Streptococcus mutans detection in saliva and colostrum samples

Presence of Streptococcus mutans and interleukin-6 and -10 in amniotic fluid

AIM

To evaluate the presence of Streptococcus mutans (SM), main pathogen of dental caries, interleukin-6 and -10 in samples of amniotic fluid (AF) and clinical and oral data of the healthy pregnancy, to investigate the SM exposition in intrauterine life and to elucidate the presence of antibodies to SM in newborns' saliva (SA) with undetectable levels of this microorganism described in the previous study.

METHODS

The study involved the participation of 26 women with term deliveries and without gestational complications. General health data were collected through a questionnaire applied to the participants. The volunteers were examined orally, the caries experience (decayed, missing, and filled teeth (DMFT) scores) was calculated and unstimulated SA was collected. The acquisition of AF was performed during cesarean sections and stocked on ice. The analysis of the presence of SM-DNA was performed by real-time PCR assays with specific primers. Levels of IL-6 and IL-10 were performed by ELISA with specific kits for these interleukins in the AF samples.

RESULTS

69.2% of the AF samples had detectable SM, and 65% of the women had the bacteria in the AF and SA at the same time. There was a positive association between the presence of SM in AF and a report of not going to the dentist frequently (p<.05). There was no statistically significant difference between the frequency of AF with or without detection of MS and active caries (p>.05). However, the DMFT scores of women with positive AF for SM were higher than that of women without detectable MS (p<.05). IL-6 levels were higher than IL-10 in AF (p<.05). There were no significant differences in the levels of interleukins between samples with detectable SM or in AF and even with clinical data analysis (p>.05).

CONCLUSIONS

The AF samples have SM in quantifiable levels, probably associated with the greatest caries experience, and seen by the highest DMFT index. Interleukin levels were not related to the presence of MS. The presence of SM in AF may explain the mucosal immune stimulation of newborn children by the previous detection of salivary antibodies against SM.

Use of an oxygen planar optode to assess the effect of high velocity microsprays on oxygen penetration in a human dental biofilms in-vitro

BACKGROUND

Dental plaque biofilms are the causative agents of caries, gingivitis and periodontitis. Both mechanical and chemical strategies are used in routine oral hygiene strategies to reduce plaque build-up. If allowed to mature biofilms can create anoxic microenvironments leading to communities which harbor pathogenic Gram-negative anaerobes. When subjected to high velocity fluid jets and sprays biofilms can be fluidized which disrupts the biofilm structure and allows the more efficient delivery of antimicrobial agents.

METHODS

To investigate how such jets may disrupt anoxic niches in the biofilm, we used planar optodes to measure the dissolved oxygen (DO) concentration at the base of in-vitro biofilms grown from human saliva and dental plaque. These biofilms were subject to "shooting" treatments with a commercial high velocity microspray (HVM) device.

RESULTS

HVM treatment resulted in removal of much of the biofilm and a concurrent rapid shift from anoxic to oxic conditions at the base of the surrounding biofilm. We also assessed the impact of HVM treatment on the microbial community by tracking 7 target species by qPCR. There was a general reduction in copy numbers of the universal 16S RNA by approximately 95%, and changes of individual species in the target region ranged from approximately 1 to 4 log reductions.

CONCLUSION

We concluded that high velocity microsprays removed a sufficient amount of biofilm to disrupt the anoxic region at the biofilm-surface interface.