Antibacterial activity of lactobacillus spp. Isolated from fermented food products against porphyromonas gingivalis / Anis Mardhiyah Mazlan

Fermented foods and drinks such as cheese, cultured milk, yogurt, pickles and tempeh contain lactic acid bacteria such as Lactobacillus that promote a lot of benefits to the human. The emergence of antibiotic resistance of oral pathogens brings a concern of the effect of Lactobacillus spp. on oral disease especially in the case of periodontitis. Porphyromonas gingivalis is the causative agents for periodontitis. Five samples of fermented foods and drinks which are cheese, cultured milk, yogurt, pickles and tempeh were collected from the local supermarket. de Man Rogosa and Sharpe (MRS) medium was used to isolate the Lactobacillus spp. The pure colonies were further identified through the morphological, biochemical tests and molecular methods. The sequences obtained from 16S rDNA gene sequencing were analyzed in BLAST and compared with the biochemical test identification. All isolates were investigated for the antagonistic activities on P. gingivalis ATCC 33277 through agar well diffusion method. One way ANOVA was employed to analyze the diameter of inhibition zones between the isolates. The presence of inhibitory substances was also determined through agar well diffusion method. Isolation of Lactobacillus from five samples found a total of 41 isolates that showed the characteristics of Lactobacillus. Biochemical tests led to the identification of the five probable species comprising Lactobacillus rhamnosus, Lactobacillus plantarum, Lactobacillus paracasei, Lactobacillus reuteri and Lactobacillus suebicus. Comparison of sequencing analysis and biochemical test identification exhibited that all isolates from cheese, cultured milk, yogurt and pickle samples showed 98-100% similarity. Meanwhile all isolates from tempeh sample were identified as L. fermentum with 91-98% similarity Isolate L. plantarum displayed the highest mean diameter of inhibition zone which was 14.00+0.58 mm and followed by L. rhamnosus and L. paracasei where the diameters of the inhibition zones were 11.67+0.33 mm and 11.00+0.58 mm, respectively. Isolates of L. fermentum were the least effective in suppressing the growth of P. gingivalis where the diameters of both species were 9.83+0.17 mm. There was significance difference of inhibition zones (p