| molecular characterization of macrolide resistance determinants [erm(b) and mef(a)] in streptococcus pneumoniae and viridans group streptococci (vgs) isolated from adult patients with cystic fibrosis (cf). | although long-term use of azithromycin has shown a significant clinical improvement for patients with cystic fibrosis (cf), its long-term effect on the susceptibility of commensal flora within cf airways has not yet been examined. we therefore suggest that long-term use of azithromycin increases macrolide resistance in commensal streptococci. | 2009 | 19584106 |
| streptococcus tigurinus, a novel member of the streptococcus mitis group, causes invasive infections. | we recently described the novel species streptococcus tigurinus sp. nov. belonging to the streptococcus mitis group. the type strain az_3a(t) of s. tigurinus was originally isolated from a patient with infective endocarditis. according to its phenotypic and molecular characteristics, s. tigurinus is most closely related to streptococcus mitis, streptococcus pneumoniae, streptococcus pseudopneumoniae, streptococcus oralis, and streptococcus infantis. accurate identification of s. tigurinus is fac ... | 2012 | 22760039 |
| minocycline resistance in an oral streptococcus infantis isolate is encoded by tet(s) on a novel small, low copy number plasmid. | we have determined the genetic basis of minocycline resistance in a strain of streptococcus infantis isolated from a healthy human oral cavity. we demonstrate that tet(s), identical to tet(s) found on the enterococcal conjugative transposon tn6000, is responsible for the observed resistance. the gene is located on a small, low copy number plasmid and is flanked by is1216 elements. the tet(s) gene is capable of excising from the plasmid together with one of the is1216 elements. the plasmid contai ... | 2014 | 24605990 |
| isolation of streptococcus tigurinus - a novel member of streptococcus mitis group from a case of periodontitis. | streptococcus tigurinus is a new member of the streptococcus viridians group and is closely related to streptococcus mitis, streptococcus pneumoniae, streptococcus pseudopneumoniae, streptococcus oralis, and streptococcus infantis. the type strain az_3a(t) of s. tigurinus was originally isolated from a patient with infective endocarditis. accurate identification of s. tigurinus is facilitated only by newer molecular methods like 16s rrna gene analysis. during the course of study on bacteraemia a ... | 2014 | 24974898 |
| the potential role of lung microbiota in lung cancer attributed to household coal burning exposures. | bacteria influence site-specific disease etiology and the host's ability to metabolize xenobiotics, such as polycyclic aromatic hydrocarbons (pahs). lung cancer in xuanwei, china has been attributed to pah-rich household air pollution from burning coal. this study seeks to explore the role of lung microbiota in lung cancer among never smoking xuanwei women and how coal burning may influence these associations. dna from sputum and buccal samples of never smoking lung cancer cases (n = 8, in dupli ... | 2014 | 24895247 |
| betel nut chewing, oral premalignant lesions, and the oral microbiome. | oral cancers are attributed to a number of causal agents including tobacco, alcohol, human papillomavirus (hpv), and areca (betel) nut. although betel nut chewing has been established as an independent cause of oral cancer, the mechanisms of carcinogenesis are poorly understood. an investigation was undertaken to evaluate the influence of betel nut chewing on the oral microbiome and oral premalignant lesions. study participants were recruited from a dental clinic in guam. structured interviews a ... | 2017 | 28225785 |
| taxa of the nasal microbiome are associated with influenza-specific iga response to live attenuated influenza vaccine. | live attenuated influenza vaccine (laiv) has demonstrated varying levels of efficacy against seasonal influenza; however, laiv may be used as a tool to measure interactions between the human microbiome and a live, replicating virus. to increase our knowledge of this interaction, we measured changes to the nasal microbiome in subjects who received laiv to determine if associations between influenza-specific iga production and the nasal microbiome exist after immunization with a live virus vaccine ... | 2016 | 27643883 |
| the novel species streptococcus tigurinus and its association with oral infection. | 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 periodont ... | 2014 | 25483862 |
| bacterial diversity of subgingival plaque in 6 healthy chinese individuals. | the subgingival microbial ecology is complex, and little is known regarding its bacteria species composition in healthy chinese individuals. this study aimed to identify the subgingival microbiota from 6 healthy chinese subjects. subgingival samples from 6 volunteers were collected, the 16s rrna gene was amplified using broad-range bacterial primers, and clone libraries were constructed. for the initial 2,439 sequences analyzed, 383 species-level operational taxonomic units (slotus) belonging to ... | 2011 | 22977615 |
| uv-c-irradiation sublethal stress does not alter antibiotic susceptibility of the viridans group streptococci to β-lactam, macrolide, and fluoroquinolone antibiotic agents. | previous work has indicated that environmental stresses on bacteria might lead to an upregulation of stress response. led curing lights (315-400 nm) and other uv lights used in tooth whitening cosmetic procedures might act as stresses. we examined the effect of uv-c light, as a high-energy surrogate to the lower-energy uv-a light used in such instruments, to examine its effect on the antibiotic susceptibility of viridans group streptococci. | 2011 | 22887906 |
| impact of monocytic cells on recovery of uncultivable bacteria from atherosclerotic lesions. | abstract. rafferty b, jönsson d, kalachikov s, demmer rt, nowygrod r, elkind msv, bush jr h, kozarov e. (columbia university medical center, new york, ny; and weill cornell medical college, new york, ny; usa) impact of monocytic cells on recovery of uncultivable bacteria from atherosclerotic lesions. j intern med 2011; 270: 273-280. objective. epidemiological evidence suggests that infections may contribute to atherogenesis. however, with the exception of chlamydophila pneumoniae, cultivable b ... | 2011 | 21366733 |
| molecular characterization and phylogenetic analysis of quinolone resistance-determining regions (qrdrs) of gyra, gyrb, parc and pare gene loci in viridans group streptococci isolated from adult patients with cystic fibrosis. | ciprofloxacin is the most frequently used member of the fluoroquinolones during initial eradication therapy of pseudomonas aeruginosa, as well as during acute pulmonary exacerbations. however, its long-term effect on the susceptibility of the commensal flora within the cystic fibrosis (cf) airways has not yet been examined. the aim of this study was therefore to examine the consequence of oral ciprofloxacin usage on the resistance of the commensal viridans group streptococci (vgs), in terms of m ... | 2010 | 21193474 |
| evolution of streptococcus pneumoniae and its close commensal relatives. | streptococcus pneumoniae is a member of the mitis group of streptococci which, according to 16s rrna-sequence based phylogenetic reconstruction, includes 12 species. while other species of this group are considered prototypes of commensal bacteria, s. pneumoniae is among the most frequent microbial killers worldwide. population genetic analysis of 118 strains, supported by demonstration of a distinct cell wall carbohydrate structure and competence pheromone sequence signature, shows that s. pneu ... | 2008 | 18628950 |
| population diversity and dynamics of streptococcus mitis, streptococcus oralis, and streptococcus infantis in the upper respiratory tracts of adults, determined by a nonculture strategy. | we reinvestigated the clonal diversity and dynamics of streptococcus mitis and two other abundant members of the commensal microbiota of the upper respiratory tract, streptococcus oralis and streptococcus infantis, to obtain information about the origin of frequently emerging clones in this habitat. a culture-independent method was used, based on cloning and sequencing of pcr amplicons of the housekeeping gene gdh, which shows remarkable, yet species-specific, genetic polymorphism. samples were ... | 2008 | 18316382 |
| possible mechanisms of antimutagenicity in fermented soymilk prepared with a coculture of streptococcus infantis and bifidobacterium infantis. | the possible mechanisms of antimutagenicity against 4-nitroquinoline-n-oxide (4-nqo; a direct mutagen) and 3,2'-dimethyl-4-amino-biphenyl (dmab; an indirect mutagen) were examined in fermented soymilk prepared with a coculture of streptococcus thermophilus and bifidobacterium infantis. the antimutagenicity in the fermented soymilk was not due to the bioantimutagenic effect of modulation of dna repair processes. the mutagenicity of dmab decreased with increased preincubation of fermented soymilk ... | 2007 | 17477279 |
| overestimation of streptococcus mutans prevalence by nested pcr detection of the 16s rrna gene. | this study was carried out in order to compare two pcr-based methods in the detection of streptococcus mutans. the first pcr method was based on primers for the 16s rrna gene and the second method was based on specific primers that targeted the glucosyltransferase gene (gtfb). each pcr was performed with eight different streptococci from the viridans group, five other streptococci and 17 different non-streptococcal bacterial strains. direct use of the s. mutans 16s rrna gene-specific primers rev ... | 2006 | 16388038 |
| competence without a competence pheromone in a natural isolate of streptococcus infantis. | many streptococcal species belonging to the mitis and anginosus phylogenetic groups are known to be naturally competent for genetic transformation. induction of the competent state in these bacteria is regulated by a quorum-sensing mechanism consisting of a secreted peptide pheromone encoded by comc and a two-component regulatory system encoded by comde. here we report that a natural isolate of a mitis group streptococcus (atu-4) is competent for genetic transformation even though it has lost th ... | 2002 | 12057935 |
| streptococcus australis sp. nov., a novel oral streptococcus. | strains of streptococci were isolated from the mouths of children attending the united dental hospital, sydney, australia. these strains were analysed biochemically using the rapid id32 strep microsystem, were subjected to dna-dna hybridization with other members of the oral streptococci and had their 165 rrna analysed. on the basis of dna-dna hybridization, their nearest relative was streptococcus parasanguinis, whereas, on the basis of 16s rrna analysis, it was streptococcus infantis. the name ... | 2001 | 11491323 |
| mannosidase production by viridans group streptococci. | the production of mannosidase activity by all currently recognized species of human viridans group streptococci was determined using an assay in which bacterial growth was dependent on the degradation of the high-mannose-type glycans of rnase b and subsequent utilization of released mannose. rnase b is an excellent substrate for the demonstration of mannosidase activity since it is a glycoprotein with a single glycosylation site which is occupied by high-mannose-type glycoforms containing five t ... | 2001 | 11230417 |
| streptococcus peroris sp. nov. and streptococcus infantis sp. nov., new members of the streptococcus mitis group, isolated from human clinical specimens. | taxonomic studies were performed on eight strains of alpha-haemolytic streptococci that showed very low dna-dna hybridization similarity values with all established members of the mitis group of the genus streptococcus. these strains were isolated from the tooth surface and pharynx of humans. 16s rrna gene sequence analysis showed that these strains belonged to the mitis group, but that they fell into two new branches. dna-dna hybridization demonstrated two new similarity groups. from the result ... | 1998 | 9734047 |
| streptococcus panodentis sp. nov. from the oral cavities of chimpanzees. | three strains tku9, tku49 and tku50(t) , were isolated from the oral cavities of chimpanzees (pan troglodytes). the isolates were all gram-positive, facultative anaerobic cocci that lacked catalase activity. analysis of partial 16s rrna gene sequences showed that the most closely related species was streptococcus infantis (96.7%). the next most closely related species to the isolates were s. rubneri, s. mitis, s. peroris and s. australis (96.6 to 96.4%). based on the rpob and gyrb gene sequences ... | 2015 | 26242550 |
| noncontiguous finished genome sequence and description of streptococcus timonensis sp. nov. isolated from the human stomach. | strain marseille-p2915(t), a gram-positive, facultative anaerobic and nonmotile coccus, was isolated from the gastric lavage of a patient with severe anaemia. the 16s rrna and rpob gene comparison exhibited a sequence identity of 98.7 and 92.6% with streptococcus infantis strain jcm 10157(t), respectively, collocating it within the 'streptococcus mitis' group. on the basis of phenotypic and genomic analysis, we propose the validation of the type strain streptococcus timonensis sp. nov. marseille ... | 2017 | 28050252 |