Contribution of Streptococcus Mutans Virulence Factors and Saliva Agglutinating Capacity to Caries Susceptibility in Children: A Preliminary Study

Amyloid hexapeptide prevent dental caries by antibiofilm formation

OBJECTIVES

Biofilm formed by cariogenic microbes is the direct cause of dental caries, therefore, prevention of dental caries should be anti-biofilm-based. Previously, we found the amyloid hexapeptides efficiently inhibited biofilm formation by aggregating into amyloid fibrils agglutinating microbes. This study aimed to select the most stable amyloid hexapeptide GIDLKI (GI6) and study its anti-caries effect.

METHODS

Biofilms of multi-species bacteria, derived from mixed saliva, were cultured to evaluate the anti-biofilm formation effect of GI6. And then, the primary cariogenic bacterium Streptococcus mutans (S.mutans) was cultured in BHI with various pH, gradient concentrations of sucrose, glucose, and calcium ions to evaluate the anti-biofilm formation effects of GI6. Then models of human enamel block caries and twenty male SPF-SD rat caries induced by S. mutans biofilm were constructed, and confocal laser scanning microscopy, scanning electron microscopy, and micro-computed tomography were applied to investigate the anti-biofilm formation, anti-caries effects and use safety of GI6.

RESULTS

GI6 could inhibit the multi-species bacteria biofilm formation and remained effective in anti-biofilm activity against S. mutans in environments closely related to caries. GI6 suppressed S. mutans biofilm formation and thus prevented or alleviated the development of caries in human tooth blocks and rat teeth. GI6 did not affect the intestinal flora, serum biochemical parameters, and the pathological changes of various organs.

CONCLUSIONS

Amyloid hexapeptides, including but not limited to GI6, are novel effective anti-caries agents that can be used to prevent dental caries safely.

CLINICAL SIGNIFICANCE

This study explored the anti-biofilm formation and anti-caries effect of GI6 in vitro, highlighting the anti-biofilm formation therapy for dental caries and setting a foundation for the practical application of GI6 for the treatment of dental caries.

Identification and Correlation of Streptococcus mutans and Streptococcus sanguinis in Caries-active and Caries-free Children: A PCR Study

Aim and objectives

Dental caries is currently considered an ecological imbalance within the oral biofilm leading to the dissolution of the tooth's hard tissues. It has been traditionally thought that two species belonging to the Streptococci group, Streptococcus mutans (SM) and Streptococcus sanguinis (SS), are the etiologically responsible for the onset of dental decay.

Materials and methods

The present in vivo study was conducted on 40 children with caries-active (CA) and caries-free (CF). They were allocated into two groups, group I (CA) = 20 and group II (CF) = 20. The whole saliva was collected into the vials with buffer solution and was stored in cold storage. Polymerase chain reaction (PCR) was done to identify and correlate SM and SS in CA and CF children.

Results

Comparison of mean SM level between CA and CF groups showed a statistically significant result at p = 0.001. Spearman's correlation between caries score and SM showed a strong correlation of 0.77 between caries score and SM, which was statistically significant at p = 0.001. Similarly, SS and caries scores showed a weak correlation of 0.22. Simple linear regression analysis to SM and caries score showed a significant increase of 4.74 units for 1 score increase in caries score, which is statistically significant.

Conclusion

The presence of SM levels in children with caries is significant, whereas, in CF children, SS levels are present in increased levels. A strong correlation was seen between caries scores and SM. The simple linear regression analysis predicts a statistically significant increase by 4.74 units per increase of 1 score of caries at p < 0.001. As caries increase, SM count increases, but SS count decreases; as SS count increases, there is a reduction in SM counts.

How to cite this article

Thimmegowda U, Belagatta V, Chikkanarasaiah N, et al. Identification and Correlation of Streptococcus mutans and Streptococcus sanguinis in Caries-active and Caries-free Children: A PCR Study. Int J Clin Pediatr Dent 2023;16(1):9-15.

The Prevalence of Streptococcus Mutans with Different ABO Blood Groups Among Healthy College Students

Objective:

This study was conducted to determine the correlation between the occurrence ofStreptococcus mutans(S. mutans) which is considered as the main pathogen responsible for the initiation and development of dental caries with blood groups and Rhesus (Rh) factor that are considered as a genetic predictor of having dental caries among healthy students.

Methods:

Saliva and blood samples were taken from 40 healthy students whose ages were between 19-23 years old in the College of Dentistry/Al-Iraqia University in Baghdad, Iraq. Estimation of the flow rate and pH was done for all the collected saliva samples within 5 min of saliva collection. Then, 100 µL of saliva was cultured on Mitis salivarius bacitracin agar (MSBA) at 37 °C for 48 h. The colonies ofS. mutanswere identified by their morphology and biochemical tests. Later, 1 to 2 drops of blood were taken from each student’s thumb to determine the blood group.

Results:

This study showed there was a greater prevalence ofS. mutansamong students of blood group A in contrast to the blood group O. In addition, Rh+ groups were dominant than Rh- groups among the study samples.

Conclusion:

S. mutanslevels were higher in the blood group A followed by AB, B, O blood groups among the college students studied.