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Infection and Immunity May 1990Thirteen strains of viridans group streptococci and two strains of other streptococci were tested for coaggregation with Candida albicans. Streptococcus sanguis strains...
Thirteen strains of viridans group streptococci and two strains of other streptococci were tested for coaggregation with Candida albicans. Streptococcus sanguis strains generally exhibited low levels of adherence to 28 degrees C-grown exponential-phase yeast cells, but starvation of yeast cells for glucose at 37 degrees C (or at 28 degrees C) increased their coaggregating activity with these streptococci by at least tenfold. This was a property common to four C. albicans strains tested, two of which were able to form mycelia (6406 and MEN) and two of which were not (MM2002 and CA2). The expression of the coaggregation adhesin during yeast cell starvation was inhibited by addition of trichodermin or amphotericin B. The strains of S. sanguis, Streptococcus gordonii, and Streptococcus oralis tested for coaggregating activity encompassed a diverse range of physiological and morphological types, yet all exhibited saturable coaggregation with starved C. albicans cells. There was no correlation of cell surface hydrophobicity, of either yeast or streptococcal cells, with their abilities to coaggregate. Strains of Streptococcus anginosus also coaggregated with starved yeast cells; Streptococcus salivarius and Streptococcus pyogenes coaggregated to a lesser degree with C. albicans, and the coaggregation with S. pyogenes was not promoted by yeast cell starvation; Streptococcus mutans and Enterococcus faecalis did not coaggregate with yeast. The coaggregation reactions of S. sanguis and S. gordonii with C. albicans were inhibited by EDTA and by heat or protease treatment of the yeast cells and were not reversible by the addition of lactose or other simple sugars. These observations extend the range of intergeneric coaggregations that are known to occur between oral microbes and suggest that coaggregations of C. albicans with viridans group streptococci may be important for colonization of oral surfaces by the yeast.
Topics: Amphotericin B; Bacterial Adhesion; Candida albicans; Culture Media; Hot Temperature; Peptide Hydrolases; Solubility; Streptococcus; Streptococcus sanguis; Surface Properties; Temperature; Trichodermin
PubMed: 2182544
DOI: 10.1128/iai.58.5.1429-1436.1990 -
Scientific Reports May 2020We examined the effect of L-arginine - (i) on the growth of L. rhamnosus GG (LrG) and (ii) combined LrG synbiotic on the growth of cariogenic S. mutans. Viability of LrG...
We examined the effect of L-arginine - (i) on the growth of L. rhamnosus GG (LrG) and (ii) combined LrG synbiotic on the growth of cariogenic S. mutans. Viability of LrG was assessed using MTT/XTT assays, confocal imaging with ADS activity measurement. The effect of L-arginine (0.5%/1%/2%) (2×/24 h) with LrG on S. mutans was evaluated by measuring the colony forming units, biofilm biomass, real-time qPCR and confocal imaging. The pH of the spent media was measured immediately and 24 h post-treatment with assessment of lactic acid. The LrG viability was highest with 2% L-arginine (p < 0.001). Confocal imaging showed that 2% L-arginine increased biofilm thickness of LrG. The 2% L-arginine and LrG synbiotic significantly inhibited the growth of S. mutans (p < 0.001) reducing the viable counts (p = 0.002) and biofilm biomass (p < 0.001). The pH of spent media was the highest when treated with 2% L-arginine and LrG synbiotic (p < 0.001) with no difference between post-treatment and 24 h post-treatment (p > 0.05). Conversely, the 2% L-arginine and LrG synbiotic showed the lowest lactic acid production (p < 0.001). This study demonstrated that L-arginine enhanced the growth of LrG. The 2% L-arginine and LrG synbiotic synergistically inhibits the growth of S. mutans with significant potential to develop as an anti-caries regimen.
Topics: Arginine; Hydrogen-Ion Concentration; Lactic Acid; Lacticaseibacillus rhamnosus; Probiotics; Streptococcus mutans; Synbiotics
PubMed: 32409686
DOI: 10.1038/s41598-020-64956-8 -
BMC Microbiology Jun 2020Viridans group streptococci of the Streptococcus mitis-oralis subgroup are important endovascular pathogens. They can rapidly develop high-level and durable...
BACKGROUND
Viridans group streptococci of the Streptococcus mitis-oralis subgroup are important endovascular pathogens. They can rapidly develop high-level and durable non-susceptibility to daptomycin both in vitro and in vivo upon exposure to daptomycin. Two consistent genetic adaptations associated with this phenotype (i.e., mutations in cdsA and pgsA) lead to the depletion of the phospholipids, phosphatidylglycerol and cardiolipin, from the bacterial membrane. Such alterations in phospholipid biosynthesis will modify carbon flow and change the bacterial metabolic status. To determine the metabolic differences between daptomycin-susceptible and non-susceptible bacteria, the physiology and metabolomes of S. mitis-oralis strains 351 (daptomycin-susceptible) and 351-D10 (daptomycin non-susceptible) were analyzed. S. mitis-oralis strain 351-D10 was made daptomycin non-susceptible through serial passage in the presence of daptomycin.
RESULTS
Daptomycin non-susceptible S. mitis-oralis had significant alterations in glucose catabolism and a re-balancing of the redox status through amino acid biosynthesis relative to daptomycin susceptible S. mitis-oralis. These changes were accompanied by a reduced capacity to generate biomass, creating a fitness cost in exchange for daptomycin non-susceptibility.
CONCLUSIONS
S. mitis-oralis metabolism is altered in daptomycin non-susceptible bacteria relative to the daptomycin susceptible parent strain. As demonstrated in Staphylococcus aureus, inhibiting the metabolic changes that facilitate the transition from a daptomycin susceptible state to a non-susceptible one, inhibits daptomycin non-susceptibility. By preventing these metabolic adaptations in S. mitis-oralis, it should be possible to deter the formation of daptomycin non-susceptibility.
Topics: Adaptation, Physiological; Amino Acids; Bacterial Proteins; Daptomycin; Drug Resistance, Bacterial; Genetic Fitness; Glucose; Microbial Sensitivity Tests; Mutation; Nucleotidyltransferases; Oxidation-Reduction; Transferases (Other Substituted Phosphate Groups); Viridans Streptococci
PubMed: 32539684
DOI: 10.1186/s12866-020-01849-w -
Archives of Disease in Childhood Sep 2006In children under 5 years of age, presenting to the paediatric emergency room with clinical and radiological findings of pneumonia, viridans streptococci were isolated...
In children under 5 years of age, presenting to the paediatric emergency room with clinical and radiological findings of pneumonia, viridans streptococci were isolated in 10/33 positive haemocultures as the only microorganism. Viridans streptococci should therefore not be ruled out as a cause of pneumonia.
Topics: Brazil; Child, Preschool; Community-Acquired Infections; Cross-Sectional Studies; Developing Countries; Humans; Infant; Pleural Effusion; Pneumonia; Streptococcal Infections; Viridans Streptococci
PubMed: 16737994
DOI: 10.1136/adc.2006.094847 -
Scientific Reports Dec 2020Dental caries is the most prevalent oral disease affecting nearly 70% of children in India and elsewhere. Micro-ecological niche based acidification due to dysbiosis in...
Dental caries is the most prevalent oral disease affecting nearly 70% of children in India and elsewhere. Micro-ecological niche based acidification due to dysbiosis in oral microbiome are crucial for caries onset and progression. Here we report the tooth bacteriome diversity compared in Indian children with caries free (CF), severe early childhood caries (SC) and recurrent caries (RC). High quality V3-V4 amplicon sequencing revealed that SC exhibited high bacterial diversity with unique combination and interrelationship. Gracillibacteria_GN02 and TM7 were unique in CF and SC respectively, while Bacteroidetes, Fusobacteria were significantly high in RC. Interestingly, we found Streptococcus oralis subsp. tigurinus clade 071 in all groups with significant abundance in SC and RC. Positive correlation between low and high abundant bacteria as well as with TCS, PTS and ABC transporters were seen from co-occurrence network analysis. This could lead to persistence of SC niche resulting in RC. Comparative in vitro assessment of biofilm formation showed that the standard culture of S. oralis and its phylogenetically similar clinical isolates showed profound biofilm formation and augmented the growth and enhanced biofilm formation in S. mutans in both dual and multispecies cultures.
Topics: Biofilms; Fusobacteria; Humans; Phylogeny; Streptococcus mutans; Streptococcus oralis
PubMed: 33277566
DOI: 10.1038/s41598-020-78057-z -
Brazilian Journal of Otorhinolaryngology 2018Peritonsillar abscess is the most common deep neck infection. The infectious microorganism may be different according to clinical factors.
INTRODUCTION
Peritonsillar abscess is the most common deep neck infection. The infectious microorganism may be different according to clinical factors.
OBJECTIVE
To identify the major causative pathogen of peritonsillar abscess and investigate the relationship between the causative pathogen, host clinical factors, and hospitalization duration.
METHODS
This retrospective study included 415 hospitalized patients diagnosed with peritonsillar abscess who were admitted to a tertiary medical center from June 1990 to June 2013. We collected data by chart review and analyzed variables such as demographic characteristics, underlying systemic disease, smoking, alcoholism, betel nut chewing, bacteriology, and hospitalization duration.
RESULTS
A total of 168 patients had positive results for pathogen isolation. Streptococcus viridans (28.57%) and Klebsiella pneumoniae (23.21%) were the most common microorganisms identified through pus culturing. The isolation rate of anaerobes increased to 49.35% in the recent 6 years (p=0.048). Common anaerobes were Prevotella and Fusobacterium spp. The identification of K. pneumoniae increased among elderly patients (age>65 years) with an odds ratio (OR) of 2.76 (p=0.03), and decreased in the hot season (mean temperature>26°C) (OR=0.49, p=0.04). No specific microorganism was associated with prolonged hospital stay.
CONCLUSION
The most common pathogen identified through pus culturing was S. viridans, followed by K. pneumoniae. The identification of anaerobes was shown to increase in recent years. The antibiotics initially selected should be effective against both aerobes and anaerobes. Bacterial identification may be associated with host clinical factors and environmental factors.
Topics: Adolescent; Adult; Anti-Bacterial Agents; Fusobacterium Infections; Fusobacterium necrophorum; Gram-Positive Bacteria; Gram-Positive Bacterial Infections; Humans; Klebsiella Infections; Klebsiella pneumoniae; Middle Aged; Peritonsillar Abscess; Prevotella; Retrospective Studies; Risk Factors; Viridans Streptococci; Young Adult
PubMed: 28756939
DOI: 10.1016/j.bjorl.2017.06.007 -
Annals of Laboratory Medicine Mar 2015Viridans group streptococci (VGS) are both commensal microbes and potential pathogens. Increasing resistance to penicillin in VGS is an ongoing issue in the clinical...
BACKGROUND
Viridans group streptococci (VGS) are both commensal microbes and potential pathogens. Increasing resistance to penicillin in VGS is an ongoing issue in the clinical environment. We investigated the difference in susceptibility and resistance to penicillin among various VGS species.
METHODS
In total 1,448 VGS isolated from various clinical specimens were analyzed over a two-yr period. Identification and antimicrobial susceptibility test was performed by the automated VITEK 2 system (bioMerieux, France) or the MicroScan MICroSTREP system (Siemens, Germany).
RESULTS
Among the 1,448 isolates, 412 were isolated from blood (28.4%). Streptococcus mitis group was the most frequently isolated (589 isolates, 40.7%), followed by the S. anginosus group (290 isolates, 20.0%), S. sanguinis group (179 isolates, 12.4%) and S. salivarius group (57 isolates, 3.9%). In total, 314 isolates could not be identified up to the species level. The overall non-susceptibility to penicillin was observed to be 40.0% (resistant, 11.2% and intermediately resistant, 28.8%) with uneven distribution among groups; 40.2% in S. sanguinis group (resistant, 5.0% and intermediately resistant, 35.2%), 60.3% in S. mitis group (resistant, 20.9% and intermediately resistant, 39.4%), 78.9% in S. salivarius group (resistant, 8.8% and intermediately resistant, 70.1%), and 6.2% in S. anginosus group (resistant, 1.7% and intermediately resistant, 4.5%).
CONCLUSIONS
Antimicrobial resistance patterns towards penicillin show differences among various VGS; this should be considered while devising an effective antimicrobial treatment against VGS.
Topics: Anti-Infective Agents; Body Fluids; Drug Resistance, Bacterial; Humans; Microbial Sensitivity Tests; Penicillins; Streptococcal Infections; Viridans Streptococci
PubMed: 25729722
DOI: 10.3343/alm.2015.35.2.205 -
Anesthesiology Aug 2006A fatal case of viridans streptococcus meningitis is reported, which occurred as a complication of epidural anesthesia. One hundred seventy-nine reported cases of... (Review)
Review
A fatal case of viridans streptococcus meningitis is reported, which occurred as a complication of epidural anesthesia. One hundred seventy-nine reported cases of post-dural puncture meningitis are reviewed. Evidence suggests that most cases are probably caused by contamination of the puncture site by aerosolized mouth commensals from medical personnel, some are caused from contamination by skin bacteria, and, less frequently, other cases are caused directly or hematogenously by spread from an endogenous infectious site. Controversy exists regarding prevention, surveillance, incidence, and treatment of this serious complication.
Topics: Adult; Anesthesia, Epidural; Anesthesia, Obstetrical; Brain Death; Brain Edema; Diagnosis, Differential; Drug Resistance, Bacterial; England; Fatal Outcome; Female; Humans; Infant, Newborn; Male; Meningitis, Bacterial; Nervous System Diseases; Postoperative Complications; Pregnancy; Spinal Puncture; Sterilization; Streptococcal Infections; Viridans Streptococci
PubMed: 16871073
DOI: 10.1097/00000542-200608000-00022 -
BMC Infectious Diseases Dec 2019The diagnosis of infective endocarditis (IE) is based on microbiological analyses and diagnostic imaging of cardiac manifestations. Echocardiography (ECHO) is preferred...
BACKGROUND
The diagnosis of infective endocarditis (IE) is based on microbiological analyses and diagnostic imaging of cardiac manifestations. Echocardiography (ECHO) is preferred for visualization of IE-induced cardiac manifestations. We investigated associations between bacterial infections and IE manifestations diagnosed by ECHO.
METHODS
In this cohort study, data from patients aged 18 years or above, with definite IE admitted at the Karolinska University Hospital between 2008 and 2017 were obtained from Swedish National Registry of Endocarditis. Bacteria registered as pathogen were primarily selected from positive blood culture and for patients with negative blood culture, bacteria found in culture or PCR from postoperative material was registered as pathogen. Patients with negative results from culture or PCR, and patients who did not undergo ECHO during hospital stay, were excluded. IE manifestations diagnosed by ECHO were obtained from the registry. Chi-squared test and two-sided Fisher's exact test was used for comparisons between categorical variables, and student's t test was used for continuous numerical variables. Multivariable analyses were performed using logistic regression. Secular trend analyses were performed using linear regression. Associations and the strength between the variables were estimated using odds ratios (ORs) with 95% confidence intervals (CIs). P < 0.05 was considered significant.
RESULTS
The most common bacteria were Staphylococcus aureus (n = 239, 49%) and viridans group streptococci (n = 102, 21%). The most common manifestations were vegetation in the mitral (n = 195, 40%), aortic (n = 190, 39%), and tricuspid valves (n = 108, 22%). Associations were seen between aortic valve vegetations and Enterococcus faecalis among patients with native aortic valves, between mitral valve vegetations and streptococci of group B or viridans group, between tricuspid valve vegetations and S. aureus among patients with intravenous drug abuse, and between perivalvular abscesses as well as cardiovascular implantable electronic device (CIED)-associated IE and coagulase negative staphylococci (all P < 0.05).
CONCLUSIONS
Associations were found between certain bacterial species and specific ECHO manifestations. Our study contributes to a better understanding of IE manifestations and their underlying bacterial etiology, which pathogens can cause severe infections and might require close follow-up and surgical treatment.
Topics: Abscess; Adult; Aged; Aortic Valve; Echocardiography; Endocarditis, Bacterial; Female; Hospital Mortality; Hospitals, University; Humans; Male; Middle Aged; Mitral Valve; Registries; Retrospective Studies; Staphylococcal Infections; Staphylococcus aureus; Streptococcal Infections; Substance Abuse, Intravenous; Sweden; Treatment Outcome; Viridans Streptococci
PubMed: 31842764
DOI: 10.1186/s12879-019-4682-z -
Journal of Clinical Microbiology Aug 2014Viridans group streptococci (VGS) are a heterogeneous group of medically important bacteria that cannot be accurately assigned to a particular species using conventional... (Comparative Study)
Comparative Study
Viridans group streptococci (VGS) are a heterogeneous group of medically important bacteria that cannot be accurately assigned to a particular species using conventional phenotypic methods. Although multilocus sequence analysis (MLSA) is considered the gold standard for VGS species-level identification, MLSA is not yet feasible in the clinical setting. Conversely, molecular methods, such as sodA and 16S rRNA gene sequencing, are clinically practical but not sufficiently accurate for VGS species-level identification. Here, we present data regarding the use of an ∼ 400-nucleotide internal fragment of the gene encoding DNA gyrase subunit B (GyrB) for VGS species-level identification. MLSA, internal gyrB, sodA, full-length, and 5' 16S gene sequences were used to characterize 102 unique VGS blood isolates collected from 2011 to 2012. When using the MLSA species assignment as a reference, full-length and 5' partial 16S gene and sodA sequence analyses failed to correctly assign all strains to a species. Precise species determination was particularly problematic for Streptococcus mitis and Streptococcus oralis isolates. However, the internal gyrB fragment allowed for accurate species designations for all 102 strains. We validated these findings using 54 VGS strains for which MLSA, 16S gene, sodA, and gyrB data are available at the NCBI, showing that gyrB is superior to 16S gene and sodA sequence analyses for VGS species identification. We also observed that specific polymorphisms in the 133-amino acid sequence of the internal GyrB fragment can be used to identify invasive VGS species. Thus, the GyrB amino acid sequence may offer a more practical and accurate method for classifying invasive VGS strains to the species level.
Topics: Bacteremia; DNA Gyrase; DNA, Bacterial; DNA, Helminth; DNA, Ribosomal; Humans; Molecular Diagnostic Techniques; Polymorphism, Genetic; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Streptococcal Infections; Viridans Streptococci
PubMed: 24899021
DOI: 10.1128/JCM.01068-14