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Future Microbiology Jun 2018Caries and periodontitis are the two most common human dental diseases and are caused by dysbiosis of oral flora. Although commensal microorganisms have been... (Review)
Review
Caries and periodontitis are the two most common human dental diseases and are caused by dysbiosis of oral flora. Although commensal microorganisms have been demonstrated to protect against pathogens and promote oral health, most previous studies have addressed pathogenesis rather than commensalism. Streptococcus sanguinis is a commensal bacterium that is abundant in the oral biofilm and whose presence is correlated with health. Here, we focus on the mechanism of biofilm formation in S. sanguinis and the interaction of S. sanguinis with caries- and periodontitis-associated pathogens. In addition, since S. sanguinis is well known as a cause of infective endocarditis, we discuss the relationship between S. sanguinis biofilm formation and its pathogenicity in endocarditis.
Topics: Animals; Biofilms; Dental Caries; Endocarditis, Bacterial; Humans; Microbiota; Streptococcus sanguis
PubMed: 29882414
DOI: 10.2217/fmb-2018-0043 -
The ISME Journal Jul 2023During oral biofilm development, interspecies interactions drive species distribution and biofilm architecture. To understand what molecular mechanisms determine these...
During oral biofilm development, interspecies interactions drive species distribution and biofilm architecture. To understand what molecular mechanisms determine these interactions, we used information gained from recent biogeographical investigations demonstrating an association of corynebacteria with streptococci. We previously reported that Streptococcus sanguinis and Corynebacterium durum have a close relationship through the production of membrane vesicle and fatty acids leading to S. sanguinis chain elongation and overall increased fitness supporting their commensal state. Here we present the molecular mechanisms of this interspecies interaction. Coculture experiments for transcriptomic analysis identified several differentially expressed genes in S. sanguinis. Due to its connection to fatty acid synthesis, we focused on the glycerol-operon. We further explored the differentially expressed type IV pili genes due to their connection to motility and biofilm adhesion. Gene inactivation of the glycerol kinase glpK had a profound impact on the ability of S. sanguinis to metabolize C. durum secreted glycerol and impaired chain elongation important for their interaction. Investigations on the effect of type IV pili revealed a reduction of S. sanguinis twitching motility in the presence of C. durum, which was caused by a decrease in type IV pili abundance on the surface of S. sanguinis as determined by SEM. In conclusion, we identified that the ability to metabolize C. durum produced glycerol is crucial for the interaction of C. durum and S. sanguinis. Reduced twitching motility could lead to a closer interaction of both species, supporting niche development in the oral cavity and potentially shaping symbiotic health-associated biofilm communities.
Topics: Glycerol; Streptococcus; Streptococcus sanguis; Biofilms; Symbiosis; Streptococcus mutans
PubMed: 37169870
DOI: 10.1038/s41396-023-01426-9 -
Virulence 2015Streptococcus tigurinus is a novel species of viridans streptococci, shown to cause severe invasive infections such as infective endocarditis, spondylodiscitis and... (Review)
Review
Streptococcus tigurinus is a novel species of viridans streptococci, shown to cause severe invasive infections such as infective endocarditis, spondylodiscitis and meningitis. S. tigurinus belongs to the Streptococcus mitis group and is most closely related to Streptococcus mitis, Streptococcus oralis, Streptococcus pneumoniae, Streptococcus pseudopneumoniae and Streptococcus infantis. The presence of S. tigurinus in the human oral cavity has been documented, including in patients with periodontal disease. This review addresses the available scientific knowledge on S. tigurinus and its association with closely related streptococci, and discusses its putative involvement in common oral infections. While there is as yet no strong evidence on the involvement of S. tigurinus with oral infections, its presence in the oral cavity and its association with endocarditis warrants special attention for a link between oral and systemic infection.
Topics: DNA, Bacterial; Endocarditis, Bacterial; Humans; Microbiota; Mouth; Periodontal Diseases; Periodontitis; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Streptococcal Infections; Streptococcus; Streptococcus mitis
PubMed: 25483862
DOI: 10.4161/21505594.2014.970472 -
Virulence Dec 2023is a ubiquitous commensal species of the oral cavity commonly involved as an opportunistic pathogen in cardiovascular infections. In this study, we investigated the...
is a ubiquitous commensal species of the oral cavity commonly involved as an opportunistic pathogen in cardiovascular infections. In this study, we investigated the functions of endopeptidase O (PepO) and a C3-degrading protease (CppA) in the systemic virulence of . Isogenic mutants of and obtained in strain SK36 showed increased susceptibility to C3b deposition and to opsonophagocytosis by human polymorphonuclear neutrophils (PMN). These mutants differ, however, in their profiles of binding to serum amyloid P component (SAP) and C1q, whereas both showed reduced interaction with C4b-binding protein (C4BP) and/or factor H (FH) regulators as compared to SK36. The two mutants showed defects in persistence in human blood, serum-mediated invasion of HCAEC endothelial cells, and virulence in a infection model. The transcriptional activities of and , assessed by RT-qPCR in nine wild-type strains, further indicated strain-specific profiles of / expression. Moreover, non-conserved amino acid substitutions were detected among the strains, mostly in CppA. Phylogenetic comparisons with homologues of streptococcal species of the oral and oropharyngeal sites suggested that PepO and CppA have independent ancestralities. Thus, this study showed that PepO and CppA are complement evasion proteins expressed by in a strain-specific manner, which are required for multiple functions associated with cardiovascular virulence.
Topics: Humans; Streptococcus sanguis; Virulence; Endothelial Cells; Phylogeny; Complement System Proteins; Bacterial Proteins
PubMed: 37563831
DOI: 10.1080/21505594.2023.2239519 -
PloS One 2018The viridans group streptococci comprise multiple species and have gained more recognition in recent years as common etiologic agents of bacterial endophthalmitis. The...
The viridans group streptococci comprise multiple species and have gained more recognition in recent years as common etiologic agents of bacterial endophthalmitis. The purpose of this study was to identify the species of human endophthalmitis isolates of viridans streptococci and to characterize their potential virulence attributes. The species of 22 endophthalmitis strains of viridans streptococci were identified by Matrix Assisted Laser Desorption Ionization Time-of-Flight. Susceptibilities to 3 antibiotics commonly used for bacterial endophthalmitis were determined. The extracellular milieu of each strain was tested for cytotoxicity of retinal pigmented epithelial cells, hemolysis of sheep erythrocytes, and protease activity using gelatin zymography. Identified species were Streptococcus mitis/oralis, S. salivarius, S. vestibularis, S. parasanguinis, S. mutans, S. constellatus, and S. gordonii. One strain of S. pseudoporcinus was also identified. All strains were sensitive to vancomycin, 77% were resistant to amikacin, and 27% had intermediate resistance to ceftazidime. Extracellular milieu from all strains except one (S. pseudoporcinus) were largely devoid of toxicity to retinal pigmented epithelial cells and sheep erythrocytes. Twelve strains, 10 of which were S. mitis/oralis, produced protease activity. Interestingly, not all of the S. mitis/oralis strains were proteolytic. These findings highlight the diversity of virulence factor production in ocular strains of the viridans streptococci not only at the group level but also at the species level.
Topics: Animals; Anti-Bacterial Agents; Ceftazidime; Endophthalmitis; Erythrocytes; Humans; Microbial Sensitivity Tests; Sheep; Vancomycin; Viridans Streptococci; Virulence; Virulence Factors
PubMed: 30576393
DOI: 10.1371/journal.pone.0209849 -
Peritoneal Dialysis International :... 2015The clinical courses and long-term outcomes of viridans streptococcus (VS) peritoneal dialysis (PD) peritonitis remain unclear.
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.
Topics: Female; Follow-Up Studies; Humans; Incidence; Kidney Failure, Chronic; Male; Middle Aged; Peritoneal Dialysis; Peritonitis; Retrospective Studies; Streptococcal Infections; Taiwan; Time Factors; Viridans Streptococci
PubMed: 24497584
DOI: 10.3747/pdi.2013.00108 -
Journal of the Pediatric Infectious... Jul 2023
Topics: Humans; Child; Fluoroquinolones; Levofloxacin; Anti-Bacterial Agents; Viridans Streptococci; Sepsis
PubMed: 37490395
DOI: 10.1093/jpids/piad049 -
Indian Journal of Pathology &... 2016The genus Streptococcus consists of more than 65 species. The taxonomic classification of these members is not well-defined. Among the viridans group streptococci (VGS),...
CONTEXT
The genus Streptococcus consists of more than 65 species. The taxonomic classification of these members is not well-defined. Among the viridans group streptococci (VGS), there are major taxonomic changes by the addition of many new species; whereas, most of the new strains are of animal origin and only a few have been reported to be isolated from humans. Rare and unusual species of VGS such as Streptococcus thoraltensis, S. pluranimalium and S. hyointestinalis are normally associated with different animals. Their isolation from human being is not yet reported.
AIM
To find out the rare and unusual species of viridans group streptococci from human oral cavity.
SETTINGS AND DESIGN
A case-controlled study carried out at hospital-based dental services in a tertiary care hospital.
MATERIALS AND METHODS
Subgingival plaque samples of the tooth were collected from 80 patients (34 with periodontitis and 46 without periodontitis) undergoing tooth extraction. Cultures were subcultured onto special media such as Tryptone Soya blood Agar supplemented with strepto supplement and Mutans-Sanguis Agar. Identification of strains and antimicrobial susceptibilities were measured as minimum inhibitory concentration using Vitek 2 (BioMérieux, Paris, France) automated system.
RESULTS
We have identified three strains of VGS - S. thoraltensis, S. pluranimalium and S. hyointestinalis from subgingival plaque samples from patients with periodontitis. S. thoraltensis and S. pluranimalium were found to be resistant to most of the antibiotics.
CONCLUSIONS
To the best of our knowledge, this is the first report of isolation of these rare and unusual strains from the human oral cavity.
Topics: Anti-Bacterial Agents; Dental Plaque; Humans; Microbial Sensitivity Tests; Mouth; Periodontitis; Streptococcal Infections; Viridans Streptococci
PubMed: 26960634
DOI: 10.4103/0377-4929.174817 -
The American Journal of Medicine May 2015
Topics: Aortic Valve; Aortic Valve Stenosis; Ceftriaxone; Endocarditis, Bacterial; Heart Valve Prosthesis Implantation; Humans; IgA Vasculitis; Male; Viridans Streptococci
PubMed: 25918924
DOI: 10.1016/j.amjmed.2014.12.031 -
Indian Heart Journal 2018To evaluate the role of periodontitis in viridans group streptococci (VGS) bacteremia and infective endocarditis (IE).
OBJECTIVES
To evaluate the role of periodontitis in viridans group streptococci (VGS) bacteremia and infective endocarditis (IE).
METHODS
A total of 200 subjects including two groups. Group A- 34 subjects undergoing tooth extraction with periodontitis, 46 subjects undergoing tooth extraction without periodontitis and 40 healthy controls. Group B: 40 confirmed cases of IE (17 with and 23 without periodontitis) and 40 healthy controls. Subgingival plaque and blood samples were obtained and processed by standard procedures.
RESULTS
A total of 53 blood samples (66.25%) yielded positive cultures after tooth extraction. The relationship between the presence of periodontitis and a positive blood culture was significantly higher (p=0.05) for tooth extraction cases with periodontitis (79.40%) than tooth extraction cases without periodontitis (56.50%). Periodontitis was observed in 42.5% of IE cases. Out of the 40 patients of IE, the blood samples yielded 40 different isolates, majority were viridans streptococci 15 (37.5%) and staphylococci nine (22.5%). No statistically significant difference was observed between the subgingival plaque and blood isolates of periodontitis in both the groups, indicating similarity of biotypes of viridans streptococci isolated from the blood and the subgingival plaque. Similarity was also observed between the antibiogram profiles of viridans streptococci from both the groups.
CONCLUSIONS
Periodontitis enhances viridans streptococcal bacteremia and may be a potential risk factor for IE.
Topics: Adult; Bacteremia; Endocarditis, Bacterial; Female; Gingiva; Humans; Male; Middle Aged; Periodontitis; Risk Factors; Streptococcal Infections; Viridans Streptococci
PubMed: 29716699
DOI: 10.1016/j.ihj.2017.06.019