In-Vitro Inhibitory Efficacy of 3 Types of Probiotics on the Growth of Aggregatibacter actinomycetemcomitans Bacteria

Background: Amongst the specific plaque pathogen Aggregatibacter actinomycetemcomitans (Aa) ATCC 43718 serotype b is one of the highly virulent bacteria that causes periodontitis. Probiotic therapy is a treatment in which the lactic acid bacteria in are utilized to impede the colonization and growth of the pathogenic bacteria to prevent the further formation of dental plaque. Objective: The present research aimed to evaluate inhibiting effect of purified bacteria from various commercially available yogurt product containing bacteria named (Lactobacillus casei strain Shirota, Lactobacillus bulgaricus and Streptococcus thermophilus, Lactobacillus reuteri Prodentis) on the growth of Aa. Methods: The research made use of the diffusion method by fixing Aa on BHIB (brain heart infusion broth) medium, incubated at 37 °C and 24 hours later planted on MHA (Mueller-Hinton agar) media. Aa were divided into four subgroups each with a paper disk, group 1 consists of untreated bacteria (i.e., control group), group 2 with purified bacteria from Yakult 0.5 µL, group 3 with purified bacteria from Cimory Yogurt Drink 0.5 µL and group 4 with purified bacteria from BioGaia Prodentis 0.5 µL. All commercially available yogurt were treated to get the purified probiotic. Additionally, it was incubated for 24 hours at 37 °C and later the inhibition zone diameter was observed. Results: In the research, it was found that the average impeding ability, so-called inhibition zone, in group 1 indicated 0 mm, group 2 indicated 12.70 mm, group 3 indicated 16.60 mm and group 4 indicated 19.60 mm. The statistical test outcomes showed a significance of 0.000 (p < 0.05). Conclusions: The purified bacteria from three probiotics indeed inhibit the growth of the Aa bacteria and a substantial difference in the diameter of the inhibition zone were found among the three probiotics.