Oral Health
K. Balamurugan, U. Prithika in Pocket Guide to Bacterial Infections, 2019
During the first months of life, species of Streptococcus are usually the first pioneering microorganisms to colonize the oral cavity with Streptococcus salivarius found mostly on the tongue dorsum and in saliva, Streptococcus mitis on the buccal mucosa, and Streptococcus sanguinis on the teeth (Socransky and Manganiello 1971; Gibbons and Houte 1975; Smith et al. 1993). The establishment of these herald microorganisms implies local ecological transformations, namely, local redox potential, pH, co-aggregation, and availability of nutrients, thereby enabling more fastidious organisms to colonize after them (Marsh 2000). As a result, we can see the appearance of Prevotellam elaninogenica, Fusobacterium nucleatum, Veillonella, Neisseria, and nonpigmented Prevotella (Kononen et al. 1992). Latter, the appearance of teeth surfaces (and with it, the gingival crevice) leads to increases of genera such as Leptotrichia, Campylobacter, Prevotelladenticola, and members of the Fusobacterium and Selenomonas genera (Kononen et al. 1994).
Rapid Infectious Diseases Diagnostics in the Critical Care Unit
Cheston B. Cunha, Burke A. Cunha in Infectious Diseases and Antimicrobial Stewardship in Critical Care Medicine, 2020
Only one S. pneumoniae UAT, the BinaxNOW (Abbott), is FDA approved and uses antibodies directed at the pneumococcal C-polysaccharide protein. Urine and cerebrospinal fluid are both acceptable specimens for testing, and turnaround time is approximately 15 minutes. Per the package insert [12], the BinaxNOW detects 23 pneumococcal serotypes, with a clinical sensitivity and specificity ranging from 86% to 90% and 71% to 94%, respectively. Cross-reactivity with closely related Streptococcus mitis is expected, and false positives from recent pneumococcal vaccination (within 5 days) are also a theoretic possibility. The severity of illness affects LFA performance. Studies using positive Streptococcus culture from sputum, pleural fluid, or blood as the diagnostic gold standard for comparison report the best LFA test performance [13–24].
Streptococcus mitis
Peter M. Lydyard, Michael F. Cole, John Holton, William L. Irving, Nino Porakishvili, Pradhib Venkatesan, Katherine N. Ward in Case Studies in Infectious Disease, 2010
The patient has subacute bacterial endocarditis (SBE) caused by Streptococcus mitis. S. mitis is one of about 20 species of α-hemolytic streptococci, also termed viridans streptococci, that are normal inhabitants of the oropharynx. In fact, collectively, viridans streptococci are the principal cause of SBE. They comprise a large fraction of the commensal microbiota of the oropharynx and many of them, particularly those that produce extracellular polysaccharide, can cause subacute bacterial endocarditis. Clinicians tend to use the trivial term ‘Streptococcus viridans’ to describe them and the clinical laboratory generally does not identify them to the species level. However, the term ‘Streptococcus viridans’ is without taxonomic standing and should not be used. As α-hemolytic streptococci are emerging as causes of head and neck infection, and because they are demonstrating increased antibiotic resistance, it is likely that these bacteria will warrant speciation in the future.
“Primary bacterial culture of bile and pancreatic juice in tumor related jaundice (TROJ) - is ascending cholangitis always our fault?”
Published in Scandinavian Journal of Gastroenterology, 2018
Tomasz Klimczak, Krzysztof Kaczka, Jerzy Klimczak, Ewa Tyczkowska-Sieroń, Anna Tyczkowska
Streptococcus mitis is a viridans streptococcus and a normal component of the human oral commensal flora. This species is a pioneer colonizer of the neonatal human oropharynx and is a numerically significant commensal throughout life [19]. A recent microbiome study showed that S.mitis is the predominant VGS (viridans group streptococci) species isolated from buccal mucosa samples from healthy persons [20]. Nevertheless, S.mitis can be the cause of many invasive diseases in immunocompromised patients especially in neutropenic patients and in patients treated with cytotoxic anticancer chemotherapy. S.mitis can primarily cause infectious endocarditis and bacteremia [19,21]. Because S.mitis is a commensal of the human oropharynx it is most likely to be translocated through epitelial barriers when patients become neutropenic (below 2.5 G/L). This seems not to be the case of our patients as only one of them developed neutropenia (she was diagnosed with S.mitis infection in the pancreatic fluid - case 3). In all other cases of S.mitis contamination neutrophil count was normal. Moreover, we did not observe any signs of S.mitis bacteremia in the follow-up of our patients. Routine blood culture examination was not performed.
Relationship between human immunodeficiency virus (HIV-1) infection and chronic periodontitis
Published in Expert Review of Clinical Immunology, 2018
Tábata Larissa S. Pólvora, Átila Vinícius V. Nobre, Camila Tirapelli, Mário Taba, Leandro Dorigan de Macedo, Rodrigo Carvalho Santana, Bruno Pozzetto, Alan Grupioni Lourenço, Ana Carolina F. Motta
Studies in the post-ART era have reported the presence of microorganisms not commonly found in the subgingival environment, including gram-positive commensal bacteria of the gastrointestinal tract as Clostridium difficile and Enterococcus faecalis, oral commensal microorganisms as Candida albicans, Mycoplasma salivarium, Entamoeba gingivalis, and opportunistic bacteria that frequently affect the respiratory or urinary tract as Staphylococcus epidermidis, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii [10,44,46]. Species of the Neisseria genus were detected in dental biofilm and saliva samples of HIV-1-infected individuals but no association with inflammation, immune parameters, or functional gene content was identified [47]. Moreover, Streptococcus mitis, which has the potential to transfer virulence factors to other bacteria, and Capnocytophaga sp., a known opportunistic commensal pathogen involved in the pathogenesis of periodontal diseases, were also detected in saliva samples [48,49]. Veillonella parvula, Prevotella pallens, Campylobacter rectus, Campylobacter concisus, and Megasphaera micronuciform were found in tongue microbiota, which may be associated with caries, periodontal diseases, and systemic infections in HIV-1-infected subjects [50].
Metagenome sequencing-based strain-level and functional characterization of supragingival microbiome associated with dental caries in children
Published in Journal of Oral Microbiology, 2019
Nezar Noor Al-Hebshi, Divyashri Baraniya, Tsute Chen, Jennifer Hill, Sumant Puri, Marisol Tellez, Nur A. Hasan, Rita R. Colwell, Amid Ismail
Over the past 15 years, Sanger sequencing of 16S rRNA clones, frequently coupled with reverse-capture checkboard DNA-DNA hybridization, has been widely employed to study the microbial community associated with dental caries [1–10]. Results of these studies have revealed significant diversity, and many novel species/phylotypes have been identified. In addition to substantiating evidence for the role of mutans streptococci and lactobacilli, they quite consistently revealed an association between a number of microorganisms and dental caries, including Propionibacterium spp., Bifidobacterium spp., Veillonella spp., Actinomyces spp. and Atopobium spp., as well as acidogenic non-mutans streptococci, especially in those subjects for which Streptococcus mutans was not detectable. It has also been possible to identify candidate health-associated bacterial species, such as Streptococcus mitis. Notably, most of these studies focused on caries of primary teeth [2,4,5,7,9,10].
Related Knowledge Centers
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