Antimicrobial effect of Lactobacillus reuteri on bacteria: periodontal-disease and dental-caries

The study was made in order to compare and evaluate "in vitro" antimicrobial effect of the lactic acid bacterium Lactobacillus reuteri as a probiotic, it is used in various products of daily life. The principal goal of this work was to determine the optimal concentration of L. reuteri capable of inhibiting the growth of bacteria selected in this study.

Method: 

Antimicrobial study was conducted with Disk Diffusion (Kirby-Bauer method), which were embedded with L. reuteri, and then they be transferred to petri dishes with soy agar tripticasein medium. The dishes were previously inoculated with the main bacteria that cause periodontal disease and dental caries: Streptococcus gordonii-10558, Streptococcus mutans-UA130, Aggregatibacter actinomycentencomitans-43718 and Bacteroides forsythus. Susceptibility testing was performed on growth bacterial and verified the effect through inhibition halo formed. 

Result: 

The results showed that L. reuteri is able to interrupt the growth of the pathogenic bacteria proposed in the study, being antibiograms halos evident on Streptococcus genus: 10.3 mm for S. mutans and 0.73 mm for S. gordonii. CHX were 13.8 mm and 12.8 mm respectively. Where there was a minor inhibitory effect, was in the case of A. naeslundii 5.8 mm, followed by Bacteroides forsythus 1.3 mm, and with CHX were 6.8 mm and 15.6 mm respectively. 

Conclusion: 

L. reuteri has a satisfactory antimicrobial action versus Streptococcus genre during growth "in vitro", it means on the bacteria responsible for periodontal disease and tooth decay. Result could be explained by the mechanism of respiration that facilitates the contact and lactic bacteria entry. L. reuteri will be a potential antiseptic oral solution and additional studies are warranted.