Characteristics of Clinical Isolates of Streptococcus mutans (original) (raw)
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Isolation and Typing of Streptococcus mutans and Streptococcus sobrinus from Caries-active Subjects
Contemporary clinical dentistry
Streptococcus mutans and Streptococcus sobrinus are main etiological agents of dental caries. The aim of the study was to isolate, identify, characterize, and determine the minimum inhibitory concentration (MIC) of S. mutans and S. sobrinus from caries-active subjects. Sixty-five plaque samples were collected from caries-active subjects aged between 35 and 44 years, processed and cultured on mitis salivarius bacitracin agar. All the bacterial isolates were subjected to morphotyping and the suspected colonies were identified by 16S rDNA sequencing. The S. mutans and S. sobrinus strains were characterized by biotyping and phylogenetic analysis. The MIC of ampicillin and erythromycin was determined by microtiter plate method. Of the study population, 41 isolates displayed typical colony morphologies of S. mutans and S. sobrinus. The 16S rDNA sequencing results revealed that 36 isolates were S. mutans and 5 isolates were S. sobrinus. The biotyping of these isolates demonstrated three bi...
Microbial Biosystems, 2021
Streptococcus mutans has significant virulence factors associated with the etiology and pathophysiology of dental plaque and caries through adherence to the tooth surface and biofilm formation. These microbes can tolerate and survive the acidic environment. The study aimed to compare the behavior of the S. mutans isolates from dental plaque and caries conditions, in addition to the evaluation of the biofilm formation by S. mutans with oral microbiota (Candida albicans). A total of 106 S. mutans isolates were recovered including 56 isolates from soft caries lesions, 30 isolates from the plaque of caries active and 20 isolates from the plaque of cariesfree samples. The isolates' virulence efficacy was assessed phenotypically by acid production, acid tolerance, and biofilm formation assays. PCR detected genes encoding these virulence traits. There was a significant difference (p < 0.05) between the three groups of isolates in biofilm formation, biofilm formation when co-cultivated with C. albicans, pH reduction by acid production, but there was no significant difference in withstanding acidic pH. S. mutans isolates harbored the genes glucosyltransferase B (gtfB), glucan binding protein B (gbpB), F1F0 membrane-bound proton-translocating ATPase C subunit (atpH) and lactate dehydrogenase (ldh) which are responsible for biofilm formation, sucrosedependent adhesion, acid tolerance and acid production, respectively. In conclusion, S. mutans isolates from caries-free and caries active dental plaque and dental caries conditions showed different virulence efficacy-based behaviour. C. albicans enhances the biofilm formation by S. mutans. Further investigation of factors influencing variable behavior of S. mutans bacteria from different lesions is warranted.
Brazilian Dental Journal, 2011
The oral cavity harbors several Streptococcus mutans genotypes, which could present distinct virulence properties. However, little is known about the diversity and virulence traits of S. mutans genotypes isolated in vivo under controlled conditions of high cariogenic challenge. This study evaluated the genotypic diversity of S. mutans isolated from dental biofilms formed in vivo under sucrose exposure, as well as their acidogenicity and aciduricity. To form biofilms, subjects rinsed their mouths with distilled water or sucrose solution 8 times/day for 3 days. S. mutans collected from saliva and biofilms were genotyped by arbitrarily-primed PCR. Genotypes identified in the biofilms were evaluated regarding their ability to lower the suspension pH through glycolysis and their acid susceptibility and F-ATPase activity. Most subjects harbored only one genotype in saliva, which was detected in almost all biofilm samples at high proportions. Genotypes isolated only in the presence of sucrose had higher acidogenicity than those isolated only in the presence of water. Genotypes from biofilms formed with sucrose were more aciduric after 30 and 60 min of incubation at pH 2.8 and 5.0, respectively. The present results suggest that biofilms formed under high cariogenic conditions may harbor more aciduric and acidogenic S. mutans genotypes.
TheScientificWorldJournal, 2014
The aim of this study was to compare the genotypic diversity and virulence traits of Streptococcus mutans isolated from carious dentin before and after partial dentin caries removal (PDR) and sealing. Carious dentin samples were obtained three months before and after the PDR and cavity sealing. Up to seven isolates of each morphological type of S. mutans were selected and strain identity was confirmed using gtfB primer. Genotyping was performed by arbitrary primer-PCR (AP-PCR). Acidogenesis and acidurance of the genotypes were evaluated as virulence traits. A paired t-test and a Wilcoxon test were used to compare the virulence of genotypes. A total of 48 representative S. mutans isolates were genotyped (31 before and 17 after the sealing). At least one of the genotypes found before the sealing was also found on dentin after the sealing. The number of genotypes found before the sealing ranged from 2 to 3 and after the sealing from 1 to 2 genotypes. No difference was observed in the a...
BMC oral health, 2017
Early childhood caries (ECC) is an aggressive condition that can affect teeth of young children. This study aimed to evaluate genotypic diversity and phenotypic traits of S. mutans isolated from dental biofilms of children with different caries status in comparison with caries free (CF) children. Streptococcus mutans strains were isolated from supragingival biofilm samples of CF, ECC and severe-ECC (S-ECC) children and genotyped by arbitrary-primer polymerase chain reaction - AP-PCR. S. mutans genotypes were tested for their ability to reduce the suspension pH through glycolysis, to tolerate extreme acid challenge and by their ability to form biofilm. Response variables were analyzed by ANOVA/Tukey or Kruskal-Wallis/Mann-Whitney tests at a 5% of significance. There was an increase in the prevalence of Streptococcus mutans in biofilms with the severity of dental caries. No differences in genotypic diversity and in acidogenicity of genotypes were found among CF, ECC and S-ECC children...
Journal of Medical Microbiology, 2004
The present study evaluated the relationship between clonal diversity and some virulence traits of Streptococcus mutans isolated from eight caries-free and eight caries-active subjects. A total of 155 S. mutans isolates from caries-free subjects and 144 isolates from caries-active subjects were obtained from samples of saliva, dental plaque and tongue surface and identified by PCR. The isolates were submitted to arbitrarily primed (AP)-PCR (OPA-2 and OPA-13) and multilocus enzyme electrophoresis (MLEE) to establish the genotypic diversity. Production of water-insoluble glucan (WIG) (monitored by SDS-PAGE), final pH of cultures and the ability of bacterial cells to adhere to smooth glass in the presence of sucrose were measured. High and comparable abilities of MLEE and AP-PCR were found to distinguish S. mutans genotypes, using Simpson's index of discrimination (0 . 971 and 0 . 968, respectively). The results showed a significant difference (P , 0 . 01) in the number of genotypes when caries-free and caries-active groups were compared by both fingerprinting methods used. Final pH (P ¼ 0 . 32) and the percentage of adherence to a glass surface (P ¼ 0 . 62) did not show differences between the two groups; however, the intensities of WIG bands from the caries-active group were greater than those from the caries-free group (P , 0 . 01). In addition, WIG was positively correlated with the ability of S. mutans to adhere to a glass surface (r ¼ 0 . 34, P ¼ 0 . 02) from caries-active subjects. These data showed that AP-PCR analysis and MLEE are both effective methods for assessing the genetic relatedness of S. mutans. Using these techniques, it was found that there is a larger number of genotypes of S. mutans with increased ability to synthesize WIG in caries-active individuals.
Brazilian Archives of Biology and Technology, 2013
The objective of this study was to analyze the genotypic diversity, frequency of serotypes and the detection of mutacins from Streptococcus mutans isolates in caries-free and caries-active individuals. A total of 260 S. mutans isolated from 28 individuals with and without dental caries were subjected to AP-PCR and PCR screening of glucosyltransferase B, mutacin and serotype genes, which showed the presence of. 70 different genotypes. There was no statistically significant association between the presence of genes for serotypes and mutacins with dental caries. However, there was a statistically significant and a strong association between the higher genotypic diversity in the subjects with caries (r = 0.72, p = 0.001). There was an increase in the number of genotypes with increasing age (p <0.01).
IOP Conference Series: Earth and Environmental Science, 2019
Streptococcus mutans is a virulent and biofilm forming bacteria causing dental caries. Dental caries lead to several diseases, including mediastinitis, sepsis, facial cellulitis, osteomyelitis, endocarditis and pneumonia. Alternative effort to suppress dental caries prefalency is early diagnostic of dental caries risk using protein biomarker. The aim of the research is to determine the antigenic protein profile of S. mutans biofilm as biomarker of dental caries and periodontal disease risk. S. mutans biofilm was formed on glass slide submerging in BHIBS media for 24 hours. Crude proteins of biofilm were obtained by lysing it using ultrasonication 7 x 30s, 40 Hz. Protein profiles of S. mutans biofilm was done by using SDS-PAGE with separation gel of 12%. Antigenic analysis of the proteins biofilm were done by Western blot method using sIgA contained in the dental caries free saliva, compared with dental caries saliva as control. Protein profile of S. mutans biofilm consist of seventeen bands