Serotype specific polymerase chain reaction identifies a higher prevalence of streptococcus mutans serotype k and e in a random group of children with dental caries from the Southern region of India

Polymerase chain reaction-based identification of various serotypes of Streptococcus mutans in adults with and without dental caries

Background

Dental caries is a multistep process which initiates the development of plaque' defined as a structured biofilm containing microbial communities. Teeth provide unique surfaces for bacterial colonization. Serotypes of Streptococcus mutans implicate the development of dental caries.

Aim

The aim of the study was to determine the prevalence and association of serotypes of S. mutans in groups with and without dental caries.

Materials and Methods

One hundred and fifty adults aged between 18 and 35 years were included in the study. Supragingival plaque samples were collected, followed by deoxyribonucleic acid extraction. Polymerase chain reaction was performed to identify S. mutans and its serotypes. Proportions of S. mutans and its serotypes were correlated with caries-active (CA) and caries-free (CF) groups.

Results

CA group showed 66.7% positivity for S. mutans and CF group showed only 42.7% of positivity. Serotype C showed a higher proportion followed by E' F, and K in the CA group, whereas in the CF group, higher proportion was observed with K followed by C' E, and F. 70.8% cases showed single serotype in the CA group and 83.3% in CF group. Multiple serotypes were seen in 29.2% in the CA group and 16.7% in the CF group.

Conclusions

The study clearly established variation in proportions of S. mutans and its serotypes between CA and CF groups. Positive correlation was observed in the CA group for S. mutans and its serotypes.

Quantity of the antigens of Streptococcus mutans serotype e and Candida albicans and its correlation with the salivary flow rate in early childhood caries

Background:

Streptococcus mutans involved in caries pathogenesis is classified into four serotypes, namely serotypes c, e, f, and k. Candida albicans can be found in the plaque of children with early childhood caries (ECC). Aims: The aim of this study was to analyze the quantity of the antigens of S. mutans serotype e and C. albicans and its correlation with the salivary flow rate in ECC.

Materials and Methods:

The antigen quantities of caries plaque samples and caries-free were determined using an enzyme-linked immunoassay with 450-nm optical density.

Results:

There was a significant difference between the quantity of S. mutans serotype e and C. albicans antigens in each salivary flow rate category (P < 0.05). The relationship between the antigen quantity of S. mutans serotype e and C. albicans was r = 0.624 (P > 0.05) for caries plaque samples and r = 0.628 (P > 0.05) for caries-free samples.

Conclusion:

the antigen quantities of S. mutans serotype e and C. albicans and the salivary flow rate might correlate to the pathogenesis of ECC.

Tropical Oral Disease: Analysing Barriers, Burden, Nutrition, Economic Impact, and Inequalities

Traditionally, a healthy mouth is a good indicator of good general health. Poor oral hygiene reflects the health of the oral cavity and is a risk factor for overall health. Although oral diseases like dental decay and periodontitis are prevalent, awareness of oral diseases is still limited. Oral disorders include a wide range of diseases that may not be confined to the oral anatomical structures but may be manifestations of systemic diseases. Identification of the risk factors of dental and oral diseases, including socio-economic determinants, plays a major role in the type of oral health care, and in the promotion of dental health awareness. This article reviews oral diseases in the Caribbean and aims to raise awareness of this subject while suggesting a research agenda for the region.

Usefulness of matrix-assisted laser desorption ionization/time of flight mass spectrometry for the identification of Streptococcus mutans

This study evaluated the reliability of MALDI-TOF MS coupled with statistical tools for the identification of Streptococcus mutans in comparison with PCR-based techniques. Bacterial isolates were identified and serotyped by conventional PCR, using S. mutans species and serotype-specific primers. For bacterial identification, mass spectra data from S. mutans and other streptococci were compared with Biotyper V 3.1 database and the mass peak lists were examined by cluster and principal component (PCA) analysis. Identification of potential biomarkers was performed using UniProtKB/Swiss-Prot and UniProtKB/TrEMBL databases and BLAST tool of the NCBI database. PCR identified 100% of the isolates as S. mutans. S. mutans strains were typed as serotypes c (85.6%), e (8.6%), k (4.8%), and f (0.9%). Although only the 70% of the strains tested were identified at species level by the Biotyper database, PCA and cluster analysis of mass peaks allowed the identification of 100% S. mutans isolates and its differentiation from the other oral and non-oral streptococci. One mass peak at m/z value of 9572.73 was identified as species-specific biomarker for S. mutans. No biomarkers were identified for S. mutans serotypes. KEY POINTS: • MALDI-TOF MS coupled with statistical tools for the identification of S. mutans. • Detection of species identifying biomarkers by MALDI-TOF MS. • PCR identification and serotyping of S. mutans from saliva samples.

Molecular and serological typing of Streptococcus mutans strains isolated from young Galician population: relationship with the oral health status

The aim of this study was to determine the prevalence of Streptococcus mutans and its serotypes in samples from oral cavity of young Galician population and their relationship with the oral health state. The variables generally associated with dental caries, such as salivary flow rate, buffering capacity, eating habits, and lifestyle, were also analysed. No relationship was found between the variables studied and the presence of S. mutans in the oral cavity or the existence of dental caries. Presumptive strains of S. mutans were isolated from saliva samples from 48% of the analysed population. The use of conventional microbiological methods, API 20 Strep system, and species-specific polymerase chain reaction (PCR) allowed to substantiate the identity of the strains as S. mutans. Multiplex PCR protocols, developed in this study for the simultaneous detection of S. mutans and serotypes c, e, and f and for detection of S. mutans and serotype k, also confirmed this result and demonstrated that serotype c was predominant in the studied young Galician population (86%). Serotypes e (8%), k (3%), and f (2%) were also detected. Serotype c was detected in carious and caries-free subjects, while the remaining serotypes were only found in subjects with caries.

Streptococcus mutans serotypes and collagen-binding proteins Cnm/Cbm in children with caries analysed by PCR

Streptococcus mutans, a primary bacterium associated with dental caries, has four known clinical serotypes (c, e, fand k). Certain serotypes, the presence of multiple serotypes and strains with collagen-binding proteins (CBP, Cnm and Cbm) have been linked with systemic disease. Evaluation of S mutans serotype distribution and caries association is needed in the United States. The purpose of this study was to evaluate the prevalence of S mutans serotypes from two cohorts of African-American children in rural Alabama using three sample types (saliva, plaque and individual S mutans isolates) by PCR detection for association with caries. Detection of CBP was also performed by PCR. In total, 129 children were evaluated and overall prevalence of serotypes were: serotype c(98%), e(26%), f(7%) and k(52%). Serotype c was statistically associated with higher caries scores in older children (P < 0.001) and serotype k was statistically more likely in females (P = 0.004). Fourteen per cent of children had CBP. Thirteen S mutans isolates from five children tested positive for both CBP. This study is the first to report on the prevalence of S mutans serotypes in a US population using the PCR-based approach. The frequency of serotype k in this study is the highest reported in any population, illustrating the need for further study to determine the prevalence of this clinically relevant serotype in the US. This is the first study to report S mutans isolates with both Cnm and Cbm in the same strain, and further analysis is needed to determine the clinical significance of these strains.

Relative presence of Streptococcus mutans, Veillonella atypica, and Granulicatella adiacens in biofilm of complete dentures

Aims and Objective:

Oral biofilms in denture wearers are populated with a large number of bacteria, a few of which have been associated with medical conditions such as sepsis and infective endocarditis (IE). The present study was designed to investigate the relative presence of pathogenic bacteria in biofilms of denture wearers specifically those that are associated with IE.

Methods:

Biofilm samples from 88 denture wearers were collected and processed to extract total genomic DNA. Eight of these samples were subjected to 16S rRNA gene sequencing analysis to first identify the general bacterial occurrence pattern. This was followed by species-specific quantitative polymerase chain reaction (qPCR) on entire batch of 88 samples to quantify the relative copy numbers of IE-associated pathogens.

Results:

16S rRNA gene analysis of eight biofilm samples identified bacteria from Firmicutes, Actinobacteria, Proteobacteria, Bacteroidetes, and Fusobacteria species. Interestingly, Streptococcus mutans, Veillonella atypica, and Granulicatella adiacens from Firmicutes, all known to be associated with early-onset sepsis and IE was present in five of eight biofilm samples. The other three samples carried bacteria from genus Proteobacteria with Neisseria flava and Neisseria mucosa, which are known to be commensals, as dominant species. Species-specific qPCR of S. mutans V. atypica, and G. adiacens on 88 biofilm DNA samples identified the presence of S. mutans in 83%, V. atypica in 79%, and G. adiacens in 76% of samples.

Conclusion:

The findings from the present study demonstrate co-occurrence of S. mutans, V. atypica, and G. adiacens in a majority of denture wearers, which is clinically significant as elderly patients with compromised immune system are more prone to develop IE. To the best of our knowledge, the co-occurrence of S. mutans, V. atypica, and G. adiacens is being reported for the first time in biofilms of denture wearers.

Assessment of clonality and serotypes of Streptococcus mutans among children by multilocus sequence typing

Studies using multilocus sequence typing (MLST) have demonstrated that Streptococcus mutans isolates are genetically diverse. Our laboratory previously demonstrated clonality of S. mutans using MLST but could not discount the possibility of sampling bias. In this study, the clonality of randomly selected S. mutans plaque isolates from African-American children was examined using MLST. Serotype and the presence of collagen-binding proteins (CBPs) encoded by cnm/cbm were also assessed. One-hundred S. mutans isolates were randomly selected for MLST analysis. Sequence analysis was performed and phylogenetic trees were generated using start2 and mega. Thirty-four sequence types were identified, of which 27 were unique to this population. Seventy-five per cent of the isolates clustered into 16 clonal groups. The serotypes observed were c (n = 84), e (n = 3), and k (n = 11). The prevalence of S. mutans isolates of serotype k was notably high, at 17.5%. All isolates were cnm/cbm negative. The clonality of S. mutans demonstrated in this study illustrates the importance of localized population studies and are consistent with transmission. The prevalence of serotype k, a recently proposed systemic pathogen, observed in this study, is higher than reported in most populations and is the first report of S. mutans serotype k in a United States population.

16S rRNA gene-based metagenomic analysis identifies a novel bacterial co-prevalence pattern in dental caries

Objective:

To identify the prevalence of acidogenic and nonacidogenic bacteria in patients with polycaries lesions, and to ascertain caries specific bacterial prevalence in relation to noncaries controls.

Materials and Methods:

Total genomic DNA extracted from saliva of three adults and four children from the same family were subjected to 16S rRNA gene sequencing analysis on a next generation sequencer, the PGS-Ion Torrent. Those bacterial genera with read counts > 1000 were considered as significant in each of the subject and used to associate the occurrence with caries.

Results and Conclusion:

Sequencing analysis indicated a higher prevalence of Streptococcus, Rothia, Granulicatella, Gemella, Actinomyces, Selenomonas, Haemophilus and Veillonella in the caries group relative to controls. While higher prevalence of Streptococcus, Rothia and Granulicatella were observed in all caries samples, the prevalence of others was observable in 29–57% of samples. Interestingly, Rothia and Selenomonas, which are known to occur within anaerobic environments of dentinal caries and subgingival plaque biofilms, were seen in the saliva of these caries patients. Taken together, the study has identified for the first time a unique co-prevalence pattern of bacteria in caries patients that may be explored as distinct caries specific bacterial signature to predict cariogenesis in high-risk primary and mixed dentition age groups.