Production of Acylated Homoserine Lactones by Psychrotrophic Members of the Enterobacteriaceae Isolated from Foods

PubMed Central

Gram, Lone; Christensen, Allan Beck; Ravn, Lars; Molin, Søren; Givskov, Michael

1999-01-01

Bacteria are able to communicate and gene regulation can be mediated through the production of acylated homoserine lactone (AHL) signal molecules. These signals play important roles in several pathogenic and symbiotic bacteria. The following study was undertaken to investigate whether AHLs are produced by bacteria found in food at temperatures and NaCl conditions commercially used for food preservation and storage. A minimum of 116 of 154 psychrotrophic Enterobacteriaceae strains isolated from cold-smoked salmon or vacuum-packed chilled meat produced AHLs. Analysis by thin-layer chromatography indicated that N-3-oxo-hexanoyl homoserine lactone was the major AHL of several of the strains isolated from cold-smoked salmon and meat. AHL-positive strains cultured at 5°C in medium supplemented with 4% NaCl produced detectable amounts of AHL(s) at cell densities of 106 CFU/ml. AHLs were detected in cold-smoked salmon inoculated with strains of Enterobacteriaceae stored at 5°C under an N2 atmosphere when mean cell densities increased to 106 CFU/g and above. Similarly, AHLs were detected in uninoculated samples of commercially produced cold-smoked salmon when the level of indigenous Enterobacteriaceae reached 106 CFU/g. This level of Enterobacteriaceae is often found in lightly preserved foods, and AHL-mediated gene regulation may play a role in bacteria associated with food spoilage or food toxicity. PMID:10427034

Analysis of Drug Resistance Determinants in Klebsiella pneumoniae Isolates from a Tertiary-Care Hospital in Beijing, China

PubMed Central

Wang, Qi; Woo, Patrick C. Y.; Tan, Lin; Jing, Hua; Gao, George F.; Liu, Cui Hua

2012-01-01

Background The rates of multidrug-resistant (MDR), extensively drug-resistant (XDR) and pandrug-resistant (PDR) isolates among Enterobacteriaceae isolates, particularly Klebsiella pneumoniae, have risen substantially worldwide. Methodology/Principal Findings To better understand the molecular mechanisms of drug resistance in K. pneumoniae, we analyzed the drug resistance determinants for K. pneumoniae isolates collected from the 306 Hospital, a tertiary-care hospital in Beijing, China, for the period of September 1, 2010-October 31, 2011. Drug susceptibility testing, PCR amplification and sequencing of the drug resistance determinants were performed. Conjugation experiments were conducted to examine the natural ability of drug resistance to disseminate among Enterobacteriaceae strains using a sodium azide-resistant Escherichia coli J53 strain as a recipient. Among the 223 consecutive non-repetitive K. pneumoniae isolates included in this study, 101 (45.3%) were extended-spectrum beta-lactamases (ESBLs) positive. The rates of MDR, XDR, and PDR isolates were 61.4% (n = 137), 22.0% (n = 49), and 1.8% (n = 4), respectively. Among the tested drug resistance-associated genes, the following ones were detected at relatively high rates bla CTX-M-10 (80, 35.9%), aacC2 (73, 32.7%), dhfr (62, 27.8%), qnrS (58, 26.0%), aacA4 (57, 25.6%), aadA1 (56, 25.1%). Results from conjugation experiments indicate that many of the drug resistance genes were transmissible. Conclusions/Significance Our data give a “snapshot” of the complex genetic background responsible for drug resistance in K. pneumoniae in China and demonstrate that a high degree of awareness and monitoring of those drug resistance determinants are urgently needed in order to better control the emergence and transmission of drug-resistant K. pneumoniae isolates in hospital settings. PMID:22860106

Characterization of the modified Hodge test-positive isolates of Enterobacteriaceae in Taiwan.

PubMed

Hung, Kuei-Hsiang; Yan, Jing-Jou; Lu, Jang-Jih; Chen, Hung-Mo; Wu, Jiunn-Jong

2013-02-01

The modified Hodge test is a phenotypic test to detect KPC-type carbapenemase producers among Enterobacteriaceae, as recommended by the Clinical Laboratory Standards Institute. However, false positive results were reported. In this study, we aimed to large-scale investigate the characterization of the modified Hodge test-positive isolates of Enterobacteriaceae collected between 2006 and 2010 in Taiwan. Fifty-six isolates, including 24 Enterobacter cloacae, 17 Escherichia coli, 10 Klebsiella pneumoniae, and 5 Citrobacter freundii, tested positive with the modified Hodge test. The in vitro activities of 10 antimicrobial agents were determined by the agar dilution method. Boronic acid combined-disk test was used to further confirm the KPC producers. Phenotype of ESBL, AmpC, class B carbapenemases, and profile of outer membrane proteins were investigated by the confirmatory test, boronic acid disk method, 2-mercaptopropionic acid double-disk method, and urea/sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), respectively. β-lactamase genes were examined by PCR and sequencing. These isolates were resistant to ceftazidime (100%), aztreonam (82.1%), ertapenem (64.3%), gentamicin (53.6%), ciprofloxacin (50%), levofloxacin (48.2%), cefepime (19.6%), imipenem (16.1%), meropenem (12.5%), and amikacin (8.9%). Phenotypic testing among isolates revealed the production of ESBLs, metallo-β-lactamases (MBLs), and AmpC in 10 (17.9%), 16 (28.6%), and 12 (44.4%) isolates, respectively. Carbapenemase and non-carbapenemase β-lactamase genes bla(TEM-1), bla(SHV), bla(CTX-M), bla(IMP-8), bla(CMY-2), and bla(DHA-1) were found in 32 (57.1%), 19 (33.9%), 4 (7.1%), 16 (28.6%), 14 (25%), and 5 (8.9%) of the strains, respectively. No class A and D carbapenemase genes were detected. Outer membrane protein profile showed obviously decreased expression in 49 (87.5%) isolates with positive result of modified Hodge test. Our data show that ESBLs, AmpC, and imipenemase-8 (IMP-8

In vitro synergistic activity of tigecycline and colistin against XDR-Acinetobacter baumannii.

PubMed

Dizbay, Murat; Tozlu, Derya Keten; Cirak, Meltem Yalinay; Isik, Yasemin; Ozdemir, Kevser; Arman, Dilek

2010-02-01

The emergence of extensive drug-resistant (XDR) Acinetobacter baumannii limits the therapeutic options and leads to high mortality in intensive care units. Combined antibiotic therapy is frequently recommended for the treatment of these infections. Colistin (CO) and tigecycline (TIG), alone or in combination with other antimicrobials, are the most commonly used antibiotics in the treatment of these resistant infections. In this study, the in vitro synergistic activity of TIG and CO were tested for 25 XDR-A. baumannii strains isolated from ventilator-associated pneumonia by the Etest method. Resistance to CO was not detected, whereas 8% of the strains were resistant to TIG. The TIG-CO combination was more synergistic than TIG-rifampin and CO-rifampin according to the fractional inhibitory concentration index. No antagonism was detected between the drugs in the study. There was no strong correlation between the activity of the combinations with reference to strains or genotypes. Our results suggest that the combined use of TIG and CO may be useful for the treatment of XDR-A. baumannii infections.

Epidemiology, susceptibility, and risk factors for acquisition of MDR/XDR Gram-negative bacteria among kidney transplant recipients with urinary tract infections.

PubMed

Yuan, Xiuhong; Liu, Taohua; Wu, Di; Wan, Qiquan

2018-01-01

Multiple drug resistant/extensively drug resistant (MDR/XDR) Gram-negative urinary tract infections (UTIs) represent a growing threat to kidney transplant recipients. This retrospective study aimed to assess the incidence and microbiological profile of MDR/XDR Gram-negative UTIs, to identify drug susceptibility of MDR/XDR bacteria, and to determine the potential risk factors for MDR/XDR UTIs in kidney recipients. During the study period, 1569 patients underwent consecutive kidney transplantation in two transplantation centers. We studied the demographics, clinical characteristics, and urine culture data from kidney recipients with MDR/XDR Gram-negative UTIs, and verified the risk factors associated with MDR/XDR infections. Eighty-one kidney recipients yielded 88 episodes of MDR/XDR Gram-negative UTIs with five patients (6.2%) succumbing to all-cause in-hospital mortality. The most frequently isolated bacterium was Escherichia coli (62.5%). Almost all MDR/XDR Gram-negative bacteria were resistant to first- and second-generation cephalosporin, and monocyclic beta-lactam. They were relatively sensitive to meropenem, amikacin, and tigecycline. As for the 12 XDR bacteria, all of them were resistant to meropenem and 25% of them were resistant to tigecycline. All XDR Acinetobacter baumannii and E. coli were susceptible to tigecycline. Nosocomial infection (odds ratio [OR] = 11.429, 95% CI = 1.311-99.625, P = 0.027) was the only independent predictor of MDR/XDR Gram-negative UTIs. Non-fermenting bacterial infection (OR = 20.161, 95% CI = 3.409-119.240, P = 0.001), polycystic kidney disease (OR = 39.871, 95% CI = 1.979-803.384, P = 0.016), and serum creatinine level > 1.5 mg/dL (OR = 8.688, 95% CI = 1.354-55.747, P = 0.023) were significantly different between XDR and MDR Gram-negative UTIs. Meropenem, amikacin, and/or tigecycline can be prescribed for MDR/XDR Gram-negative infections. Tigecycline can also be prescribed for XDR A. baumannii and E. coli . Nosocomial

AmpC-BETA Lactamases among Enterobacteriaceae Isolated at a Tertiary Hospital, South Western Uganda

PubMed Central

Nakaye, Martha; Bwanga, Freddie; Itabangi, Herbert; Stanley, Iramiot J.; Bashir, Mwambi; Bazira, Joel

2015-01-01

Aim To characterize AmpC-beta lactamases among Enterobacteriaceae isolates from clinical samples at Mbarara Regional Referral Hospital. Study Design Laboratory-based descriptive cross-sectional study Place and Duration of Study Microbiology Department, Mbarara Regional Referral Hospital and MBN clinical Laboratories, between May to September 2013. Methodology This study included 293 Enterobacteriaceae isolates recovered from clinical specimens that included blood, urine, stool and aspirates. AmpC Beta lactamase production was determined using disc placement method for cefoxitin at a break point of <18mm. Common AmpC plasmid mediated genes were EBC, ACC, FOX, DHA, CIT and MOX were; was determined by Multiplex PCR as described by Hanson and Perez-Perez. Results Plasmid mediated AmpC phenotype was confirmed in 107 of the 293 (36.5%) cefoxitin resistant isolates with 30 isolates having more than one gene coding for resistance. The commonest source that harbored AmpC beta lactamases was urine and E. coli was the most common AmpC producer (59.5%). The genotypes detected in this study, included EBC (n=36), FOX (n=18), ACC (n=11), CIT (n=10), DHA (n=07) and MOX (n=1). Conclusion Our findings showed that prevalence of AmpC beta-lactamase at MRRH was high (39.6), with EBC as the commonest genotype among Enterobacteriaceae Urine and E. coli were the commonest source and organism respectively that harbored AmpC beta-lactamases. There‘s rational antimicrobial therapy and antibiotic susceptibility tests should be requested by health workers especially patients presenting with urinary tract infections and bacteraemias. PMID:26078920

Characterisation of extended-spectrum β-lactamase and AmpC β-lactamase-producing Enterobacteriaceae isolated from companion animals in New Zealand.

PubMed

Karkaba, A; Grinberg, A; Benschop, J; Pleydell, E

2017-03-01

To assess the occurrence of, and characterise, extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase (AmpC)-producing Enterobacteriaceae isolated by veterinary diagnostic laboratories from infection sites in companion animals in New Zealand. Selected Enterobacteriaceae isolates were submitted by seven New Zealand veterinary diagnostic laboratories. They were isolated from infection sites in companion animals between June 2012 and June 2013, and were resistant to amoxicillin-clavulanic acid, fluoroquinolones, or any combination of two or more antimicrobials. Based on disk diffusion test results, the isolates were phenotypically categorised according to production of ESBL and AmpC. Genes for ESBL and AmpC production were amplified by PCR and sequenced. Escherichia coli isolates were also typed by multilocus sequence typing. A total of 115 isolates matching the inclusion criteria were obtained from the participating laboratories, of which 74 (64%) originated from dogs and 29 (25%) from cats. Seven bacterial species were identified, of which E. coli was the most common (87/115, 76%). Of the 115 isolates, 10 (9%) expressed the ESBL phenotype, 43 (37%) the AmpC phenotype, and seven (6%) both ESBL and AmpC phenotypes. Of the 60 ESBL and AmpC-producing isolates, 36 (60%) were E. coli. Amongst these isolates, 27/60 (45%) were classified as multidrug resistant, compared with 15/55 (27%) non-ESBL or AmpC-producing isolates (p<0.01). Ninety five isolates were resistant to amoxicillin-clavulanic acid and 58 (61%) of these were ESBL or AmpC-producing. The predominant ESBL genes were bla CTX-M-14 and bla CTX-M-15 , and the dominant plasmid-encoded AmpC gene was bla CMY-2 . Thirty-eight E. coli multilocus sequence types (ST) were identified, and the most prevalent were ST12 (12/89, 13%), ST131 (6/89, 7%) and ST648 (6/89, 7%). ESBL and AmpC-producing isolates accounted for 35/1,082 (3.2%) of the Enterobacteriaceae isolated by one laboratory network over the study period. ESBL

Ceftolozane/tazobactam activity against drug-resistant Enterobacteriaceae and Pseudomonas aeruginosa causing urinary tract and intraabdominal infections in Europe: report from an antimicrobial surveillance programme (2012-15).

PubMed

Pfaller, Michael A; Bassetti, Matteo; Duncan, Leonard R; Castanheira, Mariana

2017-05-01

To evaluate the in vitro activity of ceftolozane/tazobactam and comparators tested against European isolates of Enterobacteriaceae and Pseudomonas aeruginosa from hospitalized patients with urinary tract infection or intraabdominal infections. A total of 6553 Gram-negative organisms (603 P. aeruginosa and 5950 Enterobacteriaceae) were consecutively collected from 41 hospitals located in 17 European countries plus Israel and Turkey. The organisms were tested for susceptibility by broth microdilution methods and the results interpreted according to EUCAST and CLSI breakpoint criteria. Ceftolozane/tazobactam [MIC 50/90 0.25/1 mg/L; 93.5%/91.3% susceptible (S) (CLSI/EUCAST criteria)] and meropenem [MIC 50/90  ≤0.06/≤0.06 mg/L; 98.1%/98.3% S (CLSI/EUCAST)] were the most active compounds tested against Enterobacteriaceae. Among the Enterobacteriaceae isolates, 1.9% were carbapenem resistant (CRE), 15.2% exhibited an ESBL non-CRE phenotype, 14.6% were MDR, 2.2% were XDR and <0.1% were pan-drug resistant (PDR). Whereas ceftolozane/tazobactam showed activity against ESBL non-CRE phenotype isolates (MIC 50/90 0.5/8 mg/L), it lacked useful activity against strains with a CRE (MIC 50/90  >32/>32 mg/L; 3.6% S) or PDR (MIC 50  >32 mg/L; 0.0% S) phenotype. Ceftolozane/tazobactam was the most potent (MIC 50/90 0.5/4 mg/L) β-lactam agent tested against P. aeruginosa isolates, inhibiting 91.7% at an MIC of ≤4 mg/L. P. aeruginosa exhibited high rates of resistance to cefepime (20.6%), ceftazidime (23.1%), meropenem (9.0%) and piperacillin/tazobactam (26.9%) (EUCAST criteria). Among these four P. aeruginosa resistant phenotypes, 61.3%-70.4% were susceptible to ceftolozane/tazobactam. Ceftolozane/tazobactam was the most active β-lactam agent tested against P. aeruginosa and demonstrated higher in vitro activity than currently available cephalosporins and piperacillin/tazobactam when tested against Enterobacteriaceae. © The Author 2017. Published by

Genomic and Molecular Characterization of Clinical Isolates of Enterobacteriaceae Harboring mcr-1 in Colombia, 2002 to 2016.

PubMed

Saavedra, Sandra Yamile; Diaz, Lorena; Wiesner, Magdalena; Correa, Adriana; Arévalo, Stefany Alejandra; Reyes, Jinnethe; Hidalgo, Andrea Melissa; de la Cadena, Elsa; Perenguez, Marcela; Montaño, Lucy Angeline; Ardila, Javier; Ríos, Rafael; Ovalle, María Victoria; Díaz, Paula; Porras, Paola; Villegas, Maria V; Arias, Cesar A; Beltrán, Mauricio; Duarte, Carolina

2017-12-01

Polymyxins are last-resort antimicrobial agents used to treat infections caused by carbapenem-resistant Enterobacteriaceae Due to the worldwide dissemination of polymyxin resistance in animal and human isolates, we aimed to characterize polymyxin resistance associated with the presence of mcr-1 in Enterobacteriaceae and nonfermenter Gram-negative bacilli, using isolates collected retrospectively in Colombia from 2002 to 2016. A total of 5,887 Gram-negative clinical isolates were studied, and 513 were found to be resistant to the polymyxins. Susceptibility to colistin was confirmed by broth microdilution for all mcr-1 -positive isolates, and these were further subjected to whole-genome sequencing (WGS). The localization of mcr-1 was confirmed by S1 pulsed-field gel electrophoresis (S1-PFGE) and CeuI-PFGE hybridization. Transferability was evaluated by mating assays. A total of 12 colistin-resistant isolates recovered after 2013 harbored mcr-1 , including 8 Escherichia coli , 3 Salmonella enterica serovar Typhimurium, and 1 Klebsiella pneumoniae isolate . E. coli isolates were unrelated by PFGE and belonged to 7 different sequence types (STs) and phylogroups. S Typhimurium and K. pneumoniae isolates belonged to ST34 and ST307, respectively. The mcr-1 gene was plasmid borne in all isolates but two E. coli isolates which harbored it on the chromosome. Conjugation of mcr-1 was successful in 8 of 10 isolates (8.2 × 10 -5 to 2.07 × 10 -1 cell per recipient). Plasmid sequences showed that the mcr-1 plasmids belonged to four different Inc groups (a new IncP-1 variant and the IncFII, IncHI1, and IncH families). Our results indicate that mcr-1 is circulating in clinical isolates of colistin-resistant Enterobacteriaceae in Colombia and is mainly harbored in transferable plasmids. Copyright © 2017 American Society for Microbiology.

Genomic and Molecular Characterization of Clinical Isolates of Enterobacteriaceae Harboring mcr-1 in Colombia, 2002 to 2016

PubMed Central

Diaz, Lorena; Wiesner, Magdalena; Correa, Adriana; Arévalo, Stefany Alejandra; Reyes, Jinnethe; Hidalgo, Andrea Melissa; de la Cadena, Elsa; Perenguez, Marcela; Montaño, Lucy Angeline; Ardila, Javier; Ríos, Rafael; Ovalle, María Victoria; Díaz, Paula; Porras, Paola; Villegas, Maria V.; Arias, Cesar A.; Beltrán, Mauricio

2017-01-01

ABSTRACT Polymyxins are last-resort antimicrobial agents used to treat infections caused by carbapenem-resistant Enterobacteriaceae. Due to the worldwide dissemination of polymyxin resistance in animal and human isolates, we aimed to characterize polymyxin resistance associated with the presence of mcr-1 in Enterobacteriaceae and nonfermenter Gram-negative bacilli, using isolates collected retrospectively in Colombia from 2002 to 2016. A total of 5,887 Gram-negative clinical isolates were studied, and 513 were found to be resistant to the polymyxins. Susceptibility to colistin was confirmed by broth microdilution for all mcr-1-positive isolates, and these were further subjected to whole-genome sequencing (WGS). The localization of mcr-1 was confirmed by S1 pulsed-field gel electrophoresis (S1-PFGE) and CeuI-PFGE hybridization. Transferability was evaluated by mating assays. A total of 12 colistin-resistant isolates recovered after 2013 harbored mcr-1, including 8 Escherichia coli, 3 Salmonella enterica serovar Typhimurium, and 1 Klebsiella pneumoniae isolate. E. coli isolates were unrelated by PFGE and belonged to 7 different sequence types (STs) and phylogroups. S. Typhimurium and K. pneumoniae isolates belonged to ST34 and ST307, respectively. The mcr-1 gene was plasmid borne in all isolates but two E. coli isolates which harbored it on the chromosome. Conjugation of mcr-1 was successful in 8 of 10 isolates (8.2 × 10−5 to 2.07 × 10−1 cell per recipient). Plasmid sequences showed that the mcr-1 plasmids belonged to four different Inc groups (a new IncP-1 variant and the IncFII, IncHI1, and IncH families). Our results indicate that mcr-1 is circulating in clinical isolates of colistin-resistant Enterobacteriaceae in Colombia and is mainly harbored in transferable plasmids. PMID:28893788

Extended-Spectrum-β-Lactamase-Producing Enterobacteriaceae Isolated from Vegetables Imported from the Dominican Republic, India, Thailand, and Vietnam

PubMed Central

Zurfluh, Katrin; Nüesch-Inderbinen, Magdalena; Morach, Marina; Zihler Berner, Annina; Hächler, Herbert

2015-01-01

To examine to what extent fresh vegetables imported into Switzerland represent carriers of extended-spectrum-β-lactamase (ESBL)-producing Enterobacteriaceae, 169 samples of different types of fresh vegetables imported into Switzerland from the Dominican Republic, India, Thailand, and Vietnam were analyzed. Overall, 25.4% of the vegetable samples yielded one or more ESBL-producing Enterobacteriaceae, 78.3% of which were multidrug resistant. Sixty isolates were obtained: Escherichia coli, 26; Klebsiella pneumoniae, 26; Enterobacter cloacae, 6; Enterobacter aerogenes, 1; and Cronobacter sakazakii, 1. We found 29 isolates producing CTX-M-15, 8 producing CTX-M-14, 7 producing CTX-M-55, 3 producing CTX-M-65, 1 each producing CTX-M-1, CTX-M-3, CTX-M-27, and CTX-M-63, 5 producing SHV-2, 3 producing SHV-12, and 1 producing SHV-2a. Four of the E. coli isolates belonged to epidemiologically important clones: CTX-M-15-producing B2:ST131 (1 isolate), D:ST405 (1 isolate), and D:ST38 (2 isolates). One of the D:ST38 isolates belonged to the extraintestinal enteroaggregative E. coli (EAEC) D:ST38 lineage. Two of the K. pneumoniae isolates belonged to the epidemic clones sequence type 15 (ST15) and ST147. The occurrence of antibiotic-resistant pathogenic and commensal Enterobacteriaceae in imported agricultural foodstuffs constitutes a source of ESBL genes and a concern for food safety. PMID:25724954

Prevalence of Antibiotic-resistance Enterobacteriaceae strains Isolated from Chicken Meat at Traditional Markets in Surabaya, Indonesia

NASA Astrophysics Data System (ADS)

Yulistiani, R.; Praseptiangga, D.; Supyani; Sudibya; Raharjo, D.; Shirakawa, T.

2017-04-01

Antibiotic resistance in bacteria from the family Enterobacteriaceae is an important indicator of the emergence of resistant bacterial strains in the community. This study investigated the prevalence of antibiotic-resistant Enterobacteriaceae isolated from chicken meat sold at traditional markets in Surabaya Indonesia. In all, 203 isolates (43 Salmonella spp., 53 Escherichia coli, 16 Shigella spp., 22 Citrobacter spp., 13 Klebsiella spp, 24 Proteus spp., 15 Yersinia spp., 7 Enterobacter spp., 6 Serratia spp., 3 Edwardsiella spp. were resistant to tetracycline (69.95 %), nalidixid acid (54.19 %), sulfamethoxazole/sulfamethizole (42.36 %), chloramphenicol (12.81%), cefoxitin (6.40 %), gentamicin (5.91 %). Tetracycline was the antimicrobial that showed the highest frequency of resistance among Salmonella, E. coli, Citrobacter, Proteus and Erdwardsiella isolates, and nalidixid acid was second frequency of resistance. Overall, 124 (61.08 %) out of 203 isolates demonstrated multidrug resistance to at least two unrelated antimicrobial agents. The high rate of antimicrobial resistance in bacterial isolates from chicken meat may have major implications for human and animal health with adverse economic implications.

High prevalence of extended-spectrum ß-lactamase producing enterobacteriaceae among clinical isolates in Burkina Faso.

PubMed

Ouedraogo, Abdoul-Salam; Sanou, Mahamadou; Kissou, Aimée; Sanou, Soufiane; Solaré, Hermann; Kaboré, Firmin; Poda, Armel; Aberkane, Salim; Bouzinbi, Nicolas; Sano, Idrissa; Nacro, Boubacar; Sangaré, Lassana; Carrière, Christian; Decré, Dominique; Ouégraogo, Rasmata; Jean-Pierre, Hélène; Godreuil, Sylvain

2016-07-11

Nothing is known about the epidemiology and resistance mechanisms of extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-PE) in Burkina Faso. The objective of this study was to determine ESBL-PE prevalence and to characterize ESBL genes in Burkina Faso. During 2 months (June-July 2014), 1602 clinical samples were sent for bacteriologic investigations to the microbiology laboratories of the tree main hospitals of Burkina Faso. Isolates were identified by mass spectrometry using a matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) BioTyper. Antibiotic susceptibility was tested using the disk diffusion method on Müller-Hinton agar. The different ESBL genes in potential ESBL-producing isolates were detected by PCR and double stranded DNA sequencing. Escherichia coli phylogenetic groups were determined using a PCR-based method. ESBL-PE frequency was 58 % (179 strains among the 308 Enterobacteriaceae isolates identified in the collected samples; 45 % in outpatients and 70 % in hospitalized patients). The CTX-M-1 group was dominant (94 %, CTX-M-15 enzyme), followed by the CTX-M-9 group (4 %). ESBL producers were more often found in E. coli (67.5 %) and Klebsiella pneumoniae (26 %) isolates. E. coli isolates (n = 202; 60 % of all Enterobacteriaceae samples) were distributed in eight phylogenetic groups (A = 49, B1 = 15, B2 = 43, C = 22, Clade I = 7, D = 37, F = 13 and 16 unknown); 22 strains belonged to the sequence type ST131. No association between a specific strain and ESBL production was detected. This report shows the alarming spread of ESBL genes in Burkina Faso. Public health efforts should focus on education (population and healthcare professionals), surveillance and promotion of correct and restricted antibiotic use to limit their dissemination.

In Vitro Activity of Plazomicin against Gram-Negative and Gram-Positive Isolates Collected from United States Hospitals and Comparative Activity of Aminoglycosides against Carbapenem-Resistant Enterobacteriaceae and Isolates Carrying Carbapenemase Genes.

PubMed

Castanheira, Mariana; Davis, Andrew P; Mendes, Rodrigo E; Serio, Alisa W; Krause, Kevin M; Flamm, Robert K

2018-06-04

Plazomicin and comparators agents were tested using the CLSI reference broth microdilution method against 4,825 clinical isolates collected during 2014 and 2015 in 70 United States hospitals as part of the ALERT (Antimicrobial Longitudinal Evaluation and Resistance Trends) program. Plazomicin (MIC 50/90 , 0.5/2 μg/ml) inhibited 99.2% of 4,362 Enterobacteriaceae at ≤4 μg/ml. Amikacin, gentamicin, and tobramycin inhibited 98.9%, 90.3%, and 90.3% of these isolates, respectively, applying CLSI breakpoints. The activity of plazomicin was similar among Enterobacteriaceae species with MIC 50 values ranging from 0.25 to 1 μg/ml, with exception of Proteus mirabilis and indole-positive Proteaee that displayed MIC 50 values of 2 μg/ml. Against 97 carbapenem-resistant Enterobacteriaceae (CRE) that included 87 isolates carrying bla KPC , plazomicin inhibited all but 1 isolate at ≤2 μg/ml (99.0% and 98.9%, respectively). Amikacin and gentamicin inhibited 64.9% and 56.7% of the CRE isolates at the respective CLSI breakpoints. Plazomicin inhibited 96.5/95.5% of the gentamicin-resistant, 96.9/96.5% of the tobramycin-resistant and 64.3/90.0% of the amikacin-resistant isolates using CLSI/EUCAST breakpoints. The activity of plazomicin against Pseudomonas aeruginosa (MIC 50/90 , 4/16 μg/ml) and Acinetobacter spp. (MIC 50/90 , 2/16 μg/ml) isolates was similar. Plazomicin was active against coagulase-negative staphylococci (MIC 50/90 , 0.12/0.5 μg/ml) and Staphylococcus aureus (MIC 50/90 , 0.5/0.5 μg/ml), but had limited activity against Enterococcus spp. (MIC 50/90 , 16/64 μg/ml) and Streptococcus pneumoniae (MIC 50/90 , 32/64 μg/ml). Plazomicin activity against the Enterobacteriaceae tested, including CRE and isolates carrying bla KPC from U.S. hospitals, support the development plan for plazomicin to treat serious infections caused by resistant Enterobacteriaceae in patients with limited treatment options. Copyright © 2018 American Society for Microbiology.

Pattern of Antibiotic Resistance Among Community Derived Isolates of Enterobacteriaceae Using Urine Sample: A Study From Northern India

PubMed Central

Lohiya, Ayush; Kapil, Arti; Gupta, Sanjeev Kumar; Misra, Puneet; Rai, Sanjay K.

2015-01-01

Background Despite world-wide evidence of increased antibiotic resistance, there is scarce data on antibiotic resistance in community settings. One of the reason being difficulty in collection of biological specimen (traditionally stool) in community from apparently healthy individuals. Hence, finding an alternative specimen that is easier to obtain in a community setting or in large scale surveys for the purpose, is crucial. We conducted this study to explore the feasibility of using urine samples for deriving community based estimates of antibiotic resistance and to estimate the magnitude of resistance among urinary isolates of Escherichia coli and Klebsiella pneumonia against multiple antibiotics in apparently healthy individuals residing in a rural community of Haryana, North India. Materials and Methods Eligible individuals were apparently healthy, aged 18 years or older. Using the health management information system (HMIS) of Ballabgarh Health Demographic Surveillance System (HDSS), sampling frame was prepared. Potential individuals were identified using simple random sampling. Random urine sample was collected in a sterile container and transported to laboratory under ambient condition. Species identification and antibiotic susceptibility testing for Enterobacteriaceae was done using Clinical Laboratory and Standards Institute (CLSI) 2012 guidelines. Multi-drug resistant (MDR) Enterobacteriaceae, Extended Spectrum Beta Lactamase (ESBL) producing Enterobacteriaceae, and Carbapenem producing Enterobacteriaceae (CRE) were identified from the urine samples. Results A total of 433 individuals participated in the study (non-response rate – 13.4%), out of which 58 (13.4%) were positive for Enterobacteriaceae, 8.1% for E. coli and 5.3% for K. pneumoniae. Resistance against penicillin (amoxicillin/ampicillin) for E. coli and K. pneumoniae was 62.8% and 100.0% respectively. Isolates resistant to co-trimoxazole were 5.7% and 0.0% respectively. None of the isolates

Low Prevalence of carbapenem-resistant Enterobacteriaceae among wounded military personnel.

PubMed

Mende, Katrin; Beckius, Miriam L; Zera, Wendy C; Onmus-Leone, Fatma; Murray, Clinton K; Tribble, David R

2017-01-01

Multidrug-resistant organisms (MDROs) are a global health problem that affect both civilian and military populations. Among wounded warriors, MDROs further complicate the care of trauma-related infections, resulting in extended duration of hospitalization, as well as increased morbidity and mortality. During the wars in Iraq and Afghanistan, extended spectrum β-lactamase-producing Enterobacteriaceae were frequently isolated from wounded warriors. The potential emergence of difficult-to-treat carbapenem-resistant Enterobacteriaceae represented a serious challenge for clinicians. We examined carbapenem-resistant Enterobacteriaceae prevalence among wounded military personnel over a 6-year period (2009-2015). Among 4090 Enterobacteriaceae isolates collected, 16 (0.4%) were carbapenem-resistant, of which the majority was Enterobacter aerogenes (44%) followed by Klebsiella pneumoniae (37%), and Escherichia coli (19%). Five isolates (31%) collected from 2 patients were carbapenemase-producers with one associated with an infection. All 5 carbapenemase-producing isolates were resistant to all tested carbapenems and each carried one carbapenemase gene (4 with blaKPC-3 and 1 with blaNDM-1). Overall, although a large number of Enterobacteriaceae isolates were collected, only a small proportion was carbapenem-resistant and data indicate a lack of a cluster. Due to these limited numbers, it is difficult to make any conclusions regarding the association between carbapenem resistance, antibiotic exposure, and clinical outcomes.

Antimicrobial susceptibility patterns of enterobacteriaceae isolated from HIV-infected patients in Kinshasa.

PubMed

Iyamba, Jean-Marie Liesse; Wambale, José Mulwahali; Takaisi-Kikuni, Ntondo Za Balega

2014-01-01

People infected by Human Immunodeficiency Virus (HIV) are susceptible to develop severe bacterial infections. We set out to determine the frequency and the sensitivity to antibiotics of enterobaceriaceae isolated from urine and feces of HIV-infected persons. Urine and feces samples were collected from HIV-infected patients of the Centre de Traitement Ambulatoire de Kabinda (CTA/Kabinda, Kinshasa) and analyzed at the Reference National Laboratory for HIV/AIDS and Sexually Transmitted Infections. The isolated enterobacteriaceae strains were identified by conventional microbiological methods. Antibiotic sensitivity pattern was carried out by disc diffusion method. THE FOLLOWING BACTERIA PATHOGENS WERE ISOLATED: Escherichia coli, Klebsiella, Enterobacter, Proteus, and Providencia. Most species were sensitive to cefotaxim, ceftriaxon, and gentamicin and resistant to chloramphenicol, cotrimoxazole, tetracycline, and norfloxacin. The results of the present study show that the most frequently bacteria isolated were Esherichia coli and cefotaxim, ceftriaxon, and gentamicin were the most active antibiotics.

[Rapid test for detection of susceptibility to cefotaxime in Enterobacteriaceae].

PubMed

Jiménez-Guerra, Gemma; Hoyos-Mallecot, Yannik; Rodríguez-Granger, Javier; Navarro-Marí, José María; Gutiérrez-Fernández, José

In this work an "in house" rapid test based on the change in pH that is due to hydrolysis for detecting Enterobacteriaceae susceptible to cefotaxime is evaluated. The strains of Enterobacteriaceae from 1947 urine cultures were assessed using MicroScan panels and the "in house" test. This rapid test includes red phenol solution and cefotaxime. Using MicroScan panels, 499 Enterobacteriaceae isolates were evaluated, which included 27 isolates of Escherichia coli producing extended-spectrum beta-lactamases (ESBL), 16 isolates of Klebsiella pneumoniae ESBL and 1 isolate of Klebsiella oxytoca ESBL. The "in house" test offers the following values: sensitivity 98% and specificity 97%, with negative predictive value 100% and positive predictive value 78%. The "in house" test based on the change of pH is useful in our area for detecting presumptively cefotaxime-resistant Enterobacteriaceae strains. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Combination of multilocus sequence typing and pulsed-field gel electrophoresis reveals an association of molecular clonality with the emergence of extensive-drug resistance (XDR) in Salmonella.

PubMed

Cao, Yongzhong; Shen, Yongxiu; Cheng, Lingling; Zhang, Xiaorong; Wang, Chao; Wang, Yan; Zhou, Xiaohui; Chao, Guoxiang; Wu, Yantao

2018-03-01

Salmonellae is one of the most important foodborne pathogens and becomes resistant to multiple antibiotics, which represents a significant challenge to food industry and public health. However, a molecular signature that can be used to distinguish antimicrobial resistance profile, particularly multi-drug resistance or extensive-drug resistance (XDR). In the current study, 168 isolates from the chicken and pork production chains and ill chickens were characterized by serotyping, antimicrobial susceptibility test, multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). The results showed that these isolates belonged to 13 serotypes, 14 multilocus sequence types (STs), 94 PFGE genotypes, and 70 antimicrobial resistant profiles. S. Enteritidis, S. Indiana, and S. Derby were the predominant serotypes, corresponding to the ST11, ST17, and ST40 clones, respectively and the PFGE Cluster A, Cluster E, and Cluster D, respectively. Among the ST11-S. Enteritidis (Cluster A) and the ST40-S. Derby (Cluster D) clones, the majority of isolates were resistant to 4-8 antimicrobial agents, whereas in the ST17S. Indiana (Cluster E) clone, isolates showed extensive-drug resistance (XDR) to 9-16 antimicrobial agents. The bla TEM-1-like gene was prevalent in the ST11 and ST17 clones corresponding to high ampicillin resistance. The bla TEM-1-like , bla CTX-M , bla OXA-1-like , sul1, aaC4, aac(6')-1b, dfrA17, and floR gene complex was highly prevalent among isolates of ST17, corresponding to an XDR phenotype. These results demonstrated the association of the resistant phenotypes and genotypes with ST clone and PFGE cluster. Our results also indicated that the newly identified gene complex comprising bla TEM-1-like , bla CTX-M , bla OXA-1-like , sul1, aaC4, aac(6')-1b, dfrA17, and floR, was responsible for the emergence of the ST17S. Indiana XDR clone. ST17 could be potentially used as a molecular signature to distinguish S. Indiana XDR clone. Copyright © 2017

Characterization of Plasmid-Mediated Quinolone Resistance Determinants in High-Level Quinolone-Resistant Enterobacteriaceae Isolates from the Community: First Report of qnrD Gene in Algeria.

PubMed

Yanat, Betitera; Machuca, Jesús; Díaz-De-Alba, Paula; Mezhoud, Halima; Touati, Abdelaziz; Pascual, Álvaro; Rodríguez-Martínez, José-Manuel

2017-01-01

The objective was to assess the prevalence of plasmid-mediated quinolone resistance (PMQR)-producing isolates in a collection of quinolone-resistant Enterobacteriaceae of community origin isolated in Bejaia, Algeria. A total of 141 nalidixic acid-resistant Enterobacteriaceae community isolates were collected in Bejaia (Northern Algeria) and screened for PMQR genes using polymerase chain reaction (PCR). For PMQR-positive strains, antimicrobial susceptibility testing was performed by broth microdilution and disk diffusion. Mutations in the quinolone resistance-determining regions of the target genes, gyrA and parC, were detected with a PCR-based method and sequencing. Southern blotting, conjugation and transformation assays and molecular typing by pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing were also performed. The prevalence of PMQR-producing Enterobacteriaceae isolates was 13.5% (19/141); 11 of these isolates produced Aac(6')-Ib-cr and 8 were qnr-positive (4 qnrB1-like, 2 qnrS1-like, and 2 qnrD1-like), including the association with aac(6')-Ib-cr gene in three cases. PMQR gene transfer by conjugation was successful in 6 of 19 isolates tested. PFGE revealed that most of the PMQR-positive Escherichia coli isolates were unrelated, except for two groups comprising two and four isolates, respectively, including the virulent multidrug-resistant clone E. coli ST131 that were clonally related. Our findings indicate that PMQR determinants are prevalent in Enterobacteriaceae isolates from the community studied. We describe the first report of the qnrD gene in Algeria.

In Vitro Activity of Imipenem against Carbapenemase-Positive Enterobacteriaceae Isolates Collected by the SMART Global Surveillance Program from 2008 to 2014

PubMed Central

Karlowsky, James A.; Kazmierczak, Krystyna M.; Badal, Robert E.; Young, Katherine; Motyl, Mary R.; Sahm, Daniel F.

2017-01-01

ABSTRACT The Study for Monitoring Antimicrobial Resistance Trends (SMART) global surveillance program collected 103,960 isolates of Enterobacteriaceae from 2008 to 2014. From this isolate collection, all ertapenem-nonsusceptible isolates (MIC, ≥1 μg/ml; n = 3,428) and 9,371 isolates of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, and Proteus mirabilis with an ertapenem-susceptible extended-spectrum-β-lactamase (ESBL)-positive phenotype were assessed for the presence of common carbapenemase genes using a Check-MDR CT101 microarray (Check-Points, Wageningen, the Netherlands) and published multiplex PCR assays. Testing identified 1,493 isolates that harbored a carbapenemase gene (1,485 ertapenem-nonsusceptible isolates and 8 ertapenem-susceptible ESBL-positive isolates) and accounted for 1.4% (1,493/103,960) of all isolates of Enterobacteriaceae. The most frequently identified carbapenemase genes were the KPC (n = 794), OXA-48-like (n = 300), and NDM (n = 290) genes. Carbapenemase genes were most frequently identified in Klebsiella pneumoniae (n = 1,127), Escherichia coli (n = 149), and Enterobacter cloacae (n = 110). Among the carbapenemase-positive isolates, 66.7% (2/3), 37.0% (111/300), 20.0% (8/40), 3.3% (3/92), 2.3% (18/794), and 0% (0/290) of the isolates with genes for GES, OXA-48-like, IMP, VIM, KPC, and NDM, respectively, were susceptible to imipenem (MIC, ≤1 μg/ml). Isolates that tested as susceptible to imipenem were not uncommon among carbapenemase-positive isolates (9.4%, 141/1,493) and most frequently carried OXA-48-like enzymes (78.7%; 111/141); however, overall, these isolates remained rare (0.1%, 141/103,960). The practice of screening clinical isolates of Enterobacteriaceae that test as susceptible to carbapenems in vitro for the presence of carbapenemase genes remains controversial and requires further study. PMID:28298454

In Vitro Activity of Imipenem against Carbapenemase-Positive Enterobacteriaceae Isolates Collected by the SMART Global Surveillance Program from 2008 to 2014.

PubMed

Karlowsky, James A; Lob, Sibylle H; Kazmierczak, Krystyna M; Badal, Robert E; Young, Katherine; Motyl, Mary R; Sahm, Daniel F

2017-06-01

The Study for Monitoring Antimicrobial Resistance Trends (SMART) global surveillance program collected 103,960 isolates of Enterobacteriaceae from 2008 to 2014. From this isolate collection, all ertapenem-nonsusceptible isolates (MIC, ≥1 μg/ml; n = 3,428) and 9,371 isolates of Escherichia coli , Klebsiella pneumoniae , Klebsiella oxytoca , and Proteus mirabilis with an ertapenem-susceptible extended-spectrum-β-lactamase (ESBL)-positive phenotype were assessed for the presence of common carbapenemase genes using a Check-MDR CT101 microarray (Check-Points, Wageningen, the Netherlands) and published multiplex PCR assays. Testing identified 1,493 isolates that harbored a carbapenemase gene (1,485 ertapenem-nonsusceptible isolates and 8 ertapenem-susceptible ESBL-positive isolates) and accounted for 1.4% (1,493/103,960) of all isolates of Enterobacteriaceae The most frequently identified carbapenemase genes were the KPC ( n = 794), OXA-48-like ( n = 300), and NDM ( n = 290) genes. Carbapenemase genes were most frequently identified in Klebsiella pneumoniae ( n = 1,127), Escherichia coli ( n = 149), and Enterobacter cloacae ( n = 110). Among the carbapenemase-positive isolates, 66.7% (2/3), 37.0% (111/300), 20.0% (8/40), 3.3% (3/92), 2.3% (18/794), and 0% (0/290) of the isolates with genes for GES, OXA-48-like, IMP, VIM, KPC, and NDM, respectively, were susceptible to imipenem (MIC, ≤1 μg/ml). Isolates that tested as susceptible to imipenem were not uncommon among carbapenemase-positive isolates (9.4%, 141/1,493) and most frequently carried OXA-48-like enzymes (78.7%; 111/141); however, overall, these isolates remained rare (0.1%, 141/103,960). The practice of screening clinical isolates of Enterobacteriaceae that test as susceptible to carbapenems in vitro for the presence of carbapenemase genes remains controversial and requires further study. Copyright © 2017 American Society for Microbiology.

Enterobacteriaceae Isolated from the River Danube: Antibiotic Resistances, with a Focus on the Presence of ESBL and Carbapenemases.

PubMed

Kittinger, Clemens; Lipp, Michaela; Folli, Bettina; Kirschner, Alexander; Baumert, Rita; Galler, Herbert; Grisold, Andrea J; Luxner, Josefa; Weissenbacher, Melanie; Farnleitner, Andreas H; Zarfel, Gernot

2016-01-01

In a clinical setting it seems to be normal these days that a relevant proportion or even the majority of different bacterial species has already one or more acquired antibiotic resistances. Unfortunately, the overuse of antibiotics for livestock breeding and medicine has also altered the wild-type resistance profiles of many bacterial species in different environmental settings. As a matter of fact, getting in contact with resistant bacteria is no longer restricted to hospitals. Beside food and food production, the aquatic environment might also play an important role as reservoir and carrier. The aim of this study was the assessment of the resistance patterns of Escherichia coli and Klebsiella spp. out of surface water without prior enrichment and under non-selective culture conditions (for antibiotic resistance). In addition, the presence of clinically important extended spectrum beta lactamase (ESBL) and carbapenmase harboring Enterobacteriaceae should be investigated. During Joint Danube Survey 3 (2013), water samples were taken over the total course of the River Danube. Resistance testing was performed for 21 different antibiotics. Samples were additionally screened for ESBL or carbapenmase harboring Enterobacteriaceae. 39% of all isolated Escherichia coli and 15% of all Klebsiella spp. from the river Danube had at least one acquired resistance. Resistance was found against all tested antibiotics except tigecycline. Taking a look on the whole stretch of the River Danube the proportion of multiresistances did not differ significantly. In total, 35 ESBL harboring Enterobacteriaceae, 17 Escherichia coli, 13 Klebsiella pneumoniae and five Enterobacter spp. were isolated. One Klebsiella pneumoniae harboring NMD-1 carbapenmases and two Enterobacteriaceae with KPC-2 could be identified. Human generated antibiotic resistance is very common in E. coli and Klebsiella spp. in the River Danube. Even isolates with resistance patterns normally associated with intensive

Identification and characterization of potential druggable targets among hypothetical proteins of extensively drug resistant Mycobacterium tuberculosis (XDR KZN 605) through subtractive genomics approach.

PubMed

Uddin, Reaz; Siddiqui, Quratulain Nehal; Azam, Syed Sikander; Saima, Bibi; Wadood, Abdul

2018-03-01

Among the resistant isolates of tuberculosis (TB), the multidrug resistance tuberculosis (MDR-TB) and extensively drug resistant tuberculosis (XDR-TB) are the areas of growing concern for which the front-line antibiotics are no more effective. As a result, the search of new therapeutic targets against TB is an imperative need of time. On the other hand, the target identification is an a priori step in drug discovery based research. Furthermore, the availability of the complete proteomic data of extensively drug resistant Mycobacterium tuberculosis (XDR-MTB) made it possible to carry out in silico analysis for the discovery of new drug targets. In the current study, we aimed to prioritize the potential drug targets among the hypothetical proteins of XDR-TB via subtractive genomics approach. In the subtractive genomics, we stepwise reduced the complete proteome of XDR-MTB to only two hypothetical proteins and evidently proposed them as new therapeutic targets. The 3D structure of one of the two target proteins was predicted via homology modeling and later on, validated by various analysis tools. Our study suggested that the domains identified and the motif hits found in the sequences of the shortlisted drug targets are crucial for the survival of the XDR-MTB. To the best of our knowledge, the current study is the first attempt in which the complete proteomic data of XDR-MTB was subjected to the computational subtractive genomics approach and therefore, would provide an opportunity to identify the unique therapeutic targets against deadly XDR-MTB. Copyright © 2017 Elsevier B.V. All rights reserved.

Emergence of blaNDM-7-Producing Enterobacteriaceae in Gabon, 2016.

PubMed

Moussounda, Mesmin; Diene, Seydina M; Dos Santos, Sandra; Goudeau, Alain; François, Patrice; van der Mee-Marquet, Nathalie

2017-02-01

Reports of carbapenemase-producing Enterobacteriaceae in Africa remain rare and assess mostly bla OXA-48 -producing isolates from Mediterranean countries and South Africa. We identified bla NDM-7 -producing Enterobacteriaceae in Gabon in 2016. The isolates contained bla NDM-7 IncX3 plasmids that were unusual and similar to the one described in a colistin-resistant Klebsiella pneumoniae SZ04 isolate from China.

Do bacteria isolated from ICU patients 'ESKAPE' antibiotic treatment? In vitro susceptibility of the Enterobacteriaceae family to tigecycline.

PubMed

Talaga-Ćwiertnia, Katarzyna; Krzyściak, Paweł; Bulanda, Małgorzata

2017-01-01

Enterobacteriaceae are currently causing the majority of healthcare-associated infections (HAI) and simultaneously expressing increasing levels of antibiotic resistance. The purpose of this study is to assess the in vitro sensitivity of MDR strains from the family Enterobacteriaceae to tigecycline in relation to their origin from patients hospitalized in intensive care units (ICUs) and non-ICUs. The study involved 156 clinically significant strains of the Enterobacteriaceae family isolated from patients with complicated intraabdominal infections (cIAIs) and/or complicated skin and skin structure infections (cSSSIs) hospitalized in ICUs and other surgical departments. Tigecycline MICs were determined by Etest. The highest percentage of tigecycline non-susceptible (intermediate + resistant strains) in vitro strains among the Enterobacteriaceae species were observed for Serratia spp. 77.3%, followed by Citrobacter spp. (76.9%) and Enterobacter spp. (70%); whereas K. pneumoniae and E. coli showed 73-73.8% tigecycline susceptibility rates. Tigecycline demonstrates a high level of antimicrobial in vitro activity when tested against E. coli and K. pneumoniae, even those with the ESBL-phenotype. Tigecycline retained activity against merely 22-30% of Enterobacter, Citrobacter and Serratia genera.

Occurrence of Carbapenemase-Producing Enterobacteriaceae Isolates in the Wildlife: First Report of OXA-48 in Wild Boars in Algeria.

PubMed

Bachiri, Taous; Bakour, Sofiane; Lalaoui, Rym; Belkebla, Nadia; Allouache, Meriem; Rolain, Jean Marc; Touati, Abdelaziz

2018-04-01

The aim of the present study was to screen for the presence of carbapenemase-producing Enterobacteriaceae (CPE) isolates from wild boars and Barbary macaques in Algeria. Fecal samples were collected from wild boars (n = 168) and Barbary macaques (n = 212), in Bejaia, Algeria, between September 2014 and April 2016. The isolates were identified and antimicrobial susceptibility was determined. Carbapenem resistance determinants were studied using PCR and sequencing, while clonal relatedness was performed using multilocus sequence typing (MLST). PCR was used to investigate certain virulence genes. Three CPE isolates from three different samples (1.8%) recovered from wild boars were identified as Escherichia coli (two isolates) and Klebsiella pneumoniae (one isolate). These isolates were resistant to amoxicillin, amoxicillin-clavulanate, tobramycin, ertapenem, and meropenem. The results of PCR and sequencing analysis showed that all three isolates produced the OXA-48 enzyme. The MLST showed that the two E. coli isolates were assigned to the same sequence type, ST635, and belonged to phylogroup A, whereas K. pneumoniae strain belonged to ST13. The K. pneumoniae strain was positive for multiple virulence factors, whereas no virulence determinants were found in E. coli isolates. This is the first report of OXA-48-producing Enterobacteriaceae in wild animals from Algeria and Africa.

Emerging Perils of Extended Spectrum β-Lactamase Producing Enterobacteriaceae Clinical Isolates in a Teaching Hospital of Nepal.

PubMed

Parajuli, Narayan Prasad; Maharjan, Pooja; Joshi, Govardhan; Khanal, Puspa Raj

2016-01-01

Introduction . Infections due to extended spectrum β -lactamase producing Enterobacteriaceae are on the rise. They pose serious public health problems due to their resistance to large number of antibiotics. However, little is known about the genotypes of ESBL from Nepal. Therefore, the study presents results of phenotypic and molecular characterization of ESBL producing Escherichia coli and Klebsiella spp. isolated from various clinical specimens in a tertiary care teaching hospital of Nepal. Methods . A total of 172 Enterobacteriaceae clinical isolates recovered from various clinical specimens were analyzed for their antibiotic susceptibility test. Detection of ESBLs was carried out using combination disk test and multiplex PCR for their genotypes (CTX-M, SHV, and TEM). Results . Out of 172 clinical isolates, 70 (40.6%) of them were found ESBL producers. The major source of ESBL producers was urinary tract samples and the highest ESBL production was observed in Escherichia coli (46.5%). Among ESBL genotypes, CTX-M (91.4%) was most predominant, followed by TEM (65.7%) and SHV (11.4%) in both of the isolates. Conclusions . High level of drug resistance and ESBL production was observed among the clinical isolates. There is a need for longitudinal and nationwide surveillance for drug resistance in clinical isolates and antimicrobial stewardship is necessary to guide the appropriate and judicious antibiotic use.

Unusual association of NDM-1 with KPC-2 and armA among Brazilian Enterobacteriaceae isolates

PubMed Central

Quiles, M.G.; Rocchetti, T.T.; Fehlberg, L.C.; Kusano, E.J.U.; Chebabo, A.; Pereira, R.M.G.; Gales, A.C.; Pignatari, A.C.C.

2014-01-01

We report the microbiological characterization of four New Delhi metallo-β-lactamase-1 (bla NDM-1)-producing Enterobacteriaceae isolated in Rio de Janeiro, Brazil. bla NDM-1 was located on a conjugative plasmid and was associated with Klebsiella pneumoniae carbapenemase-2 (bla KPC-2) or aminoglycoside-resistance methylase (armA), a 16S rRNA methylase not previously reported in Brazil, in two distinct strains of Enterobacter cloacae. Our results suggested that the introduction of bla NDM-1 in Brazil has been accompanied by rapid spread, since our isolates showed no genetic relationship. PMID:25466163

Molecular characterization of multidrug-resistant extended-spectrum β-lactamase-producing Enterobacteriaceae isolated in Antananarivo, Madagascar

PubMed Central

2013-01-01

Background We investigated the molecular characteristics of multidrug-resistant, extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae isolated in community settings and in hospitals in Antananarivo, Madagascar. Results Forty-nine E. coli, K. pneumoniae, K. oxytoca and E. cloacae ESBL-producing isolates were studied. In antimicrobial susceptibility analyses, many of the isolates exhibited resistance to aminoglycosides, fluoroquinolones and trimethoprim-sulfamethoxazole. Gene amplification analysis and sequencing revealed that 75.5% (n=37) of the isolates harbored blaCTX-M-15 and 38.7% (n=19) harbored blaSHV-12. The non-ESBLs resistance genes detected were blaTEM-1, blaOXA-1, aac(6′)-Ib,aac(6′)-Ib-cr, tetA, sul-1, sul-2, qnrA, qnrB and catB-3. We found dfrA and aadA gene cassettes in the class 1 integron variable regions of the isolates, and the combination of dfrA17-aadA5 to be the most prevalent. All blaCTX-M-15 positive isolates also contained the ISEcp1 insertion element. Conjugation and transformation experiments indicated that 70.3% of the antibiotic resistance genes resided on plasmids. Through a PCR based replicon typing method, plasmids carrying the blaSHV-12 or blaCTX-M-15 genes were assigned to either the IncFII replicon type or, rarely, to the HI2 replicon type. All isolates were subtyped by the rep-PCR and ERIC-PCR methods. Phylogenetic grouping and virulence genotyping of the E. coli isolates revealed that most of them belonged to group A1. One isolate assigned to group B2 harbored blaCTX-M-15 and five virulence genes (traT, fyuA, iutA, iha and sfa) and was related to the O25b-ST131 clone. Conclusions Our results highlight the dissemination of multidrug resistant Enterobacteriaceae isolates in Antananarivo. These findings underline the need for a rational use of antibiotic and for appropriate methods of screening ESBL in routine laboratories in Antananarivo. PMID:23594374

Emergence of blaNDM-7–Producing Enterobacteriaceae in Gabon, 2016

PubMed Central

Moussounda, Mesmin; Diene, Seydina M.; Dos Santos, Sandra; Goudeau, Alain; van der Mee-Marquet, Nathalie

2017-01-01

Reports of carbapenemase-producing Enterobacteriaceae in Africa remain rare and assess mostly blaOXA-48–producing isolates from Mediterranean countries and South Africa. We identified blaNDM-7–producing Enterobacteriaceae in Gabon in 2016. The isolates contained blaNDM-7 IncX3 plasmids that were unusual and similar to the one described in a colistin-resistant Klebsiella pneumoniae SZ04 isolate from China. PMID:28098536

Multidrug-resistant Enterobacteriaceae from indoor air of an urban wastewater treatment plant.

PubMed

Teixeira, Juliana V; Cecílio, Pedro; Gonçalves, Daniela; Vilar, Vítor J P; Pinto, Eugénia; Ferreira, Helena N

2016-07-01

Wastewater treatment plants (WWTPs) have been recognized as sources of bioaerosols that may act as vehicles for dissemination of pathogens and multidrug-resistant (MDR) bacteria. The occurrence of MDR Enterobacteriaceae in indoor air of an urban WWTP was investigated. A possible airborne contamination with extended-spectrum beta-lactamase (ESBL) and carbapenemase-producing Enterobacteriaceae was also explored. Fourteen of 39 Enterobacteriaceae isolates were MDR. These isolates were found at all sampling sites, mainly at the secondary sedimentation settings. The highest levels of resistance were detected in three different species: Enterobacter cloacae, Escherichia coli, and Citrobacter freundii. Furthermore, one of the airborne E. coli isolates was phenotypically characterized as an ESBL producer. Additionally, five isolates showed non-susceptibility to at least one carbapenem tested. The presence of genes encoding relevant beta-lactamase types in these ESBL-producing and carbapenem-resistant Enterobacteriaceae isolates was investigated by PCR. Results showed amplification for bla CTX-M and bla OXA. These findings are relevant both in terms of occupational/public health and of environmental dissemination of MDR bacteria.

Distribution of Extended-Spectrum β-Lactamases, AmpC β-Lactamases, and Carbapenemases among Enterobacteriaceae Isolates Causing Intra-Abdominal Infections in the Asia-Pacific Region: Results of the Study for Monitoring Antimicrobial Resistance Trends (SMART)

PubMed Central

Sheng, Wang-Huei; Badal, Robert E.

2013-01-01

The increasing trend of β-lactam resistance among Enterobacteriaceae is a worldwide threat. Enterobacteriaceae isolates causing intra-abdominal infections (IAI) from the Study for Monitoring Antimicrobial Resistance Trends (SMART) collected in 2008 and 2009 from the Asia-Pacific region were investigated. Detection of extended-spectrum β-lactamases (ESBLs), AmpC β-lactamases, and carbapenemases was performed by multiplex PCR. A total of 699 Enterobacteriaceae isolates with positive genotypic results, included Escherichia coli (n = 443), Klebsiella pneumoniae (n = 187), Enterobacter cloacae (n = 45), Klebsiella oxytoca (n = 9), Citrobacter freundii (n = 5), Proteus mirabilis (n = 3), Enterobacter aerogenes (n = 2), Morganella morganii (n = 2), and one each of Enterobacter asburiae, Proteus vulgaris, and Providencia rettgeri were analyzed. Nearly 20% of these β-lactamase-producing Enterobacteriaceae isolates were from community-associated IAI. CTX-M (588 isolates, including 428 [72.8%] with CTX-M-15) was the most common ESBL, followed by SHV (n = 59) and TEM (n = 4). CMY (n = 110, including 102 [92.7%] with CMY-2) was the most common AmpC β-lactamase, followed by DHA (n = 46) and ACT/MIR (n = 40). NDM (n = 65, including 62 [95.4%] with NDM-1) was the most common carbapenemase, followed by IMP (n = 7) and OXA (n = 7). Isolates from hospital-associated IAI had more complicated β-lactamase combinations than isolates from the community. Carbapenemases were all exclusively detected in Enterobacteriaceae isolates from India, except that IMP β-lactamases were also detected in Philippines and Australia. CTX-M β-lactamases were the predominant ESBLs produced by Enterobacteriaceae causing IAI in the Asia-Pacific region. Emergence of CTX-M-15-, CMY-2-, and NDM-1-producing Enterobacteriaceae isolates is of major concern and highlights the need for further surveillance in this area. PMID:23587958

Extensively Drug-Resistant Tuberculosis (XDR TB)

MedlinePlus

... TB Reference Laboratory Network, the National TB Surveillance System in the United States, the national reference laboratory of South Korea, and ... capacity in the U.S. and abroad; and Developing education, risk, and media communications ... – United States, 1993–2006 CDC. CDC’s Role in Preventing XDR ...

Low Frequency of Ceftazidime-Avibactam Resistance among Enterobacteriaceae Isolates Carrying blaKPC Collected in U.S. Hospitals from 2012 to 2015.

PubMed

Castanheira, Mariana; Mendes, Rodrigo E; Sader, Helio S

2017-03-01

Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae isolates have been increasingly reported worldwide, and therapeutic options to treat infections caused by these organisms are limited. We evaluated the activity of ceftazidime-avibactam and comparators against 456 Enterobacteriaceae isolates carrying bla KPC collected from 79 U.S. hospitals during 2012 to 2015. Overall, ceftazidime-avibactam (MIC 50/90 , 0.5/2 μg/ml; 99.3% susceptible) and tigecycline (MIC 50/90 , 0.5/1 μg/ml; 98.9% susceptible at ≤2 μg/ml) were the most active agents. Only 80.5% and 59.0% of isolates were susceptible to colistin and amikacin, respectively. All three isolates (0.7%) displaying resistance to ceftazidime-avibactam ( K. pneumoniae ; MICs, ≥16 μg/ml) were evaluated using whole-genome sequencing analysis and relative quantification of expression levels of porins and efflux pump. Two isolates carried metallo-β-lactamase genes, bla NDM-1 or bla VIM-4 , among other β-lactam resistance mechanisms, and one displayed a premature stop codon in ompK35 and decreased expression of ompK36 Ceftazidime-avibactam was active against 100.0 and 99.3% of isolates carrying bla KPC-3 ( n = 221) and bla KPC-2 ( n = 145), respectively. Isolates carrying bla KPC were more commonly recovered from pneumonia ( n = 155), urinary tract ( n = 93), and skin/soft tissue ( n = 74) infections. Ceftazidime-avibactam (97.8 to 100.0% susceptible) was consistently active against isolates from all infection sites. K. pneumoniae (83.3% of the collection) susceptibility rates were 99.2% for ceftazidime-avibactam, 98.9% for tigecycline, and 80.1% for colistin. Ceftazidime-avibactam susceptibility did not vary substantially when comparing isolates from intensive care unit (ICU) patients to those from non-ICU patients. Ceftazidime-avibactam was active against this large collection of isolates carrying bla KPC and represents a valuable addition to the armamentarium currently available for the

Occurrence of antibiotic resistance and characterization of resistant genes and integrons in Enterobacteriaceae isolated from integrated fish farms south China

USGS Publications Warehouse

Su, Hao-Chang; Ying, Guang-Guo; Tao, Ran; Zhang, Rui-Quan; Fogarty, Lisa R.; Kolpin, Dana W.

2011-01-01

Antibiotics are still widely applied in animal husbandry to prevent diseases and used as feed additives to promote animal growth. This could result in antibiotic resistance to bacteria and antibiotic residues in animals. In this paper, Enterobacteriaceae isolated from four integrated fish farms in Zhongshan, South China were tested for antibiotic resistance, tetracycline resistance genes, sulfonamide resistance genes, and class 1 integrons. The Kirby-Bauer disk diffusion method and polymerase chain reaction (PCR) assays were carried out to test antibiotic susceptibility and resistance genes, respectively. Relatively high antibiotic resistance frequencies were found, especially for ampicillin (80%), tetracycline (52%), and trimethoprim (50%). Out of 203 Enterobacteriaceae isolates, 98.5% were resistant to one or more antibiotics tested. Multiple antibiotic resistance (MAR) was found highest in animal manures with a MAR index of 0.56. Tetracycline resistance genes (tet(A), tet(C)) and sulfonamide resistance genes (sul2) were detected in more than 50% of the isolates. The intI1 gene was found in 170 isolates (83.7%). Both classic and non-classic class 1 integrons were found. Four genes, aadA5, aadA22, dfr2, and dfrA17, were detected. To our knowledge, this is the first report for molecular characterization of antibiotic resistance genes in Enterobacteriaceae isolated from integrated fish farms in China and the first time that gene cassette array dfrA17-aadA5 has been detected in such fish farms. Results of this study indicated that fish farms may be a reservoir of highly diverse and abundant antibiotic resistant genes and gene cassettes. Integrons may play a key role in multiple antibiotic resistances posing potential health risks to the general public and aquaculture.

In Vivo Efficacy of Plazomicin Alone or in Combination with Meropenem or Tigecycline against Enterobacteriaceae Isolates Exhibiting Various Resistance Mechanisms in an Immunocompetent Murine Septicemia Model.

PubMed

Abdelraouf, Kamilia; Kim, Aryun; Krause, Kevin M; Nicolau, David P

2018-06-04

Background : Plazomicin is a next-generation aminoglycoside with potent in vitro activity against multidrug- and carbapenem-resistant Enterobacteriaceae. The objective of this study was to assess the efficacy of plazomicin exposure, alone and in combination with meropenem or tigecycline, against Enterobacteriaceae in the immunocompetent murine septicemia model. Methods : ICR mice were inoculated intraperitoneally with bacterial suspensions. Eight Enterobacteriaceae isolates with wide ranges of plazomicin, meropenem and tigecycline MICs were utilized. Treatment mice were administered plazomicin, meropenem or tigecycline human-equivalent doses alone or in combinations of plazomicin/meropenem and plazomicin/tigecycline. Treatments were initiated 1h post-infection and continued for 24h. Efficacy was assessed by survival through 96h. Results : Compared with controls, plazomicin monotherapy produced significant improvement in survival for all isolates (P<0.05) and resulted in overall survival of 86% (n=50) and 53.3% (n=30) for isolates with plazomicin MIC ≤4 and ≥8 mg/L, respectively (P<0.05). Survival of meropenem and tigecycline groups correlated well with their respective susceptibilities, with incremental increase in survival observed at lower MIC values. For isolate KP 561 (plazomicin, meropenem and tigecycline MICs of 8, >32 and 2 mg/L, respectively), combination therapies showed significant reduction in mortality compared with any monotherapy (P<0.05). Conclusion : Plazomicin monotherapy resulted in improved survival in the immunocompetent murine septicemia model, notably for isolates with plazomicin MIC ≤4 mg/L. As evidenced by our current data, co-administration of meropenem or tigecycline could potentially lead to further improvement in survival. These data support a role for plazomicin in the management of septicemia due to Enterobacteriaceae with plazomicin MIC ≤4 mg/L, including carbapenem-resistant isolates. Copyright © 2018 American Society for

Temporal trends and risks factors for antimicrobial resistant Enterobacteriaceae urinary isolates from outpatients in Guadeloupe.

PubMed

Guyomard-Rabenirina, Stéphanie; Malespine, Joyce; Ducat, Célia; Sadikalay, Syndia; Falord, Mélanie; Harrois, Dorothée; Richard, Vincent; Dozois, Charles; Breurec, Sébastien; Talarmin, Antoine

2016-06-24

Urinary tract infections are bacterial infections most commonly encountered in the community. The resistance rate of uropathogens to commonly prescribed antibiotics has increased worldwide but there are no published data concerning the resistance of strains isolated from community-acquired UTI in Guadeloupe. To assess the susceptibility patterns of Enterobacteriaceae strains isolated from outpatients in Guadeloupe we conducted a prospective study from December 2012 to May 2014 among outpatients consulting at private and public laboratories for urine analysis. Risk factors for E. coli resistance to amoxicillin, third-generation cephalosporin, and ciprofloxacin were also determined. To study the trends of E. coli resistance rates over the past 10 years, data on the susceptibility patterns of E. coli from 2003 to 2014 were also collected from three major laboratories for a retrospective study. During the prospective study, we isolated 1293 bacterial strains from the urine of outpatients presenting for urine analysis. The most commonly isolated bacteria were E. coli (57 %) and Klebsiella pneumoniae (15.5 %). Thirty seven per cent of the E. coli strains were resistant to amoxicillin. Resistance rates to third generation cephalosporin were low for E. coli and other Enterobacteriaceae (3.1 and 12.2 % respectively) and mostly due to the presence of an Extended Spectrum Beta-lactamase. Resistance to cotrimoxazole and ciprofloxacin was moderate (17.8 and 15.6 % respectively). However, the resistance rate of E. coli to ciprofloxacin has significantly increased during the last 10 years. Risk factors were consistent with previously reported data, especially for the increasing ciprofloxacin resistance with age. General practitioners in Guadeloupe need to be better informed to favor the prescription of fosfomycin-trometamol to reduce the risk of resistance to fluoroquinolones.

Molecular mechanisms of membrane impermeability in clinical isolates of Enterobacteriaceae exposed to imipenem selective pressure.

PubMed

Pavez, Monica; Vieira, Camila; de Araujo, Maria Rita; Cerda, Alvaro; de Almeida, Lara Mendes; Lincopan, Nilton; Mamizuka, Elsa Masae

2016-07-01

Intrinsic mechanisms leading to carbapenem-induced membrane impermeability and multidrug resistance are poorly understood in clinical isolates of Enterobacteriaceae. In this study, molecular behaviours during the establishment of membrane impermeability in members of the Enterobacteriaceae family under imipenem selective pressure were investigated. Clinical isolates (n = 22) exhibiting susceptibility to multiple antibiotics or characterised as extended-spectrum β-lactamase (ESBL)- or AmpC-producers were submitted to progressive passages on Mueller-Hinton agar plates containing subclinical concentrations of imipenem [0.5 × the minimum inhibitory concentration (MIC)]. Changes in outer membrane permeability were evaluated by determination of antimicrobial MICs, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), and gene expression analysis related to membrane permeability (i.e. omp35-like, omp36-like and acrA) and regulatory mechanisms (i.e. marA and ompR) by quantitative reverse transcription PCR. Following imipenem induction, 73% of isolates showed increased carbapenem MICs by ≥2 doubling dilutions. At an early stage of treatment, imipenem modulated the expression of porins and efflux pump genes, represented by a reduction of 78% in omp36-like and a two-fold increase in acrA expression. Transcriptional factors marA and ompR were also affected by imipenem induction, increasing mRNA expression by 14- and 4-fold, respectively. High marA expression levels were associated with higher values of acrA expression. These results suggest that imipenem is an important factor in the development of an adaptive response to carbapenems by regulating key genes involved in the control of efflux pumps and porins, which could lead to a multidrug-resistant profile in clinical isolates, contributing to possible treatment failure. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

[Enterobacteriaceae susceptibility to piperacillin/tazobactam in a Chilean pediatric hospital].

PubMed

Vega, Juan Rojas De la; Benadof, Dona; Veas, Abigail; Acuña, Mirta

2017-12-01

Enterobacteriaceae are a group of gram-negative rods that can cause serious infections in humans. A susceptibility in Klebsiella pneumoniae of 79.4% to piperacillin/tazobactam (PIP/TAZO) is reported in pediatric hospitals in Chile. There is no published data published to date regarding PIP/TAZO susceptibility to other Enterobacteriaceae species in this population. To measure the in vitro PIP/TAZO susceptibility in Enterobacteriaceae isolates from patients in a pediatric hospital in Chile. Descriptive and prospective study of Enterobacteriaceae positive cultures from patients assisting to the "Hospital de niños Roberto del Río" (HRRIO) between January 2013 and August 2014. PIP/TAZO susceptibility was established by gradient diffusion method (E-test®) according to the 2014 CLSI standards. 163 cases were included. The average age was 4 years and 15 days. 70.6% were female. 79.7% of samples were urine cultures. PIP/TAZO susceptibility in Enterobacteriaceae was 95.1% (n = 155). The intermediate susceptibility was 1.8% (n = 3). The isolates studied present high susceptibility to PIP/TAZO. This finding could be explained by the fact that this population has not been exposed to this antimicrobial therapy and also the low rates for ESBL in pediatric infections.

Extended-Spectrum beta (β)-Lactamases and Antibiogram in Enterobacteriaceae from Clinical and Drinking Water Sources from Bahir Dar City, Ethiopia.

PubMed

Abera, Bayeh; Kibret, Mulugeta; Mulu, Wondemagegn

2016-01-01

The spread of Extended-Spectrum beta (β)-Lactamases (ESBL)-producing Enterobacteriaceae has become a serious global problem. ESBL-producing Enterobacteriaceae vary based on differences in antibiotic use, nature of patients and hospital settings. This study was aimed at determining ESBL and antibiogram in Enterobacteriaceae isolates from clinical and drinking water sources in Bahir Dar City, Northwest Ethiopia. Enterobacteriaceae species were isolated from clinical materials and tap water using standard culturing procedures from September 2013 to March 2015. ESBL-producing-Enterobacteriaceae were detected using double-disk method by E-test Cefotaxim/cefotaxim+ clavulanic acid and Ceftazidime/ceftazidime+ clavulanic acid (BioMerieux SA, France) on Mueller Hinton agar (Oxoid, UK). Overall, 274 Enterobacteriaceae were isolated. Of these, 210 (44%) were from patients and 64 (17.1%) were from drinking water. The median age of the patients was 28 years. Urinary tract infection and blood stream infection accounted for 60% and 21.9% of Enterobacteriaceae isolates, respectively. Klebsiella pneumoniae was isolated from 9 (75%) of neonatal sepsis. The overall prevalence of ESBL-producing Enterobacteriaceae in clinical and drinking water samples were 57.6% and 9.4%, respectively. The predominant ESBL-producers were K. pneumoniae 34 (69.4%) and Escherichia coli 71 (58.2%). Statistically significant associations were noted between ESBL-producing and non- producing Enterobacteriaceae with regard to age of patients, infected body sites and patient settings (P = 0.001). ESBL-producing Enterobacteriaceae showed higher levels of resistance against chloramphenicol, ciprofloxacin and cotrimoxazole than non-ESBL producers (P = 0.001). ESBL-producing Enterobacteriaceae coupled with high levels of other antimicrobials become a major concern for treatment of patients with invasive infections such as blood stream infections, neonatal sepsis and urinary tract infections. ESBL

Extended-Spectrum beta (β)-Lactamases and Antibiogram in Enterobacteriaceae from Clinical and Drinking Water Sources from Bahir Dar City, Ethiopia

PubMed Central

Abera, Bayeh; Kibret, Mulugeta; Mulu, Wondemagegn

2016-01-01

Background The spread of Extended-Spectrum beta (β)-Lactamases (ESBL)-producing Enterobacteriaceae has become a serious global problem. ESBL-producing Enterobacteriaceae vary based on differences in antibiotic use, nature of patients and hospital settings. This study was aimed at determining ESBL and antibiogram in Enterobacteriaceae isolates from clinical and drinking water sources in Bahir Dar City, Northwest Ethiopia. Methods Enterobacteriaceae species were isolated from clinical materials and tap water using standard culturing procedures from September 2013 to March 2015. ESBL-producing-Enterobacteriaceae were detected using double-disk method by E-test Cefotaxim/cefotaxim+ clavulanic acid and Ceftazidime/ceftazidime+ clavulanic acid (BioMerieux SA, France) on Mueller Hinton agar (Oxoid, UK). Results Overall, 274 Enterobacteriaceae were isolated. Of these, 210 (44%) were from patients and 64 (17.1%) were from drinking water. The median age of the patients was 28 years. Urinary tract infection and blood stream infection accounted for 60% and 21.9% of Enterobacteriaceae isolates, respectively. Klebsiella pneumoniae was isolated from 9 (75%) of neonatal sepsis. The overall prevalence of ESBL-producing Enterobacteriaceae in clinical and drinking water samples were 57.6% and 9.4%, respectively. The predominant ESBL-producers were K. pneumoniae 34 (69.4%) and Escherichia coli 71 (58.2%). Statistically significant associations were noted between ESBL-producing and non- producing Enterobacteriaceae with regard to age of patients, infected body sites and patient settings (P = 0.001). ESBL-producing Enterobacteriaceae showed higher levels of resistance against chloramphenicol, ciprofloxacin and cotrimoxazole than non-ESBL producers (P = 0.001) Conclusions ESBL-producing Enterobacteriaceae coupled with high levels of other antimicrobials become a major concern for treatment of patients with invasive infections such as blood stream infections, neonatal sepsis and urinary

[Prevalence of ESBL-positive enterobacteriaceae in large moravian hospitals (Czech Republic)].

PubMed

Kolář, Milan; Chromá, Magdaléna; Hricová, Kristýna; Husičková, Vendula; Lovečková, Yvona; Chmelařová, Eva; Bartoníková, Nataša; Rybníkářová, Petra

2010-10-01

bacterial infections have become an important issue in current medicine. Recently, their frequency and severity have significantly increased as a result of the rising number of resistant bacteria. One of important mechanisms of resistance is production of broad-spectrum beta-lactamases, namely the ESBL type. The study aimed at determining the frequency of ESBL-positive Enterobacteriaceae in three large hospitals in Moravia, the eastern part of the Czech Republic. enterobacteriaceae were isolated from clinical material obtained from patients hospitalized in the University Hospital Olomouc, Teaching Hospital Ostrava and Bata Regional Hospital Zlín throughout 2009. Standard microbiology techniques were used for identification. The production of ESBLs was determined by the modified Double-Disk Synergy Test. ESBL-positive isolates of Escherichia coli from ICU patients were subjected to basic genetic analysis. during the study period, a total of 12,922 strains from the Enterobacteriaceae family were detected. The ESBL phenotype was found in 907 cases, i.e. 7 % of all isolates. The most prevalent species of ESBL-producing Enterobacteriaceae were Klebsiella pneumoniae, Klebsiella oxytoca and Escherichia coli. A comparison of general wards and ICUs revealed a higher percentage of ESBL-positive strains of Klebsiella pneumoniae and a lower proportion of ESBL-positive Escherichia coli isolates in intensive care patients. When assessing the patients' clinical material, ESBL-producing strains were most frequently detected in urine. Genetic analysis of ESBL-positive Escherichia coli strains from ICU patients revealed the CTX-M type of ESBL production in most isolates.

Spatial distribution of extensively drug-resistant tuberculosis (XDR TB) patients in KwaZulu-Natal, South Africa

PubMed Central

Kapwata, Thandi; Morris, Natashia; Campbell, Angela; Mthiyane, Thuli; Mpangase, Primrose; Nelson, Kristin N.; Allana, Salim; Brust, James C. M.; Moodley, Pravi; Mlisana, Koleka

2017-01-01

Background KwaZulu-Natal province, South Africa, has among the highest burden of XDR TB worldwide with the majority of cases occurring due to transmission. Poor access to health facilities can be a barrier to timely diagnosis and treatment of TB, which can contribute to ongoing transmission. We sought to determine the geographic distribution of XDR TB patients and proximity to health facilities in KwaZulu-Natal. Methods We recruited adults and children with XDR TB diagnosed in KwaZulu-Natal. We calculated distance and time from participants’ home to the closest hospital or clinic, as well as to the actual facility that diagnosed XDR TB, using tools within ArcGIS Network analyst. Speed of travel was assigned to road classes based on Department of Transport regulations. Results were compared to guidelines for the provision of social facilities in South Africa: 5km to a clinic and 30km to a hospital. Results During 2011–2014, 1027 new XDR TB cases were diagnosed throughout all 11 districts of KwaZulu-Natal, of whom 404 (39%) were enrolled and had geospatial data collected. Participants would have had to travel a mean distance of 2.9 km (CI 95%: 1.8–4.1) to the nearest clinic and 17.6 km (CI 95%: 11.4–23.8) to the nearest hospital. Actual distances that participants travelled to the health facility that diagnosed XDR TB ranged from <10 km (n = 143, 36%) to >50 km (n = 109, 27%), with a mean of 69 km. The majority (77%) of participants travelled farther than the recommended distance to a clinic (5 km) and 39% travelled farther than the recommended distance to a hospital (30 km). Nearly half (46%) of participants were diagnosed at a health facility in eThekwini district, of whom, 36% resided outside the Durban metropolitan area. Conclusions XDR TB cases are widely distributed throughout KwaZulu-Natal province with a denser focus in eThekwini district. Patients travelled long distances to the health facility where they were diagnosed with XDR TB, suggesting a

Distribution of ESBLs, AmpC β-lactamases and carbapenemases among Enterobacteriaceae isolates causing intra-abdominal and urinary tract infections in the Asia-Pacific region during 2008-14: results from the Study for Monitoring Antimicrobial Resistance Trends (SMART).

PubMed

Jean, Shio-Shin; Hsueh, Po-Ren

2017-01-01

To investigate the antimicrobial resistance and assess the molecular characteristics of β-lactamases (ESBLs, AmpC β-lactamases and carbapenemases) among Enterobacteriaceae isolates that caused intra-abdominal infections (IAIs) in patients hospitalized in the Asia-Pacific region during 2008-14. Multiplex PCR was used to detect the specific types of β-lactamase in 2893 isolates with MICs of ertapenem >0.5 mg/L. In-hospital acquisition times for most isolates were also delineated. Among 2728 (94.3%) isolates proven with β-lactamase production, the rates of non-susceptibility to imipenem were low (average = 7.9%) among IAI Enterobacteriaceae isolates from all Asia-Pacific countries except Vietnam (17.7%) and the Philippines (10.2%). A stepwise and significant increase in annual rates of carbapenemase production among these isolates was noted. CTX-M-15 and CTX-M-14 were the dominant ESBL variants in most IAI Enterobacteriaceae species. The most abundant AmpC β-lactamase variants were bla CMY-2 among isolates of Escherichia coli and bla DHA-1 among isolates of Klebsiella pneumoniae. In addition, the IAI Enterobacteriaceae isolates harbouring a bla CMY-2 or bla DHA-1 allele were associated with high community-acquired rates (38.0% and 42.6%, respectively). AmpC ACT and MIR variants were mostly detected in Enterobacter species. The bla NDM-1,4,5,7 -harbouring isolates of E. coli, K. pneumoniae and Enterobacter cloacae were most commonly identified among IAI isolates from Vietnam and the Philippines. Also of note, bla OXA-48 -harbouring IAI Enterobacteriaceae isolates were detected exclusively in Vietnam. The high resistance burden in Vietnam and the Philippines warrants aggressive control policies to combat the worsening trend in antimicrobial resistance among Enterobacteriaceae species causing IAIs. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please

Use of Faropenem as an Indicator of Carbapenemase Activity in the Enterobacteriaceae

PubMed Central

Day, Kathryn M.; Pike, Rachel; Winstanley, Trevor G.; Lanyon, Clare; Cummings, Stephen P.; Raza, Muhammad W.; Woodford, Neil

2013-01-01

The aim of this study was to determine the ability of a disc susceptibility test using faropenem (10 μg) to predict carbapenemase activity in Enterobacteriaceae. A collection of 166 isolates of carbapenemase-producing Enterobacteriaceae (CPE) and 82 isolates of Enterobacteriaceae that produced other β-lactamases was compiled from diverse sources. Disc susceptibility testing was performed using the CLSI/EUCAST methodology with discs of faropenem (10 μg), temocillin (30 μg), and four carbapenems (each 10 μg). A further prospective evaluation of the faropenem disc susceptibility test was performed using 205 consecutive isolates referred to a United Kingdom reference laboratory in parallel with molecular methods for carbapenemase detection. Of 166 isolates of CPE, 99% showed growth up to the edge of a 10-μg faropenem disc compared with only 6% of other β-lactamase producers (sensitivity, 99%; specificity, 94%). A “double zone” around 10-μg faropenem discs was frequently associated with OXA-48 producers. Of the carbapenems, the most useful agent was imipenem, where a zone diameter of ≤23 mm as a predictor of carbapenemase activity had a sensitivity of 99% and a specificity of 85%. The presence of no zone of inhibition around a 30-μg temocillin disc was a consistent feature of strains producing OXA-48 carbapenemase. For 205 isolates of Enterobacteriaceae referred to a United Kingdom reference laboratory, growth up to a 10-μg faropenem disc correctly identified 84 of 86 carbapenemase producers (98% sensitivity), with a specificity of 87%. Disc susceptibility testing using faropenem (10 μg) is a simple, convenient, and highly predictive screening test for carbapenemase-producing Enterobacteriaceae. PMID:23576544

Prevalence of carbapenemase producing Enterobacteriaceae isolated from German pig-fattening farms during the years 2011-2013.

PubMed

Roschanski, Nicole; Friese, Anika; von Salviati-Claudius, Christina; Hering, Johanna; Kaesbohrer, Annemarie; Kreienbrock, Lothar; Roesler, Uwe

2017-02-01

Since recently Enterobacteriaceae carrying bla VIM-1 genes have been isolated in German animal husbandries, the monitoring of carbapenemase producing Enterobacteriaceae (CPE) in livestock became a major topic within the European Union. Nevertheless, due to missing surveillance studies the worldwide situation in livestock and livestock associated surroundings might still be underestimated. The here described study provides an overview of the CPE-prevalence in German pig-fattening farms during the years 2011-2013 (period when previously described bla VIM-1 findings occurred on pig-fattening farms (Efsa, 2011; Fischer et al., 2012, 2013a)). Therefore, a collection of 238 bacterial anacultures derived from pooled faeces and boot swab samples, collected in a cross-sectional study including 58 pig-fattening farms throughout Germany, were investigated. The bacteria were selected on MacConkey agar plates containing 0.125μg/ml meropenem. Enterobacteriaceae which were able to grow on these plates were further investigated for the presence of carbapenemase genes. Out of eight CPE-suspicious strains, two Escherichia (E.) coli strains-deriving from the same farm-contained the carbapenemase gene bla VIM-1 . For the remaining six Enterobacteriaceae it seems to be likely that they possess other resistance mechanisms, leading to reduced carbapenem susceptibility. Based on the obtained results, the overall CPE prevalence for German pig-fattening farms, sampled during the years 2011-2013 was 1.7%; 95% CI: 0-10. However, as it is of great importance to prevent a further spread of these bacteria between farms and livestock populations as well as their introduction into the food chain, an understanding of their routes of introduction and spread in combination with intensified monitoring programs are considered necessary. Copyright © 2015 Elsevier B.V. All rights reserved.

Genetic Background of β-Lactamases in Enterobacteriaceae Isolates from Environmental Samples.

PubMed

de Oliveira, Daniele V; Nunes, Luciana S; Barth, Afonso Luís; Van Der Sand, Sueli T

2017-10-01

The prevalence of β-lactamase-producing Enterobacteriaceae has increased worldwide. Although antibiotic-resistant bacteria are usually associated with hospitals, there are a growing number of reports of resistant bacteria in other environments. Concern about resistant microorganisms outside the hospital setting highlights the need to investigate mechanisms of antibiotic resistance in isolates collected from the environment. The present study evaluated the resistance mechanism to β-lactam antibiotics in 40 isolates from hospital sewage and surface water from the Dilúvio Stream, Porto Alegre City, Southern Brazil. The multiplex PCR technique was used to detect several resistance genes of β-lactamases: extended-spectrum β-lactamases (ESBLs), carbapenemases, and β-lactamase AmpC. After genes, detection amplicons were sequenced to confirm their identification. The clonal relationship was established by DNA macrorestriction using the XbaI enzyme, followed by pulsed-field gel electrophoresis (PFGE). The results indicated that resistance genes were present in 85% of the isolates. The most prevalent genes encoded narrow-spectrum β-lactamase, such as TEM-1 and SHV-1 with 70% of the strains, followed by carbapenemase KPC and GES (45%), ESBL types SHV-5 and CTX-M-8 (27.5%), and AmpC (ACT-1/MIR-1) (2.5%). Twelve isolates contained only one resistance gene, 14 contained two, and eight isolates had three resistance genes. PFGE indicated a clonal relationship among K. pneumoniae isolates. It was not possible to establish a clonal relationship between Enterobacter sp. isolates. The results highlight the potential of these resistance genes to spread in the polluted environment and to present a health risk to communities. This report is the first description of these resistance genes present in environmental samples other than a hospital in the city of Porto Alegre/RS.

Lifestyle, attitudes and needs of uncured XDR-TB patients living in the communities of South Africa: a qualitative study.

PubMed

Senthilingam, Meera; Pietersen, Elize; McNerney, Ruth; Te Riele, Julian; Sedres, Pat; Wilson, Ruth; Dheda, Keertan

2015-09-01

Patient-level data are required to inform strategies interrupting transmission and default in patients with extensively drug-resistant TB (XDR-TB) to improve models of care and identify potential routes of transmission. We therefore explored the experiences, lifestyle, attitudes and needs of patients with uncured XDR-TB, who failed or interrupted therapy, living without treatment in the community. We conducted in-depth interviews with 12 community-based patients from South Africa. Family members were interviewed when patients were unavailable. Interviews were analysed using inductive thematic analysis. The thematic experiences identified from the interviews were as follows: (i) living with but not being cured of XDR-TB, (ii) altered lifestyle in the community, (iii) experiences with community health care, (iv) local community members, and (v) wants and needs. Patients identified mistrust in health care, futility of treatment regimens, a need for a purpose in life and subsistence as major concerns. Restriction of living in the community for patients whose treatment had failed resulted in self-imposed isolation. Defaulters focused more on the never-ending drug regimen and bad experiences with health care contributing to non-adherence. Family members emphasised an under-recognised experience of unforeseen burden, obligation, worry and discomfort. Lack of knowledge and lack of concern about transmission was evident. Current models of care are not adequately meeting the needs of patients with uncured XDR-TB and relatives. These data inform the need for community-based palliative care, vocational facilities to improve economic opportunities, home-based infection control and improved psychosocial support to increase patient adherence, reduce transmission, provide income and relieve the burden on family members. © 2015 John Wiley & Sons Ltd.

Carbapenemase-Producing Enterobacteriaceae in Yunnan Province, China.

PubMed

Rui, Zheng; Dehua, Liu; Hua, Niu; Yue, Feng; Yunmin, Xu; Jianhua, Li; Xueshan, Xia

2016-11-22

Among 144 carbapenem-resistant Enterobacteriaceae strains isolated from 4 hospitals in Yunnan province, 113 were identified as carbapenemase-producing Enterobacteriaceae (CPE). Bla KPC-2 (99/113, 87.6%) was the most common carbapenemase gene and Klebsiella pneumoniae (100/113, 88.5%) was the most common species. Bla NDM-1 (11/113, 9.7%), bla IMP-4 (10/113, 8.8%), and bla IMP-1 (1/113, 0.9%) genes were also detected. Extended-spectrum β-lactamase genes were common in CPE, and the SHV- and CTX-M-types were predominant.

Identification and characterization of plasmid-mediated quinolone resistance determinants in Enterobacteriaceae isolated from healthy poultry in Brazil.

PubMed

Ferreira, Joseane Cristina; Penha Filho, Rafael Antonio Casarin; Kuaye, Ana Paula Yorika; Andrade, Leonardo Neves; Berchieri Junior, Angelo; Darini, Ana Lúcia da Costa

2018-06-01

The expression of plasmid-mediated quinolone resistance (PMQR) genes confers low-level quinolone and fluoroquinolones resistance alone. However, the association to chromosomal resistance mechanisms determines an expressively higher resistance in Enterobacteriaceae. These mechanisms are horizontally disseminated within plasmids and have contributed to the emergence of bacteria with reduced susceptibility or resistant to therapies worldwide. The epidemiological characterization of PMQR dissemination is highly relevant in the scientific and medical context, to investigate the dissemination within enterobacteria, from different populations, including humans and food-producing animals. In the present study, 200 Enterobacteriaceae isolates were harvested from poultry with cloacal swabs and identified as Escherichia coli (90.5%), Escherichia fergusonii (5.5%), Klebsiella oxytoca (2.5%) and Klebsiella pneumoniae (1.5%). Among isolates evaluated, 46 (23%) harboured PMQR genes including qnrB (43/200), qnrS (2/200) and aac(6')-Ib-cr (1/200). All isolates carrying PMQR genes showed multidrug-resistance phenotype. The 36 E. coli isolates showed 18 different PFGE types. All E. fergusonii isolates showed the same PFGE type. The two Klebsiella oxytoca belonged to two different PFGE types. The phylogenetic groups A, B1, and D were found among the E. coli harboring PMQR genes. Based on the phylogenetic analysis and PFGE, the population structure of E. coli isolates was diverse, even within the same farm. All isolates carrying qnrB and qnrS genes also harboured ColE-like plasmids. The Southern blot hybridization using the S1-PFGE revealed that the qnrB genes were located on low molecular weight plasmids, smaller than 10Kb. Resistance plasmids were sequenced and showed 100% identity with plasmid pPAB19-3. The association of PMQR genes with mobile genetic elements, such as transferable plasmids, favours the selection and dissemination of (fluoro) quinolones resistant bacteria among

Extensively Drug-resistant Tuberculosis (XDR-TB): A daunting challenge to the current End TB Strategy and policy recommendations.

PubMed

Rahman, Md Arifur; Sarkar, Atanu

2017-07-01

Extensively Drug-resistant Tuberculosis (XDR-TB) has emerged as one of the most formidable challenges to the End TB Strategy that has targeted a 95% reduction in TB deaths and 90% reduction in cases by 2035. Globally, there were an estimated 55,100 new XDR-TB cases in 2015 in 117 countries. However, only one in 30 XDR-TB cases had been reported so far. Drug susceptibility test (DST) is the mainstay for diagnosing XDR-TB, but the lack of laboratory facilities in the resource-limited endemic countries limit its uses. A few new drugs including bedaquiline and delamanid, have the potential to improve the efficiency of XDR-TB treatment, but the drugs have been included in 39 countries only. The costs of XDR-TB treatment are several folds higher than that of the MDR-TB. Despite the financing from the donors, there is an urgent need to fill the current funding gap of US$ 2 billion to ensure effective treatment and robust surveillance. In the review article we have addressed current update on XDR-TB, including surveillance, diagnosis and the interventions needed to treat and limit its spread, emphasis on extensive financial support for implementing of current recommendations to meet the goals of End TB Strategy. Copyright © 2017 Tuberculosis Association of India. Published by Elsevier B.V. All rights reserved.

Extensively Drug-Resistant Tuberculosis (XDR-TB) - A Potential Threat in Ireland

PubMed Central

Mc Laughlin, Anne Marie; O’Donnell, Rory A; Gibbons, Noel; Scully, Mary; O’Flangan, Darina; Keane, Joseph

2007-01-01

We describe a case of a 25 year old female from Lithuania who presented with a productive cough. Chest radiograph demonstrated an infiltrate in the left upper lobe and a cavitating lesion in the right middle lobe. Sensitivity testing of her sputum led to a diagnosis of extensively drug-resistant tuberculosis (XDR-TB). This is the first case in Ireland and highlights the need for physicians to be aware of the possibility of XDR-TB. Moreover it underlines the need for improvement in service provision in terms of a TB reference laboratory and TB clinics. PMID:19340317

Pediatric Infection and Intestinal Carriage Due to Extended-Spectrum-Cephalosporin-Resistant Enterobacteriaceae

PubMed Central

Qin, Xuan; Oron, Assaf P.; Adler, Amanda L.; Wolter, Daniel J.; Berry, Jessica E.; Hoffman, Lucas; Weissman, Scott J.

2014-01-01

The objective of this study is to describe the epidemiology of intestinal carriage with extended-spectrum-cephalosporin-resistant Enterobacteriaceae in children with index infections with these organisms. Patients with resistant Escherichia coli or Klebsiella bacteria isolated from the urine or a normally sterile site between January 2006 and December 2010 were included in this study. Available infection and stool isolates underwent phenotypic and molecular characterization. Clinical data relevant to the infections were collected and analyzed. Overall, 105 patients were identified with 106 extended-spectrum-cephalosporin-resistant E. coli (n = 92) or Klebsiella (n = 14) strains isolated from urine or a sterile site. Among the 27 patients who also had stool screening for resistant Enterobacteriaceae, 17 (63%) had intestinal carriage lasting a median of 199 days (range, 62 to 1,576). There were no significant differences in demographic, clinical, and microbiological variables between those with and those without intestinal carriage. Eighteen (17%) patients had 37 subsequent resistant Enterobacteriaceae infections identified: 31 urine and 6 blood. In a multivariable analysis, antibiotic intake in the 91 days prior to subsequent urine culture was significantly associated with subsequent urinary tract infection with a resistant organism (hazard ratio, 14.3; 95% confidence interval [CI], 1.6 to 130.6). Intestinal carriage and reinfection were most commonly due to bacterial strains of the same sequence type and with the same resistance determinants as the index extended-spectrum-cephalosporin-resistant Enterobacteriaceae, but carriage and reinfection with different resistant Enterobacteriaceae strains also occurred. PMID:24798269

Suspicion of respiratory tract infection with multidrug-resistant Enterobacteriaceae: epidemiology and risk factors from a Paediatric Intensive Care Unit.

PubMed

Renk, Hanna; Stoll, Lenja; Neunhoeffer, Felix; Hölzl, Florian; Kumpf, Matthias; Hofbeck, Michael; Hartl, Dominik

2017-02-21

Multidrug-resistant (MDR) infections are a serious concern for children admitted to the Paediatric Intensive Care Unit (PICU). Tracheal colonization with MDR Enterobacteriaceae predisposes to respiratory infection, but underlying risk factors are poorly understood. This study aims to determine the incidence of children with suspected infection during mechanical ventilation and analyses risk factors for the finding of MDR Enterobacteriaceae in tracheal aspirates. A retrospective single-centre analysis of Enterobacteriaceae isolates from the lower respiratory tract of ventilated PICU patients from 2005 to 2014 was performed. Resistance status was determined and clinical records were reviewed for potential risk factors. A classification and regression tree (CRT) to predict risk factors for infection with MDR Enterobacteriaceae was employed. The model was validated by simple and multivariable logistic regression. One hundred sixty-seven Enterobacteriaceae isolates in 123 children were identified. The most frequent isolates were Enterobacter spp., Klebsiella spp. and E.coli. Among these, 116 (69%) isolates were susceptible and 51 (31%) were MDR. In the CRT analysis, antibiotic exposure for ≥ 7 days and presence of gastrointestinal comorbidity were the most relevant predictors for an MDR isolate. Antibiotic exposure for ≥ 7 days was confirmed as a significant risk factor for infection with MDR Enterobacteriaceae by a multivariable logistic regression model. This study shows that critically-ill children with tracheal Enterobacteriaceae infection are at risk of carrying MDR isolates. Prior use of antibiotics for ≥ 7 days significantly increased the risk of finding MDR organisms in ventilated PICU patients with suspected infection. Our results imply that early identification of patients at risk, rapid microbiological diagnostics and tailored antibiotic therapy are essential to improve management of critically ill children infected with

Biliary diseases as main causes of pyogenic liver abscess caused by extended-spectrum beta-lactamase-producing Enterobacteriaceae.

PubMed

Shi, Shao-Hua; Feng, Xiao-Ning; Lai, Ming-Chun; Kong, Hai-Shen; Zheng, Shu-Sen

2017-05-01

Little is known about aetiology and morbidity and clinical characteristics of pyogenic liver abscess caused by extended-spectrum beta-lactamase-producing Enterobacteriaceae. An analysis between pyogenic liver abscess patients caused by extended-spectrum beta-lactamase-producing Enterobacteriaceae isolates and those caused by non-extended-spectrum beta-lactamase-producing Enterobacteriaceae was performed. Among 817 pyogenic liver abscess patients, there were 176 patients (21.5%) with pyogenic liver abscess of biliary origin, and 67 pyogenic liver abscess patients (8.2%) caused by extended-spectrum beta-lactamase-producing Enterobacteriaceae isolates (mainly Escherichia coli and Klebsiella pneumoniae). Of 176 pyogenic liver abscess patients related to biliary disorders, there were 48 pyogenic liver abscess patients (27.3%) caused by extended-spectrum beta-lactamase-producing Enterobacteriaceae. Within 67 pyogenic liver abscess patients caused by Enterobacteriaceae expressing extended-spectrum beta-lactamases, the occurrences of 48 pyogenic liver abscess patients (71.6%) were associated with biliary disorders. When compared with pyogenic liver abscess patients caused by non-extended-spectrum beta-lactamase-producing Enterobacteriaceae, there were significantly greater incidences of polymicrobial infections, bacteremia, pulmonary infection, recurrence and death in pyogenic liver abscess patients caused by extended-spectrum beta-lactamase-producing Enterobacteriaceae. Carbapenems remain mainstay drugs against extended-spectrum beta-lactamase-producing E. coli and K. pneumoniae. Independent risk factors for occurrence of pyogenic liver abscess caused by extended-spectrum beta-lactamase-producing Enterobacteriaceae were biliary disorders including extra- and intrahepatic cholangiolithiasis and an abnormal bilioenteric communication between bile and gut, a treatment history of malignancy such as operation and chemotherapy, pulmonary infection, and diabetes mellitus

Screening for New Delhi metallo-β-lactamase-1 in Enterobacteriaceae: Is there a role for the modified Hodge test?

PubMed

Abidin, Nor Zanariah Zainol; Sulong, Anita; Alfizah, Hanafiah; Ding, Chuan Hun; Muttaqillah, Najihan Abdul Samat; Rahman, Md Mostafizur

2015-01-01

The New Delhi metallo-β-lactamase-1 (NDM-1) enzyme is a plasmid-encoded enzyme that inactivates carbapenem antibiotics. This study aims to ascertain if the modified Hodge test (MHT) has a role in screening for NDM-1 in Enterobacteriaceae with reduced carbapenem susceptibility. Over a period of one year, all Enterobacteriaceae isolates from all clinical specimens with reduced susceptibility to at least one carbapenem were subjected to MHT and conventional polymerase chain reaction (PCR) detection of the NDM-1 gene. A total of 13,098 Enterobacteriaceae isolates were screened and 63 (0.48%) had reduced susceptibility to at least one carbapenem. Out of the 63 isolates, 45 (71.4%) were MHT-positive. The NDM-1 gene was detected in 18 of the 63 isolates (28.6%). All 18 PCR-positive isolates were also MHT-positive. Thus, the sensitivity and specificity of the MHT in detecting NDM-1 in Enterobacteriaceae with reduced carbapenem susceptibility are 100% and 40%, respectively. The MHT is a useful test to screen for the presence of NDM-1 in Enterobacteriaceae with reduced carbapenem susceptibility. However, due to its rather low specificity, all MHT-positive isolates should be subjected to alternative tests (e.g. PCR) for confirmation, especially if other types of carbapenemases (e.g. KPC) are prevalent.

Prevalence of qnr determinants among extended-spectrum beta-lactamase-positive Enterobacteriaceae clinical isolates in southern Stockholm, Sweden.

PubMed

Fang, Hong; Huang, Haihui; Shi, Yuejie; Hedin, Göran; Nord, Carl Erik; Ullberg, Måns

2009-09-01

Three hundred and nineteen extended-spectrum beta-lactamase-positive Enterobacteriaceae clinical isolates were screened for qnr genes. Twelve isolates were positive for qnr, including one qnrA1, two qnrB1, three qnrB2, one qnrB4, one qnrB6 and four qnrS1. No qnr-positive strains were identified among the isolates recovered before 2006. The first qnr-positive Escherichia coli was detected from a patient in 2006. qnr genes remained rare in E. coli (6/288; 2.1%), but appeared to be more prevalent in Klebsiella pneumoniae (4/25; 16%) and Enterobacter cloacae (2/3; 66.7%). All qnr-positive isolates were resistant to nalidixic acid while presenting varied susceptibilities to fluoroquinolones. Isolates harbouring qnrB4 or qnrB6 were highly resistant to all the fluoroquinolones tested. Their high-level resistance is associated with multiple chromosomal substitutions in gyrA and parC. Alterations at codons Ser-83 and Asp-87 in GyrA and at codons Ser-80 and Glu-84 in ParC were observed in these isolates.

Presence of extended-spectrum beta-lactamase-producing Enterobacteriaceae in waste waters, Kinshasa, the Democratic Republic of the Congo.

PubMed

De Boeck, H; Lunguya, O; Muyembe, J-J; Glupczynski, Y; Jacobs, J

2012-11-01

Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae are a major public health concern. We previously demonstrated the presence of ESBL-producing Enterobacteriaceae in sachet-packaged water bags sold in Kinshasa, the Democratic Republic of the Congo. In complement to the previous study, we aimed to assess the presence of ESBL-producing Enterobacteriaceae in waste waters in Kinshasa.Enterobacteriaceae isolates recovered from environmental water samples were screened and phenotypically confirmed as ESBL-producers by disk diffusion according to Clinical and Laboratory Standards Institute (CLSI) guidelines (CLSI M100-S21). Final identification to the species level and further antimicrobial susceptibility testing were carried out with MicroScan® NBC42 panels and the identification of bla (ESBL) coding genes was performed by a commercial multiplex ligation polymerase chain reaction (PCR) microarray (Check-Points CT 101, Wageningen, the Netherlands). Overall, 194 non-duplicate Enterobacteriaceae were recovered from several sewer and river sites in nine out of 24 municipalities of Kinshasa. Fourteen isolates (7.4 %) were confirmed as ESBL-producers, the main species being Enterobacter cloacae (46.6 %) and Klebsiella pneumoniae (40.0 %). Associated resistance to both aminoglycoside and fluoroquinolone antibiotics was observed in ten isolates; the remaining isolates showed co-resistance to either fluoroquinolone (n = 3) or to aminoglycoside (n = 1) alone. All but one isolate carried bla (CTX-M) genes belonging to the CTX-M-1 group. ESBL-producing Enterobacteriaceae are increasingly being reported from various sources in the community. The present results suggest that ESBL-producing Enterobacteriaceae are widespread in the environment in the community of Kinshasa. Cities in Central Africa should be added to the map of potentially ESBL-contaminated environments and highlight the need to reinforce safe water supply and public sanitation.

Molecular characterization of extended-spectrum β-lactamase, plasmid-mediated AmpC cephalosporinase and carbapenemase genes among Enterobacteriaceae isolates in five medical centres of East and West Azerbaijan, Iran.

PubMed

Sadeghi, Mohammad Reza; Ghotaslou, Reza; Akhi, Mohammad Taghi; Asgharzadeh, Mohammad; Hasani, Alka

2016-11-01

Very little is known about the occurrence and various types of extended-spectrum β-lactamase (ESBL), AmpC and carbapenemase in Iran. The aims of this study were to determine the prevalence of ESBLs, AmpCs and carbapenemase genes among Enterobacteriaceae in Azerbaijan and to characterize the genetic composition of the detected genes. A total of 307 Enterobacteriaceae isolates, recovered from five medical centres, were screened for ESBL, AmpC and carbapenemase activities by the disc diffusion method and phenotypic confirmatory tests. The 162 selected strains (third-generation cephalosporins, cefoxitin- or carbapenem-resistant strains with positive or negative phenotypic confirmatory tests) were selected for multiplex PCR screening for β-lactamase genes, and detected genes were confirmed by sequencing. Of 162 isolates, 156 harboured 1 to 6 β-lactamase genes of 41 types. The most prevalent genes were blaTEM-1 (29.9 %), followed by blaCTX-M-15 (25.7 %). Plasmid-mediated AmpC was detected in 66 strains (21.5 %) alone or in combination with other genes. Carbapenemase-encoding genes were detected in 18 strains (5.8 %) of 27 carbapenem-non-susceptible isolates including 11, 7, 3 and 1 cases of blaOXA-48, blaNDM-1, blaKPC-2 and blaKPC-3 genes, respectively. Interestingly, 148 (94.8 %) of 156 strains with any β-lactamase gene were found to have a multidrug-resistant pattern. The rate of resistance to β-lactams and multidrug-resistant Enterobacteriaceae is high in Azerbaijan. All positive strains for carbapenemase genes were resistant to all β-lactams. The present study reveals the high occurrence of CTX-M-type ESBLs followed by TEM and SHV variants among Enterobacteriaceae isolates. East Azerbaijan seems to be an alarming focus for OXA-48, NDM-1 and KPC dissemination.

Activity of MK-7655 combined with imipenem against Enterobacteriaceae and Pseudomonas aeruginosa.

PubMed

Livermore, David M; Warner, Marina; Mushtaq, Shazad

2013-10-01

MK-7655 is a novel inhibitor of class A and C β-lactamases. We investigated its potential to protect imipenem. Chequerboard MICs were determined by CLSI agar dilution: (i) for Enterobacteriaceae with carbapenemases; (ii) for Enterobacteriaceae with carbapenem resistance contingent on combinations of impermeability together with an extended-spectrum β-lactamase or AmpC enzyme; and (iii) for Pseudomonas aeruginosa and other non-fermenters. At a concentration of 4 mg/L, MK-7655 reduced imipenem MICs for Enterobacteriaceae with KPC carbapenemases from 16-64 mg/L to 0.12-1 mg/L. Synergy also was seen for Enterobacteriaceae with impermeability-mediated carbapenem resistance, with weaker synergy seen for isolates with the OXA-48 enzyme. On the other hand, MK-7655 failed to potentiate imipenem against Enterobacteriaceae with metallo-carbapenemases. In the case of P. aeruginosa, where endogenous AmpC confers slight protection versus imipenem, 4 mg/L MK-7655 reduced the MIC of imipenem for all isolates, except those with metallo-carbapenemases: the MICs of imipenem fell from 1-2 mg/L to 0.25-0.5 mg/L for imipenem-susceptible P. aeruginosa and from 16-64 mg/L to 1-4 mg/L for OprD-deficient strains. No potentiation was seen for chryseobacteria or for Stenotrophomonas maltophilia. MK-7655 potentiated imipenem against Enterobacteriaceae with KPC carbapenemases or combinations of β-lactamase and impermeability, but not those with metallo-carbapenemases. It augmented the activity of imipenem against P. aeruginosa in general and OprD mutants in particular.

Clinical features and antimicrobial resistance profiles of important Enterobacteriaceae pathogens in Guangzhou representative of Southern China, 2001-2015.

PubMed

Xie, Jinhong; Peters, Brian M; Li, Bing; Li, Lin; Yu, Guangchao; Xu, Zhenbo; Shirtliff, Mark E

2017-06-01

This surveillance aimed to investigate the antimicrobial resistance profiles of Enterobacteriaceae pathogens in Southern China during 2001-2015. A total of 6858 Enterobacteriaceae isolates were collected, including 4276 E. coli, 1992 K. pneumoniae and 590 Enterobacter spp. Disk diffusion method and minimum inhibitory concentrations method were used for susceptibility testing, with results interpreted by the CLSI (2015). Urinary tract remained the dominant isolated site among E. coli (49.88%), whereas 53.26% K. pneumoniae and 45.25% Enterobacter spp. were from Sputum. The carbapenems maintained the highest antimicrobial activity (resistance rates <15%), followed by piperacillin-tazobactam and amikacin. Gentle increases were obtained in carbapenems-resistant K. pneumoniae and Enterobacter spp. (eg. from 4.5% to 11.2% and 3.2% to 14.5% in imipenem, repestively). The third-generation cephalosporins showed high and stable resistance among Enterobacteriaceae pathogens during the studied period, with ceftazidime as the most active third-generation cephalosporin against Enterobacteriaceae. Isolates from ICU department showed higher or similar resistance rates among Enterobacteriaceae pathogens compared to other wards. Carbapenems are the most potent antibiotic agents against Enterobacteriaceae pathogens. Due to the complicated susceptibility profiles, prescribing guidelines should be based on the knowledge of antibiogram of pathogens. Copyright © 2017 Elsevier Ltd. All rights reserved.

Isolation of three hexahydro-1,3,5-trinitro-1,3,5-triazine-degrading species of the family Enterobacteriaceae from nitramine explosive-contaminated soil.

PubMed Central

Kitts, C L; Cunningham, D P; Unkefer, P J

1994-01-01

Three species of the family Enterobacteriaceae that biochemically reduced hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) were isolated from nitramine explosive-contaminated soil. Two isolates, identified as Morganella morganii and Providencia rettgeri, completely transformed both RDX and the nitroso-RDX reduction intermediates. The third isolate, identified as Citrobacter freundii, partially transformed RDX and generated high concentrations of nitroso-RDX intermediates. All three isolates produced 14CO2 from labeled RDX under O2-depleted culture conditions. While all three isolates transformed HMX, only M. morganii transformed HMX in the presence of RDX. PMID:7811097

Analysis of ESBL- and AmpC-positive Enterobacteriaceae at the Department of Neonatology, University Hospital Olomouc.

PubMed

Husičková, Vendula; Chromá, Magdaléna; Kolář, Milan; Hricová, Kristýna; Stosová, Taťána; Kantor, Lumír; Dubrava, Lubomír

2011-06-01

Bacterial infections are an important issue in current clinical medicine. The severity of infectious diseases has increased dramatically in recent years, which is also due to increasing numbers of resistant bacteria, including strains producing broad-spectrum beta-lactamases. The study aimed at determining the prevalence of ESBL- and AmpC-positive Enterobacteriaceae at the Department of Neonatology, University Hospital Olomouc. Enterobacteriaceae were isolated from clinical samples from infants hospitalized at the Department of Neonatology, University Hospital Olomouc over a period of 2 years. ESBL- and AmpC-positive isolates were subjected to basic genetic analysis. In the study period, a total of 1,526 isolates of the Enterobacteriaceae family were identified, including 55 (3.6%) cases of the ESBL phenotype and 17 (1.1%) AmpC-positive isolates. Genetic analysis of ESBL-positive isolates revealed a majority of CTX-M enzymes. Among AmpC beta-lactamases, the EBC, CIT, DHA, and MOX types were detected. An Escherichia coli strain was isolated with mutations in the promoter region of the ampC chromosomal gene that are associated with overproduction of the relevant enzyme.

High Prevalence of Gut Microbiota Colonization with Broad-Spectrum Cephalosporin Resistant Enterobacteriaceae in a Tunisian Intensive Care Unit

PubMed Central

Maamar, Elaa; Ferjani, Sana; Jendoubi, Ali; Hammami, Samia; Hamzaoui, Zaineb; Mayonnove-Coulange, Laure; Saidani, Mabrouka; Kammoun, Aouatef; Rehaiem, Amel; Ghedira, Salma; Houissa, Mohamed; Boutiba-Ben Boubaker, Ilhem; Slim, Amine; Dubois, Veronique

2016-01-01

Healthcare-associated infections due to cefotaxime-resistant (CTX-R) Enterobacteriaceae have become a major public health threat, especially in intensive care units (ICUs). Often acquired nosocomially, CTX-R Enterobacteriaceae can be introduced initially by patients at admission. This study aimed to determine the prevalence and genetic characteristics of CTX-R Enterobacteriaceae-intestinal carriage in ICU patients, to evaluate the rate of acquisition of these organisms during hospitalization, and to explore some of the associated risk factors for both carriage and acquisition. Between December 2014 and February 2015, the 63 patients admitted in the ICU of Charles Nicolle hospital were screened for rectal CTX-R Enterobacteriaceae colonization at admission and once weekly thereafter to identify acquisition. CTX-R Enterobacteriaceae fecal carriage rate was 20.63% (13/63) at admission. Among the 50 non-carriers, 35 were resampled during their hospitalization and the acquisition rate was 42.85% (15/35). Overall, 35 CTX-R Enterobacteriaceae isolates were collected from 28 patients (25 Klebsiella pneumoniae, seven Escherichia coli, and three Enterobacter cloacae strains). Seven patients were simultaneously colonized with two CTX-R Enterobacteriaceae isolates. CTX-M-15 was detected in most of the CTX-R Enterobacteriaceae isolates (30/35, 88.23%). Three strains co-produced CMY-4 and 22 strains were carbapenem-resistant and co-produced a carbapenemase [OXA-48 (n = 13) or NDM-1 (n = 6)]. Molecular typing of K. pneumoniae strains, revealed eight Pulsed field gel electrophoresis (PFGE) patterns and four sequence types (ST) [ST101, ST147, ST429, and ST336]. However, E. coli isolates were genetically unrelated and belonged to A (n = 2), B1 (n = 2) and B2 (n = 3) phylogenetic groups and to ST131 (two strains), ST572 (two strains), ST615 (one strain) and ST617 (one strain). Five colonized patients were infected by CTX-R Enterobacteriaceae (four with the same strain identified from

Presence of mcr-1-positive Enterobacteriaceae in retail chicken meat but not in humans in the Netherlands since 2009.

PubMed

Kluytmans-van den Bergh, Marjolein F; Huizinga, Pepijn; Bonten, Marc J; Bos, Martine; De Bruyne, Katrien; Friedrich, Alexander W; Rossen, John W; Savelkoul, Paul H; Kluytmans, Jan A

2016-01-01

Recently, the plasmid-mediated colistin resistance gene mcr-1 was found in Enterobacteriaceae from humans, pigs and retail meat in China. Several reports have documented global presence of the gene in Enterobacteriaceae from humans, food animals and food since. We screened several well-characterised strain collections of Enterobacteriaceae, obtained from retail chicken meat and hospitalised patients in the Netherlands between 2009 and 2015, for presence of colistin resistance and the mcr-1 gene. A total of 2,471 Enterobacteriaceae isolates, from surveys in retail chicken meat (196 isolates), prevalence surveys in hospitalised patients (1,247 isolates), clinical cultures (813 isolates) and outbreaks in healthcare settings (215 isolates), were analysed. The mcr-1 gene was identified in three (1.5%) of 196 extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli isolates from retail chicken meat samples in 2009 and 2014. Two isolates were obtained from the same batch of meat samples, most likely representing contamination from a common source. No mcr-1-positive isolates were identified among 2,275 human isolates tested. All mcr-1-positive isolates were colistin-resistant (minimum inhibitory concentration (MIC) > 2 mg/L). Our findings indicate that mcr-1-based colistin-resistance currently poses no threat to healthcare in the Netherlands. They indicate however that continued monitoring of colistin resistance and its underlying mechanisms in humans, livestock and food is needed.

Cost-effectiveness of bedaquiline in MDR and XDR tuberculosis in Italy

PubMed Central

Codecasa, Luigi R.; Toumi, Mondher; D’Ausilio, Anna; Aiello, Andrea; Damele, Francesco; Termini, Roberta; Uglietti, Alessia; Hettle, Robert; Graziano, Giorgio; De Lorenzo, Saverio

2017-01-01

ABSTRACT Objective: To evaluate the cost-effectiveness of bedaquiline plus background drug regimens (BR) for multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) in Italy. Methods: A Markov model was adapted to the Italian setting to estimate the incremental cost-effectiveness ratio (ICER) of bedaquiline plus BR (BBR) versus BR in the treatment of MDR-TB and XDR-TB over 10 years, from both the National Health Service (NHS) and societal perspective. Cost-effectiveness was evaluated in terms of life-years gained (LYG). Clinical data were sourced from trials; resource consumption for compared treatments was modelled according to advice from an expert clinicians panel. NHS tariffs for inpatient and outpatient resource consumption were retrieved from published Italian sources. Drug costs were provided by reference centres for disease treatment in Italy. A 3% annual discount was applied to both cost and effectiveness. Deterministic and probabilistic sensitivity analyses were conducted. Results: Over 10 years, BBR vs. BR alone is cost-effective, with ICERs of €16,639/LYG and €4081/LYG for the NHS and society, respectively. The sensitivity analyses confirmed the robustness of the results from both considered perspectives. Conclusion: In Italy, BBR vs. BR alone has proven to be cost-effective in the treatment of MDR-TB and XDR-TB under a range of scenarios. PMID:28265350

Individualised second line anti-tuberculous therapy for an extensively resistant pulmonary tuberculosis (XDR PTB) in East Malaysia.

PubMed

Muhammad Redzwan, S R A; Ralph, A P; Sivaraman Kannan, K K; William, T

2015-06-01

Clinical experience with extensively Drug Resistant tuberculosis (XDR-TB) has not been reported in Malaysia before. We describe the clinical characteristics, risk factors, progress and therapeutic regimen for a healthcare worker with XDR-TB, who had failed therapy for multidrug resistant TB (MDR TB) in our institution. This case illustrates the risk of TB among healthcare workers in high TB-burden settings, the importance of obtaining upfront culture and susceptibility results in all new TB cases, the problem of acquired drug resistance developing during MDR-TB treatment, the challenges associated with XDR-TB treatment regimens, the value of surgical resection in refractory cases, and the major quality of life impact this disease can have on young, economically productive individuals.

Phenotypic Tests for the Detection of β-Lactamase-Producing Enterobacteriaceae Isolated from Different Environments.

PubMed

de Oliveira, Daniele V; Van Der Sand, Sueli T

2016-07-01

Some bacteria from the Enterobacteriaceae family are showing a significant capability to disseminate β-lactams resistance mechanisms among them, and these same mechanisms can be carried out from the hospital environment to superficial water. The aim of this study was to evaluate different phenotypic methods for the detection β-lactamases production by enterobacteria isolated from the anthropogenic environment: hospital wastewater and from a stream that cross the city of Porto Alegre. The applied tests were the modified Hodge test (MHT) and phenotypic tests with the following inhibitors: carbapenemase-phenylboronic acid (APB), metallo-β-lactamase-EDTA, AmpC β-lactamase-cloxacillin, and the confirmatory test for extended-spectrum β-lactamase (ESBL)-clavulanic acid. For this evaluation, 131 isolates were initially subjected to antibiogram using the following antimicrobials: cefotaxime (30 µg), cefpodoxime (10 μg), ceftazidime (30 µg), ertapenem (10 μg), meropenem (10 μg), and aztreonam (30 μg). After this first screening, 62 isolates showed a profile resistance for at least one antimicrobial. These isolates were subjected to all phenotypic tests. Of those, 40 isolates were positive for at least one phenotypic test. In MHT test, one isolate was positive and five were with inconclusive results. The results achieved with the inhibitors are as follows: APB 25/40 positive strains; EDTA 8/40 positive strains; and with CLOXA 2/40 positive strains. ESBL production was observed for 34/40 strains. This assessment shows a high level of bacteria which can produce enzymes that inactivate β-lactams present in the different environment like the stream waters and from the hospital settings.

Faecal carriage of extended-spectrum β-lactamase-producing Enterobacteriaceae among humans in Java, Indonesia, in 2001-2002.

PubMed

Severin, Juliëtte A; Lestari, Endang Sri; Kloezen, Wendy; Lemmens-den Toom, Nicole; Mertaniasih, Ni Made; Kuntaman, Kuntaman; Purwanta, Marijam; Duerink, D Offra; Hadi, Usman; van Belkum, Alex; Verbrugh, Henri A; Goessens, Wil H

2012-04-01

To characterise commensal Escherichia coli and other Enterobacteriaceae with reduced susceptibility to cefotaxime that were collected in a large survey carried out among 3995 patients and healthy persons in two urban regions on Java, Indonesia, in 2001-2002. The putative extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae were analysed using double-disk synergy tests, isoelectric focusing, PCR assays, DNA sequencing, and pulsed-field gel electrophoresis (PFGE). On the day of discharge after five or more days of hospitalisation, at least 95 of 999 (9.5%) patients carried ESBL-positive Enterobacteriaceae as dominant faecal flora. Six patients were simultaneously colonised with E. coli and Klebsiella pneumoniae isolates with ESBL activity. On admission, only 6 of 998 (0.6%) patients were colonised. Faecal carriage of ESBL-producing Enterobacteriaceae among healthy persons or persons visiting a public health centre was not detected. The 107 ESBL-positive strains included 68 E. coli, 35 K. pneumoniae, and four other Enterobacteriaceae. bla(CTX-M-15) was the most prevalent ESBL in both E. coli (47.1%) and K. pneumoniae (45.7%), but the E. coli O25b-ST131 clone was virtually absent. Other ESBL types found were: SHV-2, -2a, -5, -12, CTX-M-3, -9, -14, and TEM-19. PFGE revealed extensive genetic diversity among the isolates. In 2001-2002, faecal carriage of ESBL-producing Enterobacteriaceae as dominant flora in Indonesia was almost exclusively hospital-associated. The presence of various bla(ESBL) genes and the extensive genetic diversity among isolates argue against a single/dominant strain outbreak. © 2012 Blackwell Publishing Ltd.

The establishment of Enterobacteriaceae and Salmonella London in a new dairy farm environment.

PubMed

Shipp, Ginger M; Dickson, James S

2011-03-01

Salmonella spp. are important zoonotic pathogens in humans and animals. A longitudinal study was conducted at the Iowa State University's campus (at the Dairy/Animal Science Education and Discovery Facility) to observe change in Enterobacteriaceae (specifically Salmonella) before and after the placement of dairy livestock. To our knowledge, this is the first study that evaluated environmental changes of Gram-negative organisms in a new dairy farm environment. Environmental samples were taken using drag swabs and immediately processed in the laboratory using phenotypic methods (replica plating, the BBL Crystal Identification System for enteric/nonfermenter organisms™, and plating on specialized media/broths). Genotypic methods were also used (BAX PCR™ and pulsed-field gel electrophoresis). Organisms identified as Salmonella were sent to the National Veterinary Services Laboratory (Ames, IA) for confirmatory serotyping. Resistance to antibiotics (ampicillin, nalidixic acid, and tetracycline) was determined by replica plating of Enterobacteriaceae and Salmonella isolates using the guidelines of the National Antimicrobial Resistance Monitoring System and Clinical and Laboratory Standards Institute. The microflora of Enterobacteriaceae changed as cattle were introduced and as time progressed. Additionally, multidrug-resistant isolates began to appear immediately after cattle were introduced (multidrug-resistant isolates were rare prior to introduction of livestock). Variables such as temperature and humidity did not affect the proliferation of bacterial organisms. Seventeen Salmonella isolates were identified as Salmonella London and three isolates as Salmonella Montevideo. Based on pulsed-field gel electrophoresis-generated dendrograms, it is likely that 17 Salmonella London isolates and 3 Salmonella Montevideo isolates are clonal.

Antagonistic Activity of Nocardia brasiliensis PTCC 1422 Against Isolated Enterobacteriaceae from Urinary Tract Infections.

PubMed

Jalali, Hossnieh Kafshdar; Salamatzadeh, Abdolreza; Jalali, Arezou Kafshdar; Kashani, Hamed Haddad; Asbchin, Salman Ahmadi; Issazadeh, Khosro

2016-03-01

The main drawback of current antibiotic therapies is the emergence and rapid increase in antibiotic resistance. Nocardiae are aerobic, Gram-positive, catalase-positive, non-motile actinomycetes. Nocardia brasiliensis was reported as antibiotic producer. The purpose of the study was to determine antibacterial activity of N. brasiliensis PTCC 1422 against isolated Enterobacteriaceae from urinary tract infections (UTIs). The common bacteria from UTIs were isolated from hospital samples. Antimicrobial susceptibility test was performed for the isolated pathogens using Kirby-Bauer disk diffusion method according to clinical and Laboratory Standards Institute guideline. Antagonistic activity of N. brasiliensis PTCC 1422 was examined with well diffusion methods. Supernatant of N. brasiliensis PTCC 1422 by submerged culture was analyzed with gas chromatography-mass spectrometry. Isolated strains included Escherichia coli, Klebsiella pneumoniae, Serratia marcescens and Proteus mirabilis. The most common pathogen isolated was E. coli (72.5%). Bacterial isolates revealed the presence of high levels of antimicrobial resistances to ceftriaxone and low levels of resistance to cephalexin. Supernatant of N. brasiliensis PTCC 1422 showed antibacterial activity against all of the isolated microorganisms in well diffusion method. The antibiotic resistance among the uropathogens is an evolving process, so a routine surveillance to monitor the etiologic agents of UTI and the resistance pattern should be carried out timely to choose the most effective empirical treatment by the physicians. Our present investigation indicates that the substances present in the N. brasiliensis PTCC 1422 could be used to inhibit the growth of human pathogen. Antibacterial resistance among bacterial uropathogen is an evolving process. Therefore, in the field on the need of re-evaluation of empirical treatment of UTIs, our present. The study has demonstrated that N. brasiliensis PTCC 1422 has a high potential

Genomic epidemiology of global VIM-producing Enterobacteriaceae.

PubMed

Matsumura, Yasufumi; Peirano, Gisele; Devinney, Rebekah; Bradford, Patricia A; Motyl, Mary R; Adams, Mark D; Chen, Liang; Kreiswirth, Barry; Pitout, Johann D D

2017-08-01

International data on the molecular epidemiology of Enterobacteriaceae with VIM carbapenemases are limited. We performed short read (Illumina) WGS on a global collection of 89 VIM-producing clinical Enterobacteriaceae (2008-14). VIM-producing (11 varieties within 21 different integrons) isolates were mostly obtained from Europe. Certain integrons with bla VIM were specific to a country in different species and clonal complexes (CCs) (In 87 , In 624 , In 916 and In 1323 ), while others had spread globally among various Enterobacteriaceae species (In 110 and In 1209 ). Klebsiella pneumoniae was the most common species ( n  = 45); CC147 from Greece was the most prevalent clone and contained In 590 -like integrons with four different bla VIM s. Enterobacter cloacae complex was the second most common species and mainly consisted of Enterobacter hormaechei ( Enterobacter xiangfangensis , subsp. steigerwaltii and Hoffmann cluster III). CC200 (from Croatia and Turkey), CC114 (Croatia, Greece, Italy and the USA) and CC78 (from Greece, Italy and Spain) containing bla VIM-1 were the most common clones among the E. cloacae complex. This study highlights the importance of surveillance programmes using the latest molecular techniques in providing insight into the characteristics and global distribution of Enterobacteriaceae with bla VIM s. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Carbapenemase-Producing Enterobacteriaceae and Nonfermentative Bacteria, the Philippines, 2013-2016.

PubMed

Velasco, John Mark; Valderama, Maria Theresa; Peacock, Trent; Warawadee, Nirdnoy; Nogrado, Kathyleen; Navarro, Fatima Claire; Chua, Domingo; Apichai, Srijan; Sirigade, Ruekit; Macareo, Louis R; Swierczewski, Brett

2017-09-01

During 2013-2016, we isolated bla NDM - and bla VIM -harboring Enterobacteriaceae and nonfermentative bacteria from patients in the Philippines. Of 130 carbapenem-resistant isolates tested, 45 were Carba NP-positive; 43 harbored bla NDM , and 2 harbored bla VIM . Multidrug-resistant microbial pathogen surveillance and antimicrobial drug stewardship are needed to prevent further spread of New Delhi metallo-β-lactamase variants.

Managing a case of extensively drug-resistant (XDR) pulmonary tuberculosis in Singapore.

PubMed

Phua, Chee Kiang; Chee, Cynthia B E; Chua, Angeline P G; Gan, Suay Hong; Ahmed, Aneez D B; Wang, Yee Tang

2011-03-01

Extensively drug-resistant tuberculosis (XDR-TB) is an emerging global health risk. We present the first case report of XDR-TB in Singapore. A 41-year-old Indonesian lady with previously treated pulmonary tuberculosis presented with chronic cough. Her sputum was strongly acid-fast bacilli positive and grew Mycobacterium tuberculosis complex resistant to first and second-line TB medications. She received 5 months of intensive multidrug treatment without sputum smear conversion. She then underwent resection of the diseased lung. The total cost incurred amounted to over S$100,000. She achieved sputum smear/culture conversion post-surgery, but will require further medical therapy for at least 18 months. XDRTB is poorly responsive to therapy and extremely expensive to manage. Its prevention by strict compliance to therapy is paramount.

Enterobacteriaceae in dehydrated powdered infant formula manufactured in Indonesia and Malaysia.

PubMed

Estuningsih, Sri; Kress, Claudia; Hassan, Abdulwahed A; Akineden, Omer; Schneider, Elisabeth; Usleber, Ewald

2006-12-01

To determine the occurrence of Salmonella and Shigella in infant formula from Southeast Asia, 74 packages of dehydrated powdered infant follow-on formula (recommended age, > 4 months) from five different manufacturers, four from Indonesia and one from Malaysia, were analyzed. None of the 25-g test portions yielded Salmonella or Shigella. However, further identification of colonies growing on selective media used for Salmonella and Shigella detection revealed the frequent occurrence of several other Enterobacteriaceae species. A total of 35 samples (47%) were positive for Enterobacteriaceae. Ten samples (13.5%) from two Indonesian manufacturers yielded Enterobacter sakazakii. Other Enterobacteriaceae isolated included Pantoea spp. (n = 12), Escherichia hermanii (n = 10), Enterobacter cloacae (n = 8), Klebsiella pneumoniae subsp. pneumoniae (n = 3), Citrobacter spp. (n = 2), Serratia spp. (n = 2), and Escherichia coli (n = 2). To our knowledge, this is the first report to describe the contamination of dehydrated powdered infant formula from Indonesia with E. sakazakii and several other Enterobacteriaceae that could be opportunistic pathogens. Improper preparation and conservation of these products could result in a health risk for infants in Indonesia.

Carbapenem-Nonsusceptible Enterobacteriaceae in Taiwan

PubMed Central

Wang, Jann-Tay; Wu, Un-In; Lauderdale, Tsai-Ling Yang; Chen, Mei-Chen; Li, Shu-Ying; Hsu, Le-Yin; Chang, Shan-Chwen

2015-01-01

A total of 1135 carbapenem-resistant (nonsusceptible) Enterobacteriaceae (CRE) isolates were recovered between November 2010 and July 2012 (517 from 2010-2011 and 618 from 2012) from 4 hospitals in Taiwan. Carbapenemase-producing Enterobacteriaceae (CPE) comprised 5.0% (57 isolates), including 17 KPC-2 (16 Klebsiella pneumoniae and 1 Escherichia coli), 1 NDM-1 (K. oxytoca), 37 IMP-8 (26 Enterobacter cloacae, 4 Citrobacter freundii, 4 Raoultella planticola, 1 K. pneumoniae, 1 E. coli and 1 K. oxytoca), and 2 VIM-1 (1 E. cloacae, 1 E. coli). The KPC-2-positive K. pneumoniae were highly clonal even in isolates from different hospitals, and all were ST11. IMP-8 positive E. cloacae from the same hospitals showed higher similarity in PFGE pattern than those from different hospitals. A total of 518 CRE isolates (45.6%) were positive for bla ESBL, while 704 (62.0%) isolates were bla AmpC-positive, 382 (33.6% overall) of which carried both bla ESBL and bla AmpC. CTX-M (414, 80.0%) was the most common bla ESBL, while DHA (497, 70.6%) and CMY (157, 22.3%) were the most common bla AmpC. Co-carriage of bla ESBL and bla AmpC was detected in 31 (54.4%) and 15 (26.3%) of the 57 CPE, respectively. KPC-2 was the most common carbapenemase detected in K. pneumoniae (2.8%), while IMP-8 was the most common in E. cloacae (9.7%). All KPC-2-positive CRE were resistant to all three tested carbapenems. However, fourteen of the 37 IMP-8-positive CRE were susceptible to both imipenem and meropenem in vitro. Intra- and inter-hospital spread of KPC-2-producing K. pneumoniae and IMP-8-producing E. cloacae likely occurred. Although the prevalence of CPE is still low, careful monitoring is urgently needed. Non-susceptibility to ertapenem might need to be considered as one criterion of definition for CRE in areas where IMP type carbapenemase is prevalent. PMID:25794144

Comparison of in-house and commercial real time-PCR based carbapenemase gene detection methods in Enterobacteriaceae and non-fermenting gram-negative bacterial isolates.

PubMed

Smiljanic, M; Kaase, M; Ahmad-Nejad, P; Ghebremedhin, B

2017-07-10

Carbapenemase-producing gram-negative bacteria are increasing globally and have been associated with outbreaks in hospital settings. Thus, the accurate detection of these bacteria in infections is mandatory for administering the adequate therapy and infection control measures. This study aimed to establish and evaluate a multiplex real-time PCR assay for the simultaneous detection of carbapenemase gene variants in gram-negative rods and to compare the performance with a commercial RT-PCR assay (Check-Direct CPE). 116 carbapenem-resistant Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter baumannii isolates were genotyped for carbapenemase genes by PCR and sequencing. The defined isolates were used for the validation of the in-house RT-PCR by use of designed primer pairs and probes. Among the carbapenem-resistant isolates the genes bla KPC , bla VIM , bla NDM or bla OXA were detected. Both RT-PCR assays detected all bla KPC , bla VIM and bla NDM in the isolates. The in-house RT-PCR detected 53 of 67 (79.0%) whereas the commercial assay detected only 29 (43.3%) of the OXA genes. The in-house sufficiently distinguished the most prevalent OXA types (23-like and 48-like) in the melting curve analysis and direct detection of the genes from positive blood culture vials. The Check-Direct CPE and the in-house RT-PCR assay detected the carbapenem resistance from solid culture isolates. Moreover, the in-house assay enabled the identification of carbapenemase genes directly from positive blood-culture vials. However, we observed insufficient detection of various OXA genes in both assays. Nevertheless, the in-house RT-PCR detected the majority of the OXA type genes in Enterobacteriaceae and A. baumannii.

Detection of Different β-Lactamases and their Co-existence by Using Various Discs Combination Methods in Clinical Isolates of Enterobacteriaceae and Pseudomonas spp.

PubMed Central

Rawat, Vinita; Singhai, Monil; Verma, Pankaj Kumar

2013-01-01

Background: Resistance to broad spectrum beta-lactams mediated by extended spectrum β-lactamase (ESBL), AmpC, and metallobetalactamase (MBLs) enzymes are an increasing problem worldwide. The study was aimed to detect occurrence rate and to evaluate different substrates and inhibitors by disc combination method for detecting varying degree of β-lactamase enzymes and their co-production. Materials and Methods: A disc panel containing imipenem (IMP), IMP/EDTA, ceftazidime (CA), ceftazidime-tazobactum (CAT), CAT/cloxacillin (CLOX), ceftazidime-clavulanic acid (CAC), CAC/CLOX, cefoxitin (CN), and CN/CLOX in a single plate was used to detect presence of ESBLs, AmpC, and MBLs and/or their co-existence in 184 consecutive, nonrepetitive, clinical isolates of Enterobacteriace (n = 96) and Pseudomonas spp. (n = 88) from pus samples of hospitalized patients, resistant to 3rd generation cephalosporins. Results: Out of a total of 96 clinical isolates of Enterobacteriaceae, 18.7, 20.8, and 27% were pure ESBL, AmpC, and MBL producers, respectively. ESBL and AmpC were co-produced by 25% isolates. Among 88 Pseudomonas spp. 38.6, 13, and 6% were pure MBL, ESBL, and AmpC producers, respectively. ESBL/AmpC and MBL/AmpC co-production was seen in 20% and 18% isolates, respectively. Among ESBL and AmpC co-producers, CA/CAC/CLOX disc combination (DC) missed 7 of the 24 ESBL producers in Enterobacteriace and 4 of the 18 ESBL in Pseudomonas spp., which were detected by CA/CAT/CLOX DC. No mechanism was detected among 8.3% Enterobacteriaceae and 2.3% Pseudomonas isolates. Conclusion: Diagnostic problems posed by co-existence of different classes of β-lactamases in a single isolate could be solved by disc combination method by using simple panel of discs containing CA, CAT, CAT/CLOX, IMP, and IMP/EDTA. PMID:24014963

Dominance of IMP-4-Producing Enterobacter cloacae among Carbapenemase-Producing Enterobacteriaceae in Australia

PubMed Central

Townell, Nicola; Nimmo, Graeme R.; George, Narelle M.; Robson, Jennifer; Vohra, Renu; Davis, Louise; Heney, Claire; Paterson, David L.

2015-01-01

The prevalence of carbapenemase-producing Enterobacteriaceae (CPE) has been increasing worldwide. blaIMP has been reported to be the predominant carbapenemase-encoding gene within Enterobacteriaceae in Australia. However, there are limited data currently available on CPE from Queensland, Australia. A total of 58 CPE isolates were isolated between July 2009 and March 2014 from Queensland hospitals. The clonality of isolates was determined by Diversilab repetitive sequence-based PCR. The isolates were investigated for the resistance mechanisms carbapenemase, extended-spectrum β-lactamase, and AmpC β-lactamase and for aminoglycoside resistance and plasmid-mediated quinolone resistance genes by PCR. The plasmid types associated with carbapenemase-encoding genes were characterized. The majority of the CPE were Enterobacter cloacae (n = 29). The majority of Queensland CPE isolates were IMP producers and comprised 11 species (n = 48). Nine NDM-producing Enterobacteriaceae were identified. One NDM-producing Klebsiella pneumoniae isolate coproduced OXA-48. One K. pneumoniae isolate was an OXA-181 producer. The incidence of IMP producers increased significantly in 2013. blaIMP-4 was found in all IMP-producing isolates. blaTEM, qnrB, and aacA4 were common among IMP-4 producers. The HI2 (67%) and L/M (21%) replicons were associated with blaIMP-4. All HI2 plasmids were of sequence type 1 (ST1). All but one of the NDM producers possessed blaCTX-M-15. The 16S rRNA methylase genes found among NDM producers were armA, rmtB, rmtC, and rmtF. The substantial increase in the prevalence of CPE in Queensland has been associated mainly with the emergence E. cloacae strains possessing HI2 plasmids carrying blaIMP-4 over the past 2 years. The importation of NDM producers and/or OXA-48-like producers in patients also contributed to the increased emergence of CPE. PMID:25918153

Abundance of Enterobacteriaceae in the colon mucosa in diverticular disease.

PubMed

Linninge, Caroline; Roth, Bodil; Erlanson-Albertsson, Charlotte; Molin, Göran; Toth, Ervin; Ohlsson, Bodil

2018-02-15

To compare gut bacterial diversity and amount of Enterobacteriaceae in colonic mucosa between patients with and without diverticular disease (DD). Patients in a stable clinical condition with planned elective colonoscopy were included. Blood samples and colon mucosa biopsies were collected at the colonoscopy. Study questionnaires including questions about gastrointestinal symptoms were completed by the patients and physicians. DNA from mucosa samples was isolated and the amount of Enterobacteriaceae was estimated using PCR assay. Terminal restriction fragment length polymorphism was applied to assess microbial diversity. Diversity was estimated by calculations of richness (number of terminal restriction fragments) and Shannon-Wiener and Simpson's indices. A total of 51 patients were included, 16 patients with DD [68 (62-76) years] and 35 controls [62 (40-74) years] without any diverticula. Patients with DD had significantly higher levels of Enterobacteriaceae than those without DD ( P = 0.043), and there was an inverse relationship between the amount of Enterobacteriaceae and the Simpson's index (rs = -0.361, P = 0.033) and the Shannon-Wiener index (rs = -0.299, P = 0.081). The Simpson's index ( P = 0.383), Shannon-Wiener index ( P = 0.401) or number of restrictions fragments ( P = 0.776) did not differ between DD and controls. The majority of patients experienced gastrointestinal symptoms, and 22 patients (43.1%) fulfilled the criteria for irritable bowel syndrome, with no difference between the groups ( P = 0.212). Demography, socioeconomic status, lifestyle habits, inflammatory biomarkers, or symptoms were not related to the amount of Enterobacteriaceae or bacterial diversity. Patients with DD had higher amount of Enterobacteriaceae in the colon mucosa compared to patients without diverticula.

Abundance of Enterobacteriaceae in the colon mucosa in diverticular disease

PubMed Central

Linninge, Caroline; Roth, Bodil; Erlanson-Albertsson, Charlotte; Molin, Göran; Toth, Ervin; Ohlsson, Bodil

2018-01-01

AIM To compare gut bacterial diversity and amount of Enterobacteriaceae in colonic mucosa between patients with and without diverticular disease (DD). METHODS Patients in a stable clinical condition with planned elective colonoscopy were included. Blood samples and colon mucosa biopsies were collected at the colonoscopy. Study questionnaires including questions about gastrointestinal symptoms were completed by the patients and physicians. DNA from mucosa samples was isolated and the amount of Enterobacteriaceae was estimated using PCR assay. Terminal restriction fragment length polymorphism was applied to assess microbial diversity. Diversity was estimated by calculations of richness (number of terminal restriction fragments) and Shannon-Wiener and Simpson’s indices. RESULTS A total of 51 patients were included, 16 patients with DD [68 (62-76) years] and 35 controls [62 (40-74) years] without any diverticula. Patients with DD had significantly higher levels of Enterobacteriaceae than those without DD (P = 0.043), and there was an inverse relationship between the amount of Enterobacteriaceae and the Simpson’s index (rs = -0.361, P = 0.033) and the Shannon-Wiener index (rs = -0.299, P = 0.081). The Simpson’s index (P = 0.383), Shannon-Wiener index (P = 0.401) or number of restrictions fragments (P = 0.776) did not differ between DD and controls. The majority of patients experienced gastrointestinal symptoms, and 22 patients (43.1%) fulfilled the criteria for irritable bowel syndrome, with no difference between the groups (P = 0.212). Demography, socioeconomic status, lifestyle habits, inflammatory biomarkers, or symptoms were not related to the amount of Enterobacteriaceae or bacterial diversity. CONCLUSION Patients with DD had higher amount of Enterobacteriaceae in the colon mucosa compared to patients without diverticula. PMID:29487763

Outcomes of UTI and bacteriuria caused by ESBL vs. non-ESBL Enterobacteriaceae isolates in pregnancy: a matched case-control study.

PubMed

Yagel, Y; Nativ, H; Riesenberg, K; Nesher, L; Saidel-Odes, L; Smolyakov, R

2018-04-01

Infections caused by extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) have become increasingly prevalent, posing a serious public threat worldwide. It is commonly believed that untreated urinary tract infections (UTI) and asymptomatic bacteriuria (ABU) during pregnancy are associated with poor obstetric outcomes. Currently, there is a paucity of data regarding the outcomes or risk factors of such ESBL-E infections in pregnant women. We conducted a retrospective 1:2 matched case-control study of hospitalised pregnant women with ESBL-E- vs. non-ESBL-producing Enterobacteriaceae-positive urine cultures obtained between 2004 and 2015, and compared risk factors for the development of resistant bacteria, clinical course and outcomes. In total, 87 pregnant women with ESBL-E-positive urine cultures were matched to 174 controls by decade of age, ethnicity and pregnancy trimester. Significant risk factors for acquisition of ESBL-E included prior UTI/ABU episodes (50.6% vs. 26.3%, P < 0.001), previous isolation of ESBL-E in urine cultures (12.6% vs. 0.6%, P < 0.001) and prior antibiotic exposure (71.3% vs. 54%, P = 0.002). Previous hospitalisation, however, was not found to be a risk factor. No significant difference was found in adverse obstetric outcomes. We conclude that prior urinary infections and antibiotic exposure were significant risk factors for the isolation of ESBL-E pathogens from the urine of pregnant women; however, this was not associated with worse obstetric outcomes compared with non-ESBL-E pathogens.

Emergence of serine carbapenemases (KPC and SME) among clinical strains of Enterobacteriaceae isolated in the United States Medical Centers: report from the MYSTIC Program (1999-2005).

PubMed

Deshpande, Lalitagauri M; Rhomberg, Paul R; Sader, Helio S; Jones, Ronald N

2006-12-01

Among 8885 Enterobacteriaceae tested in the 1999 to 2005 period as part of the USA Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Program, 51 strains with increased imipenem and meropenem MIC values (> or =2 microg/mL) were detected. bla(KPC) was identified from 28 Klebsiella pneumoniae from 3 medical centers in the New York City area (8 ribotypes), 2 Klebsiella oxytoca from Arkansas (same ribotype), 7 Citrobacter freundii (6 from New York [5 ribotypes] and 1 from Delaware), 4 Enterobacter spp. from New York (2 species, different ribotypes), 3 Escherichia coli (2 from New York and 1 from Ohio, same ribotype), and 1 Serratia marcescens (New York). Sequencing confirmed KPC-2 or -3 in all of the strains. S. marcescens strains harboring SME-1 (2 isolates, same ribotype) and SME-2 (1 isolate) were identified from medical centers in Illinois and Washington state, respectively. Our results indicate that bla(KPC-2/3) has emerged widely (New York City area, Arkansas, Delaware, and Ohio) among Enterobacteriaceae isolated in the MYSTIC Program participant sites (2000-2005) and continues to be isolated from multiple species, as a result of clonal expansion and horizontal gene transfer. The escalating occurrence (0.35%) of serine carbapenemases could compromise the role of carbapenems and other beta-lactams in USA clinical practice although observed in only a few locations to date.

A Five-Year Experience of Carbapenem Resistance in Enterobacteriaceae Causing Neonatal Septicaemia: Predominance of NDM-1

PubMed Central

Datta, Saswati; Roy, Subhasree; Chatterjee, Somdatta; Saha, Anindya; Sen, Barsha; Pal, Titir; Som, Tapas; Basu, Sulagna

2014-01-01

Treatment of neonatal sepsis has become a challenge with the emergence of carbapenemase-producing bacteria. This study documents the trend of carbapenem susceptibility in Enterobacteriaceae that caused septicaemia in neonates over a five year period (2007–2011) and the molecular characterisation of Enterobacteriaceae resistant to carbapenems and cephalosporins. Hundred and five Enterobacteriaceae including Escherichia coli (n = 27), Klebsiella pneumoniae (n = 68) and Enterobacter spp. (n = 10) were isolated from blood of septicaemic neonates followed by antibiotic susceptibility tests, determination of MIC values, phenotypic and genotypic detection of β-lactamases. Carbapenem was the most active antimicrobial tested after tigecycline. CTX-M type was the most prevalent ESBL throughout the period (82%). New Delhi Metallo-β-lactamase-1 (NDM-1), which is a recent addition to the carbapenemase list, was the only carbapenemase identified in our setting. Fourteen percent of the isolates possessed bla NDM-1. Carbapenem non-susceptibility was first observed in 2007 and it was due to loss of Omp F/Ompk36 in combination with the presence of ESBLs/AmpCs. NDM-1 first emerged in E. coli during 2008; later in 2010, the resistance was detected in K. pneumoniae and E. cloacae isolates. NDM-1-producing isolates were resistant to other broad-spectrum antibiotics and possessed ESBLs, AmpCs, 16S-rRNA methylases, AAC(6′)-Ib-cr, bleomycin resistant gene and class 1 integron. Pulsed field gel electrophoresis of the NDM-1-producing isolates indicated that the isolates were clonally diverse. The study also showed that there was a significantly higher incidence of sepsis caused by NDM-1-harbouring isolates in the male sex, in neonates with low birth weight and neonates born at an extramural centre. However, sepsis with NDM-1-harbouring isolates did not result in a higher mortality rate. The study is the first to review the carbapenem resistance patterns in neonatal sepsis

Prevalence and characterization of extended-spectrum beta-lactamase-producing Enterobacteriaceae in spring waters.

PubMed

Li, S; Zhu, Z C; Wang, L; Zhou, Y F; Tang, Y J; Miao, Z M

2015-12-01

The purpose of this study was to investigate the prevalence and characterization of extended-spectrum beta-lactamases (ESBL)-producing Enterobacteriaceae from spring waters in Mountain Tai of China. ESBL-producing Enterobacteriaceae were found in four out of 50 sampled spring waters (4/50, 8·0%) and a total of 16 non-duplicate ESBL-producing Enterobacteriaceae were obtained, including 13 Escherichia coli (E. coli) and three Klebsiella pneumoniae (Kl. pneumoniae). All 16 nonduplicate ESBL-producing Enterobacteriaceae isolates harboured genes encoding CTX-M ESBLs, among which six expressed CTX-M-15, five produced CTX-M-14, three produced CTX-M-55 and two expressed CTX-M-27. Four multilocus sequence types (ST) were found and ST131 was the dominant type (8/16, 50·0%). Taken together, the contamination of ESBL-producing Enterobacteriaceae were present in spring waters of Mountain Tai. The results indicated that spring waters could become a reservoir of antibiotic resistant bacteria and contribute to the spread of antimicrobial-resistant bacteria via drinking water or food chain. In addition, wastewater discharge of restaurants or hotels may be an important contribution source of antibiotic resistant bacteria in spring waters. © 2015 The Society for Applied Microbiology.

The rapid spread of carbapenem-resistant Enterobacteriaceae

PubMed Central

Potter, Robert F.; D’Souza, Alaric W.; Dantas, Gautam

2016-01-01

Carbapenems, our one-time silver bullet for multidrug resistant bacterial infections, are now threatened by widespread dissemination of carbapenem-resistant Enterobacteriaceae (CRE). Successful expansion of Enterobacteriaceae clonal groups and frequent horizontal gene transfer of carbapenemase expressing plasmids are causing increasing carbapenem resistance. Recent advances in genetic and phenotypic detection facilitate global surveillance of CRE diversity and prevalence. In particular, whole genome sequencing enabled efficient tracking, annotation, and study of genetic elements colocalized with carbapenemase genes on chromosomes and on plasmids. Improved characterization helps detail the co-occurrence of other antibiotic resistance genes in CRE isolates and helps identify pan-drug resistance mechanisms. The novel β-lactamase inhibitor, avibactam, combined with ceftazidime or aztreonam, is a promising CRE treatment compared to current colistin or tigecycline regimens. To halt increasing CRE-associated morbidity and mortality, we must continue quality, cooperative monitoring and urgently investigate novel treatments. PMID:27912842

Clinical and microbiologic characteristics of cefotaxime-non-susceptible Enterobacteriaceae bacteremia: a case control study.

PubMed

Noguchi, Taro; Matsumura, Yasufumi; Yamamoto, Masaki; Nagao, Miki; Takakura, Shunji; Ichiyama, Satoshi

2017-01-07

Cefotaxime plays an important role in the treatment of patients with bacteremia due to Enterobacteriaceae, although cefotaxime resistance is reported to be increasing in association with extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase (AmpC). We conducted a case-control study in a Japanese university hospital between 2011 and 2012. We assessed the risk factors and clinical outcomes of bacteremia due to cefotaxime-non-susceptible Enterobacteriaceae (CTXNS-En) and analyzed the resistance mechanisms. Of 316 patients with Enterobacteriaceae bacteremia, 37 patients with bacteremia caused by CTXNS-En were matched to 74 patients who had bacteremia caused by cefotaxime-susceptible Enterobacteriaceae (CTXS-En). The most common CTXNS-En was Escherichia coli (43%), followed by Enterobacter spp. (24%) and Klebsiella spp. (22%). Independent risk factors for CTXNS-En bacteremia included previous infection or colonization of CTXNS-En, cardiac disease, the presence of intravascular catheter and prior surgery within 30 days. Patients with CTXNS-En bacteremia were less likely to receive appropriate empirical therapy and to achieve a complete response at 72 h than patients with CTXS-En bacteremia. Mortality was comparable between CTXNS-En and CTXS-En patients (5 vs. 3%). CTXNS-En isolates exhibited multidrug resistance but remained highly susceptible to amikacin and meropenem. CTX-M-type ESBLs accounted for 76% of the β-lactamase genes responsible for CTXNS E. coli and Klebsiella spp. isolates, followed by plasmid-mediated AmpC (12%). Chromosomal AmpC was responsible for 89% of CTXNS Enterobacter spp. isolates. CTXNS-En isolates harboring ESBL and AmpC caused delays in appropriate therapy among bacteremic patients. Risk factors and antibiograms may improve the selection of appropriate therapy for CTXNS-En bacteremia. Prevalent mechanisms of resistance in CTXNS-En were ESBL and chromosomal AmpC.

Diversity of extended-spectrum β-lactamase-producing Enterobacteriaceae on hospital admission.

PubMed

Roux, Damien; Huy, Clarisse; Lolom, Isabelle; Andremont, Antoine; Arlet, Guillaume; Armand-Lefevre, Laurence; Lucet, Jean-Christophe

2012-03-01

Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae have become prevalent in both the hospital and the community. We describe the epidemiology of ESBL-producing isolates and patient characteristics at hospital admission. Data on clinical properties, medical history, previous hospitalizations, and previous antibiotic treatments were collected. ESBL genes (bla(CTX-M), bla(TEM), and bla(SHV)) were identified by polymerase chain reaction. One hundred and sixteen patients carried 122 ESBL-producing Enterobacteriaceae: 79 Escherichia coli, 26 Klebsiella pneumoniae, 16 Enterobacter spp., and 1 Citrobacter koseri. ESBL-producing E. coli were associated with admission from home (odds ratio (OR) 3.04, p = 0.02) and a history of recent urinary tract infection (OR 3.38, p = 0.04), and exhibited a lower rate of antimicrobial resistance to aminoglycosides (p ≤ 0.005) and co-trimoxazole (p = 0.003), whereas other ESBL-producing Enterobacteriaceae tended to be associated with a recent surgery (OR 0.42, p = 0.057). Although the CTX-M enzymes were more frequently found in E. coli (76%), they were also identified in other Enterobacteriaceae (45%), suggesting penetration of CTX-M-type enzymes into both community- and hospital-acquired enterobacterial species.

Performance of CarbaNP and CIM tests in OXA-48 carbapenemase-producing Enterobacteriaceae.

PubMed

Yıldız, Serap Süzük; Kaşkatepe, Banu; Avcıküçük, Havva; Öztürk, Şükran

2017-03-01

This study applied two phenotypic tests, namely "Carbapenemase Nordmann-Poirel" (CarbaNP) test and "Carbapenem Inactivation Method" (CIM), against the isolates carrying the carbapenem resistance genes. The study included 83 carbapenem-resistant Enterobacteriaceae isolates producing oxacillinase-48 (OXA-48) and 30 carbapenem-sensitive Enterobacteriaceae isolates. Out of the total isolates studied, 77 isolates (92.77%) were identified as Klebsiella pneumoniae and six isolates (7.23%) were identified as Escherichia coli by Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry. Polymerase chain reaction (PCR) method used to detect resistance genes found that 74 isolates (89.16%) produced OXA-48 carbapenemase, whereas nine isolates (10.84%) produced both OXA-48 and New Delhi metallo-beta-lactamase-1 (NDM-1). The isolates producing both OXA-48 and NDM-1 were found to be positive by both phenotypic tests. Among isolates carrying only bla OXA-48 gene alone, nine isolates (13.04%) for CarbaNP test and two isolates for CIM test (2.90%) displayed false negative results, respectively. The sensitivity of CarbaNP and CIM tests was found to be 89.16% and 97.59%, respectively, whereas the specificity was determined to be 100% for both tests. These findings suggest that CarbaNP and CIM tests are useful tools to identify the carbapenemase producers. Molecular methods like PCR are recommended to verify false negative tests predicted to have OXA-48 activity.

Carbapenemase-Producing Enterobacteriaceae and Nonfermentative Bacteria, the Philippines, 2013–2016

PubMed Central

Valderama, Maria Theresa; Peacock, Trent; Warawadee, Nirdnoy; Nogrado, Kathyleen; Navarro, Fatima Claire; Chua, Domingo; Apichai, Srijan; Sirigade, Ruekit; Macareo, Louis R.; Swierczewski, Brett

2017-01-01

During 2013–2016, we isolated blaNDM- and blaVIM-harboring Enterobacteriaceae and nonfermentative bacteria from patients in the Philippines. Of 130 carbapenem-resistant isolates tested, 45 were Carba NP–positive; 43 harbored blaNDM, and 2 harbored blaVIM. Multidrug-resistant microbial pathogen surveillance and antimicrobial drug stewardship are needed to prevent further spread of New Delhi metallo-β-lactamase variants. PMID:28820383

Analysis of β-Lactamase Resistance Determinants in Enterobacteriaceae from Chicago Children: a Multicenter Survey

PubMed Central

Hujer, Andrea M.; Marshall, Steven H.; Domitrovic, T. Nicholas; Rudin, Susan D.; Zheng, Xiaotian; Qureshi, Nadia K.; Hayden, Mary K.; Scaggs, Felicia A.; Karadkhele, Anand; Bonomo, Robert A.

2016-01-01

Multidrug-resistant (MDR) Enterobacteriaceae infections are increasing in U.S. children; however, there is a paucity of multicentered analyses of antibiotic resistance genes responsible for MDR phenotypes among pediatric Enterobacteriaceae isolates. In this study, 225 isolates phenotypically identified as extended-spectrum β-lactamase (ESBL) or carbapenemase producers, recovered from children ages 0 to 18 years hospitalized between January 2011 and April 2015 at three Chicago area hospitals, were analyzed. We used DNA microarray platforms to detect ESBL, plasmid-mediated AmpC (pAmpC), and carbapenemase type β-lactamase (bla) genes. Repetitive-sequence-based PCR and multilocus sequence typing (MLST) were performed to assess isolate similarity. Plasmid replicon typing was conducted to classify plasmids. The median patient age was 4.2 years, 56% were female, and 44% presented in the outpatient setting. The majority (60.9%) of isolates were Escherichia coli and from urinary sources (69.8%). Of 225 isolates exhibiting ESBL- or carbapenemase-producing phenotypes, 90.7% contained a bla gene. The most common genotype was the blaCTX-M-1 group (49.8%); 1.8% were carbapenem-resistant Enterobacteriaceae (three blaKPC and one blaIMP). Overall, pAmpC (blaACT/MIR and blaCMY) were present in 14.2%. The predominant E. coli phylogenetic group was the virulent B2 group (67.6%) associated with ST43/ST131 (Pasteur/Achtman MLST scheme) containing the blaCTX-M-1 group (84%), and plasmid replicon types FIA, FII, and FIB. K. pneumoniae harboring blaKPC were non-ST258 with replicon types I1 and A/C. Enterobacter spp. carrying blaACT/MIR contained plasmid replicon FIIA. We found that β-lactam resistance in children is diverse and that certain resistance mechanisms differ from known circulating genotypes in adults in an endemic area. The potential impact of complex molecular types and the silent dissemination of MDR Enterobacteriaceae in a vulnerable population needs to be studied further

Changes in antibiotic usage and susceptibility in nosocomial Enterobacteriaceae and Pseudomonas isolates following the introduction of ertapenem to hospital formulary.

PubMed

Graber, C J; Hutchings, C; Dong, F; Lee, W; Chung, J K; Tran, T

2012-01-01

There is concern that widespread usage of ertapenem may promote cross-resistance to other carbapenems. To analyse the impact that adding ertapenem to our hospital formulary had on usage of other broad-spectrum agents and on susceptibilities of nosocomial Enterobacteriaceae and Pseudomonas isolates, we performed interrupted time-series analyses to determine the change in linear trend in antibiotic usage and change in mean proportion and linear trend of susceptibility pre- (March 2004-June 2005) and post- (July 2005-December 2008) ertapenem introduction. Usage of piperacillin-tazobactam (P=0·0013) and ampicillin-sulbactam (P=0·035) declined post-ertapenem introduction. For Enterobacteriaceae, the mean proportion susceptible to ciprofloxacin (P=0·016) and piperacillin-tazobactam (P=0·038) increased, while the linear trend in susceptibility significantly increased for cefepime (P=0·012) but declined for ceftriaxone (P=0·0032). For Pseudomonas, the mean proportion susceptible to cefepime (P=0·011) and piperacillin-tazobactam (P=0·028) increased, as did the linear trend in susceptibility to ciprofloxacin (P=0·028). Notably, no significant changes in carbapenem susceptibility were observed.

Evaluation of OXA-48 K-Se T: an immunochromatographic assay for rapid detection of OXA-48-producing Enterobacteriaceae.

PubMed

Fernández, Javier; Fleites, Ana; Rodcio, María Rosario; Vazquez, Fernando

2016-05-01

The OXA-48 K-Se T, a new immunochromatographic assay for rapid detection of OXA-48-producing Enterobacteriaceae, has been evaluated in a Spanish Hospital during a 3-month period. A collection of 100 Enterobacteriaceae including 79 isolates producing OXA-48 has been tested. Sensitivity and specificity of 100% were obtained. Copyright © 2016 Elsevier Inc. All rights reserved.

Evaluation of the Bactericidal Activity of Plazomicin and Comparators against Multidrug-resistant Enterobacteriaceae.

PubMed

Thwaites, M; Hall, D; Shinabarger, D; Serio, A W; Krause, K M; Marra, A; Pillar, C

2018-06-04

The next-generation aminoglycoside plazomicin, in development for infections due to multi-drug resistant (MDR) Enterobacteriaceae, was evaluated alongside comparators for bactericidal activity in minimum bactericidal concentration (MBC) and time-kill (TK) assays against MDR Enterobacteriaceae isolates with characterized aminoglycoside and β-lactam resistance mechanisms. Overall, plazomicin and colistin were the most potent, with plazomicin demonstrating an MBC 50/90 of 0.5/4 μg/mL and sustained 3-log 10 kill against MDR Escherichia coli , Klebsiella pneumoniae and Enterobacter spp. Copyright © 2018 Thwaites et al.

Emergence of carbapenem-resistant Enterobacteriaceae isolated from patients in a university hospital in Saudi Arabia. Epidemiology, clinical profiles and outcomes.

PubMed

Alotaibi, Fawzia E; Bukhari, Elham E; Al-Mohizea, Maha M; Hafiz, Taghreed; Essa, Eman B; AlTokhais, Yasmeen I

Carbapenemase-producing Enterobacteriaceae have been steadily spreading worldwide during the last decade. Nine patients were identified prospectively and were followed during their hospitalization course to identify the epidemiology, clinical profiles and outcomes. These patients had one or more cultures positive for a CRE isolate, contributing to a total of eleven positive cultures from various sites without including duplicates of isolates obtained from the same site. Isolates from these patients included five Klebseilla pneumoniae, three Escherichia coli, and one Enterobacter aerogenes. Five isolates were grown from blood cultures, three from wound cultures, one from urine cultures, one from respiratory cultures and one from an abscess collection. Five survived the hospital course. The other five patients died due to severe sepsis, septic shock or multi-organ failure. Of the nine isolates of CRE identified for which molecular analysis were available, four K. pneumonia were confirmed as blaNDM and one as OXA-48. For the purpose of controlling the spread of CRE in our institution, we recommend considering active surveillance cultures and screening patients transferred from other hospitals or coming from highly endemic settings at admission for these organisms. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

The role of international travel in the worldwide spread of multiresistant Enterobacteriaceae.

PubMed

van der Bij, Akke K; Pitout, Johann D D

2012-09-01

From international tourists to war-displaced refugees, more people are on the move than ever before. This provides the opportunity for a variety of antimicrobial-resistant bacteria to be carried from one geographic location to another. The Enterobacteriaceae are among the most important causes of serious hospital-acquired and community-onset bacterial infections in humans, and resistance to antimicrobial agents in these bacteria has become an increasingly relevant problem. International travel and tourism are important modes for the acquisition and spread of antimicrobial-resistant Enterobacteriaceae, especially CTX-M-producing Escherichia coli. Infections with KPC-, VIM-, OXA-48- and NDM-producing Enterobacteriaceae in developed countries have been associated with visiting and being hospitalized in endemic areas such as the USA, Greece and Israel for KPCs, Greece for VIMs, Turkey for OXA-48, and the Indian subcontinent for NDMs. To combat the spread of antimicrobial-resistant Enterobacteriaceae, the French Healthcare Safety Advisory Committee recently issued national recommendations for screening and contact isolation precautions for patients transferred from, or hospitalized outside, France. For effective public and patient health interventions, it is important to understand the role of international travel in the spread of antimicrobial-resistant Enterobacteriaceae. We urgently need well-designed studies to evaluate the transmission potential and risks for colonization and infections due to multiresistant Enterobacteriaceae in travellers who have recently visited or have been hospitalized in endemic areas. The emergence of CTX-M-, KPC- and NDM-producing bacteria is a good example of the role that globalization plays in the rapid dissemination of new antibiotic resistance mechanisms.

Use of bile-esculin agar for rapid differentiation of Enterobacteriaceae.

PubMed Central

Lindell, S S; Quinn, P

1975-01-01

Bile-esculin agar has been used for several years for the presumptive identification of group D streptococci. All members of the Enterobacteriaceae family will also grow on this medium, but only certain ones can hydrolyze esculin to 6,7-dihydroxycoumarin, which reacts with iron to produce a characteristic blackening of the medium. One thousand and six cultures from clinical specimens representing 20 genera were isolated and identified. Heavy inocula from fresh pure culture isolates on heart infusion agar were placed on bile-esculin agar slants and incubated at 35 C. The slants were examined at 4 h and again at 18 h for esculin hydrolysis. Shigella, Salmonella, Arizona, Proteus mirabilis, Proteus morganii, Providencia alcalifaciens, and Providencia stuartii all produced negative results. Klebsiella pneumoniae, Enterobacter aerogenes, Serratia marcescens, and Serratia rubidaea produced a positive reaction in 4 h. The other remaining eight genera exhibited varying results. The use of this medium in conjunction with triple sugar iron-lysine iron agar has been of great value in differentiating the Klebsiella-Enterobacter-Serratia group from other Enterobacteriaceae. PMID:1176613

[Urinary tract infection caused by Enterobacteriaceae and its relationship with vesicoureteral reflux].

PubMed

Díaz Álvarez, Manuel; Acosta Batista, Bárbara; Pérez Córdova, Rodolfo; Hernández Robledo, Ernesto

The first urinary tract infection can be a marker of a urinary tract anomaly, mainly vesicoureteral reflux. The aim of this work was to determine the association between isolated enterobacteria with the presence and grade of vesicoureteral reflux in neonatal patients with their first urinary tract infection. A retrospective, observational and analytic study of newborns, who were admitted to the Neonatal Department, University Pediatric Hospital "Juan Manuel Márquez," in Havana, Cuba, from 1992 to 2013 was conducted. The causal microorganism of urinary tract infection was from the Enterobacteriaceae family. They were evaluated by radio imaging. The association between the presence and grade of vesicoureteral reflux with the causal microorganism of the urinary tract infection was analyzed. Newborn infants with urinary tract infection (450) were studied. Bacterial isolations in the urine cultures corresponded to E. coli in 316 cases (70.2%). The prevalence of vesicoureteral reflux was 18.2%. The presence of bacteria corresponding to the Enterobacteriaceae family (other than E. coli) had significant risk association with vesicoureteral reflux (OR: 2.02; p < 0.01) and vesicoureteral reflux classification (for higher grades, p < 0.01). E. coli is the most frequent causal microorganism in neonatal urinary tract infection. However, an association between the isolation of a microorganism of the Enterobacteriaceae family different to E. coli with the presence of vesicoureteral reflux and mainly with higher grades of vesicoureteral reflux exists. Copyright © 2017 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

Salting by Vacuum Brine Impregnation in Nitrite-Free Lonza: Effect on Enterobacteriaceae.

PubMed

Serio, Annalisa; Chaves-López, Clemencia; Rossi, Chiara; Pittia, Paola; Rosa, Marco Dalla; Paparella, Antonello

2017-01-24

Lonza is a traditional Italian meat product made from whole pork muscles, which is typically cured by dry salting. In this work, we study the effects of vacuum brine impregnation (VBI) as an alternative salting method on the survival of Enterobacteriaceae, in presence and in absence of nitrites. In comparison with the traditional brining process, VBI contributed to reducing the Enterobacteriaceae population on product surface but induced contamination of the inner muscle tissues. Our results suggest that the species isolated became adapted to processing conditions, and salt tolerance was species- or strain-dependent. This result is of particular importance for future applications of VBI in lonza manufacturing.

Modified Carbapenem Inactivation Method for Phenotypic Detection of Carbapenemase Production among Enterobacteriaceae

PubMed Central

Simner, Patricia J.; Lonsway, David R.; Roe-Carpenter, Darcie E.; Johnson, J. Kristie; Brasso, William B.; Bobenchik, April M.; Lockett, Zabrina C.; Charnot-Katsikas, Angella; Ferraro, Mary Jane; Thomson, Richard B.; Jenkins, Stephen G.; Limbago, Brandi M.; Das, Sanchita

2017-01-01

ABSTRACT The ability of clinical microbiology laboratories to reliably detect carbapenemase-producing carbapenem-resistant Enterobacteriaceae (CP-CRE) is an important element of the effort to prevent and contain the spread of these pathogens and an integral part of antimicrobial stewardship. All existing methods have limitations. A new, straightforward, inexpensive, and specific phenotypic method for the detection of carbapenemase production, the carbapenem inactivation method (CIM), was recently described. Here we describe a two-stage evaluation of a modified carbapenem inactivation method (mCIM), in which tryptic soy broth was substituted for water during the inactivation step and the length of this incubation was extended. A validation study was performed in a single clinical laboratory to determine the accuracy of the mCIM, followed by a nine-laboratory study to verify the reproducibility of these results and define the zone size cutoff that best discriminated between CP-CRE and members of the family Enterobacteriaceae that do not produce carbapenemases. Bacterial isolates previously characterized through whole-genome sequencing or targeted PCR as to the presence or absence of carbapenemase genes were tested for carbapenemase production using the mCIM; isolates with Ambler class A, B, and D carbapenemases, non-CP-CRE isolates, and carbapenem-susceptible isolates were included. The sensitivity of the mCIM observed in the validation study was 99% (95% confidence interval [95% CI], 93% to 100%), and the specificity was 100% (95% CI, 82% to 100%). In the second stage of the study, the range of sensitivities observed across nine laboratories was 93% to 100%, with a mean of 97%; the range of specificities was 97% to 100%, with a mean of 99%. The mCIM was easy to perform and interpret for Enterobacteriaceae, with results in less than 24 h and excellent reproducibility across laboratories. PMID:28381609

Ability of the VITEK 2 Advanced Expert System To Identify β-Lactam Phenotypes in Isolates of Enterobacteriaceae and Pseudomonas aeruginosa

PubMed Central

Sanders, Christine C.; Peyret, Michel; Moland, Ellen Smith; Shubert, Carole; Thomson, Kenneth S.; Boeufgras, Jean-Marc; Sanders, W. Eugene

2000-01-01

The Advanced Expert System (AES) was used in conjunction with the VITEK 2 automated antimicrobial susceptibility test system to ascertain the β-lactam phenotypes of 196 isolates of the family Enterobacteriaceae and the species Pseudomonas aeruginosa. These isolates represented a panel of strains that had been collected from laboratories worldwide and whose β-lactam phenotypes had been characterized by biochemical and molecular techniques. The antimicrobial susceptibility of each isolate was determined with the VITEK 2 instrument, and the results were analyzed with the AES to ascertain the β-lactam phenotype. The results were then compared to the β-lactam resistance mechanism determined by biochemical and molecular techniques. Overall, the AES was able to ascertain a β-lactam phenotype for 183 of the 196 (93.4%) isolates tested. For 111 of these 183 (60.7%) isolates, the correct β-lactam phenotype was identified definitively in a single choice by the AES, while for an additional 46 isolates (25.1%), the AES identified the correct β-lactam phenotype provisionally within two or more choices. For the remaining 26 isolates (14.2%), the β-lactam phenotype identified by the AES was incorrect. However, for a number of these isolates, the error was due to remediable problems. These results suggest that the AES is capable of accurate identification of the β-lactam phenotypes of gram-negative isolates and that certain modifications can improve its performance even further. PMID:10655347

High Prevalence of Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae in Wild Fish from the Mediterranean Sea in Algeria.

PubMed

Brahmi, Soumia; Touati, Abdelaziz; Dunyach-Remy, Catherine; Sotto, Albert; Pantel, Alix; Lavigne, Jean-Philippe

2018-04-01

We investigated the prevalence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae among wild fish from the coast of Bejaia (Algeria) in the Mediterranean Sea. From March 2012 to August 2013, gut and gill samples of wild fish were screened for the presence of ESBL-producing Enterobacteriaceae. Strains were characterized with regard to antibiotic resistance, β-lactamase content, plasmid-mediated quinolone resistance, aminoglycoside resistance genes, and clonality (repetitive sequence-based polymerase chain reaction profiles and multilocus sequence typing). Virulence traits were performed for Escherichia coli and Klebsiella pneumoniae isolates. Of the 300 fish studied, 64 (21.3%) isolates were screened as positive for ESBL producing by the double-disc method. The isolates corresponded to E. coli, K. pneumoniae, Enterobacter cloacae, Morganella morganii, Citrobacter freundii, and Proteus vulgaris. A predominance of bla CTX-M gene was observed with a prevalence of 60.5% (n = 46). Furthermore, our study describes the association of important coresistance and virulence factors in E. coli and K. pneumoniae. Twelve of the ESBL producers carried genes of the qnr family and oqxAB gene and six carried the aac(6')-Ib-cr gene. Our results highlight for the first time the diffusion of multidrug-resistant Enterobacteriaceae isolates carrying resistance and virulence genes in fish from the Mediterranean Sea in Algeria.

High prevalence of plasmid-mediated quinolone resistance determinants qnr, aac(6')-Ib-cr, and qepA among ceftiofur-resistant Enterobacteriaceae isolates from companion and food-producing animals.

PubMed

Ma, Junying; Zeng, Zhenling; Chen, Zhangliu; Xu, Xiaogang; Wang, Xiaoying; Deng, Yuting; Lü, Dianhong; Huang, Liangzong; Zhang, Yunyuan; Liu, Jianhua; Wang, Minggui

2009-02-01

Three kinds of plasmid-mediated quinolone resistance (PMQR) determinants have been discovered and have been shown to be widely distributed among clinical isolates: qnr genes, aac(6')-Ib-cr, and qepA. Few data on the prevalence of these determinants in strains from animals are available. The presence of PMQR genes in isolates from animals was determined by PCR amplification and DNA sequencing. The production of extended-spectrum beta-lactamases (ESBLs) and AmpC beta-lactamases in the strains was detected, and their genotypes were determined. The genetic environment of PMQR determinants in selected plasmids was analyzed. All samples of ceftiofur-resistant (MICs > or = 8 microg/ml) isolates of the family Enterobacteriaceae were selected from 36 companion animals and 65 food-producing animals in Guangdong Province, China, between November 2003 and April 2007, including 89 Escherichia coli isolates, 9 Klebsiella pneumoniae isolates, and isolates of three other genera. A total of 68.3% (69/101) of the isolates produced ESBLs and/or AmpC beta-lactamases, mainly those of the CTX-M and CMY types. Of the 101 strains, PMQR determinants were present in 35 (34.7%) isolates, with qnr, aac(6')-Ib-cr, and qepA detected alone or in combination in 8 (7.9%), 19 (18.8%), and 16 (15.8%) strains, respectively. The qnr genes detected included one qnrB4 gene, four qnrB6 genes, and three qnrS1 genes. Five strains were positive for both aac(6')-Ib-cr and qepA, while one strain was positive for qnrS1, aac(6')-Ib-cr, and qepA. qnrB6 was flanked by two copies of ISCR1 with an intervening dfr gene downstream and sul1 and qacEDelta1 genes upstream. In another plasmid, aac(6')-Ib-cr followed intI1 and arr-3 was downstream. PMQR determinants are highly prevalent in ceftiofur-resistant Enterobacteriaceae strains isolated from animals in China. This is the first report of the occurrence of PMQR determinants among isolates from companion animals.

Evaluation of Antimicrobial Susceptibility of Enterobacteriaceae Causing Urinary Tract Infections in Africa

PubMed Central

Tansarli, Giannoula S.; Athanasiou, Stavros

2013-01-01

Our objective was to evaluate the antimicrobial susceptibility of Enterobacteriaceae causing urinary tract infections (UTIs) in adults in Africa. The PubMed database was systematically searched to identify relevant studies published after 2000. Google, World Health Organization, and African Field Epidemiology networks were also searched. Twenty-eight studies, accounting for 381,899 urine isolates from 14 African countries, met the inclusion criteria. Escherichia coli, Klebsiella spp., and Proteus spp. were the most commonly encountered uropathogens. Cefotaxime, imipenem, fosfomycin, and ciprofloxacin were the antibiotics with the highest activity against E. coli isolates from outpatients, with susceptibility being 92 to 99, 100, 100, and 68 to 91%, respectively. The susceptibility among Klebsiella spp. isolates from outpatients varied from 80 to 100% for amikacin and from 53 to 100% for ciprofloxacin, while susceptibility was 74 to 78, 97, and 77% for ciprofloxacin, amikacin, and fosfomycin, respectively, among Klebsiella species isolates from inpatients or patients with hospital-acquired UTIs. With regard to Proteus spp., the highest activity was observed among fluoroquinolones; 71 to 100% of the P. mirabilis isolates were susceptible to ciprofloxacin in four studies, and 74 to 100% of the P. vulgaris isolates were susceptible to ofloxacin in two studies. The currently available evidence suggests that the antimicrobial susceptibility patterns of Enterobacteriaceae uropathogens in African countries were similar to those in countries of southeast Europe. Further original studies are warranted from African countries for which there is limited published data. PMID:23689709

OXA-181 Beta Lactamase is not a Major Mediator of Carbapenem Resistance in Enterobacteriaceae

PubMed Central

Shanthi, M.; Sekar, Uma; K., Arunagiri; Bramhne, Hemant Goverdhandas

2013-01-01

Background: Detection of carbapenem hydrolyzing class D beta lactamase OXA-181, (a variant of OXA-48) in Enterobacteriaceae, is important, to institute appropriate therapy and to initiate preventive measures. This study was done to determine the presence of OXA 48 and its derivative OXA-181 in Enterobacteriaceae of pathogenic significance. Material and Methods: One hundred and eleven non–repetitive Enterobacteriaceae isolates which were resistant to any of the cephalosporin subclasses III and which exhibited reduced susceptibility to carbapenems were included in the study. Minimum inhibitory concentrations (MICs) to imipenem and meropenem was determined by broth microdilution. Production of carbapenamase was screened by Modified Hodge test (MHT). Polymerase Chain Reaction (PCR) was done to detect the presence of bla OXA-181 and bla OXA-48 .Coexistence of other carbapenemase encoding genes, namely, NDM-1, VIM, IMP and KPC were also looked for, by PCR. Results: Of all the isolates which were tested, only 2 (1.8%) revealed the presence of OXA-181 and OXA-48. These were Klebsiella pneumoniae and Citrobacter freundii. MICs of imipenem and meropenem for Klebsiella pneumoniae were 128mg/l and 64 mg/l and for Citrobacter freundii, they were 32mg/l and 16mg/l respectively. MHT was positive in both isolates. Conclusion: Production of OXA-48 / OXA-181 is not a major mechanism of carbapenem resistance. PCR is the gold standard for its routine identification in clinical microbiology laboratory. PMID:24179916

Molecular characterization and epidemiology of cefoxitin resistance among Enterobacteriaceae lacking inducible chromosomal ampC genes from hospitalized and non-hospitalized patients in Algeria: description of new sequence type in Klebsiella pneumoniae isolates.

PubMed

Gharout-Sait, Alima; Touati, Abdelaziz; Guillard, Thomas; Brasme, Lucien; de Champs, Christophe

2015-01-01

In this study, 922 consecutive non-duplicate clinical isolates of Enterobacteriaceae obtained from hospitalized and non-hospitalized patients at Bejaia, Algeria were analyzed for AmpC-type β-lactamases production. The ampC genes and their genetic environment were characterized using polymerase chain reaction (PCR) and sequencing. Plasmid incompatibility groups were determined by using PCR-based replicon typing. Phylogenetic grouping and multilocus sequence typing were determined for molecular typing of the plasmid-mediated AmpC (pAmpC) isolates. Of the isolates, 15 (1.6%) were identified as AmpC producers including 14 CMY-4-producing isolates and one DHA-1-producing Klebsiella pneumoniae. All AmpC-producing isolates co-expressed the broad-spectrum TEM-1 β-lactamase and three of them co-produced CTX-M and/or SHV-12 ESBL. Phylogenetic grouping and virulence genotyping of the E. coli isolates revealed that most of them belonged to groups D and B1. Multilocus sequence typing analysis of K. pneumoniae isolates identified four different sequence types (STs) with two new sequences: ST1617 and ST1618. Plasmid replicon typing indicates that blaCMY-4 gene was located on broad host range A/C plasmid, while LVPK replicon was associated with blaDHA-1. All isolates carrying blaCMY-4 displayed the transposon-like structures ISEcp1/ΔISEcp1-blaCMY-blc-sugE. Our study showed that CMY-4 was the main pAmpC in the Enterobacteriaceae isolates in Algeria. Copyright © 2015 Elsevier Editora Ltda. All rights reserved.

Occurrence of blaNDM Variants Among Enterobacteriaceae From a Neonatal Intensive Care Unit in a Northern India Hospital

PubMed Central

Ahmad, Nayeem; Khalid, Shamsi; Ali, Syed M.; Khan, Asad U.

2018-01-01

Carbapenem-resistance among enterobacteriaceae has become a global health concern. The objective of this study was to understand NDM producing enterobacteriaceae and their genetic basis of resistance, spreading in neonatal intensive care unit. Carbapenem resistant NDM producing enterobacteriaceae isolates were recovered from rectal swab and blood sample of infants admitted in NICU. These were determined by using Carba-NP test. All isolates were identified using BD PhoenixTM−100 and MICs were determined by broth microdilution method. The blaNDM and associated resistant markers were checked by PCR followed by sequencing. Moreover, ERIC-PCR and genetic environment of blaNDM gene were also performed for the analysis of clonal relationship and genetic surrounding of the strains. We characterized 44 isolates with blaNDM variants in Escherichia coli (45.5%), Klebsiella pneumoniae (40.9%), Citrobacter freundii (4.5%), Citrobacter braakii (2.3%), Klebsiella oxytoca (2.3%), Enterobacter cloacae (2.3%), Enterobacter aerogenes (2.2%) from NICU, showing resistance against all antibiotics except colistin and polymixin B. ISAba125 and bleomycin gene were found surrounding all blaNDM variants, besides class I integron on plasmid. (ERIC)-PCR data revealed non-clonal relatedness among most of the isolates. The transfer of resistant markers was confirmed by conjugation experiment. The PCR-based replicon typing was carried out using DNA of transconjugants. These isolates carried NDM-1 (20.45%), NDM-4 (36.36%), NDM-5 (38.64%), NDM-7 (4.55%), along with OXA, CMY, and SHV variants on conjugative plasmid of IncFIA, IncFIC, IncF, IncK, IncFIB, IncB/O, IncHI1, IncP, IncY, IncFIIA, IncI1, and IncN types. An increased number of carbapenem-resistant NDM producing enterobacteriaceae isolates recovered from NICU which is alarming signal for health workers and policy makers. Hence, it is utmost important to think about infection control measures. PMID:29563908

Isolation of three hexahydro-1,3,5-trinitro-1,3,5-triazine-degrading species of the family Enterobacteriaceae from nitramine explosive-contaminated soil

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

Kitts, C.L.; Cunningham, D.P.; Unkefer, P.J.

1994-12-01

Nitramine explosives, RDX and HMX, are used by the military in high-yield munitions. Manufacture and testing have resulted in contaminated soils and bioremediate has been proposed as a safe and cost-effective means of cleanup. Biodegradation under aerobic conditions has not been successful. However, biodegradation of both RDX and HMX has been reported under anaerobic conditions. In this report, the authors describe the isolation and identification of three individual members of the family Enterobacteriaceae, each of which degrades RDX in pure culture. 20 refs., 1 fig., 2 tabs.

Isolation and characterization of Enterobacteriaceae species infesting post-harvest strawberries and their biological control using bacteriophages.

PubMed

Kurtböke, D Ipek; Palk, A; Marker, A; Neuman, C; Moss, L; Streeter, K; Katouli, M

2016-10-01

Strawberry is a significantly consumed fruit worldwide, mostly without being subjected to disinfection processes. During the harvest and transfer from farm to consumers as well as where organic farming practises have been employed, the surface of the fruit may become contaminated by pathogenic bacteria. Post-harvest strawberry fruits in punnets available for public consumption were thus screened for the presence of enteric bacteria in the Sunshine Coast region of Queensland, Australia. Some of the tested samples (13 %) were found to carry such bacteria and even in greater numbers if organic amendments were used (69 %). The bacteria were found to belong in the genera of Escherichia, Enterobacter, Raoultella, Klebsiella, Pantoea, Shigella, Citrobacter and Cronobacter within the family Enterobacteriaceae. Some of the isolates were found to adhere to Caco-2 cells representing human gut epithelium as well as carrying virulence and toxin genes. Resistance mostly against sulphafurazole, cefoxitin, ampicillin and nitrofurantoin was found among 14 different antimicrobial agents tested including 100 % resistance to cefoxitin and ampicillin in the genus Pantoea. In the second phase of the study, bacteriophages were isolated against the isolates and were subsequently applied to post-harvest fruits. A significant (P ≤ 0.001) reduction in the number of enteric bacteria was observed when a high-titre polyvalent bacteriophage suspension (×10(12) PFU/mL) was applied to the fruit surface. Bacteriophages also decreased the adhesion of the Escherichia coli isolates to Caco-2 cells. Findings might indicate that biological control using bacteriophages might be of significant value for the industry targeting to reduce pathogenic loads of bacteria on the fruit.

Extended spectrum ß-lactamase- and constitutively AmpC-producing Enterobacteriaceae on fresh produce and in the agricultural environment.

PubMed

Blaak, Hetty; van Hoek, Angela H A M; Veenman, Christiaan; Docters van Leeuwen, Arieke E; Lynch, Gretta; van Overbeek, Wendy M; de Roda Husman, Ana Maria

2014-01-03

The attribution of fresh produce to the overall community-associated exposure of humans to ESBL- or AmpC-producing bacteria is currently unknown. To address this issue, the prevalence of ESBL- and AmpC-producing Enterobacteriaceae on fresh produce produced in the Netherlands was determined. Seven vegetable types that are consumed raw were selected: blanched celery, bunched carrots, chicory, endive, iceberg lettuce, mushrooms, and radish. The vegetables were mostly obtained from supermarkets. To determine whether the agricultural environment is the source of ESBL-producing Enterobacteriaceae on fresh produce, iceberg lettuce was also obtained directly from three farms, in conjunction with soil and irrigation water. ESBL-producing Enterobacteriaceae isolated from vegetables and environment were all environmental species: Rahnella aquatilis (n = 119), Serratia fonticola (n = 45) and Pantoea agglomerans (n = 1). ESBL genes of R. aquatilis and S. fonticola were identified as blaRAHN-1 and blaRAHN-2 and blaFONA-1, blaFONA-2, blaFONA-3/6 and blaFONA-5, respectively. For R. aquatilis and S. fonticola, different prevalence numbers were observed using different isolation methods, which could at least partially be explained by an inverse correlation between the level of cefotaxime resistance of these species and incubation temperature. R. aquatilis was isolated from 0 to 46% of soil samples and 11 to 83% of vegetable samples, and S. fonticola from 2 to 60% of soil samples and 0 to 1.3% of vegetable samples. Third generation cephalosporin-resistant faecal Enterobacteriaceae were isolated from 2.7%, 1.3% and 1.1% of supermarket vegetables, iceberg lettuce from farms, and agricultural soil respectively. Faecal Enterobacteriaceae were all identified as Citrobacter and Enterobacter species and, with the exception of one Citrobacter koseri strain, all had phenotypes indicative of constitutive AmpC production. Comparison of fresh produce and its agricultural environment indicates

Comparative evaluation of a new commercial media, the CHROMAgar™ mSuperCARBA™, for the detection of carbapenemase-producing Enterobacteriaceae.

PubMed

Amar, Ma'ayan; Shalom, Ohad; Adler, Amos

2017-05-01

A new chromogenic-based medium (mSuperCARBA™) was tested for screening carbapenemase-producing Enterobacteriaceae (CPE). mSuperCARBA™ was more sensitive (83%) in detecting CPE isolates (n=69, including KPC, NDM, OXA-48, VIM, and IMI) compared with CHROMAgar™-KPC (65%) and MacConkey agar with Imipenem (69%) with comparable specificity for non carbapenemase-producing, carbapenem-resistant Enterobacteriaceae (n=29). Copyright © 2017 Elsevier Inc. All rights reserved.

Presence of the KPC carbapenemase gene in Enterobacteriaceae causing bacteremia, and the correlation with in vitro carbapenem susceptibility

USDA-ARS?s Scientific Manuscript database

During six months, we obtained Enterobacteriaceae isolates from patients with Gram-negative bacteremia at a 1250-bed teaching hospital in St. Louis, Missouri, and compared carbapenem susceptibility with the presence of blaKPC, a transferable carbapenemase gene. Three (1.2%) out of 243 isolates were ...

Phenotypic and genotypic characteristics of carbapenem-resistant Enterobacteriaceae in a tertiary-level reference hospital in Turkey.

PubMed

Baran, Irmak; Aksu, Neriman

2016-04-06

Enterobacteriaceae are among the most common pathogens that are responsible for serious community-acquired, hospital-acquired, and health-care associated infections. The emergence and spread of carbapenem-resistant Enterobacteriaceae (CRE) have become an increasing concern for healthcare services worldwide. Infections caused by these bacteria have been associated with significant morbidity and mortality and treatment options have been limited. The rapid and accurate detection of carbapenem resistance in these bacteria is important for infection control. The aim of this study was to investigate the phenotypic and genotypic features of CRE strains isolated in a tertiary-level reference hospital in Turkey. A total of 181 CRE strains were included in the study. Antimicrobial susceptibility rates were tested using Vitek 2 system. Modified Hodge test (MHT) was performed using meropenem and ertapenem discs. Metallo-β-lactamase antimicrobial gradient test (E-test MBL strips) were used for evaluation of metallo-β-lactamase production. A multiplex PCR was used for detection of carbapenems resistance genes (IMP, VIM, KPC, NDM-1 and OXA-48). The OXA-48 gene was detected in 86 strains, NDM-1 gene in six strains, VIM gene in one strain. IMP and KPC genes were not identified. Three strains produced both OXA-48 and NDM-1 and one strain produced both OXA-48 and VIM. In two patients more than one genus of OXA-48 positive CREs was isolated. Ninety-two of the isolates were multidrug-resistant. One hundred and ten isolates were MHT with meropenem (MEM-MHT) positive and 109 isolates were MHT with ertapenem (ERT-MHT) positive. Nine of the isolates were positive with E-test MBL strips. The sensitivity of MEM-MHT and ERT-MHT for detection of OXA-48 was 70.9 and 70.6 %, respectively. MEM-MHT was found highly discriminative for OXA-48 Escherichia coli (p < 0.001). The sensitivity of E-test MBL for NDM-1 was 66.7 %. A statistically significant correlation was observed between OXA-48

Significance of Prior Digestive Colonization With Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae in Patients With Ventilator-Associated Pneumonia.

PubMed

Bruyère, Rémi; Vigneron, Clara; Bador, Julien; Aho, Serge; Toitot, Amaury; Quenot, Jean-Pierre; Prin, Sébastien; Charles, Pierre Emmanuel

2016-04-01

Ventilator-associated pneumonia is frequent in ICUs. Extended-spectrum β-lactamase-producing Enterobacteriaceae are difficult-to-treat pathogens likely to cause ventilator-associated pneumonia. We sought to assess the interest of screening for extended-spectrum β-lactamase-producing Enterobacteriaceae rectal carriage as a way to predict their involvement in ventilator-associated pneumonia. A retrospective cohort study of patients with suspected ventilator-associated pneumonia in a medical ICU was conducted. Every patient admitted between January 2006 and August 2013 was eligible if subjected to mechanical ventilation for more than 48 hours. Each patient with suspected ventilator-associated pneumonia was included in the cohort. Active surveillance culture for extended-spectrum β-lactamase-producing Enterobacteriaceae detection was routinely performed in all patients at admission and then weekly throughout the study period. Extended-spectrum β-lactamase colonization was defined by the isolation of at least one extended-spectrum β-lactamase-producing Enterobacteriaceae from rectal swab culture. None. Among 587 patients with suspected ventilator-associated pneumonia, 40 (6.8%) were colonized with extended-spectrum β-lactamase-producing Enterobacteriaceae prior to the development of pneumonia. Over the study period, 20 patients (3.4%) had ventilator-associated pneumonia caused by extended-spectrum β-lactamase-producing Enterobacteriaceae; of whom, 17 were previously detected as being colonized with extended-spectrum β-lactamase-producing Enterobacteriaceae. Sensitivity and specificity of prior extended-spectrum β-lactamase-producing Enterobacteriaceae colonization as a predictor of extended-spectrum β-lactamase-producing Enterobacteriaceae involvement in ventilator-associated pneumonia were 85.0% and 95.7%, respectively. The positive and negative predictive values were 41.5% and 99.4%, respectively. The positive likelihood ratio was 19.8. Screening for

Tawny owl (Strix aluco) as a potential transmitter of Enterobacteriaceae epidemiologically relevant for forest service workers, nature protection service and ornithologists.

PubMed

Grzywaczewski, Grzegorz; Kowalczyk-Pecka, Danuta; Cios, Szymon; Bojar, Wiktor; Jankuszew, Andrzej; Bojar, Hubert; Kolejko, Marcin

2017-03-31

Established taxa within the Enterobacteriaceae wereisolated from cloacal swabs of Strix aluco chicks in nest boxes located at five research sites. ChromID ESBL medium (bioMerieux) was used to select a pool of Enterobacteriaceae strains producing extended-spectrum beta-lactamases. Drug sensitivity of the chosen strains was determined from the full pool of Enterobacteriaceae to 6 chemotherapeutics of different mechanisms of action. The study evaluated the sensitivity of ESBL-synthesizing isolates to substances belonging to penicillins, cephalosporins, cephamycins, clavams, carbapenems and monobactams. Analysis of the results indicated a potential role of Strix aluco in the dissemination of epidemiologically-relevant Enterobacteriaceae, and, importantly, pose health risks to forest service workers, nature protection service and ornithologists. The results can also serve as the basis for further environmental studies.

In vitro activities and detection performances of cefmetazole and flomoxef for extended-spectrum β-lactamase and plasmid-mediated AmpC β-lactamase-producing Enterobacteriaceae.

PubMed

Matsumura, Yasufumi; Yamamoto, Masaki; Nagao, Miki; Tanaka, Michio; Takakura, Shunji; Ichiyama, Satoshi

2016-04-01

To investigate the in vitro activities of cephamycins (cefmetazole and flomoxef) for extended-spectrum β-lactamase (ESBL)- and plasmid-mediated AmpC β-lactamase (pAmpC)-producing Enterobacteriaceae, a total of 574 third-generation cephalosporin-resistant clinical isolates were collected at a Japanese multicenter study. PCR and sequencing identified 394 isolates with only ESBL genes, 63 isolates with only pAmpC genes, and 6 isolates with both ESBL and pAmpC genes. blaCTX-M types predominated 95.5% of the ESBL genes, and blaCMY-2 predominated 91.3% of the pAmpC genes. The MIC50/90 values of cefmetazole and flomoxef were ≤ 1/4 and ≤ 1/≤ 1 μg/mL for isolates with only ESBL genes, respectively, and 16/>16 and 8/16 μg/mL for isolates with only pAmpC genes, respectively. Flomoxef ≥ 4 μg/mL had the best screening performance for the detection of isolates with pAmpC genes. Flomoxef had better in vitro activities against ESBL-producing Enterobacteriaceae and provided a clearer distinction between ESBL and pAmpC-producing Enterobacteriaceae compared to cefmetazole. Copyright © 2016 Elsevier Inc. All rights reserved.

Inventory of Extended-Spectrum-β-Lactamase-Producing Enterobacteriaceae in France as Assessed by a Multicenter Study.

PubMed

Robin, F; Beyrouthy, R; Bonacorsi, S; Aissa, N; Bret, L; Brieu, N; Cattoir, V; Chapuis, A; Chardon, H; Degand, N; Doucet-Populaire, F; Dubois, V; Fortineau, N; Grillon, A; Lanotte, P; Leyssene, D; Patry, I; Podglajen, I; Recule, C; Ros, A; Colomb-Cotinat, M; Ponties, V; Ploy, M C; Bonnet, R

2017-03-01

The objective of this study was to perform an inventory of the extended-spectrum-β-lactamase (ESBL)-producing Enterobacteriaceae isolates responsible for infections in French hospitals and to assess the mechanisms associated with ESBL diffusion. A total of 200 nonredundant ESBL-producing Enterobacteriaceae strains isolated from clinical samples were collected during a multicenter study performed in 18 representative French hospitals. Antibiotic resistance genes were identified by PCR and sequencing experiments. The clonal relatedness between isolates was investigated by the use of the DiversiLab system. ESBL-encoding plasmids were compared by PCR-based replicon typing and plasmid multilocus sequence typing. CTX-M-15, CTX-M-1, CTX-M-14, and SHV-12 were the most prevalent ESBLs (8% to 46.5%). The three CTX-M-type EBSLs were significantly observed in Escherichia coli (37.1%, 24.2%, and 21.8%, respectively), and CTX-M-15 was the predominant ESBL in Klebsiella pneumoniae (81.1%). SHV-12 was associated with ESBL-encoding Enterobacter cloacae strains (37.9%). qnrB , aac(6 ' )-Ib-cr , and aac(3)-II genes were the main plasmid-mediated resistance genes, with prevalences ranging between 19.5% and 45% according to the ESBL results. Molecular typing did not identify wide clonal diffusion. Plasmid analysis suggested the diffusion of low numbers of ESBL-encoding plasmids, especially in K. pneumoniae and E. cloacae However, the ESBL-encoding genes were observed in different plasmid replicons according to the bacterial species. The prevalences of ESBL subtypes differ according to the Enterobacteriaceae species. Plasmid spread is a key determinant of this epidemiology, and the link observed between the ESBL-encoding plasmids and the bacterial host explains the differences observed in the Enterobacteriaceae species. Copyright © 2017 American Society for Microbiology.

Identification of Enterobacteriaceae by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry using the VITEK MS system.

PubMed

Richter, S S; Sercia, L; Branda, J A; Burnham, C-A D; Bythrow, M; Ferraro, M J; Garner, O B; Ginocchio, C C; Jennemann, R; Lewinski, M A; Manji, R; Mochon, A B; Rychert, J A; Westblade, L F; Procop, G W

2013-12-01

This multicenter study evaluated the accuracy of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry identifications from the VITEK MS system (bioMérieux, Marcy l'Etoile, France) for Enterobacteriaceae typically encountered in the clinical laboratory. Enterobacteriaceae isolates (n = 965) representing 17 genera and 40 species were analyzed on the VITEK MS system (database v2.0), in accordance with the manufacturer's instructions. Colony growth (≤72 h) was applied directly to the target slide. Matrix solution (α-cyano-4-hydroxycinnamic acid) was added and allowed to dry before mass spectrometry analysis. On the basis of the confidence level, the VITEK MS system provided a species, genus only, or no identification for each isolate. The accuracy of the mass spectrometric identification was compared to 16S rRNA gene sequencing performed at MIDI Labs (Newark, DE). Supplemental phenotypic testing was performed at bioMérieux when necessary. The VITEK MS result agreed with the reference method identification for 96.7% of the 965 isolates tested, with 83.8% correct to the species level and 12.8% limited to a genus-level identification. There was no identification for 1.7% of the isolates. The VITEK MS system misidentified 7 isolates (0.7 %) as different genera. Three Pantoea agglomerans isolates were misidentified as Enterobacter spp. and single isolates of Enterobacter cancerogenus, Escherichia hermannii, Hafnia alvei, and Raoultella ornithinolytica were misidentified as Klebsiella oxytoca, Citrobacter koseri, Obesumbacterium proteus, and Enterobacter aerogenes, respectively. Eight isolates (0.8 %) were misidentified as a different species in the correct genus. The VITEK MS system provides reliable mass spectrometric identifications for Enterobacteriaceae.

ESBL- and Carbapenemase-Producing Enterobacteriaceae in Patients with Bacteremia, Yangon, Myanmar, 2014.

PubMed

Myat, Tin O; Hannaway, Rachel F; Zin, Khwar N; Htike, Wah W; Win, Kyu K; Crump, John A; Murdoch, David R; Ussher, James E

2017-05-01

Among 42 gram-negative bloodstream isolates from inpatients in 3 hospitals in Yangon, Myanmar, admitted during July-December 2014, 16 (38%) were extended-spectrum β-lactamase-producing Enterobacteriaceae and 6 (14%) produced carbapenemase. The high prevalence of multidrug-resistant gram-negative bacteria raises concerns about the empiric treatment of patients with sepsis in Yangon.

Characteristics and management of Enterobacteriaceae harboring IMP-4 or IMP-8 carbapenemase in a tertiary hospital.

PubMed

Pang, Feng; Jia, Xiu-Qin; Song, Zhen-Zhu; Li, Yan-Hua; Wang, Bin; Zhao, Qi-Gang; Wang, Chuan-Xin; Zhang, Yi; Wang, Le-Xin

2016-03-01

The emergence of Enterobacteriaceae harboring IMP-4 or IMP-8 carbapenemases is rare. We report an occurrence of Enterobacteriaceae harboring IMP-4 or IMP-8 carbapenemases in a Chinese tertiary care hospital from November 2010 to December 2012. The clinical characteristics of 30 patients were described. The genetic relationship of isolates was determined by pulsed-field gel electrophoresis (PFGE). Carbapenemases were detected by modified Hodge test (MHT) and polymerase chain reactions (PCRs). Amplicons were sequenced and blasted to determine the genotype. Most infected patients were from intensive care unit and had complex and serious underlying illnesses requiring mechanical ventilation. PFGE revealed that Klebsiella pneumoniae showed two major PFGE types. Two Klebsiella oxytoca had an indistinguishable PFGE pattern, while four Enterobacter cloacae were different strains. The sequencing studies showed Enterobacteriaceae harboring IMP-4 or IMP-8 carbapenemase in the 23 infected patients. The majority of patients had infections with the carbapenemase-producing Enterobacteriaceae (CPE) strain, most were successfully treated with a range of antibiotics and discharged. It is important to maintain a high index of suspicion to screen for carbapenemase-producing Enterobacteriaceae strains. Rapid identification of these strains and implementation of stringent procedures are the key to prevent major outbreaks in a hospital setting.

Comparison of two commercial carbapenemase gene confirmatory assays in multiresistant Enterobacteriaceae and Acinetobacter baumannii-complex.

PubMed

Rösner, Stephan; Gehlweiler, Kevin; Küsters, Uta; Kolbert, Mathias; Hübner, Kirsten; Pfennigwerth, Niels; Mack, Dietrich

2018-01-01

Multidrug-resistant Gram-negative bacilli (MDR-GNB) producing carbapenemases are increasing at an alarming speed. Rapid confirmation of carbapenemase type will be an important diagnostic step in clinical microbiology laboratories not only to reduce the risk of transmissions but also for optimising antibiotic therapy in the future. We compared diagnostic reliability of two commercially available molecular assays (Check-Direct CPE vs. AID line probe assay) for detection and typing of carbapenemase genes in 80 well-characterized isolates of MDR-GNB. Respective strains were isolated in various clinical specimens at our clinical microbiology laboratory. The reference standard included confirmation of carbapenemase-production at the molecular level at the German National Reference Laboratory for Multidrug-resistant Gram-negative bacteria (Ruhr-University Bochum, Germany). 53 Enterobacteriaceae and 27 members of the A. baumannii-complex were used in this study. The tested assays appeared highly reliable to confirm carbapenemase-producing Enterobacteriaceae (CPE) with respective sensitivities of 97.7%, but are currently unsuitable for analysis of members of the A. baumannii-complex. Both assays are easy to perform and rapid tools for confirmation and typing of the most common carbapenemase genes in Enterobacteriaceae. Implementation should be possible for any clinical microbiology laboratory with Check-Direct CPE being easier to handle and having less technological requirements.

Characterization of Escherichia coli and other Enterobacteriaceae in producer-distributor bulk milk.

PubMed

Ntuli, V; Njage, P M K; Buys, E M

2016-12-01

The current study was undertaken to characterize Escherichia coli and other Enterobacteriaceae in raw and pasteurized producer-distributor bulk milk (PDBM). A total of 258 samples were collected from purchase points in 8 provinces in South Africa. The samples were tested for antibiotic residues, phosphatase, total aerobic bacteria, coliforms, and E. coli counts. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used for identification of isolates. Escherichia coli isolates were characterized for virulence factors, antimicrobial resistance, serotypes, and presumptive E. coli O157:H7. Antibiotic residues and alkaline phosphatase were detected in 2% of both raw and pasteurized PDBM (n=258) and 21% pasteurized PDBM (n=104) samples, respectively. A total of 729 isolates belonging to 21 genera and 59 species were identified. Escherichia coli, Enterobacter cloacae, Klebsiella oxytoca, and Raoultella ornithinolytica were the most abundant species. Spoilage Enterobacteriaceae species exceeded 50% of the total isolates. Escherichia coli was detected and isolated from 36% of the milk samples. Thirty-one E. coli isolates harbored virulence genes stx1/stx2 and 38% (n=121) were presumptive O157:H7. The prevalence of samples with presumptive shigatoxin producing E. coli was 10%. Antimicrobial-resistant E. coli isolates were detected in 70% of the milk samples with 36% of stx1/stx2 positive E. coli showing multi-drug resistance. Information obtained from the study will be used for modeling the public health risk posed by milkborne pathogens in PDBM, which in many cases is consumed by poor and vulnerable members of the population. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Single molecule sequencing to track plasmid diversity of hospital-associated carbapenemase-producing Enterobacteriaceae

PubMed Central

Conlan, Sean; Thomas, Pamela J.; Deming, Clayton; Park, Morgan; Lau, Anna F.; Dekker, John P.; Snitkin, Evan S.; Clark, Tyson A.; Luong, Khai; Song, Yi; Tsai, Yu-Chih; Boitano, Matthew; Gupta, Jyoti; Brooks, Shelise Y.; Schmidt, Brian; Young, Alice C.; Thomas, James W.; Bouffard, Gerard G.; Blakesley, Robert W.; Mullikin, James C.; Korlach, Jonas; Henderson, David K.; Frank, Karen M.; Palmore, Tara N.; Segre, Julia A.

2014-01-01

Public health officials have raised concerns that plasmid transfer between Enterobacteriaceae species may spread resistance to carbapenems, an antibiotic class of last resort, thereby rendering common healthcare-associated infections nearly impossible to treat. We performed comprehensive surveillance and genomic sequencing to identify carbapenem-resistant Enterobacteriaceae in the NIH Clinical Center patient population and hospital environment in order to to articulate the diversity of carbapenemase-encoding plasmids and survey the mobility of and assess the mobility of these plasmids between bacterial species. We isolated a repertoire of carbapenemase-encoding Enterobacteriaceae, including multiple strains of Klebsiella pneumoniae, Klebsiella oxytoca, Escherichia coli, Enterobacter cloacae, Citrobacter freundii, and Pantoea species. Long-read genome sequencing with full end-to-end assembly revealed that these organisms carry the carbapenem-resistance genes on a wide array of plasmids. Klebsiella pneumoniae and Enterobacter cloacae isolated simultaneously from a single patient harbored two different carbapenemase-encoding plasmids, overriding the epidemiological scenario of plasmid transfer between organisms within this patient. We did, however, find evidence supporting horizontal transfer of carbapenemase-encoding plasmids between Klebsiella pneumoniae, Enterobacter cloacae and Citrobacter freundii in the hospital environment. Our comprehensive sequence data, with full plasmid identification, challenges assumptions about horizontal gene transfer events within patients and identified wider possible connections between patients and the hospital environment. In addition, we identified a new carbapenemase-encoding plasmid of potentially high clinical impact carried by Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae and Pantoea species, from unrelated patients and the hospital environment. PMID:25232178

Prevalence of quinolone resistance mechanisms in Enterobacteriaceae producing acquired AmpC β-lactamases and/or carbapenemases in Spain.

PubMed

Machuca, Jesús; Agüero, Jesús; Miró, Elisenda; Conejo, María Del Carmen; Oteo, Jesús; Bou, Germán; González-López, Juan José; Oliver, Antonio; Navarro, Ferran; Pascual, Álvaro; Martínez-Martínez, Luis

2017-10-01

Quinolone resistance in Enterobacteriaceae species has increased over the past few years, and is significantly associated to beta-lactam resistance. The aim of this study was to evaluate the prevalence of chromosomal- and plasmid-mediated quinolone resistance in acquired AmpC β-lactamase and/or carbapenemase-producing Enterobacteriaceae isolates. The presence of chromosomal- and plasmid-mediated quinolone resistance mechanisms [mutations in the quinolone resistance determining region (QRDR) of gyrA and parC and qnr, aac(6')-Ib-cr and qepA genes] was evaluated in 289 isolates of acquired AmpC β-lactamase- and/or carbapenemase-producing Enterobacteriaceae collected between February and July 2009 in 35 Spanish hospitals. Plasmid mediated quinolone resistance (PMQR) genes were detected in 92 isolates (31.8%), qnr genes were detected in 83 isolates (28.7%), and the aac(6')-Ib-cr gene was detected in 20 isolates (7%). qnrB4 gene was the most prevalent qnr gene detected (20%), associated, in most cases, with DHA-1. Only 14.6% of isolates showed no mutations in gyrA or parC with a ciprofloxacin MIC of 0.5mg/L or higher, whereas PMQR genes were detected in 90% of such isolates. qnrB4 gene was the most prevalent PMQR gene detected, and was significantly associated with acquired AmpC β-lactamase DHA-1. PMQR determinants in association with other chromosomal-mediated quinolone resistance mechanisms, different to mutations in gyrA and parC (increased energy-dependent efflux, altered lipopolysaccharide or porin loss), could lead to ciprofloxacin MIC values that exceed breakpoints established by the main international committees to define clinical antimicrobial susceptibility breakpoints. Copyright © 2016 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

[Results of a multicenter study investigating plasmid mediated colistin resistance genes (mcr-1 and mcr-2) in clinical Enterobacteriaceae ısolates from Turkey].

PubMed

Sarı, Ayşe Nur; Süzük, Serap; Karatuna, Onur; Öğünç, Dilara; Karakoç, Ayşe Esra; Çizmeci, Zeynep; Alışkan, Hikmet Eda; Cömert, Füsun; Bakıcı, Mustafa Zahir; Akpolat, Nezahat; Çilli, Fatma Feriha; Zer, Yasemin; Karataş, Aysel; Akgün Karapınar, Bahar; Bayramoğlu, Gülçin; Özdamar, Melda; Kalem, Fatma; Delialioğlu, Nuran; Aktaş, Elif; Yılmaz, Nisel; Gürcan, Şaban; Gülay, Zeynep

2017-07-01

Colistin is a polymyxin antibiotic which is considered as one of the last line agents against infections due to multidrug resistant or carbapenem resistant gram-negative pathogens. Colistin resistance is associated with chromosomal alterations which can usually cause mutations in genes coding specific two component regulator systems. The first plasmid-mediated colistin resistance gene, mcr-1 was described in Escherichia coli and Klebsiella pneumoniae isolates in December 2015 and followed by another plasmid-mediated colistin resistance gene mcr-2 in 2016. The rapid and interspecies dissemination of plasmid-mediated resistance mechanisms through horizontal gene transfer, have made these genes considerably threatening. After the first reports, although mcr-1/mcr-2 producing Enterobacteriaceae isolates have been reported from many countries, there have been no reports from Turkey. Thus, the aim of this study was to investigate the presence of mcr-1/mcr-2 in clinical Enterobacteriaceae isolates from different parts of our country. A total of 329 Enterobacteriaceae isolates from 22 laboratories were collected which were isolated between March, 2015 and February, 2016. mcr-1/mcr-2 were investigated by polymerase chain reaction during February-March, 2016. Two hundred and seventeen of Klebsiella pneumoniae (66%), 75 of Salmonella spp. (22.8%), 31 of Esherichia coli (9.4%), 3 of Enterobacter cloacae (0.9%), 2 of Klebsiella oxytoca (0.6%) and 1 of Enterobacter aerogenes (0.3%) isolates were included to the study. Agarose gel electrophoresis results of PCR studies have shown expected band sizes for positive control isolates as 309 bp for mcr-1 and 567 bp for mcr-2. However, the presence of mcr-1/mcr-2 genes was not detected among the tested study isolates of Enterobacteriaceae. Although mcr-1/mcr-2 were not detected in our study isolates, it is highly important to understand the mechanism of resistance dissemination and determine the resistant isolates by considering that

Ceftolozane-tazobactam activity against drug-resistant Enterobacteriaceae and Pseudomonas aeruginosa causing healthcare-associated infections in Latin America: report from an antimicrobial surveillance program (2013-2015).

PubMed

Pfaller, Michael A; Shortridge, Dee; Sader, Helio S; Gales, Ana; Castanheira, Mariana; Flamm, Robert K

This study evaluated the in vitro activity of ceftolozane-tazobactam and comparator agents tested against Latin American isolates of Enterobacteriaceae and Pseudomonas aeruginosa from patients with health care-associated infections. Ceftolozane-tazobactam is an antipseudomonal cephalosporin combined with a well-established β-lactamase inhibitor. A total of 2415 Gram-negative organisms (537 P. aeruginosa and 1878 Enterobacteriaceae) were consecutively collected in 12 medical centers located in four Latin American countries. The organisms were tested for susceptibility by broth microdilution methods as described by the CLSI M07-A10 document and the results interpreted according to EUCAST and CLSI breakpoint criteria. Ceftolozane-tazobactam (MIC 50/90 , 0.25/32μg/mL; 84.2% susceptible) and meropenem (MIC 50/90 , ≤0.06/0.12μg/mL; 92.6% susceptible) were the most active compounds tested against Enterobacteriaceae. Among the Enterobacteriaceae isolates tested, 6.6% were carbapenem-resistant Enterobacteriaceae and 26.4% exhibited an extended-spectrum β-lactamase non-carbapenem-resistant phenotype. Whereas ceftolozane-tazobactam showed good activity against extended-spectrum beta-lactamase, non-carbapenem-resistant phenotype strains of Enterobacteriaceae (MIC 50/90 , 0.5/>32μg/mL), it lacked useful activity against strains with a (MIC 50/90 , >32/>32μg/mL; 1.6% S) carbapenem-resistant phenotype. Ceftolozane-tazobactam was the most potent (MIC 50//90 , 0.5/16μg/mL) β-lactam agent tested against P. aeruginosa isolates, inhibiting 86.8% at an MIC of ≤4μg/mL. P. aeruginosa exhibited high rates of resistance to cefepime (16.0%), ceftazidime (23.6%), meropenem (28.3%), and piperacillin-tazobactam (16.4%). Ceftolozane-tazobactam was the most active β-lactam agent tested against P. aeruginosa and demonstrated higher in vitro activity than available cephalosporins and piperacillin-tazobactam when tested against Enterobacteriaceae. Copyright © 2017 Sociedade

Limits of patient isolation measures to control extended-spectrum beta-lactamase–producing Enterobacteriaceae: model-based analysis of clinical data in a pediatric ward

PubMed Central

2013-01-01

Background Extended-spectrum beta-lactamase–producing Enterobacteriaceae (ESBL-E) are a growing concern in hospitals and the community. How to control the nosocomial ESBL-E transmission is a matter of debate. Contact isolation of patients has been recommended but evidence supporting it in non-outbreak settings has been inconclusive. Methods We used stochastic transmission models to analyze retrospective observational data from a two-phase intervention in a pediatric ward, successively implementing single-room isolation and patient cohorting in an isolation ward, combined with active ESBL-E screening. Results For both periods, model estimates suggested reduced transmission from isolated/cohorted patients. However, most of the incidence originated from sporadic sources (i.e. independent of cross-transmission), unaffected by the isolation measures. When sporadic sources are high, our model predicted that even substantial efforts to prevent transmission from carriers would have limited impact on ESBL-E rates. Conclusions Our results provide evidence that, considering the importance of sporadic acquisition, e.g. endogenous selection of resistant strains following antibiotic treatment, contact-isolation measures alone might not suffice to control ESBL-E. They also support the view that estimating cross-transmission extent is key to predicting the relative success of contact-isolation measures. Mathematical models could prove useful for those estimations and guide decisions concerning the most effective control strategy. PMID:23618041

Salmonella occurrence and Enterobacteriaceae counts in pig feed ingredients and compound feed from feed mills in Ireland.

PubMed

Burns, Anne Marie; Lawlor, Peadar G; Gardiner, Gillian E; McCabe, Evonne M; Walsh, Des; Mohammed, Manal; Grant, Jim; Duffy, Geraldine

2015-10-01

The purpose of this study was to assess the occurrence of non-typhoidal Salmonellae and Enterobacteriaceae counts in raw ingredients and compound feeds sampled from feed mills manufacturing pig diets. Between November 2012 and September 2013, feed ingredients (n=340) and compound pig feed (n=313) samples were collected from five commercial feed mills and one home compounder at various locations throughout Ireland. Feed ingredients included cereals, vegetable protein sources and by-products of oil extraction and ethanol production. The compound feeds included meal and pelleted feed for all stages of pig production. Samples were analysed for Salmonella using standard enrichment procedures. Recovered isolates were serotyped, characterised for antibiotic resistance and subtyped by multi locus variance analysis (MLVA). Total Enterobacteriaceae counts were also performed. Salmonella was recovered from 2/338 (0.6%) ingredients (wheat and soybean meal), at two of the six mills. Salmonella was also detected in 3/317 (0.95%) compound feeds including pelleted feed which undergoes heat treatment. All isolates recovered from feed ingredient and compound feed samples were verified as Salmonella enterica subsp. enterica serotype (4,[5],12:i:-) that lack the expression of flagellar Phase 2 antigens representing monophasic variants of Salmonella Typhimurium (4,[5],12:i:-). Isolates exhibited resistance to between two and seven antimicrobials. Two distinct MLVA profiles were observed, with the same profile recovered from both feed and ingredients, although these did not originate at the same mill. There was no relationship between the occurrence of Salmonella and a high Enterobacteriaceae counts but it was shown that Enterobacteriaceae counts were significantly lower in pelleted feed (heat treated) than in meal (no heat treatment) and that Enterobacteriaceae counts would be very useful indicator in HACPP programme. Overall, although the prevalence of Salmonella in pig feed and feed

Performance of Vitek 2 for Antimicrobial Susceptibility Testing of Enterobacteriaceae with Vitek 2 (2009 FDA) and 2014 CLSI Breakpoints

PubMed Central

Bobenchik, April M.; Deak, Eszter; Hindler, Janet A.; Charlton, Carmen L.

2014-01-01

Vitek 2 (bioMérieux Inc., Durham, NC) is a widely used commercial antimicrobial susceptibility test system. We compared the MIC results obtained using the Vitek 2 AST-GN69 and AST-XN06 cards to those obtained by CLSI broth microdilution (BMD) for 255 isolates of Enterobacteriaceae, including 25 isolates of carbapenem-resistant Enterobacteriaceae. In total, 25 antimicrobial agents were examined. For 10 agents, the MIC data were evaluated using two sets of breakpoints: (i) the Vitek 2 breakpoints, which utilized the 2009 FDA breakpoints at the time of the study and are equivalent to the 2009 CLSI M100-S19 breakpoints, and (ii) the 2014 CLSI M100-S24 breakpoints. There was an overall 98.7% essential agreement (EA). The categorical agreement was 95.5% (CA) using the Vitek 2 breakpoints and 95.7% using the CLSI breakpoints. There was 1 very major error (VME) (0.05%) observed using the Vitek 2 breakpoints (cefazolin) and 8 VMEs (0.5%) using the CLSI breakpoints (2 each for aztreonam, cefepime, and ceftriaxone, and 1 for cefazolin and ceftazidime). Fifteen major errors (MEs) (0.4%) were noted using the Vitek 2 breakpoints and 8 (0.5%) using the CLSI breakpoints. Overall, the Vitek 2 performance was comparable to that of BMD for testing a limited number of Enterobacteriaceae commonly isolated by clinical laboratories. Ongoing studies are warranted to assess performance in isolates with emerging resistance. PMID:25540403

Translating genomics into practice for real-time surveillance and response to carbapenemase-producing Enterobacteriaceae: evidence from a complex multi-institutional KPC outbreak.

PubMed

Kwong, Jason C; Lane, Courtney R; Romanes, Finn; Gonçalves da Silva, Anders; Easton, Marion; Cronin, Katie; Waters, Mary Jo; Tomita, Takehiro; Stevens, Kerrie; Schultz, Mark B; Baines, Sarah L; Sherry, Norelle L; Carter, Glen P; Mu, Andre; Sait, Michelle; Ballard, Susan A; Seemann, Torsten; Stinear, Timothy P; Howden, Benjamin P

2018-01-01

Until recently, Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae were rarely identified in Australia. Following an increase in the number of incident cases across the state of Victoria, we undertook a real-time combined genomic and epidemiological investigation. The scope of this study included identifying risk factors and routes of transmission, and investigating the utility of genomics to enhance traditional field epidemiology for informing management of established widespread outbreaks. All KPC-producing Enterobacteriaceae isolates referred to the state reference laboratory from 2012 onwards were included. Whole-genome sequencing was performed in parallel with a detailed descriptive epidemiological investigation of each case, using Illumina sequencing on each isolate. This was complemented with PacBio long-read sequencing on selected isolates to establish high-quality reference sequences and interrogate characteristics of KPC-encoding plasmids. Initial investigations indicated that the outbreak was widespread, with 86 KPC-producing Enterobacteriaceae isolates ( K. pneumoniae 92%) identified from 35 different locations across metropolitan and rural Victoria between 2012 and 2015. Initial combined analyses of the epidemiological and genomic data resolved the outbreak into distinct nosocomial transmission networks, and identified healthcare facilities at the epicentre of KPC transmission. New cases were assigned to transmission networks in real-time, allowing focussed infection control efforts. PacBio sequencing confirmed a secondary transmission network arising from inter-species plasmid transmission. Insights from Bayesian transmission inference and analyses of within-host diversity informed the development of state-wide public health and infection control guidelines, including interventions such as an intensive approach to screening contacts following new case detection to minimise unrecognised colonisation. A real-time combined

Comparison of effectiveness and safety of imipenem/clavulanate- versus meropenem/clavulanate-containing regimens in the treatment of MDR- and XDR-TB.

PubMed

Tiberi, Simon; Sotgiu, Giovanni; D'Ambrosio, Lia; Centis, Rosella; Abdo Arbex, Marcos; Alarcon Arrascue, Edith; Alffenaar, Jan Willem; Caminero, Jose A; Gaga, Mina; Gualano, Gina; Skrahina, Alena; Solovic, Ivan; Sulis, Giorgia; Tadolini, Marina; Alarcon Guizado, Valentina; De Lorenzo, Saverio; Roby Arias, Aurora Jazmín; Scardigli, Anna; Akkerman, Onno W; Aleksa, Alena; Artsukevich, Janina; Auchynka, Vera; Bonini, Eduardo Henrique; Chong Marín, Félix Antonio; Collahuazo López, Lorena; de Vries, Gerard; Dore, Simone; Kunst, Heinke; Matteelli, Alberto; Moschos, Charalampos; Palmieri, Fabrizio; Papavasileiou, Apostolos; Payen, Marie-Christine; Piana, Andrea; Spanevello, Antonio; Vargas Vasquez, Dante; Viggiani, Pietro; White, Veronica; Zumla, Alimuddin; Migliori, Giovanni Battista

2016-06-01

No large study to date has ever evaluated the effectiveness, safety and tolerability of imipenem/clavulanate versus meropenem/clavulanate to treat multidrug- and extensively drug-resistant tuberculosis (MDR- and XDR-TB). The aim of this observational study was to compare the therapeutic contribution of imipenem/clavulanate versus meropenem/clavulanate added to background regimens to treat MDR- and XDR-TB cases.84 patients treated with imipenem/clavulanate-containing regimens showed a similar median number of antibiotic resistances (8 versus 8) but more fluoroquinolone resistance (79.0% versus 48.9%, p<0.0001) and higher XDR-TB prevalence (67.9% versus 49.0%, p=0.01) in comparison with 96 patients exposed to meropenem/clavulanate-containing regimens. Patients were treated with imipenem/clavulanate- and meropenem/clavulanate-containing regimens for a median (interquartile range) of 187 (60-428) versus 85 (49-156) days, respectively.Statistically significant differences were observed on sputum smear and culture conversion rates (79.7% versus 94.8%, p=0.02 and 71.9% versus 94.8%, p<0.0001, respectively) and on success rates (59.7% versus 77.5%, p=0.03). Adverse events to imipenem/clavulanate and meropenem/clavulanate were reported in 5.4% and 6.5% of cases only.Our study suggests that meropenem/clavulanate is more effective than imipenem/clavulanate in treating MDR/XDR-TB patients. Copyright ©ERS 2016.

XDR-TB: an outcome of programmatic management of TB in India.

PubMed

Mishra, Gyanshankar; Ghorpade, S V; Mulani, Jasmin

2014-01-01

A significantly strengthened Revised National Tuberculosis Control Programme (RNTCP) is currently operational in India. In this case-based commentary, we describe the plight of a patient who developed extensive drug-resistant tuberculosis (XDR-TB) despite having received treatment under the RNTCP for a long period. Our aim is to analyse the programmatic management of tuberculosis in India by highlighting and discussing various issues related to the treatment received by the patient. Further, the article explores whether there is a need to incorporate an ethical element into the RNTCP as it stands today.

Prospective study on human fecal carriage of Enterobacteriaceae possessing mcr-1 and mcr-2 genes in a regional hospital in Hong Kong.

PubMed

Chan, Wai-Sing; Au, Chun-Hang; Ho, Dona N; Chan, Tsun-Leung; Ma, Edmond Shiu-Kwan; Tang, Bone Siu-Fai

2018-02-13

Human fecal carriage of Enterobacteriaceae possessing mobilized colistin resistance genes (mcr-1 and mcr-2) remains obscure in Hong Kong. As part of routine surveillance on emerging antibiotic resistance, we conducted a prospective study on this topic in a regional hospital in Hong Kong. From October 31 to November 25, 2016, all fecal specimens submitted for routine analysis were included in this surveillance study. These comprised 672 consecutive routine fecal specimens collected from 616 individuals. Fecal specimens were screened for colistin-resistant Enterobacteriaceae by culture-based method, and the presence of mcr-1 and mcr-2 genes in resistant isolates was identified by polymerase chain reaction and Sanger sequencing. Whole genome sequencing (WGS) of mcr-1-possessing Escherichia coli strains was facilitated using Illumina® MiSeq® followed by sequence analysis with appropriate bioinformatics tools. Fourteen mcr-1-positive E. coli strains were isolated from 14 separate individuals (2.08% of total fecal specimens), with 9 of them being asymptomatic, healthy clients coming for health assessment. No mcr-2-possessing Enterobacteriaceae was identified. Colistin minimum inhibitory concentrations of these mcr-1-positive isolates ranged from 2 to 4 μg/mL. All these isolates were susceptible to carbapenems with 2 being extended spectrum β-lactamase producers. WGS data revealed that these isolates belonged to at least 12 different sequence types (STs) and possessed diversified plasmid replicons, virulence and acquired antibiotic resistance genes. Further study on an E. coli ST201 strain (Pasteur scheme) revealed coexistence of 47,818-bp IncP-1 and 33,309-bp IncX4 types of mcr-1 plasmids, which was a combination of stability and high transmissibility. To the best of our knowledge, this is the first study on human fecal carriage of Enterobacteriaceae possessing mcr-1 and mcr-2 genes in Hong Kong. Our data further revealed asymptomatic carriage of mcr-1-possessing

Genotyping and molecular characteristics of multidrug-resistant Mycobacterium tuberculosis isolates from China.

PubMed

Zhang, Zhijian; Lu, Jie; Liu, Min; Wang, Yufeng; Qu, Geping; Li, Hongxia; Wang, Jichun; Pang, Yu; Liu, Changting; Zhao, Yanlin

2015-04-01

The aim of this study was to explore the population structure of multidrug-resistant (MDR) tuberculosis strains and distribution of resistance-associated nucleotide alteration among the different genotype MDR strains in China. The genotypes of 376 MDR strain were analyzed by 15-loci MIRU-VNTR and RD105 deletion-targeted multiplex PCR (DTM-PCR) method. In addition, all the MDR isolates were sequenced for genetic mutations conferring rifampicin (rpoB) and isonizid resistance (katG, inhA and oxyR-ahpC). Among the 376 MDR isolates, 261 (69.4%) belonged to Beijing genotype, including 177 modern Beijing strains (67.8%) and 84 ancient Beijing (32.2%) strains. The percentages of streptomycin-resistant, kanamycin-resistant, pre-XDR and XDR TB in modern Beijing genotype were significantly lower than ancient genotype (P < 0.05). The Beijing MDR strains had significantly higher proportions of ofloxacin-resistant and pre-XDR isolates than non-Beijing strains (P < 0.01). In addition, the clustering rate of modern Beijing strains was significantly higher than that of ancient Beijing strains (46.3% vs. 11.9%, P < 0.01). 94.7% and 79.3% of MDR isolates harbored genetic mutations conferring rifampicin and isonizid resistance, respectively, and the most prevalent mutation was located in codon rpoB531 and katG315. In addition, the rpoB531 and katG mutation were more frequently observed among Beijing genotype strains than non-Beijing strains, while non-Beijing genotype showed stronger association with isolates lacking mutation in rifampicin resistance determination region (P < 0.05). Our findings demonstrated that ancient Beijing MDR strains were associated with drug resistance, while modern Beijing MDR strains were more likely to be clustered. Copyright © 2014 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

Can Ceftazidime-Avibactam and Aztreonam Overcome β-Lactam Resistance Conferred by Metallo-β-Lactamases in Enterobacteriaceae?

PubMed

Marshall, Steven; Hujer, Andrea M; Rojas, Laura J; Papp-Wallace, Krisztina M; Humphries, Romney M; Spellberg, Brad; Hujer, Kristine M; Marshall, Emma K; Rudin, Susan D; Perez, Federico; Wilson, Brigid M; Wasserman, Ronald B; Chikowski, Linda; Paterson, David L; Vila, Alejandro J; van Duin, David; Kreiswirth, Barry N; Chambers, Henry F; Fowler, Vance G; Jacobs, Michael R; Pulse, Mark E; Weiss, William J; Bonomo, Robert A

2017-04-01

Based upon knowledge of the hydrolytic profile of major β-lactamases found in Gram-negative bacteria, we tested the efficacy of the combination of ceftazidime-avibactam (CAZ-AVI) with aztreonam (ATM) against carbapenem-resistant enteric bacteria possessing metallo-β-lactamases (MBLs). Disk diffusion and agar-based antimicrobial susceptibility testing were initially performed to determine the in vitro efficacy of a unique combination of CAZ-AVI and ATM against 21 representative Enterobacteriaceae isolates with a complex molecular background that included bla IMP , bla NDM , bla OXA-48 , bla CTX-M , bla AmpC , and combinations thereof. Time-kill assays were conducted, and the in vivo efficacy of this combination was assessed in a murine neutropenic thigh infection model. By disk diffusion assay, all 21 isolates were resistant to CAZ-AVI alone, and 19/21 were resistant to ATM. The in vitro activity of CAZ-AVI in combination with ATM against diverse Enterobacteriaceae possessing MBLs was demonstrated in 17/21 isolates, where the zone of inhibition was ≥21 mm. All isolates demonstrated a reduction in CAZ-AVI agar dilution MICs with the addition of ATM. At 2 h, time-kill assays demonstrated a ≥4-log 10 -CFU decrease for all groups that had CAZ-AVI with ATM (8 μg/ml) added, compared to the group treated with CAZ-AVI alone. In the murine neutropenic thigh infection model, an almost 4-log 10 -CFU reduction was noted at 24 h for CAZ-AVI (32 mg/kg every 8 h [q8h]) plus ATM (32 mg/kg q8h) versus CAZ-AVI (32 mg/kg q8h) alone. The data presented herein require us to carefully consider this new therapeutic combination to treat infections caused by MBL-producing Enterobacteriaceae . Copyright © 2017 American Society for Microbiology.

The Prevalence and Molecular Epidemiology of Multidrug-Resistant Enterobacteriaceae Colonization in a Pediatric Intensive Care Unit.

PubMed

Suwantarat, Nuntra; Logan, Latania K; Carroll, Karen C; Bonomo, Robert A; Simner, Patricia J; Rudin, Susan D; Milstone, Aaron M; Tekle, Tsigereda; Ross, Tracy; Tamma, Pranita D

2016-05-01

To determine the prevalence and acquisition of extended-spectrum β-lactamases (ESBLs), plasmid-mediated AmpCs (pAmpCs), and carbapenemases ("MDR Enterobacteriaceae") colonizing children admitted to a pediatric intensive care unit (PICU). Prospective study. 40-bed PICU. Admission and weekly thereafter rectal surveillance swabs were collected on all pediatric patients during a 6-month study period. Routine phenotypic identification and antibiotic susceptibility testing were performed. Enterobacteriaceae displaying characteristic resistance profiles underwent further molecular characterization to identify genetic determinants of resistance likely to be transmitted on mobile genetic elements and to evaluate relatedness of strains including DNA microarray, multilocus sequence typing, repetitive sequence-based PCR, and hsp60 sequencing typing. Evaluating 854 swabs from unique children, the overall prevalence of colonization with an MDR Enterobacteriaceae upon admission to the PICU based on β-lactamase gene identification was 4.3% (n=37), including 2.8% ESBLs (n=24), 1.3% pAmpCs (n=11), and 0.2% carbapenemases (n=2). Among 157 pediatric patients contributing 603 subsequent weekly swabs, 6 children (3.8%) acquired an incident MDR Enterobacteriaceae during their PICU stay. One child acquired a pAmpC (E. coli containing bla DHA) related to an isolate from another patient. Approximately 4% of children admitted to a PICU were colonized with MDR Enterobacteriaceae (based on β-lactamase gene identification) and an additional 4% of children who remained in the PICU for at least 1 week acquired 1 of these organisms during their PICU stay. The acquired MDR Enterobacteriaceae were relatively heterogeneous, suggesting that a single source was not responsible for the introduction of these resistance mechanisms into the PICU setting.

Dissemination of NDM-1-Producing Enterobacteriaceae Mediated by the IncX3-Type Plasmid

PubMed Central

Fu, Ying; Du, Xiaoxing; Shen, Yuqin; Yu, Yunsong

2015-01-01

The emergence and spread of NDM-1-producing Enterobacteriaceae have resulted in a worldwide public health risk that has affected some provinces of China. China is an exceptionally large country, and there is a crucial need to investigate the epidemic of bla NDM-1-positive Enterobacteriaceae in our province. A total of 186 carbapenem-resistant Enterobacteriaceae isolates (CRE) were collected in a grade-3 hospital in Zhejiang province. Carbapenem-resistant genes, including bla KPC, bla IMP, bla VIM, bla OXA-48 and bla NDM-1 were screened and sequenced. Ninety isolates were identified as harboring the bla KPC-2 genes, and five bla NDM-1-positive isolates were uncovered. XbaI-PFGE revealed that three bla NDM-1-positive K. pneumoniae isolates belonged to two different clones. S1-PFGE and southern blot suggested that the bla NDM-1 genes were located on IncX3-type plasmids with two different sizes ranging from 33.3 to 54.7 kb (n=4) and 104.5 to 138.9 kb (n=1), respectively, all of which could easily transfer to Escherichia coli by conjugation and electrotransformation. The high-throughput sequencing of two plasmids was performed leading to the identification of a smaller 54-kb plasmid, which had high sequence similarity with a previously reported pCFNDM-CN, and a larger plasmid in which only a 7.8-kb sequence of a common gene environment around bla NDM-1 (bla NDM-1-trpF- dsbC-cutA1-groEL-ΔInsE,) was detected. PCR mapping and sequencing demonstrated that four smaller bla NDM-1 plasmids contained a common gene environment around bla NDM-1 (IS5-bla NDM-1-trpF- dsbC-cutA1-groEL). We monitored the CRE epidemic in our hospital and determined that KPC-2 carbapenemase was a major risk to patient health and the IncX3-type plasmid played a vital role in the spread of the bla NDM-1 gene among the CRE. PMID:26047502

Phenotypic and Molecular Characteristics of Carbapenem-Resistant Enterobacteriaceae in a Health Care System in Los Angeles, California, from 2011 to 2013

PubMed Central

Pollett, S.; Miller, S.; Hindler, J.; Uslan, D.; Carvalho, M.

2014-01-01

Carbapenem-resistant Enterobacteriaceae (CRE) are a concern for health care in the United States but remain relatively uncommon in California. We describe the phenotype, clonality, and carbapenemase-encoding genes present in CRE isolated from patients at a Californian tertiary health care system. CRE for this study were identified by evaluating the antibiograms of Enterobacteriaceae isolated in the UCLA Health System from 2011 to 2013 for isolates that were not susceptible to meropenem and/or imipenem. The identification of these isolates was subsequently confirmed by matrix-associated laser desorption ionization–time of flight, and broth microdilution tests were repeated to confirm the CRE phenotype. Real-time PCR for blaKPC, blaSME, blaIMP, blaNDM-1, blaVIM, and blaOXA-48 was performed. Clonality was assessed by repetitive sequence-based PCR (repPCR) and multilocus sequence typing (MLST). Of 15,839 nonduplicate clinical Enterobacteriaceae isolates, 115 (0.73%) met the study definition for CRE. This number increased from 0.5% (44/8165) in the first half of the study to 0.9% (71/7674) in the second (P = 0.004). The most common CRE species were Klebsiella pneumoniae, Enterobacter aerogenes, and Escherichia coli. A carbapenemase-encoding gene was found in 81.7% (94/115) of CRE and included blaKPC (78.3%), blaNDM-1 (0.9%), and blaSME (2.6%). The majority of blaKPC genes were in K. pneumoniae isolates, which fell into 14 clonal groups on typing. blaKPC was identified in more than one species of CRE cultured from the same patient in four cases. Three blaSME-carrying Serratia marcescens isolates and one blaNDM-1 carrying Providencia rettgeri isolate were detected. CRE are increasing in California, and carbapenemases, particularly KPC, are a common mechanism for carbapenem resistance in this region. PMID:25210072

Carbapenemase-Producing Enterobacteriaceae Recovered from the Environment of a Swine Farrow-to-Finish Operation in the United States.

PubMed

Mollenkopf, Dixie F; Stull, Jason W; Mathys, Dimitria A; Bowman, Andrew S; Feicht, Sydnee M; Grooters, Susan V; Daniels, Joshua B; Wittum, Thomas E

2017-02-01

Carbapenem-resistant Enterobacteriaceae (CRE) present an urgent threat to public health. While use of carbapenem antimicrobials is restricted for food-producing animals, other β-lactams, such as ceftiofur, are used in livestock. This use may provide selection pressure favoring the amplification of carbapenem resistance, but this relationship has not been established. Previously unreported among U.S. livestock, plasmid-mediated CRE have been reported from livestock in Europe and Asia. In this study, environmental and fecal samples were collected from a 1,500-sow, U.S. farrow-to-finish operation during 4 visits over a 5-month period in 2015. Samples were screened using selective media for the presence of CRE, and the resulting carbapenemase-producing isolates were further characterized. Of 30 environmental samples collected from a nursery room on our initial visit, 2 (7%) samples yielded 3 isolates, 2 sequence type 218 (ST 218) Escherichia coli and 1 Proteus mirabilis, carrying the metallo-β-lactamase gene bla IMP-27 on IncQ1 plasmids. We recovered on our third visit 15 IMP-27-bearing isolates of multiple Enterobacteriaceae species from 11 of 24 (46%) environmental samples from 2 farrowing rooms. These isolates each also carried bla IMP-27 on IncQ1 plasmids. No CRE isolates were recovered from fecal swabs or samples in this study. As is common in U.S. swine production, piglets on this farm receive ceftiofur at birth, with males receiving a second dose at castration (≈day 6). This selection pressure may favor the dissemination of bla IMP-27 -bearing Enterobacteriaceae in this farrowing barn. The absence of this selection pressure in the nursery and finisher barns likely resulted in the loss of the ecological niche needed for maintenance of this carbapenem resistance gene. Copyright © 2017 American Society for Microbiology.

Population Distribution of Beta-Lactamase Conferring Resistance to Third-Generation Cephalosporins in Human Clinical Enterobacteriaceae in The Netherlands

PubMed Central

Voets, Guido M.; Platteel, Tamara N.; Fluit, Ad C.; Scharringa, Jelle; Schapendonk, Claudia M.; Stuart, James Cohen; Bonten, Marc J. M.; Hall, Maurine A. L.

2012-01-01

There is a global increase in infections caused by Enterobacteriaceae with plasmid-borne β-lactamases that confer resistance to third-generation cephalosporins. The epidemiology of these bacteria is not well understood, and was, therefore, investigated in a selection of 636 clinical Enterobacteriaceae with a minimal inhibitory concentration >1 mg/L for ceftazidime/ceftriaxone from a national survey (75% E. coli, 11% E. cloacae, 11% K. pneumoniae, 2% K. oxytoca, 2% P. mirabilis). Isolates were investigated for extended-spectrum β-lactamases (ESBLs) and ampC genes using microarray, PCR, gene sequencing and molecular straintyping (Diversilab and multi-locus sequence typing (MLST)). ESBL genes were demonstrated in 512 isolates (81%); of which 446 (87%) belonged to the CTX-M family. Among 314 randomly selected and sequenced isolates, bla CTX-M-15 was most prevalent (n = 124, 39%), followed by bla CTX-M-1 (n = 47, 15%), bla CTX-M-14 (n = 15, 5%), bla SHV-12 (n = 24, 8%) and bla TEM-52 (n = 13, 4%). Among 181 isolates with MIC ≥16 mg/L for cefoxitin plasmid encoded AmpCs were detected in 32 and 27 were of the CMY-2 group. Among 102 E. coli isolates with MIC ≥16 mg/L for cefoxitin ampC promoter mutations were identified in 29 (28%). Based on Diversilab genotyping of 608 isolates (similarity cut-off >98%) discriminatory indices of bacteria with ESBL and/or ampC genes were 0.994, 0.985 and 0.994 for E. coli, K. pneumoniae and E. cloacae, respectively. Based on similarity cut-off >95% two large clusters of E. coli were apparent (of 43 and 30 isolates) and 21 of 21 that were typed by belonged to ST131 of which 13 contained bla CTX-M-15. Our findings demonstrate that bla CTX-M-15 is the most prevalent ESBL and we report a larger than previously reported prevalence of ampC genes among Enterobacteriaceae responsible for resistance to third-generation cephalosporins. PMID:23284886

Complete Genome of Enterobacteriaceae Bacterium Strain FGI 57, a Strain Associated with Leaf-Cutter Ant Fungus Gardens

PubMed Central

Aylward, Frank O.; Tremmel, Daniel M.; Bruce, David C.; Chain, Patrick; Chen, Amy; Walston Davenport, Karen; Detter, Chris; Han, Cliff S.; Han, James; Huntemann, Marcel; Ivanova, Natalia N.; Kyrpides, Nikos C.; Markowitz, Victor; Mavrommatis, Kostas; Nolan, Matt; Pagani, Ioanna; Pati, Amrita; Pitluck, Sam; Deshpande, Shweta; Goodwin, Lynne; Woyke, Tanja

2013-01-01

The Enterobacteriaceae bacterium strain FGI 57 was isolated from a fungus garden of the leaf-cutter ant Atta colombica. Analysis of its single 4.76-Mbp chromosome will shed light on community dynamics and plant biomass degradation in ant fungus gardens. PMID:23469353

Decontamination and survival of Enterobacteriaceae on shredded iceberg lettuce during storage.

PubMed

Osaili, Tareq M; Alaboudi, Akram R; Al-Quran, Heba N; Al-Nabulsi, Anas A

2018-08-01

Enterobacteriaceae family can contaminate fresh produce at any stage of production either at pre-harvest or post-harvest stages. The objectives of the current study were to i) identify Enterobacteriaceae species on iceberg lettuce, ii) compare the decontamination efficiency of water, sodium hypochlorite (free chlorine 200 ppm), peroxyacetic acid (PA 80 ppm; Kenocid 2100 ® ) or their combinations and ionizing radiation against Enterobacteriaceae on shredded iceberg lettuce and iii) determine the survival of Enterobacteriaceae post-treatment storage of shredded iceberg lettuce at 4, 10 and 25 °C, for up to 7 days. Klebsiella pneumonia spp. pneumonia, Enterobacter cloacae, Klebsiella oxytoca, Pantoea spp., Leclercia adecarboxylata and Kluyvera ascorbate were identified on iceberg lettuce. No significant difference (P≥ 0.05) among Enterobacteriaceae survival after washing with water or sanitizing with sodium hypochlorite or Kenocid 2100 ® (reduction ≤ 0.6 log CFU/g) were found. Combined sanitizer treatments were more effective against Enterobacteriaceae than single washing/sanitizing treatments. Sanitization of iceberg lettuce with combined washing/sanitizing treatments reduced Enterobacteriaceae by 0.85-2.24 CFU/g. Post-treatment growth of Enterobacteriaceae during storage on samples sanitized with sodium hypochlorite and Kenocid 2100 ® was more than on samples washed with water. The D 10 -value of Enterobacteriaceae on shredded iceberg lettuce was 0.21 KGy. The reduction of Enterobacteriaceae populations on iceberg after gamma radiation (0.6 KGy) was 3 log CFU/g, however, Enterobacteriaceae counts increased post-irradiation storage by 4-5 log CFU/g. Therefore, washing shredded iceberg lettuce with combined sanitizing treatment (sodium hypochlorite/sodium hypochlorite, sodium hypochlorite/Kenocid 2100 ® , or Kenocid 2100 ® /Kenocid 2100 ® ) for total time of 6 min or exposing it to gamma irradiation (0.6 KGy) can decrease the risk of

Drug Resistance and Population Structure of Mycobacterium tuberculosis Beijing Strains Isolated in Poland.

PubMed

Kozińska, Monika; Augustynowicz-Kopeć, Ewa

2015-01-01

In total, 1095 Mycobacterium tuberculosis clinical isolates from 282 patients with drug-resistant and 813 with drug-sensitive tuberculosis (TB) in Poland during 2007-2011 were analysed. Seventy-one (6.5%) patients were found to have strains of Beijing genotype as defined by spoligotyping. The majority of patients were Polish-born; among foreign-born a large proportion came from Chechnya and Vietnam. Analysis showed strong associations between Beijing genotype infection and MDR, pre-XDR and XDR resistance, with a considerable relative risk among new patients, suggesting that this is due to increased spread of drug-resistant strains rather than acquisition of resistance during treatment.

Development and Validation of a Lateral Flow Immunoassay for Rapid Detection of NDM-Producing Enterobacteriaceae

PubMed Central

Boutal, Hervé; Naas, Thierry; Devilliers, Karine; Oueslati, Saoussen; Bernabeu, Sandrine; Simon, Stéphanie

2017-01-01

ABSTRACT The global spread of carbapenemase-producing Enterobacteriaceae (CPE) that are often resistant to most, if not all, classes of antibiotics is a major public health concern. The NDM-1 carbapenemase is among the most worrisome carbapenemases given its rapid worldwide spread. We have developed and evaluated a lateral flow immunoassay (LFIA) (called the NDM LFIA) for the rapid and reliable detection of NDM-like carbapenemase-producing Enterobacteriaceae from culture colonies. We evaluated the NDM LFIA using 175 reference enterobacterial isolates with characterized β-lactamase gene content and 74 nonduplicate consecutive carbapenem-resistant clinical isolates referred for expertise to the French National Reference Center (NRC) for Antibiotic Resistance during a 1-week period (in June 2016). The reference collection included 55 non-carbapenemase producers and 120 carbapenemase producers, including 27 NDM producers. All 27 NDM-like carbapenemase producers of the reference collection were correctly detected in less than 15 min by the NDM LFIA, including 22 strains producing NDM-1, 2 producing NDM-4, 1 producing NDM-5, 1 producing NDM-7, and 1 producing NDM-9. All non-NDM-1 producers gave a negative result with the NDM LFIA. No cross-reaction was observed with carbapenemases (VIM, IMP, NDM, KPC, and OXA-48-like), extended-spectrum β-lactamases (ESBLs) (TEM, SHV, and CTX-M), AmpCs (CMY-2, DHA-2, and ACC-1), and oxacillinases (OXA-1, -2, -9, and -10). Similarly, among the 74 referred nonduplicate consecutive clinical isolates, all 7 NDM-like producers were identified. Overall, the sensitivity and specificity of the assay were 100% for NDM-like carbapenemase detection with strains cultured on agar. The NDM LFIA was efficient, rapid, and easy to implement in the routine workflow of a clinical microbiology laboratory for the confirmation of NDM-like carbapenemase-producing Enterobacteriaceae. PMID:28404680

Use of Ancillary Carbapenemase Tests To Improve Specificity of Phenotypic Definitions for Carbapenemase-Producing Enterobacteriaceae.

PubMed

Miller, Shelley A; Hindler, Janet A; Chengcuenca, Angelo; Humphries, Romney M

2017-06-01

Carbapenemase-producing Enterobacteriaceae (CPE) are a significant threat to public health. In 2015, CDC revised the surveillance definition for CPE to include all Enterobacteriaceae resistant to any carbapenem tested. However, this definition is associated with poor specificity. We evaluated the performance of this definition, compared to carbapenemase PCR, for a collection of 125 Enterobacteriaceae We also investigated the impact of ancillary testing for carbapenemase of isolates that met the CDC CPE surveillance definition. The two ancillary tests evaluated were the Xpert Carba-R assay, a molecular test, and the carbapenem inactivation method (CIM). Two variables were evaluated for the CIM: suspension of organisms in double-distilled water (ddH 2 O) versus tryptic soy broth (TSB) to incubate disks, and incubation of plates for 6 h versus 18 to 20 h. The sensitivity and specificity of the Carba-R assay were 100% compared to the results of in-house PCR. The sensitivities of the CIM performed with TSB were 94.6% when read at 6 h and 97.7% when read at 18 to 20 h; the sensitivities with ddH 2 O were 88.0% when read at 6 h and 93.0% when incubated for 18 to 20 h. The specificity was 100% for all variables tested. Without ancillary testing, the sensitivity of the CDC definition was 98.9% for CPE, and the specificity was 6.1%. Testing isolates that screened positive by the CDC definition with the Xpert Carba-R did not change the sensitivity, and it improved the specificity to 100%. Similarly, the use of the CIM (TSB and 18 to 20 h of incubation) to confirm screen-positive isolates resulted in a sensitivity of 95.6% and specificity of 100%. Copyright © 2017 American Society for Microbiology.

Role of gyrB Mutations in Pre-extensively and Extensively Drug-Resistant Tuberculosis in Thai Clinical Isolates

PubMed Central

Disratthakit, Areeya; Prammananan, Therdsak; Tribuddharat, Chanwit; Thaipisuttikul, Iyarit; Doi, Norio; Leechawengwongs, Manoon

2016-01-01

DNA gyrase mutations are a major cause of quinolone resistance in Mycobacterium tuberculosis. We therefore conducted the first comprehensive study to determine the diversity of gyrase mutations in pre-extensively drug-resistant (pre-XDR) (n = 71) and extensively drug-resistant (XDR) (n = 30) Thai clinical tuberculosis (TB) isolates. All pre-XDR-TB and XDR-TB isolates carried at least one mutation within the quinolone resistance-determining region of GyrA (G88A [1.1%], A90V [17.4%], S91P [1.1%], or D94A/G/H/N/V/Y [72.7%]) or GyrB (D533A [1.1%], N538D [1.1%], or E540D [2.2%]). MIC and DNA gyrase supercoiling inhibition assays were performed to determine the role of gyrase mutations in quinolone resistance. Compared to the MICs against M. tuberculosis H37Rv, the levels of resistance to all quinolones tested in the isolates that carried GyrA-D94G or GyrB-N538D (8- to 32-fold increase) were significantly higher than those in isolates bearing GyrA-D94A or GyrA-A90V (2- to 8-fold increase) (P < 0.01). Intriguingly, GyrB-E540D led to a dramatic resistance to later-generation quinolones, including moxifloxacin, gatifloxacin, and sparfloxacin (8- to 16-fold increases in MICs and 8.3- to 11.2-fold increases in 50% inhibitory concentrations [IC50s]). However, GyrB-E540D caused low-level resistance to early-generation quinolones, including ofloxacin, levofloxacin, and ciprofloxacin (2- to 4-fold increases in MICs and 1.5- to 2.0-fold increases in IC50s). In the present study, DC-159a was the most active antituberculosis agent and was little affected by the gyrase mutations described above. Our findings suggest that although they are rare, gyrB mutations have a notable role in quinolone resistance, which may provide clues to the molecular basis of estimating quinolone resistance levels for drug and dose selection. PMID:27297489

Treatment of infections caused by carbapenemase-producing Enterobacteriaceae.

PubMed

Rodríguez-Baño, Jesús; Cisneros, José Miguel; Gudiol, Carlota; Martínez, José Antonio

2014-12-01

Treatment of infections caused by carbapenemase-producing Enterobacteriaceae (CPE) is currently one of the most important challenges of infectious diseases. The available information is based on in vitro studies, some animal model data and a few case studies and retrospective cohorts; appropriate data are lacking or are very scarce for some old antibiotics that are still occasionally used. Because of the heterogeneity in clinical situations, in specific carbapenemases and in the susceptibility of isolates, individualized treatment decisions must usually be made. Here we review the different antibiotics that might be useful for treating infections caused by CPE. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

Comparative efficacy and safety of treatment options for MDR and XDR Acinetobacter baumannii infections: a systematic review and network meta-analysis.

PubMed

Kengkla, Kirati; Kongpakwattana, Khachen; Saokaew, Surasak; Apisarnthanarak, Anucha; Chaiyakunapruk, Nathorn

2018-01-01

To comprehensively compare and rank the efficacy and safety of available treatment options for patients with MDR and XDR Acinetobacter baumannii (AB) infection. We searched PubMed, Embase and the Cochrane register of trials systematically for studies that examined treatment options for patients with MDR- and XDR-AB infections until April 2016. Network meta-analysis (NMA) was performed to estimate the risk ratio (RR) and 95% CI from both direct and indirect evidence. Primary outcomes were clinical cure and microbiological cure. Secondary outcomes were all-cause mortality and nephrotoxic and non-nephrotoxic adverse events. A total of 29 studies with 2529 patients (median age 60 years; 65% male; median APACHE II score 19.0) were included. Although there were no statistically significant differences between treatment options, triple therapy with colistin, sulbactam and tigecycline had the highest clinical cure rate. Colistin in combination with sulbactam was associated with a significantly higher microbiological cure rate compared with colistin in combination with tigecycline (RR 1.23; 95% CI 1.03-1.47) and colistin monotherapy (RR 1.21; 95% CI 1.06-1.38). No significant differences in all-cause mortality were noted between treatment options. Tigecycline-based therapy also appeared less effective for achieving a microbiological cure and is not appropriate for treating bloodstream MDR- and XDR-AB infections. Combination therapy of colistin with sulbactam demonstrates superiority in terms of microbiological cure with a safety profile similar to that of colistin monotherapy. Thus, our findings support the use of this combination as a treatment for MDR- and XDR-AB infections. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Esculin hydrolysis by Enterobacteriaceae.

PubMed

Edberg, S C; Pittman, S; Singer, J M

1977-08-01

Literature reports disagree concerning esculin hydrolysis in the family Enterobacteriaceae. A total of 2,490 strains of the family were investigated for esculin hydrolysis by two methods, the esculin spot test and the PathoTec incubation strip, which measures constitutive enzyme, and five growth-supporting methods, which determine both constitutive and inducible enzymes. The five growth-supporting media studied were: Vaughn-Levine, the standard esculin hydrolysis medium (P. R. Edwards and W. H. Ewing, Identification of Enterobacteriaceae, 3rd ed., 1972); Vaughn-Levine without iron; Vaughn-Levine without Andrade's indicator; and bile-esculin medium. Growth media were incubated at 35 degrees C and checked every 24 h for 120 h. On growth media, 0.3% of Escherichia coli were positive in 24 h, 34% in 48 h, and 61% in 120 h. No strains were positive on the "nongrowth" tests. It appeared that the esculin hydrolysis enzyme(s) of E. coli was inducible rather than constitutive. All esculin hydrolyzers, which yielded positive tests on "constitutive tests" and 24-h tests, were limited to the genera Klebsiella, Enterobacter, and Serratia and species of Proteus vulgaris, Proteus rettgeri, and Citrobacter diversus. When used with standardized inoculum size and incubation time, the esculin hydrolysis test is very useful for differentiation within the family Enterobacteriaceae.

Esculin hydrolysis by Enterobacteriaceae.

PubMed Central

Edberg, S C; Pittman, S; Singer, J M

1977-01-01

Literature reports disagree concerning esculin hydrolysis in the family Enterobacteriaceae. A total of 2,490 strains of the family were investigated for esculin hydrolysis by two methods, the esculin spot test and the PathoTec incubation strip, which measures constitutive enzyme, and five growth-supporting methods, which determine both constitutive and inducible enzymes. The five growth-supporting media studied were: Vaughn-Levine, the standard esculin hydrolysis medium (P. R. Edwards and W. H. Ewing, Identification of Enterobacteriaceae, 3rd ed., 1972); Vaughn-Levine without iron; Vaughn-Levine without Andrade's indicator; and bile-esculin medium. Growth media were incubated at 35 degrees C and checked every 24 h for 120 h. On growth media, 0.3% of Escherichia coli were positive in 24 h, 34% in 48 h, and 61% in 120 h. No strains were positive on the "nongrowth" tests. It appeared that the esculin hydrolysis enzyme(s) of E. coli was inducible rather than constitutive. All esculin hydrolyzers, which yielded positive tests on "constitutive tests" and 24-h tests, were limited to the genera Klebsiella, Enterobacter, and Serratia and species of Proteus vulgaris, Proteus rettgeri, and Citrobacter diversus. When used with standardized inoculum size and incubation time, the esculin hydrolysis test is very useful for differentiation within the family Enterobacteriaceae. PMID:330558

Comparison of Molecular and Phenotypic Methods for the Detection and Characterization of Carbapenem Resistant Enterobacteriaceae.

PubMed

Somily, Ali M; Garaween, Ghada A; Abukhalid, Norah; Absar, Muhammad M; Senok, Abiola C

2016-03-01

In recent years, there has been a rapid dissemination of carbapenem resistant Enterobacteriaceae (CRE). This study aimed to compare phenotypic and molecular methods for detection and characterization of CRE isolates at a large tertiary care hospital in Saudi Arabia. This study was carried out between January 2011 and November 2013 at the King Khalid University Hospital (KKUH) in Saudi Arabia. Determination of presence of extended-spectrum beta-lactamases (ESBL) and carbapenem resistance was in accordance with Clinical and Laboratory Standards Institute (CLSI) guidelines. Phenotypic classification was done by the MASTDISCS(TM) ID inhibitor combination disk method. Genotypic characterization of ESBL and carbapenemase genes was performed by the Check-MDR CT102. Diversilab rep-PCR was used for the determination of clonal relationship. Of the 883 ESBL-positive Enterobacteriaceae detected during the study period, 14 (1.6%) isolates were carbapenem resistant. Both the molecular genotypic characterization and phenotypic testing were in agreement in the detection of all 8 metalo-beta-lactamases (MBL) producing isolates. Of these 8 MBL-producers, 5 were positive for blaNDM gene and 3 were positive for blaVIM gene. Molecular method identified additional blaOXA gene isolates while MASTDISCS(TM) ID detected one AmpC producer isolate. Both methods agreed in identifying 2 carbapenem resistant isolates which were negative for carbapenemase genes. Diversilab rep-PCR analysis of the 9 Klebsiella pneumoniae isolates revealed polyclonal distribution into eight clusters. MASTDISCS(TM) ID is a reliable simple cheap phenotypic method for detection of majority of carbapenemase genes with the exception of the blaOXA gene. We recommend to use such method in the clinical laboratory.

Antibiotic consumption and Enterobacteriaceae skin colonization in hospitalized adults.

PubMed

Kirby, A; Berry, C; West, R

2017-01-01

Enterobacteriaceae are increasingly antibiotic resistant, and skin colonization may contribute to their spread in hospitals. This study screened 100 hospitalized adults for Enterobacteriaceae skin colonization, and assessed potential risk factors, including antibiotic consumption. Multi-variable analysis found that antibiotic consumption whilst an inpatient [odds ratio (OR) 3.16, 95% confidence interval (CI) 1.19-8.4] and male sex (OR 2.92, 95% CI 1.06-8.4) were risk factors for Enterobacteriaceae skin colonization. If these risk factors are confirmed, work to understand the biological mechanism involved may lead to the development of interventions to prevent Enterobacteriaceae skin colonization. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Imipenem-avibactam: a novel combination for the rapid detection of carbapenemase activity in Enterobacteriaceae and Acinetobacter baumannii by matrix-assisted laser desorption ionization-time of flight mass spectrometry.

PubMed

Oviaño, Marina; Bou, Germán

2017-02-01

In the present study, we propose a novel matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)-based method for detecting carbapenemase-producing Enterobacteriaceae and Acinetobacter baumannii. For this, we analyzed a series of 131 isolates. Among them, a total of 115 Enterobacteriaceae: 79 of them carrying a carbapenemase enzyme (15bla KPC , 7bla NDM , 11bla IMP , 12bla VIM , and 34bla OXA-48 ) and 16 A. baumannii isolates: 15 of them carrying carbapenemases (10bla OXA-23, 2bla OXA-58, 2bla OXA-24 , and 1bla OXA-237 ). The rest of the isolates were noncarbapenemase producers and used as negative controls. The isolates were submitted to susceptibility testing using a combination of imipenem-avibactam and analysis by the MALDI-TOF Biotyper Compass software (Bruker Daltonik, Germany). The assay showed an overall sensitivity and specificity for carbapenemase detection of 98% and 100%, respectively. The combination of imipenem and avibactam displayed activity against KPC and OXA-48-producing Enterobacteriaceae and thus represents a new strategy for identifying and confirming these carbapenemases. However, the combination did not provide any benefit over A. baumannii. Copyright © 2016 Elsevier Inc. All rights reserved.

Carbapenemase-producing Enterobacteriaceae: a 2-year surveillance in a hospital in Iaşi, Romania.

PubMed

Braun, Sascha D; Dorneanu, Olivia S; Vremeră, Teodora; Reißig, Annett; Monecke, Stefan; Ehricht, Ralf

2016-01-01

Limited information is currently available about the prevalence of carbapenemase-producing Enterobacteriaceae (CPE) in Romania. Routine tests of 1,993 clinical isolates at a hospital in Iaşi yielded 46 isolates that were resistant to carbapenems. All 46 isolates were phenotypically and genotypically analyzed using VITEK-2 and DNA microarray-based assays. Isolates were assigned to Klebsiella pneumoniae and Enterobacter cloacae. For 39 isolates, carbapenem resistance was confirmed and 37 harbored at least one carbapenem resistance gene. Two isolates were probably resistant due to AmpC β-lactamases in combination with a porin loss. The overall concordance between detected phenotype and genotype was 95%. Our data show that carbapenemase-producing isolates with different underlying resistance mechanisms are still rare in Iaşi, but the global rise of CPE warrants intensified surveillance.

Ceftazidime-Resistant Enterobacteriaceae Isolates from Three Polish Hospitals: Identification of Three Novel TEM- and SHV-5-Type Extended-Spectrum β-Lactamases

PubMed Central

Gniadkowski, Marek; Schneider, Ines; Jungwirth, Renate; Hryniewicz, Waleria; Bauernfeind, Adolf

1998-01-01

Twelve ceftazidime-resistant isolates of the family Enterobacteriaceae (11 Klebsiella pneumoniae isolates and 1 Escherichia coli isolate) were collected in 1995 from three Polish hospitals located in different cities. All were identified as producers of extended-spectrum β-lactamases (ESBLs). Detailed analysis of their β-lactamase contents revealed that six of them expressed SHV-5-like ESBLs. The remaining six were found to produce three different TEM enzymes, each characterized by a pI value of 6.0 and specified by new combinations of amino acid substitutions. The amino acid substitutions compared to the TEM-1 β-lactamase sequence were Gly238Ser, Glu240Lys, and Thr265Met for TEM-47; Leu21Phe, Gly238Ser, Glu240Lys, and Thr265Met for TEM-48; and Leu21Phe, Gly238Ser, Glu240Lys, Thr265Met, and Ser268Gly for TEM-49. The new TEM β-lactamases, TEM-47, TEM-48, and TEM-49, belong to a subfamily of TEM-2-related enzymes. Genes coding for TEM-47 and TEM-49 could have originated from the TEM-48-encoding sequence by various single genetic events. The new TEM derivatives probably document the already advanced microevolution of ESBLs ongoing in Polish hospitals, in a majority of which no monitoring of ESBL producers was performed before 1996. PMID:9517925

Insight into multidrug-resistant Beijing genotype Mycobacterium tuberculosis isolates in Myanmar.

PubMed

San, Lai Lai; Aye, Khin Saw; Oo, Nan Aye Thida; Shwe, Mu Mu; Fukushima, Yukari; Gordon, Stephen V; Suzuki, Yasuhiko; Nakajima, Chie

2018-06-21

Myanmar is a WHO high tuberculosis (TB) burden country with a high multidrug-resistant (MDR)-TB burden. Significantly a high prevalence of the Beijing genotype of Mycobacterium tuberculosis (MTB) among MDR-MTB has been reported previously. To explore whether an association exists between the prevalence of the Beijing MTB genotype and MDR-TB in Myanmar, we performed detailed genetic characterization of TB clinical isolates. A total of 265 MDR-MTB clinical isolates collected in 2010 and 2012 were subjected to spoligotyping, mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR) analysis, SNP typing and drug resistance-associated gene sequencing including rpoC to detect potential compensatory evolution. Of the total MDR-MTB isolates, 79.2% (210/265) were of the Beijing genotype, the majority of which were the "modern" subtype. Beijing genotype isolates were differentiated by 15-loci MIRU-VNTR and a high clustering rate (53.0%) was observed in the modern subtype. These MIRU-VNTR patterns were similar to Beijing genotype clones spreading across Russia and Central Asia. High prevalence of katG Ser315Thr, and genetic evidence of XDR and pre-XDR and compensatory mutations in rpoC were observed among clustered isolates. MDR-MTB strains of the Beijing genotype might be spreading in Myanmar and present a major challenge to TB control in this country. Copyright © 2018. Published by Elsevier Ltd.

Occurrence and characteristics of extended spectrum beta-lactamases-producing Enterobacteriaceae from foods of animal origin.

PubMed

Tekiner, İsmail Hakkı; Özpınar, Haydar

2016-01-01

Presence of extended spectrum beta-lactamases (ESBL) in bacteria is a growing health concern of global significance. The local, regional, national, and international epidemiological studies for extended spectrum beta-lactamases-producing Enterobacteriaceae and their encoding genes in foods are still incomplete. The objective of this study was to determine the occurrence of extended spectrum beta-lactamases-producing Enterobacteriaceae and the characteristics of their encoding genes from a total of 250 samples of various foods of animal-origin (100 raw chicken meat, 100 raw cow milk, and 50 raw cow milk cheese) sold in Turkey. Overall, 55 isolates were positive as extended spectrum beta-lactamases-producing Enterobacteriaceae. The most prevalent extended spectrum beta-lactamases-producing strain were identified as Escherichia coli (80%), followed by Enterobacter cloacae (9.1%), Citrobacter braakii (5.5%), Klebsiella pneumoniae (3.6%), and Citrobacter werkmanii (1.8%) by Vitek(®) MS. The simultaneous production of extended spectrum beta-lactamases and AmpC was detected in five isolates (9.1%) in E. coli (80%) and E. cloacae (20%). The frequency rates of blaTEM, blaCTX-M, and blaSHV were 96.4%, 53.7%, and 34.5%, respectively. The co-existence of bla-genes was observed in 82% of extended spectrum beta-lactamases producers with a distribution of blaTEM &blaCTX-M (52.7%), blaTEM &blaSHV (20%), blaTEM &blaCTX-M &blaSHV (12.7%), and blaSHV &blaCTX-M (1.8%). The most prevalent variant of blaCTX-M clusters was defined as blaCTX-M-1 (97.2%), followed by blaCTX-M-8 (2.8%). In summary, the analysed foods were found to be posing a health risk for Turkish consumers due to contamination by Enterobacteriaceae with a diversity of extended spectrum beta-lactamases encoding genes. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Macrolide resistance mechanisms in Enterobacteriaceae: Focus on azithromycin.

PubMed

Gomes, Cláudia; Martínez-Puchol, Sandra; Palma, Noemí; Horna, Gertrudis; Ruiz-Roldán, Lidia; Pons, Maria J; Ruiz, Joaquim

2017-02-01

From its introduction in 1952 onwards, the clinical use of macrolides has been steadily increasing, both in human and veterinary medicine. Although initially designed to the treatment of Gram-positive microorganisms, this antimicrobial family has also been used to treat specific Gram-negative bacteria. Some of them, as azithromycin, are considered in the armamentarium against Enterobacteriaceae infections. However, the facility that this bacterial genus has to gain or develop mechanisms of antibiotic resistance may compromise the future usefulness of these antibiotics to fight against Enterobacteriaceae infections. The present review is focused on the mechanisms of macrolide resistance, currently described in Enterobacteriaceae.

The occurrence of CTX-M-25-producing Enterobacteriaceae in day-old broiler chicks in Japan.

PubMed

Yossapol, Montira; Sugiyama, Michiyo; Asai, Tetsuo

2017-10-07

Day-old chicks from 3 hatcheries were placed on bedding paper and brought to a commercial broiler farm between January and July 2016. Sixty-six samples of the paper, which were stained with meconium droppings of the chicks, were collected and examined for isolation of cephalosporin-resistant Enterobacteriaceae. Cefotaxime (CTX)-resistant Klebsiella pneumoniae (1 isolate) and Enterobacter cloacae (4 isolates) were isolated from 5 (7.58%) of the 66 samples. Conjugation experiments revealed that the bla CTX-M-25 gene conferring CTX resistance was transferred from the K. pneumoniae isolate and 2 of the 4 E. cloacae isolates to Escherichia coli DH5α via IncA/C plasmids carrying the gene. Our results suggested that the bla CTX-M-25 gene originating from chicks may be spread among commercial broiler farms.

Trends in carbapenemase-producing Enterobacteriaceae, France, 2012 to 2014

PubMed Central

Dortet, Laurent; Cuzon, Gaëlle; Ponties, Valérie; Nordmann, Patrice

2017-01-01

In 2014, a total of 2,976 Enterobacteriaceae isolates with decreased susceptibility to carbapenems were received at the French Associated National Reference Center for Antibiotic Resistance (NRC) and were characterised for their molecular resistance mechanism to carbapenems and compared with results obtained during 2012 and 2013.The overall number of enterobacterial isolates with decreased susceptibility to carbapenems received at the NRC rapidly increased (more than twofold in two years) with a growing proportion of carbapenemase producers (23.1% in 2012 vs 28.6% in 2013 vs 36.2% in 2014). Between 2012 and 2014, the main carbapenemase type was OXA-48, with an increase in OXA-48 variants (mostly OXA-181) and NDM producers, whereas the number KPC producers decreased. We identified a potential spread of OXA-181 producers in the tropical region of Africa. Finally, OXA-48 and OXA-48-related enzymes remained the predominant carbapenemases in France. The number of carbapenemase-producing Escherischia coli isolates was multiplied by fivefold between 2012 and 2014, suggesting a possible dissemination in the community. PMID:28205502

Digestive tract colonization by multidrug-resistant Enterobacteriaceae in travellers: An update.

PubMed

Ruppé, Etienne; Andremont, Antoine; Armand-Lefèvre, Laurence

Enterobacteriaceae have become increasingly resistant, especially due to the acquisition and spread of extended-spectrum beta-lactamases (ESBLs), which confer resistance to the majority of beta-lactams. Multi-resistant Enterobacteriaceae (MRE) were first isolated in hospitals, but now they are disseminating in the community setting, mostly in low and middle income countries. Consequently, the increasing number of international travels leads to the importation of MRE from high-prevalence to low-prevalence countries. The Pubmed database was used to conduct research from 1980 to 2016 by combining the following key words: travel, antibiotic resistance, ESBL, Enterobacteriaceae, genomic, metagenomic, urinary tract infection, infection. The research found that the MRE acquisition rates in healthy travellers from low-prevalence countries ranged from 21% to 51% depending on the study design and the visited geographic regions. After a trip to Asia and especially to South Asia, the acquisition rate could reach 85%. A trip to Africa or to the Middle East was associated with lower rates but still worrisome (13-44%). Digestive disorder, diarrhoea and antibiotics used during travel are major risks factors associated with the acquisition of MRE. Travel to endemic areas has also been identified as a risk factor for MRE infection, including urinary tract infections. Travellers are at high risk of MRE acquisition and consequently of MRE infection. This risk should not be ignored by general practitioners. To reduce the risk of acquisition and subsequent transmission to relatives, travellers should be given recommendations prior to their travel. Copyright © 2017. Published by Elsevier Ltd.

Prevalence and Antimicrobial Resistance of Enterobacteriaceae in Shell Eggs from Small-Scale Poultry Farms and Farmers' Markets.

PubMed

Kilonzo-Nthenge, A; Nahashon, S N; Godwin, S; Liu, S; Long, D

2016-12-01

Public health concerns over the emergence of antimicrobial resistant bacteria have increased recently. The purpose of this study was to investigate the prevalence of antimicrobial resistant Enterobacteriaceae in shell eggs purchased from small poultry farms and farmers' markets. A total of 504 eggs were pooled to make 252 composite samples, consisting of 2 eggs per composite. The microbial quality of shell eggs was determined by standard quantitative, biochemical, and PCR techniques. Susceptibility to 13 antimicrobial agents was determined by the Kirby-Bauer disk diffusion technique, and results were interpreted based on Clinical and Laboratory Standards Institute values. Shell eggs and egg contents were positive for Escherichia coli (11.9 and 5.2%, respectively), Enterobacter (9.1 and 7.9%), and Serratia (11.5 and 4.8%). Salmonella was isolated from 3.6% of egg shells but not from egg contents. Mean (±SD) Enterobacteriaceae levels (4.4 ± 2.0 log CFU per eggshell) on shell eggs from poultry farms was significantly higher (P ≤ 0.05) than that on shell eggs from farmers' markets (2.1 ± 1.3 log CFU per eggshell). Of the 134 isolates recovered, resistance among isolates from farm and market shell eggs to erythromycin was most common (48.5 and 32.8%, respectively) followed by ampicillin (44.8 and 17.2%), and tetracycline (29.9 and 17.2%). The multiple antibiotic resistance index value for E. coli and Pantoea was 0.62, and that for Salmonella and Klebsiella terrigena was 0.08, indicating that Enterobacteriaceae in shell eggs can be resistant to multiple antimicrobial agents. These data reveal that shell eggs from small poultry farms and farmers' markets can harbor antimicrobial resistant pathogenic and commensal bacteria. Thus, failure to properly handle shell eggs poses a potential health hazard to consumers.

Global Molecular Epidemiology of IMP-Producing Enterobacteriaceae

PubMed Central

Peirano, Gisele; Motyl, Mary R.; Adams, Mark D.; Chen, Liang; Kreiswirth, Barry; DeVinney, Rebekah

2017-01-01

ABSTRACT International data on the molecular epidemiology of Enterobacteriaceae with IMP carbapenemases are lacking. We performed short-read (Illumina) whole-genome sequencing on a global collection of 38 IMP-producing clinical Enterobacteriaceae (2008 to 2014). IMP-producing Enterobacteriaceae (7 varieties within 11 class 1 integrons) were mainly present in the South Pacific and Asia. Specific blaIMP-containing integrons (In809 with blaIMP-4, In722 with blaIMP-6, and In687 with blaIMP-14) were circulating among different bacteria in countries such as Australia, Japan, and Thailand. In1312 with blaIMP-1 was present in Klebsiella pneumoniae from Japan and Citrobacter freundii from Brazil. Klebsiella pneumoniae (n = 22) was the most common species; clonal complex 14 (CC14) from Philippines and Japan was the most common clone and contained In1310 with blaIMP-26 and In1321 with blaIMP-6. The Enterobacter cloacae complex (n = 9) consisted of Enterobacter hormaechei and E. cloacae cluster III. CC78 (from Taiwan) containing In73 with blaIMP-8 was the most common clone among the E. cloacae complex. This study highlights the importance of surveillance programs using the latest molecular techniques for providing insight into the characteristics and global distribution of Enterobacteriaceae with blaIMP genes. PMID:28167555

The Prevalence and Molecular Epidemiology of Multidrug-Resistant Enterobacteriaceae Colonization in a Pediatric Intensive Care Unit

PubMed Central

Suwantarat, Nuntra; Logan, Latania K.; Carroll, Karen C.; Bonomo, Robert A.; Simner, Patricia J.; Rudin, Susan D.; Milstone, Aaron M.; Tekle, Tsigereda; Ross, Tracy; Tamma, Pranita D.

2016-01-01

OBJECTIVE To determine the prevalence and acquisition of extended-spectrum β-lactamases (ESBLs), plasmid-mediated AmpCs (pAmpCs), and carbapenemases (“MDR Enterobacteriaceae”) colonizing children admitted to a pediatric intensive care unit (PICU). DESIGN Prospective study. SETTING 40-bed PICU. METHODS Admission and weekly thereafter rectal surveillance swabs were collected on all pediatric patients during a 6-month study period. Routine phenotypic identification and antibiotic susceptibility testing were performed. Enterobacteriaceae displaying characteristic resistance profiles underwent further molecular characterization to identify genetic determinants of resistance likely to be transmitted on mobile genetic elements and to evaluate relatedness of strains including DNA microarray, multilocus sequence typing, repetitive sequence-based PCR, and hsp60 sequencing typing. Results Evaluating 854 swabs from unique children, the overall prevalence of colonization with an MDR Enterobacteriaceae upon admission to the PICU based on β-lactamase gene identification was 4.3% (n = 37), including 2.8% ESBLs (n =24), 1.3% pAmpCs (n =11), and 0.2% carbapenemases (n =2). Among 157 pediatric patients contributing 603 subsequent weekly swabs, 6 children (3.8%) acquired an incident MDR Enterobacteriaceae during their PICU stay. One child acquired a pAmpC (E. coli containing blaDHA) related to an isolate from another patient. Conclusions Approximately 4% of children admitted to a PICU were colonized with MDR Enterobacteriaceae (based on β-lactamase gene identification) and an additional 4% of children who remained in the PICU for at least 1 week acquired 1 of these organisms during their PICU stay. The acquired MDR Enterobacteriaceae were relatively heterogeneous, suggesting that a single source was not responsible for the introduction of these resistance mechanisms into the PICU setting. PMID:26856439

Detection of carbapenemases and other mechanisms of enzymatic resistance to β-lactams in Enterobacteriaceae with diminished susceptibility to carbapenems in a tertiary care hospital.

PubMed

Gómara, Marta; López-Calleja, Ana Isabel; Iglesia, Berta María Pilar Vela; Cerón, Isabel Ferrer; López, Antonio Rezusta; Pinilla, María José Revillo

2018-05-01

Our objective was to characterize the enzymatic β-lactam resistance in clinical Enterobacteriaceae isolates with diminished susceptibility to carbapenems from 2013 to 2014 at Hospital Universitario Miguel Servet. A total of 63 clinical isolates were analyzed for the presence of carbapenemases (KPC, OXA-48 and MBL), ESBLs and AmpC enzymes by combined disk methods and PCR detection of carbapenemase-encoding and beta-lactamase-encoding genes. Fifteen isolates had a phenotypic test compatible with carbapenemase production; two of these were confirmed by PCR as OXA-48 producers. ESBL detection was positive in 27 isolates (43%); plasmid-mediated AmpC was detected in nine isolates (14.2%) and derepressed AmpC β-lactamase was present in 18 isolates (28%). During the study period, the decreased susceptibility to carbapenems in Enterobacteriaceae in our area was not due to true carbapenemases but rather to β-lactamase activity (82.5% were ESBL or AmpC producers), probably in combination with decreased permeability of the outer membrane. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Wild Coastline Birds as Reservoirs of Broad-Spectrum-β-Lactamase-Producing Enterobacteriaceae in Miami Beach, Florida

PubMed Central

Potron, Anaïs; De La Cuesta, Carolina; Cleary, Timothy; Nordmann, Patrice; Munoz-Price, L. Silvia

2012-01-01

A high rate of broad-spectrum-β-lactamase-producing Escherichia coli isolates was identified from seagull and pelican feces collected in the Miami Beach, Florida, area. The most commonly identified resistance determinants were CMY-2 and CTX-M-15. Those wild birds might be therefore considered vehicles for wide dissemination of multidrug-resistant Enterobacteriaceae in the United States. PMID:22314536

The management of multidrug-resistant Enterobacteriaceae.

PubMed

Bassetti, Matteo; Peghin, Maddalena; Pecori, Davide

2016-12-01

Multidrug-resistant (MDR) Enterobacteriaceae are often related to the production of extended-spectrum b-lactamases (ESBLs) and carbapenemase-producing Enterobacteriaceae (CRE), and represent an increasing global threat. Recommendations for the therapeutic management of MDR-related infections, however, are mainly derived from retrospective and nonrandomized prospective studies. The aim of this review is to discuss the challenges in the treatment of patients with infections because of MDR Enterobacteriaceae and provide an expert opinion while awaiting for more definitive data. To avoid the selection of carbapenemase-producing Enterobacteriaceae, carbapenem-sparing strategies should be considered. B-lactams/b-lactamase inhibitors, mainly piperacillin-tazobactam, minimum inhibitory concentration (MIC) 16/4mg/ml or less represents the best alternative to carbapenems for the treatment of ESBL-producing strains. Overall, combination therapy may be preferred over monotherapy for CRE. The combination of a carbapenem-containing regimen with colistin or high-dose tigecycline or aminoglycoside can be administered at high-dose prolonged infusion with therapeutic drug monitoring for the treatment of CRE with MIC for meropenem 8-16 mg/l or less. For MIC higher than 8-16 mg/l, the use of meropenem should be avoided and various combination therapies based on the in-vitro susceptibility of antimicrobials (e.g., colistin, high-dose tigecycline, fosfomycin, and aminoglycosides) should be selected. Carbapenem-sparing strategies should be used, when feasible, for ESBL infections. The majority of available nonrandomized studies highlight that combination for CRE seem to offer some therapeutic advantage over monotherapy. Strict infection control measures toward MDR Gram-negative pathogens remain necessary while awaiting for new treatment options.

Beta-lactamases in Enterobacteriaceae infections in children.

PubMed

Moxon, Christopher Alan; Paulus, Stéphane

2016-07-05

Multi-drug resistance in Gram negative bacteria, particularly in Enterobacteriaceae, is a major clinical and public health challenge. The main mechanism of resistance in Enterobacteriaceae is linked to the production of beta-lactamase hydrolysing enzymes such as extended spectrum beta-lactamases (ESBL), AmpC beta-lactamases and carbapenemases (Carbapenemase Producing Enterobacteriaceae (CPE)). ESBL and CPE resistance genes are located on plasmids, which can be transmitted between Enterobacteriaceae, facilitating their spread in hospitals and communities. These plasmids usually harbour multiple additional co-resistance genes, including to trimethoprim-sulfamethoxazole, aminoglycosides, and fluoroquinolones, making these infections challenging to treat. Asymptomatic carriage in healthy children as well as community acquired infections are increasingly reported, particularly with ESBL. Therapeutic options are limited and previously little used antimicrobials such as fosfomycin and colistin have been re-introduced in clinical practice. Paediatric experience with these agents is limited hence there is a need to further examine their clinical efficacy, dosage and toxicity in children. Antimicrobial stewardship along with strict infection prevention and control practices need to be adopted widely in order to preserve currently available antimicrobials. The future development of novel agents effective against beta-lactamases producers and their applicability in children is urgently needed to address the challenge of multi-resistant Gram negative infections. Copyright © 2016 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

Global Molecular Epidemiology of IMP-Producing Enterobacteriaceae.

PubMed

Matsumura, Yasufumi; Peirano, Gisele; Motyl, Mary R; Adams, Mark D; Chen, Liang; Kreiswirth, Barry; DeVinney, Rebekah; Pitout, Johann D D

2017-04-01

International data on the molecular epidemiology of Enterobacteriaceae with IMP carbapenemases are lacking. We performed short-read (Illumina) whole-genome sequencing on a global collection of 38 IMP-producing clinical Enterobacteriaceae (2008 to 2014). IMP-producing Enterobacteriaceae (7 varieties within 11 class 1 integrons) were mainly present in the South Pacific and Asia. Specific bla IMP -containing integrons (In809 with bla IMP-4 , In722 with bla IMP-6 , and In687 with bla IMP-14 ) were circulating among different bacteria in countries such as Australia, Japan, and Thailand. In1312 with bla IMP-1 was present in Klebsiella pneumoniae from Japan and Citrobacter freundii from Brazil. Klebsiella pneumoniae ( n = 22) was the most common species; clonal complex 14 (CC14) from Philippines and Japan was the most common clone and contained In1310 with bla IMP-26 and In1321 with bla IMP-6 The Enterobacter cloacae complex ( n = 9) consisted of Enterobacter hormaechei and E. cloacae cluster III. CC78 (from Taiwan) containing In73 with bla IMP-8 was the most common clone among the E. cloacae complex. This study highlights the importance of surveillance programs using the latest molecular techniques for providing insight into the characteristics and global distribution of Enterobacteriaceae with bla IMP genes. Copyright © 2017 American Society for Microbiology.

Both sulfate-reducing bacteria and Enterobacteriaceae take part in marine biocorrosion of carbon steel.

PubMed

Bermont-Bouis, D; Janvier, M; Grimont, P A D; Dupont, I; Vallaeys, T

2007-01-01

In order to evaluate the part played in biocorrosion by microbial groups other than sulfate-reducing bacteria (SRB), we characterized the phylogenetic diversity of a corrosive marine biofilm attached to a harbour pile structure as well as to carbon steel surfaces (coupons) immersed in seawater for increasing time periods (1 and 8 months). We thus experimentally checked corroding abilities of defined species mixtures. Microbial community analysis was performed using both traditional cultivation techniques and polymerase chain reaction cloning-sequencing of 16S rRNA genes. Community structure of biofilms developing with time on immersed coupons tended to reach after 8 months, a steady state similar to the one observed on a harbour pile structure. Phylogenetic affiliations of isolates and cloned 16S rRNA genes (rrs) indicated that native biofilms (developing after 1-month immersion) were mainly colonized by gamma-proteobacteria. Among these, Vibrio species were detected in majority with molecular methods while cultivation techniques revealed dominance of Enterobacteriaceae such as Citrobacter, Klebsiella and Proteus species. Conversely, in mature biofilms (8-month immersion and pile structure), SRB, and to a lesser extent, spirochaetes were dominant. Corroding activity detection assays confirmed that Enterobacteriaceae (members of the gamma-proteobacteria) were involved in biocorrosion of metallic material in marine conditions. In marine biofilms, metal corrosion may be initiated by Enterobacteriaceae.

Spoligotyping of Mycobacterium tuberculosis isolates at a tertiary care hospital in India.

PubMed

Suzana, Shirly; Shanmugam, Sivakumar; Uma Devi, K R; Swarna Latha, P N; Michael, Joy S

2017-06-01

Spoligotyping is a valuable genotyping tool to study the genetic diversity and molecular epidemiology of Mycobacterium tuberculosis (M. tb). The aim of this study was to analyse different spoligotype patterns of M. tb strains isolated from patients with tuberculosis from different parts of India. A total of 163 M. tb isolates were spoligotyped between January 2014 and January 2015. About 47% (n = 77) were from patients with extrapulmonary tuberculosis; of these, 10 were MDR, and seven were Pre-XDR. Of the 86 M. tb isolates from patients with pulmonary tuberculosis, 25 were MDR, and 25 were Pre-XDR. We found 61 spoligo patterns, 128 clusters in the spoligotype data base (spoldb4 data base) with spoligo international type (SIT) number and 35 true unique isolates. The most pre-dominant spoligotype was EAI lineage (56), followed by Beijing (28), CAS (20), T(9), U(7), X(3), H(3), BOVIS_1 BCG(1) and LAM(1). Although our study identified EAI, CAS and Beijing strain lineages as pre-dominant, we also found a large number of orphan strains (20%) in our study. Beijing strains were more significantly associated with MDR TB than CAS and EAI lineages. Further studies on large sample sizes would help to clearly describe the epidemiology of M. tb in India. © 2017 John Wiley & Sons Ltd.

Development of quantitative real-time PCR for detection and enumeration of Enterobacteriaceae.

PubMed

Takahashi, Hajime; Saito, Rumi; Miya, Satoko; Tanaka, Yuichiro; Miyamura, Natsumi; Kuda, Takashi; Kimura, Bon

2017-04-04

The family Enterobacteriaceae, members of which are widely distributed in the environment, includes many important human pathogens. In this study, a rapid real-time PCR method targeting rplP, coding for L16 protein, a component of the ribosome large subunit, was developed for enumerating Enterobacteriaceae strains, and its efficiency was evaluated using naturally contaminated food products. The rplP-targeted real-time PCR amplified Enterobacteriaceae species with Ct values of 14.0-22.8, whereas the Ct values for non-Enterobacteriaceae species were >30, indicating the specificity of this method for the Enterobacteriaceae. Using a calibration curve of Ct=-3.025 (log CFU/g)+37.35, which was calculated from individual plots of the cell numbers in different concentrations of 5 Enterobacteriaceae species, the rplP-targeted real-time PCR was applied to 51 food samples. A <1log difference between the real-time PCR and culture methods was obtained in a majority of the food samples (81.8%), with good correlation (r 2 =0.8285). This study demonstrated that the rplP-targeted real-time PCR method could detect and enumerate Enterobacteriaceae species in foods rapidly and accurately, and therefore, it can be used for the microbiological risk analysis of foods. Copyright © 2017 Elsevier B.V. All rights reserved.

High Rates of Nonsusceptibility to Ceftazidime-avibactam and Identification of New Delhi Metallo-β-lactamase Production in Enterobacteriaceae Bloodstream Infections at a Major Cancer Center.

PubMed

Aitken, Samuel L; Tarrand, Jeffrey J; Deshpande, Lalitagauri M; Tverdek, Frank P; Jones, Anne L; Shelburne, Samuel A; Prince, Randall A; Bhatti, Micah M; Rolston, Kenneth V I; Jones, Ronald N; Castanheira, Mariana; Chemaly, Roy F

2016-10-01

Resistance to the novel β-lactam/β-lactamase inhibitor combination ceftazidime-avibactam (CAZ-AVI) among carbapenem-resistant Enterobacteriaceae (CRE) has infrequently been reported in the United States. We report unexpectedly high rates of resistance to CAZ-AVI in CRE bloodstream isolates at our institution associated with the nonoutbreak spread of New Delhi metallo-β-lactamase in diverse Enterobacteriaceae species. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Results from the Canadian Nosocomial Infection Surveillance Program on Carbapenemase-Producing Enterobacteriaceae, 2010 to 2014

PubMed Central

Mataseje, Laura F.; Abdesselam, Kahina; Vachon, Julie; Mitchel, Robyn; Bryce, Elizabeth; Roscoe, Diane; Boyd, David A.; Embree, Joanne; Katz, Kevin; Kibsey, Pamela; Simor, Andrew E.; Taylor, Geoffrey; Turgeon, Nathalie; Langley, Joanne; Gravel, Denise; Amaratunga, Kanchana

2016-01-01

Carbapenemase-producing Enterobacteriaceae (CPE) are increasing globally; here we report on the investigation of CPE in Canada over a 5-year period. Participating acute care facilities across Canada submitted carbapenem-nonsusceptible Enterobacteriaceae from 1 January 2010 to 31 December 2014 to the National Microbiology Laboratory. All CPE were characterized by antimicrobial susceptibilities, pulsed-field gel electrophoresis, multilocus sequence typing, and plasmid restriction fragment length polymorphism analysis and had patient data collected using a standard questionnaire. The 5-year incidence rate of CPE was 0.09 per 10,000 patient days and 0.07 per 1,000 admissions. There were a total of 261 CPE isolated from 238 patients in 58 hospitals during the study period. blaKPC-3 (64.8%) and blaNDM-1 (17.6%) represented the highest proportion of carbapenemase genes detected in Canadian isolates. Patients who had a history of medical attention during international travel accounted for 21% of CPE cases. The hospital 30-day all-cause mortality rate for the 5-year surveillance period was 17.1 per 100 CPE cases. No significant increase in the occurrence of CPE was observed from 2010 to 2014. Nosocomial transmission of CPE, as well as international health care, is driving its persistence within Canada. PMID:27600052

Results from the Canadian Nosocomial Infection Surveillance Program on Carbapenemase-Producing Enterobacteriaceae, 2010 to 2014.

PubMed

Mataseje, Laura F; Abdesselam, Kahina; Vachon, Julie; Mitchel, Robyn; Bryce, Elizabeth; Roscoe, Diane; Boyd, David A; Embree, Joanne; Katz, Kevin; Kibsey, Pamela; Simor, Andrew E; Taylor, Geoffrey; Turgeon, Nathalie; Langley, Joanne; Gravel, Denise; Amaratunga, Kanchana; Mulvey, Michael R

2016-11-01

Carbapenemase-producing Enterobacteriaceae (CPE) are increasing globally; here we report on the investigation of CPE in Canada over a 5-year period. Participating acute care facilities across Canada submitted carbapenem-nonsusceptible Enterobacteriaceae from 1 January 2010 to 31 December 2014 to the National Microbiology Laboratory. All CPE were characterized by antimicrobial susceptibilities, pulsed-field gel electrophoresis, multilocus sequence typing, and plasmid restriction fragment length polymorphism analysis and had patient data collected using a standard questionnaire. The 5-year incidence rate of CPE was 0.09 per 10,000 patient days and 0.07 per 1,000 admissions. There were a total of 261 CPE isolated from 238 patients in 58 hospitals during the study period. bla KPC-3 (64.8%) and bla NDM-1 (17.6%) represented the highest proportion of carbapenemase genes detected in Canadian isolates. Patients who had a history of medical attention during international travel accounted for 21% of CPE cases. The hospital 30-day all-cause mortality rate for the 5-year surveillance period was 17.1 per 100 CPE cases. No significant increase in the occurrence of CPE was observed from 2010 to 2014. Nosocomial transmission of CPE, as well as international health care, is driving its persistence within Canada. © Crown copyright 2016.

Development of an algorithm for phenotypic screening of carbapenemase-producing Enterobacteriaceae in the routine laboratory.

PubMed

Robert, Jérôme; Pantel, Alix; Merens, Audrey; Meiller, Elodie; Lavigne, Jean-Philippe; Nicolas-Chanoine, Marie-Hélène

2017-01-17

Carbapenemase-producing Enterobacteriaceae (CPE) are difficult to identify among carbapenem non-susceptible Enterobacteriaceae (NSE). We designed phenotypic strategies giving priority to high sensitivity for screening putative CPE before further testing. Presence of carbapenemase-encoding genes in ertapenem NSE (MIC > 0.5 mg/l) consecutively isolated in 80 French laboratories between November 2011 and April 2012 was determined by the Check-MDR-CT103 array method. Using the Mueller-Hinton (MH) disk diffusion method, clinical diameter breakpoints of carbapenems other than ertapenem, piperazicillin+tazobactam, ticarcillin+clavulanate and cefepime as well as diameter cut-offs for these antibiotics and temocillin were evaluated alone or combined to determine their performances (sensitivity, specificity, positive and negative likelihood ratios) for identifying putative CPE among these ertapenem-NSE isolates. To increase the screening specificity, these antibiotics were also tested on cloxacillin-containing MH when carbapenem NSE isolates belonged to species producing chromosomal cephalosporinase (AmpC) but Escherichia coli. Out of the 349 ertapenem NSE, 52 (14.9%) were CPE, including 39 producing OXA-48 group carbapenemase, eight KPC and five MBL. A screening strategy based on the following diameter cut offs, ticarcillin+clavulanate <15 mm, temocillin <15 mm, meropenem or imipenem <22 mm, and cefepime <26 mm, showed 100% sensitivity and 68.1% specificity with the better likelihood ratios combination. The specificity increased when a diameter cut-off <32 mm for imipenem (76.1%) or meropenem (78.8%) further tested on cloxacillin-containing MH was added to the previous strategy for AmpC-producing isolates. The proposed strategies that allowed for increasing the likelihood of CPE among ertapenem-NSE isolates should be considered as a surrogate for carbapenemase production before further CPE confirmatory testing.

Comparative Study of a Novel Biochemical Assay, the Rapidec Carba NP Test, for Detecting Carbapenemase-Producing Enterobacteriaceae.

PubMed

Lifshitz, Ziv; Adler, Amos; Carmeli, Yehuda

2016-02-01

The novel biochemical test, the Rapidec Carba NP (RCNP), was evaluated using carbapenemase- and non-carbapenemase-producing Enterobacteriaceae isolates. The RCNP test was compared with the Carba NP test (CNP) and the modified Hodge test. Compared to the CNP test, the RCNP test had identical sensitivity (96%) and lower specificity (93% versus 100%). The medium used to culture the isolates significantly affected test sensitivity and specificity. The RCNP test was quicker and easier to perform than the other tests. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Detection of ESBL among ampc producing enterobacteriaceae using inhibitor-based method

PubMed Central

Bakthavatchalu, Sasirekha; Shakthivel, Uma; Mishra, Tannu

2013-01-01

Introduction The occurrence of multiple β-lactamases among bacteria only limits the therapeutic options but also poses a challenge. A study using boronic acid (BA), an AmpC enzyme inhibitor, was designed to detect the combined expression of AmpC β-lactamases and extended-spectrum β-lactamases (ESBLs) in bacterial isolates further different phenotypic methods are compared to detect ESBL and AmpC. Methods A total of 259 clinical isolates of Enterobacteriaceae were isolated and screened for ESBL production by (i) CLSI double-disk diffusion method (ii) cefepime- clavulanic acid method (iii) boronic disk potentiation method. AmpC production was detected using cefoxitin alone and in combination with boronic acid and confirmation was done by three dimensional disk methods. Isolates were also subjected to detailed antibiotic susceptibility test. Results Among 259 isolates, 20.46% were coproducers of ESBL and AmpC, 26.45% were ESBL and 5.40% were AmpC. All of the 53 AmpC and ESBL coproducers were accurately detected by boronic acid disk potentiation method. Conclusion The BA disk test using Clinical and Laboratory Standards Institute methodology is simple and very efficient method that accurately detects the isolates that harbor both AmpCs and ESBLs. PMID:23504148

Extended-spectrum β-lactamase producing Enterobacteriaceae in bulk tank milk from German dairy farms.

PubMed

Odenthal, Sabrina; Akineden, Ömer; Usleber, Ewald

2016-12-05

Although the dairy farm environment is a known source of extended-spectrum β-lactamase (ESBL)-producing bacteria, surveillance data on ESBL in the milk production chain are still scarce. This study aimed at estimating the dimensions of the problem for public health and animal welfare by surveying ESBL-producing Enterobacteriaceae in raw bulk tank milk in Germany. Samples from 866 dairy farms, comprising about 1% of the total number of dairy farms in Germany, were first screened for presence of cefotaxime-resistant bacteria by selective enrichment. Suspect colonies were identified phenotypically and further characterized by biochemical and molecular methods, including analysis of resistance genes and clonal diversity in ESBL-producing isolates. Bulk tank milk from 82 (9.5%) farms yielded Enterobacteriaceae with confirmed ESBL-production. The most frequent ESBL-producing species was Escherichia coli (75.6%), followed by Citrobacter spp. (9.6%), Enterobacter cloacae (6.1%), and Klebsiella oxytoca (3.7%), a few isolates belonged to other species within the genera Hafnia, Raoutella and Serratia. The majority of isolates (95.1%) harbored the β-lactamase blaCTX-M gene, which has gained increased importance among ESBL-producing strains worldwide; the CTX-M group 1 was found to be the dominating (88.4%) phylogenetic group. All ESBL-positive Escherichia coli isolates were clonally heterogeneous, as determined by pulsed-field gel electrophoresis. The results from this survey demonstrate that ESBL-producing bacteria are distributed widely in the dairy farm environment in Germany. Therefore, raw milk is a potential source of exposure for the consumer, which is of increasing importance considering the trend of farmer-to-consumer direct marketing. Furthermore, dairy farm staff have an increased likelihood of exposure to ESBL-producing bacteria. Finally, ESBL-producing bacteria may also be transferred via waste milk to calves, thus further spreading antibiotic resistance in the

Evaluation of the BYG Carba Test, a New Electrochemical Assay for Rapid Laboratory Detection of Carbapenemase-Producing Enterobacteriaceae

PubMed Central

Yunus, Sami; Massart, Marion; Huang, Te-Din; Glupczynski, Youri

2015-01-01

Accurate detection of carbapenemase-producing Enterobacteriaceae (CPE) constitutes a major laboratory diagnostic challenge. We evaluated an electrochemical technique (the BYG Carba test) which allows detection of CPE in less than 35 min. The BYG Carba test was first validated in triplicate against 57 collection isolates with previously characterized β-lactam resistance mechanisms (OXA-48, n = 12; KPC, n = 8; NDM, n = 8; VIM, n = 8; IMP, n = 3; GIM, n = 1; GES-6, n = 1; no carbapenemase, n = 16) and against a panel of 10 isolates obtained from the United Kingdom National External Quality Assessment Service (NEQAS). The test was then evaluated prospectively against 324 isolates referred to the national reference center for suspicion of CPE. The BYG Carba test results were compared with those obtained with the Carba NP test using multiplex PCR sequencing as the gold standard. Of the 57 collection and the 10 NEQAS isolates, all but one GES-6-producing isolate were correctly identified by the Carba BYG test. Among the 324 consecutive Enterobacteriaceae isolates tested prospectively, 146 were confirmed as noncarbapenemase producers by PCR while 178 harbored a carbapenemase gene (OXA-48, n = 117; KPC, n = 25; NDM, n = 23; and VIM, n = 13). Prospectively, in comparison with PCR results, the BYG Carba test displayed 95% sensitivity and 100% specificity versus 89% and 100%, respectively, for the Carba NP test. The BYG Carba test is a novel, rapid, and efficient assay based on an electro-active polymer biosensing technology discriminating between CPE and non-CPE. The precise electrochemical signal (electrochemical impedance variations) allows the establishment of real-time objective measurement and interpretation criteria which should facilitate the accreditation process of this technology. PMID:26637378

Detection of CTX-M-15 beta-lactamases in Enterobacteriaceae causing hospital- and community-acquired urinary tract infections as early as 2004, in Dar es Salaam, Tanzania.

PubMed

Manyahi, Joel; Moyo, Sabrina J; Tellevik, Marit Gjerde; Ndugulile, Faustine; Urassa, Willy; Blomberg, Bjørn; Langeland, Nina

2017-04-17

The spread of Extended Spectrum β-lactamases (ESBLs) among Enterobacteriaceae and other Gram-Negative pathogens in the community and hospitals represents a major challenge to combat infections. We conducted a study to assess the prevalence and genetic makeup of ESBL-type resistance in bacterial isolates causing community- and hospital-acquired urinary tract infections. A total of 172 isolates of Enterobacteriaceae were collected in Dar es Salaam, Tanzania, from patients who met criteria of community and hospital-acquired urinary tract infections. We used E-test ESBL strips to test for ESBL-phenotype and PCR and sequencing for detection of ESBL genes. Overall 23.8% (41/172) of all isolates were ESBL-producers. ESBL-producers were more frequently isolated from hospital-acquired infections (32%, 27/84 than from community-acquired infections (16%, 14/88, p < 0.05). ESBL-producers showed high rate of resistance to ciprofloxacin (85.5%), doxycycline (90.2%), gentamicin (80.5%), nalidixic acid (84.5%), and trimethoprim-sulfamethoxazole (85.4%). Furthermore, 95% of ESBL-producers were multi-drug resistant compared to 69% of non-ESBL-producers (p < 0.05). The distribution of ESBL genes were as follows: 29/32 (90.6%) bla CTX-M-15 , two bla SHV-12 , and one had both bla CTX-M-15 and bla SHV-12 . Of 29 isolates carrying bla CTX-M-15 , 69% (20/29) and 31% (9/29) were hospital and community, respectively. Bla SHV-12 genotypes were only detected in hospital-acquired infections. bla CTX-M-15 is a predominant gene conferring ESBL-production in Enterobacteriaceae causing both hospital- and community-acquired infections in Tanzania.

Performance of an extended dynamic range time delay integration charge coupled device (XDR TDI CCD) for high-intrascene dynamic range scanning

NASA Astrophysics Data System (ADS)

Levine, Peter A.; Dawson, Robin M.; Andrews, James T.; Bhaskaran, Mahalingham; Furst, David; Hsueh, Fu-Lung; Meray, Grazyna M.; Sudol, Thomas M.; Swain, Pradyumna K.; Tower, John R.

2003-05-01

Many applications, such as industrial inspection and overhead reconnaissance benefit from line scanning architectures where time delay integration (TDI) significantly improves sensitivity. CCDs are particularly well suited to the TDI architecture since charge is transferred virtually noiselessly down the column. Sarnoff's TDI CCDs have demonstrated extremely high speeds where a 7200 x 64, 8 um pixel device with 120 output ports demonstrated a vertical line transfer rate greater than 800 kHz. The most recent addition to Sarnoff's TDI technology is the implementation of extended dynamic range (XDR) in high speed, back illuminated TDI CCDs. The optical, intrascene dynamic range can be adjusted in the design of the imager with measured dynamic ranges exceeding 2,000,000:1 with no degradation in low light performance. The device provides a piecewise linear response to light where multiple slopes and break points can be set during the CCD design. A description of the device architecture and measured results from fabricated XDR TDI CCDs are presented.

Molecular Characterization by Using Next-Generation Sequencing of Plasmids Containing blaNDM-7 in Enterobacteriaceae from Calgary, Canada.

PubMed

Chen, L; Peirano, G; Lynch, T; Chavda, K D; Gregson, D B; Church, D L; Conly, J; Kreiswirth, B N; Pitout, J D

2015-12-07

Enterobacteriaceae with blaNDM-7 are relatively uncommon and had previously been described in Europe, India, the United States, and Japan. This study describes the characteristics of Enterobacteriaceae (Klebsiella pneumoniae [n = 2], Escherichia coli [n = 2], Serratia marcescens [n = 1], and Enterobacter hormaechei [n = 1] isolates) with blaNDM-7 obtained from 4 patients from Calgary, Canada, from 2013 to 2014. The 46,161-bp IncX3 plasmids with blaNDM-7 are highly similar to other blaNDM-harboring IncX3 plasmids and, interestingly, showed identical structures within the different isolates. This finding may indicate horizontal transmission within our health region, or it may indicate contact with individuals from areas of endemicity within the hospital setting. Patients infected or colonized with bacteria containing blaNDM-7 IncX3 plasmids generate infection control challenges. Epidemiological and molecular studies are required to better understand the dynamics of transmission, the risk factors, and the reservoirs for bacteria harboring blaNDM-7. To the best of our knowledge, this is the first report of S. marcescens and E. hormaechei with blaNDM-7. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Molecular and microbiological report of a hospital outbreak of NDM-1-carrying Enterobacteriaceae in Mexico.

PubMed

Bocanegra-Ibarias, Paola; Garza-González, Elvira; Morfín-Otero, Rayo; Barrios, Humberto; Villarreal-Treviño, Licet; Rodríguez-Noriega, Eduardo; Garza-Ramos, Ulises; Petersen-Morfin, Santiago; Silva-Sanchez, Jesus

2017-01-01

To characterize the microbiological, molecular and epidemiological data of an outbreak of carbapenem-resistant Enterobacteriaceae (CRE) in a tertiary-care hospital in Mexico. From September 2014 to July 2015, all CRE clinical isolates recovered during an outbreak in the Hospital Civil "Fray Antonio Alcalde" in Jalisco, Mexico were screened for antimicrobial susceptibility, carbapenemase production, carbapenemase-encoding genes, and plasmid profiles. Horizontal transfer of imipenem resistance; and clonal diversity by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST); as well as biofilm production and the presence of 14 virulence genes were analyzed in selected isolates. Fifty-two carbapenem-resistant isolates corresponding to 5 species were detected, i.e., Klebsiella pneumoniae (n = 46), Enterobacter cloacae (n = 3), Escherichia coli (n = 1), Providencia rettgeri (n = 1) and Citrobacter freundii (n = 1) with carbapenemase encoding genes blaNDM-1 (n = 48), blaVIM (n = 3), blaIMP (n = 1) and blaKPC (n = 1) detected in these isolates. The blaNDM-1 gene was detected in plasmids from 130- to 170-kb in K. pneumoniae (n = 46); E. cloacae (n = 3), E. coli (n = 1) and P. rettgeri (n = 1). The transfer of plasmids harboring the blaNDM-1 gene was obtained in eight transconjugants. One plasmid restriction pattern was detected, with the blaNDM-1 identified in different restriction fragments. Predominant clone A of K. pneumoniae isolates archived 28/46 (60%) isolates and belongs to ST392. Besides, ST307, ST309, ST846, ST2399, and ST2400 were detected for K. pneumoniae; as well as E. cloacae ST182 and E. coli ST10. The fimA and uge genes were more likely to be identified in K. pneumoniae carbapenem-susceptible isolates (p = <0.001) and biofilm production was more liable to be observed in carbapenem-resistant isolates (p = <0.05). Four Enterobacteriaceae species harboring the blaNDM-1 gene were detected in a nosocomial outbreak in Mexico; horizontal

The CRISPR-Cas system in Enterobacteriaceae.

PubMed

Medina-Aparicio, Liliana; Dávila, Sonia; Rebollar-Flores, Javier E; Calva, Edmundo; Hernández-Lucas, Ismael

2018-02-01

In nature, microorganisms are constantly exposed to multiple viral infections and thus have developed many strategies to survive phage attack and invasion by foreign DNA. One of such strategies is the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated proteins (Cas) bacterial immunological system. This defense mechanism is widespread in prokaryotes including several families such as Enterobacteriaceae. Much knowledge about the CRISPR-Cas system has been generated, including its biological functions, transcriptional regulation, distribution, utility as a molecular marker and as a tool for specific genome editing. This review focuses on these aspects and describes the state of the art of the CRISPR-Cas system in the Enterobacteriaceae bacterial family. © FEMS 2018. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Antibiotic susceptibility of urinary isolates in nursing home residents consuming cranberry capsules versus placebo

PubMed Central

Madden, Gregory R.; Argraves, Stephanie M.; Van Ness, Peter H.; Juthani-Mehta, Manisha

2015-01-01

Antimicrobial susceptibility of urinary isolates is compared amongst nursing home participants from a randomized controlled trial of cranberry capsules versus placebo. We hypothesized that cranberry spares non-Escherichia coli Enterobacteriaceae, which tend to be less susceptible to oral antibiotics. Analyses showed no differences in susceptibility or proportions of non-E. coli Enterobacteriaceae. PMID:25695180

Comparison of ESBL – And AmpC Producing Enterobacteriaceae and Methicillin-Resistant Staphylococcus aureus (MRSA) Isolated from Migratory and Resident Population of Rooks (Corvus frugilegus) in Austria

PubMed Central

Mehinagic, Kemal; Rosengarten, Renate; Hoelzl, Franz; Knauer, Felix; Walzer, Chris

2013-01-01

In order to test whether rooks (Corvus frugilegus) represent good indicators for the potential circulation of antibiotics in their native habitat, two populations with different migratory behavior were tested for the presence of beta-lactamase producing Enterobacteriaceae and methicillin-resistant Staphylococcus aureus (MRSA). In all, 54 and 102 samples of fresh feces of a migratory and a resident population were investigated. A total of 24 and 3 cefotaxime-resistant enterobacterial isolates were obtained from the migratory and resident population, respectively. In these isolates CTX-M-1 (n = 15), CTX-M-3 (n = 3), and CTX-M-15 (n = 3) genes were detected. TEM-1 and OXA-1 were associated with CTX-M in 3 and 2 isolates, respectively. In two E. coli isolates CMY-2 could be detected, where from one isolate displayed an overexpression of chromosomal AmpC as well. Among E. coli isolates the most common phylogenetic group was A (n = 11) and ST1683 (n = 5). In one E. coli of B2-ST131 the rfbO25b locus was detected. Three Enterobacter isolates were stably derepressed AmpC-producers. In five samples of the migratory population, PVL positive MRSA could be isolated. Two isolates were typed SCCmec IVa, spa type t127, and ST1. Three isolates carried a SCCmec type IVc, with spa type t852 and ST22. The highly significant difference of the occurrence of antibiotic resistance between the migratory population from eastern Europe compared to resident population in our study indicates that rooks may be good indicator species for the evaluation of environmental contamination with antibiotic resistant bacteria, especially due to their ecology, foraging behavior and differing migratory behavior. PMID:24391878

Infection control, genetic assessment of drug resistance and drug susceptibility testing in the current management of multidrug/extensively-resistant tuberculosis (M/XDR-TB) in Europe: A tuberculosis network European Trialsgroup (TBNET) study.

PubMed

Bothamley, Graham H; Lange, Christoph

2017-11-01

Europe has the highest documented caseload and greatest increase in multidrug and extensively drug-resistant tuberculosis (M/XDR-TB) of all World Health Organization (WHO) regions. This survey examines how recommendations for M/XDR-TB management are being implemented. TBNET is a pan-European clinical research collaboration for tuberculosis. An email survey of TBNET members collected data in relation to infection control, access to molecular tests and basic microbiology with drug sensitivity testing. 68/105 responses gave valid information and were from countries within the WHO European Region. Inpatient beds matched demand, but single rooms with negative pressure were only available in low incidence countries; ultraviolet decontamination was used in 5 sites, all with >10 patients with M/XDR-TB per year. Molecular tests for mutations associated with rifampicin resistance were widely available (88%), even in lower income and especially in high incidence countries. Molecular tests for other first line and second line drugs were less accessible (76 and 52% respectively). A third of physicians considered that drug susceptibility results were delayed by > 2 months. Infection control for inpatients with M/XDR-TB remains a problem in high incidence countries. Rifampicin resistance is readily detected, but tests to plan regimens tailored to the drug susceptibilities of the strain of Mycobacterium tuberculosis are significantly delayed, allowing for further drug resistance to develop. Copyright © 2017 Elsevier Ltd. All rights reserved.

Indistinguishable NDM-producing Escherichia coli isolated from recreational waters, sewage, and a clinical specimen in Ireland, 2016 to 2017

PubMed Central

Mahon, Bláthnaid M; Brehony, Carina; McGrath, Elaine; Killeen, James; Cormican, Martin; Hickey, Paul; Keane, Shane; Hanahoe, Belinda; Dolan, Ann; Morris, Dearbháile

2017-01-01

In this study, New Delhi metallo-beta-lactamase (NDM)-producing Enterobacteriaceae were identified in Irish recreational waters and sewage. Indistinguishable NDM-producing Escherichia coli by pulsed-field gel electrophoresis were isolated from sewage, a fresh water stream and a human source. NDM-producing Klebsiella pneumoniae isolated from sewage and seawater in the same area were closely related to each other and to a human isolate. This raises concerns regarding the potential for sewage discharges to contribute to the spread of carbapenemase-producing Enterobacteriaceae. PMID:28449738

Phenotypic and Genotypic Characterization of Enterobacteriaceae Producing Oxacillinase-48–Like Carbapenemases, United States

PubMed Central

Zhu, Wenming; de Man, Tom J.B.; Avillan, Johannetsy J.; Anderson, Karen F.; Lonsway, David R.; Rowe, Lori A.; Batra, Dhwani; Rasheed, J. Kamile; Limbago, Brandi M.

2018-01-01

Oxacillinase (OXA)–48–like carbapenemases remain relatively uncommon in the United States. We performed phenotypic and genotypic characterization of 30 Enterobacteriaceae producing OXA-48–like carbapenemases that were recovered from patients during 2010–2014. Isolates were collected from 12 states and not associated with outbreaks, although we could not exclude limited local transmission. The alleles β-lactamase OXA-181 (blaOXA-181) (43%), blaOXA-232 (33%), and blaOXA-48 (23%) were found. All isolates were resistant to ertapenem and showed positive results for the ertapenem and meropenem modified Hodge test and the modified carbapenem inactivation method; 73% showed a positive result for the Carba Nordmann–Poirel test. Whole-genome sequencing identified extended-spectrum β-lactamase genes in 93% of isolates. In all blaOXA-232 isolates, the gene was on a ColKP3 plasmid. A total of 12 of 13 isolates harboring blaOXA-181 contained the insertion sequence ΔISEcp1. In all isolates with blaOXA-48, the gene was located on a TN1999 transposon; these isolates also carried IncL/M plasmids. PMID:29553324

A multiplex lateral flow immunoassay for the rapid identification of NDM-, KPC-, IMP- and VIM-type and OXA-48-like carbapenemase-producing Enterobacteriaceae

PubMed Central

Boutal, Hervé; Vogel, Anaïs; Bernabeu, Sandrine; Devilliers, Karine; Creton, Elodie; Cotellon, Garence; Plaisance, Marc; Oueslati, Saoussen; Dortet, Laurent; Jousset, Agnès; Simon, Stéphanie; Naas, Thierry; Volland, Hervé

2018-01-01

Abstract Objectives The global spread of carbapenemase-producing Enterobacteriaceae represents a substantial challenge in clinical practice and rapid and reliable detection of these organisms is essential. The aim of this study was to develop and validate a lateral flow immunoassay (Carba5) for the detection of the five main carbapenemases (KPC-, NDM-, VIM- and IMP-type and OXA-48-like). Methods Carba5 was retrospectively and prospectively evaluated using 296 enterobacterial isolates from agar culture. An isolated colony was suspended in extraction buffer and then loaded on the manufactured Carba5. Results All 185 isolates expressing a carbapenemase related to one of the Carba5 targets were correctly and unambiguously detected in <15 min. All other isolates gave negative results except those producing OXA-163 and OXA-405, which are considered low-activity carbapenemases. No cross-reaction was observed with non-targeted carbapenemases, ESBLs, AmpCs or oxacillinases (OXA-1, -2, -9 and -10). Overall, this assay reached 100% sensitivity and 95.3% (retrospectively) to 100% (prospectively) specificity. Conclusions Carba5 is efficient, rapid and easy to implement in the routine workflow of a clinical microbiology laboratory for confirmation of the five main carbapenemases encountered in Enterobacteriaceae. PMID:29365094

Imaging Enterobacteriaceae infection in vivo with 18F-fluorodeoxysorbitol positron emission tomography

PubMed Central

Weinstein, Edward A.; Ordonez, Alvaro A.; DeMarco, Vincent P.; Murawski, Allison M.; Pokkali, Supriya; MacDonald, Elizabeth M.; Klunk, Mariah; Mease, Ronnie C.; Pomper, Martin G.; Jain, Sanjay K.

2015-01-01

The Enterobacteriaceae are a family of rod-shaped Gram-negative bacteria that normally inhabit the gastrointestinal tract and are the most common cause of Gram-negative bacterial infections in humans. In addition to causing serious multidrug-resistant, hospital-acquired infections, a number of Enterobacteriaceae species are also recognized as biothreat pathogens. As a consequence, new tools are urgently needed to specifically identify and localize infections due to Enterobacteriaceae and to monitor antimicrobial efficacy. In this report, we used commercially available 2-[18F]-fluorodeoxyglucose (18F-FDG) to produce 2-[18F]-fluorodeoxysorbitol (18F-FDS), a radioactive probe for Enterobacteriaceae, in 30 min. 18F-FDS selectively accumulated in Enterobacteriaceae, but not in Gram-positive bacteria or healthy mammalian or cancer cells in vitro. In a murine myositis model, 18F-FDS positron emission tomography (PET) rapidly differentiated true infection from sterile inflammation with a limit of detection of 6.2 ± 0.2 log10 colony-forming units (CFU) for Escherichia coli. Our findings were extended to models of mixed Gram-positive and Gram-negative thigh co-infections, brain infection, Klebsiella pneumonia, and mice undergoing immunosuppressive chemotherapy. This technique rapidly and specifically localized infections due to Enterobacteriaceae, providing a three-dimensional holistic view within the animal. Last, 18F-FDS PET monitored the efficacy of antimicrobial treatment, demonstrating a PET signal proportionate to the bacterial burden. Therapeutic failures associated with multidrug-resistant, extended-spectrum β-lactamase (ESBL)–producing E. coli infections were detected in real time. Together, these data show that 18F-FDS is a candidate imaging probe for translation to human clinical cases of known or suspected infections owing to Enterobacteriaceae. PMID:25338757

Prospective Multicenter Study of Carbapenemase-Producing Enterobacteriaceae from 83 Hospitals in Spain Reveals High In Vitro Susceptibility to Colistin and Meropenem

PubMed Central

Ortega, Adriana; Bartolomé, Rosa; Bou, Germán; Conejo, Carmen; Fernández-Martínez, Marta; González-López, Juan José; Martínez-García, Laura; Martínez-Martínez, Luis; Merino, María; Miró, Elisenda; Mora, Marta; Oliver, Antonio; Pascual, Álvaro; Rodríguez-Baño, Jesús; Ruiz-Carrascoso, Guillermo; Ruiz-Garbajosa, Patricia; Zamorano, Laura; Bautista, Verónica; Pérez-Vázquez, María; Campos, José

2015-01-01

The aim of this study was to determine the impact of carbapenemase-producing Enterobacteriaceae (CPE) in Spain in 2013 by describing the prevalence, dissemination, and geographic distribution of CPE clones, and their population structure and antibiotic susceptibility. From February 2013 to May 2013, 83 hospitals (about 40,000 hospital beds) prospectively collected nonduplicate Enterobacteriaceae using the screening cutoff recommended by EUCAST. Carbapenemase characterization was performed by phenotypic methods and confirmed by PCR and sequencing. Multilocus sequencing types (MLST) were determined for Klebsiella pneumoniae and Escherichia coli. A total of 702 Enterobacteriaceae isolates met the inclusion criteria; 379 (54%) were CPE. OXA-48 (71.5%) and VIM-1 (25.3%) were the most frequent carbapenemases, and K. pneumoniae (74.4%), Enterobacter cloacae (10.3%), and E. coli (8.4%) were the species most affected. Susceptibility to colistin, amikacin, and meropenem was 95.5%, 81.3%, and 74.7%, respectively. The most prevalent sequence types (STs) were ST11 and ST405 for K. pneumoniae and ST131 for E. coli. Forty-five (54.1%) of the hospitals had at least one CPE case. For K. pneumoniae, ST11/OXA-48, ST15/OXA-48, ST405/OXA-48, and ST11/VIM-1 were detected in two or more Spanish provinces. ST11 isolates carried four carbapenemases (VIM-1, OXA-48, KPC-2, and OXA-245), but ST405 isolates carried OXA-48 only. A wide interregional spread of CPE in Spain was observed, mainly due to a few successful clones of OXA-48-producing K. pneumoniae (e.g., ST11 and ST405). The dissemination of OXA-48-producing E. coli is a new finding of public health concern. According to the susceptibilities determined in vitro, most of the CPE (94.5%) had three or more options for antibiotic treatment. PMID:25824224

Enterobacteriaceae resistant to third-generation cephalosporins and quinolones in fresh culinary herbs imported from Southeast Asia.

PubMed

Veldman, Kees; Kant, Arie; Dierikx, Cindy; van Essen-Zandbergen, Alieda; Wit, Ben; Mevius, Dik

2014-05-02

Since multidrug resistant bacteria are frequently reported from Southeast Asia, our study focused on the occurrence of ESBL-producing Enterobacteriaceae in fresh imported herbs from Thailand, Vietnam and Malaysia. Samples were collected from fresh culinary herbs imported from Southeast Asia in which ESBL-suspected isolates were obtained by selective culturing. Analysis included identification by MALDI-TOF mass spectrometry, susceptibility testing, XbaI-PFGE, microarray, PCR and sequencing of specific ESBL genes, PCR based replicon typing (PBRT) of plasmids and Southern blot hybridization. In addition, the quinolone resistance genotype was characterized by screening for plasmid mediated quinolone resistance (PMQR) genes and mutations in the quinolone resistance determining region (QRDR) of gyrA and parC. The study encompassed fifty samples of ten batches of culinary herbs (5 samples per batch) comprising nine different herb variants. The herbs originated from Thailand (Water morning glory, Acacia and Betel leaf), Vietnam (Parsley, Asian pennywort, Houttuynia leaf and Mint) and Malaysia (Holy basil and Parsley). By selective culturing 21 cefotaxime resistant Enterobacteriaceae were retrieved. Array analysis revealed 18 isolates with ESBL genes and one isolate with solely non-ESBL beta-lactamase genes. Mutations in the ampC promoter region were determined in two isolates with PCR and sequencing. The isolates were identified as Klebsiella pneumoniae (n=9), Escherichia coli (n=6), Enterobacter cloacae complex (n=5) and Enterobacter spp. (n=1). All isolates tested were multidrug resistant. Variants of CTX-M enzymes were predominantly found followed by SHV enzymes. PMQR genes (including aac(6')-1b-cr, qnrB and qnrS) were also frequently detected. In almost all cases ESBL and quinolone resistance genes were located on the same plasmid. Imported fresh culinary herbs from Southeast Asia are a potential source for contamination of food with multidrug resistant bacteria

Improvement of the Xpert Carba-R Kit for the Detection of Carbapenemase-Producing Enterobacteriaceae

PubMed Central

Fusaro, Mathieu

2016-01-01

The Xpert Carba-R kit, version 2 (v2), which has been improved for the efficient detection of blaOXA-181 and blaOXA-232 genes, was tested on a collection of 150 well-characterized enterobacterial isolates that had a reduced susceptibility to carbapenems. The performance of the Xpert Carba-R v2 was high, as it was able to detect the five major carbapenemases (NDM, VIM, IMP, KPC, and OXA-48). Thus, it is now well adapted to the carbapenemase-producing Enterobacteriaceae epidemiology of many countries worldwide. PMID:27021332

Analysis of OXA-204 carbapenemase-producing Enterobacteriaceae reveals possible endoscopy-associated transmission, France, 2012 to 2014

PubMed Central

Potron, Anaïs; Bernabeu, Sandrine; Cuzon, Gaëlle; Pontiès, Valérie; Blanchard, Hervé; Seringe, Elise; Naas, Thierry; Nordmann, Patrice; Dortet, Laurent

2017-01-01

OXA-48-like beta-lactamase producing bacteria are now endemic in several European and Mediterranean countries. Among this carbapenemase family, the OXA-48 and OXA-181 variants predominate, whereas other variants such as OXA-204 are rarely reported. Here, we report the molecular epidemiology of a collection of OXA-204-positive enterobacterial isolates (n = 29) recovered in France between October 2012 and May 2014. This study describes the first outbreak of OXA-204-producing Enterobacteriaceae in Europe, involving 12 isolates of an ST90 Escherichia coli clone and nine isolates of an ST147 Klebsiella pneumoniae clone. All isolates co-produced the cephalosporinase CMY-4, and 60% of them co-produced the extended-spectrum beta-lactamase CTX-M-15. The bla OXA-204 gene was located on a 150-kb IncA/C plasmid, isolated from various enterobacterial species in the same patient, indicating a high conjugative ability of this genetic vehicle. PMID:29233256

Analysis of OXA-204 carbapenemase-producing Enterobacteriaceae reveals possible endoscopy-associated transmission, France, 2012 to 2014.

PubMed

Potron, Anaïs; Bernabeu, Sandrine; Cuzon, Gaëlle; Pontiès, Valérie; Blanchard, Hervé; Seringe, Elise; Naas, Thierry; Nordmann, Patrice; Dortet, Laurent

2017-12-01

OXA-48-like beta-lactamase producing bacteria are now endemic in several European and Mediterranean countries. Among this carbapenemase family, the OXA-48 and OXA-181 variants predominate, whereas other variants such as OXA-204 are rarely reported. Here, we report the molecular epidemiology of a collection of OXA-204-positive enterobacterial isolates (n = 29) recovered in France between October 2012 and May 2014. This study describes the first outbreak of OXA-204-producing Enterobacteriaceae in Europe, involving 12 isolates of an ST90 Escherichia coli clone and nine isolates of an ST147 Klebsiella pneumoniae clone. All isolates co-produced the cephalosporinase CMY-4, and 60% of them co-produced the extended-spectrum beta-lactamase CTX-M-15. The bla OXA-204 gene was located on a 150-kb IncA/C plasmid, isolated from various enterobacterial species in the same patient, indicating a high conjugative ability of this genetic vehicle.

Prevalence and characterization of extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase producing Enterobacteriaceae in fresh pork meat at processing level in Germany.

PubMed

Schill, Franziska; Abdulmawjood, Amir; Klein, Günter; Reich, Felix

2017-09-18

ESBL or AmpC β-lactamase producing Enterobacteriaceae is an increasing concern in human medicine. A distribution via the food chain is discussed, but less is known about these bacteria on fresh pork meat. The aim of this study was to investigate the prevalence of ESBL/AmpC Enterobacteriaceae bacteria in fresh pork meat at processing level in Germany. The analysis comprised microbiological hygiene parameters and further pheno- and genotypical characterization of ESBL/AmpC isolates. The examination included three pools of meat and one corresponding meat juice sample from each of the tested pork meat batches (n=63). ESBL/AmpC producers were found in 42.9% (36.5% confirmed by genotype, gt) of the investigated batches, either in meat or meat juice. Meat juice was more often (28.6%) contaminated with ESBL/AmpC bacteria than meat (20.6%). Hygiene parameters were satisfactory in all samples and were thus not a suitable tool for predicting the presence of ESBL/AmpC producers. Most of the 37 confirmed ESBL/AmpC bacteria were identified as Escherichia coli (n=18) or Serratia fonticola (n=13). Susceptibility testing identified 32 of the 37 isolates to be multidrug-resistant. The most common resistance genes TEM, SHV, and CTX-M were found in 19 of the ESBL/AmpC isolates, mostly E. coli. A single detected AmpC β-lactamase producing E. coli carried a CMY-2 gene. Multilocus sequence typing (MLST) investigations of the ESBL/AmpC E. coli revealed 11 different sequence types. In conclusion, fresh pork meat can harbor highly diverse multidrug-resistant ESBL Enterobacteriaceae, even though at low rates. The study suggests that fresh pork meat might be a source for multidrug-resistant ESBL/AmpC Enterobacteriaceae of various origins. Therefore these data contribute to the epidemiological understanding of the distribution of resistant bacteria and the impact of the food chain on public health. Copyright © 2017 Elsevier B.V. All rights reserved.

CTX-M-15-non-ST131 Escherichia coli isolates are mainly responsible of faecal carriage with ESBL-producing Enterobacteriaceae in travellers, immigrants and those visiting friends and relatives.

PubMed

Valverde, A; Turrientes, M-C; Norman, F; San Martín, E; Moreno, L; Pérez-Molina, J A; López-Vélez, R; Cantón, R

2015-03-01

Prevalence of extended-spectrum β-lactamases (ESBL) and/or carbapenemase-producing Enterobacteriaceae (EPE and CPE) in stool samples from 75 travellers, 8 people visiting friends and relatives and 3 immigrants who had travelled or came from tropical or subtropical areas was determined. Thirty-one per cent (27/86) of the subjects were faecal carriers of EPE, and 37 EPE isolates were recovered (36 Escherichia coli, 1 Klebsiella pneumoniae). CTX-M-15 was the most prevalent enzyme (64.8%) mainly associated with E. coli belonging to phylogroup A and sequence type complex 10. Most of the ESBL-positive travellers (50%) had visited countries from Asia. Copyright © 2014 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Biotic stress shifted structure and abundance of Enterobacteriaceae in the lettuce microbiome.

PubMed

Erlacher, Armin; Cardinale, Massimiliano; Grube, Martin; Berg, Gabriele

2015-01-01

Lettuce cultivars are not only amongst the most popular vegetables eaten raw, they are also involved in severe pathogen outbreaks world-wide. While outbreaks caused by Enterobacteriaceae species are well-studied, less is known about their occurrence in natural environments as well as the impact of biotic stress. Here, we studied the ecology of the human health-relevant bacterial family Enterobacteriaceae and assessed the impact of biotic disturbances by a soil-borne phytopathogenic fungus and Gastropoda on their structure and abundance in mesocosm and pot experiments. Using a polyphasic approach including network analyses of 16S rRNA gene amplicon libraries, quantitative PCR and complementary fluorescence in situ hybridization (FISH) microscopy we found substantial yet divergent Enterobacteriaceae communities. A similar spectrum of 14 genera was identified from rhizo- and phyllospheres but the abundance of Enterobacteriaceae was on average 3fold higher in phyllosphere samples. Both stress factors shifted the bacterial community of the leaf habitat, characterized by increases of species abundance and diversity. For the rhizosphere, we observed significant structural shifts of Enterobacteriaceae communities but also a high degree of resilience. These results could be confirmed by FISH microscopy but it was difficult to visualize phyllosphere communities. Additional inoculation experiments with Escherichia coli as model revealed their presence below the wax layer as well as in the endosphere of leaves. The observed presence influenced by stress factors and the endophytic life style of Enterobacteriaceae on lettuce can be an important aspect in relation to human health.

Three cefotaximases, CTX-M-9, CTX-M-13, and CTX-M-14, among Enterobacteriaceae in the People's Republic of China.

PubMed

Chanawong, Aroonwadee; M'Zali, Fatima Hannachi; Heritage, John; Xiong, Jian-Hui; Hawkey, Peter Michael

2002-03-01

Of 15 extended-spectrum beta-lactamase (ESBL)-producing isolates of the family Enterobacteriaceae collected from the First Municipal People's Hospital of Guangzhou, in the southern part of the People's Republic of China, 9 were found to produce CTX-M ESBLs, 3 produced SHV-12, and 3 produced both CTX-M and SHV-12. Eleven isolates produced either TEM-1B or SHV-11, in addition to an ESBL. Nucleotide sequence analysis of the 12 isolates carrying bla(CTX-M) genes revealed that they harbored three different bla(CTX-M) genes, bla(CTX-M-9) (5 isolates), bla(CTX-M-13) (1 isolate), and bla(CTX-M-14) (6 isolates). These genes have 98% nucleotide homology with bla(Toho-2). The bla(CTX-M) genes were carried on plasmids that ranged in size from 35 to 150 kb. Plasmid fingerprints and pulsed-field gel electrophoresis showed the dissemination of the bla(CTX-M) genes through transfer of different antibiotic resistance plasmids to different bacteria, suggesting that these resistance determinants are highly mobile. Insertion sequence ISEcp1, found on the upstream region of these genes, may be involved in the translocation of the bla(CTX-M) genes. This is the first report of the occurrence of SHV-12 and CTX-M ESBLs in China. The presence of strains with these ESBLs shows both the evolution of bla(CTX-M) genes and their dissemination among at least three species of the family Enterobacteriaceae, Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae, isolated within a single hospital. The predominance of CTX-M type enzymes seen in this area of China appears to be similar to that seen in South America but is different from those seen in Europe and North America, suggesting different evolutionary routes and selective pressures. A more comprehensive survey of the ESBL types from China is urgently needed.

Three Cefotaximases, CTX-M-9, CTX-M-13, and CTX-M-14, among Enterobacteriaceae in the People's Republic of China

PubMed Central

Chanawong, Aroonwadee; M'Zali, Fatima Hannachi; Heritage, John; Xiong, Jian-Hui; Hawkey, Peter Michael

2002-01-01

Of 15 extended-spectrum β-lactamase (ESBL)-producing isolates of the family Enterobacteriaceae collected from the First Municipal People's Hospital of Guangzhou, in the southern part of the People's Republic of China, 9 were found to produce CTX-M ESBLs, 3 produced SHV-12, and 3 produced both CTX-M and SHV-12. Eleven isolates produced either TEM-1B or SHV-11, in addition to an ESBL. Nucleotide sequence analysis of the 12 isolates carrying blaCTX-M genes revealed that they harbored three different blaCTX-M genes, blaCTX-M-9 (5 isolates), blaCTX-M-13 (1 isolate), and blaCTX-M-14 (6 isolates). These genes have 98% nucleotide homology with blaToho-2. The blaCTX-M genes were carried on plasmids that ranged in size from 35 to 150 kb. Plasmid fingerprints and pulsed-field gel electrophoresis showed the dissemination of the blaCTX-M genes through transfer of different antibiotic resistance plasmids to different bacteria, suggesting that these resistance determinants are highly mobile. Insertion sequence ISEcp1, found on the upstream region of these genes, may be involved in the translocation of the blaCTX-M genes. This is the first report of the occurrence of SHV-12 and CTX-M ESBLs in China. The presence of strains with these ESBLs shows both the evolution of blaCTX-M genes and their dissemination among at least three species of the family Enterobacteriaceae, Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae, isolated within a single hospital. The predominance of CTX-M type enzymes seen in this area of China appears to be similar to that seen in South America but is different from those seen in Europe and North America, suggesting different evolutionary routes and selective pressures. A more comprehensive survey of the ESBL types from China is urgently needed. PMID:11850241

Incidence of multidrug-resistant, extensively drug-resistant and pan-drug-resistant bacteria in children hospitalized at Dr. Hasan Sadikin general hospital Bandung Indonesia

NASA Astrophysics Data System (ADS)

Adrizain, R.; Suryaningrat, F.; Alam, A.; Setiabudi, D.

2018-03-01

Antibiotic resistance has become a global issue, with 700,000 deaths attributable to multidrug-resistance (MDR) occurring each year. Centers for Disease Control and Prevention (CDC) show rapidly increasing rates of infection due to antibiotic-resistant bacteria. The aim of the study isto describe the incidence of MDR, extensively drug-resistant (XDR) and pan drug-resistant (PDR) in Enterococcus spp., Staphylococcus aureus, K. pneumonia, Acinetobacter baumanii, P. aeruginosin, and Enterobacter spp. (ESKAPE) pathogens in children admitted to Dr. Hasan Sadikin Hospital. All pediatric patients having blood culture drawn from January 2015 to December 2016 were retrospectively studied. Data include the number of drawn blood culture, number of positive results, type of bacteria, sensitivity pattern. International standard definitions for acquired resistance by ECDC and CDC was used as definitions for MDR, XDR and PDR bacteria. From January 2015 to December 2016, 299 from 2.542 (11.7%) blood culture was positive, with Staphylococcus aureus, Enterococcus spp., Enterobacteriaceae, Pseudomonas aeruginosa, Acinetobacter spp., respectively 5, 6, 24, 5, 20 with total 60 (20%). The MDR and XDR pathogen found were 47 and 13 patients, respectively.

[Determination of in vitro synergy by a checkerboard method when 3 core antimicrobial agents of the retreatment new scheme combined against MDR-MTB and XDR-MTB].

PubMed

Zhang, L L; Yang, H; Xiao, H P; Lu, J M; Sha, W; Zhang, Q

2016-06-01

In order to detect the in vitro synergistic effect of 4 drugs-pasiniazid (PA), moxifloxacin, rifabutin and rifapentini on multidrug-resistant mycobacterium tuberculosis (MDR-MTB) and extensively drug-resistant mycobacterium tuberculosis(XDR-MTB), which were core drugs of"The program of retreatment research of tuberculosis". The checkerboard method was used to detect the minimum inhibitory concentration (MIC) of antituberculosis drug combination schemes (moxifloxacin-PA, moxifloxacin-PA-rifabutin and moxifloxacin-PA-rifapentini) to 40 strains of clinical drug resistant MTB(20 strains of MDR-MTB and 20 XDR-MTB) and the standard strain H37Rv, by calculating the fractional inhibitory concentration index of joint action in vitro to judge the combined effect, with fractional inhibitory concentration index(FICI)≤0.5 and FICI≤0.75 as the basis of 2 drugs and 3 drugs showing synergy. The FICI of moxifloxacin-PA scheme for DR-MTB was 0.125 to 1.000, only 5 strains with a FICI ≤0.5, showing synergistic effect. The FICI of moxifloxacin-Pa-rifabutin scheme with 20 strains of MDR-MTB ranged from 0.310 to 1.260, 10 strains with a FICI≤0.75, showing synergistic effect. The FICI of moxifloxacin-PA-rifabutin scheme with 20 strains of XDR-MTB ranged from 0.215 to 1.250, 11 strains with a FICI≤0.75, showing synergistic effect. The FICI of moxifloxacin-PA-rifapentini scheme with 20 strains of MDR-MTB ranged from 0.150 to 0.780, 19 strains with a FICI≤0.75, showing synergistic effect. The FICI of moxifloxacin-PA-rifapentini scheme with 20 strains of XDR-MTB ranged from 0.200 to 1.280, 16 strains with a FICI≤0.75, showing synergistic effect. The synergistic effect of moxifloxacin-PA scheme was poor, but showing better synergy when further combined with rifabutin or rifapentini. Rifabutin showed better effect than rifapentini, but the synergistic effect of moxifloxacin-PA-rifabutin combination scheme was poor than that of moxifloxacin-PA-rifapentini combination scheme.

Extended-spectrum beta-lactamase- and carbapenemase-producing Enterobacteriaceae among Ethiopian children

PubMed Central

Legese, Melese Hailu; Weldearegay, Gebru Mulugeta; Asrat, Daniel

2017-01-01

Background Infections by extended-spectrum beta-lactamase- (ESBL) and carbapenem-resistant Enterobacteriaceae (CRE) are an emerging problem in children nowadays. Hence, the aim of this study was to determine the prevalence of ESBL- and carbapenemase-producing Enterobacteriaceae among children suspected of septicemia and urinary tract infections (UTIs). Methods A cross-sectional study was conducted from January to March 2014. A total of 322 study participants suspected of septicemia and UTIs were recruited. All blood and urine samples were cultured on blood and MacConkey agar. All positive cultures were characterized by colony morphology, Gram stain, and standard biochemical tests. Antimicrobial susceptibility test was performed on Muller-Hinton agar using disk diffusion. ESBL was detected using combination disk and double-disk synergy methods, and the results were compared. Carbapenemase was detected by modified Hodge method using meropenem. Data were analyzed using SPSS version 20. Results The overall prevalence of ESBL- and carbapenemase-producing Enterobacteriaceae was 78.57% (n=22/28) and 12.12%, respectively. Among the Enterobacteriaceae tested, Klebsiella pneumoniae (84.2%, n=16/19), Escherichia coli (100%, n=5/5), and Klebsiella oxytoca (100%, n=1/1) were positive for ESBL. Double-disk synergy method showed 90.9% sensitivity, 66.7% specificity, 95.2% positive predictive value, and 50% negative predictive value. Carbapenemase-producing Enterobacteriaceae were K. pneumoniae (9.09%, n=3/33) and Morganella morganii (3.03%, n=1/33). Conclusion Screening Enterobacteriaceae for ESBL production is essential for better antibiotics selection and preventing its further emergence and spread. In resource-limited settings, double-disk synergy method can be implemented for screening and confirming ESBL production. Moreover, occurrence of CRE in countries where no carbapenems are sold is worrying microbiologists as well as clinicians. Hence, identifying factors that induce

Multiyear, Multinational Survey of the Incidence and Global Distribution of Metallo-β-Lactamase-Producing Enterobacteriaceae and Pseudomonas aeruginosa.

PubMed

Kazmierczak, Krystyna M; Rabine, Sharon; Hackel, Meredith; McLaughlin, Robert E; Biedenbach, Douglas J; Bouchillon, Samuel K; Sahm, Daniel F; Bradford, Patricia A

2016-02-01

Metallo-β-lactamases (MBLs) hydrolyze all classes of β-lactams except monobactams and are not inhibited by classic serine β-lactamase inhibitors. Gram-negative pathogens isolated from patient infections were collected from 202 medical centers in 40 countries as part of a global surveillance study from 2012 to 2014. Carbapenem-nonsusceptible Enterobacteriaceae and Pseudomonas aeruginosa were characterized for bla genes encoding VIM, IMP, NDM, SPM, and GIM variants using PCR and sequencing. A total of 471 MBL-positive isolates included the following species (numbers of isolates are in parentheses): P. aeruginosa (308), Klebsiella spp. (85), Enterobacter spp. (39), Proteeae (16), Citrobacter freundii (12), Escherichia coli (6), and Serratia marcescens (5) and were submitted by sites from 34 countries. Of these, 69.6% were collected in 9 countries (numbers of isolates are in parentheses): Russia (72), Greece (61), Philippines (54), Venezuela (29), and Kuwait, Nigeria, Romania, South Africa, and Thailand (20 to 25 isolates each). Thirty-two different MBL variants were detected (14 VIM, 14 IMP, and 4 NDM enzymes). Seven novel MBL variants were encountered in the study, each differing from a previously reported variant by one amino acid substitution: VIM-42 (VIM-1 [V223I]), VIM-43 (VIM-4 [A24V]), VIM-44 (VIM-2 [K257N]), VIM-45 (VIM-2 [T35I]), IMP-48 (IMP-14 [I69T]), IMP-49 (IMP-18 [V49F]), and NDM-16 (NDM-1 [R264H]). The in vitro activities of all tested antibiotics against MBL-positive Enterobacteriaceae were significantly reduced with the exception of that of aztreonam-avibactam (MIC90, 0.5 to 1 μg/ml), whereas colistin was the most effective agent against MBL-positive P. aeruginosa isolates (>97% susceptible). Although the global percentage of isolates encoding MBLs remains relatively low, their detection in 12 species, 34 countries, and all regions participating in this surveillance study is concerning. Copyright © 2016, American Society for Microbiology. All

Multiyear, Multinational Survey of the Incidence and Global Distribution of Metallo-β-Lactamase-Producing Enterobacteriaceae and Pseudomonas aeruginosa

PubMed Central

Rabine, Sharon; Hackel, Meredith; McLaughlin, Robert E.; Biedenbach, Douglas J.; Bouchillon, Samuel K.; Sahm, Daniel F.; Bradford, Patricia A.

2015-01-01

Metallo-β-lactamases (MBLs) hydrolyze all classes of β-lactams except monobactams and are not inhibited by classic serine β-lactamase inhibitors. Gram-negative pathogens isolated from patient infections were collected from 202 medical centers in 40 countries as part of a global surveillance study from 2012 to 2014. Carbapenem-nonsusceptible Enterobacteriaceae and Pseudomonas aeruginosa were characterized for bla genes encoding VIM, IMP, NDM, SPM, and GIM variants using PCR and sequencing. A total of 471 MBL-positive isolates included the following species (numbers of isolates are in parentheses): P. aeruginosa (308), Klebsiella spp. (85), Enterobacter spp. (39), Proteeae (16), Citrobacter freundii (12), Escherichia coli (6), and Serratia marcescens (5) and were submitted by sites from 34 countries. Of these, 69.6% were collected in 9 countries (numbers of isolates are in parentheses): Russia (72), Greece (61), Philippines (54), Venezuela (29), and Kuwait, Nigeria, Romania, South Africa, and Thailand (20 to 25 isolates each). Thirty-two different MBL variants were detected (14 VIM, 14 IMP, and 4 NDM enzymes). Seven novel MBL variants were encountered in the study, each differing from a previously reported variant by one amino acid substitution: VIM-42 (VIM-1 [V223I]), VIM-43 (VIM-4 [A24V]), VIM-44 (VIM-2 [K257N]), VIM-45 (VIM-2 [T35I]), IMP-48 (IMP-14 [I69T]), IMP-49 (IMP-18 [V49F]), and NDM-16 (NDM-1 [R264H]). The in vitro activities of all tested antibiotics against MBL-positive Enterobacteriaceae were significantly reduced with the exception of that of aztreonam-avibactam (MIC90, 0.5 to 1 μg/ml), whereas colistin was the most effective agent against MBL-positive P. aeruginosa isolates (>97% susceptible). Although the global percentage of isolates encoding MBLs remains relatively low, their detection in 12 species, 34 countries, and all regions participating in this surveillance study is concerning. PMID:26643349

Colistin-resistant Enterobacteriaceae infections: clinical and molecular characterization and analysis of in vitro synergy.

PubMed

de Maio Carrillho, Claudia M D; Gaudereto, Juliana J; Martins, Roberta Cristina Ruedas; de Castro Lima, Victor Augusto Camarinha; de Oliveira, Larissa M; Urbano, Mariana R; Perozin, Jamile S; Levin, Anna Sara; Costa, Silvia F

2017-03-01

We described 27 polyclonal colistin-resistant Enterobacteriaceae (MIC 4-16 μg/mL) infections (12 pneumonia, 12 urinary tract infection (UTI), two Bacteremia, and one skin/soft tissue infection) in which 74% harbored KPC. The isolates were polyclonal, 6 STs were identified and the colistin resistance was due to chromosome mutations. Eight patients with UTI received monotherapy, and combination therapy was given to 19 patients. Overall mortality was 37%. In vitro synergy using time-kill assay was observed in 14 of 19 (74%) isolates tested; the synergistic effect was observed for almost all isolates for the combination of three drugs: colistin, amikacin, and tigecycline. The Kaplan-Meier survival curve showed no significant difference comparing combination therapy with 2, 3, or more drugs and risk factors associated with death were dialysis and shock. These findings reinforce the fact that colistin in combination with other classes of drugs can be useful in treating infections caused by colistin-resistant CRE. Copyright © 2016 Elsevier Inc. All rights reserved.

Biotic Stress Shifted Structure and Abundance of Enterobacteriaceae in the Lettuce Microbiome

PubMed Central

Erlacher, Armin; Cardinale, Massimiliano; Grube, Martin; Berg, Gabriele

2015-01-01

Lettuce cultivars are not only amongst the most popular vegetables eaten raw, they are also involved in severe pathogen outbreaks world-wide. While outbreaks caused by Enterobacteriaceae species are well-studied, less is known about their occurrence in natural environments as well as the impact of biotic stress. Here, we studied the ecology of the human health-relevant bacterial family Enterobacteriaceae and assessed the impact of biotic disturbances by a soil-borne phytopathogenic fungus and Gastropoda on their structure and abundance in mesocosm and pot experiments. Using a polyphasic approach including network analyses of 16S rRNA gene amplicon libraries, quantitative PCR and complementary fluorescence in situ hybridization (FISH) microscopy we found substantial yet divergent Enterobacteriaceae communities. A similar spectrum of 14 genera was identified from rhizo- and phyllospheres but the abundance of Enterobacteriaceae was on average 3fold higher in phyllosphere samples. Both stress factors shifted the bacterial community of the leaf habitat, characterized by increases of species abundance and diversity. For the rhizosphere, we observed significant structural shifts of Enterobacteriaceae communities but also a high degree of resilience. These results could be confirmed by FISH microscopy but it was difficult to visualize phyllosphere communities. Additional inoculation experiments with Escherichia coli as model revealed their presence below the wax layer as well as in the endosphere of leaves. The observed presence influenced by stress factors and the endophytic life style of Enterobacteriaceae on lettuce can be an important aspect in relation to human health. PMID:25714833

Increasing proportion of carbapenemase-producing Enterobacteriaceae and emergence of a MCR-1 producer through a multicentric study among hospital-based and private laboratories in Belgium from September to November 2015.

PubMed

Huang, Te Din; Bogaerts, Pierre; Berhin, Catherine; Hoebeke, Martin; Bauraing, Caroline; Glupczynski, Youri

2017-05-11

Carbapenemase-producing Enterobacteriaceae (CPE) strains have been increasingly reported in Belgium. We aimed to determine the proportion of CPE among Enterobacteriaceae isolated from hospitalised patients and community outpatients in Belgium in 2015. For the hospitalised patients, the results were compared to a previous similar survey performed in the same hospitals in 2012. Twenty-four hospital-based and 10 private laboratories collected prospectively 200 non-duplicated Enterobacteriaceae isolates from clinical specimens. All isolates were screened locally by carbapenem disk diffusion using European Committee on Antimicrobial Susceptibility Testing methodology. Putative CPE strains with inhibition zone diameters below the screening breakpoints were referred centrally for confirmation of carbapenemase production. From September to November 2015, we found a proportion of clinical CPE of 0.55% (26/4,705) and of 0.60% (12/1,991) among hospitalised patients and among ambulatory outpatients respectively. Klebsiella pneumoniae (26/38) and OXA-48-like carbapenemase (28/38) were the predominant species and enzyme among CPE. One OXA-48-producing Escherichia coli isolated from a hospital was found carrying plasmid-mediated MCR-1 colistin resistance. Compared with the 2012 survey, we found a significant increased proportion of clinical CPE (0.55% in 2015 vs 0.25% in 2012; p = 0.02) and an increased proportion of hospitals (13/24 in 2015 vs 8/24 in 2012) with at least one CPE detected. The study results confirmed the concerning spread of CPE including a colistin-resistant MCR-1 producer in hospitals and the establishment of CPE in the community in Belgium. This article is copyright of The Authors, 2017.

Comparison of the Modified-Hodge test, Carba NP test, and carbapenem inactivation method as screening methods for carbapenemase-producing Enterobacteriaceae.

PubMed

Yamada, Kageto; Kashiwa, Machiko; Arai, Katsumi; Nagano, Noriyuki; Saito, Ryoichi

2016-09-01

We compared three screening methods for carbapenemase-producing Enterobacteriaceae. While the Modified-Hodge test and Carba NP test produced false-negative results for OXA-48-like and mucoid NDM producers, the carbapenem inactivation method (CIM) showed positive results for these isolates. Although the CIM required cultivation time, it is well suited for general clinical laboratories. Copyright © 2016 Elsevier B.V. All rights reserved.

Enterobacteriaceae Antibiotic Resistance in Ready-to-Eat Foods Collected from Hospital and Community Canteens: Analysis of Prevalence.

PubMed

Vincenti, Sara; Raponi, Matteo; Sezzatini, Romina; Giubbini, Gabriele; Laurenti, Patrizia

2018-03-01

Foodborne diseases and antibiotic resistance are serious widespread health problems in the contemporary world. In this study, we compared the microbiological quality of ready-to-eat (RTE) foods found in community canteens versus hospital canteens in Rome, Italy, focusing on detection and quantification of Enterobacteriaceae and the antibiotic resistance of these bacteria. Our findings show a remarkable difference in Enterobacteriaceae contamination between RTE foods distributed in community canteens (33.5% of samples) and those distributed in hospital canteens (5.3% of samples). This result highlights greater attention to good manufacturing practices and good hygiene practices by the food operators in hospitals compared with food operators in community canteens. As expected, a higher percentage of cold food samples (70.9%) than of hot food samples (10.8%) were positive for these bacteria. Excluding the intrinsic resistance of each bacterial strain, 92.3% of the isolated strains were resistant to at least one antibiotic, and about half of the isolated strains were classified as multidrug resistant. The prevalence of multidrug-resistant strains was 50% in the community samples and 33.3% in hospital canteens. Our results indicate that approximately 38% of RTE foods provided in community canteens is not compliant with microbiological food safety criteria and could be a special risk for consumers through spread of antibiotic-resistant strains. Hygienic processing and handling of foods is necessary for both hospital and community canteens.

Polymyxin B Etest® compared with gold-standard broth microdilution in carbapenem-resistant Enterobacteriaceae exhibiting a wide range of polymyxin B MICs.

PubMed

Kulengowski, B; Ribes, J A; Burgess, D S

2018-04-16

Polymyxins have been revitalized to combat carbapenem-resistant Enterobacteriaceae (CRE). However, evaluating the activity of these agents by traditional broth dilution methods is not practical for busy clinical laboratories. We compared polymyxin B activity using two quantitative susceptibility testing methods, Etest ® and broth microdilution (BMD), against CRE isolates from patients at an academic medical centre. Polymyxin B activity against 70 CRE clinical isolates was determined by Etest ® according to the manufacturer and by BMD according to CLSI guidelines. Pseudomonas aeruginosa ATCC ® 27853 and Escherichia coli NCTC 13846 served as quality control strains. The EUCAST colistin susceptibility breakpoint of Enterobacteriaceae (≤2 mg/L) was used. Essential agreement was isolates with an MIC within 1 log 2 dilution over total isolates. Categorical agreement was number of isolates in the same susceptibility category (susceptible or resistant) over total isolates. Major and very major error rates were calculated using number of susceptible and number of resistant isolates, respectively, as the denominator. McNemar's test was used for determining a difference in susceptibility between methods. The CRE isolates were primarily Klebsiella spp. (49%) and Enterobacter spp. (36%). Polymyxin B susceptibility was significantly higher by Etest ® compared with BMD (97% versus 77%; p 0.0001). Categorical agreement was 80%, but essential agreement was low (10%). False non-susceptibility was never observed by Etest ® (BMD reference), but the very major errors were high (88%). Etest ® reporting of false susceptibility may result in inappropriate antibiotic use and treatment failure clinically. We do not recommend using Etest ® for polymyxin B susceptibility testing for routine patient care. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Improvement of the Xpert Carba-R Kit for the Detection of Carbapenemase-Producing Enterobacteriaceae.

PubMed

Dortet, Laurent; Fusaro, Mathieu; Naas, Thierry

2016-06-01

The Xpert Carba-R kit, version 2 (v2), which has been improved for the efficient detection of blaOXA-181 and blaOXA-232 genes, was tested on a collection of 150 well-characterized enterobacterial isolates that had a reduced susceptibility to carbapenems. The performance of the Xpert Carba-R v2 was high, as it was able to detect the five major carbapenemases (NDM, VIM, IMP, KPC, and OXA-48). Thus, it is now well adapted to the carbapenemase-producing Enterobacteriaceae epidemiology of many countries worldwide. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Characterization of Carbapenem-Resistant Enterobacteriaceae with High Rate of Autochthonous Transmission in the Arabian Peninsula

PubMed Central

Sonnevend, Ágnes; Ghazawi, Akela A.; Hashmey, Rayhan; Jamal, Wafaa; Rotimi, Vincent O.; Shibl, Atef M.; Al-Jardani, Amina; Al-Abri, Seif S.; Tariq, Waheed U. Z.; Weber, Stefan; Pál, Tibor

2015-01-01

To establish the role of local transmission versus possible pathogen import due to previous foreign exposure in infections caused by carbapenem non-susceptible Enterobacteriaceae in the Arabian Peninsula, 200 independent isolates collected in 16 hospitals of Saudi Arabia, Kuwait, Oman and the United Arab Emirates were studied. All strains were multidrug resistant; 42.5% of them also qualified as extremely drug resistant. The frequency of various carbapenemases varied according to the participating countries, but in the collection, as a whole, bla NDM-1 was the most frequently encountered carbapenemase gene (46.5%) followed by bla OXA-48-like gene (32.5%). A comparatively high rate (8.9%) of multi-clonal strains carrying both bla NDM and bla OXA-48-like genes in the United Arab Emirates, representing the most resistant subgroup, was encountered. No KPC-expressing isolates were detected. Three major clones of bla NDM-1 carrying Klebsiella pneumoniae of ST152 (n = 22, Saudi Arabia), ST14 (n = 7, United Arab Emirates) and ST147 types (n = 9, Oman) were identified, the latter two clones carrying similar, but not identical HI1b incompatibility type plasmids of >170kb. While from 78.6% of the cases with documented foreign hospitalization bla NDM positive strains were isolated, these strains formed only 25.6% of all the isolates expressing this enzyme. In fact, 56.8% of the NDM, 75.7% of OXA-48-like and 90.9% of VIM positive strains were recovered from patients without documented foreign exposure, neither in the form of travel or prior hospitalization abroad, suggesting a high rate of autochthonous infections. This, considering the extensive links of these countries to the rest of the world, predicts that trends in the local epidemiology of carbapenem resistant strains may increasingly affect the spread of these pathogens on the global scale. These results call for improved surveillance of carbapenem resistant Enterobacteriaceae in the countries of the Arabian Peninsula

Occurrence of Acquired 16S rRNA Methyltransferase-Mediated Aminoglycoside Resistance in Clinical Isolates of Enterobacteriaceae within a Tertiary Referral Hospital of Northeast India

PubMed Central

Wangkheimayum, Jayalaxmi; Paul, Deepjyoti; Dhar, Debadatta; Nepram, Rajlakshmi; Chetri, Shiela; Bhowmik, Deepshikha; Chakravarty, Atanu

2017-01-01

ABSTRACT The methylation of a ribosomal target leads to a high level of resistance to all clinically relevant aminoglycoside antibiotics, so early detection of these resistance determinants will help to reduce the incidence of treatment failures as well as lessen the dissemination rate. Here, we characterized different 16S rRNA methyltransferases responsible for aminoglycoside resistance and their epidemiological background in clinical isolates of Enterobacteriaceae in a tertiary referral hospital in India. All aminoglycoside-resistant isolates were screened for different 16S rRNA methyltransferases by PCR assay, and incompatibility typing of the conjugable plasmid harboring resistance genes was performed by PCR-based replicon typing. An assay for the stability and elimination of these resistance plasmids was performed. The coexistence of extended-spectrum β-lactamases and metallo-β-lactamases was also detected, and the heterogeneity of these isolates was determined by enterobacterial repetitive intergenic consensus PCR. The PCR assay revealed the presence of armA, rmtA, rmtB, rmtC, and rmtD in single and multiple combinations, and these were carried by a diverse group of Inc plasmids. Plasmids harboring these resistance determinants were highly stable and maintained until the 55th serial passage, but SDS treatment could easily eliminate the plasmids harboring the resistance determinants. The coexistence of blaTEM, blaPER, blaGES, and blaSHV, as well as blaVIM and blaNDM, within these isolates was also detected. Strains with different clonal patterns of aminoglycoside resistance were found to spread in this hospital setting. We observed that the 16S rRNA methyltransferase genes were encoded within different Inc plasmid types, suggesting diverse origins and sources of acquisition. Therefore, the present study is of epidemiological importance and can have a role in infection control policy in hospital settings. PMID:28320725

Beyond multidrug-resistant tuberculosis in Europe: a TBNET study.

PubMed

Günther, G; van Leth, F; Altet, N; Dedicoat, M; Duarte, R; Gualano, G; Kunst, H; Muylle, I; Spinu, V; Tiberi, S; Viiklepp, P; Lange, C

2015-12-01

The emergence of drug-resistant tuberculosis (TB) is a challenge to TB control in Europe. We evaluated second-line drug susceptibility testing in Mycobacterium tuberculosis isolates from patients with multidrug-resistant, pre-extensively drug-resistant (pre-XDR-TB) and XDR-TB at 23 TBNET sites in 16 European countries. Over 30% of bacilli from patients with pre-XDR-TB showed resistance to any fluoroquinolone and almost 70% to any second-line injectable drug. Respectively >90% and >80% of the XDR-TB strains tested showed phenotypic resistance to pyrazinamide and ethambutol. Resistance to prothionamide/ethionamide was high in bacilli from pre-XDR-TB patients (43%) and XDR-TB patients (49%).

A disc diffusion assay for detection of class A, B and OXA-48 carbapenemases in Enterobacteriaceae using phenyl boronic acid, dipicolinic acid and temocillin.

PubMed

van Dijk, K; Voets, G M; Scharringa, J; Voskuil, S; Fluit, A C; Rottier, W C; Leverstein-Van Hall, M A; Cohen Stuart, J W T

2014-04-01

Class A and B carbapenemases in Enterobacteriaceae may be detected using carbapenemase inhibition tests with boronic acid derivatives (BA) and dipicolinic acid (DPA)/EDTA, respectively. However, for OXA-48 (like) carbapenemases, no specific inhibitor is available. Because OXA-48 confers high-level temocillin resistance, a disc diffusion assay using temocillin as well as BA and DPA inhibition tests was evaluated for detection of class A, B and OXA-48 carbapenemases. The test collection included 128 well-characterized non-repeat Enterobacteriaceae isolates suspected of carbapenemase production; that is, with meropenem MICs ≥ 0.5 mg/L, including 99 carbapenemase producers (36 KPC, one GES, 31 MBL, four KPC plus VIM, 25 OXA-48, two OXA-162), and 29 ESBL and/or AmpC-producing isolates. PCR and sequencing of beta-lactamase genes was used as a reference test. Phenotypic carbapenemase detection was performed with discs (Rosco) containing meropenem (10 μg), temocillin (30 μg), meropenem + phenyl boronic acid (PBA), meropenem + DPA, meropenem + BA + DPA, and meropenem + cloxacillin (CL). Absence of synergy between meropenem and BA and/or DPA and a temocillin zone ≤10 mm was used to identify OXA-48. The sensitivity for identification of class A, B and OXA-48 carbapenemases was 95%, 90% and 100%, with 96-100% specificity. In non-Proteus species, the sensitivity for class B carbapenemase detection was 97%. All isolates without PBA or DPA synergy and a temocillin disc zone ≤10 mm were OXA-48 (like) positive. In conclusion, carbapenemase inhibition tests with PBA and DPA combined with a temocillin disc provide a reliable phenotypic confirmation method for class A, B and OXA-48 carbapenemases in Enterobacteriaceae. © 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.

Prevalence and risk factors of infections caused by extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae.

PubMed

Nakai, Hazuki; Hagihara, Mao; Kato, Hideo; Hirai, Jun; Nishiyama, Naoya; Koizumi, Yusuke; Sakanashi, Daisuke; Suematsu, Hiroyuki; Yamagishi, Yuka; Mikamo, Hiroshige

2016-05-01

To study the clinical characteristics and associated risk factors of infections caused by extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae. A case-control study at a large university hospital in Japan, comparing patients who were infected or colonized with ESBL-producing Enterobacteriaceae (n = 212) and non-ESBL-producing Enterobacteriaceae (n = 2089) in 2010-2013. Data were collected from medical charts, retrospectively. Multivariate logistic regression analysis was used to explore risk factors of ESBL-producing Enterobacteriaceae (Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Proteus mirabilis) infection or colonization for each pathogen, respectively. ESBL-producing Enterobacteriaceae [E. coli (n = 113), K. oxytoca (n = 46), K. pneumoniae (n = 41), P. mirabilis (n = 12)] were taken from patients were identified in 1409 outpatient and 892 inpatients. Infection or colonization caused by ESBL-producing Enterobacteriaceae was considered to be hospital-acquired, healthcare-associated and community-acquired in 60.4%, 17.9% and 21.7% patients, respectively. Independent risk factors for ESBL-producing Enterobacteriaceae infection or colonization were male sex, cerebrovascular disease, intubation/tracheostomy, major surgery within 60 days (p < 0.001). Moreover, antimicrobial usage (more than 4 days) during preceding 60 days, especially aminoglycoside, oxazolidinone, tetracycline, fluoroquinolone, trimethoprim/sulfamethoxazole, and second- and fourth-generation cephalosporin were risk factors (p < 0.001). However, acquisition location of infection (hospital-acquired and community-onset) was not a risk factor (p > 0.05). The problem of ESBL production is no longer limited to hospital-acquired infections. The presence of chronic illness, such as cerebrovascular disease, and recent antimicrobial use were independent risk factors for ESBL-producing Enterobacteriaceae infection or colonization. Copyright © 2016 Japanese

Detection of carbapenemase activity in Enterobacteriaceae using LC-MS/MS in comparison with the neo-rapid CARB kit using direct visual assessment and colorimetry.

PubMed

Huber, Charlotte A; Sidjabat, Hanna E; Zowawi, Hosam M; Kvaskoff, David; Reed, Sarah; McNamara, John F; McCarthy, Kate L; Harris, Patrick; Toh, Benjamin; Wailan, Alexander M; Paterson, David L

2016-12-01

It has been described that the sensitivity of the Carba NP test may be low in the case of OXA-48-like carbapenamases and mass spectrometry based methods as well as a colorimetry based method have been described as alternatives. We evaluated 84 Enterobacteriaceae isolates including 31 OXA-48-like producing isolates and 13 isolates that produced either an imipenemase (IMP; n=8), New Delhi metallo-β-lactamase (NDM; n=3), or Klebsiella pneumoniae carbapenemase (KPC; n=2), as well as 40 carbapenemase negative Enterobacteriaceae isolates. We used the Neo-Rapid CARB kit, assessing the results with the unaided eye and compared it with a colorimetric approach. Furthermore, we incubated the isolates in growth media with meropenem and measured the remaining meropenem after one and 2h of incubation, respectively, using liquid chromatography tandem mass spectrometry (LC-MS/MS). Whilst all carbapenemase producing isolates with the exception of the OXA-244 producer tested positive for both the Neo-rapid CARB test using the unaided eye or colorimetry, and the 13 isolates producing either IMP, NDM or KPC hydrolysed the meropenem in the media almost completely after 2h of incubation, the 31 OXA-48-like producing isolates exhibited very variable hydrolytic activity when incubated in growth media with meropenem. In our study, the Neo-Rapid CARB test yielded a sensitivity of 98% for both the traditional and the colorimetric approach with a specificity of 95% and 100% respectively. Our results indicate that the Neo-Rapid CARB test may have use for the detection of OXA-48 type carbapenemases and that it may be particularly important to ensure bacterial lysis for the detection of these weaker hydrolysers. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Comparison of 2 chromogenic media for the detection of extended-spectrum β-lactamase producing Enterobacteriaceae stool carriage in nursing home residents.

PubMed

Blane, Beth; Brodrick, Hayley J; Gouliouris, Theodore; Ambridge, Kirsty E; Kidney, Angela D; Ludden, Catherine M; Limmathurotsakul, Direk; Török, M Estée; Peacock, Sharon J

2016-03-01

ChromID ESBL agar and Brilliance ESBL agar were compared for the isolation of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae from 298 stools. These had comparable sensitivity and selectivity for the 116 positive samples. Pre-enrichment with cefpodoxime and extending incubation to 48 hours after direct plating both significantly increased sensitivity but reduced selectivity of both agars. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

First Report of German Cockroaches (Blattella germanica) as Reservoirs of CTX-M-15 Extended-Spectrum-β-Lactamase- and OXA-48 Carbapenemase-Producing Enterobacteriaceae in Batna University Hospital, Algeria

PubMed Central

Loucif, Lotfi; Gacemi-Kirane, Djamila; Cherak, Zineb; Chamlal, Naima; Grainat, Nadia

2016-01-01

Here we report the isolation of extended-spectrum β-lactamase (ESBL)- and carbapenemase-producing Enterobacteriaceae from German cockroaches caught in the burn unit of Batna University Hospital in Algeria. Nine of 12 isolates harbored the blaCTX-M-15 ESBL gene. One Enterobacter cloacae isolate belonging to sequence type 528 coexpressed the blaOXA-48, blaCTX-M-15, and blaTEM genes. Our findings indicate that cockroaches may be one of the most dangerous reservoirs for ESBL and carbapenemase producers in hospitals. PMID:27458214

Carbapenem-Resistant Enterobacteriaceae Transmission in Health Care Facilities - Wisconsin, February-May 2015.

PubMed

Elbadawi, Lina I; Borlaug, Gwen; Gundlach, Kristin M; Monson, Timothy; Warshauer, David; Walters, Maroya S; Kallen, Alexander; Gulvik, Christopher A; Davis, Jeffrey P

2016-09-02

Carbapenem-resistant Enterobacteriaceae (CRE) are multidrug-resistant gram-negative bacilli that can cause infections associated with high case fatality rates, and are emerging as epidemiologically important health care-associated pathogens in the United States (1). Prevention of CRE transmission in health care settings is dependent on recognition of cases, isolation of colonized and infected patients, effective use of infection control measures, and the correct use of antibiotics. The use of molecular technologies, including polymerase chain reaction (PCR) testing, pulsed-field gel electrophoresis (PFGE), and whole genome sequencing (WGS), can lead to detection of transmission events and interruption of transmission. In Wisconsin, acute care and critical access hospitals report laboratory-identified CRE to the Wisconsin Division of Public Health (WDPH), and clinical laboratories submit CRE isolates to the Wisconsin State Laboratory of Hygiene (WSLH) for molecular testing. During February-May 2015, a total of 49 CRE isolates from 46 patients were submitted to WSLH. On June 8, WSLH informed WDPH of five carbapenemase-producing CRE isolates with closely related PFGE patterns identified among four inpatients at two hospitals in southeastern Wisconsin. An investigation revealed a high degree of genetic relatedness among the patients' isolates, but did not identify the mechanism of transmission between the two facilities. No breaches in recommended practices were identified; after reviewing respiratory care procedures, no further cases were identified. Routine hospital- and laboratory-based surveillance can detect and prevent health care transmission of CRE.

Introduction of OXA-48-producing Enterobacteriaceae to Israeli hospitals by medical tourism.

PubMed

Adler, Amos; Shklyar, Maya; Schwaber, Mitchell J; Navon-Venezia, Shiri; Dhaher, Yacoub; Edgar, Rotem; Solter, Ester; Benenson, Shmuel; Masarwa, Samira; Carmeli, Yehuda

2011-12-01

The carbapenemase OXA-48 has been reported from different Mediterranean countries. It is mostly encoded on a single plasmid in various Enterobacteriaceae species. We characterized the epidemiological and molecular features of OXA-48-producing Enterobacteriaceae (OPE) in Israel. Epidemiological investigation was conducted by the National Center for Infection Control. Genotyping was performed using multilocus sequence typing. The bla(OXA-48)-carrying plasmids were investigated using S1 endonuclease and restriction fragment length polymorphism (RFLP). Conjugation efficiency of the bla(OXA-48)-carrying plasmids was studied in a filter mating experiment. Since 2007, four OPE-infected patients were identified, all non-Israeli (two Palestinian, one Jordanian and one Georgian). Three had prior hospitalization; two in Jordan and one in Georgia. The bla(OXA-48) gene was detected in three Escherichia coli strains belonging to different clonal complexes, one Klebsiella oxytoca and one Klebsiella pneumoniae sequence type 101, as previously reported from Tunisia and Spain. In all isolates, the bla(OXA-48) gene was located inside Tn1999.2 and was carried on a 60 kb plasmid with an identical RFLP pattern. The plasmid was able to conjugate from Klebsiella spp. to E. coli, and had a conjugation efficiency up to ~10000 times higher than that of pKpQIL. OPE, introduced mainly by medical tourism, are an emerging threat to patients from affected Mediterranean countries. The bla(OXA-48)-carrying plasmid demonstrated remarkable conjugation efficiency, which is probably important in the success of its dissemination.

Prevalence and Molecular Characteristics of Carbapenemase-Producing Enterobacteriaceae From Five Hospitals in Korea.

PubMed

Jeong, Seok Hoon; Kim, Han Sung; Kim, Jae Seok; Shin, Dong Hoon; Kim, Hyun Soo; Park, Min Jeong; Shin, Saeam; Hong, Jun Sung; Lee, Seung Soon; Song, Wonkeun

2016-11-01

The emergence of carbapenemase-producing Enterobacteriaceae (CPE) represents a major clinical problem because these bacteria are resistant to most antibiotics. CPE remain relatively uncommon in Korea. We report the prevalence, clinical characteristics, and molecular epidemiology of CPE isolates collected from five university hospitals in Korea. Between January and December 2015, 393 non-duplicated isolates that were nonsusceptible to ertapenem were analyzed. Production of carbapenemase, extended-spectrum β-lactamase, and AmpC β-lactamase was determined by genotypic tests. Antimicrobial susceptibility profiles were determined by using an Etest. Clonality of Klebsiella pneumoniae carbapenemase (KPC)-2-producing and oxacillinase (OXA)-232-producing Klebsiella pneumoniae isolates was determined by pulsed-field gel electrophoresis (PFGE). Of the 393 isolates tested, 79 (20.1%) were CPE. Of these 79 isolates, 47 (59.5%) harbored the bla(OXA-232) gene while the remaining isolates carried genes bla(KPC-2) (n=27), bla(IMP-1) (n=4), and bla(NDM-1) (n=1). Among the 24 KPC-2 K. pneumoniae isolates from hospital B, 100% were resistant to carbapenems, 8% to colistin, and 0% to tigecycline. Among the 45 OXA-232 K. pneumoniae at hospital C, 95% were resistant to ertapenem, 68% to imipenem, 95% to meropenem, 10% to colistin, and 24% to tigecycline. PFGE analysis revealed a unique pattern for KPC-2 K. pneumoniae and identified 30 isolates belonging to the dominant pulsotypes (PT)1 and PT2 among 41 OXA-232 K. pneumoniae isolates. CPE strains are present in Korea, with the majority of K. pneumoniae isolates producing OXA-232 and KPC-2. The prevalence and predominant genotypes of CPE show hospital-specific differences.

Characterization of extensively drug-resistant Mycobacterium tuberculosis in Nepal.

PubMed

Poudel, Ajay; Maharjan, Bhagwan; Nakajima, Chie; Fukushima, Yukari; Pandey, Basu D; Beneke, Antje; Suzuki, Yasuhiko

2013-01-01

The emergence of extensively drug-resistant tuberculosis (XDR-TB) has raised public health concern for global control of TB. Although molecular characterization of drug resistance-associated mutations in multidrug-resistant isolates in Nepal has been made, mutations in XDR isolates and their genotypes have not been reported previously. In this study, we identified and characterized 13 XDR Mycobacterium tuberculosis isolates from clinical isolates in Nepal. The most prevalent mutations involved in rifampicin, isoniazid, ofloxacin, and kanamycin/capreomycin resistance were Ser531Leu in rpoB gene (92.3%), Ser315Thr in katG gene (92.3%), Asp94Gly in gyrA gene (53.9%) and A1400G in rrs gene (61.5%), respectively. Spoligotyping and multilocus sequence typing revealed that 69% belonged to Beijing family, especially modern types. Further typing with 26-loci variable number of tandem repeats suggested the current spread of XDR M. tuberculosis. Our result highlights the need to reinforce the TB policy in Nepal with regard to control and detection strategies. Copyright © 2012 Elsevier Ltd. All rights reserved.

In vivo efficacy of human simulated regimens of carbapenems and comparator agents against NDM-1-producing Enterobacteriaceae.

PubMed

Wiskirchen, Dora E; Nordmann, Patrice; Crandon, Jared L; Nicolau, David P

2014-01-01

Doripenem and ertapenem have demonstrated efficacy against several NDM-1-producing isolates in vivo, despite having high MICs. In this study, we sought to further characterize the efficacy profiles of humanized regimens of standard (500 mg given every 8 h) and high-dose, prolonged infusion of doripenem (2 g given every 8 h, 4-h infusion) and 1 g of ertapenem given intravenously every 24 h and the comparator regimens of ceftazidime at 2 g given every 8 h (2-h infusion), levofloxacin at 500 mg every 24 h, and aztreonam at 2 g every 6 h (1-h infusion) against a wider range of isolates in a murine thigh infection model. An isogenic wild-type strain and NDM-1-producing Klebsiella pneumoniae and eight clinical NDM-1-producing members of the family Enterobacteriaceae were tested in immunocompetent- and neutropenic-mouse models. The wild-type strain was susceptible to all of the agents, while the isogenic NDM-1-producing strain was resistant to ceftazidime, doripenem, and ertapenem. Clinical NDM-1-producing strains were resistant to nearly all five of the agents (two were susceptible to levofloxacin). In immunocompetent mice, all of the agents produced ≥1-log10 CFU reductions of the isogenic wild-type and NDM-1-producing strains after 24 h. Minimal efficacy of ceftazidime, aztreonam, and levofloxacin against the clinical NDM-1-producing strains was observed. However, despite in vitro resistance, ≥1-log10 CFU reductions of six of eight clinical strains were achieved with high-dose, prolonged infusion of doripenem and ertapenem. Slight enhancements of doripenem activity over the standard doses were obtained with high-dose, prolonged infusion for three of the four isolates tested. Similar efficacy observations were noted in neutropenic mice. These data suggest that carbapenems are a viable treatment option for infections caused by NDM-1-producing Enterobacteriaceae.

Koserella trabulsii, a new genus and species of Enterobacteriaceae formerly known as Enteric Group 45.

PubMed Central

Hickman-Brenner, F W; Huntley-Carter, G P; Fanning, G R; Brenner, D J; Farmer, J J

1985-01-01

The name Koserella trabulsii is proposed for a group of Enterobacteriaceae formerly called Enteric Group 45. This group consists of 12 strains that were originally identified as atypical Hafnia alvei. K. trabulsii strains were negative for indole production, Voges-Proskauer, H2S production, urea hydrolysis, phenylalanine deaminase, and acid production from glycerol, lactose, sucrose, and D-sorbitol; they were positive for methyl red, citrate (Simmons), lysine and ornithine decarboxylases, arginine dihydrolase (negative in 1 to 2 days and positive in 3 to 7 days), and acid production from cellobiose and melibiose; and they were resistant to the Hafnia-specific bacteriophage of Guinée and Valkenburg. They were tested for DNA relatedness by the hydroxyapatite method with 32PO4-labeled DNA from the designated type strain (CDC 3349-72, ATCC 35313). The 12 strains were 87 to 99% related in 60 degrees C reactions. Relatedness of K. trabulsii to 71 DNA hybridization reference strains of representative species of Enterobacteriaceae was 4 to 37%. It was 15 to 16% related to H. alvei. All strains were susceptible to nalidixic acid, sulfadiazine, gentamicin, kanamycin, and chloramphenicol, and 83% were susceptible to nalidixic acid, sulfadiazine, gentamicin, kanamycin, and chloramphenicol, and 83% were susceptible to tetracycline. Most of the strains were resistant or intermediate to penicillin, ampicillin, carbenicillin, colistin, and cephalothin. Five of the strains were isolated from wounds, three were from the respiratory tract, and one each was from a stool, knee fluid, water, and an unknown source. The clinical significance of this organism is not known; therefore, future studies should focus on its isolation and its relationship to human disease. PMID:3968202

Post-traumatic infection of the lower limb caused by rare Enterobacteriaceae and Mucorales in a young healthy male.

PubMed

Corti, Giampaolo; Mondanelli, Nicola; Losco, Michele; Bartolini, Laura; Fontanelli, Alessandra; Paradisi, Franco

2009-03-01

Enterobacter amnigenus and Leclercia adecarboxylata are gram-negative aerobic bacilli of the family Enterobacteriaceae that have been isolated from water and, rarely, from various clinical specimens. Absidia is a filamentous fungus of the class Zygomycetes that is ubiquitous in nature and can cause infection, primarily in immunocompromised hosts. Here, we describe an infection of the left lower limb caused by E. amnigenus and L. adecarboxylata with subsequent isolation of Absidia spp. in a patient with multiple traumatic injuries after a major motor vehicle accident. The severity of the clinical picture made amputation necessary, despite aggressive anti-infective therapy with both antibacterial and antifungal agents. Prompt diagnosis and management are mandatory in order to minimize morbidity and even mortality, and reduce the social and economic cost.

Resistance pattern of 2816 isolates isolated from 17631 blood cultures and etiology of bacteremia and fungemia in a single cancer institution.

PubMed

Trupl, J; Kunová, A; Oravcová, E; Pichna, P; Kukucková, E; Grausova, S; Grey, E; Spanik, S; Demitrovicová, A; Kralóvicová, K; Lacka, J; Krupova, I; Svec, J; Koren, P; Krcméry, V

1997-01-01

The resistance pattern of 2816 isolates from 17631 blood cultures and the etiology of isolates causing bacteremia and fungemia among 14591 admissions were investigated in an 80-bed single cancer institute during seven years (1990-1996) under the same empiric therapeutic antibiotic policy but with different prophylactic strategies. No change was found in the proportion of Gram-positive versus Gram-negative bacteria isolated from bacteremias (70% vs. 30%) during the past seven years. Furthermore, the proportion of coagulase-negative staphylococci and enterococci was about the same before and after the introduction of ofloxacin in prophylaxis. However, the proportion of Pseudomonas aeruginosa and Stenotrophomonas maltophilia causing bacteremia increased. There was no increase in Candida krusei and Candida glabrata after the introduction of fluconazole into our prophylactic regimen in 1992. Penicillin-resistance in viridans streptococci increased after penicillin was introduced into prophylaxis in acute leukemia in 1993. Until 1995 no quinolone-resistant Enterobacteriaceae were observed. Susceptibility to quinolones did not significantly change within the past seven years in Enterobacteriaceae after their introduction to prophylaxis in 1991, but Pseudomonas aeruginosa decreased from 90 to 58.2%. Glycopeptide resistance in enterococci and staphylococci was minimal in the observed period (0.9-4.3%).

Effectiveness and safety of bedaquiline-containing regimens in the treatment of MDR- and XDR-TB: a multicentre study.

PubMed

Borisov, Sergey E; Dheda, Keertan; Enwerem, Martin; Romero Leyet, Rodolfo; D'Ambrosio, Lia; Centis, Rosella; Sotgiu, Giovanni; Tiberi, Simon; Alffenaar, Jan-Willem; Maryandyshev, Andrey; Belilovski, Evgeny; Ganatra, Shashank; Skrahina, Alena; Akkerman, Onno; Aleksa, Alena; Amale, Rohit; Artsukevich, Janina; Bruchfeld, Judith; Caminero, Jose A; Carpena Martinez, Isabel; Codecasa, Luigi; Dalcolmo, Margareth; Denholm, Justin; Douglas, Paul; Duarte, Raquel; Esmail, Aliasgar; Fadul, Mohammed; Filippov, Alexey; Davies Forsman, Lina; Gaga, Mina; Garcia-Fuertes, Julia-Amaranta; García-García, José-María; Gualano, Gina; Jonsson, Jerker; Kunst, Heinke; Lau, Jillian S; Lazaro Mastrapa, Barbara; Teran Troya, Jorge Lazaro; Manga, Selene; Manika, Katerina; González Montaner, Pablo; Mullerpattan, Jai; Oelofse, Suzette; Ortelli, Martina; Palmero, Domingo Juan; Palmieri, Fabrizio; Papalia, Antonella; Papavasileiou, Apostolos; Payen, Marie-Christine; Pontali, Emanuele; Robalo Cordeiro, Carlos; Saderi, Laura; Sadutshang, Tsetan Dorji; Sanukevich, Tatsiana; Solodovnikova, Varvara; Spanevello, Antonio; Topgyal, Sonam; Toscanini, Federica; Tramontana, Adrian R; Udwadia, Zarir Farokh; Viggiani, Pietro; White, Veronica; Zumla, Alimuddin; Migliori, Giovanni Battista

2017-05-01

Large studies on bedaquiline used to treat multidrug-resistant (MDR-) and extensively drug-resistant tuberculosis (XDR-TB) are lacking. This study aimed to evaluate the safety and effectiveness of bedaquiline-containing regimens in a large, retrospective, observational study conducted in 25 centres and 15 countries in five continents.428 culture-confirmed MDR-TB cases were analysed (61.5% male; 22.1% HIV-positive, 45.6% XDR-TB). MDR-TB cases were admitted to hospital for a median (interquartile range (IQR)) 179 (92-280) days and exposed to bedaquiline for 168 (86-180) days. Treatment regimens included, among others, linezolid, moxifloxacin, clofazimine and carbapenems (82.0%, 58.4%, 52.6% and 15.3% of cases, respectively).Sputum smear and culture conversion rates in MDR-TB cases were 63.6% and 30.1%, respectively at 30 days, 81.1% and 56.7%, respectively at 60 days; 85.5% and 80.5%, respectively at 90 days and 88.7% and 91.2%, respectively at the end of treatment. The median (IQR) time to smear and culture conversion was 34 (30-60) days and 60 (33-90) days. Out of 247 culture-confirmed MDR-TB cases completing treatment, 71.3% achieved success (62.4% cured; 8.9% completed treatment), 13.4% died, 7.3% defaulted and 7.7% failed. Bedaquiline was interrupted due to adverse events in 5.8% of cases. A single case died, having electrocardiographic abnormalities that were probably non-bedaquiline related.Bedaquiline-containing regimens achieved high conversion and success rates under different nonexperimental conditions. Copyright ©ERS 2017.

Emergence of an Extensively Drug-Resistant Salmonella enterica Serovar Typhi Clone Harboring a Promiscuous Plasmid Encoding Resistance to Fluoroquinolones and Third-Generation Cephalosporins.

PubMed

Klemm, Elizabeth J; Shakoor, Sadia; Page, Andrew J; Qamar, Farah Naz; Judge, Kim; Saeed, Dania K; Wong, Vanessa K; Dallman, Timothy J; Nair, Satheesh; Baker, Stephen; Shaheen, Ghazala; Qureshi, Shahida; Yousafzai, Mohammad Tahir; Saleem, Muhammad Khalid; Hasan, Zahra; Dougan, Gordon; Hasan, Rumina

2018-02-20

Antibiotic resistance is a major problem in Salmonella enterica serovar Typhi, the causative agent of typhoid. Multidrug-resistant (MDR) isolates are prevalent in parts of Asia and Africa and are often associated with the dominant H58 haplotype. Reduced susceptibility to fluoroquinolones is also widespread, and sporadic cases of resistance to third-generation cephalosporins or azithromycin have also been reported. Here, we report the first large-scale emergence and spread of a novel S  Typhi clone harboring resistance to three first-line drugs (chloramphenicol, ampicillin, and trimethoprim-sulfamethoxazole) as well as fluoroquinolones and third-generation cephalosporins in Sindh, Pakistan, which we classify as extensively drug resistant (XDR). Over 300 XDR typhoid cases have emerged in Sindh, Pakistan, since November 2016. Additionally, a single case of travel-associated XDR typhoid has recently been identified in the United Kingdom. Whole-genome sequencing of over 80 of the XDR isolates revealed remarkable genetic clonality and sequence conservation, identified a large number of resistance determinants, and showed that these isolates were of haplotype H58. The XDR S  Typhi clone encodes a chromosomally located resistance region and harbors a plasmid encoding additional resistance elements, including the bla CTX-M-15 extended-spectrum β-lactamase, and carrying the qnrS fluoroquinolone resistance gene. This antibiotic resistance-associated IncY plasmid exhibited high sequence identity to plasmids found in other enteric bacteria isolated from widely distributed geographic locations. This study highlights three concerning problems: the receding antibiotic arsenal for typhoid treatment, the ability of S  Typhi to transform from MDR to XDR in a single step by acquisition of a plasmid, and the ability of XDR clones to spread globally. IMPORTANCE Typhoid fever is a severe disease caused by the Gram-negative bacterium Salmonella enterica serovar Typhi. Antibiotic

CTX-M-producing non-Typhi Salmonella spp. isolated from humans, United States.

PubMed

Sjölund-Karlsson, Maria; Howie, Rebecca; Krueger, Amy; Rickert, Regan; Pecic, Gary; Lupoli, Kathryn; Folster, Jason P; Whichard, Jean M

2011-01-01

CTX-M-type beta-lactamases are increasing among US Enterobacteriaceae isolates. Of 2,165 non-Typhi Salmonella isolates submitted in 2007 to the National Antimicrobial Resistance Monitoring System, 100 (4.6%) displayed elevated MICs (≥2 mg/L) of ceftriaxone or ceftiofur. Three isolates (serotypes Typhimurium, Concord, and I 4,5,12:i:-) contained bla(CTX-M-5), bla(CTX-M-15), and bla(CTX-M-55/57), respectively.

CTX-M–producing Non-Typhi Salmonella spp. Isolated from Humans, United States

PubMed Central

Howie, Rebecca; Krueger, Amy; Rickert, Regan; Pecic, Gary; Lupoli, Kathryn; Folster, Jason P.; Whichard, Jean M.

2011-01-01

CTX-M–type β-lactamases are increasing among US Enterobacteriaceae isolates. Of 2,165 non-Typhi Salmonella isolates submitted in 2007 to the National Antimicrobial Resistance Monitoring System, 100 (4.6%) displayed elevated MICs (>2 mg/L) of ceftriaxone or ceftiofur. Three isolates (serotypes Typhimurium, Concord, and I 4,5,12:i:–) contained blaCTX-M-5, blaCTX-M-15, and blaCTX-M-55/57, respectively. PMID:21192864

Genome Analysis of the First Extensively Drug-Resistant (XDR) Mycobacterium tuberculosis in Malaysia Provides Insights into the Genetic Basis of Its Biology and Drug Resistance

PubMed Central

Kuan, Chee Sian; Chan, Chai Ling; Yew, Su Mei; Toh, Yue Fen; Khoo, Jia-Shiun; Chong, Jennifer; Lee, Kok Wei; Tan, Yung-Chie; Yee, Wai-Yan; Ngeow, Yun Fong; Ng, Kee Peng

2015-01-01

The outbreak of extensively drug-resistant tuberculosis (XDR-TB) has become an increasing problem in many TB-burdened countries. The underlying drug resistance mechanisms, including the genetic variation favored by selective pressure in the resistant population, are partially understood. Recently, the first case of XDR-TB was reported in Malaysia. However, the detailed genotype family and mechanisms of the formation of multiple drugs resistance are unknown. We sequenced the whole genome of the UM 1072388579 strain with a 2-kb insert-size library and combined with that from previously sequenced 500-bp-insert paired-end reads to produce an improved sequence with maximal sequencing coverage across the genome. In silico spoligotyping and phylogenetic analyses demonstrated that UM 1072388579 strain belongs to an ancestral-like, non-Beijing clade of East Asia lineage. This is supported by the presence of a number of lineage-specific markers, including fadD28, embA, nuoD and pks7. Polymorphism analysis showed that the drug-susceptibility profile is correlated with the pattern of resistance mutations. Mutations in drug-efflux pumps and the cell wall biogenesis pathway such as mmpL, pks and fadD genes may play an important role in survival and adaptation of this strain to its surrounding environment. In this work, fifty-seven putative promoter SNPs were identified. Among them, we identified a novel SNP located at -4 T allele of TetR/acrR promoter as an informative marker to recognize strains of East Asian lineage. Our work indicates that the UM 1072388579 harbors both classical and uncommon SNPs that allow it to escape from inhibition by many antibiotics. This study provides a strong foundation to dissect the biology and underlying resistance mechanisms of the first reported XDR M. tuberculosis in Malaysia. PMID:26110649

Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: an international expert proposal for interim standard definitions for acquired resistance.

PubMed

Magiorakos, A-P; Srinivasan, A; Carey, R B; Carmeli, Y; Falagas, M E; Giske, C G; Harbarth, S; Hindler, J F; Kahlmeter, G; Olsson-Liljequist, B; Paterson, D L; Rice, L B; Stelling, J; Struelens, M J; Vatopoulos, A; Weber, J T; Monnet, D L

2012-03-01

Many different definitions for multidrug-resistant (MDR), extensively drug-resistant (XDR) and pandrug-resistant (PDR) bacteria are being used in the medical literature to characterize the different patterns of resistance found in healthcare-associated, antimicrobial-resistant bacteria. A group of international experts came together through a joint initiative by the European Centre for Disease Prevention and Control (ECDC) and the Centers for Disease Control and Prevention (CDC), to create a standardized international terminology with which to describe acquired resistance profiles in Staphylococcus aureus, Enterococcus spp., Enterobacteriaceae (other than Salmonella and Shigella), Pseudomonas aeruginosa and Acinetobacter spp., all bacteria often responsible for healthcare-associated infections and prone to multidrug resistance. Epidemiologically significant antimicrobial categories were constructed for each bacterium. Lists of antimicrobial categories proposed for antimicrobial susceptibility testing were created using documents and breakpoints from the Clinical Laboratory Standards Institute (CLSI), the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the United States Food and Drug Administration (FDA). MDR was defined as acquired non-susceptibility to at least one agent in three or more antimicrobial categories, XDR was defined as non-susceptibility to at least one agent in all but two or fewer antimicrobial categories (i.e. bacterial isolates remain susceptible to only one or two categories) and PDR was defined as non-susceptibility to all agents in all antimicrobial categories. To ensure correct application of these definitions, bacterial isolates should be tested against all or nearly all of the antimicrobial agents within the antimicrobial categories and selective reporting and suppression of results should be avoided. © 2011 European Society of Clinical Microbiology and Infectious Diseases. No claim to original US government works.

Comparison of the characteristics of Mycobacterium tuberculosis isolates from sputum and lung lesions in chronic tuberculosis patients.

PubMed

Hong, M-S; Kim, Y; Cho, E-J; Lee, J-S; Kwak, H-K; Kim, J-H; Kim, C-T; Cho, J-S; Park, S-K; Jeon, D; Choi, Y-I; Lee, H; Eum, S-Y

2017-11-01

Mycobacterium tuberculosis (Mtb) in sputum originates from lung cavities in tuberculosis (TB) patients. But drug susceptibility testing (DST) of sputum Mtb can not be conducted the same as in the lung because mutagenesis of bacilli may be happening in the lung during treatment and result in the possibility of the presence of heterogeneous drug-resistant subpopulations in the different lung lesions. This could be one of the reasons for low cure rates for multi-drug resistant (MDR)-TB. We studied the resected lungs of nine surgery patients with chronic TB. The isolates isolated from the sputum and different lung lesions of each patient were tested for phenotypic DST and genotyped using restriction fragment length polymorphism (RFLP) typing method. Genetic analysis to resistance to first and second line drugs was also performed. Five of nine patients were MDR-TB and three XDR-TB. DST results for ten anti-TB drugs were in accordance among different lung lesions in eight patients. However, only three of these eight patients showed the concordance of DST with sputum. Even though the isolates were heteroresistant, genotyping them by RFLP showed the clonal population in each individual patient. Six of eight followed-up patients achieved successful cure. In conclusion, the heteroresistance between sputum and lung lesions and a clonal population without mixed infection might provide useful information in establishing treatment regimen and surgery decision for MDR- and XDR-TB.

Carriage of ESBL- and AmpC-positive Enterobacteriaceae in the gastrointestinal tract of community subjects and hospitalized patients in the Czech Republic.

PubMed

Husickova, Vendula; Cekanova, Luboslava; Chroma, Magdalena; Htoutou-Sedlakova, Miroslava; Hricova, Kristyna; Kolar, Milan

2012-12-01

The study aimed at analyzing ESBL- and AmpC-positive Enterobacteriaceae in the gastrointestinal tracts of university hospital inpatients and persons from the Olomouc Region community, and comparing the results with data from 2007. Bacteria were isolated from rectal swabs inoculated onto the ChromID(TM) ESBL selective medium (bioMérieux). Production of ESBL-type beta-lactamases was confirmed by the modified double-disk synergy test and AmpC enzyme production was detected by the AmpC disk test. ESBL- and AmpC-positive isolates were subjected to basic genetic analysis aimed at detecting the bla(TEM), bla(SHV), bla(CTX-M) and bla(AmpC) genes. Over the study period (1 March 2010 - 1 May 2010), a total of 1,279 rectal swabs (70.4% of community subjects) were analyzed on the above medium. The prevalence rates of ESBL-positive Enterobacteriaceae were 8.2% in hospitalized patients and 3.2% in community subjects. Production of the AmpC enzyme was detected in 1.1% of bacterial isolates from the community and in one (0.3%) hospital isolate. Among ESBL, the most frequent genes encoding enzymes were from the CTX-M-1-like genes. Detected AmpC beta-lactamases belonged to the CIT, DHA and EBC groups. When compared with the year 2007, the rates of carriers of ESBL-positive bacteria increased in both hospitalized patients (from 3% to 8%) and community subjects (from 1% to 3%) in 2010. Given the fact that production of extended-spectrum beta-lactamases is clinically significant, knowing the epidemiological situation is very important for selecting adequate antibiotic therapy.

Investigation of mutation distribution in DNA gyrase and topoisomerase IV genes in ciprofloxacin-non-susceptible Enterobacteriaceae isolated from blood cultures in a tertiary care university hospital in South Korea, 2005-2010.

PubMed

Nam, You Sun; Cho, Sun Young; Yang, Hee Young; Park, Kyung Sun; Jang, Ji-Hyun; Kim, Yun-Tae; Jeong, Joo-Won; Suh, Jin-Tae; Lee, Hee Joo

2013-02-01

This study investigated the distribution of mutations in DNA gyrase (gyrA and gyrB) and topoisomerase IV (parC and parE) genes and compared the distribution of these mutations with the distribution of plasmid-mediated quinolone resistance (PMQR) genes and extended-spectrum β-lactamase (ESBL) production in 101 ciprofloxacin-non-susceptible Enterobacteriaceae from blood culture isolates (80 Escherichia coli and 21 Klebsiella pneumoniae) isolated in Kyung Hee University Hospital, a tertiary care university hospital in Seoul, South Korea. Among the 101 isolates, 80 (79.2%) contained PMQR genes and 28 (27.7%) produced ESBL. Mutations in the gyrA and parC genes were observed more frequently than in the gyrB and parE genes as well as more frequently in E. coli than in K. pneumoniae isolates, even in the same ciprofloxacin minimum inhibitory concentration (MIC) range of the two species. In E. coli isolates, the distribution of the codon 529 mutation (Ile→Leu) in parE was increased with an increase in the ciprofloxacin MIC. An increase in high-level resistance to quinolones may occur with double mutations compared with a single mutation in gyrA as well as with additional mutations in parC. However, this finding could not be applied to ciprofloxacin-resistant K. pneumoniae. A higher level of quinolone resistance may be correlated with an additional mutation in parE, especially Ile529→Leu. Copyright © 2012 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Community-Onset Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae Invasive Infections in Children in a University Hospital in France.

PubMed

Toubiana, Julie; Timsit, Sandra; Ferroni, Agnès; Grasseau, Marie; Nassif, Xavier; Lortholary, Olivier; Zahar, Jean-Ralph; Chalumeau, Martin

2016-03-01

Limited data is available on pediatric community-onset infections with extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE), but such infections may affect both the efficacy of empiric antibiotic therapy and the rational use of antibiotics.We retrospectively analyzed data from 2007 to 2012 for all children ≤16 years old with a positive ESBL-PE strain from usually sterile sites within 48 hours of admission in a tertiary hospital in France. We analyzed healthcare- and community-associated infections among community-onset infections. In total, 3612 Enterobacteriaceae isolates were collected; the prevalence of ESBL-PE infection increased over the study period, from 2.4% to 5.1% (P < 0.001). Among the 90 children with a first community-onset ESBL-PE infection, 58% (n = 52) had a healthcare-associated infection, and 87% of isolates were susceptible to amikacin. As compared with patients with community-associated infections, those with healthcare-associated infections had fewer urinary tract infections (UTIs) (86% vs 97%) and Escherichia coli infections (35% vs 84%) and more Klebsiella pneumoniae infections (46% vs 8%). Inappropriate empiric treatment was prescribed for 54 patients (64%), but a favorable outcome was observed in 46 of 49 (94%) and 1 of 5 (20%) patients with UTIs and non-UTIs, respectively (P < 0.001). Among patients with community-associated infections, 85% had at least 1 risk factor for ESBL-PE infections. In conclusion, the prevalence of community-onset ESBL-PE infections doubled during the study period. These infections mainly occurred among children with healthcare-associated criteria or identified risk factors. Amikacin is an alternative to carbapenems for empiric treatment because most of these infections involved urinary tract and susceptible isolates.

Community-Onset Extended-Spectrum β-Lactamase–Producing Enterobacteriaceae Invasive Infections in Children in a University Hospital in France

PubMed Central

Toubiana, Julie; Timsit, Sandra; Ferroni, Agnès; Grasseau, Marie; Nassif, Xavier; Lortholary, Olivier; Zahar, Jean-Ralph; Chalumeau, Martin

2016-01-01

Abstract Limited data is available on pediatric community-onset infections with extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE), but such infections may affect both the efficacy of empiric antibiotic therapy and the rational use of antibiotics. We retrospectively analyzed data from 2007 to 2012 for all children ≤16 years old with a positive ESBL-PE strain from usually sterile sites within 48 hours of admission in a tertiary hospital in France. We analyzed healthcare- and community-associated infections among community-onset infections. In total, 3612 Enterobacteriaceae isolates were collected; the prevalence of ESBL-PE infection increased over the study period, from 2.4% to 5.1% (P < 0.001). Among the 90 children with a first community-onset ESBL-PE infection, 58% (n = 52) had a healthcare-associated infection, and 87% of isolates were susceptible to amikacin. As compared with patients with community-associated infections, those with healthcare-associated infections had fewer urinary tract infections (UTIs) (86% vs 97%) and Escherichia coli infections (35% vs 84%) and more Klebsiella pneumoniae infections (46% vs 8%). Inappropriate empiric treatment was prescribed for 54 patients (64%), but a favorable outcome was observed in 46 of 49 (94%) and 1 of 5 (20%) patients with UTIs and non-UTIs, respectively (P < 0.001). Among patients with community-associated infections, 85% had at least 1 risk factor for ESBL-PE infections. In conclusion, the prevalence of community-onset ESBL-PE infections doubled during the study period. These infections mainly occurred among children with healthcare-associated criteria or identified risk factors. Amikacin is an alternative to carbapenems for empiric treatment because most of these infections involved urinary tract and susceptible isolates. PMID:27015202

Comparison of Two Phenotypic Algorithms To Detect Carbapenemase-Producing Enterobacteriaceae

PubMed Central

Dortet, Laurent; Bernabeu, Sandrine; Gonzalez, Camille

2017-01-01

ABSTRACT A novel algorithm designed for the screening of carbapenemase-producing Enterobacteriaceae (CPE), based on faropenem and temocillin disks, was compared to that of the Committee of the Antibiogram of the French Society of Microbiology (CA-SFM), which is based on ticarcillin-clavulanate, imipenem, and temocillin disks. The two algorithms presented comparable negative predictive values (98.6% versus 97.5%) for CPE screening among carbapenem-nonsusceptible Enterobacteriaceae. However, since 46.2% (n = 49) of the CPE were correctly identified as OXA-48-like producers by the faropenem/temocillin-based algorithm, it significantly decreased the number of complementary tests needed (42.2% versus 62.6% with the CA-SFM algorithm). PMID:28607010

Travel to Asia and traveller's diarrhoea with antibiotic treatment are independent risk factors for acquiring ciprofloxacin-resistant and extended spectrum β-lactamase-producing Enterobacteriaceae-a prospective cohort study.

PubMed

Reuland, E A; Sonder, G J B; Stolte, I; Al Naiemi, N; Koek, A; Linde, G B; van de Laar, T J W; Vandenbroucke-Grauls, C M J E; van Dam, A P

2016-08-01

Travel to (sub)tropical countries is a well-known risk factor for acquiring resistant bacterial strains, which is especially of significance for travellers from countries with low resistance rates. In this study we investigated the rate of and risk factors for travel-related acquisition of extended spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E), ciprofloxacin-resistant Enterobacteriaceae (CIPR-E) and carbapenem-resistant Enterobacteriaceae. Data before and after travel were collected from 445 participants. Swabs were cultured with an enrichment broth and sub-cultured on selective agar plates for ESBL detection, and on plates with a ciprofloxacin disc. ESBL production was confirmed with the double-disc synergy test. Species identification and susceptibility testing were performed with the Vitek-2 system. All isolates were subjected to ertapenem Etest. ESBL and carbapenemase genes were characterized by PCR and sequencing. Twenty-seven out of 445 travellers (6.1%) already had ESBL-producing strains and 45 of 445 (10.1%) travellers had strains resistant to ciprofloxacin before travel. Ninety-eight out of 418 (23.4%) travellers acquired ESBL-E and 130 of 400 (32.5%) travellers acquired a ciprofloxacin-resistant strain. Of the 98 ESBL-E, predominantly Escherichia coli and predominantly blaCTX-M-15, 56% (55/98) were resistant to gentamicin, ciprofloxacin and co-trimoxazole. Multivariate analysis showed that Asia was a high-risk area for ESBL-E as well as CIPR-E acquisition. Travellers with diarrhoea combined with antimicrobial use were significantly at higher risk for acquisition of resistant strains. Only one carbapenemase-producing isolate was acquired, isolated from a participant after visiting Egypt. In conclusion, travelling to Asia and diarrhoea combined with antimicrobial use are important risk factors for acquiring ESBL-E and CIPR-E. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All

A combined disc method with resazurin agar plate assay for early phenotypic screening of KPC, MBL and OXA-48 carbapenemases among Enterobacteriaceae.

PubMed

Teethaisong, Y; Eumkeb, G; Nakouti, I; Evans, K; Hobbs, G

2016-08-01

To validate a combined disc method along with resazurin chromogenic agar for early screening and differentiation of Klebsiella pneumoniae carbapenemase, metallo-β-lactamase and OXA-48 carbapenemase-producing Enterobacteriaceae. The combined disc test comprising of meropenem alone and with EDTA, phenylboronic acid or both EDTA and phenylboronic acid, and temocillin alone were evaluated with the resazurin chromogenic agar plate assay against a total of 86 molecularly confirmed Enterobacteriaceae clinical isolates (11 metallo-β-lactamases, eight Kl. pneumoniae carbapenemases, 11 OXA-48, 32 AmpC and 15 extended-spectrum-β-lactamase producers and nine co-producers of extended-spectrum-β-lactamase and AmpC). The inhibition zone diameters were measured and interpreted at 7 h for the presence of carbapenemase. All carbapenemase producers were phenotypically distinguished by this assay with 100% sensitivity and specificity. This early phenotypic method is very simple, inexpensive, and reliable in the detection and differentiation of carbapenemase-producing Enterobacteriaceae. It could be exploited in any microbiological laboratory for diagnosis of these recalcitrant bacteria. This assay poses excellent performance in discrimination of Kl. pneumoniae carbapenemase, metallo-β-lactamase and OXA-48 carbapenemases within 7 h, which is much faster than conventional disc diffusion methods. The rapid detection could help clinicians screen patients, control infection and provide epidemiological surveillance. © 2016 The Society for Applied Microbiology.

Isolation, Antimicrobial Susceptibility Profile and Detection of Sul1, blaTEM, and blaSHV in Amoxicillin-Clavulanate-Resistant Bacteria Isolated From Retail Sausages in Kampar, Malaysia

PubMed Central

Tew, Lih-Shin; She, Li-Yen; Chew, Choy-Hoong

2016-01-01

Background Due to the overuse of antibiotics in livestock as a growth-promoting agent, the emergence of multi-antibiotic resistant bacteria is becoming a concern. Objectives In this study, we aimed to detect the presence and discover the molecular determinants of foodborne bacteria in retail sausages resistant towards the antibacterial agent amoxicillin-clavulanate. Methods Two grams of sausages were chopped into small pieces and transferred into sterile Luria-Bertani (LB) enrichment broths overnight before they were plated on MacConkey agar petri dishes. The bacteria isolated were then screened for amoxicillin-clavulanate resistance, and an antimicrobial susceptibility test of each isolate was performed by using the disc diffusion method. Double synergy and phenotypic tests were carried out to detect the presence of extended spectrum β-lactamase (ESBL). API 20E kit was used to identify the Enterobacteriaceae. All isolates were further examined by polymerase chain reaction (PCR) for resistant genes blaOXA-1, blaOXA-10, plasmid-mediated AmpC (blaCMY and blaDHA), and the chromosome-mediated AmpC, Sul1, blaTEM, and blaSHV genes. Results A total of 18 amoxicillin-clavulanate resistant isolates were obtained from seven different types of retail sausages. Only half of them were identified as Enterobacteriaceae, but none were ESBL-producers. All the 18 isolated strains demonstrated resistance towards amoxicillin-clavulanate, penicillin and oxacillin (100%), cefotaxime (71.4%), cefpodoxime (66.7%), and ampicillin (83.3%). blaTEM was the most frequently detected β-lactamase gene. Both plasmid- and chromosomal-bound blaTEM genes were detected in all of the isolated Enterobacteriaceae. blaSHV and Sul1 accounted for 22.2% and 11.1% of the amoxicillin-clavulanate resistant isolates, respectively, whereas blaAMPC, blaCMY, blaDHA, blaOXA-1, and blaOXA-10 were not found in any of the isolates. The only one ESBL-producing bacteria detected in this study was Chryseobacterium

Isolation, Antimicrobial Susceptibility Profile and Detection of Sul1, blaTEM, and blaSHV in Amoxicillin-Clavulanate-Resistant Bacteria Isolated From Retail Sausages in Kampar, Malaysia.

PubMed

Tew, Lih-Shin; She, Li-Yen; Chew, Choy-Hoong

2016-10-01

Due to the overuse of antibiotics in livestock as a growth-promoting agent, the emergence of multi-antibiotic resistant bacteria is becoming a concern. In this study, we aimed to detect the presence and discover the molecular determinants of foodborne bacteria in retail sausages resistant towards the antibacterial agent amoxicillin-clavulanate. Two grams of sausages were chopped into small pieces and transferred into sterile Luria-Bertani (LB) enrichment broths overnight before they were plated on MacConkey agar petri dishes. The bacteria isolated were then screened for amoxicillin-clavulanate resistance, and an antimicrobial susceptibility test of each isolate was performed by using the disc diffusion method. Double synergy and phenotypic tests were carried out to detect the presence of extended spectrum β-lactamase (ESBL). API 20E kit was used to identify the Enterobacteriaceae . All isolates were further examined by polymerase chain reaction (PCR) for resistant genes bla OXA-1, bla OXA-10, plasmid-mediated AmpC ( bla CMY and bla DHA), and the chromosome-mediated AmpC, Sul 1, bla TEM, and bla SHV genes. A total of 18 amoxicillin-clavulanate resistant isolates were obtained from seven different types of retail sausages. Only half of them were identified as Enterobacteriaceae , but none were ESBL-producers. All the 18 isolated strains demonstrated resistance towards amoxicillin-clavulanate, penicillin and oxacillin (100%), cefotaxime (71.4%), cefpodoxime (66.7%), and ampicillin (83.3%). bla TEM was the most frequently detected β-lactamase gene. Both plasmid- and chromosomal-bound bla TEM genes were detected in all of the isolated Enterobacteriaceae . bla SHV and Sul 1 accounted for 22.2% and 11.1% of the amoxicillin-clavulanate resistant isolates, respectively, whereas bla AMPC, bla CMY, bla DHA, bla OXA-1, and bla OXA-10 were not found in any of the isolates. The only one ESBL-producing bacteria detected in this study was Chryseobacterium meningosepticum , which

Molecular characterization of mutations associated with resistance to second-line tuberculosis drug among multidrug-resistant tuberculosis patients from high prevalence tuberculosis city in Morocco.

PubMed

Oudghiri, Amal; Karimi, Hind; Chetioui, Fouad; Zakham, Fathiah; Bourkadi, Jamal Eddine; Elmessaoudi, My Driss; Laglaoui, Amin; Chaoui, Imane; El Mzibri, Mohammed

2018-02-27

The emergence of extensively drug-resistant tuberculosis (XDR-TB) has raised public health concern for global TB control. Although multi drug-resistant tuberculosis (MDR- TB) prevalence and associated genetic mutations in Morocco are well documented, scarce information on XDR TB is available. Hence, the evaluation of pre-XDR and XDR prevalence, as well as the mutation status of gyrA, gyrB, rrs, tlyA genes and eis promoter region, associated with resistance to second line drugs, is of great value for better management of M/XDR TB in Morocco. To evaluate pre-XDR and XDR prevalence, as well as the mutation status of gyrA, gyrB, rrs, tlyA genes and eis promoter region, associated with resistance to second line drug resistance, in 703 clinical isolates from TB patients recruited in Casablanca, and to assess the usefulness of molecular tools in clinical laboratories for better management of M/XDR TB in Morocco. Drug susceptibility testing (DST) was performed by the proportional method for first line drugs, and then the selected MDR isolates were tested for second line drugs (Ofloxacin, Kanamycin, Amikacin and Capreomycin). Along with DST, all samples were subjected to rpoB, katG and p-inhA mutation analysis by PCR and DNA sequencing. MDR isolates as well as 30 pan-susceptible strains were subjected to PCR and DNA sequencing of gyrA, gyrB, rrs, tlyA genes and eis promoter, associated with resistance to fluoroquinolones and injectable drugs. Among the 703 analysed strains, 12.8% were MDR; Ser531Leu and Ser315Thr being the most common recorded mutations within rpoB and katG genes associated with RIF and INH resistance respectively. Drug susceptibility testing for second line drugs showed that among the 90 MDR strains, 22.2% (20/90) were resistant to OFX, 2.22% (2/90) to KAN, 3.33% (3/90) to AMK and 1.11% (1/90) to CAP. Genotypic analysis revealed that 19 MDR strains harbored mutations in the gyrA gene; the most recorded mutation being Asp91Ala accounting for 47.6% (10

Evolving beta-lactamase epidemiology in Enterobacteriaceae from Italian nationwide surveillance, October 2013: KPC-carbapenemase spreading among outpatients.

PubMed

Giani, Tommaso; Antonelli, Alberto; Caltagirone, Mariasofia; Mauri, Carola; Nicchi, Jessica; Arena, Fabio; Nucleo, Elisabetta; Bracco, Silvia; Pantosti, Annalisa; Luzzaro, Francesco; Pagani, Laura; Rossolini, Gian Maria

2017-08-03

Extended-spectrum beta-lactamases (ESBLs), AmpC-type beta-lactamases (ACBLs) and carbapenemases are among the most important resistance mechanisms in Enterobacteriaceae. This study investigated the presence of these resistance mechanisms in consecutive non-replicate isolates of Escherichia coli (n = 2,352), Klebsiella pneumoniae (n = 697), and Proteus mirabilis (n = 275) from an Italian nationwide cross-sectional survey carried out in October 2013. Overall, 15.3% of isolates were non-susceptible to extended-spectrum cephalosporins but susceptible to carbapenems (ESCR-carbaS), while 4.3% were also non-susceptible to carbapenems (ESCR-carbaR). ESCR-carbaS isolates were contributed by all three species, with higher proportions among isolates from inpatients (20.3%) but remarkable proportions also among those from outpatients (11.1%). Most ESCR-carbaS isolates were ESBL-positive (90.5%), and most of them were contributed by E. coli carrying bla CTX-M group 1 genes. Acquired ACBLs were less common and mostly detected in P. mirabilis. ESCR-carbaR isolates were mostly contributed by K. pneumoniae (25.1% and 7.7% among K. pneumoniae isolates from inpatients and outpatients, respectively), with bla KPC as the most common carbapenemase gene. Results showed an increasing trend for both ESBL and carbapenemase producers in comparison with previous Italian surveys, also among outpatients. This article is copyright of The Authors, 2017.

Epidemiology and acquisition of extended-spectrum beta-lactamase-producing Enterobacteriaceae in a septic orthopedic ward.

PubMed

Agostinho, Americo; Renzi, Gesuele; Haustein, Thomas; Jourdan, Ghislaine; Bonfillon, Chantal; Rougemont, Mathieu; Hoffmeyer, Pierre; Harbarth, Stephan; Uçkay, Ilker

2013-12-01

Wards cohorting infected orthopaedic patients may be particularly prone to transmitting extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E). We analyze their epidemic pattern by performing molecular typing of ESBL-E isolated from patients and healthcare workers (HCW) from our septic ward. Between March 2010 and November 2011, 186 patients were admitted. Among 565 anal swabs, ESBL-E were detected in 204 samples from 45 patients, suggesting prolonged carriage in affected patients. Among 25 cases with identical ESBL-E species and positive epidemiological links, only 9 were really attributable to our service. We also screened 41 healthcare workers (HCW) on 49 occasions during the study period. Six samples (13%) were positive. None of the ESBL-E detected in HCW were related to any of the patient isolates. Among 60 environmental samples taken at the peak of the epidemic none revealed ESBL-E. We conclude that HCW also were anal carriers of ESBL-E, however the ESBL- strains from the HCW were not the same strains isolated from patients in the septic ward. Moreover, the epidemiological attribution of ESBL by simple vicinity, timing, and species identification might grossly overestimate transmission within a given unit.

Activity of Simulated Human Dosage Regimens of Meropenem and Vaborbactam against Carbapenem-Resistant Enterobacteriaceae in an In Vitro Hollow-Fiber Model.

PubMed

Sabet, Mojgan; Tarazi, Ziad; Rubio-Aparicio, Debora; Nolan, Thomas G; Parkinson, Jonathan; Lomovskaya, Olga; Dudley, Michael N; Griffith, David C

2018-02-01

The objective of these studies was to evaluate the exposures of meropenem and vaborbactam that would produce antibacterial activity and prevent resistance development in carbapenem-resistant Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae strains when tested at an inoculum of 10 8 CFU/ml. Thirteen K. pneumoniae isolates, three Enterobacter cloacae isolates, and one Escherichia coli isolate were examined in an in vitro hollow-fiber model over 32 h. Simulated dosage regimens of 1 to 2 g of meropenem with 1 to 2 g of vaborbactam, with meropenem administered every 8 h by a 3-h infusion based on phase 1 or phase 3 patient pharmacokinetic data, were studied in the model. A dosage of 2 g of meropenem in combination with 2 g of vaborbactam was bactericidal against K. pneumoniae , E. cloacae , and E. coli strains, with meropenem-vaborbactam MICs of up to 8 mg/liter. When the vaborbactam exposure was adjusted to the levels observed in patients enrolled in phase 3 trials (24-h free AUC, ∼550 mg · h/liter, versus 320 mg · h/liter in the phase 1 studies), 2 g of meropenem with 2 g of vaborbactam was also bactericidal against strains with meropenem-vaborbactam MICs of 16 mg/liter. In addition, this level of vaborbactam also suppressed the development of resistance observed using phase 1 exposures. In this pharmacodynamic model, exposures similar to 2 g of meropenem in combination with 2 g of vaborbactam administered every 8 h by a 3-h infusion in phase 3 trials produced antibacterial activity and suppressed the development of resistance against carbapenem-resistant KPC-producing strains of Enterobacteriaceae . Copyright © 2018 American Society for Microbiology.

Treatment of sepsis: What is the antibiotic choice in bacteremia due to carbapenem resistant Enterobacteriaceae?

PubMed Central

Alhashem, Fatema; Tiren-Verbeet, Nicolette Leonie; Alp, Emine; Doganay, Mehmet

2017-01-01

Sepsis is one of the major challenges of today. Although gram-positive bacteria related infections are more prevalent in hospital setting, the highest mortality rate is associated with gram-negative microorganisms especially Enterobacteriaceae. Enterobacteriaceae, including Escherichia coli, Klebsiella spp., Proteus spp., Enterobacter spp. and Serratia spp. Resistance to β-lactams in Enterobacteriaceae is primarily attributed to the production of B-lactamase enzymes with subsequent antibiotic hydrolysis and to a lesser extent by alteration of efflux pump or porins expression. Carbapenem resistant Enterobacteriaceae (CRE) and Acinetobacter baumannii are the most notorious pathogens due to the high incidence of morbidity and mortality especially in the immunocompromised patients in the intensive care unit. The most appropriate antimicrobial therapy to treat CRE is still controversial. Combination therapy is preferred over monotherapy due to its broad-spectrum coverage of micro-organisms, due to its synergetic effect and to prevent development of further resistance. Current suggested therapies for CRE resistance as well as promising antibiotics that are currently under investigation for winning the war against the emerging CRE resistance are reviewed and discussed. PMID:28868304

[Enterobacteriaceae producing extended spectrum beta-lactamase: epidemiology, risk factors, and prevention].

PubMed

Vodovar, D; Marcadé, G; Raskine, L; Malissin, I; Mégarbane, B

2013-11-01

Multidrug-resistant bacteria are a major worldwide health public concern. It results from the growing increase in antibiotic prescriptions, which are responsible for selection pressure on bacteria. In France like in other countries, enterobacteriaceae producing extended spectrum beta-lactamase (EESBL) are the predominant multidrug-resistant bacteria. EESBL may be responsible for severe infections and require prescription of broad-spectrum antibacterial agents. The current EESBL outbreak is different from methicillin-resistant Staphylococcus aureus outbreak that occurred in the early 1980. Consistently, EESBL are isolated both in hospital and community. Moreover, standard hygiene measures appear ineffective since EESBL prevalence is still increasing. The current inability to contain EESBL outbreak is due to several factors, including the existence of a wide community- and hospital-acquired tank of EESBL, failure to follow strict rules for hygiene, and the current irrational prescription of antibiotics. Copyright © 2012 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.

Biosecurity measures in 48 isolation facilities managing highly infectious diseases.

PubMed

Puro, Vincenzo; Fusco, Francesco M; Schilling, Stefan; Thomson, Gail; De Iaco, Giuseppina; Brouqui, Philippe; Maltezou, Helena C; Bannister, Barbara; Gottschalk, René; Brodt, Hans-Rheinhard; Ippolito, Giuseppe

2012-06-01

Biosecurity measures are traditionally applied to laboratories, but they may also be usefully applied in highly specialized clinical settings, such as the isolation facilities for the management of patients with highly infectious diseases (eg, viral hemorrhagic fevers, SARS, smallpox, potentially severe pandemic flu, and MDR- and XDR-tuberculosis). In 2009 the European Network for Highly Infectious Diseases conducted a survey in 48 isolation facilities in 16 European countries to determine biosecurity measures for access control to the facility. Security personnel are present in 39 facilities (81%). In 35 facilities (73%), entrance to the isolation area is restricted; control methods include electronic keys, a PIN system, closed-circuit TV, and guards at the doors. In 25 facilities (52%), identification and registration of all staff entering and exiting the isolation area are required. Access control is used in most surveyed centers, but specific lacks exist in some facilities. Further data are needed to assess other biosecurity aspects, such as the security measures during the transportation of potentially contaminated materials and measures to address the risk of an "insider attack."

Biosecurity Measures in 48 Isolation Facilities Managing Highly Infectious Diseases

PubMed Central

Puro, Vincenzo; Schilling, Stefan; Thomson, Gail; De Iaco, Giuseppina; Brouqui, Philippe; Maltezou, Helena C.; Bannister, Barbara; Gottschalk, René; Brodt, Hans-Rheinhard; Ippolito, Giuseppe

2012-01-01

Biosecurity measures are traditionally applied to laboratories, but they may also be usefully applied in highly specialized clinical settings, such as the isolation facilities for the management of patients with highly infectious diseases (eg, viral hemorrhagic fevers, SARS, smallpox, potentially severe pandemic flu, and MDR- and XDR-tuberculosis). In 2009 the European Network for Highly Infectious Diseases conducted a survey in 48 isolation facilities in 16 European countries to determine biosecurity measures for access control to the facility. Security personnel are present in 39 facilities (81%). In 35 facilities (73%), entrance to the isolation area is restricted; control methods include electronic keys, a PIN system, closed-circuit TV, and guards at the doors. In 25 facilities (52%), identification and registration of all staff entering and exiting the isolation area are required. Access control is used in most surveyed centers, but specific lacks exist in some facilities. Further data are needed to assess other biosecurity aspects, such as the security measures during the transportation of potentially contaminated materials and measures to address the risk of an “insider attack.” PMID:22571373

Audit of the management of patients at high risk of carbapenemase-producing enterobacteriaceae (CPE): Are we ready?

PubMed

Ratnayake, Lasantha; Harris, Amy; Ko, Doreen; Hawtin, Linda

2017-11-01

Incidence of carbapenemase-producing enterobacteriaceae (CPE) in the UK is increasing. In 2013, Public Health England (PHE) published a toolkit to control spread of CPE within healthcare settings. To assess compliance to hospital CPE policy (adapted from PHE) in the identification, isolation and screening of suspected CPE patients. Admission booklets of 150 patients were evaluated to see whether the relevant section had been completed to identify high-risk CPE patients. Where necessary, patients were interviewed or their GPs were contacted to assess their CPE risk. Additionally, 28 patients screened for CPE were audited to assess compliance to screening and isolation. Only 23 patients out of 147 (15.6%) were risk assessed on admission. Risk status of 27 (18.4%) patients could not be assessed due to lack of data. Fifteen patients out of 28 (54%) screened for CPE were identified and isolated on admission. Ten out of 19 patients (53%) had three screens 48 h apart. This audit highlights difficulties in screening based on individual risk factors as the majority of patients were not screened on admission and documentation on isolation and screening was poor. More needs to be done to raise awareness of the requirements for routine assessment, isolation and screening.

Molecular and epidemiological characterization of carbapenemase-producing Enterobacteriaceae in Norway, 2007 to 2014.

PubMed

Samuelsen, Ørjan; Overballe-Petersen, Søren; Bjørnholt, Jørgen Vildershøj; Brisse, Sylvain; Doumith, Michel; Woodford, Neil; Hopkins, Katie L; Aasnæs, Bettina; Haldorsen, Bjørg; Sundsfjord, Arnfinn

2017-01-01

The prevalence of carbapenemase-producing Enterobacteriaceae (CPE) is increasing worldwide. Here we present associated patient data and molecular, epidemiological and phenotypic characteristics of all CPE isolates in Norway from 2007 to 2014 confirmed at the Norwegian National Advisory Unit on Detection of Antimicrobial Resistance. All confirmed CPE isolates were characterized pheno- and genotypically, including by whole genome sequencing (WGS). Patient data were reviewed retrospectively. In total 59 CPE isolates were identified from 53 patients. Urine was the dominant clinical sample source (37%) and only 15% of the isolates were obtained from faecal screening. The majority of cases (62%) were directly associated with travel or hospitalization abroad, but both intra-hospital transmission and one inter-hospital outbreak were observed. The number of CPE cases/year was low (2-14 cases/year), but an increasing trend was observed. Klebsiella spp. (n = 38) and E. coli (n = 14) were the dominant species and blaKPC (n = 20), blaNDM (n = 19), blaOXA-48-like (n = 12) and blaVIM (n = 7) were the dominant carbapenemase gene families. The CPE isolates were genetically diverse except for K. pneumoniae where clonal group 258 associated with blaKPC dominated. All isolates were multidrug-resistant and a significant proportion (21%) were resistant to colistin. Interestingly, all blaOXA-48-like, and a large proportion of blaNDM-positive Klebsiella spp. (89%) and E. coli (83%) isolates were susceptible in vitro to mecillinam. Thus, mecillinam could have a role in the treatment of uncomplicated urinary tract infections caused by OXA-48- or NDM-producing E. coli or K. pneumoniae. In conclusion, the impact of CPE in Norway is still limited and mainly associated with travel abroad, reflected in the diversity of clones and carbapenemase genes.

Seven-hour fluorescence in situ hybridization technique for enumeration of Enterobacteriaceae in food and environmental water sample.

PubMed

Ootsubo, M; Shimizu, T; Tanaka, R; Sawabe, T; Tajima, K; Ezura, Y

2003-01-01

A fluorescent in situ hybridization (FISH) technique using an Enterobacteriaceae-specific probe (probe D) to target 16S rRNA was improved in order to enumerate, within a single working day, Enterobacteriaceae present in food and environmental water samples. In order to minimize the time required for the FISH procedure, each step of FISH with probe D was re-evaluated using cultured Escherichia coli. Five minutes of ethanol treatment for cell fixation and hybridization were sufficient to visualize cultured E. coli, and FISH could be performed within 1 h. Because of the difficulties in detecting low levels of bacterial cells by FISH without cultivation, a FISH technique for detecting microcolonies on membrane filters was investigated to improve the bacterial detection limit. FISH with probe D following 6 h of cultivation to grow microcolonies on a 13 mm diameter membrane filter was performed, and whole Enterobacteriaceae microcolonies on the filter were then detected and enumerated by manual epifluorescence microscopic scanning at magnification of x100 in ca 5 min. The total time for FISH with probe D following cultivation (FISHFC) was reduced to within 7 h. FISHFC can be applied to enumerate cultivable Enterobacteriaceae in food (above 100 cells g-1) and environmental water samples (above 1 cell ml-1). Cultivable Enterobacteriaceae in food and water samples were enumerated accurately within 7 h using the FISHFC method. A FISHFC method capable of evaluating Enterobacteriaceae contamination in food and environmental water within a single working day was developed.

BioCluster: tool for identification and clustering of Enterobacteriaceae based on biochemical data.

PubMed

Abdullah, Ahmed; Sabbir Alam, S M; Sultana, Munawar; Hossain, M Anwar

2015-06-01

Presumptive identification of different Enterobacteriaceae species is routinely achieved based on biochemical properties. Traditional practice includes manual comparison of each biochemical property of the unknown sample with known reference samples and inference of its identity based on the maximum similarity pattern with the known samples. This process is labor-intensive, time-consuming, error-prone, and subjective. Therefore, automation of sorting and similarity in calculation would be advantageous. Here we present a MATLAB-based graphical user interface (GUI) tool named BioCluster. This tool was designed for automated clustering and identification of Enterobacteriaceae based on biochemical test results. In this tool, we used two types of algorithms, i.e., traditional hierarchical clustering (HC) and the Improved Hierarchical Clustering (IHC), a modified algorithm that was developed specifically for the clustering and identification of Enterobacteriaceae species. IHC takes into account the variability in result of 1-47 biochemical tests within this Enterobacteriaceae family. This tool also provides different options to optimize the clustering in a user-friendly way. Using computer-generated synthetic data and some real data, we have demonstrated that BioCluster has high accuracy in clustering and identifying enterobacterial species based on biochemical test data. This tool can be freely downloaded at http://microbialgen.du.ac.bd/biocluster/. Copyright © 2015 The Authors. Production and hosting by Elsevier Ltd.. All rights reserved.

Predominance of healthcare-associated cases among episodes of community-onset bacteraemia due to extended-spectrum β-lactamase-producing Enterobacteriaceae.

PubMed

Zahar, Jean-Ralph; Lesprit, Philippe; Ruckly, Stephane; Eden, Aurelia; Hikombo, Hitoto; Bernard, Louis; Harbarth, Stephan; Timsit, Jean-François; Brun-Buisson, Christian

2017-01-01

Extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) are endemic pathogens worldwide. Infection with ESBL-PE may be associated with inadequate antibiotic therapy and a poor outcome. However, risk factors for ESBL-PE community-acquired infections are ill-defined. An observational multicentre study was performed in 50 hospitals to identify the prevalence of and risk factors for community-acquired ESBL-PE bacteraemia. All patients presenting with community-onset Enterobacteriaceae bacteraemia were recorded over a 2-month period (between June and November 2013). Risk factors and 14-day outcomes of patients were investigated. Among 682 Enterobacteriaceae bacteraemia episodes recorded, 58 (8.5%) were caused by ESBL-PE. The most frequent species isolated were Escherichia coli (537; 76.7%) and Klebsiella spp. (68; 9.7%), of which 49 (9.1%) and 8 (11.8%), respectively, were ESBL-producers. Most ESBL-PE episodes were healthcare-associated, and only 22 (38%) were apparently community-acquired. The main risk factor for community-acquired ESBL-PE bacteraemia was a prior hospital stay of ≥5 days within the past year. The overall 14-day survival was 90%; only 4 (6.9%) of 58 patients with ESBL-PE bacteraemia died. Inadequate initial antibiotic therapy was administered to 55% of patients with ESBL-PE bacteraemia but was not associated with increased 14-day mortality. Although many patients had community-onset ESBL-PE bacteraemia, almost two-thirds of the episodes were actually healthcare-associated, and true community-acquired ESBL-PE bacteraemia remains rare. In our essentially non-severely ill population, inappropriate initial therapy was not associated with a higher risk of mortality. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Detection and characterization of carbapenemase-producing Enterobacteriaceae in wounded Syrian patients admitted to hospitals in northern Israel.

PubMed

Lerner, A; Solter, E; Rachi, E; Adler, A; Rechnitzer, H; Miron, D; Krupnick, L; Sela, S; Aga, E; Ziv, Y; Peretz, A; Labay, K; Rahav, G; Geffen, Y; Hussein, K; Eluk, O; Carmeli, Y; Schwaber, M J

2016-01-01

Since 2013, four hospitals in northern Israel have been providing care for Syrian nationals, primarily those wounded in the ongoing civil war. We analyzed carbapenemase-producing Enterobacteriaceae (CPE) isolates obtained from these patients. Isolate identification was performed using the VITEK 2 system. Polymerase chain reaction (PCR) was performed for the presence of bla KPC, bla NDM, and bla OXA-48. Susceptibility testing and genotyping were performed on selected isolates. During the study period, 595 Syrian patients were hospitalized, most of them young men. Thirty-two confirmed CPE isolates were grown from cultures taken from 30 patients. All but five isolates were identified as Klebsiella pneumoniae and Escherichia coli. Nineteen isolates produced NDM and 13 produced OXA-48. Among a further 29 isolates tested, multilocus sequence typing (MLST) showed that ST278 and ST38 were the major sequence types among the NDM-producing K. pneumoniae and OXA-48-producing E. coli isolates, respectively. Most were resistant to all three carbapenems in use in Israel and to gentamicin, but susceptible to colistin and fosfomycin. The source for bacterial acquisition could not be determined; however, some patients admitted to different medical centers were found to carry the same sequence type. CPE containing bla NDM and bla OXA-48 were prevalent among Syrian wounded hospitalized patients in northern Israel. The finding of the same sequence type among patients at different medical centers implies a common, prehospital source for these patients. These findings have implications for public health throughout the region.

Germicidal Activity against Carbapenem/Colistin-Resistant Enterobacteriaceae Using a Quantitative Carrier Test Method.

PubMed

Kanamori, Hajime; Rutala, William A; Gergen, Maria F; Sickbert-Bennett, Emily E; Weber, David J

2018-05-07

Susceptibility to germicides for carbapenem/colistin-resistant Enterobacteriaceae is poorly described. We investigated the efficacy of multiple germicides against these emerging antibiotic-resistant pathogens using the disc-based quantitative carrier test method that can produce results more similar to those encountered in healthcare settings than a suspension test. Our study results demonstrated that germicides commonly used in healthcare facilities likely will be effective against carbapenem/colistin-resistant Enterobacteriaceae when used appropriately in healthcare facilities. Copyright © 2018 American Society for Microbiology.

The use of bile - esculin agar for the taxonomic classification of the family Enterobacteriaceae.

PubMed

Edberg, S C; Pittman, S; Singer, J M

1977-01-01

Bile-esculin medium has been used for many years for the presumptive identification of group D Streptococcus. The test is based on the ability of a bacterium to grow in the presence of 40% bile and produce esculinase. 2935 strains of Enterobacteriaceae were inoculated onto bile-esculin agar slants and incubated at 35 C. Esculin hydrolysis was determined after 24 and 48 hours. At 24 hours of incubation esculin hydrolysis was limited to the genera Klebsiella, Enterobacter, Serratia, and the species P. vulgaris, P. rettgeri, and C. diversus. Not all strains of these species were positive, however. All other members of the family were negative. At 48 hours of incubation 37% of E. coli gave a positive reaction; all other Enterobacteriaceae which were negative at 24 hours remained negative. Esculin hydrolysis is a valuable test for the taxonomic classification of the family Enterobacteriaceae.

In Vitro Activity of the Siderophore Cephalosporin, Cefiderocol, against a Recent Collection of Clinically Relevant Gram-Negative Bacilli from North America and Europe, Including Carbapenem-Nonsusceptible Isolates (SIDERO-WT-2014 Study).

PubMed

Hackel, Meredith A; Tsuji, Masakatsu; Yamano, Yoshinori; Echols, Roger; Karlowsky, James A; Sahm, Daniel F

2017-09-01

Cefiderocol (formerly S-649266) is an investigational siderophore cephalosporin. Iron-depleted cation-adjusted Mueller-Hinton broth (ID-CAMHB) was prepared according to the Clinical and Laboratory Standards Institute (CLSI) protocol and used to perform broth microdilution testing of cefiderocol against a 2014-2015 collection of clinical isolates of Gram-negative bacilli from North America ( n = 4,239) and Europe ( n = 4,966). The concentrations of cefiderocol inhibiting 90% of isolates tested (MIC 90 s) were 0.5 μg/ml (North America; n = 3,007) and 1 μg/ml (Europe; n = 3,080) for all isolates of Enterobacteriaceae ; 1 μg/ml (North America; n = 30) and 4 μg/ml (Europe; n = 139) for meropenem-nonsusceptible (MIC ≥ 2 μg/ml) isolates of Enterobacteriaceae ; 0.5 μg/ml for both North American ( n = 765) and European ( n = 765) isolates of Pseudomonas aeruginosa ; 0.5 μg/ml (North America; n = 151) and 1 μg/ml (Europe; n = 202) for meropenem-nonsusceptible (MIC ≥ 4 μg/ml) isolates of P. aeruginosa ; 1 μg/ml for both North American ( n = 309) and European ( n = 839) isolates of all Acinetobacter baumannii strains as well as for both North American ( n = 173) and European ( n = 595) isolates of meropenem-nonsusceptible A. baumannii ; and 0.5μg/ml (North America; n = 152) and 0.25 μg/ml (Europe; n = 276) for isolates of Stenotrophomonas maltophilia MICs of cefiderocol were ≤4 μg/ml for 99.9% (6,078/6,087) of all Enterobacteriaceae , 97.0% (164/169) of meropenem-nonsusceptible Enterobacteriaceae , 99.9% (1,529/1,530) of all P. aeruginosa isolates, 100% (353/353) of meropenem-nonsusceptible P. aeruginosa isolates, 97.6% (1,120/1,148) of all A. baumannii isolates, 96.9% (744/768) of meropenem-nonsusceptible A. baumannii isolates, 100% of isolates of S. maltophilia (428/428) and 93.8% of isolates of Burkholderia cepecia (11/12). We conclude that cefiderocol demonstrated potent in vitro activity against a recent collection of clinical isolates of commonly

Activity of Ceftazidime-Avibactam against Fluoroquinolone-Resistant Enterobacteriaceae and Pseudomonas aeruginosa

PubMed Central

Pitart, C.; Marco, F.; Keating, T. A.; Nichols, W. W.

2015-01-01

Ceftazidime-avibactam and comparator antibiotics were tested by the broth microdilution method against 200 Enterobacteriaceae and 25 Pseudomonas aeruginosa strains resistant to fluoroquinolones (including strains with the extended-spectrum β-lactamase [ESBL] phenotype and ceftazidime-resistant strains) collected from our institution. The MICs and mechanisms of resistance to fluoroquinolone were also studied. Ninety-nine percent of fluoroquinolone-resistant Enterobacteriaceae strains were inhibited at a ceftazidime-avibactam MIC of ≤4 mg/liter (using the susceptible CLSI breakpoint for ceftazidime alone as a reference). Ceftazidime-avibactam was very active against ESBL Escherichia coli (MIC90 of 0.25 mg/liter), ESBL Klebsiella pneumoniae (MIC90 of 0.5 mg/liter), ceftazidime-resistant AmpC-producing species (MIC90 of 1 mg/liter), non-ESBL E. coli (MIC90 of ≤0.125 mg/liter), non-ESBL K. pneumoniae (MIC90 of 0.25 mg/liter), and ceftazidime-nonresistant AmpC-producing species (MIC90 of ≤0.5 mg/liter). Ninety-six percent of fluoroquinolone-resistant P. aeruginosa strains were inhibited at a ceftazidime-avibactam MIC of ≤8 mg/liter (using the susceptible CLSI breakpoint for ceftazidime alone as a reference), with a MIC90 of 8 mg/liter. Additionally, fluoroquinolone-resistant mutants from each species tested were obtained in vitro from two strains, one susceptible to ceftazidime and the other a β-lactamase producer with a high MIC against ceftazidime but susceptible to ceftazidime-avibactam. Thereby, the impact of fluoroquinolone resistance on the activity of ceftazidime-avibactam could be assessed. The MIC90 values of ceftazidime-avibactam for the fluoroquinolone-resistant mutant strains of Enterobacteriaceae and P. aeruginosa were ≤4 mg/liter and ≤8 mg/liter, respectively. We conclude that the presence of fluoroquinolone resistance does not affect Enterobacteriaceae and P. aeruginosa susceptibility to ceftazidime-avibactam; that is, there is no cross

The spread of KPC-producing Enterobacteriaceae in Spain: WGS analysis of the emerging high-risk clones of Klebsiella pneumoniae ST11/KPC-2, ST101/KPC-2 and ST512/KPC-3.

PubMed

Oteo, Jesús; Pérez-Vázquez, María; Bautista, Verónica; Ortega, Adriana; Zamarrón, Pilar; Saez, David; Fernández-Romero, Sara; Lara, Noelia; Ramiro, Raquel; Aracil, Belén; Campos, José

2016-12-01

We analysed the microbiological traits and population structure of KPC-producing Enterobacteriaceae isolates collected in Spain between 2012 and 2014. We also performed a comparative WGS analysis of the three major KPC-producing Klebsiella pneumoniae clones detected. Carbapenemase and ESBL genes were sequenced. The Institut Pasteur MLST scheme was used. WGS data were used to construct phylogenetic trees, to identify the determinants of resistance and to de novo assemble the genome of one representative isolate of each of the three major K. pneumoniae clones. Of the 2443 carbapenemase-producing Enterobacteriaceae isolates identified during the study period, 111 (4.5%) produced KPC. Of these, 81 (73.0%) were K. pneumoniae and 13 (11.7%) were Enterobacter cloacae. Three major epidemic clones of K. pneumoniae were identified: ST11/KPC-2, ST101/KPC-2 and ST512/KPC-3. ST11/KPC-2 differed from ST101/KPC-2 and ST512/KPC-3 by 27 819 and 6924 SNPs, respectively. ST101/KPC-2 differed from ST512/KPC-3 by 28 345 SNPs. Nine acquired resistance genes were found in ST11/KPC-2, 11 in ST512/KPC-3 and 13 in ST101/KPC-2. ST101/KPC-2 had the highest number of virulence genes (20). An 11 bp deletion at the end of the mgrB sequence was the cause of colistin resistance in ST512/KPC-3. KPC-producing Enterobacteriaceae are increasing in Spain. Most KPC-producing K. pneumoniae isolates belonged to only five clones: ST11 and ST512 caused interregional spread, ST101 caused regional spread and ST1961 and ST678 produced independent hospital outbreaks. ST101/KPC-2 had the highest number of resistance and virulence genes. ST101/KPC-2 and ST512/KPC-3 were recently implicated in the spread of KPC in Italy. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

The spread of KPC-producing Enterobacteriaceae in Spain: WGS analysis of the emerging high-risk clones of Klebsiella pneumoniae ST11/KPC-2, ST101/KPC-2 and ST512/KPC-3

PubMed Central

Oteo, Jesús; Pérez-Vázquez, María; Bautista, Verónica; Ortega, Adriana; Zamarrón, Pilar; Saez, David; Fernández-Romero, Sara; Lara, Noelia; Ramiro, Raquel; Aracil, Belén; Campos, José

2016-01-01

Objectives We analysed the microbiological traits and population structure of KPC-producing Enterobacteriaceae isolates collected in Spain between 2012 and 2014. We also performed a comparative WGS analysis of the three major KPC-producing Klebsiella pneumoniae clones detected. Methods Carbapenemase and ESBL genes were sequenced. The Institut Pasteur MLST scheme was used. WGS data were used to construct phylogenetic trees, to identify the determinants of resistance and to de novo assemble the genome of one representative isolate of each of the three major K. pneumoniae clones. Results Of the 2443 carbapenemase-producing Enterobacteriaceae isolates identified during the study period, 111 (4.5%) produced KPC. Of these, 81 (73.0%) were K. pneumoniae and 13 (11.7%) were Enterobacter cloacae. Three major epidemic clones of K. pneumoniae were identified: ST11/KPC-2, ST101/KPC-2 and ST512/KPC-3. ST11/KPC-2 differed from ST101/KPC-2 and ST512/KPC-3 by 27 819 and 6924 SNPs, respectively. ST101/KPC-2 differed from ST512/KPC-3 by 28 345 SNPs. Nine acquired resistance genes were found in ST11/KPC-2, 11 in ST512/KPC-3 and 13 in ST101/KPC-2. ST101/KPC-2 had the highest number of virulence genes (20). An 11 bp deletion at the end of the mgrB sequence was the cause of colistin resistance in ST512/KPC-3. Conclusions KPC-producing Enterobacteriaceae are increasing in Spain. Most KPC-producing K. pneumoniae isolates belonged to only five clones: ST11 and ST512 caused interregional spread, ST101 caused regional spread and ST1961 and ST678 produced independent hospital outbreaks. ST101/KPC-2 had the highest number of resistance and virulence genes. ST101/KPC-2 and ST512/KPC-3 were recently implicated in the spread of KPC in Italy. PMID:27530752

Results of the national surveillance of antimicrobial resistance of Enterobacteriaceae and Gram negative bacilli in health care-associated infections in Colombia, 2012-2014.

PubMed

Ovalle, María Victoria; Saavedra, Sandra Yamile; González, María Nilse; Hidalgo, Andrea Melissa; Duarte, Carolina; Beltrán, Mauricio

2017-12-01

The Colombian National Antimicrobial Resistance Monitoring System for the surveillance of healthcare-associated infections was set up to meet this problem in the third quarter of 2012. To describe resistance profiles and laboratory-based surveillance based on the information collected by the System. We conducted a retrospective and descriptive study of the information notified to the Colombian Public Health Surveillance System (Sivigila), and in the Whonet databases covering the period from July 2012 to December 2014 provided by the primary data-generating units in the country, as well as laboratory surveillance results from 1,642 phenotypic and genotypic tests on carbapenemase isolates (927 from Enterobacteriaceae, 614 from Pseudomonas spp. and 101 from Acinetobacter spp.). There was a significant increase in Escherichia coli resistance to third-generation cephalosporins (reaching 26.3% in ICUs and 22.5% in other hospital wards), and Klebsiella pneumoniae resistance to ertapenem also increased (reaching 14.6% in ICUs). Acinetobacter baumannii carbapenem resistance exceeded 50% in ICUs whereas Pseudomonas aeruginosa had lower carbapenem resistance (38.8%). KPC (n = 574) and NDM (n=57) were the most frequently occurring carbapenemases in Enterobacteriaceae, VIM (n=229) and KPC (n=114) in P. aeruginosa, and OXA-23 in A. baumannii (n=87); several carbapenemase combinations were identified, KPC + VIM being the most common in Pseudomonas spp. and Enterobacteriaceae. The data from the surveillance of healthcare-associated infections revealed significant carbapenem resistance profiles and antimicrobial resistance mechanisms circulating in Colombian healthcare institutions.

Bacteremic Urinary Tract Infection Caused by Multidrug-Resistant Enterobacteriaceae Are Associated With Severe Sepsis at Admission

PubMed Central

Lee, Yi-Chien; Hsiao, Chih-Yen; Hung, Miao-Chiu; Hung, Sheng-Che; Wang, Hung-Ping; Huang, Yun-Jhong; Wang, Jann-Tay

2016-01-01

Abstract The purpose of this study is to compare the clinical features and treatment outcomes among patients with bacteremic urinary tract infection (UTI) caused by multidrug-resistant (MDR) and non-MDR Enterobacteriaceae and to identify whether MDR pathogens were independently associated with severe sepsis or septic shock at presentation. The clinical data of adult patients visiting and being treated at Chia-Yi Christian Hospital due to bacteremic UTI caused by Enterobacteriaceae from January 2006 to August 2015 were retrospectively analyzed. A total of 585 patients were enrolled. Among them, 220 (37.6%) were caused by the MDR Enterobacteriaceae. A total of 206 patients (35.2%) developed severe sepsis or septic shock at presentation. Patients in the MDR group tend to be male and have a past history of gout, recurrent UTI, prior hospitalization, hydronephrosis, renal stone, ureteral stone, indwelling urinary catheter, newly development of renal dysfunction, severe sepsis or septic shock, intensive care unit (ICU) admission, receipt of ineffective empirical therapy, longer hospital stay, and higher in-hospital mortality (2.7% vs 1.9%, P = 0.569). Using multivariate logistic regression analysis, it is revealed that independent predictors associated with severe sepsis or septic shock at presentation were liver cirrhosis (OR 2.868; 95% CI 1.439–5.716; P = 0.003), indwelling urinary catheter (OR 1.936; 95% CI 1.238–3.027; P = 0.004), and MDR Enterobacteriaceae (OR 1.447; 95% CI 1.002–2.090; P = 0.049). Multidrug resistance was associated with the development of severe sepsis or septic shock upon presentation among patients with bacteremic UTI caused by Enterobacteriaceae. Therefore, empirical antibiotics therapy for patients with UTI presented with severe sepsis and/or septic shock should be more broad-spectrum to effectively cover MDR Enterobacteriaceae. PMID:27196480

Does appropriate empiric antibiotic therapy modify intensive care unit-acquired Enterobacteriaceae bacteraemia mortality and discharge?

PubMed

Pouwels, K B; Van Kleef, E; Vansteelandt, S; Batra, R; Edgeworth, J D; Smieszek, T; Robotham, J V

2017-05-01

Conflicting results have been found regarding outcomes of intensive care unit (ICU)-acquired Enterobacteriaceae bacteraemia and the potentially modifying effect of appropriate empiric antibiotic therapy. To evaluate these associations while adjusting for potential time-varying confounding using methods from the causal inference literature. Patients who stayed more than two days in two general ICUs in England between 2002 and 2006 were included in this cohort study. Marginal structural models with inverse probability weighting were used to estimate the mortality and discharge associated with Enterobacteriaceae bacteraemia and the impact of appropriate empiric antibiotic therapy on these outcomes. Among 3411 ICU admissions, 195 (5.7%) ICU-acquired Enterobacteriaceae bacteraemia cases occurred. Enterobacteriaceae bacteraemia was associated with an increased daily risk of ICU death [cause-specific hazard ratio (HR): 1.48; 95% confidence interval (CI): 1.10-1.99] and a reduced daily risk of ICU discharge (HR: 0.66; 95% CI: 0.54-0.80). Appropriate empiric antibiotic therapy did not significantly modify ICU mortality (HR: 1.08; 95% CI: 0.59-1.97) or discharge (HR: 0.91; 95% CI: 0.63-1.32). ICU-acquired Enterobacteriaceae bacteraemia was associated with an increased daily risk of ICU mortality. Furthermore, the daily discharge rate was also lower after acquiring infection, even when adjusting for time-varying confounding using appropriate methodology. No evidence was found for a beneficial modifying effect of appropriate empiric antibiotic therapy on ICU mortality and discharge. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

The Epidemiology of Carbapenem-Resistant Enterobacteriaceae: The Impact and Evolution of a Global Menace

PubMed Central

Weinstein, Robert A.

2017-01-01

Abstract Carbapenem-resistant Enterobacteriaceae (CRE) are a serious public health threat. Infections due to these organisms are associated with significant morbidity and mortality. Mechanisms of drug resistance in gram-negative bacteria (GNB) are numerous; β-lactamase genes carried on mobile genetic elements are a key mechanism for the rapid spread of antibiotic-resistant GNB worldwide. Transmissible carbapenem-resistance in Enterobacteriaceae has been recognized for the last 2 decades, but global dissemination of carbapenemase-producing Enterobacteriaceae (CPE) is a more recent problem that, once initiated, has been occurring at an alarming pace. In this article, we discuss the evolution of CRE, with a focus on the epidemiology of the CPE pandemic; review risk factors for colonization and infection with the most common transmissible CPE worldwide, Klebsiella pneumoniae carbapenemase–producing K. pneumoniae; and present strategies used to halt the striking spread of these deadly pathogens. PMID:28375512

Survival and detection of coliforms, Enterobacteriaceae, and gram-negative bacteria in Greek yogurt.

PubMed

Hervert, C J; Martin, N H; Boor, K J; Wiedmann, M

2017-02-01

Despite the widespread use of coliforms as indicator bacteria, increasing evidence suggests that the Enterobacteriaceae (EB) and total gram-negative groups more accurately reflect the hygienic status of high-temperature, short-time pasteurized milk and processing environments. If introduced into milk as postpasteurization contamination, these bacteria may grow to high levels and produce a wide range of sensory-related defects. However, limited information is available on the use and survival of bacterial hygiene indicators in dairy products outside of pasteurized fluid milk and cheese. The goal of this study was to (1) provide information on the survival of a diverse set of bacterial hygiene indicators in the low pH environment of Greek yogurt, (2) compare traditional and alternative detection methods for their ability to detect bacterial hygiene indicators in Greek yogurt, and (3) offer insight into optimal hygiene indicator groups for use in low-pH fermented dairy products. To this end, we screened 64 bacterial isolates, representing 24 dairy-relevant genera, for survival and detection in Greek yogurt using 5 testing methods. Before testing, isolates were inoculated into plain, 0% fat Greek yogurt (pH 4.35 to 4.65), followed by a 12-h hold period at 4 ± 1°C. Yogurts were subsequently tested using Coliform Petrifilm (3M, St. Paul, MN) to detect coliforms; Enterobacteriaceae Petrifilm (3M), violet red bile glucose agar and the D-Count (bioMérieux, Marcy-l'Étoile, France) to detect EB; and crystal violet tetrazolium agar (CVTA) to detect total gram-negative bacteria. Overall, the non-EB gram-negative isolates showed significantly larger log reductions 12 h after inoculation into Greek yogurt (based on bacterial numbers recovered on CVTA) compared with the coliform and noncoliform EB isolates tested. The methods evaluated varied in their ability to detect different microbial hygiene indicators in Greek yogurt. Crystal violet tetrazolium agar detected the highest

Antibiotic sensitivity pattern in blaNDM-1-positive and carbapenemase-producing Enterobacteriaceae

PubMed Central

Mulla, Summaiya; Charan, Jaykaran; Rajdev, Sangita

2016-01-01

Background: Some studies published in recent time revealed that many bacteria from Enterobacteriaceae group are multi-antibiotic-resistant because of the production enzymes carbapenemase particularly New Delhi metallo-beta-lactamase encoded by gene called blaNDM-1. Looking at public health importance of this issue there is a need for studies at other centers to confirm or refute published findings. Objectives: This study was designed with the aim of exploring antibiotic resistance in Enterobacteriaceae group of bacteria and also to explore gene and enzyme responsible for it. Materials and Methods: Samples of Enterobacteriaceae were collected from wards and outpatient departments. Antibiotic sensitivity was checked by an automated system (VITEK 2 COMPACT). Carbapenemase production was assessed by Modified Hodge Test. Presence of blaNDM-1 was assessed by polymerase chain reaction. Statistics: Frequency and percentage were used to describe the data. Frequency of sensitivity was compared between carbapenemase producers and noncarbapenemase producers by Fisher's exact test. Results: Forty-seven percent bacteria were found to be producing carbapenemase enzyme. These bacteria were significantly less sensitive to cefoperazone, cefepime, and amikacin. Among carbapenemase-producing organisms, 3% and 6% were resistant to tigecycline and colistin, respectively. Forty percent bacteria were found to be having blaNDM-1 gene. There was a significant difference between blaNDM-1-positive and blaNDM-1-negative for sensitivity toward cefoperazone + sulbactam, imipenem, meropenem, amikacin, tobramycine, ciprofloxacin, and levofloxacin. Conclusion: Presence of carbapenemase enzyme and blaNDM-1 gene is associated with high level of resistance in Enterobacteriaceae group of bacteria and only few antibiotics have good sensitivity for these organisms. PMID:26958516

Antibiotic-Resistant Extended Spectrum ß-Lactamase- and Plasmid-Mediated AmpC-Producing Enterobacteriaceae Isolated from Retail Food Products and the Pearl River in Guangzhou, China

PubMed Central

Ye, Qinghua; Wu, Qingping; Zhang, Shuhong; Zhang, Jumei; Yang, Guangzhu; Wang, Huixian; Huang, Jiahui; Chen, Mongtong; Xue, Liang; Wang, Juan

2017-01-01

We conducted a survey in 2015 to evaluate the presence of extended spectrum β-lactamase (ESBL)- and plasmid-mediated AmpC-producing Enterobacteriaceae in retail food and water of the Pearl River in Guangzhou, China, as well as their antibiotic resistance profiles. Samples (88 fresh food samples and 43 water samples) from eight different districts were analyzed by direct plating and after enrichment. Multidrug-resistant strains were found in 41.7 and 43.4% of food and water samples, respectively. ESBLs were found in 3.4 and 11.6% of food and water samples, respectively, and AmpC producers were found in 13.6 and 16.3% of food and water samples, respectively. Molecular characterization revealed the domination of blaCTX−Mgenes; plasmidic AmpC was of the type DHA-1 both in food and water samples. Thirteen of Fifty one β-lactamase-producing positive isolates were detected to be transconjugants, which readily received the β-lactamase genes conferring resistance to β-lactam antibiotics as well as some non-β-lactam antibiotics. These findings provide evidence that retail food and the river water may be considered as reservoirs for the dissemination of β-lactam antibiotics, and these resistance genes could readily be transmitted to humans through the food chain and water. PMID:28217112

[Metallo-beta-lactamase-mediated resistance among carbapenem-resistant Pseudomonas aeruginosa clinical isolates].

PubMed

Mereuţă, Ana Irina; Tuchiluş, Cristina; Bădescu, Aida Corina; Iancu, Luminiţa Smaranda

2011-01-01

The aim of our study was to evaluate the antimicrobial susceptibility profile and the presence of metallo-beta-lactamases (MBLs) among carbapenem-resistant Pseudomonas aeruginosa clinical isolates. A total of 84 P. aeruginosa clinical isolates collected between January 2007- February 2011 from four university hospitals in Iasi (North-East region of Romania) were randomly selected. Antimicrobial susceptibility testing was performed according to CLSI 2010 (Clinical and Laboratory Standards Institute) guidelines. The isolates were tested for MBLs using EPI (EDTA-phenanthroline-imipenem) phenotypic test and polymerase chain reaction (PCR) for bla(VIM) and bla(IMP). Fifty-eight carbapenem resistant strains were identified, from which 24 (41,3%) were positive for VIM-type MBLs. No IMP - type MBL was detected. All MBL-producing isolates displayed a MDR (multidrug resistant) phenotype, two of them were XDR (extensively drug-resistant). Colistin remained the most effective antibiotic. The high proportion of MBL producing P. aeruginosa clinical isolates urges the need for a better use of antibiotics and for efficient infection control measures to prevent dissemination of MBL producers. This is the first report of VIM-like enzymes in P. aeruginosa isolates from the Iasi area.

In vitro activity of doripenem, a carbapenem for the treatment of challenging infections caused by gram-negative bacteria, against recent clinical isolates from the United States.

PubMed

Pillar, Chris M; Torres, Mohana K; Brown, Nina P; Shah, Dineshchandra; Sahm, Daniel F

2008-12-01

Doripenem, a 1beta-methylcarbapenem, is a broad-spectrum antibiotic approved for the treatment of complicated urinary tract and complicated intra-abdominal infections. An indication for hospital-acquired pneumonia including ventilator-associated pneumonia is pending. The current study examined the activity of doripenem against recent clinical isolates for the purposes of its ongoing clinical development and future longitudinal analysis. Doripenem and comparators were tested against 12,581 U.S. clinical isolates collected between 2005 and 2006 including isolates of Staphylococcus aureus, coagulase-negative staphylococci, Streptococcus pneumoniae, Enterobacteriaceae, Pseudomonas aeruginosa, and Acinetobacter spp. MICs (microg/ml) were established by broth microdilution. By MIC(90), doripenem was comparable to imipenem and meropenem in activity against S. aureus (methicillin susceptible, 0.06; resistant, 8) and S. pneumoniae (penicillin susceptible, < or =0.015; resistant, 1). Against ceftazidime-susceptible Enterobacteriaceae, the MIC(90) of doripenem (0.12) was comparable to that of meropenem (0.12) and superior to that of imipenem (2), though susceptibility of isolates exceeded 99% for all evaluated carbapenems. The activity of doripenem was not notably altered against ceftazidime-nonsusceptible or extended-spectrum beta-lactamase screen-positive Enterobacteriaceae. Doripenem was the most potent carbapenem tested against P. aeruginosa (MIC(90)/% susceptibility [%S]: ceftazidime susceptible = 2/92%S, nonsusceptible = 16/61%S; imipenem susceptible = 1/98.5%S, nonsusceptible = 8/56%S). Against imipenem-susceptible Acinetobacter spp., doripenem (MIC(90) = 2, 89.1%S) was twice as active by MIC(90) as were imipenem and meropenem. Overall, doripenem potency was comparable to those of meropenem and imipenem against gram-positive cocci and doripenem was equal or superior in activity to meropenem and imipenem against Enterobacteriaceae, including beta

Broad-spectrum β-lactamases among Enterobacteriaceae of animal origin: molecular aspects, mobility and impact on public health.

PubMed

Smet, Annemieke; Martel, An; Persoons, Davy; Dewulf, Jeroen; Heyndrickx, Marc; Herman, Lieve; Haesebrouck, Freddy; Butaye, Patrick

2010-05-01

Broad-spectrum β-lactamase genes (coding for extended-spectrum β-lactamases and AmpC β-lactamases) have been frequently demonstrated in the microbiota of food-producing animals. This may pose a human health hazard as these genes may be present in zoonotic bacteria, which would cause a direct problem. They can also be present in commensals, which may act as a reservoir of resistance genes for pathogens causing disease both in humans and in animals. Broad-spectrum β-lactamase genes are frequently located on mobile genetic elements, such as plasmids, transposons and integrons, which often also carry additional resistance genes. This could limit treatment options for infections caused by broad-spectrum β-lactam-resistant microorganisms. This review addresses the growing burden of broad-spectrum β-lactam resistance among Enterobacteriaceae isolated from food, companion and wild animals worldwide. To explore the human health hazard, the diversity of broad-spectrum β-lactamases among Enterobacteriaceae derived from animals is compared with respect to their presence in human bacteria. Furthermore, the possibilities of the exchange of genes encoding broad-spectrum β-lactamases - including the exchange of the transposons and plasmids that serve as vehicles for these genes - between different ecosystems (human and animal) are discussed. © 2009 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Detection and Whole-Genome Sequencing of Carbapenemase-Producing Aeromonas hydrophila Isolates from Routine Perirectal Surveillance Culture

PubMed Central

Hughes, Heather Y.; Lau, Anna F.; Dekker, John P.; Michelin, Angela V.; Youn, Jung-Ho; Henderson, David K.; Frank, Karen M.; Segre, Julia A.

2016-01-01

Perirectal surveillance cultures and a stool culture grew Aeromonas species from three patients over a 6-week period and were without epidemiological links. Detection of the blaKPC-2 gene in one isolate prompted inclusion of non-Enterobacteriaceae in our surveillance culture workup. Whole-genome sequencing confirmed that the isolates were unrelated and provided data for Aeromonas reference genomes. PMID:26888898

A Rapid Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry-Based Method for Single-Plasmid Tracking in an Outbreak of Carbapenem-Resistant Enterobacteriaceae

PubMed Central

Lau, Anna F.; Wang, Honghui; Weingarten, Rebecca A.; Drake, Steven K.; Suffredini, Anthony F.; Garfield, Mark K.; Chen, Yong; Gucek, Marjan; Youn, Jung-Ho; Stock, Frida; Tso, Hanna; DeLeo, Jim; Cimino, James J.; Frank, Karen M.

2014-01-01

Carbapenem-resistant Enterobacteriaceae (CRE) have spread globally and represent a serious and growing threat to public health. Rapid methods for tracking plasmids carrying carbapenemase genes could greatly benefit infection control efforts. Here, we demonstrate that real-time, direct tracking of a single plasmid in a bacterial strain responsible for an outbreak is possible using a commercial matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) system. In this case, we retrospectively tracked the blaKPC carbapenemase gene-bearing pKpQIL plasmid responsible for a CRE outbreak that occurred at the NIH Clinical Center in 2011. An ∼11,109-Da MS peak corresponding to a gene product of the blaKPC pKpQIL plasmid was identified and characterized using a combination of proteomics and molecular techniques. This plasmid peak was present in spectra from retrospectively analyzed K. pneumoniae outbreak isolates, concordant with results from whole-genome sequencing, and absent from a diverse control set of blaKPC-negative clinical Enterobacteriaceae isolates. Notably, the gene characterized here is located adjacent to the blaKPC Tn4401 transposon on the pKpQIL plasmid. Sequence analysis demonstrates the presence of this gene in other blaKPC Tn4401-containing plasmids and suggests that this signature MS peak may be useful in tracking other plasmids conferring carbapenem resistance. Plasmid identification using this MALDI-TOF MS method was accomplished in as little as 10 min from isolated colonies and 30 min from positive (spiked) blood cultures, demonstrating the potential clinical utility for real-time plasmid tracking in an outbreak. PMID:24850353

First report of plasmid-mediated quinolone resistance qnrA1 gene in Klebsiella pneumoniae isolate of animal origin.

PubMed

Yue, Lei; Chen, Xueying; Li, Shujuan; Liao, Xiaoping; Zhuang, Na; Zhang, Yue; Liu, Ya-Hong

2011-04-01

One QnrA1-producing Klebsiella pneumoniae isolate GDKA1 from chicken was detected. The qnrA1 gene on plasmid pGDKA1 was located in a genetic environment similar to that in In36 on plasmid pHSH1 and could be cotransferred to Escherichia coli J53 Az(R) with other resistances by a conjugation experiment. Upstream of the qnrA1 gene, there was a class I integron with the dfrA27 and aadA2 cassettes. Similar genetic environments of qnrA1 in Enterobacteriaceae isolates from both human and animal origin might, to some extent, demonstrate similar mechanisms of qnrA distribution. The presence of qnrA1 in health animal commensal bacteria should be worthy of note. This is the first report of qnrA1 in K. pneumoniae and dfrA27 in an Enterobacteriaceae isolate of animal origin. © Mary Ann Liebert, Inc.

Multiresistant Bacteria Isolated from Chicken Meat in Austria

PubMed Central

Zarfel, Gernot; Galler, Herbert; Luxner, Josefa; Petternel, Christian; Reinthaler, Franz F.; Haas, Doris; Kittinger, Clemens; Grisold, Andrea J.; Pless, Peter; Feierl, Gebhard

2014-01-01

Multidrug resistant bacteria (MDR bacteria), such as extended spectrum beta-lactamase (ESBL) Enterobacteriaceae, methicillin resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococci (VRE), pose a challenge to the human health care system. In recent years, these MDR bacteria have been detected increasingly outside the hospital environment. Also the contamination of food with MDR bacteria, particularly of meat and meat products, is a concern. The aim of the study was to evaluate the occurrence of MDR bacteria in chicken meat on the Austrian market. For this study, 50 chicken meat samples were analysed. All samples originated from chickens slaughtered in Austrian slaughterhouses and were marked as produced in Austria. Samples were analysed for the presence of ESBL Enterobacteriaceae, methicillin resistant Staphylococci and VRE. Resistance genes of the isolated bacteria were characterised by PCR and sequencing. In the present study 26 ESBL producing E. coli, five mecA gene harbouring Staphylococci (but no MRSA), and four VRE were detected in chicken meat samples of Austrian origin. In 24 (48%) of the samples no ESBL Enterobacteriaceae, MRSA, methicillin resistant coagulase negative Staphylococcus (MRCNS) or VRE could be detected. None of the samples contained all three types of investigated multiresistant bacteria. In concordance to previous studies, CTX-M-1 and SHV-12 were the dominant ESBL genes. PMID:25485979

Evolution of ribosomal proteins in Enterobacteriaceae.

PubMed Central

Hori, H; Osawa, S

1978-01-01

The evolution of ribosomal proteins of about 70 bacterial strains belonging to the family Enterobacteriaceae has been studied by use of previously reported data (S. Osawa, T. Itoh, and E. Otaka, J. Bacteriol. 107:168-178, 1971) and those obtained in this paper. The proximity of the bacteria was quantified by co-chromatographing the differentially labeled ribosomal proteins from two strains on a column of carboxymethyl cellulose in various combinations. The were then classified into 12 groups (=species?) according to their ribosomal protein compositions and were placed in a phylogenic tree. PMID:346556

Performance evaluation of three automated identification systems in detecting carbapenem-resistant Enterobacteriaceae.

PubMed

He, Qingwen; Chen, Weiyuan; Huang, Liya; Lin, Qili; Zhang, Jingling; Liu, Rui; Li, Bin

2016-06-21

Carbapenem-resistant Enterobacteriaceae (CRE) is prevalent around the world. Rapid and accurate detection of CRE is urgently needed to provide effective treatment. Automated identification systems have been widely used in clinical microbiology laboratories for rapid and high-efficient identification of pathogenic bacteria. However, critical evaluation and comparison are needed to determine the specificity and accuracy of different systems. The aim of this study was to evaluate the performance of three commonly used automated identification systems on the detection of CRE. A total of 81 non-repetitive clinical CRE isolates were collected from August 2011 to August 2012 in a Chinese university hospital, and all the isolates were confirmed to be resistant to carbapenems by the agar dilution method. The potential presence of carbapenemase genotypes of the 81 isolates was detected by PCR and sequencing. Using 81 clinical CRE isolates, we evaluated and compared the performance of three automated identification systems, MicroScan WalkAway 96 Plus, Phoenix 100, and Vitek 2 Compact, which are commonly used in China. To identify CRE, the comparator methodology was agar dilution method, while the PCR and sequencing was the comparator one to identify CPE. PCR and sequencing analysis showed that 48 of the 81 CRE isolates carried carbapenemase genes, including 23 (28.4 %) IMP-4, 14 (17.3 %) IMP-8, 5 (6.2 %) NDM-1, and 8 (9.9 %) KPC-2. Notably, one Klebsiella pneumoniae isolate produced both IMP-4 and NDM-1. One Klebsiella oxytoca isolate produced both KPC-2 and IMP-8. Of the 81 clinical CRE isolates, 56 (69.1 %), 33 (40.7 %) and 77 (95.1 %) were identified as CRE by MicroScan WalkAway 96 Plus, Phoenix 100, and Vitek 2 Compact, respectively. The sensitivities/specificities of MicroScan WalkAway, Phoenix 100 and Vitek 2 were 93.8/42.4 %, 54.2/66.7 %, and 75.0/36.4 %, respectively. The MicroScan WalkAway and Viteck2 systems are more reliable in clinical identification of

Comparison of the treatment efficacy between tigecycline plus high-dose cefoperazone-sulbactam and tigecycline monotherapy against ventilator-associated pneumonia caused by extensively drug-resistant Acinetobacter baumannii.

PubMed

Qin, Youfa; Zhang, Jie; Wu, Lei; Zhang, Dailong; Fu, Lunjiao; Xue, Xiaoyan

2018-03-01

The present study examined the effect of high-dose cefoperazone-sulbactam combined with tigecycline against ventilator-associated pneumonia (VAP) caused by extensively drug-resistant Acinetobacter baumannii(XDR-AB). 42 patients with VAP due to XDR-AB infection were randomized into two groups: the TIG group (received tigecycline injection) and the TIG+CFS group (received tigecycline and cefoperazone-sulbactam (1 : 1) injection). Pulsed field gel electrophoresis (PFGE) was used for genotyping the isolated XDR-AB. The microdilution method was used to test the minimum inhibitory concentration (MIC) of cefoperazone-sulbactam or tigecycline in vitro and the combined effect was determined with the checkerboard method. The total combined effectiveness rate (including all patients who demonstrated an improved condition) was significantly higher in the TIG+CFS group (85.7%) compared with the TIG group (47.6%) (p = 0.010). No significant differences were noted with regard to the adverse reactions between the two groups. The 42 isolated XDR-AB strains were classified into four types. The MIC of the two drugs in combination was significantly lower than that of each drug used alone (p < 0.05). High dose of cefoperazone-sulbactam can improve the antimicrobial activity of tigecycline against XDR-AB.
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From multidrug-resistant to extensively drug-resistant tuberculosis in Lisbon, Portugal: the stepwise mode of resistance acquisition.

PubMed

Perdigão, João; Macedo, Rita; Silva, Carla; Machado, Diana; Couto, Isabel; Viveiros, Miguel; Jordao, Luisa; Portugal, Isabel

2013-01-01

The development and transmission of extensively drug-resistant (XDR) tuberculosis (TB) constitutes a serious threat to the effective control of TB in several countries. Here, in an attempt to further elucidate the dynamics of the acquisition of resistance to second-line drugs and investigate an eventual role for eis promoter mutations in aminoglycoside resistance, we have studied a set of multidrug-resistant (MDR)/XDR-TB isolates circulating in Lisbon, Portugal. Forty-four MDR-TB or XDR-TB isolates were genotyped and screened for mutations in genes associated with second-line drug resistance, namely tlyA, gyrA, rrs and eis. The most prevalent mutations found in each gene were Ins755GT in tlyA, A1401G in rrs, G-10A in eis and S91P in gyrA. Additionally, two genetic clusters were found in this study: Lisboa3 and Q1. The characteristic mutational profile found among recent XDR-TB circulating in Lisbon was also found in MDR-TB strains isolated in the 1990s. Also investigated was the resistance level conferred by eis G-10A mutations, revealing that eis G-10A mutations may result in amikacin resistance undetectable by widely used phenotypic assays. The analysis of the distribution of the mutations found by genetic clustering showed that in the Q1 cluster, two mutations, gyrA D94A and rrs A1401G, were enough to ensure development of XDR-TB from an MDR strain. Moreover, in the Lisboa3 cluster it was possible to elaborate a model in which the development of low-level kanamycin resistance was at the origin of the emergence of XDR-TB strains that can be discriminated by tlyA mutations.

Invitro activity of imipenem-relebactam against gram-negative bacilli isolated from patients with lower respiratory tract infections in the United States in 2015 - Results from the SMART global surveillance program.

PubMed

Lob, Sibylle H; Hackel, Meredith A; Kazmierczak, Krystyna M; Hoban, Daryl J; Young, Katherine; Motyl, Mary R; Karlowsky, James A; Sahm, Daniel F

2017-06-01

The β-lactamase inhibitor relebactam inactivates class A β-lactamases, including KPC-type carbapenemases, and class C β-lactamases. Relebactam combined with imipenem is in clinical development for several indications, including hospital-acquired and ventilator-associated pneumonia. Employing CLSI-defined broth microdilution methodology, we evaluated the activities of imipenem-relebactam (using imipenem MIC breakpoints) and comparators against non-Proteeae Enterobacteriaceae (n=853) and Pseudomonas aeruginosa (n=598) isolated from lower respiratory tract infection samples in 20 hospital laboratories in the United States participating in the 2015 SMART (Study for Monitoring Antimicrobial Resistance Trends) global surveillance program. Imipenem-relebactam and imipenem susceptibilities were 97.2% and 91.6% for non-Proteeae Enterobacteriaceae and 93.1% and 68.1% for P. aeruginosa. Relebactam restored imipenem susceptibility to 66.7% and 78.5% of imipenem-non-susceptible non-Proteeae Enterobacteriaceae isolates (n=72) and P. aeruginosa (n=191), respectively. Further development of imipenem-relebactam as therapy for lower respiratory tract infections is warranted given relebactam's ability to restore activity to imipenem against non-susceptible non-Proteeae Enterobacteriaceae and P. aeruginosa. Copyright © 2017 Elsevier Inc. All rights reserved.

Antimicrobial resistance in Enterobacteriaceae in Brazil: focus on β-lactams and polymyxins.

PubMed

Sampaio, Jorge Luiz Mello; Gales, Ana Cristina

2016-12-01

During the last 30 years there has been a dissemination of plasmid-mediated β-lactamases in Enterobacteriaceae in Brazil. Extended spectrum β-lactamases (ESBL) are widely disseminated in the hospital setting and are detected in a lower frequency in the community setting. Cefotaximases are the most frequently detected ESBL type and Klebsiella pneumoniae is the predominant species among ESBL producers. Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae became widely disseminated in Brazil during the last decade and KPC production is currently the most frequent resistance mechanism (96.2%) in carbapenem resistant K. pneumoniae. To date KPC-2 is the only variant reported in Brazil. Polymyxin B resistance in KPC-2-producing K. pneumoniae has come to an alarming rate of 27.1% in 2015 in São Paulo, the largest city in Brazil. New Delhi metallo-β-lactamase was detected in Brazil in 2013, has been reported in different Brazilian states but are not widely disseminated. Antimicrobial resistance in Enterobacteriaceae in Brazil is a very serious problem that needs urgent actions which includes both more strict adherence to infection control measures and more judicious use of antimicrobials. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Molecular characterization of multidrug-resistant Mycobacterium tuberculosis isolates from high prevalence tuberculosis states in Mexico.

PubMed

Juarez-Eusebio, Dulce Maria; Munro-Rojas, Daniela; Muñiz-Salazar, Raquel; Laniado-Laborín, Rafael; Martinez-Guarneros, Jose Armando; Flores-López, Carlos A; Zenteno-Cuevas, Roberto

2017-11-01

Mexico is one of the most important contributors of multidrug resistance tuberculosis (MDR-TB) in Latin-America, however little is known about the molecular characteristics of these strains. For this reason, the objective of this work was to determine the genotype and characterize polymorphisms in genes associated with resistance to rifampicin, isoniazid, and second-line drugs in isolates from two regions of Mexico with high prevalence of drug resistant tuberculosis. Clinical isolates from individuals with confirmed MDR-TB were genotyped using MIRU-VNTR 12 loci. To characterize the polymorphisms in genes associated with resistance to rifampicin, isoniazid and second-line drugs; rpoB, katG, inhA, rrs, eis, gyrA, gyrB and tlyA were sequenced. 22 (41%) of the 54 MDR-TB isolates recovered were from the state of Baja California, while 32 (59%) were from Veracruz. The results show the katGS315T mutation was observed in 20% (11/54) of the isolates, while rpoBS315L was present in 33% (18/54). rrs had three polymorphisms (T1239C, ntA1401C and ntA1401G), gyrB presented no modifications, whereas gyrA showed five (S95T, F60Y, A90V, S91P and P124A), eis two (G-10A and A431G) and tlyA one (insertion at codon 67). Only 20% (11/54) of isolates were confirmed as MDR-TB by sequencing, and no mutations at any of the genes sequenced were observed in 43% (23/54) of the strains. Two isolates were recognized with the proper set of mutations like pre-XDR and one was XDR-TB. Eighteen isolates were classified as orphans and the remaining thirty-six were distributed in fourteen lineages, the most frequent were S (11%), Haarlem (9%), Ghana (9%) and LAM (7%). Out of the fourteen clusters identified, seven included unknown genotypes and nine had lineages. This is one of the most detailed analyses of genotypic characteristics and mutations associated with drug resistance to first and second-line drugs in MDR-TB isolates from Mexico. An important genetic variability and significant discrepancy

High Prevalence of Faecal Carriage of ESBL-Producing Enterobacteriaceae among Children in Dar es Salaam, Tanzania.

PubMed

Tellevik, Marit G; Blomberg, Bjørn; Kommedal, Øyvind; Maselle, Samuel Y; Langeland, Nina; Moyo, Sabrina J

2016-01-01

Faecal carriage of ESBL-producing bacteria is a potential risk for transmission and infection. Little is known about faecal carriage of antibiotic resistance in Tanzania. This study aimed to investigate the prevalence of faecal carriage of ESBL-producing Enterobacteriaceae and to identify risk factors for carriage among young children in Tanzania. From August 2010 to July 2011, children below 2 years of age were recruited in Dar es Salaam, including healthy community children (n = 250) and children hospitalized due to diarrhoea (n = 250) or other diseases (n = 103). ChromID ESBL agar and ChromID CARBA SMART agar were used for screening. Antimicrobial susceptibility testing was performed by the disk diffusion method. ESBL genotypes were identified by Real-Time PCR and sequencing. The overall prevalence of ESBL carriage was 34.3% (207/ 603). The prevalence of ESBL carriage was significantly higher among hospitalized children (50.4%), compared to community children (11.6%; P < 0.001; OR = 7.75; 95% CI: 4.99-12.03). We found high prevalence of Multidrug-resistance (94%) among Escherichia coli and Klebsiella pneumoniae isolates. No resistance to carbapenems was detected. For the majority of isolates (94.7%) we detected a blaCTX-M-15-like gene. In addition, the plasmid mediated AmpC beta-lactamase CMY-2 was detected for the first time in Tanzania. ESBL prevalence was significantly higher among HIV positive (89.7%) than HIV negative (16.9%) children (P = 0.001; OR = 9.99; 95% CI: 2.52-39.57). Use of antibiotics during the past 14 days and age below 1 year was also associated with ESBL carriage. We report a high rate of faecal carriage of ESBL-producing Enterobacteriaceae among children below 2 years of age in Tanzania, particularly those with HIV-infection. Resistance to a majority of the available antimicrobials commonly used for children in Tanzania leaves few treatment options for infections when caused by these bacteria.

Alimentary Tract Bacteria Isolated and Identified with API-20E and Molecular Cloning Techniques from Australian Tropical Fruit Flies, Bactrocera cacuminata and B. tryoni

PubMed Central

Thaochan, N.; Drew, R. A. I.; Hughes, J. M.; Vijaysegaran, S.; Chinajariyawong, A.

2010-01-01

Bacteria were isolated from the crop and midgut of field collected Bactrocera cacuminata (Hering) and Bactrocera tryoni (Froggatt) (Diptera: Tephritidae). Two methods were used, firstly isolation onto two types of bacteriological culture media (PYEA and TSA) and identification using the API-20E diagnostic kit, and secondly, analysis of samples using the 16S rRNA gene molecular diagnostic method. Using the API-20E method, 10 genera and 17 species of bacteria in the family Enterobacteriaceae were identified from cultures growing on the nutrient agar. The dominant species in both the crop and midgut were Citrobacter freundii, Enterobacter cloacae and Klebsiella oxytoca. Providencia rettgeri, Klebsiella pneumoniae ssp ozaenae and Serratia marcescens were isolated from B. tryoni only. Using the molecular cloning technique that is based on 16S rRNA gene sequences, five bacteria classes were dignosed — Alpha-, Beta-, Gamma- and Delta- Proteobacteria and Firmicutes — including five families, Leuconostocaceae, Enterococcaceae, Acetobacteriaceae, Comamonadaceae and Enterobacteriaceae. The bacteria affiliated with Firmicutes were found mainly in the crop while the Gammaproteobacteria, especially the family Enterobacteriaceae, was dominant in the midgut. This paper presents results from the first known application of molecular cloning techniques to study bacteria within tephritid species and the first record of Firmicutes bacteria in these flies. PMID:20883132

In Vitro Activity of the Siderophore Cephalosporin, Cefiderocol, against Carbapenem-Nonsusceptible and Multidrug-Resistant Isolates of Gram-Negative Bacilli Collected Worldwide in 2014 to 2016.

PubMed

Hackel, Meredith A; Tsuji, Masakatsu; Yamano, Yoshinori; Echols, Roger; Karlowsky, James A; Sahm, Daniel F

2018-02-01

The in vitro activity of the investigational siderophore cephalosporin, cefiderocol (formerly S-649266), was determined against a 2014-2016, 52-country, worldwide collection of clinical isolates of carbapenem-nonsusceptible Enterobacteriaceae ( n = 1,022), multidrug-resistant (MDR) Acinetobacter baumannii ( n = 368), MDR Pseudomonas aeruginosa ( n = 262), Stenotrophomonas maltophilia ( n = 217), and Burkholderia cepacia ( n = 4) using the Clinical and Laboratory Standards Institute (CLSI) standard broth microdilution method. Iron-depleted cation-adjusted Mueller-Hinton broth (ID-CAMHB), prepared according to a recently approved (2017), but not yet published, CLSI protocol, was used to test cefiderocol; all other antimicrobial agents were tested using CAMHB. The concentration of cefiderocol inhibiting 90% (MIC 90 ) of isolates of carbapenem-nonsusceptible Enterobacteriaceae was 4 μg/ml; cefiderocol MICs ranged from 0.004 to 32 μg/ml, and 97.0% (991/1,022) of isolates demonstrated cefiderocol MICs of ≤4 μg/ml. The MIC 90 s for cefiderocol for MDR A. baumannii , MDR P. aeruginosa , and S. maltophilia were 8, 1, and 0.25 μg/ml, respectively, with 89.7% (330/368), 99.2% (260/262), and 100% (217/217) of isolates demonstrating cefiderocol MICs of ≤4 μg/ml. Cefiderocol MICs for B. cepacia ranged from 0.004 to 8 μg/ml. We conclude that cefiderocol demonstrated potent in vitro activity against a 2014-2016, worldwide collection of clinical isolates of carbapenem-nonsusceptible Enterobacteriaceae , MDR A. baumannii , MDR P. aeruginosa , S. maltophilia , and B. cepacia isolates as 96.2% of all (1,801/1,873) isolates tested had cefiderocol MICs of ≤4 μg/ml. Copyright © 2018 Hackel et al.

Efficient Detection of Carbapenemase Activity in Enterobacteriaceae by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry in Less Than 30 Minutes.

PubMed

Lasserre, Camille; De Saint Martin, Luc; Cuzon, Gaelle; Bogaerts, Pierre; Lamar, Estelle; Glupczynski, Youri; Naas, Thierry; Tandé, Didier

2015-07-01

The recognition of carbapenemase-producing Enterobacteriaceae (CPE) isolates is a major laboratory challenge, and their inappropriate or delayed detection may have negative impacts on patient management and on the implementation of infection control measures. We describe here a matrix-assisted laser desorption ionization-time of flight (MALDI-TOF)-based method to detect carbapenemase activity in Enterobacteriaceae. After a 20-min incubation of the isolate with 0.5 mg/ml imipenem at 37°C, supernatants were analyzed by MALDI-TOF in order to identify peaks corresponding to imipenem (300 Da) and an imipenem metabolite (254 Da). A total of 223 strains, 77 CPE (OXA-48 variants, KPC, NDM, VIM, IMI, IMP, and NMC-A) and 146 non-CPE (cephalosporinases, extended-spectrum β-lactamases [ESBLs], and porin defects), were tested and used to calculate a ratio of imipenem hydrolysis: mass spectrometry [MS] ratio = metabolite/(imipenem + metabolite). An MS ratio cutoff was statistically determined to classify strains as carbapenemase producers (MS ratio of ≥0.82). We validated this method first by testing 30 of our 223 isolates (15 CPE and 15 non-CPE) 10 times to calculate an intraclass correlation coefficient (ICC of 0.98), showing the excellent repeatability of the method. Second, 43 strains (25 CPE and 18 non-CPE) different from the 223 strains used to calculate the ratio cutoff were used as external controls and blind tested. They yielded sensitivity and specificity of 100%. The total cost per test is <0.10 U.S. dollars (USD). This easy-to-perform assay is time-saving, cost-efficient, and highly reliable and might be used in any routine laboratory, given the availability of mass spectrometry, to detect CPE. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

The Epidemiology of Carbapenem-Resistant Enterobacteriaceae: The Impact and Evolution of a Global Menace.

PubMed

Logan, Latania K; Weinstein, Robert A

2017-02-15

Carbapenem-resistant Enterobacteriaceae (CRE) are a serious public health threat. Infections due to these organisms are associated with significant morbidity and mortality. Mechanisms of drug resistance in gram-negative bacteria (GNB) are numerous; β-lactamase genes carried on mobile genetic elements are a key mechanism for the rapid spread of antibiotic-resistant GNB worldwide. Transmissible carbapenem-resistance in Enterobacteriaceae has been recognized for the last 2 decades, but global dissemination of carbapenemase-producing Enterobacteriaceae (CPE) is a more recent problem that, once initiated, has been occurring at an alarming pace. In this article, we discuss the evolution of CRE, with a focus on the epidemiology of the CPE pandemic; review risk factors for colonization and infection with the most common transmissible CPE worldwide, Klebsiella pneumoniae carbapenemase-producing K. pneumoniae; and present strategies used to halt the striking spread of these deadly pathogens. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

A rapid matrix-assisted laser desorption ionization-time of flight mass spectrometry-based method for single-plasmid tracking in an outbreak of carbapenem-resistant Enterobacteriaceae.

PubMed

Lau, Anna F; Wang, Honghui; Weingarten, Rebecca A; Drake, Steven K; Suffredini, Anthony F; Garfield, Mark K; Chen, Yong; Gucek, Marjan; Youn, Jung-Ho; Stock, Frida; Tso, Hanna; DeLeo, Jim; Cimino, James J; Frank, Karen M; Dekker, John P

2014-08-01

Carbapenem-resistant Enterobacteriaceae (CRE) have spread globally and represent a serious and growing threat to public health. Rapid methods for tracking plasmids carrying carbapenemase genes could greatly benefit infection control efforts. Here, we demonstrate that real-time, direct tracking of a single plasmid in a bacterial strain responsible for an outbreak is possible using a commercial matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) system. In this case, we retrospectively tracked the bla(KPC) carbapenemase gene-bearing pKpQIL plasmid responsible for a CRE outbreak that occurred at the NIH Clinical Center in 2011. An ∼ 11,109-Da MS peak corresponding to a gene product of the bla(KPC) pKpQIL plasmid was identified and characterized using a combination of proteomics and molecular techniques. This plasmid peak was present in spectra from retrospectively analyzed K. pneumoniae outbreak isolates, concordant with results from whole-genome sequencing, and absent from a diverse control set of bla(KPC)-negative clinical Enterobacteriaceae isolates. Notably, the gene characterized here is located adjacent to the bla(KPC) Tn4401 transposon on the pKpQIL plasmid. Sequence analysis demonstrates the presence of this gene in other bla(KPC) Tn4401-containing plasmids and suggests that this signature MS peak may be useful in tracking other plasmids conferring carbapenem resistance. Plasmid identification using this MALDI-TOF MS method was accomplished in as little as 10 min from isolated colonies and 30 min from positive (spiked) blood cultures, demonstrating the potential clinical utility for real-time plasmid tracking in an outbreak. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Piperacillin-Tazobactam versus Other Antibacterial Agents for Treatment of Bloodstream Infections Due to AmpC β-Lactamase-Producing Enterobacteriaceae.

PubMed

Cheng, Lucy; Nelson, Brian C; Mehta, Monica; Seval, Nikhil; Park, Sarah; Giddins, Marla J; Shi, Qiuhu; Whittier, Susan; Gomez-Simmonds, Angela; Uhlemann, Anne-Catrin

2017-06-01

In vivo induction of AmpC beta-lactamases produces high-level resistance to many beta-lactam antibiotics in Enterobacteriaceae , often resulting in the need to use carbapenems or cefepime (FEP). The clinical effectiveness of piperacillin-tazobactam (TZP), a weak inducer of AmpC beta-lactamases, is poorly understood. Here, we conducted a case-control study of adult inpatients with bloodstream infections (BSIs) due to Enterobacter , Serratia , or Citrobacter species from 2009 to 2015 to assess outcomes following treatment with TZP compared to FEP or meropenem (MEM). We collected clinical data and screened all isolates for the presence of ampC alleles by PCR. Primary study outcomes were 30-day mortality and persistent bacteremia at ≥72 h from the time of treatment initiation. Of 493 patients with bacteremia, 165 patients met the inclusion criteria, of which 88 were treated with TZP and 77 with FEP or MEM. To minimize differences between covariates, we carried out propensity score matching, which yielded 41 matched pairs. Groups only differed by age, with patients in the TZP group significantly older ( P = 0.012). There were no significant differences in 30-day mortality, persistent bacteremia, 7-day mortality, or treatment escalation between the two treatment groups, including in the propensity score-matched cohort. PCR amplification and sequencing of amp C genes revealed the presence of amp C in isolates with cefoxitin MICs below 16 μg/ml, in particular in Serratia spp., and demonstrated that these alleles were highly genetically diverse. Taken together, TZP may be a valuable treatment option for BSIs due to AmpC beta-lactamase-producing Enterobacteriaceae , diminishing the need for broader-spectrum agents. Future studies are needed to validate these findings. Copyright © 2017 American Society for Microbiology.

Extended-Spectrum β-Lactamase–Producing Enterobacteriaceae in Children: Old Foe, Emerging Threat

PubMed Central

Lukac, Paul J.; Bonomo, Robert A.; Logan, Latania K.

2015-01-01

Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae present an ever-growing burden in the hospital and community settings, across all ages and demographics. Infections due to ESBL-containing pathogens continue to be associated with significant morbidity and mortality worldwide. With widespread empiric broad-spectrum β-lactam use creating selective pressure, and the resultant emergence of stable, rapidly proliferating ESBL-producing clones with continued horizontal gene transfer across genera, addressing this issue remains imperative. Although well characterized in adults, the epidemiology, risk factors, outcomes, therapies, and control measures for ESBL-producing bacteria are less appreciated in children. This analysis provides a brief summary of ESBL-producing Enterobacteriaceae in children, with a focus on recent clinical and molecular data regarding colonization and infection in nonoutbreak settings. PMID:25595742

Volatiles emitted from eight wound-isolated bacteria differentially attract and stimulate gravid screwworm flies (Diptera: Calliphoridae) to oviposit

USDA-ARS?s Scientific Manuscript database

Bovine blood inoculated with bacteria isolated from screwworm-infested animal wounds was tested against gravid screwworm flies, Cochliomyia hominivorax (Coquerel) in the laboratory in a cage bioassay as an attractant for oviposition. Eight species of gram-negative coliform (Enterobacteriaceae) bacte...

In vitro activity of rifaximin against clinical isolates of Escherichia coli and other enteropathogenic bacteria isolated from travellers returning to the UK.

PubMed

Hopkins, Katie L; Mushtaq, Shazad; Richardson, Judith F; Doumith, Michel; de Pinna, Elizabeth; Cheasty, Tom; Wain, John; Livermore, David M; Woodford, Neil

2014-05-01

Rifaximin is licensed in the EU and USA for treating travellers' diarrhoea caused by non-invasive bacteria. Selection for resistance mechanisms of public health significance might occur if these are linked to rifamycin resistance. Rifaximin MICs were determined by agar dilution for 90 isolates each of Escherichia coli, Shigella spp., nontyphoidal Salmonella enterica, typhoidal S. enterica and Campylobacter spp., an additional 60 E. coli with CTX-M ESBLs isolated from patients with travellers' diarrhoea, and 30 non-diarrhoeal carbapenemase-producing E. coli. Comparators were rifampicin, ciprofloxacin, azithromycin, trimethoprim/sulfamethoxazole and doxycycline. Isolates with rifaximin MICs>32 mg/L were screened for arr genes, and critical rpoB regions were sequenced. Rifaximin was active at ≤32 mg/L against 436/450 (96.9%) diverse Enterobacteriaceae, whereas 81/90 (90%) Campylobacter spp. were resistant to rifaximin at ≥128 mg/L. Rifaximin MICs were ≥128 mg/L for two Shigella and five MDR E. coli producing NDM (n = 3), OXA-48 (n = 1) or CTX-M-15 (n = 1). Two of the five MDR E. coli had plasmids harbouring arr-2 together with bla(NDM), and two (one each with bla(NDM) and bla(CTX-M-15)) had His526Asn substitutions in RpoB. The rifamycin resistance mechanism remained undefined in one MDR E. coli isolate (with bla(OXA-48)) and the two Shigella isolates. Rifaximin showed good in vitro activity against diverse Enterobacteriaceae but was largely inactive against Campylobacter spp. Rifaximin has potential to co-select MDR E. coli in the gut flora, but much stronger associations were seen between ESBL and/or carbapenemase production and resistance to alternative treatments for travellers' diarrhoea, notably ciprofloxacin and azithromycin. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Surveillance of antimicrobial susceptibility of aerobic and facultative Gram-negative bacilli isolated from patients with intra-abdominal infections in China: the 2002-2009 Study for Monitoring Antimicrobial Resistance Trends (SMART).

PubMed

Yang, Qiwen; Wang, Hui; Chen, Minjun; Ni, Yuxing; Yu, Yunsong; Hu, Bijie; Sun, Ziyong; Huang, Wenxiang; Hu, Yunjian; Ye, Huifen; Badal, Robert E; Xu, Yingchun

2010-12-01

The objective of this study was to investigate the distribution and susceptibility of aerobic and facultative Gram-negative bacilli (GNB) isolated from patients with intra-abdominal infections (IAIs) in China. From 2002 to 2009, minimum inhibitory concentrations of 14 antibiotics for 3420 aerobic and facultative GNB from up to eight hospitals in six cities were determined by the broth microdilution method. Enterobacteriaceae comprised 82.9% (2834/3420) of the total isolates, with Escherichia coli (49.2%) being the most commonly isolated species followed by Klebsiella pneumoniae (17.0%), Enterobacter cloacae (5.8%) and Citrobacter freundii (2.3%). Amongst the antimicrobial agents tested, the three carbapenems (ertapenem, imipenem and meropenem) were the most active agents against Enterobacteriaceae, with susceptibility rates of 96.1-99.6% (2002-2009), 98.2-100% (2002-2009) and 99.6-100% (2002-2004), respectively, followed by amikacin (86.8-95.1%) and piperacillin/tazobactam (84.5-94.3%). Susceptibility rates of all tested third- and fourth-generation cephalosporins against Enterobacteriaceae declined by nearly 30%, with susceptibility rates of 40.2%, 39.1%, 56.3% and 51.8% in 2009 for ceftriaxone, cefotaxime, ceftazidime and cefepime, respectively. The occurrence of extended-spectrum β-lactamases increased rapidly, especially for E. coli (from 20.8% in 2002 to 64.9% in 2009). Susceptibility of E. coli to ciprofloxacin decreased from 57.6% in 2002 to 24.2% in 2009. The least active agent against Enterobacteriaceae was ampicillin/sulbactam (SAM) (25.3-44.3%). In conclusion, Enterobacteriaceae were the major pathogens causing IAIs, and carbapenems retained the highest susceptibility rates over the 8-year study period. Third- and fourth-generation cephalosporins, fluoroquinolones and SAM may not be ideal choices for empirical therapy of IAIs in China. Copyright © 2010 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Draft genome sequence of an extensively drug-resistant Pseudomonas aeruginosa isolate belonging to ST644 isolated from a footpad infection in a Magellanic penguin (Spheniscus magellanicus).

PubMed

Sellera, Fábio P; Fernandes, Miriam R; Moura, Quézia; Souza, Tiago A; Nascimento, Cristiane L; Cerdeira, Louise; Lincopan, Nilton

2018-03-01

The incidence of multidrug-resistant bacteria in wildlife animals has been investigated to improve our knowledge of the spread of clinically relevant antimicrobial resistance genes. The aim of this study was to report the first draft genome sequence of an extensively drug-resistant (XDR) Pseudomonas aeruginosa ST644 isolate recovered from a Magellanic penguin with a footpad infection (bumblefoot) undergoing rehabilitation process. The genome was sequenced on an Illumina NextSeq ® platform using 150-bp paired-end reads. De novo genome assembly was performed using Velvet v.1.2.10, and the whole genome sequence was evaluated using bioinformatics approaches from the Center of Genomic Epidemiology, whereas an in-house method (mapping of raw whole genome sequence reads) was used to identify chromosomal point mutations. The genome size was calculated at 6436450bp, with 6357 protein-coding sequences and the presence of genes conferring resistance to aminoglycosides, β-lactams, phenicols, sulphonamides, tetracyclines, quinolones and fosfomycin; in addition, mutations in the genes gyrA (Thr83Ile), parC (Ser87Leu), phoQ (Arg61His) and pmrB (Tyr345His), conferring resistance to quinolones and polymyxins, respectively, were confirmed. This draft genome sequence can provide useful information for comparative genomic analysis regarding the dissemination of clinically significant antibiotic resistance genes and XDR bacterial species at the human-animal interface. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Whole-Genome Sequencing of Mycobacterium tuberculosis Provides Insight into the Evolution and Genetic Composition of Drug-Resistant Tuberculosis in Belarus.

PubMed

Wollenberg, Kurt R; Desjardins, Christopher A; Zalutskaya, Aksana; Slodovnikova, Vervara; Oler, Andrew J; Quiñones, Mariam; Abeel, Thomas; Chapman, Sinead B; Tartakovsky, Michael; Gabrielian, Andrei; Hoffner, Sven; Skrahin, Aliaksandr; Birren, Bruce W; Rosenthal, Alexander; Skrahina, Alena; Earl, Ashlee M

2017-02-01

The emergence and spread of drug-resistant Mycobacterium tuberculosis (DR-TB) are critical global health issues. Eastern Europe has some of the highest incidences of DR-TB, particularly multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB. To better understand the genetic composition and evolution of MDR- and XDR-TB in the region, we sequenced and analyzed the genomes of 138 M. tuberculosis isolates from 97 patients sampled between 2010 and 2013 in Minsk, Belarus. MDR and XDR-TB isolates were significantly more likely to belong to the Beijing lineage than to the Euro-American lineage, and known resistance-conferring loci accounted for the majority of phenotypic resistance to first- and second-line drugs in MDR and XDR-TB. Using a phylogenomic approach, we estimated that the majority of MDR-TB was due to the recent transmission of already-resistant M. tuberculosis strains rather than repeated de novo evolution of resistance within patients, while XDR-TB was acquired through both routes. Longitudinal sampling of M. tuberculosis from 34 patients with treatment failure showed that most strains persisted genetically unchanged during treatment or acquired resistance to fluoroquinolones. HIV+ patients were significantly more likely to have multiple infections over time than HIV- patients, highlighting a specific need for careful infection control in these patients. These data provide a better understanding of the genomic composition, transmission, and evolution of MDR- and XDR-TB in Belarus and will enable improved diagnostics, treatment protocols, and prognostic decision-making. Copyright © 2017 Wollenberg et al.

Spread of mcr-1-carrying Enterobacteriaceae in sewage water from Spain.

PubMed

Ovejero, C M; Delgado-Blas, J F; Calero-Caceres, W; Muniesa, M; Gonzalez-Zorn, B

2017-04-01

The mobile colistin resistance gene mcr-1 has been identified worldwide in human and animal sources, while its occurrence in the environment is still largely unknown. The aim of this study was to investigate the presence of mcr-1 -harbouring Enterobacteriaceae in water samples obtained from rivers and waste water treatment plants in the area of Barcelona, Spain. The presence of mcr-1 was detected by PCR. Bacterial identification was performed via MALDI-TOF MS. Resistance to colistin was determined by a broth dilution method. The epidemiological relationship between the positive isolates was assessed with PFGE and ST was determined by MLST. Plasmid characterization was performed by transformation experiments, antimicrobial susceptibility testing and incompatibility group PCR. Thirty MDR isolates bearing mcr-1 , 29 Escherichia coli (ST632 and ST479) and 1 Klebsiella pneumoniae (ST526), were identified in sewage from two different waste water treatment plants, whereas the gene was not found in river water. All isolates, including the K. pneumoniae , harboured bla CTX-M-55 and bla TEM-1 . mcr-1 was in all cases associated with an IncI2 plasmid, which only conferred resistance to colistin. mcr-1 was harboured by two predominant E. coli clones that were found in both waste water treatment plants. This study showed a high occurrence of mcr-1 in the sewage of Barcelona, mainly due to the dissemination of two E. coli pulsotypes that are circulating in the population. The presence of mcr-1 in the environment is a cause for concern, and suggests high prevalence of mcr-1 in the community. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

30-day readmission, antibiotics costs and costs of delay to adequate treatment of Enterobacteriaceae UTI, pneumonia, and sepsis: a retrospective cohort study.

PubMed

Zilberberg, Marya D; Nathanson, Brian H; Sulham, Kate; Fan, Weihong; Shorr, Andrew F

2017-01-01

Enterobacteriaceae are common pathogens in pneumonia, sepsis and urinary tract infection (UTI). Though rare, carbapenem resistance (CRE) among these organisms complicates efforts to ensure adequate empiric antimicrobial therapy. In turn this negatively impacts such outcomes as mortality and hospital costs. We explored proportion of total costs represented by antibiotics, 30-day readmission rates, and per-day costs of inadequate antimicrobial coverage among patients with Enterobacteriaceae pneumonia, sepsis and/or UTI in the context of inappropriate (IET) vs. appropriate empiric (non-IET) therapy and carbapenem resistance (CRE) vs. susceptibility (CSE). We conducted a retrospective cohort study in the Premier Research database (2009-2013) of 175 US hospitals. We included all adult patients admitted with a culture-confirmed UTI, pneumonia, or sepsis as principal diagnosis, or as a secondary diagnosis in the setting of respiratory failure. Patients with hospital acquired infections or transfers from other acute facilities were excluded. IET was defined as failure to administer an antibiotic therapy in vitro active against the culture-confirmed pathogen within 2 days of admission. Among 40,137 patients with Enterobacteriaceae infections (54.2% UTI), 4984 (13.2%) received IET. CRE (3.1%) was more frequent in patients given IET (13.0%) than non-IET (1.6%, p  < 0.001). The proportions of total costs represented by antibiotics were similar in IET and non-IET (3.3% vs. 3.4%, p  = 0.01), and higher among the group with CRE than CSE (4.2% vs. 3.4%, p  < 0.001). The 30-day readmission rates were higher in both IET than non-IET (25.6% vs. 21.1%, p  < 0.001) and CRE than CSE (29.7% vs. 21.5%, p < 0.001) groups. Each additional day of inadequate therapy cost an additional $766 (95% CI $661, $870, p  < 0.001) relative to adequate treatment. In this large US cohort of Enterobacteriaceae infections, the cost of antibiotics was a small component of total

[Extended-spectrum beta-lactamase detection in Enterobacteriaceae and antibiotic susceptibility analysis].

PubMed

Cao, Wei; Tong, Ming-hua; Wang, Ji-gui

2002-02-28

To detect the extended-spectrum beta-lactamases (ESBLs) in family Enterobacteriaceae and analyze the antibiotic susceptibility of those ESBLs-producing strains. ESBLs were determined by the double-disk confirmatory test and 8 antibiotic susceptibilities were tested with the disk disffusion method in those strains producing ESBLs. Forty-seven ESBLs-producing strains comprised of 25 of E. coli, 14 of K. pneumoniae, 5 of E. cloacae, 1 of K. oxytoca, 1 of K. rhinoscleromatis, and 1 of S. liquefaciens. The susceptibility rates of those strains were: 100% for imipenem and meropenem, 89.4% for piperacillin/tazobactam, 72.4% for cefoxitin and 65.9% for cefotetan. E. coli and K. pneumoniae are the prime strains producing ESBLs in Enterobacteriaceae. Imipenem and meropenem are the best drugs to deal with those ESBLs-producing strains. Piperacillin/tazobactam is better than cephamycins and other beta-lactama/beta-lactamase inhibitor combination.

Polymyxin B Etest Fails to Distinguish Carbapenem-resistant Enterobacteriaceae with Elevated Polymyxin B MICs

PubMed Central

Kulengowski, Brandon; Brignola, Matthew; Gallagher, Chanah; Rutter, W Cliff; Ribes, Julie A; Burgess, David S

2017-01-01

Abstract Background Polymyxins are being revitalized to combat carbapenem-resistant Enterobacteriaceae (CRE). However, evaluating the activity of these agents by traditional broth dilution methods is not practical for busy clinical laboratories. We compared polymyxin B (PMB) activity utilizing two quantitative susceptibility testing methods, Etest® and broth microdilution (BMD), against CRE isolates from patients at an academic medical center. Methods PMB activity against 70 recent CRE clinical isolates was determined by BMD and Etest® according to CLSI guidelines. P. aeruginosa ATCC® 27853 was used as a quality control strain. The CLSI PMB susceptibility breakpoint of non-fermenting gram-negative bacteria (<2 mg/L) was used. Essential agreement between methods was defined as an MIC measured within 1 log2 dilution. Categorical agreement was defined between methods as classification of isolates in the same susceptibility category (susceptible or resistant). Major and very major error rates were calculated, and McNemar’s test was used for determining a difference between methods. Results CRE isolates were primarily Enterobacter spp. (43%), followed by K. pneumoniae (41%) and E. coli (9%). Essential agreement between testing methods was low (9%), but categorical agreement was 81% (P = 0.0002). Although false non-susceptibility was never observed by Etest® (BMD as reference), the rate of very major errors by Etest® was high (19%). Etest® miscalled 87% of PMB-resistant CRE. Conclusion Etest® reporting of false susceptibility may result in inappropriate antibiotic utilization and treatment failure clinically. We do not recommend using Etest® for PMB susceptibility testing for routine patient care. Disclosures All authors: No reported disclosures.

Adverse effects of members of the Enterobacteriaceae family on boar sperm quality.

PubMed

Ubeda, Juan Luis; Ausejo, Raquel; Dahmani, Yahya; Falceto, Maria V; Usan, Adan; Malo, Clara; Perez-Martinez, Francisco C

2013-10-01

Semen samples collected in 2012 from 1785 boars belonging to five different breeds were recruited from the quality control laboratory of Magapor SL, Spain. These samples came from 43 boar studs and resulted from diluting the ejaculates in commercial semen extenders. Evaluation of the semen sample characteristics (color, smell, pH, osmolality, concentration, motility of sperm cells, agglutination, acrosome integrity, short hypoosmotic swelling test, and abnormal forms) revealed that they met the international standards. The samples were also tested for the presence of aerobic bacterial contamination. In the present study, 14.73% (n = 263) of the semen samples were contaminated above 3 × 10(2) colony-forming units/mL with at least one type of bacteria. The Enterobacteriaceae family was by far the major contaminant, being present in 40.68% of the contaminated samples (n = 107). Bacterial strains of the Enterobacteriaceae family isolated from boar semen samples were in order of incidence (percentage of the contaminated samples): Serratia marcescens (12.55%), Klebsiella oxytoca (11.79%), Providencia stuartii (9.12%), Morganella morganii (3.80%), Proteus mirabilis (1.90%), and Escherichia coli (1.52%). We have seen that the presence in semen samples of S. marcescens, K. oxytoca, M. morganii, or P. mirabilis, but not P. stuartii or E. coli, was negatively associated with sperm motility (P < 0.05). The mean sperm concentration (P < 0.05), the mean percentage of spermatozoa with curled tails after the short hypoosmotic swelling test (P < 0.01), and the incidence of morphologically normal acrosomes (P < 0.05) were also lower in semen samples infected with M. morganii compared with uninfected ones. Moreover, P. mirabilis was negatively associated with the presence of abnormal forms. Thus, on the basis of the pathological effects that some of these strains may have on boar sperm quality, bacterial contamination should always be examined in semen samples prepared for

Colonization with third-generation cephalosporin-resistant Enterobacteriaceae on hospital admission: prevalence and risk factors.

PubMed

Hamprecht, A; Rohde, A M; Behnke, M; Feihl, S; Gastmeier, P; Gebhardt, F; Kern, W V; Knobloch, J K; Mischnik, A; Obermann, B; Querbach, C; Peter, S; Schneider, C; Schröder, W; Schwab, F; Tacconelli, E; Wiese-Posselt, M; Wille, T; Willmann, M; Seifert, H; Zweigner, J

2016-10-01

The objectives of this study were to prospectively assess the rectal carriage rate of third-generation cephalosporin-resistant Enterobacteriaceae (3GCREB) in non-ICU patients on hospital admission and to investigate resistance mechanisms and risk factors for carriage. Adult patients were screened for 3GCREB carriage at six German tertiary care hospitals in 2014 using rectal swabs or stool samples. 3GCREB isolates were characterized by phenotypic and molecular methods. Each patient answered a questionnaire about potential risk factors for colonization with MDR organisms (MDROs). Univariable and multivariable risk factor analyses were performed to identify factors associated with 3GCREB carriage. Of 4376 patients, 416 (9.5%) were 3GCREB carriers. Escherichia coli was the predominant species (79.1%). ESBLs of the CTX-M-1 group (67.3%) and the CTX-M-9 group (16.8%) were the most frequent β-lactamases. Five patients (0.11%) were colonized with carbapenemase-producing Enterobacteriaceae. The following risk factors were significantly associated with 3GCREB colonization in the multivariable analysis (P < 0.05): centre; previous MDRO colonization (OR = 2.12); antibiotic use within the previous 6 months (OR = 2.09); travel outside Europe (OR = 2.24); stay in a long-term care facility (OR = 1.33); and treatment of gastroesophageal reflux disease (GERD) (OR = 1.22). To our knowledge, this is the largest admission prevalence study of 3GCREB in Europe. The observed prevalence of 9.5% 3GCREB carriage was higher than previously reported and differed significantly among centres. In addition to previously identified risk factors, the treatment of GERD proved to be an independent risk factor for 3GCREB colonization. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Contaminated sinks in intensive care units: an underestimated source of extended-spectrum beta-lactamase-producing Enterobacteriaceae in the patient environment.

PubMed

Roux, D; Aubier, B; Cochard, H; Quentin, R; van der Mee-Marquet, N

2013-10-01

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBLE) outbreaks in intensive care units (ICUs) associated with contaminated handwashing sinks have been reported. To conduct a regional study to assess whether handwashing sinks in 135 ICU patient rooms are a potential source of contamination, and to identify factors associated with an increased risk of sink contamination. A multicentre study was conducted in 13 ICUs, including microbiological testing for ESBLE contamination at 185 sinks. The micro-organisms isolated were analysed using randomly amplified polymorphic DNA analysis to assess clonal spread in ICUs. Data were collected to document the use of each sink, factors that may contribute to contamination of clinical areas near to the sinks, and routine cleansing procedures for the sinks. Fifty-seven sinks were contaminated (31%) with ESBLE, mostly Klebsiella (N = 33) and Enterobacter (N = 18). In two ICUs, a high contamination rate was associated with clonal spread of an epidemic isolate. Risk factors for contamination of and by handwashing sinks were frequent: 81 sinks (44%) were used for handwashing as well as the disposal of body fluids; splash risk was identified for 67 sinks (36%), among which 23 were contaminated by ESBLE. Routine sink disinfection was frequent (85%), mostly daily (75%), and involved quaternary ammonium compounds (41%) or bleach (21%). A lower sink contamination rate was significantly associated with use of the sink being restricted to handwashing and to daily sink disinfection using bleach. In ICUs, contaminated sinks are a potential source of ESBLE in the environment of the patient, a problem that may be underestimated by ICU teams. Relatively simple measures may result in a rapid improvement of the situation, and a significant decrease of the risk of exposure of ICU patients to multiresistant Enterobacteriaceae. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Australian Group on Antimicrobial Resistance Australian Enterobacteriaceae Sepsis Outcome Programme annual report, 2014.

PubMed

Bell, Jan M; Turnidge, John D; Coombs, Geoffrey W; Daley, Denise A; Gottlieb, Thomas; Robson, Jenny; George, Narelle

2016-06-30

The Australian Group on Antimicrobial Resistance performs regular period-prevalence studies to monitor changes in antimicrobial resistance in selected enteric Gram-negative pathogens. The 2014 survey was the second year to focus on blood stream infections. During 2014, 5,798 Enterobacteriaceae species isolates were tested using commercial automated methods (Vitek 2, BioMérieux; Phoenix, BD) and results were analysed using the Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints (January 2015). Of the key resistances, non-susceptibility to the third-generation cephalosporin, ceftriaxone, was found in 9.0%/9.0% of Escherichia coli (CLSI/EUCAST criteria) and 7.8%/7.8% of Klebsiella pneumoniae, and 8.0%/8.0% K. oxytoca. Non-susceptibility rates to ciprofloxacin were 10.4%/11.6% for E. coli, 5.0%/7.7% for K. pneumoniae, 0.4%/0.4% for K. oxytoca, and 3.5%/6.5% in Enterobacter cloacae. Resistance rates to piperacillin-tazobactam were 3.2%/6.8%, 4.8%/7.2%, 11.1%/11.5%, and 19.0%/24.7% for the same 4 species respectively. Fourteen isolates were shown to harbour a carbapenemase gene, 7 blaIMP-4, 3 blaKPC-2, 3 blaVIM-1, 1 blaNDM-4, and 1 blaOXA-181-lke.

Understanding the enormous diversity of bacteriophages: the tailed phages that infect the bacterial family Enterobacteriaceae.

PubMed

Grose, Julianne H; Casjens, Sherwood R

2014-11-01

Bacteriophages are the predominant biological entity on the planet. The recent explosion of sequence information has made estimates of their diversity possible. We describe the genomic comparison of 337 fully sequenced tailed phages isolated on 18 genera and 31 species of bacteria in the Enterobacteriaceae. These phages were largely unambiguously grouped into 56 diverse clusters (32 lytic and 24 temperate) that have syntenic similarity over >50% of the genomes within each cluster, but substantially less sequence similarity between clusters. Most clusters naturally break into sets of more closely related subclusters, 78% of which are correlated with their host genera. The largest groups of related phages are superclusters united by genome synteny to lambda (81 phages) and T7 (51 phages). This study forms a robust framework for understanding diversity and evolutionary relationships of existing tailed phages, for relating newly discovered phages and for determining host/phage relationships.

Understanding the enormous diversity of bacteriophages: the tailed phages that infect the bacterial family Enterobacteriaceae

PubMed Central

Grose, Julianne H.; Casjens, Sherwood R.

2014-01-01

Bacteriophages are the predominant biological entity on the planet. The recent explosion of sequence information has made estimates of their diversity possible. We describe the genomic comparison of 337 fully sequenced tailed phages isolated on 18 genera and 31 species of bacteria in the Enterobacteriaceae. These phages were largely unambiguously grouped into 56 diverse clusters (32 lytic and 24 temperate) that have syntenic similarity over >50% of the genomes within each cluster, but substantially less sequence similarity between clusters. Most clusters naturally break into sets of more closely related subclusters, 78% of which are correlated with their host genera. The largest groups of related phages are superclusters united by genome synteny to lambda (81 phages) and T7 (51 phages). This study forms a robust framework for understanding diversity and evolutionary relationships of existing tailed phages, for relating newly discovered phages and for determining host/phage relationships. PMID:25240328

Whole Genome Sequencing Based Characterization of Extensively Drug-Resistant Mycobacterium tuberculosis Isolates from Pakistan

PubMed Central

Ali, Asho; Hasan, Zahra; McNerney, Ruth; Mallard, Kim; Hill-Cawthorne, Grant; Coll, Francesc; Nair, Mridul; Pain, Arnab; Clark, Taane G.; Hasan, Rumina

2015-01-01

Improved molecular diagnostic methods for detection drug resistance in Mycobacterium tuberculosis (MTB) strains are required. Resistance to first- and second- line anti-tuberculous drugs has been associated with single nucleotide polymorphisms (SNPs) in particular genes. However, these SNPs can vary between MTB lineages therefore local data is required to describe different strain populations. We used whole genome sequencing (WGS) to characterize 37 extensively drug-resistant (XDR) MTB isolates from Pakistan and investigated 40 genes associated with drug resistance. Rifampicin resistance was attributable to SNPs in the rpoB hot-spot region. Isoniazid resistance was most commonly associated with the katG codon 315 (92%) mutation followed by inhA S94A (8%) however, one strain did not have SNPs in katG, inhA or oxyR-ahpC. All strains were pyrazimamide resistant but only 43% had pncA SNPs. Ethambutol resistant strains predominantly had embB codon 306 (62%) mutations, but additional SNPs at embB codons 406, 378 and 328 were also present. Fluoroquinolone resistance was associated with gyrA 91–94 codons in 81% of strains; four strains had only gyrB mutations, while others did not have SNPs in either gyrA or gyrB. Streptomycin resistant strains had mutations in ribosomal RNA genes; rpsL codon 43 (42%); rrs 500 region (16%), and gidB (34%) while six strains did not have mutations in any of these genes. Amikacin/kanamycin/capreomycin resistance was associated with SNPs in rrs at nt1401 (78%) and nt1484 (3%), except in seven (19%) strains. We estimate that if only the common hot-spot region targets of current commercial assays were used, the concordance between phenotypic and genotypic testing for these XDR strains would vary between rifampicin (100%), isoniazid (92%), flouroquinolones (81%), aminoglycoside (78%) and ethambutol (62%); while pncA sequencing would provide genotypic resistance in less than half the isolates. This work highlights the importance of expanded

Whole genome sequencing based characterization of extensively drug-resistant Mycobacterium tuberculosis isolates from Pakistan.

PubMed

Ali, Asho; Hasan, Zahra; McNerney, Ruth; Mallard, Kim; Hill-Cawthorne, Grant; Coll, Francesc; Nair, Mridul; Pain, Arnab; Clark, Taane G; Hasan, Rumina

2015-01-01

Improved molecular diagnostic methods for detection drug resistance in Mycobacterium tuberculosis (MTB) strains are required. Resistance to first- and second- line anti-tuberculous drugs has been associated with single nucleotide polymorphisms (SNPs) in particular genes. However, these SNPs can vary between MTB lineages therefore local data is required to describe different strain populations. We used whole genome sequencing (WGS) to characterize 37 extensively drug-resistant (XDR) MTB isolates from Pakistan and investigated 40 genes associated with drug resistance. Rifampicin resistance was attributable to SNPs in the rpoB hot-spot region. Isoniazid resistance was most commonly associated with the katG codon 315 (92%) mutation followed by inhA S94A (8%) however, one strain did not have SNPs in katG, inhA or oxyR-ahpC. All strains were pyrazimamide resistant but only 43% had pncA SNPs. Ethambutol resistant strains predominantly had embB codon 306 (62%) mutations, but additional SNPs at embB codons 406, 378 and 328 were also present. Fluoroquinolone resistance was associated with gyrA 91-94 codons in 81% of strains; four strains had only gyrB mutations, while others did not have SNPs in either gyrA or gyrB. Streptomycin resistant strains had mutations in ribosomal RNA genes; rpsL codon 43 (42%); rrs 500 region (16%), and gidB (34%) while six strains did not have mutations in any of these genes. Amikacin/kanamycin/capreomycin resistance was associated with SNPs in rrs at nt1401 (78%) and nt1484 (3%), except in seven (19%) strains. We estimate that if only the common hot-spot region targets of current commercial assays were used, the concordance between phenotypic and genotypic testing for these XDR strains would vary between rifampicin (100%), isoniazid (92%), flouroquinolones (81%), aminoglycoside (78%) and ethambutol (62%); while pncA sequencing would provide genotypic resistance in less than half the isolates. This work highlights the importance of expanded

Rates of gastrointestinal tract colonization of carbapenem-resistant Enterobacteriaceae and Pseudomonas aeruginosa in hospitals in Saudi Arabia

PubMed Central

Abdalhamid, B.; Elhadi, N.; Alabdulqader, N.; Alsamman, K.; Aljindan, R.

2016-01-01

Carbapenem-resistant Enterobacteriaceae (CRE) and carbapenem-resistant Pseudomonas aeruginosa (CRPAE) are globally a major medical issue, especially in intensive care units. The digestive tract is the main reservoir for these isolates; therefore, rectal swab surveillance is highly recommended. The purpose of this study was to detect the prevalence of gastrointestinal tract colonization of CRE and CRPAE in patients admitted to intensive care units in Saudi Arabia. This project also aimed to characterize carbapenem-hydrolyzing enzyme production in these isolates. From February to May 2015, 200 rectal swab specimens were screened by CHROMagar KPC. Organism identification and susceptibility testing were performed using the Vitek 2 system. One CRE and 13 CRPAE strains were identified, for a prevalence of 0.5% (1/200) and 6.5% (13/200) respectively. Strains showed high genetic diversity using enterobacterial repetitive intergenic consensus sequence-based PCR. NDM type and VIM type were detected by PCR in four and one CRPAE isolates respectively. ampC overexpression was detected in eight CRPAE isolates using Mueller-Hinton agar containing 1000 μg/mL cloxacillin. CTX-M-15 type was detected in 1 CRE by PCR. The prevalence of CRE strain colonization was lower than that of CRPAE isolates. The detection of NDM and VIM in the colonizing CRPAE strains is a major infection control concern. To our knowledge, this is the first study in Saudi Arabia and the gulf region focusing on digestive tract colonization of CRE and CRPAE organisms and characterizing the mechanisms of carbapenem resistance. PMID:26933499

Strain-specific transmission in an outbreak of ESBL-producing Enterobacteriaceae in the hemato-oncology care unit: a cohort study.

PubMed

Uemura, Makiko; Imataki, Osamu; Uchida, Shumpei; Nakayama-Imaohji, Haruyuki; Ohue, Yukiko; Matsuka, Harumi; Mori, Hatsune; Dobashi, Hiroaki; Kuwahara, Tomomi; Kadowaki, Norimitsu

2017-01-05

Extended-spectrum β-lactamase (ESBL)-producing bacteria are resistant to several types of antibiotics excluding carbapenems. A transmissibility of ESBL-producing Enterobacteriaceae would be depending on each bacterial property, however, that has not been elucidated in clinical setting. In this study, we attempted to identify the source of an outbreak of ESBL-producing bacteria in a medical oncology and immunology care unit. An ESBL-producing Enterobacteriaceae (ESBL-E) outbreak observed between July 2012 and August 2012 in Kagawa University Hospital was surveyed using various molecular microbiology techniques. We used Pulsed-field gel electrophoresis (PFGE), PCR-based ESBL gene typing, and direct sequence of ESBL gene as molecular microbiology typing method to distinguish each strain. The typical prevalence of ESBL-E isolation in the unit was 7.0 per month (1.7 per week). The prevalence of ESBL-E isolation during the target research period was 20.0 per month (5.0 per week). In total, 19 isolates (11 K. pneumoniae and 8 E. coli) were obtained from clinical samples, including four control strains (two each of both bacteria), that were physically different from those obtained from other inpatient units in our hospital. Pulsed-field gel electrophoresis (PFGE) for K. pneumoniae (digested by XbaI) produced similar patterns excluding one control strain. PCR classification of the ESBL gene for K. pneumoniae revealed that all strains other than the control strain carried SHV and CTX-M-9. This result was reconfirmed by direct DNA sequencing. Although the outbreak of K. pneumoniae was considered to be "clonal," PFGE and PCR classification of the ESBL genes for E. coli uncovered at least six different "non-clonal" strains possessing individual ESBL gene patterns. According to the result of an antibiogram, the pattern of antimicrobial susceptibility was more variable for K. pneumoniae than for E. coli. Typing by PFGE and ESBL gene PCR analysis is practical for discriminating

Colistin and Polymyxin B Susceptibility Testing for Carbapenem-Resistant and mcr-Positive Enterobacteriaceae: Comparison of Sensititre, MicroScan, Vitek 2, and Etest with Broth Microdilution

PubMed Central

La, My-Van; Lin, Raymond T. P.

2017-01-01

ABSTRACT Colistin and polymyxin B remain part of the last line of antibiotics for multidrug-resistant Gram-negative bacteria, such as carbapenem-resistant Enterobacteriaceae. Current joint EUCAST-CLSI recommendations are for broth microdilution (BMD) to be performed for MIC testing of colistin. Commercial susceptibility testing methods were evaluated and compared against the reference BMD, using a susceptibility breakpoint of ≤2 mg/liter for both colistin and polymyxin B. Seventy-six Enterobacteriaceae were included, of which 21 were mcr-1 positive (18 Escherichia coli isolates, 2 Klebsiella pneumoniae isolates, and 1 Enterobacter aerogenes isolate). Rates of essential agreement (EA) of colistin test results between BMD and Vitek 2, Sensititre, and Etest were 93.4%, 89.5%, and 75.0%, respectively. Rates of EA of polymyxin B test results between BMD and Vitek 2, Sensititre, and Etest were 96.1%, 96.1%, and 48.7%, respectively. A positive MIC correlation with a categorical agreement of >90% was achieved for Sensititre (colistin Spearman's ρ = 0.863, and polymyxin B Spearman's ρ = 0.877) and Vitek 2 (polymyxin B [only] Spearman's ρ = 0.8917). Although a positive MIC correlation (Spearman's ρ = 0.873) with the reference method was achieved for colistin testing with Vitek 2, categorical agreement was <90%, with very major error rates of 36%. Correlation with the Etest MIC was lower, with very major error rates of 12% (colistin) and 26.1% (polymyxin B). MicroScan (colistin) categorical agreement was 88.2%, with a very major error rate of 4%. Colistin MICs for 15 of the 21 mcr-1-positive isolates were >2 mg/liter, and polymyxin MICs for 17 of them were >2 mg/liter by broth microdilution. The use of a lower breakpoint of ≤1 mg/liter further improves detection of mcr-1 for all testing methods. However, further data on the correlation between MICs and clinical outcome are required to determine the most suitable breakpoint to guide clinical management. PMID:28592552

Effectiveness of infection prevention measures featuring advanced source control and environmental cleaning to limit transmission of extremely-drug resistant Acinetobacter baumannii in a Thai intensive care unit: An analysis before and after extensive flooding.

PubMed

Apisarnthanarak, Anucha; Pinitchai, Uayporn; Warachan, Boonyasit; Warren, David K; Khawcharoenporn, Thana; Hayden, Mary K

2014-02-01

Advanced source control (once-daily bathing and 4-times daily oral care with chlorhexidine aqueous solution) and thorough environmental cleaning were implemented in response to an increased incidence of colonization and infection with extremely drug-resistant (XDR) Acinetobacter baumannii in a Thai medical intensive care unit (MICU). During the 12-month baseline period (P1), contact isolation, active surveillance for XDR A baumannii, cohorting of XDR A baumannii patients, twice-daily environmental cleaning with detergent-disinfectant, and antibiotic stewardship were implemented. In the 5.5-month intervention period (P2), additional measures were introduced. Sodium hypochlorite was substituted for detergent-disinfectant, and advanced source control was implemented. All interventions except cleaning with sodium hypochlorite were continued during the 12.5-month follow-up period (P3). Extensive flooding necessitating closure of the hospital for 2 months occurred between P2 and P3. A total of 1,365 patients were studied. Compared with P1 (11.1 cases/1,000 patient-days), the rate of XDR A baumannii clinical isolates declined in P2 (1.74 cases/1,000 patient-days; P < .001) and further in P3 (0.69 cases/1,000 patient-days; P < .001). Compared with P1 (12.15 cases/1,000 patient-days), the rate of XDR A baumannii surveillance isolates also declined in P2 (2.11 cases/1,000 patient-days; P < .001) and P3 (0.98 cases/1,000 patient-days; P < .001). Incidence of nosocomial infections remained stable. Six patients developed chlorhexidine-induced rash (1.4/1,000 patient-days); 31 patients developed mucositis (17.1/1,000 patient-days). These results support advanced source control and thorough environmental cleaning to limit colonization and infection with XDR A baumannii in MICUs in resource-limited settings. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

From Multidrug- to Extensively Drug-Resistant Tuberculosis: Upward Trends as Seen from a 15-Year Nationwide Study

PubMed Central

Stoffels, Karolien; Allix-Béguec, Caroline; Groenen, Guido; Wanlin, Maryse; Berkvens, Dirk; Mathys, Vanessa; Supply, Philip; Fauville-Dufaux, Maryse

2013-01-01

Background Emergence of extensively drug-resistant tuberculosis (XDR-TB) represents an enormous challenge to Public Health globally. Methods Progression towards XDR-TB was investigated in Belgium, a country with a typically low TB incidence, by analyzing the magnitude, characteristics, and treatment success of multidrug-resistant tuberculosis (MDR-TB) through a population-based study from 1994 to 2008. Results Among the 174 MDR-TB patients, 81% were foreign-born, 48% of these being asylum seekers. Although the number of MDR-TB patients remained stable through the study period at around 15 new cases annually, frequencies of resistance of the patients’ first MDR-TB isolate to second-line drugs increased, as well as the total number of antibiotics it was resistant to (p<0.001). XDR-TB cases were detected from 2002 onwards. For 24 patients, additional resistance to several second-line drugs was acquired during treatment. Molecular-guided investigations indicated little to no contribution of in-country clonal spread or exogenous re-infection. The increase of pre-XDR and XDR cases could be attributed to rising proportions of patients from Asia and Central and Eastern Europe (p<0.001) and an increase in the isolation of Beijing strains in these groups (p<0.001). Despite augmented resistance, the treatment success rate improved from 63.0% to 75.8% (p = 0.080) after implementation in 2005 of improved surveillance measures and therapeutic access. Conclusions Increasing severity in drug resistance patterns leading to more XDR- and “panresistant” TB cases in a country with a low TB incidence like Belgium represents a strong alert on worsening situations in other world regions and requires intense public health measures. PMID:23671662

Cytosolic Proteome Profiling of Aminoglycosides Resistant Mycobacterium tuberculosis Clinical Isolates Using MALDI-TOF/MS.

PubMed

Sharma, Divakar; Lata, Manju; Singh, Rananjay; Deo, Nirmala; Venkatesan, Krishnamurthy; Bisht, Deepa

2016-01-01

Emergence of extensively drug resistant tuberculosis (XDR-TB) is the consequence of the failure of second line TB treatment. Aminoglycosides are the important second line anti-TB drugs used to treat the multi drug resistant tuberculosis (MDR-TB). Main known mechanism of action of aminoglycosides is to inhibit the protein synthesis by inhibiting the normal functioning of ribosome. Primary target of aminoglycosides are the ribosomal RNA and its associated proteins. Various mechanisms have been proposed for aminoglycosides resistance but still some are unsolved. As proteins are involved in most of the biological processes, these act as a potential diagnostic markers and drug targets. In the present study we analyzed the purely cytosolic proteome of amikacin (AK) and kanamycin (KM) resistant Mycobacterium tuberculosis isolates by proteomic and bioinformatic approaches. Twenty protein spots were found to have over expressed in resistant isolates and were identified. Among these Rv3208A, Rv2623, Rv1360, Rv2140c, Rv1636, and Rv2185c are six proteins with unknown functions or undefined role. Docking results showed that AK and KM binds to the conserved domain (DUF, USP-A, Luciferase, PEBP and Polyketidecyclase/dehydrase domain) of these hypothetical proteins and over expression of these proteins might neutralize/modulate the effect of drug molecules. TBPred and GPS-PUP predicted cytoplasmic nature and potential pupylation sites within these identified proteins, respectively. String analysis also suggested that over expressed proteins along with their interactive partners might be involved in aminoglycosides resistance. Cumulative effect of these over expressed proteins could be involved in AK and KM resistance by mitigating the toxicity, repression of drug target and neutralizing affect. These findings need further exploitation for the expansion of newer therapeutics or diagnostic markers against AK and KM resistance so that an extreme condition like XDR-TB can be prevented.

Occurrence of the Plasmid-Mediated Fluoroquinolone Resistance qepA1 Gene in Two Clonal Clinical Isolates of CTX-M-15-Producing Escherichia coli from Algeria.

PubMed

Yanat, Betitera; Dali Yahia, Radia; Yazi, Leila; Machuca, Jesús; Díaz-De-Alba, Paula; Touati, Abdelaziz; Pascual, Álvaro; Rodríguez-Martínez, José-Manuel

2017-06-01

QepA is a plasmid-mediated quinolone resistance determinant of low prevalence described worldwide, mainly in Enterobacteriaceae. This study describes, for the first time in Algeria, two clonally related, QepA-producing Escherichia coli clinical isolates positive for CTX-M-15. The clonal spread of these multidrug-resistant isolates is a major public health concern.

Bacteremic Urinary Tract Infection Caused by Multidrug-Resistant Enterobacteriaceae Are Associated With Severe Sepsis at Admission: Implication for Empirical Therapy.

PubMed

Lee, Yi-Chien; Hsiao, Chih-Yen; Hung, Miao-Chiu; Hung, Sheng-Che; Wang, Hung-Ping; Huang, Yun-Jhong; Wang, Jann-Tay

2016-05-01

The purpose of this study is to compare the clinical features and treatment outcomes among patients with bacteremic urinary tract infection (UTI) caused by multidrug-resistant (MDR) and non-MDR Enterobacteriaceae and to identify whether MDR pathogens were independently associated with severe sepsis or septic shock at presentation.The clinical data of adult patients visiting and being treated at Chia-Yi Christian Hospital due to bacteremic UTI caused by Enterobacteriaceae from January 2006 to August 2015 were retrospectively analyzed.A total of 585 patients were enrolled. Among them, 220 (37.6%) were caused by the MDR Enterobacteriaceae. A total of 206 patients (35.2%) developed severe sepsis or septic shock at presentation. Patients in the MDR group tend to be male and have a past history of gout, recurrent UTI, prior hospitalization, hydronephrosis, renal stone, ureteral stone, indwelling urinary catheter, newly development of renal dysfunction, severe sepsis or septic shock, intensive care unit (ICU) admission, receipt of ineffective empirical therapy, longer hospital stay, and higher in-hospital mortality (2.7% vs 1.9%, P = 0.569). Using multivariate logistic regression analysis, it is revealed that independent predictors associated with severe sepsis or septic shock at presentation were liver cirrhosis (OR 2.868; 95% CI 1.439-5.716; P = 0.003), indwelling urinary catheter (OR 1.936; 95% CI 1.238-3.027; P = 0.004), and MDR Enterobacteriaceae (OR 1.447; 95% CI 1.002-2.090; P = 0.049).Multidrug resistance was associated with the development of severe sepsis or septic shock upon presentation among patients with bacteremic UTI caused by Enterobacteriaceae. Therefore, empirical antibiotics therapy for patients with UTI presented with severe sepsis and/or septic shock should be more broad-spectrum to effectively cover MDR Enterobacteriaceae.

Comparison of the socio-demographic and clinical features of pulmonary TB patients infected with sub-lineages within the W-Beijing and non-Beijing Mycobacterium tuberculosis.

PubMed

Hu, Yi; Mathema, Barun; Zhao, Qi; Zheng, Xubin; Li, Dange; Jiang, Weili; Wang, Weibing; Xu, Biao

2016-03-01

Highly lethal outbreaks of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis are increasing. Mycobacterium tuberculosis variant Beijing family and its members is regarded as a successful clone of M. tuberculosis that is associated with drug resistance in China. Understanding the genetic characteristics and molecular mechanism of drug resistant tuberculosis within Beijing family may help to clarify its origin and evolutionary history and the driving forces behind its emergence and current dissemination. Totally of 1222 Mycobacterium tuberculosis isolates were recovered from patients in six counties of two provinces in eastern China within 2010/2012. Strain lineage and its major subgroups were studied respectively by using Spoligotyping and MIRU-VNTR. The 1st-line drug susceptibility was analyzed by proportional method and 2nd-line drug susceptibility was determined by the HAINs MTBDRsl test. The genetic characterization of drug resistance was analyzed by sequencing the previously reported genes and loci associated with drug resistance together with the multiple genotyping including MIRU-VNTR, Spoligotyping and LSP genotyping. Of the 1222 Mtb isolates, 298 (24.4%) were resistant to 1st-line drug and 73 (5.9%) were simultaneously resistant to INH and RIF namely MDR-TB. Respectively 23.8% of 1st-line drug resistant TB and 12.0% of the drug susceptible TB contained the mutation associated with 2nd-line drugs by HAINs test. The Spoligotyping of 1222 Mtb isolates revealed the 967 (79.1%) of the isolates belonged to the W-Beijing family. Within W-Beijing family, 78.8% MDR-TB were observed in the isolates with simultaneous deletion of RD105 and RD207, with sub-lineage 181 accounting for 75% of MDR-TB. Analysis of 24 MIRU-VNTR loci revealed that 88.2% (15/17) of MDR and extensively drug resistant (XDR) clustered isolates were sub-lineage 181. Sublineage 181 might have the capacity to spread throughout the general community in rural China. This is

Increased cefepime MIC for enterobacteriacae clinical isolates.

PubMed

Najafi, Narges; Alikhani, Ahmad; Babamahmoudi, Farhang; Davoudi, Alireza; Ghasemiyan, Roya; Aliyan, Shahriar; Shoujaiifar, Arman

2013-01-01

Background : Cefepime was used as empirical treatment in ventilator-associated pneumonia (VAP) induced by gram-negative and gram-positive bacteria. This study aimed to determine the antimicrobial susceptibility pattern of cefepime against microorganism causing VAP in Mazandaran, North of Iran. This study was performed on VAP patients diagnosed with clinical pulmonary infection score (CPIS) scores in ICU of two hospitals. For each patient suspected of having VAP, quantitative culture of endotracheal aspiration (QEA) was performed and MIC was determined by micro dilution test. Data were collected and analyzed. Thirty- five cases of enterobacteriaceae were isolated orderly including E coli 13, P. aeruginosa 11, Enterobacter 7 and K. pneumonia 4 cases. All the isolated E. coli, Enterobacter and Klebsiella, 54.5% of P. aeruginosa isolated were fully resistant to cefepime. The results of this study show that cefepime is not a reasonable choice for empirical treatment of nosocomial pneumonia and VAP.

Shortening the incubation time for antimicrobial susceptibility testing by disk diffusion for Enterobacteriaceae: how short can it be and are the results accurate?

PubMed

van den Bijllaardt, Wouter; Buiting, Anton G; Mouton, Johan W; Muller, Anouk E

2017-05-01

The standard incubation time for antimicrobial susceptibility testing (AST) by disk diffusion is primarily based on laboratory working hours rather than growth and kill characteristics of bacteria. Faster AST results could result in better patient outcomes and reduced costs by initiating earlier appropriate therapy. The earliest possible reading moment for disk diffusion using established disk zone diameter breakpoints for Enterobacteriaceae was determined with a special focus on the accuracy of the results. A total of 88 Enterobacteriaceae challenge isolates, including isolates with specific resistance mechanisms such as extended-spectrum β-lactamase (ESBL), were subjected to disk diffusion with 15 antibiotics. Hourly images were automatically produced by an incubator/camera combination from 1 h to 20 h. Disk zones were plotted over time for all combinations. Essential and categorical agreement rates using the final reading after 20 h of incubation as a reference were calculated for every hour. In total, 1320 antibiotic-micro-organism combinations were tested. Clear growth with readable inhibition zones was visible after 6 h of incubation for the majority (95.8%) of plates and after 7 h for all incubated plates. However, zone sizes changed significantly after those time points for a number of strains. After 10 h of incubation, minor, major and very major error rates were 1.6% (n = 21), 0.2% (n = 1) and 0.7% (n = 4), respectively. The results of this study clearly indicate that early reading of inhibition zones to 10 h after incubation is feasible and accurate and thus may save significantly on turnaround time. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Salmonella, Escherichia coli and Enterobacteriaceae in the peanut supply chain: From farm to table.

PubMed

Nascimento, M S; Carminati, J A; Silva, I C R N; Silva, D L; Bernardi, A O; Copetti, M V

2018-03-01

Due to recent foodborne outbreaks, peanuts have been considered a potential risk for Salmonella transmission. For this reason, the aim of this study was to determine the prevalence and contamination load of Salmonella, Escherichia coli and Enterobacteriaceae throughout the peanut supply chain in Brazil. Samples of peanuts and peanut-containing processed products from post-harvest (n=129), secondary processing (n=185) and retail market (n=100) were analyzed. The results showed high Enterobacteriaceae counts in the post-harvest samples. At the end of the secondary processing, 16% of the samples remained contaminated by this group of microorganisms. Six peanut samples from primary production and one sample of peanut butter were tested positive for E. coli while Salmonella was detected in nine samples (2.2%): six from post-harvest, two from the initial stage of the secondary processing and one from retail. The Salmonella counts ranged between 0.004 and 0.092MPN/g and five serotypes were identified (Muenster, Miami, Javiana, Oranienburg, Glostrup). The results demonstrated a high prevalence of Enterobacteriaceae and low prevalence of E. coli throughout the peanut supply chain. Furthermore, it was verified that peanuts may become contaminated by Salmonella during different stages of the supply chain, especially at post-harvest. Copyright © 2017 Elsevier Ltd. All rights reserved.

Enterobacteriaceae and Salmonella recovered from non-sanitized and sanitized broiler hatching eggs

USDA-ARS?s Scientific Manuscript database

Sanitizing hatching eggs may reduce the chances that a flock will become colonized with Salmonella and reduce the numbers of other microorganisms, such as Enterobacteriaceae, that can depress hatchability. An experiment was conducted to determine if a quaternary-biguanide sanitizer applied as foam ...

Polyclonal Intestinal Colonization with Extended-Spectrum Cephalosporin-Resistant Enterobacteriaceae upon Traveling to India

PubMed Central

Pires, João; Kuenzli, Esther; Kasraian, Sara; Tinguely, Regula; Furrer, Hansjakob; Hilty, Markus; Hatz, Christoph; Endimiani, Andrea

2016-01-01

We aimed to assess the intestinal colonization dynamics by multiple extended-spectrum cephalosporin-resistant Enterobacteriaceae (ESC-R-Ent) clones in Swiss travelers to India, a country with high prevalence of these multidrug-resistant pathogens. Fifteen healthy volunteers (HVs) colonized with ESC-R-Ent after traveling to India who provided stools before, after, and at 3- and 6-month follow-up are presented in this study. Stools were enriched in a LB broth containing 3 mg/L cefuroxime and plated in standard selective media (BLSE, ChromID ESBL, Supercarba) to detect carbapenem- and/or ESC-R-Ent. At least 5 Enterobacteriaceae colonies were analyzed for each stool provided. All strains underwent phenotypic tests (MICs in microdilution) and molecular typing to define bla genes (microarray, PCR/sequencing), clonality (MLST, rep-PCR), and plasmid content. While only three HVs were colonized before the trip, all participants had positive stools after returning, but the colonization rate decreased during the follow-up period (i.e., six HVs were still colonized at both 3 and 6 months). More importantly, polyclonal acquisition (median of 2 clones, range 1–5) was identified at return in all HVs. The majority of the Escherichia coli isolates belonged to phylogenetic groups A and B1 and to high diverse non-epidemic sequence types (STs); however, 15% of them belonged to clonal complex 10 and mainly possessed blaCTX−M−15 genes. F family plasmids were constantly found (~80%) in the recovered ESC-R-Ent. Our results indicate a possible polyclonal acquisition of the ESC-R-Ent via food-chain and/or through an environmental exposure. For some HVs, prolonged colonization in the follow-up period was observed due to clonal persistence or presence of the same plasmid replicon types in a new bacterial host. Travel medicine practitioners, clinicians, and clinical microbiologists who are facing the returning travelers and their samples for different reasons should be aware of this

Surveillance of carbapenemase-producing Enterobacteriaceae in the Indian Ocean Region between January 2010 and December 2015.

PubMed

Holman, A M; Allyn, J; Miltgen, G; Lugagne, N; Traversier, N; Picot, S; Lignereux, A; Oudin, C; Belmonte, O; Allou, N

2017-09-01

The aim of this study was to trace the emergence of carbapenemase-producing Enterobacteriaceae (CPE) on Reunion Island, a French overseas territory well suited for the surveillance of CPE emergence in patients from the entire Indian Ocean Region. This retrospective multicenter study was conducted on Reunion Island between 2010 and 2015. A total of 43 CPEs were isolated during the course of the study, in 36 patients (50% in the last year alone). Among these patients, 21 had a link with a foreign country (58%), mainly Mauritius (47.6%). Over the same period, CPEs were isolated from 13 of 1735 (0.7%) repatriated patients to Reunion Island from another country of the Indian Ocean Region. The incidence of isolation of CPEs in the repatriated patients treated in Mauritius was higher (9.2%) than in patients treated in Madagascar or the Comoros Islands (<1%, P<0.001). The most commonly isolated microorganism was Klebsiella pneumoniae (39.5%). The most frequently identified carbapenemase was NDM-1 (81.4%); 100% and 56% of the NDM-1 strains were susceptible to tigecycline and colistin, respectively. In-hospital mortality rate was higher in patients presenting with CPE infection than in patients without CPE infection (75% vs. 25%, P=0.04). As elsewhere in the world, the number of CPE cases on Reunion Island is on the rise. Most cases involve patients from Mauritius, which justifies screening and isolating CPE in patients from that country. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Presence of foodborne pathogens, extended-spectrum β-lactamase -producing Enterobacteriaceae, and methicillin-resistant Staphylococcus aureus in slaughtered reindeer in northern Finland and Norway.

PubMed

Laaksonen, Sauli; Oksanen, Antti; Julmi, Jérôme; Zweifel, Claudio; Fredriksson-Ahomaa, Maria; Stephan, Roger

2017-01-03

Various food-producing animals were recognized in recent years as healthy carriers of bacterial pathogens causing human illness. In northern Fennoscandia, the husbandry of semi-domesticated reindeer (Rangifer tarandus tarandus) is a traditional livelihood and meat is the main product. This study determined the presence of selected foodborne pathogens, methicillin-resistant Staphylococcus aureus (MRSA), and extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae in healthy semi-domesticated reindeer at slaughter in northern Finland and Norway. All 470 reindeer fecal samples tested negative for Salmonella spp., whereas L. monocytogenes was detected in 3%, Yersinia spp. in 10%, and Shiga toxins genes (stx1 and/or stx2) in 33% of the samples. Listeria monocytogenes isolates belonged to the serotype 1/2a (14/15) and 4b, Yersinia spp. were identified mainly as Y. kristensenii (30/46) and Y. enterocolitica (8/46), and stx2 predominated among the Shiga toxin genes (stx2 alone or in combination with stx1 was found in 25% of the samples). With regard to the frequency and distribution of stx1/stx2, striking differences were evident among the 10 different areas of origin. Hence, reindeer could constitute a reservoir for Shiga toxin-producing E. coli (STEC), but strain isolation and characterization is required for verification purposes and to assess the potential human pathogenicity of strains. On the other hand, the favorable antibiotic resistance profiles (only 5% of 95 E. coli isolates were resistant to one or more of the tested antibiotics) and the absence of MRSA and ESBL-producing Enterobacteriaceae (when applying selective methods) suggest only a limited risk of transmission to humans. Healthy semi-domesticated reindeer in northern Finland and Norway can be carriers of certain bacterial foodborne pathogens. Strict compliance with good hygiene practices during any step of slaughter (in particular during dehiding and evisceration) is therefore of central

Development of a Novel Screening Method for the Isolation of “Cronobacter” spp. (Enterobacter sakazakii)▿

PubMed Central

Iversen, Carol; Druggan, Patrick; Schumacher, Sandra; Lehner, Angelika; Feer, Claudia; Gschwend, Karl; Joosten, Han; Stephan, Roger

2008-01-01

A differential medium, “Cronobacter” screening broth, has been designed to complement agars based on hydrolysis of chromogenic α-glucopyranoside substrates. The broth was evaluated using 329 Enterobacteriaceae strains (229 target isolates), spiked/naturally contaminated samples, and a parallel comparison with current methods for raw materials, line/end products, and factory environment samples. PMID:18310415

Impact of Low and High Doses of Marbofloxacin on the Selection of Resistant Enterobacteriaceae in the Commensal Gut Flora of Young Cattle: Discussion of Data from 2 Study Populations.

PubMed

Lhermie, Guillaume; Dupouy, Véronique; El Garch, Farid; Ravinet, Nadine; Toutain, Pierre-Louis; Bousquet-Mélou, Alain; Seegers, Henri; Assié, Sébastien

2017-03-01

In the context of requested decrease of antimicrobial use in veterinary medicine, our objective was to assess the impact of two doses of marbofloxacin administered on young bulls (YBs) and veal calves (VCs) treated for bovine respiratory disease, on the total population of Enterobacteriaceae in gut flora and on the emergence of resistant Enterobacteriaceae. In two independent experiments, 48 YBs from 6 commercial farms and 33 VCs previously colostrum deprived and exposed to cefquinome were randomly assigned to one of the three groups LOW, HIGH, and Control. In LOW and HIGH groups, animals received a single injection of, respectively, 2 and 10 mg/kg marbofloxacin. Feces were sampled before treatment, and at several times after treatment. Total and resistant Enterobacteriaceae enumerating were performed by plating dilutions of fecal samples on MacConkey agar plates that were supplemented or not with quinolone. In YBs, marbofloxacin treatment was associated with a transient decrease in total Enterobacteriaceae count between day (D)1 and D3 after treatment. Total Enterobacteriaceae count returned to baseline between D5 and D7 in all groups. None of the 48 YBs harbored marbofloxacin-resistant Enterobacteriaceae before treatment. After treatment, 1 out of 20 YBs from the Control group and 1 out of 14 YBs from the HIGH group exhibited marbofloxacin-resistant Enterobacteriaceae. In VCs, the rate of fluoroquinolone-resistant Enterobacteriaceae significantly increased after low and high doses of marbofloxacin treatment. However, the effect was similar for the two doses, which was probably related to the high level of resistant Enterobacteriaceae exhibited before treatment. Our results suggest that a single treatment with 2 or 10 mg/kg marbofloxacin exerts a moderate selective pressure on commensal Enterobacteriaceae in YBs and in VCs. A fivefold decrease of marbofloxacin regimen did not affect the selection of resistances among commensal bacteria.

Whole-Transcriptome and -Genome Analysis of Extensively Drug-Resistant Mycobacterium tuberculosis Clinical Isolates Identifies Downregulation of ethA as a Mechanism of Ethionamide Resistance

PubMed Central

de Welzen, Lynne; Eldholm, Vegard; Maharaj, Kashmeel; Manson, Abigail L.; Earl, Ashlee M.

2017-01-01

ABSTRACT Genetics-based drug susceptibility testing has improved the diagnosis of drug-resistant tuberculosis but is limited by our lack of knowledge of all resistance mechanisms. Next-generation sequencing has assisted in identifying the principal genetic mechanisms of resistance for many drugs, but a significant proportion of phenotypic drug resistance is unexplained genetically. Few studies have formally compared the transcriptomes of susceptible and resistant Mycobacterium tuberculosis strains. We carried out comparative whole-genome transcriptomics of extensively drug-resistant (XDR) clinical isolates using RNA sequencing (RNA-seq) to find novel transcription-mediated mechanisms of resistance. We identified a promoter mutation (t to c) at position −11 (t−11c) relative to the start codon of ethA that reduces the expression of a monooxygenase (EthA) that activates ethionamide. (In this article, nucleotide changes are lowercase and amino acid substitutions are uppercase.) Using a flow cytometry-based reporter assay, we show that the reduced transcription of ethA is not due to transcriptional repression by ethR. Clinical strains harboring this mutation were resistant to ethionamide. Other ethA promoter mutations were identified in a global genomic survey of resistant M. tuberculosis strains. These results demonstrate a new mechanism of ethionamide resistance that can cause high-level resistance when it is combined with other ethionamide resistance-conferring mutations. Our study revealed many other genes which were highly up- or downregulated in XDR strains, including a toxin-antitoxin module (mazF5 mazE5) and tRNAs (leuX and thrU). This suggests that global transcriptional modifications could contribute to resistance or the maintenance of bacterial fitness have also occurred in XDR strains. PMID:28993337

A prospective study of treatment of carbapenem-resistant Enterobacteriaceae infections and risk factors associated with outcome.

PubMed

de Maio Carrilho, Claudia M D; de Oliveira, Larissa Marques; Gaudereto, Juliana; Perozin, Jamile S; Urbano, Mariana Ragassi; Camargo, Carlos H; Grion, Cintia M C; Levin, Anna Sara S; Costa, Silvia F

2016-11-03

To describe the clinical and microbiological data of carbapenem-resistant Enterobacteriaceae (CRE) infections, the treatment used, hospital- and infection-related mortality, and risk factors for death. A prospective cohort conducted from March 2011 to December 2012. Clinical, demographic, and microbiological data such as in vitro sensitivity, clonality, carbapenemase gene mortality related to infection, and overall mortality were evaluated. Data were analyzed using Epi Info version 7.0 (CDC, Atlanta, GA, USA) and SPSS (Chicago, IL, USA). One hundred and twenty-seven patients were evaluated. Pneumonia, 52 (42 %), and urinary tract infections (UTI), 51 (40.2 %), were the most frequent sites of infection. The isolates were polyclonal; the Bla KPC gene was found in 75.6 % of isolates, and 27 % of isolates were resistant to colistin. Mortality related to infection was 34.6 %, and was higher among patients with pneumonia (61.4 %). Combination therapy was used in 98 (77.2 %), and monotherapy in 22.8 %; 96.5 % of them were UTI patients. Shock, age, and dialysis were independent risk factors for death. There was no difference in infection-related death comparing colistin-susceptible and colistin-resistant infections (p = 0.46); neither in survival rate comparing the use of combination therapy with two drugs or more than two drugs (p = 0.32). CRE infection mortality was higher among patients with pneumonia. Infections caused by colistin-resistant isolates did not increase mortality. The use of more than two drugs on combination therapy did not show a protective effect on outcome. The isolates were polyclonal, and the bla KPC gene was the only carbapenemase found. Shock, dialysis, and age over 60 years were independent risk factors for death.

Predictors for gut colonization of carbapenem-resistant Enterobacteriaceae in neonates in a neonatal intensive care unit.

PubMed

Singh, Narendra Pal; Choudhury, Debapriya Das; Gupta, Kavita; Rai, Sumit; Batra, Prerna; Manchanda, Vikas; Saha, Rituparna; Kaur, I R

2018-06-01

With the emergence of carbapenem-resistant isolates, the therapeutic alternatives have become limited. Various factors are responsible for carbapenem-resistant Enterobacteriaceae (CRE) gut colonization. This study was conducted to determine predictors for CRE gut colonization in neonates who were hospital delivered and admitted in a neonatal intensive care unit (NICU). Three rectal swabs were collected from 300 hospital-delivered and NICU-admitted neonates (likely to stay for >3 days). The data collected for the possible risk factors for CRE gut colonization were namely mode of delivery, prolonged rupture of membrane >18 hours, period of gestation, birth weight, meconium-stained liquor, ventilation, intravenous catheter, nasogastric (NG) tube, NG feeding, breastfeeding, katori spoon feeding, top feeding, expressed breastmilk, antibiotics administration, and duration of hospitalization. P < .05 was considered as statistically significant. A total of 26 cases of CRE were isolated from 300 neonates. Statistically significant risk factors were found to be NG tube, breastfeeding, NG feeding, top feeding, expressed breastmilk, ventilation, antibiotic administration, and duration of hospitalization. Top feeding and antibiotics administration were identified as 2 independent risk factors by multiple logistic regression. Active surveillance of cultures from hospitalized patients and implementation of preventive efforts can reduce the risk of CRE. Copyright © 2018. Published by Elsevier Inc.

Associated factors and outcomes for OXA-232 Carbapenem-resistant Enterobacteriaceae infections in a tertiary care centre in Mexico City: A case-control-control study.

PubMed

Torres-González, Pedro; Ortiz-Brizuela, Edgar; Cervera-Hernandez, Miguel Enrique; Bobadilla-Del Valle, Miriam; Martínez-Gamboa, Areli; Sifuentes-Osornio, José; Ponce-de-Leon, Alfredo

2016-10-01

We describe the outcomes and factors associated with OXA-232 producing carbapenem-resistant Enterobacteriaceae infections. A case-control-control study was performed; each case of infection by a carbapenem-resistant/OXA-232 (OXA-232-cases, n=27) was matched by isolation site, species, and date, with 2 cases of infection by carbapenem-susceptible/third-generation cephalosporin-susceptible (TGCS-controls, n=54) and 2 cases by carbapenem-susceptible/ESBL producing Enterobacteriaceae (ESBL-controls, n=54); 66% were urinary tract and 18.5% intra-abdominal infections. In the multivariable analysis with ESBL-controls, previous use β-lactam/β-lactamase antibiotics (OR 6.2; 95% CI 1.6-23.8) and, third-generation cephalosporins (OR 0.2; 95% CI 0.05-0.8) were associated with OXA-232 infection; with TGSC-controls previous use of β-lactam/β-lactamase antibiotics (OR 3.7; 95% 1.1-12.0) was associated. Among the OXA-232-cases, 29% received imipenem/cilastatin or meropenem, 11.1% ceftriaxone, 22.2% a carbapenem-based combination and 33.3% other antimicrobials as treatment. Previous β-lactam/β-lactamase antibiotics are associated with OXA-232 infections, and some may be treated with other active carbapenems or, in the absence of ESBL, third-generation cephalosporins. Copyright © 2016 Elsevier Inc. All rights reserved.

ICU Acquisition Rate, Risk Factors, and Clinical Significance of Digestive Tract Colonization With Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae: A Systematic Review and Meta-Analysis.

PubMed

Detsis, Marios; Karanika, Styliani; Mylonakis, Eleftherios

2017-04-01

To evaluate the acquisition rate, identify risk factors, and estimate the risk for subsequent infection, associated with the colonization of the digestive tract with extended-spectrum beta-lactamase-producing Enterobacteriaceae during ICU-hospitalization. PubMed, EMBASE, and reference lists of all eligible articles. Included studies provided data on ICU-acquired colonization with extended-spectrum beta-lactamase-producing Enterobacteriaceae in previously noncolonized and noninfected patients and used the double disk synergy test for extended-spectrum beta-lactamase-producing Enterobacteriaceae phenotypic confirmation. Studies reporting extended-spectrum beta-lactamase-producing Enterobacteriaceae outbreaks or data on pediatric population were excluded. Two authors independently assessed study eligibility and performed data extraction. Thirteen studies (with 15,045 ICUs-patients) were evaluated using a random-effect model and a meta-regression analysis. The acquisition rate of digestive tract colonization during ICU stay was 7% (95% CI, 5-10) and it varies from 3% (95% CI, 2-4) and 4% (95% CI, 2-6) in the Americas and Europe to 21% (95% CI, 9-35) in the Western Pacific region. Previous hospitalization (risk ratio, 1.57 [95% CI, 1.07-2.31]) or antibiotic use (risk ratio, 1.65 [95% CI, 1.15-2.37]) and exposure to beta-lactams/beta-lactamase inhibitors (risk ratio, 1.78 [95% CI, 1.24-2.56]) and carbapenems (risk ratio, 2.13 [95% CI, 1.49-3.06]) during the ICU stay were independent risk factors for ICU-acquired colonization. Importantly, colonized patients were more likely to develop an extended-spectrum beta-lactamase-producing Enterobacteriaceae infection (risk ratio, 49.62 [95% CI, 20.42-120.58]). The sensitivity and specificity of prior colonization to predict subsequent extended-spectrum beta-lactamase-producing Enterobacteriaceae infection were 95.1% (95% CI, 54.7-99.7) and 89.2% (95% CI, 77.2-95.3), respectively. The ICU acquisition rate of extended-spectrum beta

Augmented renal clearance is not a risk factor for mortality in Enterobacteriaceae bloodstream infections treated with appropriate empiric antimicrobials.

PubMed

Burnham, Jason P; Micek, Scott T; Kollef, Marin H

2017-01-01

The main objective of the study was to assess whether augmented renal clearance was a risk factor for mortality in a cohort of patients with Enterobacteriaceae sepsis, severe sepsis, or septic shock that all received appropriate antimicrobial therapy within 12 hours. Using a retrospective cohort from Barnes-Jewish Hospital, a 1,250-bed teaching hospital, we collected data on individuals with Enterobacteriaceae sepsis, severe sepsis, and septic shock who received appropriate initial antimicrobial therapy between June 2009 and December 2013. Clinical outcomes were compared according to renal clearance, as assessed by Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulas, sepsis classification, demographics, severity of illness, and comorbidities. We identified 510 patients with Enterobacteriaceae bacteremia and sepsis, severe sepsis, or septic shock. Sixty-seven patients (13.1%) were nonsurvivors. Augmented renal clearance was uncommon (5.1% of patients by MDRD and 3.0% by CKD-EPI) and was not associated with increased mortality. Our results are limited by the absence of prospective determination of augmented renal clearance. However, in this small cohort, augmented renal clearance as assessed by MDRD and CKD-EPI does not seem to be a risk factor for mortality in patients with Enterobacteriaceae sepsis. Future studies should assess this finding prospectively.

Prevalence of extended-spectrum-β-lactamase-producing Enterobacteriaceae: first systematic meta-analysis report from Pakistan.

PubMed

Abrar, Samyyia; Hussain, Shahida; Khan, Rehan Ahmad; Ul Ain, Noor; Haider, Hayat; Riaz, Saba

2018-01-01

South-Asia is known as a hub for multidrug-resistant (MDR) bacteria. Unfortunately, proper surveillance and documentation of MDR pathogens is lacking in Pakistan. The alarming increase in the prevalence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae is a serious problem. From this perspective, we analysed published data regarding ESBL-producing Enterobacteriaceae in different regions of Pakistan. A meta-analysis was performed to determine the prevalence of ESBL-producing Enterobacteriaceae in Pakistan. A Web-based search was conducted in electronic databases, including PubMed, Scopus and PakMedi Net (for non-indexed Pakistani journals). Articles published (in either indexed or non-indexed journals) between January 2002 and July 2016 were included in the study. Relevant data were extracted, and statistical analysis was performed using the Metaprop command of STATA version 14.1. A total of 68 studies were identified from the electronic data base search, and 55 of these studies met our inclusion criteria. Pakistan's overall pooled proportion of ESBL-producers was 0.40 (95% CI: 0.34-0.47). The overall heterogeneity was significant (I2 = 99.75%, p  < 0.001), and significant ES = 0 (Z = 18.41, p  < 0.001) was found. OXA, SHV, TEM and CTX-M were the most commonly found gene variants for ESBLs in these studies. The prevalence of ESBL-producing Enterobacteriaceae is high in Pakistan. Little is known about the annual frequency of ESBLs and their prevalence in different provinces of Pakistan. No data are available regarding ESBL frequency in Baluchistan. This underscores an urgent demand for regular surveillance to address this antimicrobial resistance problem. Surveillance to better understand the annual ESBL burden is crucial to improve national and regional guidelines.

CTX-M extended-spectrum β-lactamase-producing Klebsiella spp, Salmonella spp, Shigella spp and Escherichia coli isolates in Iranian hospitals.

PubMed

Bialvaei, Abed Zahedi; Kafil, Hossein Samadi; Asgharzadeh, Mohammad; Aghazadeh, Mohammad; Yousefi, Mehdi

2016-01-01

This study was conducted in Iran in order to assess the distribution of CTX-M type ESBLs producing Enterobacteriaceae. From January 2012 to December 2013, totally 198 E. coli, 139 Klebsiella spp, 54 Salmonella spp and 52 Shigella spp from seven hospitals of six provinces in Iran were screened for resistance to extended-spectrum cephalosporins. After identification and susceptibility testing, isolates presenting multiple-drug resistance (MDR) were evaluated for ESBL production by the disk combination method and by Etest using (cefotaxime and cefotaxime plus clavulanic acid). All isolates were also screened for blaCTX-M using conventional PCR. A total of 42.92%, 33.81%, 14.81% and 7.69% of the E. coli, Klebsiella spp, Salmonella spp and Shigella spp isolates were MDR, respectively. The presence of CTX-M enzyme among ESBL-producing isolates was 85.18%, 77.7%, 50%, and 66.7%, in E. coli, Klebsiella spp, Salmonella spp and Shigella spp respectively. The overall presence of CTX-M genes in Enterobacteriaceae was 15.4% and among the resistant isolates was 47.6%. This study indicated that resistance to β-lactams mediated by CTX-M enzymes in Iran had similar pattern as in other parts of the world. In order to control the spread of resistance, comprehensive studies and programs are needed. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Carbapenem-resistant Gram-negative bacilli in Canada 2009-10: results from the Canadian Nosocomial Infection Surveillance Program (CNISP).

PubMed

Mataseje, L F; Bryce, E; Roscoe, D; Boyd, D A; Embree, J; Gravel, D; Katz, K; Kibsey, P; Kuhn, M; Mounchili, A; Simor, A; Taylor, G; Thomas, E; Turgeon, N; Mulvey, M R

2012-06-01

To investigate the occurrence and molecular mechanisms associated with carbapenemases in carbapenem-resistant Gram-negative isolates from Canadian cases. Twenty hospital sites across Canada submitted isolates for a 1 year period starting 1 September 2009. All Enterobacteriaceae with MICs ≥ 2 mg/L and Acinetobacter baumannii and Pseudomonas aeruginosa with MICs ≥ 16 mg/L of carbapenems were submitted to the National Microbiology Laboratory (NML) where carbapenem MICs were confirmed by Etest and isolates were characterized by PCR for carbapenemase genes, antimicrobial susceptibilities, PFGE and plasmid isolation. A total of 444 isolates (298 P. aeruginosa, 134 Enterobacteriaceae and 12 A. baumannii) were submitted to the NML of which 274 (61.7%; 206 P. aeruginosa, 59 Enterobacteriaceae and 9 A. baumannii) met the inclusion criteria as determined by Etest. Carbapenemase genes were identified in 30 isolates: bla(GES-5) (n = 3; P. aeruginosa), bla(KPC-3) (n = 7; Enterobacteriaceae), bla(NDM-1) (n = 2; Enterobacteriaceae), bla(VIM-2) and bla(VIM-4) (n = 8; P. aeruginosa) bla(SME-2) (n = 1; Enterobacteriaceae) and bla(OXA-23) (n = m9; A. baumannii). PFGE identified a cluster in each of Enterobacteriaceae, P. aeruginosa and A. baumannii corresponding to isolates harbouring carbapenemase genes. Three KPC plasmid patterns (IncN and FllA) were identified where indistinguishable plasmid patterns were identified in unrelated clinical isolates. Carbapenemases were rare at the time of this study. Dissemination of carbapenemases was due to both dominant clones and common plasmid backbones.

Sharing of carbapenemase-encoding plasmids between Enterobacteriaceae in UK sewage uncovered by MinION sequencing

PubMed Central

Blane, Beth; Coll, Francesc; Naydenova, Plamena; Hunt, Martin; Tracey, Alan; Hopkins, Katie L.; Brown, Nicholas M.; Woodford, Neil; Parkhill, Julian

2017-01-01

Dissemination of carbapenem resistance among pathogenic Gram-negative bacteria is a looming medical emergency. Efficient spread of resistance within and between bacterial species is facilitated by mobile genetic elements. We hypothesized that wastewater contributes to the dissemination of carbapenemase-producing Enterobacteriaceae (CPE), and studied this through a cross-sectional observational study of wastewater in the East of England. We isolated clinically relevant species of CPE in untreated and treated wastewater, confirming that waste treatment does not prevent release of CPE into the environment. We observed that CPE-positive plants were restricted to those in direct receipt of hospital waste, suggesting that hospital effluent may play a role in disseminating carbapenem resistance. We postulated that plasmids carrying carbapenemase genes were exchanged between bacterial hosts in sewage, and used short-read (Illumina) and long-read (MinION) technologies to characterize plasmids encoding resistance to antimicrobials and heavy metals. We demonstrated that different CPE species (Enterobacter kobei and Raoultella ornithinolytica) isolated from wastewater from the same treatment plant shared two plasmids of 63 and 280 kb. The former plasmid conferred resistance to carbapenems (blaOXA-48), and the latter to numerous drug classes and heavy metals. We also report the complete genome sequence for Enterobacter kobei. Small, portable sequencing instruments such as the MinION have the potential to improve the quality of information gathered on antimicrobial resistance in the environment. PMID:29026655

Clonal background, resistance gene profile, and porin gene mutations modulate in vitro susceptibility to imipenem/relebactam in diverse Enterobacteriaceae.

PubMed

Gomez-Simmonds, Angela; Stump, Stephania; Giddins, Marla J; Annavajhala, Medini K; Uhlemann, Anne-Catrin

2018-06-11

Treatment options for carbapenem-resistant Enterobacteriaceae (CRE) are limited. While Klebsiella pneumoniae harboring bla KPC account for most CRE, recent evidence points to increasing diversification of CRE. We determined whether CRE species and antibiotic resistance genotype influence response to relebactam (REL), a novel beta-lactamase inhibitor with class A/C activity, combined with imipenem(IMI)/cilastatin. We carried out broth microdilution testing to IMI alone or in the presence of 4 μg/mL REL in 154 clinical isolates collected at a New York City hospital with high prevalence of bla KPC including Enterobacter spp. (n=96), K. pneumoniae (n=44), Escherichia coli (n=1), Serratia marcescens (n=9) and Citrobacter spp. (n=4). Resistance gene profiles and presence of major porin gene disruptions were ascertained by whole genome sequencing. Addition of REL decreased the IMI MIC to the susceptible range (≤1 μg/mL) in 88% of isolates. However, S. marcescens IMI/REL MICs were 4 to 8-fold higher than those of other organisms. Most bla KPC -positive isolates had IMI/REL MICs ≤1 μg/mL (88%), including E. cloacae ST171 (93%) and K. pneumoniae ST258 (82%). Nineteen isolates had IMI/REL MICs ≥2 μg/mL, of which 84% harbored bla KPC and one was bla NDM-1 -positive. Isolates with IMI/REL MICs ≥2 μg/mL versus ≤1 μg/mL were significantly more likely to demonstrate disruption of at least one porin gene (42% versus 19%, p =0.04), although most S. marcescens isolates (67%) had intact porin genes. In conclusion, while REL reduced IMI MICs in a majority of diverse CRE isolates including high-risk clones, chromosomal factors impacted IMI/REL susceptibilities and may contribute to elevated MICs in S. marcescens. Copyright © 2018 American Society for Microbiology.

Isolation and identification of gastrointestinal microbiota from the short-nosed fruit bat Cynopterus brachyotis brachyotis.

PubMed

Daniel, Diane Sunira; Ng, Yau Kit; Chua, Ee Ley; Arumugam, Yogis; Wong, Wey Lim; Kumaran, Jayaraj Vijaya

2013-10-01

Studies on the microbial ecology of gut microbiota in bats are limited and such information is necessary in determining the ecological significance of these hosts. Short-nosed fruit bats (Cynopterus brachyotis brachyotis) are good candidates for microbiota studies given their close association with humans in urban areas. Thus, this study explores the gut microbiota of this species from Peninsular Malaysia by means of biochemical tests and 16S rRNA gene sequences analysis. The estimation of viable bacteria present in the stomach and intestine of C. b. brachyotis ranged from 3.06×10(10) to 1.36×10(15)CFU/ml for stomach fluid and 1.92×10(10) to 6.10×10(15)CFU/ml for intestinal fluid. A total of 34 isolates from the stomach and intestine of seven C. b. brachyotis were retrieved. A total of 16 species of bacteria from eight genera (Bacillus, Enterobacter, Enterococcus, Escherichia, Klebsiella, Pantoea, Pseudomonas and Serratia) were identified, Enterobacteriaceae being the most prevalent, contributing 12 out of 16 species isolated. Most isolates from the Family Enterobacteriaceae have been reported as pathogens to humans and wildlife. With the possibility of human wildlife transmission, the findings of this study focus on the importance of bats as reservoirs of potential bacterial pathogens. Copyright © 2013 Elsevier GmbH. All rights reserved.

Comparative study of the impact of the administration of Amoxicillin and Algo-Bio® alternative substance to antibiotics, on the level of selection of resistant Enterobacteriaceae in the digestive flora of piglets.

PubMed

Kouadio, Innocent Kouamé; Guessennd, Nathalie; Dadié, Adjéhi; Koffi, Eugène; Dosso, Mireille

2018-01-31

The aim of study was to evaluate by comparative study the level of selection of antibiotic-resistant Enterobacteriaceae in the digestive microbiota of piglets when using amoxicillin and Algo-Bio ® . Amoxicillin and Algo-Bio ® administration was carried out over a period of 5 days (D0-D4) at a dose of 1mL/10kg body weight. A phenotypic study was carried out with enumeration of resistant Enterobacteriaceae on MacConkey agar plates in the presence and absence of amoxicillin. Escherichia coli isolates were identified and were subjected to antimicrobial susceptibility testing. The percentages of amoxicillin-resistant Enterobacteriaceae before treatment ranged from 10-15% for the four groups of piglets. Following treatment initiation, on the second day (D1) to the fifth day (D4) of treatment, the percentages increased to 54-87% for the groups treated with amoxicillin. In the group treated with Algo-Bio ® and the controls, the percentages were <50%. The percentage of amoxicillin-resistant E. coli strains to the associated antibiotics increased during days of amoxicillin treatment, whereas in the control and Algo-Bio ® groups the percentages of E. coli resistant to antibiotics did not increase. The results indicated that Algo-Bio ® constitutes a good alternative prophylactic to antibiotics to reduce bacterial growth in the digestive tract of animals. Copyright © 2018 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Carbapenemases in Enterobacteriaceae: types and molecular epidemiology.

PubMed

Martínez-Martínez, Luis; González-López, Juan José

2014-12-01

The most important mechanism of carbapenem resistance in Enterobacteriaceae is the production of carbapenemases, although resistance can also result from the synergistic activity between AmpC-type or (to a lesser extent) extended-spectrum beta-lactamases combined with decreased outer membrane permeability. Three major molecular classes of carbapenemases are recognized: A, B and D. Classes A and D are serine-beta-lactamases, whereas class B are metallo-beta-lactamases (their hydrolytic activity depends on the presence of zinc). In addition to carbapenems, carbapenemases also hydrolyze other beta-lactams, but the concrete substrate profile depends on the enzyme type. In general terms, class A enzymes are to some extent inhibited by clavulanic acid, and class B enzymes do not affect monobactams and are inhibited by zinc chelators. Given Enterobacteriaceae producing carbapenemases usually also contain gene coding for other mechanisms of resistance to beta-lactams, it is not unusual for the organisms to present complex beta-lactam resistance phenotypes. Additionally, these organisms frequently contain other genes that confer resistance to quinolones, aminoglycosides, tetracyclines, sulphonamides and other families of antimicrobial agents, which cause multiresistance or even panresistance. Currently, the most important type of class A carbapenemases are KPC enzymes, whereas VIM, IMP and (particularly) NDM in class B and OXA-48 (and related) in class D are the more relevant enzymes. Whereas some enzymes are encoded by chromosomal genes, most carbapenemases are plasmid-mediated (with genes frequently located in integrons), which favors the dissemination of the enzymes. Detailed information of the genetic platforms and the context of the genes coding for the most relevant enzymes will be presented in this review. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

Molecular characterization of class b carbapenemases in advanced stage of dissemination and emergence of class d carbapenemases in Enterobacteriaceae from Croatia.

PubMed

Bedenić, Branka; Sardelić, Sanda; Luxner, Josefa; Bošnjak, Zrinka; Varda-Brkić, Dijana; Lukić-Grlić, Amarela; Mareković, Ivana; Frančula-Zaninović, Sonja; Krilanović, Marija; Šijak, Dorotea; Grisold, Andrea; Zarfel, Gernot

2016-09-01

Carbapenemases involved in acquired carbapenem resistance in Enterobacteriaceae belong to Ambler class A serin β-lactamases, class B metallo-β-lactamases (MBL) or class D OXA-48-like β-lactamases. The aim of the present study was to analyse the molecular epidemiology and the mechanisms and routes of spread of class B and class D carbapenemases in Croatia. In total 68 isolates were analyzed. Antibiotic susceptibility was determined by broth microdilution method. PCR was used to detect antibiotic-resistance genes. Genotyping was performed by rep-PCR and MLST. Sixty-five isolates were found to harbour VIM-1 carbapenemase, seven of which were positive also for NDM-1, while two strains harboured only NDM-1. OXA-48 was detected in three isolates, two of which coproduced VIM-1. Thirty-six strains possessed additional CTX-M-15 β-lactamase whereas 64 were positive for TEM-1. CMY was found in 18 Citrobacter freundii isolates and DHA-1 in one Enterobacter cloacae isolate. Four different plasmid-incompatibility groups were found: A/C, L/M, N and FIIAs. Unlike C. freundii and E. cloacae, Klebsiella pneumoniae showed high diversity of rep-PCR patterns. E. cloacae and C. freundii predominantly belonged to one large clone which was allocated to ST105 and ST24, respectively. Three different types of carbapenemases were identified showing the complexity of CRE in Croatia. Copyright © 2016 Elsevier B.V. All rights reserved.

Emergence of Carbapenemase-Producing Escherichia coli Isolated from Companion Animals in Algeria.

PubMed

Yousfi, Massilia; Touati, Abdelaziz; Mairi, Assia; Brasme, Lucien; Gharout-Sait, Alima; Guillard, Thomas; De Champs, Christophe

2016-06-01

The emergence and worldwide spread of carbapenemase-producing Enterobacteriaceae is of great concern to public health. The aim of this study was to investigate the occurrence of carbapenemase-producing Escherichia coli in companion animals in Algeria. Two hundred fecal samples were obtained from healthy and diseased dogs and cats in one veterinary office and private owners in Bejaia city, Algeria, during November 2014 to March 2015. Isolates were screened by polymerase chain reaction for the presence of carbapenemase, acquired plasmidic AmpC (pAmpC) and extended-spectrum beta-lactamase genes. Five carbapenemase-producing E. coli isolates were detected including four OXA-48-producing isolates and one isolate producing NDM-5. Coexpression of ESBL and pAmpC genes was observed in these isolates. Phylogenetic grouping revealed that these isolates belonged to A and D phylogroups. The results of this study show that carbapenemase-producing E. coli spread to the companion animals in Algeria.

Complex multifractal nature in Mycobacterium tuberculosis genome

PubMed Central

Mandal, Saurav; Roychowdhury, Tanmoy; Chirom, Keilash; Bhattacharya, Alok; Brojen Singh, R. K.

2017-01-01

The mutifractal and long range correlation (C(r)) properties of strings, such as nucleotide sequence can be a useful parameter for identification of underlying patterns and variations. In this study C(r) and multifractal singularity function f(α) have been used to study variations in the genomes of a pathogenic bacteria Mycobacterium tuberculosis. Genomic sequences of M. tuberculosis isolates displayed significant variations in C(r) and f(α) reflecting inherent differences in sequences among isolates. M. tuberculosis isolates can be categorised into different subgroups based on sensitivity to drugs, these are DS (drug sensitive isolates), MDR (multi-drug resistant isolates) and XDR (extremely drug resistant isolates). C(r) follows significantly different scaling rules in different subgroups of isolates, but all the isolates follow one parameter scaling law. The richness in complexity of each subgroup can be quantified by the measures of multifractal parameters displaying a pattern in which XDR isolates have highest value and lowest for drug sensitive isolates. Therefore C(r) and multifractal functions can be useful parameters for analysis of genomic sequences. PMID:28440326

Complex multifractal nature in Mycobacterium tuberculosis genome

NASA Astrophysics Data System (ADS)

Mandal, Saurav; Roychowdhury, Tanmoy; Chirom, Keilash; Bhattacharya, Alok; Brojen Singh, R. K.

2017-04-01

The mutifractal and long range correlation (C(r)) properties of strings, such as nucleotide sequence can be a useful parameter for identification of underlying patterns and variations. In this study C(r) and multifractal singularity function f(α) have been used to study variations in the genomes of a pathogenic bacteria Mycobacterium tuberculosis. Genomic sequences of M. tuberculosis isolates displayed significant variations in C(r) and f(α) reflecting inherent differences in sequences among isolates. M. tuberculosis isolates can be categorised into different subgroups based on sensitivity to drugs, these are DS (drug sensitive isolates), MDR (multi-drug resistant isolates) and XDR (extremely drug resistant isolates). C(r) follows significantly different scaling rules in different subgroups of isolates, but all the isolates follow one parameter scaling law. The richness in complexity of each subgroup can be quantified by the measures of multifractal parameters displaying a pattern in which XDR isolates have highest value and lowest for drug sensitive isolates. Therefore C(r) and multifractal functions can be useful parameters for analysis of genomic sequences.

Impact of the introduction of an automated microbiologic system on the clinical outcomes of bloodstream infections caused by Enterobacteriaceae strains.

PubMed

Callefi, Luciana Azevedo; Medeiros, Eduardo Alexandrino Servolo de; Furtado, Guilherme Henrique Campos

2013-01-01

Enterobacteriaceae strains are a leading cause of bloodstream infections (BSI). The aim of this study is to assess differences in clinical outcomes of patients with BSI caused by Enterobacteriaceae strains before and after introduction of an automated microbiologic system by the microbiology laboratory. We conducted a retrospective cohort study aimed to evaluate the impact of the introduction of an automated microbiologic system (Phoenix(tm) automated microbiology system, Becton, Dickinson and Company (BD) - Diagnostic Systems, Sparks, MD, USA) on the outcomes of BSIs caused by Enterobacteriaceae strains. The study was undertaken at Hospital São Paulo, a 750-bed teaching hospital in São Paulo, Brazil. Patients with BSI caused by Enterobacteriaceae strains before the introduction of the automated system were compared with patients with BSI caused by the same pathogens after the introduction of the automated system with regard to treatment adequacy, clinical cure/improvement and 14- and 28-day mortality rates. We evaluated 90 and 106 patients in the non-automated and automated testing periods, respectively. The most prevalent species in both periods were Klebsiella spp. and Proteus spp. Clinical cure/improvement occurred in 70% and 67.9% in non-automated and automated period, respectively (p = 0.75). 14-day mortality rates were 22.2% and 30% (p = 0.94) and 28-day mortality rates were 24.5% and 40.5% (p = 0.12). There were no significant differences between the two testing periods with regard to treatment adequacy, clinical cure/improvement and 14- and 28-day mortality rates. Introduction of the BD Phoenix(tm) automated microbiology system did not impact the clinical outcomes of BSIs caused by Enterobacteriaceae strains in our setting.

Comparison of Agar Dilution, Disk Diffusion, MicroScan, and Vitek Antimicrobial Susceptibility Testing Methods to Broth Microdilution for Detection of Fluoroquinolone-Resistant Isolates of the Family Enterobacteriaceae

PubMed Central

Steward, Christine D.; Stocker, Sheila A.; Swenson, Jana M.; O’Hara, Caroline M.; Edwards, Jonathan R.; Gaynes, Robert P.; McGowan, John E.; Tenover, Fred C.

1999-01-01

Fluoroquinolone resistance appears to be increasing in many species of bacteria, particularly in those causing nosocomial infections. However, the accuracy of some antimicrobial susceptibility testing methods for detecting fluoroquinolone resistance remains uncertain. Therefore, we compared the accuracy of the results of agar dilution, disk diffusion, MicroScan Walk Away Neg Combo 15 conventional panels, and Vitek GNS-F7 cards to the accuracy of the results of the broth microdilution reference method for detection of ciprofloxacin and ofloxacin resistance in 195 clinical isolates of the family Enterobacteriaceae collected from six U.S. hospitals for a national surveillance project (Project ICARE [Intensive Care Antimicrobial Resistance Epidemiology]). For ciprofloxacin, very major error rates were 0% (disk diffusion and MicroScan), 0.9% (agar dilution), and 2.7% (Vitek), while major error rates ranged from 0% (agar dilution) to 3.7% (MicroScan and Vitek). Minor error rates ranged from 12.3% (agar dilution) to 20.5% (MicroScan). For ofloxacin, no very major errors were observed, and major errors were noted only with MicroScan (3.7% major error rate). Minor error rates ranged from 8.2% (agar dilution) to 18.5% (Vitek). Minor errors for all methods were substantially reduced when results with MICs within ±1 dilution of the broth microdilution reference MIC were excluded from analysis. However, the high number of minor errors by all test systems remains a concern. PMID:9986809

Carbapenemase-Producing Enterobacteriaceae in Spain in 2012

PubMed Central

Saez, David; Bautista, Verónica; Fernández-Romero, Sara; Hernández-Molina, Juan Manuel; Pérez-Vázquez, María; Aracil, Belén; Campos, José

2013-01-01

We report the epidemiological impact of carbapenemase-producing Enterobacteriaceae (CPE) in Spain in 2012. Of the 237 carbapenemases detected, 163 were from the OXA-48 group, 60 were from VIM-1, 8 were from KPC-2, 5 were from IMP, and 1 was from NDM-1. Interhospital spread of carbapenemase-producing Klebsiella pneumoniae was due to a limited number of multilocus sequence types (MLST) and carbapenemase types, including ST15–VIM-1, ST11–OXA-48, ST405–OXA-48, ST101–KPC-2, and ST11–VIM-1. The number of CPE cases in Spain has increased sharply in recent years, due mainly to the emergence of OXA-48. PMID:24041898

Post-surgical mediastinitis due to carbapenem-resistant Enterobacteriaceae: Clinical, epidemiological and survival characteristics.

PubMed

Abboud, C S; Monteiro, J; Stryjewski, M E; Zandonadi, E C; Barbosa, V; Dantas, D; Sousa, E E; Fonseca, M J; Jacobs, D M; Pignatari, A C; Kiffer, C; Rao, G G

2016-05-01

Invasive infections due to carbapenem-resistant Enterobacteriaceae (CRE), including polymyxin-resistant (PR-CRE) strains, are being increasingly reported. However, there is a lack of clinical data for several life-threatening infections. Here we describe a cohort of patients with post-surgical mediastinitis due to CRE, including PR-CRE. This study was a retrospective cohort design at a single cardiology centre. Patients with mediastinitis due to CRE were identified and were investigated for clinically relevant variables. Infecting isolates were studied using molecular techniques. Patients infected with polymyxin-susceptible CRE (PS-CRE) strains were compared with those infected with PR-CRE strains. In total, 33 patients with CRE mediastinitis were studied, including 15 patients (45%) with PR-CRE. The majority (61%) were previously colonised. All infecting isolates carried blaKPC genes. Baseline characteristics of patients with PR-CRE mediastinitis were comparable with those with PS-CRE mediastinitis. Of the patients studied, 70% received at least one agent considered active in vitro and most patients received at least three concomitant antibiotics. Carbapenem plus polymyxin B was the most common antibiotic combination (73%). Over 90% of patients underwent surgical debridement. Overall, in-hospital mortality was 33% and tended to be higher in patients infected with PR-CRE (17% vs. 53%; P=0.06). In conclusion, mediastinitis due to CRE, including PR-CRE, can become a significant challenge in centres with CRE and a high cardiac surgery volume. Despite complex antibiotic treatments and aggressive surgical procedures, these patients have a high mortality, particularly those infected with PR-CRE. Copyright © 2016. Published by Elsevier B.V.

[Impact of enterobacteriaceae-producing extended-spectrum beta-lactamases (ESBLE) incidence increasing on barrier precautions implementation in a university hospital].

PubMed

Bourigault, C; Corvec, S; Bemer, P; Juvin, M-E; Guillouzouic, A; Crémet, L; Reynaud, A; Leprince, C; Lepelletier, D

2013-10-01

The French national surveillance program of multidrug-resistant bacteria (MDR) shows an increase of enterobacteriaceae-producing extended-spectrum beta-lactamases (ESBLE) incidence. The objectives of this study were to assess: the incidence of EBLSE in a large French university hospital between 2005 and 2010, and the difference of barrier precautions implementation between ESBL and other MDR. The ESBLE incidence measure used data from the laboratory of bacteriology. The application of isolation and barrier precautions was analyzed from the MRB national surveillance data over a 3-year period from 2006 to 2008. Data were entered and analyzed using Epi Info software. The Chi(2) test was used for the comparison of proportions. The overall incidence of ESBLE was significantly higher in 2010 than in 2005 (0.20/1000 patients-days vs 0.03/1000 patients-days, respectively) (P<0.001). The same was observed for Escherichia coli incidence with rates ranging from 0.02/1000 patients-days in 2005 to 0.15/1000 patients-days in 2010. Isolation precautions for patients with EBLSE were applied in relation for most patients with MRB (ESBLE vs others), without significant difference. The surveillance programme of MRB showed a significant increase of ESBLE, especially for E. coli. Isolation and barrier precautions were used for most patients with MRB, including ESBLE. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Unraveling Mycobacterium tuberculosis genomic diversity and evolution in Lisbon, Portugal, a highly drug resistant setting.

PubMed

Perdigão, João; Silva, Hugo; Machado, Diana; Macedo, Rita; Maltez, Fernando; Silva, Carla; Jordao, Luisa; Couto, Isabel; Mallard, Kim; Coll, Francesc; Hill-Cawthorne, Grant A; McNerney, Ruth; Pain, Arnab; Clark, Taane G; Viveiros, Miguel; Portugal, Isabel

2014-11-18

Multidrug- (MDR) and extensively drug resistant (XDR) tuberculosis (TB) presents a challenge to disease control and elimination goals. In Lisbon, Portugal, specific and successful XDR-TB strains have been found in circulation for almost two decades. In the present study we have genotyped and sequenced the genomes of 56 Mycobacterium tuberculosis isolates recovered mostly from Lisbon. The genotyping data revealed three major clusters associated with MDR-TB, two of which are associated with XDR-TB. Whilst the genomic data contributed to elucidate the phylogenetic positioning of circulating MDR-TB strains, showing a high predominance of a single SNP cluster group 5. Furthermore, a genome-wide phylogeny analysis from these strains, together with 19 publicly available genomes of Mycobacterium tuberculosis clinical isolates, revealed two major clades responsible for M/XDR-TB in the region: Lisboa3 and Q1 (LAM).The data presented by this study yielded insights on microevolution and identification of novel compensatory mutations associated with rifampicin resistance in rpoB and rpoC. The screening for other structural variations revealed putative clade-defining variants. One deletion in PPE41, found among Lisboa3 isolates, is proposed to contribute to immune evasion and as a selective advantage. Insertion sequence (IS) mapping has also demonstrated the role of IS6110 as a major driver in mycobacterial evolution by affecting gene integrity and regulation. Globally, this study contributes with novel genome-wide phylogenetic data and has led to the identification of new genomic variants that support the notion of a growing genomic diversity facing both setting and host adaptation.

β-lactam resistance in gram-negative pathogens isolated from animals.

PubMed

Trott, Darren

2013-01-01

Although β-lactams remain a cornerstone of veterinary therapeutics, only a restricted number are actually approved for use in food-producing livestock in comparison to companion animals and wildlife. Nevertheless, both registered and off-label use of third and fourth-generation cephalosporins in livestock may have influenced the emergence of plasmid-encoded AmpC β-lactamases (pAmpC) (mainly CMY-2) and CTX-M extended-spectrum β-lactamases (ESBLs) in both Gram-negative pathogens and commensals isolated from animals. This presents a public health concern due to the potential risk of transfer of β-lactam-resistant pathogens from livestock to humans through food. The recent detection of pAmpC and ESBLs in multidrug-resistant Enterobacteriaceae isolated from dogs has also confirmed the public health importance of β-lactam resistance in companion animals, though in this case, human-to-animal transmission may be equally as relevant as animal-to-human transmission. Identification of pAmpC and ESBLs in Enterobacteriaceae isolated from wildlife and aquaculture species may be evidence of environmental selection pressure arising from both human and veterinary use of β- lactams. Such selection pressure in animals could be reduced by the availability of reliable alternative control measures such as vaccines, bacteriophage treatments and/or competitive exclusion models for endemic production animal diseases such as colibacillosis. The global emergence and pandemic spread of extraintestinal pathogenic E. coli O25-ST131 strains expressing CTX-M-15 ESBL in humans and its recent detection in livestock, companion animals and wildlife is a major cause for concern and goes against the paradigm that Gramnegative pathogens do not necessarily have to lose virulence in compensation for acquiring resistance.

MIC of amoxicillin/clavulanate according to CLSI and EUCAST: discrepancies and clinical impact in patients with bloodstream infections due to Enterobacteriaceae.

PubMed

Delgado-Valverde, Mercedes; Valiente-Mendez, Adoración; Torres, Eva; Almirante, Benito; Gómez-Zorrilla, Silvia; Borrell, Nuria; Aller-García, Ana Isabel; Gurgui, Mercedes; Almela, Manel; Sanz, Mercedes; Bou, Germán; Martínez-Martínez, Luis; Cantón, Rafael; Antonio Lepe, Jose; Causse, Manuel; Gutiérrez-Gutiérrez, Belén; Pascual, Álvaro; Rodríguez-Baño, Jesús

2017-05-01

To compare results of amoxicillin/clavulanate susceptibility testing using CLSI and EUCAST methodologies and to evaluate their impact on outcome in patients with bacteraemia caused by Enterobacteriaceae. A prospective observational cohort study was conducted in 13 Spanish hospitals. Patients with bacteraemia due to Enterobacteriaceae who received empirical intravenous amoxicillin/clavulanate treatment for at least 48 h were included. MICs were determined following CLSI and EUCAST recommendations. Outcome variables were: failure at the end of treatment with amoxicillin/clavulanate (FEAMC); failure at day 21; and 30 day mortality. Classification and regression tree (CART) analysis and logistic regression were performed. Overall, 264 episodes were included; the urinary tract was the most common source (64.7%) and Escherichia coli the most frequent pathogen (76.5%). Fifty-two isolates (19.7%) showed resistance according to CLSI and 141 (53.4%) according to EUCAST. The kappa index for the concordance between the results of both committees was only 0.24. EUCAST-derived, but not CLSI-derived, MICs were associated with failure when considered as continuous variables. CART analysis suggested a 'resistance' breakpoint of > 8/4 mg/L for CLSI-derived MICs; it predicted FEAMC in adjusted analysis (OR = 1.96; 95% CI: 0.98-3.90). Isolates with EUCAST-derived MICs >16/2 mg/L independently predicted FEAMC (OR = 2.10; 95% CI: 1.05-4.21) and failure at day 21 (OR= 3.01; 95% CI: 0.93-9.67). MICs >32/2 mg/L were only predictive of failure among patients with bacteraemia from urinary or biliary tract sources. CLSI and EUCAST methodologies showed low agreement for determining the MIC of amoxicillin/clavulanate. EUCAST-derived MICs seemed more predictive of failure than CLSI-derived ones. EUCAST-derived MICs >16/2 mg/L were independently associated with therapeutic failure. © The Author 2017. Published by Oxford University Press on behalf of the British Society

Detecting 16S rRNA Methyltransferases in Enterobacteriaceae by Use of Arbekacin

PubMed Central

Chahine, Sarah; Okafor, Darius; Ong, Ana C.; Maybank, Rosslyn; Kwak, Yoon I.; Wilson, Kerry; Zapor, Michael; Lesho, Emil; Hinkle, Mary

2015-01-01

16S rRNA methyltransferases confer resistance to most aminoglycosides, but discriminating their activity from that of aminoglycoside-modifying enzymes (AMEs) is challenging using phenotypic methods. We demonstrate that arbekacin, an aminoglycoside refractory to most AMEs, can rapidly detect 16S methyltransferase activity in Enterobacteriaceae with high specificity using the standard disk susceptibility test. PMID:26537447

Carbapenemase-producing Enterobacteriaceae: Risk factors for infection and impact of resistance on outcomes

PubMed Central

Mariappan, Shanthi; Sekar, Uma; Kamalanathan, Arunagiri

2017-01-01

Background: Carbapenemase-producing Enterobacteriaceae (CPE) have increased in recent years leading to limitations of treatment options. The present study was undertaken to detect CPE, risk factors for acquiring them and their impact on clinical outcomes. Methods: This retrospective observational study included 111 clinically significant Enterobacteriaceae resistant to cephalosporins subclass III and exhibiting a positive modified Hodge test. Screening for carbapenemase production was done by phenotypic methods, and polymerase chain reaction was performed to detect genes encoding them. Retrospectively, the medical records of the patients were perused to assess risk factors for infections with CPE and their impact. The data collected were duration of hospital stay, Intensive Care Unit (ICU) stay, use of invasive devices, mechanical ventilation, the presence of comorbidities, and antimicrobial therapy. The outcome was followed up. Univariate and multivariate analysis of the data were performed using SPSS software. Results: Carbapenemase-encoding genes were detected in 67 isolates. The genes detected were New Delhi metallo-β-lactamase, Verona integron-encoded metallo-β-lactamase, and oxacillinase-181.Although univariate analysis identified risk factors associated with acquiring CPE infections as ICU stay (P = 0.021), mechanical ventilation (P = 0.013), indwelling device (P = 0.011), diabetes mellitus (P = 0.036), usage of multiple antimicrobial agents (P = 0.007), administration of carbapenems (P = 0.042), presence of focal infection or sepsis (P = 0.013), and surgical interventions (P = 0.016), multivariate analysis revealed that all these factors were insignificant. Mortality rate was 56.7% in patients with CPE infections. By both univariate and multivariate analysis of impact of the variables on mortality in these patients, the significant factors were mechanical ventilation (odds ratio [OR]: 0.141, 95% confidence interval [CI]: 0.024–0.812) and presence of

Characterization of Plasmids in Extensively Drug-Resistant Acinetobacter Strains Isolated in India and Pakistan

PubMed Central

Carvalho, Maria J.; Toleman, Mark A.; White, P. Lewis; Connor, Thomas R.; Mushtaq, Ammara; Weeks, Janis L.; Kumarasamy, Karthikeyan K.; Raven, Katherine E.; Török, M. Estée; Peacock, Sharon J.; Howe, Robin A.; Walsh, Timothy R.

2014-01-01

The blaNDM-1 gene is associated with extensive drug resistance in Gram-negative bacteria. This probably spread to Enterobacteriaceae from Acinetobacter spp., and we characterized plasmids associated with blaNDM-1 in Acinetobacter spp. to gain insight into their role in this dissemination. Four clinical NDM-1-producing Acinetobacter species strains from India and Pakistan were investigated. A plasmid harboring blaNDM-1, pNDM-40-1, was characterized by whole-genome sequencing of Acinetobacter bereziniae CHI-40-1 and comparison with related plasmids. The presence of similar plasmids in strains from Pakistan was sought by PCR and sequencing of amplicons. Conjugation frequency was tested and stability of pNDM-40-1 investigated by real-time PCR of isolates passaged with and without antimicrobial selection pressure. A. bereziniae and Acinetobacter haemolyticus strains contained plasmids similar to the pNDM-BJ01-like plasmids identified in Acinetobacter spp. in China. The backbone of pNDM-40-1 was almost identical to that of pNDM-BJ01-like plasmids, but the transposon harboring blaNDM-1, Tn125, contained two short deletions. Escherichia coli and Acinetobacter pittii transconjugants were readily obtained. Transconjugants retained pNDM-40-1 after a 14-day passage experiment, although stability was greater with meropenem selection. Fragments of pNDM-BJ01-like plasmid backbones are found near blaNDM-1 in some genetic contexts from Enterobacteriaceae, suggesting that cross-genus transfer has occurred. pNDM-BJ01-like plasmids have been described in isolates originating from a wide geographical region in southern Asia. In vitro data on plasmid transfer and stability suggest that these plasmids could have contributed to the spread of blaNDM-1 into Enterobacteriaceae. PMID:25421466

High prevalence of Salmonella and IMP-4-producing Enterobacteriaceae in the silver gull on Five Islands, Australia.

PubMed

Dolejska, Monika; Masarikova, Martina; Dobiasova, Hana; Jamborova, Ivana; Karpiskova, Renata; Havlicek, Martin; Carlile, Nicholas; Priddel, David; Cizek, Alois; Literak, Ivan

2016-01-01

The objective of this study was to investigate the silver gull as an indicator of environmental contamination by salmonellae and carbapenemase-producing Enterobacteriaceae (CPE) in south-east Australia. A total of 504 cloacal samples were collected from gull chicks at three nesting colonies in New South Wales, Australia [White Bay (n = 144), Five Islands (n = 200) and Montague Island (n = 160)] and were examined for salmonellae and CPE. Isolates were tested for carbapenemase genes and susceptibility to 14 antibiotics. Clonality was determined by PFGE and MLST. Genetic context and conjugative transfer of the carbapenemase gene were determined. A total of 120 CPE of 10 species, mainly Escherichia coli (n = 85), carrying the gene blaIMP-4, blaIMP-38 or blaIMP-26 were obtained from 80 (40%) gulls from Five Islands. Thirty percent of birds from this colony were colonized by salmonellae. Most isolates contained the gene within a class 1 integron showing a blaIMP-4-qacG-aacA4-catB3 array. The blaIMP gene was carried by conjugative plasmids of variable sizes (80-400 kb) and diverse replicons, including HI2-N (n = 30), HI2 (11), A/C (17), A/C-Y (2), L/M (5), I1 (1) and non-typeable (6). Despite the overall high genetic variability, common clones and plasmid types were shared by different birds and bacterial isolates, respectively. Our data demonstrate a large-scale transmission of carbapenemase-producing bacteria into wildlife, likely as a result of the feeding habits of the birds at a local waste depot. The isolates from gulls showed significant similarities with clinical isolates from Australia, suggesting the human origin of the isolates. The sources of CPE for gulls on Five Islands should be explored and proper measures applied to stop the transmission into the environment. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.

Antimicrobial Susceptibility Testing of Mycobacterium bovis Isolates from Michigan White-Tailed Deer during the 2009 Hunting Season.

PubMed

Fitzgerald, Scott D; Schooley, Angie M; Berry, Dale E; Kaneene, John B

2010-12-02

Michigan has had an ongoing outbreak of endemic Mycobacterium bovis which has been recognized within and sustained by its free-ranging white-tailed deer population since 1994. Worldwide, organisms within the Mycobacterium tuberculosis complex have exhibited the ability to develop resistance to antimicrobial agents, resulting in both the multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of human tuberculosis. Michigan's Bovine Tuberculosis Working Group has conducted active antimicrobial susceptibility testing on wildlife isolates of the endemic M. bovis organism at five-year intervals to detect any emerging drug resistance patterns. The results of 33 white-tailed deer origin isolates collected from the 2009 hunting season are reported here. There continues to be no evidence of any drug resistance except for pyrazinamide resistance. These results are likely due to the lack of antibacterial treatment applied to either wildlife or domestic animals which would provide selection pressure for the development of drug resistance.

Evaluation of a real-time PCR assay for rectal screening of OXA-48-producing Enterobacteriaceae in a general intensive care unit of an endemic hospital.

PubMed

Fernández, J; Cunningham, S A; Fernández-Verdugo, A; Viña-Soria, L; Martín, L; Rodicio, M R; Escudero, D; Vazquez, F; Mandrekar, J N; Patel, R

2017-07-01

Carbapenemase-producing Enterobacteriaceae are increasing worldwide. Rectal screening for these bacteria can inform the management of infected and colonized patients, especially those admitted to intensive care units (ICUs). A laboratory developed, qualitative duplex real-time polymerase chain reaction assay for rapid detection of OXA-48-like and VIM producing Enterobacteriaceae, performed on rectal swabs, was designed and evaluated in an intensive care unit with endemic presence of OXA-48. During analytical assay validation, no cross-reactivity was observed and 100% sensitivity and specificity were obtained for both bla OXA-48-like and bla VIM in all spiked clinical samples. During the clinical part of the study, the global sensitivity and specificity of the real-time PCR assay for OXA-48 detection were 95.7% and 100% (P=0.1250), respectively, in comparison with culture; no VIM-producing Enterobacteriaceae were detected. Clinical features of patients in the ICU who were colonized or infected with OXA-48 producing Enterobacteriaceae, including outcome, were analyzed. Most had severe underlying conditions, and had risk factors for colonization with carbapenemase-producing Enterobacteriaceae before or during ICU admission, such as receiving previous antimicrobial therapy, prior healthcare exposure (including long-term care), chronic disease, immunosuppression and/or the presence of an intravascular catheter and/or mechanical ventilation device. The described real-time PCR assay is fast (~2-3hours, if DNA extraction is included), simple to perform and results are easy to interpret, features which make it applicable in the routine of clinical microbiology laboratories. Implementation in endemic hospitals could contribute to early detection of patients colonized by OXA-48 producing Enterobacteriaceae and prevention of their spread. Copyright © 2017 Elsevier Inc. All rights reserved.

International travel and acquisition of multidrug-resistant Enterobacteriaceae: a systematic review.

PubMed

Hassing, Robert Jan; Alsma, Jelmer; Arcilla, Maris S; van Genderen, Perry J; Stricker, Bruno H; Verbon, Annelies

2015-01-01

International travel is considered to be an important risk factor for acquisition of multidrug-resistant Enterobacteriaceae (MRE). The aim of this systematic review was to determine the effect of international travel on the risk of post-travel faecal carriage of MRE. Secondary outcomes were risk factors for acquisition of MRE. A systematic search for relevant literature in seven international databases was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Articles needed to report on (i) foreign travel, (ii) screening of asymptomatic participants, (iii) antimicrobial susceptibility data and (iv) faecal Enterobacteriaceae carriage. Two researchers independently screened the abstracts, assessed the full article texts for eligibility and selected or rejected them for inclusion in the systematic review. In case of disagreement, a third researcher decided on inclusion. Eleven studies were identified. In all studies, a high prevalence (>20%) of carriage of MRE after international travel was found. The highest prevalence was observed in travellers returning from southern Asia. Foreign travel was associated with an increased risk of carriage of MRE. Further research is needed to assess if this leads to an increase in the number of infections with MRE. Systematic review registration number: PROSPERO CRD42015024973.

Carbapenem-Resistant Acinetobacter baumannii and Enterobacteriaceae in South and Southeast Asia

PubMed Central

Apisarnthanarak, Anucha; Khan, Erum; Ghafur, Abdul

2016-01-01

SUMMARY Carbapenem-resistant Gram-negative bacteria, in particular the Acinetobacter baumannii-calcoaceticus complex and Enterobacteriaceae, are escalating global public health threats. We review the epidemiology and prevalence of these carbapenem-resistant Gram-negative bacteria among countries in South and Southeast Asia, where the rates of resistance are some of the highest in the world. These countries house more than a third of the world's population, and several are also major medical tourism destinations. There are significant data gaps, and the almost universal lack of comprehensive surveillance programs that include molecular epidemiologic testing has made it difficult to understand the origins and extent of the problem in depth. A complex combination of factors such as inappropriate prescription of antibiotics, overstretched health systems, and international travel (including the phenomenon of medical tourism) probably led to the rapid rise and spread of these bacteria in hospitals in South and Southeast Asia. In India, Pakistan, and Vietnam, carbapenem-resistant Enterobacteriaceae have also been found in the environment and community, likely as a consequence of poor environmental hygiene and sanitation. Considerable political will and effort, including from countries outside these regions, are vital in order to reduce the prevalence of such bacteria in South and Southeast Asia and prevent their global spread. PMID:27795305

Carbapenem-resistant Enterobacteriaceae colonization and infection in critically ill patients: a retrospective matched cohort comparison with non-carriers.

PubMed

Dickstein, Y; Edelman, R; Dror, T; Hussein, K; Bar-Lavie, Y; Paul, M

2016-09-01

To examine whether carbapenem-resistant Enterobacteriaceae (CRE) carriage is associated with incidence of clinical infection as a means of assessing whether the morbidity and mortality associated with these bacteria are mediated by underlying conditions or intrinsic properties of CRE. This retrospective matched cohort study compared the incidence of invasive infections in CRE-colonized patients and matched non-carriers in the intensive care unit (ICU). The primary outcome was infection caused by CRE of the same species as the colonizing strain among CRE carriers, and infections caused by carbapenem-sensitive strains of the same organism in non-carriers. Hospital discharge and death were considered as competing events. Competing-risks hazard analysis was performed for the entire cohort and for a nested cohort matched by Acute Physiology and Chronic Health Evaluation (APACHE) II scores, stratified by matching. In total, 146 CRE carriers were compared with 292 non-carriers. Patients were well matched for most risk factors for Enterobacteriaceae infection, including age, renal failure, previous invasive infection, previous hospitalization, APACHE II score, length of mechanical ventilation, length of hospitalization and CRE carriage. On regression analysis, colonization with CRE was independently associated with Enterobacteriaceae infection {cause-specific hazard ratio (CSHR) 2.06 [95% confidence interval (CI) 1.03-4.09]}. On regression analysis of the APACHE-II-matched cohort (N=284), colonization with CRE remained significantly associated with Enterobacteriaceae infection [CSHR 3.32 (95% CI 1.31-8.43)]. Colonization with CRE was associated with at least a two-fold increased risk of infection by the colonizing strain amongst ICU patients. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Lack of Correlation Between β-Lactamase Production and Susceptibility to Cefamandole or Cefoxitin Among Spontaneous Mutants of Enterobacteriaceae

PubMed Central

Ott, John L.; Turner, J. R.; Mahoney, David F.

1979-01-01

A large number of cultures of gram-negative bacteria were examined for their susceptibility to various concentrations of cefamandole, cefoxitin, carbenicillin, and nalidixic acid. Heterogeneity of susceptibility was demonstrated in individual cultures to all of these antibiotics. Resistant clones isolated from cefamandole or cefoxitin plates were examined for β-lactamase production. Approximately 13% of 262 resistant clones acquired the ability to produce a β-lactamase. Examination of the substrate profile of the β-lactamases from some of these clones revealed no change in the specific activity of these enzymes for cefamandole, cephaloridine, or compound 87/312 as compared with their parental enzymes. This study clearly shows that some resistant clones do not produce β-lactamases, whereas some susceptible strains produced significant amounts of these enzymes. We conclude from these findings that little correlation exists between β-lactamase production and decreased susceptibility to cefamandole or cefoxitin. The results suggest the possibility that characteristics other than β-lactamase production may be responsible for resistance in Enterobacteriaceae. PMID:311615

Evaluation of a simple phenotypic method for the detection of carbapenemase-producing Enterobacteriaceae.

PubMed

Saito, Ryoichi; Koyano, Saho; Dorin, Misato; Higurashi, Yoshimi; Misawa, Yoshiki; Nagano, Noriyuki; Kaneko, Takamasa; Moriya, Kyoji

2015-01-01

We investigated the performance of a phenotypic test, the Carbapenemase Detection Set (MAST-CDS), for the identification of carbapenemase-producing Enterobacteriaceae. Our results indicated that MAST-CDS is rapid, easily performed, simple to interpret, and highly sensitive for the identification of carbapenemase producers, particularly imipenemase producers. Copyright © 2014 Elsevier B.V. All rights reserved.

Unprecedented Silver Resistance in Clinically Isolated Enterobacteriaceae: Major Implications for Burn and Wound Management

PubMed Central

Norton, Rhy; Austin, Cindy; Mitchell, Amber; Zank, Sara; Durham, Paul

2015-01-01

Increased utilization of inorganic silver as an adjunctive to many medical devices has raised concerns of emergent silver resistance in clinical bacteria. Although the molecular basis for silver resistance has been previously characterized, to date, significant phenotypic expression of these genes in clinical settings is yet to be observed. Here, we identified the first strains of clinical bacteria expressing silver resistance at a level that could significantly impact wound care and the use of silver-based dressings. Screening of 859 clinical isolates confirmed 31 harbored at least 1 silver resistance gene. Despite the presence of these genes, MIC testing revealed most of the bacteria displayed little or no increase in resistance to ionic silver (200 to 300 μM Ag+). However, 2 isolates (Klebsiella pneumonia and Enterobacter cloacae) were capable of robust growth at exceedingly high silver concentrations, with MIC values reaching 5,500 μM Ag+. DNA sequencing of these two strains revealed the presence of genes homologous to known genetic determinants of heavy metal resistance. Darkening of the bacteria's pigment was observed after exposure to high silver concentrations. Scanning electron microscopy images showed the presence of silver nanoparticles embedded in the extracellular polymeric substance of both isolates. This finding suggested that the isolates may neutralize ionic silver via reduction to elemental silver. Antimicrobial testing revealed both organisms to be completely resistant to many commercially available silver-impregnated burn and wound dressings. Taken together, these findings provide the first evidence of clinical bacteria capable of expressing silver resistance at levels that could significantly impact wound management. PMID:26014954

Detecting 16S rRNA Methyltransferases in Enterobacteriaceae by Use of Arbekacin.

PubMed

McGann, Patrick; Chahine, Sarah; Okafor, Darius; Ong, Ana C; Maybank, Rosslyn; Kwak, Yoon I; Wilson, Kerry; Zapor, Michael; Lesho, Emil; Hinkle, Mary

2016-01-01

16S rRNA methyltransferases confer resistance to most aminoglycosides, but discriminating their activity from that of aminoglycoside-modifying enzymes (AMEs) is challenging using phenotypic methods. We demonstrate that arbekacin, an aminoglycoside refractory to most AMEs, can rapidly detect 16S methyltransferase activity in Enterobacteriaceae with high specificity using the standard disk susceptibility test. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Comparative analysis of Edwardsiella tarda isolates from fish in the eastern United States suggests the existence of two genetically distinct species, Edwardsiella tarda and Edwardsiella pseudotarda sp. nov

USDA-ARS?s Scientific Manuscript database

Edwardsiella tarda, a Gram-negative member of the family Enterobacteriaceae, is often implicated in significant losses in aquaculture facilities worldwide. Here, we assessed the intra-specific variability of a collection of E. tarda isolates from 4 different fish species in the eastern United State...

Fecal Carriage of Carbapenemase-Producing Enterobacteriaceae: a Hidden Reservoir in Hospitalized and Nonhospitalized Patients

PubMed Central

Gijón, Desirèe; Curiao, Tânia; Baquero, Fernando; Coque, Teresa M.

2012-01-01

Fecal carriage of carbapenemase-producing Enterobacteriaceae (CPE) has not been extensively investigated, except in the cases of selected patients at risk, mostly during outbreaks. A total of 1,100 fecal samples randomly collected in our institution in two different periods in 2006 (n = 600) and 2009–2010 (n = 500) from hospitalized (26.8%) and nonhospitalized (73.2%) patients were screened for CPE. The first period coincided with an outbreak of VIM-1-producing Enterobacteriaceae, and the second one coincided with the emergence of KPC enzymes in our hospital. Diluted samples in saline were cultured in Luria-Bertani broth with 1 μg/ml imipenem and subcultured in MacConkey agar plates with 4 μg/ml ceftazidime. Growing colonies were screened for CPE (modified Hodge test and EDTA and boronic acid synergy tests). Carbapenemase genes, plasmids in which they are located, and clonal relatedness were determined. Individuals who exhibited fecal carriage of CPE (11/1,043, 1.1%; 95% confidence interval [CI], 0.53 to 1.88) included 8 hospitalized (carriage rate, 2.9%; 95% CI, 1.24 to 5.55) and 3 nonhospitalized patients (carriage rate, 0.4%; 95% CI, 0.08 to 1.14), the latter being identified in 2009. Eighty-two percent of colonized patients were not infected with CPE. Isolates harboring blaVIM-1 with or without blaSHV-12 were identified as Klebsiella pneumoniae (n = 8; ST39, ST688, ST253, and ST163), Enterobacter cloacae (n = 3; two pulsed-field gel electrophoresis [PFGE] types), Escherichia coli (n = 2; ST155 and ST2441), and Citrobacter freundii (n = 1). Some of these lineages had previously been detected in our institution. The blaVIM-1 gene was a member of the class 1 integrons In110 (blaVIM-1-aacA4-aadA1) and In113 (blaVIM-1-aacA4-dhfrII) located on plasmids IncN (n = 11; 30 to 50 kb) and IncHI2 (n = 3; 300 kb), respectively. Dissemination of blaVIM-1 class-1 integrons within highly transferable plasmids in a polyclonal population has potentially contributed to the

Genomically Informed Surveillance for Carbapenem-Resistant Enterobacteriaceae in a Health Care System.

PubMed

Pecora, Nicole D; Li, Ning; Allard, Marc; Li, Cong; Albano, Esperanza; Delaney, Mary; Dubois, Andrea; Onderdonk, Andrew B; Bry, Lynn

2015-07-28

Carbapenem-resistant Enterobacteriaceae (CRE) are an urgent public health concern. Rapid identification of the resistance genes, their mobilization capacity, and strains carrying them is essential to direct hospital resources to prevent spread and improve patient outcomes. Whole-genome sequencing allows refined tracking of both chromosomal traits and associated mobile genetic elements that harbor resistance genes. To enhance surveillance of CREs, clinical isolates with phenotypic resistance to carbapenem antibiotics underwent whole-genome sequencing. Analysis of 41 isolates of Klebsiella pneumoniae and Enterobacter cloacae, collected over a 3-year period, identified K. pneumoniae carbapenemase (KPC) genes encoding KPC-2, -3, and -4 and OXA-48 carbapenemases. All occurred within transposons, including multiple Tn4401 transposon isoforms, embedded within more than 10 distinct plasmids representing incompatibility (Inc) groups IncR, -N, -A/C, -H, and -X. Using short-read sequencing, draft maps were generated of new KPC-carrying vectors, several of which were derivatives of the IncN plasmid pBK31551. Two strains also had Tn4401 chromosomal insertions. Integrated analyses of plasmid profiles and chromosomal single-nucleotide polymorphism (SNP) profiles refined the strain patterns and provided a baseline hospital mobilome to facilitate analysis of new isolates. When incorporated with patient epidemiological data, the findings identified limited outbreaks against a broader 3-year period of sporadic external entry of many different strains and resistance vectors into the hospital. These findings highlight the utility of genomic analyses in internal and external surveillance efforts to stem the transmission of drug-resistant strains within and across health care institutions. We demonstrate how detection of resistance genes within mobile elements and resistance-carrying strains furthers active surveillance efforts for drug resistance. Whole-genome sequencing is increasingly

Evaluation of the RAPIDEC® CARBA NP, the Rapid CARB Screen® and the Carba NP test for biochemical detection of carbapenemase-producing Enterobacteriaceae.

PubMed

Dortet, Laurent; Agathine, Aurélie; Naas, Thierry; Cuzon, Gaëlle; Poirel, Laurent; Nordmann, Patrice

2015-11-01

The objective of this study was the evaluation of the performance of two commercially available biochemical tests for the rapid detection of carbapenemase-producing Enterobacteriaceae compared with a home-made technique. A collection of 150 enterobacterial isolates, including 132 isolates with decreased susceptibility to at least one carbapenem molecule, were tested for carbapenemase activity using the RAPIDEC(®) CARBA NP (bioMérieux), the Rapid CARB Screen(®) (Rosco Diagnostica) and the home-made Carba NP test. This strain collection included 55 non-carbapenemase producers, 21 KPC producers, 21 NDM producers, 17 VIM producers, 11 IMP producers, 16 OXA-48 producers and 9 OXA-48-like producers (OXA-162, OXA-181, OXA-204, OXA-232 and OXA-244). The RAPIDEC(®) CARBA NP detected all carbapenemase producers except a single OXA-244 producer. Using the Rapid CARB Screen(®), one KPC-2, two NDM-1, one OXA-48 and five OXA-48 variant producers gave equivocal results and one OXA-244 producer was not detected. Using the Carba NP test, the same OXA-244 producer was not detected and one OXA-181 producer and one OXA-244 producer gave equivocal results. Sensitivity and specificity were 99% (95% CI 94.3%-99.8%) and 100% (95% CI 93.5%-100%), respectively, for the RAPIDEC(®) CARBA NP test, 89.5% (95% CI 81.7%-94.2%) and 70.9% (95% CI 57.9%-81.2%) for the Rapid CARB Screen(®) and 96.8% (95% CI 91.1%-98.9%) and 100% (95% CI 93.5%-100%) for the Carba NP test. The impact of the use of an adequate bacterial inoculum for obtaining the optimal performance with the RAPIDEC(®) CARBA NP was noted. The RAPIDEC(®) CARBA NP possesses the best performance for rapid and efficient detection of carbapenemase-producing Enterobacteriaceae. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Prevalence of ESBL-producing Pseudomonas aeruginosa isolates in Warsaw, Poland, detected by various phenotypic and genotypic methods

PubMed Central

Róg, Patrycja; Smolińska-Król, Katarzyna; Ćmiel, Milena; Słoczyńska, Alicja; Patzer, Jan; Dzierżanowska, Danuta; Wolinowska, Renata; Starościak, Bohdan; Tyski, Stefan

2017-01-01

Knowledge of the prevalence of ESBL enzymes among P. aeruginosa strains compared to the Enterobacteraiceae family is limited. The phenotypic tests recommended by EUCAST for the detection of ESBL-producing Enterobacteriaceae are not always suited for P. aeruginosa strains. This is mainly due to the presence of other families of ESBLs in P. aeruginosa isolates more often than in Enterobacteriaceae, production of natural AmpC cephalosporinase and its overexpression, and co-production of metallo-β-lactamases. The aim of this study was to determine the occurrence of ESBLs in P. aeruginosa isolated from patients from hospitals in Warsaw, to evaluate the ESBL production of these isolates using currently available phenotypic tests, their modifications, multiplex PCR and molecular typing of ESBL-positive isolates by PFGE. Clinical isolates of P. aeruginosa were collected in 2000-2014 from four Warsaw hospitals. Based on the data obtained in this study, we suggest using three DDST methods with inhibitors, such as clavulanic acid, sulbactam and imipenem, to detect ESBL-producing P. aeruginosa strains. Depending on the appearance of the plates, we suggest a reduction in the distance between discs with antibiotics to 15 mm and the addition of boronic acid at 0.4 mg per disc. The analysed isolates carried genes encoding ESBL from the families VEB (69 isolates with VEB-9), GES (6 with GES-1, 1 GES-5, 5 GES-13 and 2 with GES-15), OXA-2 (12 with OXA-15, 1 OXA-141, 1 OXA-210, 1 OXA-543 and 1 with OXA-544) and OXA-10 (5 isolates with OXA-74 and one with OXA-142). The most important result of this study was the discovery of three new genes, blaGES-15, blaOXA-141 and blaOXA-142; their nucleotide sequences have been submitted to the NCBI GenBank. It is also very important to note that this is the first report on the epidemiological problem of VEB-9-producing bacterial strains, not only in Poland but also worldwide. PMID:28658322

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) infections: are carbapenem alternatives achievable in daily practice?

PubMed

Pilmis, B; Delory, T; Groh, M; Weiss, E; Emirian, A; Lecuyer, H; Lesprit, P; Zahar, J-R

2015-10-01

To avoid the use of carbapenems, alternatives such as cephamycin, piperacillin-tazobactam, and others are suggested for the treatment of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) infections. The aim of this study was to evaluate the frequency and the feasibility of antimicrobial de-escalation for ESBL-PE-related infections. A prospective observational, bi centric cohort study was conducted. All patients with ESBL-PE infections were included. De-escalation was systematically suggested if patients were clinically stable and the isolate was susceptible to possible alternatives. Seventy-nine patients were included: 36 (45.6%) were children, 27 (34.1%) were hospitalized in intensive care units, and 37 (47%) were immunocompromised. Urinary tract infections, pneumonia, and catheter-related bloodstream infections accounted for 45.6%, 19%, and 10%, respectively, of the cohort. Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae were the three most frequent causative organisms isolated. On day 5, 47 (59.2%) of the patients were still receiving carbapenems. Antimicrobial resistance (44.7%), infection relapse (26.9%), and clinical instability (19.2%) were the most important reasons for not prescribing alternatives. E. coli-related infections appeared to be a protective factor against maintaining the carbapenem prescription (odds ratio 0.11, 95% confidence interval 0.041-0.324; p=0.0013). In clinical practice, less than 50% of patients with ESBL-PE-related infections were de-escalated after empirical treatment with carbapenems. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Comparison of the clinical efficacy between tigecycline plus extended-infusion imipenem and sulbactam plus imipenem against ventilator-associated pneumonia with pneumonic extensively drug-resistant Acinetobacter baumannii bacteremia, and correlation of clinical efficacy with in vitro synergy tests.

PubMed

Jean, Shio-Shin; Hsieh, Tai-Chin; Hsu, Chin-Wan; Lee, Wen-Sen; Bai, Kuan-Jen; Lam, Carlos

2016-12-01

To compare the clinical efficacy between salvage antimicrobial regimen consisting of tigecycline plus extended-infusion imipenem/cilastatin (TIC) and regimen of sulbactam plus imipenem/cilastatin (SIC) for patients with ventilator-associated pneumonia and pneumonic bacteremia due to extensively drug-resistant (XDR) Acinetobacter baumannii (Ab) isolates, and determine the correlation of results of in vitro tigecycline-imipenem synergy test with clinical efficacy. The comparative survey was conducted at a medical center in Taiwan in 2013. Patients comprising the TIC group (n = 28) received tigecycline plus extended-infusion imipenem/cilastatin following unresponsiveness to 3-day sulbactam-imipenem/cilastatin therapy, and those in the SIC group (n = 56) received sulbactam-imipenem/cilastatin throughout the course. Univariate and multivariate analyses were applied to explore 30-day case-fatality independent predictors. Additionally, the checkerboard test and time-kill analysis were performed for the bloodstream XDR-Ab isolates from patients in the TIC group, and molecular characterization was done for the bloodstream XDR-Ab strains of all patients. We found that the TIC scheme has a significant benefit on improving patients' survival status (the mortality rate of TIC and SIC group patients was 14.3% and 64.3%, respectively), corresponding well with in vitro synergy or additivity results by the checkerboard test. Twenty TIC group cases had monomicrobial XDR-Ab cultured from tracheal aspirates after 10 days of tigecycline-imipenem/cilastatin therapy, but none developed subsequent pneumonia. However, breakthrough primary Burkholderia cepacia (n = 3) and Pseudomonas aeruginosa (n = 1) bacteremias were attributed to four TIC case fatalities. Shock, SIC regimen usage, and development of breakthrough bacteremia were independent predictors of 30-day in-hospital mortality. Although the TIC regimen showed good efficacy, its value regarding managing XDR-Ab ventilator

Performance of the BacT Alert 3D System Versus Solid Media for Recovery and Drug Susceptibility Testing of Mycobacterium tuberculosis in a Tertiary Hospital in Korea.

PubMed

Kim, Seoung-Cheol; Jeon, Bo-Young; Kim, Jin-Sook; Choi, In Hwan; Kim, Jiro; Woo, Jeongim; Kim, Soojin; Lee, Hyeong Woo; Sezim, Monoldorova; Cho, Sang-Nae

2016-10-01

Tuberculosis (TB) is a major health problem, and accurate and rapid diagnosis of multidrug-resistant (MDR) and extended drug-resistant (XDR) TB is important for appropriate treatment. In this study, performances of solid and liquid culture methods were compared with respect to MDR- and XDR-TB isolate recovery and drug susceptibility testing. Sputum specimens from 304 patients were stained with Ziehl-Neelsen method. Mycobacterium tuberculosis (Mtb) isolates were tested for recovery on Löwenstein-Jensen (LJ) medium and the BacT Alert 3D system. For drug susceptibility testing of Mtb, isolates were evaluated on M-KIT plates and the BacT Alert 3D system. The recovery rates were 94.9% (206/217) and 98.2% (213/217) for LJ medium and the BacT Alert 3D system, respectively (kappa coefficient, 0.884). The rate of drug resistance was 13.4% for at least one or more drugs, 6.0% for MDR-TB and 2.3% for XDR-TB. M-KIT plate and BacT 3D Alert 3D system were comparable in drug susceptibility testing for isoniazid (97.7%; kappa coefficient, 0.905) and rifampin (98.6%; kappa coefficient, 0.907). Antibiotic resistance was observed using M-KIT plates for 24 of the total 29 Mtb isolates (82.8%). The liquid culture system showed greater reduction in the culture period, as compared with LJ medium; however, drug susceptibility testing using M-KIT plates was advantageous for simultaneous testing against multiple drug targets.

Phylogenomics and comparative genomic studies delineate six main clades within the family Enterobacteriaceae and support the reclassification of several polyphyletic members of the family.

PubMed

Alnajar, Seema; Gupta, Radhey S

2017-10-01

The family Enterobacteriaceae harbors many important pathogens, however it has proven difficult to reliably distinguish different members of this family or discern their interrelationships. To understand the interrelationships among the Enterobacteriaceae species, we have constructed two comprehensive phylogenetic trees for 78 genome-sequenced Enterobacteriaceae species based on 2487 core genome proteins, and another set of 118 conserved proteins. The genome sequences of Enterobacteriaceae species were also analyzed for genetic relatedness based on average amino acid identity and 16S rRNA sequence similarity. In parallel, comparative genomic studies on protein sequences from the Enterobacteriaceae have identified 88 molecular markers in the form of conserved signature indels (CSIs) that are uniquely shared by specific members of the family. All of these multiple lines of investigations provide consistent evidence that most of the species/genera within the family can be assigned to 6 different subfamily level clades which are designated as the "Escherichia clade", "Klebsiella clade", "Enterobacter clade", "Kosakonia clade", "Cronobacter clade" and "Cedecea clade". The members of the six described clades, in addition to their distinct branching in phylogenetic trees, can now be reliably demarcated in molecular terms on the basis of multiple identified CSIs that are exclusively shared by the group members. Several additional CSIs identified in this work that are either specific for individual genera (viz. Kosakonia, Kluyvera and Escherichia-Shigella), or are present at various taxonomic depths, offer information regarding the interrelationships among the different clades. The described molecular markers provide novel means for diagnostic as well as genetic and biochemical studies on the Enterobacteriaceae species and for resolving the polyphyly of its several genera viz. Escherichia, Enterobacter and Kluyvera. On the bases of our results, we are proposing the

Presence of qnr gene in Escherichia coli and Klebsiella pneumoniae resistant to ciprofloxacin isolated from pediatric patients in China.

PubMed

Wang, Aihua; Yang, Yonghong; Lu, Quan; Wang, Yi; Chen, Yuan; Deng, Li; Ding, Hui; Deng, Qiulian; Zhang, Hong; Wang, Chuanqing; Liu, Lan; Xu, Xiwei; Wang, Li; Shen, Xuzhuang

2008-05-22

Quinolone resistance in Enterobacteriaceae results mainly from mutations in type II DNA topoisomerase genes and/or changes in the expression of outer membrane and efflux pumps. Several recent studies have indicated that plasmid-mediated resistance mechanisms also play a significant role in fluoroquinolone resistance, and its prevalence is increasing worldwide. In China, the presence of the qnr gene in the clinical isolates of Enterobacteriaceae has been reported, but this transmissible quinolone resistance gene has not been detected in strains isolated singly from pediatric patients. Because quinolones associated with a variety of adverse side effects on children, they are not authorized for pediatric use. This study therefore aimed to investigate the presence of the qnr gene in clinical isolates of E. coli and K. pneumoniae from pediatric patients in China. A total 213 of non-repetitive clinical isolates resistant to ciprofloxacin from E. coli and K. pneumoniae were collected from hospitalized patients at five children's hospital in Beijing, Shanghai, Guangzhou, and Chongqing. The isolates were screened for the plasmid-mediated quinolone resistance genes of qnrA, qnrB, and qnrS by PCR. Transferability was examined by conjugation with the sodium azide-resistant E. coli J53. All qnr-positive were analyzed for clonality by enterobacterial repetitive intergenic consensus (ERIC)-PCR. The study found that 19 ciprofloxacin-resistant clinical isolates of E. coli and K. pneumoniae were positive for the qnr gene, and most of the qnr positive strains were ESBL producers. Conjugation experiments showed that quinolone resitance could be transferred to recipients. Apart from this, different DNA banding patterns were obtained by ERIC-PCR from positive strains, which means that most of them were not clonally related. This report on transferable fluoroquinolone resistance due to the qnr gene among E. coli and K. pneumoniae strains indicated that plasmid-mediated quinolone

Molecular Characteristics and Drug Susceptibility of Mycobacterium tuberculosis Isolates from Patients Co-infected with Human Immunodeficiency Virus in Beijing, China.

PubMed

Liu, Jie; Wang, Hui Zhu; Lian, Lu Lu; Yu, Yan Hua; Zhao, Xiu Qin; Guo, Cai Ping; Liu, Hai Can; Liu, Shu Mei; Zhao, Hui; Zeng, Zhao Ying; Zhao, Xiu Ying; Wan, Kang Lin

2015-03-01

70 clinical Mycobacterium tuberculosis strains isolated from AIDS patients in two HIV/AIDS referral hospitals in Beijing were used in this study. M. tuberculosis and non-tuberculosis mycobacterium (NTM) were identified by using multi-locus PCR. M. tuberculosis was genotyped by using 15-locus MIRU-VNTR technique and spoligotyping afterwards. Meanwhile, the drug susceptibilities of the strains to the four first-line anti TB drugs (rifampin, isoniazid, streptomycin, and ethambutol) and the four second-line anti-TB drugs (capreomycin, kanamycin, ofloxacin, and ethionanide) were tested with proportional method. In this study, M. tuberculosis and NTM strains isolated from AIDS patients with TB-like symptoms were identified and genotyping analysis indicated that Beijing genotype was the predominant genotype. In addition, the prevalence of drug-resistant TB, especially the prevalence of XDR-TB, was higher than that in TB patients without HIV infection. Copyright © 2015 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Prevalence of resistance to second-line tuberculosis drug among multidrug-resistant tuberculosis patients in Viet Nam, 2011

PubMed Central

Tran, Huong Thi Giang; Bui, Quyen Thi Tu

2016-01-01

Introduction Extensively drug-resistant tuberculosis (XDR-TB) represents an emerging public health problem worldwide. According to the World Health Organization, an estimated 9.7% of multidrug-resistant TB (MDR-TB) cases are defined as XDR-TB globally. The objective of this study was to determine the prevalence of drug resistance to second-line TB drugs among MDR-TB cases detected in the Fourth National Anti-Tuberculosis Drug Resistance Survey in Viet Nam. Methods Eighty clusters of TB cases were selected using a probability-proportion-to-size approach. To identify MDR-TB cases, drug susceptibility testing (DST) was performed for the four major first-line TB drugs. DST of second-line drugs (ofloxacin, amikacin, kanamycin, capreomycin) was performed on isolates from MDR-TB cases to identify pre-XDR and XDR cases. Results A total of 1629 smear-positive TB cases were eligible for culture and DST. Of those, DST results for first-line drugs were available for 1312 cases, and 91 (6.9%) had MDR-TB. Second-line DST results were available for 84 of these cases. Of those, 15 cases (17.9%) had ofloxacin resistance and 6.0% were resistant to kanamycin and capreomycin. Five MDR-TB cases (6.0%) met the criteria of XDR-TB. Conclusion This survey provides the first estimates of the proportion of XDR-TB among MDR-TB cases in Viet Nam and provides important information for local policies regarding second-line DST. Local policies and programmes that are geared towards TB prevention, early diagnosis and treatment with effective regimens are of high importance. PMID:27508089

Prevalence of resistance to second-line tuberculosis drug among multidrug-resistant tuberculosis patients in Viet Nam, 2011.

PubMed

Nguyen, Hoa Binh; Nguyen, Nhung Viet; Tran, Huong Thi Giang; Nguyen, Hai Viet; Bui, Quyen Thi Tu

2016-01-01

Extensively drug-resistant tuberculosis (XDR-TB) represents an emerging public health problem worldwide. According to the World Health Organization, an estimated 9.7% of multidrug-resistant TB (MDR-TB) cases are defined as XDR-TB globally. The objective of this study was to determine the prevalence of drug resistance to second-line TB drugs among MDR-TB cases detected in the Fourth National Anti-Tuberculosis Drug Resistance Survey in Viet Nam. Eighty clusters of TB cases were selected using a probability-proportion-to-size approach. To identify MDR-TB cases, drug susceptibility testing (DST) was performed for the four major first-line TB drugs. DST of second-line drugs (ofloxacin, amikacin, kanamycin, capreomycin) was performed on isolates from MDR-TB cases to identify pre-XDR and XDR cases. A total of 1629 smear-positive TB cases were eligible for culture and DST. Of those, DST results for first-line drugs were available for 1312 cases, and 91 (6.9%) had MDR-TB. Second-line DST results were available for 84 of these cases. Of those, 15 cases (17.9%) had ofloxacin resistance and 6.0% were resistant to kanamycin and capreomycin. Five MDR-TB cases (6.0%) met the criteria of XDR-TB. This survey provides the first estimates of the proportion of XDR-TB among MDR-TB cases in Viet Nam and provides important information for local policies regarding second-line DST. Local policies and programmes that are geared towards TB prevention, early diagnosis and treatment with effective regimens are of high importance.

Risk factors for fecal carriage of carbapenemase producing Enterobacteriaceae among intensive care unit patients from a tertiary care center in India.

PubMed

Mittal, Gajanand; Gaind, Rajni; Kumar, Deepak; Kaushik, Gaurav; Gupta, Kunj Bihari; Verma, P K; Deb, Monorama

2016-07-08

Resistance amongst the commensal flora is a serious threat because a very highly populated ecosystem like the gut, may at a later stage, be a source of extra intestinal infections, resistant strains may spread to other host or transfer genetic resistance element to other members of micro-biota including pathogens. This study was carried out to assess fecal colonization by carbapenemase producing Enterobacteriaceae (CPE) and associated risk factors among 100 patients admitted to intensive care unit (ICU). The phenotypic and molecular characterizations of CPE were also included. Colonization with CPE was observed in 6.6 % (8/122) controls. Among ICU patients, fecal carriage of CPE was significantly higher on day 4 (D4) (22 %) as compared to day 1 (D1) (11 %) (p value 0.002). The carbapenemase genes detected included OXA- 48, 181, KPC and NDM-1 with NDM-1 being the predominant carbapenemase in both ICU D1 and D4. Among the 50 CPE isolates, 8 (16 %) were susceptible to meropenem and imipenem (Minimum inhibitory concentration; MIC ≤ 1 mg/L) and all were susceptible to colistin (MIC range 0.125 - 1 mg/L) and tigecycline (MIC range 0.06- 1.5 mg/L). The risk factors associated with CPE carriage were duration of ICU stay, use of ventilator and aminoglycosides. Prior colonization with CPE could result in their influx and spread in ICU, challenging infection control measures. Exposure to ICU further increases risk of colonization with diverse carbapenemase-producing Enterobacteriaceae. Gut colonization with these strains may be a source of endogenous infection and horizontal transfer of these genes in future.

Carbapenem Resistance in Gram-Negative Bacteria: The Not-So-Little Problem in the Little Red Dot.

PubMed

Teo, Jocelyn Qi Min; Cai, Yiying; Lim, Tze-Peng; Tan, Thuan Tong; Kwa, Andrea Lay-Hoon

2016-02-16

Singapore is an international travel and medical hub and faces a genuine threat for import and dissemination of bacteria with broad-spectrum resistance. In this review, we described the current landscape and management of carbapenem resistance in Gram-negative bacteria (GNB) in Singapore. Notably, the number of carbapenem-resistant Enterobacteriaceae has exponentially increased in the past two years. Resistance is largely mediated by a variety of mechanisms. Polymyxin resistance has also emerged. Interestingly, two Escherichia coli isolates with plasmid-mediated mcr-1 genes have been detected. Evidently, surveillance and infection control becomes critical in the local setting where resistance is commonly related to plasmid-mediated mechanisms, such as carbapenemases. Combination antibiotic therapy has been proposed as a last-resort strategy in the treatment of extensively drug-resistant (XDR) GNB infections, and is widely adopted in Singapore. The diversity of carbapenemases encountered, however, presents complexities in both carbapenemase detection and the selection of optimal antibiotic combinations. One unique strategy introduced in Singapore is a prospective in vitro combination testing service, which aids physicians in the selection of individualized combinations. The outcome of this treatment strategy has been promising. Unlike countries with a predominant carbapenemase type, Singapore has to adopt management strategies which accounts for diversity in resistance mechanisms.

Carbapenem Resistance in Gram-Negative Bacteria: The Not-So-Little Problem in the Little Red Dot

PubMed Central

Teo, Jocelyn Qi Min; Cai, Yiying; Lim, Tze-Peng; Tan, Thuan Tong; Kwa, Andrea Lay-Hoon

2016-01-01

Singapore is an international travel and medical hub and faces a genuine threat for import and dissemination of bacteria with broad-spectrum resistance. In this review, we described the current landscape and management of carbapenem resistance in Gram-negative bacteria (GNB) in Singapore. Notably, the number of carbapenem-resistant Enterobacteriaceae has exponentially increased in the past two years. Resistance is largely mediated by a variety of mechanisms. Polymyxin resistance has also emerged. Interestingly, two Escherichia coli isolates with plasmid-mediated mcr-1 genes have been detected. Evidently, surveillance and infection control becomes critical in the local setting where resistance is commonly related to plasmid-mediated mechanisms, such as carbapenemases. Combination antibiotic therapy has been proposed as a last-resort strategy in the treatment of extensively drug-resistant (XDR) GNB infections, and is widely adopted in Singapore. The diversity of carbapenemases encountered, however, presents complexities in both carbapenemase detection and the selection of optimal antibiotic combinations. One unique strategy introduced in Singapore is a prospective in vitro combination testing service, which aids physicians in the selection of individualized combinations. The outcome of this treatment strategy has been promising. Unlike countries with a predominant carbapenemase type, Singapore has to adopt management strategies which accounts for diversity in resistance mechanisms. PMID:27681907

Emerging Carbapenem-Resistant Pseudomonas aeruginosa Isolates Carrying blaIMP Among Burn Patients in Isfahan, Iran.

PubMed

Radan, Mohsen; Moniri, Rezvan; Khorshidi, Ahmad; Gilasi, Hamidreza; Norouzi, Zohreh; Beigi, Fahimeh; Dasteh Goli, Yasaman

2016-09-01

Metallo-β-lactamase (MBL)-producing Pseudomonas aeruginosa is a significant pathogen in burn patients. The aim of this study was to determine the prevalence of carbapenem-resistant P. aeruginosa isolates, including those resistant to imipenemase (IMP), in a burn unit in Isfahan, Iran. One hundred and fifty P. aeruginosa isolates from burn patients were tested for antibiotic susceptibility by the disc diffusion method in accordance with CLSI guidelines. Production of MBL was identified with the EDTA disk method. DNA was purified from the MBL-positive isolates, and detection of the bla IMP gene was performed with PCR. Fifty-seven out of 150 (38%) isolates were multi-drug resistant (MDR), and 93 (62%) were extensively-drug resistant (XDR). Among all isolates, the resistance rate to ciprofloxacin, tobramycin, imipenem, meropenem, amikacin, ceftazidime, and cefepime was higher than 90%, while the resistance rates to piperacillin/tazobactam and aztreonam were 70.7% and 86%, respectively. Colistin and polymyxin B remained the most effective studied antibiotics. All of the imipenem-resistant P. aeruginosa isolates were MBL-positive, and 107 out of 144 (74.3%) of the MBL isolates were positive for the bla IMP gene. The results of this study show that the rate of P. aeruginosa -caused burn wound infections was very high, and many of the isolates were resistant to three or more classes of antimicrobials. Such extensive resistance to antimicrobial classes is important because few treatment options remain for patients with burn wound infections. bla IMP -producing P. aeruginosa isolates are a rising threat in burn-care units, and should be controlled by conducting infection-control assessments.

Regulatory T Cells Subvert Mycobacterial Containment in Patients Failing Extensively Drug-resistant TB Treatment.

PubMed

Davids, Malika; Pooran, Anil S; Pietersen, Elize; Wainwright, Helen C; Binder, Anke; Warren, Robin; Dheda, Keertan

2018-02-09

The advent of extensively (XDR-TB) and totally drug-resistant TB, with limited or no treatment options, has facilitated renewed interest in host directed immunotherapy, particularly for therapeutically destitute patients. However, the selection and utility of such approaches depend upon understanding the host immune response in XDR-TB, which hitherto remains unexplored. To determine the host immunological profile in patients with XDR-TB, compared to drug-sensitive TB, using peripheral blood and explanted lung tissue. Blood and explanted lung tissue were obtained from patients with XDR-TB (n=31), drug-sensitive TB (DS-TB, n=20) and presumed latent-TB infection (LTBI, n=20). T-cell phenotype (Th1/Th2/Th17/Tregs) was evaluated in all patient groups, and Treg function assessed in XDR-TB non-responders by co-culturing PPD pre-primed effector T-cells with H37Rv-infected monocyte-derived macrophages, with or without autologous Tregs. Mycobacterial containment was evaluated by counting colony-forming units. Patients failing XDR-TB treatment had an altered immuno-phenotype characterized by a substantial increase in the frequency (median; IQR) of CD4+CD25+FoxP3+ regulatory T-cells (11.5; 5.9-15.2) compared to DS-TB (3.4 %; 1.6-5.73; p < 0.001) and presumed LTBI (1.8 % 1.2-2.3; p < 0.001), which was unrelated to disease duration. Tregs isolated from XDR-TB patients suppressed T-cell proliferation (up to 90%) and subverted containment of H37Rv-infected monocyte-derived macrophages (by 30%; p= 0.03) by impairing effector T-cell function through a mechanism independent of direct cell-to-cell contact, IL-10, TGF-beta and CTLA-4. Collectively, these data suggest that Tregs may be contributing to immune dysfunction, and bacterial persistence, in patients with XDR-TB. The relevant cellular pathways may serve as potential targets for immunotherapeutic intervention.

Characterization of Enterobacteriaceae isolates obtained from a tertiary care hospital in Mexico, which produces extended-spectrum β-lactamase.

PubMed

Morfín-Otero, Rayo; Mendoza-Olazarán, Soraya; Silva-Sánchez, Jesús; Rodríguez-Noriega, Eduardo; Laca-Díaz, Jorge; Tinoco-Carrillo, Perla; Petersen, Luis; López, Perla; Reyna-Flores, Fernando; Alcantar-Curiel, Dolores; Garza-Ramos, Ulises; Garza-González, Elvira

2013-10-01

The prevalence and genetic characteristics of Escherichia coli and Klebsiella pneumoniae clinical isolates producing extended-spectrum β-lactamase (ESBL) were examined. Between October 2010 and March 2011, E. coli (n=460) and K. pneumoniae (n=78) isolates were collected at a tertiary care hospital in Guadalajara, Mexico. The minimum inhibitory concentration (MIC) for each isolate was determined using a broth microdilution method, and ESBL production was assayed. The presence of β-lactamase genes, blaSHV, blaCTX-M, and blaTLA-1, was detected by PCR and confirmed with sequencing. Only ESBL-producing isolates were further subjected to pulsed-field gel electrophoresis (PFGE) and plasmid profiling. All of the ESBL isolates were multidrug resistant and 75/460 (16.3%) E. coli isolates and 21/78 (26.9%) K. pneumoniae isolates were found to produce ESBL. For the E. coli isolates, >95% susceptibility to amikacin, meropenem, fosfomycin, imipenem, and nitrofurantoin was observed. For K. pneumoniae, similar results were obtained, with discrepancies observed for gentamicin and nitrofurantoin. PFGE further identified eleven pulsotypes for E. coli and three clusters of K. pneumoniae. CTX-M-15 was detected in 85% of ESBL-producing E. coli and in 76% of ESBL-producing K. pneumoniae. In contrast, SHV-5 ESBL was identified in 17% of E. coli isolates and in 86% of K. pneumoniae isolates. The bla-TLA-1 gene was not detected in any of the 96 isolates analyzed. Overall, CTX-M-15 and SHV-5 were found to have a high rate of spread throughout the hospital and were associated with strong multidrug resistance.

Reduced susceptibility to chlorhexidine disinfectant among New Delhi metallo-beta-lactamase-1 positive Enterobacteriaceae and other multidrug-resistant organisms: Report from a tertiary care hospital in Karachi, Pakistan.

PubMed

Mal, P B; Farooqi, J; Irfan, S; Hughes, M A; Khan, E

2016-01-01

We analysed susceptibility of multidrug-resistant organisms (MDROs) including New Delhi metallo-beta-lactamase-1 positive Enterobacteriaceae to chlorhexidine and compared results to their susceptible counterparts. Susceptibilities of chlorhexidine digluconate in a standard (CHX-S) preparation and two commercial disinfectants containing different CHX concentrations (2% w/v and 4% w/w) were performed. MDROs had narrower range of higher CHX-S minimum inhibitory concentrations (MICs) as compared to pan-sensitive organisms. The MIC values for commercial disinfectants products for MDROs were many folds higher (20-600 times), than CHX-S for in vitro use. Increasing antibiotic resistance among bacterial isolates can be an indirect marker of reduced susceptibility to chlorhexidine in hospital setting.

Prevalence and characterization of ESBL- and AmpC-producing Enterobacteriaceae on retail vegetables.

PubMed

van Hoek, Angela H A M; Veenman, Christiaan; van Overbeek, Wendy M; Lynch, Gretta; de Roda Husman, Ana Maria; Blaak, Hetty

2015-07-02

In total 1216 vegetables obtained from Dutch stores during 2012 and 2013 were analysed to determine the prevalence of 3rd-generation cephalosporin (3GC) resistant bacteria on soil-grown fresh produce possibly consumed raw. Vegetables grown conventionally and organically, from Dutch as well as foreign origin were compared. Included were the following vegetable types; blanched celery (n=192), bunched carrots (n=190), butterhead lettuce (n=137), chicory (n=96), endive (n=188), iceberg lettuce (n=193) and radish (n=120). Overall, 3GC-resistant Enterobacteriaceae were detected on 5.2% of vegetables. Based on primary habitat and mechanism of 3GC-resistance, these bacteria could be divided into four groups: ESBL-producing faecal species (Escherichia coli, Enterobacter spp.), AmpC-producing faecal species (Citrobacter freundii, Enterobacter spp.), ESBL-producing environmental species (Pantoea spp., Rahnella aquatilis, Serratia fonticola), and AmpC-producing environmental species (Cedecca spp., Hafnia alvei, Pantoea spp., Serratia plymuthica), which were detected on 0.8%, 1.2%, 2.6% and 0.4% of the vegetables analysed, respectively. Contamination with faecal 3GC-resistant bacteria was most frequently observed in root and bulb vegetables (average prevalence 4.4%), and less frequently in stem vegetables (prevalence 1.6%) and leafy greens (average prevalence 0.6%). In Dutch stores, only four of the included vegetable types (blanched celery, bunched carrots, endive, iceberg lettuce) were available in all four possible variants: Dutch/conventional, Dutch/organic, foreign/conventional, foreign/organic. With respect to these vegetable types, no statistically significant difference was observed in prevalence of 3GC-resistant Enterobacteriaceae between country of origin or cultivation type (5.2%, 5.7%, 5.7% and 3.3%, respectively). Vegetables consumed raw may be a source of dissemination of 3GC-resistant Enterobacteriaceae and their resistance genes to humans. The magnitude of the

Characterization of Tn3000, a Transposon Responsible for blaNDM-1 Dissemination among Enterobacteriaceae in Brazil, Nepal, Morocco, and India.

PubMed

Campos, Juliana Coutinho; da Silva, Maria José Félix; dos Santos, Paulo Roberto Nascimento; Barros, Elaine Menezes; Pereira, Mayne de Oliveira; Seco, Bruna Mara Silva; Magagnin, Cibele Massotti; Leiroz, Leonardo Kalab; de Oliveira, Théo Gremen Mimary; de Faria-Júnior, Célio; Cerdeira, Louise Teixeira; Barth, Afonso Luís; Sampaio, Suely Carlos Ferreira; Zavascki, Alexandre Prehn; Poirel, Laurent; Sampaio, Jorge Luiz Mello

2015-12-01

In Enterobacteriaceae, the blaNDM genes have been found in many different genetic contexts, and a wide diversity of plasmid scaffolds bearing those genes has been found. In August 2013, we identified NDM-1-producing Escherichia coli and Enterobacter hormaechei strains from a single rectal swab sample from a patient hospitalized in Rio de Janeiro, Brazil, who had no history of travel abroad. Complete DNA sequencing using the Illumina platform and annotation of the two plasmids harboring the blaNDM-1 gene, one from each strain, showed that they belonged to incompatibility groups IncFIIK and IncX3 and harbored a novel transposon named Tn3000. Similar genetic structures have been identified among other isolates in Brazil but also on plasmids from other continents. Our findings suggest that the blaNDM-1 gene may be transmitted by Tn3000 in different parts of the world. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Genomic characterization of an extensively-drug resistance Salmonella enterica serotype Indiana strain harboring blaNDM-1 gene isolated from a chicken carcass in China.

PubMed

Wang, Wei; Peng, Zixin; Baloch, Zulqarnain; Hu, Yujie; Xu, Jin; Zhang, Wenhui; Fanning, Séamus; Li, Fengqin

2017-11-01

The objective of this study was to genetically characterize the antimicrobial resistance mechanisms of Salmonella enterica serotype Indiana C629 isolated from a chicken carcass in China in 2014. Antimicrobial susceptibility against a panel of 23 antimicrobial agents was carried out on Salmonella enterica serotype Indiana C629 and assessed according to CLSI standards. Whole-genome sequencing of this isolate was conducted to obtain the complete genome of S. Indiana. Salmonella Indiana C629 expressed an XDR phenotype being resistant to more than 20 antimicrobial agents, including imipenem and meropenem. From the analysis of the resistance mechanisms, two mutations were identified in subunit A of DNA gyrase within the quinolone resistance determining region, in addition to the acquisition of mobile efflux pumps encoding oqxA/B/R. Additionally, four beta-lactamases resistance genes (bla CTX-M-65 , bla TEM-1 , bla OXA-1 , and bla NDM-1 ), five aminoglycosides resistance genes (aac(3)-IV, aac(6')-Ib-cr, aadA2, aadA5, and aph(4)-Ia), two phenicol resistance genes (catB3 and floR), and five trimethoprim/sulfamethoxazole resistance genes (sul1/2/3 and dfrA12/17) were also identified. A total of 191 virulence genes were identified. Among them, 57 belonged to type-three secretion system (T3SS) encoding genes, 55 belonged to fimbrial adherence encoding genes, and 39 belonged to flagella-encoding genes CONCLUSIONS: This study demonstrated that multi-resistance mechanisms consistent with an XDR-phenotype, along with various virulence encoding genes of a S. Indiana strain in China These findings highlight the importance of cooperation among different sectors in order to monitor the spread of resistant pathogens among food animal, foods of animal origin and human beings that might further take measures to protect consumers' health. Copyright © 2017 Elsevier GmbH. All rights reserved.

Near-infrared hyperspectral imaging and partial least squares regression for rapid and reagentless determination of Enterobacteriaceae on chicken fillets.

PubMed

Feng, Yao-Ze; Elmasry, Gamal; Sun, Da-Wen; Scannell, Amalia G M; Walsh, Des; Morcy, Noha

2013-06-01

Bacterial pathogens are the main culprits for outbreaks of food-borne illnesses. This study aimed to use the hyperspectral imaging technique as a non-destructive tool for quantitative and direct determination of Enterobacteriaceae loads on chicken fillets. Partial least squares regression (PLSR) models were established and the best model using full wavelengths was obtained in the spectral range 930-1450 nm with coefficients of determination R(2)≥ 0.82 and root mean squared errors (RMSEs) ≤ 0.47 log(10)CFUg(-1). In further development of simplified models, second derivative spectra and weighted PLS regression coefficients (BW) were utilised to select important wavelengths. However, the three wavelengths (930, 1121 and 1345 nm) selected from BW were competent and more preferred for predicting Enterobacteriaceae loads with R(2) of 0.89, 0.86 and 0.87 and RMSEs of 0.33, 0.40 and 0.45 log(10)CFUg(-1) for calibration, cross-validation and prediction, respectively. Besides, the constructed prediction map provided the distribution of Enterobacteriaceae bacteria on chicken fillets, which cannot be achieved by conventional methods. It was demonstrated that hyperspectral imaging is a potential tool for determining food sanitation and detecting bacterial pathogens on food matrix without using complicated laboratory regimes. Copyright © 2012 Elsevier Ltd. All rights reserved.

Incidence of class 1 and 2 integrases in clinical and commensal bacteria from livestock, companion animals, and exotics.

PubMed

Goldstein, C; Lee, M D; Sanchez, S; Hudson, C; Phillips, B; Register, B; Grady, M; Liebert, C; Summers, A O; White, D G; Maurer, J J

2001-03-01

Many pathogenic and commensal organisms are multidrug resistant due to exposure to various antibiotics. Often, this antimicrobial resistance is encoded by integrons that occur on plasmids or that are integrated into the bacterial chromosome. Integrons are commonly associated with bacterial genera in the family Enterobacteriaceae. We determined that class 1 integrases were present in approximately 46% of the isolates from the family Enterobacteriaceae; class 2 integrases were present only among Escherichia coli and Salmonella isolates. Seven percent of veterinary isolates were positive for class 3 integrase by DNA-DNA hybridization but could not be confirmed to be positive by PCR. None of the veterinary isolates possessed the class 4 integrase gene. The distribution of these integrase genes was variable within the members of the family Enterobacteriaceae when some or all integrase classes were absent from a particular genus. There was also considerable variability in the distribution of these integrases within a species, depending on the animal host. Unlike the class 1 integrases, the other integrase class, intI2, appears to be more restricted in its distribution among the members of the family Enterobacteriaceae. There is also considerable variability in the distribution of the class 1 integrases within E. coli strains isolated from different food animals. The class 1 integrases are the most widely disseminated of the four classes among the members of the family Enterobacteriaceae from both the clinical and normal flora of animals. This is the first report to closely examine the distribution of class 2 integrases in members of the family Enterobacteriaceae isolated in the United States.

In Vitro Activity and MIC of Sitafloxacin against Multidrug-Resistant and Extensively Drug-Resistant Mycobacterium tuberculosis Isolated in Thailand

PubMed Central

Leechawengwongs, Manoon; Prammananan, Therdsak; Jaitrong, Sarinya; Billamas, Pamaree; Makhao, Nampueng; Thamnongdee, Nongnard; Thanormchat, Arirat; Phurattanakornkul, Arisa; Rattanarangsee, Somcharn; Ratanajaraya, Chate; Disratthakit, Areeya

2017-01-01

ABSTRACT New fluoroquinolones (FQs) have been shown to be more active against drug-resistant Mycobacterium tuberculosis strains than early FQs, such as ofloxacin. Sitafloxacin (STFX) is a new fluoroquinolone with in vitro activity against a broad range of bacteria, including M. tuberculosis. This study aimed to determine the in vitro activity of STFX against all groups of drug-resistant strains, including multidrug-resistant M. tuberculosis (MDR M. tuberculosis), MDR M. tuberculosis with quinolone resistance (pre-XDR), and extensively drug-resistant (XDR) strains. A total of 374 drug-resistant M. tuberculosis strains were tested for drug susceptibility by the conventional proportion method, and 95 strains were randomly submitted for MIC determination using the microplate alamarBlue assay (MABA). The results revealed that all the drug-resistant strains were susceptible to STFX at a critical concentration of 2 μg/ml. Determination of the MIC90s of the strains showed different MIC levels; MDR M. tuberculosis strains had a MIC90 of 0.0625 μg/ml, whereas pre-XDR and XDR M. tuberculosis strains had identical MIC90s of 0.5 μg/ml. Common mutations within the quinolone resistance-determining region (QRDR) of gyrA and/or gyrB did not confer resistance to STFX, except that double mutations of GyrA at Ala90Val and Asp94Ala were found in strains with a MIC of 1.0 μg/ml. The results indicated that STFX had potent in vitro activity against all the groups of drug-resistant M. tuberculosis strains and should be considered a new repurposed drug for treatment of multidrug-resistant and extensively drug-resistant TB. PMID:29061759

Ugly bugs in healthy guts! Carriage of multidrug-resistant and ESBL-producing commensal Enterobacteriaceae in the intestine of healthy Nepalese adults.

PubMed

Maharjan, Anjila; Bhetwal, Anjeela; Shakya, Shreena; Satyal, Deepa; Shah, Shashikala; Joshi, Govardhan; Khanal, Puspa Raj; Parajuli, Narayan Prasad

2018-01-01

Fecal carriage of multidrug-resistant and extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae is one of the important risk factors for infection with antibiotic-resistant bacteria. In this report, we examined the prevalence of multidrug-resistant and ESBL-producing common enterobacterial strains colonizing the intestinal tract of apparently healthy adults in Kathmandu, Nepal. During a 6-month period (February-July 2016), a total of 510 stool specimens were obtained from apparently healthy students of Manmohan Memorial Institute of Health Sciences, Kathmandu, Nepal. Stool specimens were cultured, and the most common enterobacterial isolates ( Escherichia coli and Klebsiella species) were subjected to antimicrobial susceptibility tests according to the standard microbiologic guidelines. Multidrug-resistant isolates were selected for ESBL confirmation by combined disk test and E-test methods. Molecular characterization of plasmid-borne ESBL genes was performed by using specific primers of cefotaximase Munich (CTX-M), sulfhydryl variant (SHV), and temoniera (TEM) by polymerase chain reaction. Among 510 bacterial strains, E. coli (432, 84.71%) was the predominant organism followed by Klebsiella oxytoca (48, 9.41%) and K. pneumoniae (30, 5.88%). ESBLs were isolated in 9.8% of the total isolates including K. oxytoca (29.17%), E. coli (7.87%), and K. pneumoniae (6.67%). Among ESBLs, bla -TEM was the predominant type (92%) followed by bla -CTX-M (60%) and bla -SHV (4%). Multidrug-resistant and ESBL-producing enterobacterial commensal strains among healthy individuals are of serious concern. Persistent carriage of ESBL organisms in healthy individuals suggests the possibility of sustained ESBL carriage among the diseased and hospitalized patients. We recommend similar types of epidemiologic surveys in larger communities and in hospital settings to ascertain the extent of ESBL resistance.

Susceptibility Testing of Extensively Drug-Resistant and Pre-Extensively Drug-Resistant Mycobacterium tuberculosis against Levofloxacin, Linezolid, and Amoxicillin-Clavulanate

PubMed Central

Ahmed, Imran; Jabeen, Kauser; Inayat, Raunaq

2013-01-01

Pakistan is a high-burden country for tuberculosis (TB). The emergence and increasing incidence of extensively drug-resistant (XDR) TB has been reported in Pakistan. Similarly, the prevalence of multidrug-resistant TB infections with fluoroquinolone resistance (pre-XDR) is also increasing. To treat these infections, local drug susceptibility patterns of alternate antituberculosis agents, including levofloxacin (LVX), linezolid (LZD), and amoxicillin-clavulanate (AMC), is urgently needed. The aim of this study was to determine the susceptibility frequencies of drug-resistant (DR) Mycobacterium tuberculosis against LVX, LZD, and AMC. All susceptibilities were determined on Middlebrook 7H10 agar. A critical concentration was used for LVX (1 μg/ml), whereas MICs were determined for LZD and AMC. M. tuberculosis H37Rv was used as a control strain. A total of 102 M. tuberculosis isolates (XDR, n = 59; pre-XDR, n = 43) were tested. Resistance to LVX was observed in 91.2% (93/102). Using an MIC value of 0.5 μg/ml as a cutoff, resistance to LZD (MIC ≥ 1 μg/ml) was noted in 5.9% (6/102). Although the sensitivity breakpoints are not established for AMC, the MIC values were high (>16 μg/ml) in 97.1% (99/102). Our results demonstrate that LZD may be effective for the treatment of XDR and pre-XDR cases from Pakistan. High resistance rates against LVX in our study suggest the use of this drug with caution for DR-TB cases from this area. Drug susceptibility testing against LVX and AMC may be helpful in complicated and difficult-to-manage cases. PMID:23507286

Susceptibility testing of extensively drug-resistant and pre-extensively drug-resistant Mycobacterium tuberculosis against levofloxacin, linezolid, and amoxicillin-clavulanate.

PubMed

Ahmed, Imran; Jabeen, Kauser; Inayat, Raunaq; Hasan, Rumina

2013-06-01

Pakistan is a high-burden country for tuberculosis (TB). The emergence and increasing incidence of extensively drug-resistant (XDR) TB has been reported in Pakistan. Similarly, the prevalence of multidrug-resistant TB infections with fluoroquinolone resistance (pre-XDR) is also increasing. To treat these infections, local drug susceptibility patterns of alternate antituberculosis agents, including levofloxacin (LVX), linezolid (LZD), and amoxicillin-clavulanate (AMC), is urgently needed. The aim of this study was to determine the susceptibility frequencies of drug-resistant (DR) Mycobacterium tuberculosis against LVX, LZD, and AMC. All susceptibilities were determined on Middlebrook 7H10 agar. A critical concentration was used for LVX (1 μg/ml), whereas MICs were determined for LZD and AMC. M. tuberculosis H37Rv was used as a control strain. A total of 102 M. tuberculosis isolates (XDR, n = 59; pre-XDR, n = 43) were tested. Resistance to LVX was observed in 91.2% (93/102). Using an MIC value of 0.5 μg/ml as a cutoff, resistance to LZD (MIC ≥ 1 μg/ml) was noted in 5.9% (6/102). Although the sensitivity breakpoints are not established for AMC, the MIC values were high (>16 μg/ml) in 97.1% (99/102). Our results demonstrate that LZD may be effective for the treatment of XDR and pre-XDR cases from Pakistan. High resistance rates against LVX in our study suggest the use of this drug with caution for DR-TB cases from this area. Drug susceptibility testing against LVX and AMC may be helpful in complicated and difficult-to-manage cases.

Extended-spectrum beta-lactamase-producing Enterobacteriaceae in hospital urinary tract infections: incidence and antibiotic susceptibility profile over 9 years.

PubMed

Toner, Liam; Papa, Nathan; Aliyu, Sani H; Dev, Harveer; Lawrentschuk, Nathan; Al-Hayek, Samih

2016-07-01

Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae are an increasing concern regarding antibiotic resistance and their potential to cause serious infections which are difficult to treat. The purpose of this surveillance programme was to assess the incidence of ESBL in adults amongst urinary isolates, identify risk factors, and detail the antibiotic susceptibility profile in order to guide empirical treatment. From 2006 to 2014, we reviewed 21,414 positive urine cultures for E. coli and Klebsiella sp. from a University hospital in the UK and found 1420 ESBL-positive specimens. Susceptibility testing was performed by British Society of Antimicrobial Chemotherapy disc diffusion testing. ESBL screening was performed on samples resistant to cefpodoxime and confirmed by double disc diffusion (Oxoid Ltd, Basingstoke, UK). Patient gender, age, inpatient status, and catheterisation were assessed as risk factors. ESBL production amongst E. coli urine cultures increased 44 %, from 4.6 to 6.6 % of all E. coli isolates. ESBL-positive organisms were associated with increases in drug resistance, particularly amongst fluoroquinolones, trimethoprim, and cephalexin. Multidrug resistance was a feature with 75 % of ESBL+ Klebsiella sp.-resistant ≥6 antibiotic classes. ESBL producers remained largely susceptible to carbapenems. Male gender, urinary catheterisation, inpatient status, and increasing age were identified as risk factors for ESBL infection or colonisation. We demonstrate that the incidence of ESBL-producing E. coli in urine cultures is increasing and that such isolates are multidrug resistant. Carbapenems and nitrofurantoin for E. coli infections remain effective, which may guide empirical antibiotic therapy.

Mycobacterial interspersed repetitive unit typing and mutational profile for multidrug-resistant and extensively drug-resistant tuberculosis surveillance in Portugal: a 3-year period overview.

PubMed

Silva, Carla; Perdigão, João; Jordão, Luísa; Portugal, Isabel

2014-12-01

Multidrug tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) cases constitute a serious health problem in Portugal, of which the majority of isolates belong to the Lisboa family and the Q1 cluster, highly related to the Lisboa family. Here we sought to investigate the molecular basis of resistant TB as well as to determine the prevalence of specific drug resistance mutations and their association with MDR-TB and/or XDR-TB. In total, 74 Mycobacterium tuberculosis clinical isolates collected in Lisbon Health Region were genotyped by 24-loci mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR), and the mutational profile associated with first- and second-line drug resistance was studied. Seven new mutations were found, whilst the remaining 28 mutations had been previously associated with drug resistance. None of the mutations was specifically associated with MDR-TB. The mutational patterns observed among isolates belonging to Lisboa3 and Q1 clusters were also observed in isolates with unique MIRU-VNTR patterns but closely related to these strains. Such data suggest that the genotyping technique employed discriminates isolates with the same mutational profile. To establish the most adequate genotyping technique, the discriminatory power of three different MIRU-VNTR sets was analysed. The 15-loci MIRU-VNTR set showed adequate discriminatory power, comparable with the 24-loci set, allowing clustering of 60% and 86% of the MDR-TB and XDR-TB isolates, respectively, the majority of which belonged to the Lisboa3 and Q1 clusters. From an epidemiological standpoint, this study suggests combined mutational and genotyping analysis as a valuable tool for drug resistance surveillance. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Quadruple-first line drug resistance in Mycobacterium tuberculosis in Vietnam: What can we learn from genes?

PubMed

Nguyen, Huy Quang; Nguyen, Nhung Viet; Contamin, Lucie; Tran, Thanh Hoa Thi; Vu, Thuong Thi; Nguyen, Hung Van; Nguyen, Ngoc Lan Thi; Nguyen, Son Thai; Dang, Anh Duc; Bañuls, Anne-Laure; Nguyen, Van Anh Thi

2017-06-01

In Vietnam, a country with high tuberculosis (137/100.000 population) and multidrug-resistant (MDR)-TB burdens (7.8/100.000 population), little is known about the molecular signatures of drug resistance in general and more particularly of second line drug (SLD) resistance. This study is specifically focused on Mycobacterium tuberculosis isolates resistant to four first-line drugs (FLDs) that make TB much more difficult to treat. The aim is to determine the proportion of SLD resistance in these quadruple drug resistant isolates and the genetic determinants linked to drug resistance to better understand the genetic processes leading to quadruple and extremely drug resistance (XDR). 91 quadruple (rifampicin, isoniazid, ethambutol and streptomycin) FLD resistant and 55 susceptible isolates were included. Spoligotyping and 24-locus MIRU-VNTR techniques were performed and 9 genes and promoters linked to FLD and SLD resistance were sequenced. SLD susceptibility testing was carried out on a subsample of isolates. High proportion of quadruple-FLD resistant isolates was resistant to fluoroquinolones (27%) and second-line injectable drugs (30.2%) by drug susceptibility testing. The sequencing revealed high mutation diversity with prevailing mutations at positions katG315, inhA-15, rpoB531, embB306, rrs1401, rpsL43 and gyrA94. The sensitivity and specificity were high for most drug resistances (>86%), but the sensitivity was lower for injectable drug resistances (<69%). The mutation patterns revealed 23.1% of pre-XDR and 7.7% of XDR isolates, mostly belonging to Beijing family. The genotypic diversity and the variety of mutations reflect the existence of various evolutionary paths leading to FLD and SLD resistance. Nevertheless, particular mutation patterns linked to high-level resistance and low fitness costs seem to be favored. Copyright © 2017 Elsevier B.V. All rights reserved.

Antimicrobial resistance among Enterobacteriaceae in South America: history, current dissemination status and associated socioeconomic factors.

PubMed

Bonelli, Raquel Regina; Moreira, Beatriz Meurer; Picão, Renata Cristina

2014-04-01

South America exhibits some of the higher rates of antimicrobial resistance in Enterobactericeae worldwide. This continent includes 12 independent countries with huge socioeconomic differences, where the ample access to antimicrobials, including counterfeit ones, coexists with ineffective health systems and sanitation problems, favoring the emergence and dissemination of resistant strains. This work presents a literature review concerning the evolution and current status of antimicrobial resistance threats found among Enterobacteriaceae in South America. Resistance to β-lactams, fluoroquinolones and aminoglycosides was emphasized along with description of key epidemiological studies that highlight the success of specific resistance determinants in different parts of the continent. In addition, a discussion regarding political and socioeconomic factors possibly related to the dissemination of antimicrobial resistant strains in clinical settings and at the community is presented. Finally, in order to assess the possible sources of resistant bacteria, we compile the current knowledge about the occurrence of antimicrobial resistance in isolates in South American' food, food-producing animals and off-hospitals environments. By addressing that intensive intercontinental commerce and tourism neutralizes the protective effect of geographic barriers, we provide arguments reinforcing that globally integrated efforts are needed to decelerate the emergence and dissemination of antimicrobial resistant strains. Copyright © 2014 Elsevier Ltd. All rights reserved.

Enterobacteriaceae Sepsis Outcome Programme annual report, 2013.

PubMed

Turnidge, John D; Gottlieb, Thomas; Mitchell, David H; Coombs, Geoffrey W; Daly, Denise A; Bell, Jan M

2014-12-31

The Australian Group on Antimicrobial Resistance performs regular period-prevalence studies to monitor changes in antimicrobial resistance in selected enteric Gram-negative pathogens. The 2013 survey focussed for the first time on blood stream infections. Four thousand nine hundred and fifty-eight Enterobacteriaceae species were tested using commercial automated methods (Vitek® 2, BioMérieux; Phoenix™, BD). The results were analysed using Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints (January 2014). Of the key resistances, non-susceptibility to the third-generation cephalosporin, ceftriaxone, was found in 7.5%/7.5% (CLSI/EUCAST criteria respectively) of Escherichia coli; 6.3%/6.3% of Klebsiella pneumoniae, and 7.4%/7.4% of K. oxytoca. Non-susceptibility rates to ciprofloxacin were 10.3%/11.3% for E. coli, 4.6%/7.5% for K. pneumoniae, 0.6%/0.6% for K. oxytoca, and 3.6%/6.1% in Enterobacter cloacae. Resistance rates to piperacillin-tazobactam were 3.1%/6.2%, 4.2%/7.0%, 11.9% /12.6%, and 17.3% /22.2% for the same 4 species respectively. Fourteen isolates were shown to harbour a carbapenemase gene, 9 blaIMP, 3 blaKPC, and 2 blaNDM. This work is copyright. You may download, display, print and reproduce the whole or part of this work in unaltered form for your own personal use or, if you are part of an organisation, for internal use within your organisation, but only if you or your organisation do not use the reproduction for any commercial purpose and retain this copyright notice and all disclaimer notices as part of that reproduction. Apart from rights to use as permitted by the Copyright Act 1968 or allowed by this copyright notice, all other rights are reserved and you are not allowed to reproduce the whole or any part of this work in any way (electronic or otherwise) without first being given the specific written permission from the Commonwealth to do so. Requests and

In Vivo Activities of Ceftolozane, a New Cephalosporin, with and without Tazobactam against Pseudomonas aeruginosa and Enterobacteriaceae, Including Strains with Extended-Spectrum β-Lactamases, in the Thighs of Neutropenic Mice

PubMed Central

Andes, D. R.

2013-01-01

Ceftolozane is a new cephalosporin with potent activity against Pseudomonas aeruginosa and Enterobacteriaceae. A neutropenic murine thigh infection model was used to determine which pharmacokinetic/pharmacodynamic index and magnitude drives the efficacy of ceftolozane with Gram-negative bacilli, to compare the rates of in vivo killing of P. aeruginosa by ceftolozane and ceftazidime, and to determine the impact of different ratios of ceftolozane plus tazobactam on Enterobacteriaceae containing extended-spectrum β-lactamases (ESBLs). Neutropenic mice had 106.2-7.1 CFU/thigh when treated with ceftolozane for 24 h with (i) various doses (3.12 to 1,600 mg/kg) and dosage intervals (3, 6, 12, and 24 h) against two Enterobacteriaceae strains, (ii) 0.39 to 800 mg/kg every 6 h for four Enterobacteriaceae and four P. aeruginosa strains, and (iii) 400 or 800 mg/kg with 2:1. 4:1, and 8:1 ratios of tazobactam against five Enterobacteriaceae strains with ESBLs. The pharmacokinetics of ceftolozane at 25, 100, and 400 mg/kg were linear with peak/dose values of 1.0 to 1.4 and half-lives of 12 to 14 min. T>MIC was the primary index driving efficacy. For stasis (1 log kill), T>MIC was 26.3% ± 2.1% (31.6% ± 1.6%) for wild-type Enterobacteriaceae, 31.1% ± 4.9% (34.8% ± 4.4%) for Enterobacteriaceae with ESBLs, and 24.0% ± 3.3% (31.5% ± 3.9%) for P. aeruginosa. At 200 mg/kg every 3 h, the rate of in vivo killing of P. aeruginosa was faster with ceftolozane than with ceftazidime (−0.34 to −0.41 log10 CFU/thigh/h versus −0.21 to −0.24 log10 CFU/thigh/h). The 2:1 ratio of ceftolozane with tazobactam was the most potent combination studied. The T>MIC required for ceftolozane is less than with other cephalosporins and may be due to more rapid killing. PMID:23274659

Draft Genome Sequence of Pantoea ananatis GB1, a Plant-Growth-Promoting Hydrocarbonoclastic Root Endophyte, Isolated at a Diesel Fuel Phytoremediation Site Planted with Populus.

PubMed

Gkorezis, Panagiotis; Van Hamme, Jonathan D; Bottos, Eric M; Thijs, Sofie; Balseiro-Romero, Maria; Monterroso, Carmela; Kidd, Petra Suzan; Rineau, Francois; Weyens, Nele; Vangronsveld, Jaco

2016-02-25

We report the 4.76-Mb draft genome of Pantoea ananatis GB1, a Gram-negative bacterium of the family Enterobacteriaceae, isolated from the roots of poplars planted for phytoremediation of a diesel-contaminated plume at the Ford Motor Company site in Genk, Belgium. Strain GB1 promotes plant growth in various hosts and metabolizes hydrocarbons. Copyright © 2016 Gkorezis et al.

Treatment Options for Infections Caused by Carbapenem-resistant Enterobacteriaceae: Can We Apply “Precision Medicine” to Antimicrobial Chemotherapy?

PubMed Central

Perez, Federico; El Chakhtoura, Nadim G.; Papp-Wallace, Krisztina; Wilson, Brigid M; Bonomo, Robert A.

2016-01-01

Introduction For the past three decades, carbapenems played a central role in our antibiotic armamentarium, trusted to effectively treat infections caused by drug-resistant bacteria. The utility of this class of antibiotics has been compromised by the emergence of resistance especially among Enterobacteriaceae. Areas covered We review the current mainstays of pharmacotherapy against infections caused by carbapenem-resistant Enterobacteriaceae (CRE) including tigecycline, aminoglycosides, and rediscovered 'old' antibiotics such as fosfomycin and polymyxins, and discuss their efficacy and potential toxicity. We also summarize the clinical experience treating CRE infections with antibiotic combination therapy. Finally, we review ceftazidime/avibactam and imipenem/relebactam, a new generation of beta-lactamase inhibitors, which may offer alternatives to treat CRE infections. We critically evaluate the published literature, identify relevant clinical trials and review documents submitted to the United States Food and Drug Administration. Expert Opinion It is essential to define the molecular mechanisms of resistance and to apply insights about pharmacodynamic and pharmacokinetic properties of antibiotics, in order to maximize the impact of old and new therapeutic approaches against infections caused by CRE. A concerted effort is needed to carry out high-quality clinical trials that: i) establish the superiority of combination therapy vs. monotherapy; ii) confirm the role of novel beta-lactam/beta-lactamase inhibitor combinations as therapy against KPC- and OXA-48 producing Enterobacteriaceae; and, iii) evaluate new antibiotics active against CRE as they are introduced into the clinic. PMID:26799840

Faecal carriage of CTX-M extended-spectrum beta-lactamase-producing Enterobacteriaceae among street children dwelling in Mwanza city, Tanzania.

PubMed

Moremi, Nyambura; Claus, Heike; Vogel, Ulrich; Mshana, Stephen E

2017-01-01

Data on ESBL carriage of healthy people including children are scarce especially in developing countries. We analyzed the prevalence and genotypes of ESBL-producing Enterobacteriaceae (EPE) in Tanzanian street children with rare contact to healthcare facilities but significant interactions with the environment, animals and other people. Between April and July 2015, stool samples of 107 street children, who live in urban Mwanza were analyzed for EPE. Intestinal carriage of EPE was found in 34 (31.8%, 95% CI; 22.7-40.3) children. Of the 36 isolates from 34 children, 30 (83.3%) were Escherichia coli (E. coli) and six Klebsiella pneumoniae (K. pneumoniae). Out of 36 isolates, 36 (100%), 35 (97%), 25 (69%) and 16 (44%) were resistant to tetracycline, trimethoprim-sulfamethoxazole, ciprofloxacin and gentamicin, respectively. Beta-lactamase genes and the multilocus sequence types of E. coli and K. pneumoniae were characterized. ESBL gene blaCTX-M-15 was detected in 75% (27/36) of ESBL isolates. Sequence types (STs) 131, 10, 448 and 617 were the most prevalent in E. coli. Use of local herbs (OR: 3.5, 95% CI: 1.51-8.08, P = 0.003) and spending day and night on streets (OR: 3.6, 95% CI: 1.44-8.97, P = 0.005) were independent predictors of ESBL carriage. We observed a high prevalence of blaCTX-M-15 in EPE collected from street children in Tanzania. Detection of E. coli STs 131, 10, 38 and 648, which have been observed worldwide in animals and people, highlights the need for multidisciplinary approaches to understand the epidemiology and drivers of antimicrobial resistance in low-income countries.

Potential transmission of Pantoea spp. and Serratia marcescens (Enterobacteriales: Enterobacteriaceae) to plants by Lygus hesperus (Hemiptera: Miridae)

USDA-ARS?s Scientific Manuscript database

Lygus hesperus Knight (Hemiptera: Miridae) is a key agricultural pest in the western United States. In a recent study, proteins from Pantoea ananatis and Serratia marcescens (Enterobacteriales: Enterobacteriaceae) were identified in diet that was stylet-probed and fed upon by L. hesperus adults. P...

Applying definitions for multidrug resistance, extensive drug resistance and pandrug resistance to clinically significant livestock and companion animal bacterial pathogens.

PubMed

Sweeney, Michael T; Lubbers, Brian V; Schwarz, Stefan; Watts, Jeffrey L

2018-06-01

Standardized definitions for MDR are currently not available in veterinary medicine despite numerous reports indicating that antimicrobial resistance may be increasing among clinically significant bacteria in livestock and companion animals. As such, assessments of MDR presented in veterinary scientific reports are inconsistent. Herein, we apply previously standardized definitions for MDR, XDR and pandrug resistance (PDR) used in human medicine to animal pathogens and veterinary antimicrobial agents in which MDR is defined as an isolate that is not susceptible to at least one agent in at least three antimicrobial classes, XDR is defined as an isolate that is not susceptible to at least one agent in all but one or two available classes and PDR is defined as an isolate that is not susceptible to all agents in all available classes. These definitions may be applied to antimicrobial agents used to treat bovine respiratory disease (BRD) caused by Mannheimia haemolytica, Pasteurella multocida and Histophilus somni and swine respiratory disease (SRD) caused by Actinobacillus pleuropneumoniae, P. multocida and Streptococcus suis, as well as antimicrobial agents used to treat canine skin and soft tissue infections (SSTIs) caused by Staphylococcus and Streptococcus species. Application of these definitions in veterinary medicine should be considered static, whereas the classification of a particular resistance phenotype as MDR, XDR or PDR could change over time as more veterinary-specific clinical breakpoints or antimicrobial classes and/or agents become available in the future.

Contact investigation after a fatal case of extensively drug-resistant tuberculosis (XDR-TB) in an aircraft, Germany, July 2013

PubMed Central

an der Heiden, Maria; Hauer, Barbara; Fiebig, Lena; Glaser-Paschke, Gisela; Stemmler, Markus; Simon, Claudia; Rüsch-Gerdes, Sabine; Gilsdorf, Andreas; Haas, Walter

2017-01-01

In July 2013, a passenger died of infectious extensively drug-resistant tuberculosis (XDR-TB) on board of an aircraft after a 3-hour flight from Turkey to Germany. Initial information indicated the patient had moved about the aircraft coughing blood. We thus aimed to contact and inform all persons exposed within the aircraft and to test them for newly acquired TB infection. Two-stage testing within 8 weeks from exposure and at least 8 weeks after exposure was suggested, using either interferon gamma release assays (IGRAs) or tuberculin skin test (TST). The TST cut-off was defined at a diameter > 10 mm; for differentiation between conversion and boosting, conversion was defined as increase of skin induration > 5 mm. Overall, 155 passengers and seven crew members were included in the investigation: the questionnaire response rate was 83%; 112 (69%) persons were tested at least once for TB infection. In one passenger, who sat next to the area where the patient died, a test conversion was registered. As of March 2017, no secondary active TB cases have been reported. We describe an unusual situation in which we applied contact tracing beyond existing European guidelines; we found one latent tuberculosis infection in a passenger, which we consider probably newly acquired. PMID:28367796

In vitro activity of rifaximin against isolates from patients with small intestinal bacterial overgrowth.

PubMed

Pistiki, Aikaterini; Galani, Irene; Pyleris, Emmanouel; Barbatzas, Charalambos; Pimentel, Mark; Giamarellos-Bourboulis, Evangelos J

2014-03-01

Rifaximin, a non-absorbable rifamycin derivative, has published clinical efficacy in the alleviation of symptoms in patients with irritable bowel syndrome (IBS). Small intestinal bacterial overgrowth (SIBO) is associated with the pathogenesis of IBS. This study describes for the first time the antimicrobial effect of rifaximin against SIBO micro-organisms from humans. Fluid was aspirated from the third part of the duodenum from 567 consecutive patients; quantitative cultures diagnosed SIBO in 117 patients (20.6%). A total of 170 aerobic micro-organisms were isolated and the in vitro efficacy of rifaximin was studied by (i) minimum inhibitory concentration (MIC) testing by a microdilution technique and (ii) time-kill assays using bile to simulate the small intestinal environment. At a breakpoint of 32 μg/mL, rifaximin inhibited in vitro 85.4% of Escherichia coli, 43.6% of Klebsiella spp., 34.8% of Enterobacter spp., 54.5% of other Enterobacteriaceae spp., 82.6% of non-Enterobacteriaceae Gram-negative spp., 100% of Enterococcus faecalis, 100% of Enterococcus faecium and 100% of Staphylococcus aureus. For the time-kill assays, 11 E. coli, 15 non-E. coli Gram-negative enterobacteria and three E. faecalis isolates were studied. Rifaximin produced a >3 log10 decrease in the starting inoculum against most of the tested isolates at 500 μg/mL after 24h of growth. The results indicate that rifaximin has a potent effect on specific small bowel flora associated with SIBO. This conclusion should be regarded in light of the considerable time-kill effect at concentrations lower than those achieved in the bowel lumen after administration of conventional doses in humans. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

An Irish outbreak of New Delhi metallo-β-lactamase (NDM)-1 carbapenemase-producing Enterobacteriaceae: increasing but unrecognized prevalence.

PubMed

O'Connor, C; Cormican, M; Boo, T W; McGrath, E; Slevin, B; O'Gorman, A; Commane, M; Mahony, S; O'Donovan, E; Powell, J; Monahan, R; Finnegan, C; Kiernan, M G; Coffey, J C; Power, L; O'Connell, N H; Dunne, C P

2016-12-01

Carbapenemase-producing Enterobacteriaceae (CPE) may cause healthcare-associated infections with high mortality rates. New Delhi metallo-β-lactamase-1 (NDM-1) is among the most recently discovered carbapenemases. To report the first outbreak of NDM-1 CPE in Ireland, including microbiological and epidemiological characteristics, and assessing the impact of infection prevention and control measures. This was a retrospective microbiological and epidemiological review. Cases were defined as patients with a CPE-positive culture. Contacts were designated as roommates or ward mates. This outbreak involved 10 patients with a median age of 71 years (range: 45-90), located in three separate but affiliated healthcare facilities. One patient was infected (the index case); the nine others were colonized. Nine NDM-1-producing Klebsiella pneumoniae, an NDM-1-producing Escherichia coli and a K. pneumoniae carbapenemase (KPC)-producing Enterobacter cloacae were detected between week 24, 2014 and week 37, 2014. Pulsed-field gel electrophoresis demonstrated similarity. NDM-1-positive isolates were meropenem resistant with minimum inhibitory concentrations (MICs) ranging from 12 to 32 μg/mL. All were tigecycline susceptible (MICs ≤1 μg/mL). One isolate was colistin resistant (MIC 4.0 μg/mL; mcr-1 gene not detected). In 2015, four further NDM-1 isolates were detected. The successful management of this outbreak was achieved via the prompt implementation of enhanced infection prevention and control practices to prevent transmission. These patients did not have a history of travel outside of Ireland, but several had frequent hospitalizations in Ireland, raising concerns regarding the possibility of increasing but unrecognized prevalence of NDM-1 and potential decline in value of travel history as a marker of colonization risk. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Isolation and identification of halotolerant soil bacteria from coastal Patenga area.

PubMed

Rahman, Shafkat Shamim; Siddique, Romana; Tabassum, Nafisa

2017-10-30