Inhibitory activity of Varronia curassavica and Mikania laevigatafractions against pathogens associated with persistent dental infections

Herbal medicines have been studied as potential antimicrobial agents, emerging as treatments against oral diseases. The current study evaluated the antimicrobial activity of the crude extract and fractions of Mikania laevigata SchultzBip. ex Baker (ML) and Varronia curassavicaJacq (VC) against oral pathogens associated with persistent dental root infections, under planktonic and biofilm conditions. Minimal inhibitory concentrations and minimal bactericidal/fungicidal concentrations were determined for the ML and VC fractions/extracts against Enterococcus faecalis, Actinomyces israelii, Pseudomonas aeruginosa, and Candida albicans using the microdilution method. The best results were chosen for subsequent biofilm assays. All tested ML and VC extracts/fractions demonstrated inhibitory activity against E. faecalis and A. israelii. The ML ethyl acetate fraction affected the growth of all microorganisms tested. C. albicans and P. aeruginosawere not affected by any VC extract/fractions. The ML ethyl acetate fraction eliminated E. faecalis, A.israelii, and P. aeruginosa biofilms after 24h. A similar result was observed for ML crude hydroethanolic extract and its hexane fraction for A. israelii. The VC hexane fraction was able to eliminate A. israelli biofilms. None of the tested extracts or fractions eliminated C. albicans biofilm. The Mikania laevigata ethyl acetate fraction is an efficient antimicrobial agent against oral pathogens and could be indicated for the treatment of persistent dental infections.

Quantitative assessment of salivary oral bacteria according to the severity of dental caries in childhood.

This study aimed to assess differences in selected oral bacteria in children according to the severity of dental caries. One hundred and thirty-six children, 36-60 months old were divided into three groups according to caries status: caries-free (CF) (n=47), early childhood caries (ECC) (n=40) and severe-early childhood caries (S-ECC) (n=49). Saliva was collected for detection and quantification of selected oral streptococci, Actinomyces naeslundii, Lactobacillus spp., Bifidobacterium spp., and Scardovia wiggsiae by quantitative-polymerase chain reaction. The results showed that the detection and quantitative levels of S. mutans, S. sobrinus, Bifidobacterium spp. and S. wiggsiae were significantly higher in S-ECC children compared to CF and ECC children, while for S. salivarius were significantly higher in CF compared to ECC and S-ECC children. There was no statistical difference among the clinical groups for S. mitis, S. oralis, A. naeslundii and Lactobacillus spp. levels and detection. S-ECC children had a lower monthly family income, started tooth brushing later and were breastfeed for a longer duration compared to CF children. S. mutans levels were positively correlated with S. wiggsiae and Bifidobacterium spp. levels, lower mother's education and child bottle-feeding before sleeping and negatively correlated with S. salivarius. It was concluded that in addition to S. mutans, other bacterial species, including bifidobacteria, Scardovia wiggsiae and S. sobrinus, are associated with severity of early childhood caries, although their role in the progress of dental caries remains unclear.

Antimicrobial peptides in saliva of children with severe early childhood caries.

OBJECTIVE: Controversies exist regarding the relationship between the concentrations of antimicrobial peptides (AMPs) and presence of dental caries in children. Thus, the aim of this study was to examine levels of AMPs in saliva of caries-free (CF), early childhood caries (ECC) and severe early childhood caries (S-ECC) children to determine if the levels of these salivary peptides individually or in combinations were related to caries severity and mutans streptococci levels. DESIGN: 36 to 60 month-old children were selected to participate in this study. Children were grouped into CF group (n=29), ECC group (n=25) and S-ECC group (n=29). Saliva was collected from children for microbiological analysis by culture. Salivary concentrations of cathelicidin LL-37, human ß-defensin 2 (hBD-2), human ß-defensin 3 (hBD-3) and histatin-5 (HTN-5) were determined by ELISA. RESULTS: Salivary concentrations of AMPs did not differ among CF, ECC and S-ECC groups. Data showed positive correlations between mutans streptococci levels and salivary hBD-2 or HTN-5. Positive correlations were found between hBD-2, hBD-3, LL-37 and HTN-5. Combinations among AMPs, mainly LL-37, were positively associated with caries levels. CONCLUSIONS: Salivary concentrations of AMPs individually were not associated with the severity of early childhood caries. The stimulus of caries appears to trigger a biological response, however, with a combination of these peptides.