| restriction endonuclease-fragment polymorphisms of oral viridans streptococci, compared by conventional and field-inversion gel electrophoresis. | oral streptococci formerly classified as streptococcus sanguis or streptococcus mitis have recently been divided into four species. two additional species have also been proposed for this group. each species is genetically distinct, but they have many traits in common, which makes it difficult for clinical isolates to be identified by phenotypic tests. genotypic comparison may provide an alternative approach. this study used dna fingerprint analysis for comparison of genotypes of 21 reference st ... | 1992 | 1351484 |
| streptococcus crista sp. nov., a viridans streptococcus with tufted fibrils, isolated from the human oral cavity and throat. | we studied strains of an unusual streptococcus that superficially resembles streptococcus sanguis but has fibrils that are arranged in lateral tufts. these strains were originally isolated from human throats and oral cavities and have been referred to previously as "streptococcus sanguis i," the "cr group," and the "tufted-fibril group." until now, insufficient phenotypic data have been available to allow reliable differentiation of these strains from other viridans streptococcal species, partic ... | 1991 | 1742199 |
| use of restriction fragment polymorphism analysis of rrna genes to assign species to unknown clinical isolates of oral viridans streptococci. | this study evaluated restriction fragment length polymorphisms of rrna genes (ribotyping) for genotypic identification of 53 oral isolates classified as "streptococcus sanguis" by colony morphology. isolates were from 8-h buccal plaque on lower first permanent molars of 20 subjects. dna was digested with aatii and hybridized with digoxygenin-labeled cdna of escherichia coli 16s and 23s rrna. strains were ribotyped again with alwni or pvuii on the basis of the presence or absence of a 2,290-bp aa ... | 1994 | 7512095 |
| emergence in human dental plaque and host distribution of amylase-binding streptococci. | salivary amylase is known to bind specifically to several species of oral streptococci. to assess the importance of this interaction in bacterial colonization of the oral cavity, we determined the proportion and identity of amylase-binding bacteria (abb) in dental plaque of humans and various salivary amylase-secreting and non-secreting mammalian species. the numbers of abb in undisturbed plaque collected over time from tooth surfaces of six human volunteers or from 14 other mammalian species we ... | 1994 | 7523468 |
| a comparison of conventional sem techniques, low temperature sem and the electroscan wet scanning electron microscope to study the structure of a biofilm of streptococcus crista cr3. | biofilms of streptococcus crista cr3 were generated on hydroxyapatite (ha) discs for 20 h in a continuous flow system with brain heart infusion broth dripped over the disc at a rate of 6 ml h-1. this study compares the conventional scanning electron microscope (sem) preparation techniques, of critical point drying and freeze-drying, with low temperature sem (ltsem) and electroscan generated images of hydrated biofilms, which preserve the integrity of hydrated polymers. critical point drying and ... | 1994 | 8005833 |
| coaggregation of oral lactobacilli with streptococci from the oral cavity. | the ability of oral lactobacilli to coaggregate with streptococci and actinomycetes was investigated. of the 7 species of lactobacilli studied, only two were capable of coaggregation and the coaggregation was restricted to streptococci. lactobacillus salivarius strains (2/4) coaggregated with streptococcus salivarius, streptococcus gordonii, streptococcus crista and tufted streptococcus sanguis ii strains. lactobacillus fermentum (2/3) coaggregated with s. gordonii and s. sanguis. the coaggregat ... | 1993 | 8265207 |
| grouping of oral streptococcal species using fourier-transform infrared spectroscopy in comparison with classical microbiological identification. | the grouping and identification made by fourier-transform infrared spectroscopy (ft-ir) of 40 oral streptococcal strains was compared with their known taxonomic positions. grouping was obtained by cluster analysis on the spectral distances between the first derivative spectra of the strains. spectra were divided into five spectral 'windows' and cluster analysis was either on either a combination of all five windows or on a selected window. the oral streptococci were divided into two main cluster ... | 1993 | 8297255 |
| insertional inactivation of binding determinants of streptococcus crista cc5a using tn916. | intermicrobial binding plays an important role in the ecology of the oral cavity because it represents one mechanism by which specific bacteria colonize dental plaque. the formation of "corncobs", a morphologically distinct microbial unit composed of streptococcus crista and fusobacterium nucleatum, is a highly specific binding interaction that depends on the presence of polar tufts of fimbriae on the streptococci. we have used a genetic approach to examine the role of streptococcal cell surface ... | 1995 | 8602334 |
| interbacterial binding among strains of pathogenic and commensal oral bacterial species. | strong interspecies adherence was demonstrated among the periodontal pathogens treponema denticola, bacteroides forsythus and porphyromonas gingivalis, and between these pathogens and the commensal plaque organism streptococcus crista. adherence showed specificity and demonstrated saturation binding kinetics. binding between b. forsythus and p. gingivalis appeared to be a unimodal protein-protein interaction. binding between the other organisms was at least bimodal involving interactions between ... | 1996 | 8604253 |
| scba from streptococcus crista cc5a: an atypical member of the lrai gene family. | a new member of the lrai family of putative adhesin genes was cloned, from streptococcus crista cc5a, and sequenced. the gene, scba appears to be part of an abc transport operon and encodes a putative peptide of 34.7 kda. the protein contains a signal sequence with residues 17 to 21 (l-a-a-c-s) matching the consensus sequence for the prolipoprotein cleavage site of signal peptidase ii. scba is 57 to 93% identical, at the amino acid level, with the five previous sequenced members of the lrai fami ... | 1996 | 8675315 |
| natural transformation of streptococcus crista. | over the years streptococcus gordonii (sanguis) challis has become the workhorse of genetic manipulations for the sanguis group of oral streptococci. this is because strain challis was shown in early studies to be highly naturally competent for transformation. however, challis is not usually the most appropriate strain to use in studies which focus on oral microbial adherence. we report that other members of the newly reorganized sanguis group, particularly within the species s. crista, display ... | 1996 | 8807795 |
| potential for cross-contamination from use of a needleless injector. | medical devices that are used on patients in fields containing potentially infectious body fluids can become contaminated and transmit infectious agents to other sites on the patient or to other patients if the devices are not properly cleaned and decontaminated after use on each patient treatment site. one such device is the needleless or jet injector, which is widely used in medicine and dentistry to deliver local anesthetic in procedures such as bone marrow aspirations, lumbar punctures, and ... | 1998 | 9721400 |
| identification of oral mitis group streptococci by arbitrarily primed polymerase chain reaction. | "mitis group" streptococci are commensal but may play some role in dental caries, septicemia or endocarditis. rapid genotypic identification would aid studies of dental plaque ecology, or diagnostic use. ap-pcr with 58 unpaired arbitrary primers was used to characterize 7 streptococcus gordonii, 11 streptococcus sanguis, 2 streptococcus crista, 5 streptococcus parasanguis, 18 streptococcus oralis, and 36 streptococcus mitis (22 biovar 1 and 14 biovar 2). s. parasanguis 16s rrna variable region p ... | 1999 | 10204478 |
| identification of clinically relevant viridans streptococci by analysis of transfer dna intergenic spacer length polymorphism. | the utility of pcr analysis of transfer dna intergenic spacer length polymorphism (tdna-ilp) for the identification to the species level of clinically relevant viridans streptococci was evaluated with a collection of reference strains of 15 species of the salivarius, anginosus, mitis and mutans rrna homology groups. pcr products generated by using fluorescent, outwardly directed, consensus tdna primers were analysed by electrophoresis on denaturating polyacrylamide gels and by laser fluorescence ... | 1999 | 10555340 |
| prevalence of the amylase-binding protein a gene (abpa) in oral streptococci. | salivary amylase binds specifically to a number of oral streptococcal species. this interaction may play an important role in dental plaque formation. recently, a 585-bp gene was cloned and sequenced from streptococcus gordonii challis encoding a 20.5-kda amylase-binding protein (abpa). the goal of this study was to determine if related genes are present in other species of oral streptococci. biotinylated abpa was used in southern blot analysis to screen genomic dna from several strains represen ... | 1999 | 10565935 |
| effects of streptococcus crista and human saliva on the viability of fusobacterium nucleatum atcc 10953. | associations with facultative species might help planktonic oral anaerobes survive when they traverse saliva. this study investigated whether co-aggregation with streptococcus crista atcc 51110 enhanced the viability of fusobacterium nucleatum atcc 10953. two tubes each of co-aggregates and fus. nucleatum atcc 10953 alone were prepared. one of each set was resuspended in buffer, and the other in clarified saliva from each of 20 donors. after 1 h, cells were stained for viability. the median perc ... | 2000 | 10869478 |
| intergeneric communication in dental plaque biofilms. | dental plaque is a complex biofilm that accretes in a series of discrete steps proceeding from a gram-positive streptococcus-rich biofilm to a structure rich in gram-negative anaerobes. this study investigated information flow between two unrelated plaque bacteria, streptococcus cristatus and porphyromonas gingivalis. a surface protein of s. cristatus caused repression of the p. gingivalis fimbrial gene (fima), as determined by a chromosomal fima promoter-lacz reporter construct and by reverse t ... | 2000 | 11092870 |
| 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 |
| simultaneous measurement of the viability, aggregation, and live and dead adherence of streptococcus crista, streptococcus mutans and actinobacillus actinomycetemcomitans in human saliva in relation to indices of caries, dental plaque and periodontal disease. | salivary proteins have multiple functions and many share similar functions, which may be why it has been difficult to relate variations in their concentrations to oral health and ecology. an alternative is to focus on variations in the major functions of saliva. an hydroxyapatite-coated microplate model has been developed that simultaneously measures saliva-promoted bacterial viability, bacterial aggregation, and live and dead bacterial adherence, while simulating oral temperature and shearing f ... | 2002 | 12015215 |
| genetic relatedness and phenotypic characteristics of treponema associated with human periodontal tissues and ruminant foot disease. | treponema have been implicated recently in the pathogenesis of digital dermatitis (dd) and contagious ovine digital dermatitis (codd) that are infectious diseases of bovine and ovine foot tissues, respectively. previous analyses of treponemal 16s rdna sequences, pcr-amplified directly from dd or codd lesions, have suggested relatedness of animal treponema to some human oral treponema species isolated from periodontal tissues. in this study a range of adhesion and virulence-related properties of ... | 2003 | 12724370 |
| streptococcus oligofermentans sp. nov., a novel oral isolate from caries-free humans. | five streptococcal strains were isolated from dental plaque and saliva of caries-free humans. the cells were gram-positive, non-spore-forming, non-motile cocci that were arranged in short chains. the strains were catalase-negative, facultatively anaerobic and produced lactic acid exclusively from glucose fermentation. biochemical analysis that used both conventional methods and the commercial api 20 strep system showed that the five strains fermented only a few kinds of sugar. the mean dna g + c ... | 2003 | 12892133 |
| porphyromonas gingivalis genes involved in fima regulation. | porphyromonas gingivalis is an important component of the complex plaque biofilm that is a direct precursor of periodontal disease. the major fimbriae are required for attachment to oral surfaces and are an important virulence factor. fimbrillin (fima) expression in p. gingivalis is inhibited by surface molecule of streptococcus cristatus, an early colonizer of dental plaque. in this study, differential display pcr was used to identify p. gingivalis genes that are regulated in response to s. cri ... | 2004 | 14742505 |
| association of a novel high molecular weight, serine-rich protein (srpa) with fibril-mediated adhesion of the oral biofilm bacterium streptococcus cristatus. | the surface of the oral plaque bacterium streptococcus cristatus is decorated with a lateral tuft of fibrils. the fibrillar tuft functions in the adhesion of s. cristatus to heterologous bacterial species in the plaque biofilm. the tuft typically consists of a densely packed fringe of shorter fibrils 238 +/- 19 nm long with longer, less abundant fibrils 403 +/- 66 nm long projecting through the fringe of short fibrils. the two types of fibrils in the tufts of s. cristatus have been refractory to ... | 2005 | 15836513 |
| fusobacterium nucleatum transports noninvasive streptococcus cristatus into human epithelial cells. | analysis of human buccal epithelial cells frequently reveals an intracellular polymicrobial consortium of bacteria. although several oral bacteria have been demonstrated to invade cultured epithelial cells, several others appear unable to internalize. we hypothesized that normally noninvasive bacteria may gain entry into epithelial cells via adhesion to invasive bacteria. fusobacterium nucleatum is capable of binding to and invading oral epithelial cells. by contrast, streptococcus cristatus bin ... | 2006 | 16369022 |
| expression of the short fimbriae of porphyromonas gingivalis is regulated in oral bacterial consortia. | the mfa1 protein of porphyromonas gingivalis is the structural subunit of the short fimbriae and mediates coadhesion between p. gingivalis and streptococcus gordonii. we utilized a promoter-lacz reporter construct to examine the regulation of mfa1 expression in consortia with common oral plaque bacteria. promoter activity of mfa1 was inhibited by s. gordonii, streptococcus sanguinis and streptococcus mitis. in contrast, streptococcus mutans, streptococcus cristatus, actinomyces naeslundii, actin ... | 2006 | 16907740 |
| establishing a genetic system for ecological studies of streptococcus oligofermentans. | streptococcus oligofermentans is a newly characterized species belonging to the mitis group of oral streptococci. so far no correlation has been demonstrated between s. oligofermentans and dental caries. furthermore, a reverse correlation has been observed between the number of s. oligofermentans and the number of streptococcus mutans, a major cariogenic pathogen, in the oral cavity. these properties suggest that s. oligofermentans may have a potential to be used as a 'probiotics' for caries pre ... | 2006 | 17064375 |
| relationship between the ability of oral streptococci to interact with platelet glycoprotein ibalpha and with the salivary low-molecular-weight mucin, mg2. | the oral streptococci streptococcus sanguinis, streptococcus gordonii and streptococcus oralis are common aetiological agents of infective endocarditis, and their ability to adhere to and induce the aggregation of platelets is thought to be a virulence trait. the platelet glycoprotein gpibalpha has been implicated as the adhesion receptor for s. sanguinis and s. gordonii, but it is not known if this is the case for s. oralis and other species. the aim of this study was to determine the gpibalpha ... | 2006 | 17069618 |
| streptococcus cristatus isolated from a resected heart valve and blood cultures: case reports and application of phenotypic and genotypic techniques for identification. | background: viridans streptococci are known as an important cause of endocarditis, but at present no cases of endocarditis caused by streptococcus cristatus have been published, probably because phenotypic identification of viridans streptococci is tedious. using tdna-pcr, it is possible to identify to species level and to differentiate between species of the viridans group. | 2006 | 17091918 |
| streptococcus oligofermentans inhibits streptococcus mutans through conversion of lactic acid into inhibitory h2o2: a possible counteroffensive strategy for interspecies competition. | the oral microbial flora contains over 500 different microbial species that often interact as a means to compete for limited space and nutritional resources. streptococcus mutans, a major caries-causing pathogen, is a species which tends to interact competitively with other species in the oral cavity, largely due to its ability to generate copious quantities of the toxic metabolite, lactic acid. however, during a recent clinical study, we discovered a novel oral streptococcal species, streptococ ... | 2007 | 17302806 |
| salmonellae reduction in poultry by competitive exclusion bacteria lactobacillus salivarius and streptococcus cristatus. | the objective of this study was to develop a defined competitive exclusion bacteria (ce) culture that will prevent or substantially reduce salmonella colonization of poultry. the efficacy of 56 potential ce isolates in preventing or reducing salmonella colonization in chickens was determined. these potential ce were perorally administered to day-of-hatch chicks at 10(6) to 10(8) cfu per chick, and salmonellae were subsequently administered by gavage 2 days later at 5.5 x 10(3) to 5.0 x 10(4) cfu ... | 2007 | 17477255 |
| association of a high-molecular weight arginine-binding protein of fusobacterium nucleatum atcc 10953 with adhesion to secretory immunoglobulin a and coaggregation with streptococcus cristatus. | fusobacterium nucleatum coaggregates with a diverse range of bacterial species, and binds to host tissues and proteins such as immunoglobulin. these interactions may support the attachment of a variety of organisms to oral surfaces and can facilitate the invasion of soft tissues. we hypothesized that coaggregation with streptococci and immunoglobulin binding may occur by a common adhesin sensitive to l-arginine. | 2007 | 17600532 |
| demonstration of in vivo transfer of doxycycline resistance mediated by a novel transposon. | the aim of this study was to investigate the transfer of bacterial doxycycline resistance between oral bacteria in subjects receiving systemic doxycycline for the treatment of periodontitis. | 2007 | 17855723 |
| identification of a signalling molecule involved in bacterial intergeneric communication. | the development of complex multispecies communities such as biofilms is controlled by interbacterial communication systems. we have previously reported an intergeneric communication between two oral bacteria, streptococcus cristatus and porphyromonas gingivalis, that results in inhibition of fima expression. here, we demonstrate that a surface protein, arginine deiminase (arca), of s. cristatus serves as a signal that initiates intergeneric communication. an arca-deficient mutant of s. cristatus ... | 2007 | 17906122 |
| reduction of periodontal pathogens adhesion by antagonistic strains. | periodontitis results from a shift in the subgingival microflora into a more pathogenic direction with porphyromonas gingivalis, prevotella intermedia, and actinobacillus actinomycetemcomitans considered as periodontopathogens. in many cases, treatment procures only a temporary shift towards a less pathogenic microflora. an alternative treatment could be the deliberate colonization of pockets with antagonistic microorganisms to control the adhesion of periodontopathogens. the aim of this study w ... | 2008 | 18173797 |
| bacterial profiles of root caries in elderly patients. | culture-based studies have shown that streptococcus mutans and lactobacilli are associated with root caries (rc). the purpose of the present study was to assess the bacterial diversity of rc in elderly patients by use of culture-independent molecular techniques and to determine the associations of specific bacterial species or bacterial communities with healthy and carious roots. plaque was collected from root surfaces of 10 control subjects with no rc and from 11 subjects with rc. the bacterial ... | 2008 | 18385433 |
| role of differential expression of streptococcal arginine deiminase in inhibition of fima expression in porphyromonas gingivalis. | streptococcus cristatus arca inhibits production of a major adhesin, fima, in porphyromonas gingivalis, a primary periodontal pathogen. in this study, we demonstrate the differential expression of arca in two streptococcal species. the expression level of arca in streptococci appears to be controlled by both cis and trans elements. | 2008 | 18408031 |
| so-laao, a novel l-amino acid oxidase that enables streptococcus oligofermentans to outcompete streptococcus mutans by generating h2o2 from peptone. | we previously demonstrated that streptococcus oligofermentans suppressed the growth of streptococcus mutans, the primary cariogenic pathogen, by producing hydrogen peroxide (h(2)o(2)) through lactate oxidase activity. in this study, we found that the lox mutant of s. oligofermentans regained the inhibition while growing on peptone-rich plates. further studies demonstrated that the h(2)o(2) produced on peptone by s. oligofermentans was mainly derived from seven l-amino acids, i.e., l-aspartic aci ... | 2008 | 18469105 |
| [development of an identification method for streptococcus oligofermentans: a new species of oral streptococci with molecular markers]. | to establish a quick and reliable method to identify streptococcus oligofermentans, a new species of oral streptococci. | 2007 | 18476551 |
| streptococcus cristatus attenuates fusobacterium nucleatum-induced interleukin-8 expression in oral epithelial cells. | oral epithelial cells may be invaded by a polymicrobial intracellular flora, including pathogens together with commensals. various oral pathogens can induce the production of interleukin-8, a potent neutrophil chemotractant, in oral epithelial cells. evidence from the gut suggests that commensal species may modulate inflammatory responses to pathogens. the aim of this study was to examine the interleukin-8 responses of oral epithelial cells to an oral pro-inflammatory species, fusobacterium nucl ... | 2008 | 18942189 |
| aggregatibacter actinomycetemcomitans adhesion inhibited in a flow cell. | microbial interactions are considered important in the adhesion process of pathogenic bacteria in the oral cavity. this study addressed the hypothesis that a streptococcal biofilm influences the hard tissue colonization by the periodontopathogen aggregatibacter actinomycetemcomitans under hydrodynamic conditions. | 2008 | 18954361 |
| first case of streptococcus oligofermentans endocarditis determined based on soda gene sequences after amplification directly from valvular samples. | we report the first case of infection due to streptococcus oligofermentans, which is a recently described oral streptococcus species. it was responsible for the endocarditis and left forearm abscess of a 43-year-old woman. identification was made using molecular techniques performed directly from valvular and surgical samples. | 2009 | 19116351 |
| 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 |
| interference with aggregatibacter actinomycetemcomitans: colonization of epithelial cells under hydrodynamic conditions. | microbial interactions are considered to be important for bacterial colonization. interactions that inhibit colonization of pathogens could possibly be used as a new treatment approach for periodontitis. the aim of this study was to test this hypothesis on soft surfaces in vitro, taking into account the hydrodynamic forces continuously present in vivo. | 2009 | 19702952 |
| negative correlation of distributions of streptococcus cristatus and porphyromonas gingivalis in subgingival plaque. | porphyromonas gingivalis is one of the major causative agents of adult periodontitis. one of the features of this periodontal pathogen is its ability to attach to a variety of oral bacterial surfaces and to colonize subgingival dental plaque. we have shown that streptococcus cristatus cc5a inhibits expression of fima, a gene encoding the major protein subunit of long fimbriae in p. gingivalis; as a result, s. cristatus interrupts formation of p. gingivalis biofilms. here we further demonstrate t ... | 2009 | 19846640 |
| [role of dpr in hydrogen peroxide tolerance of streptococcus oligofermentans]. | streptococcus oligofermentans was a newly characterized streptococcal species, which we isolated from dental plaques of carious-free humans. our previous work indicated that in aerobic environments, it produced, as well as survived high concentration of hydrogen peroxide (4.4 mmol/l). this study analyzed the function of dpr gene in hydrogen peroxide tolerance of streptococcus oligofermentans. | 2009 | 20069880 |
| a preliminary study of biological characteristics of streptococcus oligofermentans in oral microecology. | this study was designed to explore the biological characteristics of a new oral streptococcus species streptococcus oligofermentans. plaque samples were collected from caries-free and caries-active subjects. s. oligofermentans was selectively grown on mitis salivarius agar plates and identified by using 2-step pcr and was isolated from 38% of 18 subjects. isolates were found mostly on healthy tooth surfaces. s. oligofermentans had weaker abilities in acid production and demineralizing hydroxyapa ... | 2010 | 20616551 |
| role of arginine deiminase of streptococcus cristatus in porphyromonas gingivalis colonization. | the ability to attach to a variety of oral surfaces is an important characteristic of porphyromonas gingivalis. previous studies have demonstrated that expression and production of fima, a major subunit protein of the long fimbriae, is required for p. gingivalis colonization. here we report that a surface protein, arginine deiminase (arca) of streptococcus cristatus, represses fima production and inhibits biofilm formation of p. gingivalis. this inhibitory function of arca is also observed in th ... | 2010 | 20660674 |
| bacterial 16s sequence analysis of severe caries in young permanent teeth. | previous studies have confirmed the association of the acid producers streptococcus mutans and lactobacillus spp. with childhood caries, but they also suggested these microorganisms are not sufficient to explain all cases of caries. in addition, health-associated bacterial community profiles are not well understood, including the importance of base production and acid catabolism in ph homeostasis. the bacterial community composition in health and in severe caries of the young permanent dentition ... | 2010 | 20826648 |
| clonal analysis of the microbiota of severe early childhood caries. | severe early childhood caries is a microbial infection that severely compromises the dentition of young children. the aim of this study was to characterize the microbiota of severe early childhood caries. | 2010 | 20861633 |
| 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 |
| cultivable anaerobic microbiota of severe early childhood caries. | severe early childhood caries (ecc), while strongly associated with streptococcus mutans using selective detection (culture, pcr), has also been associated with a widely diverse microbiota using molecular cloning approaches. the aim of this study was to evaluate the microbiota of severe ecc using anaerobic culture. the microbial composition of dental plaque from 42 severe ecc children was compared with that of 40 caries-free children. bacterial samples were cultured anaerobically on blood and ac ... | 2011 | 21289150 |
| streptococcus cristatus attenuates fusobacterium nucleatum-induced cytokine expression by influencing pathways converging on nuclear factor-?b. | we previously reported that streptococcus cristatus, an oral commensal, was able to downregulate the interleukin-8 (il-8) response to fusobacterium nucleatum, a putative oral pathogen in oral epithelial cells. the aim of this study was to extend the understanding of how s. cristatus regulates cytokine expression in oral epithelial cells on a broad basis, and investigate whether the modulation of a toll-like receptor (tlr) pathway was involved in this process. kb and tert-2 cells were co-cultured ... | 2011 | 21375705 |
| streptococcus cristatus modulates the fusobacterium nucleatum-induced epithelial interleukin-8 response through the nuclear factor-kappa b pathway. | zhang g, chen r, rudney jd.streptococcus cristatusmodulates thefusobacterium nucleatum-induced epithelial interleukin-8 response through the nuclear factor-kappa b pathway. j periodont res 2011; doi: 10.1111/j.1600-0765.2011.01373.x.©2011 john wiley & sons a/s background and objective: we previously reported that the interleukin-8 (il-8) response to fusobacterum nucleatum was attenuated in the presence of streptococcus cristatus. here, we further examined the underlying mechanism(s) involved in ... | 2011 | 21521225 |
| structure of type 3gn coaggregation receptor polysaccharide from streptococcus cristatus ls4. | the presence of a novel coaggregation receptor polysaccharide (rps) on the dental plaque isolate streptococcus cristatus ls4 was suggested by this strain's antigenic and coaggregation properties. examination of rps isolated from strain ls4 by a combination of 2-dimensional and pseudo 3-dimensional single quantum heteronuclear nmr methods that included detection of (13)c chemical shifts at high resolution revealed the following repeat unit structure: →6)-β-d-galf-(1→6)-β-d-galpnac-(1→3)-α-d-galp- ... | 2011 | 21601178 |
| [The influence of oxygen on the inhibition between Streptococcus oligofermentans and Streptococcus mutans]. | To investigate the effect of environmental oxygen on the inhibition between Streptococcus oligofermentans (So) and Streptococcus mutans (Sm) and the producibilities of hydrogen peroxide by So. | 2011 | 21914377 |
| 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 |
| a yada-like autotransporter, hag1 in veillonella atypica is a multivalent hemagglutinin involved in adherence to oral streptococci, porphyromonas gingivalis, and human oral buccal cells. | dental biofilm development is a sequential process, and adherence between microbes and the salivary pellicle (adhesion) as well as among different microbes (co-adhesion or coaggregation) plays a critical role in building a biofilm community. the veillonella species are among the most predominant species in the oral cavity and coaggregate with many initial, early, middle, and late colonizers. similar to oral fusobacteria, they are also considered bridging species in biofilm development. however, ... | 2015 | 25440509 |
| oral microbiota species in acute apical endodontic abscesses. | acute apical abscesses are serious endodontic diseases resulting from pulpal infection with opportunistic oral microorganisms. the objective of this study was to identify and compare the oral microbiota in patients (n=18) exhibiting acute apical abscesses, originating from the demographic region in portland, oregon. the study hypothesis is that abscesses obtained from this demographic region may contain unique microorganisms not identified in specimens from other regions. | 2016 | 26983837 |
| evaluation of the nanosphere verigene gram-positive blood culture assay with the versatrek blood culture system and assessment of possible impact on selected patients. | the verigene gram-positive blood culture (bc-gp) assay (nanosphere, northbrook, il) is a molecular method for the rapid identification of gram-positive organisms and resistance markers directly from blood culture bottles. a total of 148 versatrek redox 1 40-ml aerobic bottles demonstrating gram-positive bacteria were tested. results were compared with those from conventional biochemical and matrix-assisted laser desorption ionization-time of flight (maldi-tof) identifications. we obtained isolat ... | 2013 | 24048531 |
| antimicrobial effects of commensal oral species are regulated by environmental factors. | the objectives of this study are to identify oral commensal species which can inhibit the growth of the main periodontopathogens, to determine the antimicrobial substances involved in these inhibitory activities and to evaluate the influence of environmental factors on the magnitude of these inhibitions. | 2016 | 26875613 |
| role of operon aaoso-mutt in antioxidant defense in streptococcus oligofermentans. | previously, we have found that an insertional inactivation of aao(so), a gene encoding l-amino acid oxidase (laao), causes marked repression of the growth of streptococcus oligofermentans. here, we found that aao(so) and mutt, a homolog of pyrophosphohydrolase gene of escherichia coli, constituted an operon. deletion of either gene did not impair the growth of s. oligofermentans, but double deletion of both aao(so) and mutt was lethal. quantitative pcr showed that the transcript abundance of mut ... | 2012 | 22666463 |
| heat-stable molecule derived from streptococcus cristatus induces apobec3 expression and inhibits hiv-1 replication. | although most human immunodeficiency virus type 1 (hiv-1) cases worldwide are transmitted through mucosal surfaces, transmission through the oral mucosal surface is a rare event. more than 700 bacterial species have been detected in the oral cavity. despite great efforts to discover oral inhibitors of hiv, little information is available concerning the anti-hiv activity of oral bacterial components. here we show that a molecule from an oral commensal bacterium, streptococcus cristatus cc5a can i ... | 2014 | 25165817 |
| [protein structure prediction of the lactate dehydrogenase of streptococcus oligofermentans]. | to compare the gene sequence and protein structure of lactate dehydrogenase (ldh) in streptococcus oligofermentans with those of other bacteria with different acid generating capacities in oral cavity and to analyze the differences of their ldh. | 2013 | 24438565 |
| streptococcus cristatus arca interferes with porphyromonas gingivalis pathogenicity in mice. | porphyromonas gingivalis has been implicated as one of the major pathogens in chronic periodontitis, an infectious disease affecting the majority of the adult population. we have previously demonstrated that a surface protein, arginine deiminase (arca), of streptococcus cristatus represses production of p. gingivalis long fimbriae and interrupts the formation of p. gingivalis biofilms in vitro. our in vivo studies have also shown that the distribution of p. gingivalis and s. cristatus in human s ... | 2012 | 22448761 |
| re-evaluation of the taxonomy of the mitis group of the genus streptococcus based on whole genome phylogenetic analyses, and proposed reclassification of streptococcus dentisani as streptococcus oralis subsp. dentisani comb. nov., streptococcus tigurinus as streptococcus oralis subsp. tigurinus comb. nov., and streptococcus oligofermentans as a later synonym of streptococcus cristatus. | the mitis group of the genus streptococcus currently comprises 20 species with validly published names, including the pathogen s. pneumoniae. they have been the subject of much taxonomic confusion, due to phenotypic overlap and genetic heterogeneity, which has hampered a full appreciation of their clinical significance. the purpose of this study was to critically re-examine the taxonomy of the mitis group using 195 publicly available genomes, including designated type strains for phylogenetic an ... | 2016 | 27534397 |
| [observation of oral streptococcus oligofermentans colonization in rats]. | to study the colonization ability of streptococcus oligofermentans (s. oligofermentan) in the condition of high sucrose in oral cavity of rats. | 2016 | 27080288 |
| streptococcus oligofermentans inhibits streptococcus mutans in biofilms at both neutral ph and cariogenic conditions. | homeostasis of oral microbiota can be maintained through microbial interactions. previous studies showed that streptococcus oligofermentans, a non-mutans streptococci frequently isolated from caries-free subjects, inhibited the cariogenic streptococcus mutans by the production of hydrogen peroxide (hp). since ph is a critical factor in caries formation, we aimed to study the influence of ph on the competition between s. oligofermentans and s. mutans in biofilms. to this end, s. mutans and s. oli ... | 2015 | 26114758 |
| comparison of species identification of endocarditis associated viridans streptococci using rnpb genotyping and 2 maldi-tof systems. | streptococcus spp. are important causes of infective endocarditis but challenging in species identification. this study compared identification based on sequence determination of the rnpb gene with 2 systems of matrix-assisted laser desorption ionization-time of flight mass spectrometry, maldi biotyper (bruker) and vitek ms ivd (biomérieux). blood culture isolates of viridans streptococci from 63 patients with infective endocarditis were tested. the 3 methods showed full agreement for all 36 iso ... | 2015 | 25616316 |
| phylogenomic and maldi-tof ms analysis of streptococcus sinensis hku4t reveals a distinct phylogenetic clade in the genus streptococcus. | streptococcus sinensis is a recently discovered human pathogen isolated from blood cultures of patients with infective endocarditis. its phylogenetic position, as well as those of its closely related species, remains inconclusive when single genes were used for phylogenetic analysis. for example, s. sinensis branched out from members of the anginosus, mitis, and sanguinis groups in the 16s ribosomal rna gene phylogenetic tree, but it was clustered with members of the anginosus and sanguinis grou ... | 2014 | 25331233 |
| aminoacetone oxidase from streptococcus oligofermentans belongs to a new three-domain family of bacterial flavoproteins. | the aaoso gene from streptococcus oligofermentans encodes a 43 kda flavoprotein, aminoacetone oxidase (soaao), which was reported to possess a low catalytic activity against several different l-amino acids; accordingly, it was classified as an l-amino acid oxidase. subsequently, soaao was demonstrated to oxidize aminoacetone (a pro-oxidant metabolite), with an activity ~25-fold higher than the activity displayed on l-lysine, thus lending support to the assumption of aminoacetone as the preferred ... | 2014 | 25269103 |
| perr-regulated manganese ion uptake contributes to oxidative stress defense in an oral streptococcus. | metal homeostasis plays a critical role in antioxidative stress. streptococcus oligofermentans, an oral commensal facultative anaerobe lacking catalase activity, produces and tolerates abundant h2o2, whereas dpr (an fe(2+)-chelating protein)-dependent h2o2 protection does not confer such high tolerance. here, we report that inactivation of perr, a peroxide-responsive repressor that regulates zinc and iron homeostasis in gram-positive bacteria, increased the survival of h2o2-pulsed s. oligofermen ... | 2014 | 24487543 |
| influence of ph on inhibition of streptococcus mutans by streptococcus oligofermentans. | streptococcus oligofermentans is a novel strain of oral streptococcus that can specifically inhibit the growth of streptococcus mutans. the aims of this study were to assess the growth of s. oligofermentans and the ability of s. oligofermentans to inhibit growth of streptococcus mutans at different ph values. growth inhibition was investigated in vitro using an interspecies competition assay. the 4-aminoantipyine method was used to measure the initial production rate and the total yield of hydro ... | 2014 | 24267570 |
| complete genome sequence of an oral commensal, streptococcus oligofermentans strain as 1.3089. | streptococcus oligofermentans, an oral commensal, inhibits the growth of the dental caries pathogen streptococcus mutans by producing large amounts of hydrogen peroxide. therefore, it can be a potential probiotic for oral health. here we report the complete genome sequence of s. oligofermentans strain as 1.3089. | 2013 | 23788543 |
| ccpa-dependent carbohydrate catabolite repression regulates galactose metabolism in streptococcus oligofermentans. | streptococcus oligofermentans is an oral commensal that inhibits the growth of the caries pathogen streptococcus mutans by producing copious amounts of h(2)o(2) and that grows faster than s. mutans on galactose. in this study, we identified a novel eight-gene galactose (gal) operon in s. oligofermentans that was comprised of lacabcd, lacx, and three genes encoding a galactose-specific transporter. disruption of laca caused more growth reduction on galactose than mutation of galk, a gene in the l ... | 2012 | 22609925 |
| interspecies competition and inhibition within the oral microbial flora: environmental factors influence the inhibition of streptococcus mutans by streptococcus oligofermentans. | dental caries is a bacterial infectious disease. streptococcus mutans is the primary pathogen that causes dental caries. streptococcus oligofermentans is a new oral streptococcal species that can inhibit the growth of s. mutans specifically. the study aimed to assess the inhibition of s. mutans by s. oligofermentans under different oral environmental conditions. the inhibition under different carbohydrate and oxygen conditions was investigated in vitro using an interspecies interaction assay. th ... | 2012 | 22607333 |
| [influence of glucose concentration on the inhibition of streptococcus oligofermentans on streptococcus mutans]. | to investigate the inhibition of streptococcus oligofermentans (so) on streptococcus mutans (sm) and the producibility of hydrogen peroxide by so under the influence of glucose concentration environment. | 2012 | 22490221 |
| phylogenetic analysis supports horizontal gene transfer of l-amino acid oxidase gene in streptococcus oligofermentans. | phylogenetic analysis of 10 amino acid sequences from 19 streptococcus species showed that s. oligofermentans clustered within the mitis group. however, the l-amino acid oxidase (laao) of s. oligofermentans showed a different clustering pattern from the other proteins analyzed implicating horizontal gene transfer (hgt) in the origin of the s. oligofermentans laao gene. laao of s. oligofermentans is known to confer ability to compete with other oral cavity bacteria, most notably s. mutans; theref ... | 2012 | 22414918 |
| characterization of streptococcus oligofermentans sucrose metabolism demonstrates reduced pyruvic and lactic acid production. | streptococcus (s.) oligofermentans is a newly identified bacteria with a yet to be defined mechanism of sucrose metabolism that results in acid production. this study aimed to investigate the biochemical mechanisms of s. oligoferm-entans glucose metaolism. | 2011 | 22340167 |
| function of the pyruvate oxidase-lactate oxidase cascade in interspecies competition between streptococcus oligofermentans and streptococcus mutans. | complex interspecies interactions occur constantly between oral commensals and the opportunistic pathogen streptococcus mutans in dental plaque. previously, we showed that oral commensal streptococcus oligofermentans possesses multiple enzymes for h(2)o(2) production, especially lactate oxidase (lox), allowing it to out-compete s. mutans. in this study, through extensive biochemical and genetic studies, we identified a pyruvate oxidase (pox) gene in s. oligofermentans. a pox deletion mutant comp ... | 2012 | 22287002 |
| identification of streptococcus cristatus peptides that repress expression of virulence genes in porphyromonas gingivalis. | dental plaque is a complex multispecies biofilm, and is a direct precursor of periodontal disease. the virulence of periodontal pathogens, such as porphyromonas gingivalis, is expressed in the context of this polymicrobial community. previously, we reported an antagonistic relationship between streptococcus cristatus and p. gingivalis, and identified arginine deiminase (arca) of s. cristatus as the signaling molecule to which p. gingivalis responds by repressing the expression and production of ... | 2017 | 28469253 |