Insertional Inactivation of Genes Responsible for the d-Alanylation of Lipoteichoic Acid in Streptococcus gordonii DL1 (Challis) Affects Intrageneric Coaggregations

PubMed Central

Clemans, Daniel L.; Kolenbrander, Paul E.; Debabov, Dmitri V.; Zhang, Qunying; Lunsford, R. Dwayne; Sakone, Holly; Whittaker, Catherine J.; Heaton, Michael P.; Neuhaus, Francis C.

1999-01-01

Most human oral viridans streptococci participate in intrageneric coaggregations, the cell-to-cell adherence among genetically distinct streptococci. Two genes relevant to these intrageneric coaggregations were identified by transposon Tn916 mutagenesis of Streptococcus gordonii DL1 (Challis). A 626-bp sequence flanking the left end of the transposon was homologous to dltA and dltB of Lactobacillus rhamnosus ATCC 7469 (formerly called Lactobacillus casei). A 60-kb probe based on this flanking sequence was used to identify the homologous DNA in a fosmid library of S. gordonii DL1. This DNA encoded d-alanine-d-alanyl carrier protein ligase that was expressed in Escherichia coli from the fosmid clone. The cloned streptococcal dltA was disrupted by inserting an ermAM cassette, and then it was linearized and transformed into S. gordonii DL1 for allelic replacement. Erythromycin-resistant transformants containing a single insertion in dltA exhibited a loss of d-alanyl esters in lipoteichoic acid (LTA) and a loss of intrageneric coaggregation. This phenotype was correlated with the loss of a 100-kDa surface protein reported previously to be involved in mediating intrageneric coaggregation (C. J. Whittaker, D. L. Clemans, and P. E. Kolenbrander, Infect. Immun. 64:4137–4142, 1996). The mutants retained the parental ability to participate in intergeneric coaggregation with human oral actinomyces, indicating the specificity of the mutation in altering intrageneric coaggregations. The mutants were altered morphologically and exhibited aberrant cell septa in a variety of pleomorphs. The natural DNA transformation frequency was reduced 10-fold in these mutants. Southern analysis of chromosomal DNAs from various streptococcal species with the dltA probe revealed the presence of this gene in most viridans streptococci. Thus, it is hypothesized that d-alanyl LTA may provide binding sites for the putative 100-kDa adhesin and scaffolding for the proper presentation of this adhesin to mediate intrageneric coaggregation. PMID:10225909

Insertional inactivation of genes responsible for the D-alanylation of lipoteichoic acid in Streptococcus gordonii DL1 (Challis) affects intrageneric coaggregations.

PubMed

Clemans, D L; Kolenbrander, P E; Debabov, D V; Zhang, Q; Lunsford, R D; Sakone, H; Whittaker, C J; Heaton, M P; Neuhaus, F C

1999-05-01

Most human oral viridans streptococci participate in intrageneric coaggregations, the cell-to-cell adherence among genetically distinct streptococci. Two genes relevant to these intrageneric coaggregations were identified by transposon Tn916 mutagenesis of Streptococcus gordonii DL1 (Challis). A 626-bp sequence flanking the left end of the transposon was homologous to dltA and dltB of Lactobacillus rhamnosus ATCC 7469 (formerly called Lactobacillus casei). A 60-kb probe based on this flanking sequence was used to identify the homologous DNA in a fosmid library of S. gordonii DL1. This DNA encoded D-alanine-D-alanyl carrier protein ligase that was expressed in Escherichia coli from the fosmid clone. The cloned streptococcal dltA was disrupted by inserting an ermAM cassette, and then it was linearized and transformed into S. gordonii DL1 for allelic replacement. Erythromycin-resistant transformants containing a single insertion in dltA exhibited a loss of D-alanyl esters in lipoteichoic acid (LTA) and a loss of intrageneric coaggregation. This phenotype was correlated with the loss of a 100-kDa surface protein reported previously to be involved in mediating intrageneric coaggregation (C. J. Whittaker, D. L. Clemans, and P. E. Kolenbrander, Infect. Immun. 64:4137-4142, 1996). The mutants retained the parental ability to participate in intergeneric coaggregation with human oral actinomyces, indicating the specificity of the mutation in altering intrageneric coaggregations. The mutants were altered morphologically and exhibited aberrant cell septa in a variety of pleomorphs. The natural DNA transformation frequency was reduced 10-fold in these mutants. Southern analysis of chromosomal DNAs from various streptococcal species with the dltA probe revealed the presence of this gene in most viridans streptococci. Thus, it is hypothesized that D-alanyl LTA may provide binding sites for the putative 100-kDa adhesin and scaffolding for the proper presentation of this adhesin to mediate intrageneric coaggregation.

Bacteremia due to viridans streptococcus in neutropenic patients with cancer: clinical spectrum and risk factors.

PubMed

Bochud, P Y; Eggiman, P; Calandra, T; Van Melle, G; Saghafi, L; Francioli, P

1994-01-01

Between 1988 and 1991, 26 episodes of bacteremia due to viridans streptococci occurred in 25 neutropenic patients undergoing intensive chemotherapy for hematologic malignancies. Complications related to the bacteremia were observed in 10 episodes: unilateral pulmonary infiltrates (4), acute respiratory distress syndrome (ARDS) (4), hypotension (3), and endocarditis (2). All patients with ARDS had received high doses of cytosine arabinoside and had bacteremia due to Streptococcus mitis. Death occurred in three patients (12%) but was possibly related to bacteremia in only one case. Case patients who had received prophylaxis with quinolones were compared with matched control patients who received similar prophylaxis but who did not have bacteremia due to viridans streptococci. Multivariate analysis of predisposing factors showed that high doses of cytosine arabinoside (P = .01), the presence of mucositis (P = .02), and the absence of previous therapy with parenteral antibiotics (P = .01) were independent risk factors for the development of viridans streptococcal bacteremia. Of 259 patients who had received quinolone prophylaxis during the study period, 22 (8.5%) developed an episode of viridans streptococcal bacteremia as compared with three episodes (3.7%) in 82 patients who had received a quinolone and penicillin (P = .07). However, the latter three episodes were caused by strains with decreased susceptibility to penicillin, thus suggesting that resistance to penicillin might limit the use of this antibiotic as a prophylactic agent in the future.

Comparative genomics and evolution of the amylase-binding proteins of oral streptococci.

PubMed

Haase, Elaine M; Kou, Yurong; Sabharwal, Amarpreet; Liao, Yu-Chieh; Lan, Tianying; Lindqvist, Charlotte; Scannapieco, Frank A

2017-04-20

Successful commensal bacteria have evolved to maintain colonization in challenging environments. The oral viridans streptococci are pioneer colonizers of dental plaque biofilm. Some of these bacteria have adapted to life in the oral cavity by binding salivary α-amylase, which hydrolyzes dietary starch, thus providing a source of nutrition. Oral streptococcal species bind α-amylase by expressing a variety of amylase-binding proteins (ABPs). Here we determine the genotypic basis of amylase binding where proteins of diverse size and function share a common phenotype. ABPs were detected in culture supernatants of 27 of 59 strains representing 13 oral Streptococcus species screened using the amylase-ligand binding assay. N-terminal sequences from ABPs of diverse size were obtained from 18 strains representing six oral streptococcal species. Genome sequencing and BLAST searches using N-terminal sequences, protein size, and key words identified the gene associated with each ABP. Among the sequenced ABPs, 14 matched amylase-binding protein A (AbpA), 6 matched amylase-binding protein B (AbpB), and 11 unique ABPs were identified as peptidoglycan-binding, glutamine ABC-type transporter, hypothetical, or choline-binding proteins. Alignment and phylogenetic analyses performed to ascertain evolutionary relationships revealed that ABPs cluster into at least six distinct, unrelated families (AbpA, AbpB, and four novel ABPs) with no phylogenetic evidence that one group evolved from another, and no single ancestral gene found within each group. AbpA-like sequences can be divided into five subgroups based on the N-terminal sequences. Comparative genomics focusing on the abpA gene locus provides evidence of horizontal gene transfer. The acquisition of an ABP by oral streptococci provides an interesting example of adaptive evolution.

Effect of Periodontal Therapy With Amoxicillin-Metronidazole on Pharyngeal Carriage of Penicillin- and Erythromycin-Resistant Viridans Streptococci.

PubMed

Mombelli, Andrea; Cionca, Norbert; Almaghlouth, Adnan; Cherkaoui, Abdessalam; Schrenzel, Jacques; Giannopoulou, Catherine

2016-05-01

Previous studies have focused on antibiotic resistance of Gram-negative bacteria before and after periodontal therapy. The purpose of this analysis is to assess changes in resistance patterns of the commensal Gram-positive microbiota. The viridans group streptococci (VGS) have been suggested to serve as reservoirs of resistance genes for more pathogenic streptococci and may be implicated in some non-oral infections. In this randomized clinical trial, 80 patients with periodontitis are distributed randomly into two groups. In group A, patients received 375 mg amoxicillin and 500 mg metronidazole three times per day for 7 days during the non-surgical treatment phase (T1). In group B, the antibiotics were administered during the surgical phase (T2). Resistance of VGS to penicillin and erythromycin was determined by the epsilometer test. At baseline, VGS from 12.5% (group A) and 11.8% (group B) of patients had a minimum inhibitory concentration (MIC) >2 μg/mL to penicillin. Three months after T1, VGS from 15.6% and 16.7% of patients had an MIC >2 μg/mL, respectively. Six months after T2 VGS from 5.9% and 5.9% and 12 months after T2 VGS from 6.1% and 6.3% patients had an MIC >2 μg/mL. There was no effect of therapy with antibiotics, administered either in T1 or T2, on the carriage of penicillin-resistant VGS. Erythromycin resistance was high at baseline and remained unchanged throughout the study. MICs for penicillin and erythromycin were correlated (P <0.05). Amoxicillin plus metronidazole did not significantly affect the resistance pattern of the VGS to penicillin or erythromycin.

Presumptive identification of streptococci with a new test system.

PubMed Central

Facklam, R R; Thacker, L G; Fox, B; Eriquez, L

1982-01-01

A test is described that could replace bacitracin susceptibility for presumptive identification of group A streptococci as well as 6.5% NaCl agar tolerance for presumptive identification of enterococcal streptococci. The L-pyrrolidonyl-beta-naphthylamide test, based on hydrolysis of pyrrolidonyl-beta-naphthylamide, was used in conjunction with the CAMP and bile-esculin tests to presumptively identify the streptococci. Among the beta-hemolytic streptococci; 98% of 50 group A, 98% of 46 group B, and 100% of 70 strains that were not group A, B, or D were correctly identified by the new presumptive test scheme. Among the non-beta-hemolytic streptococci; 96% of 74 group D enterococcal, 100% of 30 group D nonenterococcal, and 82% of 112 viridans strains were correctly identified by the new presumptive test scheme. PMID:7050157

Antimicrobial susceptibility against penicillin, ampicillin and vancomycin of viridans group Streptococcus in oral microbiota of patients at risk of infective endocarditis.

PubMed

Süzük, Serap; Kaşkatepe, Banu; Çetin, Mustafa

2016-09-01

The viridans group Streptococci (VGS) are most abundant in the mouth; in some instances they might emerge as pathogens particularly in infective endocarditis (IE). In this study, we aimed to define and determine the susceptibility against antibiotics of VGS that are members of the oral microbiota of patients exhibiting a risk of developing IE. Forty-nine patients at risk of infective endocarditis were included in the study. Identification of the bacteria was performed using API STREP (bioMérieux, France). Gradient test strips (E-Test, France) were used to determine MIC of the bacteria against penicillin, ampicillin, and vancomycin. The distribution of the isolated VGS groups was determined as follows: Streptococcus mitis 32.6% and anginosus group - 32.6%, S. sanguinis group - 16.3%, S. mutans group - 12.2%, and S. salivarius group - 6.1%. The rates of resistance and reduced sensitivity of the isolates for penicillin and ampicillin were determined at 61.2% and 55.1%, respectively. However, all isolates were found to be susceptible to vancomycin. We conclude that the antimicrobial resistance of VGS should be determined on a regular basis locally, and decisions on therapeutic and prophylactic interventions should be given taking this resistance into consideration.

Viridans Streptococci in Peritoneal Dialysis Peritonitis: Clinical Courses and Long-Term Outcomes

PubMed Central

Chao, Chia-Ter; Lee, Szu-Ying; Yang, Wei-Shun; Chen, Huei-Wen; Fang, Cheng-Chung; Yen, Chung-Jen; Chiang, Chih-Kang; Hung, Kuan-Yu; Huang, Jenq-Wen

2015-01-01

♦ Background: The clinical courses and long-term outcomes of viridans streptococcus (VS) peritoneal dialysis (PD) peritonitis remain unclear. ♦ Methods: We conducted a retrospective analysis of all PD patients in a single center with gram-positive cocci (GPC) peritonitis between 2005 and 2011, and divided them into 3 groups: VS, other streptococci and other GPC (apart from VS). Clinical characteristics and outcomes of the VS group were compared with the other streptococci and other GPC groups, with prognostic factors determined. ♦ Results: A total of 140 patients with 168 episodes of GPC peritonitis (44% of all peritonitis) were identified over 7 years. Among these, 18 patients (13%) developed VS peritonitis, while 14 patients (10%) developed other streptococcal peritonitis. Patients with VS peritonitis had a high cure rate by antibiotic alone (94%), despite a high polymicrobial yield frequency (28%). We found that VS peritonitis carried a lower risk of Tenckhoff catheter removal and relapsing episodes than other GPC peritonitis (6% vs 11%), and a lower mortality than other streptococci peritonitis (0% vs 7%). However, after the index peritonitis episodes, VS, other streptococci, and other GPC group had a significantly increased peritonitis incidence compared with the period before the index peritonitis (all p < 0.01). Patients with VS peritonitis had a significantly higher incidence of refractory peritonitis compared with other streptococci or other GPC peritonitis in the long term (both p < 0.01). ♦ Conclusions: VS poses a higher risk of subsequent refractory peritonitis after the index episode as compared with other streptococcal or GPC peritonitis. It might be prudent to monitor the technique of these patients with VS peritonitis closely to avoid further peritonitis episodes. PMID:24497584

Garenoxacin treatment of experimental endocarditis caused by viridans group streptococci.

PubMed

Anguita-Alonso, Paloma; Rouse, Mark S; Piper, Kerryl E; Steckelberg, James M; Patel, Robin

2006-04-01

The activity of garenoxacin was compared to that of levofloxacin or penicillin in a rabbit model of Streptococcus mitis group (penicillin MIC, 0.125 microg/ml) and Streptococcus sanguinis group (penicillin MIC, 0.25 microg/ml) endocarditis. Garenoxacin and levofloxacin had MICs of 0.125 and 0.5 microg/ml, respectively, for both study isolates. Rabbits with catheter-induced aortic valve endocarditis were given no treatment, penicillin at 1.2x10(6) IU/8 h intramuscularly, garenoxacin at 20 mg/kg of body weight/12 h intravenously, or levofloxacin at 40 mg/kg/12 h intravenously. For both isolates tested, garenoxacin area under the curve (AUC)/MIC and maximum concentration of drug in serum (Cmax)/MIC ratios were 368 and 91, respectively. Rabbits were sacrificed after 3 days of treatment; cardiac valve vegetations were aseptically removed and quantitatively cultured. For S. mitis group experimental endocarditis, all studied antimicrobial agents were more active than no treatment (P<0.001), whereas for S. sanguinis group endocarditis, no studied antimicrobial agents were more active than no treatment. We conclude that AUC/MIC and Cmax/MIC ratios may not predict activity of some quinolones in experimental viridans group endocarditis and that garenoxacin and levofloxacin may not be ideal choices for serious infections caused by some quinolone-susceptible viridans group streptococci.

Direct identification of bacteria in positive blood culture bottles by matrix-assisted laser desorption ionisation time-of-flight mass spectrometry.

PubMed

La Scola, Bernard; Raoult, Didier

2009-11-25

With long delays observed between sampling and availability of results, the usefulness of blood cultures in the context of emergency infectious diseases has recently been questioned. Among methods that allow quicker bacterial identification from growing colonies, matrix-assisted laser desorption ionisation time-of-flight (MALDI-TOF) mass spectrometry was demonstrated to accurately identify bacteria routinely isolated in a clinical biology laboratory. In order to speed up the identification process, in the present work we attempted bacterial identification directly from blood culture bottles detected positive by the automate. We prospectively analysed routine MALDI-TOF identification of bacteria detected in blood culture by two different protocols involving successive centrifugations and then lysis by trifluoroacetic acid or formic acid. Of the 562 blood culture broths detected as positive by the automate and containing one bacterial species, 370 (66%) were correctly identified. Changing the protocol from trifluoroacetic acid to formic acid improved identification of Staphylococci, and overall correct identification increased from 59% to 76%. Lack of identification was observed mostly with viridans streptococci, and only one false positive was observed. In the 22 positive blood culture broths that contained two or more different species, only one of the species was identified in 18 samples, no species were identified in two samples and false species identifications were obtained in two cases. The positive predictive value of bacterial identification using this procedure was 99.2%. MALDI-TOF MS is an efficient method for direct routine identification of bacterial isolates in blood culture, with the exception of polymicrobial samples and viridans streptococci. It may replace routine identification performed on colonies, provided improvement for the specificity of blood culture broths growing viridans streptococci is obtained in the near future.

Comparison of species identification of endocarditis associated viridans streptococci using rnpB genotyping and 2 MALDI-TOF systems.

PubMed

Isaksson, Jenny; Rasmussen, Magnus; Nilson, Bo; Stadler, Liselott Svensson; Kurland, Siri; Olaison, Lars; Ek, Elisabeth; Herrmann, Björn

2015-04-01

Streptococcus spp. are important causes of infective endocarditis but challenging in species identification. This study compared identification based on sequence determination of the rnpB gene with 2 systems of matrix-assisted laser desorption ionization-time of flight mass spectrometry, MALDI Biotyper (Bruker) and VITEK MS IVD (bioMérieux). Blood culture isolates of viridans streptococci from 63 patients with infective endocarditis were tested. The 3 methods showed full agreement for all 36 isolates identified in the Anginosus, Bovis, and Mutans groups or identified as Streptococcus cristatus, Streptococcus gordonii, or Streptococcus sanguinis. None of the methods could reliably identify the 23 isolates to the species level when designated as Streptococcus mitis, Streptococcus oralis, or Streptococcus tigurinus. In 7 isolates classified to the Mitis group, the rnpB sequences deviated strikingly from all reference sequences, and additional analysis of sodA and groEL genes indicated the occurrence of yet unidentified Streptococcus spp. Copyright © 2015 Elsevier Inc. All rights reserved.

62 FR 6261 - Determination of Regulatory Review Period for Purposes of Patent Extension; MERREMRegister I.V.

Federal Register 2010, 2011, 2012, 2013, 2014

1997-02-11

...): Bacterial meningitis caused by Streptococcus pneumoniae, Haemophilus influenzae ( -lactamase and non.... (meropenem). MERREM I.V. is indicated as single agent therapy for the treatment of the following infections...-abdominal Infections: Complicated appendicitis and peritonitis caused by viridans group streptococci...

The effect of sodium bicarbonate oral rinse on salivary pH and oral microflora: A prospective cohort study.

PubMed

Chandel, Siddhartha; Khan, Mohsin Ali; Singh, Nishi; Agrawal, Amiya; Khare, Vinita

2017-01-01

Present study is designed to explore the effect of sodium bicarbonate oral rinse on salivary pH and oral micro flora. Twenty five healthy subjects were recruited for the study in department of dentistry in Era Medical College. Subjects were abstained from tooth brushing overnight pre rinse (control) samples were collected after one hour of dinner and were asked to rinse with pre calibrated freshly prepared sodium bicarbonate solution. The salivary samples were then collected the following morning using sterile gauze in marked bottles. Aerobic bacterial culture was done by plating the sample directly from the swab on the surface of Blood agar and Mac Conkeys media respectively. The colony forming units and ph were calculated for the pre rinse and post rinse saliva sample. Results shows that salivary pH increased significantly after sodium Bicarbonate oral rinse. There was a marginal decrease in number of CFU/ml for bacteria especially Viridans Streptococci, Moraxella species. Sodium Bicarbonate oral rinse may be considered as a cheap and effective alternative for chlorhexidine and alcohol based mouth wash, especially where long duration usage is required.

Identification of non-streptococcal organisms from human dental plaque grown on the Streptococcus-selective medium mitis-salivarius agar.

PubMed

Kim, Yeon-Hee; Lee, Si Young

2015-02-01

Mitis-salivarius (MS) agar has been used widely in microbial epidemiological studies because oral viridans streptococci can be selectively grown on this medium. Even though the previous findings reported the limited selecting power of MS agar for streptococcus strains, the identities of non-streptococcal strains from human oral samples which can grow on this medium are not clear yet. In this study, we identified non-streptococcal organisms grown on MS agar plates by polymerase chain reaction (PCR) amplification and sequencing of the 16S ribosomal RNA (rRNA) gene. Eighty bacterial colonies on MS plates were isolated from plaque samples, and bacterial identification was achieved with the rapid ID 32 Strep system and mini API reader. The bacterial colonies identified as non-streptococci by the API system were selected for further identification. The 16S rRNA gene was amplified by PCR and verified using DNA sequencing analysis for identification. Sequences were compared with those of reference organisms in the genome database of the National Center for Biotechnology Information using the Basic Local Alignment Search Tool (BLAST). Among the 11 isolated non-streptococcal strains on MS plates, 3 strains were identified as Actinomyces naeslundii, 7 strains were identified as Actinomyces oris and 1 strain were identified as Actinomyces sp. using Blastn. In this study, we showed that some oral Actinomyces species can grow on Streptococcus-selective MS agar plates. Copyright © 2014 Elsevier Ltd. All rights reserved.

Microbial Diversity in Milk of Women With Mastitis: Potential Role of Coagulase-Negative Staphylococci, Viridans Group Streptococci, and Corynebacteria.

PubMed

Mediano, Pilar; Fernández, Leonides; Jiménez, Esther; Arroyo, Rebeca; Espinosa-Martos, Irene; Rodríguez, Juan M; Marín, María

2017-05-01

Lactational mastitis constitutes a significant cause of premature weaning. However, its etiology, linked to the presence of pathogenic microorganisms, has been scarcely reported. Research aim: The aim of this study was to describe the microbial diversity in milk samples from women suffering from lactational mastitis and to identify more accurately a collection of isolates belonging to coagulase-negative staphylococci, streptococci, and coryneform bacteria. This is a cross-sectional descriptive one-group study. A total of 5,009 isolates from 1,849 mastitis milk samples was identified by culture, biochemical, and/or molecular methods at the species or genus level. A more precise identification of a collection of 211 isolates was carried out by 16S rRNA gene sequencing. Mean total bacterial count in milk samples was 4.11 log 10 colony-forming units/ml, 95% confidence interval [4.08, 4.15]. Staphylococcus epidermidis was the most common species being isolated from 91.56% of the samples, whereas Staphylococcus aureus was detected in 29.74%. Streptococci and corynebacteria constituted the second (70.20%) and third (16.60%) most prevalent bacterial groups, respectively, found in this study. In contrast, Candida spp. was present in only 0.54% of the samples. Sequencing of the 16S rRNA gene revealed a high diversity of bacterial species among identified isolates. Many coagulase-negative staphylococci, viridans group streptococci, and corynebacteria, usually dismissed as contaminant bacteria, may play an important role as etiologic agents of mastitis. Proper diagnosis of mastitis should be established after performing microbiological testing of milk based on standardized procedures. A reliable analysis must identify the mastitis-causing pathogen(s) at the species level and its(their) concentration(s).

Linezolid Surveillance Results for the United States: LEADER Surveillance Program 2011

PubMed Central

Mendes, Rodrigo E.; Ross, James E.; Sader, Helio S.; Jones, Ronald N.

2013-01-01

The LEADER surveillance program monitors the in vitro activity of linezolid and comparator agents against Gram-positive bacteria in the United States. In its eighth consecutive year (2011), a total of 60 medical centers from the United States, including seven medical centers specializing in children's health care contributed a total of 7,303 Gram-positive pathogens. The MIC90 value for Staphylococcus aureus was 2 μg/ml, and for coagulase-negative staphylococci, enterococci, Streptococcus pneumoniae, β-hemolytic streptococci, and viridans group streptococci, the MIC90 was 1 μg/ml. The “all organism” linezolid-resistant and nonsusceptible rate was only 0.19%. PMID:23254424

Surveillance of hospital-acquired central line-associated bloodstream infections in pediatric hematology-oncology patients: lessons learned, challenges ahead.

PubMed

Gaur, Aditya H; Bundy, David G; Gao, Cuilan; Werner, Eric J; Billett, Amy L; Hord, Jeff D; Siegel, Jane D; Dickens, David; Winkle, Cindi; Miller, Marlene R

2013-03-01

Across 36 US pediatric oncology centers, 576 central line-associated bloodstream infections (CLABSIs) were reported over a 21-month period. Most infections occurred in those with leukemia and/or profound neutropenia. The contribution of viridans streptococci infections was striking. Study findings depict the contemporary epidemiology of CLABSIs in hospitalized pediatric cancer patients.

THE FORMATION OF METHEMOGLOBIN BY STREPTOCOCCUS VIRIDANS

PubMed Central

Blake, Francis G.

1916-01-01

Cultures of Streptococcus viridans when brought into contact with red blood corpuscles have the power of transforming oxyhemoglobin into methemoglobin. The reaction occurs only in the presence of living streptococci when they are able to carry on their metabolic activities. The intensity of the reaction runs roughly parallel with the period of growth and multiplication of the bacteria and gradually diminishes and disappears as growth ceases. There is no apparent relation between the activity of a given strain of Streptococcus viridans in producing methemoglobin and its source or virulence. If the streptococci are suspended in salt solution they are unable to change oxyhemoglobin into methemoglobin unless some nutrient substance is present. Of the various nutrient substances tested dextrose is the most efficient in enabling the organisms to bring about the reaction. The reaction does not occur in the absence of oxygen, and is retarded by an excess of oxygen. Substances which tend to reduce the metabolic activities of the bacteria to a minimum exert an inhibitory action on methemoglobin formation. While not definitely proving it to be so, the results obtained in the above experiments strongly support the supposition that the reaction is not due to injurious substances produced by the bacteria or to products arising from the decomposition of the nutrient material present, but rather to the metabolic activities of the bacteria themselves when they are surrounded by environmental conditions which render growth and multiplication possible. The exact chemical nature of the change of oxyhemoglobin to methemoglobin is not known, but it is probably an oxidation process or a combination of reduction and oxidation processes, as pointed out by Heubner. As Cole has shown, the action of aminophenol is of great interest in this connection, in that it acts like a catalytic agent in being able to transform much more hemoglobin into methemoglobin than would be possible if the reaction were a simple molecular one. The metabolic activities of bacteria are largely in the nature of oxidation and reduction processes. The transformation of oxyhemoglobin into methemoglobin by streptococci of the viridans type, therefore, may be analogous to the action of such substances as aminophenol, and the reaction may be due to the active oxidation and reduction processes occurring in the neighborhood of the bacterial cells. The failure of the reaction to occur in the absence of oxygen and its retardation in the presence of an excess of oxygen, both with streptococci and with pneumococci (Cole) would seem to support this theory. Such results, however, may be due to the abnormal conditions surrounding the bacteria with consequent inhibition of their metabolic activities. Cole concluded as the result of his study of methemoglobin formation by pneumococci that since bacteria may injure red blood cells apparently by disturbances in oxidation in the immediate neighborhood of the organisms rather than by the production of a definite toxin, it is possible that bacteria may injure other tissue cells in a like manner and that the pathological effects produced by these bacteria may be explained on this basis. The experimental results recorded above have shown that the formation of methemoglobin by Streptococcus viridans in no way differs from its formation by pneumococci, and they lend support to the theory that bacteria may be injurious to tissues because of the disturbances in oxidation brought about by the metabolic activities of the organisms, especially those associated with growth and multiplication. It is believed that this theory may be particularly applicable to the pathological effects caused by Streptococcus vindans because the lesions produced by it, whether single or multiple, both in man and in experimental animals, are prone to be localized and associated with the actual presence of the streptococci in the lesions. PMID:19868043

Primary Super-Infection of Hydatid Cyst—Clinical Setting and Microbiology in 37 Cases

PubMed Central

García, Moncef Belhassen; Lledías, Javier Pardo; Pérez, Inmaculada Galindo; Tirado, Virginia Velasco; Pardo, Lucia Fuentes; Bellvís, Luis Muñoz; Varela, Gonzalo; Sánchez, Miguel Cordero

2010-01-01

The clinical and microbiological characteristics of super-infected hydatid cysts are described. In our cohort, 7.3% of 503 patients had a super-infected cyst. Four patients developed severe sepsis, and two of them died. Escherichia coli, viridans group streptococci, and Enterococcus species in liver cysts and Aspergillus fumigatus in lung cysts were the microorganisms most frequent involved. PMID:20207859

Viridans Group Streptococcal Infections in Children After Chemotherapy or Stem Cell Transplantation: A 10-year Review From a Tertiary Pediatric Hospital.

PubMed

Nielsen, Maryke J; Claxton, Sarah; Pizer, Barry; Lane, Steven; Cooke, Richard P D; Paulus, Stéphane; Carrol, Enitan D

2016-03-01

Viridans Group Streptococci (VGS) are associated with high mortality rates in febrile neutropenia; yet there are no recent European pediatric studies to inform antimicrobial therapy. The aim of this study was to describe the characteristics, outcome, and resistance patterns of children with VGS bacteremia (VGSB) undergoing treatment of malignancy or hematopoietic stem cell transplant. Patients aged 0 to 18 years, admitted to a tertiary pediatric hemato-oncology center with VGSB, from 2003 to 2013, were included in the study. All data were collected retrospectively from medical records. A total of 54 bacteremic episodes occurred in 46 patients. The most common underlying diagnosis was relapsed acute lymphoblastic leukemia. Streptococcus mitis was the most frequent organism. A total of 30% of isolates were resistant to penicillin and 100% sensitive to vancomycin. There were 8 episodes (14.8%) of Viridans Group Streptococcal Shock Syndrome; 6 resulted in admission to intensive care and 3 of these patients died of multiorgan failure. The potentially fatal nature of VGSB is confirmed. The high risk in relapsed acute lymphoblastic leukemia is of note. Research is needed to develop risk-stratification scores that identify children at risk of Viridans Group Streptococcal Shock Syndrome to guide empirical antimicrobial therapy in febrile neutropenia.

Viridans Group Streptococcal Infections in Children After Chemotherapy or Stem Cell Transplantation

PubMed Central

Nielsen, Maryke J.; Claxton, Sarah; Pizer, Barry; Lane, Steven; Cooke, Richard P.D.; Paulus, Stéphane; Carrol, Enitan D.

2016-01-01

Abstract Viridans Group Streptococci (VGS) are associated with high mortality rates in febrile neutropenia; yet there are no recent European pediatric studies to inform antimicrobial therapy. The aim of this study was to describe the characteristics, outcome, and resistance patterns of children with VGS bacteremia (VGSB) undergoing treatment of malignancy or hematopoietic stem cell transplant. Patients aged 0 to 18 years, admitted to a tertiary pediatric hemato-oncology center with VGSB, from 2003 to 2013, were included in the study. All data were collected retrospectively from medical records. A total of 54 bacteremic episodes occurred in 46 patients. The most common underlying diagnosis was relapsed acute lymphoblastic leukemia. Streptococcus mitis was the most frequent organism. A total of 30% of isolates were resistant to penicillin and 100% sensitive to vancomycin. There were 8 episodes (14.8%) of Viridans Group Streptococcal Shock Syndrome; 6 resulted in admission to intensive care and 3 of these patients died of multiorgan failure. The potentially fatal nature of VGSB is confirmed. The high risk in relapsed acute lymphoblastic leukemia is of note. Research is needed to develop risk-stratification scores that identify children at risk of Viridans Group Streptococcal Shock Syndrome to guide empirical antimicrobial therapy in febrile neutropenia. PMID:26945409

Molecular Relationships and Antimicrobial Susceptibilities of Viridans Group Streptococci Isolated from Blood of Neutropenic Cancer Patients

PubMed Central

Wisplinghoff, H.; Reinert, R. R.; Cornely, O.; Seifert, H.

1999-01-01

From January 1995 to May 1998, 57 episodes of bacteremia due to viridans group streptococci were identified in 50 febrile neutropenic patients with hematologic malignancies. Four patients experienced two separate episodes of streptococcal bacteremia, and one patient had four separate episodes of streptococcal bacteremia. Strains were identified to species level as Streptococcus mitis (n = 37), Streptococcus oralis (n = 19), and Streptococcus salivarius (n = 1). Epidemiologic relatedness of these strains was studied by using PCR-based fingerprinting with M13 and ERIC-2 primers and pulsed-field gel electrophoresis with restriction enzyme SmaI. All strains that were isolated from different patients exhibited unique fingerprint patterns, thus suggesting that viridans group streptococcal bacteremia usually derives from an endogenous source. Cross-transmission of strains between patients could not be established. Four S. mitis isolates recovered during four separate bacteremic episodes in a single patient had identical fingerprint patterns. Susceptibility testing was carried out by broth microdilution technique according to National Committee for Clinical Laboratory Standards guidelines. The MICs at which 90% of the isolates are inhibited were (in milligrams per liter) as follows: 0.5 (penicillin), 0.5 (amoxicillin), 0.25 (cefotaxime), 2 (chloramphenicol), 4 (erythromycin), 0.5 (clindamycin), ≥32 (tetracycline), ≥32 (trimethoprim-sulfamethoxazole), 4 (ciprofloxacin), 0.5 (sparfloxacin), 0.5 (vancomycin), 0.25 (teicoplanin), and 1 (quinupristin-dalfopristin). High-level penicillin resistance (MIC, ≥4 mg/liter) was found in one isolate only, but intermediate penicillin resistance was noted in 11 isolates (19%). Resistance rates to other drugs were as follows: 7% (amoxicillin), 4% (cefotaxime), 4% (chloramphenicol), 32% (erythromycin), 9% (clindamycin), 39% (tetracycline), 68% (trimethoprim-sulfamethoxazole), 23% (ciprofloxacin), 0% (sparfloxacin), 0% (vancomycin), 0% (teicoplanin), and 0% (quinupristin-dalfopristin). PMID:10325340

Linezolid Surveillance Results for the United States (LEADER Surveillance Program 2014)

PubMed Central

Mendes, Rodrigo E.; Hogan, Patricia A.; Streit, Jennifer M.; Ross, James E.; Jones, Ronald N.

2016-01-01

The linezolid experience and accurate determination of resistance (LEADER) surveillance program has monitored linezolid activity, spectrum, and resistance since 2004. In 2014, a total of 6,865 Gram-positive pathogens from 60 medical centers from 36 states were submitted. The organism groups evaluated were Staphylococcus aureus (3,106), coagulase-negative staphylococci (CoNS; 797), enterococci (855), Streptococcus pneumoniae (874), viridans group streptococci (359), and beta-hemolytic streptococci (874). Susceptibility testing was performed by reference broth microdilution at the monitoring laboratory. Linezolid-resistant isolates were confirmed by repeat testing. PCR and sequencing were performed to detect mutations in 23S rRNA, L3, L4, and L22 proteins and acquired genes (cfr and optrA). The MIC50/90 for Staphylococcus aureus was 1/1 μg/ml, with 47.2% of isolates being methicillin-resistant Staphylococcus aureus. Linezolid was active against all Streptococcus pneumoniae strains and beta-hemolytic streptococci with a MIC50/90 of 1/1 μg/ml and against viridans group streptococci with a MIC50/90 of 0.5/1 μg/ml. Among the linezolid-nonsusceptible MRSA strains, one strain harbored cfr only (MIC, 4 μg/ml), one harbored G2576T (MIC, 8 μg/ml), and one contained cfr and G2576T with L3 changes (MIC, ≥8 μg/ml). Among CoNS, 0.75% (six isolates) of all strains demonstrated linezolid MIC results of ≥4 μg/ml. Five of these were identified as Staphylococcus epidermidis, four of which contained cfr in addition to the presence of mutations in the ribosomal proteins L3 and L4, alone or in combination with 23S rRNA (G2576T) mutations. Six enterococci (0.7%) were linezolid nonsusceptible (≥4 μg/ml; five with G2576T mutations, including one with an additional cfr gene, and one strain with optrA only). Linezolid demonstrated excellent activity and a sustained susceptibility rate of 99.78% overall. PMID:26833165

Microbiology and antibiotic sensitivity of head and neck space infections of odontogenic origin. Differences in inpatient and outpatient management.

PubMed

Heim, Nils; Faron, Anton; Wiedemeyer, Valentin; Reich, Rudolf; Martini, Markus

2017-10-01

The microbial flora of infections of the orofacial region of odontogenic origin is typically polymicrobial. Shortly after mass production of the first antibiotics, antibiotic resistant microorganisms were observed. A 28-months retrospective study evaluated hospital records of 107 patients that were treated for head and neck infections of odontogenic origin. All patients underwent surgical incision and drainage. There were 65 male (61%) and 42 female (39%) patients ranging in age from 5 to 91 years, with a mean age of 48 years (SD = 21). 52 patients underwent outpatient management and 55 patients inpatient management. A total of 92 bacterial strains were isolated from 107 patients, accounting for 0.86 isolates per patient. Overall 46 bacterial strains were isolated from patients that underwent outpatient and 34 bacterial strains that underwent inpatient treatment. 32.6% of the strains, isolated from outpatient treated individuals showed resistances against one or more of the tested antibiotics. Isolated strains of inpatient treated individuals showed resistances in 52.9%. According to this study's data, penicillin continues to be a highly effective antibiotic to be used against viridans streptococci, group C Streptococci and prevotella, whereas clindamycin was not shown to be effective as an empirical drug of choice for most odontogenic infections. Microorganisms that show low susceptibility to one or more of the standard antibiotic therapy regimes have a significantly higher chance of causing serious health problems, a tendency of spreading and are more likely to require an inpatient management with admission of IV antibiotics. Penicillin continues to be a highly effective antibiotic to be used against viridans streptococci, group C Streptococci and prevotella, whereas clindamycin could not be shown to be effective as an empirical drug of choice for a high number of odontogenic infections. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Aetiology of Bacteraemia as a Risk Factor for Septic Shock at the Onset of Febrile Neutropaenia in Adult Cancer Patients

PubMed Central

Rosa, Regis Goulart; Goldani, Luciano Zubaran

2014-01-01

Septic shock (SS) at the onset of febrile neutropaenia (FN) is an emergency situation that is associated with high morbidity and mortality. The impact of the specific aetiology of bloodstream infections (BSIs) in the development of SS at the time of FN is not well established. The aim of this study was to evaluate the association between the aetiology of BSIs and SS at the time of FN in hospitalised adult cancer patients. This prospective cohort study was performed at a single tertiary hospital from October 2009 to August 2011. All adult cancer patients admitted consecutively to the haematology ward with FN were evaluated. A stepwise logistic regression was conducted to verify the association between the microbiological characteristics of BSIs and SS at the onset of FN. In total, 307 cases of FN in adult cancer patients were evaluated. There were 115 cases with documented BSI. A multivariate analysis showed that polymicrobial bacteraemia (P = 0.01) was associated with SS. The specific blood isolates independently associated with SS were viridans streptococci (P = 0.02) and Escherichia coli (P = 0.01). Neutropaenic cancer patients with polymicrobial bacteraemia or BSI by viridans streptococci or Escherichia coli are at increased risk for SS at the time of FN. PMID:24804223

Antimicrobial susceptibilities of Streptococcus species that cause septicemia in neutropenic patients.

PubMed Central

Venditti, M; Baiocchi, P; Santini, C; Brandimarte, C; Serra, P; Gentile, G; Girmenia, C; Martino, P

1989-01-01

Sixty-three consecutive streptococcal blood isolates from neutropenic patients, represented mainly by viridans group streptococci, were evaluated in vitro for antibiotic susceptibility. Of these isolates, 79.3% were highly susceptible to penicillin (MIC, less than or equal to 0.12 microgram/ml). Overall, imipenem was the most active agent, followed by teicoplanin and vancomycin. All other agents showed decreased activity against streptococcal isolates that were not highly susceptible to penicillin. PMID:2729950

STREPTOCOCCI IN INFECTIOUS (ATROPHIC) ARTHRITIS AND RHEUMATIC FEVER.

PubMed

Nye, R N; Waxelbaum, E A

1930-11-30

The question of the relationship of streptococci to the etiology of infectious arthritis and of rheumatic fever is of the utmost importance. If a streptococcus or group of streptococci could be shown to be associated See PDF for Structure with either disease, some form of specific treatment might be available. The possibility of primary streptococcic infection as the cause of rheumatic fever, and, to a less extent, of acute infectious arthritis would seem to be a reasonable conjecture because of the frequency of associated throat, sinus or other focal infection. To consider that these same streptococci remain in or about the affected joint and to such an extent that they are found in the blood stream in cases of chronic infectious arthritis of years' duration demands a rather unique conception. Recent investigative work has certainly tended to confirm the importance of streptococci in these diseases, but, if all the published reports are considered as a group, one can not help being impressed with the inconsistency and peculiarities of the findings. In blood cultures from cases of rheumatic fever Clawson (7) recovered Streptococcus viridans, Small (8) and Birkhaug (9) non-hemolytic (gamma type) streptococci, and Cecil et al. (3) Streptococcus viridans, rarely hemolytic and non-hemolytic streptococci. In blood cultures from cases of infectious arthritis Cecil et al. (2) recovered attenuated hemolytic streptococci and occasionally Streptococcus viridans, non-hemolytic streptococci and diphtheroids and Margolis and Dorsey (10) green-producing and indifferent streptococci and diphtheroids, whereas from synovial fluids and regional lymph nodes Forkner, Shands and Poston (4) and Poston (5) obtained Streptococcus viridans and Margolis and Dorsey (11) recovered green-producing and indifferent streptococci and diphtheroids from epiphyseal marrows, bones and synovial membranes. On the other hand, Jordan (12) and Nye and Seegal (13) and the work reported in this paper have failed to confirm these findings. If a streptococcus is the infective agent, it is difficult to explain why the organisms recovered so consistently by certain groups of investigators are so different and why the findings of other groups are entirely negative. The chances of contamination, even with the most careful manipulation, are extremely favorable when using a cultural technique which demands subculturing a fluid medium every 3 to 5 days for a period of 4 to 6 weeks. The question arises as to what organisms should be considered as contaminants. Cultures found to contain Staphylococcus albus have never been judged significant. Margolis and Dorsey (11) have excluded Gram-positive bacilli from their series, but have included diphtheroids. Cecil et al. (2) reported the recovery of diphtheroids and Micrococcus zymogenes from blood cultures which they did not consider contaminated. Jordan (12) recovered short Gram-negative bacilli and Gram-positive bacilli and questioned their importance. The occurrence of such bacteria would appear to be not unlike that of the non-hemolytic (gamma type) streptococci reported by Small (7), Birkhaug (9) and, rarely, by Cecil et al. (2) and Margolis and Dorsey (10,11). In the work reported in this paper and in previously published work (13) with blood cultures from cases of rheumatic fever, staphylococci, Gram-positive bacilli and diplococci and diphtheroids have been isolated from a certain number of the cultures. Since these were found, as a rule, in only 1 of 2 or more cultures from the same blood and since such organisms occurred about as frequently in cultures from control cases, they have been considered merely contaminants. The findings in the 9 cases of arthritis with positive blood cultures reported by Margolis and Dorsey (10) are certainly far from convincing. These authors found green-producing streptococci in 5 of the 9 cases, but duplicate cultures on the same blood, with one exception, were always negative and the two repeat cultures were negative. Furthermore, in the 3 cases yielding indifferent streptococci in one subculture all subsequent subcultures were negative. In the work reported in this paper a green-producing and a non-hemolytic streptococcus were isolated from blood cultures, but a Gram-positive diplococcus and a Gram-positive bacillus, respectively, were recovered from the same cultures. A consideration of the above would seem to point to the probability, even certainty, of streptococci occurring in some cultures as contaminants; and the work of Olitsky and Long (14) and Long, Olitsky and Stewart (15) has clearly demonstrated that the air contamination of cultures of ground material with non-hemolytic green-producing streptococci can occur just as easily as with diphtheroids and staphylococci. It is obvious, in such cases, that the types of organisms recovered are dependent on the flora of the air of the laboratory or of the throat of the laboratory worker, and this point may well explain the differences in the cultural findings under consideration. A number of years ago numerous articles (16-19) appeared relative to the bacteriologic flora of lymph nodes, particularly those from cases of Hodgkin's disease, and it is interesting to note that the organisms recovered were quite similar to those which have been recovered from the blood and tissues of cases of arthritis and rheumatic fever, with the exception that the diphtheroids were, at that time, much more in prominence. Regardless of elaborate serological studies and animal experiments, streptococci must be recovered consistently by several groups of laboratory workers before their etiologic rôle in chronic arthritis and rheumatic fever can be accepted. Duplicate cultures and repeat cultures should yield the same organism in a generous percentage of cases and cultures from cases of other diseases or from normal persons should be negative. Positive cultures from duplicate cultures opened only at the time when the first culture showed growth would make the findings more significant than if the whole series were subcultured every 3 to 5 days. The work of Cecil, Nicholls and Stainsby on the bacteriology of the blood and joints in chronic arthritis and rheumatic fever has apparently been carried out most carefully and thoroughly and their results are very consistent and convincing. In spite of attempts to follow their methods in the selection of patients and in cultural technique, the results on the relatively small series of cases which are reported here fail to confirm their findings.

Species identification of mutans streptococci by groESL gene sequence.

PubMed

Hung, Wei-Chung; Tsai, Jui-Chang; Hsueh, Po-Ren; Chia, Jean-San; Teng, Lee-Jene

2005-09-01

The near full-length sequences of the groESL genes were determined and analysed among eight reference strains (serotypes a to h) representing five species of mutans group streptococci. The groES sequences from these reference strains revealed that there are two lengths (285 and 288 bp) in the five species. The intergenic spacer between groES and groEL appears to be a unique marker for species, with a variable size (ranging from 111 to 310 bp) and sequence. Phylogenetic analysis of groES and groEL separated the eight serotypes into two major clusters. Strains of serotypes b, c, e and f were highly related and had groES gene sequences of the same length, 288 bp, while strains of serotypes a, d, g and h were also closely related and their groES gene sequence lengths were 285 bp. The groESL sequences in clinical isolates of three serotypes of S. mutans were analysed for intraspecies polymorphism. The results showed that the groESL sequences could provide information for differentiation among species, but were unable to distinguish serotypes of the same species. Based on the determined sequences, a PCR assay was developed that could differentiate members of the mutans streptococci by amplicon size and provide an alternative way for distinguishing mutans streptococci from other viridans streptococci.

Identification of clinically relevant viridans streptococci by an oligonucleotide array.

PubMed

Chen, Chao Chien; Teng, Lee Jene; Kaiung, Seng; Chang, Tsung Chain

2005-04-01

Viridans streptococci (VS) are common etiologic agents of subacute infective endocarditis and are capable of causing a variety of pyogenic infections. Many species of VS are difficult to differentiate by phenotypic traits. An oligonucleotide array based on 16S-23S rRNA gene intergenic spacer (ITS) sequences was developed to identify 11 clinically relevant VS. These 11 species were Streptococcus anginosus, S. constellatus, S. gordonii, S. intermedius, S. mitis, S. mutans, S. oralis, S. parasanguinis, S. salivarius, S. sanguinis, and S. uberis. The method consisted of PCR amplification of the ITS regions by using a pair of universal primers, followed by hybridization of the digoxigenin-labeled PCR products to a panel of species-specific oligonucleotides immobilized on a nylon membrane. After 120 strains of the 11 species of VG and 91 strains of other bacteria were tested, the sensitivity and specificity of the oligonucleotide array were found to be 100% (120 of 120 strains) and 95.6% (87 of 91 strains), respectively. S. pneumoniae cross-hybridized to the probes used for the identification of S. mitis, and simple biochemical tests such as optochin susceptibility or bile solubility should be used to differentiate S. pneumoniae from S. mitis. In conclusion, identification of species of VS by use of the present oligonucleotide array is accurate and could be used as an alternative reliable method for species identification of strains of VS.

Identification of the psaA Gene, Coding for Pneumococcal Surface Adhesin A, in Viridans Group Streptococci other than Streptococcus pneumoniae

PubMed Central

Jado, Isabel; Fenoll, Asunción; Casal, Julio; Pérez, Amalia

2001-01-01

The gene encoding the pneumococcal surface adhesin A (PsaA) protein has been identified in three different viridans group streptococcal species. Comparative studies of the psaA gene identified in different pneumococcal isolates by sequencing PCR products showed a high degree of conservation among these strains. PsaA is encoded by an open reading frame of 930 bp. The analysis of this fragment in Streptococcus mitis, Streptococcus oralis, and Streptococcus anginosus strains revealed a sequence identity of 95, 94, and 90%, respectively, to the corresponding open reading frame of the previously reported Streptococcus pneumoniae serotype 6B strain. Our results confirm that psaA is present and detectable in heterologous bacterial species. The possible implications of these results for the suitability and potential use of PsaA in the identification and diagnosis of pneumococcal diseases are discussed. PMID:11527799

Detection of oral streptococci in dental unit water lines after therapy with air turbine handpiece: biological fluid retraction more frequent than expected.

PubMed

Petti, Stefano; Moroni, Catia; Messano, Giuseppe Alessio; Polimeni, Antonella

2013-03-01

Oral streptococci detected in water from dental unit water lines (DUWLs) are a surrogate marker of patients' biological fluid retraction during therapy. We investigated oral streptococci detection rate in DUWLs in a representative sample of private offices in real-life conditions. Samples of nondisinfected water (100 ml) were collected from the DUWL designated for the air turbine handpiece in 81 dental units, immediately after dental treatment of patients with extensive air turbine handpiece use. Water was filtered and plated on a selective medium for oral streptococci and, morphologically, typical colonies of oral streptococci were counted. The lowest detection limit was 0.01 CFU/ml. The oral streptococci detection rate was 72% (95% CI: 62-81%), with a mean level of 0.7 CFU/ml. Oral streptococci detection was not affected by handpiece age or dental treatment type, but was associated with dental unit age. Biological fluid retraction into DUWLs during patient treatment and, possibly, the risk for patient-to-patient blood- or air-borne pathogen transmission are more frequent than expected.

Antibiotic prophylaxis with teicoplanin on alternate days reduces rate of viridans sepsis and febrile neutropenia in pediatric patients with acute myeloid leukemia.

PubMed

Boztug, Heidrun; Mühlegger, Nora; Pötschger, Ulrike; Attarbaschi, Andishe; Peters, Christina; Mann, Georg; Dworzak, Michael

2017-01-01

Intensive chemotherapy directed against acute myeloid leukemia of childhood is followed by profound neutropenia and high risk for bacterial and fungal infections, including viridans group streptococci as a common cause for gram-positive septicemia. Few retrospective studies have shown the efficacy of various antibiotic prophylactic regimens in children. We retrospectively studied 50 pediatric patients treated on the AML-BFM 2004 protocol between 2005 and 2015 at St. Anna Children's Hospital and assessed the effect of antibiotic prophylaxis on the frequency of febrile neutropenia and bacterial sepsis. Fifty pediatric patients underwent 199 evaluable chemotherapy cycles. Viridans sepsis occurred after none of 98 cycles with prophylactic administration of teicoplanin/vancomycin in comparison to 12 cases of viridans sepsis among 79 cycles without systemic antibacterial prophylaxis (0 vs. 15 %, p < 0.0001). In addition, there were significantly fewer episodes of febrile neutropenia in the teicoplanin/vancomycin group (44 % vs. no prophylaxis 82 %, p < 0.0001). Severity of infection seemed to be worse when no antibiotic prophylaxis had been administered with a higher rate of intensive care unit treatment (0/98, 0 %, vs. 4/79, 5 %, p = 0.038). So far, no increase of vancomycin-resistant enterococcus isolates in surveillance cultures was noticed. Antibiotic prophylaxis with teicoplanin (or vancomycin) appears safe and feasible and resulted in eradication of viridans sepsis and decreased incidence of febrile neutropenia in pediatric AML patients. The possibility to administer teicoplanin on alternate days on an outpatient basis or at home could contribute to patient's quality of life and decrease health care costs.

In Vitro Activity of Delafloxacin against Contemporary Bacterial Pathogens from the United States and Europe, 2014

PubMed Central

Pfaller, M. A.; Sader, H. S.; Rhomberg, P. R.

2017-01-01

ABSTRACT The in vitro activities of delafloxacin and comparator antimicrobial agents against 6,485 bacterial isolates collected from medical centers in Europe and the United States in 2014 were tested. Delafloxacin was the most potent agent tested against methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus, Streptococcus pneumoniae, viridans group streptococci, and beta-hemolytic streptococci and had activity similar to that of ciprofloxacin and levofloxacin against certain members of the Enterobacteriaceae. Overall, the broadest coverage of the tested pathogens (Gram-positive cocci and Gram-negative bacilli) was observed with meropenem and tigecycline in both Europe and the United States. Delafloxacin was shown to be active against organisms that may be encountered in acute bacterial skin and skin structure infections, respiratory infections, and urinary tract infections. PMID:28167542

In Vitro Activity of Delafloxacin against Contemporary Bacterial Pathogens from the United States and Europe, 2014.

PubMed

Pfaller, M A; Sader, H S; Rhomberg, P R; Flamm, R K

2017-04-01

The in vitro activities of delafloxacin and comparator antimicrobial agents against 6,485 bacterial isolates collected from medical centers in Europe and the United States in 2014 were tested. Delafloxacin was the most potent agent tested against methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus , Streptococcus pneumoniae , viridans group streptococci, and beta-hemolytic streptococci and had activity similar to that of ciprofloxacin and levofloxacin against certain members of the Enterobacteriaceae Overall, the broadest coverage of the tested pathogens (Gram-positive cocci and Gram-negative bacilli) was observed with meropenem and tigecycline in both Europe and the United States. Delafloxacin was shown to be active against organisms that may be encountered in acute bacterial skin and skin structure infections, respiratory infections, and urinary tract infections. Copyright © 2017 Pfaller et al.

PCR detection and identification of oral streptococci in saliva samples using gtf genes.

PubMed

Hoshino, Tomonori; Kawaguchi, Mamoru; Shimizu, Noriko; Hoshino, Naoko; Ooshima, Takashi; Fujiwara, Taku

2004-03-01

Oral streptococci are major constituents of dental plaque, and their prevalence is implicated in various pathologies. Therefore, accurate identification of oral streptococci would be valuable for studies of cariogenic plaque and for diagnostic use in infective endocarditis. Many oral streptococci possess glucosyltransferase enzymes that synthesize glucan, which is an obligate component of dental plaque. We established a rapid and precise method to identify oral streptococci by PCR using the species-specific region from the glucosyltransferase gene. With the species-specific primers, Streptococcus mutans, S. sobrinus, S. salivarius, S. sanguinis, S. oralis, and S. gordonii could be successfully distinguished. Further, we developed a simple method to extract the bacterial DNA from saliva. Using the resultant DNA as a template, the proposed PCR detection was performed. Their distribution was in accord with results of conventional biochemical tests. These findings indicate that the present PCR method is useful for the analysis of oral streptococci and can be successfully used in clinical applications to identify pathogenic bacteria associated with oral infectious disease and/or endocarditis.

Erythromycin and penicillin resistance mechanisms among viridans group streptococci isolated from blood cultures of adult patients with underlying diseases.

PubMed

Ergin, Alper; Eser, Özgen Köseoğlu; Hasçelik, Gülşen

2011-04-01

The aim of the study was to evaluate the species distribution, antimicrobial susceptibility and erythromycin-penicillin resistance mechanisms of viridans streptococci (VGS) isolates from blood cultures of adult patients with underlying diseases. Fifty VGS blood culture isolates were screened for their antibiotic susceptibilities against penicillin G, erythromycin and tetracycline by E-test. Clindamycin, cefotaxime, chloramphenicol, levofloxacin, linezolid and vancomycin susceptibility were performed by broth microdilution method. Erythromycin and penicillin resistance genotypes, ermB and mefA/E, pbp1a, pbp2b and pbp2x are amplified using PCR method. The clinical isolates included Streptococcus mitis (n. 19), S.oralis (n. 13), S.sanguinis, S.parasanguinis (n. 6, each), S.salivarius, S.vestibularis (n. 2, each), S.constellatus, S.sobrinus (n. 1, each). The percentage resistance against erythromycin and penicillin was 36% and 30%, respectively. The genotypic carriage rate of erythromycin resistance genes were: 56% ermB, 28% mefE, 8% ermB+mefE. Penicillin-resistant isolates carried pbp2b (33.3%) and pbp2x (20%) genes. Twenty-four VGS isolates were recovered from patients with cancer. S.mitis and S.oralis predominated among patients with cancer who had erythromycin and penicillin resistance isolates. The importance of classical antimicrobial agents like penicillin and erythromycin warrants the continuous surveillance of invasive VGS isolates and can guide better treatment options especially in patients with underlying diseases.

The effect of a probiotic strain (Lactobacillus acidophilus) on the plaque formation of oral Streptococci.

PubMed

Tahmourespour, Arezoo; Kermanshahi, Rooha Kasra

2011-02-01

The objective of this study was to investigate the ability of biofilm formation among mutans and non mutans oral streptococci and to determine the effect of Lactobacillus acidophilus DSM 20079 as a probiotic strain on the adhesion of selected streptococcal strains on the surfaces. The sample comprised 40 isolates of oral streptococci from dental plaque and caries of volunteer persons. Streptococcus mutans ATCC35668 (no24) was as an standard strain. The probiotic strain was Lactobacillus acidophilus DSM 20079. The ability of biofilm formation was investigated with colorimetric method and the strongest isolates were selected. Then the effect of probiotic strain on the adhesion of streptococci isolates was determined in polystyrene microtiter plate simultaneously and 30 minutes before streptococci entrance to the system. The results showed that 42% of mutans streptococci were strongly adherent (SA) and in non mutans streptococci, only 23.5% of isolates were found strongly adherent. The strong biofilm forming bacterium isolated was Streptococcus mutans strain22. In the next step, in the presence of probiotic strain the streptococcal adhesion were reduced, and this reduction was non significantly stronger if the probiotic strain was inoculated to the system before the oral bacteria. The Lactobacillus acidophilus had more effect on adherence of mutans streptococci than non mutans streptococci with significant difference (p < 0.05). Adhesion reduction is likely due to bacterial interactions and colonization of adhesion sites with probiotic strain before the presence of streptococci. Adhesion reduction can be an effective way on decreasing cariogenic potential of oral streptococci.

Prophylactic antibiotics reduce morbidity due to septicemia during intensive treatment for pediatric acute myeloid leukemia.

PubMed

Kurt, Beth; Flynn, Patricia; Shenep, Jerry L; Pounds, Stanley; Lensing, Shelly; Ribeiro, Raul C; Pui, Ching-Hon; Razzouk, Bassem I; Rubnitz, Jeffrey E

2008-07-15

The aim of this study was to determine whether antibiotic prophylaxis during periods of neutropenia reduced streptococcal (S. viridans) sepsis and overall bacterial sepsis. The authors reviewed outcomes of 78 evaluable patients who were consecutively treated for acute myeloid leukemia (AML) from October 2002 through January 2007. Several successive prophylactic antibiotic regimens were used. All patients received antifungal prophylaxis with oral voriconazole. Oral cephalosporins did not significantly reduce the odds of bacterial sepsis (P = .81) or streptococcal (S. viridans) sepsis (P = .90) relative to no prophylaxis. Intravenous (iv) cefepime completely prevented streptococcal (S. viridans) sepsis and reduced the odds of bacterial sepsis 91% (P < .0001) relative to no prophylaxis, but resistant gram-negative bacteria emerged in 2 patients. Vancomycin with oral ciprofloxacin or a cephalosporin reduced the odds of bacterial sepsis by 93% (P < .0001) and streptococcal (S. viridans) sepsis by 99% (P < .0001). The fungal infection rate did not differ significantly between patients who did and did not receive antibiotic prophylaxis (1.0 per 1000 patient-days for both groups). The observed reduction in average hospital days per chemotherapy course for patients given vancomycin regimens or cefepime was 5.7 (P < .0001) and 4.1 (P = .0039) days, respectively. No reduction was observed with oral cephalosporins (P = .10). Furthermore, vancomycin regimens or cefepime were associated with a 20% reduction in healthcare charges (P = .0015) relative to using no antibiotics. One patient, who was on oral cefuroxime alone, died of septicemia. Prophylaxis with intravenous cefepime or a vancomycin regimen, and voriconazole, reduced morbidity in children with AML, and resulted in dramatic decreases in the incidence of septicemia and hospitalization days.

Preventive effects of a phospholipid polymer coating on PMMA on biofilm formation by oral streptococci

NASA Astrophysics Data System (ADS)

Shibata, Yukie; Yamashita, Yoshihisa; Tsuru, Kanji; Ishihara, Kazuhiko; Fukazawa, Kyoko; Ishikawa, Kunio

2016-12-01

The regulation of biofilm formation on dental materials such as denture bases is key to oral health. Recently, a biocompatible phospholipid polymer, poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (PMB) coating, was reported to inhibit sucrose-dependent biofilm formation by Streptococcus mutans, a cariogenic bacterium, on the surface of poly(methyl methacrylate) (PMMA) denture bases. However, S. mutans is a minor component of the oral microbiome and does not play an important role in biofilm formation in the absence of sucrose. Other, more predominant oral streptococci must play an indispensable role in sucrose-independent biofilm formation. In the present study, the effect of PMB coating on PMMA was evaluated using various oral streptococci that are known to be initial colonizers during biofilm formation on tooth surfaces. PMB coating on PMMA drastically reduced sucrose-dependent tight biofilm formation by two cariogenic bacteria (S. mutans and Streptococcus sobrinus), among seven tested oral streptococci, as described previously [N. Takahashi, F. Iwasa, Y. Inoue, H. Morisaki, K. Ishihara, K. Baba, J. Prosthet. Dent. 112 (2014) 194-203]. Streptococci other than S. mutans and S. sobrinus did not exhibit tight biofilm formation even in the presence of sucrose. On the other hand, all seven species of oral streptococci exhibited distinctly reduced glucose-dependent soft biofilm retention on PMB-coated PMMA. We conclude that PMB coating on PMMA surfaces inhibits biofilm attachment by initial colonizer oral streptococci, even in the absence of sucrose, indicating that PMB coating may help maintain clean conditions on PMMA surfaces in the oral cavity.

Identification of species of viridans group streptococci in clinical blood culture isolates by sequence analysis of the RNase P RNA gene, rnpB.

PubMed

Westling, Katarina; Julander, Inger; Ljungman, Per; Vondracek, Martin; Wretlind, Bengt; Jalal, Shah

2008-03-01

Viridans group streptococci (VGS) cause severe diseases such as infective endocarditis and septicaemia. Genetically, VGS species are very close to each other and it is difficult to identify them to species level with conventional methods. The aims of the present study were to use sequence analysis of the RNase P RNA gene (rnpB) to identify VGS species in clinical blood culture isolates, and to compare the results with the API 20 Strep system that is based on phenotypical characteristics. Strains from patients with septicaemia or endocarditis were analysed with PCR amplification and sequence analysis of the rnpB gene. Clinical data were registered as well. One hundred and thirty two VGS clinical blood culture isolates from patients with septicaemia (n=95) or infective endocarditis (n=36) were analysed; all but one were identified by rnpB. Streptococcus oralis, Streptococcus sanguinis and Streptococcus gordonii strains were most common in the patients with infective endocarditis. In the isolates from patients with haematological diseases, Streptococcus mitis and S. oralis dominated. In addition in 76 of the isolates it was possible to compare the results from rnpB analysis and the API 20 Strep system. In 39/76 (51%) of the isolates the results were concordant to species level; in 55 isolates there were no results from API 20 Strep. Sequence analysis of the RNase P RNA gene (rnpB) showed that almost all isolates could be identified. This could be of importance for evaluation of the portal of entry in patients with septicaemia or infective endocarditis.

Airborne Multidrug-Resistant Bacteria Isolated from a Concentrated Swine Feeding Operation

PubMed Central

Chapin, Amy; Rule, Ana; Gibson, Kristen; Buckley, Timothy; Schwab, Kellogg

2005-01-01

The use of nontherapeutic levels of antibiotics in swine production can select for antibiotic resistance in commensal and pathogenic bacteria in swine. As a result, retail pork products, as well as surface and groundwaters contaminated with swine waste, have been shown to be sources of human exposure to antibiotic-resistant bacteria. However, it is unclear whether the air within swine operations also serves as a source of exposure to antibiotic-resistant bacterial pathogens. To investigate this issue, we sampled the air within a concentrated swine feeding operation with an all-glass impinger. Samples were analyzed using a method for the isolation of Enterococcus. A total of 137 presumptive Enterococcus isolates were identified to species level using standard biochemical tests and analyzed for resistance to erythromycin, clindamycin, virginiamycin, tetracycline, and vancomycin using the agar dilution method. Thirty-four percent of the isolates were confirmed as Enterococcus, 32% were identified as coagulase-negative staphylococci, and 33% were identified as viridans group streptococci. Regardless of bacterial species, 98% of the isolates expressed high-level resistance to at least two antibiotics commonly used in swine production. None of the isolates were resistant to vancomycin, an antibiotic that has never been approved for use in livestock in the United States. In conclusion, high-level multidrug-resistant Enterococcus, coagulase-negative staphylococci, and viridans group streptococci were detected in the air of a concentrated swine feeding operation. These findings suggest that the inhalation of air from these facilities may serve as an exposure pathway for the transfer of multidrug-resistant bacterial pathogens from swine to humans. PMID:15687049

Improved Differentiation of Streptococcus pneumoniae and Other S. mitis Group Streptococci by MALDI Biotyper Using an Improved MALDI Biotyper Database Content and a Novel Result Interpretation Algorithm.

PubMed

Harju, Inka; Lange, Christoph; Kostrzewa, Markus; Maier, Thomas; Rantakokko-Jalava, Kaisu; Haanperä, Marjo

2017-03-01

Reliable distinction of Streptococcus pneumoniae and viridans group streptococci is important because of the different pathogenic properties of these organisms. Differentiation between S. pneumoniae and closely related Sreptococcus mitis species group streptococci has always been challenging, even when using such modern methods as 16S rRNA gene sequencing or matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. In this study, a novel algorithm combined with an enhanced database was evaluated for differentiation between S. pneumoniae and S. mitis species group streptococci. One hundred one clinical S. mitis species group streptococcal strains and 188 clinical S. pneumoniae strains were identified by both the standard MALDI Biotyper database alone and that combined with a novel algorithm. The database update from 4,613 strains to 5,627 strains drastically improved the differentiation of S. pneumoniae and S. mitis species group streptococci: when the new database version containing 5,627 strains was used, only one of the 101 S. mitis species group isolates was misidentified as S. pneumoniae , whereas 66 of them were misidentified as S. pneumoniae when the earlier 4,613-strain MALDI Biotyper database version was used. The updated MALDI Biotyper database combined with the novel algorithm showed even better performance, producing no misidentifications of the S. mitis species group strains as S. pneumoniae All S. pneumoniae strains were correctly identified as S. pneumoniae with both the standard MALDI Biotyper database and the standard MALDI Biotyper database combined with the novel algorithm. This new algorithm thus enables reliable differentiation between pneumococci and other S. mitis species group streptococci with the MALDI Biotyper. Copyright © 2017 American Society for Microbiology.

Delineation of Streptococcus dysgalactiae, Its Subspecies, and Its Clinical and Phylogenetic Relationship to Streptococcus pyogenes

PubMed Central

Jensen, Anders

2012-01-01

The taxonomic status and structure of Streptococcus dysgalactiae have been the object of much confusion. Bacteria belonging to this species are usually referred to as Lancefield group C or group G streptococci in clinical settings in spite of the fact that these terms lack precision and prevent recognition of the exact clinical relevance of these bacteria. The purpose of this study was to develop an improved basis for delineation and identification of the individual species of the pyogenic group of streptococci in the clinical microbiology laboratory, with a special focus on S. dysgalactiae. We critically reexamined the genetic relationships of the species S. dysgalactiae, Streptococcus pyogenes, Streptococcus canis, and Streptococcus equi, which may share Lancefield group antigens, by phylogenetic reconstruction based on multilocus sequence analysis (MLSA) and 16S rRNA gene sequences and by emm typing combined with phenotypic characterization. Analysis of concatenated sequences of seven genes previously used for examination of viridans streptococci distinguished robust and coherent clusters. S. dysgalactiae consists of two separate clusters consistent with the two recognized subspecies dysgalactiae and equisimilis. Both taxa share alleles with S. pyogenes in several housekeeping genes, which invalidates identification based on single-locus sequencing. S. dysgalactiae, S. canis, and S. pyogenes constitute a closely related branch within the genus Streptococcus indicative of recent descent from a common ancestor, while S. equi is highly divergent from other species of the pyogenic group streptococci. The results provide an improved basis for identification of clinically important pyogenic group streptococci and explain the overlapping spectrum of infections caused by the species associated with humans. PMID:22075580

Maxillary Teeth Abscesses Result in Atypical Liver Abscesses

PubMed Central

Gupta, Vritti; Vivekanandan, Renuga; Gorby, Gary

2018-01-01

Hepatic liver abscesses are often misdiagnosed on initial presentation because pyogenic liver lesions are a rare occurrence in the United States. This leads to a delay in proper treatment and results in increasing morbidity and mortality. Our case report demonstrates the atypical presentation of a hepatic liver abscess in the elderly. The source of infection was found to be periapical abscesses of the teeth, which subsequently seeded the portal blood stream of our patient. Our findings validate the potential hazard of Viridans streptococci and illustrate how untreated dental infections can serve as a reservoir for a systemic infection. PMID:29796365

Application of adenosine triphosphate-driven bioluminescence for quantification of plaque bacteria and assessment of oral hygiene in children.

PubMed

Fazilat, Shahram; Sauerwein, Rebecca; McLeod, Jennifer; Finlayson, Tyler; Adam, Emilia; Engle, John; Gagneja, Prashant; Maier, Tom; Machida, Curtis A

2010-01-01

Dentistry has undergone a shift in caries management toward prevention and improved oral hygiene and diagnosis. Caries prevention now represents one of the most important aspects of modern dental practice. The purpose of this cross-sectional study was to demonstrate the use of adenosine triphosphate- (ATP-) driven bioluminescence as an innovative tool for the rapid chairside enumeration of oral bacteria (including plague streptococci) and assessment of oral hygiene and caries risk. Thirty-three pediatric patients (7- to 12-year-old males and females) were examined, and plague specimens, in addition to stimulated saliva, were collected from representative teeth within each quadrant. Oral specimens (n=150 specimens) were assessed by plating on enriched and selective agars, to enumerate total bacteria and streptococci, and subjected to adenosine triphosphate- (ATP-) driven bioluminescence determinations using a luciferase-based assay system. Statistical correlations, linking ATP values to numbers of total bacteria, oral streptococci and mutans streptococci, yielded highly significant r values of 0.854, 0.840, and 0.796, respectively Our clinical data is consistent with the hypothesis that ATP measurements have a strong statistical association with bacterial number in plague and saliva specimens, including numbers for oral streptococci, and may be used as a potential assessment tool for oral hygiene and caries risk in children.

Inhibition by yeast killer toxin-like antibodies of oral Streptococci adhesion to tooth surfaces in an ex vivo model.

PubMed

Conti, Stefania; Magliani, Walter; Arseni, Simona; Frazzi, Raffaele; Salati, Antonella; Ravanetti, Lara; Polonelli, Luciano

2002-06-01

Monoclonal (KTmAb) and recombinant (KTscFv) anti-idiotypic antibodies, representing the internal image of a yeast killer toxin, proved to be microbicidal in vitro against important eukaryotic and prokaryotic pathogens such as Candida albicans, Pneumocystis carinii, Mycobacterium tuberculosis, Staphylococcus aureus, S. haemolyticus, Enterococcus faecalis, E. faecium, and Streptococcus pneumoniae, including multidrug-resistant strains. KTmAb and KTscFv exerted a strong therapeutic effect in well-established animal models of candidiasis and pneumocystosis. Streptococcus mutans is the most important etiologic agent of dental caries that might result from the metabolic end products of dental plaque. Effective strategies to reduce the disease potential of dental plaque have considered the possibility of using antibiotics or antibodies against oral streptococci in general and S. mutans in particular. In this study, the activity of KTmAb and KTscFv against S. mutans and the inhibition and reduction by KTmAb of dental colonization by S. mutans and other oral streptococci in an ex vivo model of human teeth were investigated. KTscFv and KTmAb were used in a conventional colony forming unit (CFU) assay against a serotype C strain of S. mutans, and other oral streptococci (S. intermedius, S. mitis, S. oralis, S. salivarius). An ex vivo model of human teeth submerged in saliva was used to establish KTmAb potential of inhibiting or reducing the adhesion to dental surfaces by S. mutans and other oral streptococci. KTmAb and KTscFv kill in vitro S. mutans and other oral streptococci. KTmAb inhibit colonization of dental surfaces by S. mutans and oral streptococci in the ex vivo model. Killer antibodies with antibiotic activity or their engineered derivatives may have a potential in the prevention of dental caries in vivo.

Natural History of Streptococcus sanguinis in the Oral Cavity of Infants: Evidence for a Discrete Window of Infectivity

PubMed Central

Caufield, Page W.; Dasanayake, Ananda P.; Li, Yihong; Pan, Yaping; Hsu, Jay; Hardin, J. Michael

2000-01-01

The heterogeneous group of oral bacteria within the sanguinis (sanguis) streptococci comprise members of the indigenous biota of the human oral cavity. While the association of Streptococcus sanguinis with bacterial endocarditis is well described in the literature, S. sanguinis is thought to play a benign, if not a beneficial, role in the oral cavity. Little is known, however, about the natural history of S. sanguinis and its specific relationship with other oral bacteria. As part of a longitudinal study concerning the transmission and acquisition of oral bacteria within mother-infant pairs, we examined the initial acquisition of S. sanguinis and described its colonization relative to tooth emergence and its proportions in plaque and saliva as a function of other biological events, including subsequent colonization with mutans streptococci. A second cohort of infants was recruited to define the taxonomic affiliation of S. sanguinis. We found that the colonization of the S. sanguinis occurs during a discrete “window of infectivity” at a median age of 9 months in the infants. Its colonization is tooth dependent and correlated to the time of tooth emergence; its proportions in saliva increase as new teeth emerge. In addition, early colonization of S. sanguinis and its elevated levels in the oral cavity were correlated to a significant delay in the colonization of mutans streptococci. Underpinning this apparent antagonism between S. sanguinis and mutans streptococci is the observation that after mutans streptococci colonize the infant, the levels of S. sanguinis decrease. Children who do not harbor detectable levels of mutans streptococci have significantly higher levels of S. sanguinis in their saliva than do children colonized with mutans streptococci. Collectively, these findings suggest that the colonization of S. sanguinis may influence the subsequent colonization of mutans streptococci, and this in turn may suggest several ecological approaches toward controlling dental caries. PMID:10858217

Natural history of Streptococcus sanguinis in the oral cavity of infants: evidence for a discrete window of infectivity.

PubMed

Caufield, P W; Dasanayake, A P; Li, Y; Pan, Y; Hsu, J; Hardin, J M

2000-07-01

The heterogeneous group of oral bacteria within the sanguinis (sanguis) streptococci comprise members of the indigenous biota of the human oral cavity. While the association of Streptococcus sanguinis with bacterial endocarditis is well described in the literature, S. sanguinis is thought to play a benign, if not a beneficial, role in the oral cavity. Little is known, however, about the natural history of S. sanguinis and its specific relationship with other oral bacteria. As part of a longitudinal study concerning the transmission and acquisition of oral bacteria within mother-infant pairs, we examined the initial acquisition of S. sanguinis and described its colonization relative to tooth emergence and its proportions in plaque and saliva as a function of other biological events, including subsequent colonization with mutans streptococci. A second cohort of infants was recruited to define the taxonomic affiliation of S. sanguinis. We found that the colonization of the S. sanguinis occurs during a discrete "window of infectivity" at a median age of 9 months in the infants. Its colonization is tooth dependent and correlated to the time of tooth emergence; its proportions in saliva increase as new teeth emerge. In addition, early colonization of S. sanguinis and its elevated levels in the oral cavity were correlated to a significant delay in the colonization of mutans streptococci. Underpinning this apparent antagonism between S. sanguinis and mutans streptococci is the observation that after mutans streptococci colonize the infant, the levels of S. sanguinis decrease. Children who do not harbor detectable levels of mutans streptococci have significantly higher levels of S. sanguinis in their saliva than do children colonized with mutans streptococci. Collectively, these findings suggest that the colonization of S. sanguinis may influence the subsequent colonization of mutans streptococci, and this in turn may suggest several ecological approaches toward controlling dental caries.

The role of bacteria in lactational mastitis and some considerations of the use of antibiotic treatment.

PubMed

Kvist, Linda J; Larsson, Bodil Wilde; Hall-Lord, Marie Louise; Steen, Anita; Schalén, Claes

2008-04-07

The role of bacterial pathogens in lactational mastitis remains unclear. The objective of this study was to compare bacterial species in breast milk of women with mastitis and of healthy breast milk donors and to evaluate the use of antibiotic therapy, the symptoms of mastitis, number of health care contacts, occurrence of breast abscess, damaged nipples and recurrent symptoms in relation to bacterial counts. In this descriptive study, breast milk from 192 women with mastitis (referred to as cases) and 466 breast milk donors (referred to as controls) was examined bacteriologically and compared using analytical statistics. Statistical analyses were also carried out to test for relationships between bacteriological content and clinical symptoms as measured on scales, prescription of antibiotics, the number of care contacts, occurrence of breast abscess and recurring symptoms. Five main bacterial species were found in both cases and controls: coagulase negative staphylococci (CNS), viridans streptococci, Staphylococcus aureus (S. aureus), Group B streptococci (GBS) and Enterococcus faecalis. More women with mastitis had S. aureus and GBS in their breast milk than those without symptoms, although 31% of healthy women harboured S. aureus and 10% had GBS. There were no significant correlations between bacterial counts and the symptoms of mastitis as measured on scales. There were no differences in bacterial counts between those prescribed and not prescribed antibiotics or those with and without breast abscess. GBS in breast milk was associated with increased health care contacts (p = 0.02). Women with >/= 10(7) cfu/L CNS or viridans streptococci in their breast milk had increased odds for damaged nipples (p = 0.003). Many healthy breastfeeding women have potentially pathogenic bacteria in their breast milk. Increasing bacterial counts did not affect the clinical manifestation of mastitis; thus bacterial counts in breast milk may be of limited value in the decision to treat with antibiotics as results from bacterial culture of breast milk may be difficult to interpret. These results suggest that the division of mastitis into infective or non-infective forms may not be practically feasible. Daily follow-up to measure the subsidence of symptoms can help detect those in need of antibiotics.

Comprehensive update of dalbavancin activity when tested against uncommonly isolated streptococci, Corynebacterium spp., Listeria monocytogenes, and Micrococcus spp. (1357 strains).

PubMed

Jones, Ronald N; Stilwell, Matthew G

2013-06-01

Dalbavancin is an investigational lipoglycopeptide having an extended serum elimination half-life allowing once-weekly dosing. Data from testing 1357 strains of uncommonly isolated species expand the dalbavancin spectrum details as follows (MIC50/90): β-haemolytic streptococcal serogroups C, F, and G (≤0.03/≤0.03 μg/mL), 7 viridans group of streptococci (≤0.03/≤0.03-0.06 μg/mL), 5 Corynebacterium spp. (0.06/0.12 μg/mL), Listeria monocytogenes (0.06/0.12 μg/mL), and Micrococcus spp. (≤0.03/≤0.03 μg/mL). Among all reported isolates, 99.8% of tested strains were inhibited at dalbavancin MIC values at ≤0.12 μg/mL. Dalbavancin remains very potent against rarer Gram-positive pathogens, using in vitro test experience with organisms cultured through 2011. Copyright © 2013 Elsevier Inc. All rights reserved.

Etiology and Clinical Course of Febrile Neutropenia in Children with Cancer

PubMed Central

Hakim, Hana; Flynn, Patricia M.; Knapp, Katherine M.; Srivastava, Deo Kumar; Gaur, Aditya

2009-01-01

Background The etiology, clinical course and outcome of fever and neutropenia (FN) in children with cancer using the current FN guidelines and diagnostic resources in the United States have not been well described. Patients and Methods Medical records of one randomly selected FN episode per patient during 2004–2005 at a pediatric oncology center were reviewed. Patients were managed as per institutional FN guidelines and blood cultures collected in continuously-read BACTEC™ bottles. Results Of 337 FN episodes, infection was proven in 86 (25%) and probable in 75 (22%). 177 episodes (53%) were judged fever of unknown origin (FUO). Bacteremia accounted for most (41) of the proven bacterial episodes, with viridans streptococci (13), Pseudomonas spp (6) and E. coli (6) the most frequently isolated organisms. The median time to positivity of blood cultures was 12 hrs (range 5.4 – 143.7) with 93% positive within 24 hours of incubation. Viral pathogens were identified in 29 (34%) episodes. Compared to other patients, those with FUO had shorter median duration of fever (0.5 vs. 2.0 days; p<0.0001) and hospitalization (3 vs. 6 days; p<0.0001), longer median duration since last chemotherapy (6.0 vs. 4.0 days; p=0.01) and were less likely to have a diagnosis of acute myelogenous leukemia (AML) (11% vs 22%; p=0.009) or develop a clinical complication (5.1% vs 24.4%; p<0.0001). Conclusion Despite currently available diagnostic resources, the majority of patients with FN have FUO marked by a low rate of clinical complications and no infection-related mortality. Emergence of viridans streptococci as the most common blood isolate has affected FN treatment recommendations. Study findings will help further development of strategies for risk stratified management of fever with neutropenia in pediatric patients. PMID:19644403

Comparison of PCR-Electrospray Ionization Mass Spectrometry with 16S rRNA PCR and Amplicon Sequencing for Detection of Bacteria in Excised Heart Valves

PubMed Central

Peeters, Bart; Herijgers, Paul; Beuselinck, Kurt; Peetermans, Willy E.; Herregods, Marie-Christin

2016-01-01

Identification of the causative pathogen of infective endocarditis (IE) is crucial for adequate management and therapy. A broad-range PCR-electrospray ionization mass spectrometry (PCR-ESI-MS) technique was compared with broad-spectrum 16S rRNA PCR and amplicon sequencing (16S rRNA PCR) for the detection of bacterial pathogens in 40 heart valves obtained from 34 definite infective endocarditis patients according to the modified Duke criteria and six nonendocarditis patients. Concordance between the two molecular techniques was 98% for being positive or negative, 97% for concordant identification up to the genus level, and 77% for concordant identification up to the species level. Sensitivity for detecting the causative pathogen (up to the genus level) in excised heart valves was 88% for 16S rRNA PCR and 85% for PCR-ESI-MS; the specificity was 83% for both methods. The two molecular techniques were significantly more sensitive than valve culture (18%) and accurately identified bacteria in excised heart valves. In eight patients with culture-negative IE, the following results were obtained: concordant detection of Coxiella burnetii (n = 2), Streptococcus gallolyticus (n = 1), Propionibacterium acnes (n = 1), and viridans group streptococci (n = 1) by both molecular tests, detection of P. acnes by PCR-ESI-MS whereas the 16S rRNA PCR was negative (n = 1), and a false-negative result by both molecular techniques (n = 2). In one case of IE caused by viridans streptococci, PCR-ESI-MS was positive for Enterococcus spp. The advantages of PCR-ESI-MS compared to 16S rRNA PCR are its automated workflow and shorter turnaround times. PMID:27629895

Globicatella sanguinis Osteomyelitis and Bacteremia: Review of an Emerging Human Pathogen with an Expanding Spectrum of Disease

PubMed Central

Buckwalter, Seanne P.; Henry, Michael W.; Wu, Fann; Maloney, Katherine F.; Abraham, Bisrat K.; Hartman, Barry J.; Brause, Barry D.; Whittier, Susan; Walsh, Thomas J.; Schuetz, Audrey N.

2017-01-01

Abstract Background. Globicatella sanguinis is an uncommon pathogen that may be misdiagnosed as viridans group streptococci. We review the literature of Globicatella and report 2 clinical cases in which catalase-negative Gram-positive cocci resembling viridans group streptococci with elevated minimum inhibitory concentrations (MICs) to ceftriaxone were inconsistently identified phenotypically, with further molecular characterization and ultimate identification of G sanguinis. Methods. Two clinical strains (from 2 obese women; 1 with a prosthetic hip infection and the other with bacteremia) were analyzed with standard identification methods, followed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry, 16S recombinant ribonucleic acid (rRNA), and sodA polymerase chain reaction (PCR). The existing medical literature on Globicatella also was reviewed. Results. Standard phenotypic methods failed to consistently identify the isolates. 16S PCR yielded sequences that confirmed Globicatella species. sodA sequencing provided species-level identification of G sanguinis. The review of literature reveals G sanguinis as an increasingly reported cause of infections of the urine, meninges, and blood. To our knowledge, this is the first reported case of an orthopedic infection caused by Globicatella sanguinis. A review of the 37 known cases of G sanguinis infection revealed that 83% of patients are female, and 89% are at the extremes of age (<5 or >65 years). Conclusions. Globicatella sanguinis, an uncommon pathogen with elevated minimum inhibitory concentrations to third-generation cephalosporins, is difficult to identify by phenotypic methods and typically causes infections in females at the extremes of age. It may colonize skin or mucosal surfaces. Advanced molecular techniques utilizing 16S rRNA with sodA PCR accurately identify G sanguinis. PMID:28480269

Antibiotic modulation of the plasminogen binding ability of viridans group streptococci.

PubMed

Teles, Cristina; Smith, Andrew; Lang, Sue

2012-01-01

The ability of viridans group streptococci to bind human plasminogen and its subsequent activation into plasmin may contribute to the pathogenesis of infective endocarditis (IE) by leading to a decreased stability of the streptococcal vegetation and facilitating dehiscence of emboli. At levels greater than or equal to their MICs, penicillin, vancomycin, and linezolid are efficacious in the treatment of streptococcal endocarditis. However, at sub-MICs, antibiotics can modulate the expression of bacterial genes, including virulence-associated genes, which can have counterproductive effects on the treatment of endocarditis. The effects of 1/8× and 1/4× MICs of penicillin, vancomycin, and linezolid on the plasminogen binding ability of IE isolates Streptococcus mitis 881/956, Streptococcus oralis 12601, and Streptococcus sanguinis 12403 were assessed phenotypically and the expression of plasminogen receptors α-enolase and glyceraldehyde 3-phosphate dehydrogenase of S. oralis 12601 when exposed to 1/4× MIC of penicillin, was analyzed through quantitative reverse transcription (qRT)-PCR. The plasminogen binding ability of S. mitis 881/956 and S. sanguinis 12403 remained unaffected by exposure to sub-MICs of all of the antibiotics tested, while that of S. oralis 12601 was significantly enhanced by all of the antibiotics tested at sub-MICs. qRT-PCR analysis of S. oralis 12601 demonstrated an upregulation of the eno and gapdh genes, indicating an overexpression of plasminogen receptors. These findings suggest that for some endocarditis isolates, the effect of antibiotic sub-MICs, in addition to a reduced antibacterial effect, may influence the clinical response to nonsurgical therapy. It remains difficult to accurately predict isolate responses to sub-MIC antimicrobials since there appears to be interspecies variation.

Bacterium-Dependent Induction of Cytokines in Mononuclear Cells and Their Pathologic Consequences In Vivo

PubMed Central

Jiang, Yanling; Magli, Luciano; Russo, Michael

1999-01-01

Viridans streptococci are a heterogeneous group of gram-positive bacteria that are normal inhabitants of the mouth. These organisms are thought to contribute significantly to the etiology of infective endocarditis, although recently they have been implicated in serious infections in other settings. Another group of oral bacteria, gram-negative anaerobes, is associated with chronic dental infections, such as periodontal diseases or endodontic lesion formation. We evaluated the ability of the oral pathogens Streptococcus mutans and Porphyromonas endodontalis to induce a pathogenic response in vivo, with the goal of quantifying the inflammatory response in soft tissue by measuring leukocyte recruitment and hard tissues by measuring osteoclastogenesis. S. mutans induced a strong inflammatory response and was a potent inducer of osteoclast formation, while P. endodontalis was not. To further study the mechanisms by which P. endodontalis and S. mutans elicit significantly different levels of inflammatory responses in vivo, we tested the capacity of each to induce production of cytokines by mononuclear cells in vitro. S. mutans stimulated high levels of interleukin-12 (IL-12), gamma interferon (IFN-γ), and tumor necrosis factor alpha (TNF-α), all of which are associated with inflammation, enhanced monocyte function, and generation of a Th1 response. In contrast, P. endodontalis stimulated production of IL-10 but not of TNF-α, IL-12, or IFN-γ. These results demonstrate that oral pathogens differ dramatically in their abilities to induce inflammatory and immunoregulatory cytokines. Moreover, there is a high degree of correlation between the cytokine profile induced by these bacteria in vitro and their pathogenic capacity in vivo. PMID:10225864

Bacterium-dependent induction of cytokines in mononuclear cells and their pathologic consequences in vivo.

PubMed

Jiang, Y; Magli, L; Russo, M

1999-05-01

Viridans streptococci are a heterogeneous group of gram-positive bacteria that are normal inhabitants of the mouth. These organisms are thought to contribute significantly to the etiology of infective endocarditis, although recently they have been implicated in serious infections in other settings. Another group of oral bacteria, gram-negative anaerobes, is associated with chronic dental infections, such as periodontal diseases or endodontic lesion formation. We evaluated the ability of the oral pathogens Streptococcus mutans and Porphyromonas endodontalis to induce a pathogenic response in vivo, with the goal of quantifying the inflammatory response in soft tissue by measuring leukocyte recruitment and hard tissues by measuring osteoclastogenesis. S. mutans induced a strong inflammatory response and was a potent inducer of osteoclast formation, while P. endodontalis was not. To further study the mechanisms by which P. endodontalis and S. mutans elicit significantly different levels of inflammatory responses in vivo, we tested the capacity of each to induce production of cytokines by mononuclear cells in vitro. S. mutans stimulated high levels of interleukin-12 (IL-12), gamma interferon (IFN-gamma), and tumor necrosis factor alpha (TNF-alpha), all of which are associated with inflammation, enhanced monocyte function, and generation of a Th1 response. In contrast, P. endodontalis stimulated production of IL-10 but not of TNF-alpha, IL-12, or IFN-gamma. These results demonstrate that oral pathogens differ dramatically in their abilities to induce inflammatory and immunoregulatory cytokines. Moreover, there is a high degree of correlation between the cytokine profile induced by these bacteria in vitro and their pathogenic capacity in vivo.

Interference of oral hygiene products with an adhesion-based assay of salivary mutans streptococci.

PubMed

Söderling, E; Ketola, T; Parviainen, T

1991-04-01

The effect of several oral hygiene products on an adhesion-based assay for salivary mutans streptococci (Dentocult-SM Strip Mutans) was studied in three women. The mutans streptococci levels were recorded for up to 24 h after a 1-min rinse with the product. The chlorhexidine (0.05%) and stanno-amine fluoride solutions (corresponding 0.025% F) interfered selectively with the adhesion-based assay. No such effect was observed for a polyvidoneiodine solution (10 micrograms/ml) or two toothpastes containing either sodium lauryl sulfate or amine fluorides. The results indicate that antimicrobial agents showing retention in the oral cavity may interfere for several hours after their use with adhesion-based assays of salivary mutans streptococci.

Inhibition by yeast killer toxin-like antibodies of oral Streptococci adhesion to tooth surfaces in an ex vivo model.

PubMed Central

Conti, Stefania; Magliani, Walter; Arseni, Simona; Frazzi, Raffaele; Salati, Antonella; Ravanetti, Lara; Polonelli, Luciano

2002-01-01

BACKGROUND: Monoclonal (KTmAb) and recombinant (KTscFv) anti-idiotypic antibodies, representing the internal image of a yeast killer toxin, proved to be microbicidal in vitro against important eukaryotic and prokaryotic pathogens such as Candida albicans, Pneumocystis carinii, Mycobacterium tuberculosis, Staphylococcus aureus, S. haemolyticus, Enterococcus faecalis, E. faecium, and Streptococcus pneumoniae, including multidrug-resistant strains. KTmAb and KTscFv exerted a strong therapeutic effect in well-established animal models of candidiasis and pneumocystosis. Streptococcus mutans is the most important etiologic agent of dental caries that might result from the metabolic end products of dental plaque. Effective strategies to reduce the disease potential of dental plaque have considered the possibility of using antibiotics or antibodies against oral streptococci in general and S. mutans in particular. In this study, the activity of KTmAb and KTscFv against S. mutans and the inhibition and reduction by KTmAb of dental colonization by S. mutans and other oral streptococci in an ex vivo model of human teeth were investigated. MATERIALS AND METHODS: KTscFv and KTmAb were used in a conventional colony forming unit (CFU) assay against a serotype C strain of S. mutans, and other oral streptococci (S. intermedius, S. mitis, S. oralis, S. salivarius). An ex vivo model of human teeth submerged in saliva was used to establish KTmAb potential of inhibiting or reducing the adhesion to dental surfaces by S. mutans and other oral streptococci. RESULTS: KTmAb and KTscFv kill in vitro S. mutans and other oral streptococci. KTmAb inhibit colonization of dental surfaces by S. mutans and oral streptococci in the ex vivo model. CONCLUSIONS: Killer antibodies with antibiotic activity or their engineered derivatives may have a potential in the prevention of dental caries in vivo. PMID:12428062

The Changing Epidemiology of Pediatric Endocarditis.

PubMed

Elder, Robert W; Baltimore, Robert S

2015-09-01

The epidemiology of infective endocarditis (IE) appears to be related to changes in the management of children with congenital heart disease (CHD) and the virtual disappearance of rheumatic heart disease. To better understand these changes, we divide the history into: I. The pre-surgical era, II. The early years of CHD surgical intervention, correlated with introduction of antibiotics, III. The modern era of cardiac interventions. Microbiologic changes include an early predominance of viridans streptococci and an overtaking by staphylococci. Additionally, there have been advances in imaging that allow earlier detection of IE and a reduction in IE-related mortality. Copyright © 2015 Elsevier Inc. All rights reserved.

Streptococcus sanguinis brain abscess as complication of subclinical endocarditis: emphasizing the importance of prompt diagnosis.

PubMed

Kassis, Hayah; Marnejon, Thomas; Gemmel, David; Cutrona, Anthony; Gottimukkula, Rajashree

2010-06-01

A 19-year-old male patient was diagnosed with S. sanguinis brain abscess of unknown etiopathology as a complication of subclinical endocarditis. While viridans streptococci are implicated in dental seeding to the heart, S. sanguinis brain abscesses are rare. Six previous cases of S. sanguinis brain abscess in the literature reported dental procedures and maxillofacial trauma. In our patient, there was no obvious source of infective endocarditis preceding the development of brain abscess. This demonstrates the importance of prompt diagnosis and initiation of antimicrobial therapy given the potential for long-term sequelae such as focal deficits and seizures.

Effect of saliva viscosity on the co-aggregation between oral streptococci and Actinomyces naeslundii.

PubMed

Kitada, Katsuhiro; Oho, Takahiko

2012-06-01

The co-aggregation of oral bacteria leads to their clearance from the oral cavity. Poor oral hygiene and high saliva viscosity are common amongst the elderly; thus, they frequently suffer from pneumonia caused by the aspiration of oral microorganisms. To examine the direct effect of saliva viscosity on the co-aggregation of oral streptococci with actinomyces. Fifteen oral streptococcal and a single actinomyces strain were used. Co-aggregation was assessed by a visual assay in phosphate buffer and a spectrophotometric assay in the same buffer containing 0-60% glycerol or whole saliva. Nine oral streptococci co-aggregated with Actinomyces naeslundii ATCC12104 in the visual assay and were subsequently used for the spectrophotometric analysis. All tested strains displayed a decrease in co-aggregation with increasing amounts of glycerol in the buffer. The co-aggregation of Streptococcus oralis with A. naeslundii recovered to baseline level following the removal of glycerol. The per cent co-aggregation of S. oralis with A. naeslundii was significantly correlated with the viscosity in unstimulated and stimulated whole saliva samples (correlation coefficients: -0.52 and -0.48, respectively). This study suggests that saliva viscosity affects the co-aggregation of oral streptococci with actinomyces and that bacterial co-aggregation decreases with increasing saliva viscosity. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

Alkali production associated with malolactic fermentation by oral streptococci and protection against acid, oxidative, or starvation damage

PubMed Central

Sheng, Jiangyun; Baldeck, Jeremiah D.; Nguyen, Phuong T.M.; Quivey, Robert G.; Marquis, Robert E.

2011-01-01

Alkali production by oral streptococci is considered important for dental plaque ecology and caries moderation. Recently, malolactic fermentation (MLF) was identified as a major system for alkali production by oral streptococci, including Streptococcus mutans. Our major objectives in the work described in this paper were to further define the physiology and genetics of MLF of oral streptococci and its roles in protection against metabolic stress damage. l-Malic acid was rapidly fermented to l-lactic acid and CO2 by induced cells of wild-type S. mutans, but not by deletion mutants for mleS (malolactic enzyme) or mleP (malate permease). Mutants for mleR (the contiguous regulator gene) had intermediate capacities for MLF. Loss of capacity to catalyze MLF resulted in loss of capacity for protection against lethal acidification. MLF was also found to be protective against oxidative and starvation damage. The capacity of S. mutans to produce alkali from malate was greater than its capacity to produce acid from glycolysis at low pH values of 4 or 5. MLF acted additively with the arginine deiminase system for alkali production by Streptococcus sanguinis, but not with urease of Streptococcus salivarius. Malolactic fermentation is clearly a major process for alkali generation by oral streptococci and for protection against environmental stresses. PMID:20651853

Alkali production associated with malolactic fermentation by oral streptococci and protection against acid, oxidative, or starvation damage.

PubMed

Sheng, Jiangyun; Baldeck, Jeremiah D; Nguyen, Phuong T M; Quivey, Robert G; Marquis, Robert E

2010-07-01

Alkali production by oral streptococci is considered important for dental plaque ecology and caries moderation. Recently, malolactic fermentation (MLF) was identified as a major system for alkali production by oral streptococci, including Streptococcus mutans. Our major objectives in the work described in this paper were to further define the physiology and genetics of MLF of oral streptococci and its roles in protection against metabolic stress damage. L-Malic acid was rapidly fermented to L-lactic acid and CO(2) by induced cells of wild-type S. mutans, but not by deletion mutants for mleS (malolactic enzyme) or mleP (malate permease). Mutants for mleR (the contiguous regulator gene) had intermediate capacities for MLF. Loss of capacity to catalyze MLF resulted in loss of capacity for protection against lethal acidification. MLF was also found to be protective against oxidative and starvation damage. The capacity of S. mutans to produce alkali from malate was greater than its capacity to produce acid from glycolysis at low pH values of 4 or 5. MLF acted additively with the arginine deiminase system for alkali production by Streptococcus sanguinis, but not with urease of Streptococcus salivarius. Malolactic fermentation is clearly a major process for alkali generation by oral streptococci and for protection against environmental stresses.

Predictors and outcomes of viridans group streptococcal infections in pediatric acute myeloid leukemia: from the Canadian infections in AML research group.

PubMed

Lewis, Victor; Yanofsky, Rochelle; Mitchell, David; Dix, David; Ethier, Marie-Chantal; Gillmeister, Biljana; Johnston, Donna; Michon, Bruno; Stobart, Kent; Portwine, Carol; Silva, Mariana; Cellot, Sonia; Price, Victoria; Bowes, Lynette; Zelcer, Shayna; Brossard, Josee; Beyene, Joseph; Sung, Lillian

2014-02-01

Viridans group streptococci (VGS) cause significant morbidity in children treated for acute myeloid leukemia (AML). Our goals were to determine the occurrence and impact of these infections in children treated for AML and to understand the factors that increase the risk of VGS infections and viridans streptococcal shock syndrome (VSSS) in this population. We conducted a retrospective, population-based cohort study that included children ≤18 years of age with de novo AML treated at 15 Canadian centers. We evaluated factors related to VGS infection and VSSS. Among 341 children with AML, VGS occurred in 78 (22.9%) children over the entire course of therapy and 16 had recurrent episodes. VGS infection occurred in 97 of 1277 courses of chemotherapy (7.6%). VSSS occurred in 19.6% of these episodes and included 11 patients who required intensive care services with 2 VGS infections resulting in death. In multiple regression analysis, factors independently related to VGS included treatment on a Medical Research Council-based protocol (odds ratio (OR) 2.87, 95% confidence interval (CI) 1.53-5.39; P = 0.001), cytarabine dose per gram/m² (OR 1.04, 95% CI 1.01-1.07; P = 0.002) and prolonged neutropenia (OR 1.58, 95% CI: 0.97-2.56; P = 0.06). None of the evaluated factors were predictive of VSSS. VGS infections occur in 7.6% of chemotherapy courses and remain an important cause of morbidity and even mortality in children being treated for AML. Interventions to reduce VGS need to be identified.

Oral streptococci with genetic determinants similar to the glucosyltransferase regulatory gene, rgg.

PubMed Central

Vickerman, M M; Sulavik, M C; Clewell, D B

1995-01-01

The Streptococcus gordonii Challis glucosyltransferase structural gene, gtfG, is positively regulated by the upstream gene, rgg, the only described gtf regulatory determinant in oral streptococci. Southern hybridization analyses indicated that rgg-like and gtfG-like determinants were present on the same HindIII fragment in strains of S. gordonii, Streptococcus sanguis, and Streptococcus oralis, whereas no rgg-like determinants were detected in mutans streptococci, Streptococcus mitis, and Streptococcus salivarius. PMID:7591096

Characteristics of a Bacteriocin Derived from Streptococcus faecalis var. zymogenes Antagonistic to Diplococcus peumoniae

PubMed Central

Bottone, Edward; Allerhand, Jona; Pisano, Michael A.

1971-01-01

A bacteriocin-producing strain of Streptococcus faecalis var. zymogenes (E-1) was isolated from clinical material (conjunctiva). The active substance differed from bacteriocins described by other investigators primarily in its spectrum of antibacterial activity, especially by its marked inhibition of Diplococcus pneumoniae. The E-1 bacteriocin also inhibited nonhemolytic strains of enterococci as well as one-third of the Viridans group of streptococcal strains investigated. The degree of inhibition, however, as indicated by the size of the zones against the latter organisms, was significantly reduced. No activity was detected against any of the strains belonging to the following groups of bacteria: hemolytic enterococci, beta-hemolytic streptococci, nonhemolytic streptococci, staphylococci, and various gram-negative species. Similarly, three strains each of Bacillus cereus and Listeria monocytogenes and one strain of Erysipelothrix insidiosa were not inhibited. The bacteriocin was able to diffuse through bacterial membranes as well as cellulose dialyzer tubing. It was inactivated by heating to 80 C for 20 min but resisted inactivation by either trypsin or chloroform. Images PMID:4398532

EFFECT OF SILICATE ON GRAM STAINING AND VIABILITY OF PNEUMOCOCCI AND OTHER BACTERIA

PubMed Central

MacLeod, Colin M.; Roe, Amy S.

1956-01-01

Application of silicate solutions to living or heat-killed pneumococci and to certain "viridans" streptococci causes their conversion from a Gram-positive to a Gram-negative state. The original staining properties can be restored by suspending the silicate-treated bacteria in alkaline solutions of various salts but not by simple washing in water. Living pneumococci and the strains of streptococci whose staining properties are similarly affected are killed when suspended in silicate solutions. In other Gram-positive species silicate causes conversion to Gram negativity but restoration to positivity occurs upon washing in water. In a third group of Gram-positive organisms silicate has no effect on the Gram reaction. The viability of organisms in these two groups is unaffected by silicate under the conditions employed. No effect on staining or viability of Gram-negative bacteria has been observed. The effects of silicate on staining and viability are inhibited by nutrient broth or whole serum but not by purified serum albumin. Lecithin, choline, and other substituted ammonium compounds also inhibit the effects of silicate on pneumococci. PMID:13306854

Cross-reactions between alpha-streptococci and Omniserum, a polyvalent pneumococcal serum, demonstrated by direct immunofluorescence, immunoelectroosmophoresis, and latex agglutination.

PubMed Central

Holmberg, H; Danielsson, D; Hardie, J; Krook, A; Whiley, R

1985-01-01

In recent years several groups have used serological methods to demonstrate pneumococcal capsular antigens in sputum. In the present study 123 strains of alpha-hemolytic streptococci (including 97 strains from sputum or pharyngeal specimens) were tested for cross-reactions with a polyvalent antipneumococcal serum (Omniserum). Representatives of the following species were included: Streptococcus bovis, S. equinus, S. intermedius, S. lactis, S. milleri, S. mitis, S. mutans, S. sobrinus, S. salivarius, S. sanguis, S. suis, and Aerococcus viridans. Serological reactions were detected by direct immunofluorescence, immunoelectroosmophoresis, and latex agglutination. Fifteen (12%) of the strains gave positive reactions by all three methods. Positive reactions were also observed with another 32 strains (26%) with two of the methods, whereas 37 strains (30%) gave positive reactions by just one technique. Altogether 84 (68%) strains gave positive reactions with one or more of the methods. Latex agglutination gave positive reactions with 26 (21%) strains compared with 57 (46%) in immunofluorescence and 63 (51%) in immunoelectroosmophoresis. Absorption of the antiserum with one alpha-hemolytic strain reduced but did not entirely eliminate the cross-reactions with five tested strains. These findings indicate a potential risk of cross-reactions with polyvalent antipneumococcal serum in tests carried out on sputa or other specimens which may be contaminated with alpha-hemolytic streptococci. PMID:3889046

Taking the Starch out of Oral Biofilm Formation: Molecular Basis and Functional Significance of Salivary α-Amylase Binding to Oral Streptococci

PubMed Central

Nikitkova, Anna E.; Haase, Elaine M.

2013-01-01

α-Amylase-binding streptococci (ABS) are a heterogeneous group of commensal oral bacterial species that comprise a significant proportion of dental plaque microfloras. Salivary α-amylase, one of the most abundant proteins in human saliva, binds to the surface of these bacteria via specific surface-exposed α-amylase-binding proteins. The functional significance of α-amylase-binding proteins in oral colonization by streptococci is important for understanding how salivary components influence oral biofilm formation by these important dental plaque species. This review summarizes the results of an extensive series of studies that have sought to define the molecular basis for α-amylase binding to the surface of the bacterium as well as the biological significance of this phenomenon in dental plaque biofilm formation. PMID:23144140

[Infectious endocarditis due to Gemella morbillorum found by splenic infarction--a case report].

PubMed

Hosaka, Yumiko; Kimura, Takuma; Suzuki, Ryo; Chong, Tonghyo; Shoji, Michi; Aoki, Yasuko

2010-09-01

A 64-year-old man with prostate cancer and bone metastasis admitted for nausea, left abdominal pain showed no abnormal, and fever, abdominal ultrasound or chest X-ray findings. Despite antibiotics, left abdominal pain persisted for several days. Abdominal computed tomography (CT), showed splenic infarction. Transesophageal echocardiography suggested infectious endocarditis (IE) as a possible infarction cause, and roth spots were found on the retina. Gemella morbillorum was detected from blood culture. IE commonly causes Fever of Unknown Origin found by infarction. G. morbillorum, an anaerobic gram-positive, viridans group streptococci, is indigenous to the oropharynx, upper respiratory, urogenital, and gastrointestinal tracts, and is thought to have weak toxicity and pathogenicity in the body.

Growth inhibition of oral mutans streptococci and candida by commercial probiotic lactobacilli - an in vitro study

PubMed Central

2010-01-01

Background Probiotic bacteria are suggested to play a role in the maintenance of oral health. Such health promoting bacteria are added to different commercial probiotic products. The aim of the study was to investigate the ability of a selection of lactobacilli strains, used in commercially available probiotic products, to inhibit growth of oral mutans streptococci and C. albicans in vitro. Methods Eight probiotic lactobacilli strains were tested for growth inhibition on three reference strains and two clinical isolates of mutans streptococci as well as two reference strains and three clinical isolates of Candida albicans with an agar overlay method. Results At concentrations ranging from 109 to 105 CFU/ml, all lactobacilli strains inhibited the growth of the mutans streptococci completely with the exception of L. acidophilus La5 that executed only a slight inhibition of some strains at concentrations corresponding to 107 and 105 CFU/ml. At the lowest cell concentration (103 CFU/ml), only L. plantarum 299v and L. plantarum 931 displayed a total growth inhibition while a slight inhibition was seen for all five mutans streptococci strains by L. rhamnosus LB21, L. paracasei F19, L. reuteri PTA 5289 and L. reuteri ATCC 55730. All the tested lactobacilli strains reduced candida growth but the effect was generally weaker than for mutans streptococci. The two L. plantarum strains and L. reuteri ATCC 55730 displayed the strongest inhibition on Candida albicans. No significant differences were observed between the reference strains and the clinical isolates. Conclusion The selected probiotic strains showed a significant but somewhat varying ability to inhibit growth of oral mutans streptococci and Candida albicans in vitro. PMID:20598145

Growth inhibition of oral mutans streptococci and candida by commercial probiotic lactobacilli--an in vitro study.

PubMed

Hasslöf, Pamela; Hedberg, Maria; Twetman, Svante; Stecksén-Blicks, Christina

2010-07-02

Probiotic bacteria are suggested to play a role in the maintenance of oral health. Such health promoting bacteria are added to different commercial probiotic products. The aim of the study was to investigate the ability of a selection of lactobacilli strains, used in commercially available probiotic products, to inhibit growth of oral mutans streptococci and C. albicans in vitro. Eight probiotic lactobacilli strains were tested for growth inhibition on three reference strains and two clinical isolates of mutans streptococci as well as two reference strains and three clinical isolates of Candida albicans with an agar overlay method. At concentrations ranging from 109 to 105 CFU/ml, all lactobacilli strains inhibited the growth of the mutans streptococci completely with the exception of L. acidophilus La5 that executed only a slight inhibition of some strains at concentrations corresponding to 107 and 105 CFU/ml. At the lowest cell concentration (103 CFU/ml), only L. plantarum 299v and L. plantarum 931 displayed a total growth inhibition while a slight inhibition was seen for all five mutans streptococci strains by L. rhamnosus LB21, L. paracasei F19, L. reuteri PTA 5289 and L. reuteri ATCC 55730. All the tested lactobacilli strains reduced candida growth but the effect was generally weaker than for mutans streptococci. The two L. plantarum strains and L. reuteri ATCC 55730 displayed the strongest inhibition on Candida albicans. No significant differences were observed between the reference strains and the clinical isolates. The selected probiotic strains showed a significant but somewhat varying ability to inhibit growth of oral mutans streptococci and Candida albicans in vitro.

Prevention and elimination of upper respiratory colonization of mice by group A streptococci by using a bacteriophage lytic enzyme.

PubMed

Nelson, D; Loomis, L; Fischetti, V A

2001-03-27

Bacteriophage lytic enzymes quickly destroy the cell wall of the host bacterium to release progeny phage. Because such lytic enzymes specifically kill the species in which they were produced, they may represent an effective way to control pathogenic bacteria without disturbing normal microflora. In this report, we studied a murein hydrolase from the streptococcal bacteriophage C(1) termed lysin. This enzyme is specific for groups A, C, and E streptococci, with little or no activity toward several oral streptococci or other commensal organisms tested. Using purified lysin in vitro, we show that 1,000 units (10 ng) of enzyme is sufficient to sterilize a culture of approximately 10(7) group A streptococci within 5 seconds. When a single dose of lysin (250 units) is first added to the oral cavity of mice, followed by 10(7) live group A streptococci, it provides protection from colonization (28.5% infected, n = 21) compared with controls without lysin (70.5% infected, n = 17) (P < 0.03). Furthermore, when lysin (500 units) was given orally to 9 heavily colonized mice, no detectable streptococci were observed 2 h after lysin treatment. In all, these studies show that lysin represents a unique murein hydrolase that has a rapid lethal effect both in vitro and in vivo on group A streptococci, without affecting other indigenous microorganisms analyzed. This general approach may be used to either eliminate or reduce streptococci from the upper respiratory mucosal epithelium of either carriers or infected individuals, thus reducing associated disease.

Glycosyltransferase-mediated Sweet Modification in Oral Streptococci.

PubMed

Zhu, F; Zhang, H; Wu, H

2015-05-01

Bacterial glycosyltransferases play important roles in bacterial fitness and virulence. Oral streptococci have evolved diverse strategies to survive and thrive in the carbohydrate-rich oral cavity. In this review, we discuss 2 important biological processes mediated by 2 distinct groups of glycosyltransferases in oral streptococci that are important for bacterial colonization and virulence. The first process is the glycosylation of highly conserved serine-rich repeat adhesins by a series of glycosyltransferases. Using Streptococcus parasanguinis as a model, we highlight new features of several glycosyltransferases that sequentially modify the serine-rich glycoprotein Fap1. Distinct features of a novel glycosyltransferase fold from a domain of unknown function 1792 are contrasted with common properties of canonical glycosyltransferases. The second biological process we cover is involved in building sticky glucan matrix to establish cariogenic biofilms by an important opportunistic pathogen Streptococcus mutans through the action of a family of 3 glucosyltransferases. We focus on discussing the structural feature of this family as a glycoside hydrolase family of enzymes. While the 2 processes are distinct, they all produce carbohydrate-coated biomolecules, which enable bacteria to stick better in the complex oral microbiome. Understanding the making of the sweet modification presents a unique opportunity to develop novel antiadhesion and antibiofilm strategies to fight infections by oral streptococci and beyond. © International & American Associations for Dental Research 2015.

Glycosyltransferase-mediated Sweet Modification in Oral Streptococci

PubMed Central

Zhu, F.; Zhang, H.

2015-01-01

Bacterial glycosyltransferases play important roles in bacterial fitness and virulence. Oral streptococci have evolved diverse strategies to survive and thrive in the carbohydrate-rich oral cavity. In this review, we discuss 2 important biological processes mediated by 2 distinct groups of glycosyltransferases in oral streptococci that are important for bacterial colonization and virulence. The first process is the glycosylation of highly conserved serine-rich repeat adhesins by a series of glycosyltransferases. Using Streptococcus parasanguinis as a model, we highlight new features of several glycosyltransferases that sequentially modify the serine-rich glycoprotein Fap1. Distinct features of a novel glycosyltransferase fold from a domain of unknown function 1792 are contrasted with common properties of canonical glycosyltransferases. The second biological process we cover is involved in building sticky glucan matrix to establish cariogenic biofilms by an important opportunistic pathogen Streptococcus mutans through the action of a family of 3 glucosyltransferases. We focus on discussing the structural feature of this family as a glycoside hydrolase family of enzymes. While the 2 processes are distinct, they all produce carbohydrate-coated biomolecules, which enable bacteria to stick better in the complex oral microbiome. Understanding the making of the sweet modification presents a unique opportunity to develop novel antiadhesion and antibiofilm strategies to fight infections by oral streptococci and beyond. PMID:25755271

In vitro activity of RP 59500, a semisynthetic injectable pristinamycin, against staphylococci, streptococci, and enterococci.

PubMed Central

Fass, R J

1991-01-01

The in vitro activity of RP 59500, a semisynthetic pristinamycin, was compared with the activities of vancomycin, oxacillin, ampicillin, gentamicin, ciprofloxacin, and rifampin against five Staphylococcus species, five Streptococcus species, and four Enterococcus species. For staphylococci, MICs were 0.13 to 1 microgram/ml and the MICs for 90% of the strains tested (MIC90s) were 0.13 to 0.5 microgram/ml; there were no differences between oxacillin-susceptible and -resistant strains. For streptococci, MICs were 0.03 to 4 micrograms/ml and MIC90s were 0.25 to 2 micrograms/ml; viridans group streptococci were the least susceptible streptococci. For enterococci, MICs were 0.25 to 32 micrograms/ml and MIC90s were 2 to 4 micrograms/ml; Enterococcus faecalis was the least susceptible. Vancomycin was the only comparative drug with consistent activity against all species of gram-positive cocci. With RP 59500, raising the inoculum 100-fold, lowering the pH of cation-adjusted Mueller-Hinton broth to 5.5, or omitting cation supplementation had little effect on MICs, but 50% serum increased MICs 2 to 4 dilution steps. The differences between MBCs and MICs were greater for staphylococci and enterococci than for streptococci. Time-kill studies with 24 strains indicated that RP 59500 concentrations 2-, 4-, and 16-fold greater than the MICs usually killed bacteria of each species at similar rates; reductions in CFU per milliliter were less than those observed with oxacillin or vancomycin against staphylococci and less than those observed with ampicillin against enterococci. RP 59500 antagonized the bactericidal activities of oxacillin and gentamicin against Staphylococcus aureus ATCC 29213 and that of ampicillin against E. faecalis ATCC 29212. Against the latter, combination with gentamicin was indifferent. RP 59500 has a broad spectrum of in vitro activity against gram-positive cocci; combining it with other drugs is not advantageous. PMID:1903912

Insight into the Diversity of Penicillin-Binding Protein 2x Alleles and Mutations in Viridans Streptococci

PubMed Central

van der Linden, Mark; Otten, Julia; Bergmann, Carina; Latorre, Cristina; Liñares, Josefina

2017-01-01

ABSTRACT The identification of commensal streptococci species is an everlasting problem due to their ability to genetically transform. A new challenge in this respect is the recent description of Streptococcus pseudopneumoniae as a new species, which was distinguished from closely related pathogenic S. pneumoniae and commensal S. mitis by a variety of physiological and molecular biological tests. Forty-one atypical S. pneumoniae isolates have been collected at the German National Reference Center for Streptococci (GNRCS). Multilocus sequence typing (MLST) confirmed 35 isolates as the species S. pseudopneumoniae. A comparison with the pbp2x sequences from 120 commensal streptococci isolated from different continents revealed that pbp2x is distinct among penicillin-susceptible S. pseudopneumoniae isolates. Four penicillin-binding protein x (PBPx) alleles of penicillin-sensitive S. mitis account for most of the diverse sequence blocks in resistant S. pseudopneumoniae, S. pneumoniae, and S. mitis, and S. infantis and S. oralis sequences were found in S. pneumoniae from Japan. PBP2x genes of the family of mosaic genes related to pbp2x in the S. pneumoniae clone Spain23F-1 were observed in S. oralis and S. infantis as well, confirming its global distribution. Thirty-eight sites were altered within the PBP2x transpeptidase domains of penicillin-resistant strains, excluding another 37 sites present in the reference genes of sensitive strains. Specific mutational patterns were detected depending on the parental sequence blocks, in agreement with distinct mutational pathways during the development of beta-lactam resistance. The majority of the mutations clustered around the active site, whereas others are likely to affect stability or interactions with the C-terminal domain or partner proteins. PMID:28193649

Streptococcus sinensis may react with Lancefield group F antiserum.

PubMed

Woo, Patrick C Y; Teng, Jade L L; Leung, Kit-wah; Lau, Susanna K P; Tse, Herman; Wong, Beatrice H L; Yuen, Kwok-yung

2004-11-01

Lancefield group F streptococci have been found almost exclusively as members of the 'Streptococcus milleri' group, although they have been reported very occasionally in some other streptococcal species. Among 302 patients with bacteraemia caused by viridans streptococci over a 6-year period, three cases were caused by Streptococcus sinensis (type strain HKU4T, HKU5 and HKU6). All three patients had infective endocarditis complicating their underlying chronic rheumatic heart diseases. Gene sequencing showed no base differences between the 16S rRNA gene sequences of HKU5 and HKU6 and that of HKU4T. All three strains were Gram-positive, non-spore-forming cocci arranged in chains. All grew on sheep blood agar as alpha-haemolytic, grey colonies of 0.5-1 mm in diameter after 24 h incubation at 37 degrees C in ambient air. Lancefield grouping revealed that HKU5 and HKU6 were Lancefield group F, but HKU4T was non-groupable with Lancefield groups A, B, C, D, F or G antisera. HKU4T was identified by the Vitek system (GPI), API system (20 STREP) and ATB system (ID32 STREP) as 99 % Streptococcus intermedius, 51.3 % S. intermedius and 99.9 % Streptococcus anginosus, respectively. Using the same tests, HKU5 was identified as 87 % Streptococcus sanguinis/Streptococcus gordonii, 59 % Streptococcus salivarius and 99.6 % S. anginosus, respectively, and HKU6 as 87 % S. sanguinis/S. gordonii, 77 % Streptococcus pneumoniae and 98.3 % S. anginosus, respectively. The present data revealed that a proportion of Lancefield group F streptococci could be S. sinensis. Lancefield group F streptococci should not be automatically reported as 'S. milleri'.

[A Patient with a Wedge-shaped Pulmonary Lesion Associated with Streptococcus parasanguinis].

PubMed

Miyamoto, Hiroya; Gomi, Harumi; Ishioka, Haruhiko; Shirokawa, Taijiro

2016-05-01

An 84-year-old man was admitted to our hospital with bloody sputum. He was found to have a right lower lobe wedge-shaped nodular lesion with chest X-ray and computed tomography of the chest. Ceftriaxone and minocycline were started empirically based on a working diagnosis of community-acquired pneumonia. Streptococcus parasanguinis was isolated with sputum cultures obtained on three consecutive days and was identified based on its biochemical properties. S. parasanguinis is a member of the sanguinis group of viridans Streptococci. It is known as a causative pathogen for endocarditis. There are very few reports of S. parasanguinis associated with pulmonary infections. The present report describes the association of S. parasanguinis with a wedge-shaped nodular lesion in the lungs.

Surveillance of Omadacycline Activity against Clinical Isolates from a Global Collection (North America, Europe, Latin America, Asia-Western Pacific), 2010-2011

PubMed Central

Pfaller, Michael A.; Huband, Michael D.; Rhomberg, Paul R.

2017-01-01

ABSTRACT Omadacycline is a broad-spectrum aminomethylcycline in late-stage clinical development for the treatment of acute bacterial skin and skin structure infections and community-acquired pneumonia as an oral and an intravenous once-daily formulation. In this study, omadacycline and comparators were tested against 69,246 nonduplicate bacterial isolates collected prospectively during 2010 and 2011 from medical centers in Asia-Pacific (11,397 isolates), Europe (23,490 isolates), Latin America (8,038 isolates), and North America (26,321 isolates). Omadacycline was tested by broth microdilution following Clinical and Laboratory Standards Institute M07-A10 (2015) methods. A total of 99.9% of Staphylococcus aureus isolates were inhibited by ≤2 μg/ml of omadacycline (MIC50/90, 0.12/0.25 μg/ml), including 100.0% of methicillin-susceptible S. aureus isolates and 99.8% of methicillin-resistant S. aureus isolates. Omadacycline potencies were comparable for Streptococcus pneumoniae (MIC50/90, 0.06/0.06 μg/ml), viridans group streptococci (MIC50/90, 0.06/0.12 μg/ml), and beta-hemolytic streptococci (MIC50/90, 0.06/0.12 μg/ml) regardless of species and susceptibility to penicillin. Omadacycline was active against Enterobacteriaceae and was most active against Escherichia coli (MIC50/90, 0.5/2 μg/ml), Enterobacter aerogenes (MIC50/90, 2/4 μg/ml), Klebsiella oxytoca (MIC50/90, 1/4 μg/ml), and Citrobacter spp. (MIC50/90, 1/4 μg/ml). Omadacycline was active against Haemophilus influenzae (MIC50/90, 1/1 μg/ml) regardless of β-lactamase status and against Moraxella catarrhalis (MIC50/90, 0.12/0.25 μg/ml). The potent activity of omadacycline against Gram-positive and Gram-negative bacteria indicates that omadacycline merits further study in serious infections in which multidrug resistance and mixed Gram-positive and Gram-negative infections may be a concern. PMID:28223386

Experimental Models of C. albicans-Streptococcal Co-infection.

PubMed

Sobue, Takanori; Diaz, Patricia; Xu, Hongbin; Bertolini, Martinna; Dongari-Bagtzoglou, Anna

2016-01-01

Interactions of C. albicans with co-colonizing bacteria at mucosal sites can be synergistic or antagonistic in disease development, depending on the bacterial species and mucosal site. Mitis group streptococci and C. albicans colonize the oral mucosa of the majority of healthy individuals. These streptococci have been termed "accessory pathogens," defined by their ability to initiate multispecies biofilm assembly and promote the virulence of the mixed bacterial biofilm community in which they participate. To demonstrate whether interactions with Mitis group streptococci limit or promote the potential of C. albicans to become an opportunistic pathogen, in vitro and in vivo co-infection models are needed. Here, we describe two C. albicans-streptococcal co-infection models: an organotypic oral mucosal tissue model that incorporates salivary flow and a mouse model of oral co-infection that requires reduced levels of immunosuppression compared to single fungal infection.

Serological diversity demonstrable by a set of monoclonal antibodies to eight serotypes of the mutans streptococci.

PubMed

Ota, F; Ota, M; Mahmud, Z H; Mohammad, A; Yamato, M; Kassu, A; Kato, Y; Tomotake, H; Batoni, G; Campa, M

2006-01-01

A set of monoclonal antibodies were prepared by the conventional cell fusion of myeloma cells (SP2/0-Ag14) with spleen cells from BALB/c mice immunised with whole cells of a strain of mutans streptococci. Their specificities were examined against 35 reference strains of mutans streptococci, 34 reference strains of other oral streptococci and 8 reference strains of other microorganisms often inhabiting the oral cavity. Specificity was examined by enzyme immunoassay using whole cells. A total of 52 strains, consisting of 19 strains isolated in Japan, 19 strains isolated in Italy and 14 strains isolated in England, were characterised by conventional physiological and biochemical tests and then serotyped by the use of 8 monoclonal antibodies with different specificities. They were also confirmed by guanine-plus-cytosine contents of their nucleic acid and DNA-DNA hybridisation test. The results indicated that all monoclonal antibodies are useful for identification of 8 serotypes of the mutans streptococci responsible for dental caries. They also suggest the existence of more serological varieties among mutans species.

Major outbreak of toxic shock-like syndrome caused by Streptococcus mitis.

PubMed

Lu, Hong-Zhou; Weng, Xin-Hua; Zhu, Bai; Li, Haijing; Yin, You-Kuan; Zhang, Yong-Xin; Haas, David W; Tang, Yi-Wei

2003-07-01

Severe illness caused by viridans streptococci rarely occurs in immunocompetent hosts. Between December 1990 and May 1991, thousands of patients in the YangZi River Delta area of Jiangsu Province, China, suffered from scarlet fever-like pharyngitis. Fewer cases occurred in subsequent years with the same seasonality. Approximately half of the cases developed complications characteristic of streptococcal toxic shock-like syndrome (TSLS). Throat cultures yielded predominant growth of alpha-hemolytic streptococci. All cases admitted to Haian People's Hospital were investigated. Clinical specimens were collected, medical records were reviewed, and bacterial isolates were identified phenotypically and analyzed by 16S rRNA gene sequencing and pulsed-field gel electrophoresis (PFGE). Proteins were purified from culture supernatants by extraction, ammonium sulfate precipitation, and fast-protein liquid chromatography. Biological activities of protein components were determined by subcutaneous inoculation into rabbits. A total of 178 cases of non-beta-hemolytic streptococcal scarlet fever-like pharyngitis were studied. In 88 (79.3%) of 111 patients, oropharyngeal swab cultures grew morphologically identical alpha-hemolytic streptococci. A protein in culture supernatants was pyrogenic in rabbits, was mitogenic for splenocytes, and enhanced rabbit susceptibility to endotoxin challenge. The N-terminal amino acid sequence of this 34-kDa protein showed no homology with known Streptococcus pyrogenic exotoxins. The organism was identified as Streptococcus mitis based on biochemical and 16S rRNA sequence analyses. Representative outbreak isolates from 1990 to 1995 displayed identical PFGE patterns. This TSLS outbreak in southeastern China was caused by a toxigenic clone of S. mitis. An apparently novel toxin may explain the unusual virulence of this organism.

Mitis group streptococci express variable pilus islet 2 pili.

PubMed

Zähner, Dorothea; Gandhi, Ashish R; Yi, Hong; Stephens, David S

2011-01-01

Streptococcus oralis, Streptococcus mitis, and Streptococcus sanguinis are members of the Mitis group of streptococci and agents of oral biofilm, dental plaque and infective endocarditis, disease processes that involve bacteria-bacteria and bacteria-host interactions. Their close relative, the human pathogen S. pneumoniae uses pilus-islet 2 (PI-2)-encoded pili to facilitate adhesion to eukaryotic cells. PI-2 pilus-encoding genetic islets were identified in S. oralis, S. mitis, and S. sanguinis, but were absent from other isolates of these species. The PI-2 islets resembled the genetic organization of the PI-2 islet of S. pneumoniae, but differed in the genes encoding the structural pilus proteins PitA and PitB. Two and three variants of pitA (a pseudogene in S. pneumoniae) and pitB, respectively, were identified that showed ≈20% difference in nucleotide as well as corresponding protein sequence. Species-independent combinations of pitA and pitB variants indicated prior intra- and interspecies horizontal gene transfer events. Polyclonal antisera developed against PitA and PitB of S. oralis type strain ATCC35037 revealed that PI-2 pili in oral streptococci were composed of PitA and PitB. Electronmicrographs showed pilus structures radiating >700 nm from the bacterial surface in the wild type strain, but not in an isogenic PI-2 deletion mutant. Anti-PitB-antiserum only reacted with pili containing the same PitB variant, whereas anti-PitA antiserum was cross-reactive with the other PitA variant. Electronic multilocus sequence analysis revealed that all PI-2-encoding oral streptococci were closely-related and cluster with non-PI-2-encoding S. oralis strains. This is the first identification of PI-2 pili in Mitis group oral streptococci. The findings provide a striking example of intra- and interspecies horizontal gene transfer. The PI-2 pilus diversity provides a possible key to link strain-specific bacterial interactions and/or tissue tropisms with pathogenic traits in the Mitis group streptococci.

Infective Endocarditis in Patients With Bicuspid Aortic Valve or Mitral Valve Prolapse.

PubMed

Zegri-Reiriz, Isabel; de Alarcón, Arístides; Muñoz, Patricia; Martínez Sellés, Manuel; González-Ramallo, Victor; Miro, Jose M; Falces, Carles; Gonzalez Rico, Claudia; Kortajarena Urkola, Xabier; Lepe, José Antonio; Rodriguez Alvarez, Regino; Reguera Iglesias, Jose Maria; Navas, Enrique; Dominguez, Fernando; Garcia-Pavia, Pablo

2018-06-19

There is little information concerning infective endocarditis (IE) in patients with bicuspid aortic valve (BAV) or mitral valve prolapse (MVP). Currently, IE antibiotic prophylaxis (IEAP) is not recommended for these conditions. This study sought to describe the clinical and microbiological features of IE in patients with BAV and MVP and compare them with those of IE patients with and without IEAP indication, to determine the potential benefit of IEAP in these conditions. This analysis involved 3,208 consecutive IE patients prospectively included in the GAMES (Grupo de Apoyo al Manejo de la Endocarditis infecciosa en España) registry at 31 Spanish hospitals. Patients were classified as high-risk IE with IEAP indication (high-risk group; n = 1,226), low- and moderate-risk IE without IEAP indication (low/moderate-risk group; n = 1,839), and IE with BAV (n = 54) or MVP (n = 89). BAV and MVP patients had a higher incidence of viridans group streptococci IE than did high-risk group and low/moderate-risk group patients (35.2% and 39.3% vs. 12.1% and 15.0%, respectively; all p < 0.01). A similar pattern was seen for IE from suspected odontologic origin (14.8% and 18.0% vs. 5.8% and 6.0%; all p < 0.01). BAV and MVP patients had more intracardiac complications than did low/moderate-risk group (50% and 47.2% vs. 30.6%, both p < 0.01) patients and were similar to high-risk group patients. IE in patients with BAV and MVP have higher rates of viridans group streptococci IE and IE from suspected odontologic origin than in other IE patients, with a clinical profile similar to that of high-risk IE patients. Our findings suggest that BAV and MVP should be classified as high-risk IE conditions and the case for IEAP should be reconsidered. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Effect of xylitol on cariogenic and beneficial oral streptococci: a randomized, double-blind crossover trial

PubMed Central

Bahador, A; Lesan, S; Kashi, N

2012-01-01

Background/purpose Although habitual consumption of xylitol reduces cariogenic streptococci levels, its effect on beneficial oral streptococci is less clear. The main aim of the study is to investigate the effect of short-term xylitol consumption on the oral beneficial streptococci level of saliva, Streptococcus sanguinis and S. mitis. Material and Methods Twenty four volunteers with a median age of 23.7 years (range: 20-28) harboring Streptococcus mutans, S. sobrinus, S. sanguinis and S. mitis participated in the randomized, double-blind, cross-over study. The experimental chewing gum (1.5 g/pellet) contained 70% xylitol w/w while the control gum contained 63% sorbitol w/w. Saliva samples were collected before and after two three-week test periods with a four-week washout interval. Colony-forming units (CFU)/ml were enumerated for the estimation of S. mutans levels on Mitis Salivarius-Mutans valinomycin (MS-MUTV), S. sobrinus on Mitis Salivarius-Sobrinus (MS-SOB), S. sanguinis on Modified Medium 10-Sucrose (MM10-S) and S. mitis on Mitis Salivarius Agar with Tellurite (MSAT) media. Results The S. mutans and S. sobrinus counts of the saliva samples decreased significantly (p = 0.01 and p = 0.011, respectively) in the xylitol gum group but not in the sorbitol gum group. The salivary S. sanguinis and S. mitis counts did not decrease in both xylitol and sorbitol gum groups. Conclusions Based on the findings of this study, xylitol consumption reduced S. mutans and S. sobrinus counts in saliva but appeared not to effect numbers of S. sanguinis and S. mitis in saliva. So, habitual consumption of xylitol reduces cariogenic streptococci levels without any effect on beneficial sterptococci for the oral cavity. PMID:22973473

High Pressure Liquid Chromatography in the Analysis of Fatty Acid Composition of Oral Streptococci and its Comparison to Gas Chromatography.

DTIC Science & Technology

1977-10-04

pentadeca— noic (Cl5 :0) #29 , and heptadeconic (Cl9:0) #30. Eicosenoic acid had been reported to be present in Strepto- coccus salivarius and Streptococcus ...Inutans but not in other oral streptococci. We noted in the chromnatograms of both S. mutans and S. salivarius cultures there was a shoulder off peak...representative chromatogram of S. mutans is shown in Fig. 14. Several points about these representative chromatograms should be emphasized. The first is the

Quantitative analysis of changes in salivary mutans streptococci after orthodontic treatment.

PubMed

Jung, Woo-Sun; Kim, Ho; Park, So-Yoon; Cho, Eun-Jung; Ahn, Sug-Joon

2014-05-01

The purpose of this study was to analyze the initial changes in salivary mutans streptococci levels after orthodontic treatment with fixed appliances. Our subjects consisted of 58 adults. Whole saliva and simplified oral hygiene index values were obtained at 4 time points: at debonding (T1), 1 week after debonding (T2), 5 weeks after debonding (T3), and 13 weeks after debonding (T4). Repeated measures analysis of variance was used to determine the time-related differences in salivary bacterial levels and the simplified oral hygiene index values among the 4 time points after quantifying the salivary levels of Streptococcus mutans, Streptococcus sobrinus, and total bacteria with real-time polymerase chain reaction. Simplified oral hygiene index values and total bacteria significantly decreased, but salivary mutans streptococci levels significantly increased after orthodontic treatment. The amounts of total bacteria in saliva significantly decreased at T3 (T1, T2 > T3, T4), and the simplified oral hygiene index values decreased at T2 (T1 > T2, T3, T4). However, salivary S mutans and S sobrinus significantly increased at T3 and T4, respectively (T1, T2 < T3 < T4). Furthermore, the proportion of mutans streptococci to total bacteria significantly increased at T4 (T1, T2, T3 < T4). This study suggests that careful hygienic procedures are needed to reduce the risk for dental caries after orthodontic treatment, despite overall improved oral hygiene status. Copyright © 2014 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Coaggregation-Mediated Interactions of Streptococci and Actinomyces Detected in Initial Human Dental Plaque

PubMed Central

Palmer, Jr., Robert J.; Gordon, Sharon M.; Cisar, John O.; Kolenbrander, Paul E.

2003-01-01

Streptococci and actinomyces that initiate colonization of the tooth surface frequently coaggregate with each other as well as with other oral bacteria. These observations have led to the hypothesis that interbacterial adhesion influences spatiotemporal development of plaque. To assess the role of such interactions in oral biofilm formation in vivo, antibodies directed against bacterial surface components that mediate coaggregation interactions were used as direct immunofluorescent probes in conjunction with laser confocal microscopy to determine the distribution and spatial arrangement of bacteria within intact human plaque formed on retrievable enamel chips. In intrageneric coaggregation, streptococci such as Streptococcus gordonii DL1 recognize receptor polysaccharides (RPS) borne on other streptococci such as Streptococcus oralis 34. To define potentially interactive subsets of streptococci in the developing plaque, an antibody against RPS (anti-RPS) was used together with an antibody against S. gordonii DL1 (anti-DL1). These antibodies reacted primarily with single cells in 4-h-old plaque and with mixed-species microcolonies in 8-h-old plaque. Anti-RPS-reactive bacteria frequently formed microcolonies with anti-DL1-reactive bacteria and with other bacteria distinguished by general nucleic acid stains. In intergeneric coaggregation between streptococci and actinomyces, type 2 fimbriae of actinomyces recognize RPS on the streptococci. Cells reactive with antibody against type 2 fimbriae of Actinomyces naeslundii T14V (anti-type-2) were much less frequent than either subset of streptococci. However, bacteria reactive with anti-type-2 were seen in intimate association with anti-RPS-reactive cells. These results are the first direct demonstration of coaggregation-mediated interactions during initial plaque accumulation in vivo. Further, these results demonstrate the spatiotemporal development and prevalence of mixed-species communities in early dental plaque. PMID:12754239

Innocent until proven guilty: mechanisms and roles of Streptococcus–Candida interactions in oral health and disease

PubMed Central

Xu, H; Jenkinson, HF; Dongari-Bagtzoglou, A

2014-01-01

Summary Candida albicans and streptococci of the mitis group colonize the oral cavities of the majority of healthy humans. While C. albicans is considered an opportunistic pathogen, streptococci of this group are broadly considered avirulent or even beneficial organisms. However, recent evidence suggests that multi-species biofilms with these organisms may play detrimental roles in host homeostasis and may promote infection. In this review we summarize the literature on molecular interactions between members of this streptococcal group and C. albicans, with emphasis on their potential role in the pathogenesis of opportunistic oral mucosal infections. PMID:24877244

In vitro antibacterial activity of doripenem against clinical isolates from French teaching hospitals: proposition of zone diameter breakpoints.

PubMed

Lascols, C; Legrand, P; Mérens, A; Leclercq, R; Armand-Lefevre, L; Drugeon, H B; Kitzis, M D; Muller-Serieys, C; Reverdy, M E; Roussel-Delvallez, M; Moubareck, C; Lemire, A; Miara, A; Gjoklaj, M; Soussy, C-J

2011-04-01

The aims of the study were to determine the in vitro activity of doripenem, a new carbapenem, against a large number of bacterial pathogens and to propose zone diameter breakpoints for clinical categorization in France according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) minimum inhibitory concentration (MIC) breakpoints. The MICs of doripenem were determined by the broth microdilution method against 1,547 clinical isolates from eight French hospitals. The disk diffusion test was performed (10-μg discs) according to the Comité de l'Antibiogramme de la Société Française de Microbiologie (CASFM) method. The MIC(50/90) (mg/L) values were as follows: methicillin-susceptible Staphylococcus aureus (MSSA) (0.03/0.25), methicillin-resistant Staphylococcus aureus (MRSA) (1/2), methicillin-susceptible coagulase-negative staphylococci (MSCoNS) (0.03/0.12), methicillin-resistant coagulase-negative staphylococci (MRCoNS) (2/8), Streptococcus pneumoniae (0.016/0.25), viridans group streptococci (0.016/2), β-hemolytic streptococci (≤0.008/≤0.008), Enterococcus faecalis (2/4), Enterococcus faecium (128/>128), Enterobacteriaceae (0.06/0.25), Pseudomonas aeruginosa (0.5/8), Acinetobacter baumannii (0.25/2), Haemophilus influenzae (0.12/0.25), and Moraxella catarrhalis (0.03/0.06). According to the regression curve, the zone diameter breakpoints were 24 and 19 mm for MICs of 1 and 4 mg/L, respectively. This study confirms the potent in vitro activity of doripenem against Pseudomonas aeruginosa, Acinetobacter, Enterobacteriaceae, MSSA, MSCoNS, and respiratory pathogens. According to the EUCAST MIC breakpoints (mg/L) ≤1/>4 for Enterobacteriaceae, Pseudomonas aeruginosa, and Acinetobacter, and ≤1/>1 for streptococci, pneumococci, and Haemophilus, the zone diameter breakpoints could be (mm) ≥24/<19 and ≥24/<24, respectively.

Antimicrobial photodynamic therapy with two photosensitizers on two oral streptococci: an in vitro study

NASA Astrophysics Data System (ADS)

Vahabi, S.; Fekrazad, R.; Ayremlou, S.; Taheri, S.; Lizarelli, R. F. Z.; Kalhori, K. A. M.

2011-12-01

Periodontal diseases are caused by infection of tissues supporting the teeth due to complex aggregate of bacteria known as biofilm and firstly colonized by streptococci. The aim of this in vitro study was to evaluate the effect of Radachlorin® and Toluidine Blue O (TBO)-mediated photodynamic therapy (PDT) on the viability of two oral streptococci. Bacterial suspensions of Streptococcus mutans and Streptococcus sanguis were subjected to either TBO or Radachlorin®, Then exposed to two different diode laser light at energy densities of 3, 6 J/cm2 at 633 nm and 6, 12 J/cm2 at 662 nm, respectively. The control groups were subjected to laser light alone, photosensitizer alone or received neither photosensitizer nor light exposure. The suspensions were then spread over specific agar mediums and viable microorganisms were counted after overnight incubation aerobically at 37°C, 5% CO2 and then reported as colony forming unit. The results indicated that photosensitization by the energy density of 6 J/cm2 with Radachlorin® and both 3 and 6 J/cm2 with TBO caused significant reduction in bacterial colony formation ( p < 0.05). Radachlorin® and TBO-mediated photodynamic therapy seem to show excellent potential in significantly killing of two oral streptococci in vitro.

Detection of endocarditis bacteria in tonsillar mucosa of Afghan population.

PubMed

Ruggiero, F; Carbone, D; Mugavero, R; Palmieri, A; Lauritano, D; Baggi, L; Nardone, M; Carinci, F; Martinelli, M

2018-01-01

Endocarditis is a cardiovascular disease caused by the inflammation of the inner tissues of the heart, the endocardium, usually of the valves. Bacteraemia is essential in the development of endocarditis, and there are some findings that the main pathogens of endocarditis are viridans group streptococci: Streptococcus oralis, Streptococcus sanguinis, and Enterococcus faecalis. There is strong evidence that endocarditis bacteria are present in the tonsillar microbiota, so that tonsillar infection is associated with an increased risk of endocarditis. The aim of this manuscript is to investigate the presence of the main pathogens of endocarditis in tonsillar microbiota of an Afghan population group. A sample of 80 tonsil swabs were analyzed by quantitative real time PCR to detect endocarditis pathogens and an estimation of the total bacterial load. The median bacterial load in PCR reaction was 1.4x106 (interquartile range 4,7x105 - 2,9x106). Three species, S. Oralis, S. Sanguinis, and E. Faecalis were found in large amounts in all specimens. On the other hand, S. Mitis was never detected. The S. Aureus was found in 3 samples with a prevalence of 0.04 (C.I. 0.01-0.10). The S. Mutans was found in 33 samples with a prevalence of 0.41 (C.I. 0.31-0.52). Endocarditis bacteria has been found into the tonsillar microbiota, so there is sufficient evidence to justify that the oral cavity is a reservoir of endocarditis bacteria that can have a significant impact on the cardiovascular function.

[Clinical and microbiological characteristics of complicated intra-abdominal infection in Colombia: a multicenter study].

PubMed

Vallejo, Marta; Cuesta, Diana P; Flórez, Luz E; Correa, Adriana; Llanos, Carmen E; Isaza, Berenice; Vanegas, Stella; Osorio, Johanna; Casanova, Lucía; Villegas, María V

2016-06-01

Complicated community-acquired intra-abdominal infections (CA-cIAI) are a common cause of acute abdomen. To identify the clinical and microbiology profile of CA-cIAI in four Colombian hospitals. This is a prospective, descriptive study, between 08-2012 and 09-2014, including patients with CA-cIAI > 15 years. Data collected included: socio-demographic, clinical, diagnosis, and isolates of the first culture obtained aseptically during surgery with antimicrobial susceptibility. 192 patients were included, 62% men, median age 47.3 years. Co-morbidities were present in 38.4%, 13% had been hospitalized in the previous year 13%, and 9.4% had received antibiotics in the last 6 months; 44.3% were admitted for appendicitis, 17.7% for peritonitis and 16.7% for bowel perforation. CA-cIAI were assessed as moderate in 64.1% of the cases and were treated with ampicillin/sulbactam (SAM) and ertapenem. In 70.8% of cases a bacteria was isolated: 65.1% were gramnegative rods (80.0% Escherichia coli, 44.8% of them susceptible to pipercillin/tazobactam, 65.7% to SAM; 11.2 % were K.pneumoniae, 85% was susceptible for SAM; 16.7% were grampositive cocci (28.1% Streptococci viridans group). The median hospital stay was 7 days and 15.1% died. E. coli, K. pneumoniae and S. viridans were the main organisms to consider in an empiric therapy for CA-cIAI and it is important to know the local epidemiology in order to choose the right antibiotic.

Human T-cell responses to oral streptococci in human PBMC-NOD/SCID mice.

PubMed

Salam, M A; Nakao, R; Yonezawa, H; Watanabe, H; Senpuku, H

2006-06-01

We investigated cellular and humoral immune responses to oral biofilm bacteria, including Streptococcus mutans, Streptococcus anginosus, Streptococcus sobrinus, and Streptococcus sanguinis, in NOD/SCID mice immunized with human peripheral blood mononuclear cells (hu-PBMC-NOD/SCID mice) to explore the pathogenicity of each of those organisms in dental and oral inflammatory diseases. hu-PBMC-NOD/SCID mice were immunized by intraperitoneal injections with the whole cells of the streptococci once a week for 3 weeks. FACS analyses were used to determine the percentages of various hu-T cell types, as well as intracellular cytokine production of interleukin-4 and interferon-gamma. Serum IgG and IgM antibody levels in response to the streptococci were also determined by enzyme-linked immunosorbent assay. S. anginosus induced a significant amount of the proinflammatory cytokine interferon-gamma in CD4(+) and CD8(+) T cells in comparison with the other streptococci. However, there was no significant differences between the streptococci in interleukin-4 production by CD4(+) and CD8(+) T cells after inoculation. Further, S. mutans significantly induced human anti-S. mutans IgG, IgG(1), IgG(2), and IgM antibodies in comparison with the other organisms. In conclusion, S. anginosus up-regulated Th1 and Tc1 cells, and S. mutans led to increasing levels of their antibodies, which was associated with the induction of Th2 cells. These results may contribute to a better understanding of human lymphocyte interactions to biofilm bacteria, along with their impact on dental and mucosal inflammatory diseases, as well as endocarditis.

Two autonomous structural modules in the fimbrial shaft adhesin FimA mediate Actinomyces interactions with streptococci and host cells during oral biofilm development

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

Mishra, Arunima; Devarajan, Bharanidharan; Reardon, Melissa E.

2011-09-06

By combining X-ray crystallography and modelling, we describe here the atomic structure of distinct adhesive moieties of FimA, the shaft fimbrillin of Actinomyces type 2 fimbriae, which uniquely mediates the receptor-dependent intercellular interactions between Actinomyces and oral streptococci as well as host cells during the development of oral biofilms. The FimA adhesin is built with three IgG-like domains, each of which harbours an intramolecular isopeptide bond, previously described in several Gram-positive pilins. Genetic and biochemical studies demonstrate that although these isopeptide bonds are dispensable for fimbrial assembly, cell-cell interactions and biofilm formation, they contribute significantly to the proteolytic stability ofmore » FimA. Remarkably, FimA harbours two autonomous adhesive modules, which structurally resemble the Staphylococcus aureus Cna B domain. Each isolated module can bind the plasma glycoprotein asialofetuin as well as the polysaccharide receptors present on the surface of oral streptococci and epithelial cells. Thus, FimA should serve as an excellent paradigm for the development of therapeutic strategies and elucidating the precise molecular mechanisms underlying the interactions between cellular receptors and Gram-positive fimbriae.« less

Two Autonomous Structural Modules in the Fimbrial Shaft Adhesin FimA Mediate Actinomyces Interactions with Streptococci and Host Cells during Oral Biofilm Development

PubMed Central

Mishra, Arunima; Devarajan, Bharanidharan; Reardon, Melissa E.; Dwivedi, Prabhat; Krishnan, Vengadesan; Cisar, John O.; Das, Asis; Narayana, Sthanam V. L; Ton-That, Hung

2011-01-01

By combining X-ray crystallography and modeling, we describe here the atomic structure of distinct adhesive moieties of FimA, the shaft fimbrillin of Actinomyces type 2 fimbriae, which uniquely mediates the receptor-dependent intercellular interactions between Actinomyces and oral streptococci as well as host cells during the development of oral biofilms. The FimA adhesin is built with three IgG-like domains, each of which harbors an intramolecular isopeptide bond, previously described in several Gram-positive pilins. Genetic and biochemical studies demonstrate that although these isopeptide bonds are dispensable for fimbrial assembly, cell-cell interactions and biofilm formation, they contribute significantly to the proteolytic stability of FimA. Remarkably, FimA harbors two autonomous adhesive modules, which structurally resemble the Staphylococcus aureus Cna B domain. Each isolated module can bind the plasma glycoprotein asialofetuin as well as the polysaccharide receptors present on the surface of oral streptococci and epithelial cells. Thus, FimA should serve as an excellent paradigm for the development of therapeutic strategies and elucidating the precise molecular mechanisms underlying the interactions between cellular receptors and Gram-positive fimbriae. PMID:21696465

Streptococcus mitis Strains Causing Severe Clinical Disease in Cancer Patients

PubMed Central

Sahasrabhojane, Pranoti; Saldana, Miguel; Yao, Hui; Su, Xiaoping; Horstmann, Nicola; Thompson, Erika; Flores, Anthony R.

2014-01-01

The genetically diverse viridans group streptococci (VGS) are increasingly recognized as the cause of a variety of human diseases. We used a recently developed multilocus sequence analysis scheme to define the species of 118 unique VGS strains causing bacteremia in patients with cancer; Streptococcus mitis (68 patients) and S. oralis (22 patients) were the most frequently identified strains. Compared with patients infected with non–S. mitis strains, patients infected with S. mitis strains were more likely to have moderate or severe clinical disease (e.g., VGS shock syndrome). Combined with the sequence data, whole-genome analyses showed that S. mitis strains may more precisely be considered as >2 species. Furthermore, we found that multiple S. mitis strains induced disease in neutropenic mice in a dose-dependent fashion. Our data define the prominent clinical effect of the group of organisms currently classified as S. mitis and lay the groundwork for increased understanding of this understudied pathogen. PMID:24750901

Infective Endocarditis in Children in Italy from 2000 to 2015.

PubMed

Esposito, Susanna; Mayer, Alessandra; Krzysztofiak, Andrzej; Garazzino, Silvia; Lipreri, Rita; Galli, Luisa; Osimani, Patrizia; Fossali, Emilio; Di Gangi, Maria; Lancella, Laura; Denina, Marco; Pattarino, Giulia; Montagnani, Carlotta; Salvini, Filippo; Villani, Alberto; Principi, Nicola; Italian Pediatric Infective Endocarditis Registry

2016-01-01

The Italian Society for Pediatric Infectious Diseases created a registry on children with infective endocarditis (IE) hospitalized in Italy. A cross-sectional survey was conducted on patients hospitalized due to IE in Italian paediatric wards between January 1, 2000, and June 30, 2015. Over the 15-year study period, 47 IE episodes were observed (19 males; age range, 2-17 years). Viridans Streptococci were the most common pathogens among patients with predisposing cardiac conditions and Staphylococcus aureus among those without (37.9% vs. 5.5%, p = 0.018, and 6.9% vs. 27.8%, p = 0.089, respectively). Six of the 7 (85.7%) S. aureus strains were methicillin-resistant. The majority of patients with and without predisposing cardiac conditions recovered without any complications. In Italy, paediatric IE develops without any previous predisposing factors in a number of children, methicillin-resistant S. aureus has emerged as a common causative agent and the therapeutic approach is extremely variable.

Prolonged fever and involuntary weight loss as manifestations of bacterial endocarditis: A case report

NASA Astrophysics Data System (ADS)

Sukmawati, N. M. D. D.; Merati, T. P.; Somia, A.; Utama, S.; Gayatri, Y.

2018-03-01

We reported an unusual presentation of prolonged fever and involuntary weight loss in older adult as a manifestation of infective bacterial endocarditis. The patient had pre-existing compensated asymptomatic valvular heart disease without treatment. A positive fecal occult blood test is prompting an investigation of malignancy of gastrointestinal as one of other possible cause of prolonged fever with wasting, evaluation of HIV serostatus shows seronegative. The case fulfilled criteria for definitive infective endocarditis: one major criterion of positive blood culture for Streptococcus mitis, which was one of viridans group streptococci and three minor criteria of fever at least 38°Celsius, immunologic phenomena in the form of glomerulonephritis, and a predisposing heart condition. One course of third-generation cephalosporin successfully cleared the Streptococcus mitis infection proven by culture. Infective endocarditis should be considered as one of the causes of prolonged fever with wasting, especially in cases with the previous history of heart disease.

Effect of cimetidine and antacid on gastric microbial flora.

PubMed Central

Snepar, R; Poporad, G A; Romano, J M; Kobasa, W D; Kaye, D

1982-01-01

The effect of a standard regimen of cimetidine on the gastric flora of 20 male volunteers was studied in a double-blind manner and compared with the effects of a standard antacid regimen. Postprandial microbial titers in gastric aspirates were significantly higher at 4, 8, and 16 weeks of therapy in subjects taking antacids and at 4 weeks in subjects taking cimetidine when compared with their pretreatment titers. Although not significant, there was a tendency for fasting microbial titers to be higher in subjects receiving cimetidine as compared with pretreatment titers. The higher titers were primarily related to increases in survival of mouth flora (viridans streptococci and Neisseria spp.); Enterobacteriaceae and other nitrate-reducing organisms were unusual isolates. There was no significant difference in the total titers or types of organisms isolated when subjects taking cimetidine were compared with those taking antacid. PMID:7085070

[Protease activity of microflora in the oral cavity of patients with periodontitis].

PubMed

Voropaeva, E A; Baĭrakova, A L; Bichucher, A M; D'iakov, V L; Kozlov, L V

2008-01-01

Microbial spectrum and non-specific as well as specific IgA1 protease activity of isolated microorganisms were investigated in gingival liquid of patients with periodontitis. Microorganisms from the gingival liqud of these patients belonged to conditional-pathogenic obligate and facultatively anaerobic bacteria. 24 strains of microorganisms have been identified. Nonspecific proteolytic activity was found in the following microorganisms: Actinomyces israelii, Actinomyces naeslundii, Aerococcus viridans, Bifidobacterium longum, Neisseria subflave, Streptococcus parvulus, Eubacterium alactolyticum, Lactobaccilus catenoforme, Bacillus spp. Specific IgA1-protease activity and lack of proteolytic activity towards IgG was found in Streptococcus acidominimus, Streptococcus hansenii, Streptococcus salivarius, Leptotrychia buccalis, Staphylococcus haemolyticus and Neisseria sicca. No proteolytic activity was found in cultivation medium of Eubacterium alactolyticum (1 strain), Prevotella buccalis, Aerococcus viridans and Streptococcus sanguis.

The significance of oral streptococci in patients with pneumonia with risk factors for aspiration: the bacterial floral analysis of 16S ribosomal RNA gene using bronchoalveolar lavage fluid.

PubMed

Akata, Kentaro; Yatera, Kazuhiro; Yamasaki, Kei; Kawanami, Toshinori; Naito, Keisuke; Noguchi, Shingo; Fukuda, Kazumasa; Ishimoto, Hiroshi; Taniguchi, Hatsumi; Mukae, Hiroshi

2016-05-11

Aspiration pneumonia has been a growing interest in an aging population. Anaerobes are important pathogens, however, the etiology of aspiration pneumonia is not fully understood. In addition, the relationship between the patient clinical characteristics and the causative pathogens in pneumonia patients with aspiration risk factors are unclear. To evaluate the relationship between the patient clinical characteristics with risk factors for aspiration and bacterial flora in bronchoalveolar lavage fluid (BALF) in pneumonia patients, the bacterial floral analysis of 16S ribosomal RNA gene was applied in addition to cultivation methods in BALF samples. From April 2010 to February 2014, BALF samples were obtained from the affected lesions of pneumonia via bronchoscopy, and were evaluated by the bacterial floral analysis of 16S rRNA gene in addition to cultivation methods in patients with community-acquired pneumonia (CAP) and healthcare-associated pneumonia (HCAP). Factors associated with aspiration risks in these patients were analyzed. A total of 177 (CAP 83, HCAP 94) patients were enrolled. According to the results of the bacterial floral analysis, detection rate of oral streptococci as the most detected bacterial phylotypes in BALF was significantly higher in patients with aspiration risks (31.0 %) than in patients without aspiration risks (14.7 %) (P = 0.009). In addition, the percentages of oral streptococci in each BALF sample were significantly higher in patients with aspiration risks (26.6 ± 32.0 %) than in patients without aspiration risks (13.8 ± 25.3 %) (P = 0.002). A multiple linear regression analysis showed that an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of ≥3, the presence of comorbidities, and a history of pneumonia within a previous year were significantly associated with a detection of oral streptococci in BALF. The bacterial floral analysis of 16S rRNA gene revealed that oral streptococci were mostly detected as the most detected bacterial phylotypes in BALF samples in CAP and HCAP patients with aspiration risks, especially in those with a poor ECOG-PS or a history of pneumonia.

High risk of streptococcal septicemia after high dose cytosine arabinoside treatment for acute myelogenous leukemia.

PubMed

Kern, W; Kurrle, E; Vanek, E

1987-08-17

Twenty-nine adult patients with acute myelogenous leukemia AML who received 40 treatment courses with high dose cytosine arabinoside (HD-A), alone or combined with other cytotoxic drugs, for remission induction (RI) or postremission intensive consolidation (IC) were retrospectively analysed for types and severity of infectious complications. In this paper, we report the unusually high rate of streptococcal septicemia in our patients. Of 13 bacteremic infections in a total of 45 infectious episodes, 10 were caused by streptococci (9 viridans streptococci, 1 group B hemolytic streptococcus). Three of them were lethal. After reviewing all documented cases of streptococcal septicemia in the same study period, four additional cases among adult patients with AML were identified. Three of them have had antileukemic chemotherapy without HD-A, while one have had HD-A as a conditioning regimen for bone marrow transplantation. Only three cases were documented to occur in adult patients with AML. Patients treated with HD-A for RI or IC had a significantly lower risk of streptococcal septicemia during previous chemotherapy-associated febrile neutropenic episodes (1/55 vs 10/45; P = 0.01). Neither prophylactic regimens including trimethoprim-sulfamethoxazole nor those without it were effective in preventing streptococcal septicemia. Further studies are needed to confirm these data before the value of additional or alternative prophylactic antibiotics is proven necessary.

Identification of Anion Channels Responsible for Fluoride Resistance in Oral Streptococci

PubMed Central

Takeshita, Toru; Yamashita, Yoshihisa

2016-01-01

Recently, it has been reported that eriC and crcB are involved in bacterial fluoride resistance. However, the fluoride-resistance mechanism in oral streptococci remains unclear. BLAST studies showed that two types of eriCs (eriC1 and eriC2) and two types of crcBs (crcB1 and crcB2) are present across 18 oral streptococci, which were identified in ≥ 10% of 166 orally healthy subjects with ≥ 0.01% of the mean relative abundance. They were divided into three groups based on the distribution of these four genes: group I, only eriC1; group II, eriC1 and eriC2; and group III, eriC2, crcB1, and crcB2. Group I consisted of Streptococcus mutans, in which one of the two eriC1s predominantly affected fluoride resistance. Group II consisted of eight species, and eriC1 was responsible for fluoride resistance, but eriC2 was not, in Streptococcus anginosus as a representative species. Group III consisted of nine species, and both crcB1 and crcB2 were crucial for fluoride resistance, but eriC2 was not, in Streptococcus sanguinis as a representative species. Based on these results, either EriC1 or CrcBs play a role in fluoride resistance in oral streptococci. Complementation between S. mutans EriC1 and S. sanguinis CrcB1/CrcB2 was confirmed in both S. mutans and S. sanguinis. However, neither transfer of S. sanguinis CrcB1/CrcB2 into wild-type S. mutans nor S. mutans EriC1 into wild-type S. sanguinis increased the fluoride resistance of the wild-type strain. Co-existence of different F− channels (EriC and CrcB) did not cause the additive effect on fluoride resistance in oral Streptococcus species. PMID:27824896

New method for the isolation of Streptococcus mutans and its differentiation from other oral streptococci.

PubMed

Linke, H A

1977-06-01

A new, improved agar medium for the isolation of Streptococcus mutans, the etiological agent of dental caries, was developed. In contrast to mitis-salivarius agar, this medium not only recovers a greater number of S. mutans strains from most oral specimens but, because of its mannitol and sorbitol content, it also facilitates the differentiation of S. mutans from other oral streptococci, e.g., S. salivarius, S. mitis, and S. sanguis, which do not grow or produce scanty growth only after 10 days of incubation. The medium is easy to prepare because of its simple and unique composition, is characterized by the presence of an acid indicator, and can be utilized under aerobic and anaerobic conditions as well. The medium cannot be used to distinguish among the eight serotypes, a to g and SL-1, of S. mutans. Mannitol-utilizing bacteria such as streptococci (e.g., S. faecalis) and other microorganisms (e.g., Staphylococcus aureus) are able to grow on this medium and can be distinguished from S. mutans by their unique colony morphology.

[Count of salivary Streptococci mutans in pregnant women of the metropolitan region of Chile: cross-sectional study].

PubMed

Villagrán, E; Linossier, A; Donoso, E

1999-02-01

Salivary Streptococci mutans contamination is considered the main microbiological risk factor for the initiation of caries. To assess the oral health of pregnant women, counting Salivary Streptococci mutants. One hundred seventy four pregnant women, in the first, second and third trimester of pregnancy, aged 27 +/- 5 years old, consulting at a public primary health center, were studied. Puerperal women that had their delivery two months before, were studied as a control group. Salivary samples were obtained and Streptococci mutans colonies were counted using quantitative and semiquantitative methods. There was a good concordance between both counting methods. No differences in Streptococci mutans counts were observed among the three groups of pregnant women, but the latter as a group had higher counts than puerperal women. Women with more than 5 caries had also higher counts. Semiquantitative Streptococci mutans counts are easy, rapid and non invasive and have a good concordance with quantitative counts in saliva.

Coaggregation between probiotic bacteria and caries-associated strains: an in vitro study.

PubMed

Twetman, Lisa; Larsen, Ulla; Fiehn, Nils-Erik; Stecksén-Blicks, Christina; Twetman, Svante

2009-01-01

To evaluate the in vitro abilities of probiotic bacteria derived from consumer products to coaggregate with caries-associated mutans streptococci. Six lactobacillus strains (L. acidophilus (CCUG 5917), L. plantarum 299v, L. rhamnosus GG and LB21, L. paracasei F19, L. reuteri PTA5289) were cultivated under anaerobic conditions at 37°C in Man Rogosa Sharpe (MSB) broth for 24 h. Four strains of human streptococci (S. mutans Ingbritt, S. mutans (ATCC 25175), S. mutans GS-5, S. sobrinus (ATCC 33478) were similarly grown in Brain Heart Infusion (BHI) broth. A gastrointestinal pathogen (Escherichia coli) was aerobically cultivated on BHI broth as a positive control. After incubation, the bacteria were aerobically harvested, washed, and suspended in 10 mmol/l phosphate-buffered saline (pH 7.2). The probiotic strains were characterized with the API 50 CH system to confirm their identity. Coaggregation was determined by spectrophotometry in mixtures and bacterial suspensions alone after 1, 2, 4, and 24 h and expressed as the aggregation ratio (%). All probiotic strains showed coaggregation abilities with the oral pathogens and the results were strain specific and dependent on time. S. mutans GS-5 exhibited a significantly higher ability to coaggregate with all the probiotic strains than the other mutans streptococci and E. coli. The differences among the probiotic strains were modest with L. acidophilus being the most prone and L. rhamnosus LB21 the least prone to coaggregate with the oral streptococci. The results demonstrated different abilities of lactobacilli-derived probiotic bacteria to coaggregate with selected oral streptococci. Aggregation assays may be a useful complement for screening of probiotic candidates with possible anti-caries properties.

LEADER Program Results for 2009: an Activity and Spectrum Analysis of Linezolid Using 6,414 Clinical Isolates from 56 Medical Centers in the United States▿†

PubMed Central

Farrell, David J.; Mendes, Rodrigo E.; Ross, James E.; Sader, Helio S.; Jones, Ronald N.

2011-01-01

The LEADER Program monitors the in vitro activity of linezolid in sampled U.S. medical centers using reference broth microdilution methods with supporting molecular investigations in a central laboratory design. This report summarizes data obtained in 2009, the 6th consecutive year of this longitudinal study. A total of 6,414 isolates from 56 medical centers in all nine Census regions across the United States participated in 2009. For the six leading species/groups, the following linezolid MIC90 values were observed: Staphylococcus aureus, 2 μg/ml; coagulase-negative staphylococci (CoNS), 1 μg/ml; Enterococcus spp., 2 μg/ml; Streptococcus pneumoniae, 1 μg/ml; viridans group streptococci, 1 μg/ml; and beta-hemolytic streptococci, 1 μg/ml. Linezolid resistance was only 0.34% overall, with no evidence of significant increase in the LEADER Program since 2006. The predominant linezolid resistant mechanism found was a G2576T mutation in the 23S rRNA. L3/L4 riboprotein mutations were also found. The mobile multidrug-resistant cfr gene was found in four strains (two S. aureus strains and one strain each of S. epidermidis and S. capitis) from four different states, suggesting persistence but a lack of dissemination. Linezolid continues to exhibit excellent activity and spectrum, and this study documents the need for continued monitoring of emerging mechanisms of resistance over a wide geographic area. PMID:21670176

Impact of minocycline ointment for periodontal treatment of oral bacteria.

PubMed

Nakao, Ryoma; Takigawa, Satoko; Sugano, Naoyuki; Koshi, Ryosuke; Ito, Koichi; Watanabe, Haruo; Senpuku, Hidenobu

2011-01-01

Topical tetracyclines, such as minocycline ointment, are frequently used for the treatment of periodontal infection. We investigated the influence of minocycline ointment use on oral bacteria, using supragingival plaque samples from adults who had not taken any antibiotics for 6 months. Initially we investigated the effect of topical minocycline administration on the emergence of tetracycline-resistant oral bacteria in four healthy adults. The isolation frequency of tetracycline-resistant oral bacteria to total viable bacteria increased substantially on day 6 after treatment, although it returned to baseline on day 25. Subsequently we investigated the isolation frequency of tetracycline-resistant oral streptococci (TOS) as a representative oral bacterium, using samples from 41 subjects with periodontal diseases. The percentage of TOS (of the total oral streptococci) increased significantly (from 11.9±15.6% to 34.2±24.0%) after minocycline treatment. Various TOS species were identified; S. mitis, S. salivarius, S. sanguinis, and S. oralis were frequently isolated. PCR and Southern blotting allowed us to identify tetM on the Tn916-like elements as the gene responsible for tetracycline-resistance. These findings suggest that the potential risk of the spread of similar genetic elements through bacteria in the oral cavity should be considered.

Oral Streptococcal Endocarditis, Oral Hygiene Habits, and Recent Dental Procedures: A Case-Control Study.

PubMed

Duval, Xavier; Millot, Sarah; Chirouze, Catherine; Selton-Suty, Christine; Moby, Vanessa; Tattevin, Pierre; Strady, Christophe; Euvrard, Edouard; Agrinier, Nelly; Thomas, Daniel; Hoen, Bruno; Alla, François

2017-06-15

We aimed to compare oral hygiene habits, orodental status, and dental procedures in patients with infective endocarditis (IE) according to whether the IE-causing microorganism originated in the oral cavity. We conducted an assessor-blinded case-control study in 6 French tertiary-care hospitals. Oral hygiene habits were recorded using a self-administered questionnaire. Orodental status was analyzed by trained dental practitioners blinded to the microorganism, using standardized clinical examination and dental panoramic tomography. History of dental procedures was obtained through patient and dentist interviews. Microorganisms were categorized as oral streptococci or nonoral pathogens using an expert-validated list kept confidential during the course of the study. Cases and controls had definite IE caused either by oral streptococci or nonoral pathogens, respectively. Participants were enrolled between May 2008 and January 2013. Cases (n = 73) were more likely than controls (n = 192) to be aged <65 years (odds ratio [OR], 2.85; 95% CI, 1.41-5.76), to be female (OR, 2.62; 95% CI, 1.20-5.74), to have native valve disease (OR, 2.44; 95% CI, 1.16-5.13), to use toothpicks, dental water jet, interdental brush, and/or dental floss (OR, 3.48; 95% CI, 1.30-9.32), and to have had dental procedures during the prior 3 months (OR, 3.31; 95% CI, 1.18-9.29), whereas they were less likely to brush teeth after meals. The presence of gingival inflammation, calculus, and infectious dental diseases did not significantly differ between groups. Patients with IE caused by oral streptococci differ from patients with IE caused by nonoral pathogens regarding background characteristics, oral hygiene habits, and recent dental procedures, but not current orodental status. © 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

Acute meningitis of piglets and mice caused by co-infected with Streptococcus suis and Aerococcus viridans.

PubMed

Pan, Zihao; Ma, Ye; Ma, Jiale; Dong, Wenyang; Yao, Huochun

2017-05-01

The two opportunistic pathogens, Streptococcus suis (S. suis) and Aerococcus. viridans (A. viridans) were isolated from the brains of piglets suffered bacterial meningitis in a farm of China. The murine model has been established to evaluate the pathogenicity and symbiotic relationship of S. suis and A. viridans simultaneously infection. Our results demonstrated the ability of new serotype S. suis to cause the classical bacterial meningitis and death were greatly enhanced during co-infection with A. viridans in mice at a proportion. We also examined the distribution and titer of bacteria coinfection in organs, the titer of S. suis appeared a significant trend for an increase in the lung meanwhile the concentration titer of A. viridans maintain a low level. This is the first reported the A. viridans and S. suis coinfection cause the bacterial meningitis outbroke in the piglets and mice. Moreover, further investigation of the pathogenesis of A. viridans and S. suis is urgently needed in swine industry. Copyright © 2016 Elsevier Ltd. All rights reserved.

Trends in risk factors and etiology of 606 cases of infective endocarditis over 23 years (1984-2006) in slovakia.

PubMed

Hricak, V; Liska, B; Kovackova, J; Mikusova, J; Fischer, V; Kovacik, J; Karvaj, M; Jurco, R; Ondrusova, A; Kalavsky, E; Marks, P; Beno, P; Krcmery, V

2007-04-01

The aim of this study was to assess trends in risk factors, etiology, outcome and treatment strategies for endocarditis over 23 years in Slovakia. A prospective survey of 606 cases of infective endocarditis (IE) was conducted from 1984-2006. Rheumatic fever as well as previous dental surgery showed decreasing trends within the last 23 years. Also embolic complications of IE declined along with increasing rates of surgically treated patients. No significant changes in etiology were detected apart from the fact that culture-negative endocarditis increased from 10.7% to 55.4% between 1998-2001. Surgically treated patients increased from 22.7% (1984-1990) to 50.1% (2002-2006) and mortality dramatically decreased from 26.7% (1984-1990) to 5.3% (2002-2006). Staphylococcus aureus and coagulase-negative staphylococci were the leading causes (22.4% - 48%) followed by viridans streptococci (12.2%-18.2%) were a relatively stable trend over 23 years of IE in Slovakia.

Antimicrobial resistance surveillance of flomoxef in China.

PubMed

Cui, Lanqing; Li, Yun; Lv, Yuan; Xue, Feng; Liu, Jian

2015-05-01

The aim of this study was to investigate the susceptibility of flomoxef against clinical isolates collected from China and understand the trend of antimicrobial resistance. A total of 2955 pathogenic strains isolated from 18 tertiary hospitals in 18 cities of China over the period from July 2011 to June 2012 were studied. And the susceptibility tests were performed using agar dilution method recommended by CLSI in central laboratory. Flomoxef showed good potency against Enterobacteriaceae with susceptibility rate 85%-100%. The susceptibility rates of flomoxef against Staphylococcus spp. isolates were 63.9%-92.2%; 98.8% of MSSA and 88.2% of MSSE were susceptible to this drug. For other tested bacteria including Moraxella catarrhalis, Haemophilus spp., and Streptococcus spp. (except Viridans group streptococci) flomoxef showed good potency with susceptibility rate more than 95%. All these results strongly suggest that flomoxef is a potent antibacterial agent against major pathogens in China. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Multiple alcohol dehydrogenases but no functional acetaldehyde dehydrogenase causing excessive acetaldehyde production from ethanol by oral streptococci.

PubMed

Pavlova, Sylvia I; Jin, Ling; Gasparovich, Stephen R; Tao, Lin

2013-07-01

Ethanol consumption and poor oral hygiene are risk factors for oral and oesophageal cancers. Although oral streptococci have been found to produce excessive acetaldehyde from ethanol, little is known about the mechanism by which this carcinogen is produced. By screening 52 strains of diverse oral streptococcal species, we identified Streptococcus gordonii V2016 that produced the most acetaldehyde from ethanol. We then constructed gene deletion mutants in this strain and analysed them for alcohol and acetaldehyde dehydrogenases by zymograms. The results showed that S. gordonii V2016 expressed three primary alcohol dehydrogenases, AdhA, AdhB and AdhE, which all oxidize ethanol to acetaldehyde, but their preferred substrates were 1-propanol, 1-butanol and ethanol, respectively. Two additional dehydrogenases, S-AdhA and TdhA, were identified with specificities to the secondary alcohol 2-propanol and threonine, respectively, but not to ethanol. S. gordonii V2016 did not show a detectable acetaldehyde dehydrogenase even though its adhE gene encodes a putative bifunctional acetaldehyde/alcohol dehydrogenase. Mutants with adhE deletion showed greater tolerance to ethanol in comparison with the wild-type and mutant with adhA or adhB deletion, indicating that AdhE is the major alcohol dehydrogenase in S. gordonii. Analysis of 19 additional strains of S. gordonii, S. mitis, S. oralis, S. salivarius and S. sanguinis showed expressions of up to three alcohol dehydrogenases, but none showed detectable acetaldehyde dehydrogenase, except one strain that showed a novel ALDH. Therefore, expression of multiple alcohol dehydrogenases but no functional acetaldehyde dehydrogenase may contribute to excessive production of acetaldehyde from ethanol by certain oral streptococci.

Multiple alcohol dehydrogenases but no functional acetaldehyde dehydrogenase causing excessive acetaldehyde production from ethanol by oral streptococci

PubMed Central

Pavlova, Sylvia I.; Jin, Ling; Gasparovich, Stephen R.

2013-01-01

Ethanol consumption and poor oral hygiene are risk factors for oral and oesophageal cancers. Although oral streptococci have been found to produce excessive acetaldehyde from ethanol, little is known about the mechanism by which this carcinogen is produced. By screening 52 strains of diverse oral streptococcal species, we identified Streptococcus gordonii V2016 that produced the most acetaldehyde from ethanol. We then constructed gene deletion mutants in this strain and analysed them for alcohol and acetaldehyde dehydrogenases by zymograms. The results showed that S. gordonii V2016 expressed three primary alcohol dehydrogenases, AdhA, AdhB and AdhE, which all oxidize ethanol to acetaldehyde, but their preferred substrates were 1-propanol, 1-butanol and ethanol, respectively. Two additional dehydrogenases, S-AdhA and TdhA, were identified with specificities to the secondary alcohol 2-propanol and threonine, respectively, but not to ethanol. S. gordonii V2016 did not show a detectable acetaldehyde dehydrogenase even though its adhE gene encodes a putative bifunctional acetaldehyde/alcohol dehydrogenase. Mutants with adhE deletion showed greater tolerance to ethanol in comparison with the wild-type and mutant with adhA or adhB deletion, indicating that AdhE is the major alcohol dehydrogenase in S. gordonii. Analysis of 19 additional strains of S. gordonii, S. mitis, S. oralis, S. salivarius and S. sanguinis showed expressions of up to three alcohol dehydrogenases, but none showed detectable acetaldehyde dehydrogenase, except one strain that showed a novel ALDH. Therefore, expression of multiple alcohol dehydrogenases but no functional acetaldehyde dehydrogenase may contribute to excessive production of acetaldehyde from ethanol by certain oral streptococci. PMID:23637459

Oral sugar clearance and root caries prevalence in rheumatic patients with dry mouth symptoms.

PubMed

Risheim, H; Arneberg, P; Birkhed, D

1992-01-01

The relationship between root caries, oral sugar clearance, salivary flow rate, and salivary counts of mutans streptococci, lactobacilli and candida has been studied in a group of 22 rheumatic patients (age range 40-72 years). The study group comprised all subjects volunteering for a clinical trial on relief of dry mouth symptoms. The median salivary flow was 0.09 ml/min at rest and 0.9 ml/min during chewing stimulation. The median sugar clearance time was about 5 min in the sublingual area and 16 min in the lower buccal vestibule. For subjects with 0-2 root caries lesions the clearance time at both sites was shorter than for subjects with 3 or more lesions (p < 0.05). A long oral clearance time was significantly correlated with age, root caries (DS and DFS), low resting salivary flow, and high salivary counts of mutans streptococci. It is concluded that root caries in rheumatic patients with low salivary flow is significantly related to oral sugar clearance time.

Relation of Salivary PAF Periodontal Disease in Periodontal Maintenance and Refractory Periodontitis Patients

DTIC Science & Technology

1991-05-01

Knox, 1974). Studies have demonstrated the presence of streptococci and lactobacilli throughout the oral cavity , as well as in developing dental... oral cavity , it is apparent that these compounds have the potential to play a role in the initiation and progression of inflammatory oral disease...junctional epithelium and into the gingival sulcus and oral cavity . The perivascular connective tissue matrix becomes altered most likely by

Effect of removable orthodontic appliances on oral colonisation by mutans streptococci in children.

PubMed

Batoni, G; Pardini, M; Giannotti, A; Ota, F; Giuca, M R; Gabriele, M; Campa, M; Senesi, S

2001-12-01

Little is known about the effect of removable orthodontic appliances on oral colonisation by mutans streptococci (MS). In the present study, the frequency of isolation and serotype distribution of MS were evaluated in two groups of children, one undergoing therapy with removable appliances and the other not subjected to any kind of orthodontic treatment, respectively. Streptococci isolated from dental plaque samples from both groups of children were identified as mutans streptococci on the basis of their morphological and biochemical properties and were then serotyped in an enzyme immuno-assay using monoclonal antibodies. The number of subjects harbouring MS in their dental plaque was statistically higher in the group of orthodontic children without caries experience (CF) in comparison with CF children of the control group (10/12, 83.3% vs. 15/44, 34%). No clear difference was observed in the distribution of the different MS serotypes between the experimental and control group: S. mutans c,f serotype was the most frequently isolated in both groups of children followed by S. mutans serotype e and S. sobrinus serotype g. Such results suggest that the use of removable appliances may lead to the creation of new retentive areas and surfaces, which favour the local adherence and growth of MS. The data obtained stress the importance of a careful monitoring of patients treated orthodontically for risk of caries development.

Patients with community-acquired bacteremia of unknown origin: clinical characteristics and usefulness of microbiological results for therapeutic issues: a single-center cohort study.

PubMed

Courjon, Johan; Demonchy, Elisa; Degand, Nicolas; Risso, Karine; Ruimy, Raymond; Roger, Pierre-Marie

2017-05-19

Bacteremia of unknown origin (BUO) are associated with increased mortality compared to those with identified sources. Microbiological data of those patients could help to characterize an appropriate empirical antibiotic treatment before bloodcultures results are available during sepsis of unknown origin. Based on the dashboard of our ward that prospectively records several parameters from each hospitalization, we report 101 community-acquired BUO selected among 1989 bacteremic patients from July 2005 to April 2016, BUO being defined by the absence of clinical and paraclinical infectious focus and no other microbiological samples retrieving the bacteria isolated from blood cultures. The in-hospital mortality rate was 9%. We retrospectively tested two antibiotic associations: amoxicillin-clavulanic acid + gentamicin (AMC/GM) and 3rd generation cephalosporin + gentamicin (3GC/GM) considered as active if the causative bacteria was susceptible to at least one of the two drugs. The mean age was 71 years with 67% of male, 31 (31%) were immunocompromised and 52 (51%) had severe sepsis. Eleven patients had polymicrobial infections. The leading bacterial species involved were Escherichia coli 25/115 (22%), group D Streptococci 12/115 (10%), viridans Streptococci 12/115 (10%) and Staphylococcus aureus 11/115 (9%). AMC/GM displayed a higher rate of effectiveness compared to 3GC/GM: 100/101 (99%) vs 94/101 (93%) (p = 0.04): one Enterococcus faecium strain impaired the first association, Bacteroides spp. and Enterococcus spp. the second. In case of community-acquired sepsis of unknown origin, AMC + GM should be considered.

A genome-wide study of two-component signal transduction systems in eight newly sequenced mutans streptococci strains

PubMed Central

2012-01-01

Background Mutans streptococci are a group of gram-positive bacteria including the primary cariogenic dental pathogen Streptococcus mutans and closely related species. Two component systems (TCSs) composed of a signal sensing histidine kinase (HK) and a response regulator (RR) play key roles in pathogenicity, but have not been comparatively studied for these oral bacterial pathogens. Results HKs and RRs of 8 newly sequenced mutans streptococci strains, including S. sobrinus DSM20742, S. ratti DSM20564 and six S. mutans strains, were identified and compared to the TCSs of S. mutans UA159 and NN2025, two previously genome sequenced S. mutans strains. Ortholog analysis revealed 18 TCS clusters (HK-RR pairs), 2 orphan HKs and 2 orphan RRs, of which 8 TCS clusters were common to all 10 strains, 6 were absent in one or more strains, and the other 4 were exclusive to individual strains. Further classification of the predicted HKs and RRs revealed interesting aspects of their putative functions. While TCS complements were comparable within the six S. mutans strains, S. sobrinus DSM20742 lacked TCSs possibly involved in acid tolerance and fructan catabolism, and S. ratti DSM20564 possessed 3 unique TCSs but lacked the quorum-sensing related TCS (ComDE). Selected computational predictions were verified by PCR experiments. Conclusions Differences in the TCS repertoires of mutans streptococci strains, especially those of S. sobrinus and S. ratti in comparison to S. mutans, imply differences in their response mechanisms for survival in the dynamic oral environment. This genomic level study of TCSs should help in understanding the pathogenicity of these mutans streptococci strains. PMID:22475007

Plaque retention by self-ligating vs elastomeric orthodontic brackets: quantitative comparison of oral bacteria and detection with adenosine triphosphate-driven bioluminescence.

PubMed

Pellegrini, Peter; Sauerwein, Rebecca; Finlayson, Tyler; McLeod, Jennifer; Covell, David A; Maier, Tom; Machida, Curtis A

2009-04-01

Enamel decalcification is a common problem in orthodontics. The objectives of this randomized clinical study were to enumerate and compare plaque bacteria surrounding 2 bracket types, self-ligating (SL) vs elastomeric ligating (E), and to determine whether adenosine triphosphate (ATP)-driven bioluminescence could be used for rapid assessment of bacterial load in plaque. Patients (ages, 11-17 years) were bonded with SL and E brackets in 14 maxillary and 12 mandibular arches by using a split-mouth design. Recall visits were at 1 and 5 weeks after bonding. Plaque specimens were assayed for oral bacteria and subjected to ATP-driven bioluminescence determinations with a luciferin-based assay. In most patients, teeth bonded with SL attachments had fewer bacteria in plaque than did teeth bonded with E brackets. At 1 and 5 weeks after bonding, the means for SL vs E brackets were statistically lower for total bacteria and oral streptococci (P <0.05). ATP bioluminescence values were statistically correlated to the total oral bacteria and oral streptococci, with correlation coefficients of 0.895 and 0.843, respectively. SL appliances promote reduced retention of oral bacteria, and ATP bioluminescence might be a useful tool in the rapid quantification of bacterial load and the assessment of oral hygiene during orthodontic treatment.

Comparison of oral streptococci biofilm in caries-free and caries-affected preschool Mexican children.

PubMed

Martinez-Martinez, Rita E; Fujiwara, Taku; Patiño-Marin, Nuria; Hoshino, Tomonori; Wilson, Michael; Loyola-Rodríguez, Juan P

2012-01-01

Interaction of oral streptococci biofilm is the main etiological factor for dental caries. The aim of the study was to compare oral streptococci (OS) distribution in the biofilm of primary dentition from caries-free and caries-affected preschool Mexican children. This cross-sectional study involved 40 caries-free and 40 caries-affected children with primary dentition. Each child was examined using the dmfs index, DNA was extracted from saliva and presence of OS was determined by PCR. Data obtained showed no statistical difference regarding age and gender (P > 0.05). Streptococcus mutans (Smut), Streptococcus sobrinus (Ssob) and their combination showed significant statistical differences between groups (P < 0.05). Smut, Streptococcus sanguinis and Streptococcus gordonii had an inverse relation with dmfs index and Ssob had a direct relation similar to combined with Smut. Smut-Ssob combined with other OS showed statistical differences (P < 0.05). In free-caries group Streptococcus gordonii was more frequently identified than Smut. The ratio Smut/Streptococcus sanguinis could represent a high risk of dental caries development; this ratio was higher in the caries-affected (1.18) than in the caries-free group (0.32). In conclusion, OS play an important role in dental caries predisposition and severity, not only the presence of Smut and Srob, but also the complexity and distribution of OS in the biofilm.

The Actinomyces oris Type 2 Fimbrial Shaft FimA Mediates Coaggregation with Oral Streptococci, Adherence to RBC and Biofilm Development

PubMed Central

Mishra, Arunima; Wu, Chenggang; Yang, Jinghua; Cisar, John O.; Das, Asis; Ton-That, Hung

2010-01-01

Interbacterial interactions between oral streptococci and actinomyces and their adherence to tooth surface and the associated host cells are key early events that promote development of the complex oral biofilm referred to as dental plaque. These interactions depend largely on a lectin-like activity associated with the Actinomyces oris type 2 fimbria, a surface structure assembled by sortase (SrtC2)-dependent polymerization of the shaft and tip fimbrillins, FimA and FimB, respectively. To dissect the function of specific fimbrillins in various adherence processes, we have developed a convenient new technology for generating unmarked deletion mutants of A. oris. Here, we show that the fimB mutant, which produced type 2 fimbriae composed only of FimA, like the wild type coaggregated strongly with receptor-bearing streptococci, agglutinated with sialidase-treated RBC, and formed monospecies biofilm. In contrast, the fimA and srtC2 mutants lacked type 2 fimbriae and were non-adherent in each of these assays. Plasmidbased expression of the deleted gene in respective mutants restored adherence to wild-type levels. These findings uncover the importance of the lectin-like activity of the polymeric FimA shaft rather than the tip. The multivalent adhesive function of FimA makes it an ideal molecule for exploring novel intervention strategies to control plaque biofilm formation. PMID:20545853

Relationship between the ability of oral streptococci to interact with platelet glycoprotein Ibalpha and with the salivary low-molecular-weight mucin, MG2.

PubMed

Plummer, Christopher; Douglas, Charles William Ian

2006-12-01

The oral streptococci Streptococcus sanguinis, Streptococcus gordonii and Streptococcus oralis are common aetiological agents of infective endocarditis, and their ability to adhere to and induce the aggregation of platelets is thought to be a virulence trait. The platelet glycoprotein GPIbalpha has been implicated as the adhesion receptor for S. sanguinis and S. gordonii, but it is not known if this is the case for S. oralis and other species. The aim of this study was to determine the GPIbalpha-interactive capability of a range of oral streptococci and to determine the relationship between this capability and their ability to interact with the salivary constituents that they would encounter in their normal habitat. All platelet-adhesive S. sanguinis strains and most S. gordonii strains adhered in a GPIbalpha-dependent manner, but strains of S. oralis, Streptococcus cristatus, Streptococcus parasanguinis and Streptococcus mitis had no direct affinity for platelets. Those strains that were able to bind GPIbalpha also bound to the low-molecular-weight submandibular salivary mucin, MG2, and this interaction was sialic acid-dependent. The data suggest that S. sanguinis and S. gordonii may be efficient colonizers of platelet vegetations because of their adaptation to recognize sialylated salivary mucins. In contrast, S. oralis does not interact with platelets and so is likely to colonize vegetations through an as yet unidentified mechanism.

Hydrogen Peroxide Contributes to the Epithelial Cell Death Induced by the Oral Mitis Group of Streptococci

PubMed Central

Okahashi, Nobuo; Sumitomo, Tomoko; Nakata, Masanobu; Sakurai, Atsuo; Kuwata, Hirotaka; Kawabata, Shigetada

2014-01-01

Members of the mitis group of streptococci are normal inhabitants of the commensal flora of the oral cavity and upper respiratory tract of humans. Some mitis group species, such as Streptococcus oralis and Streptococcus sanguinis, are primary colonizers of the human oral cavity. Recently, we found that hydrogen peroxide (H2O2) produced by S. oralis is cytotoxic to human macrophages, suggesting that streptococcus-derived H2O2 may act as a cytotoxin. Since epithelial cells provide a physical barrier against pathogenic microbes, we investigated their susceptibility to infection by H2O2-producing streptococci in this study. Infection by S. oralis and S. sanguinis was found to stimulate cell death of Detroit 562, Calu-3 and HeLa epithelial cell lines at a multiplicity of infection greater than 100. Catalase, an enzyme that catalyzes the decomposition of H2O2, inhibited S. oralis cytotoxicity, and H2O2 alone was capable of eliciting epithelial cell death. Moreover, S. oralis mutants lacking the spxB gene encoding pyruvate oxidase, which are deficient in H2O2 production, exhibited reduced cytotoxicity toward Detroit 562 epithelial cells. In addition, enzyme-linked immunosorbent assays revealed that both S. oralis and H2O2 induced interleukin-6 production in Detroit 562 epithelial cells. These results suggest that streptococcal H2O2 is cytotoxic to epithelial cells, and promotes bacterial evasion of the host defense systems in the oral cavity and upper respiratory tracts. PMID:24498253

StreptoBase: An Oral Streptococcus mitis Group Genomic Resource and Analysis Platform.

PubMed

Zheng, Wenning; Tan, Tze King; Paterson, Ian C; Mutha, Naresh V R; Siow, Cheuk Chuen; Tan, Shi Yang; Old, Lesley A; Jakubovics, Nicholas S; Choo, Siew Woh

2016-01-01

The oral streptococci are spherical Gram-positive bacteria categorized under the phylum Firmicutes which are among the most common causative agents of bacterial infective endocarditis (IE) and are also important agents in septicaemia in neutropenic patients. The Streptococcus mitis group is comprised of 13 species including some of the most common human oral colonizers such as S. mitis, S. oralis, S. sanguinis and S. gordonii as well as species such as S. tigurinus, S. oligofermentans and S. australis that have only recently been classified and are poorly understood at present. We present StreptoBase, which provides a specialized free resource focusing on the genomic analyses of oral species from the mitis group. It currently hosts 104 S. mitis group genomes including 27 novel mitis group strains that we sequenced using the high throughput Illumina HiSeq technology platform, and provides a comprehensive set of genome sequences for analyses, particularly comparative analyses and visualization of both cross-species and cross-strain characteristics of S. mitis group bacteria. StreptoBase incorporates sophisticated in-house designed bioinformatics web tools such as Pairwise Genome Comparison (PGC) tool and Pathogenomic Profiling Tool (PathoProT), which facilitate comparative pathogenomics analysis of Streptococcus strains. Examples are provided to demonstrate how StreptoBase can be employed to compare genome structure of different S. mitis group bacteria and putative virulence genes profile across multiple streptococcal strains. In conclusion, StreptoBase offers access to a range of streptococci genomic resources as well as analysis tools and will be an invaluable platform to accelerate research in streptococci. Database URL: http://streptococcus.um.edu.my.

Effect of fermented milk containing Lactobacillus rhamnosus SD11 on oral microbiota of healthy volunteers: A randomized clinical trial.

PubMed

Rungsri, P; Akkarachaneeyakorn, N; Wongsuwanlert, M; Piwat, S; Nantarakchaikul, P; Teanpaisan, R

2017-10-01

The aims of this study were to evaluate whether short-term consumption of fermented milk containing Lactobacillus rhamnosus SD11 affected levels of oral microbiota in vivo and whether L. rhamnosus SD11 could colonize in the human mouth. We also monitored for potential side effects of the probiotic. The applicability of using L. rhamnosus SD11 compared with Lactobacillus bulgaricus as a starter culture for fermented milk was evaluated. After informed consent, 43 healthy young adults were recruited and randomly assigned to either the probiotic or control group and received fermented milk containing L. rhamnosus SD11 or L. bulgaricus, respectively, once daily for 4 wk. The numbers of mutans streptococci, lactobacilli, and total bacteria in saliva were counted at baseline and then after 4 and 8 wk. An oral examination was performed at baseline and after 8 wk. The persistence of L. rhamnosus SD11 was investigated by DNA fingerprinting using arbitrary primer-PCR. Results demonstrated that statistically significant reductions in mutans streptococci and total bacteria were observed in the probiotic group compared with the control group, and the number of lactobacilli was significantly increased in both groups after receiving fermented milks. Lactobacillus rhamnosus SD11 could be detected (in >80% of subjects) up to 4 wk following cessation of dosing among subjects in the probiotic group. No side effects were reported. Thus, L. rhamnosus SD11 could be used as a starter culture for fermented milk. Daily consumption of L. rhamnosus SD11-containing fermented milk for 4 wk may have beneficial effects on oral health by reducing salivary levels of mutans streptococci. The probiotic was apparently able to colonize the oral cavity for a longer time than previously reported. However, the potential benefits of probiotic L. rhamnosus SD11 on oral health require further evaluation with a larger group of volunteers in a longer-term study. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Influence of type of prosthesis on oral environment and the number of missing teeth in elderly persons.

PubMed

Tanaka, Junko; Tanaka, Masahiro

2010-01-01

The purpose of this study was to investigate the relationship between the number of missing teeth (MT) and the statuses of oral environmental factors (the stimulated salivary flow rate, buffering capacity, and the counts of mutans streptococci, lactobacilli, and Candida) in the elderly. The subjects were 64 elderly subjects with fixed prostheses and 49 who wore removable partial dentures aged over 65 years. We used one-way ANOVA to test for overall differences of the number of MT among 5 oral environmental factors. The significant differences were observed in the lactobacilli counts for different number of MT. The number of MT increased with an increase in the lactobacilli counts with removable denture. In conclusion, for the patients wearing removable dentures, increasing number of MT was associated with an increase in the lactobacilli counts in saliva. For the patients with crowns and fixed partial dentures, the number of MT was not significantly affected by salivary mutans streptococci, lactobacilli, and Candida counts.

[Study of bacterial flora in the oral cavity and stomach of elderly patients receiving nasogastric tube feeding].

PubMed

Matsuura, T; Suzuki, K; Yamakoshi, M; Yamamoto, T; Yamamoto, T; Yoshitomo, K; Tonegawa, K; Ariga, K; Odawara, F

1997-05-01

To investigate the significance of oropharyngeal flora and gastric flora in elderly patients receiving nasogastric tube feeding, throat secretions and gastric aspirates were cultured and the pH of the latter was measured. Of 116 bacterial isolates from throat secretions of 27 elderly patients, 30 were beta-streptococci and 28 were Pseudomonas aeruginosa. Bacteria isolated from gastric aspirates numbered 86 and 24 (27.9%) of them were the same species as those found in the throat secretions. Patients with gastric pH were below 3.5 had significantly lower concentrations of gram-negative bacili in gastric aspirates. We also studied oropharyngeal flora in 33 elderly patients who were admitted to Nagoyashi Koseiin Geriatric Hospital. The major bacterial isolates from throat swabs of bedridden patients were gram-negative bacilli and beta-streptococci, especially group B streptococci (GBS). We measured the level of antibody to GBS in these patients. Those from whom GBS were isolated had high titers. These results suggest that in elderly patients receiving enteral nasogastric) tube feeding, large numbers of bacteria colonize the oral cavity and stomach. The measurement of type-specific antibody to GBS may be useful in managing such patients.

Recolonization of mutans Streptococci after application of chlorhexidine gel.

PubMed

Vale, Glauber Campos; Cury, Altair Antoninha Del Bel; Arthur, Rodrigo Alex; Cury, Jaime Aparecido; Tabchoury, Cínthia Pereira Machado

2014-01-01

Streptococcus mutans is specifically suppressed by intensive treatment with chlorhexidine gel, but the time for recolonization and the effect on other oral bacteria are not totally clear. In this study, recolonization of mutans streptococci was evaluated in nine healthy adult volunteers, who were highly colonized with this microorganism. Stimulated saliva was collected before (baseline) and at 1, 7, 14, 21 and 28 days after application of 1% chlorhexidine gel on volunteers' teeth for two consecutive days. On each day, the gel was applied using disposable trays for 3 x 5 min with intervals of 5 min between each application. Saliva was plated on blood agar to determine total microorganisms (TM); on mitis salivarius agar to determine total streptococci (TS) and on mitis salivarius agar plus bacitracin to determine mutans streptococci (MS). Chlorhexidine was capable of reducing the counts of MS and the proportion of MS with regard to total microorganisms (%MS/TM) (p<0.05), but these values did not differ statistically from baseline (p>0.05) after 14 days for MS and 21 days for %MS/TM. The counts of TM and TS and the proportion of MS to total streptococci did not differ statistically from baseline (p>0.05) after chlorhexidine treatment. The results suggest that the effect of chlorhexidine gel treatment on suppression of mutans streptococci is limited to less than a month in highly colonized individuals.

Adherence of oral streptococci: evidence for nonspecific adsorption to saliva-coated hydroxylapatite surfaces.

PubMed Central

Staat, R H; Peyton, J C

1984-01-01

It is proposed that binding of oral streptococci to saliva-coated hydroxylapatite (SHA) surfaces is a multifactorial process involving both specific and nonspecific receptors. In this context, specific binding is described as a high-affinity, saturable interaction between the cell and binding surface. Conversely, nonspecific binding is considered to be a nonsaturable, generalized, low-affinity reaction. Experimental differentiation of specific binding from nonspecific binding was achieved with a competition assay which utilized a large excess of nonradiolabeled bacteria to compete with the 3H-labeled cells for attachment to receptors on 1.5 mg of SHA crystals. Competition assays of Streptococcus sanguis and Streptococcus mitis adhesion clearly demonstrated that the total binding isotherm was composed of a saturable specific binding reaction and a minor nonspecific binding component. This was further substantiated by analysis of nonlinear Scatchard plots of the total binding data. The competition data for Streptococcus mutans binding indicated that ca. 50% of the S. mutans binding appeared to be specific, although saturation of the SHA surfaces with bacterial cells could not be demonstrated. Experiments measuring desorption of radiolabeled cells from SHA crystals into buffer showed that ca. 50% of the bound S. mutans cells were removed after 4 h, whereas less than 5% of the S. sanguis cells were eluted from the SHA surfaces. The kinetics of attachment were studied by using an extract of Persea americana as a noncompetitive inhibitor of adherence. The total cell binding data for these experiments suggested a very rapid binding reaction followed by a slower rate of attachment. It was concluded from these three different experimental approaches that adherence of selected oral streptococci to SHA surfaces involves specific, high-affinity and nonspecific, low-affinity binding reactions. The concept is developed that in vitro streptococcal attachment to SHA can be described as a two-reaction process in which the low-affinity interaction of the cell with the SHA surface precedes the establishment of the stronger, specific bonds needed for the maintenance of streptococci in the oral cavity. PMID:6327530

Prophylaxis for infective endocarditis. Who needs it? How effective is it?

PubMed Central

Press, N.; Montessori, V.

2000-01-01

OBJECTIVE: To review guidelines for using antibiotic prophylaxis to prevent infective endocarditis, and to present recent changes and controversies regarding these guidelines. QUALITY OF EVIDENCE: Data are from physiologic and in vitro studies, as well as studies of animal models, and from retrospective analyses of human endocarditis cases. Systematic reviews and guidelines are also examined. As no randomized clinical trials have examined prophylaxis for bacterial endocarditis, many recommendations presented are based on consensus guidelines. MAIN MESSAGE: Antibiotic prophylaxis to prevent bacterial endocarditis should be used in high- and moderate-risk patients with cardiac disease. It should be given before procedures in which bacteremias are likely with organisms that cause endocarditis, such as viridans streptococci. For most procedures, a single dose of amoxicillin (2 g by mouth 1 hour before the procedure) is sufficient to ensure adequate serum levels before and after the procedure. CONCLUSION: Infective endocarditis continues to have high rates of morbidity and mortality. Antibiotic prophylaxis, therefore, is important to combat this preventable disease. For high- and moderate-risk patients with cardiac disease, the cost-benefit ratio favours prophylaxis. PMID:11143584

Prophylaxis for infective endocarditis. Who needs it? How effective is it?

PubMed

Press, N; Montessori, V

2000-11-01

To review guidelines for using antibiotic prophylaxis to prevent infective endocarditis, and to present recent changes and controversies regarding these guidelines. Data are from physiologic and in vitro studies, as well as studies of animal models, and from retrospective analyses of human endocarditis cases. Systematic reviews and guidelines are also examined. As no randomized clinical trials have examined prophylaxis for bacterial endocarditis, many recommendations presented are based on consensus guidelines. Antibiotic prophylaxis to prevent bacterial endocarditis should be used in high- and moderate-risk patients with cardiac disease. It should be given before procedures in which bacteremias are likely with organisms that cause endocarditis, such as viridans streptococci. For most procedures, a single dose of amoxicillin (2 g by mouth 1 hour before the procedure) is sufficient to ensure adequate serum levels before and after the procedure. Infective endocarditis continues to have high rates of morbidity and mortality. Antibiotic prophylaxis, therefore, is important to combat this preventable disease. For high- and moderate-risk patients with cardiac disease, the cost-benefit ratio favours prophylaxis.

Clinical Significance and Characterization of Streptococcus tigurinus Isolates in an Adult Population.

PubMed

Bourassa, Lori; Clarridge, J E

2015-11-01

Streptococcus tigurinus is a newly described member of the Streptococcus mitis group. Due to the difficulty in distinguishing viridans group streptococci (VGS) by phenotype, analysis of 16S rRNA sequences is necessary for the accurate identification of most species. Through a laboratory policy of analyzing all clinically significant isolates from the VGS group by16S rRNA gene sequencing, we identified 14 S. tigurinus isolates from 11 patients. The Vitek 2 system most commonly gave an excellent rating to an incorrect identification (e.g., Streptococcus mitis), as did matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) (e.g., Streptococcus oralis). S. tigurinus strains were recovered from numerous body sites, including the blood, peritoneal fluid, bone, synovial fluid, a perianal abscess, and an arm wound. Retrospective chart review indicated that most isolates were clinically significant, with bacteremia (n = 5), soft tissue infections (n = 3) osteomyelitis (n = 2), infected joint prosthesis (n = 2), and peritonitis (n = 2) being the most common, thus expanding the spectrum of disease associated with S. tigurinus. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Antimicrobial effects of herbal extracts on Streptococcus mutans and normal oral streptococci.

PubMed

Lee, Sung-Hoon

2013-08-01

Streptococcus mutans is associated with dental caries. A cariogenic biofilm, in particular, has been studied extensively for its role in the formation of dental caries. Herbal extracts such as Cudrania tricuspidata, Sophora flavescens, Ginkgo biloba, and Betula Schmidtii have been used as a folk remedy for treating diseases. The purpose of this study was to evaluate and compare the antibacterial activity of herbal extracts against normal oral streptococci, planktonic and biofilm of S. mutans. Streptococcus gordonii, Streptococcus oralis, Streptococcus salivarius, Streptococcus sanguinis, and S. mutans were cultivated with brain heart infusion broth and susceptibility assay for the herbal extracts was performed according to the protocol of Clinical and Laboratory Standard Institute. Also, S. mutans biofilm was formed on a polystyrene 12-well plate and 8-well chamber glass slip using BHI broth containing 2% sucrose and 1% mannose after conditioning the plate and the glass slip with unstimulated saliva. The biofilm was treated with the herbal extracts in various concentrations and inoculated on Mitis-Salivarius bacitracin agar plate for enumeration of viable S. mutans by counting colony forming units. Planktonic S. mutans showed susceptibility to all of the extracts and S. mutans biofilm exhibited the highest level of sensitivity for the extracts of S. flavescens. The normal oral streptococci exhibited a weak susceptibility in comparison to S. mutans. S. oralis, however, was resistant to all of the extracts. In conclusion, the extract of S. flavescens may be a potential candidate for prevention and management of dental caries.

Role of aqueous extract of morinda citrifolia (Indian noni) ripe fruits in inhibiting dental caries-causing streptococcus mutans and streptococcus mitis.

PubMed

Kumarasamy, Barani; Manipal, Sunayana; Duraisamy, Prabu; Ahmed, Adil; Mohanaganesh, Sp; Jeevika, C

2014-11-01

Use of alternative medicine to control oral streptococci is a new topic worthy of further investigation. This study aimed to elucidate the dose-dependent anti-bacterial activity of crude aqueous extract of ripe Morinda citrifolia L. (Family: Rubiaceae) fruits against oral streptococci i.e. Streptococcus mutans and Streptococcus mitis, that cause dental caries in humans. Fresh ripe M. citrifolia fruits (750g) were ground in an electronic blender with sterile water (500ml). The crude aqueous extract was lyophilized to yield a brown colored powder. Various concentrations (1000-100μg/ ml) of the extract were tested for its antibacterial activity (Kirby and Bauer method) against whole cells of S. mutans and S. mitis. Minimum Inhibitory Concentration (MIC) was determined by micro-dilution method, using serially diluted (2 folds) fruit extract, according to the National Committee for Clinical Laboratory Standards (NCCLS). Crude aqueous extract (1000μg/ ml) of ripe M. citrifolia fruits effectively inhibited the growth of S. mutans (19±0.5 mm) and S. mitis (18.6±0.3 mm) compared to the streptomycin control (21.6±0.3 mm). The growth inhibition was clearly evident with "nil" bacteriostasis, even after 48 hours of incubation at 37°C. The MIC of the extract for S. mutans and S. mitis was 125 μg and 62.5 μg, respectively. Our results suggest that phytochemicals naturally synthesized by M. citrifolia have an inhibitory effect on oral streptococci. Furthermore, purification and molecular characterization of the "bioactive principle" would enable us to formulate a sustainable oral hygiene product.

Role of Aqueous Extract of Morinda Citrifolia (Indian Noni) Ripe Fruits in Inhibiting Dental Caries-Causing Streptococcus Mutans and Streptococcus Mitis

PubMed Central

Kumarasamy, Barani; Manipal, Sunayana; Duraisamy, Prabu; Ahmed, Adil; Mohanaganesh, SP; Jeevika, C

2014-01-01

Objectives: Use of alternative medicine to control oral streptococci is a new topic worthy of further investigation. This study aimed to elucidate the dose-dependent anti-bacterial activity of crude aqueous extract of ripe Morinda citrifolia L. (Family: Rubiaceae) fruits against oral streptococci i.e. Streptococcus mutans and Streptococcus mitis, that cause dental caries in humans. Methods: Fresh ripe M. citrifolia fruits (750g) were ground in an electronic blender with sterile water (500ml). The crude aqueous extract was lyophilized to yield a brown colored powder. Various concentrations (1000-100μg/ ml) of the extract were tested for its antibacterial activity (Kirby and Bauer method) against whole cells of S. mutans and S. mitis. Minimum Inhibitory Concentration (MIC) was determined by micro-dilution method, using serially diluted (2 folds) fruit extract, according to the National Committee for Clinical Laboratory Standards (NCCLS). Results: Crude aqueous extract (1000μg/ ml) of ripe M. citrifolia fruits effectively inhibited the growth of S. mutans (19±0.5 mm) and S. mitis (18.6±0.3 mm) compared to the streptomycin control (21.6±0.3 mm). The growth inhibition was clearly evident with “nil” bacteriostasis, even after 48 hours of incubation at 37°C. The MIC of the extract for S. mutans and S. mitis was 125 μg and 62.5 μg, respectively. Conclusion: Our results suggest that phytochemicals naturally synthesized by M. citrifolia have an inhibitory effect on oral streptococci. Furthermore, purification and molecular characterization of the “bioactive principle” would enable us to formulate a sustainable oral hygiene product. PMID:25628701

Evaluation of an Automated System for Reading and Interpreting Disk Diffusion Antimicrobial Susceptibility Testing of Fastidious Bacteria.

PubMed

Idelevich, Evgeny A; Becker, Karsten; Schmitz, Janne; Knaack, Dennis; Peters, Georg; Köck, Robin

2016-01-01

Results of disk diffusion antimicrobial susceptibility testing depend on individual visual reading of inhibition zone diameters. Therefore, automated reading using camera systems might represent a useful tool for standardization. In this study, the ADAGIO automated system (Bio-Rad) was evaluated for reading disk diffusion tests of fastidious bacteria. 144 clinical isolates (68 β-haemolytic streptococci, 28 Streptococcus pneumoniae, 18 viridans group streptococci, 13 Haemophilus influenzae, 7 Moraxella catarrhalis, and 10 Campylobacter jejuni) were tested on Mueller-Hinton agar supplemented with 5% defibrinated horse blood and 20 mg/L β-NAD (MH-F, Oxoid) according to EUCAST. Plates were read manually with a ruler and automatically using the ADAGIO system. Inhibition zone diameters, indicated by the automated system, were visually controlled and adjusted, if necessary. Among 1548 isolate-antibiotic combinations, comparison of automated vs. manual reading yielded categorical agreement (CA) without visual adjustment of the automatically determined zone diameters in 81.4%. In 20% (309 of 1548) of tests it was deemed necessary to adjust the automatically determined zone diameter after visual control. After adjustment, CA was 94.8%; very major errors (false susceptible interpretation), major errors (false resistant interpretation) and minor errors (false categorization involving intermediate result), calculated according to the ISO 20776-2 guideline, accounted to 13.7% (13 of 95 resistant results), 3.3% (47 of 1424 susceptible results) and 1.4% (21 of 1548 total results), respectively, compared to manual reading. The ADAGIO system allowed for automated reading of disk diffusion testing in fastidious bacteria and, after visual validation of the automated results, yielded good categorical agreement with manual reading.

Infective Endocarditis: Identification of Catalase-Negative, Gram-Positive Cocci from Blood Cultures by Partial 16S rRNA Gene Analysis and by Vitek 2 Examination.

PubMed

Abdul-Redha, Rawaa Jalil; Kemp, Michael; Bangsborg, Jette M; Arpi, Magnus; Christensen, Jens Jørgen

2010-01-01

Streptococci, enterococci and Streptococcus-like bacteria are frequent etiologic agents of infective endocarditis and correct species identification can be a laboratory challenge. Viridans streptococci (VS) not seldomly cause contamination of blood cultures. Vitek 2 and partial sequencing of the 16S rRNA gene were applied in order to compare the results of both methods. STRAINS ORIGINATED FROM TWO GROUPS OF PATIENTS: 149 strains from patients with infective endocarditis and 181 strains assessed as blood culture contaminants. Of the 330 strains, based on partial 16S rRNA gene sequencing results, 251 (76%) were VS strains, 10 (3%) were pyogenic streptococcal strains, 54 (16%) were E. faecalis strains and 15 (5%) strains belonged to a group of miscellaneous catalase-negative, Gram-positive cocci. Among VS strains, respectively, 220 (87,6%) and 31 (12,3%) obtained agreeing and non-agreeing identifications with the two methods with respect to allocation to the same VS group. Non-agreeing species identification mostly occurred among strains in the contaminant group, while for endocarditis strains notably fewer disagreeing results were observed.Only 67 of 150 strains in the mitis group strains obtained identical species identifications by the two methods. Most VS strains belonging to the groups of salivarius, anginosus, and mutans obtained agreeing species identifications with the two methods, while this only was the case for 13 of the 21 bovis strains. Pyogenic strains (n=10), Enterococcus faecalis strains (n=54) and a miscellaneous group of catalase-negative, Gram-positive cocci (n=15) seemed well identified by both methods, except that disagreements in identifications in the miscellaneous group of strains occurred for 6 of 15 strains.

High-Throughput Identification of Bacteria and Yeast by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry in Conventional Medical Microbiology Laboratories ▿

PubMed Central

van Veen, S. Q.; Claas, E. C. J.; Kuijper, Ed J.

2010-01-01

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) is suitable for high-throughput and rapid diagnostics at low costs and can be considered an alternative for conventional biochemical and molecular identification systems in a conventional microbiological laboratory. First, we evaluated MALDI-TOF MS using 327 clinical isolates previously cultured from patient materials and identified by conventional techniques (Vitek-II, API, and biochemical tests). Discrepancies were analyzed by molecular analysis of the 16S genes. Of 327 isolates, 95.1% were identified correctly to genus level, and 85.6% were identified to species level by MALDI-TOF MS. Second, we performed a prospective validation study, including 980 clinical isolates of bacteria and yeasts. Overall performance of MALDI-TOF MS was significantly better than conventional biochemical systems for correct species identification (92.2% and 83.1%, respectively) and produced fewer incorrect genus identifications (0.1% and 1.6%, respectively). Correct species identification by MALDI-TOF MS was observed in 97.7% of Enterobacteriaceae, 92% of nonfermentative Gram-negative bacteria, 94.3% of staphylococci, 84.8% of streptococci, 84% of a miscellaneous group (mainly Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella [HACEK]), and 85.2% of yeasts. MALDI-TOF MS had significantly better performance than conventional methods for species identification of staphylococci and genus identification of bacteria belonging to HACEK group. Misidentifications by MALDI-TOF MS were clearly associated with an absence of sufficient spectra from suitable reference strains in the MALDI-TOF MS database. We conclude that MALDI-TOF MS can be implemented easily for routine identification of bacteria (except for pneumococci and viridans streptococci) and yeasts in a medical microbiological laboratory. PMID:20053859

High-throughput identification of bacteria and yeast by matrix-assisted laser desorption ionization-time of flight mass spectrometry in conventional medical microbiology laboratories.

PubMed

van Veen, S Q; Claas, E C J; Kuijper, Ed J

2010-03-01

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) is suitable for high-throughput and rapid diagnostics at low costs and can be considered an alternative for conventional biochemical and molecular identification systems in a conventional microbiological laboratory. First, we evaluated MALDI-TOF MS using 327 clinical isolates previously cultured from patient materials and identified by conventional techniques (Vitek-II, API, and biochemical tests). Discrepancies were analyzed by molecular analysis of the 16S genes. Of 327 isolates, 95.1% were identified correctly to genus level, and 85.6% were identified to species level by MALDI-TOF MS. Second, we performed a prospective validation study, including 980 clinical isolates of bacteria and yeasts. Overall performance of MALDI-TOF MS was significantly better than conventional biochemical systems for correct species identification (92.2% and 83.1%, respectively) and produced fewer incorrect genus identifications (0.1% and 1.6%, respectively). Correct species identification by MALDI-TOF MS was observed in 97.7% of Enterobacteriaceae, 92% of nonfermentative Gram-negative bacteria, 94.3% of staphylococci, 84.8% of streptococci, 84% of a miscellaneous group (mainly Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella [HACEK]), and 85.2% of yeasts. MALDI-TOF MS had significantly better performance than conventional methods for species identification of staphylococci and genus identification of bacteria belonging to HACEK group. Misidentifications by MALDI-TOF MS were clearly associated with an absence of sufficient spectra from suitable reference strains in the MALDI-TOF MS database. We conclude that MALDI-TOF MS can be implemented easily for routine identification of bacteria (except for pneumococci and viridans streptococci) and yeasts in a medical microbiological laboratory.

Amoxicillin-resistant oral streptococci identified in dental plaque specimens from healthy Japanese adults.

PubMed

Masuda, Katsuhiko; Nemoto, Hirotoshi; Nakano, Kazuhiko; Naka, Shuhei; Nomura, Ryota; Ooshima, Takashi

2012-05-01

Infective endocarditis (IE) is known to be a life-threatening disease and invasive dental procedures are considered to be important factors. Oral amoxicillin (AMPC) is widely used for prophylaxis in patients with heart disorders who are at risk for IE. However, there is only limited information regarding the inhibition of oral bacteria by AMPC. Dental plaque specimens were obtained from 120 healthy Japanese adult subjects, then diluted and streaked onto selective medium for oral streptococci. The minimum inhibitory concentration (MIC) of AMPC was evaluated using a macro-dilution method by Clinical Laboratory Standard Institute (2006). Seven strains with an MIC of AMPC of 16μg/mL or more were isolated from 5 subjects. The bacterial species were confirmed by sequence analysis of 16S rRNA from each strain, which demonstrated that most were Streptococcus sanguinis, followed by Streptococcus oralis. Dental plaque specimens collected from these 5 subjects again after an interval of 2-3 months possessed no strains with an MIC of AMPC of 16μg/mL or more. These findings suggest that strains with a high MIC of AMPC are present in the oral cavities of Japanese adults, though they may be transient rather than inhabitants. Copyright © 2012 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

[The microbiological aspects of orthodontic treatment of children with dental maxillary anomalies].

PubMed

Chesnokov, V A; Chesnokova, M G; Leontiev, V K; Mironov, A Yu; Lomiashvili, L M; Kriga, A S

2015-03-01

The issues of pre-nosologic diagnostic and effectiveness of treatment of diseases of oral cavity is an actual issue in dentistry. The long- duration orthodontic treatment of patients with dentoalveolar anomalies using non-removable devices is followed by such negative consequences as development demineralization of enamel and caries registered during treatment and after remove ofdevices. The level of quantitative content of oral streptococci was analyzed and dental status in children with dentoalveolar anomalies was evaluated during treatment with non-removable devices was evaluated. The caries and inflammation of periodontium of oral cavity were most often detected in children with high level of content of streptococci. In different periods of study the firm tendency of increasing of concentration of Streptococcus mutans and S. sanguis of dental plaque of oral cavity is established. The established index indicators of dental status of patients testify intensity of caries damage, level of poor hygiene of oral cavity, development of average degree of severity of inflammation process of periodontium. The obtained results substantiate involvement ofstreptococci, associates of microbiota of dental plaque of oral cavity in children, in process of development of caries. The characteristics of micro-ecology of dental plaque to evaluate cariesgenic situation that can be used as a basis for constructing diagnostic algorithm under monitoring of patients with dentoalveolar anomalies with purpose of forthcoming planning and implementation of effective orthodontic treatment.

Rapid Succession within the Veillonella Population of a Developing Human Oral Biofilm In Situ

PubMed Central

Palmer, Robert J.; Diaz, Patricia I.; Kolenbrander, Paul E.

2006-01-01

Streptococci are the primary component of the multispecies oral biofilm known as supragingival dental plaque; they grow by fermentation of sugars to organic acids, e.g., lactic acid. Veillonellae, a ubiquitous component of early plaque, are unable to use sugars; they ferment organic acids, such as lactate, to a mixture of shorter-chain-length acids, CO2, and hydrogen. Certain veillonellae bind to (coaggregate with) streptococci in vitro. We show that, between 4 and 8 hours into plaque development, the dominant strains of Veillonella change in their phenotypic characteristics (coaggregation and antibody reactivity) as well as in their genotypic characteristics (16S RNA gene sequences as well as strain level fingerprint patterns). This succession is coordinated with the development of mixed-species bacterial colonies. Changes in community structure can occur very rapidly in natural biofilm development, and we suggest that this process may influence evolution within this ecosystem. PMID:16707703

Susceptibility to Dental Caries and the Salivary Proline-Rich Proteins

PubMed Central

Levine, Martin

2011-01-01

Early childhood caries affects 28% of children aged 2–6 in the US and is not decreasing. There is a well-recognized need to identify susceptible children at birth. Caries-free adults neutralize bacterial acids in dental biofilms better than adults with severe caries. Saliva contains acidic and basic proline-rich proteins (PRPs) which attach to oral streptococci. The PRPs are encoded within a small region of chromosome 12. An acidic PRP allele (Db) protects Caucasian children from caries but is more common in African Americans. Some basic PRP allelic phenotypes have a three-fold greater frequency in caries-free adults than in those with severe caries. Early childhood caries may associate with an absence of certain basic PRP alleles which bind oral streptococci, neutralize biofilm acids, and are in linkage disequilibrium with Db in Caucasians. The encoding of basic PRP alleles is updated and a new technology for genotyping them is described. PMID:22190937

Effects of Actinobolin on Growth and Some Metabolic Activities of Cariogenic Streptococci In Vitro and In Vivo

PubMed Central

Keele, Bernard B.; Powell, Hubert L.; Navia, Juan M.; McGhee, Jerry

1971-01-01

Actinobolin, a known inhibitor of protein synthesis, has been shown not to interfere selectively with acid production or dextransucrase activity in a cariogenic streptococcus when the antibiotic is added to a concentration of 500 μg/ml. It has also been shown that actinobolin does not alter the total in vivo flora of the oral cavity of the rat when tested in a rat caries model system. A culture of cariogenic streptococci, adapted to in vitro growth in the presence of 1 mg of actinobolin per ml, has also been isolated. PMID:4944810

The Collagen Binding Proteins of Streptococcus mutans and Related Streptococci

PubMed Central

Avilés-Reyes, Alejandro; Miller, James H.; Lemos, José A.; Abranches, Jacqueline

2016-01-01

Summary The ability of Streptococcus mutans to interact with collagen through the expression of collagen-binding proteins (CBPs) bestows this oral pathogen with an alternative to the sucrose-dependent mechanism of colonization classically attributed to caries development. Based on the abundance and distribution of collagen throughout the human body, stringent adherence to this molecule grants S. mutans with the opportunity to establish infection at different host sites. Surface proteins, such as SpaP, WapA, Cnm and Cbm, have been shown to bind collagen in vitro, and it has been suggested that these molecules play a role in colonization of oral and extra-oral tissues. However, robust collagen binding is not achieved by all strains of S. mutans, particularly those that lack Cnm or Cbm. These observations merit careful dissection of the contribution from these different CBPs towards tissue colonization and virulence. In this review, we will discuss the current understanding of mechanisms utilized by S. mutans and related streptococci to colonize collagenous tissues, and the possible contribution of CBPs to infections in different sites of the host. PMID:26991416

Lancefield group G Streptococcus dysgalactiae subsp. equisimilis: an unusual aetiology of perianal streptococcal dermatitis acquired from heterosexual oral-anal intercourse.

PubMed

Abdolrasouli, A; Hemmati, Y; Amin, A; Roushan, A; Butler, I

2012-12-01

Perianal streptococcal dermatitis (PSD) is an uncommon superficial cutaneous infection of the perianal area, almost exclusively described in children and mainly caused by group A streptococci. We report here a case of PSD caused by Streptococcus dysgalactiae subsp. equisimilis, Lancefield group G, in an adult man due to heterosexual oral-anal sexual contact.

Cariogenicity of a lactate dehydrogenase-deficient mutant of Streptococcus mutans serotype c in gnotobiotic rats.

PubMed

Fitzgerald, R J; Adams, B O; Sandham, H J; Abhyankar, S

1989-03-01

A lactate dehydrogenase-deficient (Ldh-) mutant of a human isolate of Streptococcus mutans serotype c was tested in a gnotobiotic rat caries model. Compared with the wild-type Ldh-positive (Ldh+) strains, it was significantly (alpha less than or equal to 0.005) less cariogenic in experiments with two different sublines of Sprague-Dawley rats. The Ldh- mutant strain 044 colonized the oral cavity of the test animals to the same extent as its parent strain 041, although its initial implantation was slightly but not significantly (P greater than or equal to 0.2) less. Multiple oral or fecal samples plated on 2,3,5-triphenyltetrazolium indicator medium revealed no evidence of back mutation from Ldh- to Ldh+ in vivo. Both Ldh+ strain 041 and Ldh- strain 044 demonstrated bacteriocinlike activity in vitro against a number of human strains of mutans streptococci representing serotype a (S. cricetus) and serotypes c and e (S. mutans). Serotypes b (S. rattus) and f (S. mutans) and strains of S. mitior, S. sanguis, and S. salivarius were not inhibited. Thus, Ldh mutant strain 044 possesses a number of desirable traits that suggest it should be investigated further as a possible effector strain for replacement therapy of dental caries. These traits include its stability and low cariogenicity in the sensitive gnotobiotic rat caries model, its bacteriocinlike activity against certain other cariogenic S. mutans (but not against more inocuous indigenous oral streptococci), and the fact that it is a member of the most prevalent human serotype of cariogenic streptococci.

The pathogenic persona of community associated oral streptococci

PubMed Central

Whitmore, Sarah E.; Lamont, Richard J.

2011-01-01

Summary The mitis group streptococci (MGS) are widespread in the oral cavity and are traditionally associated with oral health. However, these organisms have many attributes that contribute to the development of pathogenic oral communities. MGS adhere rapidly to saliva-coated tooth surfaces, thereby providing an attachment substratum for more overtly pathogenic organisms such as Porphyromonas gingivalis, and the two species assemble into heterotypic communities. Close physical association facilitates physiologic support, and pathogens such as Actinobacillus actinomycetemcomitans display resource partitioning to favour carbon sources generated by streptococcal metabolism. MGS exchange information with community members through a number of interspecies signaling systems including AI-2 and contact dependent mechanisms. Signal transduction systems induced in P. gingivalis are based on protein dephosphorylation mediated by the tyrosine phosphatase Ltp1, and converge on a LuxR-family transcriptional regulator, CdhR. Phenotypic responses in P. gingivalis include regulation of hemin uptake systems and gingipain activity, processes that are intimately linked to the virulence of the organism. Furthermore, communities of S. gordonii with P. gingivalis or with A. actinomycetemcomitans are more pathogenic in animal models than the constituent species alone. We propose that MGS should be considered accessory pathogens, organisms whose pathogenic potential only becomes evident in the context of a heterotypic microbial community. PMID:21635580

The pathogenic persona of community-associated oral streptococci.

PubMed

Whitmore, Sarah E; Lamont, Richard J

2011-07-01

The mitis group streptococci (MGS) are widespread in the oral cavity and are traditionally associated with oral health. However, these organisms have many attributes that contribute to the development of pathogenic oral communities. MGS adhere rapidly to saliva-coated tooth surfaces, thereby providing an attachment substratum for more overtly pathogenic organisms such as Porphyromonas gingivalis, and the two species assemble into heterotypic communities. Close physical association facilitates physiologic support, and pathogens such as Aggregatibacter actinomycetemcomitans display resource partitioning to favour carbon sources generated by streptococcal metabolism. MGS exchange information with community members through a number of interspecies signalling systems including AI-2 and contact dependent mechanisms. Signal transduction systems induced in P. gingivalis are based on protein dephosphorylation mediated by the tyrosine phosphatase Ltp1, and converge on a LuxR-family transcriptional regulator, CdhR. Phenotypic responses in P. gingivalis include regulation of hemin uptake systems and gingipain activity, processes that are intimately linked to the virulence of the organism. Furthermore, communities of S. gordonii with P. gingivalis or with A. actinomycetemcomitans are more pathogenic in animal models than the constituent species alone. We propose that MGS should be considered accessory pathogens, organisms whose pathogenic potential only becomes evident in the context of a heterotypic microbial community. © 2011 Blackwell Publishing Ltd.

Comparison of 'time to detection' values between BacT/ALERT VIRTUO and BacT/ALERT 3D instruments for clinical blood culture samples.

PubMed

Congestrì, Francesco; Pedna, Maria Federica; Fantini, Michela; Samuelli, Michela; Schiavone, Pasqua; Torri, Arianna; Bertini, Stefania; Sambri, Vittorio

2017-09-01

The early detection of bacteraemia and fungemia is of paramount importance to guide antimicrobial therapy in septic patients. In this study the 'time to detection' (TTD) value for the new blood culture system BacT/ALERT VIRTUO (VIRTUO) was evaluated in 1462 positive clinical bottles and compared with the TTD for 1601 positive clinical bottles incubated in the BacT/ALERT 3D system (BTA-3D). The most representative microorganisms isolated from bottles incubated in both blood culture systems were divided into eight categories (in order of frequency): coagulase-negative staphylococci (CoNS), Escherichia coli, Enterobacteriaceae (other than E. coli), Staphylococcus aureus, Enterococcus spp, viridans group streptococci, Pseudomonas aeruginosa, and Candida spp. The comparison of TTD values for the two blood culture systems strongly indicated that growth of the first five groups listed above was detected earlier with VIRTUO than with BTA-3D (p < 0.05). The new VIRTUO blood culture system can reduce the TTD for more than 75% of isolated microorganisms. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Complete genome sequence of Streptococcus mutans GS-5, a serotype c strain.

PubMed

Biswas, Saswati; Biswas, Indranil

2012-09-01

Streptococcus mutans, a principal causative agent of dental caries, is considered to be the most cariogenic among all oral streptococci. Of the four S. mutans serotypes (c, e, f, and k), serotype c strains predominate in the oral cavity. Here, we present the complete genome sequence of S. mutans GS-5, a serotype c strain originally isolated from human carious lesions, which is extensively used as a laboratory strain worldwide.

Collagen-binding proteins of Streptococcus mutans and related streptococci.

PubMed

Avilés-Reyes, A; Miller, J H; Lemos, J A; Abranches, J

2017-04-01

The ability of Streptococcus mutans to interact with collagen through the expression of collagen-binding proteins (CBPs) bestows this oral pathogen with an alternative to the sucrose-dependent mechanism of colonization classically attributed to caries development. Based on the abundance and distribution of collagen throughout the human body, stringent adherence to this molecule grants S. mutans with the opportunity to establish infection at different host sites. Surface proteins, such as SpaP, WapA, Cnm and Cbm, have been shown to bind collagen in vitro, and it has been suggested that these molecules play a role in colonization of oral and extra-oral tissues. However, robust collagen binding is not achieved by all strains of S. mutans, particularly those that lack Cnm or Cbm. These observations merit careful dissection of the contribution from these different CBPs towards tissue colonization and virulence. In this review, we will discuss the current understanding of mechanisms used by S. mutans and related streptococci to colonize collagenous tissues, and the possible contribution of CBPs to infections in different sites of the host. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Development of resistance of mutans streptococci and Porphyromonas gingivalis to chlorhexidine digluconate and amine fluoride/stannous fluoride-containing mouthrinses, in vitro.

PubMed

Kulik, Eva M; Waltimo, Tuomas; Weiger, Roland; Schweizer, Irene; Lenkeit, Krystyna; Filipuzzi-Jenny, Elisabeth; Walter, Clemens

2015-07-01

The aim if this study was to determine the minimal inhibitory concentrations of chlorhexidine digluconate and an amine fluoride/stannous fluoride-containing mouthrinse against Porphyromonas gingivalis and mutans streptococci during an experimental long-term subinhibitory exposition. Five P. gingivalis strains and four mutans streptococci were subcultivated for 20-30 passages in subinhibitory concentrations of chlorhexidine digluconate or an amine fluoride/stannous fluoride-containing mouthrinse. Pre-passaging minimal inhibitory concentrations for chlorhexidine ranged from 0.5 to 2 mg/l for mutans streptococci and from 2 to 4 mg/l for the P. gingivalis isolates. For the amine fluoride/stannous fluoride-containing mouthrinse minimal inhibitory values from 0.125 to 0.25% for the mutans streptococci and from 0.063 to 0.125% for the P. gingivalis isolates were determined. Two- to fourfold increased minimal inhibitory concentrations against chlorhexidine were detected for two of the five P. gingivalis isolates, whereas no increase in minimal inhibitory concentrations was found for the mutans streptococci after repeated passaging through subinhibitory concentrations. Repeated exposure to subinhibitory concentrations of the amine fluoride/stannous fluoride-containing mouthrinse did not alter the minimally inhibitory concentrations of the bacterial isolates tested. Chlorhexidine and the amine fluoride/stannous fluoride-containing mouthrinse are effective inhibitory agents against the oral bacterial isolates tested. No general development of resistance against chlorhexidine or the amine fluoride/stannous fluoride-containing mouthrinse was detected. However, some strains showed potential to develop resistance against chlorhexidine after prolonged exposure. The use of chlorhexidine should be limited to short periods of time. The amine fluoride/stannous fluoride-containing mouthrinse appears to have the potential to be used on a long-term basis.

A distinct sortase SrtB anchors and processes a streptococcal adhesin AbpA with a novel structural property

PubMed Central

Liang, Xiaobo; Liu, Bing; Zhu, Fan; Scannapieco, Frank A.; Haase, Elaine M.; Matthews, Steve; Wu, Hui

2016-01-01

Surface display of proteins by sortases in Gram-positive bacteria is crucial for bacterial fitness and virulence. We found a unique gene locus encoding an amylase-binding adhesin AbpA and a sortase B in oral streptococci. AbpA possesses a new distinct C-terminal cell wall sorting signal. We demonstrated that this C-terminal motif is required for anchoring AbpA to cell wall. In vitro and in vivo studies revealed that SrtB has dual functions, anchoring AbpA to the cell wall and processing AbpA into a ladder profile. Solution structure of AbpA determined by NMR reveals a novel structure comprising a small globular α/β domain and an extended coiled-coil heliacal domain. Structural and biochemical studies identified key residues that are crucial for amylase binding. Taken together, our studies document a unique sortase/adhesion substrate system in streptococci adapted to the oral environment rich in salivary amylase. PMID:27492581

Novel Twin Streptolysin S-Like Peptides Encoded in the sag Operon Homologue of Beta-Hemolytic Streptococcus anginosus

PubMed Central

Tabata, Atsushi; Nakano, Kota; Ohkura, Kazuto; Tomoyasu, Toshifumi; Kikuchi, Ken; Whiley, Robert A.

2013-01-01

Streptococcus anginosus is a member of the anginosus group streptococci, which form part of the normal human oral flora. In contrast to the pyogenic group streptococci, our knowledge of the virulence factors of the anginosus group streptococci, including S. anginosus, is not sufficient to allow a clear understanding of the basis of their pathogenicity. Generally, hemolysins are thought to be important virulence factors in streptococcal infections. In the present study, a sag operon homologue was shown to be responsible for beta-hemolysis in S. anginosus strains by random gene knockout. Interestingly, contrary to pyogenic group streptococci, beta-hemolytic S. anginosus was shown to have two tandem sagA homologues, encoding streptolysin S (SLS)-like peptides, in the sag operon homologue. Gene deletion and complementation experiments revealed that both genes were functional, and these SLS-like peptides were essential for beta-hemolysis in beta-hemolytic S. anginosus. Furthermore, the amino acid sequence of these SLS-like peptides differed from that of the typical SLS of S. pyogenes, especially in their propeptide domain, and an amino acid residue indicated to be important for the cytolytic activity of SLS in S. pyogenes was deleted in both S. anginosus homologues. These data suggest that SLS-like peptides encoded by two sagA homologues in beta-hemolytic S. anginosus may be potential virulence factors with a different structure essential for hemolytic activity and/or the maturation process compared to the typical SLS present in pyogenic group streptococci. PMID:23292771

The Antibacterial Effect of Ethanol Extract of Polish Propolis on Mutans Streptococci and Lactobacilli Isolated from Saliva

PubMed Central

Dziedzic, Arkadiusz; Kubina, Robert; Wojtyczka, Robert D.; Kabała-Dzik, Agata; Tanasiewicz, Marta; Morawiec, Tadeusz

2013-01-01

Dental caries occurrence is caused by the colonization of oral microorganisms and accumulation of extracellular polysaccharides synthesized by Streptococcus mutans with the synergistic influence of Lactobacillus spp. bacteria. The aim of this study was to determine ex vivo the antibacterial properties of ethanol extract of propolis (EEP), collected in Poland, against the main cariogenic bacteria: salivary mutans streptococci and lactobacilli. The isolation of mutans streptococci group bacteria (MS) and Lactobacillus spp. (LB) from stimulated saliva was performed by in-office CRT bacteria dip slide test. The broth diffusion method and AlamarBlue assay were used to evaluate the antimicrobial activity of EEP, with the estimation of its minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The biochemical composition of propolis components was assessed. The mean MIC and MBC values of EEP, in concentrations ranging from 25 mg/mL to 0.025 mg/mL, for the MS and LB were found to be 1.10 mg/mL versus 0.7 mg/mL and 9.01 mg/mL versus 5.91 mg/mL, respectively. The exposure to an extract of Polish propolis affected mutans streptococci and Lactobacillus spp. viability, exhibiting an antibacterial efficacy on mutans streptococci group bacteria and lactobacilli saliva residents, while lactobacilli were more susceptible to EEP. Antibacterial measures containing propolis could be the local agents acting against cariogenic bacteria. PMID:23606887

Endodontic cellulitis 'flare-up'. Case report.

PubMed

Matusow, R J

1995-02-01

Endodontic cellulitis involves facial swelling which can vary from mild to severe and can occur as a primary case or a flare-up following initial treatment of asymptomatic teeth with periapical lesions. The microbial spectrum in primary cases involves a significant mixture of anaerobic and facultative aerobic microbes, chiefly streptococci. In a previous study, cultures from flare-up cases, utilizing the same anaerobic techniques as in primary cases, revealed an absence of obligate anaerobes and an 80 per cent incidence of facultative aerobic streptococci. These cases also revealed a significant time lapse from onset of symptoms to the cellulitis phase. No sex or age factors were noted in the primary or flare-up cases. The purpose of this case report is to restate a traditional theory, namely, the alteration of the oxidation/reduction potential (Eh), as a major factor for endodontic cellulitis flare-ups; to confirm the pathogenic potential of oral facultative streptococci; and that asymptomatic endodontic lesions tend to exist with mixed aerobic/anaerobic microbial flora.

Antimicrobial effect of sophoraflavanone G isolated from Sophora flavescens against mutans streptococci.

PubMed

Kim, Chun Sung; Park, Soon-Nang; Ahn, Sug-Joon; Seo, Young-Woo; Lee, Young-Ju; Lim, Yun Kyong; Freire, Marcelo Oliveira; Cho, Eugene; Kook, Joong-Ki

2013-02-01

In this study, the antibacterial properties of sophoraflavanone G isolated from the methanol extract of Sophora flavescens were tested against 16 strains of mutans streptococci to screen and determine the optimal concentration of anti-caries natural extract. The antimicrobial activity was evaluated by measuring minimum bactericidal concentration (MBC). The cell viability of normal human gingival fibroblast (NHGF) cells was tested using the methyl thiazolyl tetrazolium assay after exposure to sophoraflavanone G. The data showed that sophoraflavanone G had a remarkable antimicrobial effect on the bacteria tested with an MBC ranging from 0.5 μg/ml to 4 μg/ml. Sophoraflavanone G had no cytotoxic effect on NHGF cells at concentrations where it produced an antimicrobial effect. These findings demonstrate that sophoraflavanone G has strong antimicrobial activity against mutans streptococci and could be useful in the development of novel oral hygiene products, such as a gargle solution or dentifrice. Copyright © 2012 Elsevier Ltd. All rights reserved.

Mucosal microflora in head and neck cancer patients.

PubMed

Almståhl, A; Finizia, C; Carlén, A; Fagerberg-Mohlin, B; Alstad, T

2018-05-15

To analyse the tongue and buccal microflora prospectively in head and neck cancer patients treated with radiation therapy (RT). In 33 dentate patients, microbial samples from the tongue and buccal mucosa were collected pretreatment, during treatment, and 6 months, 1 year and 2 years post-treatment. Microorganisms associated with oral health and oral disorders were analysed using cultivation technique. Oral mucositis was scored at the appointment during treatment. Compared with pretreatment, lactobacilli and Candida increased on the tongue, while streptococci and Neisseria decreased during treatment. Two years post-treatment, Neisseria and Prevotella were decreased and Candida increased. On the buccal mucosa, an increased growth of lactobacilli and increased detection frequencies of the opportunistic bacteria Staphylococcus aureus, Gram-negative enteric rods and enterococci were seen during treatment compared with pretreatment. Seventy per cent showed severe mucositis during treatment. Two years post-treatment the total count as well as streptococci, Neisseria and Fusobacterium nucleatum were decreased and lactobacilli increased compared with pretreatment. Despite improvements in treatment for cancer in the head and neck region, microorganisms associated with oral health decrease during treatment and mucosal pathogens increase. Two years post-treatment, levels of acid-tolerant (lactobacilli and Candida) were increased, while acid-sensitive microorganisms (Neisseria and F. nucleatum) were decreased, plausibly due to persisting decreased salivary secretion rate. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

In vitro antibacterial activity of ceftobiprole against clinical isolates from French teaching hospitals: proposition of zone diameter breakpoints.

PubMed

Lascols, C; Legrand, P; Mérens, A; Leclercq, R; Muller-Serieys, C; Drugeon, H B; Kitzis, M D; Reverdy, M E; Roussel-Delvallez, M; Moubareck, C; Brémont, S; Miara, A; Gjoklaj, M; Soussy, C-J

2011-03-01

The aims of this study were to determine the in vitro activity profile of ceftobiprole, a pyrrolidinone cephalosporin, against a large number of bacterial pathogens and to propose zone diameter breakpoints for clinical categorisation according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) minimum inhibitory concentration (MIC) breakpoints. MICs of ceftobiprole were determined by broth microdilution against 1548 clinical isolates collected in eight French hospitals. Disk diffusion testing was performed using 30 μg disks according to the method of the Comité de l'Antibiogramme de la Société Française de Microbiologie (CA-SFM). The in vitro activity of ceftobiprole, expressed by MIC(50/90) (MICs for 50% and 90% of the organisms, respectively) (mg/L), was as follows: meticillin-susceptible Staphylococcus aureus, 0.25/0.5; meticillin-resistant S. aureus (MRSA), 1/2; meticillin-susceptible coagulase-negative staphylococci (CoNS), 0.12/0.5; meticillin-resistant CoNS, 1/2; penicillin-susceptible Streptococcus pneumoniae, ≤ 0.008/0.03; penicillin-resistant S. pneumoniae, 0.12/0.5; viridans group streptococci, 0.03/0.12; β-haemolytic streptococci, ≤ 0.008/0.016; Enterococcus faecalis, 0.25/1; Enterococcus faecium, 64/128; Enterobacteriaceae, 0.06/32; Pseudomonas aeruginosa, 4/16; Acinetobacter baumannii, 0.5/64; Haemophilus influenzae, 0.03/0.12; and Moraxella catarrhalis, 0.25/0.5. According to the regression curve, zone diameter breakpoints could be 28, 26, 24 and 22 mm for MICs of 0.5, 1, 2 and 4 mg/L respectively. In conclusion, this study confirms the potent in vitro activity of ceftobiprole against many Gram-positive bacteria, including MRSA but not E. faecium, whilst maintaining a Gram-negative spectrum similar to the advanced-generation cephalosporins such as cefepime. Thus ceftobiprole appears to be well suited for the empirical treatment of a variety of healthcare-associated infections. Copyright © 2011 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Characteristics of Aerococcus viridans isolated from bovine subclinical mastitis and its effect on milk SCC, yield, and composition.

PubMed

Sun, Meng; Gao, Jian; Ali, Tariq; Yu, Dan; Zhang, Shiyao; Khan, Saeed U; Fanning, Séamus; Han, Bo

2017-04-01

Aerococcus viridians (A. viridans), an environmental Gram-positive bacterium, has been documented to be associated with bovine mastitis. However, its exact role in bovine mastitis and the changes it brings about in milk characteristics are not yet known. The objectives of the current study were to describe the antibiotic resistance of A. viridans from bovine mastitis as well as the correlation between existence of this pathogen in udders and the somatic cell counts (SCC), daily milk yield, and composition of individual cow. One-year sampling for subclinical mastitis composite milk was conducted based on monthly DHI data from September 2013 to August 2014, in a commercial herd located in Beijing, China. All samples were cultured and pathogens were identified using microbiology method. A. viridians isolates were further identified by API identification system and 16S ribosomal RNA (rRNA) sequencing method. Kirby-Bauer disk diffusion method was used to test the antibiotic resistance of A. viridians against kinds of antimicrobial substance. SCC, milk yield, and milk composition data were from monthly Dairy Herd Improvement (DHI) results. Results showed that a total of 279 (16.67%) A. viridans isolates were identified from among 1674 bacterial isolates cultured from milk samples with high SCC. The incidence of mastitis caused by A. viridans was the highest (48-53%) during the summer season. Majority of the isolates were susceptible to most of antimicrobial compounds tested, especially to β-lactams, but were found to be resistant (50-90%) to aminoglycosides, sulfonamides, and tetracycline. The average SCC of the A. viridans infected cows was significantly higher (1000.0 × 10 3  cells/mL) (P < 0.01) as compared to healthy cows (72.4 × 10 3  cells/mL) and daily milk yield decreased (P > 0.05) by 1.86 kg/day. Reductions were also observed in fat content (P > 0.05), lactose (P < 0.01), and total solids (P > 0.05), whereas protein content increased significantly (P < 0.01) in milk samples of cows infected with A. viridans. The results of this study suggest that A. viridans could be considered as an emerging aetiological agent of bovine subclinical mastitis wherein it exerts an effect on SCC, milk yield, and composition.

Fungal-bacterial interactions and their relevance to oral health: linking the clinic and the bench

PubMed Central

Diaz, Patricia I.; Strausbaugh, Linda D.; Dongari-Bagtzoglou, Anna

2014-01-01

High throughput sequencing has accelerated knowledge on the oral microbiome. While the bacterial component of oral communities has been extensively characterized, the role of the fungal microbiota in the oral cavity is largely unknown. Interactions among fungi and bacteria are likely to influence oral health as exemplified by the synergistic relationship between Candida albicans and oral streptococci. In this perspective, we discuss the current state of the field of fungal-bacterial interactions in the context of the oral cavity. We highlight the need to conduct longitudinal clinical studies to simultaneously characterize the bacterial and fungal components of the human oral microbiome in health and during disease progression. Such studies need to be coupled with investigations using disease-relevant models to mechanistically test the associations observed in humans and eventually identify fungal-bacterial interactions that could serve as preventive or therapeutic targets for oral diseases. PMID:25120959

Fungal-bacterial interactions and their relevance to oral health: linking the clinic and the bench.

PubMed

Diaz, Patricia I; Strausbaugh, Linda D; Dongari-Bagtzoglou, Anna

2014-01-01

High throughput sequencing has accelerated knowledge on the oral microbiome. While the bacterial component of oral communities has been extensively characterized, the role of the fungal microbiota in the oral cavity is largely unknown. Interactions among fungi and bacteria are likely to influence oral health as exemplified by the synergistic relationship between Candida albicans and oral streptococci. In this perspective, we discuss the current state of the field of fungal-bacterial interactions in the context of the oral cavity. We highlight the need to conduct longitudinal clinical studies to simultaneously characterize the bacterial and fungal components of the human oral microbiome in health and during disease progression. Such studies need to be coupled with investigations using disease-relevant models to mechanistically test the associations observed in humans and eventually identify fungal-bacterial interactions that could serve as preventive or therapeutic targets for oral diseases.

Fueling the caries process: carbohydrate metabolism and gene regulation by Streptococcus mutans

PubMed Central

Moye, Zachary D.; Zeng, Lin; Burne, Robert A.

2014-01-01

The nature of the oral cavity and host behaviors has mandated that the oral microbiota evolve mechanisms for coping with environmental fluctuations, especially changes in the type and availability of carbohydrates. In the case of human dental caries, the presence of excess carbohydrates is often responsible for altering the local environment to be more favorable for species associated with the initiation and progression of disease, including Streptococcus mutans. Some of the earliest endeavors to understand how cariogenic species respond to environmental perturbations were carried out using chemostat cultivation, which provides fine control over culture conditions and bacterial behaviors. The development of genome-scale methodologies has allowed for the combination of sophisticated cultivation technologies with genome-level analysis to more thoroughly probe how bacterial pathogens respond to environmental stimuli. Recent investigations in S. mutans and other closely related streptococci have begun to reveal that carbohydrate metabolism can drastically impact pathogenic potential and highlight the important influence that nutrient acquisition has on the success of pathogens; inside and outside of the oral cavity. Collectively, research into pathogenic streptococci, which have evolved in close association with the human host, has begun to unveil the essential nature of careful orchestration of carbohydrate acquisition and catabolism to allow the organisms to persist and, when conditions allow, initiate or worsen disease. PMID:25317251

Toxic Shock Syndrome within 24 H of an Office Hysteroscopy.

PubMed

Bhagat, Nanak; Karthikeyan, Akilandeshwari; Kalkur, Sanjaya

2017-01-01

Office hysteroscopy is now a common procedure performed to look at the endometrial cavity and is relatively free of serious complications. A 68-year-old lady, previously fit and well, presented with abdominal pain, rigors, sweats, and vomiting within 24 h of an outpatient hysteroscopy for postmenopausal bleeding. She was diagnosed with streptococcal toxic shock syndrome (STSS) due to Group A beta-hemolytic streptococci. She was managed in the Intensive Care Unit, with inotropic and antibiotic support. She recovered eventually and was discharged home with oral antibiotics. Toxic shock syndrome due to Streptococci is an unusual occurrence, whose incidence has been slowly increasing over the years. However, this appears to be the first case of STSS manifesting within 24 h following an outpatient hysteroscopy.

Characterization of growth inhibition of oral bacteria by sophorolipid using a microplate-format assay.

PubMed

Solaiman, Daniel K Y; Ashby, Richard D; Uknalis, Joseph

2017-05-01

Sophorolipid (SL) is a class of glycolipid biosurfactant produced by yeast and has potent antimicrobial activity against many microorganisms. In this paper, a microplate-based method was developed to characterize the growth inhibition by SL on five representative species of caries-causing oral bacteria. Bacterial growth on microplate in the absence and presence of varying concentrations of SL was continuously monitored by recording the absorbance at 600nm of the cultures using a microplate reader. The results showed that SL completely inhibited the growth of the Lactobacilli at ≥1mg/ml and the Streptococci at much lower concentrations of ≥50μg/ml. More importantly, we further defined the mechanism of antimicrobial activity of SL by analyzing the pattern of the cell growth curves. SL at sublethal concentrations (<1mg/ml) is bactericidal towards the Lactobacilli; it lengthens the apparent cell-doubling time (T d ) and decreases the final cell density (as indicated by A 600nm ) in a concentration-dependent manner. Against the oral Streptococci, on the other hand, SL at sublethal concentrations (<50μg/ml) is bacteriostatic; it delays the onset of cell growth in a concentration-dependent fashion, but once the cell growth is commenced there is no noticeable adverse effect on T d and the final A 600nm . Scanning electron microscopic (SEM) study of L. acidophilus grown in sublethal concentration of SL reveals extensive structural damage to the cells. S. mutans grown in sublethal level of SL did not show morphological damage to the cells, but numerous protruding structures could be seen on the cell surface. At the respective lethal levels of SL, L. acidophilus cells were lysed (at 1mg/ml SL) and the cell surface structure of S. mutans (at 130μg/ml SL) was extensively deformed. In summary, this paper presents the first report on a detailed analysis of the effects of SL on Lactobacilli and Streptococci important to oral health and hygiene. Published by Elsevier B.V.

In vitro activity and human pharmacokinetics of teicoplanin.

PubMed Central

Verbist, L; Tjandramaga, B; Hendrickx, B; Van Hecken, A; Van Melle, P; Verbesselt, R; Verhaegen, J; De Schepper, P J

1984-01-01

The in vitro activity of teicoplanin, a new antibiotic related to vancomycin, was determined against 456 gram-positive cocci. The activity of teicoplanin in comparison with that of vancomycin was similar against staphylococci but 4 to 40 times higher against enterococci and beta-hemolytic and viridans streptococci. The single-dose pharmacokinetics of teicoplanin were studied in six healthy volunteers after administration of 3 and 6 mg/kg intravenously and of 3 mg/kg intramuscularly. The kinetic parameters after both intravenous doses were very similar. The curves for concentration in plasma for the 3- and 6-mg/kg intravenous doses showed a triexponential decline with elimination half-lives of 47.3 and 44.1 h, respectively. The percentages of the doses recovered in urine (0 to 102 h) were 43.2 and 44.1%, respectively. The areas under the plasma curves were dose related: 256.5 and 520.9 micrograms/h per ml, respectively. The bioavailability of teicoplanin after injection of 3 mg/kg intramuscularly was 90%, and the peak level was 7.1 micrograms/ml. The mean levels in plasma 24 h after the 3-mg/kg doses were 2.1 and 2.3 micrograms/ml, respectively, and the mean level in plasma 24 h after the 6-mg/kg intravenous dose was 4.2 micrograms/ml. PMID:6240962

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%).

Fasting hypochlorhydria with gram positive gastric flora is highly prevalent in healthy old people.

PubMed Central

Husebye, E; Skar, V; Høverstad, T; Melby, K

1992-01-01

Fifteen healthy old people mean age 84 years (range 80-91 years), were examined to assess the effect of advanced age on the microecology of the upper gastrointestinal tract. Twelve of 15 (80%) were hypochlorhydric with pH 6.6 (0.3) (mean (SEM) and a mean bacterial count of 10(8) colony forming units (CFU) per ml (range 10(5)-10(10)) in fasting gastric aspirate. Normochlorhydric subjects had low counts (< or = 10(1) CFU/ml). The microbial flora was dominated by viridans streptococci, coagulase negative staphylococci, and Haemophilus sp. Only one subject harboured significant concentrations of Gram negative bacilli with Escherichia coli (10(4-5) CFU/ml) and Klebsiella (10(4-5)). Strict anaerobes were not found. The total concentration of short chain fatty acids in gastric aspirate was 10.6 (2.9) mmol/l (mean (SEM). Absence of significant, intraluminal fermentation of xylose to CO2 was shown by the 14C-d Xylose breath test, and ambulatory manometry showed preserved fasting motility pattern of the small intestine. Serum immunoglobulins were normal. Advanced age is accompanied by fasting hypochlorhydria and colonisation with mainly Gram positive flora in the upper gut. Other factors than old age and fasting hypochlorhydria are required for colonisation with Gram negative bacilli. PMID:1446855

Endocarditis associated with vertebral osteomyelitis and septic arthritis of the axial skeleton.

PubMed

Murillo, Oscar; Grau, Imma; Gomez-Junyent, Joan; Cabrera, Celina; Ribera, Alba; Tubau, Fe; Peña, Carmen; Ariza, Javier; Pallares, Roman

2018-04-01

The relationship between infective endocarditis (IE) and osteoarticular infections (OAIs) are not well known. We aimed to study the characteristics of patients with IE and OAIs, and the interactions between these two infections. An observational study (1993-2014) which includes two cohorts: (1) patients with IE (n = 607) and (2) patients with bacteremic OAIs (n = 458; septic arthritis of peripheral and axial skeleton, and vertebral and peripheral osteomyelitis). These two cohorts were prospectively collected, and we retrospectively reviewed the clinical and microbiological variables. There were 70 cases of IE with concomitant OAIs, representing 11.5% of IE cases and 15% of bacteremic OAI cases. Among cases with IE, the associated OAIs mainly involved the axial skeleton (n = 54, 77%): 43 were vertebral osteomyelitis (61%), mainly caused by "less virulent" bacteria (viridans and bovis streptococci, enterococci, and coagulase-negative staphylococci), and 15 were septic arthritis of the axial skeleton (21%), which were mainly caused by Staphylococcus aureus. OAIs with involvement of the axial skeleton were associated with IE (adjusted OR = 2.2; 95% CI 1.1-4.3) independently of age, sex, and microorganisms. Among patients with IE, the associated OAIs mainly involve the axial skeleton. Transesophageal echocardiography should be carefully considered in patients presenting with these bacteremic OAIs.

In vitro adherence of oral streptococci to zirconia core and veneering glass-ceramics.

PubMed

Rosentritt, Martin; Behr, Michael; Bürgers, Ralf; Feilzer, Albert J; Hahnel, Sebastian

2009-10-01

Plaque formation on dental ceramics may cause gingival inflammation and secondary caries. This in vitro study compared the susceptibility of various dental ceramics to adhere oral streptococci, and verified the influence of substratum surface roughness and surface hydrophobicity. Three zirconia ceramic materials and three veneering glass-ceramics were investigated. Fifteen test specimens were prepared for each material, polished, and surface roughness and hydrophobicity were determined. After incubation with artificial saliva (2 h, 37 degrees C) for pellicle formation, specimens were incubated with suspensions of Streptococcus gordonii DSMZ 6777, Streptococcus mutans DSMZ 20523, Streptococcus oralis DSMZ 20627, or Streptococcus sanguinis DSMZ 20068, respectively, for 2.5 h at 37 degrees C. Adherent bacteria were quantified using a fluorescence dye for viable cell quantification (Alamar Blue/Resazurin). Statistical analysis was performed using one- and two-way ANOVA and the Tukey-Kramer multiple comparison test for post hoc analysis (alpha < 0.05). Surface roughness and surface hydrophobicity differed significantly among the various ceramics; protein coating hydrophilized the surfaces, and led to a homogenization of the surface hydrophobicity of the various ceramics. Before protein coating, almost similar relative fluorescence intensities indicating similar adhesion of streptococci were found for the various ceramics; more distinct differences were observed after protein coating. Correlations between surface parameters and streptococcal adhesion were poor. Within the limitations of these experiments, the findings of this in vitro study indicate only little differences between zirconia and glass ceramic with regard to streptococcal adhesion. Judging from these results, it is unlikely that exposed zirconia surfaces yield more plaque than glass ceramic surfaces in vivo. (c) 2009 Wiley Periodicals, Inc.

Reduced salivary flow and colonization by mutans streptococci in children with Down syndrome

PubMed Central

Areias, Cristina; Sampaio-Maia, Benedita; de Lurdes Pereira, Maria; Azevedo, Álvaro; Melo, Paulo; Andrade, Casimiro; Scully, Crispian

2012-01-01

OBJECTIVES: Although individuals with Down syndrome have considerable oral disease, the prevalence of dental caries in this group is low. The present study aimed to compare known risk factors for dental caries development in children with Down syndrome and a matched population (siblings). In both populations, the number of acidogenic microorganisms, such as mutans streptococci, lactobacilli and Candida species, and the paraffin-stimulated pH, flow rate and IgA concentration in whole saliva were evaluated and compared. METHOD: Saliva was collected, and the caries index was evaluated in 45 sibling pairs aged between 6 and 18 years old. The salivary IgA concentration was determined by immunoturbidimetry. Salivary mutans streptococci, lactobacilli and Candida species were quantified on mitis salivarius agar containing bacitracin and 20% sucrose, rogosa agar supplemented with glacial acetic acid and sabouraud agar supplemented with chloramphenicol, respectively. RESULTS: Down syndrome children had a higher caries-free rate (p<0.05) and lower salivary mutans streptococci counts (p<0.03) compared to their siblings. Similar numbers of lactobacilli and Candida species were found in both groups. Salivary flow rates were 36% lower in Down syndrome children compared to their siblings (p<0.05). The salivary pH did not differ between Down syndrome children and controls. The Down syndrome children had an IgA secretion rate 29% lower than that of their siblings, but this difference was not statistically significant. CONCLUSIONS: In conclusion, the lower number of mutans streptococci in the saliva may be one of the factors contributing to the lower caries rate observed in Down syndrome children, despite evidence of hyposalivation. PMID:23018295

An In Vitro Study of the Effect of Fluoridated Milk on Oral Bacterial Biofilms

PubMed Central

Pratten, J.; Bedi, R.; Wilson, M.

2000-01-01

Microcosmic dental plaques were grown in artificial saliva and supplemented with either milk or fluoridated milk. The presence of fluoride in the milk increased the pH of the biofilms and reduced the proportions of streptococci, demonstrating that in this model, fluoridation of milk produces biofilms with reduced cariogenic potential. PMID:10742268

Association of oral flora with orbital complications of acute sinusitis.

PubMed

Flam, Juliette O; Platt, Michael P; Sobel, Rachel; Devaiah, Anand K; Brook, Christopher D

2016-07-01

Acute and chronic sinusitis in children and adults can spread to the orbit. Oral flora has been seen in orbital infections, but the extent of synergy between pathogens in such infections remains unknown. A retrospective case series of patients with complicated sinusitis that involved the orbit from acute sinusitis who were admitted to a tertiary care hospital from January 2000 to December 2014 and who had surgical cultures obtained. Patients were identified by the International Classification of Diseases, Ninth Revision code for periorbital cellulitis, subperiosteal abscess, or orbital abscess. Sixteen patients underwent surgical drainage via external drainage or endoscopic sinus surgery of an orbital infection associated with sinusitis and had cultures obtained. Nine patients (56%) grew organisms that exist in oral flora, whereas seven patients (44%) grew common respiratory pathogens. The most common organisms recovered were viridans group streptococcus (VGS) (50%), Staphylococcus aureus (31%), Eikenella corrodens (25%), and Prevotella species (19%). Oral flora anaerobes were cultured alongside a VGS species in seven of eight patients (88%) as opposed to the respiratory pathogens, which were less frequently associated with concomitant VGS infection (29%) (p = 0.04). There are two main sources for infectious orbital complications from acute sinusitis: respiratory pathogens and oral flora. The high prevalence of concurrent anaerobic oral flora and VGS infection supports a suspected synergy between VGS and other oral organisms.

Adherence of oral streptococci to nanostructured titanium surfaces.

PubMed

Narendrakumar, Krunal; Kulkarni, Mukta; Addison, Owen; Mazare, Anca; Junkar, Ita; Schmuki, Patrik; Sammons, Rachel; Iglič, Aleš

2015-12-01

Peri-implantitis and peri-mucositis pose a severe threat to the success of dental implants. Current research focuses on the development of surfaces that inhibit biofilm formation while not inferring with tissue integration. This study compared the adherence of two oral bacterial species, Streptococcus sanguinis and Streptococcus mutans to nanostructured titanium surfaces. The samples included TiO2 nanotubes formed by anodization of titanium foil of 100, 50 and 15nm diameter (NT15, NT50, NT100), a nanoporous (15nm pore diameter) surface and compact TiO2 control. Adherent surviving bacteria were enumerated after 1h in an artificial saliva medium containing bovine mucin. Lowest numbers of adherent bacteria of both species were recovered from the original titanium foil and nanoporous surface and highest numbers from the Ti100 nanotubes. Numbers of attached S. sanguinis increased in the order (NT15

The oral microbiome in dental caries.

PubMed

Struzycka, Izabela

2014-01-01

Dental caries is one of the most common chronic and multifactorial diseases affecting the human population. The appearance of a caries lesion is determined by the coexistence of three main factors: acidogenic and acidophilic microorganisms, carbohydrates derived from the diet, and host factors. Socio-economic and behavioral factors also play an important role in the etiology of the disease. Caries develops as a result of an ecological imbalance in the stable oral microbiom. Oral microorganisms form dental plaque on the surfaces of teeth, which is the cause of the caries process, and shows features of the classic biofilm. Biofilm formation appears to be influenced by large scale changes in protein expression over time and under genetic control Cariogenic microorganisms produce lactic, formic, acetic and propionic acids, which are a product of carbohydrate metabolism. Their presence causes a decrease in pH level below 5.5, resulting in demineralization of enamel hydroxyapatite crystals and proteolytic breakdown of the structure of tooth hard tissues. Streptococcus mutans, other streptococci of the so-called non-mutans streptococci group, Actinomyces and Lactobacillus play a key role in this process. Dental biofilm is a dynamic, constantly active metabolically structure. The alternating processes of decrease and increase of biofilm pH occur, which are followed by the respective processes of de- and remineralisation of the tooth surface. In healthy conditions, these processes are in balance and no permanent damage to the tooth enamel surface occurs.

Distribution of amoxicillin-resistant oral streptococci in dental plaque specimens obtained from Japanese children and adolescents at risk for infective endocarditis.

PubMed

Nemoto, Hirotoshi; Nomura, Ryota; Ooshima, Takashi; Nakano, Kazuhiko

2013-11-01

Infective endocarditis (IE) is known to be a life-threatening disease and prevention of its onset is important. Oral amoxicillin (AMPC) is generally prescribed to patients at risk for IE prior to undergoing risky procedures, such as invasive dental treatments. We previously found that approximately 5% of systemically healthy Japanese subjects harbor strains highly resistant to AMPC. In the present study, the prevalence of strains in patients at risk for IE was investigated. Thirty-four Japanese children and adolescents designated at risk for IE by their cardiovascular surgeons participated. Dental plaque specimens were obtained at recall examinations for dental checkups and placed in sterile phosphate-buffered saline, then diluted and streaked onto selective media for oral streptococci and also media containing AMPC. Nine strains with a minimum inhibitory concentration of AMPC of 16μg/mL or more were isolated from 7 of the subjects (20.6%), each of which was also resistant to other antibiotics analyzed except for new quinolone drugs. The 16S rRNA sequence of each strain demonstrated that all were oral streptococcal species. In addition, dental plaque specimens collected from 5 subjects after an additional interval of 3-4 months showed that 2 harbored the same clones at different time points. These findings suggest a higher prevalence of AMPC-resistant strains in children and adolescents at risk for IE as compared to systemically healthy subjects. Thus, alternative antibiotics should be considered for such subjects when performing prophylaxis procedures. Copyright © 2013 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Phylogenetic relationship and virulence inference of Streptococcus Anginosus Group: curated annotation and whole-genome comparative analysis support distinct species designation

PubMed Central

2013-01-01

Background The Streptococcus Anginosus Group (SAG) represents three closely related species of the viridans group streptococci recognized as commensal bacteria of the oral, gastrointestinal and urogenital tracts. The SAG also cause severe invasive infections, and are pathogens during cystic fibrosis (CF) pulmonary exacerbation. Little genomic information or description of virulence mechanisms is currently available for SAG. We conducted intra and inter species whole-genome comparative analyses with 59 publically available Streptococcus genomes and seven in-house closed high quality finished SAG genomes; S. constellatus (3), S. intermedius (2), and S. anginosus (2). For each SAG species, we sequenced at least one numerically dominant strain from CF airways recovered during acute exacerbation and an invasive, non-lung isolate. We also evaluated microevolution that occurred within two isolates that were cultured from one individual one year apart. Results The SAG genomes were most closely related to S. gordonii and S. sanguinis, based on shared orthologs and harbor a similar number of proteins within each COG category as other Streptococcus species. Numerous characterized streptococcus virulence factor homologs were identified within the SAG genomes including; adherence, invasion, spreading factors, LPxTG cell wall proteins, and two component histidine kinases known to be involved in virulence gene regulation. Mobile elements, primarily integrative conjugative elements and bacteriophage, account for greater than 10% of the SAG genomes. S. anginosus was the most variable species sequenced in this study, yielding both the smallest and the largest SAG genomes containing multiple genomic rearrangements, insertions and deletions. In contrast, within the S. constellatus and S. intermedius species, there was extensive continuous synteny, with only slight differences in genome size between strains. Within S. constellatus we were able to determine important SNPs and changes in VNTR numbers that occurred over the course of one year. Conclusions The comparative genomic analysis of the SAG clarifies the phylogenetics of these bacteria and supports the distinct species classification. Numerous potential virulence determinants were identified and provide a foundation for further studies into SAG pathogenesis. Furthermore, the data may be used to enable the development of rapid diagnostic assays and therapeutics for these pathogens. PMID:24341328

Caries risk indicators in children with type 1 diabetes mellitus in relation to metabolic control.

PubMed

El-Tekeya, Magda; El Tantawi, Maha; Fetouh, Hend; Mowafy, Ehsan; Abo Khedr, Nashwa

2012-01-01

The purpose of this study was to investigate the interaction of caries risk indicators and metabolic control in children with type 1 diabetes mellitus. The study included 50 children with type 1 DM and 50 healthy controls, all 6 to 9 years old. Diabetic children were classified into 3 groups: well, fairly, and poorly controlled based on glycosilated hemoglobin level. Personal, family data, medical and dental history were collected. Children were examined for caries experience, plaque, and gingival condition. Saliva samples were obtained for culturing mutans streptococci, lactobacilli, and Candida, and colony forming units were counted. No significant differences existed between all groups regarding caries experience or mean log count of micro-organisms. Diabetic children differed significantly from healthy children in parental occupation and education, dental visits, oral hygiene, and plaque and gingival indices, whereas no differences were observed among children with different levels of metabolic control regarding these factors. Regression analysis identified mutans streptococci as a significant variable affecting caries experience in diabetic children. Regarding the interaction of caries risk indicators and metabolic control on caries experience in diabetic children, the only variable that showed a significant effect was mutans streptococci.

Physiological and molecular characterization of genetic competence in Streptococcus sanguinis.

PubMed

Rodriguez, A M; Callahan, J E; Fawcett, P; Ge, X; Xu, P; Kitten, T

2011-04-01

Streptococcus sanguinis is a major component of the oral flora and an important cause of infective endocarditis. Although S. sanguinis is naturally competent, genome sequencing has suggested significant differences in the S. sanguinis competence system relative to those of other streptococci. An S. sanguinis mutant possessing an in-frame deletion in the comC gene, which encodes competence-stimulating peptide (CSP), was created. Addition of synthetic CSP induced competence in this strain. Gene expression in this strain was monitored by microarray analysis at multiple time-points from 2.5 to 30 min after CSP addition, and verified by quantitative reverse transcription-polymerase chain reaction. Over 200 genes were identified whose expression was altered at least two-fold in at least one time point, with the majority upregulated. The 'late' response was typical of that seen in previous studies. However, comparison of the 'early' response in S. sanguinis with that of other oral streptococci revealed unexpected differences with regard to the number of genes induced, the nature of those genes, and their putative upstream regulatory sequences. Streptococcus sanguinis possesses a comparatively limited early response, which may define a minimal streptococcal competence regulatory circuit. © 2011 John Wiley & Sons A/S.

Physiological and molecular characterization of genetic competence in Streptococcus sanguinis

PubMed Central

Rodriguez, Alejandro Miguel; Callahan, Jill E.; Fawcett, Paul; Ge, Xiuchun; Xu, Ping; Kitten, Todd

2011-01-01

SUMMARY Streptococcus sanguinis is a major component of the oral flora and an important cause of infective endocarditis. Although S. sanguinis is naturally competent, genome sequencing has suggested significant differences in the S. sanguinis competence system relative to those of other streptococci. An S. sanguinis mutant possessing an in-frame deletion in the comC gene, which encodes competence-stimulating peptide (CSP), was created. Addition of synthetic CSP induced competence in this strain. Gene expression in this strain was monitored by microarray analysis at multiple time points from 2.5 to 30 min after CSP addition, and verified by quantitative RT-PCR. Over 200 genes were identified whose expression was altered at least two-fold in at least one time point, with the majority upregulated. The “late” response was typical of that seen in previous studies. However, comparison of the “early” response in S. sanguinis with that of other oral streptococci revealed unexpected differences with regard to the number of genes induced, the nature of these genes, and their putative upstream regulatory sequences. S. sanguinis possesses a comparatively limited early response, which may define a minimal streptococcal competence regulatory circuit. PMID:21375701

Candida-streptococcal mucosal biofilms display distinct structural and virulence characteristics depending on growth conditions and hyphal morphotypes.

PubMed

Bertolini, M M; Xu, H; Sobue, T; Nobile, C J; Del Bel Cury, A A; Dongari-Bagtzoglou, A

2015-08-01

Candida albicans and streptococci of the mitis group form communities in multiple oral sites, where moisture and nutrient availability can change spatially or temporally. This study evaluated structural and virulence characteristics of Candida-streptococcal biofilms formed on moist or semidry mucosal surfaces, and tested the effects of nutrient availability and hyphal morphotype on dual-species biofilms. Three-dimensional models of the oral mucosa formed by immortalized keratinocytes on a fibroblast-embedded collagenous matrix were used. Infections were carried out using Streptococcus oralis strain 34, in combination with a C. albicans wild-type strain, or pseudohyphal-forming mutant strains. Increased moisture promoted a homogeneous surface biofilm by C. albicans. Dual biofilms had a stratified structure, with streptococci growing in close contact with the mucosa and fungi growing on the bacterial surface. Under semidry conditions, Candida formed localized foci of dense growth, which promoted focal growth of streptococci in mixed biofilms. Candida biofilm biovolume was greater under moist conditions, albeit with minimal tissue invasion, compared with semidry conditions. Supplementing the infection medium with nutrients under semidry conditions intensified growth, biofilm biovolume and tissue invasion/damage, without changing biofilm structure. Under these conditions, the pseudohyphal mutants and S. oralis formed defective superficial biofilms, with most bacteria in contact with the epithelial surface, below a pseudohyphal mass, resembling biofilms growing in a moist environment. The presence of S. oralis promoted fungal invasion and tissue damage under all conditions. We conclude that moisture, nutrient availability, hyphal morphotype and the presence of commensal bacteria influence the architecture and virulence characteristics of mucosal fungal biofilms. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

[Ecologic and epidemiologic features of the circulation of streptococcus group B at a maternity clinic].

PubMed

Bochkov, I A; Shevchuk, M S; Semina, N A; Fiks, L I; Elinkova, Ia

1989-04-01

In a maternity clinic the circulation of group B streptococci among the newborns, their mothers and the personnel was established during the period of 1982-1985. Group B streptococci were detected at different biotypes of newborns (the pharynx, the imbilical stump, external suditory meatus, nasal and oral mucosa, eyes and feces), their mothers (the vagina, the perianal area, breast milk, the pharynx, urine, the umbilical cord, amniotic fluid) and in the pharynx of the personnel. In this maternity clinic 15 combinations of type antigens were detected, two combinations (1a/c and 1 b/c) prevailing among them. These results confirmed earlier data concerning two possible ways of transferring infection to newborn infants: vertical, i.e. from the mother to the child during parturition, and nosocomial, i.e. from contaminated newborns or members of the personnel.

Bacterial Infections in Children With Acute Myeloid Leukemia Receiving Ciprofloxacin Prophylaxis.

PubMed

Al Omar, Suha; Anabtawi, Nadine; Al Qasem, Wiam; Rihani, Rawad

2017-04-01

The aim of the study was to describe the incidence and type of bacterial infections associated with the use of ciprofloxacin prophylaxis as single agent in pediatric patients with acute myeloid leukemia (AML). This was a retrospective review of all patients with AML, who were treated according to the AML02 protocol between 2011 and 2015. The medical records were reviewed for any positive cultures from the initiation of the protocol until death or protocol discontinuation. Patient demographics, type of infections, type of isolated bacteria, and intensive care unit admissions were recorded. A total of 50 patients were evaluated, who were of a mean age of 8 years±5.1 (SD). We identified 77 episodes of bacterial infections in 42 (84%) patients. Among those bacterial infections, 73 episodes were with bacteremia and included 45 (62%) gram-positive bacterial infections, 24 (33%) gram-negative bacterial infections, and 4 (6%) mixed gram-negative and gram-positive bacterial infections. Coagulase-negative Staphylococcus and Viridans streptococci were the most commonly isolated bacteria in 33% and 30% of the episodes, respectively. Seventeen (45%) patients with bacteremia required intensive care unit admission. A high rate of bacterial infection was detected in patients who received the AML02 protocol, mainly gram-positive bacterial infections. The prophylactic regimen should be reconsidered for its efficacy, and other antibacterial prophylaxis may be used.

Contaminants in blood cultures: importance, implications, interpretation and prevention.

PubMed

Dargère, S; Cormier, H; Verdon, R

2018-04-03

Despite the development of new microbiologic technologies, blood cultures (BCs) remain the first-line tool for the diagnosis of bloodstream infections. Their diagnostic value may be affected when a microorganism of questionable evidence is isolated-for example, coagulase-negative staphylococci, Bacillus spp., viridans group streptococci, Corynebacterium spp., Propionibacterium spp. and Micrococcus spp. Finally, making a correct diagnosis of pathogenicity (vs. contamination) is challenging. To review the current ways of dealing with the problem of BC contaminants (BCCs) and to provide practical suggestions to decrease BCC rates. PubMed electronic databases and existing reviews were searched up to December 2017 to retrieve relevant publications related to the topic. This review describes the burden of BCC and analyses the main current issues and controversies in interpreting the occurrence of potential BC contaminants. It focuses on the best-described approaches to decide whether BCC is present and discusses the different strategies of prevention in adults. Each institution should have an efficient policy to prevent BCC, emphasizing the importance of following guidelines for prescribing and collecting BCs. Training healthcare workers should focus on detrimental influence on patient care and highlight the work and costs due to contaminants. The accurate differentiation of a contaminant from a true pathogen relies on a multidisciplinary approach and the clinical judgement of experienced practitioners. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Etiology of pleural effusions: analysis of more than 3,000 consecutive thoracenteses.

PubMed

Porcel, José M; Esquerda, Aureli; Vives, Manuel; Bielsa, Silvia

2014-05-01

To investigate the etiology of pleural effusions (PE) in adults and the accuracy of pleural fluid (PF) cytology and cultures in malignant and infectious PE, respectively. Retrospective analysis of all consecutive patients with PE undergoing diagnostic thoracentesis during the last 19 years in a university hospital. The leading causes of PE among the 3,077 patients were: cancer (27%), heart failure (21%), pneumonia (19%), tuberculosis (9%), abdominal surgery (4%), pericardial diseases (4%) and cirrhosis (3%). Tuberculosis was the most common etiology in patients <34 years of age (52%), whereas heart failure predominated in octogenarians (45%). The most common primary tumors in malignant PE were lung (37%) and breast (16%). The overall accuracy of PF cytology was 59%, although it was significantly lower in mesotheliomas (27%) and squamous cell lung cancer (25%). In infectious PE, only 30% of cultures yielded positive results, a percentage which increased two-fold (66%) in purulent fluids (empyemas). Viridans streptococci were the most commonly isolated pathogens (25.5%). The sensitivity of solid media cultures of PF for Mycobacterium tuberculosis was low (18.5%). Three-quarters of patients with PE in whom a diagnostic thoracentesis was indicated had cancer, heart failure, pneumonia or tuberculosis. PF cytology and cultures give false negative results in a significant number of cases. Copyright © 2013 SEPAR. Published by Elsevier Espana. All rights reserved.

Comprehensive Evaluation of Streptococcus sanguinis Cell Wall-Anchored Proteins in Early Infective Endocarditis▿ †

PubMed Central

Turner, Lauren Senty; Kanamoto, Taisei; Unoki, Takeshi; Munro, Cindy L.; Wu, Hui; Kitten, Todd

2009-01-01

Streptococcus sanguinis is a member of the viridans group of streptococci and a leading cause of the life-threatening endovascular disease infective endocarditis. Initial contact with the cardiac infection site is likely mediated by S. sanguinis surface proteins. In an attempt to identify the proteins required for this crucial step in pathogenesis, we searched for surface-exposed, cell wall-anchored proteins encoded by S. sanguinis and then used a targeted signature-tagged mutagenesis (STM) approach to evaluate their contributions to virulence. Thirty-three predicted cell wall-anchored proteins were identified—a number much larger than those found in related species. The requirement of each cell wall-anchored protein for infective endocarditis was assessed in the rabbit model. It was found that no single cell wall-anchored protein was essential for the development of early infective endocarditis. STM screening was also employed for the evaluation of three predicted sortase transpeptidase enzymes, which mediate the cell surface presentation of cell wall-anchored proteins. The sortase A mutant exhibited a modest (∼2-fold) reduction in competitiveness, while the other two sortase mutants were indistinguishable from the parental strain. The combined results suggest that while cell wall-anchored proteins may play a role in S. sanguinis infective endocarditis, strategies designed to interfere with individual cell wall-anchored proteins or sortases would not be effective for disease prevention. PMID:19703977

Comprehensive evaluation of Streptococcus sanguinis cell wall-anchored proteins in early infective endocarditis.

PubMed

Turner, Lauren Senty; Kanamoto, Taisei; Unoki, Takeshi; Munro, Cindy L; Wu, Hui; Kitten, Todd

2009-11-01

Streptococcus sanguinis is a member of the viridans group of streptococci and a leading cause of the life-threatening endovascular disease infective endocarditis. Initial contact with the cardiac infection site is likely mediated by S. sanguinis surface proteins. In an attempt to identify the proteins required for this crucial step in pathogenesis, we searched for surface-exposed, cell wall-anchored proteins encoded by S. sanguinis and then used a targeted signature-tagged mutagenesis (STM) approach to evaluate their contributions to virulence. Thirty-three predicted cell wall-anchored proteins were identified-a number much larger than those found in related species. The requirement of each cell wall-anchored protein for infective endocarditis was assessed in the rabbit model. It was found that no single cell wall-anchored protein was essential for the development of early infective endocarditis. STM screening was also employed for the evaluation of three predicted sortase transpeptidase enzymes, which mediate the cell surface presentation of cell wall-anchored proteins. The sortase A mutant exhibited a modest (approximately 2-fold) reduction in competitiveness, while the other two sortase mutants were indistinguishable from the parental strain. The combined results suggest that while cell wall-anchored proteins may play a role in S. sanguinis infective endocarditis, strategies designed to interfere with individual cell wall-anchored proteins or sortases would not be effective for disease prevention.

[Meningitis and white matter lesions due to Streptococcus mitis in a previously healthy child].

PubMed

Yiş, Reyhan; Yüksel, Ciğdem Nükhet; Derundere, Umit; Yiş, Uluç

2011-10-01

Streptococcus mitis, an important member of viridans streptococci, is found in the normal flora of the oropharynx, gastrointestinal tract, female genital tract and skin. Although it is of low pathogenicity and virulence, it may cause serious infections in immunocompromised patients. Meningitis caused by S.mitis has been described in patients with previous spinal anesthesia, neurosurgical procedure, malignancy, bacterial endocarditis with neurological complications and alcoholics, but it is rare in patients who are previously healthy. In this report, a rare case of meningoencephalitis caused by S.mitis developed in a previously healthy child has been presented. A previously healthy eight-year-old girl who presented with fever, altered state of consciousness, and headache was hospitalized in intensive care unit with the diagnosis of meningitis. Past history revealed that she was treated with amoxicillin-clavulanate for acute sinusitis ten days before her admission. Whole blood count revealed the followings: hemoglobin 13 g/dl, white blood cell count 18.6 x 109/L (90% neutrophils), platelet count 200 x 109/L and 150 leucocytes were detected on cerebrospinal fluid (CSF) examination. Protein and glucose levels of CSF were 80 mg/dl and 40 mg/dl (concomitant blood glucose 100 mg/dl), respectively. Brain magnetic resonance imaging (MRI) revealed widespread white matter lesions, and alpha-hemolytic streptococci were grown in CSF culture. The isolate was identified as S.mitis with conventional methods, and also confirmed by VITEK2 (bioMerieux, France) and API 20 STREP (bioMerieux, France) systems. Isolate was found susceptible to penicillin, erythromycin, clindamycin, tetracycline, cefotaxime, vancomycin and chloramphenicol. Regarding the etiology, echocardiography revealed no vegetation nor valve pathology, and peripheral blood smear showed no abnormality. Immunoglobulin and complement levels were within normal limits. Ongoing inflammation in maxillary sinuses detected in brain MRI suggested that meningitis could be related to previous sinus infection. After 14 days of ceftriaxone treatment, the patient was discharged from the hospital with cure. The aim of this case presentation was to emphasize that S.mitis may cause meningitis and white matter lesions in previously healthy children with concomitant sinusitis.

Update of contemporary antimicrobial resistance rates across China: reference testing results for 12 medical centers (2011).

PubMed

Jones, Ronald N; Castanheira, Mariana; Hu, Bijie; Ni, Yuxing; Lin, Stephen S F; Mendes, Rodrigo E; Wang, Yao

2013-11-01

Antimicrobial resistance (R) surveillance across Asia and especially in China has documented unique patterns and mechanisms. This 2011 study reports results for 2278 isolates from 12 hospitals in China (94-216 strains/site); most from bacteremia (20.4%), pneumonias (29.1%), or skin and skin structure infections (20.9%). Samples were tested by reference broth microdilution methods, interpreted by published susceptibility (S) breakpoints. The most common species were Staphylococcus aureus (343, 45.8% MRSA), Escherichia coli (EC; 288), Pseudomonas aeruginosa (PSA; 221), Klebsiella spp. (KSP; 208), acinetobacters (ACB; 178), enterobacters (155), Streptococcus pneumoniae (SPN; 154, 46.8% penicillin-S), and enterococci (ENT; 137). Among 849 Gram-positive (GP) cocci, linezolid, tigecycline (TIG), daptomycin, and vancomycin provided best antimicrobial coverage (≥99.7% S). Resistance patterns of concern were 0.3% VISA, 15.4% teicoplanin non-S coagulase-negative staphylococci, 1.5% vancomycin-R ENT (all Enterococcus faecium), 1.9% levofloxacin-R β-haemolytic streptococci, and 35.1 and 12.7% ceftriaxone-non-S rates for SPN and viridans group streptococci, respectively. For Gram-negative bacilli, R among Enterobacteriaceae was highest against β-lactams (extended spectrum β-lactamase-phenotype strains at 73.6 and 42.8% in EC and KSP, respectively; carbapenem-R was only 2.1-4.3% with KPC and IMP type enzymes detected in KSP). The widest spectrum agents were cefoperazone/sulbactam (79.5-86.1%), piperacillin/tazobactam (88.9-92.0%), TIG (98.6-100%), amikacin (AMK; 91.8-93.7%), and meropenem (95.7-97.1% S). PSA was most inhibited by AMK (90.5% S) and colistin (COL; 99.5%), with cefepime (67.9%) best among the tested β-lactams. Only COL (100% S) and TIG (MIC90, 2 μg/mL) showed significant potencies against ACB. In conclusion, R among pathogens from 12 Chinese hospitals illustrates several agents active against GP pathogens, but more serious R problems were noted among Enterobacteriaceae, PSA, and ACB. Combination treatment for the latter multidrug-R strains appears necessary, guided by local antibiograms and national surveillance results applying reference methods. © 2013.

Susceptibility rates in Latin American nations: report from a regional resistance surveillance program (2011).

PubMed

Jones, Ronald N; Guzman-Blanco, Manuel; Gales, Ana C; Gallegos, Belisario; Castro, Aura Lucia Leal; Martino, Marines Dalla Valle; Vega, Silvio; Zurita, Jeannete; Cepparulo, Mario; Castanheira, Mariana

2013-01-01

To establish a resistance (R) surveillance program monitoring antimicrobial susceptibility patterns in Latin America (LATAM; Argentina [ARG], Brazil [BRA], Chile, Colombia [CBA], Costa Rica, Ecuador [ECU], Guatemala [GUA], Mexico [MEX], Panama [PAN], Peru, and Venezuela [VEN]). In 2011, 4979 organisms were collected from 11 nations (20 laboratories) for susceptibility testing in a central laboratory design. Antimicrobials were tested by CLSI methods and results interpreted by CLSI and EUCAST breakpoints. Most common Gram-positive (Staphylococcus aureus [SA, 921], other staphylococci [CoNS; 299], enterococci [218], Streptococcus pneumoniae [SPN; 182], β-haemolytic streptococci [115]) and Gram-negative (E. coli [EC; 644], Klebsiella spp. [KSP; 517], Enterobacters [272], Pseudomonas aeruginosa [PSA; 586], Acinetobacters [ACB; 494]) pathogens were analyzed against linezolid (LZD), vancomycin (VAN), tigecycline (TIG), colistin (COL), cefoperazone/sulbactam (C/S), and amikacin (AMK). MRSA rates varied from 29% (CBA, BRA) to 79% (Peru); but LZD (MIC90, 2mg/L), TIG (MIC90, 0.12mg/L) and VAN (MIC90, 1mg/L) covered all strains. Enterococci showed a 14% VRE rate, highest in BRA and MEX; all inhibited by TIG and daptomycin, but not LZD (three non-susceptible with G2576T mutations or cfr). Penicillin-R among SPN and viridans streptococci was 51.6 and 41.1%, respectively. LZD overall R against Gram-positives was 0.3%. High ESBL rates were observed in EC (54-71%) and KSP (≥50%) from GUA, MEX and Peru, and six nations, respectively. Carbapenem-R in KSP was 9%, highest rates associated with KPC in BRA, CBA, ECU, PAN and VEN; also a NDM-1 in KSP from CBA. AMK, TIG, C/S and carbapenems were the broadest-spectrum agents tested against Enterobacteriaceae. Only COL inhibited >90% of PSA; COL and TIG (≤2mg/L) covered ≥85% of ACB. LATAM nations demonstrated variable levels of antimicrobial R especially among Enterobacteriaceae (β-lactamase-mediated), PSA and ACB. MRSA (48%), VRE (14%) and multidrug-R SPN were also regional therapeutic challenges. Copyright © 2013 Elsevier Editora Ltda. All rights reserved.

Evaluation of the effect of photodynamic antimicrobial therapy in dentin caries: a pilot in vivo study

NASA Astrophysics Data System (ADS)

Borges, F. M. C.; de-Melo, M. A. S.; Lima, J. M. P.; Zanin, I. C. J.; Rodrigues, L. K. A.; Nobre-dos-Santos, M.

2010-02-01

In vitro and in situ studies have demonstrated that the photodynamic antimicrobial therapy (PACT) is effective in reducing Streptococcus mutans population in artificially carious dentin. This pilot in vivo study evaluated the antimicrobial effect of PACT using toluidine blue O (TBO) and a light-emitting diode (LED) in carious dentin lesions. Five healthy adult volunteers (19-36 yr), with at least 4 active carious cavities each, participated in this study. Teeth of each volunteer were randomly divided into four groups: (1) without TBO and without light (Control); (2) with TBO alone (TBO); (3) with LED at 94/J cm2 alone (LED); and (4) with TBO plus LED at 94 J/cm2 (PACT). Each cavity was divided into two halves. The baseline carious dentin sample was collected from half of each cavity. Following, the treatments were performed using a random distribution of tooth into treatments. Then, the second collection of carious dentin samples was performed. Before and after treatments, dentin samples were analyzed with regard to the counts of total viable microorganisms, total streptococci, mutans streptococci, and lactobacilli. The data were statistically analyzed by Kruskal-Wallis and Student-Newman-Keuls tests (α=5%). Log reductions ranged from -0.12 to 2.68 and significant reductions were observed for PACT (group 4) when compared to the other groups (1, 2, and 3) for total streptococci and mutans streptococci. Concluding, PACT was effective in killing oral microorganisms present in in vivo carious dentin lesions and may be a promising technique for eliminating bacteria from dentin before restoration.

[The origin of hydrogen peroxide in oral cavity and its role in oral microecology balance].

PubMed

Keke, Zhang; Xuedong, Zhou; Xin, Xu

2017-04-01

Hydrogen peroxide, an important antimicrobial agent in oral cavity, plays a significant role in the balance of oral microecology. At the early stage of biofilm formation, about 80% of the detected initial colonizers belong to the genus Streptococcus. These oral streptococci use different oxidase to produce hydrogen peroxide. Recent studies showed that the produced hydrogen peroxide plays a critical role in modulating oral microecology. Hydrogen peroxide modulates biofilm development attributed to its growth inhibitory nature. Hydrogen peroxide production is closely associated with extracellular DNA(eDNA) release from microbe and the development of its competent cell which are critical for biofilm development and also serves as source for horizontal gene transfer. Microbe also can reduce the damage to themselves through several detoxification mechanisms. Moreover, hydrogen peroxide is also involved in the regulation of interactions between oral microorganisms and host. Taken together, hydrogen peroxide is an imperative ecological factor that contributes to the microbial equilibrium in the oral cavity. Here we will give a brief review of both the origin and the function in the oral microecology balance of hydrogen peroxide.

Genome of the opportunistic pathogen Streptococcus sanguinis.

PubMed

Xu, Ping; Alves, Joao M; Kitten, Todd; Brown, Arunsri; Chen, Zhenming; Ozaki, Luiz S; Manque, Patricio; Ge, Xiuchun; Serrano, Myrna G; Puiu, Daniela; Hendricks, Stephanie; Wang, Yingping; Chaplin, Michael D; Akan, Doruk; Paik, Sehmi; Peterson, Darrell L; Macrina, Francis L; Buck, Gregory A

2007-04-01

The genome of Streptococcus sanguinis is a circular DNA molecule consisting of 2,388,435 bp and is 177 to 590 kb larger than the other 21 streptococcal genomes that have been sequenced. The G+C content of the S. sanguinis genome is 43.4%, which is considerably higher than the G+C contents of other streptococci. The genome encodes 2,274 predicted proteins, 61 tRNAs, and four rRNA operons. A 70-kb region encoding pathways for vitamin B(12) biosynthesis and degradation of ethanolamine and propanediol was apparently acquired by horizontal gene transfer. The gene complement suggests new hypotheses for the pathogenesis and virulence of S. sanguinis and differs from the gene complements of other pathogenic and nonpathogenic streptococci. In particular, S. sanguinis possesses a remarkable abundance of putative surface proteins, which may permit it to be a primary colonizer of the oral cavity and agent of streptococcal endocarditis and infection in neutropenic patients.

[In vitro utilization of fructooligosaccharide by streptococci mutans].

PubMed

Linardi, M M; Rosa, O P; Buzalaf, M A; Torres, S A

2001-01-01

Neosugar is the trade name of a fructooligosaccharide (FOS) whose utilization by oral bacteria is not well known yet. The aim of the present study was to evaluate in vitro the effect of this product on the growth, fermentation and production of plaque by mutans streptococci: S. mutans, serotypes c, e and f, S. sobrinus, serotype d, S. downei, serotype h, S. cricetus, serotype a and S. rattus, serotype b. The evaluation of growth was carried out in Brain Heart Infusion (BHI) broths containing or not sucrose and FOS and in buffered broths having glucose or FOS as carbon sources, through optical density reading in spectrophotometer after 24 hours of incubation at 37 degrees C. Thereafter the reading of pH was made in the same media. The plaque produced on glass sticks in BHI broths containing 5% sucrose or FOS was weighed and carbohydrates and proteins were assayed. The possible cariogenicity of Neosugar was confirmed, since it sustained the same growth and intensity of fermentation of sucrose in BHI broth for all streptococci and permitted in vitro production of plaque by some of them. The amount of plaque as well as its content of proteins and carbohydrates were smaller than those produced with sucrose, although the difference was statistically significant only for carbohydrates.

Effect of Probiotic Lactobacillus reuteri on Salivary Cariogenic Bacterial Counts among Groups of Preschool Children in Jeddah, Saudi Arabia: A Randomized Clinical Trial.

PubMed

Alamoudi, Najlaa M; Almabadi, Eman S; El Ashiry, Eman A; El Derwi, Douaa A

2018-05-15

To evaluate the effect of probiotic Lactobacilli reuteri lozenges on caries-associated salivary bacterial counts (Mutans streptococci and Lactobacillus), dental plaque accumulation, and salivary buffer capacity in a group of preschool children. The study group consisted of 178 healthy children (aged 3-6 years). Children were randomly grouped: the experimental group (n = 90) received L. reuteri probiotic lozenges and the control group (n = 88) received placebo lozenges, twice daily, for 28 days. Salivary Mutans streptococci and Lactobacillus counts, and buffer capacity were assessed using chair-side caries-risk test (CRT®) kits. The Simplified Oral Hygiene index (OHI-S) was used to assess dental plaque accumulation at baseline and after 28 days. After 28 days, the experimental group had a statistically significant reduction in Mutans streptococci and lactobacilli (p = 0.000 and p = 0.020, respectively) and both groups had less plaque accumulation than at baseline. While the buffer capacity in the experimental group increased more than in the control group, it was not statistically significant (p = 0.577). Compliance was 90%, with no adverse events. Consumption of probiotic lozenges containing L. reuteri reduces caries-associated bacterial counts significantly. Probiotics consumption may have a beneficial caries-preventive effect.

Increase in detectable opportunistic bacteria in the oral cavity of orthodontic patients.

PubMed

Kitada, K; de Toledo, A; Oho, T

2009-05-01

This study was performed to detect the opportunistic bacteria and fungi from the oral cavities of orthodontic patients and examine the ability of the organisms to adhere to saliva-coated metallic brackets. Opportunistic bacteria and fungi were isolated from 58 patients (orthodontic group: 42; non-orthodontic group: 16) using culture methods and were identified based on their biochemical and enzymatic profiles. Seven opportunistic and four streptococcal strains were tested for their ability to adhere to saliva-coated metallic brackets. More opportunistic bacteria and fungi were detected in the orthodontic group than in the non-orthodontic group (P < 0.05). Opportunistic bacteria adhered to saliva-coated metallic brackets to the same degree as oral streptococci. The isolation frequencies of opportunistic bacteria and fungi increase during orthodontic treatment, suggesting the importance of paying special attention to oral hygiene in orthodontic patients to prevent periodontal disease and the aggravation of systemic disease in immunocompromised conditions.

The influence of a salivary coating on the molecular surface composition of oral streptococci as determined by Fourier transform infrared spectroscopy

NASA Astrophysics Data System (ADS)

van der Mei, H. C.; Noordmans, J.; Busscher, H. J.

In order to determine the influence of saliva treatment on the molecular surface composition of oral streptococci, infrared transmission spectroscopy on freeze-dried cells mixed in KBr was used. All IR spectra show similar absorption bands for the saliva-coated and uncoated strains involved, with the most important absorption bands located at 2930cm -1 (CH), 1653 cm -1 (AmI), 1541 cm -1 (AmII) and two bands at 1236 cm -1 and 1082cm -1, which were assigned to phosphate and sugar groups. However, calculation of absorption band ratios normalized with respect to the CH band around 2930cm -1, showed major differences between the saliva-coated and uncoated strains. All strains demonstrated an increase in the AmI/CH and AmII/CH absorption band ratios after saliva treatment indicative for protein adsorption, except for Streptococcus mitis BA showing a small decrease in the AmI/CH absorption band ratio. Two positive relationships could furthermore be established both between the AmII/CH absorption band ratio with the N/C elemental surface concentration ratio of the strains, previously determined from X-ray Photoelectron Spectroscopy (XPS) as well as between AmI/CH with the fraction of carbon atoms at the surface involved in amide bonds, also determined by XPS. This study clearly demonstrates the possibility of IR spectroscopy to determine the molecular surface properties of freeze-dried micro-organisms, as illustrated here from a comparison between the molecular composition of untreated and saliva-treated oral streptococcal strains.

Mutans streptococcal serotypes in children with gastroesophageal reflux disease.

PubMed

Hölttä, P; Aine, L; Mäki, M; Ruuska, T; Vuento, R; Ashorn, M; Alaluusua, S

1997-01-01

It has been suggested that vomiting acid gastric contents in bulimia might favor oral growth of Streptococcus sobrinus. We studied the colonization of Streptococcus sobrinus (serotypes g and d) and Streptococcus mutans (serotypes c, e and f) in sixteen children, ages five to fifteen years, who had suffered for four to eleven years from gastroesophageal reflux, another condition with recurrent acid regurgitation. Our aim was to find out if the prevalence of Streptococcus sobrinus would be higher also in this patient group. Mutants streptococci were detected in twelve out of sixteen (75 percent) study patients of the saliva samples cultured on MSB agar. For the Mutans streptococci positive children healthy controls were matched by salivary levels of mutans streptococci and age as closely as possible. From each child three to six isolates representing both Streptococcus mutans and Streptococcus sobrinus (n = 103) were serotyped by immunodiffusion method. The distribution of serotypes in the study/control group was: c: 7/10; e: 4/2; f: 0/1; g:3/2; d:0/0. One strain in the study group remained untypable. All patients infected with Streptococcus sobrinus were also infected with Streptococcus mutans. Our results indicate the great similarity in the distribution of ms serotypes in the gastroesophageal reflux children and their healthy controls. The data do not suggest that the acid regurgitation would have an influence on the prevalence of Streptococcus sobrinus.

Caries risk profiles in orthodontic patients at follow-up using Cariogram.

PubMed

Al Mulla, Anas H; Kharsa, Saad Al; Kjellberg, Heidrun; Birkhed, Dowen

2009-03-01

To analyze caries-related factors shortly after orthodontic treatment and to use the Cariogram computer program to describe caries risk profiles at follow-up in these patients. One hundred orthodontic patients age 12-29 years, with a mean age of 17.5 years, were included in the study. They were divided into two groups (50 in each) based on their prebonding decayed, filled surfaces index (DFS). High (5 > or = DFS) and low (2 < or = DFS) groups were created. All patients were examined after debonding in the following order: interview, plaque score, caries examination, saliva samples, bitewing radiographs, panoramic radiographs, and intra-oral digital photos. All types of carious lesions in both the enamel and dentine were diagnosed clinically and radiographically and included in the DFS index. A paraffin-stimulated whole saliva sample was collected for estimations of secretion rate, buffer capacity, and number of mutans streptococci and lactobacilli. The low caries group (2 < or = DFS) displayed a statistically significant difference and low values for the following factors, DFS (P < .001), lactobacilli (P < .001), mutans streptococci (P < .001), and high Cariogram percent (P < .001). The plaque index displayed very close significance (P = .051). Patients with high (5 > or = DFS) numbers before orthodontic treatment ran a higher risk of developing caries. They had significantly higher numbers of mutans streptococci and lactobacilli and had less chance of avoiding new cavities according to the Cariogram.

Infectious Complications in Children With Acute Myeloid Leukemia and Down Syndrome: Analysis of the Prospective Multicenter Trial AML-BFM 2004.

PubMed

Hassler, Angela; Bochennek, Konrad; Gilfert, Julia; Perner, Corinna; Schöning, Stefan; Creutzig, Ursula; Reinhardt, Dirk; Lehrnbecher, Thomas

2016-06-01

Children with acute myeloid leukemia (AML) and Down syndrome have high survival rates with intensity-reduced chemotherapeutic regimens, although the optimal balance between dose intensity and treatment toxicity has not been determined. We, therefore, characterized infectious complications in children with AML and Down syndrome treated according to AML-BFM 2004 study (ClinicalTrials.gov NCT00111345; amended 2006 for Down syndrome with reduced intensity). Data on infectious complications were gathered from the medical records in the hospital where the patient was treated. Infectious complications were categorized as fever without identifiable source (FUO), or as microbiologically or clinically documented infections. A total of 157 infections occurred in 61 patients (60.5% FUO, 9.6% and 29.9% clinically and microbiologically documented infections, respectively). Almost 90% of the pathogens isolated from the bloodstream were Gram-positive bacteria, and approximately half of them were viridans group streptococci. All seven microbiologically documented episodes of pneumonia were caused by viruses. Infection-related mortality was 4.9%, and all three patients died due to viral infection. Our data demonstrate that a reduced-intensity chemotherapeutic regimen in children with AML and Down syndrome is still associated with high morbidity. Although no patient died due to bacteria or fungi, viruses were responsible for all lethal events. Future studies, therefore, have to focus on the impact of viruses on morbidity and mortality of patients with AML and Down syndrome. © 2016 Wiley Periodicals, Inc.

Rapid identification of bacteria in positive blood culture by matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

PubMed

Schmidt, V; Jarosch, A; März, P; Sander, C; Vacata, V; Kalka-Moll, W

2012-03-01

Blood culture is probably the most significant specimen used for the diagnosis of bacterial infections, especially for bloodstream infections. In the present study, we compared the resin-containing BD BACTEC™ Plus-Aerobic (Becton Dickinson), non-charcoal-containing BacT/Alert(®) SA (bioMérieux), and charcoal-containing BacT/Alert(®) FA (bioMérieux) blood culture bottles with direct identification by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). A total of 103 bacterial isolates, from clinical blood cultures, representing the most frequent 13 genera and 24 species were examined. Bacteria were extracted from positive blood culture broth by density centrifugation and then subjected to identification by MALDI-TOF MS using two different volumes and chemical treatments. Overall, correct identification by MALDI-TOF MS was obtained for the BD BACTEC™ Plus-Aerobic, BacT/Alert(®) SA, and BacT/Alert(®) FA blood culture bottles in 72%, 45.6%, and 23%, respectively, for gram-negative bacteria in 86.6%, 69.2%, and 47.1%, respectively, and for gram-positive bacteria in 60.0%, 28.8%, and 5.4%, respectively. The lack of identification was observed mainly with viridans streptococci. Depending on the blood culture bottles used in routine diagnostic procedures and the protocol for bacterial preparation, the applied MALDI-TOF MS represents an efficient and rapid method for direct bacterial identification.

Therapeutic significance of penicillin tolerance in experimental streptococcal endocarditis.

PubMed Central

Brennan, R O; Durack, D T

1983-01-01

Tolerance to penicillin exists among the viridans group of streptococci, but its therapeutic significance is unknown. We studied the effect of penicillin alone and in combination with streptomycin, in vivo and in vitro, on three strains of dextran-producing Streptococcus sanguis serotype II which possess widely various degrees of penicillin tolerance. In rabbits with experimental endocarditis, treatment with procaine penicillin (250 mg/kg intramuscularly twice daily for 5 days) decreased the number of viable organisms in valvular vegetations from 8.82 log10 +/- 0.98 CFU/g in untreated controls to 5.31 +/- 1.19 for a highly tolerant strain, 4.22 +/- 1.05 for a less tolerant strain, and 1.79 +/- 1.72 for a nontolerant strain (P less than or equal to 0.01 for comparison between any of the four groups). None of 36 rabbits infected with tolerant strains were cured by 5 days of treatment with penicillin, but 10 of 23 animals infected with the nontolerant strain were cured (P = 0.00002). When streptomycin was given in combination with penicillin, rabbits infected with the nontolerant strain were cured within 3 days, and rabbits infected with the tolerant strain were cured within 5 days. These findings indicate that tolerance can exert a critical influence on the response of S. sanguis to penicillin therapy in vivo and that the combination of penicillin plus streptomycin exerts a synergistic effect against tolerant as well as nontolerant organisms. PMID:6838188

Dental plaque as a biofilm: the significance of pH in health and caries.

PubMed

Marsh, Philip D

2009-03-01

Dental plaque is an example of a biofilm; its presence is natural and it supports the host in its defense against invading microbes. In health, the microbial composition of dental plaque is diverse and remains relatively stable over time (microbial homeostasis). The predominant microorganisms prefer host molecules (eg, salivary mucins) and a neutral pH for growth. Under certain circumstances, this microbial homeostasis can break down and diseases such as caries can occur. In dental caries, there is a shift toward increased proportions of acid-producing and acid-tolerating species, such as mutans streptococci and Lactobacilli, although other species with relevant traits can participate in demineralization. Strategies to control caries include effective oral hygiene practices to reduce biofilm development, and adoption of a low-sugar diet to restrict periods of acidic challenge to teeth. These conventional approaches also should be augmented by interference with the factors that enable the cariogenic bacteria to outcompete the organisms associated with health. Evidence suggests that regular conditions of low pH in plaque select for mutans streptococci and Lactobacilli. Therefore, the suppression of sugar catabolism and acid production by the use of metabolic inhibitors in oral care products, the consumption of nonfermentable sweeteners in snacks, the stimulation of saliva flow, and/or other strategies that maintain supragingival plaque at a pH around neutrality will assist in the maintenance of microbial homeostasis in plaque.

An unreported clindamycin adverse reaction: wrist monoarthritis.

PubMed

Alikhani, Ahmad; Salehifar, Ebrahim

2012-01-01

Clindamycin is a lincosamide antibiotic which is approved for the treatment of Anaerobic, Streptococcal and Staphylococcal infections. There has been an increased interest in the use of clindamycin since it achieves high intracellular levels in phagocytic cells, high levels in bone and appears to have an antitoxin effect against the toxin elaborating strains of streptococci and staphylococci. Clindamycin is considered as a bacteriostatic antibiotic, while it is bactericidal against some strains of Staphylococci, Streptococci and Anaerobes such as B. fragilis. Its major disadvantage is its propensity to cause antibiotic-associated diarrhea. In spite of expanded use of clindamycin in bone infections, the adverse reactions of this antibiotic are minor. Polyarthritis is a rare adverse effect of this antibiotic. In this case report, we studied a 75-year-old male patient with past history of drop attack and subdural hematoma who developed skull osteomyelitis after the surgery. After two weeks of intravenous antibiotic therapy, wound discharge was stopped and the patient was discharged from the hospital with the maintenance oral antibiotic therapy including clindamycin 300 mg q8 h, ciprofloxacin 500 mg q12 h and rifampin 600 mg fasting. Six days after the beginning of oral antibiotics, right wrist monoarthritis was developed. It was unresponsive to nonsteroidal anti-inflammatory drug and improved after decreased doses of clindamycin. As best as we know, monoarthritis was not reported with clindamycin previously.

Limited prevalence of gaffkaemia (Aerococcus viridans var. homari) isolated from wild-caught European lobsters Homarus gammarus in England and Wales.

PubMed

Stebbing, P D; Pond, M J; Peeler, E; Small, H J; Greenwood, S J; Verner-Jeffreys, D

2012-08-27

Gaffkaemia, caused by Aerococcus viridans var. homari, causes fatal infections in Homarus spp. (clawed lobsters). Despite its high economic significance to the lobster fisheries in the USA and northern Europe, data on its prevalence in captured and wild populations, particularly in Europe, is scarce. Following an outbreak of gaffkaemia in a European lobster holding facility in South Wales (UK), a base-line survey was conducted for gaffkaemia in wild populations of European lobster Homarus gammarus around the coast of England and Wales. In addition, isolates recovered from the original outbreak and the survey were typed using pulsed-field gel electrophoresis (PFGE) and compared with previously characterised isolates from the USA, UK and Canada. Locally caught H. gammarus were sampled at 30 sites from around the coast of England and Wales between March 2006 and October 2008. Results confirmed that the prevalence of gaffkaemia in populations of H. gammarus was low, with only 9 positive isolates recovered from 952 samples examined. PFGE analysis showed that the isolates from the outbreak investigation shared the same pulsotype as A. viridans var. homari isolates from the USA, Norway and Canada, as well as an isolate (NCIMB 1119) reportedly recovered from an outbreak of European lobsters in England in the 1960s. This confirms earlier studies that suggest virulent strains of A. viridans var. homari show very limited geographical or temporal genetic variation and were introduced into the UK with American lobsters H. americanus.

Humoral Immunity to Commensal Oral Bacteria in Human Infants: Salivary Secretory Immunoglobulin A Antibodies Reactive with Streptococcus mitis biovar 1, Streptococcus oralis, Streptococcus mutans, and Enterococcus faecalis during the First Two Years of Life

PubMed Central

Cole, Michael F.; Bryan, Stacey; Evans, Mishell K.; Pearce, Cheryl L.; Sheridan, Michael J.; Sura, Patricia A.; Wientzen, Raoul L.; Bowden, George H. W.

1999-01-01

Secretory immunoglobulin A (SIgA) antibodies reactive with the pioneer oral streptococci Streptococcus mitis biovar 1 and Streptococcus oralis, the late oral colonizer Streptococcus mutans, and the pioneer enteric bacterium Enterococcus faecalis in saliva samples from 10 human infants from birth to age 2 years were analyzed. Low levels of salivary SIgA1 and SIgA2 antibodies reactive with whole cells of all four species were detected within the first month after birth, even though S. mutans and E. faecalis were not recovered from the mouths of the infants during the study period. Although there was a fivefold increase in the concentration of SIgA between birth and age 2 years, there were no differences between the concentrations of SIgA1 and SIgA2 antibodies reactive with the four species over this time period. When the concentrations of SIgA1 and SIgA2 antibodies reactive with all four species were normalized to the concentrations of SIgA1 and SIgA2 in saliva, SIgA1 and SIgA2 antibodies reactive with these bacteria showed a significant decrease from birth to 2 years of age. Adsorption of each infant’s saliva with cells of one species produced a dramatic reduction of antibodies recognizing the other three species. Sequential adsorption of saliva samples removed all SIgA antibody to the bacteria, indicating that the SIgA antibodies were directed to antigens shared by all four species. The induction by the host of a limited immune response to common antigens that are likely not involved in adherence may be among the mechanisms that commensal streptococci employ to persist in the oral cavity. PMID:10085031

Structural determinants of Actinomyces sortase SrtC2 required for membrane localization and assembly of type 2 fimbriae for interbacterial coaggregation and oral biofilm formation.

PubMed

Wu, Chenggang; Mishra, Arunima; Reardon, Melissa E; Huang, I-Hsiu; Counts, Sarah C; Das, Asis; Ton-That, Hung

2012-05-01

As a pioneer colonizer of the oral cavity, Actinomyces oris expresses proteinaceous pili (also called fimbriae) to mediate the following two key events in biofilm formation: adherence to saliva deposits on enamel and interbacterial associations. Assembly of type 2 fimbriae that directly facilitate coaggregation with oral streptococci and Actinomyces biofilm development requires the class C sortase SrtC2. Although the general sortase-associated mechanisms have been elucidated, several structural attributes unique to the class C sortases require functional investigation. Mutational studies reported here suggest that the N-terminal transmembrane (TM) region of SrtC2, predicted to contain a signal peptide sequence, is cleaved off the mature protein and that this processing is critical for the proper integration of the enzyme at the cytoplasmic membrane, which is mediated by the extended hydrophobic C terminus containing a TM domain and a cytoplasmic tail. Deletion of this putative TM or the entire cytoplasmic domain abolished the enzyme localization and functionality. Alanine substitution of the conserved catalytic Cys-His dyad abrogated the SrtC2 enzymatic activity. In contrast, mutations designed to alter a "lid" domain that covers the catalytic pocket of a class C sortase showed no effect on enzyme activity. Finally, each of the deleterious mutations that affected SrtC2 activity or membrane localization also eliminated Actinomyces species biofilm development and bacterial coaggregation with streptococci. We conclude that the N terminus of SrtC2, which contains the signal sequence, is required for proper protein translocation and maturation, while the extended C-terminal hydrophobic region serves as a stable membrane anchor for proper enzyme functionality.

Structural Determinants of Actinomyces sortase SrtC2 Required for Membrane Localization and Assembly of Type 2 Fimbriae for Interbacterial Coaggregation and Oral Biofilm Formation

PubMed Central

Wu, Chenggang; Mishra, Arunima; Reardon, Melissa E.; Huang, I-Hsiu; Counts, Sarah C.; Das, Asis

2012-01-01

As a pioneer colonizer of the oral cavity, Actinomyces oris expresses proteinaceous pili (also called fimbriae) to mediate the following two key events in biofilm formation: adherence to saliva deposits on enamel and interbacterial associations. Assembly of type 2 fimbriae that directly facilitate coaggregation with oral streptococci and Actinomyces biofilm development requires the class C sortase SrtC2. Although the general sortase-associated mechanisms have been elucidated, several structural attributes unique to the class C sortases require functional investigation. Mutational studies reported here suggest that the N-terminal transmembrane (TM) region of SrtC2, predicted to contain a signal peptide sequence, is cleaved off the mature protein and that this processing is critical for the proper integration of the enzyme at the cytoplasmic membrane, which is mediated by the extended hydrophobic C terminus containing a TM domain and a cytoplasmic tail. Deletion of this putative TM or the entire cytoplasmic domain abolished the enzyme localization and functionality. Alanine substitution of the conserved catalytic Cys-His dyad abrogated the SrtC2 enzymatic activity. In contrast, mutations designed to alter a “lid” domain that covers the catalytic pocket of a class C sortase showed no effect on enzyme activity. Finally, each of the deleterious mutations that affected SrtC2 activity or membrane localization also eliminated Actinomyces species biofilm development and bacterial coaggregation with streptococci. We conclude that the N terminus of SrtC2, which contains the signal sequence, is required for proper protein translocation and maturation, while the extended C-terminal hydrophobic region serves as a stable membrane anchor for proper enzyme functionality. PMID:22447896

[Enterococcal endocarditis: a multicenter study of 76 cases].

PubMed

Martínez-Marcos, Francisco Javier; Lomas-Cabezas, José Manuel; Hidalgo-Tenorio, Carmen; de la Torre-Lima, Javier; Plata-Ciézar, Antonio; Reguera-Iglesias, José María; Ruiz-Morales, Josefa; Márquez-Solero, Manuel; Gálvez-Acebal, Juan; de Alarcón-González, Arístides

2009-12-01

Although enterococci occupy the third position among microorganisms producing infectious endocarditis (IE) following streptococci and Staphylococcus aureus, few multicenter studies have provided an in-depth analysis of enterococcal IE. Description of the characteristics of 76 cases of enterococcal left-sided infectious endocarditis (LSIE) (native: 59, prosthetic: 17) retrieved from the database of the Cardiovascular Infections Study Group of the Andalusian Society of Infectious Diseases, with emphasis on the comparison with non-enterococcal LSIE. Enterococci were the causal agent in 76 of the 696 episodes of LSIE (11%). Compared with non-enterococcal LSIE, enterococcal LSIE was more commonly seen in patients older than 65 (47.4% vs. 27.6%, P<0.0005), and those with chronic diseases (75% vs. 54.6%, P<0.001), calcified valves (18.6% vs. 10%, P<0.05), and previous urinary (30.3% vs. 2.1%, P<0.00001) or abdominal (10.5% vs. 3.1%, P<0.01) infections, and produced a higher rate of relapses (6.6% vs. 2.3%, P<0.05). Enterococcal LSIE was associated with fewer peripheral vascular or skin manifestations (14.5% vs. 27.1%, P<0.05) and fewer immunological phenomena (10.5% vs. 24%, P<0.01). Among the total of patients with enterococcal LSIE, 36.8% underwent valve surgery during hospitalization. In-hospital mortality was 32.9% for enterococcal LSIE, 9.3% for viridans group streptococci (VGS) LSIE and 48.6% for S. aureus LSIE (enterococci vs VGS: P<0.0001; enterococci vs S. aureus: P=0.02). Enterococcal LSIE patients treated with the combination of a penicillin or vancomycin plus an aminoglycoside (n=60) and those treated with ampicillin plus ceftriaxone (n=6) showed similar in-hospital mortality (26.7% vs 33.3%, P=0.66). High-level resistance to gentamicin was detected in 5 of 38 episodes of enterococcal LSIE (13.1%). Enterococcal LSIE appears in patients with well-defined clinical characteristics, and causes few peripheral vascular or skin manifestations and few immunological phenomena. The relapse rate is higher than in non-enterococcal LSIE. Mortality due to enterococcal LSIE is lower than that of S. aureus LSIE, and much higher than that of VGS LSIE. Mortality due to enterococcal LSIE is similar in patients treated with ampicillin plus ceftriaxone or with a combination of penicillin or vancomycin plus an aminoglycoside. High-level resistance to gentamicin remains uncommon in enterococci causing LSIE.

Adhesion of mutans streptococci to self-ligating ceramic brackets: in vivo quantitative analysis with real-time polymerase chain reaction.

PubMed

Jung, Woo-Sun; Yang, Il-Hyung; Lim, Won Hee; Baek, Seung-Hak; Kim, Tae-Woo; Ahn, Sug-Joon

2015-12-01

To analyze in vivo mutans streptococci (MS) adhesion to self-ligating ceramic brackets [Clarity-SL (CSL) and Clippy-C (CC)] and the relationships between bacterial adhesion and oral hygiene indices. Four central incisor brackets from the maxilla and mandible were collected from 40 patients (20 patients per each bracket type) at debonding immediately after plaque and gingival indices were measured. Adhesions of Streptococcus mutans, S. sobrinus, and total bacteria were quantitatively determined using real-time polymerase chain reaction after genomic DNA was extracted. Factorial analysis of variance was used to analyze bacterial adhesion to the brackets with respect to the bracket type and jaw position. Correlation coefficients were calculated to determine the relationships of bacterial adhesion to oral hygiene indices. Adhesion of total bacteria and S. mutans to CSL was higher than that to CC (P < 0.001). Adhesion of total bacteria to the mandibular brackets was higher than that to the maxillary ones (P < 0.001), while adhesion of S. mutans to the maxillary brackets were higher than that in the mandibular ones (P < 0.001). In particular, the proportion of S. mutans to total bacteria in CSL was higher than CC (P < 0.05) in the maxillary anterior teeth (P < 0.001). There were no significant differences in adhesion of S. sobrinus between the brackets and jaw positions. Interestingly, no significant relationships were found between bacterial adhesions and oral hygiene indices. Complex bracket configurations may significantly influence bacterial adhesion to orthodontic brackets. Further in vivo study using bracket raw materials will help to define the relationships between bacteria adhesion and enamel demineralization. Because oral hygiene indices were not significantly correlated with adhesions of MS to self-ligating ceramic brackets, careful examinations around the brackets should be needed to prevent enamel demineralization, regardless of oral hygiene status. © The Author 2015. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Necrotizing fasciitis due to Streptococcus mitis caused by accidental human bite.

PubMed

Bastug, Aliye; Kislak, Sumeyye; Mutlu, Nevzat Mehmet; Akcaboy, Zeynep Nur; Koksal, Asude; Sertcelik, Ahmet; Ünlü, Ramazan Erkin; Akinci, Esragul; Bodur, Hurrem

2016-01-31

Human bite wounds are more prone to infection than animal bites, which may cause necrotizing soft tissue infections such as myositis, fasciitis. Both aerobic and anaerobic microorganisms may be responsible, including Streptococcus spp., Staphylococcus aureus, Peptostreptococcus spp. Necrotizing fasciitis is characterized by serious tissue destruction and systemic toxicity with high morbidity and mortality. We report a patient with Streptococcus mitis associated necrotizing fasciitis on the upper extremity resulting from an accidental human bite, which caused nearly fatal infection. Prophylactic antibiotic treatment should be given after a human bite to prevent infection. If the infection signs and symptoms develop, rapid diagnosis, appropriate antibiotic and surgical therapy should be administered immediately. Streptococcus mitis is a viridans streptococcus, usually known as a relatively benign oral streptococcus. To our knowledge, this is the first necrotizing fasciitis case due to Streptococcus mitis after human bite.

Bacterial invasion into radicular dentine-an in vitro study.

PubMed

Stauffacher, Simone; Lussi, Adrian; Nietzsche, Sandor; Neuhaus, Klaus W; Eick, Sigrun

2017-06-01

We wanted to investigate differences in invasiveness into radicular dentinal tubules by monocultured and co-cultured bacteria frequently found in infected root canals. Fifty-one human roots were incubated for 8 weeks with monocultured Streptococcus gordonii ATCC 10558, Streptococcus sanguinis ATCC 10556, and with five capnophiles/anaerobes as well as with capnophiles/anaerobes co-cultured with a streptococcal species. Thereafter, bacterial samples were cultured from the inner, middle, and outer third of the root dentine of longitudinally broken teeth (n = 5). In addition, scanning electron microscopy (SEM) images were obtained. Single gram-positive species were able to penetrate into the middle and outer third of the root dentine. Fusobacterium nucleatum ATCC 25586 was not found in any of the dentine specimens. Prevotella intermedia ATCC 25611 and Porphyromonas gingivalis ATCC 33277 were found in the inner and middle third. The bacterial load of streptococci was higher in all thirds in co-cultures compared to single infections. In co-cultures with streptococci, Actinomyces oris ATCC 43146 was found in the outer third in 9/10 samples, whereas P. intermedia ATCC 25611 was not detectable inside dentine. Co-culture with S. sanguinis ATCC 10556 enabled F. nucleatum ATCC 25586 to invade dentine; SEM images showed that F. nucleatum ATCC 25586 had a swollen shape. Invasiveness of bacteria into dentinal tubules is species-specific and may change depending on culturing as a single species or co-culturing with other bacteria. Oral streptococci may promote or inhibit invasion of capnophiles/anaerobes into radicular dentine.

Mechanism of oil-pulling therapy - in vitro study.

PubMed

Asokan, Sharath; Rathinasamy, T K; Inbamani, N; Menon, Thangam; Kumar, S Senthil; Emmadi, Pamela; Raghuraman, R

2011-01-01

Oil pulling has been used extensively as a traditional Indian folk remedy without scientific proof for many years for strengthening teeth, gums and jaws and to prevent decay, oral malodor, bleeding gums and dryness of throat and cracked lips. The aim of this study was to evaluate the antibacterial activity of sesame oil and lignans isolated from sesame oil on oral microorganisms and to check whether saponification or emulsification occurs during oil-pulling therapy. The in vitro study was carried out in three different phases: (1) Antibacterial activity of the lignans and sesame oil were tested by minimum inhibitory concentration assay by agar dilution method and agar well diffusion method, respectively. (2) Increase in free fatty acid level of oil and the quantity of sodium hydroxide (NaOH) used up in the titration are good indicators of saponification process. This was assessed using analytical tests for vegetable oils. (3) Swished oil was observed under light microscope to assess the status of the oil, presence of microorganisms, oral debris and foreign bodies. Sesamin and sesamolin isolated from sesame oil did not have any antibacterial effect against oral microorganisms like Streptococcus mutans, Streptococcus mitis and Streptococcus viridans. Emulsification of sesame oil occurs during oil-pulling therapy. Increased consumption of NaOH in titration is a definite indication of a possible saponification process. The myth that the effect of oil-pulling therapy on oral health was just a placebo effect has been broken and there are clear indications of possible saponification and emulsification process, which enhances its mechanical cleaning action.

Dental procedures, antibiotic prophylaxis, and endocarditis among people with prosthetic heart valves: nationwide population based cohort and a case crossover study

PubMed Central

Blotière, Pierre-Olivier; Hoen, Bruno; Lesclous, Philippe; Millot, Sarah; Rudant, Jérémie; Weill, Alain; Coste, Joel; Alla, François; Duval, Xavier

2017-01-01

Objective To assess the relation between invasive dental procedures and infective endocarditis associated with oral streptococci among people with prosthetic heart valves. Design Nationwide population based cohort and a case crossover study. Setting French national health insurance administrative data linked with the national hospital discharge database. Participants All adults aged more than 18 years, living in France, with medical procedure codes for positioning or replacement of prosthetic heart valves between July 2008 and July 2014. Main outcome measures Oral streptococcal infective endocarditis was identified using primary discharge diagnosis codes. In the cohort study, Poisson regression models were performed to estimate the rate of oral streptococcal infective endocarditis during the three month period after invasive dental procedures compared with non-exposure periods. In the case crossover study, conditional logistic regression models calculated the odds ratio and 95% confidence intervals comparing exposure to invasive dental procedures during the three month period preceding oral streptococcal infective endocarditis (case period) with three earlier control periods. Results The cohort included 138 876 adults with prosthetic heart valves (285 034 person years); 69 303 (49.9%) underwent at least one dental procedure. Among the 396 615 dental procedures performed, 103 463 (26.0%) were invasive and therefore presented an indication for antibiotic prophylaxis, which was performed in 52 280 (50.1%). With a median follow-up of 1.7 years, 267 people developed infective endocarditis associated with oral streptococci (incidence rate 93.7 per 100 000 person years, 95% confidence interval 82.4 to 104.9). Compared with non-exposure periods, no statistically significant increased rate of oral streptococcal infective endocarditis was observed during the three months after an invasive dental procedure (relative rate 1.25, 95% confidence interval 0.82 to 1.82; P=0.26) and after an invasive dental procedure without antibiotic prophylaxis (1.57, 0.90 to 2.53; P=0.08). In the case crossover analysis, exposure to invasive dental procedures was more frequent during case periods than during matched control periods (5.1% v 3.2%; odds ratio 1.66, 95% confidence interval 1.05 to 2.63; P=0.03). Conclusion Invasive dental procedures may contribute to the development of infective endocarditis in adults with prosthetic heart valves. PMID:28882817

Incidence of Bacteriocins Produced by Food-Related Lactic Acid Bacteria Active towards Oral Pathogens

PubMed Central

Zoumpopoulou, Georgia; Pepelassi, Eudoxie; Papaioannou, William; Georgalaki, Marina; Maragkoudakis, Petros A.; Tarantilis, Petros A.; Polissiou, Moschos; Tsakalidou, Effie; Papadimitriou, Konstantinos

2013-01-01

In the present study we investigated the incidence of bacteriocins produced by 236 lactic acid bacteria (LAB) food isolates against pathogenic or opportunistic pathogenic oral bacteria. This set of LAB contained several strains (≥17%) producing bacteriocins active against food-related bacteria. Interestingly only Streptococcus macedonicus ACA-DC 198 was able to inhibit the growth of Streptococcus oralis, Streptococcus sanguinis and Streptococcus gordonii, while Lactobacillus fermentum ACA-DC 179 and Lactobacillus plantarun ACA-DC 269 produced bacteriocins solely against Streptococcus oralis. Thus, the percentage of strains that were found to produce bacteriocins against oral bacteria was ~1.3%. The rarity of bacteriocins active against oral LAB pathogens produced by food-related LAB was unexpected given their close phylogenetic relationship. Nevertheless, when tested in inhibition assays, the potency of the bacteriocin(s) of S. macedonicus ACA-DC 198 against the three oral streptococci was high. Fourier-transform infrared spectroscopy combined with principal component analysis revealed that exposure of the target cells to the antimicrobial compounds caused major alterations of key cellular constituents. Our findings indicate that bacteriocins produced by food-related LAB against oral LAB may be rare, but deserve further investigation since, when discovered, they can be effective antimicrobials. PMID:23443163

Role of hydrogen peroxidein competition and cooperation between Streptococcus gordonii and Actinomyces naeslundii

PubMed Central

Jakubovics, Nicholas S.; Gill, Steven R.; Vickerman, M. Margaret; Kolenbrander, Paul E.

2010-01-01

In dental plaque α-haemolytic streptococci, including Streptococcus gordonii, are considered beneficial for oral health. These organisms produce hydrogen peroxide (H2O2) at concentrations sufficient to kill many oral bacteria. Streptococci do not produce catalase yet tolerate H2O2. We recently demonstrated that coaggregation with Actinomyces naeslundii stabilizes arginine biosynthesis in S. gordonii. Protein arginine residues are sensitive to oxidation by H2O2. Here, the ability of A. naeslundii to protect S. gordonii against self-produced H2O2 was investigated. Coaggregation with A. naeslundii enabled S. gordonii to grow in the absence of arginine, and promoted survival of S. gordonii following growth with or without added arginine. Arginine-replete S. gordonii monocultures contained 20–30 μM H2O2 throughout exponential growth. Actinomyces naeslundii did not produce H2O2 but synthesized catalase, removed H2O2 from coaggregate cultures and decreased protein oxidation in S. gordonii. On solid medium, S. gordonii inhibited growth of A. naeslundii; exogenous catalase overcame this inhibition. In coaggregate cultures, A. naeslundii cell numbers were >90% lower than in monocultures after 24 h. These results indicate that coaggregation with A. naeslundii protects S. gordonii from oxidative damage. However, high cell densities of S. gordonii inhibit A. naeslundii. Therefore, H2O2 may drive these organisms towards an ecologically balanced community in natural dental plaque. PMID:18785881

Difference in initial dental biofilm accumulation between night and day.

PubMed

Dige, Irene; Schlafer, Sebastian; Nyvad, Bente

2012-12-01

The study of initial microbial colonization on dental surfaces is a field of intensive research because of the aetiological role of biofilms in oral diseases. Most previous studies of de novo accumulation and composition of dental biofilms in vivo do not differentiate between biofilms formed during day and night. This study hypothesized that there is a diurnal variation in the rate of accumulation of bacteria on solid surfaces in the oral cavity. In situ biofilm from healthy individuals was collected for 12 h during day and night, respectively, subjected to fluorescent in situ hybridization and visualized using confocal laser scanning microscopy. Analysis of the biofilms using stereological methods and digital image analysis revealed a consistent statistically significant difference between both the total number of bacteria and the biovolume in the two 12-h groups (p = 0.012), with the highest accumulation of bacteria during daytime (a factor of 8.8 and 6.1 higher, respectively). Hybridization with probes specific for streptococci and Actinomyces naeslundii indicated a higher proportion of streptococci in biofilms grown during daytime as compared to night-time. No differences could be observed for A. naeslundii. The degree of microbial coverage and the bacterial composition varied considerably between different individuals. The data provide firm evidence that initial biofilm formation decreases during the night, which may reflect differences in the availability of salivary nutrients. This finding is of significant importance when studying population dynamics during experimental dental biofilm formation.

Targeted Killing of Streptococcus mutans by a Pheromone-Guided “Smart” Antimicrobial Peptide

PubMed Central

Eckert, Randal ; He, Jian; Yarbrough, Daniel K.; Qi, Fengxia; Anderson, Maxwell H.; Shi, Wenyuan

2006-01-01

Within the repertoire of antibiotics available to a prescribing clinician, the majority affect a broad range of microorganisms, including the normal flora. The ecological disruption resulting from antibiotic treatment frequently results in secondary infections or other negative clinical consequences. To address this problem, our laboratory has recently developed a new class of pathogen-selective molecules, called specifically (or selectively) targeted antimicrobial peptides (STAMPs), based on the fusion of a species-specific targeting peptide domain with a wide-spectrum antimicrobial peptide domain. In the current study, we focused on achieving targeted killing of Streptococcus mutans, a cavity-causing bacterium that resides in a multispecies microbial community (dental plaque). In particular, we explored the possibility of utilizing a pheromone produced by S. mutans, namely, the competence stimulating peptide (CSP), as a STAMP targeting domain to mediate S. mutans-specific delivery of an antimicrobial peptide domain. We discovered that STAMPs constructed with peptides derived from CSP were potent against S. mutans grown in liquid or biofilm states but did not affect other oral streptococci tested. Further studies showed that an 8-amino-acid region within the CSP sequence is sufficient for targeted delivery of the antimicrobial peptide domain to S. mutans. The STAMPs presented here are capable of eliminating S. mutans from multispecies biofilms without affecting closely related noncariogenic oral streptococci, indicating the potential of these molecules to be developed into “probiotic” antibiotics which could selectively eliminate pathogens while preserving the protective benefits of a healthy normal flora. PMID:17060534

Human Leucocyte Antigen Profile and Transmission of Mutans Streptococci in Mother-Child Pairs.

PubMed

Wallengren, Marie L; Hedström, Kristin; Zbroszczyk, Katarzyna; Hamberg, Kristina

2015-01-01

To investigate possible association between the transmission of mutans streptococci and sharing the immune system component Human Leucocyte Antigen (HLA) class II in mother-child pairs. Plaque samples from 43 mother-child pairs were cultivated and screened for mutans streptococci. In 14 pairs where both mother and child harboured the bacteria, the strains were genotyped by Random Amplified Polymorphic DNA and samples were run on PAGE gels. Analysis of genetic identity between mother and child strains was performed with help of software and Dice similarity index. The distribution of HLA of serogroup DR4 (HLA DR4) was studied in relation to maternal transmission and mutans streptococci colonisation in children. The study hypothesis was that in pairs where both mother and child were HLA DR4 positive, transmission of mutans streptococci was more likely. No correlation between the presence of HLA DR4 in mother and child and maternal transmission of mutans streptococci was established. However, the results showed no linkage between mutans streptococci colonisation and HLA DR 4. Of 15 children with mutans streptococci, 12 were HLA DR4 positive. The result suggests that presence of HLA DR4 could be a predisposing factor for colonisation with mutans streptococci in children.

Colonization with group B streptococci in pregnancy and adverse outcome. VIP Study Group.

PubMed

Regan, J A; Klebanoff, M A; Nugent, R P; Eschenbach, D A; Blackwelder, W C; Lou, Y; Gibbs, R S; Rettig, P J; Martin, D H; Edelman, R

1996-04-01

Our purpose was to study the association of cervicovaginal colonization with group B streptococci with pregnancy and neonatal outcome. A prospective study was conducted at seven medical centers between 1984 and 1989. Genital tract cultures were obtained at 23 to 26 weeks' gestation and at delivery. Prematurity and neonatal sepsis rates were compared between group B streptococci positive and negative women. Group B streptococci was recovered from 2877 (21%) of 13,646 women at enrollment. Heavy colonization was associated with a significant risk of delivering a preterm infant who had a low birth weight (odds ratio = 1.5, 95% confidence interval 1.1 to 1.9). Heavily colonized women given antibiotics effective against group B streptococci had little increased risk of a preterm, low-birth-weight birth. Women with light colonization were at the same risk of adverse outcome as the uncolonized women. Neonatal group B streptococci sepsis occurred in 2.6 of 1000 live births in women with and 1.6 of 1000 live births in women without group B streptococci at 23 to 26 weeks' gestation (p = 0.11). However, sepsis occurred in 16 of 1000 live births to women with and 0.4 of 1000 live births to women without group B streptococci at delivery (p < 0.001). Heavy group B streptococci colonization of 23 to 26 weeks' gestation was associated with an increased risk of delivering a preterm, low-birth-weight infant. Cervicovaginal colonization with group B streptococci at 23 to 26 weeks' gestation was not a reliable predictor of neonatal group B streptococci sepsis. Colonization at delivery was associated with sepsis.

Multicenter Evaluation of the Vitek MS Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry System for Identification of Gram-Positive Aerobic Bacteria

PubMed Central

Burnham, Carey-Ann D.; Bythrow, Maureen; Garner, Omai B.; Ginocchio, Christine C.; Jennemann, Rebecca; Lewinski, Michael A.; Manji, Ryhana; Mochon, A. Brian; Procop, Gary W.; Richter, Sandra S.; Sercia, Linda; Westblade, Lars F.; Ferraro, Mary Jane; Branda, John A.

2013-01-01

Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF) is gaining momentum as a tool for bacterial identification in the clinical microbiology laboratory. Compared with conventional methods, this technology can more readily and conveniently identify a wide range of organisms. Here, we report the findings from a multicenter study to evaluate the Vitek MS v2.0 system (bioMérieux, Inc.) for the identification of aerobic Gram-positive bacteria. A total of 1,146 unique isolates, representing 13 genera and 42 species, were analyzed, and results were compared to those obtained by nucleic acid sequence-based identification as the reference method. For 1,063 of 1,146 isolates (92.8%), the Vitek MS provided a single identification that was accurate to the species level. For an additional 31 isolates (2.7%), multiple possible identifications were provided, all correct at the genus level. Mixed-genus or single-choice incorrect identifications were provided for 18 isolates (1.6%). Although no identification was obtained for 33 isolates (2.9%), there was no specific bacterial species for which the Vitek MS consistently failed to provide identification. In a subset of 463 isolates representing commonly encountered important pathogens, 95% were accurately identified to the species level and there were no misidentifications. Also, in all but one instance, the Vitek MS correctly differentiated Streptococcus pneumoniae from other viridans group streptococci. The findings demonstrate that the Vitek MS system is highly accurate for the identification of Gram-positive aerobic bacteria in the clinical laboratory setting. PMID:23658261

Impact of High-Level Daptomycin Resistance in the Streptococcus mitis Group on Virulence and Survivability during Daptomycin Treatment in Experimental Infective Endocarditis

PubMed Central

Garcia-de-la-Maria, C.; Xiong, Y. Q.; Pericas, J. M.; Armero, Y.; Moreno, A.; Mishra, N. N.; Rybak, M. J.; Tran, T. T.; Arias, C. A.; Sullam, P. M.; Bayer, A. S.

2017-01-01

ABSTRACT Among the viridans group streptococci, the Streptococcus mitis group is the most common cause of infective endocarditis. These bacteria have a propensity to be β-lactam resistant, as well as to rapidly develop high-level and durable resistance to daptomycin (DAP). We compared a parental, daptomycin-susceptible (DAPs) S. mitis/S. oralis strain and its daptomycin-resistant (DAPr) variant in a model of experimental endocarditis in terms of (i) their relative fitness in multiple target organs in this model (vegetations, kidneys, spleen) when animals were challenged individually and in a coinfection strategy and (ii) their survivability during therapy with daptomycin-gentamicin (an in vitro combination synergistic against the parental strain). The DAPr variant was initially isolated from the cardiac vegetations of animals with experimental endocarditis caused by the parental DAPs strain following treatment with daptomycin. The parental strain and the DAPr variant were comparably virulent when animals were individually challenged. In contrast, in the coinfection model without daptomycin therapy, at both the 106- and 107-CFU/ml challenge inocula, the parental strain outcompeted the DAPr variant in all target organs, especially the kidneys and spleen. When the animals in the coinfection model of endocarditis were treated with DAP-gentamicin, the DAPs strain was completely eliminated, while the DAPr variant persisted in all target tissues. These data underscore that the acquisition of DAPr in S. mitis/S. oralis does come at an intrinsic fitness cost, although this resistance phenotype is completely protective against therapy with a potentially synergistic DAP regimen. PMID:28264848

Minimizing the Workup of Blood Culture Contaminants: Implementation and Evaluation of a Laboratory-Based Algorithm

PubMed Central

Richter, S. S.; Beekmann, S. E.; Croco, J. L.; Diekema, D. J.; Koontz, F. P.; Pfaller, M. A.; Doern, G. V.

2002-01-01

An algorithm was implemented in the clinical microbiology laboratory to assess the clinical significance of organisms that are often considered contaminants (coagulase-negative staphylococci, aerobic and anaerobic diphtheroids, Micrococcus spp., Bacillus spp., and viridans group streptococci) when isolated from blood cultures. From 25 August 1999 through 30 April 2000, 12,374 blood cultures were submitted to the University of Iowa Clinical Microbiology Laboratory. Potential contaminants were recovered from 495 of 1,040 positive blood cultures. If one or more additional blood cultures were obtained within ±48 h and all were negative, the isolate was considered a contaminant. Antimicrobial susceptibility testing (AST) of these probable contaminants was not performed unless requested. If no additional blood cultures were submitted or there were additional positive blood cultures (within ±48 h), a pathology resident gathered patient clinical information and made a judgment regarding the isolate's significance. To evaluate the accuracy of these algorithm-based assignments, a nurse epidemiologist in approximately 60% of the cases performed a retrospective chart review. Agreement between the findings of the retrospective chart review and the automatic classification of the isolates with additional negative blood cultures as probable contaminants occurred among 85.8% of 225 isolates. In response to physician requests, AST had been performed on 15 of the 32 isolates with additional negative cultures considered significant by retrospective chart review. Agreement of pathology resident assignment with the retrospective chart review occurred among 74.6% of 71 isolates. The laboratory-based algorithm provided an acceptably accurate means for assessing the clinical significance of potential contaminants recovered from blood cultures. PMID:12089259

Cell-free released components of Streptococcus sanguis inhibit human platelet aggregation.

PubMed Central

Herzberg, M C; Brintzenhofe, K L; Clawson, C C

1983-01-01

To study the role of surface components in the selective binding and aggregation of platelet-rich plasma (PRP) by strains of viridans streptococci, we treated the binding, aggregation strain Streptococcus sanguis I 2017-78 by sonication or trypsinization. Morphologically identifiable electron-dense fibrils were released from the cell wall, apparently from an inner electron-dense layer, under conditions that left cells intact. These controlled conditions were determined to cause submaximal loss in adhesion to platelet ghosts and PRP aggregation by treated, washed S. sanguis. Soluble components were recovered from the controlled sonic or L-(tosylamido 2-phenyl)ethyl chloromethyl ketone-trypsin treatments. Each showed dose-response inhibition of aggregation when preincubated with PRP before challenge with fresh, untreated S. sanguis. The time to onset of PRP aggregation was inhibited by 50% with 0.2 mg of TPCK-trypsin peptides or 1.0 mg of the sonicate per ml per 2 X 10(8) platelets. Components of both preparations were immunologically cross-reactive, but lipoteichoic acid was not a major antigen of either. By weight, the TPCK-trypsin peptides were virtually all protein; the sonicate residues identified were about 50% protein and 7% hexose. Each was a complex mixture of components as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. More than 8 TPCK-trypsin peptides and 16 sonicate components were so identified. In contrast, at least four or five components from either preparation were recognized as surface determinants by a rabbit antiserum to whole homologous microbes. Platelet-binding ligands of S. sanguis could be among these determinants. Images PMID:6618669

Multicenter evaluation of the Vitek MS matrix-assisted laser desorption ionization-time of flight mass spectrometry system for identification of Gram-positive aerobic bacteria.

PubMed

Rychert, Jenna; Burnham, Carey-Ann D; Bythrow, Maureen; Garner, Omai B; Ginocchio, Christine C; Jennemann, Rebecca; Lewinski, Michael A; Manji, Ryhana; Mochon, A Brian; Procop, Gary W; Richter, Sandra S; Sercia, Linda; Westblade, Lars F; Ferraro, Mary Jane; Branda, John A

2013-07-01

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF) is gaining momentum as a tool for bacterial identification in the clinical microbiology laboratory. Compared with conventional methods, this technology can more readily and conveniently identify a wide range of organisms. Here, we report the findings from a multicenter study to evaluate the Vitek MS v2.0 system (bioMérieux, Inc.) for the identification of aerobic Gram-positive bacteria. A total of 1,146 unique isolates, representing 13 genera and 42 species, were analyzed, and results were compared to those obtained by nucleic acid sequence-based identification as the reference method. For 1,063 of 1,146 isolates (92.8%), the Vitek MS provided a single identification that was accurate to the species level. For an additional 31 isolates (2.7%), multiple possible identifications were provided, all correct at the genus level. Mixed-genus or single-choice incorrect identifications were provided for 18 isolates (1.6%). Although no identification was obtained for 33 isolates (2.9%), there was no specific bacterial species for which the Vitek MS consistently failed to provide identification. In a subset of 463 isolates representing commonly encountered important pathogens, 95% were accurately identified to the species level and there were no misidentifications. Also, in all but one instance, the Vitek MS correctly differentiated Streptococcus pneumoniae from other viridans group streptococci. The findings demonstrate that the Vitek MS system is highly accurate for the identification of Gram-positive aerobic bacteria in the clinical laboratory setting.

Streptococcus mutans, Streptococcus sobrinus and Candida albicans in oral samples from caries-free and caries-active children.

PubMed

Fragkou, S; Balasouli, C; Tsuzukibashi, O; Argyropoulou, A; Menexes, G; Kotsanos, N; Kalfas, S

2016-10-01

This was to examine the occurrence of S. mutans, S. sobrinus and C. albicans in dental plaque and saliva from caries-free and caries-active Greek children. Saliva and dental plaque samples from 46 caries-free and 51 caries-active 3-to-13-year-old children were examined using selective media for the three microbes. Identification of isolated mutans streptococci (S. mutans and S. sobrinus) was performed with biochemical test and specific DNA probes. The salivary levels of mutans streptococci were additionally determined by a chair-side test (Dentocult ® SM strips). The isolation frequencies of S. mutans, S. sobrinus and C. albicans were 66, 11 and 18 %, respectively. Caries-active children harboured more frequently and at significantly higher numbers the specific microbes than caries-free children. A similar pattern was observed with the Dentocult ® SM strip scores. No correlation was found between the presence of these microbes and the age or gender of the children. Caries experience was statistically significantly related to the presence of all three microbes under study, both in dental plaque and saliva.

Improved artificial saliva for studying the cariogenic effect of carbohydrates.

PubMed

Björklund, Marika; Ouwehand, Arthur C; Forssten, Sofia D

2011-07-01

Saliva is a complex fluid that possesses many important functions regarding oral health. Many in vitro studies require relatively large quantities of saliva. While natural saliva would be the material of choice, it is difficult to obtain in sufficient quantities and varies in composition. Substitutes mimicking the physicochemical properties of saliva have been developed, but these are not appropriate to study the growth of mutans streptococci. Brain Heart Infusion (BHI) has been commonly used for this, but this medium is richer in nutrients than saliva. We therefore developed artificial saliva (AS) with nutrient levels resembling those in natural saliva as a substitute for natural human saliva (HS) to study the influence of different carbon sources on mutans streptococci growth. Growth of a wild-type Streptococcus mutans strain and S. mutans ATCC 15175 in BHI, HS, and AS was monitored anaerobically. Growth of S. mutans in the modified AS was very similar to the growth in HS, both in the absence and presence of different carbon sources. We therefore conclude that the developed AS is suitable for in vitro tests on S. mutans growth.

Raman Spectroscopy of Xylitol Uptake and Metabolism in Gram-Positive and Gram-Negative Bacteria▿

PubMed Central

Palchaudhuri, Sunil; Rehse, Steven J.; Hamasha, Khozima; Syed, Talha; Kurtovic, Eldar; Kurtovic, Emir; Stenger, James

2011-01-01

Visible-wavelength Raman spectroscopy was used to investigate the uptake and metabolism of the five-carbon sugar alcohol xylitol by Gram-positive viridans group streptococcus and the two extensively used strains of Gram-negative Escherichia coli, E. coli C and E. coli K-12. E. coli C, but not E. coli K-12, contains a complete xylitol operon, and the viridans group streptococcus contains an incomplete xylitol operon used to metabolize the xylitol. Raman spectra from xylitol-exposed viridans group streptococcus exhibited significant changes that persisted even in progeny grown from the xylitol-exposed mother cells in a xylitol-free medium for 24 h. This behavior was not observed in the E. coli K-12. In both viridans group streptococcus and the E. coli C derivative HF4714, the metabolic intermediates are stably formed to create an anomaly in bacterial normal survival. The uptake of xylitol by Gram-positive and Gram-negative pathogens occurs even in the presence of other high-calorie sugars, and its stable integration within the bacterial cell wall may discontinue bacterial multiplication. This could be a contributing factor for the known efficacy of xylitol when taken as a prophylactic measure to prevent or reduce occurrences of persistent infection. Specifically, these bacteria are causative agents for several important diseases of children such as pneumonia, otitis media, meningitis, and dental caries. If properly explored, such an inexpensive and harmless sugar-alcohol, alone or used in conjunction with fluoride, would pave the way to an alternative preventive therapy for these childhood diseases when the causative pathogens have become resistant to modern medicines such as antibiotics and vaccine immunotherapy. PMID:21037297

Genetic variability of mutans streptococci revealed by wide whole-genome sequencing

PubMed Central

2013-01-01

Background Mutans streptococci are a group of bacteria significantly contributing to tooth decay. Their genetic variability is however still not well understood. Results Genomes of 6 clinical S. mutans isolates of different origins, one isolate of S. sobrinus (DSM 20742) and one isolate of S. ratti (DSM 20564) were sequenced and comparatively analyzed. Genome alignment revealed a mosaic-like structure of genome arrangement. Genes related to pathogenicity are found to have high variations among the strains, whereas genes for oxidative stress resistance are well conserved, indicating the importance of this trait in the dental biofilm community. Analysis of genome-scale metabolic networks revealed significant differences in 42 pathways. A striking dissimilarity is the unique presence of two lactate oxidases in S. sobrinus DSM 20742, probably indicating an unusual capability of this strain in producing H2O2 and expanding its ecological niche. In addition, lactate oxidases may form with other enzymes a novel energetic pathway in S. sobrinus DSM 20742 that can remedy its deficiency in citrate utilization pathway. Using 67 S. mutans genomes currently available including the strains sequenced in this study, we estimates the theoretical core genome size of S. mutans, and performed modeling of S. mutans pan-genome by applying different fitting models. An “open” pan-genome was inferred. Conclusions The comparative genome analyses revealed diversities in the mutans streptococci group, especially with respect to the virulence related genes and metabolic pathways. The results are helpful for better understanding the evolution and adaptive mechanisms of these oral pathogen microorganisms and for combating them. PMID:23805886

Salivary density of Streptococcus mutans and Streptococcus sobrinus and dental caries in children and adolescents with Down syndrome

PubMed Central

SCALIONI, Flávia; CARRADA, Camila; MACHADO, Fernanda; Karina, DEVITO; RIBEIRO, Luiz Cláudio; CESAR, Dionéia; RIBEIRO, Rosangela

2017-01-01

Abstract Streptococcus mutans and Streptococcus sobrinus are strongly associated with dental caries. However, the relationship between oral streptococci and dental caries in children with Down syndrome is not well characterized. Objective To assess and compare dental caries experience and salivary S. mutans, S. sobrinus, and streptococci counts between groups of Down syndrome and non-Down syndrome children and adolescents. Material and Methods This study included a sample of 30 Down syndrome children and adolescents (G-DS) and 30 age- and sex-matched non-Down syndrome subjects (G-ND). Dental caries experience was estimated by the number of decayed, missing, and filled teeth in the primary dentition and the permanent dentition. Unstimulated whole saliva samples were collected from all participants. The fluorescence in situ hybridization technique was used to identify the presence and counts of the bacteria. The statistical analysis included chi-square, Student’s t-test and Spearman’s correlation. Results The G-DS exhibited a significantly higher caries-free rate (p<0.001) and a lower S. mutans salivary density (p<0.001). No significant differences were found in the salivary densities of S. sobrinus or streptococci between the groups (p=0.09 and p=0.21, respectively). The salivary S. mutans or S. sobrinus densities were not associated with dental caries experience in neither group. Conclusion The reduced dental caries experience observed in this group of Down syndrome children and adolescents cannot be attributed to lower salivary S. mutans densities, as determined with the fluorescence in situ hybridization technique. PMID:28678943

Diet intake and caries prevalence in four-year-old children living in a low-prevalence country.

PubMed

Ohlund, I; Holgerson, P L; Backman, B; Lind, T; Hernell, O; Johansson, I

2007-01-01

Preventive measures have dramatically decreased the prevalence of dental caries in children. However, risk factors for the disease in children living in low-prevalence areas remain elusive. In the present study we evaluated associations between dental caries, saliva levels of mutans streptococci and lactobacilli, and diet with special emphasis on the intake of fermentable carbohydrates and dairy products in 4-year-old children living in an area where the overall caries prevalence was low. Dietary intake was recorded in 234 infants as part of the Study of Infant Nutrition in Umeå, Sweden (SINUS). Of these the parents of 124 children gave consent to participate in a follow-up at 4 years of age. Dietary intake, height and weight, dental caries, oral hygiene, including tooth brushing habits, presence of plaque and gingival inflammation, fluoride habits and numbers of mutans streptococci and lactobacilli in saliva were recorded. Using multivariate stepwise logistic regression, caries experience was negatively associated with intake frequency of cheese (OR = 0.67; 95% CI = 0.44-0.98) and positively associated with the salivary level of mutans streptococci (OR = 1.57; 95% CI = 1.21-2.03). Caries experience was not correlated with intake frequency or amounts of carbohydrate-containing foods, with any other particular food, or with daily intake of energy, carbohydrate or any other macro- or micronutrient. We conclude that cheese intake may have a caries-protective effect in childhood populations where the overall caries prevalence and caries experience are low and the children are regularly exposed to fluoride from toothpaste.

Mutans Streptococci Colonization in Relation to Feeding Practices, Age and the Number of Teeth in 6 to 30-Month-Old Children: An in vivo Study

PubMed Central

Prabhakar, AR; Gaur, Anupama

2012-01-01

ABSTRACT Background: Early childhood caries has been characterized as first affecting the primary maxillary anterior teeth, followed by the involvement of the primary molars. Other terms for dental caries in preschool children, which inappropriately may imply cause for the disease, includes baby bottle tooth decay, nursing caries, milk bottle syndrome, baby bottle caries, nursing bottle mouth and nursing mouth. Aim: To explore the relationships of feeding practices, age and number of teeth present with mutans streptococci colonization in infants. Design and setting: A comparative clinical study conducted on 160 children aged from 6 to 30 months in the Department of Pedodontics and Preventive Dentistry, Bapuji Dental College and Hospital in collaboration with Child Health Institute and Research Center and Department of Oral Pathology and Microbiology, Bapuji Dental College and Hospital, Davangere. Materials and methods: Baseline data collection included: (i) Parents of the infants were asked open ended questions about the baby feeding practices, (ii) The age of the subjects were obtained from the immunization register maintained at Child Health Institute and Research Center and were grouped into group I (6-11 months), group II (12-17 months), group III (18-23 months) and group IV (24-30 months), (iii) Clinical examination of children was done by using mouth mirror and explorer in flash light.6 For each child number and location of erupted teeth was recorded, (iv) Microbial screening for mutans streptococci involved sampling of saliva from each child was performed by placing a sterile wooden tongue blade on the dorsum of the tongue and the number of colony forming units (CFU) were recorded. Results: According to feeding practices, 34 children were in breastfed category, 39 were in baby bottle category and 87 children reported no bottle usage. Out of 160 children examined, a total 142 children were colonized with mutans streptococci. 18 children were found to be colonized with low colony forming units, 78 children were found to be colonized with moderate colony forming units and 64 children were colonized with high colony forming units. In baby bottle group, all of 39 subjects were reported to have sweetened milk, sugar in the bottle. Conclusion: Among different feeding practices, all the three subgroups viz breastfed children, children with nursing bottle usage and children with no bottle usage, all have shown mutans streptococci acquisition. But breastfed children have shown least number of high colony forming units, which is increased in the case of children using nursing bottle and is maximum in the children who were neither breastfed nor fed with nursing bottle. Percentage of children colonized with mutans streptococci increases with age and as the number of teeth increase, number of colony forming units were also found to be increasing. How to cite this article: Sharma R, Prabhakar AR, Gaur A. Mutans Streptococci Colonization in Relation to Feeding Practices, Age and the Number of Teeth in 6 to 30-Month-Old Children: An in vivo Study. Int J Clin Pediatr Dent 2012;5(2): 124-131. PMID:25206151

Efficacy of azithromycin or clarithromycin for prophylaxis of viridans group streptococcus experimental endocarditis.

PubMed Central

Rouse, M S; Steckelberg, J M; Brandt, C M; Patel, R; Miro, J M; Wilson, W R

1997-01-01

The efficacy of azithromycin or clarithromycin was compared to that of amoxicillin, clindamycin, or erythromycin for the prevention of viridans group streptococcus experimental endocarditis. Rabbits with catheter-induced aortic valve vegetations were given no antibiotics or two doses of amoxicillin at 25 mg/kg of body weight, azithromycin at 10 mg/kg, clarithromycin at 10 mg/kg, clindamycin at 40 mg/kg followed by clindamycin at 20 mg/kg, or erythromycin at 10 mg/kg. Antibiotics were administered 0.5 h before and 5.5 h after intravenous infusion of 5 x 10(5) CFU of Streptococcus milleri. Forty-eight hours after bacterial inoculation, the rabbits were killed and aortic valve vegetations were aseptically removed and cultured for bacteria. Infective endocarditis occurred in 88% of untreated animals, 1% of animals receiving amoxicillin, 9% of animals receiving erythromycin, 0% of animals receiving clindamycin, 2.5% of animals receiving clarithromycin, and 1% of animals receiving azithromycin. All five regimens were more effective (P < 0.001) than no prophylaxis. Erythromycin was less effective (P < 0.05) than amoxicillin or clindamycin. Azithromycin or clarithromycin was as effective as amoxicillin, clindamycin, or erythromycin for the prevention of viridans group streptococcus experimental endocarditis in this model. PMID:9257739

Association between group A beta-haemolytic streptococci and vulvovaginitis in adult women: a case-control study.

PubMed

Bruins, M J; Damoiseaux, R A M J; Ruijs, G J H M

2009-08-01

Guidelines for the management of vaginal discharge mention Candida albicans, Trichomonas vaginalis, bacterial vaginosis, Chlamydia trachomatis and Neisseria gonorrhoeae as causes and do not recommend full microbiological culture. The role of non-group B beta-haemolytic streptococci in vaginal cultures is unclear, except for group A streptococci that are known to cause vulvovaginitis in children. In a case-control study, we investigated the association between non-group B beta-haemolytic streptococci and vulvovaginitis in adult women. Cases were women with recurrent vaginal discharge from whom a sample was cultured. Controls were asymptomatic women who consented to submitting a vaginal swab. Group A streptococci were isolated from 49 (4.9%) of 1,010 cases and not from the 206 controls (P < 0.01). Isolation rates of group C, F and G streptococci were low and did not differ statistically between cases and controls. Group A beta-haemolytic streptococci are associated with vaginal discharge in adult women. The other non-group B streptococci require more study. For the adequate management of vaginal discharge, culturing is necessary if initial treatment fails. Guidelines should be amended according to these results.

The F-ATPase operon from the oral streptococci S. mutans and S. sanguis: How structure relates to function

NASA Astrophysics Data System (ADS)

Kuhnert, Wendi Lee

1999-10-01

The oral microbe, Streptococcus mutans is known to be a primary contributor to the most common infection in humans, dental caries. In the plaque environment, resident bacteria metabolize dietary sucrose which results in the production of organic acids and a decrease in plaque pH. The proton-translocating ATPase (F-ATPase) protects the bacteria from acidification by extruding protons, at the expense of ATP, to maintain an internal pH which is more neutral than the external environment. Examination of this enzyme will help us to gain insight regarding its contribution to the aciduricity characteristics of oral bacteria. In this work, our goal was to begin the molecular dissection of the mechanism by which streptococcal ATPases are regulated and function enzymatically. Sequence analysis of the F-ATPase from the non-pathogenic S. sanguis revealed that the structural genes are homologous to S. mutans as well as other sequenced F-ATPases. Cloned subunits were functionally similar as shown by complementing E. coli ATPase mutants. S. sanguis/E. coli hybrid enzymes hydrolyzed ATP, but proton conduction was uncoupled as demonstrated with inhibition studies. Transcriptional regulation of the F-ATPase operon from S. mutans was examined using chloramphenicol acetyltransferase gene fusions. Fusions containing 136 bp of DNA upstream of the promoter showed higher levels of expression as compared to those with only 16 bp. Similar to ATPase enzymatic activity, CAT expression also increased during growth at low pH. Analysis of RNA demonstrated that ATPase mRNA levels were higher at low pH, which supported the CAT activity data. Therefore, the F-ATPase from S. mutans was regulated, at least partially, by both the DNA located upstream of the promoter as well as by pH. Examination of structural models of the F-ATPase from the pathogenic oral organisms S. mutans and Lactobacillus casei and the non- pathogenic S. sanguis showed that the differences noted in the sequence of the catalytic β subunit do not result in structural alterations. Therefore, the contribution that the F-ATPase makes towards the aciduricity of the oral streptococci is linked to its increased expression at low pH or perhaps to structural differences in the other, less-conserved, domains of the enzyme.

Traditional Medicinal Plant Extracts and Natural Products with Activity against Oral Bacteria: Potential Application in the Prevention and Treatment of Oral Diseases

PubMed Central

Palombo, Enzo A.

2011-01-01

Oral diseases are major health problems with dental caries and periodontal diseases among the most important preventable global infectious diseases. Oral health influences the general quality of life and poor oral health is linked to chronic conditions and systemic diseases. The association between oral diseases and the oral microbiota is well established. Of the more than 750 species of bacteria that inhabit the oral cavity, a number are implicated in oral diseases. The development of dental caries involves acidogenic and aciduric Gram-positive bacteria (mutans streptococci, lactobacilli and actinomycetes). Periodontal diseases have been linked to anaerobic Gram-negative bacteria (Porphyromonas gingivalis, Actinobacillus, Prevotella and Fusobacterium). Given the incidence of oral disease, increased resistance by bacteria to antibiotics, adverse affects of some antibacterial agents currently used in dentistry and financial considerations in developing countries, there is a need for alternative prevention and treatment options that are safe, effective and economical. While several agents are commercially available, these chemicals can alter oral microbiota and have undesirable side-effects such as vomiting, diarrhea and tooth staining. Hence, the search for alternative products continues and natural phytochemicals isolated from plants used as traditional medicines are considered as good alternatives. In this review, plant extracts or phytochemicals that inhibit the growth of oral pathogens, reduce the development of biofilms and dental plaque, influence the adhesion of bacteria to surfaces and reduce the symptoms of oral diseases will be discussed further. Clinical studies that have investigated the safety and efficacy of such plant-derived medicines will also be described. PMID:19596745

Salivary levels of mutans streptococci and Lactobacilli among Palestinian school children in East Jerusalem.

PubMed

Steinberg, Doron; Eskander, Lana; Zini, Avraham; Sgan-Cohen, Harold; Bajali, Musa

2014-04-01

The aim of the present study was to investigate the distribution of oral cariogenic bacteria among 12-year-old Palestinian children attending schools in East Jerusalem. Salivary levels of mutans streptococci (MS) and Lactobacilli (LB) were examined by semi-quantitative commercial kits and then correlated to social-demographic parameters. Overall, 52.1 % of the examined children presented the highest possible ranking score categories for MS bacteria, with only 5.4 % in the lowest category. Only 12.6 % of the school children presented the highest LB score, while 25 % had the lowest ranking score. Salivary MS levels in children attending private schools were lower than those of children in government schools and United Nations Relief and Works Agency (UNRWA) schools. Conversely, levels of LB were lowest in children attending UNRWA schools compared to government and private schools. Girls had significantly higher amounts of MS and LB than boys (p = 0.001). Lower MS levels were significantly related to the following socioeconomic variables: higher father's education level (p = 0.037), higher mother's education level (p = 0.063), mother's employment status (p = 0.012), and lower home density (p = 0.001). For LB, the only significant socioeconomic variable was higher father's employment level, which was related to lower LB level (p = 0.025). Levels of MS and LB were found to be strongly related with socioeconomic status among Palestinian children in East Jerusalem. The relatively high prevalence of cariogenic bacteria suggests that oral care prevention and treatment demands special attention from the health care institutions and authorities.

Antibacterial effect of electrolyzed water on oral bacteria.

PubMed

Lee, Sung-Hoon; Choi, Bong-Kyu

2006-08-01

This study investigated the antibacterial effect of electrolyzed water on oral bacteria both in vitro and in vivo. Tap water was electrolyzed in a water vessel using platinum cell technology. The electrolyzed tap water (called Puri-water) was put in contact with five major periodontopathogens or toothbrushes contaminated with these bacteria for 30 sec. In addition, Puri-water was used as a mouthwash for 30 sec in 16 subjects and the antibacterial effect on salivary bacteria was evaluated. Puri-water significantly reduced the growth of all periodontopathogens in culture and on toothbrushes, and that of aerobic and anaerobic bacteria in saliva, when compared to the effect of tap water. It also significantly reduced mutans streptococci growing on mitis salivarius-bacitracin agar. Our results demonstrate that the electrolyzed tap water is effective as a mouthwash and for toothbrush disinfection.

Non-group A streptococci in the pharynx. Pathogens or innocent bystanders?

PubMed

Hayden, G F; Murphy, T F; Hendley, J O

1989-07-01

To determine whether beta-hemolytic streptococci from groups other than A are an important cause of sporadic pharyngitis in children. Cross-sectional, case-referent survey. General pediatric clinic at a military base in Ohio. One hundred fifty children with symptomatic pharyngitis and 150 controls matched for age and time of presentation over a 20-month study period. None. Anaerobic culture technique was used to improve isolation of beta-hemolytic streptococci. Group A beta-hemolytic streptococci were detected significantly more often among the ill children than among the controls (39% vs 16%, respectively). In contrast, non-group A beta-hemolytic streptococci were isolated in similar frequency from the ill and control children (17% vs 21%, respectively). Non-group A beta-hemolytic streptococci from groups B, C, F, and G were each isolated in similar frequency among the ill and control children. The isolation rate of non-group A organisms increased with age among both patients and controls. Non-group A beta-hemolytic streptococci seemed not to be an important cause of sporadic pharyngitis in this pediatric population.

Microbial contamination of used dental handpieces.

PubMed

Smith, Gordon; Smith, Andrew

2014-09-01

Microbial contamination of used, unprocessed internal components of dental handpieces (HPs) was assessed. HPs were dismantled aseptically, immersed in phosphate-buffered saline, ultrasonicated, and cultured. A median of 200 CFU per turbine (n = 40), 400 CFU per spray channel (n = 40), and 1000 CFU per item of surgical gear (n = 20) was detected. Isolates included oral streptococci, Pseudomonas spp, and Staphylococcus aureus. Recovery of S aureus confirms the need for appropriate HP cleaning and sterilization after each patient to prevent cross-infection. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Amino Sugars Enhance the Competitiveness of Beneficial Commensals with Streptococcus mutans through Multiple Mechanisms

PubMed Central

Farivar, Tanaz; Burne, Robert A.

2016-01-01

ABSTRACT Biochemical and genetic aspects of the metabolism of the amino sugars N-acetylglucosamine (GlcNAc) and glucosamine (GlcN) by commensal oral streptococci and the effects of these sugars on interspecies competition with the dental caries pathogen Streptococcus mutans were explored. Multiple S. mutans wild-type isolates displayed long lag phases when transferred from glucose-containing medium to medium with GlcNAc as the primary carbohydrate source, but commensal streptococci did not. Competition in liquid coculture or dual-species biofilms between S. mutans and Streptococcus gordonii showed that S. gordonii was particularly dominant when the primary carbohydrate was GlcN or GlcNAc. Transcriptional and enzymatic assays showed that the catabolic pathway for GlcNAc was less highly induced in S. mutans than in S. gordonii. Exposure to H2O2, which is produced by S. gordonii and antagonizes the growth of S. mutans, led to reduced mRNA levels of nagA and nagB in S. mutans. When the gene for the transcriptional regulatory NagR was deleted in S. gordonii, the strain produced constitutively high levels of nagA (GlcNAc-6-P deacetylase), nagB (GlcN-6-P deaminase), and glmS (GlcN-6-P synthase) mRNA. Similar to NagR of S. mutans (NagRSm), the S. gordonii NagR protein (NagRSg) could bind to consensus binding sites (dre) in the nagA, nagB, and glmS promoter regions of S. gordonii. Notably, NagRSg binding was inhibited by GlcN-6-P, but G-6-P had no effect, unlike for NagRSm. This study expands the understanding of amino sugar metabolism and NagR-dependent gene regulation in streptococci and highlights the potential for therapeutic applications of amino sugars to prevent dental caries. IMPORTANCE Amino sugars are abundant in the biosphere, so the relative efficiency of particular bacteria in a given microbiota to metabolize these sources of carbon and nitrogen might have a profound impact on the ecology of the community. Our investigation reveals that several oral commensal bacteria have a much greater capacity to utilize amino sugars than the dental pathogen Streptococcus mutans and that the ability of the model commensal Streptococcus gordonii to compete against S. mutans is substantively enhanced by the presence of amino sugars commonly found in the oral cavity. The mechanisms underlying the greater capacity and competitive enhancements of the commensal are shown to depend on how the genes for the catabolic enzymes are regulated, the role of the allosteric modulators affecting such regulation, and the ability of amino sugars to enhance certain activities of the commensal that are antagonistic to S. mutans. PMID:27084009

Amino Sugars Enhance the Competitiveness of Beneficial Commensals with Streptococcus mutans through Multiple Mechanisms.

PubMed

Zeng, Lin; Farivar, Tanaz; Burne, Robert A

2016-06-15

Biochemical and genetic aspects of the metabolism of the amino sugars N-acetylglucosamine (GlcNAc) and glucosamine (GlcN) by commensal oral streptococci and the effects of these sugars on interspecies competition with the dental caries pathogen Streptococcus mutans were explored. Multiple S. mutans wild-type isolates displayed long lag phases when transferred from glucose-containing medium to medium with GlcNAc as the primary carbohydrate source, but commensal streptococci did not. Competition in liquid coculture or dual-species biofilms between S. mutans and Streptococcus gordonii showed that S. gordonii was particularly dominant when the primary carbohydrate was GlcN or GlcNAc. Transcriptional and enzymatic assays showed that the catabolic pathway for GlcNAc was less highly induced in S. mutans than in S. gordonii Exposure to H2O2, which is produced by S. gordonii and antagonizes the growth of S. mutans, led to reduced mRNA levels of nagA and nagB in S. mutans When the gene for the transcriptional regulatory NagR was deleted in S. gordonii, the strain produced constitutively high levels of nagA (GlcNAc-6-P deacetylase), nagB (GlcN-6-P deaminase), and glmS (GlcN-6-P synthase) mRNA. Similar to NagR of S. mutans (NagRSm), the S. gordonii NagR protein (NagRSg) could bind to consensus binding sites (dre) in the nagA, nagB, and glmS promoter regions of S. gordonii Notably, NagRSg binding was inhibited by GlcN-6-P, but G-6-P had no effect, unlike for NagRSm This study expands the understanding of amino sugar metabolism and NagR-dependent gene regulation in streptococci and highlights the potential for therapeutic applications of amino sugars to prevent dental caries. Amino sugars are abundant in the biosphere, so the relative efficiency of particular bacteria in a given microbiota to metabolize these sources of carbon and nitrogen might have a profound impact on the ecology of the community. Our investigation reveals that several oral commensal bacteria have a much greater capacity to utilize amino sugars than the dental pathogen Streptococcus mutans and that the ability of the model commensal Streptococcus gordonii to compete against S. mutans is substantively enhanced by the presence of amino sugars commonly found in the oral cavity. The mechanisms underlying the greater capacity and competitive enhancements of the commensal are shown to depend on how the genes for the catabolic enzymes are regulated, the role of the allosteric modulators affecting such regulation, and the ability of amino sugars to enhance certain activities of the commensal that are antagonistic to S. mutans. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

A comparative study of plaque mutans streptococci levels in children receiving glass ionomer cement and amalgam restorations.

PubMed

Ertuğrul, Fahinur; Eltem, Rengin; Eronat, Cemal

2003-01-01

The restorative materials amalgam (Standalloy F) and glass ionomer cements (Chelon Silver) were comparatively investigated to determine the number of mutans streptococci Saliva and plaque were collected from patients before and 40 days after the insertion of their restorations. Total bateria and mutans streptococci counts were found to be statistically significantly reduced when compared with the prerestoration counts in the saliva samples (P<0.001). Microbiological analysis of the dental plaque showed that the number of mutans streptococci in the glass ionomer cements was significantly lower than in the amalgam restorations (P<0.001). This study showed that silver glass ionomer cements inhibited the growth of mutans streptococci.

Salivary secretory IgA, pH, flow rates, mutans streptococci and Candida in children with rampant caries.

PubMed

Thaweboon, Sroisiri; Thaweboon, Boonyanit; Nakornchai, Siriruk; Jitmaitree, Sukritta

2008-09-01

The aim of this study was to determine the levels of secretory IgA (SIgA), pH, flow rates, mutans streptococci (MS) and Candida in saliva of children with rampant caries compared to those caries-free. Thirty children (age 62-123 months) were enrolled and divided into two groups: Group I, children with rampant caries, Group II, caries-free children. The average salivary flow rate was measured from the volume yielded within 5 minutes and the pH was determined using a pH-electrode. Measurement of SIgA was performed using an immunoassay kit. The levels of MS and Candida were determined by culture on Mitis-Salivarius Bacitracin agar and Sabouraud dextrose agar. It was found that children with rampant caries presented with significantly higher levels of salivary SIgA, MS and Candida. However, the mean values for salivary flow rates and pH were similar between the groups. The results reveal that children with rampant caries had significantly higher levels of SIgA, MS and Candida in their oral cavities. This finding tends to support the hypothesis that higher levels of salivary SIgA may reflect a past exposure of the host to cariogenic microorganisms.

The Interaction between Heterotrophic Bacteria and Coliform, Fecal Coliform, Fecal Streptococci Bacteria in the Water Supply Networks.

PubMed

Amanidaz, Nazak; Zafarzadeh, Ali; Mahvi, Amir Hossein

2015-12-01

This study investigated the interaction between heterotrophic bacteria and coliform, fecal coliforms, fecal streptococci bacteria in water supply networks. This study was conducted during 2013 on water supply distribution network in Aq Qala City, Golestan Province, Northern Iran and standard methods were applied for microbiological analysis. The surface method was applied to test the heterotrophic bacteria and MPN method was used for coliform, fecal coliform and fecal streptococci bacteria measurements. In 114 samples, heterotrophic bacteria count were over 500 CFU/ml, which the amount of fecal coliform, coliform, and fecal streptococci were 8, 32, and 20 CFU/100 ml, respectively. However, in the other 242 samples, with heterotrophic bacteria count being less than 500 CFU/ml, the amount of fecal coliform, coliform, and fecal streptococci was 7, 23, and 11 CFU/100ml, respectively. The relationship between heterotrophic bacteria, coliforms and fecal streptococci was highly significant (P<0.05). We observed the concentration of coliforms, fecal streptococci bacteria being high, whenever the concentration of heterotrophic bacteria in the water network systems was high. Interaction between heterotrophic bacteria and coliform, fecal coliforms, fecal streptococci bacteria in the Aq Qala City water supply networks was not notable. It can be due to high concentrations of organic carbon, bio-films and nutrients, which are necessary for growth, and survival of all microorganisms.

The Interaction between Heterotrophic Bacteria and Coliform, Fecal Coliform, Fecal Streptococci Bacteria in the Water Supply Networks

PubMed Central

AMANIDAZ, Nazak; ZAFARZADEH, Ali; MAHVI, Amir Hossein

2015-01-01

Background: This study investigated the interaction between heterotrophic bacteria and coliform, fecal coliforms, fecal streptococci bacteria in water supply networks. Methods: This study was conducted during 2013 on water supply distribution network in Aq Qala City, Golestan Province, Northern Iran and standard methods were applied for microbiological analysis. The surface method was applied to test the heterotrophic bacteria and MPN method was used for coliform, fecal coliform and fecal streptococci bacteria measurements. Results: In 114 samples, heterotrophic bacteria count were over 500 CFU/ml, which the amount of fecal coliform, coliform, and fecal streptococci were 8, 32, and 20 CFU/100 ml, respectively. However, in the other 242 samples, with heterotrophic bacteria count being less than 500 CFU/ml, the amount of fecal coliform, coliform, and fecal streptococci was 7, 23, and 11 CFU/100ml, respectively. The relationship between heterotrophic bacteria, coliforms and fecal streptococci was highly significant (P<0.05). We observed the concentration of coliforms, fecal streptococci bacteria being high, whenever the concentration of heterotrophic bacteria in the water network systems was high. Conclusion: Interaction between heterotrophic bacteria and coliform, fecal coliforms, fecal streptococci bacteria in the Aq Qala City water supply networks was not notable. It can be due to high concentrations of organic carbon, bio-films and nutrients, which are necessary for growth, and survival of all microorganisms. PMID:26811820

Efficacy and mechanisms of non-antibacterial, chemical plaque control by dentifrices--an in vitro study.

PubMed

Busscher, Henk J; White, Don J; Atema-Smit, Jelly; van der Mei, Henny C

2007-04-01

The provision of antiplaque benefits to dentifrices assists patients in improving hygiene and reducing susceptibility to gingivitis and caries. Chemical plaque control involves different mechanisms and is mostly associated with antibacterial effects, but also includes effects on pellicle surface chemistry to improve cleansing or discourage renewed plaque formation. It is the aim of this paper to analyze in vitro detachment of co-aggregating oral actinomyces and streptococci from pellicle surfaces by dentifrice supernates and to study subsequent de novo streptococcal deposition. Detachment by dentifrices of a co-adhering bacterial pair was studied in the parallel plate flow chamber on a 16 h pellicle coated surface. After detachment by perfusing the chamber with a dentifrice, re-deposition was initiated by flowing with a fresh streptococcal suspension. The dentifrices included both a regular, SLS-fluoride based formulation as well a pyrophosphate, anticalculus and antimicrobial formulations. All dentifrice supernates containing SLS were effective in detaching co-adhering bacteria from pellicles surfaces, except in combination with SnF(2). When hexametaphosphate was added immediate detachment was relatively low, but continued even during re-deposition. The re-deposition of streptococci after detachment by other, NaF containing dentifrices involved relatively few large aggregates, presumably because fluoride was able to block bi-dentate calcium binding sites on the bacterial cell surfaces, mediating co-adhesion. When pyrophosphate was present in addition to NaF, re-deposition involved significantly more large aggregates, likely because pyrophosphate served as a bi-dentate bridge between calcium bound on the bacterial cell surfaces. Commercially available dentifrice formulations differ in their ability to stimulate bacterial detachment from pellicles and dependent on their composition yield the formation of large co-adhering aggregates of actinomyces and streptococci in de novo deposition.

The SUCCESS model for laboratory performance and execution of rapid molecular diagnostics in patients with sepsis.

PubMed

Dekmezian, Mhair; Beal, Stacy G; Damashek, Mary Jane; Benavides, Raul; Dhiman, Neelam

2015-04-01

Successful performance and execution of rapid diagnostics in a clinical laboratory hinges heavily on careful validation, accurate and timely communication of results, and real-time quality monitoring. Laboratories must develop strategies to integrate diagnostics with stewardship and evidence-based clinical practice guidelines. We present a collaborative SUCCESS model for execution and monitoring of rapid sepsis diagnostics to facilitate timely treatment. Six months after execution of the Verigene Gram-Positive Blood Culture (BC-GP) and the AdvanDx PNA-FISH assays, data were collected on 579 and 28 episodes of bacteremia and fungemia, respectively. Clinical testing was executed using a SUCCESS model comprising the following components: stewardship, utilization of resources, core strategies, concierge services, education, support, and surveillance. Stewardship needs were identified by evaluating the specialty services benefiting from new testing. Utilization of resources was optimized by reviewing current treatment strategies and antibiogram and formulary options. Core strategies consisted of input from infectious disease leadership, pharmacy, and laboratory staff. Concierge services included automated Micro-eUpdate and physician-friendly actionable reports. Education modules were user-specific, and support was provided through a dedicated 24/7 microbiology hotline. Surveillance was performed by daily audit by the director. Using the SUCCESS model, the turnaround time for the detailed report with actionable guidelines to the physician was ∼3 hours from the time of culture positivity. The overall correlation between rapid methods and culture was 94% (546/579). Discrepant results were predominantly contaminants such as a coagulase-negative staphylococci or viridans streptococci in mixed cultures. SUCCESS is a cost-effective and easily adaptable model for clinical laboratories with limited stewardship resources.

Predisposing cardiac conditions, interventional procedures, and antibiotic prophylaxis among patients with infective endocarditis.

PubMed

Chirillo, Fabio; Faggiano, Pompilio; Cecconi, Moreno; Moreo, Antonella; Squeri, Angelo; Gaddi, Oscar; Cecchi, Enrico

2016-09-01

Efficacy and safety of antibiotic prophylaxis (AP) for prevention of infective endocarditis (IE) in patients with predisposing cardiac condition (PCC) undergoing invasive procedures is still debated. We sought to assess the prevalence of PCC, the type of interventional procedures preceding the onset of symptoms, and the usefulness of AP in a large cohort of consecutive patients with definite IE. We examined 677 (median age 65.34 years; male 492 [73%]) consecutive patients with IE enrolled from July 2007 through 2010 into the Italian Registry of Infective Endocarditis. Predisposing cardiac condition was present in 341 patients (50%).Thirty-two patients (4.7%) underwent dental procedures. Of 20 patients with PCC undergoing dental procedure, 13 had assumed AP. Viridans group streptococci were isolated from blood cultures in 8 of 20 patients with PCC and prior dental procedure. Nondental procedures preceded IE in 139 patients (21%). They were significantly older and had more comordibities compared with patients undergoing dental procedures. Predisposing cardiac condition was identified in 91 patients. Perioperative antimicrobial prophylaxis was administered to 67 patients. Staphylococcus aureus was the most frequent causative agent. Cardiac surgery was necessary in 85 patients (20 with prior dental and 65 with nondental procedure). Surgical mortality (12% vs 0%, P = .03) and hospital mortality (23% vs 3%, P = .001) were significantly larger among patients with nondental procedures. In a large unselected cohort of patients with IE, the incidence of preceding dental procedures was minimal. The number of cases potentially preventable by means of AP was negligible. Nondental procedures were more frequent than dental procedures and were correlated with poorer prognosis. Copyright © 2016 Elsevier Inc. All rights reserved.

Infective endocarditis in the Western Cape Province of South Africa: a three-year prospective study.

PubMed

Koegelenberg, C F N; Doubell, A F; Orth, H; Reuter, H

2003-03-01

The last 50 years have seen major changes in the epidemiology of infective endocarditis (IE). To evaluate local patient characteristics, risk factors, clinical sequelae, microbiology, morbidity and mortality in patients with definite IE. Prospective observational study. Over a three-year period, patients referred with probable IE were prospectively enrolled. All received a standardized diagnostic evaluation. Epidemiological data were documented; underlying risk factors for IE were sought. Initial evaluation and follow-up (to 6 months) included the documentation of vascular or immunological phenomena, morbidity and mortality. Of 92 patients referred with probable IE, 47 had definite IE. These patients had a mean age of 37.7 years with a male predominance (1.6:1). Rheumatic heart disease was present in 36 (76.6%). Eight had prosthetic valves. Three had congenital heart disease, mitral valve prolapse or multiple central intravascular catheters, respectively. All denied the use of intravenous recreational drugs and only one tested seropositive for HIV. Renal involvement (59.6%) and clubbing (29.8%) were commonly observed. The 6-month mortality rate was 35.6%, while 44.7% needed valvular replacement. An aetiological diagnosis was made in 21, with viridans streptococci the most common isolate. Infective endocarditis in the Western Cape of South Africa is a disease of younger adults, with a male predominance. Rheumatic heart disease is the major predisposing factor. Degenerative heart disease and intravenous drug abuse are not important risk factors. Our data do not support the notion that HIV infection is an independent risk factor for IE. Local mortality rates are much higher than recent international figures, as is the proportion of 'culture-negative' IE.

ELIMINATION OF INTRACANAL INFECTION IN DOGS' TEETH WITH INDUCED PERIAPICAL LESIONS AFTER ROTARY INSTRUMENTATION: INFLUENCE OF DIFFERENT CALCIUM HYDROXIDE PASTES

PubMed Central

Soares, Janir Alves; Leonardo, Mário Roberto; da Silva, Léa Assed Bezerra; Tanomaru, Mário; Ito, Izabel Yoko

2006-01-01

The aim of this study was to evaluate the antiseptic efficacy of rotary instrumentation associated with calcium hydroxide-based pastes prepared with different vehicles and antiseptics. Chronic periapical lesions were experimentally induced in 72 premolar root canals of four dogs. Under controlled asepsis, after initial microbiological sampling (A1), the root canals were instrumented using the ProFile system in conjunction with 5.25% sodium hypochlorite and the intracanal medication was placed. Four experimental groups were formed according to the pastes used: group 1- Calen (n=18), group 2- Calen+CPMC (n=20), group 3- Ca(OH)2 p.a.+ anaesthetic solution (n=16) and group 4- Ca(OH)2 p.a.+ 2% chlorhexidine digluconate (n=18). After 21 days, the pastes were removed; the canals were emptied and 96 hours later a second microbiological sample was obtained (A2). The incidence of positive microbiological cultures and the number of cfus in stages A1 and A2 were compared statistically by the Wilcoxon test while the influence of the different treatments in intracanal infection was evaluated by Kruskal-Wallis test at 5% significance level (p<0.05). Large numbers of strict and facultative anaerobes, and viridans group streptococci were found in 100% of root canals of A1 samples. Among A2 samples, all treatments showed significant reduction of cfus and positive cultures (p<0.05), but only groups 3 and 4 showed 100% of root canals free of microorganisms. Rotary instrumentation plus NaOCl 5.25% associated with intracanal medication produced a drastic reduction or elimination of intracanal microbiota, whose performance was not influenced by the nature of the vehicle or the antiseptic added to the Ca(OH)2 p.a. PMID:19089068

[Infective endocarditis in adult patients with congenital heart disease. Experience from a reference centre].

PubMed

Loureiro-Amigo, Jose; Fernández-Hidalgo, Nuria; Pijuan-Domènech, Antonia; Dos-Subirà, Laura; Subirana-Domènech, Teresa; Gonzàlez-Alujas, Teresa; González-López, Juan José; Tornos-Mas, Pilar; García-Dorado, David; Almirante, Benito

2016-12-01

A growing number of patients with congenital heart disease (CHD) will reach adulthood. Infective endocarditis (IE) is a major complication in this population. The aim of this study was to describe the features of IE in adults with CHD treated in a reference centre. A retrospective review was performed on a cohort of patients over 16 years of age with CHD who presented with IE (defined by the modified Duke criteria) between 1996 and 2014. Only the first episode from each patient was considered for the descriptive analysis. IE was observed in 27 patients. The median age at diagnosis of IE was 27.7 years, and 63% were male. Comorbidity was low (median Charlson index was 0). IE was mostly community-acquired (78%). The most frequent CHD were ventricular septal defect (33%). A repair was performed in 48% of patients, and 19% received palliative treatment. Forty-one percent of patients had some type of prosthesis. A residual defect was observed in 81%. The IE was detected in the right side of 44% of the patients. The most frequent aetiological agents were viridans group streptococci (41%) and Staphylococcus epidermidis (30%). Surgery was required to treat IE in 37% of patients. There were five re-infections and three relapses. Two patients died, both as a result of recurrence. IE in adults with CHD occurred in young patients, and almost all of them carried some prosthetic material or a residual defect. The IE is frequently right-sided. Although surgical treatment was required in many cases, mortality was low, except in the case of relapses. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Molecular Evolution Perspectives on Intraspecific Lateral DNA Transfer of Topoisomerase and Gyrase Loci in Streptococcus pneumoniae, with Implications for Fluoroquinolone Resistance Development and Spread

PubMed Central

Stanhope, Michael J.; Walsh, Stacey L.; Becker, Julie A.; Italia, Michael J.; Ingraham, Karen A.; Gwynn, Michael N.; Mathie, Tom; Poupard, James A.; Miller, Linda A.; Brown, James R.; Amrine-Madsen, Heather

2005-01-01

Fluoroquinolones are an important class of antibiotics for the treatment of infections arising from the gram-positive respiratory pathogen Streptococcus pneumoniae. Although there is evidence supporting interspecific lateral DNA transfer of fluoroquinolone target loci, no studies have specifically been designed to assess the role of intraspecific lateral transfer of these genes in the spread of fluoroquinolone resistance. This study involves a comparative evolutionary perspective, in which the evolutionary history of a diverse set of S. pneumoniae clinical isolates is reconstructed from an expanded multilocus sequence typing data set, with putative recombinants excluded. This control history is then assessed against networks of each of the four fluoroquinolone target loci from the same isolates. The results indicate that although the majority of fluoroquinolone target loci from this set of 60 isolates are consistent with a clonal dissemination hypothesis, 3 to 10% of the sequences are consistent with an intraspecific lateral transfer hypothesis. Also evident were examples of interspecific transfer, with two isolates possessing a parE-parC gene region arising from viridans group streptococci. The Spain 23F-1 clone is the most dominant fluoroquinolone-nonsusceptible clone in this set of isolates, and the analysis suggests that its members act as frequent donors of fluoroquinolone-nonsusceptible loci. Although the majority of fluoroquinolone target gene sequences in this set of isolates can be explained on the basis of clonal dissemination, a significant number are more parsimoniously explained by intraspecific lateral DNA transfer, and in situations of high S. pneumoniae population density, such events could be an important means of resistance spread. PMID:16189113

Immunohistochemical analysis of the gingiva with periodontitis of type I plasminogen deficiency compared to gingiva with gingivitis and periodontitis and healthy gingiva.

PubMed

Kurtulus Waschulewski, Idil; Gökbuget, Aslan Y; Christiansen, Nina M; Ziegler, Maike; Schuster, Volker; Wahl, Gerhard; Götz, Werner

2016-12-01

Type I plasminogen deficiency (Plgdef) is an uncommon chronic inflammation of mucous membranes. Gingival enlargements usually proceed with progressive periodontal destruction and tooth-loss. Plasmin(ogen)-independent enzymatic mechanisms for fibrin clearance have already been discussed in the literature. Our primary objective was to verify, immunohistochemically, the occurrence of different enzymatic factors involved in tissue breakdown of inflamed compared to healthy gingiva. Secondly, we tried to find out, if these patients have a similar microbiological profile to the patients with known gingivitis and periodontitis. Immunohistochemical analysis of enzymes elastase, plasminogen (plg), cathepsin G, matrix-metalloproteinase (MMP)-3 and MMP-7 and of glycoprotein fibrinogen were performed with gingival tissues from 3 healthy controls, 8 patients with Plgdef and 3 patients with gingivitis and periodontitis. Furthermore, plaque from 5 patients with plasminogen deficiency were also obtained to determine the microbiological profile. Significantly high numbers of elastase positive leukocytes were detected in all samples. Staining for MMP-3 and MMP-7 was seen in samples with gingivitis and periodontitis with a stronger staining in samples with periodontitis by Plgdef. Fibrinogen was detectable in all samples. Staining for plg was stronger in samples with periodontitis than in other samples. Staining for cathepsin G was weak in gingivitis and periodontitis. Subgingival microbial flora showed elevated colony forming units of Prevotella intermedia/nigrescens, Fusobacterium spp., Eikenella corrodens, Porphyromonas gingivalis and viridans streptococci. Strong staining of elastase, MMP-3 and MMP-7 and weak staining of plg in Plgdef samples supports the plasmin(ogen) - independent fibrin clearance. Similar subgingival microbiological flora was observed in periodontitis with Plgdef as in other periodontal diseases. Further investigations should determine the exact pathomechanism and focus on effective treatment methods of this entity. Copyright © 2016. Published by Elsevier Ltd.

Definition, clinical profile, microbiological spectrum, and prognostic factors of early-onset prosthetic valve endocarditis.

PubMed

López, Javier; Revilla, Ana; Vilacosta, Isidre; Villacorta, Eduardo; González-Juanatey, Carlos; Gómez, Itziar; Rollán, María Jesús; San Román, José Alberto

2007-03-01

There is no agreement in the best cutoff time to distinguish between early- and late- onset prosthetic valve endocarditis (PVE). Our objectives are to define early-onset PVE according to the microbiological spectrum and to analyse the profile and short-term prognosis of this entity. The microbiological profile of 172 non-drug users, who were patients with PVE, were compared according to the time elapsed from surgery among 640 endocarditis diagnosed between 1996 and 2004. There were no differences in the microbiological profile of patients with PVE occurred within 2 months of valve replacement and those accounting between 2 and 12 months. The proportion of coagulase-negative Staphylococci (CNS) was higher during the first year post-intervention (37 vs. 18%, P = 0.005) and Streptococci viridans were more common after 1 year (18 vs. 1%, P = 0.001). The percentage of methicilin-resistant CNS strains was higher before 1 year (77 vs. 30%, P = 0.004). Early-onset PVE represented 38% of all episodes of PVE, CNS being the most frequent isolated microorganisms (37%), most of them methicilin resistant (77%). In-hospital mortality of patients who needed urgent surgery was 46% and elective surgery 25%. Overall, in-hospital mortality was 38% and no differences were seen between surgical and medical groups (32 vs. 45%, P = 0.30). Periannular complications were associated with higher in-hospital mortality (60 vs. 27%, P = 0.007). According to the microbiological profile, the most appropriate cutoff time to distinguish between early- and late-onset PVE was 1 year. Methicilin-resistant CNS are the most frequent pathogens and periannular complications, the only risk factor for in-hospital mortality.

Odontogenic bacteria in periodontal disease and resistance patterns to common antibiotics used as treatment and prophylaxis in odontology in Spain.

PubMed

Maestre, J R; Bascones, A; Sánchez, P; Matesanz, P; Aguilar, Lorenzo; Giménez, M J; Pérez-Balcabao, I; Granizo, J J; Prieto, J

2007-03-01

Resistance in streptococci or Gram-negative bacteria is associated with antibiotic consumption. Scarce information exists on the antibiotic susceptibility of bacterial isolates from patients with periodontitis in countries with high antibiotic consumption, as this is an area in which microbiological testing is not performed in daily practice. The present study was undertaken to explore the susceptibility of bacterial isolates in periodontitis to antibiotics prescribed in odontology in Spain as treatment for local infections or prophylaxis for distant focal infections. Periodontal samples were prospectively collected in 48 patients classified by pocket depth of <4 mm and >or=4 mm. Species were identified by culture, selecting the five most frequent morphotypes per sample, and polymerase chain reaction (PCR). Susceptibility was determined by E-test. A total of 261 isolates were identified: 72.9% patients had Streptococcus oralis; 70.8% Streptococcus mitis; 60.4% Prevotella buccae; 39.6% Prevotella denticola; 37.5% Fusobacterium nucleatum; 35.4% Prevotella intermedia; 25% Capnocytophaga spp.; 23% Veillonella spp.; 22.9% Prevotella melaninogenica and Streptococcus sanguis; and <20% other species. Streptococcus viridans resistance rates were 0% for amoxicillin, approximately 10% for clindamycin, 9-22% for tetracycline, and for azithromycin ranged from 18.2% for S. sanguis to 47.7% for S. mitis. Prevotella isolates were susceptible to amoxicillin-clavulanic acid, with amoxicillin resistance ranging from 17.1% in P. buccae to 26.3% in P. denticola. Metronidazole resistance was <6% in all Prevotella species, while clindamycin resistance ranged from 0 to 21.1%. beta-Lactamase production was positive in 54.1% Prevotella spp., 38.9% F. nucleatum, 30% Capnocytophaga spp., and 10% Veillonella spp. In this study, amoxicillin-clavulanic acid was the most active antibiotic against all species tested, followed by metronidazole in the case of anaerobes.

A Prospective, Holistic, Multicenter Approach to Tracking and Understanding Bloodstream Infections in Pediatric Hematology-Oncology Patients.

PubMed

Gaur, Aditya H; Bundy, David G; Werner, Eric J; Hord, Jeffrey D; Miller, Marlene R; Tang, Li; Lawlor, John P; Billett, Amy L

2017-06-01

OBJECTIVE To assess the burden of bloodstream infections (BSIs) among pediatric hematology-oncology (PHO) inpatients, to propose a comprehensive, all-BSI tracking approach, and to discuss how such an approach helps better inform within-center and across-center differences in CLABSI rate DESIGN Prospective cohort study SETTING US multicenter, quality-improvement, BSI prevention network PARTICIPANTS PHO centers across the United States who agreed to follow a standardized central-line-maintenance care bundle and track all BSI events and central-line days every month. METHODS Infections were categorized as CLABSI (stratified by mucosal barrier injury-related, laboratory-confirmed BSI [MBI-LCBI] versus non-MBI-LCBI) and secondary BSI, using National Healthcare Safety Network (NHSN) definitions. Single positive blood cultures (SPBCs) with NHSN defined common commensals were also tracked. RESULTS Between 2013 and 2015, 34 PHO centers reported 1,110 BSIs. Among them, 708 (63.8%) were CLABSIs, 170 (15.3%) were secondary BSIs, and 232 (20.9%) were SPBCs. Most SPBCs (75%) occurred in patients with profound neutropenia; 22% of SPBCs were viridans group streptococci. Among the CLABSIs, 51% were MBI-LCBI. Excluding SPBCs, CLABSI rates were higher (88% vs 77%) and secondary BSI rates were lower (12% vs 23%) after the NHSN updated the definition of secondary BSI (P<.001). Preliminary analyses showed across-center differences in CLABSI versus secondary BSI and between SPBC and CLABSI versus non-CLABSI rates. CONCLUSIONS Tracking all BSIs, not just CLABSIs in PHO patients, is a patient-centered, clinically relevant approach that could help better assess across-center and within-center differences in infection rates, including CLABSI. This approach enables informed decision making by healthcare providers, payors, and the public. Infect Control Hosp Epidemiol 2017;38:690-696.

Effect of mixed mutans streptococci colonization on caries development.

PubMed

Seki, M; Yamashita, Y; Shibata, Y; Torigoe, H; Tsuda, H; Maeno, M

2006-02-01

To evaluate the clinical importance of mixed mutans streptococci colonization in predicting caries in preschool children. Caries prevalence was examined twice, with a 6-month interval, in 410 preschool children aged 3-4 years at baseline. A commercial strip method was used to evaluate the mutans streptococci score in plaque collected from eight selected interdental spaces and in saliva. Mutans streptococci typing polymerase chain reaction (PCR) assays (Streptococcus sobrinus and Streptococcus mutans, including serotypes c, e, and f) were performed using colonies on the strips as template. Twenty variables were examined in a univariate analysis to predict caries development: questionnaire variables, results of clinical examination, mutans streptococci scores, and PCR detection of S. sobrinus and S. mutans (including serotypes c, e, and f). Sixteen variables showed statistically significant associations (P < 0.04) in the univariate analysis. However, when entered into a logistic regression, only five variables remained significant (P < 0.05): caries experience at baseline; mixed colonization of S. sobrinus and S. mutans including S. mutans serotypes; high plaque mutans streptococci score; habitual use of sweet drinks; and nonuse of fluoride toothpaste. 'Mixed mutans streptococci colonization' is a novel measure correlated with caries development in their primary dentition.

[Group B streptococcal perinatal infection: A Global, Latin American and Mexican Overview].

PubMed

Palacios-Saucedo, Gerardo C; Hernández-Hernández, Talyha Itzel; Rivera-Morales, Lydia Guadalupe; Briones-Lara, Evangelina; Caballero-Trejo, Amílcar; Vázquez-Guillén, José M; Amador-Patiño, Gustavo I; García-Cabello, Ricardo; Solórzano-Santos, Fortino; Rodríguez-Padillacs, Cristina

2017-01-01

Group B streptococci (Streptococcus agalactiae) cause a number of infections in women during pregnancy and postpartum, such as urinary tract infection, chorioamnionitis and endometritis, consequently may affect the newborn. Group B streptococci is the most common cause of severe infections in newborns in developed countries. Studies on the epidemiology of group B streptococci infections in Latin America are still limited. This information is also unknown in Mexico, but studies carried out in the center of the country have found high rates of vaginal colonization in pregnant women and there are case series and case reports of newborns. Microbiological and molecular epidemiology studies in Mexico have shown that populations of group B streptococci have a clonal distribution and that there are clones with genetic and phenotypic characteristics of high virulence that appear to be responsible for most of perinatal pathology. However, the actual role of group B streptococci in perinatal pathology in Mexico is unknown. Consequently, whether to perform or not the screening for determining the group B streptococci colonization status in pregnant women, and the indication or not for intrapartum antibiotic prophylaxis to prevent neonatal group B streptococci infection in Mexico, are still controversial.

[The electron microscopic observation of the effect of monoclonal antibody on the form and structure of mutans streptococci OMZ176].

PubMed

Wen, L; Yue, S

1996-01-01

The effect of monoclonal antibody on the form and structure of Mutans Streptococci OMZ176 was studied. The result showed that a great number of Mutans Streptococci OMZ176 was agglutianated after treating with monoclonal antibody prepared by a cell wall protein antigen (molecular weight 220 kd) of Mutans Streptococci OMZ176. Bacterial cells were swollen obviously. The gap between cell wall and cytoplasmic was widened. The electronic density of cell plasm was greatly decreased.

Nutritionally Variant Streptococci Interfere with Streptococcus mutans Adhesion Properties and Biofilm Formation.

PubMed

Angius, Fabrizio; Madeddu, Maria Antonietta; Pompei, Raffaello

2015-04-01

The bacterial species Streptococcus mutans is known as the main cause of dental caries in humans. Therefore, much effort has focused on preventing oral colonization by this strain or clearing it from oral tissues. The oral cavity is colonized by several bacterial species that constitute the commensal oral flora, but none of these is able to interfere with the cariogenic properties of S. mutans. This paper describes the interfering ability of some nutritionally variant streptococcal strains (NVS) with S. mutans adhesion to glass surfaces and also to hydroxylapatite. In mixed cultures, NVS induce a complete inhibition of S. mutans microcolony formation on cover glass slides. NVS can also block the adherence of radiolabeled S. mutans to hydroxylapatite in the presence of both saliva and sucrose. The analysis of the action mechanism of NVS demonstrated that NVS are more hydrophobic than S. mutans and adhere tightly to hard surfaces. In addition, a cell-free culture filtrate of NVS was also able to interfere with S. mutans adhesion to hydroxylapatite. Since NVS are known to secrete some important bacteriolytic enzymes, we conclude that NVS can be a natural antagonist to the cariogenic properties of S. mutans.

Streptococcus mitis: walking the line between commensalism and pathogenesis.

PubMed

Mitchell, J

2011-04-01

Streptococcus mitis is a viridans streptococcus and a normal commensal of the human oropharynx. However, S. mitis can escape from this niche and cause a variety of infectious complications including infective endocarditis, bacteraemia and septicaemia. It uses a variety of strategies to effectively colonize the human oropharynx. These include expression of adhesins, immunoglobulin A proteases and toxins, and modulation of the host immune system. These various colonization factors allow S. mitis to compete for space and nutrients in the face of its more pathogenic oropharyngeal microbial neighbours. However, it is likely that in vulnerable immune-compromised patients S. mitis will use the same colonization and immune modulation factors as virulence factors promoting its opportunistic pathogenesis. The recent publication of a complete genome sequence for S. mitis strain B6 will allow researchers to thoroughly investigate which genes are involved in S. mitis host colonization and pathogenesis. Moreover, it will help to give insight into where S. mitis fits in the complicated oral microbiome. This review will discuss the current knowledge of S. mitis factors involved in host colonization, their potential role in virulence and what needs to be done to fully understand how a an oral commensal successfully transitions to a virulent pathogen. © 2011 John Wiley & Sons A/S.

Anaerobic Killing of Oral Streptococci by Reduced, Transition Metal Cations

PubMed Central

Dunning, J. C.; Ma, Y.; Marquis, R. E.

1998-01-01

Reduced, transition metal cations commonly enhance oxidative damage to cells caused by hydroperoxides formed as a result of oxygen metabolism or added externally. As expected, the cations Fe2+ and Cu+ enhanced killing of Streptococcus mutans GS-5 by hydroperoxides. However, unexpectedly, they also induced lethal damage under fully anaerobic conditions in a glove box with no exposure to O2 or hydroperoxides from initial treatment with the cations. Sensitivities to anaerobic killing by Fe2+ varied among the organisms tested. The oral streptococci Streptococcus gordonii ATCC 10558, Streptococcus rattus FA-1, and Streptococcus sanguis NCTC 10904 were approximately as sensitive as S. mutans GS-5. Enterococcus hirae ATCC 9790, Actinomyces viscosus OMZ105E, and Actinomyces naeslundii WVU45 had intermediate sensitivity, while Lactobacillus casei ATCC 4646 and Escherichia coli B were insensitive. Killing of S. mutans GS-5 in response to millimolar levels of added Fe2+ occurred over a wide range of temperatures and pH. The organism was able to take up ferrous iron, but ferric reductase activity could not be detected. Chelators, uric acid, and thiocyanate were not effective inhibitors of the lethal damage. Sulfhydryl compounds, ferricyanide, and ferrocyanide were protective if added prior to Fe2+ exposure. Fe2+, but not Fe3+, acted to reduce the acid tolerance of glycolysis by intact cells of S. mutans. The reduction in acid tolerance appeared to be related directly to Fe2+ inhibition of F-ATPase, which could be assayed with permeabilized cells, isolated membranes, or F1 enzyme separated from membranes. Cu+ and Cu2+ also inhibited F-ATPase and sensitized glycolysis by intact cells to acid. All of these damaging actions occurred anaerobically and thus did not appear to involve reactive oxygen species. PMID:9435058

Proteome Analysis Identifies the Dpr Protein of Streptococcus mutans as an Important Factor in the Presence of Early Streptococcal Colonizers of Tooth Surfaces

PubMed Central

Yoshida, Akihiro; Niki, Mamiko; Yamamoto, Yuji; Yasunaga, Ai; Ansai, Toshihiro

2015-01-01

Oral streptococci are primary colonizers of tooth surfaces and Streptococcus mutans is the principal causative agent of dental caries in humans. A number of proteins are involved in the formation of monospecies biofilms by S. mutans. This study analyzed the protein expression profiles of S. mutans biofilms formed in the presence or absence of S. gordonii, a pioneer colonizer of the tooth surface, by two-dimensional gel electrophoresis (2-DE). After identifying S. mutans proteins by Mass spectrometric analysis, their expression in the presence of S. gordonii was analyzed. S. mutans was inoculated with or without S. gordonii DL1. The two species were compartmentalized using 0.2-μl Anopore membranes. The biofilms on polystyrene plates were harvested, and the solubilized proteins were separated by 2-DE. When S. mutans biofilms were formed in the presence of S. gordonii, the peroxide resistance protein Dpr of the former showed 4.3-fold increased expression compared to biofilms that developed in the absence of the pioneer colonizer. In addition, we performed a competition assay using S. mutans antioxidant protein mutants together with S. gordonii and other initial colonizers. Growth of the dpr-knockout S. mutans mutant was significantly inhibited by S. gordonii, as well as by S. sanguinis. Furthermore, a cell viability assay revealed that the viability of the dpr-defective mutant was significantly attenuated compared to the wild-type strain when co-cultured with S. gordonii. Therefore, these results suggest that Dpr might be one of the essential proteins for S. mutans survival on teeth in the presence of early colonizing oral streptococci. PMID:25816242

Effect of three-year consumption of erythritol, xylitol and sorbitol candies on various plaque and salivary caries-related variables.

PubMed

Runnel, Riina; Mäkinen, Kauko K; Honkala, Sisko; Olak, Jana; Mäkinen, Pirkko-Liisa; Nõmmela, Rita; Vahlberg, Tero; Honkala, Eino; Saag, Mare

2013-12-01

The objective of the present paper is to report results from oral biologic studies carried out in connection with a caries study. Samples of whole-mouth saliva and dental plaque were collected from initially 7- to 8-year-old subjects who participated in a 3-year school-based programme investigating the effect of the consumption of polyol-containing candies on caries rates. The subjects were randomized in three cohorts, consumed erythritol, xylitol, or sorbitol candies. The daily polyol consumption from the candies was approximately 7.5 g. A significant reduction in dental plaque weight from baseline (p<0.05) occurred in the erythritol group during almost all intervention years while no changes were found in xylitol and sorbitol groups. Usage of polyol candies had no significant or consistent effect on the levels of plaque protein, glucose, glycerol, or calcium, determined yearly in connection with caries examinations. After three years, the plaque of erythritol-receiving subjects contained significantly (p<0.05) lower levels of acetic acid and propionic acid than that of subjects receiving xylitol or sorbitol. Lactic acid levels partly followed the same pattern. The consumption of erythritol was generally associated with significantly (p<0.05) lower counts of salivary and plaque mutans streptococci compared with the other groups. There was no change in salivary Lactobacillus levels. Three-year consumption of erythritol-containing candies by initially 7- to 8-year old children was associated with reduced plaque growth, lower levels of plaque acetic acid and propionic acid, and reduced oral counts of mutans streptococci compared with the consumption of xylitol or sorbitol candies. Copyright © 2013 Elsevier Ltd. All rights reserved.

Successful Continuation of Pregnancy After Treatment of Group A Streptococci Sepsis.

PubMed

Alhousseini, Ali; Layne, Mia E; Gonik, Bernard; Bryant, David; Patwardhan, Sanjay; Patwardhan, Manasi

2017-05-01

Invasive group A streptococci infections in pregnancy have historically led to severe maternal and neonatal morbidity and mortality. We are reporting a rare and novel case of successful treatment of third-trimester group A streptococci infection with early, aggressive intervention and maintenance of the pregnancy to term. A 35 year old woman initially presented with fever, flu-like symptoms, and preterm contractions at 34 weeks of gestation. She demonstrated signs of early stages of septic shock, ultimately attributed to group A streptococci bacteremia. Early, aggressive intervention allowed the pregnancy to continue until 38 weeks of gestation with normal maternal and neonatal outcomes. Early and aggressive treatment of invasive group A streptococci infection during pregnancy can potentially avoid severe maternal and perinatal morbidity and mortality with a successful continuation of pregnancy.

Association between prolonged breast-feeding and early childhood caries: a hierarchical approach.

PubMed

Nunes, Ana Margarida Melo; Alves, Claudia Maria Coelho; Borba de Araújo, Fernando; Ortiz, Tânia Mara Lopes; Ribeiro, Marizélia Rodrigues Costa; Silva, Antônio Augusto Moura da; Ribeiro, Cecília Claudia Costa

2012-12-01

This study was conducted to investigate the association between prolonged breastfeeding and early childhood caries(ECC) with adjustment for important confounders, using hieraschical approach. This retrospective cohort study involved 260 low-income children (18-42 months). The number of decayed teeth was used as a measure of caries. Following a theoretical framework, the hierarchical model was built in a forward fashion, by adding the following levels in succession: level 1: age; level 2: social variables; level 3: health variables; level 4: behavioral variables; level 5: oral hygiene-related variables; level 6: oral hygiene quality measured by visible plaque; and level 7: contamination by mutans streptococci. Sequential forward multiple Poisson regression analysis was employed. Breast-feeding was not a risk factor for ECC after adjustment for some confounders (incidence density ratio, 1.15; 95% confidence interval, 0.84-1.59, P = 0.363). Prolonged breast-feeding was not a risk factor for ECC while age, high sucrose comption between main meals and the quality of oral higiene were associated with disease in children. © 2012 John Wiley & Sons A/S.

Longitudinal research on the oral environment of elderly wearing fixed or removable prostheses.

PubMed

Tanaka, Junko; Tanaka, Masahiro; Kawazoe, Takayoshi

2009-04-01

The purpose of this study was to investigate oral environmental risk factors involved in caries incidence in the elderly. We investigated the relationship between the oral environment factors of the elderly with both fixed prostheses and removable prostheses at baseline and at follow-up and examined time-course changes of each oral environmental factor by prosthesis type. The subject group consisted 11 elderly patients with fixed prostheses and 11 who wore removable prostheses. We examined oral environmental factors by saliva tests. Five oral environmental factors were examined: the stimulated salivary flow rate, buffering capacity, and the counts of mutans streptococci (SM), lactobacilli (LB), and Candida (CA). We compared these factors for subjects with fixed prostheses and those wearing removable prostheses at baseline and at follow-up. Furthermore, 3-year changes in the factors of each oral environment were compared and evaluated. Significant differences were observed between the two groups in the salivary microbial counts of SM and LB at baseline and at follow-up. The LB counts increased in the Denture group during the 3-year period and significant differences were noted. We found that fixed prostheses are less cariogenic, and removable prostheses cause an increase in the cariogenic bacterial count. Regarding time-course changes by the type of prosthesis, the LB count tended to increase in the subjects with removable prostheses. The risk of caries due to a fixed prosthesis may be lower than that of removable prostheses.

Comparison of Directigen Group A Strep Test with a traditional culture technique for detection of group A beta-hemolytic streptococci.

PubMed Central

McCusker, J J; McCoy, E L; Young, C L; Alamares, R; Hirsch, L S

1984-01-01

The Directigen Group A Strep Test (DGAST), a new rapid method of detecting group A beta-hemolytic streptococci directly from throat swabs, was compared with a traditional culture technique for the detection of group A beta-hemolytic streptococci. Five hundred oropharyngeal swabs from pediatric and adult patients were cultured and then processed by using the DGAST. Of the 144 specimens positive by culture, 131 were DGAST positive (sensitivity, 90.9%). Of the 356 specimens negative by culture, 353 were DGAST negative (specificity, 99.2%). Twelve of the 13 false-negative DGAST results were from pediatric patients. One hundred isolates of non-group A beta-hemolytic streptococci were recovered, primarily groups C, F, and G. The DGAST is easy to perform, rapid, sensitive, and very specific for detection of group A beta-hemolytic streptococci directly from swabs. Supplementing the DGAST with a culture on a 5% sheep blood agar plate would enhance detection of group A beta-hemolytic streptococci, especially in pediatric patients. PMID:6386884

STUDIES ON THE BIOLOGY OF STREPTOCOCCUS

PubMed Central

Stevens, Franklin A.; Dochez, A. R.

1924-01-01

1. Strains of hemolytic streptococci from cases of scarlet fever occurring in New York, San Francisco, Chicago, Baltimore, and Copenhagen, Denmark, all interagglutinate with immune sera prepared with these strains. 2. Sera prepared with these strains do not agglutinate pyogenic streptococci or strains isolated from cases of septic sore throat. 3. The strains obtained from the throats of patients from an epidemic of scarlet fever and the strain from the milk responsible for this epidemic fall into the scarlatinal group according to these agglutination tests. 4. Absorption tests can be carried out with these strains and sera under proper conditions. 5. A group of hemolytic streptococci biologically distinct from streptococci from other sources than scarlet fever is constantly associated with scarlatina. They constitute a group of closely related streptococci which may be identified by agglutination tests. PMID:19868913

21 CFR 558.450 - Oxytetracycline.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Lobsters: For control of gaffkemia caused by Aerococcus viridans. Administer as sole ration for 5 consecutive days; withdraw medicated feed 30 d before harvesting lobsters. 066104 (6) Oxytetracycline may be...

21 CFR 558.450 - Oxytetracycline.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Lobsters: For control of gaffkemia caused by Aerococcus viridans. Administer as sole ration for 5 consecutive days; withdraw medicated feed 30 d before harvesting lobsters. 066104 (6) Oxytetracycline may be...

Efficacy of direct Gram stain in differentiating staphylococci from streptococci in blood cultures positive for gram-positive cocci.

PubMed Central

Agger, W A; Maki, D G

1978-01-01

A preponderance of clusters seen on direct Gram stain of blood cultures positive for gram-positive cocci was 98% sensitive and 100% specific for identification of staphylococcal species or of Peptococcus. A preponderance of chains, pairs, or both was 100% sensitive and 98% specific for identifying streptococci. Further presumptive identification of either staphylococci or streptococci based on microscopic morphology was unreliable. The direct Gram stain is highly reliable for differentiating staphylococci from streptococci and should be of considerable value to clinicians selecting initial antimicrobial therapy. PMID:75888

The Microbiome in Populations with a Low and High Prevalence of Caries.

PubMed

Johansson, I; Witkowska, E; Kaveh, B; Lif Holgerson, P; Tanner, A C R

2016-01-01

The oral microbiota was compared between Romanian adolescents with a high prevalence of caries and no dental care and Swedish caries-active and caries-free adolescents in caries prevention programs and with a low prevalence of caries. Biofilm samples were analyzed by FLX+ pyrosequencing of the V1 to V4 hypervariable regions of the 16S rRNA gene and polymerase chain reaction (PCR)/quantitative PCR (qPCR) for Streptococcus mutans and Streptococcus sobrinus. Sequences obtained blasted to 9 phyla, 66 genera, and 401 human oral taxa (HOT) in the 16S rRNA Human Oral Microbiome Database, of which 295 were represented by ≥20 sequences. The Romanian adolescents had more sequences in Firmicutes and fewer in Actinobacteria phyla and more sequences in the genera Bacteroidetes [G-3], Porphyromonas, Abiotrophia, Filifactor, Peptostreptococcaceae [11][G-4], Pseudoramibacter, Streptococcus, and Neisseria and fewer in Actinomyces, Selenomonas, Veillonella, Campylobacter, and TM7 [G-1] than the Swedish groups. Multivariate modeling employing HOT, S. sobrinus and S. mutans (PCR/qPCR), and sugar snacks separated Romanian from Swedish adolescents. The Romanian adolescents' microbiota was characterized by a panel of streptococci, including S. mutans, S. sobrinus, and Streptococcus australis, and Alloprevotella, Leptotrichia, Neisseria, Porphyromonas, and Prevotella. The Swedish adolescents were characterized by sweet snacks, and those with caries activity were also characterized by Prevotella, Actinomyces, and Capnocytophaga species and those free of caries by Actinomyces, Prevotella, Selenomonas, Streptococcus, and Mycoplasma. Eight species including Streptococcus mitis and Streptococcus species HOT070 were prevalent in Romanian and Swedish caries-active subjects but not caries-free subjects. In conclusion, S. mutans and S. sobrinus correlated with Romanian adolescents with caries and with limited access to dental care, whereas S. mutans and S. sobrinus were detected infrequently in Swedish adolescents in dental care programs. Swedish caries-active adolescents were typically colonized by Actinomyces, Selenomonas, Prevotella, and Capnocytophaga. Hence, the role of mutans streptococci as a primary caries pathogen appears less pronounced in populations with prevention programs compared to populations lacking caries treatment and prevention strategies. © International & American Associations for Dental Research 2015.

[Occurrence and drug-resistance of beta-hemolytic streptococci].

PubMed

Mikołajczyk, Dorota; Budzyńska, Anna; Kaczmarek, Agnieszka; Gospodarek, Eugenia

2007-01-01

The aim of this study was the analysis of drug-resistance and frequency appearance of beta-hemolytic streptococci strains which were isolated in 2003-2005 in the University Hospital at the L. Rydygier Collegium Medicum in Bydgoszcz University of Nicolaus Copernicus in Toruń. Among investigeted beta-hemolytic streptococci the most frequency isolated species was S. agalactiae. All isolates examined in our study were susceptible to penicillin, the higest rate of resistance was found for tetracycline. The rates of resistence to macrolide-lincosamide-streptogramin B (phenotyp MLS(B)) were as follows: S. agalactiae (18.7%), S. pyogenes (10.1%), group G streptococci (10.6%) and group C streptococci (8.0%). In our study we presented also a special case patient from which in investigeted period S. agalactiae was isolated twenty eight times. For ten chromosomal DNA isolated from this patient three different PFGE profiles were obtained.

Streptococci and Actinomyces induce antibodies which cross react with epithelial antigens in periodontitis

PubMed Central

Ye, P; Harty, D W S; Chapple, C C; Nadkarni, M A; Carlo, A A D E; Hunter, N

2003-01-01

Perturbation of epithelial structure is a prominent but poorly understood feature of the immunopathological response to bacterial antigens which characterizes the destructive lesion of periodontitis. Western analysis of sera from 22 patients with periodontitis detected multiple antigens in extracts of epithelial cells whereas sera from 12 periodontally healthy subjects displayed only trace reaction with epithelial antigens. To investigate a possible relationship between the bacterial flora adjacent to diseased sites and the presence of antibodies reactive with epithelium, subgingival plaque samples were taken from deep periodontal pockets and cultured anaerobically. Gram positive bacteria containing antigens cross-reactive with epithelial cells were reproducibly isolated by probing membrane colony-lifts with affinity-isolated (epithelium-specific) antibodies and identified by 16S rDNA sequence homology as streptococci (S. mitis, S. constellatus and two S. intermedius strains) and Actinomyces (A. georgiae, and A. sp. oral clone). Conversely, when serum from patients with periodontitis was absorbed with the captured bacterial species the number of epithelial antigens recognized was specifically reduced. It was concluded that development of cross-reactive antibodies related to these organisms may contribute to perturbation of the epithelial attachment to the tooth and the progression of periodontitis. These autoreactive antibodies could also be a contributing factor in other diseases affecting epithelia. PMID:12605700

Nutritionally Variant Streptococci Bacteremia in Cancer Patients: A Retrospective Study, 1999–2014

PubMed Central

Yacoub, Abraham T.; Krishnan, Jayasree; Acevedo, Ileana M.; Halliday, Joseph; Greene, John N.

2015-01-01

Background Nutritionally variant Streptococci (NVS), Abiotrophia and Granulicatella are implicated in causing endocarditis and blood stream infections more frequently than other sites of infection. Neutropenia and mucositis are the most common predisposing factors for infection with other pathogens in cancer patients. In this study, we investigated the clinical characteristics of NVS bacteremia in cancer patients and identified risk factors and outcomes associated with these infections. Materials and Methods We retrospectively reviewed all cases of NVS bacteremia occurring from June 1999 to April 2014 at H. Lee Moffitt Cancer Center and Research Institute. The computerized epidemiology report provided by the microbiology laboratory identified thirteen cancer patients with NVS bacteremia. We collected data regarding baseline demographics and clinical characteristics such as age, sex, underlying malignancy, neutropenic status, duration of neutropenia, treatment, and outcome. Results Thirteen patients were identified with positive NVS blood stream infection. Ten patients (77%) had hematologic malignancies, including chronic lymphocytic leukemia (CLL)(1), multiple myeloma (MM)(1), acute myelogenous leukemia (AML)(4), and non-Hodgkin’s lymphoma (NHL)(4). The non-hematologic malignancies included esophageal cancer(2) and bladder cancer (1). Conclusion NVS should be considered as a possible agent of bacteremia in cancer patients with neutropenia and a breach in oral, gastrointestinal and genitourinary mucosa (gingivitis/mucositis). PMID:25960858

In vitro antimicrobial activities against cariogenic streptococci and their antioxidant capacities: A comparative study of green tea versus different herbs.

PubMed

Tsai, Tzung-Hsun; Tsai, Tsung-Hsien; Chien, You-Chia; Lee, Chi-Wei; Tsai, Po-Jung

2008-10-15

The antimicrobial activity against cariogenic bacteria, total antioxidant capacity and phenolic constituents of methanolic extracts from 11 herbs were investigated and compared with those of green tea (Camellia sinensis). Among the 12 tested herbs, eight herbal extracts could inhibit the growth of Streptococcus sanguinis. Jasmine, jiaogulan, and lemongrass were the most potent, with minimum inhibitory concentrations (MIC) of 1mg/ml, while green tea was less effective, with a MIC of 4mg/ml. Among them, only rosemary could inhibit the growth of S. mutans at a MIC of 4mg/ml. Total antioxidant capacities of herbal extracts were analyzed by three different assays, including 2,2-diphenyl-1-picrylhydrazyl (DPPH·) radical scavenging activity, trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC). Regardless of the assays used, green tea exhibited the highest antioxidant capacity, followed by osmanthus. Wide variations in total phenolics and total flavonoids of herbal tea extracts were observed. Chlorogenic acid was detected in high amount in honeysuckle and duzhong. These data suggest that rosemary is a potent inhibitor of oral streptococci, and green tea and osmanthus may be effective potential sources of natural antioxidants. Copyright © 2008 Elsevier Ltd. All rights reserved.

Salivary microbiota and caries occurrence in Mutans Streptococci-positive school children.

PubMed

ElSalhy, M; Söderling, E; Honkala, E; Fontana, M; Flannagan, S; Kokaras, A; Paster, B J; Varghese, A; Honkala, S

2016-09-01

To compare the composition of the salivary microbiota in caries-affected vs. caries-free mutans streptococci (MS)- positive children with mixed dentition. Twenty eight healthy, 11-12-year-old schoolchildren with high MS counts (>10⊃5 CFU/mL) were included in this study. The children were screened with the Dentocult SM Strip Mutans test (Orion Diagnostica, Espoo, Finland) and examined using the International Caries Detection and Assessment System (ICDAS). The microbial composition of the saliva was assessed using the Human Oral Microbe Identification Microarray (HOMIM). Microbial differences between caries-affected (n=18) and caries-free children (n=10) were compared by Mann-Whitney analysis. The microbiota of the caries-affected vs. caries-free children was rather similar. Abiotrophia defectiva and Actinomyces meyeri/A. odontolyticus were significantly higher in caries-affected than in caries-free children (p=0.006, 0.046, respectively). Shuttleworthia satelles was significantly higher in caries-free compared to caries-affected children (p=0.031). A. defectiva and A. meyeri/A. odontolyticus correlated positively with caries severity measured by ICDAS Caries Index (p = 0.494, 0.454, 0.400 respectively) while S. satelles was negatively correlated with caries severity (p= -0.489). Salivary A. defectiva and A. meyeri/A. odontolyticus and are associated with caries occurrence in MS-positive children with mixed dentition.

Feasibility, efficacy, and adverse effects of outpatient antibacterial prophylaxis in children with acute myeloid leukemia

PubMed Central

Inaba, Hiroto; Gaur, Aditya H; Cao, Xueyuan; Flynn, Patricia M; Pounds, Stanley B; Avutu, Viswatej; Marszal, Lindsay N; Howard, Scott C; Pui, Ching-Hon; Ribeiro, Raul C; Hayden, Randall T; Rubnitz, Jeffrey E

2014-01-01

BACKGROUND Intensive chemotherapy for pediatric acute myeloid leukemia (AML) incurs the risk of infectious complications, but the benefits of antibiotic prophylaxis remain unclear. METHODS In 103 children treated on the AML02 protocol between October 2002 and October 2008 at St. Jude Children’s Research Hospital, we retrospectively assessed the effect of antibiotic prophylaxis on the frequency of febrile neutropenia, clinically or microbiologically confirmed infections (including bacteremia), and antibiotic resistance, and on the results of nasal and rectal surveillance cultures. Initially, patients received no prophylaxis or oral cephalosporin (Group A). Then the protocol was amended to give intravenous cefepime alone or intravenous vancomycin plus either oral cephalosporin, oral ciprofloxacin, or intravenous cefepime (Group B). RESULTS There were 334 infectious episodes. Group A had a significantly greater frequency of documented infections and bacteremia (both P < .0001) (including gram-positive and gram-negative bacteremia, P = .0003 and .001, respectively) than Group B, especially viridans streptococcal bacteremia (P = .001). The incidence of febrile neutropenia without documented infection was not different between the two groups. Five cases of bacteremia with vancomycin-resistant enterococci (VRE) occurred in group B (vs. none in Group A), without related mortality. Two of these cases were preceded by positive VRE rectal surveillance cultures. CONCLUSIONS Outpatient intravenous antibiotic prophylaxis is feasible in children with AML and reduces the frequency of documented infection but not of febrile neutropenia. Despite emergence of VRE bacteremia, the benefits favor antibiotic prophylaxis. Creative approaches to shorten the duration of prophylaxis and thereby minimize resistance should be explored. PMID:24677028

Salivary proteins and microbiota as biomarkers for early childhood caries risk assessment

PubMed Central

Hemadi, Abdullah S; Huang, Ruijie; Zhou, Yuan; Zou, Jing

2017-01-01

Early childhood caries (ECC) is a term used to describe dental caries in children aged 6 years or younger. Oral streptococci, such as Streptococcus mutans and Streptococcus sorbrinus, are considered to be the main etiological agents of tooth decay in children. Other bacteria, such as Prevotella spp. and Lactobacillus spp., and fungus, that is, Candida albicans, are related to the development and progression of ECC. Biomolecules in saliva, mainly proteins, affect the survival of oral microorganisms by multiple innate defensive mechanisms, thus modulating the oral microflora. Therefore, the protein composition of saliva can be a sensitive indicator for dental health. Resistance or susceptibility to caries may be significantly correlated with alterations in salivary protein components. Some oral microorganisms and saliva proteins may serve as useful biomarkers in predicting the risk and prognosis of caries. Current research has generated abundant information that contributes to a better understanding of the roles of microorganisms and salivary proteins in ECC occurrence and prevention. This review summarizes the microorganisms that cause caries and tooth-protective salivary proteins with their potential as functional biomarkers for ECC risk assessment. The identification of biomarkers for children at high risk of ECC is not only critical for early diagnosis but also important for preventing and treating the disease. PMID:29125139

STUDIES ON THE BIOLOGY OF STREPTOCOCCUS

PubMed Central

Bliss, Walter Parks

1922-01-01

1. Hemolytic streptococcus has been found in 100 per cent of the throats of patients with scarlet fever during the 1st week of the disease. 2. The average length of time that these organisms are present in the throat varies from 10 to 20 days. 3. No morphological or cultural characteristics peculiar to the hemolytic streptococcus from scarlet fever can be demonstrated. 4. Ten immune sera have been prepared from different strains of scarlet fever streptococci and each of the sera agglutinated more than 80 per cent of the strains isolated from scarlatinal throats. On the other hand, scarlatinal streptococci are not agglutinated by immune sera prepared from hemolytic streptococci isolated from other pathological sources. 5. Serum from patients convalescent from scarlet fever agglutinates weakly or not at all the homologous strain of hemolytic streptococcus. 6. The specificity of the agglutination reaction of scarlatinal streptococci is confirmed by absorption experiments. 7. Scarlatinal antistreptococcic serum affords some degree of protection against virulent scarlet fever streptococci but has no protective power against hemolytic streptococci from other diseases. 8. In a small epidemic of scarlet fever a healthy carrier of hemolytic streptococcus was detected; the organism carried was identical in its serological reactions with strains of hemolytic streptococci isolated from active cases of scarlet fever. 9. In a study of a number of contacts with a case of scarlet fever, in only one instance was a scarlatinal type of hemolytic streptococcus recovered from the throat. PMID:19868695

Salivary cariogenic bacteria counts are associated with obesity in student women at a Malaysian university.

PubMed

Yeo, Wey-Zheng; Lim, Sheng-Pei; Say, Yee-How

2018-01-01

The counts of cariogenic bacteria lactobacilli and mutans streptococci have been studied and correlated with sugar intake. This study was to investigate the association between salivary lactobacilli and mutans streptococci counts with sweet food eating behavior and sweet sensitivity among 120 Malaysian women (101 ethnic Chinese, 19 ethnic Indians), while taking into account anthropometric and menstruation variables. Demographics, anthropometric measurements and menstrual history were taken. Hedonic preference, intake frequency of a list of sweet foods, intensity perception and pleasantness ratings of sweet stimuli were assessed. Saliva was collected for lactobacilli and mutans streptococci culture. We found that centrally obese subjects (high waist circumference and waist-hip ratio) had significantly higher salivary lactobacilli and mutans streptococci counts (all p<0.05), while overweight and high total body fat subjects had significantly higher salivary mutans streptococci counts (p<0.001). The sweetness intensity perception of chocolate malt drinks was significantly lower in women who were in their pre-menstrual (post-ovulation) phase. However, menstruation variables (menstrual phases, regularity and pre-menstrual syndromes) did not play a role in determining compulsive eating, sweets/chocolate craving and salivary lactobacilli and mutans streptococci counts. Taken together, salivary lactobacilli and mutans streptococci counts of the Malaysian women are associated with central obesity, but not sweet food eating behaviour, sweet sensitivity and menstruation variables. Salivary microbiome analysis could be useful as a potential diagnostic indicator of diseases such as obesity.

Viridans streptococcal shock syndrome during bone marrow transplantation.

PubMed

Martino, R; Manteiga, R; Sánchez, I; Brunet, S; Sureda, A; Badell, I; Argilés, B; Subirá, M; Bordes, R; Domingo-Albós, A

1995-01-01

Of 320 patients receiving a marrow transplant at the Hospital de Sant Pau between 1986 and 1992, 12% developed viridans streptococcal bacteremia during severe neutropenia. Five of these patients (13%) developed a rapidly progressive fatal shock syndrome characterized by bilateral pulmonary infiltrates, acute respiratory failure (ARDS) and septic shock early in the transplantation course (6 or 7 days posttransplantation). All patients were transplanted for acute leukemia in remission, and 2 received an allogeneic and 3 an autologous transplant. Four of these subjects were younger than 15 years of age and all had received cyclophosphamide and total body irradiation as conditioning regimen for marrow transplantation. All 5 patients died, and postmortem examinations revealed diffuse pulmonary lesions characteristic of the ARDS. These observations contribute to defining the clinical and pathologic characteristics of this serious complication of intensive anticancer treatment.

Detection of Serum Thermolabile β-2 Macroglycoprotein (Hakata Antigen) by Enzyme-Linked Immunosorbent Assay Using Polysaccharide Produced by Aerococcus viridans

PubMed Central

Tsujimura, Mitsushi; Ishida, Chuzo; Sagara, Yasuko; Miyazaki, Takashi; Murakami, Koichi; Shiraki, Hiroshi; Okochi, Kazuo; Maeda, Yoshiaki

2001-01-01

Although a serum thermolabile β-2 macroglycoprotein (TMG) may play a role in host defense as a lectin, little is known of its related physiological functions, mainly due to a lack of appropriate methods for tracing the functions of TMG. We identified a polysaccharide from Aerococcus viridans, PSA, which reacts with TMG, and based on this finding, we developed an enzyme-linked immunosorbent assay to trace the functions of TMG. Using ethanol precipitation and DEAE-Sepharose and Sephacryl S-400 column chromatographies, we isolated PSA from cultured medium of A. viridans, and it exhibited specific binding against TMG in blood samples. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), the isolated PSA showed ladder bands that implied the existence of repeating units composed of d-glucose, N-acetyl-d-glucosamine, d-mannose, and d-xylose, as confirmed by gas chromatography-mass spectrometry. SDS-PAGE and immunochemical analysis, using rabbit anti-TMG antibody, showed that PSA specifically binds solely to intact serum TMG but not to TMG heated at 56°C for 30 min, a condition under which antigenicity is lost. TMG in serum samples bound to PSA in a dose-dependent manner, and this binding was clearly suppressed by addition of PSA. These observations indicate that PSA is a useful adsorbent to TMG and can be used to develop appropriate methods for tracing the functions of TMG. PMID:11238239

Recovery and screening for antibiotic susceptibility of potential bacterial pathogens from the oral cavity of shark species involved in attacks on humans in Recife, Brazil.

PubMed

Interaminense, J A; Nascimento, D C O; Ventura, R F; Batista, J E C; Souza, M M C; Hazin, F H V; Pontes-Filho, N T; Lima-Filho, J V

2010-08-01

The number of incidents involving sharks and humans at beaches in Recife, on the north-eastern Brazilian coast, is among the highest worldwide. In addition, wound infections in survivors are common; but the nature and risk of the aetiological agents is unknown. In the present study, 81 potential bacterial pathogens were identified in the oral cavity of sharks involved in attacks in Recife, and were subjected to antibiotic susceptibility tests using the standardized disc-diffusion method. The majority were enterobacteria such as Enterobacter spp., Citrobacter spp., Proteus spp., Providencia alcalifaciens, Escherichia coli, Moellerella wisconcensis and Leclercia adecarboxylata. Other Gram-negative bacteria included Vibrio spp., Burkholderia cepacia, Acinetobacter spp. and Pseudomonas spp. In addition, coagulase-positive and coagulase-negative Staphylococcus spp., Enterococcus spp. and Micrococcus spp. were identified, besides Streptococcus spp. from the viridans group. Resistance was especially found in the Proteus mirabilis and Citrobacter freundii, and ranged from 4 to 6 antibiotics out of the 13 tested. Gentamicin and vancomycin were the most effective against Gram-positive cocci strains, whereas levofloxacin was fully inhibitory against Gram-positive and Gram-negative bacteria. These data are discussed in light of a retrospective evaluation of the medical records of three shark victims treated at Restauração Hospital in Recife.

Ceftobiprole Activity When Tested Against Contemporary Bacteria Causing Bloodstream Infections in the US (2016)

PubMed Central

Flamm, Robert K; Duncan, Leonard R; Shortridge, Dee; Smart, Jennifer I; Hamed, Kamal; Mendes, Rodrigo E; Sader, Helio S

2017-01-01

Abstract Background Ceftobiprole medocaril (prodrug of ceftobiprole) is an advanced cephalosporin, approved for adults in multiple European countries for the treatment of hospital-acquired pneumonia (excluding ventilator-associated pneumonia) or community-acquired pneumonia. It is not approved in the US; however, it has achieved qualified infectious disease product status and two phase 3 studies supported by BARDA are planned to begin in the US in 2017. Methods A total of 2,787 Gram-positive (GP) and -negative (GN) isolates from bloodstream infections (BSI) from 30 medical centers in the SENTRY Antimicrobial Surveillance Program were evaluated. Isolates were collected in the US during 2016. Susceptibility (S) testing was performed by reference broth microdilution method against ceftobiprole and comparators. Isolates included 693 Staphylococcus aureus (SA), 216 coagulase-negative staphylococci (CoNS), 244 enterococci, 63 Streptococcus pneumoniae (SPN), 74 viridans group streptococci (VGS), 138 β-haemolytic streptococci (BHS), 1,105 Enterobacteriaceae (ENT), 129 Pseudomonas aeruginosa (PSA), 41 Acinetobacter spp. (ASP), 30 Stenotrophomonas maltophila, 19 Haemophilus spp. and 35 miscellaneous bacteria. Results Methicillin-resistant S. aureus (MRSA) S rates were lower than for methicillin-susceptible S. aureus (MSSA) for most agents. For levofloxacin (LEV) and erythromycin (ERY), the S rates were LEV: MRSA, 23.2%; MSSA, 86.1%; ERY: MRSA, 9.0%; MSSA, 69.3%. All MSSA and 99.0% of MRSA were S to ceftobiprole, while all MSSA and 96.5% of MRSA were S to ceftaroline (CPT). For CoNS, 98.1% of ceftobiprole MIC values were ≤2mg/L. Ceftobiprole was active against Enterococcus faecalis (96.1% ≤2mg/L) and not against E. faecium (18.9% ≤2mg/L). Against ENT, ceftobiprole (85.0%S) was similar in activity to ceftazidime (CAZ, 87.2%S) and cefepime (FEP, 88.9%S). The MIC50/90 values for ceftobiprole, FEP, and CAZ against PSA were identical at 2/16 mg/L. Conclusion Ceftobiprole exhibited potent in vitro activity against GP and GN isolates from contemporary BSI in the US. These results support further clinical evaluation of ceftobiprole for the treatment of BSI. Disclosures R. K. Flamm, Basilea Pharmaceutica International Ltd.: Research Contractor, Research grant; L. R. Duncan, Basilea Pharmaceutica International Ltd.: Research Contractor, Research grant; D. Shortridge, Basilea Pharmaceutica International Ltd.: Research Contractor, Research grant; J. I. Smart, Basilea Pharmaceutica International Ltd.: Employee, Salary; K. Hamed, Basilea Pharmaceutica International Ltd.: Employee, Salary; R. E. Mendes, Basilea Pharmaceutica International Ltd.: Research Contractor, Research grant; H. S. Sader, Basilea Pharmaceutica International Ltd.: Research Contractor, Research grant

Recolonization of mutans steptococci on teeth with orthodontic appliances after antimicrobial therapy.

PubMed

Attin, R; Thon, C; Schlagenhauf, U; Werner, C; Wiegand, A; Hannig, C; Attin, T

2005-10-01

The aim of the present study was to compare the recolonization pattern of mutans streptococci on densely colonized teeth with and without fixed orthodontic appliances after treatment with a 40 per cent chlorhexidine (CHX) varnish (EC 40, Explore). Healthy subjects free of carious lesions requiring fixed orthodontic appliance treatment but with high bacterial mutans streptococci saliva counts were recruited (n = 10). For baseline registration, plaque from buccal sites was sampled and cultivated on Dentocult strips. Following professional tooth cleaning, CHX varnish was applied to all teeth for 8 minutes. Subsequently, orthodontic brackets and bands were inserted in either the upper or lower arch. Eight weeks after varnish application the degree of recolonization with mutans streptococci was reassessed on the buccal sites. Statistical analysis showed that recolonization with mutans streptococci was significantly higher (P < 0.05) on teeth with orthodontic appliances. The results indicate that the use of fixed orthodontic appliances creates artificial environments suitable for the proliferation of mutans streptococci after CHX varnish suppression.

[Evaluation of Prolex for the rapid identification of streptococci isolated in medical microbiology].

PubMed

Loubinoux, J; Mihaila-Amrouche, L; Bouvet, A

2004-10-01

The need to rapidly identify streptococci responsible for acute infectious diseases has led to the development of agglutination techniques that are able to identify streptococcal group antigens (A, B, C, D, F, and G) directly from primoculture colonies on blood agar. The Prolex agglutination tests (Pro-Lab Diagnostics, Richmond Hill, Ontario, Canada), distributed in France by i2a, have been used for the determination of group antigens of 166 isolates of streptococci and enterococci previously identified in the National Reference Center for Streptococci. The results obtained with the Prolex reagents have permitted to correctly identify all pyogenic beta-hemolytic streptococci (23 Streptococcus pyogenes, 21 Streptococcus agalactiae, 33 Streptococcus dysgalactiae subsp. equisimilis including 6 group C and 27 group G, and 5 Streptococcus porcinus including 4 group B). Four differences between unexpected agglutinations (A or F) and species identifications have been obtained. These differences were observed for four non-hemolytic isolates of Streptococcus mutans, Streptococcus gordonii, Streptococcus infantarius, and Streptococcus suis. The anti-D reagent has been of value as a marker for isolates of enterococci. Thus, these results confirm the abilities of these agglutination tests for the grouping of beta-hemolytic streptococci. Moreover, the use of Prolex has the advantage to be rapid because of the non-enzymatic but chemical extraction of streptococcal antigens.

Diagnostic accuracy of different caries risk assessment methods. A systematic review.

PubMed

Senneby, Anna; Mejàre, Ingegerd; Sahlin, Nils-Eric; Svensäter, Gunnel; Rohlin, Madeleine

2015-12-01

To evaluate the accuracy of different methods used to identify individuals with increased risk of developing dental coronal caries. Studies on following methods were included: previous caries experience, tests using microbiota, buffering capacity, salivary flow rate, oral hygiene, dietary habits and sociodemographic variables. QUADAS-2 was used to assess risk of bias. Sensitivity, specificity, predictive values, and likelihood ratios (LR) were calculated. Quality of evidence based on ≥3 studies of a method was rated according to GRADE. PubMed, Cochrane Library, Web of Science and reference lists of included publications were searched up to January 2015. From 5776 identified articles, 18 were included. Assessment of study quality identified methodological limitations concerning study design, test technology and reporting. No study presented low risk of bias in all domains. Three or more studies were found only for previous caries experience and salivary mutans streptococci and quality of evidence for these methods was low. Evidence regarding other methods was lacking. For previous caries experience, sensitivity ranged between 0.21 and 0.94 and specificity between 0.20 and 1. Tests using salivary mutans streptococci resulted in low sensitivity and high specificity. For children with primary teeth at baseline, pooled LR for a positive test was 3 for previous caries experience and 4 for salivary mutans streptococci, given a threshold ≥10(5) CFU/ml. Evidence on the validity of analysed methods used for caries risk assessment is limited. As methodological quality was low, there is a need to improve study design. Low validity for the analysed methods may lead to patients with increased risk not being identified, whereas some are falsely identified as being at risk. As caries risk assessment guides individualized decisions on interventions and intervals for patient recall, improved performance based on best evidence is greatly needed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Precision-guided antimicrobial peptide as a targeted modulator of human microbial ecology.

PubMed

Guo, Lihong; McLean, Jeffrey S; Yang, Youngik; Eckert, Randal; Kaplan, Christopher W; Kyme, Pierre; Sheikh, Omid; Varnum, Brian; Lux, Renate; Shi, Wenyuan; He, Xuesong

2015-06-16

One major challenge to studying human microbiome and its associated diseases is the lack of effective tools to achieve targeted modulation of individual species and study its ecological function within multispecies communities. Here, we show that C16G2, a specifically targeted antimicrobial peptide, was able to selectively kill cariogenic pathogen Streptococcus mutans with high efficacy within a human saliva-derived in vitro oral multispecies community. Importantly, a significant shift in the overall microbial structure of the C16G2-treated community was revealed after a 24-h recovery period: several bacterial species with metabolic dependency or physical interactions with S. mutans suffered drastic reduction in their abundance, whereas S. mutans' natural competitors, including health-associated Streptococci, became dominant. This study demonstrates the use of targeted antimicrobials to modulate the microbiome structure allowing insights into the key community role of specific bacterial species and also indicates the therapeutic potential of C16G2 to achieve a healthy oral microbiome.

Redefining the management of pediatric tonsillopharyngitis with cefprozil.

PubMed

Jerath, Nameet; Shetty, Ganesh

2007-12-01

Tonsillopharyngitis is very common in children, with Group A Streptococci being the most common bacterial etiology. Effective antibacterial treatment is imperative due to risk of rheumatic fever. Cephalosporins have been used successfully for the treatment of Group A beta-hemolytic Streptococcal (GABHS) tonsillopharyngitis. Cefprozil is a novel broad-spectrum oral cephalosporin. Cefprozil is rapidly absorbed from the gastrointestinal tract with high bioavailability. The excellent penetration of cefprozil into tonsillar and adenoidal tissue corresponds well with the clinical outcome. The drug provides excellent coverage against both gram-negative and -positive bacteria that may cause pharyngitis/tonsillitis. The beta-lactamase stability of cefprozil appears to exceed that of other oral cephalosporins for important gram negative pathogens. In clinical trials, cefprozil appears to be at least as effective as commonly used comparison agents such as cefaclor and cefixime. Additionally, cefprozil is better tolerated than the latter, especially with regard to gastrointestinal adverse effects. Thus cefprozil can be considered a safe and reliable drug for the treatment of Streptococcal tonsillopharyngitis in children.

Population structure of Streptococcus oralis

PubMed Central

Do, Thuy; Jolley, Keith A.; Maiden, Martin C. J.; Gilbert, Steven C.; Clark, Douglas; Wade, William G.; Beighton, David

2009-01-01

Streptococcus oralis is a member of the normal human oral microbiota, capable of opportunistic pathogenicity; like related oral streptococci, it exhibits appreciable phenotypic and genetic variation. A multilocus sequence typing (MLST) scheme for S. oralis was developed and the resultant data analysed to examine the population structure of the species. Analysis of 113 isolates, confirmed as belonging to the S. oralis/mitis group by 16S rRNA gene sequencing, characterized the population as highly diverse and undergoing inter- and intra-species recombination with a probable clonal complex structure. ClonalFrame analysis of these S. oralis isolates along with examples of Streptococcus pneumoniae, Streptococcus mitis and Streptococcus pseudopneumoniae grouped the named species into distinct, coherent populations and did not support the clustering of S. pseudopneumoniae with S. mitis as reported previously using distance-based methods. Analysis of the individual loci suggested that this discrepancy was due to the possible hybrid nature of S. pseudopneumoniae. The data are available on the public MLST website (http://pubmlst.org/soralis/). PMID:19423627

The Biofilm Community-Rebels with a Cause.

PubMed

Aruni, A Wilson; Dou, Yuetan; Mishra, Arunima; Fletcher, Hansel M

2015-03-01

Oral Biofilms are one of the most complex and diverse ecosystem developed by successive colonization of more than 600 bacterial taxa. Development starts with the attachment of early colonizers such as Actinomyces species and oral streptococci on the acquired pellicle and tooth enamel. These bacteria not only adhere to tooth surface but also interact with each other and lay foundation for attachment of bridging colonizer such as Fusobacterium nucleatum followed by late colonizers including the red complex species: Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola -the founders of periodontal disease. As the biofilm progresses from supragingival sites to subgingival sites, the environment changes from aerobic to anaerobic thus favoring the growth of mainly Gram-negative obligate anaerobes while restricting the growth of the early Gram-positive facultative aerobes. Microbes present at supragingival level are mainly related to gingivitis and root-caries whereas subgingival species advance the destruction of teeth supporting tissues and thus causing periodontitis. This review summarizes our present understanding and recent developments on the characteristic features of supra- and subgingival biofilms, interaction between different genera and species of bacteria constituting these biofilms and draws our attention to the role of some of the recently discovered members of the oral community.

The Biofilm Community-Rebels with a Cause

PubMed Central

Aruni, A. Wilson; Dou, Yuetan; Mishra, Arunima; Fletcher, Hansel M.

2015-01-01

Oral Biofilms are one of the most complex and diverse ecosystem developed by successive colonization of more than 600 bacterial taxa. Development starts with the attachment of early colonizers such as Actinomyces species and oral streptococci on the acquired pellicle and tooth enamel. These bacteria not only adhere to tooth surface but also interact with each other and lay foundation for attachment of bridging colonizer such as Fusobacterium nucleatum followed by late colonizers including the red complex species: Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola-the founders of periodontal disease. As the biofilm progresses from supragingival sites to subgingival sites, the environment changes from aerobic to anaerobic thus favoring the growth of mainly Gram-negative obligate anaerobes while restricting the growth of the early Gram-positive facultative aerobes. Microbes present at supragingival level are mainly related to gingivitis and root-caries whereas subgingival species advance the destruction of teeth supporting tissues and thus causing periodontitis. This review summarizes our present understanding and recent developments on the characteristic features of supra- and subgingival biofilms, interaction between different genera and species of bacteria constituting these biofilms and draws our attention to the role of some of the recently discovered members of the oral community. PMID:26120510

Streptococcus gordonii pheromone s.g.cAM373 may influence the reservoir of antibiotic resistance determinants of Enterococcus faecalis origin in the oral metagenome.

PubMed

Mansfield, Jillian M; Herrmann, Paul; Jesionowski, Amy M; Vickerman, M Margaret

2017-11-01

Streptococcus gordonii produces a pheromone heptapeptide, s.g.cAM373, which induces a conjugative mating response in Enterococcus faecalis cells carrying the responsive plasmid, pAM373. We investigated the extent of this intergeneric signaling on DNA acquisition by streptococcal species likely to cohabit oral biofilms. E. faecalis/pAM373/pAMS470 cells were incubated with synthetic s.g.cAM373, reverse peptide s.g.cAM373-R, or peptide-free medium and examined for their abilities to transfer plasmid DNA to streptococcal species in the presence of DNase. Preinduction of E. faecalis donors with s.g.cAM373 resulted in transconjugation frequencies in non-pheromone producing strains of Streptococcus mutans, Streptococcus sanguinis, Streptococcus anginosus, and Streptococcus suis that were significantly higher than frequencies when donors were preincubated with s.g.cAM373-R or medium alone. Peptide-mediated communication between commensal streptococci and E. faecalis carrying pheromone-responsive plasmids may facilitate conjugative DNA transfer to bystander species, and influence the reservoir of antibiotic resistance determinants of enterococcal origin in the oral metagenome.

Organization of the capsule biosynthesis gene locus of the oral streptococcus Streptococcus anginosus.

PubMed

Tsunashima, Hiroyuki; Miyake, Katsuhide; Motono, Makoto; Iijima, Shinji

2012-03-01

The capsular polysaccharide (CPS) of the important oral streptococcus Streptococcus anginosus, which causes endocarditis, and the genes for its synthesis have not been clarified. In this study, we investigated the gene locus required for CPS synthesis in S. anginosus. Southern hybridization using the cpsE gene of the well-characterized bacterium S. agalactiae revealed that there is a similar gene in the genome of S. anginosus. By using the colony hybridization technique and inverse PCR, we isolated the CPS synthesis (cps) genes of S. anginosus. This gene cluster consisted of genes containing typical regulatory genes, cpsA-D, and glycosyltransferase genes coding for glucose, rhamnose, N-acetylgalactosamine, and galactofuranose transferases. Furthermore, we confirmed that the cps locus is required for CPS synthesis using a mutant strain with a defective cpsE gene. The cps cluster was found to be located downstream the nrdG gene, which encodes ribonucleoside triphosphate reductase activator, as is the case in other oral streptococci such as S. gordonii and S. sanguinis. However, the location of the gene cluster was different from those of S. pneumonia and S. agalactiae. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Characterization of bacteriophage communities and CRISPR profiles from dental plaque

PubMed Central

2014-01-01

Background Dental plaque is home to a diverse and complex community of bacteria, but has generally been believed to be inhabited by relatively few viruses. We sampled the saliva and dental plaque from 4 healthy human subjects to determine whether plaque was populated by viral communities, and whether there were differences in viral communities specific to subject or sample type. Results We found that the plaque was inhabited by a community of bacteriophage whose membership was mostly subject-specific. There was a significant proportion of viral homologues shared between plaque and salivary viromes within each subject, suggesting that some oral viruses were present in both sites. We also characterized Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) in oral streptococci, as their profiles provide clues to the viruses that oral bacteria may be able to counteract. While there were some CRISPR spacers specific to each sample type, many more were shared across sites and were highly subject specific. Many CRISPR spacers matched viruses present in plaque, suggesting that the evolution of CRISPR loci may have been specific to plaque-derived viruses. Conclusions Our findings of subject specificity to both plaque-derived viruses and CRISPR profiles suggest that human viral ecology may be highly personalized. PMID:24981669

Presumptive identification and antibiotic susceptibility of group B streptococci.

PubMed Central

Jokipii, A M; Jokipii, L

1976-01-01

The comparative performance of three presumptive identification tests for group B haemolytic streptococci was investigated, using 371 different clinical isolates of group B streptococci. Hippurate was hydrolysed by 96-1%, the CAMP reaction was positive in 95-0%, and pigment was produced by 97-3%. A combination of any two tests would have detected over 99-8%. On bile esculin agar 99-0% were able to grow, but non hydrolysed esculin; 5-1% were susceptible to bacitracin. The minimum inhibitory concentrations of five antibiotics for 279 group B streptococci were determined. All were susceptible to penicillin G, ampicillin, cephalothin, and erythromycin, while 80% were resistant to tetracycline. The MIC distributions were independent of the results of any identification test. PMID:783206

Short communication: Genotypic and phenotypic identification of environmental streptococci and association of Lactococcus lactis ssp. lactis with intramammary infections among different dairy farms.

PubMed

Werner, B; Moroni, P; Gioia, G; Lavín-Alconero, L; Yousaf, A; Charter, M E; Carter, B Moslock; Bennett, J; Nydam, D V; Welcome, F; Schukken, Y H

2014-11-01

Lactococcus species are counted among a large and closely related group of environmental streptococci and streptococci-like bacteria that include bovine mastitis pathogenic Streptococcus, Enterococcus, and Aerococcus species. Phenotypic and biochemical identification methods can be inaccurate and unreliable for species within this group, particularly for Lactococcus spp. As a result, the incidence of Lactococcus spp. on the farm may have been historically underreported and consequently little is known about the clinical importance of this genus as a mastitis pathogen. We used molecular genetic identification methods to accurately differentiate 60 environmental streptococci and streptococci-like bacteria isolated from cows with high somatic cell count and chronic intramammary infection (IMI; >2 somatic cell scores above 4) among 5 geographically distinct farms in New York and Minnesota that exhibited an observed increase in IMI. These isolates were phenotypically identified as Streptococcus uberis and Streptococcus spp. Genetic methods identified 42 isolates (70%) as Lactococcus lactis ssp. lactis, including all 10 isolates originally phenotypically identified as Streptococcus uberis. Antibiotic inhibition testing of all Lc. lactis ssp. lactis showed that 7 isolates were resistant to tetracycline. In the present study, a predominance of Lc. lactis ssp. lactis was identified in association with chronic, clinical bovine IMI among all 5 farms and characterized antimicrobial resistance for treatment therapies. Routine use by mastitis testing labs of molecular identification methods for environmental streptococci and streptococci-like bacteria can further define the role and prevalence of Lc. lactis ssp. lactis in association with bovine IMI and may lead to more targeted therapies. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Incidence and clinical variables associated with streptococcal throat infections: a prospective diagnostic cohort study

PubMed Central

Little, Paul; Hobbs, FD Richard; Mant, David; McNulty, Cliodna AM; Mullee, Mark

2012-01-01

Background Management of pharyngitis is commonly based on features which are thought to be associated with Lancefield group A beta-haemolytic streptococci (GABHS) but it is debatable which features best predict GABHS. Non-group A strains share major virulence factors with group A, but it is unclear how commonly they present and whether their presentation differs. Aim To assess the incidence and clinical variables associated with streptococcal infections. Design and setting Prospective diagnostic cohort study in UK primary care. Method The presence of pathogenic streptococci from throat swabs was assessed among patients aged ≥5 years presenting with acute sore throat. Results Pathogenic streptococci were found in 204/597 patients (34%, 95% CI = 31 to 38%): 33% (68/204) were non-group A streptococci, mostly C (n = 29), G (n = 18) and B (n = 17); rarely D (n = 3) and Streptococcus pneumoniae (n = 1). Patients presented with similar features whether the streptococci were group A or non-group A. The features best predicting A, C or G beta-haemolytic streptococci were patient’s assessment of severity (odds ratio [OR] for a bad sore throat 3.31, 95% CI = 1.24 to 8.83); doctors’ assessment of severity (severely inflamed tonsils OR 2.28, 95% CI = 1.39 to 3.74); absence of a bad cough (OR 2.73, 95% CI = 1.56 to 4.76), absence of a coryza (OR 1.54, 95% CI = 0.99 to 2.41); and moderately bad or worse muscle aches (OR 2.20, 95% CI = 1.41 to 3.42). Conclusion Non-group A strains commonly cause streptococcal sore throats, and present with similar symptomatic clinical features to group A streptococci. The best features to predict streptococcal sore throat presenting in primary care deserve revisiting. PMID:23211183

Incidence and clinical variables associated with streptococcal throat infections: a prospective diagnostic cohort study.

PubMed

Little, Paul; Hobbs, F D Richard; Mant, David; McNulty, Cliodna A M; Mullee, Mark

2012-11-01

Management of pharyngitis is commonly based on features which are thought to be associated with Lancefield group A beta-haemolytic streptococci (GABHS) but it is debatable which features best predict GABHS. Non-group A strains share major virulence factors with group A, but it is unclear how commonly they present and whether their presentation differs. To assess the incidence and clinical variables associated with streptococcal infections. Prospective diagnostic cohort study in UK primary care. The presence of pathogenic streptococci from throat swabs was assessed among patients aged ≥5 years presenting with acute sore throat. Pathogenic streptococci were found in 204/597 patients (34%, 95% CI = 31 to 38%): 33% (68/204) were non-group A streptococci, mostly C (n = 29), G (n = 18) and B (n = 17); rarely D (n = 3) and Streptococcus pneumoniae (n = 1). Patients presented with similar features whether the streptococci were group A or non-group A. The features best predicting A, C or G beta-haemolytic streptococci were patient's assessment of severity (odds ratio [OR] for a bad sore throat 3.31, 95% CI = 1.24 to 8.83); doctors' assessment of severity (severely inflamed tonsils OR 2.28, 95% CI = 1.39 to 3.74); absence of a bad cough (OR 2.73, 95% CI = 1.56 to 4.76), absence of a coryza (OR 1.54, 95% CI = 0.99 to 2.41); and moderately bad or worse muscle aches (OR 2.20, 95% CI = 1.41 to 3.42). Non-group A strains commonly cause streptococcal sore throats, and present with similar symptomatic clinical features to group A streptococci. The best features to predict streptococcal sore throat presenting in primary care deserve revisiting.

Probiotic bacteria affect the composition of salivary pellicle and streptococcal adhesion in vitro.

PubMed

Haukioja, A; Loimaranta, V; Tenovuo, J

2008-08-01

The use of probiotic bacteria is increasing worldwide and at least some of them can transiently colonize the oral cavity. Several studies have shown that probiotic bacteria, which are often thought of in relation only to intestinal health, can also affect the oral ecology, but the mechanisms for this are largely unknown. The aim of this study was to investigate in vitro if the probiotic bacteria used in commercial products affect the protein composition of the salivary pellicle and the adherence of other oral bacteria. Salivary pellicle on hydroxyapatite and the adhesion of two oral streptococci, Streptococcus mutans and Streptococcus gordonii, were used as a model. Probiotic bacteria that bound to saliva-coated hydroxyapatite reduced the adhesion of S. mutans but the inhibitory effect on the adherence of S. gordonii was weaker. Salivary pellicle protein composition was modified by all the strains tested. The modifications in the pellicle affected the adherence of S. mutans but not of S. gordonii. Two of the proteins missing from the pellicles made of saliva-treated with the probiotic bacteria were identified as salivary agglutinin gp340 and salivary peroxidase. All bacterial strains bound salivary agglutinin gp340. The ability of the probiotic bacteria to degrade peroxidase was demonstrated with purified bovine lactoperoxidase and two of the probiotic strains. This in vitro study showed that probiotic strains used in commercial products may affect the oral ecology by specifically preventing the adherence of other bacteria and by modifying the protein composition of the salivary pellicle.

Interactions between Streptococcus oralis, Actinomyces oris, and Candida albicans in the development of multispecies oral microbial biofilms on salivary pellicle.

PubMed

Cavalcanti, I M G; Del Bel Cury, A A; Jenkinson, H F; Nobbs, A H

2017-02-01

The fungus Candida albicans is carried orally and causes a range of superficial infections that may become systemic. Oral bacteria Actinomyces oris and Streptococcus oralis are abundant in early dental plaque and on oral mucosa. The aims of this study were to determine the mechanisms by which S. oralis and A. oris interact with each other and with C. albicans in biofilm development. Spatial distribution of microorganisms was visualized by confocal laser scanning microscopy of biofilms labeled by differential fluorescence or by fluorescence in situ hybridization (FISH). Actinomyces oris and S. oralis formed robust dual-species biofilms, or three-species biofilms with C. albicans. The bacterial components tended to dominate the lower levels of the biofilms while C. albicans occupied the upper levels. Non-fimbriated A. oris was compromised in biofilm formation in the absence or presence of streptococci, but was incorporated into upper biofilm layers through binding to C. albicans. Biofilm growth and hyphal filament production by C. albicans was enhanced by S. oralis. It is suggested that the interkingdom biofilms are metabolically coordinated to house all three components, and this study demonstrates that adhesive interactions between them determine spatial distribution and biofilm architecture. The physical and chemical communication processes occurring in these communities potentially augment C. albicans persistence at multiple oral cavity sites. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Oral health status and salivary properties in relation to gluten-free diet in children with celiac disease.

PubMed

Shteyer, Eyal; Berson, Tamar; Lachmanovitz, Odelia; Hidas, Ariela; Wilschanski, Michael; Menachem, Moti; Shachar, Edna; Shapira, Joseph; Steinberg, Doron; Moskovitz, Moti

2013-07-01

Patients with celiac disease (CD) have a wide variety of symptoms, from being asymptomatic to having chronic diarrhea, abdominal pain, and extraintestinal symptoms. In the oral cavity, enamel defects and recurrent aphthous stomatitis are the most common symptoms. The aim of the study was to assess oral health, bacterial colonization and salivary buffering capacity of patients with CD at diagnosis were compared with patients with CD receiving a gluten-free diet (GFD) and healthy children. Three groups were prospectively investigated: newly diagnosed CD, CD treated with GFD, and a control group. All of the children were examined by pediatric dentists, and saliva samples were collected for bacterial and pH analysis. Ninety children were enrolled in the study, 30 in each group. A higher prevalence of enamel hypoplasia (66%) was found in children with CD. Plaque index was significantly lower in the celiac-treated group, which correlated with oral health behavior: teeth brushing and frequency of eating between meals. Children receiving GFD brushed their teeth and used fluoride significantly more often than other children in the study. No difference between groups was found in snack consumption, mutans streptococci and lactobacilli counts in saliva, as well as pH and buffer capacity. A lower degree of plaque was found in children with CD receiving GFD. This finding could not be explained by salivary properties or bacteria, but rather by better oral hygiene. The results should raise the awareness of pediatric gastroenterologists toward oral health-related issues in children with CD.

Familial Oral Microbial Imbalance and Dental Caries Occurrence in Their Children

PubMed Central

Bretz, Walter A.; Thomas, John G.; weyant, Robert J.

2013-01-01

Objective Develop a familial liability index for oral microbial status that reflects an imbalance of oral domains based on the presence of risk indicators in saliva, inter-proximal plaque, tongue, and throat. Methods Fifty-six mother-child pairs from Webster and Nicholas counties, West Virginia, USA, participated in this study. Saliva samples were assayed for mutans streptococci (MS), interproximal plaque samples for the BANA Test (BT) species, tongue swabs for BT, and throat swabs for any of the sentinel organisms (Staphylococcus aureus, Streptococcus pyogenes, and yeasts). The corresponding thresholds for a (+) risk indicator were, respectively, ≥105 CFU of MS salivary levels, one or more BT-(+) plaques (>105 CFU/mg of plaque of at least one of BT-(+) species), weak-(+) BT for a tongue swab (>104-<105), and >104 CFU/swab for any of the sentinel markers. Results The mean age of mothers and children was 41.6 and 14.6 years. Ninety-one % of both mothers and children had at least one (+) risk indicator. Overall, 76% of mother child-pairs had at least one (+) concordant oral microbial risk indicator. Accordingly, the relative risk (RR) of children having concordant results with their mothers was increased 1.36 (BT-plaque), 1.37 (BT-tongue), 0.94 (sentinel organisms) and 1.13 (MS) times. Principal component analysis revealed distinct sets of oral microbial risk indicators in mothers and children that correlated with dental caries prevalence rates in children. Conclusions Mother-child pairs shared similarities of oral microbial risk indicators that allow for the development of a liability index that can elucidate caries in the children. PMID:24600078

Prevalence, distribution of serotypes, and cariogenic potential in hamsters of mutans streptococci from elderly individuals.

PubMed

Fitzgerald, D B; Fitzgerald, R J; Adams, B O; Morhart, R E

1983-08-01

The prevalence of mutans streptococci (Streptococcus mutans, Streptococcus cricetus, Streptococcus sobrinus, and Streptococcus rattus) was determined in the salivas of 169 elderly individuals ranging in age from 60 to 87 years. Approximately 40% of these individuals were edentulous and wore full upper and lower dentures. With the exception of a higher proportion of saliva counts below 1,000 CFU/ml in the full-denture wearers, the prevalence and the serotype and species distributions of the mutans streptococci were similar in the denture wearers and individuals with natural teeth only. The species and serotype distributions of mutans streptococci in this elderly population were also consistent with reported observations of other workers on younger, more caries-prone populations. A total of 87 representative isolates of the mutans streptococci were tested for cariogenic potential in a hamster model system. A considerable degree of variation in virulence between different strains was observed. However, these differences were not relatable to individual species or serotypes or to whether the organisms were isolated from denture wearers or naturally dentate subjects. The results of our studies indicate that elderly individuals with either natural or artificial dentitions may be a hitherto unrecognized reservoir of mutans streptococci having varying degrees of potential cariogenicity. Hence, in close family situations they could serve, along with parents and siblings, as vectors in the initial transmission of cariogenic microorganisms to young children.

Identification and molecular characterization of serological group C streptococci isolated from diseased pigs and monkeys in Indonesia.

PubMed Central

Soedarmanto, I; Pasaribu, F H; Wibawan, I W; Lämmler, C

1996-01-01

The present study was designed to comparatively investigate 34 beta-hemolytic streptococci isolated from infected pigs and monkeys from various islands in Indonesia. According to the serological and biochemical data, all 34 isolates were Lancefield's serological group C streptococci and could be identified as Streptococcus equi subsp. zooepidemicus. Of the 34 group C streptococci investigated, 28 grew on solid media in large, mucoid colonies, in fluid media at a uniform turbidity, and in soft agar in diffuse colonies. A decapsulation test with a hyaluronidase-producing Staphylococcus aureus strain revealed the hyaluronic acid nature of the capsular material. The remaining six streptococci grew on solid media in small, nonmucoid colonies, in fluid media as sediment with clear supernatant, and in soft agar in compact colonies. Determination of surface hydrophobicity by salt aggregation revealed a hydrophilic surface for the encapsulated bacteria and a hydrophobic surface for the unencapsulated group C streptococci. To further analyze the epidemiological relationships, all 34 mucoid and nonmucoid isolates from pigs and monkeys were subjected to protein and DNA fingerprinting. The latter was performed by pulsed-field gel electrophoresis. The protein profiles of all 34 isolates and the DNA profiles of 32 isolates appeared to be identical, with the DNA profiles of 2 isolates being closely related, indicating that a single virulent clone is responsible for this disease outbreak in Indonesia. PMID:8862585

Class II glass ionomer/silver cermet restorations and their effect on interproximal growth of mutans streptococci.

PubMed

Berg, J H; Farrell, J E; Brown, L R

1990-02-01

The release of fluoride from glass ionomer materials is one of the most important features of this newly implemented material, and the remineralization effects of this phenomenon have been documented (Hicks and Silverstone 1986). This paper examines the effects of glass ionomer/silver cermet restorations on the plaque levels of interproximal mutans streptococci. Fifteen patients with Class II lesions in primary molars were selected for study. Interproximal plaque samples were obtained from each of the lesion sites and from one caries-free site approximal to a primary molar. One lesion was restored with composite resin to serve as a treated control to the glass ionomer/silver cermet (Ketac Silver, ESPE/Premier Sales Corp., Norristown, Pennsylvania) test site. A sound (unaltered) interproximal site served as the untreated control site. Plaque samples were collected before and at one week, one month, and three months post-treatment. Samples were serially diluted to enable colony counts of mutans streptococci. One week post-treatment counts showed that the glass ionomer/silver cermet restorations significantly reduced (P less than 0.05) the approximal plaque levels of mutans streptococci. Conversely, the untreated and treated control sites did not exhibit reductions in approximal plaque levels of mutans streptococci. These results indicate that glass ionomer restorations may be inhibitory to the growth of mutans streptococci in dental plaque approximal to this restorative material in the primary dentition.

Evaluation of a new selective enrichment broth for detection of group B streptococci in pregnant women.

PubMed

Heelan, Judith S; Struminsky, Judith; Lauro, Patricia; Sung, C James

2005-02-01

Studies at two Brown Medical School-affiliated hospitals were undertaken to evaluate a new selective broth medium (GBS broth) and to compare it to the LIM broth currently used to culture for group B streptococci. Beta-hemolytic group B streptococci produce a carotenoid pigment that turns GBS broth an orange color. From a total of 580 pregnant women, duplicate vaginal-rectal swabs were collected at 35 to 37 weeks of gestation and cultured for group B streptococci, using either LIM broth (a selective broth containing antibiotics) or GBS broth for enrichment. Specimens were either transported to the laboratory or immediately placed in the respective enrichment broths and delivered to the laboratory. GBS broth medium had sensitivity, specificity, and positive and negative predictive values of 87.8, 100, 100, and 95.1% when planted in the laboratory and 90.3, 100, 100 and 97.6%, respectively, when inoculated at bedside. Use of GBS broth would satisfy Centers for Disease Control and Prevention requirements and would provide faster, more-sensitive, and cost-effective detection of group B streptococci in pregnant women.

What Happened to the Streptococci: Overview of Taxonomic and Nomenclature Changes

PubMed Central

Facklam, Richard

2002-01-01

Since the division of the Streptococcus genus into enterococci, lactococci, and streptococci in 1984, many changes in the nomenclature and taxonomy of the Streptococcus genus have taken place. The application of genetic comparisons has improved the proper classification of the different species. The Lancefield system of serogrouping the streptococci by the expression of beta-hemolysis on blood agar plates is still very useful for the identification of streptococci for patient management. The Lancefield grouping system cannot be used in itself for accurate identification of specific beta-hemolytic species, but it can be a useful part of the identification procedure. Except for identification of the “Streptococcus bovis group” of species and Streptococcus suis, Lancefield grouping is of little value in identification of the non-beta-hemolytic streptococci and related genera. In fact, identification of the non-beta-hemolytic species is problematic for conventional as well as commercially available identification procedures. A combination of conventional tests and specific chromogenic tests suggested by several investigators is presented and discussed. Tables are included that suggest tests and procedures to guide investigators attempting to identify all the species. PMID:12364372

Food-borne outbreak of group G streptococcal sore throat in an Israeli military base.

PubMed Central

Cohen, D.; Ferne, M.; Rouach, T.; Bergner-Rabinowitz, S.

1987-01-01

A food-borne outbreak of sore throat caused by Lancefield group G beta-haemolytic streptococci and involving 50 persons occurred in May 1983 in an Israeli military camp. All of the patients available for clinical examination had sore throat and difficulty in swallowing. Exudative tonsillitis occurred in 46% of the patients and the body temperature was above 37.5 degrees C in 81%. The pattern of attack was uniform over the base and 37 became ill during the night and morning of the 5 May. Thirty-two (84%) of the throat cultures taken from 37 patients grew group G beta-haemolytic streptococci. Eight of 29 contacts were positive for group G beta-haemolytic streptococci and 6 of the 28 foodhandlers examined had positive cultures of the same group. The organism was also isolated from one food sample. The epidemiological and laboratory investigations indicated that a food handler, a convalescent carrier of group G streptococci, might have been the source of infection. Assumptions on the potential of non-group A streptococci to cause epidemics are discussed. PMID:3678389

Isolation and characterization of a specific receptor for human albumin on a group L Streptococcus.

PubMed

Lämmler, C

1988-08-01

Certain group L streptococci demonstrate surface receptors for human albumin. Binding of 125I-albumin to group L streptococci could be inhibited by unlabelled albumin preparations from humans, dogs, mice and bovines, but not by albumin from rabbits. The albumin-binding proteins (ABP) could be solubilized from the streptococcal surface by hot acid treatment of the bacteria and isolated by affinity chromatography on human-albumin sepharose. ABP and specific antisera produced against ABP inhibited 125I-albumin binding to group L streptococci. The molecular weight of ABP determined by SDS-PAGE and Western blotting, was approximately 48,000 Dalton. ABP preparations of group G streptococci isolated from bovines and humans demonstrated cross reactivity with antiserum produced against group L streptococcal ABP.

A Novel α-Hemolytic Streptococcus Species (Streptococcus azizii sp. nov.) Associated with Meningoencephalitis in Naïve Weanling C57BL/6 Mice

PubMed Central

Braden, Gillian C; Arbona, Rodolfo Ricart; Lepherd, Michelle; Monette, Sébastien; Toma, Aziz; Fox, James G; Dewhirst, Floyd E; Lipman, Neil S

2015-01-01

During 1 year, experimentally naïve C57BL/6NCrl weanlings born to timed-pregnant dams from a single vendor demonstrated markedly increased mortality associated with runting, abnormal gait, and decreased activity. Gram-positive, aerobic, α-hemolytic, coccoid bacteria were isolated from the meninges (n = 16), blood (n = 1), and kidneys (n = 1) of clinically affected weanlings (n = 15); from the uterus (n = 1), meninges (n = 1), and oral cavity (n = 2) of 3 dams; and from the meninges and oral cavity of a clinically affected 86-d-old mouse in the same colony. Multifocal, necrosuppurative meningoencephalitis and ventriculitis with intralesional gram-positive coccoid bacteria were present in all but 2 affected animals. The bacterium also was isolated from the oral cavity of an asymptomatic timed-pregnant dam (1 of 23) from the same vendor and from 8 mice at the vendor's facility. All isolates (n = 25) were identified by using 2 semiautomated rapid-identification systems, one of which consistently identified the causative bacterium as Aerococcus viridans 2 (n = 12) or 3 (n = 13), with probabilities of 55.7% to 98.3%. The bacterium did not grow in 6.5% NaCl at 10 °C, thus suggesting a Streptococcus species. Partial 16S rRNA sequencing of 4 isolates suggested S. hyointestinalis (probability, 93.4%) and S. gallinaceus (99.5%). Full 16S rRNA sequences for 3 isolates identified the bacterium as a novel Streptococcus species most closely related to S. acidominimus strain LGM (96.5%) and Streptococcus species strain Smarlab 3301444 (96.3%) and for which we propose the name S. azizii. PMID:26141443

Effect of an oxygenating agent on oral bacteria in vitro and on dental plaque composition in healthy young adults.

PubMed

Fernandez y Mostajo, Mercedes; van der Reijden, Wil A; Buijs, Mark J; Beertsen, Wouter; Van der Weijden, Fridus; Crielaard, Wim; Zaura, Egija

2014-01-01

Oral bacteria live in symbiosis with the host. Therefore, when mouthwashes are indicated, selective inhibition of taxa contributing to disease is preferred instead of broad-spectrum antimicrobials. The potential selectivity of an oxygenating mouthwash, Ardox-X® (AX), has not been assessed. The aim of this study was to determine the antimicrobial potential of AX and the effects of a twice-daily oral rinse on dental plaque composition. In vitro, 16 oral bacterial strains were tested using agar diffusion susceptibility, minimum inhibitory and minimum bactericidal concentration tests. A pilot clinical study was performed with 25 healthy volunteers. Clinical assessments and microbiological sampling of supragingival plaque were performed at 1 month before the experiment (Pre-exp), at the start of the experiment (Baseline) and after the one-week experimental period (Post-exp). During the experiment individuals used AX mouthwash twice daily in absence of other oral hygiene measures. The microbiological composition of plaque was assessed by 16S rRNA gene amplicon sequencing. AX showed high inter-species variation in microbial growth inhibition. The tested Prevotella strains and Fusobacterium nucleatum showed the highest sensitivity, while streptococci and Lactobacillus acidophilus were most resistant to AX. Plaque scores at Pre-exp and Baseline visits did not differ significantly (p = 0.193), nor did the microbial composition of plaque. During a period of 7-days non-brushing but twice daily rinsing plaque scores increased from 2.21 (0.31) at Baseline to 2.43 (0.39) Post-exp. A significant microbial shift in composition was observed: genus Streptococcus and Veillonella increased while Corynebacterium, Haemophilus, Leptotrichia, Cardiobacterium and Capnocytophaga decreased (p ≤ 0.001). AX has the potential for selective inhibition of oral bacteria. The shift in oral microbiome after 1 week of rinsing deserves further research.

Antibacterial properties of 2% lidocaine and reduced rate of endophthalmitis after intravitreal injection.

PubMed

Tustin, Aaron; Kim, Stephen J; Chomsky, Amy; Hubbard, G Baker; Sheng, Jinsong

2014-05-01

To determine whether the application of subconjunctival 2% lidocaine/0.1% methylparaben for anesthesia may reduce rates of endophthalmitis after intravitreal (IVT) injection. We performed in vitro experiments to determine the antibacterial properties of 2% lidocaine/0.1% methylparaben (lidocaine) against causative organisms of endophthalmitis. Isolates of Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus viridans from patients with endophthalmitis were incubated with or without lidocaine. Aliquots (100 µL) were plated on Mueller-Hinton (S. aureus and S. epidermidis) or blood agar plates (S. viridans) at 0, 10, 30, 120, and 240 minutes, and colonies were counted after 24 hours. A retrospective review of 15,042 IVT injections was performed from January 2004 to February 2011 to determine the rate of endophthalmitis with or without application of subconjunctival lidocaine for anesthesia. Lidocaine demonstrated rapid bactericidal effects against all 3 organisms. After 10 minutes of exposure, there was approximately a 90% (P < 0.01), 95% (P < 0.001), and 92% (P < 0.001) reduction in colony forming units when compared with time 0 for S. aureus, S. epidermidis, and S. viridans, respectively. Complete elimination of colony forming units occurred at subsequent time points for each organism in contrast to logarithmic increase for control plates. There were a total of 0 cases of endophthalmitis of 6,853 IVT injections performed with subconjunctival lidocaine and 8 cases of endophthalmitis of 8,189 (0.1%) IVT injections performed with other methods of anesthesia (P = 0.03). Application of subconjunctival 2% lidocaine/0.1% methylparaben for anesthesia may reduce the incidence of endophthalmitis after IVT injection.

Antimicrobial activity of ethanol extracts of Laminaria japonica against oral microorganisms.

PubMed

Kim, Yeon-Hee; Kim, Jeong Hwan; Jin, Hyung-Joo; Lee, Si Young

2013-06-01

Laminaria japonica is a brown alga, which is consumed widely in Korea, Japan, and China. This study investigated the antimicrobial activity of ethanol extracts of L. japonica against oral microbial species to assess the possible application of L. japonica extracts in dental care products. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined in culture medium using a microdilution method. The MICs of ethanol extracts of L. japonica with oral streptococci were 62.5-500 μg/ml and the MBCs were 125-1000 μg/ml. The MICs of Actinomyces naeslundii and Actinomyces odontolyticus were 250 and 62.5 μg/ml, respectively. The MBCs of A. naeslundii and A. odontolyticus were 500 and 250 μg/ml, respectively. The MICs were 250 and 62.5 μg/ml for Fusobacterium nucleatum and Porphyromonas gingivalis, respectively. The killing of Streptococcus mutans and P. gingivalis was dependent on the incubation time. The killing of S. mutans, A. odontolyticus, and P. gingivalis was significantly dependent on the extract concentration. Bacterial treatment with L. japonica extracts changed the cell surface texture of S. mutans, A. odontolyticus, and P. gingivalis. The results of this study suggest that L. japonica extracts may be useful for the development of antimicrobial agents to combat oral pathogens. Copyright © 2013 Elsevier Ltd. All rights reserved.

Efficacy of chlorhexidine digluconate-containing formulations and other mouthrinses against periodontopathogenic microorganisms.

PubMed

Eick, Sigrun; Goltz, Susann; Nietzsche, Sandor; Jentsch, Holger; Pfister, Wolfgang

2011-09-01

To determine in vitro the action of chlorhexidine digluconate and different commercially available mouthrinses on oral microorganisms. Minimal inhibitory concentrations and possible induction of resistance by chlorhexidine digluconate, an essential oil-containing mouthwash and an amine fluoride/stannous fluoride solution, were determined against microorganisms normally found in the oral cavity (10 streptococci, 2 enterobacteria, 1 Candida albicans, 8 Porphyromonas gingivalis, 6 Aggregatibacter actinomycetemcomitans, and 1 Fusobacterium nucleatum). Further, the effect of a 1-minute exposure on cell and bacterial viability was studied. The susceptibility of the oral microorganisms to chlorhexidine digluconate ranged from 0.01% to 0.50%. Passages on agar plates containing subinhibitory concentrations of chlorhexidine digluconate resulted in a transitory moderate increase in the tolerance to chlorhexidine digluconate in five of the 24 isolates. After 1 minute of exposure, chlorhexidine digluconate solutions as well as the essential oil and the amine/stannous fluoride-containing solutions showed a high activity against the tested microorganisms. Commercially available chlorhexidine digluconate formulations (ie, those with antidiscoloration systems) were partly less efficient than the corresponding manually prepared chlorhexidine digluconate preparation. The determination of MTT resulted in a strong cytotoxicity of all tested preparations to gingival fibroblasts. The results indicate that most of the chlorhexidine digluconate formulations as well as essential oil and the amine fluoride/stannous fluoride solutions are active against oral microbes. Long-term use of these agents would not result in emergent antimicrobial resistance.

Identification of Streptococcus sanguinis Genes Required for Biofilm Formation and Examination of Their Role in Endocarditis Virulence▿

PubMed Central

Ge, Xiuchun; Kitten, Todd; Chen, Zhenming; Lee, Sehmi P.; Munro, Cindy L.; Xu, Ping

2008-01-01

Streptococcus sanguinis is one of the pioneers in the bacterial colonization of teeth and is one of the most abundant species in the oral biofilm called dental plaque. S. sanguinis is also the most common viridans group streptococcal species implicated in infective endocarditis. To investigate the association of biofilm and endocarditis, we established a biofilm assay and examined biofilm formation with a signature-tagged mutagenesis library of S. sanguinis. Four genes that have not previously been associated with biofilm formation in any other bacterium, purB, purL, thrB, and pyrE, were putatively identified as contributing to in vitro biofilm formation in S. sanguinis. By examining 800 mutants for attenuation in the rabbit endocarditis model and for reduction in biofilm formation in vitro, we found some mutants that were both biofilm defective and attenuated for endocarditis. However, we also identified mutants with only reduced biofilm formation or with only attenuation in the endocarditis model. This result indicates that the ability to form biofilms in vitro is not associated with endocarditis virulence in vivo in S. sanguinis. PMID:18390999

Identification of Streptococcus sanguinis genes required for biofilm formation and examination of their role in endocarditis virulence.

PubMed

Ge, Xiuchun; Kitten, Todd; Chen, Zhenming; Lee, Sehmi P; Munro, Cindy L; Xu, Ping

2008-06-01

Streptococcus sanguinis is one of the pioneers in the bacterial colonization of teeth and is one of the most abundant species in the oral biofilm called dental plaque. S. sanguinis is also the most common viridans group streptococcal species implicated in infective endocarditis. To investigate the association of biofilm and endocarditis, we established a biofilm assay and examined biofilm formation with a signature-tagged mutagenesis library of S. sanguinis. Four genes that have not previously been associated with biofilm formation in any other bacterium, purB, purL, thrB, and pyrE, were putatively identified as contributing to in vitro biofilm formation in S. sanguinis. By examining 800 mutants for attenuation in the rabbit endocarditis model and for reduction in biofilm formation in vitro, we found some mutants that were both biofilm defective and attenuated for endocarditis. However, we also identified mutants with only reduced biofilm formation or with only attenuation in the endocarditis model. This result indicates that the ability to form biofilms in vitro is not associated with endocarditis virulence in vivo in S. sanguinis.

Infective endocarditis not related to intravenous drug abuse in HIV-1-infected patients: report of eight cases and review of the literature.

PubMed

Losa, J E; Miro, J M; Del Rio, A; Moreno-Camacho, A; Garcia, F; Claramonte, X; Marco, F; Mestres, C A; Azqueta, M; Gatell, J M

2003-01-01

To add to the limited information on infective endocarditis (IE) not related to intravenous drug abuse (IVDA) in HIV-1-infected patients. We have reviewed the characteristics of eight cases of IE in non-IVDA HIV-1 infected patients diagnosed in our institution between 1979 and 1999 as well as cases in the literature. All our patients were male, and the mean age was 44 years (range 29-64). HIV-1 risk factors were: homosexuality in five, heterosexuality in two, and the use of blood products in one. HIV stage C was found in six cases, and the median (range) CD4 cell count was 22/microL (4-274 cells/microL). IE was caused by Enterococcus faecalis in three cases, staphylococci in two cases, and Salmonella enteritidis, viridans group streptococci and Coxiella burnetii in one case each. Three patients acquired IE while in the hospital. All IE cases involved a native valve, and underlying valve disease was found in three patients. The aortic valve was the most frequently affected (five cases). Two patients underwent surgery, with a good outcome, and one patient died. Fourteen cases of IE not related to IVDA in HIV-1-infected patients were found in the literature review. The most common causative agents were Salmonella spp. and fungi (four cases each). Two patients had prosthetic valve IE, and the mitral valve was the most frequently affected (10 cases). The remaining clinical characteristics and the outcome were similar to those in the present series. IE not related to IVDA is rare in HIV-1-infected patients. In more than half of the cases, IE develops in patients with advanced HIV-1 disease. A wide etiologic range is found, reflecting different clinical and environmental conditions. None of the patients who underwent surgery died, and the overall mortality rate was not higher than in non-HIV-1-infected patients with IE.

Cis-encoded non-coding antisense RNAs in streptococci and other low GC Gram (+) bacterial pathogens

PubMed Central

Cho, Kyu Hong; Kim, Jeong-Ho

2015-01-01

Due to recent advances of bioinformatics and high throughput sequencing technology, discovery of regulatory non-coding RNAs in bacteria has been increased to a great extent. Based on this bandwagon, many studies searching for trans-acting small non-coding RNAs in streptococci have been performed intensively, especially in the important human pathogen, group A and B streptococci. However, studies for cis-encoded non-coding antisense RNAs in streptococci have been scarce. A recent study shows antisense RNAs are involved in virulence gene regulation in group B streptococcus, S. agalactiae. This suggests antisense RNAs could have important roles in the pathogenesis of streptococcal pathogens. In this review, we describe recent discoveries of chromosomal cis-encoded antisense RNAs in streptococcal pathogens and other low GC Gram (+) bacteria to provide a guide for future studies. PMID:25859258

Probiotics reduce mutans streptococci counts in humans: a systematic review and meta-analysis.

PubMed

Laleman, Isabelle; Detailleur, Valentine; Slot, Dagmar Else; Slomka, Vera; Quirynen, Marc; Teughels, Wim

2014-07-01

Systematically review the available literature regarding the caries-preventive effect of probiotics. An electronic search was conducted in three databases (PubMed MEDLINE, ISI Web of Science and Cochrane Library) to identify all suitable studies. The outcomes had to be presented as the effect of probiotics on the incidence of caries or on the levels of mutans streptococci and/or Lactobacillus species. Human studies, written in English, with at least 15 participants, comparing a probiotic product with a placebo/no probiotic were included. Where possible, a meta-analysis was performed to obtain quantitative data. Since only two articles presented useful data on the caries incidence, we focused on the surrogate endpoints: mutans streptococci and/or Lactobacillus counts. The meta-analysis showed that when the probiotic and control group are compared after treatment, significantly more patients in the probiotic group had low mutans streptococci (<10(5) CFU/ml) counts and significantly less patients had high (>10(6) CFU/ml) counts. Regarding the Lactobacillus counts, comparing the probiotic and control group at the end of the probiotic use, no significant differences could be observed, neither in low (<10(4) CFU/ml) nor in high Lactobacillus (>10(6) CFU/ml) counts. Within the limitations of the available data, it may be concluded that probiotics decrease the mutans streptococci counts. This suggests that probiotics could have a positive effect in the prevention of caries. There is insufficient evidence that probiotics can prevent caries, but they can reduce the mutans streptococci counts.

Inorganic Cation Transport and Energy Transduction in Enterococcus hirae and Other Streptococci

PubMed Central

Kakinuma, Yoshimi

1998-01-01

Energy metabolism by bacteria is well understood from the chemiosmotic viewpoint. We know that bacteria extrude protons across the plasma membrane, establishing an electrochemical potential that provides the driving force for various kinds of physiological work. Among these are the uptake of sugars, amino acids, and other nutrients with the aid of secondary porters and the regulation of the cytoplasmic pH and of the cytoplasmic concentration of potassium and other ions. Bacteria live in diverse habitats and are often exposed to severe conditions. In some circumstances, a proton circulation cannot satisfy their requirements and must be supplemented with a complement of primary transport systems. This review is concerned with cation transport in the fermentative streptococci, particularly Enterococcus hirae. Streptococci lack respiratory chains, relying on glycolysis or arginine fermentation for the production of ATP. One of the major findings with E. hirae and other streptococci is that ATP plays a much more important role in transmembrane transport than it does in nonfermentative organisms, probably due to the inability of this organism to generate a large proton potential. The movements of cations in streptococci illustrate the interplay between a variety of primary and secondary modes of transport. PMID:9841664

Short-term effect of mechanical plaque control on salivary mutans streptococci in preschool children.

PubMed

Liu, Min; Ge, Lihong; Zheng, Shuguo; Yuan, Chao; Zhang, Bo; Xu, Tao

2014-01-01

To determine the effect of mechanical tooth cleaning by toothbrush and dental floss on mutans streptococci in the saliva of preschool children. This blinded, randomised controlled clinical trial included 54 3-year-old preschool children with detectable mutans streptococci in saliva. The children were randomly divided into a test and a control group. Dental college students cleaned the teeth of test group participants with toothbrush and dental floss under the indication of a plaque disclosing agent once a day. The control group received no intervention. Dentocult SM Strip mutans (D-SM) strips were used to test the mutans streptococci in saliva. The D-SM test scores declined from 1.82 to 0.95 for the test group after the teeth were cleaned 10 times (P < 0.001) and the scores increased to 1.62 after tooth cleaning ceased for 2 weeks (P > 0.05 compared with baseline). The D-SM level of the control group did not change significantly. Meticulous and continuous plaque control with toothbrush and dental floss can decrease the mutans streptococci level in preschool children. However, the effect ceased as the intervention ceased.

Sodium chloride-esculin hydrolysis test for rapid identification of enterococci.

PubMed Central

Qadri, S M; Flournoy, D J; Qadri, S G

1987-01-01

The ability of enterococci to cause severe disease in humans and their relative resistance to chemotherapeutic agents make it desirable to rapidly differentiate these organisms from other streptococci. We developed and evaluated a test that within 2 h distinguishes enterococci from other alpha-, beta-, or nonhemolytic streptococci in a buffered solution containing 0.2% esculin and 5% sodium chloride. All 239 strains of enterococci tested gave a positive reaction within 2 h, whereas 95 of 96 isolates of other streptococci remained negative at 4 h. PMID:3597753

Linear response of mutans streptococci to increasing frequency of xylitol chewing gum use: a randomized controlled trial [ISRCTN43479664].

PubMed

Ly, Kiet A; Milgrom, Peter; Roberts, Marilyn C; Yamaguchi, David K; Rothen, Marilynn; Mueller, Greg

2006-03-24

Xylitol is a naturally occurring sugar substitute that has been shown to reduce the level of mutans streptococci in plaque and saliva and to reduce tooth decay. It has been suggested that the degree of reduction is dependent on both the amount and the frequency of xylitol consumption. For xylitol to be successfully and cost-effectively used in public health prevention strategies dosing and frequency guidelines should be established. This study determined the reduction in mutans streptococci levels in plaque and unstimulated saliva to increasing frequency of xylitol gum use at a fixed total daily dose of 10.32 g over five weeks. Participants (n = 132) were randomized to either active groups (10.32 g xylitol/day) or a placebo control (9.828 g sorbitol and 0.7 g maltitol/day). All groups chewed 12 pieces of gum per day. The control group chewed 4 times/day and active groups chewed xylitol gum at a frequency of 2 times/day, 3 times/day, or 4 times/day. The 12 gum pieces were evenly divided into the frequency assigned to each group. Plaque and unstimulated saliva samples were taken at baseline and five-weeks and were cultured on modified Mitis Salivarius agar for mutans streptococci enumeration. There were no significant differences in mutans streptococci level among the groups at baseline. At five-weeks, mutans streptococci levels in plaque and unstimulated saliva showed a linear reduction with increasing frequency of xylitol chewing gum use at the constant daily dose. Although the difference observed for the group that chewed xylitol 2 times/day was consistent with the linear model, the difference was not significant. There was a linear reduction in mutans streptococci levels in plaque and saliva with increasing frequency of xylitol gum use at a constant daily dose. Reduction at a consumption frequency of 2 times per day was small and consistent with the linear-response line but was not statistically significant.

Production of broad-spectrum bacteriocin-like activity by group A streptococci of particular M-types.

PubMed

Hynes, W L; Tagg, J R

1985-04-01

Application of a bacteriocin production (P)-typing scheme to group A streptococci has shown that approximately 10% of the tested strains inhibit the growth of all 9 indicator bacteria, an activity referred to as P-type 777. Production of such activity was found to be restricted to 14 M-serotypes and within these M-types the incidence of P-type 777 activity was very high. There was no evidence of any correlation with the T-antigenic composition of the bacteria. Investigations of the conditions for production of P-type 777 activity and of its spectrum of activity indicate that the same inhibitory substance(s) are responsible for this inhibition in the various M-types of streptococci. Group C streptococcus strain T277 produces an inhibitor which has a similar activity spectrum to that of the P-type 777 group A streptococci, but there were considerable differences in the production conditions. Whereas the group C inhibitor was particularly dependent on conditions of incubation (37 degrees C, anaerobic) the group A activity was more dependent on the composition of the test medium (source of blood agar base and blood requirement). All of the tested P-type 777 group A streptococci had identical inhibitory spectra. This was principally directed against gram-positive bacteria, including the producer strains themselves. Of interest was the occurrence of some insensitive strains in otherwise susceptible species of bacteria and the discovery of one sensitive gram-negative strain, Bacteroides intermedius. Production of P-type 777 activity does not appear to correlate with production of various streptococcal enzymes, including protease, hemolysin, DNase and amylase. Many P-type 777 strains are producers of opacity factor, another M-type-associated product of group A streptococci. It is suggested that by the combined testing of group A streptococci for P-type 777 activity and for opacity factor it would be possible to narrow the choice of M-antisera to be used for typing purposes.

THE OCCURRENCE OF POLYGLYCEROPHOSPHATE AS AN ANTIGENIC COMPONENT OF VARIOUS GRAM-POSITIVE BACTERIAL SPECIES

PubMed Central

McCarty, Maclyn

1959-01-01

A bacterial substance has been described which gives a precipitin reaction with certain antisera to Group A streptococci. The precipitating antigen is present in various Gram-positive bacteria, including most hemolytic streptococci, staphylococci, and aerobic sporulating bacilli. It is not present in any of the Gram-negative species examined or in pneumococci, clostridia, or corynebacteria. Analysis of purified preparations obtained from Group A streptococci indicates that the antigen is a simple polymer of glycerophosphate. The identification has been confirmed by immunochemical studies, including precipitin tests and specific inhibition with synthetic polyglycerophosphates. In addition, the infrared spectra of bacterial and synthetic polyglycerophosphate are shown to be closely similar. Immunochemical analysis suggests that the amount of polyglycerophosphate present in Group A streptococci and staphylococci is approximately 1 per cent of the dry weight of the cells. The cellular localization and function of the polyglycerophosphate have not been established. PMID:13641562

Interactions between oral bacteria: inhibition of Streptococcus mutans bacteriocin production by Streptococcus gordonii.

PubMed

Wang, Bing-Yan; Kuramitsu, Howard K

2005-01-01

Streptococcus mutans has been recognized as an important etiological agent in human dental caries. Some strains of S. mutans also produce bacteriocins. In this study, we sought to demonstrate that bacteriocin production by S. mutans strains GS5 and BM71 was mediated by quorum sensing, which is dependent on a competence-stimulating peptide (CSP) signaling system encoded by the com genes. We also demonstrated that interactions with some other oral streptococci interfered with S. mutans bacteriocin production both in broth and in biofilms. The inhibition of S. mutans bacteriocin production by oral bacteria was stronger in biofilms than in broth. Using transposon Tn916 mutagenesis, we identified a gene (sgc; named for Streptococcus gordonii challisin) responsible for the inhibition of S. mutans bacteriocin production by S. gordonii Challis. Interruption of the sgc gene in S. gordonii Challis resulted in attenuated inhibition of S. mutans bacteriocin production. The supernatant fluids from the sgc mutant did not inactivate the exogenous S. mutans CSP as did those from the parent strain Challis. S. gordonii Challis did not inactivate bacteriocin produced by S. mutans GS5. Because S. mutans uses quorum sensing to regulate virulence, strategies designed to interfere with these signaling systems may have broad applicability for biological control of this caries-causing organism.

Microbial profiling of dental plaque from mechanically ventilated patients

PubMed Central

Twigg, Joshua A.; Lewis, Michael A. O.; Wise, Matt P.; Marchesi, Julian R.; Smith, Ann; Wilson, Melanie J.; Williams, David W.

2016-01-01

Micro-organisms isolated from the oral cavity may translocate to the lower airways during mechanical ventilation (MV) leading to ventilator-associated pneumonia (VAP). Changes within the dental plaque microbiome during MV have been documented previously, primarily using culture-based techniques. The aim of this study was to use community profiling by high throughput sequencing to comprehensively analyse suggested microbial changes within dental plaque during MV. Bacterial 16S rDNA gene sequences were obtained from 38 samples of dental plaque sampled from 13 mechanically ventilated patients and sequenced using the Illumina platform. Sequences were processed using Mothur, applying a 97 % gene similarity cut-off for bacterial species level identifications. A significant ‘microbial shift’ occurred in the microbial community of dental plaque during MV for nine out of 13 patients. Following extubation, or removal of the endotracheal tube that facilitates ventilation, sampling revealed a decrease in the relative abundance of potential respiratory pathogens and a compositional change towards a more predominantly (in terms of abundance) oral microbiota including Prevotella spp., and streptococci. The results highlight the need to better understand microbial shifts in the oral microbiome in the development of strategies to reduce VAP, and may have implications for the development of other forms of pneumonia such as community-acquired infection. PMID:26690690

Microbial profiling of dental plaque from mechanically ventilated patients.

PubMed

Sands, Kirsty M; Twigg, Joshua A; Lewis, Michael A O; Wise, Matt P; Marchesi, Julian R; Smith, Ann; Wilson, Melanie J; Williams, David W

2016-02-01

Micro-organisms isolated from the oral cavity may translocate to the lower airways during mechanical ventilation (MV) leading to ventilator-associated pneumonia (VAP). Changes within the dental plaque microbiome during MV have been documented previously, primarily using culture-based techniques. The aim of this study was to use community profiling by high throughput sequencing to comprehensively analyse suggested microbial changes within dental plaque during MV. Bacterial 16S rDNA gene sequences were obtained from 38 samples of dental plaque sampled from 13 mechanically ventilated patients and sequenced using the Illumina platform. Sequences were processed using Mothur, applying a 97% gene similarity cut-off for bacterial species level identifications. A significant 'microbial shift' occurred in the microbial community of dental plaque during MV for nine out of 13 patients. Following extubation, or removal of the endotracheal tube that facilitates ventilation, sampling revealed a decrease in the relative abundance of potential respiratory pathogens and a compositional change towards a more predominantly (in terms of abundance) oral microbiota including Prevotella spp., and streptococci. The results highlight the need to better understand microbial shifts in the oral microbiome in the development of strategies to reduce VAP, and may have implications for the development of other forms of pneumonia such as community-acquired infection.

A Pilot Study to Evaluate the Oral Microbiome and Dental Health in Primary Open-Angle Glaucoma.

PubMed

Polla, Daniel; Astafurov, Konstantin; Hawy, Eman; Hyman, Leslie; Hou, Wei; Danias, John

2017-04-01

To evaluate possible associations between primary open-angle glaucoma (POAG), dental health, and the oral microbiome. Case-control study was conducted at SUNY Downstate. Adult subjects (40 to 87 y) were recruited as POAG cases (n=119) and controls without glaucoma (n=78) based on visual field and optic nerve criteria. Overall 74.6% were African Americans (AA). Information on medical history and oral health was collected and ophthalmologic examinations were performed. Mouthwash specimens (28 AA cases and 17 controls) were analyzed for bacterial DNA amounts. Analyses were limited to AAs as the predominant racial group. Outcome measures included number of natural teeth, self-reported periodontal health parameters, and amounts and prevalence of oral bacterial species. Logistic regression was used to evaluate associated factors and potential interactions. Cases and controls had similar age (mean: 62.2 and 60.9 y, respectively, P>0.48), and frequency of hypertension, diabetes, but cases had a higher proportion of men (P<0.04). On average (±SD), cases had fewer natural teeth than controls [18.0 (±11.1) vs. 20.7 (±9.4)]. Having more natural teeth was inversely associated with POAG, in multivariable analyses, at older ages [eg, odds ratio (95% confidence interval) at age 55: 1.0 (0.95-1.06), P=0.98 vs. at age 85: 0.87 (0.79-0.96), P=0.007]. Amounts of Streptococci were higher in cases than controls (P<0.03) in samples from the subset of subjects analyzed. The number of teeth (an oral health indicator) and alterations in the amounts of oral bacteria may be associated with glaucoma pathology. Further investigation of the association between dental health and glaucoma is warranted.

Defining the ABC of gene essentiality in streptococci.

PubMed

Charbonneau, Amelia R L; Forman, Oliver P; Cain, Amy K; Newland, Graham; Robinson, Carl; Boursnell, Mike; Parkhill, Julian; Leigh, James A; Maskell, Duncan J; Waller, Andrew S

2017-05-31

Utilising next generation sequencing to interrogate saturated bacterial mutant libraries provides unprecedented information for the assignment of genome-wide gene essentiality. Exposure of saturated mutant libraries to specific conditions and subsequent sequencing can be exploited to uncover gene essentiality relevant to the condition. Here we present a barcoded transposon directed insertion-site sequencing (TraDIS) system to define an essential gene list for Streptococcus equi subsp. equi, the causative agent of strangles in horses, for the first time. The gene essentiality data for this group C Streptococcus was compared to that of group A and B streptococci. Six barcoded variants of pGh9:ISS1 were designed and used to generate mutant libraries containing between 33,000-66,000 unique mutants. TraDIS was performed on DNA extracted from each library and data were analysed separately and as a combined master pool. Gene essentiality determined that 19.5% of the S. equi genome was essential. Gene essentialities were compared to those of group A and group B streptococci, identifying concordances of 90.2% and 89.4%, respectively and an overall concordance of 83.7% between the three species. The use of barcoded pGh9:ISS1 to generate mutant libraries provides a highly useful tool for the assignment of gene function in S. equi and other streptococci. The shared essential gene set of group A, B and C streptococci provides further evidence of the close genetic relationships between these important pathogenic bacteria. Therefore, the ABC of gene essentiality reported here provides a solid foundation towards reporting the functional genome of streptococci.

Oral Microbial Profile Discriminates Breastfed from Formula-Fed Infants

PubMed Central

Holgerson, Pernilla Lif; Vestman, Nelly Romani; Claesson, Rolf; Öhman, Carina; Domellöf, Magnus; Tanner, Anne CR; Hernell, Olle; Johansson, Ingegerd

2012-01-01

Objectives Little is known about the impact of diet on the oral microbiota of infants although diet is known to affect the gut microbiota. The aims of the present study were to compare the oral microbiota in breastfed and formula-fed infants, and investigate growth inhibition of streptococci by infant-isolated lactobacilli. Subjects and Methods 207 mothers consented to participation of their three-month old infants. 146 (70.5%) infants were exclusively and 38 (18.4%) partially breastfed, and 23 (11.1%) were exclusively formula-fed. Saliva from all infants was cultured for Lactobacillus species, with isolate identifications from 21 infants. Lactobacillus isolates were tested for their ability to supress Streptococcus mutans and Streptococcus sanguinis. Oral swabs from 73 infants were analysed by the Human Oral Microbe Identification Microarray (HOMIM) and by q-PCR for Lactobacilius gasseri. Results Lactobacilli were cultured from 27.8% of exclusively and partially breastfed infants, but not from formula-fed infants. The prevalence of 14 HOMIM detected taxa, and total salivary lactobacilli counts differed by feeding method. Multivariate modelling of HOMIM detected bacteria and possible confounders clustered samples from breastfed infants separately from formula-fed infants. The microbiota of breastfed infants differed based on vaginal or C-section delivery. Isolates of Lactobacillus plantarum, L. gasseri and Lactobacillus vaginalis inhibited growth of the cariogenic S. mutans and the commensal S. sanguinis: L. plantarum > L. gasseri > L. vaginalis. Conclusion The microbiota of the mouth differs between breastfed and formula-fed three-month-old infants. Possible mechanisms for microbial differences observed include species suppression by lactobacilli indigenous to breast milk. PMID:22955450

Food components with anticaries activity.

PubMed

Gazzani, Gabriella; Daglia, Maria; Papetti, Adele

2012-04-01

Caries is the most common oral infectious disease in the world. Its development is influenced also by diet components that interfere with pathogen mutans group Streptococci (MGS) activity. A very active research to identify functional foods and their components that are generally recognised as safe has been ongoing, with the aim of developing alternative approaches, to the use of synthetic chlorhexidine, and at the reduction or prevention of caries. Until now convincing evidence exists only for green tea as a functional food for oral health, partly owing to its high content of catechins, especially epigallocatechin-gallate. A number of other foods showed potential anticaries activity. Some other foods able to act against MGS growth and/or their virulence factors in in vitro tests are: apple, red grape seeds, red wine (proanthocyanidins), nutmeg (macelignan), ajowan caraway (nafthalen-derivative), coffee (trigonelline, nicotinic and chlorogenic acids, melanoidins), barley coffee (melanoidins), chicory and mushroom (quinic acid). In vivo anticaries activity has been shown by cranberry (procyanidins), glycyrrhiza root (glycyrrhizol-A), myrtus ethanolic extract, garlic aqueous extract, cocoa extracts (procyanidins), and propolis (apigenin, tt-farnesol). Copyright © 2011 Elsevier Ltd. All rights reserved.

Epidemiology of intramammary infections with Staphylococcus aureus and mastitis streptococci in a dairy cattle herd with a history of recurrent clinical mastitis.

PubMed

Vlkova, H; Babak, V; Vrtkova, I; Cervinkova, D; Marosevic, D; Moravkova, M; Jaglic, Z

2017-03-28

The aim of the present work was to examine a dairy herd with an anamnesis of recurrent clinical mastitis and decreased milk production. A total of 239 individual cow milk samples originating from asymptomatic cows were collected at four-month intervals and examined mainly for the presence of Staphylococcus aureus and mastitis streptococci using standard cultivation methods. In total, 29.7% and 9.2% samples were positive for S. aureus and mastitis streptococci, respectively. Unlike for mastitis streptococci, the prevalence of animals positive for S. aureus had an increasing trend (p<0.05; Chi-squared test for trend) with rising parity. Despite in vitro susceptibility of S. aureus to potentiated penicillins and cephalosporins, the persistence of S. aureus was observed in cows undergoing intramammary treatment with amoxicillin/clavulanic acid (a potentiated penicillin antibiotic). All isolates of S. aureus were biofilm-positive and had the same macrorestriction pattern. Furthermore, no dependence was observed between the occurrence of S. aureus in milk and previous cases of clinical mastitis, reproductive and periparturient disorders and administration of antibiotics. In contrast to S. aureus, the occurrence of mastitis streptococci in milk was linked with previous cases of clinical mastitis and intramammary administration of antibiotics.

Probiotics: health benefits in the mouth.

PubMed

Stamatova, Iva; Meurman, Jukka H

2009-12-01

Probiotics or health-beneficial bacteria have only recently been introduced in dentistry and oral medicine after years of successful use in mainly gastro-intestinal disorders. The concept of bacteriotherapy and use of health-beneficial micro-organisms to heal diseases or support immune function was first introduced in the beginning of the 20th century. Later the concept lead to the development of modem dairy industry and even today most probiotic strains are lactobacilli or bifidobacteria used in milk fermentation. The mechanisms of probiotic action are mainly unknown but the inter-microbial species interactions are supposed to play a key role in this together with their immuno-stimulatory effects. The introduction of probiotic bacteria in the mouth calls for ascertainment of their particular safety. Since acid production from sugar is detrimental to teeth, care must be taken not to select strains with high fermentation capacity. The first randomized controlled trials have nevertheless shown that probiotics may control dental caries in children due to their inhibitory action against cariogenic streptococci. Less evidence exists on their role in periodontal disease or oral yeast infections. Furthermore the best vehicles for oral probiotic applications need to be assessed. So far mainly dairy products have been investigated but other means such as probiotics in chewing gums or lozenges have also been studied. From the clinical practitioner's point of view direct recommendations for the use of probiotics cannot yet be given. However, scientific evidence so far indicates that probiotic therapy may be a reality also in dentistry and oral medicine in the future.

Correlation of CD4 count with cariogenic oral flora indicators and dental caries in HIV-seropositive children undergoing antiretroviral therapy in Mangaluru, South India.

PubMed

Muraleedharan, Soumya; Panchmal, Ganesh Shenoy; Shenoy, Rekha P; Jodalli, Praveen; Sonde, Laxminarayan; Pasha, Imran

2018-05-01

The aim of the present study was to compare the association of CD4 count with cariogenic oral flora indicators and dental caries in HIV-seropositive children receiving antiretroviral therapy (ART). A descriptive study was conducted among HIV-seropositive children receiving ART at Snehasadan Camillian Care and Support Center HIV/AIDS in Mangaluru, India. Demographic details and r recent CD4 counts were recorded. For dental caries, the Decayed, Missing, Filled Teeth (DMFT)/decayed, missing, filled/decayed, extracted, filled index was used. Data were analyzed using SPSS version 22. Spearman's correlation was used to correlate CD4 count with dental caries and cariogenic oral flora indicators (mutans streptococci and lactobacilli). The study population comprised 35 patients. Dental caries prevalence was 54.1% in deciduous teeth and 41.2% in permanent teeth. Age and DMFT showed a significant, positive correlation; age and dmft showed a negative correlation (P < .05). A weak, negative correlation was found between age and Streptococcus mutans (S. mutans), and also CD4 count; S. mutans and CD4 count and dmft were not found to be statistically significant (P < .05). No statistically-significant correlation was found between CD4 count and cariogenic oral flora indicators in HIV-positive patients. The presence of a minimum number of restored teeth compared to decayed teeth suggests a lack of dental care being given to HIV-positive patients. © 2017 John Wiley & Sons Australia, Ltd.

Second Era of OMICS in Caries Research: Moving Past the Phase of Disillusionment.

PubMed

Nascimento, M M; Zaura, E; Mira, A; Takahashi, N; Ten Cate, J M

2017-07-01

Novel approaches using OMICS techniques enable a collective assessment of multiple related biological units, including genes, gene expression, proteins, and metabolites. In the past decade, next-generation sequencing ( NGS) technologies were improved by longer sequence reads and the development of genome databases and user-friendly pipelines for data analysis, all accessible at lower cost. This has generated an outburst of high-throughput data. The application of OMICS has provided more depth to existing hypotheses as well as new insights in the etiology of dental caries. For example, the determination of complete bacterial microbiomes of oral samples rather than selected species, together with oral metatranscriptome and metabolome analyses, supports the viewpoint of dysbiosis of the supragingival biofilms. In addition, metabolome studies have been instrumental in disclosing the contributions of major pathways for central carbon and amino acid metabolisms to biofilm pH homeostasis. New, often noncultured, oral streptococci have been identified, and their phenotypic characterization has revealed candidates for probiotic therapy. Although findings from OMICS research have been greatly informative, problems related to study design, data quality, integration, and reproducibility still need to be addressed. Also, the emergence and continuous updates of these computationally demanding technologies require expertise in advanced bioinformatics for reliable interpretation of data. Despite the obstacles cited above, OMICS research is expected to encourage the discovery of novel caries biomarkers and the development of next-generation diagnostics and therapies for caries control. These observations apply equally to the study of other oral diseases.

Cross-reactions of Streptococcus mutans due to cell wall teichoic acid.

PubMed Central

Chorpenning, F W; Cooper, H R; Rosen, S

1975-01-01

Antisera to the whole cells of Streptococcus mutans cross-reacted with antigen extracts from four other gram-positive species, as well as with those of three other oral streptococci. Similarly, antisera to these bacteria cross-reacted with extracts from S. mutans and with those from each other. Using a purified phenol extract of the walls of S. mutans, which was identified by chemical, immunochemical, and enzymatic analyses as glycerol teichoic acid, the cross-reactions were shown to be specific for a determinant of the teichoic acid backbone. Results were confirmed in immunodiffusion tests where clear bands of identify were shown. These observations point out the need for caution in sereological research empolying extracts of gram-positive bacteria and may be of interest in investigations of periodontal disease. Images PMID:809357

Evaluation of Pfizer selective enterococcus and KF media for recovery of fecal streptococci from water by membrane filtration.

PubMed Central

Brodsky, M H; Schiemann, D A

1976-01-01

Pfizer selective enterococcus (PSE) and KF agars were compared for their recovery of fecal streptococci from sewage effluent on membrane filters. The results showed that PSE agar is highly selective for the enterococci. The tan color resulting from esculin hydrolysis, which was not always visible on the surfaces of the colonies, is not considered a necessary differential characteristic on PSE agar since more than 90% of all colonies recovered on membrane filters were confirmed as fecal streptococci and 86% were confirmed as enterococci. The detection of esculin hydrolysis on membrane filters was not improved by using the new Millipore type HC filter. KF agar recovered significantly greater numbers of organisms but was not as selective, with 83% of the typical colonies being confirmed as fecal streptococci and 54% as enterococci. An attempt to improve the selectivity of KF agar while retaining its inclusiveness by incubation at 45 C was not successful. PMID:818956

Effects of medium composition on penicillin-induced hydrolysis and loss of RNA and culture turbidity in group A streptococci.

PubMed Central

McDowell, T D; Reed, K E

1989-01-01

Exposure to penicillin G of exponentially growing cultures of group A streptococci growing in chemically defined medium (CDM) can lead to extensive loss of culture turbidity. Significant reductions in culture turbidity did not accompany comparable treatments of group A streptococci growing in Todd-Hewitt broth (THB). Studies with THB and a high-molecular-weight (greater than 12,000) fraction of THB demonstrated that components in this complex medium inhibited the efflux of RNA hydrolysis products from otherwise intact cells. Hydrolysis products accumulated intracellularly and inhibited the extensive hydrolysis of RNA and consequently the loss of culture turbidity. Results of survival studies with cultures of group A streptococci exposed to penicillin G in THB demonstrated that this treatment protocol produces conditions of phenotypic tolerance relative to exposure in CDM. In combination, these findings provide further support for the hypothesis of RNA hydrolysis as the bactericidal mechanism of penicillin G action in this nonlytic death phenotype. PMID:2480343

Effects of medium composition on penicillin-induced hydrolysis and loss of RNA and culture turbidity in group A streptococci.

PubMed

McDowell, T D; Reed, K E

1989-12-01

Exposure to penicillin G of exponentially growing cultures of group A streptococci growing in chemically defined medium (CDM) can lead to extensive loss of culture turbidity. Significant reductions in culture turbidity did not accompany comparable treatments of group A streptococci growing in Todd-Hewitt broth (THB). Studies with THB and a high-molecular-weight (greater than 12,000) fraction of THB demonstrated that components in this complex medium inhibited the efflux of RNA hydrolysis products from otherwise intact cells. Hydrolysis products accumulated intracellularly and inhibited the extensive hydrolysis of RNA and consequently the loss of culture turbidity. Results of survival studies with cultures of group A streptococci exposed to penicillin G in THB demonstrated that this treatment protocol produces conditions of phenotypic tolerance relative to exposure in CDM. In combination, these findings provide further support for the hypothesis of RNA hydrolysis as the bactericidal mechanism of penicillin G action in this nonlytic death phenotype.

Effect of Chocobar Ice Cream Containing Bifidobacterium on Salivary Streptococcus mutans and Lactobacilli: A Randomised Controlled Trial.

PubMed

Nagarajappa, Ramesh; Daryani, Hemasha; Sharda, Archana J; Asawa, Kailash; Batra, Mehak; Sanadhya, Sudhanshu; Ramesh, Gayathri

2015-01-01

To examine the effect of chocobar ice cream containing bifidobacteria on salivary mutans streptococci and lactobacilli. A double-blind, randomised controlled trial was conducted with 30 subjects (18 to 22 years of age) divided into 2 groups, test (chocobar ice cream with probiotics) and control (chocobar ice cream without probiotics). The subjects were instructed to eat the allotted chocobar ice cream once daily for 18 days. Saliva samples collected at intervals were cultured on Mitis Salivarius agar and Rogosa agar and examined for salivary mutans streptococci and lactobacilli, respectively. The Mann-Whitney U-test, Friedman and Wilcoxon signed-rank tests were used for statistical analysis. Postingestion in the test group, a statistically significant reduction (p < 0.05) of salivary mutans streptococci was recorded, but a non-significant trend was seen for lactobacilli. Significant differences were was also observed between follow-ups. Short-term daily ingestion of ice cream containing probiotic bifidobacteria may reduce salivary levels of mutans streptococci in young adults.

Linear response of mutans streptococci to increasing frequency of xylitol chewing gum use: a randomized controlled trial [ISRCTN43479664

PubMed Central

Ly, Kiet A; Milgrom, Peter; Roberts, Marilyn C; Yamaguchi, David K; Rothen, Marilynn; Mueller, Greg

2006-01-01

Background Xylitol is a naturally occurring sugar substitute that has been shown to reduce the level of mutans streptococci in plaque and saliva and to reduce tooth decay. It has been suggested that the degree of reduction is dependent on both the amount and the frequency of xylitol consumption. For xylitol to be successfully and cost-effectively used in public health prevention strategies dosing and frequency guidelines should be established. This study determined the reduction in mutans streptococci levels in plaque and unstimulated saliva to increasing frequency of xylitol gum use at a fixed total daily dose of 10.32 g over five weeks. Methods Participants (n = 132) were randomized to either active groups (10.32 g xylitol/day) or a placebo control (9.828 g sorbitol and 0.7 g maltitol/day). All groups chewed 12 pieces of gum per day. The control group chewed 4 times/day and active groups chewed xylitol gum at a frequency of 2 times/day, 3 times/day, or 4 times/day. The 12 gum pieces were evenly divided into the frequency assigned to each group. Plaque and unstimulated saliva samples were taken at baseline and five-weeks and were cultured on modified Mitis Salivarius agar for mutans streptococci enumeration. Results There were no significant differences in mutans streptococci level among the groups at baseline. At five-weeks, mutans streptococci levels in plaque and unstimulated saliva showed a linear reduction with increasing frequency of xylitol chewing gum use at the constant daily dose. Although the difference observed for the group that chewed xylitol 2 times/day was consistent with the linear model, the difference was not significant. Conclusion There was a linear reduction in mutans streptococci levels in plaque and saliva with increasing frequency of xylitol gum use at a constant daily dose. Reduction at a consumption frequency of 2 times per day was small and consistent with the linear-response line but was not statistically significant. PMID:16556326

Group B streptococci in women fitted with intrauterine devices.

PubMed Central

Mitchell, R G; Guillebaud, J; Day, D G

1977-01-01

A survey was made of group B streptococcal carriage at various sites in 100 women attending a clinic for the insertion of an intrauterine contraceptive device (IUD). Twenty-three women carried streptococci at one or more sites at the preinsertion visit, the vaginal carriage rate being 16%. Six months after insertion changes in carrier status were noted and there was evidence of a change of strain in four patients. Twenty-nine women were carriers at one or more sites at some stage of the study. There was no evidence that symptoms attributable to infection in patients fitted with an IUD were caused by group B streptococci. PMID:338639

The role of complex carbohydrate catabolism in the pathogenesis of invasive streptococci

PubMed Central

Shelburne, Samuel A.; Davenport, Michael T.; Keith, David B.; Musser, James M.

2009-01-01

Historically, the study of bacterial catabolism of complex carbohydrates has contributed to understanding basic bacterial physiology. Recently, however, genome-wide screens of streptococcal pathogenesis have identified genes encoding proteins involved in complex carbohydrate catabolism as participating in pathogen infectivity. Subsequent studies have focused on specific mechanisms by which carbohydrate utilization proteins might contribute to the ability of streptococci to colonize and infect the host. Moreover, transcriptome and biochemical analyses have uncovered novel regulatory pathways by which streptococci link environmental carbohydrate availability to virulence factor production. Herein we review new insights into the role of complex carbohydrates in streptococcal host-pathogen interaction. PMID:18508271

The oral bacterial microbiome of occlusal surfaces in children and its association with diet and caries.

PubMed

Ribeiro, Apoena Aguiar; Azcarate-Peril, Maria Andrea; Cadenas, Maria Belen; Butz, Natasha; Paster, Bruce J; Chen, Tsute; Bair, Eric; Arnold, Roland R

2017-01-01

Dental caries is the most prevalent disease in humans globally. Efforts to control it have been invigorated by an increasing knowledge of the oral microbiome composition. This study aimed to evaluate the bacterial diversity in occlusal biofilms and its relationship with clinical surface diagnosis and dietary habits. Anamneses were recorded from thirteen 12-year-old children. Biofilm samples collected from occlusal surfaces of 46 permanent second molars were analyzed by 16S rRNA amplicon sequencing combined with the BLASTN-based search algorithm for species identification. The overall mean decayed, missing and filled surfaces modified index [DMFSm Index, including active white spot lesions (AWSL)] value was 8.77±7.47. Biofilm communities were highly polymicrobial collectively, representing 10 bacterial phyla, 25 classes, 29 orders, 58 families, 107 genera, 723 species. Streptococcus sp_Oral_Taxon_065, Corynebacterium matruchotii, Actinomyces viscosus, Actinomyces sp_Oral_Taxon_175, Actinomyces sp_Oral_Taxon_178, Actinomyces sp_Oral_Taxon_877, Prevotella nigrescens, Dialister micraerophilus, Eubacterium_XI G 1 infirmum were more abundant among surfaces with AWSL, and Streptococcus gordonii, Streptococcus sp._Oral_Taxon_058, Enterobacter sp._str._638 Streptococcus australis, Yersinia mollaretii, Enterobacter cloacae, Streptococcus sp._Oral_Taxon_71, Streptococcus sp._Oral_Taxon_F11, Centipeda sp._Oral_Taxon_D18 were more abundant among sound surfaces. Streptococcus mutans was detected on all surfaces in all patients, while Streptococcus sobrinus was detected only in three patients (mean relative abundances 7.1% and 0.6%, respectively). Neither species differentiated healthy from diseased sites. Diets of nine of the subjects were scored as high in fermentable carbohydrates (≧2X/day between meals). A direct association between relative abundances of bacteria and carbohydrate consumption was observed among 18 species. High consumption of fermentable carbohydrates and sound surfaces were associated with a reduction in bacterial diversity. PCoA plots displayed differences in bacterial community profiles between sound and diseased surfaces. Our study showed that, in addition to mutans streptococci, other species may be associated with the initiation of dental caries on occlusal surfaces, and that biofilm diversity of tooth surfaces is influenced by carbohydrate consumption and a surface's health status.

The oral bacterial microbiome of occlusal surfaces in children and its association with diet and caries

PubMed Central

Azcarate-Peril, Maria Andrea; Cadenas, Maria Belen; Butz, Natasha; Paster, Bruce J.; Chen, Tsute; Bair, Eric

2017-01-01

Dental caries is the most prevalent disease in humans globally. Efforts to control it have been invigorated by an increasing knowledge of the oral microbiome composition. This study aimed to evaluate the bacterial diversity in occlusal biofilms and its relationship with clinical surface diagnosis and dietary habits. Anamneses were recorded from thirteen 12-year-old children. Biofilm samples collected from occlusal surfaces of 46 permanent second molars were analyzed by 16S rRNA amplicon sequencing combined with the BLASTN-based search algorithm for species identification. The overall mean decayed, missing and filled surfaces modified index [DMFSm Index, including active white spot lesions (AWSL)] value was 8.77±7.47. Biofilm communities were highly polymicrobial collectively, representing 10 bacterial phyla, 25 classes, 29 orders, 58 families, 107 genera, 723 species. Streptococcus sp_Oral_Taxon_065, Corynebacterium matruchotii, Actinomyces viscosus, Actinomyces sp_Oral_Taxon_175, Actinomyces sp_Oral_Taxon_178, Actinomyces sp_Oral_Taxon_877, Prevotella nigrescens, Dialister micraerophilus, Eubacterium_XI G 1 infirmum were more abundant among surfaces with AWSL, and Streptococcus gordonii, Streptococcus sp._Oral_Taxon_058, Enterobacter sp._str._638 Streptococcus australis, Yersinia mollaretii, Enterobacter cloacae, Streptococcus sp._Oral_Taxon_71, Streptococcus sp._Oral_Taxon_F11, Centipeda sp._Oral_Taxon_D18 were more abundant among sound surfaces. Streptococcus mutans was detected on all surfaces in all patients, while Streptococcus sobrinus was detected only in three patients (mean relative abundances 7.1% and 0.6%, respectively). Neither species differentiated healthy from diseased sites. Diets of nine of the subjects were scored as high in fermentable carbohydrates (≧2X/day between meals). A direct association between relative abundances of bacteria and carbohydrate consumption was observed among 18 species. High consumption of fermentable carbohydrates and sound surfaces were associated with a reduction in bacterial diversity. PCoA plots displayed differences in bacterial community profiles between sound and diseased surfaces. Our study showed that, in addition to mutans streptococci, other species may be associated with the initiation of dental caries on occlusal surfaces, and that biofilm diversity of tooth surfaces is influenced by carbohydrate consumption and a surface’s health status. PMID:28678838

Capsular typing of Streptococcus agalactiae (Lancefield group B streptococci) from fish using multiplex PCR and serotyping

USDA-ARS?s Scientific Manuscript database

Streptococcus spp. including Streptococcus agalactiae (Lancefield group B streptococci) are considered emerging pathogens responsible for approximately $1 billion USD in annual losses to the global tilapia (Oreochromis sp.) aquaculture industry. This study evaluated a published multiplex PCR capsul...

Effect of an oxygenating agent on oral bacteria in vitro and on dental plaque composition in healthy young adults

PubMed Central

Fernandez y Mostajo, Mercedes; van der Reijden, Wil A.; Buijs, Mark J.; Beertsen, Wouter; van der Weijden, Fridus; Crielaard, Wim; Zaura, Egija

2014-01-01

Oral bacteria live in symbiosis with the host. Therefore, when mouthwashes are indicated, selective inhibition of taxa contributing to disease is preferred instead of broad-spectrum antimicrobials. The potential selectivity of an oxygenating mouthwash, Ardox-X® (AX), has not been assessed. The aim of this study was to determine the antimicrobial potential of AX and the effects of a twice-daily oral rinse on dental plaque composition. Material and methods: In vitro, 16 oral bacterial strains were tested using agar diffusion susceptibility, minimum inhibitory and minimum bactericidal concentration tests. A pilot clinical study was performed with 25 healthy volunteers. Clinical assessments and microbiological sampling of supragingival plaque were performed at 1 month before the experiment (Pre-exp), at the start of the experiment (Baseline) and after the one-week experimental period (Post-exp). During the experiment individuals used AX mouthwash twice daily in absence of other oral hygiene measures. The microbiological composition of plaque was assessed by 16S rRNA gene amplicon sequencing. Results: AX showed high inter-species variation in microbial growth inhibition. The tested Prevotella strains and Fusobacterium nucleatum showed the highest sensitivity, while streptococci and Lactobacillus acidophilus were most resistant to AX. Plaque scores at Pre-exp and Baseline visits did not differ significantly (p = 0.193), nor did the microbial composition of plaque. During a period of 7-days non-brushing but twice daily rinsing plaque scores increased from 2.21 (0.31) at Baseline to 2.43 (0.39) Post-exp. A significant microbial shift in composition was observed: genus Streptococcus and Veillonella increased while Corynebacterium, Haemophilus, Leptotrichia, Cardiobacterium and Capnocytophaga decreased (p ≤ 0.001). Conclusion: AX has the potential for selective inhibition of oral bacteria. The shift in oral microbiome after 1 week of rinsing deserves further research. PMID:25101249

Maturation of Oral Microbiota in Children with or without Dental Caries.

PubMed

Lif Holgerson, Pernilla; Öhman, Carina; Rönnlund, Agneta; Johansson, Ingegerd

2015-01-01

The aim of this longitudinal study was to evaluate the oral microbiota in children from age 3 months to 3 years, and to determine the association of the presence of caries at 3 years of age. Oral biofilms and saliva were sampled from children at 3 months (n = 207) and 3 years (n = 155) of age, and dental caries was scored at 3 years of age. Oral microbiota was assessed by culturing of total lactobacilli and mutans streptococci, PCR detection of Streptococcus mutans and Streptococcus sobrinus, 454 pyrosequencing and HOMIM (Human Oral Microbe Identification Microarray) microarray detection of more then 300 species/ phylotypes. Species richness and taxa diversity significantly increased from 3 months to 3 years. Three bacterial genera, present in all the 3-month-old infants, persisted at 3 years of age, whereas three other genera had disappeared by this age. A large number of new taxa were also observed in the 3-year-olds. The microbiota at 3 months of age, except for lactobacilli, was unrelated to caries development at a later age. In contrast, several taxa in the oral biofilms of the 3-year-olds were linked with the presence or absence of caries. The main species/phylotypes associated with caries in 3-year-olds belonged to the Actinobaculum, Atopobium, Aggregatibacter, and Streptococcus genera, whereas those influencing the absence of caries belonged to the Actinomyces, Bergeyella, Campylobacter, Granulicatella, Kingella, Leptotrichia, and Streptococcus genera. Thus, during the first years of life, species richness and taxa diversity in the mouth increase significantly. Besides the more prevalent colonization of lactobacilli, the composition of the overall microbiota at 3 months of age was unrelated to caries development at a later age. Several taxa within the oral biofilms of the 3-year-olds could be linked to the presence or absence of caries.

Maturation of Oral Microbiota in Children with or without Dental Caries

PubMed Central

Lif Holgerson, Pernilla; Öhman, Carina; Rönnlund, Agneta; Johansson, Ingegerd

2015-01-01

Background The aim of this longitudinal study was to evaluate the oral microbiota in children from age 3 months to 3 years, and to determine the association of the presence of caries at 3 years of age. Methods and findings Oral biofilms and saliva were sampled from children at 3 months (n = 207) and 3 years (n = 155) of age, and dental caries was scored at 3 years of age. Oral microbiota was assessed by culturing of total lactobacilli and mutans streptococci, PCR detection of Streptococcus mutans and Streptococcus sobrinus, 454 pyrosequencing and HOMIM (Human Oral Microbe Identification Microarray) microarray detection of more then 300 species/ phylotypes. Species richness and taxa diversity significantly increased from 3 months to 3 years. Three bacterial genera, present in all the 3-month-old infants, persisted at 3 years of age, whereas three other genera had disappeared by this age. A large number of new taxa were also observed in the 3-year-olds. The microbiota at 3 months of age, except for lactobacilli, was unrelated to caries development at a later age. In contrast, several taxa in the oral biofilms of the 3-year-olds were linked with the presence or absence of caries. The main species/phylotypes associated with caries in 3-year-olds belonged to the Actinobaculum, Atopobium, Aggregatibacter, and Streptococcus genera, whereas those influencing the absence of caries belonged to the Actinomyces, Bergeyella, Campylobacter, Granulicatella, Kingella, Leptotrichia, and Streptococcus genera. Conclusions Thus, during the first years of life, species richness and taxa diversity in the mouth increase significantly. Besides the more prevalent colonization of lactobacilli, the composition of the overall microbiota at 3 months of age was unrelated to caries development at a later age. Several taxa within the oral biofilms of the 3-year-olds could be linked to the presence or absence of caries. PMID:26020247

SXT and Taxo A Disks for Presumptive Identification of Group A and B Streptococci in Throat Cultures

PubMed Central

Gunn, Bruce A.

1976-01-01

A bacitracin (0.04 units, BBL)-SXT (trimethoprim, 1.25 mg, plus sulfamethoxazole, 23.75 mg, BBL) susceptibility test was 94% accurate in presumptively identifying streptococci as either group A, B or not group A and B. PMID:965480

Streptococcus mutans SpaP binds to RadD of Fusobacterium nucleatum ssp. polymorphum.

PubMed

Guo, Lihong; Shokeen, Bhumika; He, Xuesong; Shi, Wenyuan; Lux, Renate

2017-10-01

Adhesin-mediated bacterial interspecies interactions are important elements in oral biofilm formation. They often occur on a species-specific level, which could determine health or disease association of a biofilm community. Among the key players involved in these processes are the ubiquitous fusobacteria that have been recognized for their ability to interact with numerous different binding partners. Fusobacterial interactions with Streptococcus mutans, an important oral cariogenic pathogen, have previously been described but most studies focused on binding to non-mutans streptococci and specific cognate adhesin pairs remain to be identified. Here, we demonstrated differential binding of oral fusobacteria to S. mutans. Screening of existing mutant derivatives indicated SpaP as the major S. mutans adhesin specific for binding to Fusobacterium nucleatum ssp. polymorphum but none of the other oral fusobacteria tested. We inactivated RadD, a known adhesin of F. nucleatum ssp. nucleatum for interaction with a number of gram-positive species, in F. nucleatum ssp. polymorphum and used a Lactococcus lactis heterologous SpaP expression system to demonstrate SpaP interaction with RadD of F. nucleatum ssp. polymorphum. This is a novel function for SpaP, which has mainly been characterized as an adhesin for binding to host proteins including salivary glycoproteins. In conclusion, we describe an additional role for SpaP as adhesin in interspecies adherence with RadD-SpaP as the interacting adhesin pair for binding between S. mutans and F. nucleatum ssp. polymorphum. Furthermore, S. mutans attachment to oral fusobacteria appears to involve species- and subspecies-dependent adhesin interactions. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Persistence of the Oral Probiotic Streptococcus salivarius M18 Is Dose Dependent and Megaplasmid Transfer Can Augment Their Bacteriocin Production and Adhesion Characteristics

PubMed Central

Burton, Jeremy P.; Wescombe, Philip A.; Macklaim, Jean M.; Chai, Melissa H. C.; MacDonald, Kyle; Hale, John D. F.; Tagg, John; Reid, Gregor; Gloor, Gregory B.; Cadieux, Peter A.

2013-01-01

Bacteriocin-producing probiotic Streptococcus salivarius M18 offers beneficial modulatory capabilities within the oral microbiome, apparently through potent inhibitory activity against potentially deleterious bacteria, such as Streptococcus pyogenes. The oral cavity persistence of S. salivarius M18 was investigated in 75 subjects receiving four different doses for 28 days. Sixty per cent of the subjects already had some inhibitor-producing S. salivarius in their saliva prior to probiotic intervention. Strain M18’s persistence was dependent upon the dose, but not the period of administration. Culture analysis indicated that in some individuals the introduced strain had almost entirely replaced the indigenous S. salivarius, though the total numbers of the species did not increase. Selected subjects showing either high or low probiotic persistence had their salivary populations profiled using Illumina sequencing of the V6 region of the 16S rRNA gene. Analysis indicated that while certain bacterial phenotypes were markedly modulated, the overall composition of the oral microbiome was not modified by the probiotic treatment. Megaplasmids encoding bacteriocins and adhesion factors were transferred in vitro to generate a transconjugant S. salivarius exhibiting enhanced antimicrobial production and binding capabilities to HEp-2 cells. Since no widespread perturbation of the existing indigenous microbiota was associated with oral instillation and given its antimicrobial activity against potentially pathogenic streptococci, it appears that application of probiotic strain M18 offers potential low impact alternative to classical antibiotic prophylaxis. For candidate probiotic strains having relatively poor antimicrobial or adhesive properties, unique derivatives displaying improved probiotic performance may be engineered in vitro by megaplasmid transfer. PMID:23785463

Persistence of the oral probiotic Streptococcus salivarius M18 is dose dependent and megaplasmid transfer can augment their bacteriocin production and adhesion characteristics.

PubMed

Burton, Jeremy P; Wescombe, Philip A; Macklaim, Jean M; Chai, Melissa H C; Macdonald, Kyle; Hale, John D F; Tagg, John; Reid, Gregor; Gloor, Gregory B; Cadieux, Peter A

2013-01-01

Bacteriocin-producing probiotic Streptococcus salivarius M18 offers beneficial modulatory capabilities within the oral microbiome, apparently through potent inhibitory activity against potentially deleterious bacteria, such as Streptococcus pyogenes. The oral cavity persistence of S. salivarius M18 was investigated in 75 subjects receiving four different doses for 28 days. Sixty per cent of the subjects already had some inhibitor-producing S. salivarius in their saliva prior to probiotic intervention. Strain M18's persistence was dependent upon the dose, but not the period of administration. Culture analysis indicated that in some individuals the introduced strain had almost entirely replaced the indigenous S. salivarius, though the total numbers of the species did not increase. Selected subjects showing either high or low probiotic persistence had their salivary populations profiled using Illumina sequencing of the V6 region of the 16S rRNA gene. Analysis indicated that while certain bacterial phenotypes were markedly modulated, the overall composition of the oral microbiome was not modified by the probiotic treatment. Megaplasmids encoding bacteriocins and adhesion factors were transferred in vitro to generate a transconjugant S. salivarius exhibiting enhanced antimicrobial production and binding capabilities to HEp-2 cells. Since no widespread perturbation of the existing indigenous microbiota was associated with oral instillation and given its antimicrobial activity against potentially pathogenic streptococci, it appears that application of probiotic strain M18 offers potential low impact alternative to classical antibiotic prophylaxis. For candidate probiotic strains having relatively poor antimicrobial or adhesive properties, unique derivatives displaying improved probiotic performance may be engineered in vitro by megaplasmid transfer.

Oral microbial profile discriminates breast-fed from formula-fed infants.

PubMed

Holgerson, Pernilla L; Vestman, Nelly R; Claesson, Rolf; Ohman, Carina; Domellöf, Magnus; Tanner, Anne C R; Hernell, Olle; Johansson, Ingegerd

2013-02-01

Little is known about the effect of diet on the oral microbiota of infants, although diet is known to affect the gut microbiota. The aims of the present study were to compare the oral microbiota in breast-fed and formula-fed infants, and investigate growth inhibition of streptococci by infant-isolated lactobacilli. A total of 207 mothers consented to participation of their 3-month-old infants. A total of 146 (70.5%) infants were exclusively and 38 (18.4%) partially breast-fed, and 23 (11.1%) were exclusively formula-fed. Saliva from all of their infants was cultured for Lactobacillus species, with isolate identifications from 21 infants. Lactobacillus isolates were tested for their ability to suppress Streptococcus mutans and S sanguinis. Oral swabs from 73 infants were analysed by the Human Oral Microbe Identification Microarray (HOMIM) and by quantitative polymerase chain reaction for Lactobacillus gasseri. Lactobacilli were cultured from 27.8% of exclusively and partially breast-fed infants, but not from formula-fed infants. The prevalence of 14 HOMIM-detected taxa, and total salivary lactobacilli counts differed by feeding method. Multivariate modelling of HOMIM-detected bacteria and possible confounders clustered samples from breast-fed infants separately from formula-fed infants. The microbiota of breast-fed infants differed based on vaginal or C-section delivery. Isolates of L plantarum, L gasseri, and L vaginalis inhibited growth of the cariogenic S mutans and the commensal S sanguinis: L plantarum >L gasseri >L vaginalis. The microbiota of the mouth differs between 3-month-old breast-fed and formula-fed infants. Possible mechanisms for microbial differences observed include species suppression by lactobacilli indigenous to breast milk.

Chemoprophylaxis of infective endocarditis.

PubMed

Finch, R

1990-01-01

Infective endocarditis is a serious disease with a continuing mortality of approximately 20%. Risk factors include a variety of congenital and acquired heart diseases. Infection follows an episode of bacteraemia which is most commonly due to oral bacteria, notably streptococci. Less commonly bacteraemia may arise from surgical procedures or diseases of the gastrointestinal and genitourinary tracts or from sepsis at other body sites, including intravenous drug abuse. Several societies and associations have published recommendations for the prevention of bacteraemia in those at risk from endocarditis through the use of perioperative antibiotic chemoprophylaxis. The recommendations are targetted at patients with defined cardiovascular lesions undergoing dental and other procedures known to predictably produce bacteraemia. The major recommendations for standard risk patients undergoing dental procedures without general anaesthesia is high-dose oral penicillin or amoxycillin. Alternative agents include erythromycin and clindamycin. For those requiring general anaesthesia, parenteral regimens are generally recommended although the British Society for Antimicrobial Chemotherapy permits an oral amoxycillin regimen 4 hours preoperatively. For specified gastrointestinal and genitourinary procedures a 2-drug regimen of ampicillin/amoxycillin (or vancomycin for penicillin-allergic patients) plus an aminoglycoside is generally recommended. The emphasis has been to simplify the earlier regimens without compromising the antimicrobial protection with a view to encouraging maximum compliance. The latter continues to be a problem where drug recommendations are either complex or include multiple drug or dosage recommendations. The emphasis on maintaining good dental health is endorsed by all authorities.

Salivary agglutinin, which binds Streptococcus mutans and Helicobacter pylori, is the lung scavenger receptor cysteine-rich protein gp-340.

PubMed

Prakobphol, A; Xu, F; Hoang, V M; Larsson, T; Bergstrom, J; Johansson, I; Frängsmyr, L; Holmskov, U; Leffler, H; Nilsson, C; Borén, T; Wright, J R; Strömberg, N; Fisher, S J

2000-12-22

Salivary agglutinin is a high molecular mass component of human saliva that binds Streptococcus mutans, an oral bacterium implicated in dental caries. To study its protein sequence, we isolated the agglutinin from human parotid saliva. After trypsin digestion, a portion was analyzed by matrix-assisted laser/desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), which gave the molecular mass of 14 unique peptides. The remainder of the digest was subjected to high performance liquid chromatography, and the separated peptides were analyzed by MALDI-TOF/post-source decay; the spectra gave the sequences of five peptides. The molecular mass and peptide sequence information showed that salivary agglutinin peptides were identical to sequences in lung (lavage) gp-340, a member of the scavenger receptor cysteine-rich protein family. Immunoblotting with antibodies that specifically recognized either lung gp-340 or the agglutinin confirmed that the salivary agglutinin was gp-340. Immunoblotting with an antibody specific to the sialyl Le(x) carbohydrate epitope detected expression on the salivary but not the lung glycoprotein, possible evidence of different glycoforms. The salivary agglutinin also interacted with Helicobacter pylori, implicated in gastritis and peptic ulcer disease, Streptococcus agalactiae, implicated in neonatal meningitis, and several oral commensal streptococci. These results identify the salivary agglutinin as gp-340 and suggest it binds bacteria that are important determinants of either the oral ecology or systemic diseases.

Genital streptococcal infection in non-pregnant women: a case-note review.

PubMed

Sonnex, C

2013-06-01

The purpose of this case-note review was to examine the clinical features and management of women with either vulval or vaginal swabs culturing positive for streptococci. Group B haemolytic streptococcus was isolated in all cases. The majority of women with vulval streptococci presented with irritation or soreness. Candidal infection was found in 43% and a dermatosis in 27%. All women with positive vaginal culture had vaginal soreness and/or discharge. Candida was isolated in 27% and there were features of desquamative vaginitis in 20%. Women treated with erythromycin failed to improve symptomatically. The findings of this study suggest that streptococci mostly play a secondary role and colonize an already damaged genital epithelium.

Colonisation of babies and their families by group B streptococci.

PubMed Central

Weindling, A M; Hawkins, J M; Coombes, M A; Stringer, J

1981-01-01

A high incidence of group B streptococcal disease of the newborn in West Berkshire led to a prospective study of the condition. Cultures taken from 1090 babies shortly after birth showed that 65 (6%) were colonised with the streptococcus. Thirty of these babies were assigned to group 1. Bacteriological samples were taken from babies and mothers at birth and at four, eight, and 12 weeks, and also from fathers and siblings. Fifty uncolonised babies and their families were similarly studied and served as controls (group 2). In group 1,28 of the 30 mothers and 14 of the 28 fathers examined were colonised by group B streptococci. In group 2 the streptococci were isolated from three babies, 12 mothers, and 11 out of 45 fathers during follow-up. These findings suggest that group B streptococci are carried predominantly in the lower gastrointestinal and genitourinary tracts. Most families are lightly colonised, but in others maternal colonisation is stable and heavy and the incidence of paternal colonisation high. Results of serotyping suggest that sexual transmission occurs, which may explain the difficulty in eradicating the organism during pregnancy. PMID:6799041

Comparison among four proposed direct blood culture microbial identification methods using MALDI-TOF MS.

PubMed

Bazzi, Ali M; Rabaan, Ali A; El Edaily, Zeyad; John, Susan; Fawarah, Mahmoud M; Al-Tawfiq, Jaffar A

Matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) mass spectrometry facilitates rapid and accurate identification of pathogens, which is critical for sepsis patients. In this study, we assessed the accuracy in identification of both Gram-negative and Gram-positive bacteria, except for Streptococcus viridans, using four rapid blood culture methods with Vitek MALDI-TOF-MS. We compared our proposed lysis centrifugation followed by washing and 30% acetic acid treatment method (method 2) with two other lysis centrifugation methods (washing and 30% formic acid treatment (method 1); 100% ethanol treatment (method 3)), and picking colonies from 90 to 180min subculture plates (method 4). Methods 1 and 2 identified all organisms down to species level with 100% accuracy, except for Streptococcus viridans, Streptococcus pyogenes, Enterobacter cloacae and Proteus vulgaris. The latter two were identified to genus level with 100% accuracy. Each method exhibited excellent accuracy and precision in terms of identification to genus level with certain limitations. Copyright © 2016 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

FACTORS AFFECTING THE CHAIN LENGTH OF GROUP A STREPTOCOCCI

PubMed Central

Ekstedt, Richard D.; Stollerman, Gene H.

1960-01-01

Group A streptococci which grew in long chains in the presence of homologous anti-M antibody were split into their original length by the addition of an excess of homologous M protein to the culture. The chain-splitting reaction showed temperature and pH optima (37°C., 7.5) and was completely inhibited at 0°C. or by heat-killing the long chains at 56°C. prior to the addition of M protein. Addition of sublethal doses of HgCl2, or of penicillin, inhibited the chain-splitting reaction. Pneumococci behaved in entirely comparable fashion to streptococci in similar experiments. Virulent strains of streptococci formed the shortest chains when broth media was enriched with serum. The chain-shortening effect of serum enrichment of the media was most apparent with encapsulated strains and under cultural conditions that favored capsule formation. Loss of capsules by mutation or by unfavorable growth conditions resulted in increase in chain length. The activity of the chain-splitting mechanism seemed to be independent of M protein, however, since encapsulated M-negative variants also formed very short chain in serum-enriched media. The physical presence of the capsule was not essential for chain shortening since enzymatic removal of the capsule with hyaluronidase during growth did not affect chain length. These results strongly suggest that chain-splitting of streptococci and pneumococci occurs by an active metabolic mechanism, presumably enzymatic, which is inhibited by the union of surface antigens with specific antibody. PMID:13726267

Rapid identification of pneumococci, enterococci, beta-haemolytic streptococci and S. aureus from positive blood cultures enabling early reports.

PubMed

Larsson, Marie C; Karlsson, Ewa; Woksepp, Hanna; Frölander, Kerstin; Mårtensson, Agneta; Rashed, Foad; Annika, Wistedt; Schön, Thomas; Serrander, Lena

2014-03-19

The aim of this study was to evaluate diagnostic tests in order to introduce a diagnostic strategy to identify the most common gram-positive bacteria (pneumococci, enterococci, β-haemolytic streptococci and S. aureus) found in blood cultures within 6 hours after signalling growth. The tube coagulase test was optimized and several latex agglutination tests were compared and evaluated before a validation period of 11 months was performed on consecutive positive blood culture patient samples from Kalmar County Hospital, Sweden. During the validation period 150 (91%) of a total of 166 gram-positive cocci (119 in clusters, 45 in chains or pairs and 2 undefined morphology) were correctly identified as S. aureus, CoNS, Pneumococci, Enterococci or group A streptococci (GAS), group B streptococci (GBS), group G streptococci (GGS) within 6 hours with a minimal increase in work-load and costs. The remaining samples (9%) were correctly identified during the next day. No samples were incorrectly grouped with this diagnostic strategy and no patient came to risk by early reporting. A simple strategy gives reliable and cost-effective reporting of >90% of the most common gram-positive cocci within 6 hours after a blood cultures become positive. The high specificity of the tests used makes preliminary reports reliable. The reports can be used to indicate the focus of infection and not the least, support faster administration of proper antimicrobial treatment for patients with serious bacterial infections.

Natural antigenic differences in the functionally equivalent extracellular DNABII proteins of bacterial biofilms provide a means for targeted biofilm therapeutics

PubMed Central

Rocco, Christopher J.; Davey, Mary Ellen; Bakaletz, Lauren O.; Goodman, Steven D.

2016-01-01

SUMMARY Bacteria that persist in the oral cavity exist within complex biofilm communities. A hallmark of biofilms is the presence of an extracellular polymeric substance (EPS), which consists of polysaccharides, extracellular DNA (eDNA), and proteins, including the DNABII family of proteins. The removal of DNABII proteins from a biofilm results in the loss of structural integrity of the eDNA and the collapse of the biofilm structure. We examined the role of DNABII proteins in the biofilm structure of the periodontal pathogen Porphyromonas gingivalis and the oral commensal Streptococcus gordonii. Co-aggregation with oral streptococci is thought to facilitate the establishment of P. gingivalis within the biofilm community. We demonstrate that DNABII proteins are present in the EPS of both S. gordonii and P. gingivalis biofilms, and that these biofilms can be disrupted through the addition of antisera derived against their respective DNABII proteins. We provide evidence that both eDNA and DNABII proteins are limiting in S. gordonii but not in P. gingivalis biofilms. In addition, these proteins are capable of complementing one another functionally. We also found that while antisera derived against most DNABII proteins are capable of binding a wide variety of DNABII proteins, the P. gingivalis DNABII proteins are antigenically distinct. The presence of DNABII proteins in the EPS of these biofilms and the antigenic uniqueness of the P. gingivalis proteins provide an opportunity to develop therapies that are targeted to remove P. gingivalis and biofilms that contain P. gingivalis from the oral cavity. PMID:26988714

Throat carriage rate and antimicrobial susceptibility pattern of group A Streptococci (GAS) in healthy Ethiopian school children.

PubMed

Abdissa, Alemseged; Asrat, Daniel; Kronvall, Göran; Shitu, Belay; Achiko, Dilachew; Zeidan, Mohammed; Yamuah, Lawrence K; Aseffa, Abraham

2011-04-01

Group A Streptococci (GAS) or Streptococcus pyogenes are the most frequent cause of pharyngitis and skin infection in children and lead to post infection complications including acute rheumatic fever and glomerulonephritis. Pharyngeal carriage rates of GAS among healthy school children vary with geographical location and seasons. There is not much information on the screening of children for carriage of GAS in Ethiopia. The study aimed at assessing the carriage rate of Group A Streptococci and antimicrobial susceptibility of the isolates in healthy Ethiopian school children. A total of 937 children residing in Addis Ababa (n=491), Gondar (n=265) and Dire-Dawa (n=181) were investigated during a period between November 2004 and January 2005. Throat specimens were collected and cultured using standard procedure. Beta haemolytic streptococci were serogrouped by agglutination tests using specific antisera. Antimicrobial susceptibility testing of the isolates was performed by diffusion method. The median and the mean ages of the study participants were 11 (range 6-14) years. Girls constituted 52% (486/937) of the study participants. A total of 167 (17.8%) beta haemolytic streptococci were recovered from 937 children investigated GAS accounted for 91/167 (54.5%) of beta hemolytic streptococcal isolates. The carrier rate for GAS was 9.7% (91/937) of the screened children followed by group G with 3.2% (30/937) and group C streptococci with 2.2% (21/937). All GAS isolates were sensitive to oxacillin, penicillin, erythromycin, clindamycin and trimethoprim-sulphamethoxazole. Lower frequency of resistance was observed against tetracycline and vanocmycin. The present study revealed that GAS was the most predominant beta-haemolytic streptococcus among healthy Ethiopian school children. Our results showed that pharyngeal carriage of GAS in school children should not be underestimated. Therefore it is recommended to conduct regular screening and GAS surveillance in schools, and maintain rational use of antibiotics to minimize GAS resistance.

Microbial interactions in building of communities

PubMed Central

Wright, Christopher J.; Burns, Logan H.; Jack, Alison A.; Back, Catherine R.; Dutton, Lindsay C.; Nobbs, Angela H.; Lamont, Richard J.; Jenkinson, Howard F.

2012-01-01

SUMMARY Establishment of a community is considered to be essential for microbial growth and survival in the human oral cavity. Biofilm communities have increased resilience to physical forces, antimicrobial agents, and nutritional variations. Specific cell-to-cell adherence processes, mediated by adhesin-receptor pairings on respective microbial surfaces, are able to direct community development. These interactions co-localize species in mutually beneficial relationships, such as streptococci, veillonellae, Porphyromonas gingivalis and Candida albicans. In transition from the planktonic mode of growth to a biofilm community, microorganisms undergo major transcriptional and proteomic changes. These occur in response to sensing of diffusible signals, such as autoinducer molecules, and to contact with host tissues or other microbial cells. Underpinning many of these processes are intracellular phosphorylation events that regulate a large number of microbial interactions relevant to community formation and development. PMID:23253299

Novel aspects of sialoglycan recognition by the Siglec-like domains of streptococcal SRR glycoproteins.

PubMed

Bensing, Barbara A; Khedri, Zahra; Deng, Lingquan; Yu, Hai; Prakobphol, Akraporn; Fisher, Susan J; Chen, Xi; Iverson, Tina M; Varki, Ajit; Sullam, Paul M

2016-11-01

Serine-rich repeat glycoproteins are adhesins expressed by commensal and pathogenic Gram-positive bacteria. A subset of these adhesins, expressed by oral streptococci, binds sialylated glycans decorating human salivary mucin MG2/MUC7, and platelet glycoprotein GPIb. Specific sialoglycan targets were previously identified for the ligand-binding regions (BRs) of GspB and Hsa, two serine-rich repeat glycoproteins expressed by Streptococcus gordonii While GspB selectively binds sialyl-T antigen, Hsa displays broader specificity. Here we examine the binding properties of four additional BRs from Streptococcus sanguinis or Streptococcus mitis and characterize the molecular determinants of ligand selectivity and affinity. Each BR has two domains that are essential for sialoglycan binding by GspB. One domain is structurally similar to the glycan-binding module of mammalian Siglecs (sialic acid-binding immunoglobulin-like lectins), including an arginine residue that is critical for glycan recognition, and that resides within a novel, conserved YTRY motif. Despite low sequence similarity to GspB, one of the BRs selectively binds sialyl-T antigen. Although the other three BRs are highly similar to Hsa, each displayed a unique ligand repertoire, including differential recognition of sialyl Lewis antigens and sulfated glycans. These differences in glycan selectivity were closely associated with differential binding to salivary and platelet glycoproteins. Specificity of sialoglycan adherence is likely an evolving trait that may influence the propensity of streptococci expressing Siglec-like adhesins to cause infective endocarditis. Published by Oxford University Press 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Characterization of biosurfactants produced by Lactobacillus spp. and their activity against oral streptococci biofilm.

PubMed

Ciandrini, Eleonora; Campana, Raffaella; Casettari, Luca; Perinelli, Diego R; Fagioli, Laura; Manti, Anita; Palmieri, Giovanni Filippo; Papa, Stefano; Baffone, Wally

2016-08-01

Lactic acid bacteria (LAB) can interfere with pathogens through different mechanisms; one is the production of biosurfactants, a group of surface-active molecules, which inhibit the growth of potential pathogens. In the present study, biosurfactants produced by Lactobacillus reuteri DSM 17938, Lactobacillus acidophilus DDS-1, Lactobacillus rhamnosus ATCC 53103, and Lactobacillus paracasei B21060 were dialyzed (1 and 6 kDa) and characterized in term of reduction of surface tension and emulsifying activity. Then, aliquots of the different dialyzed biosurfactants were added to Streptococcus mutans ATCC 25175 and Streptococcus oralis ATCC 9811 in the culture medium during the formation of biofilm on titanium surface and the efficacy was determined by agar plate count, biomass analyses, and flow cytometry. Dialyzed biosurfactants showed abilities to reduce surface tension and to emulsifying paraffin oil. Moreover, they significantly inhibited the adhesion and biofilm formation on titanium surface of S. mutans and S. oralis in a dose-dependent way, as demonstrated by the remarkable decrease of cfu/ml values and biomass production. The antimicrobial properties observed for dialyzed biosurfactants produced by the tested lactobacilli opens future prospects for their use against microorganisms responsible of oral diseases.

Application of surface plasmon resonance biosensor for the detection of Candida albicans

NASA Astrophysics Data System (ADS)

Yodmongkol, Sirasa; Thaweboon, Sroisiri; Thaweboon, Boonyanit; Puttharugsa, Chokchai; Sutapun, Boonsong; Amarit, Ratthasart; Somboonkaew, Armote; Srikhirin, Toemsak

2016-02-01

In this study, surface plasmon resonance imaging (SPR imaging) was developed for the detection of Candida albicans which is a causal agent of oral infection. The detection was based on the sandwich assay. The capture antibody was covalently immobilized on the mixed self assemble monolayers (SAMs). The ratio of mixed SAMs between 11-mercaptoundecanoic acid and 3-mercaptopropanol was varied to find the optimal ratio for use as a sensor surface. The results showed that the suitable surface for C. albicans detection was SAM of carboxylic (mixed SAMs 1:0), even though mixed SAMs 1:40 had a high detection signal in comparison to mixed SAMs 1:0, but the non-specific signal was higher. The detection limit was 107 cells/ml for direct detection, and was increased to 106 cells/ml with sandwich antibody. The use of polyclonal C. albicans antibody as capture and sandwich antibody showed good selectivity against the relevant oral bacteria including Escherichia coli, Streptococcus mutan, Staphylococcus aureus, β-streptococci, and Lactobacillus casei. SPR platform in this study could detect C. albicans from the mixed microbial suspension without requirement of skillful technician. This SPR imaging biosensor could be applied for Candida identification after cultivation.

Significance of Hemolytic Colonies in Throat Cultures

PubMed Central

Quinn, Robert W.; Lowry, P. Nye

1969-01-01

These studies indicate that a single strain of hemolytic streptococci almost exclusively predominates the bacterial flora in patients with streptococcal infections and in the carrier state. One can proceed with confidence that, in isolating streptococci from throat swabs cultured on blood-agar plates, only a single hemolytic colony need be picked for serological grouping and typing. PMID:4888863

The high vaginal swab in general practice: clinical correlates of possible pathogens.

PubMed

Dykhuizen, R S; Harvey, G; Gould, I M

1995-06-01

Clinical features, diagnosis and treatment of 286 women whose high vaginal swabs (HVS) submitted by their general practitioners showed pure, heavy growth of Staphylococcus aureus, beta haemolytic streptococci groups A, C or G, Streptococcus milleri, Streptococcus pneumoniae or Haemophilus influenzae were analysed. Women with group A, C and G streptococci frequently had clinical vulvovaginitis and although the numbers were too small for statistical confirmation, S. pneumoniae and H. influenzae appeared to cause clinical disease as well. The association of S. aureus or S. milleri with clinical vulvovaginitis was much less convincing. It seems relevant for laboratories to report sensitivities for group A, C and G streptococci. Further research is needed to determine the pathogenicity of S. pneumoniae and H. influenzae.

[Method and procedures in bacteriological study of necrotic teeth].

PubMed

Rodríguez-Ponce, A; López Campos, A; López Paz, J; Pazos Sierra, R

1991-01-01

Research was conducted of 160 radicular canals with necrotic pulp. Results of different bacteriological analyses are presented. Culture analyses in aerobic and anaerobic media, resulted in the isolation of Staphylococcus Epidermidis, Streptococcus Viridans and Corynebacterium sp in the group studied, as the most frequent bacteria. There was no evidence of a specific germ linked with the pulp necrosis.

Evaluation and improvement of real-time PCR assays targeting lytA, ply, and psaA genes for detection of pneumococcal DNA.

PubMed

Carvalho, Maria da Gloria S; Tondella, Maria Lucia; McCaustland, Karen; Weidlich, Luciana; McGee, Lesley; Mayer, Leonard W; Steigerwalt, Arnold; Whaley, Melissa; Facklam, Richard R; Fields, Barry; Carlone, George; Ades, Edwin W; Dagan, Ron; Sampson, Jacquelyn S

2007-08-01

The accurate diagnosis of pneumococcal disease has frequently been hampered not only by the difficulties in obtaining isolates of the organism from patient specimens but also by the misidentification of pneumococcus-like viridans group streptococci (P-LVS) as Streptococcus pneumoniae. This is especially critical when the specimen comes from the respiratory tract. In this study, three novel real-time PCR assays designed for the detection of specific sequence regions of the lytA, ply, and psaA genes were developed (lytA-CDC, ply-CDC, and psaA, respectively). These assays showed high sensitivity (<10 copies for lytA-CDC and ply-CDC and an approximately twofold less sensitivity for psaA). Two additional real-time PCR assays for lytA and ply described previously for pneumococcal DNA detection were also evaluated. A panel of isolates consisting of 67 S. pneumoniae isolates (44 different serotypes and 3 nonencapsulated S. pneumoniae isolates from conjunctivitis outbreaks) and 104 nonpneumococcal isolates was used. The 67 S. pneumoniae isolates were reactive in all five assays. The new real-time detection assays targeting the lytA and psaA genes were the most specific for the detection of isolates confirmed to be S. pneumoniae, with lytA-CDC showing the greatest specificity. Both ply PCRs were positive for all isolates of S. pseudopneumoniae, along with 13 other isolates of other P-LVS isolates confirmed to be non-S. pneumoniae by DNA-DNA reassociation. Thus, the use of the ply gene for the detection of pneumococci can lead to false-positive reactions in the presence of P-LVS. The five assays were applied to 15 culture-positive cerebrospinal fluid specimens with 100% sensitivity; and serum and ear fluid specimens were also evaluated. Both the lytA-CDC and psaA assays, particularly the lytA-CDC assay, have improved specificities compared with those of currently available assays and should therefore be considered the assays of choice for the detection of pneumococcal DNA, particularly when upper respiratory P-LVS might be present in the clinical specimen.

Development of a rapid recombinase polymerase amplification assay for the detection of Streptococcus pneumoniae in whole blood.

PubMed

Clancy, Eoin; Higgins, Owen; Forrest, Matthew S; Boo, Teck Wee; Cormican, Martin; Barry, Thomas; Piepenburg, Olaf; Smith, Terry J

2015-10-29

Streptococcus pneumoniae is an important cause of microbial disease in humans. The introduction of multivalent vaccines has coincided with a dramatic decrease in the number of pneumococcal-related deaths. In spite of this, at a global level, pneumococcal infection remains an important cause of death among children under 5 years of age and in adults 65 years of age or older. In order to properly manage patients and control the spread of infection, a rapid and highly sensitive diagnostic method is needed for routine implementation, especially in resource-limited regions where pneumococcal disease is most prevalent. Using the gene encoding leader peptidase A as a molecular diagnostics target, a real-time RPA assay was designed and optimised for the detection of S. pneumoniae in whole blood. The performance of the assay was compared to real-time PCR in terms of its analytical limit of detection and specificity. The inhibitory effect of human genomic DNA on amplification was investigated. The potential clinical utility of the assay was investigated using a small number of clinical samples. The RPA assay has a limit of detection equivalent to PCR (4.0 and 5.1 genome equivalents per reaction, respectively) and was capable of detecting the equivalent of <1 colony forming unit of S. pneumoniae when spiked into human whole blood. The RPA assay was 100 % inclusive (38/38 laboratory reference strains and 19/19 invasive clinical isolates) and 100 % exclusive; differentiating strains of S. pneumoniae species from other viridans group streptococci, including S. pseudopneumoniae. When applied to the analysis of a small number (n = 11) of clinical samples (blood culture positive for S. pneumoniae), the RPA assay was demonstrated to be both rapid and sensitive. The RPA assay developed in this work is shown to be as sensitive and as specific as PCR. In terms of reaction kinetics, the RPA assay is shown to exceed those of the PCR, with the RPA running to completion in 20 minutes and capable generating a positive signal in as little as 6 minutes. This work represents a potentially suitable assay for application in point-of-care settings.

[Significance of group A streptococcal infections in human pathology].

PubMed

Cvjetković, Dejan; Jovanović, Jovana; Hrnjaković-Cvjetković, Ivana; Aleksić-Dordević, Mirjana; Stefan-Mikić, Sandra

2008-01-01

Group A streptococci is the causative agent in 80 percents of human streptococcal infections. The only member of this group is Streptococcus pyogenes. CLINICALFEATURES OF GAS INFECTIONS: The various clinical entities and related complications caused by pyogenic streptococci are reviewed in the article. Pharyngitis, scarlet fever, skin and soft tissue infections (pyoderma, cellulitis, perianal dermatitis, necrotising fasciitis) and streptococcal toxic shock syndrome are described. The way of setting the diagnosis including epidemiological data, clinical features and the course of illness, laboratory findings and supportive diagnostic methods are represented in the article. The most important clinical entities which should be discussed in differential diagnosis of diseases caused by pyogenic streptococci are listed. The major principles of etiologic treatment through widely accepted strategies related to first choice antibiotics and alternatives are reviewed.

The relation between oral Candida load and bacterial microbiome profiles in Dutch older adults.

PubMed

Kraneveld, Eefje A; Buijs, Mark J; Bonder, Marc J; Visser, Marjolein; Keijser, Bart J F; Crielaard, Wim; Zaura, Egija

2012-01-01

Currently there are no evidence-based ecological measures for prevention of overgrowth and subsequent infection by fungi in the oral cavity. The aim of this study was to increase our knowledge on fungal-bacterial ecological interactions. Salivary Candida abundance of 82 Dutch adults aged 58-80 years was established relative to the bacterial load by quantitative PCR analysis of the Internal Transcribed (ITS) region (Candida) and 16S rDNA gene (bacteria). The salivary microbiome was assessed using barcoded pyrosequencing of the bacterial hypervariable regions V5-V7 of 16S rDNA. Sequencing data was preprocessed by denoising and chimera removal, clustered in Operational Taxonomic Units (OTUs) and assigned to taxonomy. Both OTU-based (PCA, diversity statistics) and phylogeny-based analyses (UniFrac, PCoA) were performed. Saliva of Dutch older adults contained 0-4 × 10(8) CFU/mL Candida with a median Candida load of 0.06%. With increased Candida load the diversity of the salivary microbiome decreased significantly (p<0.001). Increase in the Candida load correlated positively with class Bacilli, and negatively with class Fusobacteria, Flavobacteria, and Bacteroidia. Microbiomes with high Candida load were less diverse and had a distinct microbial composition towards dominance by saccharolytic and acidogenic bacteria--streptococci. The control of the acidification of the oral environment may be a potential preventive measure for Candida outgrowth that should be evaluated in longitudinal clinical intervention trials.

The Relation between Oral Candida Load and Bacterial Microbiome Profiles in Dutch Older Adults

PubMed Central

Kraneveld, Eefje A.; Buijs, Mark J.; Bonder, Marc J.; Visser, Marjolein; Keijser, Bart J. F.; Crielaard, Wim; Zaura, Egija

2012-01-01

Currently there are no evidence-based ecological measures for prevention of overgrowth and subsequent infection by fungi in the oral cavity. The aim of this study was to increase our knowledge on fungal–bacterial ecological interactions. Salivary Candida abundance of 82 Dutch adults aged 58–80 years was established relative to the bacterial load by quantitative PCR analysis of the Internal Transcribed (ITS) region (Candida) and 16S rDNA gene (bacteria). The salivary microbiome was assessed using barcoded pyrosequencing of the bacterial hypervariable regions V5–V7 of 16S rDNA. Sequencing data was preprocessed by denoising and chimera removal, clustered in Operational Taxonomic Units (OTUs) and assigned to taxonomy. Both OTU-based (PCA, diversity statistics) and phylogeny-based analyses (UniFrac, PCoA) were performed. Saliva of Dutch older adults contained 0–4 × 108 CFU/mL Candida with a median Candida load of 0.06%. With increased Candida load the diversity of the salivary microbiome decreased significantly (p<0.001). Increase in the Candida load correlated positively with class Bacilli, and negatively with class Fusobacteria, Flavobacteria, and Bacteroidia. Microbiomes with high Candida load were less diverse and had a distinct microbial composition towards dominance by saccharolytic and acidogenic bacteria - streptococci. The control of the acidification of the oral environment may be a potential preventive measure for Candida outgrowth that should be evaluated in longitudinal clinical intervention trials. PMID:22900048

Inhibition of purified enolases from oral bacteria by fluoride.

PubMed

Guha-Chowdhury, N; Clark, A G; Sissons, C H

1997-04-01

Enolase activity in strains of oral streptococci previously has been found to be inhibited by 50% (Ki) by fluoride concentrations ranging from 50 to 300 microM or more in the presence of 0.5 to 1.0 mM inorganic phosphate ions. In this study, enolase was extracted and partly purified by a two-step process from five oral bacterial species and the effect of fluoride on the kinetics of enolase examined. The molecular weight of the putative enolase proteins was 46-48 kDa. The Vmax values ranged from 20 to 323 IU/mg and K(m) for glycerate-2-phosphate from 0.22 to 0.74 mM. Enolase activity was inhibited competitively by fluoride, with Ki values ranging from 16 to 54 microM in the presence of 5 mM inorganic phosphate ions. Ki values for phosphate ranged from 2 to 8 mM. The enolase from Streptococcus sanguis ATCC 10556 was more sensitive to fluoride (Ki = 16 +/- 2) than was enolase from Streptococcus salivarius ATCC 10575 (Ki = 19 +/- 2) or Streptococcus mutans NCTC 10449 (Ki = 40 +/- 4) and all three streptococcal strains were more sensitive to fluoride than either Actinomyces naeslundii WVU 627 (Ki = 46 +/- 6) or Lactobacillus rhamnosus ATCC 7469 (Ki = 54 +/- 6) enolases. The levels of fluoride found to inhibit the streptococcal enolases in this study are much lower than previously reported and are likely to be present in plaque, especially during acidogenesis, and could exert an anti-glycolytic effect.

Absence of Capsule Reveals Glycan-Mediated Binding and Recognition of Salivary Mucin MUC7 by Streptococcus pneumoniae

PubMed Central

Thamadilok, Supaporn; Roche-Håkansson, Hazeline; Håkansson, Anders P.; Ruhl, Stefan

2015-01-01

SUMMARY Salivary proteins modulate bacterial colonization in the oral cavity and interact with systemic pathogens that pass through the oropharynx. An interesting example is the opportunistic respiratory pathogen Streptococcus pneumoniae that normally resides in the nasopharynx, but belongs to the greater Mitis group of streptococci, most of which colonize the oral cavity. S. pneumoniae also expresses a serine-rich repeat (SRR) adhesin, PsrP, that is a homologue to oral Mitis group SRR adhesins, such as Hsa of S. gordonii and SrpA of S. sanguinis. Since the latter bind to salivary glycoproteins through recognition of terminal sialic acids, we wanted to determine whether S. pneumoniae also binds to salivary proteins through possibly the same mechanism. We found that only a capsule-free mutant of S. pneumoniae TIGR4 binds to salivary proteins, most prominently to mucin MUC7, but that this binding was not mediated through PsrP or recognition of sialic acid. We also found, however, that PsrP is involved in agglutination of human red blood cells (RBCs). After removal of PsrP, an additional previously masked lectin-like adhesin activity mediating agglutination of sialidase-treated RBCs becomes revealed. Using a custom-spotted glycoprotein and neoglycoprotein dot blot array, we identify candidate glycan motifs recognized by PsrP and by the putative S. pneumoniae adhesin that could perhaps be responsible for pneumococcal binding to salivary MUC7 and glycoproteins on RBCs. PMID:26172471

Passive Immunization with Milk Produced from an Immunized Cow Prevents Oral Recolonization by Streptococcus mutans

PubMed Central

Shimazaki, Yoshihiro; Mitoma, Morihide; Oho, Takahiko; Nakano, Yoshio; Yamashita, Yoshihisa; Okano, Kaoru; Nakano, Yutaka; Fukuyama, Masataka; Fujihara, Noboru; Nada, Youichi; Koga, Toshihiko

2001-01-01

Cell surface protein antigen (PAc) and water-insoluble glucan-synthesizing enzyme (GTF-I) produced by cariogenic Streptococcus mutans are two major factors implicated in the colonization of the human oral cavity by this bacterium. We examined the effect of bovine milk, produced after immunization with a fusion protein of functional domains of these proteins, on the recolonization of S. mutans. To prepare immune milk, a pregnant Holstein cow was immunized with the fusion protein PAcA-GB, a fusion of the saliva-binding alanine-rich region (PAcA) of PAc and the glucan-binding (GB) domain of GTF-I. After eight adult subjects received cetylpyridinium chloride (CPC) treatment, one subgroup (n = 4) rinsed their mouths with immune milk and a control group (n = 4) rinsed with nonimmune milk. S. mutans levels in saliva and dental plaque decreased after CPC treatment in both groups. Mouth rinsing with immune milk significantly inhibited recolonization of S. mutans in saliva and plaque. On the other hand, the numbers of S. mutans cells in saliva and plaque in the control group increased immediately after the CPC treatment and surpassed the baseline level 42 and 28 days, respectively, after the CPC treatment. The ratios of S. mutans to total streptococci in saliva and plaque in the group that received immune milk were lower than those in the control group. These results suggest that milk produced from immunized cow may be useful for controlling S. mutans in the human oral cavity. PMID:11687453

Prevalence of dental erosion and association with lifestyle factors in Swedish 20-year olds.

PubMed

Isaksson, Helén; Birkhed, Dowen; Wendt, Lill-Kari; Alm, Anita; Nilsson, Mats; Koch, Göran

2014-08-01

To investigate the prevalence, distribution and severity of dental erosion and its association with lifestyle, oral and general health in young adults. Four hundred and ninety-four individuals, 20-years of age, participated. Dental erosion in molars and maxillary incisors was evaluated. Caries, plaque and gingivitis were registered. Saliva samples were taken and the subjects were interviewed about behavioural and dietary habits and oral and general health. Body mass index (BMI) was calculated. The individuals were sub-divided into two groups according to the presence and absence of dental erosion: within the group with erosion was a sub-group of individuals with extensive erosion. Of the individuals 25% had no erosion, 75% had erosion and 18% had extensive erosion. Erosion was found in molars in 74% of the individuals and on buccal and palatal surfaces in maxillary incisors in 4% and 7%, respectively. Cupping was seen in 65% of individuals and severe erosion in molars in 1.6%. Compared to subjects with no erosion, those with extensive erosion had a higher consumption of soft drinks (p = 0.05), caries prevalence (p < 0.01), prevalence of mutans Streptococci (p < 0.01) and BMI (p < 0.05). Furthermore, subjects with erosion had higher caries prevalence (p < 0.01) and BMI (p < 0.01) than those with no erosion. Swedish young adults have a high prevalence of dental erosion, but the level of severe erosion is low. The study disclosed a relationship between dental erosion and behavioural factors, oral health and BMI.

Levofloxacin versus azithromycin on the oropharyngeal carriage and selection of antibacterial- resistant streptococci in the microflora of healthy adults.

PubMed

Nord, Carl Erik; Peterson, Janet; Ambruzs, Mary; Fisher, Alan C

2009-06-01

To determine the proportion of subjects with oropharyngeal streptococci resistant to either levofloxacin or azithromycin prior to and during antibacterial exposure, and to follow temporal changes in the proportion of resistant and susceptible isolates through 6 weeks post-exposure. This randomized, open-label, single-center study is registered with ClinicalTrials.gov (identifier: NCT00821782). A total of 143 healthy volunteers (levofloxacin, n = 71; azithromycin, n = 72) without antibacterial exposure in the previous 90 days received either levofloxacin 750 mg once daily for 5 days or azithromycin 500 mg once daily on day 1 and 250 mg once daily on days 2 through 5. Oropharyngeal cultures were obtained pre-exposure, at day 5, and at 2, 4, and 6 weeks post-dosing. Bacterial strains were identified and the minimum inhibitory concentrations for levofloxacin and azithromycin were determined. At study entry 117 streptococci were isolated from 72 subjects randomized to azithromycin and 53 (45.3%) were azithromycin-resistant. None of the 121 streptococci isolated from 71 subjects randomized to.levofloxacin were colonized by a levofloxacin-resistant microorganism prior to dosing. At the end of dosing, the number of subjects with resistant streptococci (S. mitis, S. salivarius, S. sanguis, or alpha streptococcus species [spp.]) increased in azithromycin-exposed subjects and resistant isolates remained through 6 weeks post-dosing. In contrast, a small number of levofloxacin-resistant streptococci were observed at the end of dosing but decreased by week 2 post-dosing and continued to decrease through the 6-week evaluation period (p < 0.001 azithromycin vs. levofloxacin for S. mitis, S. salivarius, S. sanguis and alpha streptococcus spp. at week 6). Limitations of this study included the fact that, since previous antibiotic use was self-reported, genetic typing was not done. The results of this study may not be completely generalizable, because subjects in this study received study drug under directly-observed conditions, thus ensuring compliance. Both antibacterial agents were well tolerated. Levofloxacin 750 mg administered for 5 days was associated with less microbial resistance than that observed with azithromycin in healthy subjects.

Early Childhood Caries

PubMed Central

Kawashita, Yumiko; Kitamura, Masayasu; Saito, Toshiyuki

2011-01-01

Dental caries is one of the most common childhood diseases, and people continue to be susceptible to it throughout their lives. Although dental caries can be arrested and potentially even reversed in its early stages, it is often not self-limiting and progresses without proper care until the tooth is destroyed. Early childhood caries (ECC) is often complicated by inappropriate feeding practices and heavy infection with mutans streptococci. Such children should be targeted with a professional preventive program that includes oral hygiene instructions for mothers or caregivers, along with fluoride and diet counseling. However, these strategies alone are not sufficient to prevent dental caries in high-risk children; prevention of ECC also requires addressing the socioeconomic factors that face many families in which ECC is endemic. The aim of this paper is to systematically review information about ECC and to describe why many children are suffering from dental caries. PMID:22007218

The microbiota of acute apical abscesses.

PubMed

Siqueira, J F; Rôças, I N

2009-01-01

As the breadth of bacterial diversity in the oral cavity has been deciphered by molecular studies, several newly identified species/phylotypes have emerged as potential pathogens. We hypothesized that many of these species/phylotypes could also be involved with the etiology of endodontic abscesses. Abscess aspirates from 42 persons were analyzed for the presence of 81 species/phylotypes by means of a reverse-capture checkerboard hybridization assay. Associations between the most frequently detected taxa were calculated. The most prevalent taxa were Fusobacterium nucleatum, Parvimonas micra, and Porphyromonas endodontalis. Other frequently found taxa included Olsenella uli, streptococci, Eikenella corrodens, some as-yet-uncultivated phylotypes (Bacteroidetes clone X083 and Synergistes clone BA121), and newly named species (Prevotella baroniae and Dialister invisus). Several positive bacterial associations were disclosed. Findings not only strengthen the association of many cultivable species with abscesses, but also include some newly named species and uncultivated phylotypes in the set of candidate pathogens associated with this disease.

Natural antigenic differences in the functionally equivalent extracellular DNABII proteins of bacterial biofilms provide a means for targeted biofilm therapeutics.

PubMed

Rocco, C J; Davey, M E; Bakaletz, L O; Goodman, S D

2017-04-01

Bacteria that persist in the oral cavity exist within complex biofilm communities. A hallmark of biofilms is the presence of an extracellular polymeric substance (EPS), which consists of polysaccharides, extracellular DNA (eDNA), and proteins, including the DNABII family of proteins. The removal of DNABII proteins from a biofilm results in the loss of structural integrity of the eDNA and the collapse of the biofilm structure. We examined the role of DNABII proteins in the biofilm structure of the periodontal pathogen Porphyromonas gingivalis and the oral commensal Streptococcus gordonii. Co-aggregation with oral streptococci is thought to facilitate the establishment of P. gingivalis within the biofilm community. We demonstrate that DNABII proteins are present in the EPS of both S. gordonii and P. gingivalis biofilms, and that these biofilms can be disrupted through the addition of antisera derived against their respective DNABII proteins. We provide evidence that both eDNA and DNABII proteins are limiting in S. gordonii but not in P. gingivalis biofilms. In addition, these proteins are capable of complementing one another functionally. We also found that whereas antisera derived against most DNABII proteins are capable of binding a wide variety of DNABII proteins, the P. gingivalis DNABII proteins are antigenically distinct. The presence of DNABII proteins in the EPS of these biofilms and the antigenic uniqueness of the P. gingivalis proteins provide an opportunity to develop therapies that are targeted to remove P. gingivalis and biofilms that contain P. gingivalis from the oral cavity. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Etiology of Cellulitis and Clinical Prediction of Streptococcal Disease: A Prospective Study

PubMed Central

Bruun, Trond; Oppegaard, Oddvar; Kittang, Bård R.; Mylvaganam, Haima; Langeland, Nina; Skrede, Steinar

2016-01-01

Background. The importance of bacteria other than group A streptococci (GAS) in different clinical presentations of cellulitis is unclear, commonly leading to treatment with broad-spectrum antibiotics. The aim of this study was to describe the etiological and clinical spectrum of cellulitis and identify clinical features predicting streptococcal etiology. Methods. We prospectively enrolled 216 patients hospitalized with cellulitis. Clinical details were registered. Bacterial culture was performed from blood, cutaneous or subcutaneous tissue, and/or swabs from skin lesions. Paired serum samples were analyzed for anti-streptolysin O and anti-deoxyribonuclease B antibodies. Results. Serology or blood or tissue culture confirmed β-hemolytic streptococcal (BHS) etiology in 72% (146 of 203) of cases. An additional 13% (27 of 203) of cases had probable BHS infection, indicated by penicillin response or BHS cultured from skin swabs. β-hemolytic streptococcal etiology was predominant in all clinical subgroups, including patients without sharply demarcated erythema. β-hemolytic group C or G streptococci (GCS/GGS) were more commonly isolated than GAS (36 vs 22 cases). This predominance was found in the lower extremity infections. Group C or G streptococci in swabs were associated with seropositivity just as often as GAS. Staphylococcus aureus was cultured from swabs as a single pathogen in 24 cases, 14 (64%) of which had confirmed BHS etiology. Individual BHS-associated clinical characteristics increased the likelihood of confirmed BHS disease only slightly; positive likelihood ratios did not exceed 2.1. Conclusions. β-hemolytic streptococci were the dominating cause of cellulitis in all clinical subgroups and among cases with S aureus in cutaneous swabs. Group C or G streptococci were more frequently detected than GAS. No single clinical feature substantially increased the probability of confirmed BHS etiology. PMID:26734653

Growth of Carnobacterium spp. from permafrost under low pressure, temperature, and anoxic atmosphere has implications for Earth microbes on Mars.

PubMed

Nicholson, Wayne L; Krivushin, Kirill; Gilichinsky, David; Schuerger, Andrew C

2013-01-08

The ability of terrestrial microorganisms to grow in the near-surface environment of Mars is of importance to the search for life and protection of that planet from forward contamination by human and robotic exploration. Because most water on present-day Mars is frozen in the regolith, permafrosts are considered to be terrestrial analogs of the martian subsurface environment. Six bacterial isolates were obtained from a permafrost borehole in northeastern Siberia capable of growth under conditions of low temperature (0 °C), low pressure (7 mbar), and a CO(2)-enriched anoxic atmosphere. By 16S ribosomal DNA analysis, all six permafrost isolates were identified as species of the genus Carnobacterium, most closely related to C. inhibens (five isolates) and C. viridans (one isolate). Quantitative growth assays demonstrated that the six permafrost isolates, as well as nine type species of Carnobacterium (C. alterfunditum, C. divergens, C. funditum, C. gallinarum, C. inhibens, C. maltaromaticum, C. mobile, C. pleistocenium, and C. viridans) were all capable of growth under cold, low-pressure, anoxic conditions, thus extending the low-pressure extreme at which life can function.

Growth of Carnobacterium spp. from permafrost under low pressure, temperature, and anoxic atmosphere has implications for Earth microbes on Mars

PubMed Central

Nicholson, Wayne L.; Krivushin, Kirill; Gilichinsky, David; Schuerger, Andrew C.

2013-01-01

The ability of terrestrial microorganisms to grow in the near-surface environment of Mars is of importance to the search for life and protection of that planet from forward contamination by human and robotic exploration. Because most water on present-day Mars is frozen in the regolith, permafrosts are considered to be terrestrial analogs of the martian subsurface environment. Six bacterial isolates were obtained from a permafrost borehole in northeastern Siberia capable of growth under conditions of low temperature (0 °C), low pressure (7 mbar), and a CO2-enriched anoxic atmosphere. By 16S ribosomal DNA analysis, all six permafrost isolates were identified as species of the genus Carnobacterium, most closely related to C. inhibens (five isolates) and C. viridans (one isolate). Quantitative growth assays demonstrated that the six permafrost isolates, as well as nine type species of Carnobacterium (C. alterfunditum, C. divergens, C. funditum, C. gallinarum, C. inhibens, C. maltaromaticum, C. mobile, C. pleistocenium, and C. viridans) were all capable of growth under cold, low-pressure, anoxic conditions, thus extending the low-pressure extreme at which life can function. PMID:23267097

STREPTOCOCCI OCCURRING IN SOUR MILK

PubMed Central

Jones, F. S.

1921-01-01

A well defined group of rod-like and coccoid organisms arranged in pairs and chains has been encountered in sour milk. The group comprises at least three species; the largest number ferment dextrose, lactose, maltose, mannitol, and salicin, and fail to ferment saccharose, raffinose, and inulin. A smaller number ferment saccharose in addition to dextrose, lactose, maltose, mannitol, and salicin. A few fail to attack mannitol. All three types grow luxuriantly at room temperature, coagulate milk, reduce litmus, and produce large amounts of acid in fermented bouillon containing dextrose. Specific morphological and cultural differences exist between the lactic acid streptococci and those associated with mastitis and those occurring in the udder. The lactic acid organisms outgrow the udder streptococci in the milk-souring process. When both types are implanted in sterile milk the udder type soon disappears. PMID:19868477

Caries prevention during pregnancy: results of a 30-month study.

PubMed

Brambilla, E; Felloni, A; Gagliani, M; Malerba, A; García-Godoy, F; Strohmenger, L

1998-07-01

The purpose of this 30-month study was to explore the effectiveness of a caries-preventive regimen in lowering the salivary mutans streptococci level in pregnant women and, subsequently, in inhibiting the growth of these bacteria in their young children. Beginning at the end of the sixth month of pregnancy and continuing until delivery, subjects rinsed daily with 0.05 percent sodium fluoride and 0.12 percent chlorhexidine. The authors monitored the salivary mutans streptococci levels during the last six months of pregnancy and every six months thereafter for 24 months. They also measured bacterial levels in the children every six months until they reached age 24 months. The results show that treatment significantly reduced salivary mutans streptococci levels in mothers and delayed the colonization of bacteria in their children for about four months.

[Five days ceftibuten versus 10 days penicillin in the treatment of 2099 patients with A-streptococcal tonsillopharyngitis].

PubMed

Adam, D; Scholz, H; Helmerking, M

2001-07-19

Group A Streptococci have remained sensitive to penicillins and other betalactam antibiotics, e. g. cephalosporins. Since the beginning of the 1950s oral penicillin V given three times daily in a dose of 50,000 IU daily has been the drug of choice against Group A streptococcal infection. The German Society for Pediatric Infectious Diseases (DGPI) undertook a large scale multicenter randomized study of culture-proven A-streptococcal tonsillopharyngitis to compare the efficacy and safety of a five day regimen of ceftibuten (9 mg/kg KG, once daily) with 10 days of penicillin V (50,000 I.E./kg KG, divided in three doses), testing for equivalence of clinical and bacteriological efficacy. A one year follow-up served to assess poststreptococcal sequelae like rheumatic fever or glomerulonephritis. The clinical efficacy at the clinical end-point 7-9 days after end of treatment was 86.9% (419/482) for ceftibuten and 88.6% (1,198/1,352) for penicillin V. This result is statistically equivalent (P = 0.0152). Resolution of clinical symptoms was significantly faster in the ceftibuten group (P = 0.043/Fisher-Test) and compliance was significantly superior as well (P (0.001). Eradication of group A streptococci at an early control 2-4 days after end of treatment was not equivalent, 78.49% for ceftibuten and 84.42% for penicillin V (P = 0.5713). Both eradication rates were comparable 7-8 weeks after end of treatment (84.65%, 375/443 ceftibuten vs. 86.82%, 1,067/1,229 penicillin V), the difference not being significant. No cases of poststreptococcal sequelae, e.g. rheumatic fever or glomerulonephritis, attributable to either ceftibuten or penicillin were observed in the course of the study.

Effect of Psidium cattleianum leaf extract on enamel demineralisation and dental biofilm composition in situ.

PubMed

Brighenti, Fernanda Lourenção; Gaetti-Jardim, Elerson; Danelon, Marcelle; Evangelista, Gustavo Vaz; Delbem, Alberto Carlos Botazzo

2012-08-01

Previous evaluations of Psidium cattleianum leaf extract were not done in conditions similar to the oral environment. The aim of this study was to evaluate the effect of P. cattleianum leaf extract on enamel demineralisation, extracellular polysaccharide formation, and the microbial composition of dental biofilms formed in situ. Ten volunteers took part in this crossover study. They wore palatal appliances containing 4 enamel blocks for 14 days. Each volunteer dripped 20% sucrose 8 times per day on the enamel blocks. Twice a day, deionised water (negative control), extract, or a commercial mouthwash (active control) was dripped after sucrose application. On the 12th and 13th days of the experiment, plaque acidogenicity was measured with a microelectrode, and the pH drop was calculated. On the 14th day, biofilms were harvested and total anaerobic microorganisms (TM), total streptococci (TS), mutans streptococci (MS), and extracellular polysaccharides (EPS) were evaluated. Enamel demineralisation was evaluated by the percentage change of surface microhardness (%ΔSMH) and integrated loss of subsurface hardness (ΔKHN). The researcher was blinded to the treatments during data collection. The extract group showed lower TM, TS, MS, EPS, %ΔSMH, and ΔKHN values than the negative control group. There were no differences between the active and negative control groups regarding MS and EPS levels. There were no differences in pH drop between the extract and active control groups, although they were significantly different from the negative control group. For all other parameters, the extract differed from the active control group. Psidium cattleianum leaf extract exhibits a potential anticariogenic effect. Copyright © 2012 Elsevier Ltd. All rights reserved.

Body weight maintenance and levels of mutans streptococci and lactobacilli in a group of Swedish women seven years after completion of a Weight Watchers' diet.

PubMed

Köhler, Birgitta; Andreén, Ingrid

2011-01-01

The long-term effect of the WW programme on weight and oral cariogenic bacteria was evaluated after 7 yr. All WW who completed the 8-wk dietary regimen in an earlier study (n=33) and the persons in the reference group (REF) (n=27) were invited to participate. The salivary secretion rate, numbers of mutans streptococci (MS) and lactobacilli (lbc) were determined. The WW were weighed. Sustaining a 5% weight loss from the initial weight was regarded as successful weight maintenance. An interview according to a standardised questionnaire was conducted on medication,the intake of antimicrobial agents, dietary changes and experience of dental caries during the last 7 yr. 25 WW and 21 REF qualified to participate. On a group basis, weight, salivary MS and lbc displayed pre-diet levels after 7yr. 15 of the WW (60%) were below their initial weight. Successful weight maintenance was achieved by 32%. Reported changes in the intake of fat-rich products differed significantly between the WW and the REF. Nine WW reported fewer carious lesions after joining the WW. Ninety per cent of REF did not regard caries as a problem. Comparisons of pre- and post-diet data and 7 yr data indicated short-term compliance and varying outcome in terms of long-term compliance. No association was found between salivary levels of bacteria and long-term weight maintenance on a group basis. However,further well-designed longitudinal studies are required to confirm whether salivary MS could be used on an individual basis to validate reported sucrose intake in a dietary regimen.

Dental caries increments and related factors in children with type 1 diabetes mellitus.

PubMed

Siudikiene, J; Machiulskiene, V; Nyvad, B; Tenovuo, J; Nedzelskiene, I

2008-01-01

The aim of this study was to analyse possible associations between caries increments and selected caries determinants in children with type 1 diabetes mellitus and their age- and sex-matched non-diabetic controls, over 2 years. A total of 63 (10-15 years old) diabetic and non-diabetic pairs were examined for dental caries, oral hygiene and salivary factors. Salivary flow rates, buffer effect, concentrations of mutans streptococci, lactobacilli, yeasts, total IgA and IgG, protein, albumin, amylase and glucose were analysed. Means of 2-year decayed/missing/filled surface (DMFS) increments were similar in diabetics and their controls. Over the study period, both unstimulated and stimulated salivary flow rates remained significantly lower in diabetic children compared to controls. No differences were observed in the counts of lactobacilli, mutans streptococci or yeast growth during follow-up, whereas salivary IgA, protein and glucose concentrations were higher in diabetics than in controls throughout the 2-year period. Multivariable linear regression analysis showed that children with higher 2-year DMFS increments were older at baseline and had higher salivary glucose concentrations than children with lower 2-year DMFS increments. Likewise, higher 2-year DMFS increments in diabetics versus controls were associated with greater increments in salivary glucose concentrations in diabetics. Higher increments in active caries lesions in diabetics versus controls were associated with greater increments of dental plaque and greater increments of salivary albumin. Our results suggest that, in addition to dental plaque as a common caries risk factor, diabetes-induced changes in salivary glucose and albumin concentrations are indicative of caries development among diabetics. Copyright 2008 S. Karger AG, Basel.

Advanced Caries Microbiota in Teeth with Irreversible Pulpitis.

PubMed

Rôças, Isabela N; Lima, Kenio C; Assunção, Isauremi V; Gomes, Patrícia N; Bracks, Igor V; Siqueira, José F

2015-09-01

Bacterial taxa in the forefront of caries biofilms are candidate pathogens for irreversible pulpitis and are possibly the first ones to invade the pulp and initiate endodontic infection. This study examined the microbiota of the most advanced layers of dentinal caries in teeth with irreversible pulpitis. DNA extracted from samples taken from deep dentinal caries associated with pulp exposures was analyzed for the presence and relative levels of 33 oral bacterial taxa by using reverse-capture checkerboard hybridization assay. Quantification of total bacteria, streptococci, and lactobacilli was also performed by using real-time quantitative polymerase chain reaction. Associations between the target bacterial taxa and clinical signs/symptoms were also evaluated. The most frequently detected taxa in the checkerboard assay were Atopobium genomospecies C1 (53%), Pseudoramibacter alactolyticus (37%), Streptococcus species (33%), Streptococcus mutans (33%), Parvimonas micra (13%), Fusobacterium nucleatum (13%), and Veillonella species (13%). Streptococcus species, Dialister invisus, and P. micra were significantly associated with throbbing pain, S. mutans with pain to percussion, and Lactobacillus with continuous pain (P < .05). Quantitative polymerase chain reaction revealed a mean total bacterial load of 1 × 10(8) (range, 2.05 × 10(5) to 4.5 × 10(8)) cell equivalents per milligram (wet weight) of dentin. Streptococci and lactobacilli were very prevalent but comprised only 0.09% and 2% of the whole bacterial population, respectively. Several bacterial taxa were found in advanced caries lesions in teeth with exposed pulps, and some of them were significantly associated with symptoms. A role for these taxa in the etiology of irreversible pulpitis is suspected. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Myosin: A Link between Streptococci and Heart

NASA Astrophysics Data System (ADS)

Krisher, Karen; Cunningham, Madeleine W.

1985-01-01

Murine monoclonal antibodies to Streptococcus pyogenes reacted with skeletal muscle myosin. High molecular weight proteins in extracts of human heart tissue that reacted with an antibody to S. pyogenes also reacted with a monoclonal antibody to ventricular myosin. Adsorption of the antibody to streptococci with S. pyogenes simultaneously removed reactivity of the antibody for either S. pyogenes or myosin. These results indicate that myosin shares immunodeterminants with a component of S. pyogenes.

rpoB Gene Sequence-Based Identification of Aerobic Gram-Positive Cocci of the Genera Streptococcus, Enterococcus, Gemella, Abiotrophia, and Granulicatella

PubMed Central

Drancourt, Michel; Roux, Véronique; Fournier, Pierre-Edouard; Raoult, Didier

2004-01-01

We developed a new molecular tool based on rpoB gene (encoding the beta subunit of RNA polymerase) sequencing to identify streptococci. We first sequenced the complete rpoB gene for Streptococcus anginosus, S. equinus, and Abiotrophia defectiva. Sequences were aligned with these of S. pyogenes, S. agalactiae, and S. pneumoniae available in GenBank. Using an in-house analysis program (SVARAP), we identified a 740-bp variable region surrounded by conserved, 20-bp zones and, by using these conserved zones as PCR primer targets, we amplified and sequenced this variable region in an additional 30 Streptococcus, Enterococcus, Gemella, Granulicatella, and Abiotrophia species. This region exhibited 71.2 to 99.3% interspecies homology. We therefore applied our identification system by PCR amplification and sequencing to a collection of 102 streptococci and 60 bacterial isolates belonging to other genera. Amplicons were obtained in streptococci and Bacillus cereus, and sequencing allowed us to make a correct identification of streptococci. Molecular signatures were determined for the discrimination of closely related species within the S. pneumoniae-S. oralis-S. mitis group and the S. agalactiae-S. difficile group. These signatures allowed us to design a S. pneumoniae-specific PCR and sequencing primer pair. PMID:14766807

Semi-Quantitative Method for Streptococci Magnetic Detection in Raw Milk.

PubMed

Duarte, Carla; Costa, Tiago; Carneiro, Carla; Soares, Rita; Jitariu, Andrei; Cardoso, Susana; Piedade, Moisés; Bexiga, Ricardo; Freitas, Paulo

2016-04-27

Bovine mastitis is the most costly disease for dairy farmers and the most frequent reason for the use of antibiotics in dairy cattle; thus, control measures to detect and prevent mastitis are crucial for dairy farm sustainability. The aim of this study was to develop and validate a sensitive method to magnetically detect Streptococcus agalactiae (a Group B streptococci) and Streptococcus uberis in raw milk samples. Mastitic milk samples were collected aseptically from 44 cows with subclinical mastitis, from 11 Portuguese dairy farms. Forty-six quarter milk samples were selected based on bacterial identification by conventional microbiology. All samples were submitted to PCR analysis. In parallel, these milk samples were mixed with a solution combining specific antibodies and magnetic nanoparticles, to be analyzed using a lab-on-a-chip magnetoresistive cytometer, with microfluidic sample handling. This paper describes a point of care methodology used for detection of bacteria, including analysis of false positive/negative results. This immunological recognition was able to detect bacterial presence in samples spiked above 100 cfu/mL, independently of antibody and targeted bacteria used in this work. Using PCR as a reference, this method correctly identified 73% of positive samples for streptococci species with an anti-S. agalactiae antibody, and 41% of positive samples for an anti-GB streptococci antibody.

Semi-Quantitative Method for Streptococci Magnetic Detection in Raw Milk

PubMed Central

Duarte, Carla; Costa, Tiago; Carneiro, Carla; Soares, Rita; Jitariu, Andrei; Cardoso, Susana; Piedade, Moisés; Bexiga, Ricardo; Freitas, Paulo

2016-01-01

Bovine mastitis is the most costly disease for dairy farmers and the most frequent reason for the use of antibiotics in dairy cattle; thus, control measures to detect and prevent mastitis are crucial for dairy farm sustainability. The aim of this study was to develop and validate a sensitive method to magnetically detect Streptococcus agalactiae (a Group B streptococci) and Streptococcus uberis in raw milk samples. Mastitic milk samples were collected aseptically from 44 cows with subclinical mastitis, from 11 Portuguese dairy farms. Forty-six quarter milk samples were selected based on bacterial identification by conventional microbiology. All samples were submitted to PCR analysis. In parallel, these milk samples were mixed with a solution combining specific antibodies and magnetic nanoparticles, to be analyzed using a lab-on-a-chip magnetoresistive cytometer, with microfluidic sample handling. This paper describes a point of care methodology used for detection of bacteria, including analysis of false positive/negative results. This immunological recognition was able to detect bacterial presence in samples spiked above 100 cfu/mL, independently of antibody and targeted bacteria used in this work. Using PCR as a reference, this method correctly identified 73% of positive samples for streptococci species with an anti-S. agalactiae antibody, and 41% of positive samples for an anti-GB streptococci antibody. PMID:27128950

Phylogenetic group- and species-specific oligonucleotide probes for single-cell detection of lactic acid bacteria in oral biofilms

PubMed Central

2011-01-01

Background The purpose of this study was to design and evaluate fluorescent in situ hybridization (FISH) probes for the single-cell detection and enumeration of lactic acid bacteria, in particular organisms belonging to the major phylogenetic groups and species of oral lactobacilli and to Abiotrophia/Granulicatella. Results As lactobacilli are known for notorious resistance to probe penetration, probe-specific assay protocols were experimentally developed to provide maximum cell wall permeability, probe accessibility, hybridization stringency, and fluorescence intensity. The new assays were then applied in a pilot study to three biofilm samples harvested from variably demineralized bovine enamel discs that had been carried in situ for 10 days by different volunteers. Best probe penetration and fluorescent labeling of reference strains were obtained after combined lysozyme and achromopeptidase treatment followed by exposure to lipase. Hybridization stringency had to be established strictly for each probe. Thereafter all probes showed the expected specificity with reference strains and labeled the anticipated morphotypes in dental plaques. Applied to in situ grown biofilms the set of probes detected only Lactobacillus fermentum and bacteria of the Lactobacillus casei group. The most cariogenic biofilm contained two orders of magnitude higher L. fermentum cell numbers than the other biofilms. Abiotrophia/Granulicatella and streptococci from the mitis group were found in all samples at high levels, whereas Streptococcus mutans was detected in only one sample in very low numbers. Conclusions Application of these new group- and species-specific FISH probes to oral biofilm-forming lactic acid bacteria will allow a clearer understanding of the supragingival biome, its spatial architecture and of structure-function relationships implicated during plaque homeostasis and caries development. The probes should prove of value far beyond the field of oral microbiology, as many of them detect non-oral species and phylogenetic groups of importance in a variety of medical conditions and the food industry. PMID:21247450

Effects of short-term xylitol gum chewing on the oral microbiome.

PubMed

Söderling, Eva; ElSalhy, Mohamed; Honkala, Eino; Fontana, Margherita; Flannagan, Susan; Eckert, George; Kokaras, Alexis; Paster, Bruce; Tolvanen, Mimmi; Honkala, Sisko

2015-03-01

The aim of this study was to determine the effects of short-term xylitol gum chewing on the salivary microbiota of children. The study was a randomised, controlled, double-blind trial. Healthy children used xylitol chewing gum (xylitol group, n = 35) or sorbitol chewing gum (control group, n = 38) for 5 weeks. The daily dose of xylitol/sorbitol was approximately 6 g/day. At baseline and at the end of the test period, unstimulated and paraffin-stimulated saliva were collected. The microbial composition of the saliva was assessed using human oral microbe identification microarray (HOMIM). Mutans streptococci (MS) were plate cultured. As judged by HOMIM results, no xylitol-induced changes in the salivary microbiota took place in the xylitol group. In the control group, Veillonella atypica showed a significant decrease (p = 0.0001). The xylitol gum chewing decreased viable counts of MS in both stimulated (p = 0.006) and unstimulated (p = 0.002) saliva, but similar effects were also seen in the control group. The use of xylitol gum decreased MS, in general, but did not change the salivary microbial composition. Short-term consumption of xylitol had no impact on the composition of the salivary microbiota, but resulted in a decrease in the levels of MS.

Relationship between Cariogenic Bacteria and pH of Dental Plaque at Margin of Fixed Prostheses

PubMed Central

Tanaka, Junko; Mukai, Norio; Tanaka, Muto; Tanaka, Masahiro

2012-01-01

Objective. The purpose of this study was to investigate whether teeth that have undergone prosthetic restoration are under conditions that promote caries recurrence. Methods. The subjects were 20 dentate adults with both a healthy tooth and an affected tooth entirely covered with a complete cast crown in the molar regions of the same arch. The pH was measured in plaque adhering to the margin of the tooth covered with a complete cast crown and adhering to the cervicobuccal area of the natural tooth. In addition, the numbers of cariogenic bacteria (mutans streptococci and lactobacilli) were measured employing the saliva test. The relationships between the number of cariogenic bacteria and plaque pH of the natural tooth and between the number of cariogenic bacteria and plaque pH of the tooth covered with a complete cast crown were investigated. Results. The plaque pH of the tooth covered with a complete cast crown decreased as the numbers of SM and LB increased. The natural tooth were also influenced by the number of SM. Conclusion. Secondary caries are likely to develop from the marginal region of the crown in the oral cavity with a high caries risk unless a preventive program is prepared and the oral environment is improved following the program. PMID:22287964

Numbers of fecal streptococci and Escherichia coli in fresh and dry cattle, horse, and sheep manure.

PubMed

Weaver, R W; Entry, J A; Graves, Alexandria

2005-10-01

Livestock are known contributors to stream pollution. Numbers of fecal streptococci and Escherichia coli in manure naturally deposited by livestock in the field are needed for activities related to bacterial source tracking and determining maximum daily bacterial loading of streams. We measured populations of fecal streptococci and E. coli in fresh and dry manure from cattle (Bos taurus L.), horses (Equus caballus L.), and sheep (Ovis aires L.) on farms in southern Idaho. Populations of indicator bacteria in dry manure were often as high as that in fresh manure from horse and sheep. There was a 2 log10 drop in the population of fecal coliform numbers in dry cattle manure from cattle in pastures but not from cattle in pens. Bacterial isolates used in source tracking should include isolates from both fresh and dry manure to better represent the bacterial source loading of streams.

Pyogenic liver abscess presenting after malignant polypectomy.

PubMed

Harnik, Ian G

2007-12-01

Streptococcus bovis bacteremia has been linked to the presence of occult colon cancer since 1977. We present a case of pyogenic liver abscess and bacteremia with a different Streptococcus viridans 1 week after colonic adenocarcinoma was removed via polypectomy, discuss the likely etiology and review whether there is evidence to support looking for colon cancer in patients who present similarly but have not already undergone screening.

Rapid identification of enterococci.

PubMed Central

Brown, L H; Peterson, E M; de la Maza, L M

1983-01-01

Enterococci were identified in 4 h with bile esculin agar and the Autobac system (General Diagnostics, Warner-Lambert Co., Morris Plains, N.J.), which was used to incubate and monitor salt broth for growth. Of 86 group D streptococci tested, 41 enterococci grew in salt broth and were bile esculin positive within 4 h; none of 45 group D nonenterococcal streptococci exhibited growth in the salt broth, and only 38 of them were bile esculin positive within 4 h. PMID:6403579

Comparative Genomics Analysis of Streptococcus Isolates from the Human Small Intestine Reveals their Adaptation to a Highly Dynamic Ecosystem

PubMed Central

Van den Bogert, Bartholomeus; Boekhorst, Jos; Herrmann, Ruth; Smid, Eddy J.; Zoetendal, Erwin G.; Kleerebezem, Michiel

2013-01-01

The human small-intestinal microbiota is characterised by relatively large and dynamic Streptococcus populations. In this study, genome sequences of small-intestinal streptococci from S. mitis, S. bovis, and S. salivarius species-groups were determined and compared with those from 58 Streptococcus strains in public databases. The Streptococcus pangenome consists of 12,403 orthologous groups of which 574 are shared among all sequenced streptococci and are defined as the Streptococcus core genome. Genome mining of the small-intestinal streptococci focused on functions playing an important role in the interaction of these streptococci in the small-intestinal ecosystem, including natural competence and nutrient-transport and metabolism. Analysis of the small-intestinal Streptococcus genomes predicts a high capacity to synthesize amino acids and various vitamins as well as substantial divergence in their carbohydrate transport and metabolic capacities, which is in agreement with observed physiological differences between these Streptococcus strains. Gene-specific PCR-strategies enabled evaluation of conservation of Streptococcus populations in intestinal samples from different human individuals, revealing that the S. salivarius strains were frequently detected in the small-intestine microbiota, supporting the representative value of the genomes provided in this study. Finally, the Streptococcus genomes allow prediction of the effect of dietary substances on Streptococcus population dynamics in the human small-intestine. PMID:24386196

Group A streptococcal infections of the pharynx in a rural population in south India.

PubMed

Menon, Thangam; Shanmugasundaram, S; Kumar, M Palani; Kumar, C P Girish

2004-05-01

There has been a resurgence in the incidence of rheumatic heart disease all over the world and hence surveillance and strain characterization are important. The aim of this study was to screen children in a rural community in south India for throat carriage of group A streptococci and to clinically assess them for signs of rheumatic heart disease. Throat swabs were collected from children (5-14 yr) in the village of Orathur, Tamil Nadu and cultured on tryptose blood agar plates. Beta haemolytic streptococci were serogrouped using Streptex kit and biotyped based on their ability to ferment carbohydrates and production of beta-glucuronidase enzyme. Blood samples were also collected and antibodies to streptolysin O demonstrated by latex agglutination tests. All the children were examined by a paediatrician; ECG and echocardiography were performed to assess cardiac function. Eighty of the 310 children included in the study had symptoms of acute respiratory infections; 16 of them grew beta haemolytic streptococci of which 8 belonged to group A (10%). Biotype 4 was most common. Antistreptolysin O (ASO) test did not correlate with culture results. Two of 310 children had rheumatic heart disease but both were culture negative. Pharyngeal carriage of group A streptococci was common in this population. The prevalence of rheumatic heart disease was 0.6 per cent. The study emphasizes the need for active surveillance and characterization of GAS isolates.

Streptococcal toxic-shock syndrome due to Streptococcus dysgalactiae subspecies equisimilis in breast cancer-related lymphedema: a case report.

PubMed

Sumazaki, Makoto; Saito, Fumi; Ogata, Hideaki; Yoshida, Miho; Kubota, Yorichika; Magoshi, Syunsuke; Kaneko, Hironori

2017-07-14

Breast cancer-related lymphedema often causes cellulitis and is one of the most common complications after breast cancer surgery. Streptococci are the major pathogens underlying such cellulitis. Among the streptococci, the importance of the Lancefield groups C and G is underappreciated; most cases involve Streptococcus dysgalactiae subspecies equisimilis. Despite having a relatively weak toxicity compared with group A streptococci, Streptococcus dysgalactiae subspecies equisimilis is associated with a mortality rate that is as high as that of group A streptococci in cases of invasive infection because Streptococcus dysgalactiae subspecies equisimilis mainly affects elderly individuals who already have various comorbidities. An 83-year-old Japanese woman with breast cancer-related lymphedema in her left upper limb was referred to our hospital with high fever and acute pain with erythema in her left arm. She showed septic shock with disseminated intravascular coagulation. Blood culture showed positive results for Streptococcus dysgalactiae subspecies equisimilis, confirming a diagnosis of streptococcal toxic-shock syndrome. She survived after successful intensive care. To the best of our knowledge, this case represents the first report of Streptococcus dysgalactiae subspecies equisimilis-induced streptococcal toxic-shock syndrome in a patient with breast cancer-related lymphedema. Breast cancer-related lymphedema is a common problem, and we must pay attention to invasive streptococcal soft tissue infections, particularly in elderly patients with chronic disease.

Quantitative assessment of salivary oral bacteria according to the severity of dental caries in childhood.

PubMed

Colombo, Natália H; Kreling, Paula F; Ribas, Laís F F; Pereira, Jesse A; Kressirer, Christine A; Klein, Marlise I; Tanner, Anne C R; Duque, Cristiane

2017-11-01

This study aimed to assess differences in selected oral bacteria in children according to the severity of dental caries. One hundred and thirty-six children, 36-60 months old were divided into three groups according to caries status: caries-free (CF) (n=47), early childhood caries (ECC) (n=40) and severe-early childhood caries (S-ECC) (n=49). Saliva was collected for detection and quantification of selected oral streptococci, Actinomyces naeslundii, Lactobacillus spp., Bifidobacterium spp., and Scardovia wiggsiae by quantitative-polymerase chain reaction. The results showed that the detection and quantitative levels of S. mutans, S. sobrinus, Bifidobacterium spp. and S. wiggsiae were significantly higher in S-ECC children compared to CF and ECC children, while for S. salivarius were significantly higher in CF compared to ECC and S-ECC children. There was no statistical difference among the clinical groups for S. mitis, S. oralis, A. naeslundii and Lactobacillus spp. levels and detection. S-ECC children had a lower monthly family income, started tooth brushing later and were breastfeed for a longer duration compared to CF children. S. mutans levels were positively correlated with S. wiggsiae and Bifidobacterium spp. levels, lower mother's education and child bottle-feeding before sleeping and negatively correlated with S. salivarius. It was concluded that in addition to S. mutans, other bacterial species, including bifidobacteria, Scardovia wiggsiae and S. sobrinus, are associated with severity of early childhood caries, although their role in the progress of dental caries remains unclear. Copyright © 2017 Elsevier Ltd. All rights reserved.

Urease activity in dental plaque and saliva of children during a three-year study period and its relationship with other caries risk factors

PubMed Central

Morou-Bermudez, E; Elias-Boneta, A; Billings, RJ; Burne, RA; Garcia-Rivas, V; Brignoni-Nazario, V; Suarez-Perez, E

2011-01-01

Bacterial urease activity in dental plaque and in saliva generates ammonia, which can increase the plaque pH and can protect acid-sensitive oral bacteria. Recent cross-sectional studies suggest that reduced ability to generate ammonia from urea in dental plaque can be an important caries risk factor. In spite of this proposed important clinical role, there is currently no information available regarding important clinical aspects of oral ureolysis in children. OBJECTIVE The objective of this study was to evaluate the distribution and pattern of urease activity in the dental plaque and in the saliva of children during a three-year period, and to examine the relationship of urease with some important caries risk factors. METHODS A longitudinal study was conducted with repeated measures over a three-year period on a panel of 80 children, ages three to six years at recruitment. The dynamics of change in urease activity were described and associated with clinical, biological, and behavioral caries risk factors. RESULTS Urease activity in plaque showed a trend to remain stable during the study period and was negatively associated with sugar consumption (P<0.05). Urease activity in unstimulated saliva increased with age, and it was positively associated with the levels of mutans streptococci in saliva and with the educational level of the parents (P<0.05). CONCLUSIONS The results of this study reveal interesting and complex interactions between oral urease activity and some important caries risk factors. Urease activity in saliva could be an indicator of mutans infection in children. PMID:21616477

Salivary Actinomyces naeslundii genospecies 2 and Lactobacillus casei levels predict pregnancy outcomes.

PubMed

Dasanayake, Ananda P; Li, Yihong; Wiener, Howard; Ruby, John D; Lee, Men-Jean

2005-02-01

Gravida's poor periodontal health is emerging as a modifiable independent risk factor for preterm delivery and low birth weight. To test the hypothesis that oral bacteria other than periodontal pathogens are also associated with pregnancy outcomes, specific oral bacterial levels measured during pregnancy were evaluated in relation to gestational age and birth weight while controlling for demographic, medical, and dental variables. The study population consisted of 297 predominantly African- American women who were pregnant for the first time. The salivary bacterial levels evaluated were Streptococcus mutans, Streptococcus sobrinus, Streptococcus sanguinus, Lactobacillus acidophilus, Lactobacillus casei, Actinomyces naeslundii genospecies (gsp) 1 and 2, total streptococci, and total cultivable organisms. For 1 unit increase in log(10) A. naeslundii gsp 2 levels, there was a 60 gm decrease in birth weight (beta = -59.7 g; SE = 29.1; P = 0.04), and a 0.17 week decrease in gestational age (beta = -0.17 wk; SE = 0.09; P = 0.05). In contrast, per 1 unit increase in log(10) L. casei levels, there was a 42 gm increase in birth weight (beta = 42.2 g; SE = 19.3; P = 0.03), and a 0.13 week increase in gestational age (beta = 0.13 week; SE = 0.06; P = 0.04). We conclude that other oral bacterial species can also be related to pregnancy outcomes in addition to previously reported periodontal pathogens. These organism levels may not only predict poor pregnancy outcomes, but also be used as modifiable risk factors in reducing prematurity and low birth weight.

Urease activity in dental plaque and saliva of children during a three-year study period and its relationship with other caries risk factors.

PubMed

Morou-Bermudez, E; Elias-Boneta, A; Billings, R J; Burne, R A; Garcia-Rivas, V; Brignoni-Nazario, V; Suarez-Perez, E

2011-11-01

Bacterial urease activity in dental plaque and in saliva generates ammonia, which can increase the plaque pH and can protect acid-sensitive oral bacteria. Recent cross-sectional studies suggest that reduced ability to generate ammonia from urea in dental plaque can be an important caries risk factor. In spite of this proposed important clinical role, there is currently no information available regarding important clinical aspects of oral ureolysis in children. The objective of this study was to evaluate the distribution and pattern of urease activity in the dental plaque and in the saliva of children during a three-year period, and to examine the relationship of urease with some important caries risk factors. A longitudinal study was conducted with repeated measures over a three-year period on a panel of 80 children, aged 3-6 years at recruitment. The dynamics of change in urease activity were described and associated with clinical, biological, and behavioural caries risk factors. Urease activity in plaque showed a trend to remain stable during the study period and was negatively associated with sugar consumption (P<0.05). Urease activity in unstimulated saliva increased with age, and it was positively associated with the levels of mutans streptococci in saliva and with the educational level of the parents (P<0.05). The results of this study reveal interesting and complex interactions between oral urease activity and some important caries risk factors. Urease activity in saliva could be an indicator of mutans infection in children. Copyright © 2011 Elsevier Ltd. All rights reserved.

Investigation of Salivary Function and Oral Microbiota of Radiation Caries-Free People with Nasopharyngeal Carcinoma

PubMed Central

Zhang, Jingyang; Liu, Hongling; Liang, Xue; Zhang, Min; Wang, Renke; Peng, Guang; Li, Jiyao

2015-01-01

Radiation caries have been reported to be correlated with radiotherapy-induced destruction of salivary function and changes in oral microbiota. There have been no published reports detailing patients who have remained radiation caries-free following radiotherapy for nasopharyngeal carcinoma. The aim of this study was to investigate the relationship between salivary function, oral microbiota and the absence of radiation caries. Twelve radiation caries-free patients and nine patients exhibiting radiation caries following irradiated nasopharyngeal carcinoma were selected. V40, the dose at which the volume of the contralateral parotid gland receives more than 40 Gy, was recorded. Stimulated saliva flow rate, pH values and buffering capacity were examined to assess salivary function. Stimulated saliva was used for molecular profiling by Denaturing Gradient Gel Electrophoresis. Mutans streptococci and Lactobacilli in saliva were also cultivated. There were no significant differences in V40 between radiation caries-free individuals and those with radiation caries. Compared with normal values, the radiation caries-free group had significantly decreased simulated saliva flow rate, while there were no significant differences in the saliva pH value and buffering capacity. Similar results were observed in the radiation caries group. There was no statistical difference in microbial diversity, composition and log CFU counts in cultivation from the radiation caries-free group and the radiation caries group. Eleven genera were detected in these two groups, among which Streptococcus spp. and Neisseria spp. had the highest distribution. Our results suggest that changes in salivary function and in salivary microbiota do not explain the absence of radiation caries in radiation caries-free individuals. PMID:25860481

Investigation of salivary function and oral microbiota of radiation caries-free people with nasopharyngeal carcinoma.

PubMed

Zhang, Jingyang; Liu, Hongling; Liang, Xue; Zhang, Min; Wang, Renke; Peng, Guang; Li, Jiyao

2015-01-01

Radiation caries have been reported to be correlated with radiotherapy-induced destruction of salivary function and changes in oral microbiota. There have been no published reports detailing patients who have remained radiation caries-free following radiotherapy for nasopharyngeal carcinoma. The aim of this study was to investigate the relationship between salivary function, oral microbiota and the absence of radiation caries. Twelve radiation caries-free patients and nine patients exhibiting radiation caries following irradiated nasopharyngeal carcinoma were selected. V40, the dose at which the volume of the contralateral parotid gland receives more than 40 Gy, was recorded. Stimulated saliva flow rate, pH values and buffering capacity were examined to assess salivary function. Stimulated saliva was used for molecular profiling by Denaturing Gradient Gel Electrophoresis. Mutans streptococci and Lactobacilli in saliva were also cultivated. There were no significant differences in V40 between radiation caries-free individuals and those with radiation caries. Compared with normal values, the radiation caries-free group had significantly decreased simulated saliva flow rate, while there were no significant differences in the saliva pH value and buffering capacity. Similar results were observed in the radiation caries group. There was no statistical difference in microbial diversity, composition and log CFU counts in cultivation from the radiation caries-free group and the radiation caries group. Eleven genera were detected in these two groups, among which Streptococcus spp. and Neisseria spp. had the highest distribution. Our results suggest that changes in salivary function and in salivary microbiota do not explain the absence of radiation caries in radiation caries-free individuals.

Caries-preventive effectiveness of fluoride varnish as adjunct to oral health promotion and supervised tooth brushing in preschool children: a double-blind randomized controlled trial.

PubMed

Agouropoulos, A; Twetman, S; Pandis, N; Kavvadia, K; Papagiannoulis, L

2014-10-01

To evaluate the effect of biannual fluoride varnish applications in preschool children as an adjunct to school-based oral health promotion and supervised tooth brushing with 1000ppm fluoride toothpaste. 424 preschool children, 2-5 year of age, from 10 different pre schools in Athens were invited to this double-blind randomized controlled trial and 328 children completed the 2-year programme. All children received oral health education with hygiene instructions twice yearly and attended supervised tooth brushing once daily. The test group was treated with fluoride varnish (0.9% diflurosilane) biannually while the control group had placebo applications. The primary endpoints were caries prevalence and increment; secondary outcomes were gingival health, mutans streptococci growth and salivary buffer capacity. The groups were balanced at baseline and no significant differences in caries prevalence or increment were displayed between the groups after 1 and 2 years, respectively. There was a reduced number of new pre-cavitated enamel lesions during the second year of the study (p=0.05) but the decrease was not statistically significant. The secondary endpoints were unaffected by the varnish treatments. Under the present conditions, biannual fluoride varnish applications in preschool children did not show significant caries-preventive benefits when provided as an adjunct to school-based supervised tooth brushing with 1000ppm fluoride toothpaste. In community based, caries prevention programmes, for high caries risk preschool children, a fluoride varnish may add little to caries prevention, when 1000ppm fluoride toothpaste is used daily. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluation of the oxolinic acid--esculin--azide medium for the isolation and enumeration of faecal streptococci in a routine monitoring programme for bathing waters.

PubMed

Figueras, M J; Inza, I; Polo, F; Guarro, J

1998-10-01

m-Enterococcus agar (m-Ent) has been generally considered the reference medium for faecal streptococci in bathing waters. However, it shows several shortcomings, and therefore it is important to test newly developed media that can guarantee more precise results. In this sense, the recently described oxolinic acid--esculin--azide agar medium (OAA) and m-enterococcus agar (m-Ent) were comparatively evaluated for the detection of faecal streptococci from seawater and fresh water. The OAA medium showed a significantly higher relative recovery percentage and specificity for both types of water than m-Ent. A similar spectrum of species was recorded from both media, Enterococcus faecium being predominant in fresh water and Enterococcus faecalis, in seawater. The superior performance of the OAA medium in both types of bathing waters, added to the fact that it does not require the use of complementary confirmative tests, makes this medium an excellent candidate to be employed for monitoring programmes.

[Invasive infection caused Streptococcus group A and streptococcal toxic shock syndrome].

PubMed

Danilova, T A

2001-01-01

Modern data on the etiology and pathogenesis of invasive streptococcal infection and the syndrome of streptococcal toxic shock are presented. In the course of the last 10-15 years essential changes in the system of interaction of group A streptococci and the macroorganism have been noted. The growth of morbidity in severe invasive forms of streptococcal infection with different clinical manifestations, including the syndrome of toxic shock, is observed. Most often this disease develops in elderly people, making up a group of risk, but sometimes affects healthy young people. Different pathogenicity factors of streptococci, capable of inducing the development of infection, are analyzed. Special attention is given to superantigens: pyrogenic toxins and M-protein. The suggestion that the development of the disease is seemingly linked with the state of specific protective immunity is substantiated. In spite of achievements in the field of the microbiology and immunology of group A streptococci, the causes of the appearance and development of invasive streptococcal infection have not yet been determined.

Neonatal streptococcal infections.

PubMed Central

Parker, M. T.

1977-01-01

Most serious neonatal streptococcal infections are caused by group-B streptococci. The pattern of serious group-B neonatal disease in Britain resembles that described in other countries; both "early-onset" and "late-onset" forms are seen, but reliable incidence rates have not yet been determined. Serological-type III strains predominate in neonatal meningitis in Britain, but not so markedly as in some parts of the U.S.A. A deficiency of group-II strains in meningitis is, however, apparent in both countries. Present information about the carriage of group-B streptococci suggests that antibiotic prophylaxis administered to mothers or infants is unlikely to reduce greatly the frequency of "early-onset" disease. The continuous presence of a suitable chemical disinfectant in the vagina during labour might be more effective. Insufficient is known about the epidemiology of "late-onset" neonatal disease for rational preventive measures to be designed. More information is required about the postnatal acquisition of group-B streptococci by neonates and its sources, and about passive transfer of type-specific antibody from the mother to her child. PMID:339212

THE PRESENCE OF A GROUP A VARIANT-LIKE ANTIGEN IN STREPTOCOCCI OF OTHER GROUPS WITH SPECIAL REFERENCE TO GROUP N

PubMed Central

Elliott, S. D.; Hayward, John; Liu, T. Y.

1971-01-01

A Group A variant-like antigen has been detected in streptococci belonging to Groups D, E, G, M, and N. In Groups D and N the variant-like antigen was located in the streptococcal cell walls. In two strains of Group N streptococci (C559 and B209) the cell walls were chemically different and serologically distinct. In strain C559 N-acetylgalactosamine, and in strain B209, N-acetylglucosamine were the major determinants of serological specificity. The cell walls of strain C559 contained at least three serologically reactive components: a rhamnose-containing fraction that precipitated with an antiserum to Group A-variant carbohydrate; a strain-specific polysaccharide composed of galactosamine and glucosamine, both in the N-acetylated form and probably polymerized with an unidentified phosphorylated substance; and a component of unknown composition serologically related to a Group D streptococcus strain C3 (S. durans). An analogy is drawn between the cell wall structure in streptococcus and Salmonella. PMID:5111438

Efficacy of Waterless Hand Hygiene Compared with Handwashing with Soap: A Field Study in Dar es Salaam, Tanzania

PubMed Central

Pickering, Amy J.; Boehm, Alexandria B.; Mwanjali, Mathew; Davis, Jennifer

2010-01-01

Effective handwashing with soap requires reliable access to water supplies. However, more than three billion persons do not have household-level access to piped water. This research addresses the challenge of improving hand hygiene within water-constrained environments. The antimicrobial efficacy of alcohol-based hand sanitizer, a waterless hand hygiene product, was evaluated and compared with handwashing with soap and water in field conditions in Dar es Salaam, Tanzania. Hand sanitizer use by mothers resulted in 0.66 and 0.64 log reductions per hand of Escherichia coli and fecal streptococci, respectively. In comparison, handwashing with soap resulted in 0.50 and 0.25 log reductions per hand of E. coli and fecal streptococci, respectively. Hand sanitizer was significantly better than handwashing with respect to reduction in levels of fecal streptococci (P = 0.01). The feasibility and health impacts of promoting hand sanitizer as an alternative hand hygiene option for water-constrained environments should be assessed. PMID:20134005

Plasticity of the Pyruvate Node Modulates Hydrogen Peroxide Production and Acid Tolerance in Multiple Oral Streptococci.

PubMed

Cheng, Xingqun; Redanz, Sylvio; Cullin, Nyssa; Zhou, Xuedong; Xu, Xin; Joshi, Vrushali; Koley, Dipankar; Merritt, Justin; Kreth, Jens

2018-01-15

Commensal Streptococcus sanguinis and Streptococcus gordonii are pioneer oral biofilm colonizers. Characteristic for both is the SpxB-dependent production of H 2 O 2 , which is crucial for inhibiting competing biofilm members, especially the cariogenic species Streptococcus mutans H 2 O 2 production is strongly affected by environmental conditions, but few mechanisms are known. Dental plaque pH is one of the key parameters dictating dental plaque ecology and ultimately oral health status. Therefore, the objective of the current study was to characterize the effects of environmental pH on H 2 O 2 production by S. sanguinis and S. gordonii S. sanguinis H 2 O 2 production was not found to be affected by moderate changes in environmental pH, whereas S. gordonii H 2 O 2 production declined markedly in response to lower pH. Further investigation into the pyruvate node, the central metabolic switch modulating H 2 O 2 or lactic acid production, revealed increased lactic acid levels for S. gordonii at pH 6. The bias for lactic acid production at pH 6 resulted in concomitant improvement in the survival of S. gordonii at low pH and seems to constitute part of the acid tolerance response of S. gordonii Differential responses to pH similarly affect other oral streptococcal species, suggesting that the observed results are part of a larger phenomenon linking environmental pH, central metabolism, and the capacity to produce antagonistic amounts of H 2 O 2 IMPORTANCE Oral biofilms are subject to frequent and dramatic changes in pH. S. sanguinis and S. gordonii can compete with caries- and periodontitis-associated pathogens by generating H 2 O 2 Therefore, it is crucial to understand how S. sanguinis and S. gordonii adapt to low pH and maintain their competitiveness under acid stress. The present study provides evidence that certain oral bacteria respond to environmental pH changes by tuning their metabolic output in favor of lactic acid production, to increase their acid survival, while others maintain their H 2 O 2 production at a constant level. The differential control of H 2 O 2 production provides important insights into the role of environmental conditions for growth competition of the oral flora. Copyright © 2018 American Society for Microbiology.

Effectiveness of a motionless ultrasonic toothbrush in reducing plaque and gingival inflammation in patients with fixed orthodontic appliances.

PubMed

Saruttichart, Thayika; Chantarawaratit, Pintu-On; Leevailoj, Chalermpol; Thanyasrisung, Panida; Pitiphat, Waranuch; Matangkasombut, Oranart

2017-03-01

To compare the effectiveness of a motionless ultrasonic toothbrush to a manual toothbrush in reducing dental plaque, gingival inflammation, and mutans streptococci in patients with fixed orthodontic appliances. Twenty-five orthodontic patients were recruited to this crossover study. The patients were randomized into two groups starting with manual or motionless ultrasonic toothbrushes for 30 days. After a 30-day washout period, the patients switched to the other toothbrush type for 30 days. Plaque and gingival indices were evaluated by two calibrated-blinded examiners before and after each 30-day period of brushing. Salivary samples were also collected for quantification of mutans streptococci. On the bracket side, the motionless ultrasonic toothbrush showed a significantly higher mean plaque index bracket score after 30-day usage than baseline (P = .049), while the manual toothbrush group showed no difference between the before and after brushing periods (P = .10). The changes in plaque index bracket score were significantly more favorable in the manual toothbrush group than in the ultrasonic toothbrush group (P = .04). In contrast, no difference was observed on the nonbracket side. There was no significant difference in the changes of gingival index or the numbers of mutans streptococci between the two groups. Manual toothbrushing performed better than brushing with the motionless ultrasonic toothbrush in plaque removal on the bracket side in orthodontic patients. However, no difference was observed in terms of gingival status and the numbers of mutans streptococci.

Ten years of treating necrotizing fasciitis.

PubMed

Nordqvist, Gunnar; Walldén, Axel; Brorson, Håkan; Tham, Johan

2015-05-01

Necrotizing fasciitis is a soft tissue infection characterized by rapid progression and a high mortality rate. The objective of this study was to investigate diagnosis, causative microbial agents, comorbidities, antibiotic regimen and outcome regarding this disease at Skåne University Hospital in Malmö, Sweden. From medical records, we identified 33 patients treated from January 2003 to January 2013, 31 of whom could be included in our investigation. The infections were monomicrobial in 87% of the cases, and most were caused by group A streptococci. The rate of polymicrobial infections was lower than in other studies. In addition to blood and wound cultures, a rapid antigen detection test for group A streptococci was used in a majority of the cases as a supplement to other diagnostic tools. The time from onset of symptoms to surgery proved to be significantly shorter for patients infected with group A streptococci than for other patients. The mortality rate among all patients was 19%, which is lower than much of the historical material but in line with some more recent studies of this disease. Our results indicate that low mortality rates can be achieved by surgery, appropriate antibiotics and good supportive care. Furthermore, we show that the use of the rapid antigen detection test for group A streptococci, in this setting, helps to shorten the time to surgical intervention in patients suffering from necrotizing fasciitis. This also helps to guide the antibiotic treatment into a narrower spectrum.

High frequency of fluoroquinolone- and macrolide-resistant streptococci among clinically isolated group B streptococci with reduced penicillin susceptibility.

PubMed

Kimura, Kouji; Nagano, Noriyuki; Nagano, Yukiko; Suzuki, Satowa; Wachino, Jun-ichi; Shibayama, Keigo; Arakawa, Yoshichika

2013-03-01

Recently several clinical isolates of Streptococcus agalactiae [also known as group B Streptococcus (GBS)] that have acquired reduced penicillin susceptibility (PRGBS) by amino acid substitutions in the penicillin-binding protein 2X have emerged. The frequency of fluoroquinolone (FQ)- and macrolide-resistant streptococci among PRGBS is not yet known. Fifty-seven GBS [19 PRGBS and 38 penicillin-susceptible GBS (PSGBS)], isolated from different medical institutions in Japan, were studied. For GBS, the MICs of penicillin G, levofloxacin and erythromycin were determined using the agar dilution method. Nineteen PRGBS were previously confirmed as genetically diverse streptococci by PFGE. Further, the mechanisms underlying penicillin, FQ and macrolide non-susceptibility/resistance were analysed. The frequency of non-susceptibility to FQs among PSGBS was 18.4% (7/38), whereas that among PRGBS was 100% (19/19). The frequency of resistance to erythromycin among PSGBS was 7.9% (3/38), while that among PRGBS was 47.4% (9/19). Statistical significance was determined using Fisher's exact test between reduced penicillin susceptibility and FQ non-susceptibility (P ≤ 0.0001) and macrolide resistance (P=0.0012). The resistance/non-susceptibility mechanisms among PRGBS were diverse, suggesting that the PRGBS examined were not clonal. PRGBS isolates tend to show resistance to FQs and/or macrolides. Because the drug choice for treating these multidrug-resistant GBS is more limited than that for usual GBS, these strains may present future public health challenges.

Temporal trends of β-haemolytic streptococcal osteoarticular infections in western Norway.

PubMed

Oppegaard, Oddvar; Skrede, Steinar; Mylvaganam, Haima; Kittang, Bård Reiakvam

2016-10-04

Beta-haemolytic streptococci are important contributors to the global burden of osteoarticular infections (OAI). Knowledge on the disease traits specific for streptococcal OAI, however, remains scarce. We wished to explore temporal trends of OAI caused by Group A Streptococci (GAS), Group B Streptococci (GBS) and Group C and G Streptococci (GCGS), and furthermore, to describe the associated host and pathogen characteristics. All cases of microbiologically verified β-haemolytic streptococcal OAI in Health Region Bergen, Norway, in the period 1999-2013 were retrospectively identified. Clinical data were extracted from medical records. Microbial isolates were submitted to antibiotic susceptibility testing and molecular typing. A total of 24 GAS, 45 GBS and 42 GCGS acute OAI were identified. The cumulative incidence of GCGS OAI, but not GAS or GBS OAI, increased significantly from the first to the last 5-year period (IRR 5.7, p = 0.0003), with the annual incidence peaking at 1.9/100 000 in 2013. GAS OAI generally produced the most acute and severe clinical presentation, whereas GBS and GCGS predominantly affected the elderly, and were significantly associated with the presence of host risk factors of systemic and focal origin, respectively. We found a significantly increasing incidence of GCGS OAI, likely related to the presence of host susceptibility factors, including prosthetic material and pre-existing joint disease. With an increasing application of therapeutic and diagnostic bone and joint procedures, the rising trend of OAI caused by GCGS is likely to continue. Sustained epidemiological attentiveness to GCGS seems warranted.

Epidemiology and outcomes associated with moderate to heavy Candida colonization during pregnancy. Vaginal Infections and Prematurity Study Group.

PubMed

Cotch, M F; Hillier, S L; Gibbs, R S; Eschenbach, D A

1998-02-01

Our purpose was to determine the risk factors, physical findings, microflora, and pregnancy outcome among pregnant women with moderate to heavy vaginal growth of Candida albicans and other Candida species. A multicenter cohort of 13,914 women were enrolled between 23 and 26 weeks' gestation. Women completed a questionnaire, underwent a physical examination, and had genital specimens taken for culture. A subset of 1459 women were reexamined during the third trimester. Pregnancy outcomes were recorded at delivery. The prevalence of moderate to heavy Candida colonization at midgestation was 10%. Colonized women, 83% of whom carried C. albicans, were more likely to be black or Hispanic, unmarried, a previous oral contraceptive user, and to manifest clinical signs indicative of Candida carriage. Candida colonization was positively associated with Trichomonas vaginalis, group B streptococci, and aerobic Lactobacillus and was not associated with adverse pregnancy outcome. These results suggest that Candida colonization is not associated with low birth weight or preterm delivery.

Characterization of salivary alpha-amylase binding to Streptococcus sanguis

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

Scannapieco, F.A.; Bergey, E.J.; Reddy, M.S.

1989-09-01

The purpose of this study was to identify the major salivary components which interact with oral bacteria and to determine the mechanism(s) responsible for their binding to the bacterial surface. Strains of Streptococcus sanguis, Streptococcus mitis, Streptococcus mutans, and Actinomyces viscosus were incubated for 2 h in freshly collected human submandibular-sublingual saliva (HSMSL) or parotid saliva (HPS), and bound salivary components were eluted with 2% sodium dodecyl sulfate. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western transfer, alpha-amylase was the prominent salivary component eluted from S. sanguis. Studies with {sup 125}I-labeled HSMSL or {sup 125}I-labeled HPS also demonstrated a componentmore » with an electrophoretic mobility identical to that of alpha-amylase which bound to S. sanguis. Purified alpha-amylase from human parotid saliva was radiolabeled and found to bind to strains of S. sanguis genotypes 1 and 3 and S. mitis genotype 2, but not to strains of other species of oral bacteria. Binding of ({sup 125}I)alpha-amylase to streptococci was saturable, calcium independent, and inhibitable by excess unlabeled alpha-amylases from a variety of sources, but not by secretory immunoglobulin A and the proline-rich glycoprotein from HPS. Reduced and alkylated alpha-amylase lost enzymatic and bacterial binding activities. Binding was inhibited by incubation with maltotriose, maltooligosaccharides, limit dextrins, and starch.« less

Antibacterial effects of fluoride varnish compared with chlorhexidine plus fluoride in disabled children.

PubMed

Baygin, Ozgul; Tuzuner, Tamer; Kusgoz, Adem; Senel, Ahmet Can; Tanriver, Mehmet; Arslan, Ipek

2014-01-01

To evaluate the effects of fluoride varnish vs a combination of chlorhexidine-thymol varnish plus a gel containing chlorhexidine and fluoride on oral hygiene and caries prevention in disabled children. Ninety patients aged 3-17 years who were treated under general anaesthesia were randomly assigned into three groups as follows: group 1: Fluor Protector (0.1% fluoride varnish); group 2: Cervitec Plus (1% chlorhexidine- 1% thymol varnish) + Cervitec Gel (0.2% chlorhexidine-0.2% sodium fluoride); group 3: control (toothbrushing only). Mutans streptococci (MS) and lactobacilli (LB) levels, visible plaque index (VPI) and gingival bleeding index (GBI) were evaluated at four stages: T0, before general anaesthesia; T1, one month after treatment; T2, six months after treatment; T3, twelve months after treatment. The data were evaluated using Kruskal-Wallis and Mann-Whitney U-tests (P < 0.05). Groups 1 and 2 showed significantly lower scores than group 3 for all parameters at T1 and T2. No statistically significant difference was detected among any of the the groups at T3 (P > 0.05). The use of materials that include both fluoride and chlorhexidine as routine treatment of children with disability may increase the success of restorations by improving oral hygiene, reduce the need for future restorative treatments and thus the need for general anaesthesia.

Comparison of suction device with saliva ejector for aerosol and spatter reduction during ultrasonic scaling.

PubMed

Holloman, Jessica L; Mauriello, Sally M; Pimenta, Luiz; Arnold, Roland R

2015-01-01

Aerosols and spatter are concerns in health care owing to their potential adverse health effects. The Isolite illuminated isolation system (Isolite Systems) and a saliva ejector were compared for aerosol and spatter reduction during and after ultrasonic scaling. Fifty participants were randomized to control (n = 25, saliva ejector) or test (n = 25, Isolite) groups and received a prophylaxis with an ultrasonic scaler. Aerosols were collected in a petri dish containing transport media, dispersed, and plated to anaerobic blood agar to determine colony-forming units (CFUs). The authors analyzed the data using a t test. No significant difference occurred between groups in aerosol and spatter reduction (P = .25). Mean (standard deviation) of log10 CFUs per milliliter collected during ultrasonic scaling in the control and test groups were 3.61 (0.95) and 3.30 (0.88), respectively. All samples contained α-hemolytic streptococci, and many samples contained strictly oral anaerobes. A significant amount of contamination occurred during ultrasonic scaling in both groups, as indicated by high numbers of CFUs and the identification of strictly oral anaerobes in all plates. Neither device reduced aerosols and spatter effectively, and there was no significant difference in reduction between the 2 devices. Additional measures should be taken with these devices to reduce the likelihood of disease transmission. Copyright © 2015 American Dental Association. Published by Elsevier Inc. All rights reserved.

Antibacterial Activity of Freshly Prepared Ozonated Water and Chlorhexidine on Mutans Streptococcus When Used as an Oral Rinse - A Randomised Clinical Study.

PubMed

Anumula, Lavanya; Kumar, Kv Suneel; Krishna, Chnv Murali; Lakshmi, K Sree

2017-07-01

Dental caries is one of the most common causes of morbidity of the tooth. Attempts have been made to reduce the pathogen population size i.e., Mutans Streptococci (MS) to demote the incidence of caries and increase the resistance of the tooth to cariogenic attack. To evaluate the antibacterial efficacy of freshly prepared ozonated water, in proposing it as an alternative mouth rinse on MS in comparison to Chlorhexidine (CHX). Subjects with high caries incidence and MS counts more than 105 Colony Forming Unit (CFU) were selected and divided by block randomization into two groups of 23 subjects each. The subjects were advised to use the respective mouth rinses under the operator surveillance, consecutively for 14 days. Stimulated salivary samples were collected from the subjects on the first day, 7 th and 14 th day to analyse the changes in MS counts during the course of use of oral rinses. The obtained data was tabulated and statistically analysed. Freshly prepared ozonated water showed a statistically significant reduction in MS counts after an interval of 7 days and 14 days when compared to CHX. Ozonated water when consecutively used as a mouth rinse resulted in a significant reduction of MS counts. Hence, it can be used as an alternative to chlorhexidine.

Maternal Oral Bacterial Levels Predict Early Childhood Caries Development

PubMed Central

Chaffee, B.W.; Gansky, S.A.; Weintraub, J.A.; Featherstone, J.D.B.; Ramos-Gomez, F.J.

2014-01-01

Objective: To calculate the association of maternal salivary bacterial challenge (mutans streptococci [MS] and lactobacilli [LB]) from pregnancy through 24 months’ postpartum with child caries incidence (≥1 cavitated or restored teeth) at 36 months. Materials & Methods: Dental, salivary bacterial, sociodemographic, and behavioral measures were collected at three- to six-month intervals from a birth cohort of low-income Hispanic mother-child dyads (N = 243). We calculated the relative child caries incidence, adjusted for confounding, following higher maternal challenge of MS (>4500 colony-forming units per milliliter of saliva [CFU/mL]) and LB (>50 CFU/mL) based on multivariable models. Results: Salivary MS and LB levels were greater among mothers of caries-affected children versus caries-free children. Mothers with higher salivary MS challenge were more likely to have MS-positive children (>0 CFU/mL), but maternal LB challenge was not a statistically significant predictor of child LB-positive status. Adjusting for sociodemographics, feeding and care practices, and maternal dental status, higher maternal salivary challenge of both MS and LB over the study period predicted nearly double the child caries incidence versus lower MS and LB (cumulative incidence ratio: 1.9; 95% confidence interval: 1.1, 3.8). Conclusion: Maternal salivary bacterial challenge not only is associated with oral infection among children but also predicts increased early childhood caries occurrence. PMID:24356441

Streptococcus mutans copper chaperone, CopZ, is critical for biofilm formation and competitiveness.

PubMed

Garcia, S S; Du, Q; Wu, H

2016-12-01

The oral cavity is a dynamic environment characterized by hundreds of bacterial species, saliva, and an influx of nutrients and metal ions such as copper. Although there is a physiologic level of copper in the saliva, the oral cavity is often challenged with an influx of copper ions. At high concentrations copper is toxic and must therefore be strictly regulated by pathogens for them to persist and cause disease. The cariogenic pathogen Streptococcus mutans manages excess copper using the copYAZ operon that encodes a negative DNA-binding repressor (CopY), the P1-ATPase copper exporter (CopA), and the copper chaperone (CopZ). These hypothetical roles of the copYAZ operon in regulation and copper transport to receptors led us to investigate their contribution to S. mutans virulence. Mutants defective in the copper chaperone CopZ, but not CopY or CopA, were impaired in biofilm formation and competitiveness against commensal streptococci. Characterization of the CopZ mutant biofilm revealed a decreased secretion of glucosyltransferases and reduced expression of mutacin genes. These data suggest that the function of copZ on biofilm and competitiveness is independent of copper resistance and CopZ is a global regulator for biofilm and other virulence factors. Further characterization of CopZ may lead to the identification of new biofilm pathways. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Genetic studies on reference strains of mutans streptococci.

PubMed

Ota, Fusao; Yamato, Masayuki; Hayashi, Mie; Ota, Masayuki; Koga, Tetsuro; Sherin, Ahmed; Mukai, Chiharu; Sakai, Kentaro; Yamamoto, Shigeru

2002-01-01

Twenty four reference strains (serotype a-h) belonging to the mutans group of streptococci were compared for DNA fragment patterns of rDNA after treatment with Hind III. It was shown that Streptococcus cricetus (serotype a), S. rattus (serotype b), and S. downei (serotype h) reveals comparatively homogeneous patterns while S. mutans (serotype c, e and f) exhibits differences between the different serotypes as well as within single serotypes. S. sobrinus had an intermediary diversity. These data support the previous findings that S. mutans is heterogeneous at the serological, biochemical and genetical level.

MICROBIOLOGICAL ASPECTS OF THE ORTHODONTIC TREATMENT.

PubMed

Zharmagambetova, A; Tuleutayeva, S; Akhmetova, S; Zharmagambetov, A

2017-03-01

An orthodontic appliance in the mouth worsens conditions for its self-cleaning, complicates the teeth care and makes an environment favorable to the soft tooth deposit, in turn, leads to the teeth enamel demineralization. In literature, the majority of works are devoted to the study of the microbial landscape with fixed orthodontic treatment. Despite the obvious relevance, the formation problem of opportunistic and pathogenic microorganisms when treating dentoalveolar anomalies with a removable orthodontic appliance remains understudied. The research aim was to investigate the influence of the removable type of orthodontic treatment of patients aged 12 with dentoalveolar anomalies on the mouth microbiocenosis. The dental examination and microbiological study was conducted to 100 children aged 12 with dentoalveolar anomalies. The dental examination included assessment of the oral hygiene state by the OHI-S index. The microbiological research was conducted in the following sequence: the bacterioscopy smear of plaque, stained by the Gram and Burri method with the assessment of morphological and tinctorial properties of microorganisms. The statistical data analysis was performed using SPSS v22.0 forWindows program. The dental examination showed that the oral hygiene state varied according to the orthodontic treatment stage. During the orthodontic treatment the OHI-S Index was 2.1 score, indicating a satisfactory oral hygiene level. The microbiological study showed that persistent contaminants were lactobacilli, streptococci, staphylococci, and yeast-like fungi. However, the treatment showed a decrease of normal flora level and the increase in number of Candidaalbicans, Staphylococcusaureus and Streptococcusmutans, that was a trigger in the development of dental caries and periodontal disease. During the orthodontic treatment, children with dentoalveolar anomalies are at high risk of dental caries and periodontal disease.

Inhibiting effects of Streptococcus salivarius on competence-stimulating peptide-dependent biofilm formation by Streptococcus mutans.

PubMed

Tamura, S; Yonezawa, H; Motegi, M; Nakao, R; Yoneda, S; Watanabe, H; Yamazaki, T; Senpuku, H

2009-04-01

The effects of Streptococcus salivarius on the competence-stimulating peptide (CSP)-dependent biofilm formation by Streptococcus mutans were investigated. Biofilms were grown on 96-well microtiter plates coated with salivary components in tryptic soy broth without dextrose supplemented with 0.25% sucrose. Biofilm formations were stained using safranin and quantification of stained biofilms was performed by measuring absorbance at 492 nm. S. mutans formed substantial biofilms, whereas biofilms of S. salivarius were formed poorly in the medium conditions used. Furthermore, in combination cultures, S. salivarius strongly inhibited biofilm formation when cultured with S. mutans. This inhibition occurred in the early phase of biofilm formation and was dependent on inactivation of the CSP of S. mutans, which is associated with competence, biofilm formation, and antimicrobial activity of the bacterium, and is induced by expression of the comC gene. Comparisons between the S. mutans clinical strains FSC-3 and FSC-3DeltaglrA in separate dual-species cultures with S. salivarius indicated that the presence of the bacitracin transport ATP-binding protein gene glrA caused susceptibility to inhibition of S. mutans biofilm formation by S. salivarius, and was also associated with the regulation of CSP production by com gene-dependent quorum sensing systems. It is considered that regulation of CSP by glrA in S. mutans and CSP inactivation by S. salivarius are important functions for cell-to-cell communication between biofilm bacteria and oral streptococci such as S. salivarius. Our results provide useful information for understanding the ecosystem of oral streptococcal biofilms, as well as the competition between and coexistence of multiple species in the oral cavity.

Autoinducer-2 detection among commensal oral streptococci is dependent on pH and boric acid.

PubMed

Cuadra, Giancarlo A; Frantellizzi, Ashley J; Gaesser, Kimberly M; Tammariello, Steven P; Ahmed, Anika

2016-07-01

Autoinducer-2, considered a universal signaling molecule, is produced by many species of bacteria; including oral strains. Structurally, autoinducer-2 can exist bound to boron (borated autoinducer-2). Functionally, autoinducer-2 has been linked to important bacterial processes such as virulence and biofilm formation. In order to test production of autoinducer-2 by a given bacterial strain, a bioassay using marine bioluminescent bacteria Vibrio harveyi as a reporter for autoinducer-2 has been designed. We hypothesize that pH adjustment and addition of boron are required for optimal bioluminescence and accurate autoinducer-2 detection. Using this reporter strain we tested autoinducer-2 activity from two oral commensal species, Streptococcus gordonii DL1 and Streptococcus oralis 34. Spent broth was collected and adjusted to pH 7.5 and supplemented with boric acid prior to measuring autoinducer- 2 activity. Results show that low pH inhibits bioluminescence of the reporter strain, but pH 7.5 allows for bioluminescence induction and proper readings of autoinducer-2 activity. Addition of boric acid also has a positive effect on bioluminescence allowing for a more sensitive detection of autoinducer-2 activity. Our data suggests that although autoinducer-2 is present in spent broth, low pH and/or low levels of boric acid become an obstacle for proper autoinducer-2 detection. For proper autoinducer-2 detection, we propose a protocol using this bioassay to include pH adjustment and boric acid addition to spent broth. Studies on autoinducer-2 activity in several bacteria species represent an important area of study as this universal signaling molecule is involved in critical bacterial phenotypes such as virulence and biofilm formation.

Levels and complexity of IgA antibody against oral bacteria in samples of human colostrum.

PubMed

Petrechen, L N; Zago, F H; Sesso, M L T; Bertoldo, B B; Silva, C B; Azevedo, K P; de Lima Pereira, S A; Geraldo-Martins, V R; Ferriani, V P L; Nogueira, R D

2015-01-01

Streptococcus mutans (SM) have three main virulence antigens: glucan binding protein B (gbpB), glucosyltransferase (Gtf) and antigens I/II (Ag I/II) envolved in the capacity of those bacteria to adhere and accumulate in the dental biofilm. Also, the glycosyltransferases 153 kDa of Streptococcus gordonii (SGO) and 170kDa of Streptococcus sanguinis (SSA) were important antigens associated with the accumulation of those bacterias. Streptococcus mitis (SMI) present IgA1 protease of 202 kDa. We investigated the specificity and levels IgA against those antigens of virulence in samples of human colostrum. This study involved 77 samples of colostrum that were analyzed for levels of immunoglobulian A, M and G by Elisa. The specificity of IgA against extracts of SM and initials colonizators (SSA, SMI, SGO) were analyzed by the Western blot. The mean concentration of IgA was 2850.2 (±2567.2) mg/100 mL followed by IgM and IgG (respectively 321.8±90.3 and 88.3±51.5), statistically different (p<0.05). Results showed that the majority of samples had detectable levels of IgA antibodies to extracts of bacteria antigens and theirs virulence antigens. To SM, the GbpB was significantly lower detected than others antigens of SM (p<0.05). High complexities of response to Ags were identified in the samples. There were no significant differences in the mean number of IgA-reactive Ags between the antigens (p>0.4). So, the breast milk from first hours after birth presented significant levels of IgA specific against important virulence of antigens those oral streptococci, which can disrupt the installation and accumulation process of these microorganisms in the oral cavity. Copyright © 2014 Elsevier GmbH. All rights reserved.

Purification and genetic characterisation of the novel bacteriocin LS2 produced by the human oral strain Lactobacillus salivarius BGHO1.

PubMed

Busarcevic, Milos; Dalgalarrondo, Michèle

2012-08-01

The aim of this study was to investigate the antimicrobial potential of Lactobacillus salivarius BGHO1, a human oral strain with probiotic characteristics and a broad inhibitory spectrum both against Gram-positive and Gram-negative pathogens. Here we present the bacteriocin LS2, an extremely pH- and heat-stable peptide with antilisterial activity. LS2 is a novel member of the class IId bacteriocins, unique among all currently characterised bacteriocins. It is somewhat similar to putative bacteriocins from several oral streptococci, including the cariogenic Streptococcus mutans. LS2 is a 41-amino-acid, highly hydrophobic cationic peptide of 4115.1Da that is sensitive to proteolytic enzymes. LS2 was purified from cells of strain BGHO1 by solvent extraction and reverse-phase chromatography. Mass spectrometry was used to determine the molecular mass of the purified peptide. N-terminal amino acid sequencing enabled identification of the LS2 structural gene bacls2 by a reverse genetics approach. Downstream of the bacls2 gene, two bacteriocin-like genes were found, named blp1a and blp1b, and one putative bacteriocin immunity gene named bimlp. We also present the identification of the 242-kb megaplasmid pMPHO1 by pulsed-field gel electrophoresis, which harbours the genes bacls2, blp1a, blp1b and bimlp. Two peptides with antimicrobial activity, whose approximate sizes corresponded to those of blp1a and blp1b, were identified only after culturing strain BGHO1 in a chemically defined medium. This study demonstrated the capacity of Lactobacillus salivarius BGHO1 to produce multiple bacteriocins and further established this strain as a promising probiotic candidate. Copyright © 2012 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Comparison of genes required for H2O2 resistance in Streptococcus gordonii and Streptococcus sanguinis

PubMed Central

Xu, Yifan; Itzek, Andreas

2014-01-01

Hydrogen peroxide (H2O2) is produced by several members of the genus Streptococcus mainly through the pyruvate oxidase SpxB under aerobic growth conditions. The acute toxic nature of H2O2 raises the interesting question of how streptococci cope with intrinsically produced H2O2, which subsequently accumulates in the microenvironment and threatens the closely surrounding population. Here, we investigate the H2O2 susceptibility of oral Streptococcus gordonii and Streptococcus sanguinis and elucidate potential mechanisms of how they protect themselves from the deleterious effect of H2O2. Both organisms are considered primary colonizers and occupy the same intraoral niche making them potential targets for H2O2 produced by other species. We demonstrate that S. gordonii produces relatively more H2O2 and has a greater ability for resistance to H2O2 stress. Functional studies show that, unlike in Streptococcus pneumoniae, H2O2 resistance is not dependent on a functional SpxB and confirms the important role of the ferritin-like DNA-binding protein Dps. However, the observed increased H2O2 resistance of S. gordonii over S. sanguinis is likely to be caused by an oxidative stress protection machinery present even under anaerobic conditions, while S. sanguinis requires a longer period of time for adaptation. The ability to produce more H2O2 and be more resistant to H2O2 might aid S. gordonii in the competitive oral biofilm environment, since it is lower in abundance yet manages to survive quite efficiently in the oral biofilm. PMID:25280752

Oral Microbiota of Children in a School-based Dental Clinic

PubMed Central

Soncini, Jennifer A; Kanasi, Eleni; Lu, Shulin C.; Nunn, Martha E.; Henshaw, Michelle M; Tanner, Anne CR

2010-01-01

Objectives Dental caries disproportionately affects disadvantaged subjects. This study hypothesized that there were greater caries extent and higher levels of caries-associated and anaerobic subgingival bacterial species in oral samples of Hispanic and immigrant children compared with non-Hispanic and US born children. Methods Children from a school-based dental clinic serving a community with a large Hispanic component were examined, and the extent of caries was recorded. Microbial samples were taken from teeth and the tongues of children. Samples were analyzed using DNA probes to 18 oral bacterial species. Results Seventy five children were examined. Extent of caries increased with child age in immigrant, but not in US born or Hispanic children. There were no differences in the microbiota based on ethnicity or whether the child was born in US or not. There was a higher species detection frequency from teeth than tongue samples. Levels of Streptococcus mutans and other Streptococcus species increased with caries extent. Prevotella intermedia, Tannerella forsythia and Selenomonas species were detected at low levels in these children. Conclusions We conclude that, while there was a high rate of dental caries in disadvantaged school children, there were no differences in the caries-associated microbiota, including S. mutans, based on ethnicity or immigration status. Furthermore, while anaerobic subgingival, periodontal pathogens were also detected in children, there was no difference in species detection based on ethnicity or immigration status. Increased levels of streptococci, including S. mutans, however, were detected with high caries levels. This suggested that while it is beneficial to target preventive and treatment programs to disadvantaged populations, there is likely no additional benefit to focus on subgroups within a population already at high risk for dental disease. PMID:19879369

Oral microbiota of children in a school-based dental clinic.

PubMed

Soncini, Jennifer A; Kanasi, Eleni; Lu, Shulin C; Nunn, Martha E; Henshaw, Michelle M; Tanner, Anne C R

2010-06-01

Dental caries disproportionately affects disadvantaged subjects. This study hypothesized that there were greater caries extent and higher levels of caries-associated and anaerobic subgingival bacterial species in oral samples of Hispanic and immigrant children compared with non-Hispanic and US born children. Children from a school-based dental clinic serving a community with a large Hispanic component were examined, and the extent of caries was recorded. Microbial samples were taken from teeth and the tongues of children. Samples were analyzed using DNA probes to 18 oral bacterial species. Seventy five children were examined. Extent of caries increased with child age in immigrant, but not in US born or Hispanic children. There were no differences in the microbiota based on ethnicity or whether the child was born in US or not. There was a higher species detection frequency from teeth than tongue samples. Levels of Streptococcus mutans and other Streptococcus spp increased with caries extent. Prevotella intermedia, Tannerella forsythia and Selenomonas spp were detected at low levels in these children. We conclude that, while there was a high rate of dental caries in disadvantaged school children, there were no differences in the caries-associated microbiota, including S. mutans, based on ethnicity or immigration status. Furthermore, while anaerobic subgingival, periodontal pathogens were also detected in children, there was no difference in species detection based on ethnicity or immigration status. Increased levels of streptococci, including S. mutans, however, were detected with high caries levels. This suggested that while it is beneficial to target preventive and treatment programs to disadvantaged populations, there is likely no additional benefit to focus on subgroups within a population already at high risk for dental disease. 2009 Elsevier Ltd. All rights reserved.

The effect of traditional African food mixtures on growth, pH and extracellular polysaccharide production by mutans streptococci in vitro.

PubMed

Toi, Cheryl Sam; Cleaton-Jones, Peter

2006-04-01

Four, traditional African food mixtures (maize plus milk and sugar, maize plus gravy, samp plus beans, brown bread plus margarine and peanut butter) were evaluated for their ability to sustain the growth of mutans streptococci in batch culture. A synthetic complex medium, brain heart infusion with 3% sucrose was used as an experimental control. Six NCTC laboratory reference strains and five clinical isolates collected from the plaque of children were investigated. The doubling time of bacterial strains was prolonged in maize plus gravy (2.5-6.0 h) and samp plus beans (1.3-9.9h), and the number of cell divisions was low, compared with bread plus margarine plus peanut butter (0.7-5.1h). The least amount of acid was produced in maize plus milk plus sugar (3.92+/-8.15 mmole/mL), and the average pH during the fermentation of maize plus milk plus sugar, maize plus gravy and samp plus beans did not drop below the critical point for enamel demineralisation, pH 5.7. Bacterial growth in samp plus beans produced a small quantity of lactic acid (0.46+/-1.10 mmole/mL) compared to bread plus margarine and peanut butter (2.64+/-3.30 mmole/mL) and BHI plus 3% sucrose (12.23+/-10.72 mmole/mL). Extracellular polysaccharide (ECP) produced was lowest in maize plus milk and sugar (0.22+/-0.33 mg/mL), compared with the remaining food mixtures (0.47-1.75 mg/mL). Statistical analysis showed that the influence of the mixed-foods on doubling time (F=3.01, P=0.03), pH (F=14.41, P<0.0001) and ECP (F=135.32, P<0.0001) was greater than the significant variance found between mutans streptococci strains. Results suggest that the level of mutans streptococci activity in samp plus beans, maize plus milk and sugar and maize plus gravy contributes little towards the formation of dental caries, and that significant differences exist between mutans streptococci laboratory reference and clinical strains in response to traditional African food mixtures.

Analysis of Anaerobic Blood Cultures in Burned Patients

DTIC Science & Technology

2007-01-01

Serratia marsescens 12 (3.5) 25 (4.0) 11 1 (9.1) Streptococcus viridans group 10 (2.9) 12 (1.9) 5 1 (20.0) Proteus mirabilis 7 (2.0) 7 (1.1) 4 1 (25.0...Streptococcus group D 7 (2.0) 7 (1.1) 2 1 (50.0) Enterococcus spp. 6 (1.7) 15 (2.4) 8 2 (25.0) Bacillus sp . (not anthracis) 6 (1.7) 6 (1.0) 4 2 (50.0

Conformational flexibility related to enzyme activity: evidence for a dynamic active-site gatekeeper function of Tyr(215) in Aerococcus viridans lactate oxidase.

PubMed

Stoisser, Thomas; Brunsteiner, Michael; Wilson, David K; Nidetzky, Bernd

2016-06-15

L-Lactate oxidase (LOX) belongs to a large family of flavoenzymes that catalyze oxidation of α-hydroxy acids. How in these enzymes the protein structure controls reactivity presents an important but elusive problem. LOX contains a prominent tyrosine in the substrate binding pocket (Tyr(215) in Aerococcus viridans LOX) that is partially responsible for securing a flexible loop which sequesters the active site. To characterize the role of Tyr(215), effects of substitutions of the tyrosine (Y215F, Y215H) were analyzed kinetically, crystallographically and by molecular dynamics simulations. Enzyme variants showed slowed flavin reduction and oxidation by up to 33-fold. Pyruvate release was also decelerated and in Y215F, it was the slowest step overall. A 2.6-Å crystal structure of Y215F in complex with pyruvate shows the hydrogen bond between the phenolic hydroxyl and the keto oxygen in pyruvate is replaced with a potentially stronger hydrophobic interaction between the phenylalanine and the methyl group of pyruvate. Residues 200 through 215 or 216 appear to be disordered in two of the eight monomers in the asymmetric unit suggesting that they function as a lid controlling substrate entry and product exit from the active site. Substitutions of Tyr(215) can thus lead to a kinetic bottleneck in product release.

Induced resistance to infection of lobsters Homarus americanus by Aerococcus viridans (var.) homari, the bacterium causing gaffkemia.

PubMed

Stewart, James E; Arie, B; Marks, L J

2004-12-13

A vaccine composed of steam sterilized (autoclaved) cells of a virulent strain of Aerococcus viridans (var.) homari was effective in protecting lobsters Homarus americanus against gaffkemia. At 15 degrees C the heat-killed vaccines (HKV) at concentrations between 1 and 5 x 10(7) particles kg(-1) lobster body wt induced maximal protection in induction periods ranging from 7 to 11 d. Protection was substantial over the course of a 30 d post-induction trial period. Spring-caught lobsters (i.e. those more fully rehabilitated following ecdysis) gained more protection (LD50 = 1.9 x 10(4)) from the vaccination than did those caught in the late fall-early winter period (lobsters that were not yet fully recovered from ecdysis) (LD50 = 3.2 x 10(3)). The protection offered by the HK vaccine was comparable to that induced by a vaccine produced by incubating the pathogen with low concentrations (2 pg ml(-1)) of the antibiotic vancomycin. The bacterins produced by both methods exhibited similar new properties: (1) agglutination at low titres by lobster hemolymph serum, suggesting an impaired capsule layer, and (2) increased permeability to the large Alcian Blue molecule. With both vaccines, the protection may be a direct result of increased exposure to intact bacterial cell structures by the lobster defences, an exposure which otherwise would be prevented by an intact capsule.

A Decennium of Etiology and Antimicrobial Susceptibility Patterns in Patients with Infective Endocarditis at a University Hospital, Thailand.

PubMed

Nakaranurack, Chotirat; Puttilerpong, Chankit; Suwanpimolkul, Gompol

2017-05-24

Infective endocarditis is an infection with a high mortality rate. Antimicrobial therapy is important for treatment, but data on antimicrobial susceptibilities are limited. This retrospective study analyzed data on the causative microorganisms and antimicrobial susceptibility patterns in patients with infective endocarditis 18 years of age or older who received inpatient care between 2006 and 2015 at King Chulalongkorn Memorial Hospital. A total of 213 patients fulfilled the inclusion criteria. Streptococcus spp. (54.5%) was the most common organism. Viridans streptococcus (46%) was the leading pathogen, followed by Group B streptococcus (27%). The majority of Streptococcus spp. were susceptible to penicillin (82.7%). Among Streptococcus spp., Streptococcus suis had the highest MIC 90 of penicillin and cefotaxime (1.65 and 0.95 μg/ml, respectively). There was a statistically significant increase in the MICs of penicillin and cefotaxime for Streptococcus suis (P = 0.03 and 0.04). Only 45.5% of Streptococcus suis and 77.5% of Viridans streptococcus were susceptible to penicillin. All Enterococcus spp. and Staphylococcus spp. were susceptible to vancomycin. In conclusion, the prevalence of Group B streptococcus isolates increased among patients with infective endocarditis in Thailand. Streptococcus suis had the highest MIC 90 and proportion of isolates not susceptible to penicillin. Rigorous restriction of the use of antimicrobial agents in animal feeds should be a primary concern.

Outcome of the Vaginal Infections and Prematurity Study: results of a clinical trial of erythromycin among pregnant women colonized with group B streptococci.

PubMed

Klebanoff, M A; Regan, J A; Rao, A V; Nugent, R P; Blackwelder, W C; Eschenbach, D A; Pastorek, J G; Williams, S; Gibbs, R S; Carey, J C

1995-05-01

Our purpose was to determine whether erythromycin treatment of pregnant women colonized with group B streptococci would reduce the occurrence of low birth weight (< 2500 gm) and preterm (< 37 completed weeks) birth. In a double-blind clinical trial, 938 carriers of group B streptococci were randomized to receive erythromycin base (333 mg three times a day) or matching placebo beginning during the third trimester and before 30 weeks and continuing for 10 weeks or until 35 weeks 6 days of pregnancy. Pregnancy outcomes were available for 97% of randomized women; 14% of subjects withdrew from the trial. Birth weight < 2500 gm occurred in 8.6% of the erythromycin and 6.1% of the placebo recipients (relative risk 1.4, 0.9 to 2.2, p = 0.16). Preterm delivery occurred in 11.4% of women randomized to erythromycin and in 12.3% randomized to placebo (relative risk 0.9, 95% confidence limits 0.6 to 1.3, p = 0.65). Greater benefit of erythromycin in reducing these outcomes was not observed among women reporting the best compliance. In this study of pregnant women colonized with group B streptococci treatment with erythromycin was not shown to be effective at prolonging gestation or reducing low birth weight. Greater than anticipated complicating factors, including spontaneous clearance of the organism, use of nontrial antibiotics, and density of colonization, may have resulted in population sizes too small to detect a benefit of treatment. Future studies should take these factors into account in determining sample sizes.

[Analysis of causes and whole microbial structure in a case of rampant caries].

PubMed

Hu, Xiao-Yu; Yao, Yu-Fei; Cui, Bo-Miao; Lv, Jun; Shen, Xin; Ren, Biao; Li, Ming-Yun; Guo, Qiang; Huang, Rui-Jie; Li, Yan

2016-10-20

To analyze the whole microbial structure in a case of rampant caries to provide evidence for its prevention and treatment. Clinical samples including blood, supragingival plaque, plaque in the caries cavity, saliva, and mucosal swabs were collected with the patient's consent. The blood sample was sent for routine immune test, and the others samples were stained using Gram method and cultured for identifying colonies and 16S rRNA sequencing. DNA was extracted from the samples and tested for the main cariogenic bacterium (Streptococcus mutans) with qPCR, and the whole microbial structure was analyzed using DGGE. The patient had a high levels of IgE and segmented neutrophils in his blood. Streptococci with extremely long chains were found in the saliva samples under microscope. Culture of the samples revealed the highest bacterial concentration in the saliva. The relative content of hemolytic bacterium was detected in the samples, the highest in the caries cavity; C. albicans was the highest in the dental plaque. In addition, 33 bacterial colonies were identified by VITEK system and 16S rDNA sequence phylogenetic analysis, and among them streptococci and Leptotrichia wade were enriched in the dental plaque sample, Streptococcus mutans, Fusobacterium nucleatum, and Streptococcus tigurinus in the caries cavity, and Lactobacillus in the saliva. S. mutans was significantly abundant in the mucosal swabs, saliva and plaque samples of the caries cavity as shown by qPCR. Compared to samples collected from a healthy individual and another two patients with rampant caries, the samples from this case showed a decreased bacterial diversity and increased bacterial abundance shown by PCR-DGGE profiling, and multiple Leptotrichia sp. were detected by gel sequencing. The outgrowth of such pathogenic microorganisms as S. mutans and Leptotrichia sp., and dysbiosis of oral microbial community might contribute to the pathogenesis of rampant caries in this case.

Extraction of Cell-Wall Polysaccharide Antigen from Streptococci

PubMed Central

Slade, Hutton D.

1965-01-01

Slade, Hutton D. (Northwestern University Medical School, Chicago, Ill., and Max-Planck Institut für Immunbiologie, Freiburg, Germany). Extraction of cell-wall polysaccharide antigen from streptococci. J. Bacteriol. 90:667–672. 1965.—The carbohydrate grouping antigens in the cell walls of streptococci belonging to groups A, E, G, L, and T were extracted with 5% trichloroacetic acid at 90 C. The antigens were removed also from dry whole cells by extraction with trichloroacetic acid followed by treatment with phenol-water. Details of the methods are presented. The antigens obtained by use of either of these procedures were suitable for studies on immunological specificity and chemical structure. Quantitative enzymatic and chemical analyses of two group E antigens and one group T preparation showed the presence of l-rhamnose (22 to 44%), d-glucose (7 to 22%), d-galactose (T antigen only, 26%), glucosamine (2 to 16%), and galactosamine (T antigen only, 3%). In addition, analyses of A and G antigen preparations are presented. The protein and phosphate content of the A and E antigens were about 1% each. Quantitative precipitin curves of these antigens are presented. PMID:16562065

Stimulation of complement component C3 synthesis in macrophagelike cell lines by group B streptococci.

PubMed Central

Goodrum, K J

1987-01-01

Complement levels and complement activation are key determinants in streptococcus-induced inflammatory responses. Activation of macrophage functions, such as complement synthesis, by group B streptococci (GBS) was examined as a possible component of GBS-induced chronic inflammation. Using an enzyme-linked immunosorbent assay, secreted C3 from mouse macrophagelike cell lines (PU5-1.8 and J774A.1) was monitored after cultivation with GBS. Whole, heat-killed GBS (1 to 10 CFU per macrophage) of both type Ia and III strains induced 25 to 300% increases in secreted C3 in both cell lines after a 24-h cultivation. GBS-treated cell lines exhibited increases in secreted lysozyme (10%) and in cellular protein (25 to 50%). Inhibition of macrophage phagocytosis by cytochalasin B inhibited GBS stimulation of C3. Purified cell walls of GBS type III strain 603-79 (1 to 10 micrograms/ml) also enhanced C3 synthesis. Local enhancement of macrophage C3 production by ingested streptococci or by persistent cell wall antigens may serve to promote chronic inflammatory responses. PMID:3552987

Horizontal transmission of streptococcus mutans in schoolchildren

PubMed Central

Castillo, Ana M.; Liébana, Maria J.; Castillo, Francisca; Martín-Platero, Antonio; Liébana, José

2012-01-01

Objetive: The aim of this study was to analyze possible horizontal transmission patterns of S. mutans among 6-7-yr-old schoolchildren from the same class, identifying genotypes and their diversity and relationship with caries disease status. Study Design: Caries indexes and saliva mutans streptococci and lactobacilli counts were recorded in 42 schoolchildren. Mutans streptococci colonies were identified by means of biochemical tests and all S. mutans strains were genotyped by arbitrarily primed polymerase chain reaction. A child was considered free of S. mutans when it could not be isolated in 3 samples at 1-week intervals. Results: S. mutans was isolated in 30 schoolchildren: 20 having one genotype and 10 two genotypes. Higher mutans streptococci and caries index values were found in those with two genotypes. Five genotypes were isolated in more than 1 schoolchild and one of these was isolated in 3 schoolchildren. Our results suggest that horizontal transmission may take place. Conclusion: Schoolchildren aged 6-7 yrs may be the source of mutual transmission of S. mutans. Key words:Streptococcus mutans, Horizontal transmission, AP-PCR, genotyping PMID:22143733

Differentiation of Cariogenic Streptococci by Fluorescent Antibody1

PubMed Central

Jablon, James M.; Zinner, Doran D.

1966-01-01

Jablon, J. M. (University of Miami, Miami, Fla.), and D. D. Zinner. Differentiation of cariogenic streptococci by fluorescent antibody. J. Bacteriol. 92:1590–1596. 1966.—Eight strains of streptococci were isolated from human carious lesions by the fluorescent-antibody (FA) technique. Seven of these strains produced experimental caries in hamsters or rats maintained on a high sucrose diet. The eighth strain was noncariogenic in animals but possessed some antigenic components in common with the cariogenic strains. On the basis of antigen-antibody reactions by microprecipitin and agar-gel diffusion patterns, the strains were divided into four groups; these groups differed with regard to their cariogenic activity in hamsters. Fluorescein-conjugated antisera, prepared against the human strains, showed some cross-reactions which interfered with the efficacy of the FA technique in differentiating between the related streptococcal groups. To eliminate these cross-reactions, a small amount of related-strain antisera was added to the fluorescein-conjugated antisera to the cariogenic strains. This technique is effective in blocking cross-reactions and should be tried wherever cross-reactions are encountered in the FA technique. Images PMID:5334765

Differentiation of Streptococcus lactis var. maltigenes from Other Lactic Streptococci1

PubMed Central

Gordon, D. F.; Morgan, M. E.; Tucker, J. S.

1963-01-01

Strains of lactic streptococci isolated from samples of raw milk which had developed a malty aroma were subjected to the cultural, physiological, and serological tests commonly employed in the classification of streptococci. None of the strains could be differentiated from Streptococcus lactis by these tests. Resting cells of strains which produced an organoleptically detectable malty aroma when cultured in milk were usually found to possess an active α-ketoacid decarboxylase, indicating the presence of the mechanism responsible for the characteristic aroma production. This decarboxylase activity was either weak or nonexistent in the nonmalty strains, and no activity was detected in known strains of S. lactis, S. cremoris, or S. diacetilactis. The malty strains usually produced higher acidities in milk than did the nonmalty strains, and, in most instances, they developed a granular type of growth sediment in broth, as opposed to a viscid sediment. Many of them gave weakly positive Voges-Proskauer tests in glucose broth with or without added citrate and appeared to be somewhat more resistant to nisin than the nonmalty strains. PMID:13949187

STUDIES ON NON-HEMOLYTIC STREPTOCOCCI ISOLATED FROM THE RESPIRATORY TRACT OF MAN

PubMed Central

Horsfall, Frank L.

1951-01-01

The type specific immunological properties of certain non-hemolytic streptococci, including Str. salivarius type I and type II, present in the respiratory tract of human beings appear to be dependent upon the presence of capsular polysaccharides. The levans formed from sucrose by Str. salivarius (encapsulated S cells or non-encapsulated R variants), or by cell-free enzymes derived from these microorganisms, are indistinguishable immunologically and show no evidence of type specificity. Such levans appear to be immunologically distinct from and unrelated to the capsular polysaccharides of the microorganisms which produce them. PMID:14824398

[Streptococcus pyogenes or group A streptococcal infections in child: French national reference center data].

PubMed

Bidet, P; Plainvert, C; Doit, C; Mariani-Kurkdjian, P; Bonacorsi, S; Lepoutre, A; Bouvet, A; Poyart, C; Bingen, E

2010-02-01

Since the 1980s, infections due to Streptococcus pyogenes or group A streptococci (GAS) were marked by the increase in invasive infections and the emergence of clones which were resistant to macrolides. Those challenges led the French national reference center for streptococci to enhance the epidemiological survey and the characterization of GAS strains, in collaboration with the National Institute for Public Health Surveillance. Active surveillance is of major importance for implementation of therapeutic and prophylactic guidelines and for evaluation of future streptococcal vaccines. Copyright 2009 Elsevier Masson SAS. All rights reserved.

Bacterial Pollution Indicators in the Intestinal Tract of Freshwater Fish

PubMed Central

Geldreich, Edwin E.; Clarke, Norman A.

1966-01-01

A study was made of the occurrence, distribution, and persistence of coliforms, fecal coliforms, and fecal streptococci in the intestinal tract of freshwater fish. A total of 132 fish representing 14 different species were used in various phases of these experiments. Examination of the intestinal contents of 78 fish from moderately polluted sections of the Little Miami River indicated that fecal coliform densities were lowest in bluegills (less than 20 per gram) and highest in catfish (1,090,000 per gram). Levels of fecal streptococci for these two species were 220 and 240,000 per gram, respectively. The occurrence of fecal coliforms in fish caught in this stream reflected the warm-blooded-animal-pollution level of the water. All fish used in this phase of the study were caught during July, August, and September when the water temperatures were between 13 and 18 C. The fate of fecal coliforms and Streptococcus faecalis in the fish intestine indicated that these organisms can probably survive and multiply when fish and water temperatures are 20 C or higher, but only when the organisms are retained in the gut for periods beyond 24 hr. Based on the biochemical reactions for 3,877 coliform strains isolated from 132 freshwater fish of 14 different species, 91.4% of all strains were composed of five IMViC types. In a similar study of the biochemical reactions of 850 streptococci isolated from the intestinal tract of 55 freshwater fish, the predominant strains included S. faecalis and various closely associated biotypes. No consistently recurring pattern for either coliforms or streptococci could be developed to identify species of fish investigated. The composition of the intestinal flora is, however, related in varying degree to the level of contamination of water and food in the environment. Images Fig. 1 Fig. 2 PMID:6008184

Effects of Lactobacillus salivarius-containing tablets on caries risk factors: a randomized open-label clinical trial

PubMed Central

2014-01-01

Background To evaluate the effects of the lactic acid bacterium Lactobacillus salivarius on caries risk factors. Methods The study was performed in 64 healthy volunteers to evaluate the effects of L. salivarius-containing tablets on caries risk factors. The participants were divided randomly into four groups, and took tablets containing L. salivarius WB21, L. salivarius TI 2711, Ovalgen® DC (antibody against glucosyltransferase from Streptococcus mutans), or xylitol. Levels of mutans streptococci and lactobacilli, amount of salivary flow, salivary pH, and salivary buffering capacity were assessed before and after taking the tablets. Subsequently, a short-term administration trial using L. salivarius WB21-containing tablets was performed in eight healthy volunteers. The participants took L. salivarius WB21-containing tablets (2.0 × 109 colony forming units/day) for 2 weeks, and the numbers of mutans streptococci in saliva were counted. Results The levels of mutans streptococci seemed to decrease in the L. salivarius WB21, TI 2711, and Ovalgen® DC groups compared to the xylitol group, with no significant differences between the groups. Lactobacilli levels significantly increased in the L. salivarius WB21 and TI 2711 groups compared to the other groups. Concerning salivary flow and salivary pH, no significant differences were observed between the groups. The salivary buffering capacity significantly increased in the L. salivarius TI 2711 group (P = 0.003) and Ovalgen® DC group (P = 0.002) compared to the xylitol group. The short-term administration trial showed that the L. salivarius WB21-containing tablets significantly decreased the number of mutans streptococci (P = 0.039). Conclusion L. salivarius-containing tablets were suggested to increase resistance to caries risk factors. Trial registration UMIN000013160 (registration date: February 14, 2014). PMID:25178882

Streptococcal throat infections and exacerbation of chronic plaque psoriasis: a prospective study.

PubMed

Gudjonsson, J E; Thorarinsson, A M; Sigurgeirsson, B; Kristinsson, K G; Valdimarsson, H

2003-09-01

Guttate psoriasis has a well-known association with streptococcal throat infections but the effects of these infections in patients with chronic psoriasis remains to be evaluated in a prospective study. To determine whether streptococcal throat infections are more common in and can cause exacerbation in patients with chronic psoriasis. Two hundred and eight patients with chronic plaque psoriasis and 116 unrelated age-matched household controls were followed for 1 year. At recruitment all patients were examined, their disease severity scored and throat swabs taken. Patients and corresponding controls were then re-examined and tested for streptococcal colonization whenever they reported sore throat or exacerbation of their psoriasis during the study period. The psoriasis patients reported sore throat significantly more often than controls (61 of 208 vs. three of 116, P < 0.0001), and beta-haemolytic streptococci of Lancefield groups A, C and G (M protein-positive streptococci) were more often cultured from the patients than the controls (19 of 208 vs. one of 116, P = 0.003). A significant exacerbation of psoriasis (P = 0.004) was observed only if streptococci were isolated and the patients were assessed 4 days or later after the onset of sore throat. No difference was observed between groups A, C or G streptococci in this respect. This study confirms anecdotal and retrospective reports that streptococcal throat infections can cause exacerbation of chronic plaque psoriasis. It is concluded that psoriasis patients should be encouraged to report sore throat to their physician and that early treatment of streptococcal throat infections might be beneficial in psoriasis. A controlled trial for assessing potential benefits of tonsillectomy in patients with severe psoriasis should also be considered.

Use of phylogenetic and phenotypic analyses to identify nonhemolytic streptococci isolated from bacteremic patients.

PubMed

Hoshino, Tomonori; Fujiwara, Taku; Kilian, Mogens

2005-12-01

The aim of this study was to evaluate molecular and phenotypic methods for the identification of nonhemolytic streptococci. A collection of 148 strains consisting of 115 clinical isolates from cases of infective endocarditis, septicemia, and meningitis and 33 reference strains, including type strains of all relevant Streptococcus species, were examined. Identification was performed by phylogenetic analysis of nucleotide sequences of four housekeeping genes, ddl, gdh, rpoB, and sodA; by PCR analysis of the glucosyltransferase (gtf) gene; and by conventional phenotypic characterization and identification using two commercial kits, Rapid ID 32 STREP and STREPTOGRAM and the associated databases. A phylogenetic tree based on concatenated sequences of the four housekeeping genes allowed unequivocal differentiation of recognized species and was used as the reference. Analysis of single gene sequences revealed deviation clustering in eight strains (5.4%) due to homologous recombination with other species. This was particularly evident in S. sanguinis and in members of the anginosus group of streptococci. The rate of correct identification of the strains by both commercial identification kits was below 50% but varied significantly between species. The most significant problems were observed with S. mitis and S. oralis and 11 Streptococcus species described since 1991. Our data indicate that identification based on multilocus sequence analysis is optimal. As a more practical alternative we recommend identification based on sodA sequences with reference to a comprehensive set of sequences that is available for downloading from our server. An analysis of the species distribution of 107 nonhemolytic streptococci from bacteremic patients showed a predominance of S. oralis and S. anginosus with various underlying infections.

Lysis of grouped and ungrouped streptococci by lysozyme.

PubMed

Coleman, S E; van de Rijn, I; Bleiweis, A S

1970-11-01

Thirty strains of streptococci were tested for lysis with lysozyme, and 29 of these could be lysed by the following method: (i) suspension of the cells to a Klett reading of 200 units (no. 42 filter) in 0.01 m tris(hydroxymethyl)aminomethane buffer, pH 8.2, after washing twice with the buffer; (ii) addition of lysozyme to a final concentration of 250 mug/ml with incubation for 60 min at 37 C; (iii) addition of sodium lauryl sulfate (SLS) to a final concentration of 0.2% and incubation up to an additional 15 min at 37 C. Significant lysis was obtained only after the addition of SLS. (Strains of groups A, E, and G were treated with trypsin at a concentration of 200 mug/ml for 2 hr at 37 C before exposure to lysozyme.) These parameters for optimal lysis of streptococci by lysozyme were established by testing the group D Streptococcus faecalis strain 31 which lyses readily with lysozyme and the group H strain Challis which is less susceptible to the action of the enzyme. Viability of S. faecalis decreased 96% after 3 min of exposure to 250 mug of lysozyme per ml, whereas the more resistant strain Challis retained 27% of the initial viability after the same period. After 60 min, there was almost total loss of viability in each case. Variations of three methods of lysing streptococci with lysozyme were compared with respect to the decrease in turbidity and the release of protein and deoxyribonucleic acid (DNA) effected by each variation. The method presented in this paper allowed the greatest release of these cytoplasmic constituents from S. faecalis and strain Challis. Transformation experiments using DNA obtained from strain Challis (streptomycinresistant) by this method showed that the DNA released is biologically active.

Effects of Lactobacillus salivarius-containing tablets on caries risk factors: a randomized open-label clinical trial.

PubMed

Nishihara, Tetsuyo; Suzuki, Nao; Yoneda, Masahiro; Hirofuji, Takao

2014-09-02

To evaluate the effects of the lactic acid bacterium Lactobacillus salivarius on caries risk factors. The study was performed in 64 healthy volunteers to evaluate the effects of L. salivarius-containing tablets on caries risk factors. The participants were divided randomly into four groups, and took tablets containing L. salivarius WB21, L. salivarius TI 2711, Ovalgen® DC (antibody against glucosyltransferase from Streptococcus mutans), or xylitol. Levels of mutans streptococci and lactobacilli, amount of salivary flow, salivary pH, and salivary buffering capacity were assessed before and after taking the tablets. Subsequently, a short-term administration trial using L. salivarius WB21-containing tablets was performed in eight healthy volunteers. The participants took L. salivarius WB21-containing tablets (2.0 × 10(9) colony forming units/day) for 2 weeks, and the numbers of mutans streptococci in saliva were counted. The levels of mutans streptococci seemed to decrease in the L. salivarius WB21, TI 2711, and Ovalgen® DC groups compared to the xylitol group, with no significant differences between the groups. Lactobacilli levels significantly increased in the L. salivarius WB21 and TI 2711 groups compared to the other groups. Concerning salivary flow and salivary pH, no significant differences were observed between the groups. The salivary buffering capacity significantly increased in the L. salivarius TI 2711 group (P = 0.003) and Ovalgen® DC group (P = 0.002) compared to the xylitol group. The short-term administration trial showed that the L. salivarius WB21-containing tablets significantly decreased the number of mutans streptococci (P = 0.039). L. salivarius-containing tablets were suggested to increase resistance to caries risk factors. UMIN000013160 (registration date: February 14, 2014).

Alanine racemase is essential for the growth and interspecies competitiveness of Streptococcus mutans.

PubMed

Wei, Yuan; Qiu, Wei; Zhou, Xue-Dong; Zheng, Xin; Zhang, Ke-Ke; Wang, Shi-Da; Li, Yu-Qing; Cheng, Lei; Li, Ji-Yao; Xu, Xin; Li, Ming-Yun

2016-12-16

D-alanine (D-Ala) is an essential amino acid that has a key role in bacterial cell wall synthesis. Alanine racemase (Alr) is a unique enzyme that interconverts L-alanine and D-alanine in most bacteria, making this enzyme a potential target for antimicrobial drug development. Streptococcus mutans is a major causative factor of dental caries. The factors involved in the survival, virulence and interspecies interactions of S. mutans could be exploited as potential targets for caries control. The current study aimed to investigate the physiological role of Alr in S. mutans. We constructed alr mutant strain of S. mutans and evaluated its phenotypic traits and interspecies competitiveness compared with the wild-type strain. We found that alr deletion was lethal to S. mutans. A minimal supplement of D-Ala (150 μg·mL -1 ) was required for the optimal growth of the alr mutant. The depletion of D-alanine in the growth medium resulted in cell wall perforation and cell lysis in the alr mutant strain. We also determined the compromised competitiveness of the alr mutant strain relative to the wild-type S. mutans against other oral streptococci (S. sanguinis or S. gordonii), demonstrated using either conditioned medium assays or dual-species fluorescent in situ hybridization analysis. Given the importance and necessity of alr to the growth and competitiveness of S. mutans, Alr may represent a promising target to modulate the cariogenicity of oral biofilms and to benefit the management of dental caries.

Evaluation of the specificity and effectiveness of selected oral hygiene actives in salivary biofilm microcosms.

PubMed

Ledder, Ruth G; Sreenivasan, Prem K; DeVizio, William; McBain, Andrew J

2010-12-01

The microbiological effects of biocidal products used for the enhancement of oral hygiene relate to the active compound(s) as well as other formulation components. Here, we test the specificities of selected actives in the absence of multiple excipients. Salivary ecosystems were maintained in tissue culture plate-based hydroxyapatite disc models (HDMs) and modified drip-flow biofilm reactors (MDFRs). Test compounds stannous fluoride (SF), SDS, triclosan (TCS), zinc lactate (ZL) and ZL with SF in combination (ZLSF) were delivered to the HDMs once and four times daily for 6 days to MDFRs. Plaques were characterized by differential viable counting and PCR-denaturing gradient gel electrophoresis (DGGE). TCS and SDS were the most effective compounds against HDM plaques, significantly reducing total viable counts (P<0.05), whilst SF, ZL and ZLSF were comparatively ineffective. TCS exhibited specificity for streptococci (P<0.01) and Gram-negative anaerobes (P<0.01) following a single dosing and also on repeated dosing in MDFRs. In contrast to single exposures, multiple dosing with ZLSF also significantly reduced all bacterial groups, whilst SF and ZL caused significant but transient reductions. According to PCR-DGGE analyses, significant (P<0.05) reductions in eubacterial diversity occurred following 6 day dosing with both TCS and ZLSF. Concordance of MDFR eubacterial profiles with salivary inocula ranged between 58 and 97%. TCS and ZL(SF) exhibited similar specificities to those reported for formulations. TCS was the most potent antibacterial, after single and multiple dosage regimens.

Role of Streptococcus sanguinis sortase A in bacterial colonization.

PubMed

Yamaguchi, Masaya; Terao, Yutaka; Ogawa, Taiji; Takahashi, Toshihito; Hamada, Shigeyuki; Kawabata, Shigetada

2006-10-01

Streptococcus sanguinis, a normal inhabitant of the human oral cavity, has low cariogenicity, though colonization on tooth surfaces by this bacterium initiates aggregation by other oral bacteria and maturation of dental plaque. Additionally, S. sanguinis is frequently isolated from infective endocarditis patients. We investigated the functions of sortase A (SrtA), which cleaves LPXTG-containing proteins and anchors them to the bacterial cell wall, as a possible virulence factor of S. sanguinis. We identified the srtA gene of S. sanguinis by searching a homologous gene of Streptococcus mutans in genome databases. Next, we constructed an srtA-deficient mutant strain of S. sanguinis by insertional inactivation and compared it to the wild type strain. In the case of the mutant strain, some surface proteins could not anchor to the cell wall and were partially released into the culture supernatant. Furthermore, adherence to saliva-coated hydroxyapatite beads and polystyrene plates, as well as adherence to and invasion of human epithelial cells were reduced significantly in the srtA-deficient strain when compared to the wild type. In addition, antiopsonization levels and bacterial survival of the srtA-deficient mutant were decreased in human whole blood. This is the first known study to report that SrtA contributes to antiopsonization in streptococci. Our results suggest that SrtA anchors surface adhesins as well as some proteins that function as antiopsonic molecules as a means of evading the human immune system. Furthermore, they demonstrate that SrtA of S. sanguinis plays important roles in bacterial colonization.

Complete genome sequence of Streptococcus troglodytae TKU31 isolated from the oral cavity of a chimpanzee (Pan troglodytes).

PubMed

Okamoto, Masaaki; Naito, Mariko; Miyanohara, Mayu; Imai, Susumu; Nomura, Yoshiaki; Saito, Wataru; Momoi, Yasuko; Takada, Kazuko; Miyabe-Nishiwaki, Takako; Tomonaga, Masaki; Hanada, Nobuhiro

2016-12-01

Streptococcus troglodytae TKU31 was isolated from the oral cavity of a chimpanzee (Pan troglodytes) and was found to be the most closely related species of the mutans group streptococci to Streptococcus mutans. The complete sequence of TKU31 genome consists of a single circular chromosome that is 2,097,874 base pairs long and has a G + C content of 37.18%. It possesses 2082 coding sequences (CDSs), 65 tRNAs and five rRNA operons (15 rRNAs). Two clustered regularly interspaced short palindromic repeats, six insertion sequences and two predicted prophage elements were identified. The genome of TKU31 harbors some putative virulence associated genes, including gtfB, gtfC and gtfD genes encoding glucosyltransferase and gbpA, gbpB, gbpC and gbpD genes encoding glucan-binding cell wall-anchored protein. The deduced amino acid identity of the rhamnose-glucose polysaccharide F gene (rgpF), which is one of the serotype determinants, is 91% identical with that of S. mutans LJ23 (serotype k) strain. However, two other virulence-associated genes cnm and cbm, which encode the collagen-binding proteins, were not found in the TKU31 genome. The complete genome sequence of S. troglodytae TKU31 has been deposited at DDBJ/European Nucleotide Archive/GenBank under the accession no. AP014612. © 2016 The Societies and John Wiley & Sons Australia, Ltd.

[Streptococcus group B in a maternity home with a decentralized system of newborn infant care (of the mother-child type)].

PubMed

Shevchuk, M S; Bochkov, I A; Semina, N A; Severov, A M; Jelinková, J; Motlová, I; Cherkasskaia, R S; Darbeeva, O S

1991-03-01

In a maternity hospital with the decentralized system of infant care the presence of the group B streptococcal colonization of puerperants (13.0 +/- 4.5%), newborn infants (25.0 +/- 4.4%) and medical staff (16.9 +/- 3.2%) was established. The strains isolated in this hospital belonged to 13 different serotypes and antigenic combinations with type 1 a/c dominating among them (28.7 +/- 4.8%). Group B streptococci were found to be transmitted by the vertical way in one out of two colonized mother-child pairs, in all other cases the nosocomial spread of streptococci occurred.

Protein A-like activity and streptococcal cross-reactions.

PubMed Central

Kingston, D

1981-01-01

Recognition of the protein A-like activity of some strains of group A streptococci has thrown doubt on much previous work suggesting antigenic cross-reactions between these streptococci and mammalian tissues. The strains used in our previous studies have now been examined by the mixed reverse passive antiglobulin reaction (MRPAH) for the 'non-specific' absorption of purified Fc portion of human IgG. They were found to have only traces of activity. The strain of Staphylococcus aureus used to control 'non-specific' absorption by bacterial cell walls was strongly positive. Protein A-like material as detected in this way was not therefore responsible for our earlier results. PMID:7039880

Detection of group B streptococci in Lim broth by use of group B streptococcus peptide nucleic acid fluorescent in situ hybridization and selective and nonselective agars.

PubMed

Montague, Naomi S; Cleary, Timothy J; Martinez, Octavio V; Procop, Gary W

2008-10-01

The sensitivity, specificity, and positive and negative predictive values for the detection of group B streptococci from Lim enrichment broth with sheep blood agar (SBA), with selective Streptococcus agar (SSA), and by a peptide nucleic acid fluorescent in situ hybridization (PNA FISH) assay were as follows: for culture on SBA, 68.4%, 100%, 100%, and 87.9%, respectively; for culture on SSA, 85.5%, 100%, 100%, and 94.1%, respectively; and for the PNA FISH assay, 97.4%, 98.3%, 96.1%, and 98.9%, respectively.

Detection of Group B Streptococci in Lim Broth by Use of Group B Streptococcus Peptide Nucleic Acid Fluorescent In Situ Hybridization and Selective and Nonselective Agars▿

PubMed Central

Montague, Naomi S.; Cleary, Timothy J.; Martinez, Octavio V.; Procop, Gary W.

2008-01-01

The sensitivity, specificity, and positive and negative predictive values for the detection of group B streptococci from Lim enrichment broth with sheep blood agar (SBA), with selective Streptococcus agar (SSA), and by a peptide nucleic acid fluorescent in situ hybridization (PNA FISH) assay were as follows: for culture on SBA, 68.4%, 100%, 100%, and 87.9%, respectively; for culture on SSA, 85.5%, 100%, 100%, and 94.1%, respectively; and for the PNA FISH assay, 97.4%, 98.3%, 96.1%, and 98.9%, respectively. PMID:18667597

In vitro bactericidal and bacteriolytic activity of ceragenin CSA-13 against planktonic cultures and biofilms of Streptococcus pneumoniae and other pathogenic streptococci.

PubMed

Moscoso, Miriam; Esteban-Torres, María; Menéndez, Margarita; García, Ernesto

2014-01-01

Ceragenin CSA-13, a cationic steroid, is here reported to show a concentration-dependent bactericidal/bacteriolytic activity against pathogenic streptococci, including multidrug-resistant Streptococcus pneumoniae. The autolysis promoted by CSA-13 in pneumococcal cultures appears to be due to the triggering of the major S. pneumoniae autolysin LytA, an N-acetylmuramoyl-L-alanine amidase. CSA-13 also disintegrated pneumococcal biofilms in a very efficient manner, although at concentrations slightly higher than those required for bactericidal activity on planktonic bacteria. CSA-13 has little hemolytic activity which should allow testing its antibacterial efficacy in animal models.

Presumptive speciation of Streptococcus bovis and other group D streptococci from human sources by using arginine and pyruvate tests.

PubMed Central

Gross, K C; Houghton, M P; Senterfit, L B

1975-01-01

A simplified method for speciation of group D streptococci is described. A total of 4,156 streptococcal isolates from human clinical material was tested for ability to hydrolyze esculin in the presence of 40% bile, ferment pyruvate, hydrolyze arginine, and grow in media containing 40% bile or 6.5% NaCl. Streptococci which hydrolyzed esculin in 40% bile, but which did not hydrolyze arginine, were also tested for their ability to ferment raffinose or sorbose. Sixty percent (2,503) of the isolates hydrolyzed esculin in the presence of 40% bile and were thus presumptively identified as group D. By application of the other criteria, 84% of these were speciated as Streptococcus faecalis, 7% were speciated as S. faecium, 6% were speciated as S. bovis, 2% were speciated as S. avium, and 1% were not identified. This scheme was shown to be both reliable and practical for use in the diagnostic laboratory. S. avium and S. bovis isolates were characterized, and 18 S. bovis isolates from patients with bacterial endocarditis were compared physiologically with 151 isolates of this species from other sources. PMID:1176592

Pediatric autoimmune neuropsychiatric disorders associated with streptococci (PANDAS): update.

PubMed

Shulman, Stanford T

2009-02-01

To review recent developments related to the proposed entity Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococci (so-called 'PANDAS'). The relationship between obsessive-compulsive disorder (OCD) or tics/Tourette's syndrome in childhood to antecedent group A streptococci (GAS) is unclear. One recent prospective cohort study found that more than 85% of clinical exacerbations in OCD/tic behavior in patients who met criteria for PANDAS had no relationship to GAS infection. Another study found no correlation between clinical exacerbations and changes in a variety of markers of brain autoimmunity, the proposed pathogenesis of PANDAS. A third recent study concluded that, compared with specialty clinic diagnoses, patients diagnosed with tics or Tourette's by physicians in the community were significantly more likely to be diagnosed with PANDAS without meeting the proposed criteria, most lacked supporting laboratory evidence of GAS infection, and they were more likely to be treated with unjustified short-term to chronic antibiotic and/or immunomodulatory therapy. Despite continued research in the field, the relationship between GAS and specific neuropsychiatric disorders (PANDAS) remains elusive. It is possible that GAS infection may be but one of the many stressors that can exacerbate tic/Tourette's or OCD in a subset of such patients.

Salivary mutans streptococci and lactobacilli modulations in young children on consumption of probiotic ice-cream containing Bifidobacterium lactis Bb12 and Lactobacillus acidophilus La5.

PubMed

Singh, Richa Polka; Damle, Satyawan Gangaram; Chawla, Amrita

2011-11-01

To compare the levels of mutans streptococci and lactobacilli in saliva of school children, before and after consumption of probiotic and control ice-cream. A double-blind, cross-over, placebo-controlled trial was carried out in forty, 12-14 year-old children, with no clinically detectable caries. The selected children were randomized equally into two groups I and II. Following an initial run-in period of 1 week, children in group I and II were given ice-creams 'A' and 'B', respectively, for 10 days. Being a cross-over study, the ice-creams were interchanged in the two groups after a 2-week wash-out period. Saliva samples at baseline and follow-up were assessed using Dentocult SM and Dentocult LB kits. On statistical evaluation, it was seen that probiotic ice-cream brought about a statistically significant reduction (p-value = 0.003) in salivary mutans streptococci levels with no significant effect on lactobacilli levels. In conclusion, probiotic ice-cream containing Bifidobacterium lactis Bb-12 ATCC27536 and Lactobacillus acidophilus La-5 can reduce the levels of certain caries-associated micro-organisms in saliva.