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Revista Argentina de Microbiologia 2022The aim of this review is to present an update on the susceptibility of viridans group streptococci (VGS) to β-lactam antimicrobials, with emphasis on the Argentinean... (Review)
Review
The aim of this review is to present an update on the susceptibility of viridans group streptococci (VGS) to β-lactam antimicrobials, with emphasis on the Argentinean scenario. VGS are a heterogeneous group including five groups of species, each one exhibiting peculiar susceptibility patterns to penicillin (PEN). Species of the Streptococcus mitis group are frequently nonsusceptible to PEN. PEN resistance is associated with changes in PEN-binding proteins. In Argentina, one to two thirds of VGS are nonsusceptible to PEN. Third generation cephalosporins and carbapenems are currently more effective in vitro than PEN against VGS. Mortality was associated to nonsusceptibility to PEN in at least two studies involving patients with bacteremia caused by VGS. Treatment of endocarditis due to VGS should be adjusted/to the PEN susceptibility of the isolates. Vancomycin may be an alternative choice for treating endocarditis caused by PEN-resistant isolates (MIC≥4μg/ml).
Topics: Humans; Microbial Sensitivity Tests; Streptococcal Infections; Viridans Streptococci; Penicillins; Monobactams; beta-Lactams; Anti-Bacterial Agents; Endocarditis
PubMed: 36266147
DOI: 10.1016/j.ram.2022.06.004 -
Circulation May 2021In 2007, the American Heart Association published updated evidence-based guidelines on the recommended use of antibiotic prophylaxis to prevent viridans group... (Review)
Review
BACKGROUND
In 2007, the American Heart Association published updated evidence-based guidelines on the recommended use of antibiotic prophylaxis to prevent viridans group streptococcal (VGS) infective endocarditis (IE) in cardiac patients undergoing invasive procedures. The 2007 guidelines significantly scaled back the underlying conditions for which antibiotic prophylaxis was recommended, leaving only 4 categories thought to confer the highest risk of adverse outcome. The purpose of this update is to examine interval evidence of the acceptance and impact of the 2007 recommendations on VGS IE and, if needed, to make revisions based on this evidence.
METHODS AND RESULTS
A writing group was formed consisting of experts in prevention and treatment of infective endocarditis including members of the American Dental Association, the Infectious Diseases Society of America, and the American Academy of Pediatrics, in addition to the American Heart Association. MEDLINE database searches were done for English language articles on compliance with the recommendations in the 2007 guidelines and the frequency of and morbidity or mortality from VGS IE after publication of the 2007 guidelines. Overall, there was good general awareness of the 2007 guidelines but variable compliance with recommendations. There was no convincing evidence that VGS IE frequency, morbidity, or mortality has increased since 2007.
CONCLUSIONS
On the basis of a review of the available evidence, there are no recommended changes to the 2007 VGS IE prevention guidelines. We continue to recommend VGS IE prophylaxis only for categories of patients at highest risk for adverse outcome while emphasizing the critical role of good oral health and regular access to dental care for all. Randomized controlled studies to determine whether antibiotic prophylaxis is effective against VGS IE are needed to further refine recommendations.
Topics: American Heart Association; Endocarditis; Humans; United States; Viridans Streptococci
PubMed: 33853363
DOI: 10.1161/CIR.0000000000000969 -
Microbiology Spectrum Jan 2019As a major etiological agent of human dental caries, resides primarily in biofilms that form on the tooth surfaces, also known as dental plaque. In addition to caries,...
As a major etiological agent of human dental caries, resides primarily in biofilms that form on the tooth surfaces, also known as dental plaque. In addition to caries, is responsible for cases of infective endocarditis with a subset of strains being indirectly implicated with the onset of additional extraoral pathologies. During the past 4 decades, functional studies of have focused on understanding the molecular mechanisms the organism employs to form robust biofilms on tooth surfaces, to rapidly metabolize a wide variety of carbohydrates obtained from the host diet, and to survive numerous (and frequent) environmental challenges encountered in oral biofilms. In these areas of research, has served as a model organism for ground-breaking new discoveries that have, at times, challenged long-standing dogmas based on bacterial paradigms such as and . In addition to sections dedicated to carbohydrate metabolism, biofilm formation, and stress responses, this article discusses newer developments in biology research, namely, how interspecies and cross-kingdom interactions dictate the development and pathogenic potential of oral biofilms and how next-generation sequencing technologies have led to a much better understanding of the physiology and diversity of as a species.
Topics: Biofilms; Carbohydrate Metabolism; Dental Caries; Dental Plaque; Humans; Signal Transduction; Streptococcus mutans
PubMed: 30657107
DOI: 10.1128/microbiolspec.GPP3-0051-2018 -
Frontiers in Cellular and Infection... 2024Streptococci are primary colonizers of the oral cavity where they are ubiquitously present and an integral part of the commensal oral biofilm microflora. The role oral... (Review)
Review
Streptococci are primary colonizers of the oral cavity where they are ubiquitously present and an integral part of the commensal oral biofilm microflora. The role oral streptococci play in the interaction with the host is ambivalent. On the one hand, they function as gatekeepers of homeostasis and are a prerequisite for the maintenance of oral health - they shape the oral microbiota, modulate the immune system to enable bacterial survival, and antagonize pathogenic species. On the other hand, also recognized pathogens, such as oral and , which trigger the onset of dental caries belong to the genus . In the context of periodontitis, oral streptococci as excellent initial biofilm formers have an accessory function, enabling late biofilm colonizers to inhabit gingival pockets and cause disease. The pathogenic potential of oral streptococci fully unfolds when their dissemination into the bloodstream occurs; streptococcal infection can cause extra-oral diseases, such as infective endocarditis and hemorrhagic stroke. In this review, the taxonomic diversity of oral streptococci, their role and prevalence in the oral cavity and their contribution to oral health and disease will be discussed, focusing on the virulence factors these species employ for interactions at the host interface.
Topics: Humans; Dental Caries; Streptococcus; Streptococcus mutans; Streptococcus sobrinus; Mouth; Biofilms
PubMed: 38456080
DOI: 10.3389/fcimb.2024.1357631 -
Frontiers in Cellular and Infection... 2021
Topics: Biofilms; Candida albicans; Fungi; Streptococcus mutans
PubMed: 34513739
DOI: 10.3389/fcimb.2021.753650 -
Frontiers in Cellular and Infection... 2023
Topics: Dental Caries Susceptibility; Biofilms; Streptococcus mutans
PubMed: 38106468
DOI: 10.3389/fcimb.2023.1332907 -
Frontiers in Cellular and Infection... 2023As one of the most common oral diseases in kids, early childhood caries affects the health of children throughout the world. Clinical investigations show the copresence... (Review)
Review
As one of the most common oral diseases in kids, early childhood caries affects the health of children throughout the world. Clinical investigations show the copresence of and in ECC lesions, and mechanistic studies reveal co-existence of and affects both of their cariogenicity. Clearly a comprehensive understanding of the interkingdom interaction between these two microorganisms has important implications for ECC treatment and prevention. To this end, this review summarizes advances in our understanding of the virulence of both and . More importantly, the synergistic and antagonistic interactions between these two microbes are discussed.
Topics: Child; Humans; Child, Preschool; Candida albicans; Streptococcus mutans; Dental Caries Susceptibility; Dental Caries; Biofilms
PubMed: 37260705
DOI: 10.3389/fcimb.2023.1151532 -
Frontiers in Cellular and Infection... 2023Dental biofilms are highly assembled microbial communities surrounded by an extracellular matrix, which protects the resident microbes. The microbes, including commensal... (Review)
Review
Dental biofilms are highly assembled microbial communities surrounded by an extracellular matrix, which protects the resident microbes. The microbes, including commensal bacteria and opportunistic pathogens, coexist with each other to maintain relative balance under healthy conditions. However, under hostile conditions such as sugar intake and poor oral care, biofilms can generate excessive acids. Prolonged low pH in biofilm increases proportions of acidogenic and aciduric microbes, which breaks the ecological equilibrium and finally causes dental caries. Given the complexity of oral microenvironment, controlling the acidic biofilms using antimicrobials that are activated at low pH could be a desirable approach to control dental caries. Therefore, recent researches have focused on designing novel kinds of pH-activated strategies, including pH-responsive antimicrobial agents and pH-sensitive drug delivery systems. These agents exert antibacterial properties only under low pH conditions, so they are able to disrupt acidic biofilms without breaking the neutral microenvironment and biodiversity in the mouth. The mechanisms of low pH activation are mainly based on protonation and deprotonation reactions, acids labile linkages, and H-triggered reactive oxygen species production. This review summarized pH-activated antibiofilm strategies to control dental caries, concentrating on their effect, mechanisms of action, and biocompatibility, as well as the limitation of current research and the prospects for future study.
Topics: Humans; Dental Caries; Streptococcus sanguis; Streptococcus mutans; Biofilms; Anti-Infective Agents; Hydrogen-Ion Concentration
PubMed: 36949812
DOI: 10.3389/fcimb.2023.1130506 -
Indian Journal of Medical Microbiology 2016The viridans group streptococci are a heterogeneous group of organisms which exist as commensals in the oropharynx and the gut. They cause serious infections when they... (Review)
Review
The viridans group streptococci are a heterogeneous group of organisms which exist as commensals in the oropharynx and the gut. They cause serious infections when they gain entry into sterile sites particularly in patients with predisposing conditions. Classification and species differentiation of these organisms has always been a challenge because of phenotypic differences between strains of the same species. Facklam's typing scheme based on six metabolic properties has been the most widely used and many commercial identification systems are based on it. Due to the ambiguity in species differentiation based on phenotypic tests, nucleic acid-based methods have been developed to improve the identification of these organisms. Results using genotypic methods such as 16S rRNA and sodA gene sequencing have been promising. Multilocus sequence analysis of seven house-keeping genes map, pfl, pyk, ppaC, rpoB, soda and tuf amplified by polymerase chain reaction was found to be an accurate alternative to other methods and could be useful in the characterisation of larger collections of isolates.
Topics: Bacterial Proteins; Bacterial Typing Techniques; Humans; Molecular Diagnostic Techniques; Multilocus Sequence Typing; RNA, Bacterial; RNA, Ribosomal, 16S; Streptococcal Infections; Viridans Streptococci
PubMed: 27934818
DOI: 10.4103/0255-0857.195371 -
PloS One 2020The purpose of this study was to evaluate the adherence of streptococci to disks of titanium (commercially pure titanium: CpTi) and zirconia (tetragonal zirconia...
The purpose of this study was to evaluate the adherence of streptococci to disks of titanium (commercially pure titanium: CpTi) and zirconia (tetragonal zirconia polycrystals: TZP). CpTi and yttria-stabilized TZP disks with a mirror-polished surface were used as specimens. The arithmetic mean surface roughness (Ra and Sa) and the surface wettability of the experimental specimens were measured. For analyzing the outermost layer of the experimental specimens, X-ray photoelectron spectroscopy (XPS) analysis was performed. Streptococcus sanguinis, S. gordonii, S. oralis, and S. mutans were used as streptococcal bacterial strains. These bacterial cultures were grown for 24 h on CpTi and TZP. The number of bacterial adhesions was estimated using an ATP-bioluminescent assay, and scanning electron microscope (SEM) observation of the adhered bacterial specimens was performed. No significant differences in surface roughness or wettability were found between CpTi and TZP. In XPS analyses, outermost layer of CpTi included Ti0 and Ti4+, and outermost layer of TZP included Zr4+. In the cell adhesion assay, the adherences of S. sanguinis, S. gordonii, and S. oralis to TZP were significantly lower than those to CpTi (p < 0.05); however, significant difference was not observed for S. mutans among the specimens. The adherence to CpTi and TZP of S. mutans was significantly lower than that of S. sanguinis, S. gordonii, and S. oralis. These results were confirmed by SEM. S. sanguinis, S. gordonii, and S. oralis adhered less to TZP than to CpTi, but the adherence of S. mutans was similar to both surfaces. S. mutans was less adherent compare with the other streptococci tested in those specimens.
Topics: Bacterial Adhesion; Materials Testing; Microscopy, Electron, Scanning; Photoelectron Spectroscopy; Streptococcus sanguis; Surface Properties; Titanium; Yttrium; Zirconium
PubMed: 32579584
DOI: 10.1371/journal.pone.0234524