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The New Microbiologica Apr 2011The aim of the study was to evaluate the species distribution, antimicrobial susceptibility and erythromycin-penicillin resistance mechanisms of viridans streptococci...
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.
Topics: Adult; Aged; Aged, 80 and over; Blood; Drug Resistance, Multiple, Bacterial; Erythromycin; Female; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Penicillins; Streptococcal Infections; Viridans Streptococci; Young Adult
PubMed: 21617831
DOI: No ID Found -
PloS One 2019Streptococcus mutans primary thrives on the biofilm formation on the tooth surface in sticky biofilms and under certain conditions can lead to carious lesions on the...
Streptococcus mutans primary thrives on the biofilm formation on the tooth surface in sticky biofilms and under certain conditions can lead to carious lesions on the tooth surface. To search for a new preventive material for oral biofilm-associated diseases, including dental caries, we investigated the effects of polypyrrole, which contains an electrochemical polymer and causes protonation and incorporation of anion under low pH condition, on the biofilm formation of S. mutans and other streptococci. In this study, polypyrrole was applied in biofilm formation assays with the S. mutans strains UA159 and its gtfB and gtfC double mutant (gtfBC mutant), S. sanguinis, S. mitis and S. gordonii on human saliva and bovine serum albumin-coated 96-well microtiter plates in tryptic soy broth supplemented with 0.25% sucrose. The effects of polypyrrole on biofilm formation were quantitatively and qualitatively observed. High concentrations of polypyrrole significantly inhibited the biofilm formation of S. mutans UA159 and S. sanguinis. As an inhibition mechanism, polypyrrole attached to the surface of bacterial cells, increased chains and aggregates, and incorporated proteins involving GTF-I and GTF-SI produced by S. mutans. In contrast, the biofilm formation of gtfBC mutant, S. sanguinis, S. mitis and S. gordonii was temporarily induced by the addition of low polypyrrole concentrations on human saliva-coated plate but not on the uncoated and bovine serum albumin-coated plates. Moreover, biofilm formation depended on live cells and, likewise, specific interaction between cells and binding components in saliva. However, these biofilms were easily removed by increased frequency of water washing. In this regard, the physical and electrochemical properties in polypyrrole worked effectively in the removal of streptococci biofilms. Polypyrrole may have the potential to alter the development of biofilms associated with dental diseases.
Topics: Adult; Biofilms; Humans; Polymers; Pyrroles; Saliva; Streptococcus mutans; Young Adult
PubMed: 31774855
DOI: 10.1371/journal.pone.0225584 -
Sichuan Da Xue Xue Bao. Yi Xue Ban =... May 2023Dental caries is a chronic infectious disease that occurs in the hard tissue of teeth under the influence of multiple factors, among which bacteria being a key factor.... (Review)
Review
Dental caries is a chronic infectious disease that occurs in the hard tissue of teeth under the influence of multiple factors, among which bacteria being a key factor. ( ) is considered a major pathogen that causes caries. Secondary metabolites, including bacteriocins and polyketides/non-ribosomal peptides, are a class of small-molecule compounds synthesized by . To date, polyketides/non-ribosomal peptides identified in include mutanobactin, mutanocyclin, and mutanofactin, which are synthesized by the , , and biosynthetic gene clusters, respectively. These polyketides/non-ribosomal peptides play important roles in bacterial inter-species competition, oxidative stress, and biofilm formation. In this review, we provided an overview of the synthesis, function and regulation of three polyketides/non-ribosomal peptides of , including mutanobactin, mutanocyclin, and mutanofactin, aiming to provide new insights into the cariogenic mechanism of and to promote the better management of dental caries.
Topics: Humans; Streptococcus mutans; Dental Caries; Peptides; Tooth; Biofilms
PubMed: 37248606
DOI: 10.12182/20230560302 -
Journal of Oral Science Jun 2005Dental caries is an infectious and transmissible disease, in which many genetic, environmental and behavioral risk factors interact. The mutans streptococci (MS), mainly... (Review)
Review
Dental caries is an infectious and transmissible disease, in which many genetic, environmental and behavioral risk factors interact. The mutans streptococci (MS), mainly Streptococcus mutans and Streptococcus sobrinus are the microorganisms most strongly associated with this disease. The main virulence factors associated with MS cariogenicity include adhesion, acidogenicity and acid tolerance. These properties work together to modify the physico-chemical properties of the biofilm, resulting in ecological changes in the form of increased proportions of S. mutans and other acidogenic and aciduric species. In addition, reports of higher numbers of S. mutans genotypes with increased virulence in caries-active subjects suggest the importance of microenvironmental factors in increasing the risk of caries. This review focuses on the transmission and establishment of different genotypes of S. mutans and the role they play in the development of dental caries.
Topics: Animals; Bacterial Adhesion; Bacteriocins; Dental Caries; Genetic Variation; Genotype; Humans; Streptococcal Infections; Streptococcus mutans; Streptococcus sobrinus; Virulence Factors
PubMed: 16050484
DOI: 10.2334/josnusd.47.59 -
Journal of the American Heart... Jun 2019Background Chronic infections have been reported to be risk factors for both coronary heart disease and ischemic stroke. DNA of oral bacteria, mainly from the viridans...
Background Chronic infections have been reported to be risk factors for both coronary heart disease and ischemic stroke. DNA of oral bacteria, mainly from the viridans streptococci group, has been detected in coronary thrombus aspirates of myocardial infarction and cerebral aneurysms. Viridans streptococci are known to cause infective endocarditis and possess thrombogenic properties. We studied the presence of oral bacterial DNA in thrombus aspirates of patients with acute ischemic stroke treated with mechanical thrombectomy. Methods and Results Thrombus aspirates and arterial blood were taken from 75 patients (69% men; mean age, 67 years) with acute ischemic stroke. The presence of Streptococcus species, mainly the Streptococcus mitis group, belonging to viridans streptococci as well as Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans in samples were determined using a quantitative polymerase chain reaction with specific primers and probes. The relative amount of bacterial DNA in a sample was determined with the comparative threshold cycle method. Bacterial DNA was detected in 84% (n=63) of aspired thrombi, and 16% (n=12) of samples were considered bacterial DNA negative. DNA of Streptococcus species, mainly the S mitis group, was found in 79% (n=59) of samples. The median relative amount of Streptococcus species DNA was 5.10-fold higher compared with the control blood samples from the same patients. All thrombi were negative for both P gingivalis and A actinomycetemcomitans. Conclusions This is the first study showing the common presence of bacterial DNA from viridans streptococci in aspired thrombi of patients with acute ischemic stroke. Streptococcal bacteria, mostly of oral origin, may contribute to the progression and thrombotic events of cerebrovascular diseases.
Topics: Aged; Aggregatibacter actinomycetemcomitans; Bacteria; Brain Ischemia; Female; Humans; Intracranial Thrombosis; Male; Middle Aged; Mouth; Porphyromonas gingivalis; Risk Factors; Stroke; Thrombectomy; Viridans Streptococci
PubMed: 31117858
DOI: 10.1161/JAHA.119.012330 -
Yonsei Medical Journal Mar 2011The aim of this study was to review our experience with splenic abscesses, with respect to the relevant aspects of splenic abscesses and treatment outcomes. (Review)
Review
PURPOSE
The aim of this study was to review our experience with splenic abscesses, with respect to the relevant aspects of splenic abscesses and treatment outcomes.
MATERIALS AND METHODS
We reviewed the cases of 18 patients who had splenic abscesses and who were treated at our hospital from November 1993 to December 2008.
RESULTS
The most common symptom at presentation was abdominal pain in 12 patients (66.7%). The median duration from symptom onset until establishment of a diagnosis was 22 days. Streptococcus viridans was the most common pathogen (27.8%), follow by Klebsiella pneumoniae (22.2%). The mortality rate during the inpatient period and the previous 90 days was 16.6%. Three of four patients with Klebsiella pneumoniae showed a single abscess pocket. Four patients (22.2%) underwent percutaneous drainage, eight (44.5%) received antibiotic treatment only and six (33.3%) underwent splenectomy.
CONCLUSION
There is no gold standard for treating splenic abscesses. Treatment should be customized for each patient.
Topics: Abscess; Adult; Aged; Anti-Bacterial Agents; Drainage; Female; Humans; Klebsiella Infections; Klebsiella pneumoniae; Male; Middle Aged; Splenectomy; Splenic Diseases; Streptococcal Infections; Treatment Outcome; Viridans Streptococci; Young Adult
PubMed: 21319348
DOI: 10.3349/ymj.2011.52.2.288 -
Biocontrol Science 2020Viridans group streptococci (VGS) are a common cause of infective endocarditis, and dental plaque is the major source of these bacteria. The present study examined the...
Viridans group streptococci (VGS) are a common cause of infective endocarditis, and dental plaque is the major source of these bacteria. The present study examined the antibiotic resistance of 635 VGS isolates obtained from dental plaques. Isolates from supragingival plaques were identified using the rapid ID 32 Strep and mini API reader (bioMérieux, France), and minimal inhibitory concentrations (MICs) were determined by a broth microdilution method. High rates of resistance to ampicillin and tetracycline were detected among the isolates. The most resistant species were Streptococcus sanguinis and Streptococcus salivarius. Among the 635 isolates, 9.1% were resistant to erythromycin, and 20.6% to tetracycline. All isolates were sensitive to vancomycin. Resistance to amoxicillin was observed in 0.2% of all isolates. In this study, we showed the incidence of antimicrobial resistance and the susceptibility patterns among 635 VGS isolates from dental plaque.
Topics: Anti-Bacterial Agents; Dental Plaque; Drug Resistance, Bacterial; Humans; Microbial Sensitivity Tests; Viridans Streptococci
PubMed: 32938847
DOI: 10.4265/bio.25.173 -
Journal of the American College of... Aug 2021Endocarditis has emerged as one of the most impactful adverse events after transcatheter pulmonary valve replacement (TPVR), but there is limited information about risk...
BACKGROUND
Endocarditis has emerged as one of the most impactful adverse events after transcatheter pulmonary valve replacement (TPVR), but there is limited information about risk factors for and outcomes of this complication.
OBJECTIVES
The purpose of this study was to evaluate risk factors for and outcomes of endocarditis in a large multicenter cohort.
METHODS
The authors established an international registry focused on characterizing endocarditis after TPVR, including the incidence, risk factors, characteristics, and outcomes.
RESULTS
Investigators submitted data for 2,476 patients who underwent TPVR between July 2005 and March 2020 and were followed for 8,475 patient-years. In total, 182 patients were diagnosed with endocarditis a median of 2.7 years after TPVR, for a cumulative incidence of 9.5% (95% CI: 7.9%-11.1%) at 5 years and 16.9% (95% CI: 14.2%-19.8%) at 8 years (accounting for competing risks: death, heart transplant, and explant) and an annualized incidence of 2.2 per 100 patient-years. Staphylococcus aureus and Viridans group Streptococcus species together accounted for 56% of cases. Multivariable analysis confirmed that younger age, a previous history of endocarditis, and a higher residual gradient were risk factors for endocarditis, but transcatheter pulmonary valve type was not. Overall, right ventricular outflow tract (RVOT) reintervention was less often to treat endocarditis than for other reasons, but valve explant was more often caused by endocarditis. Endocarditis was severe in 44% of patients, and 12 patients (6.6%) died, nearly all of whom were infected with Staphylococcus aureus.
CONCLUSIONS
The incidence of endocarditis in this multicenter registry was constant over time and consistent with prior smaller studies. The findings of this study, along with ongoing efforts to understand and mitigate risk, will be critical to improve the lifetime management of patients with heart disease involving the RVOT. Although endocarditis can be a serious adverse outcome, TPVR remains an important tool in the management of RVOT dysfunction.
Topics: Adult; Cardiac Catheterization; Endocarditis; Female; Heart Valve Prosthesis Implantation; Humans; Incidence; International Cooperation; Male; Pulmonary Valve; Registries; Reoperation; Staphylococcus aureus; Ventricular Outflow Obstruction; Viridans Streptococci
PubMed: 34353535
DOI: 10.1016/j.jacc.2021.05.044 -
The European Respiratory Journal Sep 2019Pleural infection is a major cause of morbidity and mortality among adults. Identification of the offending organism is key to appropriate antimicrobial therapy. It is...
BACKGROUND AND OBJECTIVES
Pleural infection is a major cause of morbidity and mortality among adults. Identification of the offending organism is key to appropriate antimicrobial therapy. It is not known whether the microbiological pattern of pleural infection is variable temporally or geographically. This systematic review aimed to investigate available literature to understand the worldwide pattern of microbiology and the factors that might affect such pattern.
DATA SOURCES AND ELIGIBILITY CRITERIA
Ovid MEDLINE and Embase were searched between 2000 and 2018 for publications that reported on the microbiology of pleural infection in adults. Both observational and interventional studies were included. Studies were excluded if the main focus of the report was paediatric population, tuberculous empyema or post-operative empyema.
STUDY APPRAISAL AND SYNTHESIS METHODS
Studies of ≥20 patients with clear reporting of microbial isolates were included. The numbers of isolates of each specific organism/group were collated from the included studies. Besides the overall presentation of data, subgroup analyses by geographical distribution, infection setting (community hospital) and time of the report were performed.
RESULTS
From 20 980 reports returned by the initial search, 75 articles reporting on 10 241 patients were included in the data synthesis. The most common organism reported worldwide was . Geographically, pneumococci and viridans streptococci were the most commonly reported isolates from tropical and temperate regions, respectively. The microbiological pattern was considerably different between community- and hospital-acquired infections, where more Gram-negative and drug-resistant isolates were reported in the hospital-acquired infections. The main limitations of this systematic review were the heterogeneity in the method of reporting of certain bacteria and the predominance of reports from Europe and South East Asia.
CONCLUSIONS
In pleural infection, the geographical location and the setting of infection have considerable bearing on the expected causative organisms. This should be reflected in the choice of empirical antimicrobial treatment.
Topics: Acinetobacter; Adult; Aged; Anti-Bacterial Agents; Enterobacteriaceae; Global Health; Humans; Klebsiella; Middle Aged; Pleural Diseases; Pseudomonas; Risk; Staphylococcal Infections; Staphylococcus aureus; Streptococcus pneumoniae; Viridans Streptococci
PubMed: 31248959
DOI: 10.1183/13993003.00542-2019 -
Antimicrobial Agents and Chemotherapy Sep 2004We assessed the mechanisms of resistance to macrolide-lincosamide-streptogramin B (MLS(B)) antibiotics and related antibiotics in erythromycin-resistant viridans group...
Molecular basis of resistance to macrolides and other antibiotics in commensal viridans group streptococci and Gemella spp. and transfer of resistance genes to Streptococcus pneumoniae.
We assessed the mechanisms of resistance to macrolide-lincosamide-streptogramin B (MLS(B)) antibiotics and related antibiotics in erythromycin-resistant viridans group streptococci (n = 164) and Gemella spp. (n = 28). The macrolide resistance phenotype was predominant (59.38%); all isolates with this phenotype carried the mef(A) or mef(E) gene, with mef(E) being predominant (95.36%). The erm(B) gene was always detected in strains with constitutive and inducible MLS(B) resistance and was combined with the mef(A/E) gene in 47.44% of isolates. None of the isolates carried the erm(A) subclass erm(TR), erm(A), or erm(C) genes. The mel gene was detected in all but four strains carrying the mef(A/E) gene. The tet(M) gene was found in 86.90% of tetracycline-resistant isolates and was strongly associated with the presence of the erm(B) gene. The cat(pC194) gene was detected in seven chloramphenicol-resistant Streptococcus mitis isolates, and the aph(3')-III gene was detected in four viridans group streptococcal isolates with high-level kanamycin resistance. The intTn gene was found in all isolates with the erm(B), tet(M), aph(3')-III, and cat(pC194) gene. The mef(E) and mel genes were successfully transferred from both groups of bacteria to Streptococcus pneumoniae R6 by transformation. Viridans group streptococci and Gemella spp. seem to be important reservoirs of resistance genes.
Topics: Anti-Bacterial Agents; Bacterial Proteins; Chloramphenicol Resistance; Drug Resistance, Bacterial; Gene Transfer, Horizontal; Kanamycin; Kanamycin Kinase; Macrolides; Microbial Sensitivity Tests; Staphylococcaceae; Streptococcus pneumoniae; Tetracycline Resistance; Viridans Streptococci
PubMed: 15328112
DOI: 10.1128/AAC.48.9.3462-3467.2004