Detection Of Streptococcus Mutans Research Articles

Monitoring Caries Risks before the Window of Infection and Later Caries Increment: A Caries Prediction Study on Rapid Detection of Streptococcus mutans Using Monoclonal Antibodies

A new semi-quantitative enumeration system has been developed for the detection of Streptococcus mutans in saliva. Using two kinds of species-specific monoclonal antibodies, this system can quickly detect salivary S. mutans within 30 min and classify the results into three levels. The aim of this study was to evaluate the potential of this test kit in determining risk for the development of caries. Saliva samples collected during a compulsory dental examination from 56 children aged 18-months were tested. The children were classified into 3 groups according to the level of salivary S. mutans determined. After 18 months, 36 of the children underwent a second examination to investigate whether there was a correlation between salivary S. mutans level at the first examination and subsequent increment in caries. The results showed a good correlation between the two. This indicates that salivary S. mutans level before the window of infection is an indicator of caries risk and can be quickly detected using this test kit. This rapid test should be particularly useful in assessing risk of future caries in very young children.

AP-PCR detection of Streptococcus mutans and Streptococcus sobrinus in caries-free and caries-active subjects

The aim of the study was to identify the number and distribution of genotypes of Streptococcus mutans (S. mutans) and Streptococcus sobrinus (S. sobrinus) isolated from caries-free and caries-active subjects. Non-stimulated saliva, buccal smooth surface of the right upper teeth, fissures of sound occlusal surface, and carious surface were sampled from 7 caries-free and 7 caries-active (DMFT ≥ 6) students aged 22-24 years. S. mutans and S. sobrinus were isolated using Chelex-100 and primarily identified by colony morphology and biochemical characteristics. The isolates of S. mutans were genotyped using arbitrarily primed polymerase chain reaction. A total of 516 isolates of S. mutans were genotyped from 47 sites in 14 students, and 44 different genotypes were determined. All of the caries-free individuals harbored S. mutans but not S. sobrinus, although individuals 3 and 7 had no S. mutans in their saliva. The CFU value of S. mutans on carious surfaces was the highest, and values in saliva, fissures, and occlusal surfaces were higher in caries-active individuals than in caries-free individuals. We detected 28 genotypes of S. mutans in caries-free individuals, each of who carried more than 3 genotypes. However, we found only 16 genotypes of S. mutans in caries-active individuals, each of who carried no more than 3 genotypes. More genotypes are harbored in the saliva, fissures, and smooth surfaces of caries-free individuals than of caries-active individuals. The proportion of samples positive for S. mutans and S. sobrinus was significantly higher in caries-active individuals than in caries-free individuals, and the presence of these species is a risk factor for high DMFT in dental caries. Isolates of S. mutans exist that have apparent genetic diversity. The genotypes of isolates might relate to differences in caries susceptibility.

Polymerase Chain Reaction for detection of Streptococcus mutans and Streptococcus sobrinus in dental plaque of children from Cartagena, Colombia

Objectives: To detect the presence of Streptococcus mutans and Streptococcus sobrinus in dental plaque of children from Cartagena and correlate it to dental caries precavity stages, applying a standardized PCR-based technique for epidemiological purposes.Methods: Descriptive study using a non-probabilistic sample of 50 children between 3 and 5 years of age, preschoolers from a Caribbean population in Colombia. Criteria for selection were that children should exhibit plaque accumulations on the surface of the cervical margins of the rearmost molars, and placed in one of two study groups: carious lesions and sound surfaces. Dental plaque samples from both groups were subjected to molecular analysis and statistical analysis was applied to determine the difference between the two groups using the frequencies of presence of S. mutans, S. sobrinus or both in thetwo groups applying Fisher’s exact test for association between the presence of microorganisms and the state of the tooth surface from where the dental plaque was taken.Results: The frequency of S. mutans in carious lesions was 76% and 24% in healthy surfaces. The frequency of S. sobrinus in carious lesions was 81.9% and 18.1% in caries-free surfaces. There was statistical significance between the presence of S. mutans and the presence of caries (p=0.001) and between the presence of S. sobrinus (p=0.02) and the presence of caries.There was no statistical significance between the presence of caries and the simultaneous presence of both microorganisms (p=0.08).Conclusions: The presence of S. mutans and S. sobrinus in dental plaque samples is highly prevalent and associated to non cavitated carious lesions, being the molecular identification of these microorganisms by PCR a sensitive, fast, and easy to use detection method for the mutans group of oral bacteria.

PCR detection of Streptococcus mutans and Streptococcus sobrinus in plaque samples from Mongolian mother-child pairs

Early childhood caries results in a considerable burden of pain and suffering as well as poorer general health. Streptococcus mutans (serotypes c , e and f ) and Streptococcus sobrinus (serotype d and g ) are the species closely associated with dental caries. The exact age at which their colonization occurs in children is controversial. The objective of this study was to detect S. mutans and S. sobrinus in plaque samples of Mongolian mother-child pairs by PCR and to compare their presence with the caries status. Dental examination and caries risk assessment using the Cariostat ® carried out on 320 children aged 6–30 months and their mothers. The presence of S. mutans and S. sobrinus was checked by PCR. The caries prevalence and DEFT scores of mothers enrolled in the present study were 98% and 11.5±0.7, respectively. In children, the prevalence and deft scores of the 6–18-month-olds were 29% and 1.3±0.2 while those of the 19–30-month-olds were 59% and 3.4±0.4 correspondingly. Twenty nine percent of the 6–18-months old children of high-risk mothers and 53.1% of the 19–30-months old children of high-risk mothers had high caries risk ( P <0.001). There was a statistically significant correlation between caries risk of 19–30 month-old children and their mothers ( P <0.001). In mothers, the prevalence of S. mutans and S. sobrinus was 79% and 33%, respectively; 54% harbored S. mutans alone, 8% harbored S. sobrinus alone, 25% harbored both strains. In children, 45% were positive for S. mutans alone, 9% were positive for S. sobrinus alone, 18% were positive for both strains. Either or both strains were detected in 67.3% of 6–18-months old children and 76.5% of 19–30-months old children. In conclusion, our results showed that S. mutans and/or S. sobrinus first colonized infants’ teeth from 6–18 months, and the colonization increased with increasing age, so that by 30 months of age, 76.5% of children harbored the bacteria.

PCR detection of Streptococcus mutans and Aggregatibacter actinomycetemcomitans in dental plaque samples from Haitian adolescents

Streptococcus mutans and Aggregatibacter actinomycetemcomitans are oral pathogens associated with dental caries and periodontitis, respectively. The aim of this study was to determine the colonization of these two microorganisms in the dental plaque of a group of Haitian adolescents using two different polymerase chain reaction (PCR) methods, standard PCR, and quantitative real-time PCR (qPCR) assays. Fifty-four pooled supra-gingival plaque samples and 98 pooled sub-gingival plaque samples were obtained from 104 12- to19-year-old rural-dwelling Haitians. The total genomic DNA of bacteria was isolated from these samples, and all participants also received caries and periodontal examinations. Caries prevalence was 42.2%, and the mean decayed, missing, and filled surface (DMFS) was 2.67 ± 5.3. More than half of the adolescents (53.3%) experienced periodontal pockets (Community Periodontal Index score ≥3). S. mutans was detected in 67.3% by qPCR and 38.8% by PCR of the supra-gingival plaque samples (p < 0.01), and 36.6% by qPCR and 8.1% by PCR of the sub-gingival samples (p < 0.01). A. actinomycetemcomitans was detected in 85.1% by qPCR and 44.0% by PCR of the sub-gingival samples (p < 0.01), but the prevalence was similar, 67.3% by qPCR and 59.2% by PCR, in the supra-gingival plaque samples. Neither age nor gender was significantly correlated to the bacterial colonization. The results demonstrated a moderate-to-high prevalence of S. mutans and A. actinomycetemcomitans in the Haitian adolescent population, and qPCR is more sensitive than standard PCR in field conditions. These findings suggest that qPCR should be considered for field oral epidemiologic studies and may be necessary in investigations having major logistic challenges.

Detection of mutans streptococci in plaque samples from Mongolian preschool and school children

Detection of mutans streptococci in plaque samples from Mongolian preschool and school children

Detection of mutans streptococci in plaque samples from Mongolian preschool and school children

Mutans streptococci, in particular Streptococcus mutans and Streptococcus sobrinus , are generally considered to be the principal microbial pathogen of dental caries. The objective of the study was to isolate S. mutans and S. sobrinus , identify them by PCR, and to compare their presence with the caries status and caries risk in Mongolian preschool and school children. Forty one preschool children aged 3–5 years and 40 school children aged 12–15 years were enrolled in this study. As assessed using Cariostat test, 75.6% of preschool children had high caries risk and 37.5% of school children had high caries risk. In preschool children, the prevalence of S. mutans and S. sobrinus were 100% and 36.6%, respectively; 63.4% were positive for S. mutans alone and 36.6% were positive for both S. mutans and S. sobrinus . In school children, the prevalence of S. mutans and S. sobrinus were 100% and 25.0%, respectively; 75.0% carried S. mutans alone and 25.0% had both S. mutans and S. sobrinus . The percentage of children positive for both S. mutans and S. sobrinus in the high caries risk group were significantly higher than those in the low risk group of either preschool (42.0% vs. 10.0%, P< 0.001) or school children (46.6% vs. 12.0%, P< 0.001). Moreover, the caries status of children positive for both S. mutans and S. sobrinus were significantly higher than those positive for S. mutans alone ( P< 0.01 for preschool children, and P< 0.05 for school children).

Culture-based PCR analysis of plaque samples of Japanese school children to assess the presence of six common cariogenic bacteria and its association with caries risk

The aim of the study was to assess the presence of six common cariogenic bacteria from Cariostat-inoculated plaque samples of Japanese elementary school children through PCR analysis and check its associations with caries risk testing the validity of Cariostat as a caries risk assessment tool. This epidemiological school-based study investigated plaque samples of 399 Japanese elementary school children. Assessed using the Cariostat, 48.2% of the children had high caries risk. DNA detection of Streptococcus mutans, Streptococcus sobrinus, Streptococcus salivarius, Lactobacillus casei, Lactobacillus plantarum, Lactobacillus fermentum and both S. mutans and S. sobrinus was seen in 65.2%, 24.1%, 69.7%, 17.5%, 7.8%, 19.3%, and 17.3% of the participants, respectively. Except for S. salivarius, the presence of all other investigated bacteria resulted in a statistically significant increase among the proportion of subjects with high caries risk. Caries risk assessed using Cariostat was significantly influenced by the presence of cariogenic bacteria. Being a selective medium for cariogenic bacteria, the Cariostat can be a useful and direct source of cariogenic bacterial DNA for PCR analysis while effectively assessing caries risk.

Association of free amino acids with caries experience and mutans streptococci levels in whole saliva of children with early childhood caries

Objective The aim of the present study was to identify the free amino acid content in whole saliva of children with (CE) and without early childhood caries (CF) (ECC), correlating these findings with caries experience and mutans streptococci (MS) levels in saliva. Design Seventy-eight healthy children, both genders, 6–71 months age, were selected to participate in the study. Following examination for dmft scores calculation, unstimulated whole saliva was collected from all 78 participants, stored at −80 °C, and used for amino acid analysis, on a Biochem 20 plus amino acid analyzer. Stimulated whole saliva was collected from 52 children, transported, diluted and plated on MSB agar medium for detection of MS in cfu/mL. Results Forty different free amino acids were identified in whole saliva, with great variation in their concentration. A statistically significant relation was found between caries experience and the presence of free proline and glycine. While proline ( p = 0.0182) was more frequently absent in the CF group, the absence of glycine ( p = 0.0397) was more often observed in the CE group. In the presence of higher levels of MS, free glycine reduced the risk of experiencing dental caries ( p = 0.0419). Conversely, the presence of proline was found to increase the risk of experiencing the disease ( p = 0.0492). Conclusions The presence of free proline and absence of free glycine in children with ECC, highly contaminated with MS, increased the chances of experiencing dental caries in the present population. Further studies are needed to better understand this phenomenon.

Arbitrarily primed-PCR detection of Streptococcus mutans and Streptococcus sobrinus in dental plaque of children with high dmft and no caries

To isolate and identify Streptococcus mutans (Sm) and Streptococcus sobrinus (Ss) in dental plaque of children with high dmft and no caries by selective medium, biochemical methods and arbitrarily primed-polymerase chain reaction (AP-PCR). A total of 401 3-4-year-old children from seven kindergartens were recruited using cluster sampling and their dental caries status were examined. From 30% of children with the highest dmft score (dmft >/= 5), 20 children were chosen randomly as test group and 20 age and gender-matched caries-free children were selected as control. Plaque samples were collected from buccal surfaces of the molars and plated onto TYCSB plate. Sm and Ss were primarily identified by colony morphology and biochemical characteristics. Then chromosomal DNA of the strains was isolated and Sm or Ss were confirmed by AP-PCR. The proportion positive for Sm and Ss in children with high dmft was 100% and 40% respectively while that in caries-free children was 75% and 5% by AP-PCR analysis. The differences were statistically significant between the two groups. The proportions positive for Sm and Ss detected by AP-PCR method were significantly higher in children with high dmft than in caries-free children and it is a risk factor for high dmft in deciduous teeth harboring Sm and Ss.

Evaluation of Cariogenic Bacteria

The evaluation of Mutans streptococci (MS) is one of the index for caries risk. Dentocult(TM) and CRT(TM) are commercial kits to detect and evaluate MS, conveniently. However, the evaluation of MS has also been carried out simply using an instruction manual. But the instruction manual is not easy to use for evaluation of MS. The aim of this study was to examine the utility of modified Mitis-Salivalius Bacitracin (MSB) agar medium compared with MSB agar medium and commercial kits, and to establish a convenient kit (mMSB-kit) using modified MSB agar. The MS in stimulated saliva from 27 subjects were detected by MSB, modified MSB agar medium and commercial kits. Laboratory and clinically isolated strains of MS were similarly evaluated. The ratios of MS in detected bacteria were compared by ELISA. The scores using an mMSB-kit on the basis of modified MSB agar medium were tabulated. Saliva samples showed different levels of MS between culture methods and the commercial kit. Some samples which were full of MS were not detected by the commercial kit. The detection of MS by modified MSB agar medium and mMSB-kit were significantly higher when compared with MSB agar medium,CRT(TM), (P< .01) and Dentocult SM(TM) (P<.05). The sensitivity for detection of MS is higher for modified MSB agar medium when compared with MSB agar medium. The mMSB-kit can be used simply, and can be an important contributor for the evaluation of MS as a caries risk factor.

Detection of streptococcus mutans and streptococcus sobrinus in dental plaque samples from Brazilian preschool children by polymerase chain reaction

The purposes of this study were to detect S. mutans and S. sobrinus by polymerase chain reaction (PCR) amplification, and to relate their presence to the incidence of dental caries in 42 Brazilian preschool children. Dental plaque samples were collected from the cervical margin of all erupted teeth of 5-6 years old children with primary dentition, using a sterile explorer. Examination of the dmft (decayed, missing, filled teeth) index, performed following the World Health Organization (WHO) caries diagnostic criteria, showed a 2.71 score. Prevalence of S. mutans and S. sobrinus was respectively, of 85.7% and 14.3%; no dental plaque sample was either positive or negative for both bacterial species. Children harboring either S. mutans or S. sobrinus presented the same caries prevalence. PCR showed good discriminative ability for differentiation between these species, and suggested that it is a technique suitable for epidemiological studies on mutans streptococci.

Comparative Analysis of a Monoclonal Antibody-BasedStreptococcus mutansDetection Method with Selective Culture Assays Using Polymerase Chain Reaction as a Gold Standard

The aim of this study was to compare a recently developed monoclonal antibody (MAb)-based salivary Streptococcus mutans detection method with various selective media using polymerase chain reaction (PCR) as the gold standard. Salivary S. mutans cells were enumerated with a MAb-based method, along with three commonly used selective media, mitis-salivarius-bacitracin agar (MSB), trypticase yeast-extract cystine sucrose bacitracin agar (TYCSB), and glucose-sucrose-potassium tellurite-bacitracin (GSTB) agar. Statistical analysis showed no significant correlations between each method. With PCR as the standard, a MAb-based detection method was found to provide the highest sensitivity (91%) and specificity (96%) among these four methods. This study demonstrates that the MAb-based detection method may provide more accurate enumeration of salivary S. mutans than selective media.

Quantitative detection of Streptococcus mutans in the dental plaque of Japanese preschool children by real-time PCR

To detect quantitatively the total bacteria and Streptococcus mutans in dental plaque by real-time PCR with prbac, Sm and GTF-B primers, and to compare their presence with the prevalence of dental caries in Japanese preschool children. Human dental plaque samples were collected from the labial surfaces of the upper primary central incisors of 107 children. The dental status was recorded as dft by WHO caries diagnostic criteria. Positive dt and dft scores by the Sm or GTF-B primer were significantly higher than negative scores (P < 0.01). The proportions of Strep. mutans to the total bacteria from sound, and sound and/or filled upper primary incisors were significantly lower than those from decayed or filled, and decayed incisors, respectively (P < 0.01). The ratios of Strep. mutans to total bacteria in plaque detected by real-time PCR with Sm and GTF-B primers were closely associated with the prevalence of dental caries in Japanese preschool children. These assays may be useful for the assessment of an individual's risk of dental caries.

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 revealed that Streptococcus gordonii and Streptococcus infantis were also detected. After amplifying the 16S rRNA gene with universal primers and subsequently performing nested PCR, the S. mutans-specific nested primers based on the 16S rRNA gene detected all tested streptococci. There was no cross-reaction of the gtfB primers after direct PCR. Our results indicate that direct PCR and nested PCR based on 16S rRNA genes can reveal false-positive results for oral streptococci and lead to an overestimation of the prevalence of S. mutans with regards to its role as the most prevalent causative agent of dental caries.

Detection of Streptococcus mutans and Streptococcus sobrinus on the Permanent First Molars of the Mosuo People in China

Streptococcus mutans and Streptococcus sobrinus are associated with the development of dental caries. The purpose of this study was to differentiate these bacteria by morphology, biochemical characteristics and PCR, and to compare their occurrence with the prevalence of dental caries in the Mosuo people. Plaque samples were collected from the permanent first molar in 126 Mosuo people (83 females, 43 males, aged 25–55 years, average age 36.1 ± 7.73). Dental status was recorded as DMFT by WHO caries diagnostic criteria. Males had a significantly lower prevalence of caries and DMFT than females: 11.4 vs. 86.9% and 1.65 vs. 6.95, respectively (p < 0.001). Morphological and biochemical tests gave unreliable results. The prevalence of S. mutans and S. sobrinus was 75.4 and 57.1%, respectively. 26.5% of females and 53.5% of males were positive for S. mutans alone, 18.1% of females and 16.3% of males were positive for S. sobrinus alone, while 50.6% of females and 18.6% of males were positive for both S. mutans and S. sobrinus and4.8% of females and 11.6% of maleswere negative for bothspecies. The DMFT scores of subjects positive for both S. mutans and S. sobrinus were significantly higher than of those positive for either S. mutans or S. sobrinus alone. These results indicate that subjects harboring both S. mutans and S. sobrinus have a significantly higher prevalence of dental caries than those with S. mutans or S. sobrinus alone.

PCR detection of Streptococcus mutans and S. sobrinus in dental plaque samples from Japanese pre-school children.

Streptococcus mutans and S. sobrinus are associated with the development of dental caries. These bacteria were detected by PCR and then their presence was compared with the incidence of dental caries in 77 Japanese pre-school children. Plaque samples were collected from all erupted tooth sites in the subjects, aged 3-5 years old and each with primary dentition, with a sterile toothbrush. A dental examination was performed for dmft (decayed, missing, filled, total) with the WHO caries diagnostic criteria. In all subjects, the prevalence of S. mutans and S. sobrinus was 72.8% and 61.1%, respectively; 19 (24.7%) were positive for S. mutans alone, 10 (13.0%) were positive for S. sobrinus alone, 37 (48.1%) were positive for both S. mutans and S. sobrinus, and 11 (14.3%) were negative for both S. mutans and S. sobrinus. The dmft scores of children positive for both S. mutans and S. sobrinus were significantly higher than those positive for S. mutans alone. These results indicate that children harbouring both S. mutans and S. sobrinus have a significantly higher incidence of dental caries than those with S. mutans alone.

Relationships between dietary behaviours, oral hygiene and mutans streptococci in dental plaque of a group of infants in southern England

This report is part of a prospective study on dietary behaviours, feeding practices, oral hygiene and dental health during the first 18 months of life in a cohort of infants living in southern England. In this part of the study the prevalence of mutans streptococci in the plaque of 1-year-old children and its correlation with sociodemographic status, dietary behaviour and oral hygiene practices over the first 12 months of life were studied. Dietary habits, oral hygiene and dental health at 18 months were also studied. The study group comprised 163 infants. At 12 months of age all children had a dental examination and a plaque sample was removed from the labial surfaces of upper incisors for microbiological examination. A further dental examination took place at 18 months of age; no plaque was sampled. Longitudinal dietary information was obtained with a 3-day food diary at 6, 12 and 18 months of age. Parents/carers completed two structured questionnaires on sociodemographic factors, oral hygiene and feeding behaviour over the first 18 months of life when their children were 12- and 18-month-old. No child exhibited dental caries at 12 and 18 months of age; 18 and 25% had visible dental plaque at 12 and 18 months, respectively. Seven children (4%) had detectable mutans streptococci in their plaque at 12 months of age. Children who had started brushing their teeth or who had had their teeth brushed by 12 months of age were less likely to have detectable mutans streptococci in their plaque than those who had not ( P=0.02). The amount of mutans streptococci was significantly correlated with the total number of eating/drinking events per day ( P<0.001) and bordered on significant correlation with the mean daily frequency of consumption of foods and drinks containing non-milk extrinsic sugars ( P=0.05). None of the sociodemographic variables—sex, social class, mother’s level of education—were associated with the detection of mutans streptococci in this group of infants. Multiple logistic regression analysis revealed that two variables were independently and positively correlated with the presence of mutans streptococci in the plaque; these were age when tooth brushing started and total eating and drinking events per day.

Dental caries and caries-associated microorganisms in Uruguayan preschool children

The prevalence of dental caries was studied in 3-5-year-old Uruguayan children (n = 76) living in 2 areas with different socioeconomic and cultural conditions. More children from the low socioeconomic area of Las Acacias had caries (68%) than children from the middle- to high-class neighborhood of Pocitos (19%). They also had poorer oral hygiene and a significantly higher caries prevalence (P < 0.05) than those from Pocitos. The occurrence of mutans streptococci and lactobacilli was determined in whole unstimulated saliva and compared with that in debris collected with a loop from the dorsum of the tongue. Mutans streptococci were detected in 42% of the children with significant correlations between the salivary levels of the microorganism and caries experience. Lactobacilli were recovered less frequently (18%). The detection of mutans streptococci in the tongue-loop samples was significantly correlated with that in whole saliva.

Rapid and quantitative detection of Streptococcus mutans with species-specific monoclonal antibodies.

Streptococcus mutans is known to be a prime etiologic agent for the initiation and progression of human dental caries. Rapid, accurate, and quantitative detection of S. mutans will help us better understand the pathogenic mechanisms of dental caries and will help to develop methods for caries diagnosis and risk assessment. This study describes the development of three highly species-specific monoclonal IgG antibodies against S. mutans. The antibodies were used to develop a number of methods that quantitatively detect S. mutans in less <1 min and are sensitive enough to detect a single bacterial cell. These methods could be widely used in basic and clinical studies related to S. mutans and in the clinical diagnosis and treatment of caries in humans.