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Internal Medicine (Tokyo, Japan) Nov 2021A 77-year-old man developed peritoneal dialysis-related peritonitis caused by Streptococcus oralis, a rare pathogen causing the disease. The infection, which was not... (Review)
Review
A 77-year-old man developed peritoneal dialysis-related peritonitis caused by Streptococcus oralis, a rare pathogen causing the disease. The infection, which was not controlled by one-week intraperitoneal administration of cefazolin and ceftazidime, was cured only after switching to two-week intravenous administration of cefazolin and ceftazidime. The patient had no major dental disease or recent history of dental intervention. This case suggests that S. oralis might cause peritoneal dialysis-related peritonitis with persistent systemic inflammation via an extra-oral infection route. The clinical course is discussed along with a review of the literature.
Topics: Aged; Anti-Bacterial Agents; Humans; Male; Peritoneal Dialysis; Peritoneal Dialysis, Continuous Ambulatory; Peritonitis; Streptococcus oralis
PubMed: 34024849
DOI: 10.2169/internalmedicine.6234-20 -
Molecular Microbiology Jul 2011The mitis group streptococci (MGS) are widespread in the oral cavity and are traditionally associated with oral health. However, these organisms have many attributes... (Review)
Review
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.
Topics: Aggregatibacter actinomycetemcomitans; Carrier State; Humans; Microbial Interactions; Mouth; Porphyromonas gingivalis; Signal Transduction; Streptococcal Infections; Viridans Streptococci
PubMed: 21635580
DOI: 10.1111/j.1365-2958.2011.07707.x -
Revista Argentina de Microbiologia 2019Members of the viridans group streptococci (VGS) are the cause of local and invasive infections. Due to the severity of these infections and taking into account that...
Members of the viridans group streptococci (VGS) are the cause of local and invasive infections. Due to the severity of these infections and taking into account that reports regarding epidemiological aspects are scarce, the aims of this work were the identification and the study of the antibiotic susceptibility profiles of the isolates recovered from patients that were hospitalized in order to find out about the resistance level and the epidemiology of infections in which VGS are involved. A hundred and thirty two isolates identified as VGS were isolated at Hospital de Clínicas «José de San Martín» during the period 2011-2015. The identification was performed by biochemical test and mass spectrometry by Matrix Assisted Laser Desorption Ionization -Time of Flight Mass Spectrometry. Streptococcus anginosus group was prevalent (42%) followed by Streptococcus mitis group (33%). In the latter, isolates of Streptococcus pneumoniae were excluded. All the VGS isolates were susceptible to ertapenem, meropenem, linezolid and vancomycin; 25.8% were resistant (I+R) to penicillin, being prevalent in the S. mitis group. Regarding ceftriaxone and cefepime 96.9% of the isolates were susceptible. Only two isolates were resistant to levofloxacin, 27.2% to tetracycline and it was not found high level resistance to gentamycin (MIC range 0.5-32μg/ml). Resistance to erythromycin was 17.4% with no significant difference between M and MLS phenotypes. The most active antibiotics were in addition to ceftriaxone and cefepime, vancomycin, ertapenem, meropenem and linezolid. These results highlight the importance of the continuous surveillance of the infections caused by VGS in order to predict a correct antibiotic therapy.
Topics: Anti-Bacterial Agents; Argentina; Drug Resistance, Bacterial; Hospitalization; Hospitals, Teaching; Humans; Microbial Sensitivity Tests; Streptococcal Infections; Urban Health; Viridans Streptococci
PubMed: 29941157
DOI: 10.1016/j.ram.2018.03.004 -
PloS One 2018Oral microbiota consists of hundreds of different species of bacteria, fungi, protozoa and archaea, important for oral health. Oral mycoses, mostly affecting mucosae,...
Oral microbiota consists of hundreds of different species of bacteria, fungi, protozoa and archaea, important for oral health. Oral mycoses, mostly affecting mucosae, are mainly caused by the opportunistic pathogen Candida albicans. They become relevant in denture-wearers elderly people, in diabetic patients, and in immunocompromised individuals. Differently, bacteria are responsible for other pathologies, such as dental caries, gingivitis and periodontitis, which affect even immune-competent individuals. An appropriate oral hygiene can avoid (or at least ameliorate) such pathologies: the regular and correct use of toothbrush, toothpaste and mouthwash helps prevent oral infections. Interestingly, little or no information is available on the effects (if any) of mouthwashes on the composition of oral microbiota in healthy individuals. Therefore, by means of in vitro models, we assessed the effects of alcohol-free commercial mouthwashes, with different composition (4 with chlorhexidine digluconate, 1 with fluoride, 1 with essential oils, 1 with cetylpyridinium chloride and 1 with triclosan), on several virulence traits of C. albicans, and a group of viridans streptococci, commonly colonizing the oral cavity. For the study here described, a reference strain of C. albicans and of streptococci isolates from pharyngeal swabs were used. Chlorhexidine digluconate- and cetylpyridinium chloride-containing mouthwashes were the most effective in impairing C. albicans capacity to adhere to both abiotic and biotic surfaces, to elicit proinflammatory cytokine secretion by oral epithelial cells and to escape intracellular killing by phagocytes. In addition, these same mouthwashes were effective in impairing biofilm formation by a group of viridans streptococci that, notoriously, cooperate with the cariogenic S. mutans, facilitating the establishment of biofilm by the latter. Differently, these mouthwashes were ineffective against other viridans streptococci that are natural competitors of S. mutans. Finally, by an in vitro model of mixed biofilm, we showed that mouthwashes-treated S. salivarius overall failed to impair C. albicans capacity to form a biofilm. In conclusion, the results described here suggest that chlorhexidine- and cetylpyridinium-containing mouthwashes may be effective in regulating microbial homeostasis of the oral cavity, by providing a positive balance for oral health. On the other side, chlorhexidine has several side effects that must be considered when prescribing mouthwashes containing this molecule.
Topics: Animals; Anti-Infective Agents, Local; Biofilms; Candida albicans; Cell Adhesion; Cell Line; Enterococcus faecalis; Epithelial Cells; Homeostasis; Humans; Mice; Microglia; Mouth; Mouthwashes; Phagocytosis; Viridans Streptococci; Virulence
PubMed: 30439994
DOI: 10.1371/journal.pone.0207262 -
Annals of Laboratory Medicine Sep 2017Two matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS)-based methods were compared for their ability to identify viridans...
Identification of viridans streptococci With Matrix-Assisted Laser Desorption & Ionization Time-of-flight Mass Spectrometry by an In-house Method and a Commercially Available System.
Two matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS)-based methods were compared for their ability to identify viridans streptococci. One approach employed a reference database and software developed in-house. All inhouse measurements were performed using an Autoflex II Instrument (Bruker Daltonics GmbH, Germany). The other system, a VITEK-MS (BioMérieux, France) was operated on the commercially available V2.0 Knowledge Base for Clinical Use database. Clinical isolates of viridans streptococci (n=184) were examined. Discrepant results were resolved by 16S rDNA sequencing. Species-level identification percentages were compared by a chi-square test. The in-house method correctly identified 179 (97%) and 175 (95%) isolates to the group and species level respectively. In comparison, the VITEK-MS system correctly identified 145 (79%) isolates to the group and species level. The difference between the two methods was statistically significant at both group and species levels. Using the Autoflex II instrument combined with an extraction method instead of whole cell analysis resulted in more reliable viridans streptococci identification. Our results suggest that combining extraction with powerful analysis software and the careful choice of well-identified strains included into the database was useful for identifying viridans streptococci species.
Topics: Databases, Factual; Humans; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Streptococcal Infections; Viridans Streptococci
PubMed: 28643493
DOI: 10.3343/alm.2017.37.5.434 -
Journal of Dental Research Apr 2023As oral bacteria grow and persist within biofilms attached to the tooth's surface, they interact with other species to form synergistic or antagonistic exchanges that...
As oral bacteria grow and persist within biofilms attached to the tooth's surface, they interact with other species to form synergistic or antagonistic exchanges that govern homeostasis for the overall population. One example are the interactions between the cariogenic species and oral commensal streptococci. Previously, we showed that the cell-cell signaling pathways of were inhibited during coculture with other oral streptococci species, leading us to posit that the transcriptome and behaviors are broadly altered during growth with these species. To test this hypothesis, we performed whole transcriptome sequencing (RNA-seq) on cocultures of with either , , or and a quadculture containing all 4 species in comparison to grown alone. Our results reveal that in addition to species-dependent changes to the transcriptome, a conserved response to oral streptococci in general can be observed. We monitored the behavior of by both microscopy imaging of biofilms and in a bacteriocin overlay assay and verified that acts similarly with each of these species but noted divergences in phenotypes when cocultured with another cariogenic () or with oral nonstreptococci species. RNA-seq with oral nonstreptococci showed lack of a consistent gene expression profile and overlap of differentially expressed genes found with commensal streptococci. Finally, we investigated the role of upregulated genes within our data sets to determine if they provided a fitness benefit during interspecies interactions. Eleven total genes were studied, and we found that a majority impacted the fitness of in various assays, highlighted by increased biomass of commensal streptococci in mixed-species biofilms. These results confirm a common, species-independent modification of behaviors with oral commensal streptococci that emphasizes the need to further evaluate oral bacteria within multispecies settings.
Topics: Streptococcus mutans; Streptococcus sanguis; Streptococcus gordonii; Symbiosis; Microbiota; Biofilms
PubMed: 36688378
DOI: 10.1177/00220345221145906 -
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 -
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 -
Mikrobiyoloji Bulteni Jan 2017Accurate identification of viridans group streptococci (VGS) frequently encountered as a causative agent of infective endocarditis is always a challenge for the clinical... (Comparative Study)
Comparative Study
Accurate identification of viridans group streptococci (VGS) frequently encountered as a causative agent of infective endocarditis is always a challenge for the clinical microbiology laboratory. Clinical microbiology laboratories generally use semi automatic/full automatic systems, molecular methods and also conventional methods for the identification of these bacteria. There are recent published studies that have used MALDI-TOF (Matrix Assisted Laser Ionization Mass Spectrometry-Time of Flight) systems in the identification of VGS. The aim of the study was to compare the performance of the conventional methods, semi automatic and MALDI-TOF MS system used in identification of VGS in oral microbiota of persons under the risk of infective endocarditis, with the gold standard method 16S rRNA sequence analysis and to create a diagnosis algorithm for the identification of VGS in clinical microbiology laboratories according to the obtained data.The study was conducted with 51 VGS strains isolated from oral microbiota of the patients with rheumatologic cardiac, valve and/or prosthetic valve diseases, under the risk of development of infective endocarditis, who have admitted to Ankara Numune Training and Research Hospital, Department of Cardiology, between February-June 2015. Standard microbiology procedures, optochin susceptibility and bile solubility tests were done for the isolation of bacteria. Bacteria were also identified with APISTREP (bioMérieux, France) and MALDI-TOF MS Bruker Microflex (Bruker Biotyper; Bruker Daltonics, Bremen, Germany) methods. BSF-8 (5´-AGAGTTTGATCCTGGCTCAG-3´) and BSR-534(5´-ATTACCGCGGCTGCTGGC-3´) primers were used in the 16S rRNA sequence analysis of bacteria. ABI PRISM 3100 Avan t Genetic Analyzer (Applied Biossytems, Foster City, CA, USA) were used for the sequence analysis. Electropherograms were analyzed in SeqScape Software (Applied Biosystems, Foster City, CA, USA) and compared with the reference sequences in GenBank with BLASTN (NCBI). According to the result of optochin and bile solubility tests, with API STREP system, 16 (31,37%) of the isolates were identified as Mitis group, 15 (29.41%) as Anginosus group, 9 (17.5%) as Salivarius group, 7 (13,73%) as Sanguinis group and 4 (7.84%) as Bovis group among optochin and bile resistant alpha hemolytic streptococci. Moreover, of the same isolates 20 (39.22%) were identified as Mitis group, 14 (27.45%) as Anginosus group, 13 (25.49%) as Salivarius group and 4 (7.84%) as Sanguinis group with MALDI-TOF system. In the identification with 16S rRNA, 25 (49.02%) of the isolates were identified as Mitis group, 13 (25.49%) as Anginosus group, 12 (23.53%) as Salivarius group and 1 (1.96%) as Sanguinis group. According to the results, it was determined that 33 (64.70%) of the isolates identified in MALDI-TOF MS system and 31 (60.78%) of the isolates identified in API STREP system were compatible with 16S rRNA sequence analysis method. For Mitis group, API STREP test sensitivity was 48.00% and specificity was 84.62% and MALDI-TOF system sensitivity was 80.00% and specificity was 100%. As VGS identification is a complicated process, we believe a single method will be insufficient for the identification of these isolates in clinical microbiology laboratories. We suggest that MALDI-TOF system can be used for VGS diagnosis, however, optochin test and/or molecular methods should also be included in the diagnosis algorithm when necessary.
Topics: Algorithms; Humans; RNA, Ribosomal, 16S; Sensitivity and Specificity; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Viridans Streptococci
PubMed: 28283005
DOI: 10.5578/mb.46504