also indicates that VPI influences T stage dependent on tumor size, and it can be suggested that tumors of larger than 5cm but 7cm or less with VPI should be upgraded to T3 stage.

New Class of Precision Antimicrobials Redefines Role of Clostridium difficile S-layer in Virulence and Viability

PubMed Central

Kirk, Joseph A.; Gebhart, Dana; Buckley, Anthony M.; Lok, Stephen; Scholl, Dean; Douce, Gillian R.; Govoni, Gregory R.; Fagan, Robert P.

2017-01-01

Avidocin-CDs are a new class of precision bactericidal agents that do not damage resident gut microbiota and are unlikely to promote the spread of antibiotic resistance. The precision killing properties result from the fusion of bacteriophage receptor binding proteins (RBPs) to a lethal contractile scaffold from an R-type bacteriocin. We recently described the prototypic Avidocin-CD, Av-CD291.2, that specifically kills C. difficile ribotype 027 strains and prevents colonization of mice. We have since selected two rare Av-CD291.2 resistant mutants of strain R20291 (RT027; S-layer cassette type-4, SCLT-4). These mutants have distinct point mutations in the slpA gene that result in an S-layer null phenotype. Reversion of the mutations to wild-type restored normal SLCT-4 S-layer formation and Av-CD291.2 sensitivity; however, complementation with other SCLT alleles did not restore Av-CD291.2 sensitivity despite restoring S-layer formation. Using newly identified phage RBPs, we constructed a panel of new Avidocin-CDs that kill C. difficile isolates in an SLCT-dependent manner, confirming the S-layer as the receptor in every case. In addition to bacteriophage adsorption, characterization of the S-layer null mutant also uncovered important roles for SlpA in sporulation, resistance to lysozyme and LL-37, and toxin production. Surprisingly, the S-layer-null mutant was found to persist in the hamster gut despite its completely attenuated virulence. Avidocin-CDs have significant therapeutic potential for the treatment and prevention of C. difficile Infection (CDI) given their exquisite specificity for the pathogen. Furthermore, the emergence of resistance forces mutants to trade virulence for continued viability and, therefore, greatly reduce their potential clinical impact. PMID:28878013

Diversity and Evolution in the Genome of Clostridium difficile

PubMed Central

Knight, Daniel R.; Elliott, Briony; Chang, Barbara J.; Perkins, Timothy T.

2015-01-01

SUMMARY Clostridium difficile infection (CDI) is the leading cause of antimicrobial and health care-associated diarrhea in humans, presenting a significant burden to global health care systems. In the last 2 decades, PCR- and sequence-based techniques, particularly whole-genome sequencing (WGS), have significantly furthered our knowledge of the genetic diversity, evolution, epidemiology, and pathogenicity of this once enigmatic pathogen. C. difficile is taxonomically distinct from many other well-known clostridia, with a diverse population structure comprising hundreds of strain types spread across at least 6 phylogenetic clades. The C. difficile species is defined by a large diverse pangenome with extreme levels of evolutionary plasticity that has been shaped over long time periods by gene flux and recombination, often between divergent lineages. These evolutionary events are in response to environmental and anthropogenic activities and have led to the rapid emergence and worldwide dissemination of virulent clonal lineages. Moreover, genome analysis of large clinically relevant data sets has improved our understanding of CDI outbreaks, transmission, and recurrence. The epidemiology of CDI has changed dramatically over the last 15 years, and CDI may have a foodborne or zoonotic etiology. The WGS era promises to continue to redefine our view of this significant pathogen. PMID:26085550

Using fiberglass volumes for VPI of superconductive magnetic systems’ insulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andreev, I. S.; Bezrukov, A. A.; Pischugin, A. B.

2014-01-29

The paper describes the method of manufacturing fiberglass molds for vacuum pressure impregnation (VPI) of high-voltage insulation of superconductive magnetic systems (SMS) with epoxidian hot-setting compounds. The basic advantages of using such vacuum volumes are improved quality of insulation impregnation in complex-shaped areas, and considerable cost-saving of preparing VPI of large-sized components due to dispensing with the stage of fabricating a metal impregnating volume. Such fiberglass vacuum molds were used for VPI of high-voltage insulation samples of an ITER reactor’s PF1 poloidal coil. Electric insulation of these samples has successfully undergone a wide range of high-voltage and mechanical tests atmore » room and cryogenic temperatures. Some results of the tests are also given in this paper.« less

Bacteroides thetaiotaomicron VPI-5482 glycoside hydrolase family 66 homolog catalyzes dextranolytic and cyclization reactions.

PubMed

Kim, Young-Min; Yamamoto, Eiji; Kang, Min-Sun; Nakai, Hiroyuki; Saburi, Wataru; Okuyama, Masayuki; Mori, Haruhide; Funane, Kazumi; Momma, Mitsuru; Fujimoto, Zui; Kobayashi, Mikihiko; Kim, Doman; Kimura, Atsuo

2012-09-01

Bacteroides thetaiotaomicron VPI-5482 harbors a gene encoding a putative cycloisomaltooligosaccharide glucanotransferase (BT3087) belonging to glycoside hydrolase family 66. The goal of the present study was to characterize the catalytic properties of this enzyme. Therefore, we expressed BT3087 (recombinant endo-dextranase from Bacteroides thetaiotaomicron VPI-5482) in Escherichia coli and determined that recombinant endo-dextranase from Bacteroides thetaiotaomicron VPI-5482 preferentially synthesized isomaltotetraose and isomaltooligosaccharides (degree of polymerization > 4) from dextran. The enzyme also generated large cyclic isomaltooligosaccharides early in the reaction. We conclude that members of the glycoside hydrolase 66 family may be classified into three types: (a) endo-dextranases, (b) dextranases possessing weak cycloisomaltooligosaccharide glucanotransferase activity, and (c) cycloisomaltooligosaccharide glucanotransferases. © 2012 The Authors Journal compilation © 2012 FEBS.

In Vitro Activities of Ramoplanin, Teicoplanin, Vancomycin, Linezolid, Bacitracin, and Four Other Antimicrobials against Intestinal Anaerobic Bacteria

PubMed Central

Citron, D. M.; Merriam, C. V.; Tyrrell, K. L.; Warren, Y. A.; Fernandez, H.; Goldstein, E. J. C.

2003-01-01

By using an agar dilution method, the in vitro activities of ramoplanin, teicoplanin, vancomycin, linezolid, and five other agents were determined against 300 gram-positive and 54 gram-negative strains of intestinal anaerobes. Ramoplanin was active at ≤2 μg/ml against 287 of 300 (95.7%) gram-positive organisms, including 18 strains of Clostridium difficile for which MICs of ramoplanin were 0.25 to 0.5 μg/ml; for 3 of these, linezolid MICs were 8 to 16 μg/ml. Nineteen Clostridium innocuum strains for which the vancomycin MIC at which 90% of strains were inhibited was 16 μg/ml were susceptible to ramoplanin at 0.06 to 0.25 μg/ml and to teicoplanin at 0.125 to 1.0 μg/ml. All strains of Eubacterium, Actinomyces, Propionibacterium, and Peptostreptococcus spp. were inhibited by ≤0.25 μg of ramoplanin per ml and ≤1 μg of vancomycin per ml. Ramoplanin was also active at ≤4 μg/ml against 15 of 22 of the Prevotella and Porphyromonas strains tested, but ramoplanin MICs for all 31 strains of the Bacteroides fragilis group, the Fusobacterium mortiferum-Fusobacterium varium group, and Veillonella spp. were ≥256 μg/ml. Ramoplanin displays excellent activity against C. difficile and other gram-positive enteric anaerobes, including vancomycin-resistant strains; however, it has poor activity against most gram-negative anaerobes and thus potentially has a lesser effect on the ecological balance of normal fecal flora. PMID:12821492

The role of vancomycin and metronidazole for the treatment of Clostridium difficile-associated diarrhea.

PubMed

Tart, Serina B

2013-10-01

For the treatment of Clostridium difficile-associated diarrhea (CDAD), metronidazole and vancomycin remain the most commonly used agents. The major advantage of metronidazole is its low cost, while the advantage of oral vancomycin is a more favorable pharmacokinetic profile. The epidemiology and clinical severity of CDAD have changed due to the emergence of a hypervirulent strain (BI/NAP1/027). In 2010, the Infectious Diseases Society of America/Society for Health Care Epidemiology of America expert panel defined severe CDAD and recommended oral vancomycin to treat these patients. Metronidazole remains the preferred agent for treatment of mild to moderate CDAD.

Next-Generation Probiotics Targeting Clostridium difficile through Precursor-Directed Antimicrobial Biosynthesis

PubMed Central

Auchtung, Jennifer; Brown, Aaron; Boonma, Prapaporn; Oezguen, Numan; Ross, Caná L.; Luna, Ruth Ann; Runge, Jessica; Versalovic, James; Peniche, Alex; Dann, Sara M.; Britton, Robert A.; Haag, Anthony; Savidge, Tor C.

2017-01-01

ABSTRACT Integration of antibiotic and probiotic therapy has the potential to lessen the public health burden of antimicrobial-associated diseases. Clostridium difficile infection (CDI) represents an important example where the rational design of next-generation probiotics is being actively pursued to prevent disease recurrence. Because intrinsic resistance to clinically relevant antibiotics used to treat CDI (vancomycin, metronidazole, and fidaxomicin) is a desired trait in such probiotic species, we screened several bacteria and identified Lactobacillus reuteri to be a promising candidate for adjunct therapy. Human-derived L. reuteri bacteria convert glycerol to the broad-spectrum antimicrobial compound reuterin. When supplemented with glycerol, strains carrying the pocR gene locus were potent reuterin producers, with L. reuteri 17938 inhibiting C. difficile growth at a level on par with the level of growth inhibition by vancomycin. Targeted pocR mutations and complementation studies identified reuterin to be the precursor-induced antimicrobial agent. Pathophysiological relevance was demonstrated when the codelivery of L. reuteri with glycerol was effective against C. difficile colonization in complex human fecal microbial communities, whereas treatment with either glycerol or L. reuteri alone was ineffective. A global unbiased microbiome and metabolomics analysis independently confirmed that glycerol precursor delivery with L. reuteri elicited changes in the composition and function of the human microbial community that preferentially targets C. difficile outgrowth and toxicity, a finding consistent with glycerol fermentation and reuterin production. Antimicrobial resistance has thus been successfully exploited in the natural design of human microbiome evasion of C. difficile, and this method may provide a prototypic precursor-directed probiotic approach. Antibiotic resistance and substrate bioavailability may therefore represent critical new determinants of probiotic efficacy in clinical trials. PMID:28760934

Clostridium difficile and inflammatory bowel disease: role in pathogenesis and implications in treatment.

PubMed

Nitzan, Orna; Elias, Mazen; Chazan, Bibiana; Raz, Raul; Saliba, Walid

2013-11-21

Clostridium difficile (C. difficile) is the leading cause of antibiotic associated colitis and nosocomial diarrhea. Patients with inflammatory bowel disease (IBD) are at increased risk of developing C. difficile infection (CDI), have worse outcomes of CDI-including higher rates of colectomy and death, and experience higher rates of recurrence. However, it is still not clear whether C. difficile is a cause of IBD or a consequence of the inflammatory state in the intestinal environment. The burden of CDI has increased dramatically over the past decade, with severe outbreaks described in many countries, which have been attributed to a new and more virulent strain. A parallel rise in the incidence of CDI has been noted in patients with IBD. IBD patients with CDI tend be younger, have less prior antibiotic exposure, and most cases of CDI in these patients represent outpatient acquired infections. The clinical presentation of CDI in these patients can be unique-including diversion colitis, enteritis and pouchitis, and typical findings on colonoscopy are often absent. Due to the high prevalence of CDI in patients hospitalized with an IBD exacerbation, and the prognostic implications of CDI in these patients, it is recommended to test all IBD patients hospitalized with a disease flare for C. difficile. Treatment includes general measures such as supportive care and infection control measures. Antibiotic therapy with either oral metronidazole, vancomycin, or the novel antibiotic-fidaxomicin, should be initiated as soon as possible. Fecal macrobiota transplantation constitutes another optional treatment for severe/recurrent CDI. The aim of this paper is to review recent data on CDI in IBD: role in pathogenesis, diagnostic methods, optional treatments, and outcomes of these patients.

Sensitizing Clostridium difficile Spores with Germinants on Skin and Environmental Surfaces Represents a New Strategy for Reducing Spores via Ambient Mechanisms

PubMed Central

Nerandzic, Michelle M.; Donskey, Curtis J.

2017-01-01

Background Clostridium difficile is a leading cause of healthcare-associated infections worldwide. Prevention of C. difficile transmission is challenging because spores are not killed by alcohol-based hand sanitizers or many commonly used disinfectants. One strategy to control spores is to induce germination, thereby rendering the spores more susceptible to benign disinfection measures and ambient stressors. Methods/Results C. difficile spores germinated on skin after a single application of cholic acid-class bile salts and co-germinants; for 4 C. difficile strains, recovery of viable spores from skin was reduced by ~0.3 log10CFU to 2 log10CFU after 2 hours and ~1 log10CFU to > 2.5 log10CFU after 24 hours. The addition of taurocholic acid to 70% and 30% ethanol significantly enhanced reduction of viable spores on skin and on surfaces. Desiccation, and to a lesser extent the presence of oxygen, were identified as the stressors responsible for reductions of germinated spores on skin and surfaces. Additionally, germinated spores became susceptible to killing by pH 1.5 hydrochloric acid, suggesting that germinated spores that remain viable on skin and surfaces might be killed by gastric acid after ingestion. Antibiotic-treated mice did not become colonized after exposure to germinated spores, whereas 100% of mice became colonized after exposure to the same quantity of dormant spores. Conclusions Germination could provide a new approach to reduce C. difficile spores on skin and in the environment and to render surviving spores less capable of causing infection. Our findings suggest that it may be feasible to develop alcohol-based hand sanitizers containing germinants that reduce spores on hands. PMID:29167835

Improving culture media for the isolation of Clostridium difficile from compost.

PubMed

Dharmasena, Muthu; Jiang, Xiuping

2018-06-01

This study was to optimize the detection methods for Clostridium difficile from the animal manure-based composts. Both autoclaved and unautoclaved dairy composts were inoculated with a 12-h old suspension of a non-toxigenic C. difficile strain (ATCC 43593) and then plated on selected agar for vegetative cells and endospores. Six types of enrichment broths supplemented with taurocholate and l-cysteine were assessed for detecting a low level of artificially inoculated C. difficile (ca. 5 spores/g) from dairy composts. The efficacy of selected enrichment broths was further evaluated by isolating C. difficile from 29 commercial compost samples. Our results revealed that using heat-shock was more effective than using ethanol-shock for inducing endospore germination, and the highest endospore count (p < 0.05) was yielded at 60 °C for 25 min. C. difficile agar base, supplemented with 0.1% l-cysteine, 7% defibrinated horse blood, and cycloserine-cefoxitin (CDA-CYS-H-CC agar) was the best medium (p < 0.05) for recovering vegetative cells from compost. C. difficile endospore populations from both types of composts enumerated on both CDA-CYS-H-CC agar supplemented with 0.1% sodium taurocholate (CDA-CYS-H-CC-T agar) and brain heart infusion agar supplemented with 0.5% yeast extract, 0.1% l-cysteine, cycloserine-cefoxitin, and 0.1% sodium taurocholate (BHIA-YE-CYS-CC-T agar) media were not significantly different from each other (p > 0.05). Overall, enrichment of inoculated compost samples in broths containing moxalactam-norfloxacin (MN) produced significantly higher (p < 0.05) spore counts than in non-selective broths or broths supplemented with CC. Enrichment in BHIB-YE-CYS-MN-T broth followed by culturing on an agar containing 7% horse blood and 0.1% taurocholate provided a more sensitive and selective combination of media for detecting a low population of C. difficile from environmental samples with high background microflora. Copyright © 2018 Elsevier Ltd. All rights reserved.

Polarization Mechanisms in Phase II Poly(Vinylidene Fluoride) Films.

DTIC Science & Technology

1981-11-12

34 OdRO a mnk W) Poly(Vinylidene Fluoride), x-rays, piezelectricity, polarization, poling FAWWRmCT ffls~ -ew nam 9 Uf"Oo me..Mv £*mM NOWsA Unoriented...phase II films were poled with fields up to 3.2 MV/cm at room o) temperature. A determination of the piezoelectric strain coefficient provided a measure...sT. VW OtU.4LF-41U.4" ". . -. I u CIImVP CLAI IaICATIOM OV- VPI PU.I (Ul... O111 111..41 the poling field and different polarization mechanisms appear

Antimicrobial susceptibility of animal and human isolates of Clostridium difficile by broth microdilution.

PubMed

Pirš, Tina; Avberšek, Jana; Zdovc, Irena; Krt, Brane; Andlovic, Alenka; Lejko-Zupanc, Tatjana; Rupnik, Maja; Ocepek, Matjaž

2013-09-01

A total of 188 human (n = 92) and animal (n = 96) isolates of Clostridium difficile of different PCR ribotypes were screened for susceptibility to 30 antimicrobials using broth microdilution. When comparing the prevalence of antimicrobial resistance, the isolates of animal origin were significantly more often resistant to oxacillin, gentamicin and trimethoprim/sulfamethoxazole (P<0.01). The most significant difference between the animal and human populations (P = 0.0006) was found in the level of imipenem resistance, with a prevalence of 53.3 % in isolates of human origin and 28.1 % in isolates of animal origin. Overall, the results show similar MICs for the majority of tested antimicrobials for isolates from human and animal sources, which were collected from the same geographical region and in the same time interval. This supports the hypothesis that C. difficile could be transmissible between human and animal hosts. Resistant isolates have been found in all animal species tested, including food and companion animals, and also among non-toxigenic isolates. The isolates of the most prevalent PCR ribotype 014/020 had low resistance rates for moxifloxacin, erythromycin, rifampicin and daptomycin, but a high resistance rate for imipenem. Multiresistant strains were found in animals and humans, belonging to PCR ribotypes 012, 017, 027, 045, 046, 078 and 150, and also to non-toxigenic strains of PCR ribotypes 010 and SLO 080.

Comparison of the efficacy of a hydrogen peroxide dry-mist disinfection system and sodium hypochlorite solution for eradication of Clostridium difficile spores.

PubMed

Barbut, F; Menuet, D; Verachten, M; Girou, E

2009-06-01

To compare a hydrogen peroxide dry-mist system and a 0.5% hypochlorite solution with respect to their ability to disinfect Clostridium difficile-contaminated surfaces in vitro and in situ. Prospective, randomized, before-after trial. Two French hospitals affected by C. difficile. In situ efficacy of disinfectants was assessed in rooms that had housed patients with C. difficile infection. A prospective study was performed at 2 hospitals that involved randomization of disinfection processes. When a patient with C. difficile infection was discharged, environmental contamination in the patient's room was evaluated before and after disinfection. Environmental surfaces were sampled for C. difficile by use of moistened swabs; swab samples were cultured on selective plates and in broth. Both disinfectants were tested in vitro with a spore-carrier test; in this test, 2 types of material, vinyl polychloride (representative of the room's floor) and laminate (representative of the room's furniture), were experimentally contaminated with spores from 3 C. difficile strains, including the epidemic clone ribotype 027-North American pulsed-field gel electrophoresis type 1. There were 748 surface samples collected (360 from rooms treated with hydrogen peroxide and 388 from rooms treated with hypochlorite). Before disinfection, 46 (24%) of 194 samples obtained in the rooms randomized to hypochlorite treatment and 34 (19%) of 180 samples obtained in the rooms randomized to hydrogen peroxide treatment showed environmental contamination. After disinfection, 23 (12%) of 194 samples from hypochlorite-treated rooms and 4 (2%) of 180 samples from hydrogen peroxide treated rooms showed environmental contamination, a decrease in contamination of 50% after hypochlorite decontamination and 91% after hydrogen peroxide decontamination (P < .005). The in vitro activity of 0.5% hypochlorite was time dependent. The mean (+/-SD) reduction in initial log(10) bacterial count was 4.32 +/- 0.35 log(10) colony-forming units after 10 minutes of exposure to hypochlorite and 4.18 +/- 0.8 log(10) colony-forming units after 1 cycle of hydrogen peroxide decontamination. In situ experiments indicate that the hydrogen peroxide dry-mist disinfection system is significantly more effective than 0.5% sodium hypochlorite solution at eradicating C. difficile spores and might represent a new alternative for disinfecting the rooms of patients with C. difficile infection.

1H, 13C, and 15N resonance assignments of an enzymatically active domain from the catalytic component (CDTa, residues 216-420) of a binary toxin from Clostridium difficile.

PubMed

Roth, Braden M; Godoy-Ruiz, Raquel; Varney, Kristen M; Rustandi, Richard R; Weber, David J

2016-04-01

Clostridium difficile is a bacterial pathogen and is the most commonly reported source of nosocomial infection in industrialized nations. Symptoms of C. difficile infection (CDI) include antibiotic-associated diarrhea, pseudomembranous colitis, sepsis and death. Over the last decade, rates and severity of hospital infections in North America and Europe have increased dramatically and correlate with the emergence of a hypervirulent strain of C. difficile characterized by the presence of a binary toxin, CDT (C. difficile toxin). The binary toxin consists of an enzymatic component (CDTa) and a cellular binding component (CDTb) that together form the active binary toxin complex. CDTa harbors a pair of structurally similar but functionally distinct domains, an N-terminal domain (residues 1-215; (1-215)CDTa) that interacts with CDTb and a C-terminal domain (residues 216-420; (216-420)CDTa) that harbors the intact ADP-ribosyltransferase (ART) active site. Reported here are the (1)H, (13)C, and (15)N backbone resonance assignments of the 23 kDa, 205 amino acid C-terminal enzymatic domain of CDTa, termed (216-420)CDTa. These NMR resonance assignments for (216-420)CDTa represent the first for a family of ART binary toxins and provide the framework for detailed characterization of the solution-state protein structure determination, dynamic studies of this domain, as well as NMR-based drug discovery efforts.

Oscillating behavior of Clostridium difficile Min proteins in Bacillus subtilis.

PubMed

Makroczyová, Jana; Jamroškovič, Ján; Krascsenitsová, Eva; Labajová, Nad'a; Barák, Imrich

2016-06-01

In rod-shaped bacteria, the proper placement of the division septum at the midcell relies, at least partially, on the proteins of the Min system as an inhibitor of cell division. The main principle of Min system function involves the formation of an inhibitor gradient along the cell axis; however, the establishment of this gradient differs between two well-studied gram-negative and gram-positive bacteria. While in gram-negative Escherichia coli, the Min system undergoes pole-to-pole oscillation, in gram-positive Bacillus subtilis, proper spatial inhibition is achieved by the preferential attraction of the Min proteins to the cell poles. Nevertheless, when E.coli Min proteins are inserted into B.subtilis cells, they still oscillate, which negatively affects asymmetric septation during sporulation in this organism. Interestingly, homologs of both Min systems were found to be present in various combinations in the genomes of anaerobic and endospore-forming Clostridia, including the pathogenic Clostridium difficile. Here, we have investigated the localization and behavior of C.difficile Min protein homologs and showed that MinDE proteins of C.difficile can oscillate when expressed together in B.subtilis cells. We have also investigated the effects of this oscillation on B.subtilis sporulation, and observed decreased sporulation efficiency in strains harboring the MinDE genes. Additionally, we have evaluated the effects of C.difficile Min protein expression on vegetative division in this heterologous host. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Identification and Characterization of Clostridium difficile Sequence Type 37 Genotype by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry.

PubMed

Li, Ruxin; Xiao, Di; Yang, Jing; Sun, Suju; Kaplan, Samuel; Li, Zhirong; Niu, Yanan; Qiang, Cuixin; Zhai, Yu; Wang, Xiaoming; Zhao, Xingzhen; Zhao, Baoxin; Welker, Martin; Pincus, David H; Jin, Dazhi; Kamboj, Mini; Zheng, Guanghui; Zhang, Guojun; Zhang, Jianzhong; Tang, Yi-Wei; Zhao, Jianhong

2018-05-01

Clostridium difficile multilocus sequence type 37 (ST37), which mainly corresponds to ribotype 017, has been a dominant genotype circulating in China. In this study, we report the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) to analyze and characterize 204 C. difficile clinical isolates, including 49 ST37 and 155 non-ST37 isolates collected in China and other countries. The distributions of two major protein peaks ( m/z 3,242 and 3,286) were significantly different between ST37 and non-ST37 prototype strains and clinical isolates. This difference was reproducible when analysis was performed on different colonies in different runs. This finding was repeated and confirmed by both bioMérieux Vitek MS and Bruker Microflex LT systems on isolates recovered from a variety of geographic regions worldwide. The combination of the two peaks was present in 47 of 49 ST37 isolates, resulting in a sensitivity of 95.9%. In contrast, the peak combination was absent in 153 of 155 non-ST37 isolates, resulting in a specificity of 98.7%. Our results suggest that MALDI-TOF MS is a rapid and reliable tool to identify C. difficile genotype ST37. Work is in progress to characterize the two molecules having peaks at m/z 3,242 and 3,286, which appear to be specific to C. difficile genotype ST37. Copyright © 2018 American Society for Microbiology.

Obstructive Sleep Apnea Syndrome in Children with 22q11.2 Deletion Syndrome after Operative Intervention for Velopharyngeal Insufficiency

PubMed Central

Crockett, David Jeffrey; Goudy, Steven L.; Chinnadurai, Sivakumar; Wootten, Christopher Todd

2014-01-01

Introduction: Surgical treatment of velopharyngeal insufficiency (VPI) in 22q11.2 deletion syndrome is often warranted. In this patient population, VPI is characterized by poor palatal elevation and muscular hypotonia with an intact palate. We hypothesize that 22q11.2 deletion patients are at greater risk of obstructive sleep apnea (OSA) after surgical correction of VPI, due, in part, to their functional hypotonia, large velopharyngeal gap size, and the need to surgically obstruct the velopharynx. Methods: We performed a retrospective analysis of patients with 22q11.2 deletion syndrome treated at a tertiary pediatric hospital between the years of 2002 and 2012. The incidence of VPI, need for surgery, post-operative polysomnogram, post-operative VPI assessment, and OSA treatments were evaluated. Results: Forty-three patients (18 males, 25 females, ages 1–14 years) fitting the inclusion criteria were identified. Twenty-eight patients were evaluated by speech pathology due to hypernasality. Twenty-one patients had insufficient velopharyngeal function and required surgery. Fifteen underwent pharyngeal flap surgery, three underwent sphincter pharyngoplasty, two underwent Furlow palatoplasty, and one underwent combined sphincter pharyngoplasty with Furlow palatoplasty. Of these, eight had post-operative snoring. Six of these underwent polysomnography (five underwent pharyngeal flap surgeries and one underwent sphincter pharyngoplasty). Four patients were found to have OSA based on the results of the polysomnography (average apnea/hypopnea index of 4.9 events/h, median = 5.1, SD = 2.1). Two required continuous positive airway pressure (CPAP) due to moderate OSA. Conclusion: Surgery is often necessary to correct VPI in patients with 22q11.2 deletion syndrome. Monitoring for OSA should be considered after surgical correction of VPI due to a high occurrence in this population. Furthermore, families should be counseled of the risk of OSA after surgery and the potential need for treatment with CPAP. PMID:25157342

Fidaxomicin - the new drug for Clostridium difficile infection

PubMed Central

Vaishnavi, Chetana

2015-01-01

Clostridium difficile is one of the many aetiological agents of antibiotic associated diarrhoea and is implicated in 15-25 per cent of the cases. The organism is also involved in the exacearbation of inflammatory bowel disease and extracolonic manifestations. Due to increase in the incidence of C. difficile infection (CDI), emergence of hypervirulent strains, and increased frequency of recurrence, the clinical management of the disease has become important. The management of CDI is based on disease severity, and current antibiotic treatment options are limited to vancomycin or metronidazole in the developing countries. this review article briefly describes important aspects of CDI, and the new drug, fidaxomicin, for its treatment. Fidaxomicin is particularly active against C. difficile and acts by inhibition of RNA synthesis. Clinical trials done to compare the efficacy and safety of fidaxomicin with that of vancomycin in treating CDI concluded that fidaxomicin was non-inferior to vancomycin for treatment of CDI and that there was a significant reduction in recurrences. The bactericidal properties of fidaxomicin make it an ideal alternative for CDI treatment. However, fidaxomicin use should be considered taking into account the potential benefits of the drug, along with the medical requirements of the patient, the risks of treatment and the high cost of fidaxomicin compared to other treatment regimens. PMID:26112840

Measuring the severity of Clostridium difficile infection: implications for management and drug development.

PubMed

Belmares, Jaime; Gerding, Dale N; Tillotson, Glenn; Johnson, Stuart

2008-12-01

The appropriate management of Clostridium difficile infection (CDI) has become a growing clinical and economic issue, as a new epidemic strain with enhanced virulence is causing increased morbidity and mortality. Presently, only two antibiotics (metronidazole and vancomycin) are routinely used to treat CDI. Both increasing disease severity and recurrent infections have been an impetus not only to develop new agents, but also to better recognize which patients are at highest risk for treatment failure and/or recurrence so that treatments can be optimized from the outset. The availability of a standardized and validated system for stratifying CDI severity could improve patient management and potentially accelerate the development of new treatment agents.

Clostridium difficile Infection and Fecal Microbiota Transplant

PubMed Central

Liubakka, Alyssa; Vaughn, Byron P.

2017-01-01

Clostridium difficile infection (CDI) is a major source of morbidity and mortality for hospitalized patients. Although most patients have a clinical response to existing antimicrobial therapies, recurrent infection develops in up to 30% of patients. Fecal microbiota transplant is a novel approach to this complex problem, with an efficacy rate of nearly 90% in the setting of multiple recurrent CDI. This review covers the current epidemiology of CDI (including toxigenic and nontoxigenic strains, risk factors for infection, and recurrent infection), methods of diagnosis, existing first-line therapies in CDI, the role of fecal microbiota transplant for multiple recurrent CDIs, and the potential use of fecal microbial transplant for patients with severe or refractory infection. PMID:27959316

[Individualized treatment strategies for Clostridium difficile infections].

PubMed

Solbach, P; Dersch, P; Bachmann, O

2017-07-01

Upon hospitalization, up to 15.5% of patients are already colonized with a toxigenic Clostridium difficile strain (TCD). The rate of asymptomatic colonization is 0-3% in healthy adults and up to 20-40% in hospitalized patients. The incidence and mortality of C. difficile infection (CDI) has significantly increased during recent years. Mortality lies between 3 and 14%. CDI is generally caused by intestinal dysbiosis, which can be triggered by various factors, including antibiotics or immune suppressants. If CDI occurs, ongoing antibiotic therapy should be discontinued. The choice of treatment is guided by the clinical situation: Mild courses of CDI should be treated with metronidazole. Oral vancomycin is suitable as a first-line therapy of mild CDI occurring during pregnancy and lactation, as well as in cases of intolerance or allergy to metronidazole. Severe courses should be treated with vancomycin. Recurrence should be treated with vancomycin or fidaxomicin. Multiple recurrences should be treated with vancomycin or fidaxomicin; if necessary, a vancomycin taper regimen may also be used. An alternative is fecal microbiota transplant (FMT), with healing rates of more than 80%. Bezlotoxumab is the first available monoclonal antibody which neutralizes the C. difficile toxin B, and in combination with an antibiotic significantly reduces the rate of a new C. difficile infection compared to placebo. A better definition of clinical and microbiota-associated risk factors and the ongoing implementation of molecular diagnostics are likely to lead to optimized identification of patients at risk, and an increasing individualization of prophylactic and therapeutic approaches.

In vitro activity of flomoxef compared to moxalactam, cefoxitin, cefotaxime, and clindamycin against anaerobes.

PubMed

Werner, H; Heizmann, W; Luft, G

1988-11-01

To assess the in vitro activity of flomoxef (6315-S), moxalactam, cefoxitin, cefotaxime, and clindamycin against anaerobes 197 clinical isolates (27 Bacteroides fragilis, 42 B. thetaiotaomicron, 10 B. vulgatus, 7 B. ovatus, 6 B. uniformis, 6 B. distasonis, 7 Bacteroides melaninogenicus group, 11 Bacteroides oralis group, 21 Clostridium difficile, 7 C. perfringens, 3 C. sporogenes, 3 Clostridium spp., 33 Propionibacterium acnes, 14 Peptococcaceae) were studied by means of agar dilution tests. The MIC90 of B. fragilis was less than 2 micrograms/ml for flomoxef, less than 4 micrograms/ml for moxalactam, less than 16 micrograms/ml for cefoxitin, less than 128 micrograms/ml for cefotaxime and less than 2 micrograms/ml for clindamycin. The respective MIC90's of B. thetaiotaomicron were less than 64, less than 128, less than 32, less than 256 and 8 micrograms/ml. Strains of the other Bacteroides species and groups were more susceptible to flomoxef and the other antibiotics than B. thetaiotaomicron. Against Clostridium difficile flomoxef (MIC90 less than 4 micrograms/ml) proved to be superior to the other agents tested. Most of the Clostridium strains other than C. difficile were also susceptible to flomoxef; anaerobic grampositive cocci and Propionibacterium acnes were very sensitive (MIC90's less than 1 and less than or equal to 0.125 micrograms/ml, respectively). Its anti-anaerobic activity, together with its efficacy against aerobes, should make flomoxef a useful adjunct to the arsenal of modern antibiotic therapy.

Prevalence, genetic relatedness and antibiotic resistance of hospital-acquired clostridium difficile PCR ribotype 018 strains.

PubMed

Seo, Mi-Ran; Kim, Jieun; Lee, Yangsoon; Lim, Dong-Gyun; Pai, Hyunjoo

2018-05-01

Clostridium difficile infection (CDI) is a major healthcare-associated infection. The aim of this study was to investigate the genetic relatedness of the endemic C. difficile PCR ribotype 018 strains in an institution and changes to their characteristics during a five-year period. A total of 207 isolates from inpatients at Hanyang University Hospital from 2009 to 2013 were analysed using multilocus variable-number tandem-repeat analysis (MLVA). Minimum inhibitory concentrations (MICs) of several antibiotics were determined. In total, 204 (98.6%) were genetically related, with a summed tandem-repeat distance (STRD) ≤ 10. Minimum-spanning-tree analysis identified 78 MLVA types, categorized into six clonal complexes (CCs). The largest cluster, CC-I, included 51 MLVA types from 148 isolates (71.5%) and the second largest cluster, CC-II, included 10 MLVA types from 36 isolates (17.4%). Resistance rates for antibiotics were: clindamycin (CLI), 97.6%; moxifloxacin (MXF), 98.6%; vancomycin (VAN), 1.4%; and rifaximin (RFX), 8.2%. All isolates were susceptible to piperacillin/tazobactam (TZP) and metronidazole (MTZ). Comparing the MICs of antibiotics for the isolates each year from 2009 to 2013, MICs of antibiotics that promote CDI, such as CLI, MXF, TZP and RFX, increased over the five-year period (P-value by Kruskal-Wallis test: < 0.0001, <0.0001, <0.0001, and <0.0001 respectively); however, MICs of VAN or MTZ, antibiotics for treatment of CDI, did not increase or decreased over the same time period (P-value by Kruskal-Wallis test: 0.166, <0.0001). C. difficile RT018 isolates in a tertiary hospital over a five-year period presented a close clonal relationship. MICs of antibiotics promoting CDI increased with this clonal expansion. Copyright © 2018 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

31P magnetization transfer measurements of Pi→ATP flux in exercising human muscle

PubMed Central

Savage, David B.; Williams, Guy B.; Porter, David; Carpenter, T. Adrian; Brindle, Kevin M.; Kemp, Graham J.

2016-01-01

Fundamental criticisms have been made over the use of 31P magnetic resonance spectroscopy (MRS) magnetization transfer estimates of inorganic phosphate (Pi)→ATP flux (VPi-ATP) in human resting skeletal muscle for assessing mitochondrial function. Although the discrepancy in the magnitude of VPi-ATP is now acknowledged, little is known about its metabolic determinants. Here we use a novel protocol to measure VPi-ATP in human exercising muscle for the first time. Steady-state VPi-ATP was measured at rest and over a range of exercise intensities and compared with suprabasal oxidative ATP synthesis rates estimated from the initial rates of postexercise phosphocreatine resynthesis (VATP). We define a surplus Pi→ATP flux as the difference between VPi-ATP and VATP. The coupled reactions catalyzed by the glycolytic enzymes GAPDH and phosphoglycerate kinase (PGK) have been shown to catalyze measurable exchange between ATP and Pi in some systems and have been suggested to be responsible for this surplus flux. Surplus VPi-ATP did not change between rest and exercise, even though the concentrations of Pi and ADP, which are substrates for GAPDH and PGK, respectively, increased as expected. However, involvement of these enzymes is suggested by correlations between absolute and surplus Pi→ATP flux, both at rest and during exercise, and the intensity of the phosphomonoester peak in the 31P NMR spectrum. This peak includes contributions from sugar phosphates in the glycolytic pathway, and changes in its intensity may indicate changes in downstream glycolytic intermediates, including 3-phosphoglycerate, which has been shown to influence the exchange between ATP and Pi catalyzed by GAPDH and PGK. PMID:26744504

31P magnetization transfer measurements of Pi→ATP flux in exercising human muscle.

PubMed

Sleigh, Alison; Savage, David B; Williams, Guy B; Porter, David; Carpenter, T Adrian; Brindle, Kevin M; Kemp, Graham J

2016-03-15

Fundamental criticisms have been made over the use of (31)P magnetic resonance spectroscopy (MRS) magnetization transfer estimates of inorganic phosphate (Pi)→ATP flux (VPi-ATP) in human resting skeletal muscle for assessing mitochondrial function. Although the discrepancy in the magnitude of VPi-ATP is now acknowledged, little is known about its metabolic determinants. Here we use a novel protocol to measure VPi-ATP in human exercising muscle for the first time. Steady-state VPi-ATP was measured at rest and over a range of exercise intensities and compared with suprabasal oxidative ATP synthesis rates estimated from the initial rates of postexercise phosphocreatine resynthesis (VATP). We define a surplus Pi→ATP flux as the difference between VPi-ATP and VATP. The coupled reactions catalyzed by the glycolytic enzymes GAPDH and phosphoglycerate kinase (PGK) have been shown to catalyze measurable exchange between ATP and Pi in some systems and have been suggested to be responsible for this surplus flux. Surplus VPi-ATP did not change between rest and exercise, even though the concentrations of Pi and ADP, which are substrates for GAPDH and PGK, respectively, increased as expected. However, involvement of these enzymes is suggested by correlations between absolute and surplus Pi→ATP flux, both at rest and during exercise, and the intensity of the phosphomonoester peak in the (31)P NMR spectrum. This peak includes contributions from sugar phosphates in the glycolytic pathway, and changes in its intensity may indicate changes in downstream glycolytic intermediates, including 3-phosphoglycerate, which has been shown to influence the exchange between ATP and Pi catalyzed by GAPDH and PGK. Copyright © 2016 the American Physiological Society.

Guidewire exchange vs new site placement for temporary dialysis catheter insertion in ICU patients: is there a greater risk of colonization or dysfunction?

PubMed

Coupez, Elisabeth; Timsit, Jean-François; Ruckly, Stéphane; Schwebel, Carole; Gruson, Didier; Canet, Emmanuel; Klouche, Kada; Argaud, Laurent; Bohe, Julien; Garrouste-Orgeas, Maïté; Mariat, Christophe; Vincent, François; Cayot, Sophie; Cointault, Olivier; Lepape, Alain; Darmon, Michael; Boyer, Alexandre; Azoulay, Elie; Bouadma, Lila; Lautrette, Alexandre; Souweine, Bertrand

2016-07-30

Intensive care unit (ICU) patients require dialysis catheters (DCs) for renal replacement therapy (RRT). They carry a high risk of developing end-stage renal disease, and therefore their vascular access must be preserved. Guidewire exchange (GWE) is often used to avoid venipuncture insertion (VPI) at a new site. However, the impact of GWE on infection and dysfunction of DCs in the ICU is unknown. Our aim was to compare the effect of GWE and VPI on DC colonization and dysfunction in ICU patients. Using data from the ELVIS randomized controlled trial (RCT) (1496 ICU adults requiring DC for RRT or plasma exchange) we performed a matched-cohort analysis. Cases were DCs inserted by GWE (n = 178). They were matched with DCs inserted by VPI. Matching criteria were participating centre, simplified acute physiology score (SAPS) II +/-10, insertion site (jugular or femoral), side for jugular site, and length of ICU stay before DC placement. We used a marginal Cox model to estimate the effect of DC insertion (GWE vs. VPI) on DC colonization and dysfunction. DC colonization rate was not different between GWE-DCs and VPI-DCs (10 (5.6 %) for both groups) but DC dysfunction was more frequent with GWE-DCs (67 (37.6 %) vs. 28 (15.7 %); hazard ratio (HR), 3.67 (2.07-6.49); p < 0.01). Results were similar if analysis was restricted to DCs changed for dysfunction. GWE for DCs in ICU patients, compared with VPI did not contribute to DC colonization or infection but was associated with more than twofold increase in DC dysfunction. This study is registered with ClinicalTrials.gov, number NCT00563342 . Registered 2 April 2009.

Readability of online patient education materials for velopharyngeal insufficiency.

PubMed

Xie, Deborah X; Wang, Ray Y; Chinnadurai, Sivakumar

2018-01-01

Evaluate the readability of online and mobile application health information about velopharyngeal insufficiency (VPI). Top website and mobile application results for search terms "velopharyngeal insufficiency", "velopharyngeal dysfunction", "VPI", and "VPD" were analyzed. Readability was determined using 10 algorithms with Readability Studio Professional Edition (Oleander Software Ltd; Vandalia, OH). Subgroup analysis was performed based on search term and article source - academic hospital, general online resource, peer-reviewed journal, or professional organization. 18 unique articles were identified. Overall mean reading grade level was a 12.89 ± 2.9. The highest reading level among these articles was 15.47-approximately the level of a college senior. Articles from "velopharyngeal dysfunction" had the highest mean reading level (13.73 ± 2.11), above "velopharyngeal insufficiency" (12.30 ± 1.56) and "VPI" (11.66 ± 1.70). Articles from peer-reviewed journals had the highest mean reading level (15.35 ± 2.79), while articles from academic hospitals had the lowest (12.81 ± 1.66). There were statistically significant differences in reading levels between the different search terms (P < 0.01) and article source types (P < 0.05). Only one mobile application was identified with VPI information, with a readability of 10.68. Despite published reading level guidelines, online patient education materials for VPI are disseminated with language too complex for most readers. There is also a lack of VPI-related mobile application data available for patients. Patients will benefit if future updates to websites and disseminated patient information are undertaken with health literacy in mind. Future studies will investigate patient comprehension of these materials. Copyright © 2017 Elsevier B.V. All rights reserved.

Cognitive Styles and Educational-Vocational Preferences and Selection

ERIC Educational Resources Information Center

Osipow, Samuel H.

1969-01-01

Vocational Preference Inventory (VPI) and other instruments administered to 365 students, both undecided and in various interest fields, revealed several differences in cognitive style. No differences regarding cognitive style variations and VPI high-point codes or ease of vocational selection were observed. (Author/CJ)

Personality Characteristics of Black Adolescents

ERIC Educational Resources Information Center

Brown, Nina W.

1977-01-01

This research attempted to determine 1) the personality profiles of disadvantaged Black adolescents on Holland's Vocational Preference Inventory (VPI) and Gough's Adjective Checklist (ACL), 2) if this group differed significantly on the VPI from Blacks attending college, and 3) what implications for programming and planning could be determined…

Fidaxomicin: A novel agent for the treatment of Clostridium difficile infection

PubMed Central

Zhanel, George G; Walkty, Andrew J; Karlowsky, James A

2015-01-01

BACKGROUND: Due to the limitations of existing treatment options for Clostridium difficile infection (CDI), new therapies are needed. OBJECTIVE: To review the available data on fidaxomicin regarding chemistry, mechanisms of action and resistance, in vitro activity, pharmacokinetic and pharmacodynamic properties, efficacy and safety in clinical trials, and place in therapy. METHODS: A search of PubMed using the terms “fidaxomicin”, “OPT-80”, “PAR-101”, “OP-1118”, “difimicin”, “tiacumicin” and “lipiarmycin” was performed. All English-language articles from January 1983 to November 2014 were reviewed, as well as bibliographies of all articles. RESULTS: Fidaxomicin is the first macrocyclic lactone antibiotic with activity versus C difficile. It inhibits RNA polymerase, therefore, preventing transcription. Fidaxomicin (and its active metabolite OP-1118) is bactericidal against C difficile and exhibits a prolonged postantibiotic effect (approximately 10 h). Other than for C difficile, fidaxomicin demonstrated only moderate inhibitory activity against Gram-positive bacteria and was a poor inhibitor of normal colonic flora, including anaerobes and enteric Gram-negative bacilli. After oral administration (200 mg two times per day for 10 days), fidaxomicin achieved low serum concentration levels but high fecal concentration levels (mean approximately 1400 μg/g stool). Phase 3 clinical trials involving adults with CDI demonstrated that 200 mg fidaxomicin twice daily for 10 days was noninferior to 125 mg oral vancomycin four times daily for 10 days in regard to clinical response at the end of therapy. Fidaxomicin was, however, reported to be superior to oral vancomycin in reducing recurrent CDI and achieving a sustained clinical response (assessed at day 28) for patients infected with non-BI/NAP1/027 strains. CONCLUSION: Fidaxomicin was noninferior to oral vancomycin with regard to clinical response at the end of CDI therapy. Fidaxomicin has been demonstated to be as safe as oral vancomycin, but superior to vancomycin in achieving a sustained clinical response for CDI in patients infected with non-BI/NAP1/027 strains. Caution should be exercised in using fidaxomicin monotherapy for treatment of severe complicated CDI because limited data are available. Whether fidaxomicin is cost effective (due to its significantly higher acquisition cost versus oral vancomycin) depends on the acceptable willingness to pay threshold per quality-adjusted life year as a measure of assessing cost effectiveness. PMID:26744587

Fidaxomicin: A novel agent for the treatment of Clostridium difficile infection.

PubMed

Zhanel, George G; Walkty, Andrew J; Karlowsky, James A

2015-01-01

Due to the limitations of existing treatment options for Clostridium difficile infection (CDI), new therapies are needed. To review the available data on fidaxomicin regarding chemistry, mechanisms of action and resistance, in vitro activity, pharmacokinetic and pharmacodynamic properties, efficacy and safety in clinical trials, and place in therapy. A search of PubMed using the terms "fidaxomicin", "OPT-80", "PAR-101", "OP-1118", "difimicin", "tiacumicin" and "lipiarmycin" was performed. All English-language articles from January 1983 to November 2014 were reviewed, as well as bibliographies of all articles. Fidaxomicin is the first macrocyclic lactone antibiotic with activity versus C difficile. It inhibits RNA polymerase, therefore, preventing transcription. Fidaxomicin (and its active metabolite OP-1118) is bactericidal against C difficile and exhibits a prolonged postantibiotic effect (approximately 10 h). Other than for C difficile, fidaxomicin demonstrated only moderate inhibitory activity against Gram-positive bacteria and was a poor inhibitor of normal colonic flora, including anaerobes and enteric Gram-negative bacilli. After oral administration (200 mg two times per day for 10 days), fidaxomicin achieved low serum concentration levels but high fecal concentration levels (mean approximately 1400 μg/g stool). Phase 3 clinical trials involving adults with CDI demonstrated that 200 mg fidaxomicin twice daily for 10 days was noninferior to 125 mg oral vancomycin four times daily for 10 days in regard to clinical response at the end of therapy. Fidaxomicin was, however, reported to be superior to oral vancomycin in reducing recurrent CDI and achieving a sustained clinical response (assessed at day 28) for patients infected with non-BI/NAP1/027 strains. Fidaxomicin was noninferior to oral vancomycin with regard to clinical response at the end of CDI therapy. Fidaxomicin has been demonstated to be as safe as oral vancomycin, but superior to vancomycin in achieving a sustained clinical response for CDI in patients infected with non-BI/NAP1/027 strains. Caution should be exercised in using fidaxomicin monotherapy for treatment of severe complicated CDI because limited data are available. Whether fidaxomicin is cost effective (due to its significantly higher acquisition cost versus oral vancomycin) depends on the acceptable willingness to pay threshold per quality-adjusted life year as a measure of assessing cost effectiveness.

Update on Clostridium difficile infections.

PubMed

Le Monnier, A; Zahar, J-R; Barbut, F

2014-08-01

Clostridium difficile infections (CDI) occur primarily in hospitalized patients with risk factors such as concomitant or recent use of antibiotics. CDI related additional costs are important for the global population and health-care facilities. CDI epidemiology has changed since 2003: they became more frequent boosted by large outbreaks, more severe, more resistant to antibiotic treatment, and spread to new groups of population without any risk factor. This is partly due to the emergence and worldwide dissemination of new and more virulent C. difficile strains such as the epidemic clone 027/NAP1/BI. The host immune response plays a central role in the pathogenesis of CDI and could also be involved in the occurrence of recurrent or severe forms. New guidelines including new molecular tests (NAAT) have recently clarified and simplified the diagnostic strategies for the microbiological diagnosis of CDI. The CDI incidence was proven to be related to the level of clinical suspicion and the frequency of microbiological screening for C. difficile. The current recommendations for the treatment of CDI mention oral metronidazole as the first line treatment for mild to moderate diarrhea. Oral vancomycin use should be restricted to severe cases. In the absence of consensus, the treatment of multiple recurrences remains a major concern. New and more targeted antibiotics and innovative therapeutic strategies (fecal transplantation, monoclonal antibodies, and vaccination) have emerged as new therapies for CDI. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Population genetic analysis of oral treponemes by multilocus enzyme electrophoresis.

PubMed

Dahle, U R; Olsen, I; Tronstad, L; Caugant, D A

1995-10-01

Seventeen treponemes recently isolated from necrotic pulps, periodontal and periapical infections and 17 previously well characterized oral treponemal strains were analyzed by multilocus enzyme electrophoresis. Ten genetic loci were characterized on the basis of the electrophoretic mobilities of their enzymatic products. All loci were polymorphic. The average number of alleles per locus was 7.8. The genetic diversity among the electrophoretic types at each locus ranged from 0.624 to 0.836 with a mean genetic diversity per locus of 0.751. The 34 strains represented 34 electrophoretic types, constituting 6 main divisions (I-VI) separated at genetic distances greater than 0.75. Several of the previously characterized treponemes revealed multiple bands of enzyme activity at several loci, indicating that they were not pure. The characterized strains usually clustered within established species, whereas fresh clinical isolates overlapped species borders. There was a large genetic difference between some reference and clinical strains, indicating that the latter may contain undescribed species. Treponema socranskii and Treponema denticola strains clustered in distinct divisions (IV and V, respectively), with the exception of T. denticola strain FDC 51B2 and T. socranskii subsp. paredis strain VPI D46CPE1, both previously well described. This indicated that the taxonomic assignment of these 2 strains should be reconsidered.

VPI - VIBRATION PATTERN IMAGER: A CONTROL AND DATA ACQUISITION SYSTEM FOR SCANNING LASER VIBROMETERS

NASA Technical Reports Server (NTRS)

Rizzi, S. A.

1994-01-01

The Vibration Pattern Imager (VPI) system was designed to control and acquire data from laser vibrometer sensors. The PC computer based system uses a digital signal processing (DSP) board and an analog I/O board to control the sensor and to process the data. The VPI system was originally developed for use with the Ometron VPI Sensor (Ometron Limited, Kelvin House, Worsley Bridge Road, London, SE26 5BX, England), but can be readily adapted to any commercially available sensor which provides an analog output signal and requires analog inputs for control of mirror positioning. VPI's graphical user interface allows the operation of the program to be controlled interactively through keyboard and mouse-selected menu options. The main menu controls all functions for setup, data acquisition, display, file operations, and exiting the program. Two types of data may be acquired with the VPI system: single point or "full field". In the single point mode, time series data is sampled by the A/D converter on the I/O board at a user-defined rate for the selected number of samples. The position of the measuring point, adjusted by mirrors in the sensor, is controlled via a mouse input. In the "full field" mode, the measurement point is moved over a user-selected rectangular area with up to 256 positions in both x and y directions. The time series data is sampled by the A/D converter on the I/O board and converted to a root-mean-square (rms) value by the DSP board. The rms "full field" velocity distribution is then uploaded for display and storage. VPI is written in C language and Texas Instruments' TMS320C30 assembly language for IBM PC series and compatible computers running MS-DOS. The program requires 640K of RAM for execution, and a hard disk with 10Mb or more of disk space is recommended. The program also requires a mouse, a VGA graphics display, a Four Channel analog I/O board (Spectrum Signal Processing, Inc.; Westborough, MA), a break-out box and a Spirit-30 board (Sonitech International, Inc.; Wellesley, MA) which includes a TMS320C30 DSP processor, 256Kb zero wait state SRAM, and a daughter board with 8Mb one wait state DRAM. Please contact COSMIC for additional information on required hardware and software. In order to compile the provided VPI source code, a Microsoft C version 6.0 compiler, a Texas Instruments' TMS320C30 assembly language compiler, and the Spirit 30 run time libraries are required. A math co-processor is highly recommended. A sample MS-DOS executable is provided on the distribution medium. The standard distribution medium for this program is one 5.25 inch 360K MS-DOS format diskette. The contents of the diskettes are compressed using the PKWARE archiving tools. The utility to unarchive the files, PKUNZIP.EXE, is included. VPI was developed in 1991-1992.

Black-White Differences on the Vocational Preference Inventory

ERIC Educational Resources Information Center

Doughtie, Eugene B.; And Others

1976-01-01

The Vocational Preference Inventory (VPI) was administered to black and white undergraduates. The overall VPI profiles of the two groups were significantly different. The black students scored higher on the Social, Conventional, Enterprising, Self-Control, Status, and Infrequency scales. The white students scored higher on the Masculinity scale.…

Prevalence of Clostridium difficile infection in hospitalized patients with diarrhoea: Results of a Polish multicenter, prospective, biannual point-prevalence study.

PubMed

Pituch, Hanna; Obuch-Woszczatyński, Piotr; Lachowicz, Dominika; Kuthan, Robert; Dzierżanowska-Fangrat, Katarzyna; Mikucka, Agnieszka; Jermakow, Katarzyna; Pituch-Zdanowska, Aleksandra; Davies, Kerrie

2018-04-13

We aimed to measure the underdiagnosis of Clostridium difficile infection across Poland and the distribution of PCR-ribotypes of C. difficile. Twenty seven Polish healthcare facilities (HCFs) participated in this prospective study. Each HCF systematically sent all diarrhoeal stools received from inpatients at their laboratories on two days (one in January 2013 and one in July 2013), independently of CDI test request, to the National Coordinating Laboratory (NCL) for standardized testing of CDI. Positive samples (using two-stage algorithm), had CDI, confirmed by qPCR and toxigenic culture. C. difficile isolates were characterized by PCR-ribotyping. Hospitals were questioned about their methods and testing policy for CDI during the study period: September 2011 to August 2013. During the study period, participating hospitals reported a mean of 33.2 tests for CDI per 10 000 patient-days and a mean of 8.4 cases of CDI per 10 000 patient-days. The overall prevalence of positive CDI patients at NCL was 16.5%. Due to absence of clinical suspicion, 19.1% of these patients were not diagnosed by the local diagnostic laboratory. We identified 23 different PCR-ribotypes among 87C. difficile strains isolated from patients. PCR-ribotype 027 (48%) was the most prevalent. The incidence of CDI in Poland in study period was very high. It should be noted however, that there is a lack of clinical suspicion and underestimation of the need to perform diagnostic tests for CDI in hospitalized patients. This will have an impact on the reported epidemiological status of CDI in Poland. Copyright © 2018 Medical University of Bialystok. Published by Elsevier B.V. All rights reserved.

Shedding of Clostridium difficile PCR ribotype 078 by zoo animals, and report of an unstable metronidazole-resistant isolate from a zebra foal (Equus quagga burchellii).

PubMed

Álvarez-Pérez, Sergio; Blanco, José L; Martínez-Nevado, Eva; Peláez, Teresa; Harmanus, Celine; Kuijper, Ed; García, Marta E

2014-03-14

Clostridium difficile is an emerging and potentially zoonotic pathogen, but its prevalence in most animal species, including exhibition animals, is currently unknown. In this study we assessed the prevalence of faecal shedding of C. difficile by zoo animals, and determined the ribotype, toxin profile and antimicrobial susceptibility of recovered isolates. A total of 200 samples from 40 animal species (36.5% of which came from plains zebra, Equus quagga burchellii) were analysed. C. difficile was isolated from 7 samples (3.5% of total), which came from the following animal species: chimpanzee (Pan troglodytes troglodytes), dwarf goat (Capra hircus), and Iberian ibex (Capra pyrenaica hispanica), with one positive sample each; and plains zebra, with 4 positive samples from 3 different individuals. Most recovered isolates (4/7, 57.1%) belonged to the epidemic PCR ribotype 078, produced toxins A and B, and had the genes encoding binary toxin (i.e. A(+)B(+)CDT(+) isolates). The remaining three isolates belonged to PCR ribotypes 039 (A(-)B(-)CDT(-)), 042 (A(+)B(+)CDT(-)) and 110 (A(-)B(+)CDT(-)). Regardless of their ribotype, all isolates displayed high-level resistance to the fluoroquinolones ciprofloxacin, enrofloxacin and levofloxacin. Some isolates were also resistant to meropenem and/or ertapenem. A ribotype 078 isolate recovered from a male zebra foal initially showed in vitro resistance to metronidazole (MIC ≥ 256 μg/ml), but lost that trait after subculturing on non-selective media. We conclude that zoo animals belonging to different species can carry ribotype 078 and other toxigenic strains of C. difficile showing resistance to antimicrobial compounds commonly used in veterinary and/or human medicine. Copyright © 2014 Elsevier B.V. All rights reserved.

Clostridium difficile-associated disease: impact of the updated SHEA/IDSA guidelines.

PubMed

Kincaid, Scott E

2010-12-01

Clostridium difficile-associated disease (CDAD) is an increasingly difficult condition to treat because of the emergence of antibiotic resistance and highly pathogenic strains of bacteria. These newly identified strains affect patients in every facet of health care, from individuals in the community to those in intensive care units and all points in between. Appropriate management regarding diagnosis, infection control, pharmacotherapy, and prevention is the key to good outcomes in all patient populations. Geriatric patients are particularly at risk of acquiring CDAD as a result of their gradually declining immune systems and increased exposure to health care facilities. Therefore, they merit a higher level of attention when CDAD is suspected. In an effort to identify the best practices, the Society for Healthcare Epidemiology of America in conjunction with the Infectious Diseases Society of America developed guidelines regarding the diagnosis and management of Clostridium-associated disease. By utilizing these guidelines to educate other health care practitioners and by considering the recommendations in their own practice, pharmacists can have a positive impact on every facet of CDAD prevention and management.

Emerging therapies for Clostridium difficile infections.

PubMed

McFarland, Lynne V

2011-09-01

Clostridium difficile infection (CDI) is the leading identifiable gastrointestinal disease in healthcare institutions, but the response rates to the two standard therapies for CDI are declining and so innovative therapies are being developed for CDI. The purpose of this paper is to review the data on the efficacy and safety of emerging therapies for CDI and assess their potential for effectiveness based on the clinical phase of development and marketing challenges. Emerging therapies for CDI are reviewed including new antibiotics, peptides, immune regulators, probiotics and toxin binders. PubMed, Medline and Google Scholar and online clinical trial registers are searched from 1976 to 2010 for articles unrestricted by language. Secondary searches by author, manufacturing companies and FDA websites are also performed. Of the emerging therapies for CDI, several may ultimately reduce the incidence of CDI and the economic burden of this disease on the healthcare system. Several emerging treatments (fidaxomicin, rifaximin and mAbs) show the most promise, although only one is currently being actively developed. Use of other clostridial strains, probiotic strains and immune enhancers have great potential as therapies, but require further development.

Biochemical and full genome sequence analyses of clinical Vibrio cholerae isolates in Mexico reveals the presence of novel V. cholerae strains.

PubMed

Díaz-Quiñonez, José Alberto; Hernández-Monroy, Irma; Montes-Colima, Norma Angélica; Moreno-Pérez, María Asunción; Galicia-Nicolás, Adriana Guadalupe; López-Martínez, Irma; Ruiz-Matus, Cuitláhuac; Kuri-Morales, Pablo; Ortíz-Alcántara, Joanna María; Garcés-Ayala, Fabiola; Ramírez-González, José Ernesto

2016-05-01

The first week of September 2013, the National Epidemiological Surveillance System identified two cases of cholera in Mexico City. The cultures of both samples were confirmed as Vibrio cholerae serogroup O1, serotype Ogawa, biotype El Tor. Initial analyses by PFGE and by PCR-amplification of the virulence genes, suggested that both strains were similar, but different from those previously reported in Mexico. The following week, four more cases were identified in a community in the state of Hidalgo, located 121 km northeast of Mexico City. Thereafter a cholera outbreak started in the region of La Huasteca. Genomic analyses of the four strains obtained in this study confirmed the presence of Pathogenicity Islands VPI-1 and -2, VSP-1 and -2, and of the integrative element SXT. The genomic structure of the 4 isolates was similar to that of V. cholerae strain 2010 EL-1786, identified during the epidemic in Haiti in 2010. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Studies on the Pathogenesis of Hepatitis A and Feasibility Studies on a Hepatitis A Vaccine

DTIC Science & Technology

1988-06-14

side. Previous studies with FMDV peptides had shown that smaller fragments of FMDV VPI sometimes were more effective as protective immunogens than was...the entire FMDV VPI protein, presumably because the protein fragment presented the appropriate epitope to the immune system in a fashion more similar

Clostridial toxins active locally in the gastrointestinal tract.

PubMed

Wilkins, T; Krivan, H; Stiles, B; Carman, R; Lyerly, D

1985-01-01

Clostridium difficile and Clostridium spiroforme have only in recent years been recognized as intestinal pathogens. They both produce toxins that are also produced by other clostridia. C. difficile toxins A and B are produced by C. sordellii and a few strains of C. perfringens whereas C. spiroforme produces the same toxins as C. perfringens Type E (iota toxin). Iota toxin activity may be the product of two proteins. Toxigenic strains of C. spiroforme and Type E produce two antigens which possess much more biological activity when administered together than when given alone. C. difficile was thought for some time to produce only a single toxin, but then the enterotoxic activity was shown to be due to a separate toxin (toxin A). This toxin increases the oral toxicity of toxin B (the main cytotoxin) and may increase the permeability of the colon. Toxin A binds to a specific receptor in hamster brush border membranes and in the membranes of rabbit erythrocytes. This receptor appears to be a glycoprotein. The receptor can be extracted from the membrane with Triton and binds to immobilized toxin A. The receptor can be extracted and used to coat plastic plates as a first phase in an ELISA assay. Another assay has been developed in which the toxin A binds to the red cells and then the erythrocytes are agglutinated with antitoxin. An even more sensitive assay consists of using rabbit erythrocyte ghosts to bind the toxin and then precipitating the ghosts with antibody to toxin A attached to latex beads. Monoclonal antibodies to toxin A also have been developed and are used in these and other assays.

Cwp19 Is a Novel Lytic Transglycosylase Involved in Stationary-Phase Autolysis Resulting in Toxin Release in Clostridium difficile.

PubMed

Wydau-Dematteis, Sandra; El Meouche, Imane; Courtin, Pascal; Hamiot, Audrey; Lai-Kuen, René; Saubaméa, Bruno; Fenaille, François; Butel, Marie-José; Pons, Jean-Louis; Dupuy, Bruno; Chapot-Chartier, Marie-Pierre; Peltier, Johann

2018-06-12

Clostridium difficile is the major etiologic agent of antibiotic-associated intestinal disease. Pathogenesis of C. difficile is mainly attributed to the production and secretion of toxins A and B. Unlike most clostridial toxins, toxins A and B have no signal peptide, and they are therefore secreted by unusual mechanisms involving the holin-like TcdE protein and/or autolysis. In this study, we characterized the cell surface protein Cwp19, a newly identified peptidoglycan-degrading enzyme containing a novel catalytic domain. We purified a recombinant His 6 -tagged Cwp19 protein and showed that it has lytic transglycosylase activity. Moreover, we observed that Cwp19 is involved in cell autolysis and that a C. difficile cwp19 mutant exhibited delayed autolysis in stationary phase compared to the wild type when bacteria were grown in brain heart infusion (BHI) medium. Wild-type cell autolysis is correlated to strong alterations of cell wall thickness and integrity and to release of cytoplasmic material. Furthermore, we demonstrated that toxins were released into the extracellular medium as a result of Cwp19-induced autolysis when cells were grown in BHI medium. In contrast, Cwp19 did not induce autolysis or toxin release when cells were grown in tryptone-yeast extract (TY) medium. These data provide evidence for the first time that TcdE and bacteriolysis are coexisting mechanisms for toxin release, with their relative contributions in vitro depending on growth conditions. Thus, Cwp19 is an important surface protein involved in autolysis of vegetative cells of C. difficile that mediates the release of the toxins from the cell cytosol in response to specific environment conditions. IMPORTANCE Clostridium difficile -associated disease is mainly known as a health care-associated infection. It represents the most problematic hospital-acquired infection in North America and Europe and exerts significant economic pressure on health care systems. Virulent strains of C. difficile generally produce two toxins that have been identified as the major virulence factors. The mechanism for release of these toxins from bacterial cells is not yet fully understood but is thought to be partly mediated by bacteriolysis. Here we identify a novel peptidoglycan hydrolase in C. difficile , Cwp19, exhibiting lytic transglycosylase activity. We show that Cwp19 contributes to C. difficile cell autolysis in the stationary phase and, consequently, to toxin release, most probably as a response to environmental conditions such as nutritional signals. These data highlight that Cwp19 constitutes a promising target for the development of new preventive and curative strategies. Copyright © 2018 Wydau-Dematteis et al.

We can predict postpalatoplasty velopharyngeal insufficiency in cleft palate patients.

PubMed

Leclerc, Jacques E; Godbout, Audrey; Arteau-Gauthier, Isabelle; Lacour, Sophie; Abel, Kati; McConnell, Elisa-Maude

2014-02-01

To find an anatomical measurement of the cleft palate (or a calculated parameter) that predicts the occurrence of velopharyngeal insufficiency (VPI) after palatal cleft repair. Retrospective cohort study. Charts were reviewed from cleft palate patients who underwent palatoplasty by the Von Langenbeck technique for isolated cleft palate or Bardach two-flap palatoplasty for cleft lip-palate. Seven anatomical cleft parameters were prospectively measured during the palatoplasty procedure. Three blinded speech-language pathologists retrospectively scored the clinically assessed VPI at 4 years of age. The recommendation of pharyngoplasty was also used as an indicator of VPI. From 1993 to 2008, 67 patients were enrolled in the study. The best predicting parameter was the ratio a/(30 - b1), in which a is defined as the posterior gap between the soft palate and the posterior pharyngeal wall and b1 is the width of the cleft at the hard palate level. An a/(30 - b1) ratio >0.7 to 0.8 is associated with a higher risk of developing VPI (relative risk = 2.2-5.1, sensitivity = 72%-81%, P < .03). The width of the cleft at the hard palate level and the posterior gap between the soft palate and the posterior pharyngeal wall were found to be the most significant parameters in predicting VPI. The best correlation was obtained with the ratio a/(30 - b1). 4. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

Incidence of Speech-Correcting Surgery in Children With Isolated Cleft Palate.

PubMed

Gustafsson, Charlotta; Heliövaara, Arja; Leikola, Junnu; Rautio, Jorma

2018-01-01

Speech-correcting surgeries (pharyngoplasty) are performed to correct velopharyngeal insufficiency (VPI). This study aimed to analyze the need for speech-correcting surgery in children with isolated cleft palate (ICP) and to determine differences among cleft extent, gender, and primary technique used. In addition, we assessed the timing and number of secondary procedures performed and the incidence of operated fistulas. Retrospective medical chart review study from hospital archives and electronic records. These comprised the 423 consecutive nonsyndromic children (157 males and 266 females) with ICP treated at the Cleft Palate and Craniofacial Center of Helsinki University Hospital during 1990 to 2016. The total incidence of VPI surgery was 33.3% and the fistula repair rate, 7.8%. Children with cleft of both the hard and soft palate (n = 300) had a VPI secondary surgery rate of 37.3% (fistula repair rate 10.7%), whereas children with only cleft of the soft palate (n = 123) had a corresponding rate of 23.6% (fistula repair rate 0.8%). Gender and primary palatoplasty technique were not considered significant factors in need for VPI surgery. The majority of VPI surgeries were performed before school age. One fifth of patients receiving speech-correcting surgery had more than one subsequent procedure. The need for speech-correcting surgery and fistula repair was related to the severity of the cleft. Although the majority of the corrective surgeries were done before the age of 7 years, a considerable number were performed at a later stage, necessitating long-term observation.

Vibration Pattern Imager (VPI): A control and data acquisition system for scanning laser vibrometers

NASA Technical Reports Server (NTRS)

Rizzi, Stephen A.; Brown, Donald E.; Shaffer, Thomas A.

1993-01-01

The Vibration Pattern Imager (VPI) system was designed to control and acquire data from scanning laser vibrometer sensors. The PC computer based system uses a digital signal processing (DSP) board and an analog I/O board to control the sensor and to process the data. The VPI system was originally developed for use with the Ometron VPI Sensor, but can be readily adapted to any commercially available sensor which provides an analog output signal and requires analog inputs for control of mirror positioning. The sensor itself is not part of the VPI system. A graphical interface program, which runs on a PC under the MS-DOS operating system, functions in an interactive mode and communicates with the DSP and I/O boards in a user-friendly fashion through the aid of pop-up menus. Two types of data may be acquired with the VPI system: single point or 'full field.' In the single point mode, time series data is sampled by the A/D converter on the I/O board (at a user-defined sampling rate for a selectable number of samples) and is stored by the PC. The position of the measuring point (adjusted by mirrors in the sensor) is controlled via a mouse input. The mouse input is translated to output voltages by the D/A converter on the I/O board to control the mirror servos. In the 'full field' mode, the measurement point is moved over a user-selectable rectangular area. The time series data is sampled by the A/D converter on the I/O board (at a user-defined sampling rate for a selectable number of samples) and converted to a root-mean-square (rms) value by the DSP board. The rms 'full field' velocity distribution is then uploaded for display and storage on the PC.

Correspondence of Constructs in Holland's Theory for Male and Female College Students

ERIC Educational Resources Information Center

Alston, Herbert L.; And Others

1976-01-01

The constructs in Holland's theory were compared for male and female college students using the Vocational Preference Inventory (VPI) and an adjective checklist (ACL). The correspondence between the VPI for male and female college students' was high. The correspondence between the variables as measured by the ACL for male and female students was…

Fecal microbiota transplantation for management of Clostridium difficile infection.

PubMed

Vaishnavi, Chetana

2014-07-01

The widespread use of antibiotics has led Clostridium difficile infection (CDI) to become a common problem with pronounced medical and economic effects. The recurrence of CDI after treatment with standard antibiotics is becoming more common with the emergence of more resistant strains of C. difficile. As CDI is an antibiotic-associated disease, further treatment with antibiotic is best avoided. As the gut flora is severely disturbed in CDI, approaches that restore the gut microbiota may become good alternative modes of CDI therapies. Fecal microbiota transplantation (FMT) is the procedure of transplantation of fecal bacteria from a healthy donor individual into a patient for restoration of the normal colonic flora. Thus, FMT helps in the eradication of C. difficile and resolution of clinical symptoms such as diarrhea, cramping, and urgency. Though this approach to treatment is not new, presently, it has become an alternative and promising way of combating infections. The procedure is not in regular use because of the time required to identify a suitable donor, the risk of introducing opportunistic pathogens, and a general patient aversion to the transplant. However, FMT is gaining popularity because of its success rate as a panacea for recurrent attacks of CDI and is being increasingly used in clinical practice. This review describes the rationale, the indications, the results, the techniques, the potential donors, the benefits as well as the complications of fecal microbiota instillation to CDI patients in order to restore the normal gut flora.

A Clostridium difficile Lineage Endemic to Costa Rican Hospitals Is Multidrug Resistant by Acquisition of Chromosomal Mutations and Novel Mobile Genetic Elements

PubMed Central

Ramírez-Vargas, Gabriel; Quesada-Gómez, Carlos; Acuña-Amador, Luis; López-Ureña, Diana; Murillo, Tatiana; del Mar Gamboa-Coronado, María; Chaves-Olarte, Esteban; Thomson, Nicholas; Rodríguez-Cavallini, Evelyn

2017-01-01

ABSTRACT The antimicrobial resistance (AMR) rates and levels recorded for Clostridium difficile are on the rise. This study reports the nature, levels, diversity, and genomic context of the antimicrobial resistance of human C. difficile isolates of the NAPCR1/RT012/ST54 genotype, which caused an outbreak in 2009 and is endemic in Costa Rican hospitals. To this end, we determined the susceptibilities of 38 NAPCR1 isolates to 10 antibiotics from seven classes using Etests or macrodilution tests and examined 31 NAPCR1 whole-genome sequences to identify single nucleotide polymorphisms (SNPs) and genes that could explain the resistance phenotypes observed. The NAPCR1 isolates were multidrug resistant (MDR) and commonly exhibited very high resistance levels. By sequencing their genomes, we showed that they possessed resistance-associated SNPs in gyrA and rpoB and carried eight to nine acquired antimicrobial resistance (AMR) genes. Most of these genes were located on known or novel mobile genetic elements shared by isolates recovered at different hospitals and at different time points. Metronidazole and vancomycin remain the first-line treatment options for these isolates. Overall, the NAPCR1 lineage showed an enhanced ability to acquire AMR genes through lateral gene transfer. On the basis of this finding, we recommend further vigilance and the adoption of improved control measures to limit the dissemination of this lineage and the emergence of more C. difficile MDR strains. PMID:28137804

The relationship between temporal aspects of oral-nasal balance and classification of velopharyngeal status in speakers with cleft palate.

PubMed

Jones, D L

2000-07-01

The purpose of this investigation was to determine whether temporal patterns of oral-nasal balance differentiate speakers with cleft palate who exhibit adequate and inadequate velopharyngeal function. The Nasal Accelerometric Vibrational Index (NAVI) was used to measure the time course and amplitude of oral-nasal balance during the productions of syllables, words, and sentences. The measures obtained include mean amplitude, time integral (area under the curve), absolute duration, relative duration, rise time, and fall time. The subjects for this study were 20 children with repaired cleft palates with or without cleft lip. Ten children (aged 5 through 18 years) were assigned to the velopharyngeal competence (VPC) group (normal oral-nasal resonance, no nasal emission of air). Ten children (aged 3 through 19) were assigned to the velopharyngeal insufficiency (VPI) group (hypernasal speech, velopharyngeal gap observed via nasal endoscopy). Both mean amplitude and time integral of NAVI were greater in the VPI group than in the VPC group (p < .01). Absolute duration and relative duration of the NAVI signal were greater in the VPI group (p < .01). NAVI rise time was shorter in the VPI group (p < .01), and NAVI fall time was longer in the VPI group (p < .01). The amplitude measures contributed the most to discrimination of speaker group, but the durational measures become increasingly influential as a function of a speech task. Although amplitude of nasalization may have the strongest perceptual salience in classification of velopharyngeal status, the temporal component may exert greater influence during more complex speech tasks.

Genetic Relatedness of Clostridium difficile Isolates from Various Origins Determined by Triple-Locus Sequence Analysis Based on Toxin Regulatory Genes tcdC, tcdR, and cdtR▿

PubMed Central

Bouvet, Philippe J. M.; Popoff, Michel R.

2008-01-01

A triple-locus nucleotide sequence analysis based on toxin regulatory genes tcdC, tcdR and cdtR was initiated to assess the sequence variability of these genes among Clostridium difficile isolates and to study the genetic relatedness between isolates. A preliminary investigation of the variability of the tcdC gene was done with 57 clinical and veterinary isolates. Twenty-three isolates representing nine main clusters were selected for tcdC, tcdR, and cdtR analysis. The numbers of alleles found for tcdC, tcdR and cdtR were nine, six, and five, respectively. All strains possessed the cdtR gene except toxin A-negative toxin B-positive variants. All but one binary toxin CDT-positive isolate harbored a deletion (>1 bp) in the tcdC gene. The combined analyses of the three genes allowed us to distinguish five lineages correlated with the different types of deletion in tcdC, i.e., 18 bp (associated or not with a deletion at position 117), 36 bp, 39 bp, and 54 bp, and with the wild-type tcdC (no deletion). The tcdR and tcdC genes, though located within the same pathogenicity locus, were found to have evolved separately. Coevolution of the three genes was noted only with strains harboring a 39-bp or a 54-bp deletion in tcdC that formed two homogeneous, separate divergent clusters. Our study supported the existence of the known clones (PCR ribotype 027 isolates and toxin A-negative toxin B-positive C. difficile variants) and evidence for clonality of isolates with a 39-bp deletion (toxinotype V, PCR ribotype 078) that are frequently isolated worldwide from human infections and from food animals. PMID:18832125

Epidemiology of Clostridium difficile infection.

PubMed

Depestel, Daryl D; Aronoff, David M

2013-10-01

There has been dramatic change in the epidemiology of Clostridium difficile infection (CDI) since the turn of the 21st century noted by a marked increase in incidence and severity, occurring at a disproportionately higher frequency in older patients. Historically considered a nosocomial infection associated with antibiotic exposure, CDI has now also emerged in the community in populations previously considered low risk. Emerging risk factors and disease recurrence represent continued challenges in the management of CDI. The increased incidence and severity associated with CDI has coincided with the emergence and rapid spread of a previously rare strain, ribotype 027. Recent data from the United States and Europe suggest that the incidence of CDI may have reached a crescendo in the recent years and is perhaps beginning to plateau. The acute care direct costs of CDI were estimated to be US$4.8 billion in 2008. However, nearly all the published studies have focused on CDI diagnosed and treated in the acute care hospital setting and fail to measure the burden outside the hospital, including recently discharged patients, outpatients, and those in long-term care facilities. Enhanced surveillance methods are needed to monitor the incidence, to identify populations at risk, and to characterize the molecular epidemiology of strains causing CDI.

Epidemiology of Clostridium difficile Infection

PubMed Central

DePestel, Daryl D.; Aronoff, David M.

2014-01-01

There has been dramatic change in the epidemiology of Clostridium difficile infection (CDI) since the turn of the 21st Century noted by a marked increase in incidence and severity, occurring at a disproportionately higher frequency in older patients. Historically considered a nosocomial infection associated with antibiotic exposure, CDI has now also emerged in the community in populations previously considered low risk. Emerging risk factors and disease recurrence represent continued challenges in the management of CDI. The increased incidence and severity associated with CDI has coincided with the emergence and rapid spread of a previously rare strain, ribotype 027. Recent data from the U.S. and Europe suggest the incidence of CDI may have reached a crescendo in recent years and is perhaps beginning to plateau. The acute-care direct costs of CDI were estimated to be $4.8 billion in 2008. However, nearly all the published studies have focused on CDI diagnosed and treated in acute-care hospital setting and fail to measure the burden outside the hospital, including recently discharged patients, outpatients, and those in long-term care facilities. Enhanced surveillance methods are needed to monitor the incidence, identify populations at risk, and characterize the molecular epidemiology of strains causing CDI. PMID:24064435

Models for the study of Clostridium difficile infection

PubMed Central

Best, Emma L.; Freeman, Jane; Wilcox, Mark H.

2012-01-01

Models of Clostridium difficile infection (C. difficile) have been used extensively for Clostridium difficile (C. difficile) research. The hamster model of C. difficile infection has been most extensively employed for the study of C. difficile and this has been used in many different areas of research, including the induction of C. difficile, the testing of new treatments, population dynamics and characterization of virulence. Investigations using in vitro models for C. difficile introduced the concept of colonization resistance, evaluated the role of antibiotics in C. difficile development, explored population dynamics and have been useful in the evaluation of C. difficile treatments. Experiments using models have major advantages over clinical studies and have been indispensible in furthering C. difficile research. It is important for future study programs to carefully consider the approach to use and therefore be better placed to inform the design and interpretation of clinical studies. PMID:22555466

Dentists, antibiotics and Clostridium difficile-associated disease.

PubMed

Beacher, N; Sweeney, M P; Bagg, J

2015-09-25

Dentists prescribe significant volumes of antimicrobial drugs within primary care settings. There is good evidence that many of the prescriptions are not justified by current clinical guidance and that that there is considerable misuse of these drugs in dentistry. One of the risks associated with antibiotic administration is Clostridium difficile-associated disease (CDAD), an entity of which many healthcare workers, including dentists, have little knowledge or understanding. This review seeks to identify the extent and nature of the problem and provides an up to date summary of current views on CDAD, with particular reference to community acquired disease. As for all healthcare workers, scrupulous attention to standard infection control procedures and reducing inappropriate antibiotic prescribing are essential to reduce the risks of CDAD, prevent emergence of further resistant strains of microorganisms and maintain the value of the arsenal of antibiotics currently available to us.

Clostridium difficile suppresses colonic vasoactive intestinal peptide associated with altered motility.

PubMed

Nassif, A; Longo, W E; Sexe, R; Stratton, M; Standeven, J; Vernava, A M; Kaminski, D L

1995-01-01

We investigated whether Clostridium difficile toxin alters colonic tissue levels of vasoactive intestinal peptide (VIP) at the expense of changes in colonic motility in the isolated perfused rabbit left colon. Colonic inflammation was induced by the intracolonic administration of 10(-8) M C. difflcile toxin. Strain gauge transducers were sewn onto the serosal surface of the colon to evaluate colonic motility. C. difflcile administration produced histologic changes consistent with epithelial damage. This was associated with an increased production of prostaglandin E(2) and thromboxane B(2). Tissue levels of VIP but not substance P were significantly reduced. This was associated with an increased number of contractions per minute and an average force of each colonic contraction. These results suggest that tissue levels of VIP are suppressed by C. difflcile and may participate in colonic dysmotility during active inflammation.

Multiple copies of a bile acid-inducible gene in Eubacterium sp. strain VPI 12708.

PubMed Central

Gopal-Srivastava, R; Mallonee, D H; White, W B; Hylemon, P B

1990-01-01

Eubacterium sp. strain VPI 12708 is an anaerobic intestinal bacterium which possesses inducible bile acid 7-dehydroxylation activity. Several new polypeptides are produced in this strain following induction with cholic acid. Genes coding for two copies of a bile acid-inducible 27,000-dalton polypeptide (baiA1 and baiA2) have been previously cloned and sequenced. We now report on a gene coding for a third copy of this 27,000-dalton polypeptide (baiA3). The baiA3 gene has been cloned in lambda DASH on an 11.2-kilobase DNA fragment from a partial Sau3A digest of the Eubacterium DNA. DNA sequence analysis of the baiA3 gene revealed 100% homology with the baiA1 gene within the coding region of the 27,000-dalton polypeptides. The baiA2 gene shares 81% sequence identity with the other two genes at the nucleotide level. The flanking nucleotide sequences associated with the baiA1 and baiA3 genes are identical for 930 bases in the 5' direction from the initiation codon and for at least 325 bases in the 3' direction from the stop codon, including the putative promoter regions for the genes. An additional open reading frame (occupying from 621 to 648 bases, depending on the correct start codon) was found in the identical 5' regions associated with the baiA1 and baiA3 clones. The 5' sequence 930 bases upstream from the baiA1 and baiA3 genes was totally divergent. The baiA2 gene, which is part of a large bile acid-inducible operon, showed no homology with the other two genes either in the 5' or 3' direction from the polypeptide coding region, except for a 15-base-pair presumed ribosome-binding site in the 5' region. These studies strongly suggest that a gene duplication (baiA1 and baiA3) has occurred and is stably maintained in this bacterium. Images PMID:2376563

Radiolabelled leucocyte scintigraphy versus conventional radiological imaging for the management of late, low-grade vascular prosthesis infections.

PubMed

Erba, P A; Leo, G; Sollini, M; Tascini, C; Boni, R; Berchiolli, R N; Menichetti, F; Ferrari, M; Lazzeri, E; Mariani, G

2014-02-01

In this study we evaluated the diagnostic performance of (99m)Tc-HMPAO-leucocyte ((99m)Tc-HMPAO-WBC) scintigraphy in a consecutive series of 55 patients (46 men and 9 women, mean age 71 ± 9 years, range 50 - 88 years) with a suspected late or a low-grade late vascular prosthesis infection (VPI), also comparing the diagnostic accuracy of WBC with that of other radiological imaging methods. All patients suspected of having VPI underwent clinical examination, blood tests, microbiology, US and CT, and were classified according to the Fitzgerald criteria. A final diagnosis of VPI was established in 47 of the 55 patients, with microbiological confirmation after surgical removal of the prosthesis in 36 of the 47. In the 11 patients with major contraindications to surgery, the final diagnosis was based on microbiology and clinical follow-up of at least 18 months. (99m)Tc-HMPAO-WBC planar, SPECT and SPECT/CT imaging identified VPI in 43 of 47 patients (20 of these also showed infection at extra-prosthetic sites). In the remaining eight patients without VPI, different sites of infections were found. The use of SPECT/CT images led to a significant reduction in the number of false-positive findings in 37% of patients (sensitivity and specificity 100 %, versus 85.1% and 62.5% for stand-alone SPECT). Sensitivity and specificity were 34% and 75% for US, 48.9% and 83.3% for CT, and 68.1% and 62.5% for the FitzGerald classification. Perioperative mortality was 5.5%, mid-term mortality 12%, and long-term mortality 27%. Survival rates were similar in patients treated with surgery and antimicrobial therapy compared to patients treated with antimicrobial therapy alone (61% versus 63%, respectively), while infection eradication at 12 months was significantly higher following surgery (83.3% versus 45.5%). (99m)Tc-HMPAO-WBC SPECT/CT is useful for detecting, localizing and defining the extent of graft infection in patients with late and low-grade late VPI with inconclusive radiological findings. (99m)Tc-HMPAO-WBC SPECT/CT might be used to optimize patient management.

In vitro activities of the new semisynthetic glycopeptide telavancin (TD-6424), vancomycin, daptomycin, linezolid, and four comparator agents against anaerobic gram-positive species and Corynebacterium spp.

PubMed

Goldstein, Ellie J C; Citron, Diane M; Merriam, C Vreni; Warren, Yumi A; Tyrrell, Kerin L; Fernandez, Helen T

2004-06-01

Telavancin is a new semisynthetic glycopeptide anti-infective with multiple mechanisms of action, including inhibition of bacterial membrane phospholipid synthesis and inhibition of bacterial cell wall synthesis. We determined the in vitro activities of telavancin, vancomycin, daptomycin, linezolid, quinupristin-dalfopristin, imipenem, piperacillin-tazobactam, and ampicillin against 268 clinical isolates of anaerobic gram-positive organisms and 31 Corynebacterium strains using agar dilution methods according to National Committee for Clinical Laboratory Standards procedures. Plates with daptomycin were supplemented with Ca(2+) to 50 mg/liter. The MICs at which 90% of isolates tested were inhibited (MIC(90)s) for telavancin and vancomycin were as follows: Actinomyces spp. (n = 45), 0.25 and 1 microg/ml, respectively; Clostridium difficile (n = 14), 0.25 and 1 microg/ml, respectively; Clostridium ramosum (n = 16), 1 and 4 microg/ml, respectively; Clostridium innocuum (n = 15), 4 and 16 microg/ml, respectively; Clostridium clostridioforme (n = 15), 8 and 1 microg/ml, respectively; Eubacterium group (n = 33), 0.25 and 2 microg/ml, respectively; Lactobacillus spp. (n = 26), 0.5 and 4 microg/ml, respectively; Propionibacterium spp. (n = 34), 0.125 and 0.5 microg/ml, respectively; Peptostreptococcus spp. (n = 52), 0.125 and 0.5 microg/ml, respectively; and Corynebacterium spp. (n = 31), 0.03 and 0.5 microg/ml, respectively. The activity of TD-6424 was similar to that of quinupristin-dalfopristin for most strains except C. clostridioforme and Lactobacillus casei, where quinupristin-dalfopristin was three- to fivefold more active. Daptomycin had decreased activity (MIC > 4 microg/ml) against 14 strains of Actinomyces spp. and all C. ramosum, Eubacterium lentum, and Lactobacillus plantarum strains. Linezolid showed decreased activity (MIC > 4 microg/ml) against C. ramosum, two strains of C. difficile, and 15 strains of Lactobacillus spp. Imipenem and piperacillin-tazobactam were active against >98% of strains. The MICs of ampicillin for eight Clostridium spp. and three strains of L. casei were >1 microg/ml. The MIC(90) of TD-6424 for all strains tested was

CRISPR-Cas and Contact-Dependent Secretion Systems Present on Excisable Pathogenicity Islands with Conserved Recombination Modules.

PubMed

Carpenter, Megan R; Kalburge, Sai S; Borowski, Joseph D; Peters, Molly C; Colwell, Rita R; Boyd, E Fidelma

2017-05-15

Pathogenicity islands (PAIs) are mobile integrated genetic elements that contain a diverse range of virulence factors. PAIs integrate into the host chromosome at a tRNA locus that contains their specific bacterial attachment site, attB , via integrase-mediated site-specific recombination generating attL and attR sites. We identified conserved recombination modules (integrases and att sites) previously described in choleragenic Vibrio cholerae PAIs but with novel cargo genes. Clustered regularly interspaced short palindromic repeat (CRISPR)-associated proteins (Cas proteins) and a type VI secretion system (T6SS) gene cluster were identified at the Vibrio pathogenicity island 1 (VPI-1) insertion site in 19 V. cholerae strains and contained the same recombination module. Two divergent type I-F CRISPR-Cas systems were identified, which differed in Cas protein homology and content. The CRISPR repeat sequence was identical among all V. cholerae strains, but the CRISPR spacer sequences and the number of spacers varied. In silico analysis suggests that the CRISPR-Cas systems were active against phages and plasmids. A type III secretion system (T3SS) was present in 12 V. cholerae strains on a 68-kb island inserted at the same tRNA-serine insertion site as VPI-2 and contained the same recombination module. Bioinformatics analysis showed that two divergent T3SSs exist among the strains examined. Both the CRISPR and T3SS islands excised site specifically from the bacterial chromosome as complete units, and the cognate integrases were essential for this excision. These data demonstrated that identical recombination modules that catalyze integration and excision from the chromosome can acquire diverse cargo genes, signifying a novel method of acquisition for both CRISPR-Cas systems and T3SSs. IMPORTANCE This work demonstrated the presence of CRISPR-Cas systems and T3SSs on PAIs. Our work showed that similar recombination modules can associate with different cargo genes and catalyze their incorporation into bacterial chromosomes, which could convert a strain into a pathogen with very different disease pathologies. Each island had the ability to excise from the chromosome as distinct, complete units for possible transfer. Evolutionary analysis of these regions indicates that they were acquired by horizontal transfer and that PAIs are the units of transfer. Similar to the case for phage evolution, PAIs have a modular structure where different functional regions are acquired by identical recombination modules. Copyright © 2017 American Society for Microbiology.

Enhanced surveillance of Clostridium difficile infection occurring outside hospital, England, 2011 to 2013.

PubMed

Fawley, Warren N; Davies, Kerrie A; Morris, Trefor; Parnell, Peter; Howe, Robin; Wilcox, Mark H

2016-07-21

There are limited national epidemiological data for community-associated (CA)-Clostridium difficile infections (CDIs). Between March 2011 and March 2013, laboratories in England submitted to the Clostridium difficile Ribotyping Network (CDRN) up to 10 diarrhoeal faecal samples from successive patients with CA-CDI, defined here as C. difficile toxin-positive diarrhoea commencing outside hospital (or less than 48 hours after hospital admission), including those cases associated with community-based residential care, with no discharge from hospital within the previous 12 weeks. Patient demographics and C. difficile PCR ribotypes were compared for CA-CDIs in our study and presumed healthcare-associated (HA) CDIs via CDRN. Ribotype diversity indices, ranking and relative prevalences were very similar in CA- vs HA-CDIs, although ribotypes 002 (p ≤ 0.0001),020 (p = 0.009) and 056 (p < 0.0001) predominated in CA-CDIs; ribotype 027 (p = 0.01) predominated in HA-CDIs. Epidemic ribotypes 027 and 078 predominated in institutional residents with CDI (including care/nursing homes) compared with people with CDI living at home. Ribotype diversity decreased with increasing age in HA-CDIs, but not in CA-CDIs. Ribotype 078 CA-CDIs were significantly more common in elderly people (3.4% (6/174) vs 8.7% (45/519) in those aged < 65 and ≥ 65 years, respectively; p = 0.019). No antibiotics were prescribed in the previous four weeks in about twofold more CA-CDI vs HAs (38.6% (129/334) vs 20.3% (1,226/6,028); p < 0.0001). We found very similar ribotype distributions in CA- and HA-CDIs, although a few ribotypes significantly predominated in one setting. These national data emphasise the close interplay between, and likely common reservoirs for, CDIs, particularly when epidemic strains are not dominant. This article is copyright of The Authors, 2016.

Laboratory and Clinical features of EIA Toxin-positive and EIA Toxin-negative Community-acquired Clostridium difficile Infection.

PubMed

Patel, Hiren; Randhawa, Jeewanjot; Nanavati, Sushant; Marton, L Randy; Baddoura, Walid J; DeBari, Vincent A

2015-01-01

Studies have described the clinical course of patients with Clostridium difficile infection (CDI) with positive enzyme immunoassay (EIA) for toxins A and B. Limited information is available for the patients with negative EIA but positive for the toxin B gene (TcdB) by the PCR. The aim of our study is to determine if there are any differences that exist among the clinical and laboratory parameters in the patients tested to be positive by EIA for toxin and those who were negative. This is a retrospective cohort study conducted in a 700-bed teaching hospital. We reviewed charts of the patients with presumptive CDI between January 2006 and July 2013. We divided these patients into two groups, EIA-positive and EIA-negative, based on result of EIA for toxins A and B and the requirement for a positive PCR analysis of the TcdB gene. The EIA-positive group had significantly higher white blood cell counts (p<0.001), with a significantly greater percentage of bands (p<0.0001). Albumin and total protein both exhibit significantly (p<0.0001, both comparisons) lower values in the EIA-positive group. Among clinical findings, the EIA-positive group had significantly longer length of hospital stay (p=0.010). These data suggest that an infection with an EIA-negative strain of C. difficile presents laboratory markers closer to those of healthy subjects and clinical features suggesting considerably less severe than infection with EIA-positive C. difficile. © 2015 by the Association of Clinical Scientists, Inc.

Prevention program for Clostridium difficile infection: a single-centre Serbian experience.

PubMed

Brkic, Snezana; Pellicano, Rinaldo; Turkulov, Vesna; Radovanovic, Marija; Abenavoli, Ludovico

2016-06-01

Clostridium difficile (C. difficile) diarrhea is a common, iatrogenic, nosocomial disease with a worldwide diffusion. Recent studies reported that the incidence of C. difficile infection (CDI) is rising, due to aging of the population and to greater prevalence of hypervirulent strains. We investigated whether the application of a prevention program lead to a decline in the incidence of intrahospital CDI. The study was designed as observational, to compare the efficacy of Schülke preventive program with the standard protocols, in a period of 4 months. For every patient with community-onset healthcare facility-associated (HCFA) CDI, we randomly selected four controls (1:4) with the same ICD code but without HCFA CDI. For statistical analysis the nonparametric, one-way ANOVA, univariate regression analysis, univariate analysis of variance, and Welch and Brown-Forsythe Test were used. Clinical features of HCFA CDI were typical. HCFA CDI group was significantly older than control group (P=0.008 and F=6.686; Partial Eta Square=0.013). Patients with HCFA CDI stayed significantly longer in hospital (P=0.000 and F=69.379; Partial Eta Square=0.117). Acquiring CDI prolonged the hospitalization of 14.52 days. HCFA CDI significantly increases the total cost of hospitalization as well as each element of the price respectively. With the application of the prevention program the annual incidence of CDI dropped from 49.01 in 2013 to 18.22/10000 bed days in 2014. Applying Schülke preventive program, implemented in 2014, has led to significant savings for the hospital compared to previous methods.

Structural Insight into the Clostridium difficile Ethanolamine Utilisation Microcompartment

PubMed Central

Faulds-Pain, Alexandra; Lewis, Richard J.; Marles-Wright, Jon

2012-01-01

Bacterial microcompartments form a protective proteinaceous barrier around metabolic enzymes that process unstable or toxic chemical intermediates. The genome of the virulent, multidrug-resistant Clostridium difficile 630 strain contains an operon, eut, encoding a bacterial microcompartment with genes for the breakdown of ethanolamine and its utilisation as a source of reduced nitrogen and carbon. The C. difficile eut operon displays regulatory genetic elements and protein encoding regions in common with homologous loci found in the genomes of other bacteria, including the enteric pathogens Salmonella enterica and Enterococcus faecalis. The crystal structures of two microcompartment shell proteins, CD1908 and CD1918, and an uncharacterised protein with potential enzymatic activity, CD1925, were determined by X-ray crystallography. CD1908 and CD1918 display the same protein fold, though the order of secondary structure elements is permuted in CD1908 and this protein displays an N-terminal β-strand extension. These proteins form hexamers with molecules related by crystallographic and non-crystallographic symmetry. The structure of CD1925 has a cupin β-barrel fold and a putative active site that is distinct from the metal-ion dependent catalytic cupins. Thin-section transmission electron microscopy of Escherichia coli over-expressing eut proteins indicates that CD1918 is capable of self-association into arrays, suggesting an organisational role for CD1918 in the formation of this microcompartment. The work presented provides the basis for further study of the architecture and function of the C. difficile eut microcompartment, its role in metabolism and the wider consequences of intestinal colonisation and virulence in this pathogen. PMID:23144756

Efficacy of the World Health Organization-recommended handwashing technique and a modified washing technique to remove Clostridium difficile from hands.

PubMed

Deschênes, Philippe; Chano, Frédéric; Dionne, Léa-Laurence; Pittet, Didier; Longtin, Yves

2017-08-01

The efficacy of the World Health Organization (WHO)-recommended handwashing technique against Clostridium difficile is uncertain, and whether it could be improved remains unknown. Also, the benefit of using a structured technique instead of an unstructured technique remains unclear. This study was a prospective comparison of 3 techniques (unstructured, WHO, and a novel technique dubbed WHO shortened repeated [WHO-SR] technique) to remove C difficile. Ten participants were enrolled and performed each technique. Hands were contaminated with 3 × 10 6 colony forming units (CFU) of a nontoxigenic strain containing 90% spores. Efficacy was assessed using the whole-hand method. The relative efficacy of each technique and of a structured (either WHO or WHO-SR) vs an unstructured technique were assessed by Mann-Whitney U test and Wilcoxon signed-rank test. The median effectiveness of the unstructured, WHO, and WHO-SR techniques in log 10 CFU reduction was 1.30 (interquartile range [IQR], 1.27-1.43), 1.71 (IQR, 1.34-1.91), and 1.70 (IQR, 1.54-2.42), respectively. The WHO-SR technique was significantly more efficacious than the unstructured technique (P = .01). Washing hands with a structured technique was more effective than washing with an unstructured technique (median, 1.70 vs 1.30 log 10 CFU reduction, respectively; P = .007). A structured washing technique is more effective than an unstructured technique against C difficile. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Use of probiotics in pediatric infectious diseases.

PubMed

Caffarelli, Carlo; Cardinale, Fabio; Povesi-Dascola, Carlotta; Dodi, Icilio; Mastrorilli, Violetta; Ricci, Giampaolo

2015-01-01

We summarize current evidence and recommendations for the use of probiotics in childhood infectious diseases. Probiotics may be of benefit in treating acute infectious diarrhea and reducing antibiotic-associated diarrhea. Potential benefits of probiotic on prevention of traveler's diarrhea,Clostridium difficile-associated diarrhea, side effects of triple therapy in Helicobacter pylori eradication, necrotizing enterocolitis, acute diarrhea, acute respiratory infections and recurrent urinary tract infections remain unclear. More studies are needed to investigate optimal strain, dosage, bioavailability of drops and tablets, duration of treatment and safety. Probiotics and recombinant probiotic strain represent a promising source of molecules for the development of novel anti-infectious therapy.

Current Controversies in Diagnosis and Management of Cleft Palate and Velopharyngeal Insufficiency

PubMed Central

Ysunza, Pablo Antonio; Repetto, Gabriela M.; Pamplona, Maria Carmen; Calderon, Juan F.; Shaheen, Kenneth; Chaiyasate, Konkgrit; Rontal, Matthew

2015-01-01

Background. One of the most controversial topics concerning cleft palate is the diagnosis and treatment of velopharyngeal insufficiency (VPI). Objective. This paper reviews current genetic aspects of cleft palate, imaging diagnosis of VPI, the planning of operations for restoring velopharyngeal function during speech, and strategies for speech pathology treatment of articulation disorders in patients with cleft palate. Materials and Methods. An updated review of the scientific literature concerning genetic aspects of cleft palate was carried out. Current strategies for assessing and treating articulation disorders associated with cleft palate were analyzed. Imaging procedures for assessing velopharyngeal closure during speech were reviewed, including a recent method for performing intraoperative videonasopharyngoscopy. Results. Conclusions from the analysis of genetic aspects of syndromic and nonsyndromic cleft palate and their use in its diagnosis and management are presented. Strategies for classifying and treating articulation disorders in patients with cleft palate are presented. Preliminary results of the use of multiplanar videofluoroscopy as an outpatient procedure and intraoperative endoscopy for the planning of operations which aimed to correct VPI are presented. Conclusion. This paper presents current aspects of the diagnosis and management of patients with cleft palate and VPI including 3 main aspects: genetics and genomics, speech pathology and imaging diagnosis, and surgical management. PMID:26273595

Clostridium difficile Infection in Children: Current State and Unanswered Questions

PubMed Central

Tamma, Pranita D.; Sandora, Thomas J.

2012-01-01

The incidence of Clostridium difficile infection (CDI) in children has increased over the past decade. In recent years, new and intriguing data on pediatric CDI have emerged. Community-onset infections are increasingly recognized, even in children who have not previously received antibiotics. A hypervirulent strain is responsible for up to 20% of pediatric CDI cases. Unique risk factors for CDI in children have been identified. Advances in diagnostic testing strategies, including the use of nucleic acid amplification tests, have raised new questions about the optimal approach to diagnosing CDI in children. Novel therapeutic options are available for adult patients with CDI, raising questions about the use of these agents in children. Updated recommendations about infection prevention and control measures are now available. We summarize these recent developments in pediatric CDI in this review and also highlight remaining knowledge gaps that should be addressed in future research efforts. PMID:23687578

From Stool Transplants to Next-generation Microbiota Therapeutics

PubMed Central

2014-01-01

The epidemic of Clostridium difficile infection fueled by new virulent strains of the organism has led to increased use of fecal microbiota transplantation (FMT). The procedure is effective for even the most desperate cases, after failure of multiple courses of antibiotics. The approach recognizes microbiota to be integral to normal human physiology, and microbiota being used in FMT represents a new class of therapeutics. Imbalance in the composition and altered activity of the microbiota are associated with many diseases. Consequently, there is growing interest in applying FMT to non-C. difficile indications. However, this may succeed only if microbiota therapeutics are developed systematically, based on mechanistic understanding, and applying updo-date principles of microbial ecology. We discuss two pathways in development of this new therapeutic class: whole microbial communities separated from donor stool and an assembly of specific fecal microorganisms grown in vitro. PMID:24412527

Clostridium difficile suppresses colonic vasoactive intestinal peptide associated with altered motility

PubMed Central

Nassif, A.; Sexe, R.; Stratton, M.; Standeven, J.; Vernava, A. M.; Kaminski, D. L.

1995-01-01

We investigated whether Clostridium difficile toxin alters colonic tissue levels of vasoactive intestinal peptide (VIP) at the expense of changes in colonic motility in the isolated perfused rabbit left colon. Colonic inflammation was induced by the intracolonic administration of 10−8 M C. difflcile toxin. Strain gauge transducers were sewn onto the serosal surface of the colon to evaluate colonic motility. C. difflcile administration produced histologic changes consistent with epithelial damage. This was associated with an increased production of prostaglandin E2 and thromboxane B2. Tissue levels of VIP but not substance P were significantly reduced. This was associated with an increased number of contractions per minute and an average force of each colonic contraction. These results suggest that tissue levels of VIP are suppressed by C. difflcile and may participate in colonic dysmotility during active inflammation. PMID:18475679

Hospital management of Clostridium difficile infection: a review of the literature.

PubMed

Khanafer, N; Voirin, N; Barbut, F; Kuijper, E; Vanhems, P

2015-06-01

The emergence of the epidemic Clostridium difficile 027 strain has renewed interest in infection control practices. To review the effectiveness of different practices to reduce hospital C. difficile infection (CDI) in non-outbreak settings. Data sources were identified by a MEDLINE search in English and French. The ORION statement was used to extract key data from articles describing interventions to manage CDI. Twenty-one studies, published between 1982 and December 2013, were reviewed. Most studies were before-after interventions, and a few studies were planned, formal, prospective investigations. The effects of the following single or combined interventions were described: antibiotic management; environmental disinfection and/or cleaning; hand hygiene; bathing; surveillance; cohorting; and isolation of infected patients in private rooms. With many methodological weaknesses and some inadequate research reporting, the observed reduction in CDI may not be entirely attributable to interventions. Although infection control programmes involving education and handwashing/gloving protocols were found to have contributed to a reduction in the incidence of CDI, these measures were usually a component of multi-faceted interventions that did not provide for evaluation of the relative impact of each factor. Appropriate environmental disinfection and antibiotic stewardship would appear to offer the most effective benefits. Copyright © 2015 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Clostridium difficile in the ICU: the struggle continues.

PubMed

Bobo, Linda D; Dubberke, Erik R; Kollef, Marin

2011-12-01

Clostridium difficile infection (CDI) management has become more daunting over the past decade because of alarming increases in CDI incidence and severity both in the hospital and in the community. This increase has concomitantly caused significant escalation of the health-care economic burden caused by CDI, and it will likely be translated to increased ICU admission and attributable mortality. Some possible causes for difficulty in management of CDI are as follows: (1) inability to predict and prevent development of severe/complicated or relapsing CDI in patients who initially present with mild symptoms; (2) lack of a method to determine who would have benefited a priori from initiating vancomycin treatment first instead of treatment with metronidazole; (3) lack of sensitive and specific CDI diagnostics; (4) changing epidemiology of CDI, including the emergence of a hypervirulent, epidemic C difficile strain associated with increased morbidity and mortality; (5) association of certain high-usage nonantimicrobial medications with CDI; and (6) lack of treatment regimens that leave the normal intestinal flora undisturbed while treating the primary infection. The objective of this article is to present current management and prevention guidelines for CDI based on recommendations by the Society for Healthcare Epidemiology of America and Infectious Diseases Society of America and potential new clinical management strategies on the horizon.

Clostridium difficile in the ICU

PubMed Central

Dubberke, Erik R.; Kollef, Marin

2011-01-01

Clostridium difficile infection (CDI) management has become more daunting over the past decade because of alarming increases in CDI incidence and severity both in the hospital and in the community. This increase has concomitantly caused significant escalation of the health-care economic burden caused by CDI, and it will likely be translated to increased ICU admission and attributable mortality. Some possible causes for difficulty in management of CDI are as follows: (1) inability to predict and prevent development of severe/complicated or relapsing CDI in patients who initially present with mild symptoms; (2) lack of a method to determine who would have benefited a priori from initiating vancomycin treatment first instead of treatment with metronidazole; (3) lack of sensitive and specific CDI diagnostics; (4) changing epidemiology of CDI, including the emergence of a hypervirulent, epidemic C difficile strain associated with increased morbidity and mortality; (5) association of certain high-usage nonantimicrobial medications with CDI; and (6) lack of treatment regimens that leave the normal intestinal flora undisturbed while treating the primary infection. The objective of this article is to present current management and prevention guidelines for CDI based on recommendations by the Society for Healthcare Epidemiology of America and Infectious Diseases Society of America and potential new clinical management strategies on the horizon. PMID:22147824

Association of Velopharyngeal Insufficiency With Quality of Life and Patient-Reported Outcomes After Speech Surgery.

PubMed

Bhuskute, Aditi; Skirko, Jonathan R; Roth, Christina; Bayoumi, Ahmed; Durbin-Johnson, Blythe; Tollefson, Travis T

2017-09-01

Patients with cleft palate and other causes of velopharyngeal insufficiency (VPI) suffer adverse effects on social interactions and communication. Measurement of these patient-reported outcomes is needed to help guide surgical and nonsurgical care. To further validate the VPI Effects on Life Outcomes (VELO) instrument, measure the change in quality of life (QOL) after speech surgery, and test the association of change in speech with change in QOL. Prospective descriptive cohort including children and young adults undergoing speech surgery for VPI in a tertiary academic center. Participants completed the validated VELO instrument before and after surgical treatment. The main outcome measures were preoperative and postoperative VELO scores and the perceptual speech assessment of speech intelligibility. The VELO scores are divided into subscale domains. Changes in VELO after surgery were analyzed using linear regression models. VELO scores were analyzed as a function of speech intelligibility adjusting for age and cleft type. The correlation between speech intelligibility rating and VELO scores was estimated using the polyserial correlation. Twenty-nine patients (13 males and 16 females) were included. Mean (SD) age was 7.9 (4.1) years (range, 4-20 years). Pharyngeal flap was used in 14 (48%) cases, Furlow palatoplasty in 12 (41%), and sphincter pharyngoplasty in 1 (3%). The mean (SD) preoperative speech intelligibility rating was 1.71 (1.08), which decreased postoperatively to 0.79 (0.93) in 24 patients who completed protocol (P < .01). The VELO scores improved after surgery (P<.001) as did most subscale scores. Caregiver impact did not change after surgery (P = .36). Speech Intelligibility was correlated with preoperative and postoperative total VELO score (P < .01) and to preoperative subscale domains (situational difficulty [VELO-SiD, P = .005] and perception by others [VELO-PO, P = .05]) and postoperative subscale domains (VELO-SiD [P = .03], VELO-PO [P = .003]). Neither the VELO total nor subscale score change after surgery was correlated with change in speech intelligibility. Speech surgery improves VPI-specific quality of life. We confirmed validation in a population of untreated patients with VPI and included pharyngeal flap surgery, which had not previously been included in validation studies. The VELO instrument provides patient-specific outcomes, which allows a broader understanding of the social, emotional, and physical effects of VPI. 2.

A 35-year experience with syndromic cleft palate repair: operative outcomes and long-term speech function.

PubMed

Basta, Marten N; Silvestre, Jason; Stransky, Carrie; Solot, Cynthia; Cohen, Marilyn; McDonald-McGinn, Donna; Zackai, Elaine; Kirschner, Richard; Low, David W; Randall, Peter; LaRossa, Don; Jackson, Oksana A

2014-12-01

Associated comorbidities can put syndromic patients with cleft palate at risk for poor speech outcomes. Reported rates of velopharyngeal insufficiency (VPI) vary from 8% to 64%, and need for secondary VPI surgery from 23% to 64%, with few studies providing long-term follow-up. The purpose of this study was to describe our institutional long-term experience with syndromic patients undergoing cleft palatoplasty. A retrospective review was conducted of all patients with syndromic diagnoses undergoing primary Furlow palatoplasty from 1975 to 2011. Outcomes included postoperative oronasal fistula (ONF) and need for secondary VPI surgery. Speech scores for verbal patients 5 years or older were collected via the Pittsburgh scale for speech assessment. Aggregate scores categorized the velopharyngeal mechanism as competent, borderline, or incompetent. Outcomes were analyzed by patient and operative factors. One hundred thirty-two patients were included with average age at repair of 20.7 months. Cleft type was 9% submucosal, 16% Veau class I, 50% class II, 12% class III, and 13% class IV. Forty-five syndromes were recorded, most commonly Stickler syndrome (n = 32) and 22q11.2 deletion syndrome [22q11.2DS (n = 19)]. Forty-four patients also had associated Pierre Robin sequence (PRS). The overall ONF rate was 4.5% and was highest in Veau class IV clefts (P = 0.048). Seventy-six patients were included in speech analysis, with an average age at last assessment of 10.4 years. Overall, 60.5% of patients had a competent velopharyngeal mechanism, 23.7% borderline, and 15.8% incompetent mechanism. Fifty percent of 22q11.2DS patients had borderline speech and none had competent speech, compared to 73.3% with Stickler syndrome (P = 0.01) and 71.4% of patients with associated PRS (P = 0.02). Secondary VPI surgery was performed in 11.4% of patients overall. Patients with PRS (13.6%) and with Stickler syndrome (15.6%) had secondary VPI surgery, compared to 31.6% of patients with 22q11.2DS (P = 0.01). This study demonstrates low rates of postoperative ONF after modified Furlow palatoplasty in syndromic patients. Speech outcomes were comparable to nonsyndromic patients at our institution, but patients with 22q11.2DS consistently had borderline-incompetent speech and a 3-fold higher incidence of secondary VPI surgery.

Gut Microbiota Patterns Associated with Colonization of Different Clostridium difficile Ribotypes

PubMed Central

Skraban, Jure; Dzeroski, Saso; Zenko, Bernard; Mongus, Domen; Gangl, Simon; Rupnik, Maja

2013-01-01

C. difficile infection is associated with disturbed gut microbiota and changes in relative frequencies and abundance of individual bacterial taxons have been described. In this study we have analysed bacterial, fungal and archaeal microbiota by denaturing high pressure liquid chromatography (DHPLC) and with machine learning methods in 208 faecal samples from healthy volunteers and in routine samples with requested C. difficile testing. The latter were further divided according to stool consistency, C. difficile presence or absence and C. difficile ribotype (027 or non-027). Lower microbiota diversity was a common trait of all routine samples and not necessarily connected only to C. difficile colonisation. Differences between the healthy donors and C. difficile positive routine samples were detected in bacterial, fungal and archaeal components. Bifidobacterium longum was the single most important species associated with C. difficile negative samples. However, by machine learning approaches we have identified patterns of microbiota composition predictive for C. difficile colonization. Those patterns also differed between samples with C. difficile ribotype 027 and other C. difficile ribotypes. The results indicate that not only the presence of a single species/group is important but that certain combinations of gut microbes are associated with C. difficile carriage and that some ribotypes (027) might be associated with more disturbed microbiota than the others. PMID:23469128

Evaluation of formalin-inactivated Clostridium difficile vaccines administered by parenteral and mucosal routes of immunization in hamsters.

PubMed Central

Torres, J F; Lyerly, D M; Hill, J E; Monath, T P

1995-01-01

Clostridium difficile produces toxins that cause inflammation, necrosis, and fluid in the intestine and is the most important cause of nosocomial antibiotic-associated diarrhea and colitis. We evaluated C. difficile antigens as vaccines to protect against systemic and intestinal disease in a hamster model of clindamycin colitis. Formalin-inactivated culture filtrates from a highly toxigenic strain were administered by mucosal routes (intranasal, intragastric, and rectal) with cholera toxin as a mucosal adjuvant. A preparation of culture filtrate and killed whole cells was also tested rectally. The toxoid was also tested parenterally (subcutaneously and intraperitoneally) and by a combination of three intranasal immunizations followed by a combined intranasal-intraperitoneal boost. Serum antibodies against toxins A and B and whole-cell antigen were measured by enzyme-linked immunosorbent assay, neutralization of cytotoxic activity, and bacterial agglutination. The two rectal immunization regimens induced low antibody responses and protected only 20% of hamsters against death and 0% against diarrhea. The intragastric regimen induced high antibody responses but low protection, 40% against death and 0% against diarrhea. Hamsters immunized by the intranasal, intraperitoneal, and subcutaneous routes were 100% protected against death and partially protected (40, 40, and 20%, respectively) against diarrhea. Among the latter groups, intraperitoneally immunized animals had the highest serum anticytotoxic activity and the highest agglutinating antibody responses. Hamsters immunized intranasally and revaccinated intraperitoneally were 100% protected against both death and diarrhea. Protection against death and diarrhea correlated with antibody responses to all antigens tested. The results indicate that optimal protection against C. difficile disease can be achieved with combined parenteral and mucosal immunization. PMID:7591115

Faecal lactoferrin and calprotectin in patients with Clostridium difficile infection: a case-control study.

PubMed

Barbut, F; Gouot, C; Lapidus, N; Suzon, L; Syed-Zaidi, R; Lalande, V; Eckert, C

2017-12-01

Calprotectin and lactoferrin are released by the gastrointestinal tract in response to infection and mucosal inflammation. Our objective was to assess the usefulness of quantifying faecal lactoferrin and calprotectin concentrations in Clostridium difficile infection (CDI) patients with or without free toxins in the stools. We conducted a single-centre 22-month case-control study. Patients with a positive CDI diagnosis were compared to two control groups: group 1 = diarrhoeic patients negative for C. difficile and matched (1:1) to CDI cases on the ward location and age, and group 2 = diarrhoeic patients colonised with a non-toxigenic strain of C. difficile. Faecal lactoferrin and calprotectin concentrations in faeces were determined for patients with CDI and controls. Of 135 patients with CDI, 87 (64.4%) had a positive stool cytotoxicity assay (free toxin) and 48 (35.6%) had a positive toxigenic culture without detectable toxins in the stools. The median lactoferrin values were 26.8 μg/g, 8.0 μg/g and 15.8 μg/g in CDI patients and groups 1 and 2, respectively. The median calprotectin values were 218.0 μg/g, 111.5 μg/g and 111.3 μg/g, respectively. Among patients with CDI, faecal lactoferrin and calprotectin levels were higher in those with free toxins in their stools (39.2 vs. 10.2 μg/g, p = 0.003 and 274.0 vs. 166.0 μg/g, p = 0.051, respectively). Both faecal calprotectin and lactoferrin were higher in patients with CDI, especially in those with detectable toxin in faeces, suggesting a correlation between intestinal inflammation and toxins in stools.

Harnessing the glucosyltransferase activities of Clostridium difficile for functional studies of toxins A and B.

PubMed

Darkoh, Charles; Kaplan, Heidi B; Dupont, Herbert L

2011-08-01

The incidence of Clostridium difficile infection (CDI) has been increasing within the last decade. Pathogenic strains of C. difficile produce toxin A and/or toxin B, which are important virulence factors in the pathogenesis of this bacterium. Current methods for diagnosing CDI are mostly qualitative tests that detect either the bacterium or the toxins. We have developed an assay (Cdifftox activity assay) to detect C. difficile toxin A and B activities that is quantitative and cost-efficient and utilizes a substrate that is stereochemically similar to the native substrate of the toxins (UDP-glucose). To characterize toxin activity, toxins A and B were purified from culture supernatants by ammonium sulfate precipitation and chromatography through DEAE-Sepharose and gel filtration columns. The activities of the final fractions were quantitated using the Cdifftox activity assay and compared to the results of a toxin A- and B-specific enzyme-linked immunosorbent assay (ELISA). The affinity for the substrate was >4-fold higher for toxin B than for toxin A. Moreover, the rate of cleavage of the substrate was 4.3-fold higher for toxin B than for toxin A. The optimum temperature for both toxins ranged from 35 to 40°C at pH 8. Culture supernatants from clinical isolates obtained from the stools of patients suspected to be suffering from CDI were tested using the Cdifftox activity assay, and the results were compared to those of ELISA and PCR amplification of the toxin genes. Our results demonstrate that this new assay is comparable to the current commercial ELISA for detecting the toxins in the samples tested and has the added advantage of quantitating toxin activity.

Update of treatment algorithms for Clostridium difficile infection.

PubMed

Ooijevaar, R E; van Beurden, Y H; Terveer, E M; Goorhuis, A; Bauer, M P; Keller, J J; Mulder, C J J; Kuijper, E J

2018-05-01

Clostridium difficile is the leading cause of antibiotic-associated diarrhoea, both in healthcare facilities and in the community. The recurrence rate of C. difficile infection (CDI) remains high, up to 20%. Since the publication of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) guidance document on CDI treatment in 2014, new therapeutic approaches have been developed and tested to achieve higher sustained clinical cure in CDI. To review novel treatments and approaches for CDI, except probiotics and vaccines. We focused on new antibiotics, antibiotic inactivators, monoclonal antibodies and gut microbiota modulating therapies. A literature review was performed for clinical trials published in PubMed, Embase or Cochrane Library between January 2013 and November 2017. We analysed 28 clinical trials and identified 14 novel agents. Completed phase 2 studies were found for cadazolid, LFF571, ridinilazole and nontoxigenic C. difficile strains. Four phase 3 active comparator studies comparing vancomycin with bezlotoxumab, surotomycin (n = 2) and rifaximin have been published. Seven clinical trials for treatment of multiple recurrent CDI with faecal microbiota transplantation were analysed, describing faecal microbiota transplantation by upper or lower gastrointestinal route (n = 5) or by capsules (n = 2). Metronidazole is mentioned in the ESCMID guideline as first-line therapy, but we propose that oral vancomycin will become the first choice when antibiotic treatment for CDI is necessary. Fidaxomicin is a good alternative, especially in patients at risk of relapse. Vancomycin combined with faecal microbiota transplantation remains the primary therapy for multiple recurrent CDI. We anticipate that new medication that protects the gut microbiota will be further developed and tested to prevent CDI during antibiotic therapy. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Multiplex Real-Time PCR Method for Simultaneous Identification and Toxigenic Type Characterization of Clostridium difficile From Stool Samples

PubMed Central

Alam, Mohammad J.; Tisdel, Naradah L.; Shah, Dhara N.; Yapar, Mehmet; Lasco, Todd M.; Garey, Kevin W.

2015-01-01

Background The aim of this study was to develop and validate a multiplex real-time PCR assay for simultaneous identification and toxigenic type characterization of Clostridium difficile. Methods The multiplex real-time PCR assay targeted and simultaneously detected triose phosphate isomerase (tpi) and binary toxin (cdtA) genes, and toxin A (tcdA) and B (tcdB) genes in the first and sec tubes, respectively. The results of multiplex real-time PCR were compared to those of the BD GeneOhm Cdiff assay, targeting the tcdB gene alone. The toxigenic culture was used as the reference, where toxin genes were detected by multiplex real-time PCR. Results A total of 351 stool samples from consecutive patients were included in the study. Fifty-five stool samples (15.6%) were determined to be positive for the presence of C. difficile by using multiplex real-time PCR. Of these, 48 (87.2%) were toxigenic (46 tcdA and tcdB-positive, two positive for only tcdB) and 11 (22.9%) were cdtA-positive. The sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of the multiplex real-time PCR compared with the toxigenic culture were 95.6%, 98.6%, 91.6%, and 99.3%, respectively. The analytical sensitivity of the multiplex real-time PCR assay was determined to be 103colonyforming unit (CFU)/g spiked stool sample and 0.0625 pg genomic DNA from culture. Analytical specificity determined by using 15 enteric and non-clostridial reference strains was 100%. Conclusions The multiplex real-time PCR assay accurately detected C. difficile isolates from diarrheal stool samples and characterized its toxin genes in a single PCR run. PMID:25932438

Comparison of Diagnostic Algorithms for Detecting Toxigenic Clostridium difficile in Routine Practice at a Tertiary Referral Hospital in Korea.

PubMed

Moon, Hee-Won; Kim, Hyeong Nyeon; Hur, Mina; Shim, Hee Sook; Kim, Heejung; Yun, Yeo-Min

2016-01-01

Since every single test has some limitations for detecting toxigenic Clostridium difficile, multistep algorithms are recommended. This study aimed to compare the current, representative diagnostic algorithms for detecting toxigenic C. difficile, using VIDAS C. difficile toxin A&B (toxin ELFA), VIDAS C. difficile GDH (GDH ELFA, bioMérieux, Marcy-l'Etoile, France), and Xpert C. difficile (Cepheid, Sunnyvale, California, USA). In 271 consecutive stool samples, toxigenic culture, toxin ELFA, GDH ELFA, and Xpert C. difficile were performed. We simulated two algorithms: screening by GDH ELFA and confirmation by Xpert C. difficile (GDH + Xpert) and combined algorithm of GDH ELFA, toxin ELFA, and Xpert C. difficile (GDH + Toxin + Xpert). The performance of each assay and algorithm was assessed. The agreement of Xpert C. difficile and two algorithms (GDH + Xpert and GDH+ Toxin + Xpert) with toxigenic culture were strong (Kappa, 0.848, 0.857, and 0.868, respectively). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of algorithms (GDH + Xpert and GDH + Toxin + Xpert) were 96.7%, 95.8%, 85.0%, 98.1%, and 94.5%, 95.8%, 82.3%, 98.5%, respectively. There were no significant differences between Xpert C. difficile and two algorithms in sensitivity, specificity, PPV and NPV. The performances of both algorithms for detecting toxigenic C. difficile were comparable to that of Xpert C. difficile. Either algorithm would be useful in clinical laboratories and can be optimized in the diagnostic workflow of C. difficile depending on costs, test volume, and clinical needs.

Results of speech improvement following simultaneous push-back together with velopharyngeal flap surgery in cleft palate patients.

PubMed

Wermker, Kai; Lünenbürger, Henning; Joos, Ulrich; Kleinheinz, Johannes; Jung, Susanne

2014-07-01

Velopharyngeal insufficiency (VPI) can be caused by a variety of disorders. The most common cause of VPI is the association with cleft palate. The aim of this study was to evaluate the effectiveness of different surgical techniques for cleft palate patients with VPI: (1) velopharyngoplasty with an inferiorly based posterior pharyngeal flap (VPP posterior, Schönborn-Rosenthal), and (2) combination of VPP posterior and push-back operation (Dorrance). 41 subjects (26 females, 15 males) with VPI were analysed. Hypernasality was judged subjectively and nasalance data were assessed objectively using the NasalView system preoperative and 6 months postoperative. Subjective analysis showed improved speech results regarding hypernasality for all OP-techniques with good results for VPP posterior and VPP posterior combined with push-back with success rates of 94.4% and 87.7%, respectively. Objective analysis showed a statistically significant reduction of nasalance for both VPP posterior and VPP posterior combined with push-back (p < 0.01). However, there were no statistically significant differences concerning measured nasalance values postoperatively between the VPP posterior and VPP posterior combined with push-back. Based on our findings, both VPP posterior and VPP posterior combined with push-back showed good results in correction of hypernasality in cleft patients with velopharyngeal insufficiency. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

A New Class of Metal-Cyclam-Based Zirconium Metal-Organic Frameworks for CO2 Adsorption and Chemical Fixation.

PubMed

Zhu, Jie; Usov, Pavel M; Xu, Wenqian; Celis-Salazar, Paula J; Lin, Shaoyang; Kessinger, Matthew C; Landaverde-Alvarado, Carlos; Cai, Meng; May, Ann M; Slebodnick, Carla; Zhu, Dunru; Senanayake, Sanjaya D; Morris, Amanda J

2018-01-24

Metal-organic frameworks (MOFs) have shown great promise in catalysis, mainly due to their high content of active centers, large internal surface areas, tunable pore size, and versatile chemical functionalities. However, it is a challenge to rationally design and construct MOFs that can serve as highly stable and reusable heterogeneous catalysts. Here two new robust 3D porous metal-cyclam-based zirconium MOFs, denoted VPI-100 (Cu) and VPI-100 (Ni), have been prepared by a modulated synthetic strategy. The frameworks are assembled by eight-connected Zr 6 clusters and metallocyclams as organic linkers. Importantly, the cyclam core has accessible axial coordination sites for guest interactions and maintains the electronic properties exhibited by the parent cyclam ring. The VPI-100 MOFs exhibit excellent chemical stability in various organic and aqueous solvents over a wide pH range and show high CO 2 uptake capacity (up to ∼9.83 wt% adsorption at 273 K under 1 atm). Moreover, VPI-100 MOFs demonstrate some of the highest reported catalytic activity values (turnover frequency and conversion efficiency) among Zr-based MOFs for the chemical fixation of CO 2 with epoxides, including sterically hindered epoxides. The MOFs, which bear dual catalytic sites (Zr and Cu/Ni), enable chemistry not possible with the cyclam ligand under the same conditions and can be used as recoverable stable heterogeneous catalysts without losing performance.

Speech in 10-Year-Olds Born With Cleft Lip and Palate: What Do Peers Say?

PubMed

Nyberg, Jill; Havstam, Christina

2016-09-01

The aim of this study was to explore how 10-year-olds describe speech and communicative participation in children born with unilateral cleft lip and palate in their own words, whether they perceive signs of velopharyngeal insufficiency (VPI) and articulation errors of different degrees, and if so, which terminology they use. Methods/Participants: Nineteen 10-year-olds participated in three focus group interviews where they listened to 10 to 12 speech samples with different types of cleft speech characteristics assessed by speech and language pathologists (SLPs) and described what they heard. The interviews were transcribed and analyzed with qualitative content analysis. The analysis resulted in three interlinked categories encompassing different aspects of speech, personality, and social implications: descriptions of speech, thoughts on causes and consequences, and emotional reactions and associations. Each category contains four subcategories exemplified with quotes from the children's statements. More pronounced signs of VPI were perceived but referred to in terms relevant to 10-year-olds. Articulatory difficulties, even minor ones, were noted. Peers reflected on the risk to teasing and bullying and on how children with impaired speech might experience their situation. The SLPs and peers did not agree on minor signs of VPI, but they were unanimous in their analysis of clinically normal and more severely impaired speech. Articulatory impairments may be more important to treat than minor signs of VPI based on what peers say.

Combination of culture, antigen and toxin detection, and cytotoxin neutralization assay for optimal Clostridium difficile diagnostic testing

PubMed Central

Alfa, Michelle J; Sepehri, Shadi

2013-01-01

BACKGROUND: There has been a growing interest in developing an appropriate laboratory diagnostic algorithm for Clostridium difficile, mainly as a result of increases in both the number and severity of cases of C difficile infection in the past decade. A C difficile diagnostic algorithm is necessary because diagnostic kits, mostly for the detection of toxins A and B or glutamate dehydrogenase (GDH) antigen, are not sufficient as stand-alone assays for optimal diagnosis of C difficile infection. In addition, conventional reference methods for C difficile detection (eg, toxigenic culture and cytotoxin neutralization [CTN] assays) are not routinely practiced in diagnostic laboratory settings. OBJECTIVE: To review the four-step algorithm used at Diagnostic Services of Manitoba sites for the laboratory diagnosis of toxigenic C difficile. RESULT: One year of retrospective C difficile data using the proposed algorithm was reported. Of 5695 stool samples tested, 9.1% (n=517) had toxigenic C difficile. Sixty per cent (310 of 517) of toxigenic C difficile stools were detected following the first two steps of the algorithm. CTN confirmation of GDH-positive, toxin A- and B-negative assays resulted in detection of an additional 37.7% (198 of 517) of toxigenic C difficile. Culture of the third specimen, from patients who had two previous negative specimens, detected an additional 2.32% (12 of 517) of toxigenic C difficile samples. DISCUSSION: Using GDH antigen as the screening and toxin A and B as confirmatory test for C difficile, 85% of specimens were reported negative or positive within 4 h. Without CTN confirmation for GDH antigen and toxin A and B discordant results, 37% (195 of 517) of toxigenic C difficile stools would have been missed. Following the algorithm, culture was needed for only 2.72% of all specimens submitted for C difficile testing. CONCLUSION: The overview of the data illustrated the significance of each stage of this four-step C difficile algorithm and emphasized the value of using CTN assay and culture as parts of an algorithm that ensures accurate diagnosis of toxigenic C difficile. PMID:24421808

Trypsin-dependent production of an antibacterial substance by a human Peptostreptococcus strain in gnotobiotic rats and in vitro.

PubMed

Ramare, F; Nicoli, J; Dabard, J; Corring, T; Ladire, M; Gueugneau, A M; Raibaud, P

1993-09-01

An antibacterial substance appeared within 1 day in feces of gnotobiotic rats harboring a human intestinal Peptostreptococcus strain. It disappeared when the rat bile-pancreatic duct was ligatured or when the rats ingested a trypsin inhibitor. Anaerobic cultures of the Peptostreptococcus strain in a medium supplemented with trypsin also exhibited an antibacterial activity, which was also inhibited by the trypsin inhibitor. In vitro the antibacterial substance from both feces and culture medium was active against several gram-positive bacteria, including other Peptostreptococcus spp., potentially pathogenic Clostridium spp. such as C. perfringens, C. difficile, C. butyricum, C. septicum, and C. sordellii, Eubacterium spp., Bifidobacterium spp., and Bacillus spp. Whatever the order of inoculation of the strains, a sensitive strain of C. perfringens was eliminated within 1 day from the intestine of rats monoassociated with the Peptostreptococcus strain. These findings demonstrate for the first time that very potent antibacterial substances can be produced through a mechanism involving intestinal bacteria and exocrine pancreatic secretions.

Clostridium difficile infection in solid organ transplant recipients.

PubMed

Nanayakkara, Deepa; Nanda, Neha

2017-08-01

Clostridium difficile infection (CDI) is a major healthcare-associated infection that causes significant morbidity and an economic impact in the United States. In this review, we provide an overview of Clostridium difficile infection in solid organ transplant recipients with an emphasis on recent literature. C. difficile in solid organ transplant population has unique risk factors. Fecal microbiota transplantation has shown favorable results in treatment of recurrent C. difficile in this population. Preliminary data from animal studies suggests excellent efficacy with immunization against C. difficile toxins. Over the last decade, number of individuals receiving solid organ transplants has increased exponentially making peri-transplant complications a common occurrence.C. difficile is a frequent cause of morbidity in solid organ transplant recipients. Early and accurate diagnosis of C. difficile requires a stepwise approach. Differentiating between asymptomatic carriage and infection is a diagnostic challenge. Microbial diversity is inversely proportional to risk of C. difficile infection. Antimicrobial stewardship programs help to retain microbial diversity in individuals susceptible to CDI. Recurrent or relapsing C. difficile infection require fecal microbiota transplantation for definitive cure.

C. difficile Infection

MedlinePlus

... Patients Home / Digestive Health Topic / C. Difficile Infection C. Difficile Infection Basics Overview Diarrhea is a frequent ... that change the normal colon bacteria allowing the C. difficile bacteria to grow and produce its toxins. ...

Functional Intestinal Bile Acid 7α-Dehydroxylation by Clostridium scindens Associated with Protection from Clostridium difficile Infection in a Gnotobiotic Mouse Model.

PubMed

Studer, Nicolas; Desharnais, Lyne; Beutler, Markus; Brugiroux, Sandrine; Terrazos, Miguel A; Menin, Laure; Schürch, Christian M; McCoy, Kathy D; Kuehne, Sarah A; Minton, Nigel P; Stecher, Bärbel; Bernier-Latmani, Rizlan; Hapfelmeier, Siegfried

2016-01-01

Bile acids, important mediators of lipid absorption, also act as hormone-like regulators and as antimicrobial molecules. In all these functions their potency is modulated by a variety of chemical modifications catalyzed by bacteria of the healthy gut microbiota, generating a complex variety of secondary bile acids. Intestinal commensal organisms are well-adapted to normal concentrations of bile acids in the gut. In contrast, physiological concentrations of the various intestinal bile acid species play an important role in the resistance to intestinal colonization by pathogens such as Clostridium difficile . Antibiotic therapy can perturb the gut microbiota and thereby impair the production of protective secondary bile acids. The most important bile acid transformation is 7α-dehydroxylation, producing deoxycholic acid (DCA) and lithocholic acid (LCA). The enzymatic pathway carrying out 7α-dehydroxylation is restricted to a narrow phylogenetic group of commensal bacteria, the best-characterized of which is Clostridium scindens . Like many other intestinal commensal species, 7-dehydroxylating bacteria are understudied in vivo . Conventional animals contain variable and uncharacterized indigenous 7α-dehydroxylating organisms that cannot be selectively removed, making controlled colonization with a specific strain in the context of an undisturbed microbiota unfeasible. In the present study, we used a recently established, standardized gnotobiotic mouse model that is stably associated with a simplified murine 12-species "oligo-mouse microbiota" (Oligo-MM 12 ). It is representative of the major murine intestinal bacterial phyla, but is deficient for 7α-dehydroxylation. We find that the Oligo-MM 12 consortium carries out bile acid deconjugation, a prerequisite for 7α-dehydroxylation, and confers no resistance to C. difficile infection (CDI). Amendment of Oligo-MM 12 with C. scindens normalized the large intestinal bile acid composition by reconstituting 7α-dehydroxylation. These changes had only minor effects on the composition of the native Oligo-MM 12 , but significantly decreased early large intestinal C. difficile colonization and pathogenesis. The delayed pathogenesis of C. difficile in C. scindens -colonized mice was associated with breakdown of cecal microbial bile acid transformation.

Clinical and Microbiologic Characteristics of Clostridium difficile Infection Caused by Binary Toxin Producing Strain in Korea.

PubMed

Kim, Jieun; Seo, Mi-Ran; Kang, Jung Oak; Choi, Tae Yeal; Pai, Hyunjoo

2013-06-01

Binary toxin-producing Clostridium difficile infections (CDI) are known to be more severe and to cause higher case fatality rates than those by binary toxin-negative isolates. There has been few data of binary toxin-producing CDI in Korea. Objective of the study is to characterize clinical and microbiological trait of CDI cause by binary-toxin producing isolates in Korea. From September 2008 through January 2010, clinical characteristics, medication history and treatment outcome of all the CDI patients were collected prospectively. Toxin characterization, PCR ribotyping and antibiotic susceptibility were performed with the stool isolates of C. difficile. During the period, CDI caused by 11binary toxin-producing isolates and 105 toxin A & toxin B-positive binary toxin-negative isolates were identified. Comparing the disease severity and clinical findings between two groups, leukocytosis and mucoid stool were more frequently observed in patients with binary toxin-positive isolates (OR: 5.2, 95% CI: 1.1 to 25.4, P = 0.043; OR: 7.6, 95% CI: 1.6 to 35.6, P = 0.010, respectively), but clinical outcome of 2 groups did not show any difference. For the risk factors for acquisition of binary toxin-positive isolates, previous use of glycopeptides was the significant risk factor (OR: 6.2, 95% CI: 1.4 to 28.6, P = 0.019), but use of probiotics worked as an inhibitory factor (OR: 0.1, 95% CI: 0.0 to 0.8; P = 0.026). PCR ribotypes of binary toxinproducing C. difficile showed variable patterns: ribotype 130, 4 isolates; 027, 3 isolates; 267 and 122, 1 each isolate and unidentified C1, 2 isolates. All 11 binary toxin-positive isolates were highly susceptible to clindamycin, moxifloxacin, metronidazole, vancomycin and piperacillin-tazobactam, however, 1 of 11 of the isolates was resistant to rifaximin. Binary toxin-producing C. difficile infection was not common in Korea and those isolates showed diverse PCR ribotypes with high susceptibility to antimicrobial agents. Glycopeptide use was a risk factor for CDI by those isolates.

Clinical and Microbiologic Characteristics of Clostridium difficile Infection Caused by Binary Toxin Producing Strain in Korea

PubMed Central

Kim, Jieun; Seo, Mi-ran; Kang, Jung Oak; Choi, Tae Yeal

2013-01-01

Background Binary toxin-producing Clostridium difficile infections (CDI) are known to be more severe and to cause higher case fatality rates than those by binary toxin-negative isolates. There has been few data of binary toxin-producing CDI in Korea. Objective of the study is to characterize clinical and microbiological trait of CDI cause by binary-toxin producing isolates in Korea. Materials and Methods From September 2008 through January 2010, clinical characteristics, medication history and treatment outcome of all the CDI patients were collected prospectively. Toxin characterization, PCR ribotyping and antibiotic susceptibility were performed with the stool isolates of C. difficile. Results During the period, CDI caused by 11binary toxin-producing isolates and 105 toxin A & toxin B-positive binary toxin-negative isolates were identified. Comparing the disease severity and clinical findings between two groups, leukocytosis and mucoid stool were more frequently observed in patients with binary toxin-positive isolates (OR: 5.2, 95% CI: 1.1 to 25.4, P = 0.043; OR: 7.6, 95% CI: 1.6 to 35.6, P = 0.010, respectively), but clinical outcome of 2 groups did not show any difference. For the risk factors for acquisition of binary toxin-positive isolates, previous use of glycopeptides was the significant risk factor (OR: 6.2, 95% CI: 1.4 to 28.6, P = 0.019), but use of probiotics worked as an inhibitory factor (OR: 0.1, 95% CI: 0.0 to 0.8; P = 0.026). PCR ribotypes of binary toxinproducing C. difficile showed variable patterns: ribotype 130, 4 isolates; 027, 3 isolates; 267 and 122, 1 each isolate and unidentified C1, 2 isolates. All 11 binary toxin-positive isolates were highly susceptible to clindamycin, moxifloxacin, metronidazole, vancomycin and piperacillin-tazobactam, however, 1 of 11 of the isolates was resistant to rifaximin. Conclusions Binary toxin-producing C. difficile infection was not common in Korea and those isolates showed diverse PCR ribotypes with high susceptibility to antimicrobial agents. Glycopeptide use was a risk factor for CDI by those isolates. PMID:24265965

Clostridium Difficile Infections

MedlinePlus

Clostridium difficile (C. difficile) is a bacterium that causes diarrhea and more serious intestinal conditions such as colitis. Symptoms include Watery ... Loss of appetite Nausea Abdominal pain or tenderness C. difficile is more common in people who need ...

[Clostridium difficile epidemic, Chile 2012: report of the Chilean Society for Infectious Diseases. A scientific historical analysis].

PubMed

Cabello, Felipe

2012-08-01

A Summary Report from the Chilean Society for Infectious Diseases regarding the presence of a Clostridium difficile epidemic with several fatalities in Chile's premier emergency public hospital in Santiago is used to make a scientific historical analysis of the situation. This Summary Report identifies several hygienic and sanitary shortcomings that may have played a role in triggering this major epidemic. These include deficiencies in hand washing policies, overcrowding of beds in wards, relaxation of infection control policies, antimicrobial therapy mismanagement and lack of laboratory support. The relevance of these shortcomings to the epidemic is further supported by the lack of any laboratory evidence for the presence of hypertoxigenic strains of C. difficile. In an era of whole genome sequencing of pathogens to guide therapy, prevention, and epidemiological studies of infectious diseases, it is illuminating and sobering, as this report so clearly demonstrates, to realize that many epidemics of hospital infections still result from breakdowns in classical and ancillary asepsis and infection control measures developed in the nineteenth century by Semmelweis, Nightingale and Lister. As the Summary Report suggests, such hygienic breakdowns in countries like Chile are usually brought about by lack of implementation and regulation of national hospital infection control policies resulting from the shift of economic resources from the public to the private sector, despite the former being responsible for health care of 80% of the population.

A case of toxic megacolon caused by clostridium difficile infection and treated with fecal microbiota transplantation.

PubMed

Gweon, Tae Geun; Lee, Kyung Jin; Kang, Dong Hoon; Park, Sung Soo; Kim, Kyung Hoon; Seong, Hyeon Jin; Ban, Tae Hyun; Moon, Sung Jin; Kim, Jin Su; Kim, Sang Woo

2015-03-01

Clostridium difficile infection. The mortality rate of fulminant C. difficile infection is reported to be as high as 50%. Fecal microbiota transplantation is a highly effective treatment in patients with recurrent or refractory C. difficile infection. However, there are few published articles on the use of such transplantation for fulminant C. difficile infection. Here, we report on a patient with toxic megacolon complicated by C. difficile infection who was treated successfully with fecal mi-crobiota transplantation. (Gut Liver, 2015;9:247-250).

A New Class of Metal-Cyclam-Based Zirconium Metal–Organic Frameworks for CO 2 Adsorption and Chemical Fixation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Jie; Usov, Pavel M.; Xu, Wenqian

Metal–organic frameworks (MOFs) have shown great promise in catalysis, mainly due to their high content of active centers, large internal surface areas, tunable pore size, and versatile chemical functionalities. However, it is a challenge to rationally design and construct MOFs that can serve as highly stable and reusable heterogeneous catalysts. Here two new robust 3D porous metal-cyclam-based zirconium MOFs, denoted VPI-100 (Cu) and VPI-100 (Ni), have been prepared by a modulated synthetic strategy. The frameworks are assembled by eight-connected Zr 6 clusters and metallocyclams as organic linkers. Importantly, the cyclam core has accessible axial coordination sites for guest interactions andmore » maintains the electronic properties exhibited by the parent cyclam ring. The VPI-100 MOFs exhibit excellent chemical stability in various organic and aqueous solvents over a wide pH range and show high CO 2 uptake capacity (up to ~9.83 wt% adsorption at 273 K under 1 atm). Moreover, VPI-100 MOFs demonstrate some of the highest reported catalytic activity values (turnover frequency and conversion efficiency) among Zr-based MOFs for the chemical fixation of CO 2 with epoxides, including sterically hindered epoxides. Thus, the MOFs, which bear dual catalytic sites (Zr and Cu/Ni), enable chemistry not possible with the cyclam ligand under the same conditions and can be used as recoverable stable heterogeneous catalysts without losing performance.« less

A New Class of Metal-Cyclam-Based Zirconium Metal–Organic Frameworks for CO 2 Adsorption and Chemical Fixation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Jie; Usov, Pavel M.; Xu, Wenqian

Metal-organic frameworks (MOFs) have shown great promise in catalysis, mainly due to their high content of active centers, large internal surface areas, tunable pore size, and versatile chemical functionalities. However, it is a challenge to rationally design and construct MOFs that can serve as highly stable and reusable heterogeneous catalysts. Here two new robust 3D porous metal-cyclam-based zirconium MOFs, denoted VPI-100 (Cu) and VPI-100 (Ni), have been prepared by a modulated synthetic strategy. The frameworks are assembled by eight-connected Zr-6 clusters and metallocyclams as organic linkers. Importantly, the cyclam core has accessible axial coordination sites for guest interactions and maintainsmore » the electronic properties exhibited by the parent cyclam ring. The VPI-100 MOFs exhibit excellent chemical stability in various organic and aqueous solvents over a wide pH range and show high CO2 uptake capacity (up to similar to 9.83 wt% adsorption at 273 K under 1 atm). Moreover, VPI-100 MOFs demonstrate some of the highest reported catalytic activity values (turnover frequency and conversion efficiency) among Zr-based MOFs for the chemical fixation of CO2 with epoxides, including sterically hindered epoxides. The MOFs, which bear dual catalytic sites (Zr and Cu/Ni), enable chemistry not possible with the cyclam ligand under the same conditions and can be used as recoverable stable heterogeneous catalysts without losing performance.« less

A New Class of Metal-Cyclam-Based Zirconium Metal–Organic Frameworks for CO 2 Adsorption and Chemical Fixation

DOE PAGES

Zhu, Jie; Usov, Pavel M.; Xu, Wenqian; ...

2017-12-22

Metal–organic frameworks (MOFs) have shown great promise in catalysis, mainly due to their high content of active centers, large internal surface areas, tunable pore size, and versatile chemical functionalities. However, it is a challenge to rationally design and construct MOFs that can serve as highly stable and reusable heterogeneous catalysts. Here two new robust 3D porous metal-cyclam-based zirconium MOFs, denoted VPI-100 (Cu) and VPI-100 (Ni), have been prepared by a modulated synthetic strategy. The frameworks are assembled by eight-connected Zr 6 clusters and metallocyclams as organic linkers. Importantly, the cyclam core has accessible axial coordination sites for guest interactions andmore » maintains the electronic properties exhibited by the parent cyclam ring. The VPI-100 MOFs exhibit excellent chemical stability in various organic and aqueous solvents over a wide pH range and show high CO 2 uptake capacity (up to ~9.83 wt% adsorption at 273 K under 1 atm). Moreover, VPI-100 MOFs demonstrate some of the highest reported catalytic activity values (turnover frequency and conversion efficiency) among Zr-based MOFs for the chemical fixation of CO 2 with epoxides, including sterically hindered epoxides. Thus, the MOFs, which bear dual catalytic sites (Zr and Cu/Ni), enable chemistry not possible with the cyclam ligand under the same conditions and can be used as recoverable stable heterogeneous catalysts without losing performance.« less

High Variability in Nosocomial Clostridium difficile Infection Rates Across Hospitals After Colorectal Resection.

PubMed

Aquina, Christopher T; Probst, Christian P; Becerra, Adan Z; Hensley, Bradley J; Iannuzzi, James C; Noyes, Katia; Monson, John R T; Fleming, Fergal J

2016-04-01

Hospital-acquired Clostridium difficile infection is associated with adverse patient outcomes and high medical costs. The incidence and severity of C. difficile has been rising in both medical and surgical patients. Our aim was to assess risk factors and variation associated with the development of nosocomial C. difficile colitis among patients undergoing colorectal resection. This was a retrospective cohort study. The study included segmental colectomy and proctectomy cases in New York State from 2005 to 2013. The study cohort included 150,878 colorectal resections. Patients with a documented previous history of C. difficile infection or residence outside of New York State were excluded. A diagnosis of C. difficile colitis either during the index hospital stay or on readmission within 30 days was the main measure. C. difficile colitis occurred in 3323 patients (2.2%). Unadjusted C. difficile colitis rates ranged from 0% to 11.3% among surgeons and 0% to 6.8% among hospitals. After controlling for patient, surgeon, and hospital characteristics using mixed-effects multivariable analysis, significant unexplained variation in C. difficile rates remained present across hospitals but not surgeons. Patient factors explained only 24% of the total hospital-level variation, and known surgeon and hospital-level characteristics explained an additional 8% of the total hospital-level variation. Therefore, ≈70% of the hospital variation in C. difficile infection rates remained unexplained by captured patient, surgeon, and hospital factors. Furthermore, there was an ≈5-fold difference in adjusted C. difficile rates across hospitals. A limited set of hospital and surgeon characteristics was available. Colorectal surgery patients appear to be at high risk for C. difficile infection, and alarming variation in nosocomial C. difficile infection rates currently exists among hospitals after colorectal resection. Given the high morbidity and cost associated with C. difficile colitis, adopting institutional quality improvement programs and maintaining strict prevention strategies are of the utmost importance.

Do piperacillin/tazobactam and other antibiotics with inhibitory activity against Clostridium difficile reduce the risk for acquisition of C. difficile colonization?

PubMed

Kundrapu, Sirisha; Sunkesula, Venkata C K; Jury, Lucy A; Cadnum, Jennifer L; Nerandzic, Michelle M; Musuuza, Jackson S; Sethi, Ajay K; Donskey, Curtis J

2016-04-18

Systemic antibiotics vary widely in in vitro activity against Clostridium difficile. Some agents with activity against C. difficile (e.g., piperacillin/tazobactam) inhibit establishment of colonization in mice. We tested the hypothesis that piperacillin/tazobactam and other agents with activity against C. difficile achieve sufficient concentrations in the intestinal tract to inhibit colonization in patients. Point-prevalence culture surveys were conducted to compare the frequency of asymptomatic rectal carriage of toxigenic C. difficile among patients receiving piperacillin/tazobactam or other inhibitory antibiotics (e.g. ampicillin, linezolid, carbapenems) versus antibiotics lacking activity against C. difficile (e.g., cephalosporins, ciprofloxacin). For a subset of patients, in vitro inhibition of C. difficile (defined as a reduction in concentration after inoculation of vegetative C. difficile into fresh stool suspensions) was compared among antibiotic treatment groups. Of 250 patients, 32 (13 %) were asymptomatic carriers of C. difficile. In comparison to patients receiving non-inhibitory antibiotics or prior antibiotics within 90 days, patients currently receiving piperacillin/tazobactam were less likely to be asymptomatic carriers (1/36, 3 versus 7/36, 19 and 15/69, 22 %, respectively; P = 0.024) and more likely to have fecal suspensions with in vitro inhibitory activity against C. difficile (20/28, 71 versus 3/11, 27 and 4/26, 15 %; P = 0.03). Patients receiving other inhibitory antibiotics were not less likely to be asymptomatic carriers than those receiving non-inhibitory antibiotics. Our findings suggest that piperacillin/tazobactam achieves sufficient concentrations in the intestinal tract to inhibit C. difficile colonization during therapy.

Clostridium difficile infection worsens the prognosis of ulcerative colitis

PubMed Central

Negrón, María E; Barkema, Herman W; Rioux, Kevin; De Buck, Jeroen; Checkley, Sylvia; Proulx, Marie-Claude; Frolkis, Alexandra; Beck, Paul L; Dieleman, Levinus A; Panaccione, Remo; Ghosh, Subrata; Kaplan, Gilaad G

2014-01-01

BACKGROUND: The impact of Clostridium difficile infections among ulcerative colitis (UC) patients is well characterized. However, there is little knowledge regarding the association between C difficile infections and postoperative complications among UC patients. OBJECTIVE: To determine whether C difficile infection is associated with undergoing an emergent colectomy and experiencing postoperative complications. METHODS: The present population-based case-control study identified UC patients admitted to Calgary Health Zone hospitals for a flare between 2000 and 2009. C difficile toxin tests ordered in hospital or 90 days before hospital admission were provided by Calgary Laboratory Services (Calgary, Alberta). Hospital records were reviewed to confirm diagnoses and to extract clinical data. Multivariate logistic regression analyses were performed among individuals tested for C difficile to examine the association between C difficile infection and emergent colectomy and diagnosis of any postoperative complications and, secondarily, an infectious postoperative complication. Estimates were presented as adjusted ORs with 95% CIs. RESULTS: C difficile was tested in 278 (58%) UC patients and 6.1% were positive. C difficile infection was associated with an increased risk for emergent colectomy (adjusted OR 3.39 [95% CI 1.02 to 11.23]). Additionally, a preoperative diagnosis of C difficile was significantly associated with the development of postoperative infectious complications (OR 4.76 [95% CI 1.10 to 20.63]). CONCLUSION: C difficile diagnosis worsened the prognosis of UC by increasing the risk of colectomy and postoperative infectious complications following colectomy. Future studies are needed to explore whether early detection and aggressive management of C difficile infection will improve UC outcomes. PMID:25157528

[Clostridium difficile infection: epidemiology, disease burden and therapy].

PubMed

Gulácsi, László; Kertész, Adrienne; Kopcsóné Németh, Irén; Banai, János; Ludwig, Endre; Prinz, Gyula; Reményi, Péter; Strbák, Bálint; Zsoldiné Urbán, Edit; Baji, Petra; Péntek, Márta; Brodszky, Valentin

2013-07-28

C. difficile causes 25 percent of the antibiotic associated infectious nosocomial diarrhoeas. C. difficile infection is a high-priority problem of public health in each country. The available literature of C. difficile infection's epidemiology and disease burden is limited. Review of the epidemiology, including seasonality and the risk of recurrences, of the disease burden and of the therapy of C. difficile infection. Review of the international and Hungarian literature in MEDLINE database using PubMed up to and including 20th of March, 2012. The incidence of nosocomial C. difficile associated diarrhoea is 4.1/10 000 patient day. The seasonality of C. difficile infection is unproved. 20 percent of the patients have recurrence after metronidazole or vancomycin treatment, and each recurrence increases the chance of a further one. The cost of C. difficile infection is between 130 and 500 thousand HUF (430 € and 1665 €) in Hungary. The importance of C. difficile infection in public health and the associated disease burden are significant. The available data in Hungary are limited, further studies in epidemiology and health economics are required.

Escherichia coli and selected veterinary and zoonotic pathogens isolated from environmental sites in companion animal veterinary hospitals in southern Ontario.

PubMed

Murphy, Colleen P; Reid-Smith, Richard J; Boerlin, Patrick; Weese, J Scott; Prescott, John F; Janecko, Nicol; Hassard, Lori; McEwen, Scott A

2010-09-01

Hospital-based infection control in veterinary medicine is emerging and the role of the environment in hospital-acquired infections (HAI) in veterinary hospitals is largely unknown. This study was initiated to determine the recovery of Escherichia coli and selected veterinary and zoonotic pathogens from the environments of 101 community veterinary hospitals. The proportion of hospitals with positive environmental swabs were: E. coli--92%, Clostridium difficile--58%, methicillin-resistant Staphylococcus aureus (MRSA)--9%, CMY-2 producing E. coli--9%, methicillin-resistant Staphylococcus pseudintermedius--7%, and Salmonella--2%. Vancomycin-resistant Enterococcus spp., canine parvovirus, and feline calicivirus were not isolated. Prevalence of antimicrobial resistance in E. coli isolates was low. Important potential veterinary and human pathogens were recovered including Canadian epidemic strains MRSA-2 and MRSA-5, and C. difficile ribotype 027. There is an environmental reservoir of pathogens in veterinary hospitals; therefore, additional studies are required to characterize risk factors associated with HAI in companion animals, including the role of the environment.

Clostridium difficile infection in the Lao People's Democratic Republic: first isolation and review of the literature.

PubMed

Cheong, Elaine; Roberts, Tamalee; Rattanavong, Sayaphet; Riley, Thomas V; Newton, Paul N; Dance, David A B

2017-09-21

Current knowledge of the epidemiology of Clostridium difficile infection in Asia, and in particular the Greater Mekong Subregion, is very limited. Only a few studies from Thailand and Vietnam have been reported from the region with variable testing methods and results, and no studies from Lao People's Democratic Republic (PDR). Therefore we investigated the presence of C. difficile in a single centre in the Lao PDR and determined the ribotypes present. Seventy unformed stool samples from hospital inpatients at Mahosot Hospital, Vientiane, were tested for the presence of C. difficile using selective differential agar and confirmed by latex agglutination. C. difficile isolates were further characterised by ribotyping and toxin gene detection. C. difficile was isolated from five of the 70 patients, and five different ribotypes were identified (014, 017, 020, QX 107 and QX 574). This is the first isolation of C. difficile from human stool samples in the Lao PDR. These results will add to the limited amount of data on C. difficile in the region. In addition, we hope this information will alert clinicians to the presence of C. difficile in the country and will help inform future investigations into the epidemiology and diagnosis of C. difficile in Lao PDR.

Treatment of Stress Velopharyngeal Incompetence With Injection of Hyaluronic Acid.

PubMed

Koprowski, Steven; VanLue, Michael J; McCormick, Michael E

2018-04-01

Stress velopharyngeal incompetence (VPI) is a challenging clinical entity that can be managed by a variety of surgical and nonsurgical approaches. We describe the case of a clarinetist who presented with nasal air escape while playing. She had successful improvement in her symptoms after targeted injection of a hyaluronic acid compound to her posterior pharyngeal wall. Our objective is to describe the safety and efficacy of this technique, to emphasize the multidisciplinary management of patients with stress VPI, and to review the importance of both nasopharyngoscopy and videofluoroscopy in their evaluation.

Psychrotrophic Clostridium spp. associated with 'blown pack' spoilage of chilled vacuum-packed red meats and dog rolls in gas-impermeable plastic casings.

PubMed

Broda, D M; DeLacy, K M; Bell, R G; Braggins, T J; Cook, R L

1996-04-01

'Blown pack' spoilage of vacuum-packed chilled beef, lamb and venison, and of a cooked meat product, chilled dog rolls packed in an oxygen-impermeable plastic casing, was characterised by sensory, chemical and microbiological analysis. Investigation of the probable causative agents led to the isolation of eight strains of psychrotrophic clostridia. Three strains have been provisionally identified as C. difficile, C. beijerinckii and C. lituseburense; the other five remain unidentified. In inoculation studies only one isolate produced significant amount of gas on meat, causing pack 'blowing'. It is, therefore, possible that 'blown pack' spoilage involves a synergism with one or more other organisms.

Probiotics for the treatment of Clostridium difficile associated disease

PubMed Central

Fitzpatrick, Leo R

2013-01-01

The purpose of this review paper is to update the current and potential future role of probiotics for Clostridium difficile-associated disease (CDAD). Included in this review, is an update on the testing of newer probiotics (e.g., Bacillus coagulans GBI-30, 6086) in animal models of CDAD. There is a focus on the modulation of signal transduction pathways (i.e., transcription factors like cAMP response element-binding, activator protein 1, and nuclear factor kappa B), as well as the inhibition of certain kinases (e.g., p38 mitogen activated protein kinases) by probiotics. Inhibition of signal transduction by probiotics, such as Saccharomyces boulardii, result in multiple effects on intestinal fluid secretion, neutrophil influx into the colon, inflammation, and colonocyte apoptosis that may positively impact CDAD. Recent clinical approaches with probiotics, for the prevention of primary and recurrent CDAD, are also summarized in this review paper. Future directions for the treatment of CDAD by probiotics are also mentioned in this review. In particular, the use of multi-strain probiotic formulations such as Ecologic® AAD and VSL #3® may represent a rationale pharmacological approach, particularly as adjunctive therapies for CDAD. Understanding the mechanistic basis of CDAD, and how probiotics interfere at ceratin steps in the pathogenic process, may also present the opportunity to design other multi-strain probiotics that could have a future impact on CDAD. PMID:23946887

Costs of Clostridium difficile infection in pediatric operations: A propensity score-matching analysis.

PubMed

Kulaylat, Afif N; Rocourt, Dorothy V; Podany, Abigail B; Engbrecht, Brett W; Twilley, Marianne; Santos, Mary C; Cilley, Robert E; Hollenbeak, Christopher S; Dillon, Peter W

2017-05-01

The purpose of this analysis was to assess the burden of Clostridium difficile infection in the hospitalized pediatric surgical population and to characterize its influence on the costs of care. There were 313,664 patients age 1-18 years who underwent a general thoracic or abdominal procedure in the Kids' Inpatient Database during 2003, 2006, 2009, and 2012. Logistic regression was used to model factors associated with the development of C difficile infection. A propensity score-matching analysis was performed to evaluate the influence of C difficile infection on mortality, duration of stay, and costs in similar patient cohorts. Population weights were used to estimate the national excess burden of C difficile infection on these outcomes. The overall prevalence of C difficile infection in the sampled cohort was 0.30%, with an increasing trend of C difficile infection over time in non-children's hospitals (P < .001). C difficile infection was associated with younger age, nonelective procedures, increasing comorbidities, and urban teaching hospital status (P < .001). An estimated 1,438 children developed C difficile infection after operation. After propensity score matching, the mean excess duration of stay and costs attributable to C difficile infection were 5.8 days and $12,801 (P < .001), accounting for 8,295 days spent in the hospital and $18.4 million (2012 USD) in spending annually. C difficile infection is a relatively uncommon but costly complication after pediatric operative procedures. Given the increasing trend of C difficile infection among hospitalized surgical patients, there is substantial opportunity for reduction of inpatient burden and associated costs in this potentially preventable nosocomial infection. Copyright © 2016 Elsevier Inc. All rights reserved.

The effect of hospital-acquired infection with Clostridium difficile on length of stay in hospital.

PubMed

Forster, Alan J; Taljaard, Monica; Oake, Natalie; Wilson, Kumanan; Roth, Virginia; van Walraven, Carl

2012-01-10

The effect of hospital-acquired infection with Clostridium difficile on length of stay in hospital is not yet fully understood. We determined the independent impact of hospital-acquired infection with C. difficile on length of stay in hospital. We conducted a retrospective observational cohort study of admissions to hospital between July 1, 2002, and Mar. 31, 2009, at a single academic hospital. We measured the association between infection with hospital-acquired C. difficile and time to discharge from hospital using Kaplan-Meier methods and a Cox multivariable proportional hazards regression model. We controlled for baseline risk of death and accounted for C. difficile as a time-varying effect. Hospital-acquired infection with C. difficile was identified in 1393 of 136,877 admissions to hospital (overall risk 1.02%, 95% confidence interval [CI] 0.97%-1.06%). The crude median length of stay in hospital was greater for patients with hospital-acquired C. difficile (34 d) than for those without C. difficile (8 d). Survival analysis showed that hospital-acquired infection with C. difficile increased the median length of stay in hospital by six days. In adjusted analyses, hospital-acquired C. difficile was significantly associated with time to discharge, modified by baseline risk of death and time to acquisition of C. difficile. The hazard ratio for discharge by day 7 among patients with hospital-acquired C. difficile was 0.55 (95% CI 0.39-0.70) for patients in the lowest decile of baseline risk of death and 0.45 (95% CI 0.32-0.58) for those in the highest decile; for discharge by day 28, the corresponding hazard ratios were 0.74 (95% CI 0.60-0.87) and 0.61 (95% CI 0.53-0.68). Hospital-acquired infection with C. difficile significantly prolonged length of stay in hospital independent of baseline risk of death.

Interobserver variability and feasibility of polymerase chain reaction-based assay in distinguishing ischemic colitis from Clostridium difficile colitis in endoscopic mucosal biopsies.

PubMed

Wiland, Homer O; Procop, Gary W; Goldblum, John R; Tuohy, Marion; Rybicki, Lisa; Patil, Deepa T

2013-06-01

Polymerase chain reaction (PCR)-based assays using stool samples are currently the most effective method of detecting Clostridium difficile. This study examines the feasibility of this assay using mucosal biopsy samples and evaluates the interobserver reproducibility in diagnosing and distinguishing ischemic colitis from C difficile colitis. Thirty-eight biopsy specimens were reviewed and classified by 3 observers into C difficile and ischemic colitis. The findings were correlated with clinical data. PCR was performed on 34 cases using BD GeneOhm C difficile assay. The histologic interobserver agreement was excellent (κ= 0.86) and the agreement between histologic and clinical diagnosis was good (κ = 0.84). All 19 ischemic colitis cases tested negative (100% specificity) and 3 of 15 cases of C difficile colitis tested positive (20% sensitivity). C difficile colitis can be reliably distinguished from ischemic colitis using histologic criteria. The C difficile PCR test on endoscopic biopsy specimens has excellent specificity but limited sensitivity.

The potential value of Clostridium difficile vaccine: an economic computer simulation model.

PubMed

Lee, Bruce Y; Popovich, Michael J; Tian, Ye; Bailey, Rachel R; Ufberg, Paul J; Wiringa, Ann E; Muder, Robert R

2010-07-19

Efforts are currently underway to develop a vaccine against Clostridium difficile infection (CDI). We developed two decision analytic Monte Carlo computer simulation models: (1) an Initial Prevention Model depicting the decision whether to administer C. difficile vaccine to patients at-risk for CDI and (2) a Recurrence Prevention Model depicting the decision whether to administer C. difficile vaccine to prevent CDI recurrence. Our results suggest that a C. difficile vaccine could be cost-effective over a wide range of C. difficile risk, vaccine costs, and vaccine efficacies especially, when being used post-CDI treatment to prevent recurrent disease. (c) 2010 Elsevier Ltd. All rights reserved.

The Potential Value of Clostridium difficile Vaccine: An Economic Computer Simulation Model

PubMed Central

Lee, Bruce Y.; Popovich, Michael J.; Tian, Ye; Bailey, Rachel R.; Ufberg, Paul J.; Wiringa, Ann E.; Muder, Robert R.

2010-01-01

Efforts are currently underway to develop a vaccine against Clostridium difficile infection (CDI). We developed two decision analytic Monte Carlo computer simulation models: (1) an Initial Prevention Model depicting the decision whether to administer C. difficile vaccine to patients at-risk for CDI and (2) a Recurrence Prevention Model depicting the decision whether to administer C. difficile vaccine to prevent CDI recurrence. Our results suggest that a C. difficile vaccine could be cost-effective over a wide range of C. difficile risk, vaccine costs, and vaccine efficacies especially when being used post-CDI treatment to prevent recurrent disease. PMID:20541582

Neutrophil-mediated inflammation in the pathogenesis of Clostridium difficile infections

PubMed Central

Jose, Shinsmon; Madan, Rajat

2016-01-01

Clostridium difficile is the most important cause of nosocomial infectious diarrhea in the western world. C. difficile infections are a major healthcare burden with approximately 500,000 new cases every year and an estimated annual cost of nearly $1 billion in the U.S. Furthermore, the infections are no longer restricted to health care facilities, and recent studies indicate spread of C. difficile infection to the community as well. The clinical spectrum of C. difficile infection ranges from asymptomatic colonization to severe diarrhea, fulminant colitis and death. This spectrum results from a complex interplay between bacterial virulence factors, the colonic microbiome and the host inflammatory response. The overall vigor of host inflammatory response is believed to be an important determinant of C. difficile disease severity, and a more robust immune response is associated with worse outcomes. Neutrophils are the primary cells that respond to C. difficile invasion and neutrophilic inflammation is the hallmark of C. difficile-associated disease. In this review, we will focus on the role of neutrophils (infiltration to infected tissue, pathogen clearance and resolution of inflammation) in the immuno-pathogenesis of C. difficile-associated disease (CDAD). PMID:27063896

Neutrophil-mediated inflammation in the pathogenesis of Clostridium difficile infections.

PubMed

Jose, Shinsmon; Madan, Rajat

2016-10-01

Clostridium difficile is the most important cause of nosocomial infectious diarrhea in the western world. C. difficile infections are a major healthcare burden with approximately 500,000 new cases every year and an estimated annual cost of nearly $1 billion in the U.S. Furthermore, the infections are no longer restricted to health care facilities, and recent studies indicate spread of C. difficile infection to the community as well. The clinical spectrum of C. difficile infection ranges from asymptomatic colonization to severe diarrhea, fulminant colitis and death. This spectrum results from a complex interplay between bacterial virulence factors, the colonic microbiome and the host inflammatory response. The overall vigor of host inflammatory response is believed to be an important determinant of C. difficile disease severity, and a more robust immune response is associated with worse outcomes. Neutrophils are the primary cells that respond to C. difficile invasion and neutrophilic inflammation is the hallmark of C. difficile-associated disease. In this review, we will focus on the role of neutrophils (infiltration to infected tissue, pathogen clearance and resolution of inflammation) in the immuno-pathogenesis of C. difficile-associated disease (CDAD). Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessment of Portal Venous and Hepatic Artery Haemodynamic Variation in Non-Alcoholic Fatty Liver Disease (NAFLD) Patients.

PubMed

Balasubramanian, Padhmini; Boopathy, Vinoth; Govindasamy, Ezhumalai; Venkatesh, Basavaiya Prabhu

2016-08-01

Non-Alcoholic Fatty Liver Disease (NAFLD) has various spectrums of liver diseases like isolated fatty liver, steatohepatitis and cirrhosis usually progressing in a linear fashion. In this process they are known to cause certain haemodynamic changes in the portal flow and hepatic artery flow. The aim of the study was to study these haemodynamic changes in patients with NAFLD and to correlate it with the disease severity. Ninety patients diagnosed to have NAFLD based on ultrasound abdomen (30 each in grade1, grade2 and grade3 NAFLD) and 30 controls (Normal liver on ultrasound abdomen) were subjected to portal vein and hepatic artery Doppler study. Peak maximum velocity (Vmax), Peak minimum velocity (Vmin), Mean flow velocity (MFV), and Vein pulsality index (VPI) of the portal vein and hepatic artery resistivity index (HARI) of the hepatic artery were the doppler parameters which were assessed. Liver span was also assessed both for the fatty liver and controls. The mean Vmax, Vmin, MFV and VPI of the portal vein in patients with NAFLD was 12.23±1.74cm/sec, 9.31±1.45cm/sec, 10.76±1.48cm/sec, and 0.24±0.04 as compared to 14.05±2.43cm/sec, 10.01±2.27cm/sec, 12.23±2.47cm/sec, 0.3±0.08 in controls respectively. All these differences were statistically significant except for Vmin. The Mean HARI in patients with fatty liver was 0.65±0.06 when compared to controls of 0.75±0.06 (p=0.001). HARI (r-value of -0.517) had a better negative correlation followed by VPI (r-value of -0.44) and Vmax (r-value of -0.293) with the severity of NAFLD. MFV had a very weak negative correlation (r-value of -0.182) with the severity of NAFLD. The Vmax, MFV, VPI and HARI were significantly less when compared to controls suggesting a reduced portal flow and an increased hepatic arterial flow in patients with NAFLD. Among the parameters, HARI correlated better with the severity of NAFLD followed by VPI.

An Evaluation of Food as a Potential Source for Clostridium difficile Acquisition in Hospitalized Patients.

PubMed

Kwon, Jennie H; Lanzas, Cristina; Reske, Kimberly A; Hink, Tiffany; Seiler, Sondra M; Bommarito, Kerry M; Burnham, Carey-Ann D; Dubberke, Erik R

2016-12-01

OBJECTIVE To determine whether Clostridium difficile is present in the food of hospitalized patients and to estimate the risk of subsequent colonization associated with C. difficile in food. METHODS This was a prospective cohort study of inpatients at a university-affiliated tertiary care center, May 9, 2011-July 12, 2012. Enrolled patients submitted a portion of food from each meal. Patient stool specimens and/or rectal swabs were collected at enrollment, every 3 days thereafter, and at discharge, and were cultured for C. difficile. Clinical data were reviewed for evidence of infection due to C. difficile. A stochastic, discrete event model was developed to predict exposure to C. difficile from food, and the estimated number of new colonization events from food exposures per 1,000 admissions was determined. RESULTS A total of 149 patients were enrolled and 910 food specimens were obtained. Two food specimens from 2 patients were positive for C. difficile (0.2% of food samples; 1.3% of patients). Neither of the 2 patients was colonized at baseline with C. difficile. Discharge colonization status was available for 1 of the 2 patients and was negative. Neither was diagnosed with C. difficile infection while hospitalized or during the year before or after study enrollment. Stochastic modeling indicated contaminated hospital food would be responsible for less than 1 newly colonized patient per 1,000 hospital admissions. CONCLUSIONS The recovery of C. difficile from the food of hospitalized patients was rare. Modeling suggests hospital food is unlikely to be a source of C. difficile acquisition. Infect Control Hosp Epidemiol 2016;1401-1407.

Allergic diseases among very preterm infants according to nutrition after hospital discharge.

PubMed

Zachariassen, Gitte; Faerk, Jan; Esberg, Birgitte H; Fenger-Gron, Jesper; Mortensen, Sven; Christesen, Henrik T; Halken, Susanne

2011-08-01

To determine whether a cow's milk-based human milk fortifier (HMF) added to mother's milk while breastfeeding or a cow's milk-based preterm formula compared to exclusively mother's milk after hospital discharge, increases the incidence of developing allergic diseases among very preterm infants (VPI) during the first year of life. Of a cohort of 324 VPI (gestational age 24-32 wk), the exclusively breastfed VPI were shortly before discharge randomized to breastfeeding without fortification or supplementing with a fortifier. Those not breastfed were fed a preterm formula. The intervention period was from discharge until 4 months corrected age (CA). Follow-up was performed at 4 and 12 months CA including specific IgE to a panel of allergens at 4 months CA. The incidence during and prevalence at 12 months CA of recurrent wheezing (RW) was 39.2% and 32.7%, while atopic dermatitis (AD) was 18.0% and 12.1%, respectively. Predisposition to allergic disease increased the risk of developing AD (p=0.04) [OR 2.6 (95% CI 1.0-6.4)] and the risk of developing RW (p=0.02) [OR 2.7 (95% CI 1.2-6.3)]. Boys had an increased risk of developing RW (p=0.003) [OR 3.1 (95% CI 1.5-6.5)]. No difference was found between nutrition groups. None developed food allergy. Compared to exclusively breastfed, VPI supplemented with HMF or fed exclusively a preterm formula for 4 months did not have an increased risk of developing allergic diseases during the first year of life. © 2011 John Wiley & Sons A/S.

Vector Flow Visualization of Urinary Flow Dynamics in a Bladder Outlet Obstruction Model.

PubMed

Ishii, Takuro; Yiu, Billy Y S; Yu, Alfred C H

2017-11-01

Voiding dysfunction that results from bladder outlet (BO) obstruction is known to alter significantly the dynamics of urine passage through the urinary tract. To non-invasively image this phenomenon on a time-resolved basis, we pursued the first application of a recently developed flow visualization technique called vector projectile imaging (VPI) that can track the spatiotemporal dynamics of flow vector fields at a frame rate of 10,000 fps (based on plane wave excitation and least-squares Doppler vector estimation principles). For this investigation, we designed a new anthropomorphic urethral tract phantom to reconstruct urinary flow dynamics under controlled conditions (300 mm H 2 O inlet pressure and atmospheric outlet pressure). Both a normal model and a diseased model with BO obstruction were developed for experimentation. VPI cine loops were derived from these urinary flow phantoms. Results show that VPI is capable of depicting differences in the flow dynamics of normal and diseased urinary tracts. In the case with BO obstruction, VPI depicted the presence of BO flow jet and vortices in the prostatic urethra. The corresponding spatial-maximum flow velocity magnitude was estimated to be 2.43 m/s, and it is significantly faster than that for the normal model (1.52 m/s) and is in line with values derived from computational fluid dynamics simulations. Overall, this investigation demonstrates the feasibility of using vector flow visualization techniques to non-invasively examine internal flow characteristics related to voiding dysfunction in the urethral tract. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Winding Pack Height Management During Fabrication of the ITER CS Module

NASA Astrophysics Data System (ADS)

Martovetsky, Nicolai N.; Irick, David K.; Reed, Richard P.; Haefelfinger, Rolf; Salazar, Erica

The Central Solenoid (CS) stack consists of six modules, 2.1 m tall each [1]. In order to verify good impregnation, we performed a vacuum pressure impregnation (VPI) test of a full cross section of the CS module (CSM), 40 conductors tall and 14 conductors wide [2]. It was discovered that after preparation of the full cross section stack until completion of the VPI, the stack shrunk in height by 20-25 mm. Our study of the literature and discussions with the leading experts in VPI did not reveal obvious reasons for this change of height, so we launched a study to address this issue. We assembled two 12x1 (tall by wide) arrays and several 7x1 arrays in order to study characteristics of the dry winding pack under compressive force and effects of different fabrication steps. Then we impregnated these arrays in different conditions under compressive force and studied change of height as a result of compression, impregnation, gelling and curing of the stack of insulated conductors. We showed that by controlling the application of the compressive force, before closing the mold and during impregnation, one can reduce the height uncertainty. Most of the height reduction takes place while the glass is dry under the dead weight and the applied compressive force. Reduction of height during injection of the resin and during gelling, curing and cooling of the coil is noticeable, reproducible and relatively small. The paper presents results of our studies and recommendations for assembly and VPI of tall windings.

Longitudinal Improvement in Periodontal Parameters between RPD Abutment Teeth with Direct and Indirect Retainers, after Periodontal Therapy.

PubMed

Almeida, Mariana Linhares; Tôrres, Ana Clara Soares de Paiva; de Oliveira, Kleiton Clécio; Calderon, Patrícia Dos Santos; Carreiro, Adriana da Fonte Porto; Gurgel, Bruno César de Vasconcelos

2018-03-06

To evaluate the effect of basic periodontal treatment on clinical periodontal parameters associated with abutment teeth of patients with mandibular Kennedy class I removable partial dentures (RPD) 18 months after treatment. Thirty patients with periodontal disease were treated and evaluated according to the following periodontal parameters: visible plaque index (VPI), bleeding on probing (BOP), probing depth (PD), gingival recession (GR), clinical attachment loss (CAL), and keratinized mucosa (KM). These parameters were compared between abutment teeth with direct and indirect retainers at baseline, and after 6 and 18 months. Data were analyzed by Friedman Test and Wilcoxon Test for all variables. Most patients (n = 26; 86.7%) included in the study were female and had a mean age of 61 years (±7.54). Results showed that VPI and BOP decreased over time, and that VPI values were higher in abutment teeth with direct retainers (p = 0.001). There was a reduction in PD after 6 months, which was maintained up to 18 months. In general, abutment teeth with direct retainers had significantly higher values for PD, GR, and CAL (p = 0.029). Data also indicated that the parameters for VPI, BOP, and PD improved; however, abutment teeth with direct retainers presented smaller improvements, compared with abutment teeth with indirect retainers, which presented significant improvements for almost all variables. Periodontal treatment and oral hygiene care of patients were adequate for maintenance of adequate periodontal conditions, regardless of the use of prostheses. © 2018 by the American College of Prosthodontists.

Clostridium difficile infection: Evolution, phylogeny and molecular epidemiology.

PubMed

Elliott, Briony; Androga, Grace O; Knight, Daniel R; Riley, Thomas V

2017-04-01

Over the recent decades, Clostridium difficile infection (CDI) has emerged as a global public health threat. Despite growing attention, C. difficile remains a poorly understood pathogen, however, the exquisite sensitivity offered by next generation sequencing (NGS) technology has enabled analysis of the genome of C. difficile, giving us access to massive genomic data on factors such as virulence, evolution, and genetic relatedness within C. difficile groups. NGS has also demonstrated excellence in investigations of outbreaks and disease transmission, in both small and large-scale applications. This review summarizes the molecular epidemiology, evolution, and phylogeny of C. difficile, one of the most important pathogens worldwide in the current antibiotic resistance era. Copyright © 2016 Elsevier B.V. All rights reserved.

Clostridium difficile-associated reactive arthritis in two children.

PubMed

Löffler, Helga A; Pron, Benedicte; Mouy, Richard; Wulffraat, Nico M; Prieur, Anne-Marie

2004-01-01

In adults, reactive arthritis (ReA) following Clostridium difficile-enterocolitis has been documented. In children, only one case of C. difficile-associated ReA has been reported. We now describe two other cases of ReA associated with C. difficile in children. The characteristics of ReA due to C. difficile appear to be similar in adults and children. Both children show polyarthritis after an episode of diarrhoea with positive stool cultures for C. difficile. Arthritis is asymmetrical with a self-limiting course. Nonsteroidal antiinflammatory drug (NSAID) therapy is sufficient. One case is remarkable because of its prolonged course of ReA despite NSAID therapy, and its association with the presence of HLA-B27 antigen.

Detection of Mixed Infection from Bacterial Whole Genome Sequence Data Allows Assessment of Its Role in Clostridium difficile Transmission

PubMed Central

Eyre, David W.; Cule, Madeleine L.; Griffiths, David; Crook, Derrick W.; Peto, Tim E. A.

2013-01-01

Bacterial whole genome sequencing offers the prospect of rapid and high precision investigation of infectious disease outbreaks. Close genetic relationships between microorganisms isolated from different infected cases suggest transmission is a strong possibility, whereas transmission between cases with genetically distinct bacterial isolates can be excluded. However, undetected mixed infections—infection with ≥2 unrelated strains of the same species where only one is sequenced—potentially impairs exclusion of transmission with certainty, and may therefore limit the utility of this technique. We investigated the problem by developing a computationally efficient method for detecting mixed infection without the need for resource-intensive independent sequencing of multiple bacterial colonies. Given the relatively low density of single nucleotide polymorphisms within bacterial sequence data, direct reconstruction of mixed infection haplotypes from current short-read sequence data is not consistently possible. We therefore use a two-step maximum likelihood-based approach, assuming each sample contains up to two infecting strains. We jointly estimate the proportion of the infection arising from the dominant and minor strains, and the sequence divergence between these strains. In cases where mixed infection is confirmed, the dominant and minor haplotypes are then matched to a database of previously sequenced local isolates. We demonstrate the performance of our algorithm with in silico and in vitro mixed infection experiments, and apply it to transmission of an important healthcare-associated pathogen, Clostridium difficile. Using hospital ward movement data in a previously described stochastic transmission model, 15 pairs of cases enriched for likely transmission events associated with mixed infection were selected. Our method identified four previously undetected mixed infections, and a previously undetected transmission event, but no direct transmission between the pairs of cases under investigation. These results demonstrate that mixed infections can be detected without additional sequencing effort, and this will be important in assessing the extent of cryptic transmission in our hospitals. PMID:23658511

Prevalence of Clostridium difficile in uncooked ground meat products from Pittsburgh, Pennsylvania.

PubMed

Curry, Scott R; Marsh, Jane W; Schlackman, Jessica L; Harrison, Lee H

2012-06-01

The prevalence of Clostridium difficile in retail meat samples has varied widely. The food supply may be a source for C. difficile infections. A total of 102 ground meat and sausage samples from 3 grocers in Pittsburgh, PA, were cultured for C. difficile. Brand A pork sausages were resampled between May 2011 and January 2012. Two out of 102 (2.0%) meat products initially sampled were positive for C. difficile; both were pork sausage from brand A from the same processing facility (facility A). On subsequent sampling of brand A products, 10/19 samples from processing facility A and 1/10 samples from 3 other facilities were positive for C. difficile. The isolates recovered were inferred ribotype 078, comprising 6 genotypes. The prevalence of C. difficile in retail meat may not be as high as previously reported in North America. When contamination occurs, it may be related to events at processing facilities.

Intravenous immunoglobulin therapy for severe Clostridium difficile colitis

PubMed Central

Salcedo, J; Keates, S; Pothoulakis, C; Warny, M; Castagliuolo, I; LaMont, J; Kelly, C

1997-01-01

Background—Many individuals have serum antibodies against Clostridium difficile toxins. Those with an impaired antitoxin response may be susceptible to recurrent, prolonged, or severe C difficile diarrhoea and colitis. 
Aims—To examine whether treatment with intravenous immunoglobulin might be effective in patients with severe pseudomembranous colitis unresponsive to standard antimicrobial therapy. 
Patients—Two patients with pseudomembranous colitis not responding to metronidazole and vancomycin were given normal pooled human immunoglobulin intravenously (200-300 mg/kg). 
Methods—Antibodies against C difficile toxins were measured in nine immunoglobulin preparations by ELISA and by cytotoxin neutralisation assay. 
Results—Both patients responded quickly as shown by resolution of diarrhoea, abdominal tenderness, and distension. All immunoglobulin preparations tested contained IgG against C difficile toxins A and B by ELISA and neutralised the cytotoxic activity of C difficile toxins in vitro at IgG concentrations of 0.4-1.6 mg/ml. 
Conclusion—Passive immunotherapy with intravenous immunoglobulin may be a useful addition to antibiotic therapy for severe, refractory C difficile colitis. IgG antitoxin is present in standard immunoglobulin preparations and C difficile toxin neutralising activity is evident at IgG concentrations which are readily achieved in the serum by intravenous immunoglobulin administration. 

 Keywords: Clostridium difficile; toxin; diarrhoea; IgG; immunotherapy; antibiotic PMID:9378393

The epidemiology and economic burden of Clostridium difficile infection in Korea.

PubMed

Choi, Hyung-Yun; Park, So-Youn; Kim, Young-Ae; Yoon, Tai-Young; Choi, Joong-Myung; Choe, Bong-Keun; Ahn, So-Hee; Yoon, Seok-Jun; Lee, Ye-Rin; Oh, In-Hwan

2015-01-01

The prevalence of Clostridium difficile infection and the associated burden have recently increased in many countries. While the main risk factors for C. difficile infection include old age and antibiotic use, the prevalence of this infection is increasing in low-risk groups. These trends highlight the need for research on C. difficile infection. This study pointed out the prevalence and economic burden of C. difficile infection and uses the representative national data which is primarily from the database of the Korean Health Insurance Review and Assessment Service, for 2008-2011. The annual economic cost was measured using a prevalence approach, which sums the costs incurred to treat C. difficile infection. C. difficile infection prevalence was estimated to have increased from 1.43 per 100,000 in 2008 to 5.06 per 100,000 in 2011. Moreover, mortality increased from 69 cases in 2008 to 172 in 2011. The economic cost increased concurrently, from $2.4 million in 2008 to $7.6 million, $10.5 million, and $15.8 million in 2009, 2010, and 2011, respectively. The increasing economic burden of C. difficile infection over the course of the study period emphasizes the need for intervention to minimize the burden of a preventable illness like C. difficile infection.

c-di-GMP Turn-Over in Clostridium difficile Is Controlled by a Plethora of Diguanylate Cyclases and Phosphodiesterases

PubMed Central

Bordeleau, Eric; Fortier, Louis-Charles; Malouin, François; Burrus, Vincent

2011-01-01

Clostridium difficile infections have become a major healthcare concern in the last decade during which the emergence of new strains has underscored this bacterium's capacity to cause persistent epidemics. c-di-GMP is a bacterial second messenger regulating diverse bacterial phenotypes, notably motility and biofilm formation, in proteobacteria such as Vibrio cholerae, Pseudomonas aeruginosa, and Salmonella. c-di-GMP is synthesized by diguanylate cyclases (DGCs) that contain a conserved GGDEF domain. It is degraded by phosphodiesterases (PDEs) that contain either an EAL or an HD-GYP conserved domain. Very little is known about the role of c-di-GMP in the regulation of phenotypes of Gram-positive or fastidious bacteria. Herein, we exposed the main components of c-di-GMP signalling in 20 genomes of C. difficile, revealed their prevalence, and predicted their enzymatic activity. Ectopic expression of 31 of these conserved genes was carried out in V. cholerae to evaluate their effect on motility and biofilm formation, two well-characterized phenotype alterations associated with intracellular c-di-GMP variation in this bacterium. Most of the predicted DGCs and PDEs were found to be active in the V. cholerae model. Expression of truncated versions of CD0522, a protein with two GGDEF domains and one EAL domain, suggests that it can act alternatively as a DGC or a PDE. The activity of one purified DGC (CD1420) and one purified PDE (CD0757) was confirmed by in vitro enzymatic assays. GTP was shown to be important for the PDE activity of CD0757. Our results indicate that, in contrast to most Gram-positive bacteria including its closest relatives, C. difficile encodes a large assortment of functional DGCs and PDEs, revealing that c-di-GMP signalling is an important and well-conserved signal transduction system in this human pathogen. PMID:21483756

Epidemiology of Clostridium difficile infections in Australia: enhanced surveillance to evaluate time trends and severity of illness in Victoria, 2010-2014.

PubMed

Worth, L J; Spelman, T; Bull, A L; Brett, J A; Richards, M J

2016-07-01

With epidemic strains of Clostridium difficile posing a substantial healthcare burden internationally, there is a need for longitudinal evaluation of Clostridium difficile infection (CDI) events in Australia. To evaluate time trends and severity of illness for CDI events in Australian healthcare facilities. All CDI events in patients admitted to Victorian public hospitals between 1(st) October 2010 and 31(st) December 2014 were reported to the Victorian Healthcare Associated Infection Surveillance System. CDI was defined as the isolation of a toxin-producing C. difficile organism in a diarrhoeal specimen, and classified as community-associated (CA-CDI) or healthcare-associated (HA-CDI). Severe disease was defined as admission to an intensive care unit, requirement for surgery and/or death due to infection. Time trends were examined using a mixed-effects Poisson regression model, and the Walter and Edward test of seasonality was applied to evaluate potential cyclical patterns. In total, 6736 CDI events were reported across 89 healthcare facilities. Of these, 4826 (71.6%) were HA-CDI, corresponding to a rate of 2.49/10,000 occupied bed days (OBDs). The incidence of HA-CDI was highest in the fifth quarter of surveillance (3.6/10,000 OBDs), followed by a reduction. Severe disease was reported in 1.66% of events, with the proportion being significantly higher for CA-CDI compared with HA-CDI (2.21 vs 1.45%, P = 0.03). The highest and lowest incidence of HA-CDI occurred in March and October, respectively. A low incidence of HA-CDI was reported in Victoria compared with US/European surveillance reports. Seasonality was evident, together with diminishing HA-CDI rates in 2012-2014. Severe infections were more common in CA-CDI, supporting future enhanced surveillance in community settings. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

The emergence of Clostridium difficile infection in Asia: A systematic review and meta-analysis of incidence and impact.

PubMed

Borren, Nienke Z; Ghadermarzi, Shadi; Hutfless, Susan; Ananthakrishnan, Ashwin N

2017-01-01

Clostridium difficile infection (CDI) is the most common healthcare associated infection and is highly prevalent in Europe and North America. Limited data is available on the prevalence of CDI in Asia. However, secular increases in prevalence of risk factors for CDI suggest that it may be emerging as a major cause of morbidity, highlighting the urgent need for a systematic study of the prevalence of CDI in Asia. We systematically searched PubMed/Medline and Embase for publications from Asia between 2000-16 examining prevalence of CDI. A random-effects meta-analysis was performed to calculate the pooled prevalence of CDI in Asia and to identify subgroups and regions at high risk. Our meta-analysis included 51 studies from throughout Asia including 37,663 patients at risk among whom confirmed CDI was found in 4,343 patients. The pooled proportion of confirmed CDI among all patients with diarrhea was 14.8% with a higher prevalence in East Asia (19.5%), compared with South Asia (10.5%) or the Middle East (11.1%). There were an estimated 5.3 episodes of CDI per 10,000 patient days, similar to rates reported from Europe and North America. Infections due to hypervirulent strains were rare. CDI-related mortality was 8.9%. In a meta-analysis of 51 studies, we observed similar rates of CDI in Asia in comparison to Europe and North America. Increased awareness and improved surveillance of Clostridium difficile is essential to reduce incidence and morbidity.

Management of Clostridium difficile Infection in Inflammatory Bowel Disease: Expert Review from the Clinical Practice Updates Committee of the AGA Institute.

PubMed

Khanna, Sahil; Shin, Andrea; Kelly, Ciarán P

2017-02-01

The purpose of this expert review is to synthesize the existing evidence on the management of Clostridium difficile infection in patients with underlying inflammatory bowel disease. The evidence reviewed in this article is a summation of relevant scientific publications, expert opinion statements, and current practice guidelines. This review is a summary of expert opinion in the field without a formal systematic review of evidence. Best Practice Advice 1: Clinicians should test patients who present with a flare of underlying inflammatory bowel disease for Clostridium difficile infection. Best Practice Advice 2: Clinicians should screen for recurrent C difficile infection if diarrhea or other symptoms of colitis persist or return after antibiotic treatment for C difficile infection. Best Practice Advice 3: Clinicians should consider treating C difficile infection in inflammatory bowel disease patients with vancomycin instead of metronidazole. Best Practice Advice 4: Clinicians strongly should consider hospitalization for close monitoring and aggressive management for inflammatory bowel disease patients with C difficile infection who have profuse diarrhea, severe abdominal pain, a markedly increased peripheral blood leukocyte count, or other evidence of sepsis. Best Practice Advice 5: Clinicians may postpone escalation of steroids and other immunosuppression agents during acute C difficile infection until therapy for C difficile infection has been initiated. However, the decision to withhold or continue immunosuppression in inflammatory bowel disease patients with C difficile infection should be individualized because there is insufficient existing robust literature on which to develop firm recommendations. Best Practice Advice 6: Clinicians should offer a referral for fecal microbiota transplantation to inflammatory bowel disease patients with recurrent C difficile infection. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Sensitive and selective culture medium for detection of environmental Clostridium difficile isolates without requirement for anaerobic culture conditions.

PubMed

Cadnum, Jennifer L; Hurless, Kelly N; Deshpande, Abhishek; Nerandzic, Michelle M; Kundrapu, Sirisha; Donskey, Curtis J

2014-09-01

Effective and easy-to-use methods for detecting Clostridium difficile spore contamination would be useful for identifying environmental reservoirs and monitoring the effectiveness of room disinfection. Culture-based detection methods are sensitive for detecting C. difficile, but their utility is limited due to the requirement of anaerobic culture conditions and microbiological expertise. We developed a low-cost selective broth medium containing thioglycolic acid and l-cystine, termed C. difficile brucella broth with thioglycolic acid and l-cystine (CDBB-TC), for the detection of C. difficile from environmental specimens under aerobic culture conditions. The sensitivity and specificity of CDBB-TC (under aerobic culture conditions) were compared to those of CDBB (under anaerobic culture conditions) for the recovery of C. difficile from swabs collected from hospital room surfaces. CDBB-TC was significantly more sensitive than CDBB for recovering environmental C. difficile (36/41 [88%] versus 21/41 [51%], respectively; P = 0.006). C. difficile latex agglutination, an enzyme immunoassay for toxins A and B or glutamate dehydrogenase, and a PCR for toxin B genes were all effective as confirmatory tests. For 477 total environmental cultures, the specificity of CDBB-TC versus that of CDBB based upon false-positive yellow-color development of the medium without recovery of C. difficile was 100% (0 false-positive results) versus 96% (18 false-positive results), respectively. False-positive cultures for CDBB were attributable to the growth of anaerobic non-C. difficile organisms that did not grow in CDBB-TC. Our results suggest that CDBB-TC provides a sensitive and selective medium for the recovery of C. difficile organisms from environmental samples, without the need for anaerobic culture conditions. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

The association of hospital prevention processes and patient risk factors with the risk of Clostridium difficile infection: a population-based cohort study.

PubMed

Daneman, N; Guttmann, A; Wang, X; Ma, X; Gibson, D; Stukel, T A

2015-07-01

Clostridium difficile is the most common cause of healthcare-acquired infection; the real-world impacts of some proposed C. difficile prevention processes are unknown. We conducted a population-based retrospective cohort study of all patients admitted to acute care hospitals between April 2011 and March 2012 in Ontario, Canada. Hospital prevention practices were determined by survey of infection control programmes; responses were linked to patient-level risk factors and C. difficile outcomes in Ontario administrative databases. Multivariable generalised estimating equation (GEE) regression models were used to assess the impact of selected understudied hospital prevention processes on the patient-level risk of C. difficile infection, accounting for patient risk factors, baseline C. difficile rates and structural hospital characteristics. C. difficile infections complicated 2341 of 653 896 admissions (3.6 per 1000 admissions). Implementation of the selected C. difficile prevention practices was variable across the 159 hospitals with isolation of all patients at onset of diarrhoea reported by 43 (27%), auditing of antibiotic stewardship compliance by 26 (16%), auditing of cleaning practices by 115 (72%), on-site diagnostic testing by 74 (47%), vancomycin as first-line treatment by 24 (15%) and reporting rates to senior leadership by 52 (33%). None of these processes were associated with a significantly reduced risk of C. difficile after adjustment for baseline C. difficile rates, structural hospital characteristics and patient-level factors. Patient-level factors were strongly associated with C. difficile risk, including age, comorbidities, non-elective and medical admissions. In the largest study to date, selected hospital prevention strategies were not associated with a statistically significant reduction in patients' risk of C. difficile infection. These prevention strategies have either limited effectiveness or were ineffectively implemented during the study period. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Underdiagnosis of Clostridium difficile across Europe: the European, multicentre, prospective, biannual, point-prevalence study of Clostridium difficile infection in hospitalised patients with diarrhoea (EUCLID).

PubMed

Davies, Kerrie A; Longshaw, Christopher M; Davis, Georgina L; Bouza, Emilio; Barbut, Frédéric; Barna, Zsuzsanna; Delmée, Michel; Fitzpatrick, Fidelma; Ivanova, Kate; Kuijper, Ed; Macovei, Ioana S; Mentula, Silja; Mastrantonio, Paola; von Müller, Lutz; Oleastro, Mónica; Petinaki, Efthymia; Pituch, Hanna; Norén, Torbjörn; Nováková, Elena; Nyč, Otakar; Rupnik, Maja; Schmid, Daniela; Wilcox, Mark H

2014-12-01

Variations in testing for Clostridium difficile infection can hinder patients' care, increase the risk of transmission, and skew epidemiological data. We aimed to measure the underdiagnosis of C difficile infection across Europe. We did a questionnaire-based study at 482 participating hospitals across 20 European countries. Hospitals were questioned about their methods and testing policy for C difficile infection during the periods September, 2011, to August, 2012, and September, 2012, to August, 2013. On one day in winter, 2012-13 (December, 2012, or January, 2013), and summer, 2013 (July or August), every hospital sent all diarrhoeal samples submitted to their microbiology laboratory to a national coordinating laboratory for standardised testing of C difficile infection. Our primary outcome measures were the rates of testing for and cases of C difficile infection per 10 000 patient bed-days. Results of local and national C difficile infection testing were compared with each other. If the result was positive at the national laboratory but negative at the local hospital, the result was classified as undiagnosed C difficile infection. We compared differences in proportions with the Mann-Whitney test, or McNemar's test if data were matched. During the study period, participating hospitals reported a mean of 65·8 tests (country range 4·6-223·3) for C difficile infection per 10 000 patient-bed days and a mean of 7·0 cases (country range 0·7-28·7) of C difficile infection per 10 000 patient-bed days. Only two-fifths of hospitals reported using optimum methods for testing of C difficile infection (defined by European guidelines), although the number of participating hospitals using optimum methods increased during the study period, from 152 (32%) of 468 in 2011-12 to 205 (48%) of 428 in 2012-13. Across all 482 European hospitals on the two sampling days, 148 (23%) of 641 samples positive for C difficile infection (as determined by the national laboratory) were not diagnosed by participating hospitals because of an absence of clinical suspicion, equating to about 74 missed diagnoses per day. A wide variety of testing strategies for C difficile infection are used across Europe. Absence of clinical suspicion and suboptimum laboratory diagnostic methods mean that an estimated 40 000 inpatients with C difficile infection are potentially undiagnosed every year in 482 European hospitals. Astellas Pharmaceuticals Europe. Copyright © 2014 Elsevier Ltd. All rights reserved.

Stool C difficile toxin

MedlinePlus

... toxin; Colitis - toxin; Pseudomembranous - toxin; Necrotizing colitis - toxin; C difficile - toxin ... be analyzed. There are several ways to detect C difficile toxin in the stool sample. Enzyme immunoassay ( ...

Prevalence of Clostridium difficile infection in acute care hospitals, long-term care facilities, and outpatient clinics: Is Clostridium difficile infection underdiagnosed in long-term care facility patients?

PubMed

Krishna, Amar; Pervaiz, Amina; Lephart, Paul; Tarabishy, Noor; Varakantam, Swapna; Kotecha, Aditya; Awali, Reda A; Kaye, Keith S; Chopra, Teena

2017-10-01

Clostridium difficile infection is a common cause of diarrhea in long-term care facility (LTCF) patients. The high prevalence of C difficile infection in LTCFs noted in our study calls for a critical need to educate LTCF staff to send diarrheal stool for C difficile testing to identify more cases and prevent transmission. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Intestinal Epithelial Cell Response to Clostridium difficile Flagella.

PubMed

Batah, Jameel; Kansau, Imad

2016-01-01

Clostridium difficile is the bacterium responsible for most antibiotic-associated diarrhea in North America and Europe. This bacterium, which colonizes the gut of humans and animals, produces toxins that are known to contribute directly to damage of the gut. It is known that bacterial flagella are involved in intestinal lesions through the inflammatory host response. The C. difficile flagellin recognizes TLR5 and consequently activates the NF-κB and the MAPK signaling pathways which elicit the synthesis of pro-inflammatory cytokines. Increasing interest on the role of C. difficile flagella in eliciting this cell response was recently developed and the development of tools to study cell response triggered by C. difficile flagella will improve our understanding of the pathogenesis of C. difficile.

Genomic and Phenotypic Characterization of Vibrio cholerae Non-O1 Isolates from a US Gulf Coast Cholera Outbreak

PubMed Central

Grim, Christopher J.; Onifade, Tiffiani J.; Cinar, Hediye N.; Tall, Ben D.; Taviani, Elisa; Hasan, Nur A.; Abdullah, AbdulShakur H.; Carter, Laurenda; Sahu, Surasri N.; Kothary, Mahendra H.; Chen, Arlene; Baker, Ron; Hutchinson, Richard; Blackmore, Carina; Cebula, Thomas A.; Huq, Anwar; Colwell, Rita R.

2014-01-01

Between November 2010, and May 2011, eleven cases of cholera, unrelated to a concurrent outbreak on the island of Hispaniola, were recorded, and the causative agent, Vibrio cholerae serogroup O75, was traced to oysters harvested from Apalachicola Bay, Florida. From the 11 diagnosed cases, eight isolates of V. cholerae were isolated and their genomes were sequenced. Genomic analysis demonstrated the presence of a suite of mobile elements previously shown to be involved in the disease process of cholera (ctxAB, VPI-1 and -2, and a VSP-II like variant) and a phylogenomic analysis showed the isolates to be sister taxa to toxigenic V. cholerae V51 serogroup O141, a clinical strain isolated 23 years earlier. Toxigenic V. cholerae O75 has been repeatedly isolated from clinical cases in the southeastern United States and toxigenic V. cholerae O141 isolates have been isolated globally from clinical cases over several decades. Comparative genomics, phenotypic analyses, and a Caenorhabditis elegans model of infection for the isolates were conducted. This analysis coupled with isolation data of V. cholerae O75 and O141 suggests these strains may represent an underappreciated clade of cholera-causing strains responsible for significant disease burden globally. PMID:24699521

Genomic and phenotypic characterization of Vibrio cholerae non-O1 isolates from a US Gulf Coast cholera outbreak.

PubMed

Haley, Bradd J; Choi, Seon Young; Grim, Christopher J; Onifade, Tiffiani J; Cinar, Hediye N; Tall, Ben D; Taviani, Elisa; Hasan, Nur A; Abdullah, Abdulshakur H; Carter, Laurenda; Sahu, Surasri N; Kothary, Mahendra H; Chen, Arlene; Baker, Ron; Hutchinson, Richard; Blackmore, Carina; Cebula, Thomas A; Huq, Anwar; Colwell, Rita R

2014-01-01

Between November 2010, and May 2011, eleven cases of cholera, unrelated to a concurrent outbreak on the island of Hispaniola, were recorded, and the causative agent, Vibrio cholerae serogroup O75, was traced to oysters harvested from Apalachicola Bay, Florida. From the 11 diagnosed cases, eight isolates of V. cholerae were isolated and their genomes were sequenced. Genomic analysis demonstrated the presence of a suite of mobile elements previously shown to be involved in the disease process of cholera (ctxAB, VPI-1 and -2, and a VSP-II like variant) and a phylogenomic analysis showed the isolates to be sister taxa to toxigenic V. cholerae V51 serogroup O141, a clinical strain isolated 23 years earlier. Toxigenic V. cholerae O75 has been repeatedly isolated from clinical cases in the southeastern United States and toxigenic V. cholerae O141 isolates have been isolated globally from clinical cases over several decades. Comparative genomics, phenotypic analyses, and a Caenorhabditis elegans model of infection for the isolates were conducted. This analysis coupled with isolation data of V. cholerae O75 and O141 suggests these strains may represent an underappreciated clade of cholera-causing strains responsible for significant disease burden globally.

Asymptomatic Carriers Contribute to Nosocomial Clostridium difficile Infection: A Cohort Study of 4508 Patients.

PubMed

Blixt, Thomas; Gradel, Kim Oren; Homann, Christian; Seidelin, Jakob Benedict; Schønning, Kristian; Lester, Anne; Houlind, Jette; Stangerup, Marie; Gottlieb, Magnus; Knudsen, Jenny Dahl

2017-04-01

Nosocomial infections with Clostridium difficile present a considerable problem despite numerous attempts by health care workers to reduce risk of transmission. Asymptomatic carriers of C difficile can spread their infection to other patients. We investigated the effects of asymptomatic carriers on nosocomial C difficile infections. We performed a population-based prospective cohort study at 2 university hospitals in Denmark, screening all patients for toxigenic C difficile in the intestine upon admittance, from October 1, 2012, to January 31, 2013. Screening results were blinded to patients, staff, and researchers. Patients were followed during their hospital stay by daily registration of wards and patient rooms. The primary outcomes were rate of C difficile infection in exposed and unexposed patients and factors associated with transmission. C difficile infection was detected in 2.6% of patients not exposed to carriers and in 4.6% of patients exposed to asymptomatic carriers at the ward level (odds ratio for infection if exposed to carrier, 1.79; 95% confidence interval, 1.16-2.76). Amount of exposure correlated with risk of C difficile infection, from 2.2% in the lowest quartile to 4.2% in the highest quartile of exposed patients (P = .026). Combining the load of exposure to carriers and length of stay seemed to have an additive effect on the risk of contracting C difficile. In a population-based prospective cohort study in Denmark, we found that asymptomatic carriers of toxigenic C difficile in hospitals increase risk of infection in other patients. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Six rapid tests for direct detection of Clostridium difficile and its toxins in fecal samples compared with the fibroblast cytotoxicity assay.

PubMed

Turgeon, David K; Novicki, Thomas J; Quick, John; Carlson, LaDonna; Miller, Pat; Ulness, Bruce; Cent, Anne; Ashley, Rhoda; Larson, Ann; Coyle, Marie; Limaye, Ajit P; Cookson, Brad T; Fritsche, Thomas R

2003-02-01

Clostridium difficile is one of the most frequent causes of nosocomial gastrointestinal disease. Risk factors include prior antibiotic therapy, bowel surgery, and the immunocompromised state. Direct fecal analysis for C. difficile toxin B by tissue culture cytotoxin B assay (CBA), while only 60 to 85% sensitive overall, is a common laboratory method. We have used 1,003 consecutive, nonduplicate fecal samples to compare six commercially available immunoassays (IA) for C. difficile detection with CBA: Prima System Clostridium difficile Tox A and VIDAS Clostridium difficile Tox A II, which detect C. difficile toxin A; Premier Cytoclone A/B and Techlab Clostridium difficile Tox A/B, which detect toxins A and B; and ImmunoCard Clostridium difficile and Triage Micro C. difficile panels, which detect toxin A and a species-specific antigen. For all tests, Triage antigen was most sensitive (89.1%; negative predictive value [NPV] = 98.7%) while ImmunoCard was most specific (99.7%; positive predictive value [PPV] = 95.0%). For toxin tests only, Prima System had the highest sensitivity (82.2%; NPV = 98.0%) while ImmunoCard had the highest specificity (99.7%; PPV = 95.0%). Hematopoietic stem cell transplant (HSCT) patients contributed 44.7% of all samples tested, and no significant differences in sensitivity or specificity were noted between HSCT and non-HSCT patients. IAs, while not as sensitive as direct fecal CBA, produce reasonable predictive values, especially when both antigen and toxin are detected. They also offer significant advantages over CBA in terms of turnaround time and ease of use.

Clostridium difficile – From Colonization to Infection

PubMed Central

Schäffler, Holger; Breitrück, Anne

2018-01-01

Clostridium difficile is the most frequent cause of nosocomial antibiotic-associated diarrhea. The incidence of C. difficile infection (CDI) has been rising worldwide with subsequent increases in morbidity, mortality, and health care costs. Asymptomatic colonization with C. difficile is common and a high prevalence has been found in specific cohorts, e.g., hospitalized patients, adults in nursing homes and in infants. However, the risk of infection with C. difficile differs significantly between these cohorts. While CDI is a clear indication for therapy, colonization with C. difficile is not believed to be a direct precursor for CDI and therefore does not require treatment. Antibiotic therapy causes alterations of the intestinal microbial composition, enabling C. difficile colonization and consecutive toxin production leading to disruption of the colonic epithelial cells. Clinical symptoms of CDI range from mild diarrhea to potentially life-threatening conditions like pseudomembranous colitis or toxic megacolon. While antibiotics are still the treatment of choice for CDI, new therapies have emerged in recent years such as antibodies against C. difficile toxin B and fecal microbial transfer (FMT). This specific therapy for CDI underscores the role of the indigenous bacterial composition in the prevention of the disease in healthy individuals and its role in the pathogenesis after alteration by antibiotic treatment. In addition to the pathogenesis of CDI, this review focuses on the colonization of C. difficile in the human gut and factors promoting CDI. PMID:29692762

Conserved Oligopeptide Permeases Modulate Sporulation Initiation in Clostridium difficile

PubMed Central

Edwards, Adrianne N.; Nawrocki, Kathryn L.

2014-01-01

The anaerobic gastrointestinal pathogen Clostridium difficile must form a metabolically dormant spore to survive in oxygenic environments and be transmitted from host to host. The regulatory factors by which C. difficile initiates and controls the early stages of sporulation in C. difficile are not highly conserved in other Clostridium or Bacillus species. Here, we investigated the role of two conserved oligopeptide permeases, Opp and App, in the regulation of sporulation in C. difficile. These permeases are known to positively affect sporulation in Bacillus species through the import of sporulation-specific quorum-sensing peptides. In contrast to other spore-forming bacteria, we discovered that inactivating these permeases in C. difficile resulted in the earlier expression of early sporulation genes and increased sporulation in vitro. Furthermore, disruption of opp and app resulted in greater virulence and increased the amounts of spores recovered from feces in the hamster model of C. difficile infection. Our data suggest that Opp and App indirectly inhibit sporulation, likely through the activities of the transcriptional regulator SinR and its inhibitor, SinI. Taken together, these results indicate that the Opp and App transporters serve a different function in controlling sporulation and virulence in C. difficile than in Bacillus subtilis and suggest that nutrient availability plays a significant role in pathogenesis and sporulation in vivo. This study suggests a link between the nutritional status of the environment and sporulation initiation in C. difficile. PMID:25069979

Efficacy of cleaning products for C. difficile: environmental strategies to reduce the spread of Clostridium difficile-associated diarrhea in geriatric rehabilitation.

PubMed

Macleod-Glover, Nora; Sadowski, Cheryl

2010-05-01

To review the evidence for the efficacy of products used for environmental or hand cleaning on the rates of Clostridium difficile-associated diarrhea (CDAD). MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews were searched for articles pertinent to the efficacy of cleaning products against C. difficile or studies with outcomes related to rates of CDAD. Evidence was level II. Minimizing the incidence of CDAD in geriatric rehabilitation units is essential to achieving the goals of increasing patient function and independence for discharge into the community. Attention to environmental control of C. difficile and its spores by health care workers and patient visitors is an important secondary prevention strategy. Chlorine-releasing agents are more effective than detergents for killing spores produced by C. difficile. No level I evidence is available to determine if the use of chlorine-releasing agents has an effect on rates of CDAD. Hand-washing is currently the recommended strategy for reducing transmission of C. difficile. Alcohol gels do not inactivate C. difficile spores; however, increased use of alcohol hand gel has not been associated with higher rates of CDAD.

Dissemination of Clostridium difficile in food and the environment: Significant sources of C. difficile community-acquired infection?

PubMed

Warriner, K; Xu, C; Habash, M; Sultan, S; Weese, S J

2017-03-01

Clostridium difficile is a significant pathogen with over 300 000 cases reported in North America annually. Previously, it was thought that C. difficile was primarily a clinically associated infection. However, through the use of whole genome sequencing it has been revealed that the majority of cases are community acquired. The source of community-acquired C. difficile infections (CDI) is open to debate with foodborne being one route considered. Clostridium difficile fits the criteria of a foodborne pathogen with respect to being commonly encountered in a diverse range of foods that includes meat, seafood and fresh produce. However, no foodborne illness outbreaks have been directly linked to C. difficile there is also no conclusive evidence that its spores can germinate in food matrices. This does not exclude food as a potential vehicle but it is likely that the pathogen is also acquired through zoonosis and the environment. The most significant factor that defines susceptibility to CDI is the host microbiome and functioning immune system. In this respect, effective control can be exercised by reducing the environmental burden of C. difficile along with boosting the host defences against the virulent enteric pathogen. © 2016 The Society for Applied Microbiology.

In vitro activities of dalbavancin and nine comparator agents against anaerobic gram-positive species and corynebacteria.

PubMed

Goldstein, Ellie J C; Citron, Diane M; Merriam, C Vreni; Warren, Yumi; Tyrrell, Kerin; Fernandez, Helen T

2003-06-01

Dalbavancin is a novel semisynthetic glycopeptide with enhanced activity against gram-positive species. Its comparative in vitro activities and those of nine comparator agents, including daptomycin, vancomycin, linezolid, and quinupristin-dalfopristin, against 290 recent gram-positive clinical isolates strains, as determined by the NCCLS agar dilution method, were studied. The MICs of dalbavancin at which 90% of various isolates tested were inhibited were as follows: Actinomyces spp., 0.5 microg/ml; Clostridium clostridioforme, 8 microg/ml; C. difficile, 0.25 microg/ml; C. innocuum, 0.25 microg/ml; C. perfringens, 0.125 microg/ml; C. ramosum, 1 microg/ml; Eubacterium spp., 1 microg/ml; Lactobacillus spp., >32 microg/ml, Propionibacterium spp., 0.5 microg/ml; and Peptostreptococcus spp., 0.25 microg/ml. Dalbavancin was 1 to 3 dilutions more active than vancomycin against most strains. Dalbavancin exhibited excellent activity against gram-positive strains tested and warrants clinical evaluation.

Glycans coated silver nanoparticles induces autophagy and necrosis in HeLa cells

NASA Astrophysics Data System (ADS)

Panzarini, Elisa; Mariano, Stefania; Dini, Luciana

2015-06-01

This study reports the induction of autophagy by two concentrations (2×103 or 2×104 NPs/cell) of 30 nm sized β-D-Glucose- and β-D-Glucose/Sucrose-coated silver NanoParticles (AgNPs-G and AgNPs-GS respectively) in HeLa cells treated for 6, 12, 24 and 48 hrs. Cell viability was assessed by Neutral Red (NR) test and morphological evaluation. In addition ROS generation (NBT test) and induction of apoptosis/necrosis (Annexin V/Propidium Iodide-Annexin V/PI staining) and autophagy (Monodansylcadaverine-MDC staining) were evaluated. Cytotoxicity, ROS generation and morphology changes depend on NPs type and amount, and incubation time. As a general result, AgNPs-G are more toxic than AgNPs-GS. Moreover, the lowest AgNPs-GS concentration is ineffective on cell viability and ROS generation. Only 10% and 25% of viable HeLa cells were found at the end of incubation time in the presence of higher amount of AgNPs - G and AgNPs-GS respectively and in parallel ROS generation is induced. To elucidate the type of cell death, Annexin V/PI and MDC staining was performed. Interestingly, irrespective of coating type and NPs amount the percentage of apoptotic cells (Annexin V+/PI-) is similar to viable HeLa cells. At contrary, we observed a NPs amount dependent autophagy and necrosis induction. In fact, the lower amount of NPs induces autophagy (MDC+/PI- cells) whereas the higher one induces necrosis (Annexin V+/PI+ cells). Our findings suggest that AgNPs-induced cytotoxicity depends on AgNPs amount and type and provide preliminary evidence of induction of autophagy in HeLa cells cultured in the presence of AgNPs.

The Conserved Spore Coat Protein SpoVM Is Largely Dispensable in Clostridium difficile Spore Formation.

PubMed

Ribis, John W; Ravichandran, Priyanka; Putnam, Emily E; Pishdadian, Keyan; Shen, Aimee

2017-01-01

The spore-forming bacterial pathogen Clostridium difficile is a leading cause of health care-associated infections in the United States. In order for this obligate anaerobe to transmit infection, it must form metabolically dormant spores prior to exiting the host. A key step during this process is the assembly of a protective, multilayered proteinaceous coat around the spore. Coat assembly depends on coat morphogenetic proteins recruiting distinct subsets of coat proteins to the developing spore. While 10 coat morphogenetic proteins have been identified in Bacillus subtilis , only two of these morphogenetic proteins have homologs in the Clostridia : SpoIVA and SpoVM. C. difficile SpoIVA is critical for proper coat assembly and functional spore formation, but the requirement for SpoVM during this process was unknown. Here, we show that SpoVM is largely dispensable for C. difficile spore formation, in contrast with B. subtilis . Loss of C. difficile SpoVM resulted in modest decreases (~3-fold) in heat- and chloroform-resistant spore formation, while morphological defects such as coat detachment from the forespore and abnormal cortex thickness were observed in ~30% of spoVM mutant cells. Biochemical analyses revealed that C. difficile SpoIVA and SpoVM directly interact, similarly to their B. subtilis counterparts. However, in contrast with B. subtilis , C. difficile SpoVM was not essential for SpoIVA to encase the forespore. Since C. difficile coat morphogenesis requires SpoIVA-interacting protein L (SipL), which is conserved exclusively in the Clostridia , but not the more broadly conserved SpoVM, our results reveal another key difference between C. difficile and B. subtilis spore assembly pathways. IMPORTANCE The spore-forming obligate anaerobe Clostridium difficile is the leading cause of antibiotic-associated diarrheal disease in the United States. When C. difficile spores are ingested by susceptible individuals, they germinate within the gut and transform into vegetative, toxin-secreting cells. During infection, C. difficile must also induce spore formation to survive exit from the host. Since spore formation is essential for transmission, understanding the basic mechanisms underlying sporulation in C. difficile could inform the development of therapeutic strategies targeting spores. In this study, we determine the requirement of the C. difficile homolog of SpoVM, a protein that is essential for spore formation in Bacillus subtilis due to its regulation of coat and cortex formation. We observed that SpoVM plays a minor role in C. difficile spore formation, in contrast with B. subtilis , indicating that this protein would not be a good target for inhibiting spore formation.

The Conserved Spore Coat Protein SpoVM Is Largely Dispensable in Clostridium difficile Spore Formation

PubMed Central

Ribis, John W.; Ravichandran, Priyanka; Putnam, Emily E.; Pishdadian, Keyan

2017-01-01

ABSTRACT The spore-forming bacterial pathogen Clostridium difficile is a leading cause of health care-associated infections in the United States. In order for this obligate anaerobe to transmit infection, it must form metabolically dormant spores prior to exiting the host. A key step during this process is the assembly of a protective, multilayered proteinaceous coat around the spore. Coat assembly depends on coat morphogenetic proteins recruiting distinct subsets of coat proteins to the developing spore. While 10 coat morphogenetic proteins have been identified in Bacillus subtilis, only two of these morphogenetic proteins have homologs in the Clostridia: SpoIVA and SpoVM. C. difficile SpoIVA is critical for proper coat assembly and functional spore formation, but the requirement for SpoVM during this process was unknown. Here, we show that SpoVM is largely dispensable for C. difficile spore formation, in contrast with B. subtilis. Loss of C. difficile SpoVM resulted in modest decreases (~3-fold) in heat- and chloroform-resistant spore formation, while morphological defects such as coat detachment from the forespore and abnormal cortex thickness were observed in ~30% of spoVM mutant cells. Biochemical analyses revealed that C. difficile SpoIVA and SpoVM directly interact, similarly to their B. subtilis counterparts. However, in contrast with B. subtilis, C. difficile SpoVM was not essential for SpoIVA to encase the forespore. Since C. difficile coat morphogenesis requires SpoIVA-interacting protein L (SipL), which is conserved exclusively in the Clostridia, but not the more broadly conserved SpoVM, our results reveal another key difference between C. difficile and B. subtilis spore assembly pathways. IMPORTANCE The spore-forming obligate anaerobe Clostridium difficile is the leading cause of antibiotic-associated diarrheal disease in the United States. When C. difficile spores are ingested by susceptible individuals, they germinate within the gut and transform into vegetative, toxin-secreting cells. During infection, C. difficile must also induce spore formation to survive exit from the host. Since spore formation is essential for transmission, understanding the basic mechanisms underlying sporulation in C. difficile could inform the development of therapeutic strategies targeting spores. In this study, we determine the requirement of the C. difficile homolog of SpoVM, a protein that is essential for spore formation in Bacillus subtilis due to its regulation of coat and cortex formation. We observed that SpoVM plays a minor role in C. difficile spore formation, in contrast with B. subtilis, indicating that this protein would not be a good target for inhibiting spore formation. PMID:28959733

Fecal microbiota transplantation in children with recurrent Clostridium difficile infection.

PubMed

Pierog, Anne; Mencin, Ali; Reilly, Norelle Rizkalla

2014-11-01

Clostridium difficile eradication using fecal microbiota transplantation (FMT) has been successful in adults but little information is available in pediatrics. We report 6 pediatric patients with refractory C. difficile cured by FMT with no recurrences to date. Our results demonstrate that FMT can be an effective treatment for refractory C. difficile infection in pediatrics. Long-term safety and efficacy need to be studied.

The Burden of Clostridium difficile after Cervical Spine Surgery.

PubMed

Guzman, Javier Z; Skovrlj, Branko; Rothenberg, Edward S; Lu, Young; McAnany, Steven; Cho, Samuel K; Hecht, Andrew C; Qureshi, Sheeraz A

2016-06-01

Study Design Retrospective database analysis. Objective The purpose of this study is to investigate incidence, comorbidities, and impact on health care resources of Clostridium difficile infection after cervical spine surgery. Methods A total of 1,602,130 cervical spine surgeries from the Nationwide Inpatient Sample database from 2002 to 2011 were included. Patients were included for study based on International Classification of Diseases Ninth Revision, Clinical Modification procedural codes for cervical spine surgery for degenerative spine diagnoses. Baseline patient characteristics were determined. Multivariable analyses assessed factors associated with increased incidence of C. difficile and risk of mortality. Results Incidence of C. difficile infection in postoperative cervical spine surgery hospitalizations is 0.08%, significantly increased since 2002 (p < 0.0001). The odds of postoperative C. difficile infection were significantly increased in patients with comorbidities such as congestive heart failure, renal failure, and perivascular disease. Circumferential cervical fusion (odds ratio [OR] = 2.93, p < 0.0001) increased the likelihood of developing C. difficile infection after degenerative cervical spine surgery. C. difficile infection after cervical spine surgery results in extended length of stay (p < 0.0001) and increased hospital costs (p < 0.0001). Mortality rate in patients who develop C. difficile after cervical spine surgery is nearly 8% versus 0.19% otherwise (p < 0.0001). Moreover, multivariate analysis revealed C. difficile to be a significant predictor of inpatient mortality (OR = 3.99, p < 0.0001). Conclusions C. difficile increases the risk of in-hospital mortality and costs approximately $6,830,695 per year to manage in patients undergoing elective cervical spine surgery. Patients with comorbidities such as renal failure or congestive heart failure have increased probability of developing infection after surgery. Accepted antibiotic guidelines in this population must be followed to decrease the risk of developing postoperative C. difficile colitis.

An Economic Analysis of Strategies to Control Clostridium Difficile Transmission and Infection Using an Agent-Based Simulation Model.

PubMed

Nelson, Richard E; Jones, Makoto; Leecaster, Molly; Samore, Matthew H; Ray, William; Huttner, Angela; Huttner, Benedikt; Khader, Karim; Stevens, Vanessa W; Gerding, Dale; Schweizer, Marin L; Rubin, Michael A

2016-01-01

A number of strategies exist to reduce Clostridium difficile (C. difficile) transmission. We conducted an economic evaluation of "bundling" these strategies together. We constructed an agent-based computer simulation of nosocomial C. difficile transmission and infection in a hospital setting. This model included the following components: interactions between patients and health care workers; room contamination via C. difficile shedding; C. difficile hand carriage and removal via hand hygiene; patient acquisition of C. difficile via contact with contaminated rooms or health care workers; and patient antimicrobial use. Six interventions were introduced alone and "bundled" together: (a) aggressive C. difficile testing; (b) empiric isolation and treatment of symptomatic patients; (c) improved adherence to hand hygiene and (d) contact precautions; (e) improved use of soap and water for hand hygiene; and (f) improved environmental cleaning. Our analysis compared these interventions using values representing 3 different scenarios: (1) base-case (BASE) values that reflect typical hospital practice, (2) intervention (INT) values that represent implementation of hospital-wide efforts to reduce C. diff transmission, and (3) optimal (OPT) values representing the highest expected results from strong adherence to the interventions. Cost parameters for each intervention were obtained from published literature. We performed our analyses assuming low, normal, and high C. difficile importation prevalence and transmissibility of C. difficile. INT levels of the "bundled" intervention were cost-effective at a willingness-to-pay threshold of $100,000/quality-adjusted life-year in all importation prevalence and transmissibility scenarios. OPT levels of intervention were cost-effective for normal and high importation prevalence and transmissibility scenarios. When analyzed separately, hand hygiene compliance, environmental decontamination, and empiric isolation and treatment were the interventions that had the greatest impact on both cost and effectiveness. A combination of available interventions to prevent CDI is likely to be cost-effective but the cost-effectiveness varies for different levels of intensity of the interventions depending on epidemiological conditions such as C. difficile importation prevalence and transmissibility.

Recovery of the gut microbiome following fecal microbiota transplantation.

PubMed

Seekatz, Anna M; Aas, Johannes; Gessert, Charles E; Rubin, Timothy A; Saman, Daniel M; Bakken, Johan S; Young, Vincent B

2014-06-17

Clostridium difficile infection is one of the most common health care-associated infections, and up to 40% of patients suffer from recurrence of disease following standard antibiotic therapy. Recently, fecal microbiota transplantation (FMT) has been successfully used to treat recurrent C. difficile infection. It is hypothesized that FMT aids in recovery of a microbiota capable of colonization resistance to C. difficile. However, it is not fully understood how this occurs. Here we investigated changes in the fecal microbiota structure following FMT in patients with recurrent C. difficile infection, and imputed a hypothetical functional profile based on the 16S rRNA profile using a predictive metagenomic tool. Increased relative abundance of Bacteroidetes and decreased abundance of Proteobacteria were observed following FMT. The fecal microbiota of recipients following transplantation was more diverse and more similar to the donor profile than the microbiota prior to transplantation. Additionally, we observed differences in the imputed metagenomic profile. In particular, amino acid transport systems were overrepresented in samples collected prior to transplantation. These results suggest that functional changes accompany microbial structural changes following this therapy. Further identification of the specific community members and functions that promote colonization resistance may aid in the development of improved treatment methods for C. difficile infection. Within the last decade, Clostridium difficile infection has surpassed other bacterial infections to become the leading cause of nosocomial infections. Antibiotic use, which disrupts the gut microbiota and its capability in providing colonization resistance against C. difficile, is a known risk factor in C. difficile infection. In particular, recurrent C. difficile remains difficult to treat with standard antibiotic therapy. Fecal microbiota transplantation (FMT) has provided a successful treatment method for some patients with recurrent C. difficile infection, but its mechanism and long-term effects remain unknown. Our results provide insight into the structural and potential metabolic changes that occur following FMT, which may aid in the development of new treatment methods for C. difficile infection. Copyright © 2014 Seekatz et al.

Environmental Contamination in Households of Patients with Recurrent Clostridium difficile Infection

PubMed Central

Bobr, Aleh; Kuskowski, Michael A.; Johnston, Brian D.; Sadowsky, Michael J.; Khoruts, Alexander

2016-01-01

Recurrent Clostridium difficile infection (R-CDI) is common and difficult to treat, potentially necessitating fecal microbiota transplantation (FMT). Although C. difficile spores persist in the hospital environment and cause infection, little is known about their potential presence or importance in the household environment. Households of R-CDI subjects in the peri-FMT period and of geographically matched and age-matched controls were analyzed for the presence of C. difficile. Household environmental surfaces and fecal samples from humans and pets in the household were examined. Households of post-FMT subjects were also examined (environmental surfaces only). Participants were surveyed regarding their personal history and household cleaning habits. Species identity and molecular characteristics of presumptive C. difficile isolates from environmental and fecal samples were determined by using the Pro kit (Remel, USA), Gram staining, PCR, toxinotyping, tcdC gene sequencing, and pulsed-field gel electrophoresis (PFGE). Environmental cultures detected C. difficile on ≥1 surface in 8/8 (100%) peri-FMT households, versus 3/8 (38%) post-FMT households and 3/8 (38%) control households (P = 0.025). The most common C. difficile-positive sites were the vacuum (11/27; 41%), toilet (8/30; 27%), and bathroom sink (5/29; 17%). C. difficile was detected in 3/36 (8%) fecal samples (two R-CDI subjects and one household member). Nine (90%) of 10 households with multiple C. difficile-positive samples had a single genotype present each. In conclusion, C. difficile was found in the household environment of R-CDI patients, but whether it was found as a cause or consequence of R-CDI is unknown. If household contamination leads to R-CDI, effective decontamination may be protective. PMID:26921425

The housefly Musca domestica as a mechanical vector of Clostridium difficile.

PubMed

Davies, M P; Anderson, M; Hilton, A C

2016-11-01

Clostridium difficile is a bacterial healthcare-associated infection that may be transferred by houseflies (Musca domestica) due to their close ecological association with humans and cosmopolitan nature. To determine the ability of M. domestica to transfer C. difficile both mechanically and following ingestion. M. domestica were exposed to independent suspensions of vegetative cells and spores of C. difficile, then sampled on to selective agar plates immediately postexposure and at 1-h intervals to assess the mechanical transfer of C. difficile. Fly excreta was cultured and alimentary canals were dissected to determine internalization of cells and spores. M. domestica exposed to vegetative cell suspensions and spore suspensions of C. difficile were able to transfer the bacteria mechanically for up to 4h upon subsequent contact with surfaces. The greatest numbers of colony-forming units (CFUs) per fly were transferred immediately following exposure (mean CFUs 123.8 +/- 66.9 for vegetative cell suspension and 288.2 +/- 83.2 for spore suspension). After 1h, this had reduced (21.2 +/- 11.4 for vegetative cell suspension and 19.9 +/- 9 for spores). Mean C. difficile CFUs isolated from the M. domestica alimentary canal was 35 +/- 6.5, and mean C. difficile CFUs per faecal spot was 1.04 +/- 0.58. C. difficile could be recovered from fly excreta for up to 96h. This study describes the potential for M. domestica to contribute to environmental persistence and spread of C. difficile in hospitals, highlighting flies as realistic vectors of this micro-organism in clinical areas. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Risk factors for Clostridium difficile infection in HIV-infected patients.

PubMed

Imlay, Hannah; Kaul, Daniel; Rao, Krishna

2016-01-01

Clostridium difficile infection is a healthcare-associated infection resulting in significant morbidity. Although immunosuppression is associated with Clostridium difficile infection acquisition and adverse outcomes, the epidemiology of Clostridium difficile infection in HIV-infected patients has been little studied in the era of antiretroviral therapy. This study identifies the risk factors for acquisition of Clostridium difficile infection in HIV-infected patients. A retrospective, propensity score-matched case-control study design was employed, with patients selected from our institution's outpatient HIV clinic. Clostridium difficile infection cases were defined as having positive stool testing plus an appropriate clinical presentation. The propensity score was generated via multiple logistic regression from year of HIV diagnosis, age at first contact, duration of follow-up, gender, and initial CD4 count. The 46 cases included were matched to a total of 180 controls. Prior antibiotic treatment was a significant predictor of Clostridium difficile infection (odds ratio: 13, 95% confidence interval: 3.49-48.8, p  < .001) as was number of hospital admissions in the preceding year (odds ratio: 4.02, confidence interval: 1.81-8.94, p  < .001). Having both proton pump inhibitor use and CD4 count <200 cells/µL significantly increased odds of Clostridium difficile infection in the multivariable model (odds ratio: 15.17, confidence interval: 1.31-175.9, p  = .021). As in the general population, frequent hospitalizations and exposure to antimicrobials are independent predictors of Clostridium difficile infection acquisition in patients with HIV. Additionally, low CD4 count and proton pump inhibitor use are new potentially modifiable variables that can be targeted for prevention of Clostridium difficile infection in future interventional studies.

Real-Time Electronic Tracking of Diarrheal Episodes and Laxative Therapy Enables Verification of Clostridium difficile Clinical Testing Criteria and Reduction of Clostridium difficile Infection Rates.

PubMed

Truong, Cynthia Y; Gombar, Saurabh; Wilson, Richard; Sundararajan, Gopalakrishnan; Tekic, Natasa; Holubar, Marisa; Shepard, John; Madison, Alexandra; Tompkins, Lucy; Shah, Neil; Deresinski, Stan; Schroeder, Lee F; Banaei, Niaz

2017-05-01

Health care-onset health care facility-associated Clostridium difficile infection (HO-CDI) is overdiagnosed for several reasons, including the high prevalence of C. difficile colonization and the inability of hospitals to limit testing to patients with clinically significant diarrhea. We conducted a quasiexperimental study from 22 June 2015 to 30 June 2016 on consecutive inpatients with C. difficile test orders at an academic hospital. Real-time electronic patient data tracking was used by the laboratory to enforce testing criteria (defined as the presence of diarrhea [≥3 unformed stools in 24 h] and absence of laxative intake in the prior 48 h). Outcome measures included C. difficile test utilization, HO-CDI incidence, oral vancomycin utilization, and clinical complications. During the intervention, 7.1% (164) and 9.1% (211) of 2,321 C. difficile test orders were canceled due to absence of diarrhea and receipt of laxative therapy, respectively. C. difficile test utilization decreased upon implementation from an average of 208.8 tests to 143.0 tests per 10,000 patient-days ( P < 0.001). HO-CDI incidence rate decreased from an average of 13.0 cases to 9.7 cases per 10,000 patient-days ( P = 0.008). Oral vancomycin days of therapy decreased from an average of 13.8 days to 9.4 days per 1,000 patient-days ( P = 0.009). Clinical complication rates were not significantly different in patients with 375 canceled orders compared with 869 episodes with diarrhea but negative C. difficile results. Real-time electronic clinical data tracking is an effective tool for verification of C. difficile clinical testing criteria and safe reduction of inflated HO-CDI rates. Copyright © 2017 American Society for Microbiology.

Mortality and Clostridium difficile infection in an Australian setting.

PubMed

Mitchell, Brett G; Gardner, Anne; Hiller, Janet E

2013-10-01

To quantify the risk of death associated with Clostridium difficile infection, in an Australian tertiary hospital. Two reviews examining Clostridium difficile infection and mortality indicate that Clostridium difficile infection is associated with increased mortality in hospitalized patients. Studies investigating the mortality of Clostridium difficile infection in settings outside of Europe and North America are required, so that the epidemiology of Clostridium difficile infection in these regions can be understood and appropriate prevention strategies made. An observational non-concurrent cohort study design was used. Data from all persons who had (exposed) and a matched sample of persons who did not have Clostridium difficile infection, for the calendar years 2007-2010, were analysed. The risk of dying within 30, 60, 90 and 180 days was compared using the two groups. Kaplan-Meier survival analysis and conditional logistic regression models were applied to the data to examine time to death and mortality risk adjusted for comorbidities using the Charlson Comorbidity Index. One hundred and fifty-eight cases of infection were identified. A statistically significant difference in all-cause mortality was identified between exposed and non-exposed groups at 60 and 180 days. In a conditional regression model, mortality in the exposed group was significantly higher at 180 days. In this Australian study, Clostridium difficile infection was associated with increased mortality. In doing so, it highlights the need for nurses to immediately instigate contact precautions for persons suspected of having Clostridium difficile infection and to facilitate a timely faecal collection for testing. Our findings support ongoing surveillance of Clostridium difficile infection and associated prevention and control activities. © 2013 Blackwell Publishing Ltd.

The effect of bezlotoxumab for prevention of recurrent Clostridium difficile infection (CDI) in Japanese patients.

PubMed

Mikamo, Hiroshige; Aoyama, Norihiro; Sawata, Miyuki; Fujimoto, Go; Dorr, Mary Beth; Yoshinari, Tomoko

2018-02-01

Recurrent Clostridium difficile infection is considered as a significant health care burden. The global study (MODIFY II) of antibody treatment (bezlotoxumab) for the prevention of recurrent C. difficile infection includes Japanese patients (95 subjects); The aim of this subgroup analysis is to report the data obtained from Japanese patients. Patients with C. difficile infection receiving standard of care antibiotic treatment and a single infusion of bezlotoxumab 10 mg/kg, actoxumab 10 mg/kg + bezlotoxumab 10 mg/kg or placebo. Recurrent C. difficile infection through Week 12 was evaluated. In the Full Analysis Set (93 subjects), 91% were older than 65 years of age and 93% were hospitalized at the time of study entry. The standard of care antibiotic for C. difficile infection was metronidazole for 57 subjects and vancomycin for 36 subjects. The recurrent C. difficile infection rate was 46% in the placebo, 21% in the bezlotoxumab (p = 0.0197) and 28% in the actoxumab + bezlotoxumab group. No additive recurrent C. difficile infection-reducing effect with the addition of actoxumab was demonstrated. There were no events representing safety concern in bezlotoxumab. Among 54 clinical isolates of C. difficile as a baseline culture in Japanese patients, the common ribotypes were 052 (28%), 018 (19%), 002 (15%) and 369 (9%). It showed distinctly different distribution from that in the United States and Europe. The superior effect of bezlotoxumab 10 mg/kg in the prevention of recurrent C. difficile infection suggests that the agent will be useful in the rapidly aging Japanese society. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Escherichia coli and selected veterinary and zoonotic pathogens isolated from environmental sites in companion animal veterinary hospitals in southern Ontario

PubMed Central

Murphy, Colleen P.; Reid-Smith, Richard J.; Boerlin, Patrick; Weese, J. Scott; Prescott, John F.; Janecko, Nicol; Hassard, Lori; McEwen, Scott A.

2010-01-01

Hospital-based infection control in veterinary medicine is emerging and the role of the environment in hospital-acquired infections (HAI) in veterinary hospitals is largely unknown. This study was initiated to determine the recovery of Escherichia coli and selected veterinary and zoonotic pathogens from the environments of 101 community veterinary hospitals. The proportion of hospitals with positive environmental swabs were: E. coli — 92%, Clostridium difficile — 58%, methicillin-resistant Staphylococcus aureus (MRSA) — 9%, CMY-2 producing E. coli — 9%, methicillin-resistant Staphylococcus pseudintermedius — 7%, and Salmonella — 2%. Vancomycin-resistant Enterococcus spp., canine parvovirus, and feline calicivirus were not isolated. Prevalence of antimicrobial resistance in E. coli isolates was low. Important potential veterinary and human pathogens were recovered including Canadian epidemic strains MRSA-2 and MRSA-5, and C. difficile ribotype 027. There is an environmental reservoir of pathogens in veterinary hospitals; therefore, additional studies are required to characterize risk factors associated with HAI in companion animals, including the role of the environment. PMID:21119862

Fecal Microbiota Transplantation: Therapeutic Potential for a Multitude of Diseases beyond Clostridium difficile.

PubMed

Bakker, Guido J; Nieuwdorp, Max

2017-08-01

The human intestinal tract contains trillions of bacteria, collectively called the gut microbiota. Recent insights have linked the gut microbiota to a plethora of diseases, including Clostridium difficile infection (CDI), inflammatory bowel disease (IBD), and metabolic diseases such as obesity, type 2 diabetes (T2D), and nonalcoholic steatohepatitis (NASH). Fecal microbiota transplantation (FMT) is currently tested as a therapeutic option in various diseases and can also help to dissect association from causality with respect to gut microbiota and disease. In CDI, FMT has been shown to be superior to antibiotic treatment. For IBD, T2D, and NASH, several placebo-controlled randomized controlled trials are under way. Moreover, techniques and standardization are developing. With the extension of FMT as a treatment modality in diseases other than CDI, a whole new treatment option may be emerging. Moreover, correlating alterations in specific strains to disease outcome may prove pivotal in finding new bacterial targets. Thus, although causality of the gut microbiota in various diseases still needs to be proven, FMT may prove to be a powerful tool providing us with diagnostic and therapeutic leads.

Gleaning Insights from Fecal Microbiota Transplantation and Probiotic Studies for the Rational Design of Combination Microbial Therapies

PubMed Central

Hudson, Lauren E.; Anderson, Sarah E.; Corbett, Anita H.

2016-01-01

SUMMARY Beneficial microorganisms hold promise for the treatment of numerous gastrointestinal diseases. The transfer of whole microbiota via fecal transplantation has already been shown to ameliorate the severity of diseases such as Clostridium difficile infection, inflammatory bowel disease, and others. However, the exact mechanisms of fecal microbiota transplant efficacy and the particular strains conferring this benefit are still unclear. Rationally designed combinations of microbial preparations may enable more efficient and effective treatment approaches tailored to particular diseases. Here we use an infectious disease, C. difficile infection, and an inflammatory disorder, the inflammatory bowel disease ulcerative colitis, as examples to facilitate the discussion of how microbial therapy might be rationally designed for specific gastrointestinal diseases. Fecal microbiota transplantation has already shown some efficacy in the treatment of both these disorders; detailed comparisons of studies evaluating commensal and probiotic organisms in the context of these disparate gastrointestinal diseases may shed light on potential protective mechanisms and elucidate how future microbial therapies can be tailored to particular diseases. PMID:27856521

Rifaximin therapy for metronidazole-unresponsive Clostridium difficile infection: a prospective pilot trial

PubMed Central

Patrick Basu, P.; Dinani, Amreen; Rayapudi, Krishna; Pacana, Tommy; Shah, Niraj James; Hampole, Hemant; Krishnaswamy, N. V.; Mohan, Vinod

2010-01-01

Background: Clostridium difficile infection (CDI) is a recent epidemic in the United States, particularly in the hospital setting. Oral metronidazole is standard therapy for C. difficile infection, but resistance to metronidazole is becoming a clinical challenge. Methods: We evaluated the efficacy of the nonsystemic oral antibiotic rifaximin for the treatment of metronidazole-resistant C. difficile infection. Twenty-five patients with C. difficile infection were enrolled in the study. All had mild-to-moderate C. difficile infection (5–10 bowel movements a day without sepsis) unresponsive to metronidazole (i.e. stools positive for toxins A and B after oral metronidazole 500 mg three times daily [t.i.d.] for 5 days). After discontinuation of metronidazole, rifaximin 400 mg t.i.d. for 14 days was prescribed. Patients were followed for 56 days and stool was tested for C. difficile using polymerase chain reaction (PCR) to assess the effect of treatment. A negative PCR test result was interpreted as a favorable response to rifaximin. Results: Sixteen of 22 patients (73%) were eligible for study inclusion and completed rifaximin therapy experienced eradication of infection (stool negative for C. difficile) immediately after rifaximin therapy and 56 days post-treatment. Three patients (12%) discontinued therapy because of abdominal distention. Rifaximin was generally well tolerated. Conclusions: In conclusion, rifaximin may be considered for treatment of mild-to-moderate C. difficile infection that is resistant to metronidazole. Larger randomized trials are needed to confirm these positive findings. PMID:21180604

Rifaximin therapy for metronidazole-unresponsive Clostridium difficile infection: a prospective pilot trial.

PubMed

Patrick Basu, P; Dinani, Amreen; Rayapudi, Krishna; Pacana, Tommy; Shah, Niraj James; Hampole, Hemant; Krishnaswamy, N V; Mohan, Vinod

2010-07-01

Clostridium difficile infection (CDI) is a recent epidemic in the United States, particularly in the hospital setting. Oral metronidazole is standard therapy for C. difficile infection, but resistance to metronidazole is becoming a clinical challenge. We evaluated the efficacy of the nonsystemic oral antibiotic rifaximin for the treatment of metronidazole-resistant C. difficile infection. Twenty-five patients with C. difficile infection were enrolled in the study. All had mild-to-moderate C. difficile infection (5-10 bowel movements a day without sepsis) unresponsive to metronidazole (i.e. stools positive for toxins A and B after oral metronidazole 500 mg three times daily [t.i.d.] for 5 days). After discontinuation of metronidazole, rifaximin 400 mg t.i.d. for 14 days was prescribed. Patients were followed for 56 days and stool was tested for C. difficile using polymerase chain reaction (PCR) to assess the effect of treatment. A negative PCR test result was interpreted as a favorable response to rifaximin. Sixteen of 22 patients (73%) were eligible for study inclusion and completed rifaximin therapy experienced eradication of infection (stool negative for C. difficile) immediately after rifaximin therapy and 56 days post-treatment. Three patients (12%) discontinued therapy because of abdominal distention. Rifaximin was generally well tolerated. In conclusion, rifaximin may be considered for treatment of mild-to-moderate C. difficile infection that is resistant to metronidazole. Larger randomized trials are needed to confirm these positive findings.

Prevalence and risk factors of Clostridium difficile infection in patients hospitalized for flare of inflammatory bowel disease: a retrospective assessment.

PubMed

Regnault, Helene; Bourrier, Anne; Lalande, Valerie; Nion-Larmurier, Isabelle; Sokol, Harry; Seksik, Philippe; Barbut, Frederic; Cosnes, Jacques; Beaugerie, Laurent

2014-12-01

Recent studies have identified a high frequency of Clostridium difficile infections in patients with active inflammatory bowel disease. To retrospectively assess the determinants and results of Clostridium difficile testing upon the admission of patients hospitalized with active inflammatory bowel disease in a tertiary care centre and to determine the predicting factors of Clostridium difficile infections. We reviewed all admissions from January 2008 and December 2010 for inflammatory bowel disease flare-ups. A toxigenic culture and a stool cytotoxicity assay were performed for all patients tested for Clostridium difficile. Out of 813 consecutive stays, Clostridium difficile diagnostic assays have been performed in 59% of inpatients. The independent predictive factors for the testing were IBD (ulcerative colitis: OR 2.0, 95% CI 1.5-2.9; p<0.0001) and colonic involvement at admission (OR 2.2, 95% CI 1.5-3.1, p<0.0001). Clostridium difficile infection was present in 7.0% of the inpatients who underwent testing. In a multivariate analysis, the only independent predictor was the intake of nonsteroidal anti-inflammatory drugs within the two months before admission (OR 3.8, 95% CI 1.2-12.3; p=0.02). Clostridium difficile infection is frequently associated with active inflammatory bowel disease. Our study suggests that a recent intake of nonsteroidal anti-inflammatory drugs is a risk factor for inflammatory bowel disease -associated Clostridium difficile infection. Copyright © 2014 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Clostridium difficile contamination of health care workers' hands and its potential contribution to the spread of infection: Review of the literature.

PubMed

Jullian-Desayes, Ingrid; Landelle, Caroline; Mallaret, Marie-Reine; Brun-Buisson, Christian; Barbut, Frédéric

2017-01-01

Clostridium difficile infection (CDI) can be transmitted from patient to patient by the hands of health care workers (HCWs); however, the relative importance of this route in the spread of C difficile in the hospital is currently unknown. Our aim was to review studies examining HCWs' hand carriage and its potential role in CDI transmission. First, English-speaking references addressing HCWs' hand sampling obtained from the PubMed database were reviewed. Second, C difficile outbreaks definitely or probably implicating HCWs were retrieved from the Outbreak Database Web site (www.outbreak-database.com). Finally, cases of C difficile occurring in HCWs after contact with an infected patient were retrieved from PubMed. A total of 11 studies dealing with HCWs' hand carriage were selected and reviewed. Between 0% and 59% of HCWs' hands were found contaminated with C difficile after caring for a patient with CDI. There were several differences between studies regarding site of hands sampling, timing after contact, and bacteriologic methods. Only 2 C difficile outbreaks implicating HCWs and 6 series of cases of transmission from patients to HCWs have been reported. This review shows that HCWs' hands could play an important role in the transmission of C difficile. Hand hygiene and reduction of environmental contamination are essential to control C difficile transmission. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Conserved oligopeptide permeases modulate sporulation initiation in Clostridium difficile.

PubMed

Edwards, Adrianne N; Nawrocki, Kathryn L; McBride, Shonna M

2014-10-01

The anaerobic gastrointestinal pathogen Clostridium difficile must form a metabolically dormant spore to survive in oxygenic environments and be transmitted from host to host. The regulatory factors by which C. difficile initiates and controls the early stages of sporulation in C. difficile are not highly conserved in other Clostridium or Bacillus species. Here, we investigated the role of two conserved oligopeptide permeases, Opp and App, in the regulation of sporulation in C. difficile. These permeases are known to positively affect sporulation in Bacillus species through the import of sporulation-specific quorum-sensing peptides. In contrast to other spore-forming bacteria, we discovered that inactivating these permeases in C. difficile resulted in the earlier expression of early sporulation genes and increased sporulation in vitro. Furthermore, disruption of opp and app resulted in greater virulence and increased the amounts of spores recovered from feces in the hamster model of C. difficile infection. Our data suggest that Opp and App indirectly inhibit sporulation, likely through the activities of the transcriptional regulator SinR and its inhibitor, SinI. Taken together, these results indicate that the Opp and App transporters serve a different function in controlling sporulation and virulence in C. difficile than in Bacillus subtilis and suggest that nutrient availability plays a significant role in pathogenesis and sporulation in vivo. This study suggests a link between the nutritional status of the environment and sporulation initiation in C. difficile. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Evaluation of Xpert C. difficile, BD MAX Cdiff, IMDx C. difficile for Abbott m2000, and Illumigene C. difficile Assays for Direct Detection of Toxigenic Clostridium difficile in Stool Specimens.

PubMed

Shin, Bo-Moon; Yoo, Sun Mee; Shin, Won Chang

2016-03-01

We evaluated the performance of four commercial nucleic acid amplification tests (NAATs: Xpert C. difficile, BD MAX Cdiff, IMDx C. difficile for Abbott m2000, and Illumigene C. difficile) for direct and rapid detection of Clostridium difficile toxin genes. We compared four NAATs on the same set of 339 stool specimens (303 prospective and 36 retrospective specimens) with toxigenic culture (TC). Concordance rate among four NAATs was 90.3% (306/339). Based on TC results, the sensitivity and specificity were 90.0% and 92.9% for Xpert; 86.3% and 89.3% for Max; 84.3% and 94.4% for IMDx; and 82.4% and 93.7% for Illumigene, respectively. For 306 concordant cases, there were 11 TC-negative/NAATs co-positive cases and 6 TC-positive/NAATs co-negative cases. Among 33 discordant cases, 18 were only single positive in each NAAT (Xpert, 1; Max, 12; IMDx, 1; Illumigene, 4). Positivity rates of the four NAATs were associated with those of semi-quantitative cultures, which were maximized in grade 3 (>100 colony-forming unit [CFU]) compared with grade 1 (<10 CFU). Commercial NAATs may be rapid and reliable methods for direct detection of tcdA and/or tcdB in stool specimens compared with TC. Some differences in the sensitivity of the NAATs may partly depend on the number of toxigenic C. difficile in stool specimens.

Clostridium difficile shows no trade-off between toxin and spore production within the human host.

PubMed

Blanco, Natalia; Walk, Seth; Malani, Anurag N; Rickard, Alexander; Benn, Michele; Eisenberg, Marisa; Zhang, Min; Foxman, Betsy

2018-05-01

This study aimed to describe the correlation between Clostridium difficile spore and toxin levels within the human host. In addition, we assessed whether overgrowth of Candida albicans modified this association. We measured toxin, spore and Candida albicans levels among 200 successively collected stool samples that tested positive for C. difficile, and PCR ribotyped these C. difficile isolates. Analysis of variance and linear regression were used to test the association between spore and toxin levels. Kruskal-Wallis tests and t-tests were used to compare the association between spore or toxin levels and host, specimen, or pathogen characteristics. C. difficile toxin and spore levels were positively associated (P<0.001); this association did not vary significantly with C. albicans overgrowth [≥5 logs of C. albicans colony-forming units (c.f.u.) g -1 ]. However, ribotypes 027 and 078-126 were significantly associated with higher levels of toxin and spores, and C. albicans overgrowth. The strong positive association observed between in vivo levels of C. difficile toxin and spores suggests that patients with more severe C. difficile infections may have increased spore production, enhancing C. difficile transmission. Although, on average, spore levels were higher in toxin-positive samples than in toxin-negative/PCR-positive samples, spores were found in almost all toxin-negative samples. The ubiquity of spore production among toxin-negative and formed stool samples emphasizes the importance of following infection prevention and control measures for all C. difficile-positive patients during their entire hospital stay.

Clostridium difficile from food and surface samples in a Belgian nursing home: an unlikely source of contamination.

PubMed

Rodriguez, C; Korsak, N; Taminiau, B; Avesani, V; Van Broeck, J; Brach, P; Delmée, M; Daube, G

2015-04-01

This study investigates the contamination of foods and surfaces with Clostridium difficile in a single nursing home. C. difficile PCR-ribotype 078 was found in one food sample and in none of the tested surfaces. These results indicate that food and surfaces are an unlikely source of C. difficile infection in this setting. Copyright © 2015 Elsevier Ltd. All rights reserved.

Improved control strategy for wind-powered refrigerated storage of apples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baldwin, J.D.C.; Vaughan, D.H.

1981-01-01

A refrigerated apple storage facility was constructed at the VPI and SU Horticultural Research Farm in Blacksburg, Virginia and began operation in March 1978. The system included a 10-kW electric wind generator, electrical battery storage, thermal (ice) storage, and auxiliary power. The need for an improved control system for the VPI and SU system was determined from tests on the individual components and in situ performance tests. The results of these tests formed the basis for an improved control strategy to improve the utilization of available wind energy and reduce the need for auxiliary power while maintaining an adequate applemore » storage environment.« less

Taste, umami-enhance effect and amino acid sequence of peptides separated from silkworm pupa hydrolysate.

PubMed

Yu, Zilin; Jiang, Hongrui; Guo, Rongcan; Yang, Bo; You, Gang; Zhao, Mouming; Liu, Xiaoling

2018-06-01

Four umami peptides were separated and purified by ultrafiltration, gel filtration chromatography and identified by ultra-performance liquid chromatography tandem mass-spectrometry (UPLC-MS/MS), the amino acid sequences of four peptides are Val-Pro-Tyr (VPY), Thr-Ala-Tyr (TAY), Ala-Ala-Pro-Tyr (AAPY) and Gly-Phe-Pro (GFP). The result illustrates that the umami amino acids are not the content of umami peptides, but bitter amino acids are included. The threshold of VPY, TAY, AAPY and GFP were 1.65 mmol/L, 1.76 mmol/L, 2.97 mmol/L and 6.26 mmol/L, respectively. The peptide TAY, VPY and AAPY had an umami-enhancement effect on the monosodium glutamate (MSG) + sodium chloride (NaCl) solution, their concentrations were 2.5 g/L, 5 g/L and 5 g/L, respectively, while GFP has no significant umami-enhancement effect in solution. In addition, the peptides have better taste than its composing amino acids, which indicates that the taste of peptide does not depend on its composing amino acids. Copyright © 2018. Published by Elsevier Ltd.

Update on Antimicrobial Resistance in Clostridium difficile: Resistance Mechanisms and Antimicrobial Susceptibility Testing

PubMed Central

Peng, Zhong; Kim, Hyeun Bum; Stratton, Charles W.; Wu, Bin

2017-01-01

ABSTRACT Oral antibiotics such as metronidazole, vancomycin and fidaxomicin are therapies of choice for Clostridium difficile infection. Several important mechanisms for C. difficile antibiotic resistance have been described, including the acquisition of antibiotic resistance genes via the transfer of mobile genetic elements, selective pressure in vivo resulting in gene mutations, altered expression of redox-active proteins, iron metabolism, and DNA repair, as well as via biofilm formation. This update summarizes new information published since 2010 on phenotypic and genotypic resistance mechanisms in C. difficile and addresses susceptibility test methods and other strategies to counter antibiotic resistance of C. difficile. PMID:28404671

Special Concerns for Seniors: Clostridium difficile

MedlinePlus

... and Drugs" Home | Contact Us Special Concerns for Seniors Clostridium difficile - an introduction Clostridium difficile (“C. diff”) ... see APUA’s contribution to CDC’s Vital Signs campaign . Seniors are especially at risk People over the age ...

Comparison of traditional gas chromatography (GC), headspace GC, and the microbial identification library GC system for the identification of Clostridium difficile.

PubMed Central

Cundy, K V; Willard, K E; Valeri, L J; Shanholtzer, C J; Singh, J; Peterson, L R

1991-01-01

Three gas chromatography (GC) methods were compared for the identification of 52 clinical Clostridium difficile isolates, as well as 17 non-C. difficile Clostridium isolates. Headspace GC and Microbial Identification System (MIS) GC, an automated system which utilizes a software library developed at the Virginia Polytechnic Institute to identify organisms based on the fatty acids extracted from the bacterial cell wall, were compared against the reference method of traditional GC. Headspace GC and MIS were of approximately equivalent accuracy in identifying the 52 C. difficile isolates (52 of 52 versus 51 of 52, respectively). However, 7 of 52 organisms required repeated sample preparation before an identification was achieved by the MIS method. Both systems effectively differentiated C. difficile from non-C. difficile clostridia, although the MIS method correctly identified only 9 of 17. We conclude that the headspace GC system is an accurate method of C. difficile identification, which requires only one-fifth of the sample preparation time of MIS GC and one-half of the sample preparation time of traditional GC. PMID:2007632

Impact of toxigenic Clostridium difficile polymerase chain reaction testing on the clinical microbiology laboratory and inpatient epidemiology.

PubMed

Napierala, Maureen; Munson, Erik; Skonieczny, Patrice; Rodriguez, Sonia; Riederer, Nancy; Land, Gayle; Luzinski, Mary; Block, Denise; Hryciuk, Jeanne E

2013-08-01

Conversion from Clostridium difficile toxin A/B EIA to tcdB polymerase chain reaction for diagnosis of C. difficile infection (CDI) resulted in significant decreases in laboratory testing volume and largely unchanged C. difficile toxin detection rates. Decreases in healthcare-associated CDI rates (P ≤ 0.05) reflected a clinical practice benefit of this conversion. Copyright © 2013 Elsevier Inc. All rights reserved.

Coinfection and Emergence of Rifamycin Resistance during a Recurrent Clostridium difficile Infection.

PubMed

Stevenson, Emma C; Major, Giles A; Spiller, Robin C; Kuehne, Sarah A; Minton, Nigel P

2016-11-01

Clostridium difficile (Peptoclostridium difficile) is a common health care-associated infection with a disproportionately high incidence in elderly patients. Disease symptoms range from mild diarrhea to life-threatening pseudomembranous colitis. Around 20% of patients may suffer recurrent disease, which often requires rehospitalization of patients. C. difficile was isolated from stool samples from a patient with two recurrent C. difficile infections. PCR ribotyping, whole-genome sequencing, and phenotypic assays were used to characterize these isolates. Genotypic and phenotypic screening of C. difficile isolates revealed multiple PCR ribotypes present and the emergence of rifamycin resistance during the infection cycle. Understanding both the clinical and bacterial factors that contribute to the course of recurrent infection could inform strategies to reduce recurrence. (This study has been registered at ClinicalTrials.gov under registration no. NCT01670149.). Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Fecal Microbiota Transplant for Clostridium difficile Infection in a Pregnant Patient.

PubMed

Saeedi, Bejan J; Morison, Doree Gardner; Kraft, Colleen S; Dhere, Tanvi

2017-03-01

Clostridium difficile infection has been associated with negative outcomes in the general population and in pregnant patients. Fecal microbiota transplant has become the standard for treatment of recurrent as well as refractory C difficile infection. We present a case of a 28-year-old pregnant woman who presented with recurrent C difficile infection despite treatment with vancomycin and fidaxomicin and underwent a successful fecal microbiota transplant through colonoscopy at 18 weeks of gestation. She no longer required antibiotics for the remainder of her pregnancy to treat C difficile and had a term vaginal delivery at 39 weeks of gestation. Our pregnant patient tolerated and responded to a fecal microbiota transplant for treatment of recurrent C difficile infection. Future large-scale studies are needed to determine the efficacy, safety, and long-term effects of manipulating the microbiome in pregnant patients and the neonates.

Inactivation of Clostridium difficile spores by microwave irradiation.

PubMed

Ojha, Suvash Chandra; Chankhamhaengdecha, Surang; Singhakaew, Sombat; Ounjai, Puey; Janvilisri, Tavan

2016-04-01

Spores are a potent agent for Clostridium difficile transmission. Therefore, factors inhibiting spores have been of continued interest. In the present study, we investigated the influence of microwave irradiation in addition to conductive heating for C. difficile spore inactivation in aqueous suspension. The spores of 15 C. difficile isolates from different host origins were exposed to conductive heating and microwave irradiation. The complete inhibition of spore viability at 10(7) CFU/ml was encountered following microwave treatment at 800 W for 60 s, but was not observed in the conductive-heated spores at the same time-temperature exposure. The distinct patterns of ultrastructural alterations following microwave and conductive heat treatment were observed and the degree of damages by microwave was in the exposure time-dependent manner. Microwave would therefore be a simple and time-efficient tool to inactivate C. difficile spores, thus reducing the risk of C. difficile transmission. Copyright © 2015 Elsevier Ltd. All rights reserved.

The emergence of Clostridium difficile infection in Asia: A systematic review and meta-analysis of incidence and impact

PubMed Central

Borren, Nienke Z.; Ghadermarzi, Shadi; Hutfless, Susan

2017-01-01

Background Clostridium difficile infection (CDI) is the most common healthcare associated infection and is highly prevalent in Europe and North America. Limited data is available on the prevalence of CDI in Asia. However, secular increases in prevalence of risk factors for CDI suggest that it may be emerging as a major cause of morbidity, highlighting the urgent need for a systematic study of the prevalence of CDI in Asia. Methods We systematically searched PubMed/Medline and Embase for publications from Asia between 2000–16 examining prevalence of CDI. A random-effects meta-analysis was performed to calculate the pooled prevalence of CDI in Asia and to identify subgroups and regions at high risk. Results Our meta-analysis included 51 studies from throughout Asia including 37,663 patients at risk among whom confirmed CDI was found in 4,343 patients. The pooled proportion of confirmed CDI among all patients with diarrhea was 14.8% with a higher prevalence in East Asia (19.5%), compared with South Asia (10.5%) or the Middle East (11.1%). There were an estimated 5.3 episodes of CDI per 10,000 patient days, similar to rates reported from Europe and North America. Infections due to hypervirulent strains were rare. CDI-related mortality was 8.9%. Conclusions In a meta-analysis of 51 studies, we observed similar rates of CDI in Asia in comparison to Europe and North America. Increased awareness and improved surveillance of Clostridium difficile is essential to reduce incidence and morbidity. PMID:28463987

Newly identified bacteriolytic enzymes that target a wide range of clinical isolates of Clostridium difficile.

PubMed

Mehta, Krunal K; Paskaleva, Elena E; Wu, Xia; Grover, Navdeep; Mundra, Ruchir V; Chen, Kevin; Zhang, Yongrong; Yang, Zhiyong; Feng, Hanping; Dordick, Jonathan S; Kane, Ravi S

2016-12-01

Clostridium difficile has emerged as a major cause of infectious diarrhea in hospitalized patients, with increasing mortality rate and annual healthcare costs exceeding $3 billion. Since C. difficile infections are associated with the use of antibiotics, there is an urgent need to develop treatments that can inactivate the bacterium selectively without affecting commensal microflora. Lytic enzymes from bacteria and bacteriophages show promise as highly selective and effective antimicrobial agents. These enzymes often have a modular structure, consisting of a catalytic domain and a binding domain. In the current work, using consensus catalytic domain and cell-wall binding domain sequences as probes, we analyzed in silico the genome of C. difficile, as well as phages infecting C. difficile. We identified two genes encoding cell lytic enzymes with possible activity against C. difficile. We cloned the genes in a suitable expression vector, expressed and purified the protein products, and tested enzyme activity in vitro. These newly identified enzymes were found to be active against C. difficile cells in a dose-dependent manner. We achieved a more than 4-log reduction in the number of viable bacteria within 5 h of application. Moreover, we found that the enzymes were active against a wide range of C. difficile clinical isolates. We also characterized the biocatalytic mechanism by identifying the specific bonds cleaved by these enzymes within the cell wall peptidoglycan. These results suggest a new approach to combating the growing healthcare problem associated with C. difficile infections. Biotechnol. Bioeng. 2016;113: 2568-2576. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

A microbiological study to investigate the carriage and transmission-potential of Clostridium difficile spores on single-use and reusable sharps containers.

PubMed

Grimmond, Terry; Neelakanta, Anu; Miller, Barbara; Saiyed, Asif; Gill, Pam; Cadnum, Jennifer; Olmsted, Russell; Donskey, Curtis; Pate, Kimberly; Miller, Katherine

2018-05-22

A 2015 study matching use of disposable and reusable sharps containers (DSCs, RSCs) with Clostridium difficile infection (CDI) incidence found a decreased incidence with DSCs. We conducted microbiologic samplings and examined the literature and disease-transmission principles to evaluate the scientific feasibility of such an association. (i) 197 RSCs were sampled for C. difficile at processing facilities; (ii) RSCs were challenged with high C. difficile densities to evaluate efficacy of automated decontamination; and (iii) 50 RSCs and 50 DSCs were sampled in CDI patient rooms in 7 hospitals. Results were coupled with epidemiologic studies, clinical requirements, and chain-of-infection principles, and tests of evidence of disease transmission were applied. C. difficile spores were found on 9 of 197 (4.6%) RSCs prior to processing. Processing completely removed C. difficile. In CDI patient rooms, 4 of 50 RSCs (8.0%) and 8 of 50 DSCs (16.0%) had sub-infective counts of C. difficile (P = .27). DSCs were in permanent wall cabinets; RSCs were removed and decontaminated frequently. With C. difficile bioburden being sub-infective on both DSCs and RSCs, sharps containers being no-touch, and glove removal required after sharps disposal, we found 2 links in the chain of infection to be broken and 5 of 7 tests of evidence to be unmet. We conclude that sharps containers pose no risk of C. difficile transmission. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Diagnostic trends in Clostridium difficile detection in Finnish microbiology laboratories.

PubMed

Könönen, Eija; Rasinperä, Marja; Virolainen, Anni; Mentula, Silja; Lyytikäinen, Outi

2009-12-01

Due to increased interest directed to Clostridium difficile-associated infections, a questionnaire survey of laboratory diagnostics of toxin-producing C. difficile was conducted in Finland in June 2006. Different aspects pertaining to C. difficile diagnosis, such as requests and criteria used for testing, methods used for its detection, yearly changes in diagnostics since 1996, and the total number of investigations positive for C. difficile in 2005, were asked in the questionnaire, which was sent to 32 clinical microbiology laboratories, including all hospital-affiliated and the relevant private clinical microbiology laboratories in Finland. The situation was updated by phone and email correspondence in September 2008. In June 2006, 28 (88%) laboratories responded to the questionnaire survey; 24 of them reported routinely testing requested stool specimens for C. difficile. Main laboratory methods included toxin detection (21/24; 88%) and/or anaerobic culture (19/24; 79%). In June 2006, 18 (86%) of the 21 laboratories detecting toxins directly from feces, from the isolate, or both used methods for both toxin A (TcdA) and B (TcdB), whereas only one laboratory did so in 1996. By September 2008, all of the 23 laboratories performing diagnostics for C. difficile used methods for both TcdA and TcdB. In 2006, the number of specimens processed per 100,000 population varied remarkably between different hospital districts. In conclusion, culturing C. difficile is common and there has been a favorable shift in toxin detection practice in Finnish clinical microbiology laboratories. However, the variability in diagnostic activity reported in 2006 creates a challenge for national monitoring of the epidemiology of C. difficile and related diseases.

Characterization of Clostridium difficile Spores Lacking Either SpoVAC or Dipicolinic Acid Synthetase

PubMed Central

Donnelly, M. Lauren; Fimlaid, Kelly A.

2016-01-01

ABSTRACT The spore-forming obligate anaerobe Clostridium difficile is a leading cause of antibiotic-associated diarrhea around the world. In order for C. difficile to cause infection, its metabolically dormant spores must germinate in the gastrointestinal tract. During germination, spores degrade their protective cortex peptidoglycan layers, release dipicolinic acid (DPA), and hydrate their cores. In C. difficile, cortex hydrolysis is necessary for DPA release, whereas in Bacillus subtilis, DPA release is necessary for cortex hydrolysis. Given this difference, we tested whether DPA synthesis and/or release was required for C. difficile spore germination by constructing mutations in either spoVAC or dpaAB, which encode an ion channel predicted to transport DPA into the forespore and the enzyme complex predicted to synthesize DPA, respectively. C. difficile spoVAC and dpaAB mutant spores lacked DPA but could be stably purified and were more hydrated than wild-type spores; in contrast, B. subtilis spoVAC and dpaAB mutant spores were unstable. Although C. difficile spoVAC and dpaAB mutant spores exhibited wild-type germination responses, they were more readily killed by wet heat. Cortex hydrolysis was not affected by this treatment, indicating that wet heat inhibits a stage downstream of this event. Interestingly, C. difficile spoVAC mutant spores were significantly more sensitive to heat treatment than dpaAB mutant spores, indicating that SpoVAC plays additional roles in conferring heat resistance. Taken together, our results demonstrate that SpoVAC and DPA synthetase control C. difficile spore resistance and reveal differential requirements for these proteins among the Firmicutes. IMPORTANCE Clostridium difficile is a spore-forming obligate anaerobe that causes ∼500,000 infections per year in the United States. Although spore germination is essential for C. difficile to cause disease, the factors required for this process have been only partially characterized. This study describes the roles of two factors, DpaAB and SpoVAC, which control the synthesis and release of dipicolinic acid (DPA), respectively, from bacterial spores. Previous studies of these proteins in other spore-forming organisms indicated that they are differentially required for spore formation, germination, and resistance. We now show that the proteins are dispensable for C. difficile spore formation and germination but are necessary for heat resistance. Thus, our study further highlights the diverse functions of DpaAB and SpoVAC in spore-forming organisms. PMID:27044622

Development of a consensus method for culture of Clostridium difficile from meat and its use in a survey of U.S. retail meats.

PubMed

Limbago, Brandi; Thompson, Angela D; Greene, Sharon A; MacCannell, Duncan; MacGowan, Charles E; Jolbitado, Beverly; Hardin, Henrietta D; Estes, Stephanie R; Weese, J Scott; Songer, J Glenn; Gould, L Hannah

2012-12-01

Three previously described methods for culture of Clostridium difficile from meats were evaluated by microbiologists with experience in C. difficile culture and identification. A consensus protocol using BHI broth enrichment followed by ethanol shock and plating to selective and non-selective media was selected for use, and all participating laboratories received hands-on training in the use of this method prior to study initiation. Retail meat products (N = 1755) were cultured for C. difficile over 12 months during 2010-2011 at 9 U.S. FoodNet sites. No C. difficile was recovered, although other clostridia were isolated. Published by Elsevier Ltd.

Development of a consensus method for culture of Clostridium difficile from meat and its use in a survey of U.S. retail meats

PubMed Central

Limbago, Brandi; Thompson, Angela D.; Greene, Sharon A.; MacCannell, Duncan; MacGowan, Charles E.; Jolbitado, Beverly; Hardin, Henrietta D.; Estes, Stephanie R.; Weese, J. Scott; Songer, J. Glenn; Gould, L. Hannah

2017-01-01

Three previously described methods for culture of Clostridium difficile from meats were evaluated by microbiologists with experience in C. difficile culture and identification. A consensus protocol using BHI broth enrichment followed by ethanol shock and plating to selective and non-selective media was selected for use, and all participating laboratories received hands-on training in the use of this method prior to study initiation. Retail meat products (N = 1755) were cultured for C. difficile over 12 months during 2010-2011 at 9 U.S. FoodNet sites. No C. difficile was recovered, although other clostridia were isolated. PMID:22986214

The relationship between patient functional status and environmental contamination by Clostridium difficile: a pilot study

PubMed Central

Blakney, Rebekah; Gudnadottir, Unnur; Warrack, Simone; O'Horo, John C.; Anderson, Michael; Sethi, Ajay; Schmitz, Michelle; Wang, Jennifer; Duster, Megan; Ide, Emma; Safdar, Nasia

2016-01-01

Introduction Limited data exist on patient factors related to environmental contamination with Clostridium difficile. Methods We evaluated the association between the functional status of patients with C. difficile infection (CDI) and environmental contamination with C. difficile. Results Contamination of patient rooms was frequent and higher functional status was associated with contaminated surfaces remote from the bed. All but one environmental isolates matched the corresponding patient's stool isolate for the seven patients tested. Conclusion Functional status is a factor that influences environmental contamination with C. difficile. Future studies should evaluate strategies to reduce contamination in CDI patient rooms, taking into account the patient's functional status. PMID:25869819

Bacteraemia and breast abscess: unusual extra-intestinal manifestations of Clostridium difficile infection.

PubMed

Durojaiye, Oyewole; Gaur, Soma; Alsaffar, Layth

2011-03-01

Extra-intestinal manifestations of Clostridium difficile infection are uncommon. Most cases are associated with gastrointestinal disease and often occur as a mixed infection with other gut flora. We report a case of breast abscess following monomicrobial C. difficile bacteraemia in a female with background chronic hepatitis C infection and alcoholic liver disease. No evidence of colitis was found. Our case shows that C. difficile is indeed capable of spreading from the gastrointestinal tract.

The risk of Clostridium difficile infection in patients with pernicious anaemia: a retrospective cohort study using primary care database.

PubMed

Othman, Fatmah; Crooks, Colin J; Card, Timothy R

2017-11-01

Studies have found an association between proton pump inhibitor (PPI) use and Clostridium difficile infection. The purpose of this study was to determine whether the mechanism by which PPIs induce an increased risk of C. difficile infection is supported by the same mechanism acting in another cause of achlorhydria, pernicious anaemia. Using a database of anonymised primary care records between 1990 and 2013, we selected exposed patients with a diagnosis of pernicious anaemia treated with vitamin B12 therapy. Each exposed patient was matched by age, gender and general practice to up to 10 controls. Cox regression analysis was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for C. difficile infection with pernicious anaemia, adjusted for potential confounders. We identified 45,467 exposed patients matched to 449,635 controls. The crude incidence rate of C. difficile infection was 1.85/1000 person-years for the exposed cohort and 1.09/1000 person-years for controls. Patients with pernicious anaemia had a greater risk of C. difficile infection than the controls (adjusted HR 1.57, 95% CI 1.40-1.76). Pernicious anaemia patients have an increased risk of C. difficile infection. This supports the theory that severe achlorhydria is the mechanism that increases the risk of C. difficile infection in long-term PPI users.

The risk of Clostridium difficile infection in patients with pernicious anaemia: a retrospective cohort study using primary care database

PubMed Central

Crooks, Colin J; Card, Timothy R

2017-01-01

Background Studies have found an association between proton pump inhibitor (PPI) use and Clostridium difficile infection. The purpose of this study was to determine whether the mechanism by which PPIs induce an increased risk of C. difficile infection is supported by the same mechanism acting in another cause of achlorhydria, pernicious anaemia. Methods Using a database of anonymised primary care records between 1990 and 2013, we selected exposed patients with a diagnosis of pernicious anaemia treated with vitamin B12 therapy. Each exposed patient was matched by age, gender and general practice to up to 10 controls. Cox regression analysis was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for C. difficile infection with pernicious anaemia, adjusted for potential confounders. Results We identified 45,467 exposed patients matched to 449,635 controls. The crude incidence rate of C. difficile infection was 1.85/1000 person-years for the exposed cohort and 1.09/1000 person-years for controls. Patients with pernicious anaemia had a greater risk of C. difficile infection than the controls (adjusted HR 1.57, 95% CI 1.40–1.76). Conclusions Pernicious anaemia patients have an increased risk of C. difficile infection. This supports the theory that severe achlorhydria is the mechanism that increases the risk of C. difficile infection in long-term PPI users. PMID:29163961

An Economic Analysis of Strategies to Control Clostridium Difficile Transmission and Infection Using an Agent-Based Simulation Model

PubMed Central

Nelson, Richard E.; Jones, Makoto; Leecaster, Molly; Samore, Matthew H.; Ray, William; Huttner, Angela; Huttner, Benedikt; Khader, Karim; Stevens, Vanessa W.; Gerding, Dale; Schweizer, Marin L.; Rubin, Michael A.

2016-01-01

Background A number of strategies exist to reduce Clostridium difficile (C. difficile) transmission. We conducted an economic evaluation of “bundling” these strategies together. Methods We constructed an agent-based computer simulation of nosocomial C. difficile transmission and infection in a hospital setting. This model included the following components: interactions between patients and health care workers; room contamination via C. difficile shedding; C. difficile hand carriage and removal via hand hygiene; patient acquisition of C. difficile via contact with contaminated rooms or health care workers; and patient antimicrobial use. Six interventions were introduced alone and "bundled" together: (a) aggressive C. difficile testing; (b) empiric isolation and treatment of symptomatic patients; (c) improved adherence to hand hygiene and (d) contact precautions; (e) improved use of soap and water for hand hygiene; and (f) improved environmental cleaning. Our analysis compared these interventions using values representing 3 different scenarios: (1) base-case (BASE) values that reflect typical hospital practice, (2) intervention (INT) values that represent implementation of hospital-wide efforts to reduce C. diff transmission, and (3) optimal (OPT) values representing the highest expected results from strong adherence to the interventions. Cost parameters for each intervention were obtained from published literature. We performed our analyses assuming low, normal, and high C. difficile importation prevalence and transmissibility of C. difficile. Results INT levels of the “bundled” intervention were cost-effective at a willingness-to-pay threshold of $100,000/quality-adjusted life-year in all importation prevalence and transmissibility scenarios. OPT levels of intervention were cost-effective for normal and high importation prevalence and transmissibility scenarios. When analyzed separately, hand hygiene compliance, environmental decontamination, and empiric isolation and treatment were the interventions that had the greatest impact on both cost and effectiveness. Conclusions A combination of available interventions to prevent CDI is likely to be cost-effective but the cost-effectiveness varies for different levels of intensity of the interventions depending on epidemiological conditions such as C. difficile importation prevalence and transmissibility. PMID:27031464

Dissemination of Clostridium difficile spores between environment and households: Dog paws and shoes.

PubMed

Janezic, Sandra; Mlakar, Sabina; Rupnik, Maja

2018-04-23

Clostridium difficile is an anaerobic, spore-forming bacterium that causes intestinal infections. Although C. difficile is still predominantly considered as a nosocomial pathogen, there has been an increase in the number of community-associated infections. Since C. difficile is ubiquitous and can be isolated from nearly any environment, one of the possibilities for community acquisition could be exposure to spores in the domestic environment. The aim of this study was to evaluate the presence of C. difficile spores on shoes, slippers and on dog paws and to explore the importance of these surfaces as vectors for the dissemination of C. difficile in a domestic environment. Overall, C. difficile was present in 14 (70%) of 20 households and in 31 of 90 (34%) collected samples. Shoes and slippers had the highest positivity rates, 19 of 44 (43%) and 6 of 21 (28%), respectively, followed by dog paws 6 of 25 (24%). Thirteen C. difficilePCR ribotypes were identified with half of the isolates belonging to ribotype 014/020, which is the predominant type circulating in human population and is also commonly found in the environment (e.g. soil and water) in Slovenia. In three households, identical PCR ribotypes were found on dog paws, shoes and slippers. To understand the fine-scale genetic relatedness of these isolates, we sequenced the genomes. Low level of single nucleotide variant (SNV) differences between isolates from the same households, consistent with a recent transmission from a common source, were seen for isolates of PCR ribotype 014/020 but not for PCR ribotype 010. Our results suggest that shoe soles and dog paws could serve for the dissemination of C. difficile spores between households and environment and could contribute to community-relevant sources for C. difficile infection in humans. © 2018 Blackwell Verlag GmbH.

Second generation cephalosporin antibiotic prophylaxis and Clostridium difficile infection in hip and knee arthroplasty.

PubMed

Al-Tawil, K; Babu, A; Loeffler, M; Williams, T

2017-05-01

Introduction The use of broad spectrum cephalosporin antibiotics has been discouraged by the Department of Health in England because of the link to increased Clostridium difficile infection rates. The aim of this study was to evaluate whether a local protocol that included the use of second generation cephalosporin (cefuroxime) antibiotics as a prophylactic agent was associated with increased risk of C difficile in elective hip and knee arthroplasty patients. Methods A retrospective intention-to-treat study was conducted. An infection control database of all cases of C difficile infection both in hospital and in the community was reviewed and cross-referenced against surgical records. A positive correlation was identified when a C difficile positive sample was documented within eight weeks of arthroplasty surgery. Results Only 1 case (0.02%) of C difficile positive diarrhoea was identified that correlated to the 8-week postoperative period following 4,488 arthroplasty procedures. Conclusions The use of cephalosporin antibiotic prophylaxis in the elective hip and knee arthroplasty setting does not appear to be associated with increased C difficile infection rates, achieving surgical site infection rates that are comparable with the national average.

High colonization rate and prolonged shedding of Clostridium difficile in pediatric oncology patients.

PubMed

Dominguez, Samuel R; Dolan, Susan A; West, Kelly; Dantes, Raymund B; Epson, Erin; Friedman, Deborah; Littlehorn, Cynthia A; Arms, Lesley E; Walton, Karen; Servetar, Ellen; Frank, Daniel N; Kotter, Cassandra V; Dowell, Elaine; Gould, Carolyn V; Hilden, Joanne M; Todd, James K

2014-08-01

Surveillance testing for Clostridium difficile among pediatric oncology patients identified stool colonization in 29% of patients without gastrointestinal symptoms and in 55% of patients with prior C. difficile infection (CDI). A high prevalence of C. difficile colonization and diarrhea complicates the diagnosis of CDI in this population. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Comparison of Simplexa universal direct PCR with cytotoxicity assay for diagnosis of Clostridium difficile infection: performance, cost, and correlation with disease.

PubMed

Landry, Marie L; Ferguson, David; Topal, Jeffrey

2014-01-01

Simplexa Clostridium difficile universal direct PCR, a real-time PCR assay for the detection of the C. difficile toxin B (tcdB) gene using the 3M integrated cycler, was compared with a two-step algorithm which includes the C. Diff Chek-60 glutamate dehydrogenase (GDH) antigen assay followed by cytotoxin neutralization. Three hundred forty-two liquid or semisolid stools submitted for diagnostic C. difficile testing, 171 GDH antigen positive and 171 GDH antigen negative, were selected for the study. All samples were tested by the C. Diff Chek-60 GDH antigen assay, cytotoxin neutralization, and Simplexa direct PCR. Of 171 GDH-positive samples, 4 were excluded (from patients on therapy or from whom duplicate samples were obtained) and 88 were determined to be true positives for toxigenic C. difficile. Of the 88, 67 (76.1%) were positive by the two-step method and 86 (97.7%) were positive by PCR. Seventy-nine were positive by the GDH antigen assay only. Of 171 GDH antigen-negative samples, none were positive by PCR. One antigen-negative sample positive by the cytotoxin assay only was deemed a false positive based on chart review. Simplexa C. difficile universal direct PCR was significantly more sensitive for detecting toxigenic C. difficile bacteria than cytotoxin neutralization (P = 0.0002). However, most PCR-positive/cytotoxin-negative patients did not have clear C. difficile disease. The estimated cost avoidance provided by a more rapid molecular diagnosis was outweighed by the cost of isolating and treating PCR-positive/cytotoxin-negative patients. The costs, clinical consequences, and impact on nosocomial transmission of treating and/or isolating patients positive for toxigenic C. difficile by PCR but negative for in vivo toxin production merit further study.

Premarket evaluations of the IMDx C. difficile for Abbott m2000 Assay and the BD Max Cdiff Assay.

PubMed

Stellrecht, K A; Espino, A A; Maceira, V P; Nattanmai, S M; Butt, S A; Wroblewski, D; Hannett, G E; Musser, K A

2014-05-01

Clostridium difficile-associated diarrhea is a well-recognized complication of antibiotic use. Historically, diagnosing C. difficile has been difficult, as antigen assays are insensitive and culture-based methods require several days to yield results. Nucleic acid amplification tests (NAATs) are quickly becoming the standard of care. We compared the performance of two automated investigational/research use only (IUO/RUO) NAATs for the detection of C. difficile toxin genes, the IMDx C. difficile for Abbott m2000 Assay (IMDx) and the BD Max Cdiff Assay (Max). A prospective analysis of 111 stool specimens received in the laboratory for C. difficile testing by the laboratory's test of record (TOR), the BD GeneOhm Cdiff Assay, and a retrospective analysis of 88 specimens previously determined to be positive for C. difficile were included in the study. One prospective specimen was excluded due to loss to follow-up discrepancy analysis. Of the remaining 198 specimens, 90 were positive by all three methods, 9 were positive by TOR and Max, and 3 were positive by TOR only. One negative specimen was initially inhibitory by Max. The remaining 95 specimens were negative by all methods. Toxigenic C. difficile culture was performed on the 12 discrepant samples. True C. difficile-positive status was defined as either positive by all three amplification assays or positive by toxigenic culture. Based on this definition, the sensitivity and specificity were 96.9% and 95% for Max and 92.8% and 100% for IMDx. In summary, both highly automated systems demonstrated excellent performance, and each has individual benefits, which will ensure that they will both have a niche in clinical laboratories.

Clostridium perfringens and Clostridium difficile in cooked beef sold in Côte d'Ivoire and their antimicrobial susceptibility.

PubMed

Kouassi, Kra Athanase; Dadie, Adjéhi Thomas; N'Guessan, Kouadio Florent; Dje, Koffi Marcellin; Loukou, Yao Guillaume

2014-08-01

The aim of this study was to evaluate the prevalence of Clostridium difficile and Clostridium perfringens in cooked beef sold in the streets in Côte d'Ivoire and their antimicrobial susceptibility. A total of 395 kidney and flesh samples of cooked beef were collected from vendors at Abidjan and subjected to C. difficile and C. perfringens isolation and identification by using biochemical tests, API 20A system and PCR detection. Subsequently, the antimicrobial susceptibility test was performed for confirmed isolates. Our results showed the prevalence of 12.4% for C. difficile (11.04% in kidney and 13.45% in flesh) and 5.06% for C. perfringens (2.32% in kidney and 7.17% in flesh). Metronidazole and vancomycin remained the most potent antimicrobial agents against C. difficile while metronidazole and penicillin G were the most potent agents against C. perfringens. The resistance rates to tetracycline, doxycycline, chloramphenicol and erythromycin against C. difficile and C. perfringens isolates ranged from 2.05% to 8.16% and from 20% to 50%, respectively. Among all antimicrobial agents tested against C. difficile, percentages of resistance to quinolones ciprofloxacin, norfloxacin and nalidixic acid as well as to gentamicin and cefotaxime were the highest. Eight resistant phenotypes were defined for C. difficile isolates and eleven resistant phenotypes for C. perfringens isolates. Clindamycin/gentamicin/cefotaxime/ciprofloxacin/norfloxacin/nalidixic acid resistance was the most common phenotype for C. difficile (55.10% of isolates) while norfloxacin/nalidixic acid resistance was the most common phenotype for C. perfringens (20% of isolates). Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Disease Progression and Resolution in Rodent Models of Clostridium difficile Infection and Impact of Antitoxin Antibodies and Vancomycin.

PubMed

Warn, Peter; Thommes, Pia; Sattar, Abdul; Corbett, David; Flattery, Amy; Zhang, Zuo; Black, Todd; Hernandez, Lorraine D; Therien, Alex G

2016-11-01

Clostridium difficile causes infections of the colon in susceptible patients. Specifically, gut dysbiosis induced by treatment with broad-spectrum antibiotics facilitates germination of ingested C. difficile spores, expansion of vegetative cells, and production of symptom-causing toxins TcdA and TcdB. The current standard of care for C. difficile infections (CDI) consists of administration of antibiotics such as vancomycin that target the bacterium but also perpetuate gut dysbiosis, often leading to disease recurrence. The monoclonal antitoxin antibodies actoxumab (anti-TcdA) and bezlotoxumab (anti-TcdB) are currently in development for the prevention of recurrent CDI. In this study, the effects of vancomycin or actoxumab/bezlotoxumab treatment on progression and resolution of CDI were assessed in mice and hamsters. Rodent models of CDI are characterized by an early severe phase of symptomatic disease, associated with high rates of morbidity and mortality; high intestinal C. difficile burden; and a disrupted intestinal microbiota. This is followed in surviving animals by gradual recovery of the gut microbiota, associated with clearance of C. difficile and resolution of disease symptoms over time. Treatment with vancomycin prevents disease initially by inhibiting outgrowth of C. difficile but also delays microbiota recovery, leading to disease relapse following discontinuation of therapy. In contrast, actoxumab/bezlotoxumab treatment does not impact the C. difficile burden but rather prevents the appearance of toxin-dependent symptoms during the early severe phase of disease, effectively preventing disease until the microbiota (the body's natural defense against C. difficile) has fully recovered. These data provide insight into the mechanism of recurrence following vancomycin administration and into the mechanism of recurrence prevention observed clinically with actoxumab/bezlotoxumab. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Clostridium difficile rates in asymptomatic and symptomatic hospitalized patients using nucleic acid testing.

PubMed

Truong, Cynthia; Schroeder, Lee F; Gaur, Rajiv; Anikst, Victoria Emma; Komo, Ikuko; Watters, Colleen; McCalley, Erin; Kulik, Carole; Pickham, David; Lee, Nancy J; Banaei, Niaz

2017-04-01

The Clostridium difficile rate in symptomatic patients represents both those with C. difficile infection (CDI) and those with colonization. To predict the extent of CDI overdiagnosis, we compared the asymptomatic colonization rate to the symptomatic positivity rate in hospitalized patients using nucleic acid testing. Between July 2014 and April 2015, formed stool samples were collected from asymptomatic patients after admission to 3 hospital wards at the Stanford Hospital. Stool samples from symptomatic patients with suspected CDI in the same wards were collected for testing per provider order. The GeneXpert C. difficile tcdB polymerase chain reaction (PCR) assay (Cepheid, Sunnyvale, CA, USA) was performed on all stool samples and PCR cycle threshold was used as a measure of genomic equivalents. Chart review was performed to obtain clinical history and medication exposure. We found an asymptomatic C. difficile carriage rate of 11.8% (43/365) (95% confidence interval [CI], 8.5-15.1%) and a positivity rate in symptomatic patients of 15.4% (54/351) (95% CI, 11.6-19.2%; P=0.19). The median PCR cycle thresholds was not significantly different between asymptomatic carriers and symptomatic positives (29.5 versus 27.3; P=0.07). Among asymptomatic patients, 11.6% (5/43) of carriers and 8.4% (27/322; P=0.56) of noncarriers subsequently became symptomatic CDI suspects within the same hospitalization. Single and multivariate analysis did not identify any demographic or clinical factors as being significantly associated with C. difficile carriage. Asymptomatic C. difficile carriage rate was similar to symptomatic positivity rate. This suggests the majority of PCR-positive results in symptomatic patients are likely due to C. difficile colonization. Disease-specific biomarkers are needed to accurately diagnose patients with C. difficile disease. Copyright © 2017 Elsevier Inc. All rights reserved.

PIV Flow Field Measurements of Hovering Rotors with Leading Edge Protuberances

DTIC Science & Technology

2017-05-22

CP P/ R CP P / R CPi CP CP C / / CT T / R CP / CT / F M P /P M Nb P...c c c c c CT / ± . × CP / ± . × μ dt M b R Nb /Nb dt dt dt μ μ f c c c c c c c c T P CT CP T CT A R P CP A R A R R V r...ps x y Vp · dps × Vp · dps n n n Vpi · ps × Vpi · ps u u u/ u u u/ i i i CT / CP / CT / . CT / . F M CP / CP CT /

Bis-Cyclic-Guanidine as a Novel Class of Compounds Potent Against Clostridium Difficile.

PubMed

Li, Chunhui; Teng, Peng; Peng, Zhong; Sang, Peng; Sun, Xingmin; Cai, Jianfeng

2018-05-16

Clostridium difficile infection (CDI) symptoms range from diarrhea to severe toxic megacolon and even death. Due to its rapid acquisition of resistance, C. difficile is listed as an urgent antibiotic-resistant threat, and has surpassed methicillin-resistant Staphylococcus aureus (MRSA) as the most common hospital-acquired infections in the USA. To combat the pathogen, the new structural class of pseudo peptides that exhibit antimicrobial activities could play an important role. Herein, we report that bis-cyclic guanidine compounds that exhibit potent antibacterial activity against C. difficile with decent selectivity. Eight compounds showed high in vitro potency against C. difficile UK6 with MIC of 1.0 μg/mL, and cytotoxic selectivity index (SI) up to 37. Moreover, the most selective compound 13 is also effective upon the treatment of C. difficile-induced diseases in the mouse model of CDI, and appears to be a very promising new candidate for the treatment of CDI. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The potential for emerging therapeutic options for Clostridium difficile infection

PubMed Central

Mathur, Harsh; Rea, Mary C; Cotter, Paul D; Ross, R Paul; Hill, Colin

2014-01-01

Clostridium difficile is mainly a nosocomial pathogen and is a significant cause of antibiotic-associated diarrhea. It is also implicated in the majority of cases of pseudomembranous colitis. Recently, advancements in next generation sequencing technology (NGS) have highlighted the extent of damage to the gut microbiota caused by broad-spectrum antibiotics, often resulting in C. difficile infection (CDI). Currently the treatment of choice for CDI involves the use of metronidazole and vancomycin. However, recurrence and relapse of CDI, even after rounds of metronidazole/vancomycin administration is a problem that must be addressed. The efficacy of alternative antibiotics such as fidaxomicin, rifaximin, nitazoxanide, ramoplanin and tigecycline, as well as faecal microbiota transplantation has been assessed and some have yielded positive outcomes against C. difficile. Some bacteriocins have also shown promising effects against C. difficile in recent years. In light of this, the potential for emerging treatment options and efficacy of anti-C. difficile vaccines are discussed in this review. PMID:25564777

Loss of Microbiota-Mediated Colonization Resistance to Clostridium difficile Infection With Oral Vancomycin Compared With Metronidazole

PubMed Central

Lewis, Brittany B.; Buffie, Charlie G.; Carter, Rebecca A.; Leiner, Ingrid; Toussaint, Nora C.; Miller, Liza C.; Gobourne, Asia; Ling, Lilan; Pamer, Eric G.

2015-01-01

Antibiotic administration disrupts the intestinal microbiota, increasing susceptibility to pathogens such as Clostridium difficile. Metronidazole or oral vancomycin can cure C. difficile infection, and administration of these agents to prevent C. difficile infection in high-risk patients, although not sanctioned by Infectious Disease Society of America guidelines, has been considered. The relative impacts of metronidazole and vancomycin on the intestinal microbiota and colonization resistance are unknown. We investigated the effect of brief treatment with metronidazole and/or oral vancomycin on susceptibility to C. difficile, vancomycin-resistant Enterococcus, carbapenem-resistant Klebsiella pneumoniae, and Escherichia coli infection in mice. Although metronidazole resulted in transient loss of colonization resistance, oral vancomycin markedly disrupted the microbiota, leading to prolonged loss of colonization resistance to C. difficile infection and dense colonization by vancomycin-resistant Enterococcus, K. pneumoniae, and E. coli. Our results demonstrate that vancomycin, and to a lesser extent metronidazole, are associated with marked intestinal microbiota destruction and greater risk of colonization by nosocomial pathogens. PMID:25920320

Discovery of LFF571: An Investigational Agent for Clostridium difficile Infection

DOE Office of Scientific and Technical Information (OSTI.GOV)

LaMarche, Matthew J.; Leeds, Jennifer A.; Amaral, Adam

Clostridium difficile (C. difficile) is a Gram positive, anaerobic bacterium that infects the lumen of the large intestine and produces toxins. This results in a range of syndromes from mild diarrhea to severe toxic megacolon and death. Alarmingly, the prevalence and severity of C. difficile infection are increasing; thus, associated morbidity and mortality rates are rising. 4-Aminothiazolyl analogues of the antibiotic natural product GE2270 A (1) were designed, synthesized, and optimized for the treatment of C. difficile infection. The medicinal chemistry effort focused on enhancing aqueous solubility relative to that of the natural product and previous development candidates (2, 3)more » and improving antibacterial activity. Structure-activity relationships, cocrystallographic interactions, pharmacokinetics, and efficacy in animal models of infection were characterized. These studies identified a series of dicarboxylic acid derivatives, which enhanced solubility/efficacy profile by several orders of magnitude compared to previously studied compounds and led to the selection of LFF571 (4) as an investigational new drug for treating C. difficile infection.« less

76 FR 14021 - Agency Forms Undergoing Paperwork Reduction Act Review

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-15

... Project Clostridium difficile Infection (CDI) Surveillance--New--National Center for Emerging and Zoonotic... Description Steady increases in the rate and severity of Clostridium difficile infection (CDI) indicate a clear need to conduct longitudinal assessments of the impact of CDI in the United States. C. difficile...

Dipicolinic Acid Release by Germinating Clostridium difficile Spores Occurs through a Mechanosensing Mechanism.

PubMed

Francis, Michael B; Sorg, Joseph A

2016-01-01

Classically, dormant endospores are defined by their resistance properties, particularly their resistance to heat. Much of the heat resistance is due to the large amount of dipicolinic acid (DPA) stored within the spore core. During spore germination, DPA is released and allows for rehydration of the otherwise-dehydrated core. In Bacillus subtilis , 7 proteins are encoded by the spoVA operon and are important for DPA release. These proteins receive a signal from the activated germinant receptor and release DPA. This DPA activates the cortex lytic enzyme CwlJ, and cortex degradation begins. In Clostridium difficile , spore germination is initiated in response to certain bile acids and amino acids. These bile acids interact with the CspC germinant receptor, which then transfers the signal to the CspB protease. Activated CspB cleaves the cortex lytic enzyme, pro-SleC, to its active form. Subsequently, DPA is released from the core. C. difficile encodes orthologues of spoVAC , spoVAD , and spoVAE . Of these, the B. subtilis SpoVAC protein was shown to be capable of mechanosensing. Because cortex degradation precedes DPA release during C. difficile spore germination (opposite of what occurs in B. subtilis ), we hypothesized that cortex degradation would relieve the osmotic constraints placed on the inner spore membrane and permit DPA release. Here, we assayed germination in the presence of osmolytes, and we found that they can delay DPA release from germinating C. difficile spores while still permitting cortex degradation. Together, our results suggest that DPA release during C. difficile spore germination occurs though a mechanosensing mechanism. IMPORTANCE Clostridium difficile is transmitted between hosts in the form of a dormant spore, and germination by C. difficile spores is required to initiate infection, because the toxins that are necessary for disease are not deposited on the spore form. Importantly, the C. difficile spore germination pathway represents a novel pathway for bacterial spore germination. Prior work has shown that the order of events during C. difficile spore germination (cortex degradation and DPA release) is flipped compared to the events during B. subtilis spore germination, a model organism. Here, we further characterize the C. difficile spore germination pathway and summarize our findings indicating that DPA release by germinating C. difficile spores occurs through a mechanosensing mechanism in response to the degradation of the spore cortex.

Clinical and economic consequences of vancomycin and fidaxomicin for the treatment of Clostridium difficile infection in Canada.

PubMed

Wagner, Monika; Lavoie, Louis; Goetghebeur, Mireille

2014-03-01

Clostridium difficile infection (CDI) represents a public health problem with increasing incidence and severity. To evaluate the clinical and economic consequences of vancomycin compared with fidaxomicin in the treatment of CDI from the Canadian health care system perspective. A decision-tree model was developed to compare vancomycin and fidaxomicin for the treatment of severe CDI. The model assumed identical initial cure rates and included first recurrent episodes of CDI (base case). Treatment of patients presenting with recurrent CDI was examined as an alternative analysis. Costs included were for study medication, physician services and hospitalization. Cost effectiveness was measured as incremental cost per recurrence avoided. Sensitivity analyses of key input parameters were performed. In a cohort of 1000 patients with an initial episode of severe CDI, treatment with fidaxomicin led to 137 fewer recurrences at an incremental cost of $1.81 million, resulting in an incremental cost of $13,202 per recurrence avoided. Among 1000 patients with recurrent CDI, 113 second recurrences were avoided at an incremental cost of $18,190 per second recurrence avoided. Incremental costs per recurrence avoided increased with increasing proportion of cases caused by the NAP1/B1/027 strain. Results were sensitive to variations in recurrence rates and treatment duration but were robust to variations in other parameters. The use of fidaxomicin is associated with a cost increase for the Canadian health care system. Clinical benefits of fidaxomicin compared with vancomycin depend on the proportion of cases caused by the NAP1/B1/027 strain in patients with severe CDI.

Clinical efficacy of a 1% Matricaria chamomile L. mouthwash and 0.12% chlorhexidine for gingivitis control in patients undergoing orthodontic treatment with fixed appliances.

PubMed

Goes, Paula; Dutra, Caio S; Lisboa, Mário R P; Gondim, Delane V; Leitão, Renata; Brito, Gerly A C; Rego, Rodrigo O

2016-01-01

This pilot study evaluated the clinical efficacy of a mouthwash containing 1% Matricaria chamomilla L. (MTC) extract in reducing gingival inflammation and plaque formation in patients undergoing orthodontic treatment with fixed appliances. This randomized, double-blind, placebo-controlled study enrolled a total of 30 males and females (age, 10-40 years) with fixed orthodontic appliances and a minimum of 20 natural teeth. The participants were allocated to three groups (n = 10 each) and asked to rinse with 15 mL of a placebo, 0.12% chlorhexidine (CHX), or 1% MTC mouthwash, immediately after brushing for 1 min, in the morning and evening, for 15 days. Data (mean ± SD) on visible plaque index (VPI) and gingival bleeding index (GBI) were recorded on days 1 and 15. The placebo group exhibited increases in VPI and GBI (10.2% and 23.1%, respectively) from day 1 to day 15. As compared with placebo, VPI and GBI significantly decreased in the MTC group (-25.6% and -29.9%, respectively) and the CHX group (-39.9% and -32.0%, respectively). In summary, MTC reduced biofilm accumulation and gingival bleeding in patients with gingivitis, probably because of its antimicrobial and anti-inflammatory activities.(J Oral Sci 58, 569-574, 2016).

The nature of articulation errors in Egyptian Arabic-speaking children with velopharyngeal insufficiency due to cleft palate.

PubMed

Abou-Elsaad, Tamer; Baz, Hemmat; Afsah, Omayma; Mansy, Alzahraa

2015-09-01

Even with early surgical repair, the majority of cleft palate children demonstrate articulation errors and have typical cleft palate speech. Was to determine the nature of articulation errors of Arabic consonants in Egyptian Arabic-speaking children with velopharyngeal insufficiency (VPI). Thirty Egyptian Arabic-speaking children with VPI due to cleft palate (whether primary repaired or secondary repaired) were studied. Auditory perceptual assessment (APA) of children speech was conducted. Nasopharyngoscopy was done to assess the velopharyngeal port (VPP) movements while the child was repeating speech tasks. Mansoura Arabic Articulation test (MAAT) was performed to analyze the consonants articulation of these children. The most frequent type of articulatory errors observed was substitution, more specifically, backing. Pharyngealization of anterior fricatives was the most frequent substitution, especially for the /s/ sound. The most frequent substituting sounds for other sounds were /ʔ/ followed by /k/ and /n/ sounds. Significant correlations were found between the degrees of the open nasality and VPP closure and the articulation errors. On the other hand, the sounds (/ʔ/,/ħ/,/ʕ/,/n/,/w/,/j/) were normally articulated in all studied group. The determination of articulation errors in VPI children could guide the therapists for designing appropriate speech therapy programs for these cases. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Visual-perceptual impairment in children with cerebral palsy: a systematic review.

PubMed

Ego, Anne; Lidzba, Karen; Brovedani, Paola; Belmonti, Vittorio; Gonzalez-Monge, Sibylle; Boudia, Baya; Ritz, Annie; Cans, Christine

2015-04-01

Visual perception is one of the cognitive functions often impaired in children with cerebral palsy (CP). The aim of this systematic literature review was to assess the frequency of visual-perceptual impairment (VPI) and its relationship with patient characteristics. Eligible studies were relevant papers assessing visual perception with five common standardized assessment instruments in children with CP published from January 1990 to August 2011. Of the 84 studies selected, 15 were retained. In children with CP, the proportion of VPI ranged from 40% to 50% and the mean visual perception quotient from 70 to 90. None of the studies reported a significant influence of CP subtype, IQ level, side of motor impairment, neuro-ophthalmological outcomes, or seizures. The severity of neuroradiological lesions seemed associated with VPI. The influence of prematurity was controversial, but a lower gestational age was more often associated with lower visual motor skills than with decreased visual-perceptual abilities. The impairment of visual perception in children with CP should be considered a core disorder within the CP syndrome. Further research, including a more systematic approach to neuropsychological testing, is needed to explore the specific impact of CP subgroups and of neuroradiological features on visual-perceptual development. © 2015 The Authors. Developmental Medicine & Child Neurology © 2015 Mac Keith Press.

Clostridium difficile in Food and Animals: A Comprehensive Review.

PubMed

Rodriguez, C; Taminiau, B; Van Broeck, J; Delmée, M; Daube, G

2016-01-01

Zoonoses are infections or diseases that can be transmitted between animals and humans through direct contact, close proximity or the environment. Clostridium difficile is ubiquitous in the environment, and the bacterium is able to colonise the intestinal tract of both animals and humans. Since domestic and food animals frequently test positive for toxigenic C. difficile, even without showing any signs of disease, it seems plausible that C. difficile could be zoonotic. Therefore, animals could play an essential role as carriers of the bacterium. In addition, the presence of the spores in different meats, fish, fruits and vegetables suggests a risk of foodborne transmission. This review summarises the current available data on C. difficile in animals and foods, from when the bacterium was first described up to the present.

Antimicrobial effects of virgin coconut oil and its medium-chain fatty acids on Clostridium difficile.

PubMed

Shilling, Michael; Matt, Laurie; Rubin, Evelyn; Visitacion, Mark Paul; Haller, Nairmeen A; Grey, Scott F; Woolverton, Christopher J

2013-12-01

Clostridium difficile is the leading cause of hospital-acquired antibiotic-associated diarrhea worldwide; in addition, the proliferation of antibiotic-resistant C. difficile is becoming a significant problem. Virgin coconut oil (VCO) has been shown previously to have the antimicrobial activity. This study evaluates the lipid components of VCO for the control of C. difficile. VCO and its most active individual fatty acids were tested to evaluate their antimicrobial effect on C. difficile in vitro. The data indicate that exposure to lauric acid (C12) was the most inhibitory to growth (P<.001), as determined by a reduction in colony-forming units per milliliter. Capric acid (C10) and caprylic acid (C8) were inhibitory to growth, but to a lesser degree. VCO did not inhibit the growth of C. difficile; however, growth was inhibited when bacterial cells were exposed to 0.15-1.2% lipolyzed coconut oil. Transmission electron microscopy (TEM) showed the disruption of both the cell membrane and the cytoplasm of cells exposed to 2 mg/mL of lauric acid. Changes in bacterial cell membrane integrity were additionally confirmed for VCO and select fatty acids using Live/Dead staining. This study demonstrates the growth inhibition of C. difficile mediated by medium-chain fatty acids derived from VCO.

The potential economic value of screening hospital admissions for Clostridium difficile.

PubMed

Bartsch, S M; Curry, S R; Harrison, L H; Lee, B Y

2012-11-01

Asymptomatic Clostridium difficile carriage has a prevalence reported as high as 51-85 %; with up to 84 % of incident hospital-acquired infections linked to carriers. Accurately identifying carriers may limit the spread of Clostridium difficile. Since new technology adoption depends heavily on its economic value, we developed an analytic simulation model to determine the cost-effectiveness screening hospital admissions for Clostridium difficile from the hospital and third party payer perspectives. Isolation precautions were applied to patients testing positive, preventing transmission. Sensitivity analyses varied Clostridium difficile colonization rate, infection probability among secondary cases, contact isolation compliance, and screening cost. Screening was cost-effective (i.e., incremental cost-effectiveness ratio [ICER] ≤ $50,000/QALY) for every scenario tested; all ICER values were ≤ $256/QALY. Screening was economically dominant (i.e., saved costs and provided health benefits) with a ≥10.3 % colonization rate and ≥5.88 % infection probability when contact isolation compliance was ≥25 % (hospital perspective). Under some conditions screening led to cost savings per case averted (range, $53-272). Clostridium difficile screening, coupled with isolation precautions, may be a cost-effective intervention to hospitals and third party payers, based on prevalence. Limiting Clostridium difficile transmission can reduce the number of infections, thereby reducing its economic burden to the healthcare system.

Saccharomyces boulardii for the prevention of hospital onset Clostridium difficile infection.

PubMed

Flatley, Elizabeth A; Wilde, Ashley M; Nailor, Michael D

2015-03-01

Probiotics, including Saccharomyces boulardii, have been advocated for the prevention of Clostridium difficile infection. The aim of this project was to evaluate the effects of the removal of S. boulardii from an automatic antibiotic order set and hospital formulary on hospital onset C. difficile infection rates. A retrospective chart review was performed on all patients with hospital onset C. difficile infection during the 13 months prior (control group) and the 13 months after (study group) removal of an automatic order set linking S. boulardii capsules to certain broad spectrum antibiotics. A large 800+ bed tertiary hospital. Among all hospitalized patients, the rate of hospital onset C. difficile infection was 0.99 per 1000 patient days while the S. boulardii protocol was active compared with 1.04 per 1000 patient days (p=0.10) after S. boulardii was removed from the formulary. No difference in the rate of hospital onset C. difficile infection was detected in patients receiving the linked broad spectrum antibiotics during and after the removal of the protocol (1.25% vs. 1.51%, respectively; p=0.70). Removal of S. boulardii administration to patients receiving broad spectrum antibiotics and the hospital formulary did not impact the rate of hospital onset C. difficile infection in either the hospital population or patients receiving broad spectrum antibiotics.

[Epidemiology, risk factors and prevention of Clostridium difficile nosocomial infections].

PubMed

Barbut, F; Petit, J C

2000-10-01

Clostridium difficile is responsible for 10-25% of cases of antibiotic-associated diarrhea (AAD) and for virtually all cases of antibiotic-associated pseudo-membranous colitis (PMC). This anaerobic spore-forming bacterium has been identified as the leading cause of nosocomial infectious diarrhea in adults. Pathogenesis relies on a disruption of the normal bacterial flora of the colon, a colonization by C. difficile and the release of toxins A and B that cause mucosal damage and inflammation. Incidence of C. difficile intestinal disorders usually varies from one to 40 per thousand patient admissions. Risk factors for C. difficile-associated diarrhea include antimicrobial therapy, older age (> 65 years), antineoplastic chemotherapy, and length of hospital stay. Nosocomial transmission of C. difficile via oro-fecal route occurs in 3-30% of total patient admissions but it remains asymptomatic in more than 66% of cases. Persistent environmental contamination and carrying of the organism on the hands of hospital staff are common. Measures that are effective in reducing cross-infection consist of an accurate and rapid diagnosis, an appropriate treatment, an implementation of enteric precautions for symptomatic patients, a reinforcement of hand-washing and a daily environmental disinfection. C. difficile is a common cause of infectious diarrhea and should be therefore systematically investigated in patients with nosocomial diarrhea.

The Potential Economic Value of Screening Hospital Admissions for Clostridium difficile

PubMed Central

Bartsch, Sarah M.; Curry, Scott R.; Harrison, Lee H.; Lee, Bruce Y.

2012-01-01

Purpose Asymptomatic Clostridium difficile carriage has a prevalence reported as high as 51% to 85%; with up to 84% of incident hospital-acquired infections linked to carriers. Accurately identifying carriers may limit the spread of Clostridium difficile. Methods Since new technology adoption depends heavily on its economic value, we developed a analytic simulation model to determine the cost-effectiveness screening hospital admissions for Clostridium difficile from the hospital and third party payer perspectives. Isolation precautions were applied to patients testing positive, preventing transmission. Sensitivity analyses varied Clostridium difficile colonization rate, infection probability among secondary cases, contact isolation compliance, and screening cost. Results Screening was cost-effective [i.e., incremental cost-effectiveness ratio (ICER) ≤$50,000/QALY] for every scenario tested; all ICER values ≤$256/QALY. Screening was economically dominant (i.e., saved costs and provided health benefits) with a ≥10.3% colonization rate and ≥5.88% infection probability when contact isolation compliance was ≥25% (hospital perspective). Under some conditions screening led to cost-savings per case averted (range: $53 to $272). Conclusion Clostridium difficile screening, coupled with isolation precautions, may be a cost-effective intervention to hospitals and third party payers, based on prevalence. Limiting Clostridium difficile transmission can reduce the number of infections, thereby reducing its economic burden to the healthcare system. PMID:22752150

Bezlotoxumab for the prevention of Clostridium difficile recurrence.

PubMed

Couture-Cossette, Antoine; Carignan, Alex; Ilangumaran, Subburaj; Valiquette, Louis

2017-11-01

Clostridium difficile infection is a major economic and clinical burden, due to its high frequency of recurrence. Currently recommended treatments are not efficient for prevention and may contribute to the risk of recurrent infection. In recent years, research has focused on strategies to lessen this risk. Bezlotoxumab is a monoclonal antibody that prevents recurrences of C. difficile infection through the antagonism of toxin B. Areas covered: In this review, the authors discuss the burden of C. difficile infection and its recurrences, the mechanisms underlying the recurrences, and current C. difficile treatments. They subsequently analyze the strategic therapeutic rationale for bezlotoxumab use, as well as the supporting clinical evidence. Expert opinion: Bezlotoxumab is an attractive solution for reducing the unacceptable level of recurrence that occurs with the currently recommended C. difficile treatments and other alternative therapies under consideration. Even though bezlotoxumab has not been tested in large-scale trials exclusively in cases of already established recurrent C.difficile infection (rCDI), it has an advantage over current treatments in that it does not interfere with the patient's gut flora while directly neutralizing the key virulence factor. Although cost remains an important factor against its widespread use, simpler administration, fewer side-effects, and better social acceptability justify its consideration for treating rCDI.

Control of Clostridium difficile infection by defined microbial communities

PubMed Central

Collins, James

2017-01-01

Summary Each year in the United States, billions of dollars are spent combating almost half a million Clostridium difficile infections (CDI) and trying to reduce the ~29,000 patient deaths where C. difficile has an attributed role (1). In Europe, disease prevalence varies by country and level of surveillance, though yearly costs are estimated at €3 billion (2). One factor contributing to the significant healthcare burden of C. difficile is the relatively high frequency of recurrent C. difficile infections(3). Recurrent C. difficile infection (rCDI), i.e., a second episode of symptomatic CDI occurring within eight weeks of successful initial CDI treatment, occurs in ~25% of patients with 35-65% of these patients experiencing multiple episodes of recurrent disease(4, 5). Using microbial communities to treat rCDI, either as whole fecal transplants or as defined consortia of bacterial isolates have shown great success (in the case of fecal transplants) or potential promise (in the case of defined consortia of isolates). This review will briefly summarize the epidemiology and physiology of C. difficile infection, describe our current understanding of how fecal microbiota transplants treat recurrent CDI, and outline potential ways through which that knowledge can be used to rationally-design and test alternative microbe-based therapeutics. PMID:28936948

The impact of Clostridum difficile on surgical rate among ulcerative colitis patients: A systemic review and meta-analysis.

PubMed

Peng, Jiang-Chen; Shen, Jun; Zhu, Qi; Ran, Zhi-Hua

2015-01-01

There is growing recognition of the impact of Clostridum difficile infection (CDI) on patients with inflammatory bowel disease. Clostridium difficile infection causes greater morbidity and mortality. This study aimed to evaluate the impact of C. difficile on surgical risk among ulcerative colitis (UC) patients. We searched the following databases: MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, ACP Journal Club, DARE, CMR, and HTA. Studies were included if fulfilled the following criteria: (1) Cohort or case-control studies, which involved a comparison group that lacked CDI, (2) Patients were given a primary diagnosis of UC, (3) Comorbidity of CDI was evaluated by enzyme immunoassay of stool for C. difficile toxin A and B or C. difficile stool culture, (4) Studies evaluated surgical rate, and (5) Studies reported an estimate of odds ratio, accompanied by a corresponding measure of uncertainty. Five studies with 2380 patients fulfilled the inclusion criteria. Overall, meta-analysis showed that UC with CDI patients had a significant higher surgical rate than patients with UC alone. (OR=1.76, 95% CI=1.36-2.28). C. difficile infection increased the surgical rate in UC patients. However, results should be interpreted with caution, given the limitations of this stud.

Effects of intestinal colonization by Clostridium difficile and Staphylococcus aureus on microbiota diversity in healthy individuals in China.

PubMed

Dong, Danfeng; Ni, Qi; Wang, Chen; Zhang, Lihua; Li, Zhen; Jiang, Cen; EnqiangMao; Peng, Yibing

2018-05-03

Intestinal colonization by pathogenic bacteria is a risk factor for infection, and contributes to environmental contamination and disease dissemination. Alteration of gut microbiota also plays a pivotal role in the development of disease. Although Clostridium difficile and Staphylococcus aureus are well-recognized pathogens causing nosocomial and community infections, the intestinal colonization was not fully investigated. Herein, we explored their overall carriage rates in healthy adults from the community, and characterized the gut microbiomes of C. difficile and S. aureus carriers. Fecal samples were collected from 1709 healthy volunteers from communities in Shanghai, China, and tested for the presence of C. difficile, methicillin-sensitive S. aureus (MSSA), and methicillin-resistant S. aureus (MRSA) using culture-based techniques. To explore differences in the gut microbiome, 16S rRNA gene sequencing was conducted using samples from non-carriers (CH), C. difficile carriers (CCD), MRSA carriers (CM), and MSSA carriers (CS). Overall, we detected 12 C. difficile and 60 S. aureus isolates, accounting for 0.70% and 3.51% of total isolates, respectively. Eight isolates were determined to be MRSA, accounting for 13.3% of the S. aureus population. Sequencing data revealed that the microbial diversity and richness were similar among the four groups. However, at the phylum level, carriage of C. difficile or MRSA was associated with a paucity of Bacteroidetes and an overabundance of Proteobacteria compared with non-carriers. At the genus level, the prevalence of the genera Bacteroides, Prevotella, Faecalibacterium, and Roseburia was decreased in C. difficile-positive samples compared with the controls, while the proportion of Clostridium cluster XIVa species was increased. MRSA carriers exhibited a higher proportion of the genera Parasutterella and Klebsiella, but a decreased prevalence of Bacteroides. Compared with MSSA carriers, Klebsiella was the only genus found to be significantly enriched in MRSA carriers. In healthy adults, colonization by C. difficile or S. aureus did not significantly affect gut microbiota diversity. However, the alteration of the gut microbiota composition in C. difficile carriers could indicate a predisposition to further infection. Our study provides essential data on the prevalence and effects of C. difficile and S. aureus colonization on gut microbiota composition in healthy adults.

A meta-analysis of metronidazole and vancomycin for the treatment of Clostridium difficile infection, stratified by disease severity.

PubMed

Di, Xiuzhen; Bai, Nan; Zhang, Xin; Liu, Bin; Ni, Wentao; Wang, Jin; Wang, Kai; Liang, Beibei; Liu, Youning; Wang, Rui

2015-01-01

The aim of this meta-analysis was to compare the efficacy of metronidazole and vancomycin for the treatment of Clostridium difficile infection, especially to investigate which agent was superior for treating either mild or severe C. difficile infection. A meta-analysis of randomized controlled trials and cohort studies identified in Pubmed, Embase, and the Cochrane Library was conducted. Four randomized controlled trials and two cohort studies involving 1218 patients were included in this meta-analysis. Metronidazole was inferior to vancomycin for treating C. difficile infection in terms of both initial clinical cure rates (risk ratio, RR=0.91, 95% confidence interval, CI=0.84-0.98, p=0.02) and sustained cure rates (RR=0.88, 95% CI=0.82-0.96, p=0.003). For mild C. difficile infection, the efficacy of metronidazole and vancomycin resulted in similar clinical cure rates (RR=0.94, 95% CI=0.84-1.04, p=0.21) and sustained cure rates (RR=0.93, 95% CI=0.83-1.05, p=0.26). For severe C. difficile infection the efficacy of vancomycin was superior to metronidazole in terms of clinical cure rates (RR=0.81, 95% CI=0.69-0.95, p=0.009), whereas sustained cure rates were similar (RR=0.86, 95% CI=0.72-1.02, p=0.08). Regarding microbiological cure metronidazole therapy was as effective as vancomycin therapy (RR=0.88, 95% CI=0.64-1.21, p=0.43). Recurrence rates with metronidazole and vancomycin for both mild C. difficile infection (RR=0.95, 95% CI=0.56-1.60, p=0.85) and severe C. difficile infection (RR=1.27, 95% CI=0.85-1.91, p=0.25) were not different. Likewise, no difference in all-cause mortality was found as well (RR=0.87, 95% CI=0.56-1.35, p=0.53). In conclusion, vancomycin provides improved initial clinical and sustained cure rates in patients with C. difficile infection compared with metronidazole, especially in patients with severe C. difficile infection. In view of these data, vancomycin may be considered first line therapy for severe C. difficile infection. Copyright © 2015 Elsevier Editora Ltda. All rights reserved.

Evaluation of an interdisciplinary re-isolation policy for patients with previous Clostridium difficile diarrhea.

PubMed

Boone, N; Eagan, J A; Gillern, P; Armstrong, D; Sepkowitz, K A

1998-12-01

Diarrhea caused by Clostridium difficile is increasingly recognized as a nosocomial problem. The effectiveness and cost of a new program to decrease nosocomial spread by identifying patients scheduled for readmission who were previously positive for toxin was evaluated. The Memorial Sloan-Kettering Cancer Center is a 410-bed comprehensive cancer center in New York City. Many patients are readmitted during their course of cancer therapy. In 1995 as a result of concern about the nosocomial spread of C difficile, we implemented a policy that all patients who were positive for C difficile toxin in the previous 6 months with no subsequent toxin-negative stool as an outpatient would be placed into contact isolation on readmission pending evaluation of stool specimens. Patients who were previously positive for C difficile toxin were identified to infection control and admitting office databases via computer. Admitting personnel contacted infection control with all readmissions to determine whether a private room was required. Between July 1, 1995, and June 30, 1996, 47 patients who were previously positive for C difficile toxin were readmitted. Before their first scheduled readmission, the specimens for 15 (32%) of these patients were negative for C difficile toxin. They were subsequently cleared as outpatients and were readmitted without isolation. Workup of the remaining 32 patients revealed that the specimens for 7 patients were positive for C difficile toxin and 86 isolation days were used. An additional 25 patients used 107 isolation days and were either cleared after a negative specimen was obtained in-house or discharged without having an appropriate specimen sent. Four patients (9%) had reoccurring C difficile after having toxin-negative stools. We estimate (because outpatient specimens were not collected) the cost incurred at $48,500 annually, including the incremental cost of hospital isolation and equipment. Our policy to control the spread of nosocomial C difficile required interdisciplinary cooperation between infection control and the admitting department. By identifying patients who were positive for toxin through admitting, we were able to place all potentially infected patients into isolation. Our positivity rate of 15% on readmission demonstrates the importance of this policy. The cost of controlling C difficile can be significantly lowered by clearing patients who were previously positive for toxin before hospital readmission.

Evaluation of automated repetitive-sequence-based PCR (DiversiLab) compared to PCR ribotyping for rapid molecular typing of community- and nosocomial-acquired Clostridium difficile.

PubMed

Church, Deirdre L; Chow, Barbara L; Lloyd, Tracie; Gregson, Daniel B

2011-06-01

Automated repetitive PCR (rep-PCR; DiversiLab) was compared to PCR ribotyping of the 16S-23S RNA intergenic spacer of Clostridium difficile (CD) as the "gold standard" method for CD typing. PCR products were separated on DiversiLab LabChips (bioMérieux, St. Laurent, Quebec, Canada) utilizing a 2100 Bioanalyzer (Agilent Technologies, Santa Clara, CA) operating the DiversiLab v1.4 assay. Bioanalyzer data were exported to a secure DiversiLab website and analyzed with DiversiLab v3.4 software. Replicability of each method was verified by confirming that the 5 CD reference strains (RS) formed distinct clusters (CD4, CD6, VL0047, VL0013 [ribotype 027], VL0018 [ribotype 001]) by both typing methods. Ninety randomly selected clinical isolates (CS) were analyzed by both methods: 49 from community-acquired and 41 from hospital-acquired cases. A similarity index (SI) of ≥90% was used to define clusters when comparing the known RS cluster to the PCR ribotyping and rep-PCR patterns of CS. Fourteen different PCR-ribotype clusters were identified, but most CS formed 4 major clusters (i.e., CD4 [15/90; 17%], CD6 [17%], 027 [12%], and 001 [9%]). A total of 7 rep-PCR types were identified, but most CS formed 2 major rep-PCR clusters (i.e., CD4 [29/90; 32%] and CD6 [23%]); several PCR ribotypes occurred within a single rep-PCR cluster. Rep-PCR did not distinguish 027 or 001 isolates; i) 027 RS strain did not cluster, ii) eleven 027 CS strains clustered as CD4, iii) no 027 CS strains clustered with the 027 RS, and iv) only 2 001 CS clustered with the RS. Agreement between the PCR-ribotype and rep-PCR clusters only occurred for 35/90 (39%) of the CS using a rep-PCR SI of ≥90%. Rep-PCR time to results was similar, but the annual costs of routinely using this method are 32% higher than PCR ribotyping. Routine use of rep-PCR for CD typing is limited by its lack of definitive separation of the hypertoxigenic 027 or 001 outbreak CD strains. Copyright © 2011 Elsevier Inc. All rights reserved.

How Common-and How Serious- Is Clostridium difficile Colitis After Geriatric Hip Fracture? Findings from the NSQIP Dataset.

PubMed

Bovonratwet, Patawut; Bohl, Daniel D; Russo, Glenn S; Ondeck, Nathaniel T; Nam, Denis; Della Valle, Craig J; Grauer, Jonathan N

2018-03-01

Patients with geriatric hip fractures may be at increased risk for postoperative Clostridium difficile colitis, which can cause severe morbidity and can influence hospital quality metrics. However, to our knowledge, no large database study has calculated the incidence of, factors associated with, and effect of C. difficile colitis on geriatric patients undergoing hip fracture surgery. To use a large national database with in-hospital and postdischarge data (National Surgical Quality Improvement Program [NSQIP®]) to (1) determine the incidence and timing of C. difficile colitis in geriatric patients who underwent surgery for hip fracture, (2) identify preoperative and postoperative factors associated with the development of C. difficile colitis in these patients, and (3) test for an association between C. difficile colitis and postoperative length of stay, 30-day readmission, and 30-day mortality. This is a retrospective study. Patients who were 65 years or older who underwent hip fracture surgery were identified in the 2015 NSQIP database. The primary outcome was a diagnosis of C. difficile colitis during the 30-day postoperative period. Preoperative and procedural factors were tested for association with the development of C. difficile colitis through a backward stepwise multivariate model. Perioperative antibiotic type and duration were not included in the model, as this information was not recorded in the NSQIP. The association between C. difficile colitis and postoperative length of stay, 30-day readmission, and 30-day mortality were tested through multivariate regressions, which adjusted for preoperative and procedural characteristics such as age, comorbidities, and surgical procedure. A total of 6928 patients who were 65 years or older and underwent hip fracture surgery were identified. The incidence of postoperative C. difficile colitis was 1.05% (95% CI, 0.81%-1.29%; 73 of 6928 patients). Of patients who had C. difficile colitis develop, 64% (47 of 73 patients) were diagnosed postdischarge and 79% (58 of 73 patients) did not have a preceding infectious diagnosis. Preoperative factors identifiable before surgery that were associated with the development of C. difficile colitis included admission from any type of chronic care facility (versus admitted from home; relative risk [RR] = 1.98; 95% CI, 1.11-3.55; p = 0.027), current smoker within 1 year (RR = 1.95; 95% CI, 1.03-3.69; p = 0.041), and preoperative anemia (RR = 1.76; 95% CI, 1.07-2.92; p = 0.027). Patients who had pneumonia (RR = 2.58; 95% CI, 1.20-5.53; p = 0.015), sepsis (RR = 4.20; 95% CI, 1.27-13.82; p = 0.018), or "any infection" (RR = 2.26; 95% CI, 1.26-4.03; p = 0.006) develop after hip fracture were more likely to have C. difficile colitis develop. Development of C. difficile colitis was associated with greater postoperative length of stay (22 versus 5 days; p < 0.001), 30-day readmission (RR = 3.41; 95% CI, 2.17-5.36; p < 0.001), and 30-day mortality (15% [11 of 73 patients] versus 6% [439 of 6855 patients]; RR = 2.16; 95% CI, 1.22-3.80; p = 0.008). C. difficile colitis is a serious infection after hip fracture surgery in geriatric patients that is associated with 15% mortality. Patients at high risk, such as those admitted from any type of chronic care facility, those who had preoperative anemia, and current smokers within 1 year, should be targeted with preventative measures. From previous studies, these measures include enforcing strict hand hygiene with soap and water (not alcohol sanitizers) if a provider is caring for patients at high risk and those who are C. difficile-positive. Further, other studies have shown that certain antibiotics, such as fluoroquinolones and cephalosporins, can predispose patients to C. difficile colitis. These medications perhaps should be avoided when prescribing prophylactic antibiotics or managing infections in patients at high risk. Future prospective studies should aim to determine the best prophylactic antibiotic regimens, probiotic formula, and discharge timing that minimize postoperative C. difficile colitis in patients with hip fractures. Level III, therapeutic study.

Clostridium difficile colitis in patients undergoing lumbar spine surgery.

PubMed

Skovrlj, Branko; Guzman, Javier Z; Silvestre, Jason; Al Maaieh, Motasem; Qureshi, Sheeraz A

2014-09-01

Retrospective database analysis. To investigate incidence, comorbidities, and impact on health care resources of Clostridium difficile infection after lumbar spine surgery. C. difficile colitis is reportedly increasing in hospitalized patients and can have a negative impact on patient outcomes. No data exist on estimates of C. difficile infection rates and its consequences on patient outcomes and health care resources among patients undergoing lumbar spine surgery. The Nationwide Inpatient Sample was examined from 2002 to 2011. Patients were included for study based on International Classification of Diseases, Ninth Revision, Clinical Modification, procedural codes for lumbar spine surgery for degenerative diagnoses. Baseline patient characteristics were determined and multivariable analyses assessed factors associated with increased incidence of C. difficile and risk of mortality. The incidence of C. difficile infection in patients undergoing lumbar spine surgery is 0.11%. At baseline, patients infected with C. difficile were significantly older (65.4 yr vs. 58.9 yr, P<0.0001) and more likely to have diabetes with chronic complications, neurological complications, congestive heart failure, pulmonary disorders, coagulopathy, and renal failure. Lumbar fusion (P=0.0001) and lumbar fusion revision (P=0.0003) were associated with increased odds of postoperative infection. Small hospital size was associated with decreased odds (odds ratio [OR], 0.5; P<0.001), whereas urban hospitals were associated with increased odds (OR, 2.14; P<0.14) of acquiring infection. Uninsured (OR, 1.62; P<0.0001) and patients with Medicaid (OR, 1.33; P<0.0001) were associated with higher odds of acquiring postoperative infection. C. difficile increased hospital length of stay by 8 days (P<0.0001), hospital charges by 2-fold (P<0.0001), and inpatient mortality to 4% from 0.11% (P<0.0001). C. difficile infection after lumbar spine surgery carries a 36.4-fold increase in mortality and costs approximately $10,658,646 per year to manage. These data suggest that great care should be taken to avoid C. difficile colitis in patients undergoing lumbar spine surgery because it is associated with longer hospital stays, greater overall costs, and increased inpatient mortality. 3.

Cost-effectiveness analysis evaluating fidaxomicin versus oral vancomycin for the treatment of Clostridium difficile infection in the United States.

PubMed

Stranges, Paul M; Hutton, David W; Collins, Curtis D

2013-01-01

Fidaxomicin is a novel treatment for Clostridium difficile infections (CDIs). This new treatment, however, is associated with a higher acquisition cost compared with alternatives. The objective of this study was to evaluate the cost-effectiveness of fidaxomicin or oral vancomycin for the treatment of CDIs. We performed a cost-utility analysis comparing fidaxomicin with oral vancomycin for the treatment of CDIs in the United States by creating a decision analytic model from the third-party payer perspective. The incremental cost-effectiveness ratio with fidaxomicin compared with oral vancomycin was $67,576/quality-adjusted life-year. A probabilistic Monte Carlo sensitivity analysis showed that fidaxomicin had an 80.2% chance of being cost-effective at a willingness-to-pay threshold of $100,000/quality-adjusted life-year. Fidaxomicin remained cost-effective under all fluctuations of both fidaxomicin and oral vancomycin costs. The decision analytic model was sensitive to variations in clinical cure and recurrence rates. Secondary analyses revealed that fidaxomicin was cost-effective in patients receiving concominant antimicrobials, in patients with mild to moderate CDIs, and when compared with oral metronidazole in patients with mild to moderate disease. Fidaxomicin was dominated by oral vancomycin if CDI was caused by the NAP1/Bl/027 Clostridium difficile strain and was dominant in institutions that did not compound oral vancomycin. Results of our model showed that fidaxomicin may be a more cost-effective option for the treatment of CDIs when compared with oral vancomycin under most scenarios tested. Copyright © 2013 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

A Decade of Experience in Primary Prevention of Clostridium difficile Infection at a Community Hospital Using the Probiotic Combination Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2 (Bio-K+).

PubMed

Maziade, Pierre-Jean; Pereira, Pascale; Goldstein, Ellie J C

2015-05-15

In August 2003, the 284-bed community hospital Pierre-Le Gardeur (PLGH) in Quebec experienced a major outbreak associated with the Clostridium difficile NAP1/027/BI strain. Augmented standard preventive measures (SPMs) were not able to control this outbreak. It was decided in February 2004 to give to every adult inpatient on antibiotics, without any exclusion, a probiotic (Bio-K+: Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2) within 12 hours of the antibiotic prescription. Augmented SPMs were continued. The use of the probiotic in addition to SPMs was associated with a marked reduction of C. difficile infection (CDI). During the 10 years of observation, 44 835 inpatients received Bio-K+, and the CDI rate at PLGH declined from 18.0 cases per 10,000 patient-days and remained at low mean levels of 2.3 cases per 10,000 patient-days. Additionally, 10-year data collected by the Ministry of Health in Quebec comparing the CDI rate between Quebec hospitals showed that CDI rates at PLGH were consistently and continuously lower compared with those at similar hospitals. Blood cultures were monitored at PLGH for Lactobacillus bacteremia through the 10 years' experience, and no Lactobacillus bacteremias were detected. Despite the limitation of an observational study, we concluded that the probiotic Bio-K+ was safe and effective in decreasing our primary CDI rate. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Novel Riboswitch-Binding Flavin Analog That Protects Mice against Clostridium difficile Infection without Inhibiting Cecal Flora

PubMed Central

Megyola, Cynthia; Plummer, Mark; Osterman, David; O'Connell, Tim; Aristoff, Paul; Quinn, Cheryl; Chrusciel, R. Alan; Poel, Toni J.; Schostarez, Heinrich J.; Stewart, Catherine A.; Walker, Daniel P.; Wuts, Peter G. M.

2015-01-01

Novel mechanisms of action and new chemical scaffolds are needed to rejuvenate antibacterial drug discovery, and riboswitch regulators of bacterial gene expression are a promising class of targets for the discovery of new leads. Herein, we report the characterization of 5-(3-(4-fluorophenyl)butyl)-7,8-dimethylpyrido[3,4-b]quinoxaline-1,3(2H,5H)-dione (5FDQD)—an analog of riboflavin that was designed to bind riboswitches that naturally recognize the essential coenzyme flavin mononucleotide (FMN) and regulate FMN and riboflavin homeostasis. In vitro, 5FDQD and FMN bind to and trigger the function of an FMN riboswitch with equipotent activity. MIC and time-kill studies demonstrated that 5FDQD has potent and rapidly bactericidal activity against Clostridium difficile. In C57BL/6 mice, 5FDQD completely prevented the onset of lethal antibiotic-induced C. difficile infection (CDI). Against a panel of bacteria representative of healthy bowel flora, the antibacterial selectivity of 5FDQD was superior to currently marketed CDI therapeutics, with very little activity against representative strains from the Bacteroides, Lactobacillus, Bifidobacterium, Actinomyces, and Prevotella genera. Accordingly, a single oral dose of 5FDQD caused less alteration of culturable cecal flora in mice than the comparators. Collectively, these data suggest that 5FDQD or closely related analogs could potentially provide a high rate of CDI cure with a low likelihood of infection recurrence. Future studies will seek to assess the role of FMN riboswitch binding to the mechanism of 5FDQD antibacterial action. In aggregate, our results indicate that riboswitch-binding antibacterial compounds can be discovered and optimized to exhibit activity profiles that merit preclinical and clinical development as potential antibacterial therapeutic agents. PMID:26169403

Evaluation of NVB302 versus vancomycin activity in an in vitro human gut model of Clostridium difficile infection.

PubMed

Crowther, Grace S; Baines, Simon D; Todhunter, Sharie L; Freeman, Jane; Chilton, Caroline H; Wilcox, Mark H

2013-01-01

First-line treatment options for Clostridium difficile infection (CDI) are limited. NVB302 is a novel type B lantibiotic under evaluation for the treatment of CDI. We compared the responses to NVB302 and vancomycin when used to treat simulated CDI in an in vitro gut model. We used ceftriaxone to elicit simulated CDI in an in vitro gut model primed with human faeces. Vancomycin and NVB302 were instilled into separate gut models and the indigenous gut microbiota and C. difficile total viable counts, spores and toxin levels were monitored throughout. Ceftriaxone instillation promoted C. difficile germination and high-level toxin production. Commencement of NVB302 and vancomycin instillation reduced C. difficile total viable counts rapidly with only C. difficile spores remaining within 3 and 4 days, respectively. Cytotoxin was reduced to undetectable levels 5 and 7 days after vancomycin and NVB302 instillation commenced in vessel 2 and 3, respectively, and remained undetectable for the remainder of the experiments. C. difficile spores were unaffected by the presence of vancomycin or NVB302. NVB302 treatment was associated with faster resolution of Bacteroides fragilis group. Both NVB302 and vancomycin were effective in treating simulated CDI in an in vitro gut model. C. difficile spore recrudescence was not observed following successful treatment with either NVB302 or vancomycin. NVB302 displayed non-inferiority to vancomycin in the treatment of simulated CDI, and had less deleterious effects against B. fragilis group. NVB302 warrants further clinical investigation as a potentially novel antimicrobial agent for the treatment of CDI.

Proton pump inhibitor use and recurrent Clostridium difficile-associated disease: a case-control analysis matched by propensity score.

PubMed

Kim, Yong Gil; Graham, David Y; Jang, Byung Ik

2012-01-01

Clostridium difficile has been increasingly diagnosed in hospitalized patients. An association between proton pump inhibitors (PPIs) use and Clostridium difficile-associated disease (CDAD) and between recurrent CDAD has been suggested. The aim of this study is to investigate whether PPI use is associated with the development of recurrent CDAD. This was a retrospective case-control study of patients with CDAD at Yeungnam University Medical Center, seen from January 2004 to December 2008. C. difficile infection was diagnosed by the presence of C. difficile toxin in the stool. Those with recurrent disease were matched with nonrecurrent controls using multivariate matched sampling methods that incorporated the propensity score. Recurrent CDAD developed in 28 (14.1%) of the 198 patients with diarrhea and positive C. difficile stool toxin assays. Multivariate analysis of the total population of recurrent versus nonrecurrent CDAD revealed that additional use of non-C. difficile antimicrobial therapy (concomitant with the treatment or after or both), poor response to therapy with metronidazole or vancomycin, and recent gastrointestinal surgery were risk factors for recurrent CDAD. We were able to match 21 recurrent CDAD subjects with 21 without recurrent CDAD. Among the matched patients only PPI use was associated with recurrent CDAD (ie, 47.6% vs. 4.8%, P=0.004 for recurrent vs. nonrecurrent CDAD, respectively). Among the matched patient groups, only PPI therapy was associated with recurrent CDAD. Prospective studies are needed to clarify whether avoidance of PPIs or specific cotherapies will reduce the incidence of recurrent C. difficile-associated diarrhea.

The Recent Emergence of Clostridium difficile Infection in Romanian Hospitals is Associated with a High Prevalence of Polymerase Chain Reaction Ribotype 027.

PubMed

Popescu, Gabriel Adrian; Serban, Roxana; Pistol, Adriana; Niculcea, Andreea; Preda, Andreea; Lemeni, Daniela; Macovei, Ioana Sabina; Tălăpan, Daniela; Rafila, Alexandru; Florea, Dragoş

2018-03-15

To investigate the epidemiology of Clostridium difficile infection in Romanian hospitals. A survey was conducted at nine hospitals throughout Romania between November 2013 and February 2014. The survey identified 393 patients with Clostridium difficile infection. The median age was 67 years (range: 2-94 years); 56% of patients were aged >65 years. The mean prevalence of Clostridium difficile infection was 5.2 cases per 10.000 patient-days. The highest prevalences were 24.9 and 20 per 10.000 patient-days in hospitals specializing in gastroenterology and infectious diseases, respectively. Clostridium difficile infections were health care-associated in 70.5% patients and community-acquired in 10.2%. The origin was not determined in 19.3%. Clostridium difficile infection was severe in 12.3% of patients, and the in-hospital all-cause mortality was 8.8%. Polymerase chain reaction ribotype 027 had the highest prevalence in all participating hospitals and represented 82.6% of the total ribotyped isolates. The minimum inhibitory concentration of moxifloxacin was >4 μg/mL for 59 of 80 tested isolates (73.8%). Of 59 isolates, 54 were highly resistant to moxifloxacin (minimum inhibitory concentration ≥32 μg/mL), and the majority were polymerase chain reaction ribotype 027 (p<0.0001). The ribotype 027 was the predominant cause of Clostridium difficile infections in Romania. In some specialized hospitals, the prevalence of Clostridium difficile infection was higher than the European mean prevalence, and this demonstrates the need for strict adherence to infection control programs.

Antibiotic-Induced Alterations of the Murine Gut Microbiota and Subsequent Effects on Colonization Resistance against Clostridium difficile

PubMed Central

Schubert, Alyxandria M.; Sinani, Hamide

2015-01-01

ABSTRACT Perturbations to the gut microbiota can result in a loss of colonization resistance against gastrointestinal pathogens such as Clostridium difficile. Although C. difficile infection is commonly associated with antibiotic use, the precise alterations to the microbiota associated with this loss in function are unknown. We used a variety of antibiotic perturbations to generate a diverse array of gut microbiota structures, which were then challenged with C. difficile spores. Across these treatments we observed that C. difficile resistance was never attributable to a single organism, but rather it was the result of multiple microbiota members interacting in a context-dependent manner. Using relative abundance data, we built a machine learning regression model to predict the levels of C. difficile that were found 24 h after challenging the perturbed communities. This model was able to explain 77.2% of the variation in the observed number of C. difficile per gram of feces. This model revealed important bacterial populations within the microbiota, which correlation analysis alone did not detect. Specifically, we observed that populations associated with the Porphyromonadaceae, Lachnospiraceae, Lactobacillus, and Alistipes were protective and populations associated with Escherichia and Streptococcus were associated with high levels of colonization. In addition, a population affiliated with the Akkermansia indicated a strong context dependency on other members of the microbiota. Together, these results indicate that individual bacterial populations do not drive colonization resistance to C. difficile. Rather, multiple diverse assemblages act in concert to mediate colonization resistance. PMID:26173701

Clostridium difficile colonization and/or infection during infancy and the risk of childhood allergic diseases.

PubMed

Lee, Sun Hwa; Gong, Yun Na; Ryoo, Eell

2017-05-01

The gut microbiota can influence several diseases through immune modulation; however, the exact role of microbes such as Clostridium difficile and the relationship between microbiota colonization and allergic diseases are not well known. This study aimed to determine the relationship between C. difficile colonization and/or infection (CDCI) during infancy and allergic diseases during early childhood. Infants 1-12 months of age presenting changes in bowel habits for more than 2 weeks were enrolled in this study. After dividing them into 2 groups according to the presence and absence of C. difficile , the risk of allergic disease development during childhood was identified and compared. Sixty-five patients were included in this study; 22 (33.8%) were diagnosed with CDCI. No significant differences were observed in baseline characteristics between the C. difficile -positive and -negative groups except for antibiotic exposure (22.7% vs. 60.5%, P =0.004). Compared to the C. difficile -negative group, the risk of developing at least one allergic disease was higher in the C. difficile -positive group after adjusting other variables (adjusted odds ratios, 5.61; 95% confidence interval, 1.52-20.74; P =0.007). Furthermore, food allergies were more prevalent in the C. difficile -positive group ( P =0.03). CDCI during infancy were associated with a higher risk of developing allergic diseases during early childhood. These results suggest that CDCI during infancy might reflect the reduced diversity of the intestinal microbiota, which is associated with an increased risk of allergic sensitization. To identify the underlying mechanism, further investigation and a larger cohort study will be needed.

Evaluation of Correlation between Pretest Probability for Clostridium difficile Infection and Clostridium difficile Enzyme Immunoassay Results

PubMed Central

Reske, Kimberly A.; Hink, Tiffany; Dubberke, Erik R.

2016-01-01

ABSTRACT The objective of this study was to evaluate the clinical characteristics and outcomes of hospitalized patients tested for Clostridium difficile and determine the correlation between pretest probability for C. difficile infection (CDI) and assay results. Patients with testing ordered for C. difficile were enrolled and assigned a high, medium, or low pretest probability of CDI based on clinical evaluation, laboratory, and imaging results. Stool was tested for C. difficile by toxin enzyme immunoassay (EIA) and toxigenic culture (TC). Chi-square analyses and the log rank test were utilized. Among the 111 patients enrolled, stool samples from nine were TC positive and four were EIA positive. Sixty-one (55%) patients had clinically significant diarrhea, 19 (17%) patients did not, and clinically significant diarrhea could not be determined for 31 (28%) patients. Seventy-two (65%) patients were assessed as having a low pretest probability of having CDI, 34 (31%) as having a medium probability, and 5 (5%) as having a high probability. None of the patients with low pretest probabilities had a positive EIA, but four were TC positive. None of the seven patients with a positive TC but a negative index EIA developed CDI within 30 days after the index test or died within 90 days after the index toxin EIA date. Pretest probability for CDI should be considered prior to ordering C. difficile testing and must be taken into account when interpreting test results. CDI is a clinical diagnosis supported by laboratory data, and the detection of toxigenic C. difficile in stool does not necessarily confirm the diagnosis of CDI. PMID:27927930

[New methodological advances: algorithm proposal for management of Clostridium difficile infection].

PubMed

González-Abad, María José; Alonso-Sanz, Mercedes

2015-06-01

Clostridium difficile infection (CDI) is considered the most common cause of health care-associated diarrhea and also is an etiologic agent of community diarrhea. The aim of this study was to assess the potential benefit of a test that detects glutamate dehydrogenase (GDH) antigen and C. difficile toxin A/B, simultaneously, followed by detection of C. difficile toxin B (tcdB) gene by PCR as confirmatory assay on discrepant samples, and to propose an algorithm more efficient. From June 2012 to January 2013 at Hospital Infantil Universitario Niño Jesús, Madrid, the stool samples were studied for the simultaneous detection of GDH and toxin A/B, and also for detection of toxin A/B alone. When results between GDH and toxin A/B were discordant, a single sample for patient was selected for detection of C. difficile toxin B (tcdB) gene. A total of 116 samples (52 patients) were tested. Four were positive and 75 negative for toxigenic C. difficile (Toxin A/B, alone or combined with GDH). C. difficile was detected in the remaining 37 samples but not toxin A/B, regardless of the method used, except one. Twenty of the 37 specimens were further tested for C. difficile toxin B (tcdB) gene and 7 were positive. The simultaneous detection of GDH and toxin A/B combined with PCR recovered undiagnosed cases of CDI. In accordance with our data, we propose a two-step algorithm: detection of GDH and PCR (in samples GDH positive). This algorithm could provide a superior cost-benefit ratio in our population.

Emerging monoclonal antibodies against Clostridium difficile infection.

PubMed

Péchiné, Séverine; Janoir, Claire; Collignon, Anne

2017-04-01

Clostridium difficile infections are characterized by a high recurrence rate despite antibiotic treatments and there is an urgent need to develop new treatments such as fecal transplantation and immonotherapy. Besides active immunotherapy with vaccines, passive immunotherapy has shown promise, especially with monoclonal antibodies. Areas covered: Herein, the authors review the different assays performed with monoclonal antibodies against C. difficile toxins and surface proteins to treat or prevent primary or recurrent episodes of C. difficile infection in animal models and in clinical trials as well. Notably, the authors lay emphasis on the phase III clinical trial (MODIFY II), which allowed bezlotoxumab to be approved by the Food and Drug Administration and the European Medicines Agency. They also review new strategies for producing single domain antibodies and nanobodies against C. difficile and new approaches to deliver them in the digestive tract. Expert opinion: Only two human Mabs against TcdA and TcdB have been tested alone or in combination in clinical trials. However, many animal model studies have provided rationale for the use of Mabs and nanobodies in C. difficile infection and pave the way for further clinical investigation.

Clostridium difficile associated diarrhoea: An increased problem.

PubMed

Urbina Soto, Leticia; García Ávila, Sara; Córdoba Alonso, Ana Isabel; Roiz Mesones, M Pía; Arnaiz García, Ana M; Valero Díaz de Lamadrid, M Carmen

2016-12-16

Clostridium difficile associated diarrhoea is a major health problem that seems to be on the increase. In our study, we analyse the changes in the incidence of this infection over the last 11 years. A descriptive study in hospitalised patients with Clostridium difficile associated diarrhoea in University Hospital Marqués de Valdecilla (Santander, Spain) from 2004 to 2014. A total of 244 adults were identified [53% men; 66 (SD 15) years]. The cases of nosocomial acquisition (80%), with respect to community acquired Clostridium difficile infection, were older [67 (SD 15) years vs. 63 (19) years; P=.01), high comorbidity (86% vs. 75%; P=.01), use of antibiotics (95% vs. 75%; P<.001) and proton pump inhibitors (87% vs. 48% P<.001). There has been an increasing incidence of Clostridium difficile associated diarrhoea in our hospital over an 11-year period. The clinical profile of patients with Clostridium difficile diarrhoea varies by place of acquisition of infection. The prevalence of this disease is increasing. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

Clostridium difficile in faeces from healthy dogs and dogs with diarrhea.

PubMed

Wetterwik, Karl-Johan; Trowald-Wigh, Gunilla; Fernström, Lise-Lotte; Krovacek, Karel

2013-03-12

This study was conducted to evaluate the faecal occurrence and characterization of Clostridium difficile in clinically healthy dogs (N = 50) and in dogs with diarrhea (N = 20) in the Stockholm-Uppsala region of Sweden. Clostridium difficile was isolated from 2/50 healthy dogs and from 2/20 diarrheic dogs. Isolates from healthy dogs were negative for toxin A and B and for the tcdA and tcdB genes. Both isolates from diarrheic dogs were positive for toxin B and for the tcdA and tcdB genes. The C. difficile isolates from healthy dogs had PCR ribotype 009 (SE-type 6) and 010 (SE-type 3) whereas both isolates from dogs with diarrhoea had the toxigenic ribotype 014 (SE-type 21). One of the isolates from healthy dogs was initially resistant to metronidazole. This study revealed presence of toxigenic C. difficile in faecal samples of diarrheic dogs and low number of non- toxigenic isolates in healthy dogs from Uppsala-Stockholm region in Sweden. However, more comprehensive studies are warranted to investigate the role of C. difficile in gastrointestinal disease in dogs.

Impact of microbial derived secondary bile acids on colonization resistance against Clostridium difficile in the gastrointestinal tract.

PubMed

Winston, Jenessa A; Theriot, Casey M

2016-10-01

Clostridium difficile is an anaerobic, Gram positive, spore-forming bacillus that is the leading cause of nosocomial gastroenteritis. Clostridium difficile infection (CDI) is associated with increasing morbidity and mortality, consequently posing an urgent threat to public health. Recurrence of CDI after successful treatment with antibiotics is high, thus necessitating discovery of novel therapeutics against this pathogen. Susceptibility to CDI is associated with alterations in the gut microbiota composition and bile acid metabolome, specifically a loss of microbial derived secondary bile acids. This review aims to summarize in vitro, ex vivo, and in vivo studies done by our group and others that demonstrate how secondary bile acids affect the different stages of the C. difficile life cycle. Understanding the dynamic interplay of C. difficile and microbial derived secondary bile acids within the gastrointestinal tract will shed light on how bile acids play a role in colonization resistance against C. difficile. Rational manipulation of secondary bile acids may prove beneficial as a treatment for patients with CDI. Published by Elsevier Ltd.

Atypical Presentation of C. Difficile Infection: Report of a Case with Literature Review

PubMed Central

Towheed, Arooge; Tul Llah, Sibghat; Bin Abdulhak, Aref; Tilson-Mallett, Nancy R; Salkind, Alan

2016-01-01

Clostridium difficile (C. difficile) is a gram-positive, obligate, anaerobic spore-forming bacillus first reported by Hall and O'Toole in 1935. It occurs mostly after antibiotic use and invariably presents with watery diarrhea. We describe an atypical presentation of C. difficile in a 64-year-old Caucasian female who presented to the our emergency department with abdominal pain, nausea, and vomiting for one day. A complete blood count revealed leukocytosis 30 x 109/L and a subsequent computed tomography (CT) scan of the abdomen and the pelvis, showed fluid filled small bowel loops consistent with enteritis. Her presentation was unusual for lack of diarrhea, the hallmark of C. difficile infection. She was admitted and treated with oral vancomycin. The polymerase chain reaction (PCR) value in the stool for C. difficile was positive. The patient responded very well: her abdominal pain resolved and leukocyte count normalized after a few doses of vancomycin (125 mg po qid). The patient's progress was followed in our clinic for the last three months. PMID:27190728

Sensitive assays enable detection of serum IgG antibodies against Clostridium difficile toxin A and toxin B in healthy subjects and patients with Clostridium difficile infection.

PubMed

Zhao, Xuemei; Bender, Florent; Shukla, Rajiv; Kang, John J; Caro-Aguilar, Ivette; Laterza, Omar F

2016-04-01

Pathogenic Clostridium difficile produces two proinflammatory exotoxins, toxin A and toxin B. Low level of serum antitoxin IgG antibodies is a risk factor for the development of primary and recurrent C. difficile infection (CDI). We developed and validated two sensitive, titer-based electrochemiluminescence assays for the detection of serum antibody levels against C. difficile toxins A and B. These assays demonstrated excellent precision. The sensitivity of the assays allowed the detection of antitoxin A and antitoxin B IgG antibodies in all tested serum samples during assay validation. The validated titer-based assays enable assessment of antitoxin A and antitoxin B IgG antibodies as potential biomarkers to identify patients with CDI at increased risk for CDI recurrence.

Fecal Microbiota Transplantation for Refractory Clostridium difficile Colitis in Solid Organ Transplant Recipients

PubMed Central

Friedman-Moraco, R. J.; Mehta, A. K.; Lyon, G. M.; Kraft, C. S.

2015-01-01

Fecal microbiota transplantation (FMT) has been shown to be safe and efficacious in individuals with refractory Clostridium difficile . It has not been widely studied in individuals with immunosuppression due to concerns about infectious complications. We describe two solid organ transplant recipients, one lung and one renal, in this case report that both had resolution of their diarrhea caused by C. difficile after FMT. Both recipients required two FMTs to achieve resolution of their symptoms and neither had infectious complications. Immunosuppressed individuals are at high risk for acquisition of C. difficile and close monitoring for infectious complications after FMT is necessary, but should not preclude its use in patients with refractory disease due to C. difficile . Sequential FMT may be used to achieve cure in these patients with damaged microbiota from antibiotic use and immunosuppression. PMID:24433460

Prevalence of Clostridium Difficile Infection in Patients After Radical Cystectomy and Neoadjuvant Chemotherapy.

PubMed

Cotter, Katherine J; Fan, Yunhua; Sieger, Gretchen K; Weight, Christopher J; Konety, Badrinath R

2017-10-27

Clostridium Difficile is the most common cause of nosocomial infectious diarrhea. This study evaluates the prevalence and predictors of Clostridium Difficile infections in patients undergoing radical cystectomy with or without neoadjuvant chemotherapy. Retrospective chart review was performed of all patients undergoing cystectomy and urinary diversion at a single institution from 2011-2017. Infection was documented in all cases with testing for Clostridium Difficile polymerase chain reaction toxin B. Patient and disease related factors were compared for those who received neoadjuvant chemotherapy vs. those who did not in order to identify potential risk factors associated with C. Difficile infections. Chi squared test and logistic regression analysis were used to determine statistical significance. Of 350 patients who underwent cystectomy, 41 (11.7%) developed Clostridium Difficile in the 30 day post-operative period. The prevalence of C. Difficile infection was higher amongst the patients undergoing cystectomy compared to the non-cystectomy admissions at our hospital (11.7 vs. 2.9%). Incidence was not significantly different among those who underwent cystectomy for bladder cancer versus those who underwent the procedure for other reasons. Median time to diagnosis was 6 days (range 3-28 days). The prevalence of C. Diff infections was not significantly different among those who received neoadjuvant chemotherapy vs. those who did not (11% vs. 10.4% p  = 0.72). A significant association between C. Difficile infection was not seen with proton pump inhibitor use ( p  = 0.48), patient BMI ( p  = 0.67), chemotherapeutic regimen ( p  = 0.94), individual surgeon ( p  = 0.54), type of urinary diversion (0.41), or peri-operative antibiotic redosing ( p  = 0.26). Clostridium Difficile infection has a higher prevalence in patients undergoing cystectomy. No significant association between prevalence and exposure to neoadjuvant chemotherapy was seen.

Clostridium difficile Testing in the Clinical Laboratory by Use of Multiple Testing Algorithms ▿

PubMed Central

Novak-Weekley, Susan M.; Marlowe, Elizabeth M.; Miller, John M.; Cumpio, Joven; Nomura, Jim H.; Vance, Paula H.; Weissfeld, Alice

2010-01-01

The incidence of Clostridium difficile infection (CDI) has risen almost 3-fold in the United States over the past decade, emphasizing the need for rapid and accurate tests for CDI. The Cepheid Xpert C. difficile assay is an integrated, closed, nucleic acid amplification system that automates sample preparation and real-time PCR detection of the toxin B gene (tcdB). A total of 432 stool specimens from symptomatic patients were tested by a glutamate dehydrogenase (GDH) assay, a toxin A and B enzyme immunoassay (EIA), the Xpert C. difficile assay, and a cell culture cytotoxicity neutralization assay (CCCN). The results of these methods, used individually and in combination, were compared to those of toxigenic culture. Results for the Xpert C. difficile assay alone showed a sensitivity, specificity, positive predictive value, and negative predictive value (NPV) of 94.4, 96.3, 84.0, and 98.8%, while the EIA alone gave corresponding values of 58.3, 94.7, 68.9, and 91.9%, respectively. An algorithm using the GDH assay and the EIA (plus the CCCN if the EIA was negative) showed corresponding values of 83.1, 96.7, 83.1, and 96.1%. The Xpert C. difficile assay was statistically superior to the EIA (P, <0.001 by Fisher's exact test) and to the GDH-EIA-CCCN algorithm (P, 0.0363). Combining the GDH and Xpert C. difficile assays lowered both the sensitivity and the NPV of the Xpert assay. The GDH-EIA-CCCN procedure required, on average, 2 days to complete testing on GDH-positive results, while testing by the Xpert C. difficile assay was completed, on average, in less than 1 h. Xpert C. difficile testing yielded the highest sensitivity and NPV, in the least amount of time, of the individual- and multiple-test algorithms evaluated in this study. PMID:20071552

Comparison of the Vidas C. difficile GDH Automated Enzyme-Linked Fluorescence Immunoassay (ELFA) with Another Commercial Enzyme Immunoassay (EIA) (Quik Chek-60), Two Selective Media, and a PCR Assay for gluD for Detection of Clostridium difficile in Fecal Samples.

PubMed

Davies, K A; Berry, C E; Morris, K A; Smith, R; Young, S; Davis, T E; Fuller, D D; Buckner, R J; Wilcox, M H

2015-06-01

Prevention and management of Clostridium difficile infection (CDI) can be improved by rapid and reliable diagnostics. The Vidas C. difficile glutamate dehydrogenase assay had performance comparable to that of the Quik Chek-60 assay (overall agreement, 95%) and a sensitivity of >93%; thus, it is suitable as the first test in two-stage algorithms for a CDI diagnosis. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Clostridium difficile in the Long-Term Care Facility: Prevention and Management

PubMed Central

Jump, Robin L. P.; Donskey, Curtis J.

2014-01-01

Residents of long-term care facilities are at high risk for Clostridium difficile infection due to frequent antibiotic exposure in a population already rendered vulnerable to infection due to advanced age, multiple comorbid conditions and communal living conditions. Moreover, asymptomatic carriage of toxigenic C. difficile and recurrent infections are prevalent in this population. Here, we discuss epidemiology and management of C. difficile infection among residents of long-term care facilities. Also, recognizing that both the population and culture differs significantly from that of hospitals, we also address prevention strategies specific to LTCFs. PMID:25685657

Hospital Clostridium difficile outbreak linked to laundry machine malfunction.

PubMed

Sooklal, Shelini; Khan, Ayesha; Kannangara, Saman

2014-06-01

Clostridium difficile is a gram-positive, spore-forming anaerobic bacillus that is associated with diarrheal disease. C difficile is shed in the feces of affected individuals and its spores can survive on surfaces for prolonged periods of time. These spores can contaminate a hospital environment by spread through health care workers and suboptimal environmental cleaning practices. We report an outbreak of health care facility-onset C difficile infection that was eventually linked to contaminated mop pads after a laundry machine malfunction. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Flooding and Clostridium difficile Infection: A Case-Crossover Analysis

PubMed Central

Lin, Cynthia J.; Wade, Timothy J.; Hilborn, Elizabeth D.

2015-01-01

Clostridium difficile is a bacterium that can spread by water. It often causes acute gastrointestinal illness in older adults who are hospitalized and/or receiving antibiotics; however, community-associated infections affecting otherwise healthy individuals have become more commonly reported. A case-crossover study was used to assess emergency room (ER) and outpatient visits for C. difficile infection following flood events in Massachusetts from 2003 through 2007. Exposure status was based on whether or not a flood occurred prior to the case/control date during the following risk periods: 0–6 days, 7–13 days, 14–20 days, and 21–27 days. Fixed-effects logistic regression was used to estimate the risk of diagnosis with C. difficile infection following a flood. There were 129 flood events and 1575 diagnoses of C. difficile infection. Among working age adults (19–64 years), ER and outpatient visits for C. difficile infection were elevated during the 7–13 days following a flood (Odds Ratio, OR = 1.69; 95% Confidence Interval, CI: 0.84, 3.37). This association was more substantial among males (OR = 3.21; 95% CI: 1.01–10.19). Associations during other risk periods were not observed (p < 0.05). Although we were unable to differentiate community-associated versus nosocomial infections, a potential increase in C. difficile infections should be considered as more flooding is projected due to climate change. PMID:26090609

Clostridium difficile: A healthcare-associated infection of unknown significance in adults in sub-Saharan Africa.

PubMed

Keeley, Alexander J; Beeching, Nicholas J; Stott, Katharine E; Roberts, Paul; Watson, Alastair J; Beadsworth, Michael Bj

2016-06-01

Clostridium difficile infection (CDI) causes a high burden of disease in high-resource healthcare systems, with significant morbidity, mortality, and financial implications. CDI is a healthcare-associated infection for which the primary risk factor is antibiotic usage, and it is the leading cause of bacterial diarrhoea in HIV-infected patients in the United States. Little is known about the disease burden of CDI in sub-Saharan Africa, where HIV and healthcare-associated infections are more prevalent and antibiotic usage is less restricted. This article reviews published literature on CDI in sub-Saharan Africa, highlighting areas for future research. English language publications since 1995 were identified from online databases (PubMed, Medline, Google Scholar, and SCOPUS), using combinations of keywords "C. difficile" , "Africa", and "HIV". Ten relevant studies were identified. There was considerable variation in the methodologies used to assess for carriage of toxigenic C. difficile and its associations. Eight studies reported carriage of toxigenic C. difficile . Three (of three) studies found an association with antibiotic usage. One (of four) studies showed an association with HIV infection. One study showed no association with degree of immunosuppression in HIV. Two (of three) studies showed an association between carriage of toxigenic C. difficile and diarrhoeal illness. While the carriage of toxigenic C. difficile is well described in sub-Saharan Africa, the impact of CDI in the region remains poorly understood and warrants further research.

Effect of broad- and narrow-spectrum antimicrobials on Clostridium difficile and microbial diversity in a model of the distal colon

PubMed Central

Rea, Mary C.; Dobson, Alleson; O'Sullivan, Orla; Crispie, Fiona; Fouhy, Fiona; Cotter, Paul D.; Shanahan, Fergus; Kiely, Barry; Hill, Colin; Ross, R. Paul

2011-01-01

Vancomycin, metronidazole, and the bacteriocin lacticin 3147 are active against a wide range of bacterial species, including Clostridium difficile. We demonstrate that, in a human distal colon model, the addition of each of the three antimicrobials resulted in a significant decrease in numbers of C. difficile. However, their therapeutic use in the gastrointestinal tract may be compromised by their broad spectrum of activity, which would be expected to significantly impact on other members of the human gut microbiota. We used high-throughput pyrosequencing to compare the effect of each antimicrobial on the composition of the microbiota. All three treatments resulted in a decrease in the proportion of sequences assigned to the phyla Firmicutes and Bacteroidetes, with a corresponding increase in those assigned to members of the Proteobacteria. One possible means of avoiding such “collateral damage” would involve the application of a narrow-spectrum antimicrobial with specific anti-C. difficile activity. We tested this hypothesis using thuricin CD, a narrow-spectrum bacteriocin produced by Bacillus thuringiensis, which is active against C. difficile. The results demonstrated that this bacteriocin was equally effective at killing C. difficile in the distal colon model but had no significant impact on the composition of the microbiota. This offers the possibility of developing a targeted approach to eliminating C. difficile in the colon, without collateral damage. PMID:20616009

Prevalence of Clostridium difficile colonization among healthcare workers

PubMed Central

2013-01-01

Background Clostridium difficile infection (CDI) has increased to epidemic proportions in recent years. The carriage of C. difficile among healthy adults and hospital inpatients has been established. We sought to determine whether C. difficile colonization exists among healthcare workers (HCWs) in our setting. Methods A point prevalence study of stool colonization with C. difficile among doctors, nurses and allied health staff at a large regional teaching hospital in Geelong, Victoria. All participants completed a short questionnaire and all stool specimens were tested by Techlab® C.diff Quik Check enzyme immunoassay followed by enrichment culture. Results Among 128 healthcare workers, 77% were female, of mean age 43 years, and the majority were nursing staff (73%). Nineteen HCWs (15%) reported diarrhoea, and 12 (9%) had taken antibiotics in the previous six weeks. Over 40% of participants reported having contact with a patient with known or suspected CDI in the 6 weeks before the stool was collected. C. difficile was not isolated from the stool of any participants. Conclusion Although HCWs are at risk of asymptomatic carriage and could act as a reservoir for transmission in the hospital environment, with the use of a screening test and culture we were unable to identify C. difficile in the stool of our participants in a non-outbreak setting. This may reflect potential colonization resistance of the gut microbiota, or the success of infection prevention strategies at our institution. PMID:24090343

The economic burden of Clostridium difficile

PubMed Central

McGlone, S. M.; Bailey, R. R.; Zimmer, S. M.; Popovich, M. J.; Tian, Y.; Ufberg, P.; Muder, R. R.; Lee, B. Y.

2013-01-01

Although Clostridium difficile (C. difficile) is the leading cause of infectious diarrhoea in hospitalized patients, the economic burden of this major nosocomial pathogen for hospitals, third-party payers and society remains unclear. We developed an economic computer simulation model to determine the costs attributable to healthcare-acquired C. difficile infection (CDI) from the hospital, third-party payer and societal perspectives. Sensitivity analyses explored the effects of varying the cost of hospitalization, C. difficile-attributable length of stay, and the probability of initial and secondary recurrences. The median cost of a case ranged from $9179 to $11 456 from the hospital perspective, $8932 to $11 679 from the third-party payor perspective, and $13 310 to $16 464 from the societal perspective. Most of the costs incurred were accrued during a patient’s primary CDI episode. Hospitals with an incidence of 4.1 CDI cases per 100 000 discharges would incur costs ≥$3.2 million (hospital perspective); an incidence of 10.5 would lead to costs ≥$30.6 million. Our model suggests that the annual US economic burden of CDI would be ≥$496 million (hospital perspective), ≥$547 million (third-party payer perspective) and ≥$796 million (societal perspective). Our results show that C. difficile infection is indeed costly, not only to third-party payers and the hospital, but to society as well. These results are consistent with current literature citing C. difficile as a costly disease. PMID:21668576

Flooding and Clostridium difficile Infection: A Case-Crossover Analysis.

PubMed

Lin, Cynthia J; Wade, Timothy J; Hilborn, Elizabeth D

2015-06-17

Clostridium difficile is a bacterium that can spread by water. It often causes acute gastrointestinal illness in older adults who are hospitalized and/or receiving antibiotics; however, community-associated infections affecting otherwise healthy individuals have become more commonly reported. A case-crossover study was used to assess emergency room (ER) and outpatient visits for C. difficile infection following flood events in Massachusetts from 2003 through 2007. Exposure status was based on whether or not a flood occurred prior to the case/control date during the following risk periods: 0-6 days, 7-13 days, 14-20 days, and 21-27 days. Fixed-effects logistic regression was used to estimate the risk of diagnosis with C. difficile infection following a flood. There were 129 flood events and 1575 diagnoses of C. difficile infection. Among working age adults (19-64 years), ER and outpatient visits for C. difficile infection were elevated during the 7-13 days following a flood (Odds Ratio, OR = 1.69; 95% Confidence Interval, CI: 0.84, 3.37). This association was more substantial among males (OR = 3.21; 95% CI: 1.01-10.19). Associations during other risk periods were not observed (p < 0.05). Although we were unable to differentiate community-associated versus nosocomial infections, a potential increase in C. difficile infections should be considered as more flooding is projected due to climate change.