Molecular and clinical analyses of the gene encoding the collagen-binding adhesin of Streptococcus mutans.
ABSTRACT Streptococcus mutans is a known pathogen of dental caries and its major cell surface antigens have been widely investigated. Recently, an approximately 120 kDa Cnm protein with binding properties to type I collagen was identified, and its encoding gene (cnm) cloned and sequenced. In the present study, we sequenced cnm from 47 different clinical S. mutans strains and found that the nucleotide alignment of the collagen-binding domain was well conserved. We devised a PCR method for identifying the cnm gene, examined the prevalence of cnm-positive S. mutans strains in various mother-child groups, and assessed the significance of such strains for transmission and dental caries. The detection rate of cnm-positive strains was significantly lower in strains isolated from Japanese children in the 2000s (8.0 %) as compared to those isolated in the 1980s (15.8 %) (P<0.05). Furthermore, the presence of S. mutans possessing cnm in salivary specimens collected from 55 S. mutans-positive mother-child pairs was 40 and 32.7 % in the mothers and children, respectively. The frequency of cnm-positive children whose mothers were also positive was 72 %, which was significantly higher than that of cnm-positive children with negative mothers (P<0.0001, odds ratio 17.5). In addition, clinical parameters indicating dental caries were significantly increased in children with cnm-positive S. mutans in saliva (n=13), as compared to those with cnm-negative S. mutans (n=15) and S. mutans-negative children (n=20) (P<0.01). These results indicate that cnm-positive S. mutans strains are closely correlated with dental caries, while vertical transmission in cnm-positive mother-child pairs was also demonstrated.
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ABSTRACT: Objectives: A systematic review was performed with the aim of determining whether there is scientific evidence of the transmission of Streptococcus mutans from mother to child. Data: The eligibility criteria, based on the PECO strategy, were the following: observational human studies whose subjects were mother and child pairs (P) contaminated by S. mutans (E); comparison according to the presence or absence of S. mutans (C); and whether there is transmission (O). The qualitative analysis was performed by assessing the risk of bias of the included studies, while quantitative synthesis was performed through comprehensive Meta-Analysis software (p < 0.05). Sources: Two reviewers performed the database search of studies published between January 1950 and May 2014. The strategy included observational studies that assessed the vertical transmission of S. mutans from mothers to children through analyzing genetic strains. Study selection: It was found 166 non-duplicated studies. However, after reviewing the articles in full and applying the eligibility criteria, 36 papers were selected for qualitative analysis and 19 for quantitative analysis. The cumulative meta-analysis demonstrated vertical transmission of S. mutans from mother to child (p < 0.001). Conclusions: The present systematic review and meta-analysis demonstrated evidence of vertical transmission of S. mutans from mother to child because there was an association between S. mutans n mothers and their respective children. Clinical significance: The knowledge of the S. mutans strains is important because the viru-lence of the microorganisms is varied; also, the virulence affects the dental caries evolution rate, being more or less aggressive.Journal of dentistry 01/2015; 43(2):181-191. · 3.20 Impact Factor
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ABSTRACT: Objective Streptococcus mutans, a major pathogen of dental caries, is considered to be one of the causative agents of infective endocarditis (IE). Two types of cell surface collagen‐binding proteins, Cnm and Cbm, have been identified in the organism. The aim of the present study was to analyze these proteins as possible etiologic factors for IE. Materials and Methods The binding activities of S. mutans strains to collagen types I, III, and IV were analyzed relative to the presence of Cnm and Cbm, as were their adhesion and invasion properties with human umbilical vein endothelial cells (HUVEC). In addition, distributions of the genes encoding Cnm and Cbm in S. mutans‐positive heart valve specimens extirpated from IE and non‐IE patients were analyzed by PCR. ResultsMost of the Cbm‐positive strains showed higher levels of binding to type I collagen as well as higher rates of adhesion and invasion with HUVEC as compared to the Cnm‐positive strains. Furthermore, the gene encoding Cbm was detected significantly more frequently in heart valve specimens from IE patients than from non‐IE patients. Conclusions These results suggest that the collagen‐binding protein Cbm of S. mutans may be one of the potential important factor associated with the pathogenesis of IE.Oral Diseases 05/2013; 19(4). · 2.40 Impact Factor
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ABSTRACT: The prevalence of Streptococcus mutans serotype k, which was speculated that might be associated with the development of cardiovascular diseases, has been reported in adult cardiovascular surgery patients. There is no information about presence of serotype k in children with cardiac disease. The aim of this study was to determine the salivary prevalence of S. mutans serotype k in children with congenital heart disease. Salivary samples of 25 patients undergoing elective surgery for congenital heart defects with cardiopulmonary bypass and an age and gender matched control group of 25 healthy children were enrolled in the study. Species-specific 16SrRNA gene sequences were used for S. mutans and serotype-specific rgpF gene sequences were used for S. mutans serotype k determination in stimulated saliva samples. S. mutans was detected in 19 (76%) of the study and 15 (60%) of the control children. The difference was not shown to be statistically significant. Serotype k was determined from 3 (12%) of the study group, while it was not determined from the samples of the control group. Our results indicate that those children with congenital heart disease may possess S. mutans serotype k in oral cavity at a higher frequency as similar with the adult cardiac surgery patients.The Journal of clinical pediatric dentistry 01/2013; 38(2):175-8. · 0.34 Impact Factor