The Co-aggregation effects of probiotic lactobacillus against some pathogenic bacteria

Abstract

Background and Aim: Nowadays, probiotic Lactobacilli are as suitable candidate to control and treat diseases, due to their microbial characteristics and especially co-aggregation which prevent attachment and colonization of pathogenic bacteria. The aim of this study is investigation of antimicrobial and co-aggregation of probiotic bacteria, Lactobacillus.plantarum PTCC 1601, Lactobacillus.casei PTCC 1801, and isolated Lactobacilli from dairy products of Sabzevar city against some pathogenic bacteria. Materials and Methods: Isolation and purification of probiotic lactobacilli from Sabsevar traditional dairy products was done by common methods. Among 10 isolated probiotic lactobacilli,two of them which had more probiotic potentail were selected and their phylogenetic and molecular characteristics was investigated by 16s rDNA sequencing technique. Antimicrobial and anti-adhesive effect of probiotic bacteria was examined by Modified Double Layer, Co-Culture and Co-aggregation methods. Co-aggregation of probotic bacteria with pathogens was seen by ATM microscope. Results: In this study, isolated probotic lactobacilli from Sabsevar traditional dairy products and standard bacteria, L.plantarum and L.casei shown the most antimicrobial effect and co-aggregation with pathogenic bacteria, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus, respectively. Inhibition of pathogenic bacteria in the presence of probotic bacteria was seen by co-culture method. Conclusions: According to this study, all used probiotic bacteria in this research inhibited the growth of pathogenic bacteria, among them L.casei had spectacular antimicrobial effect and co-aggregation with pathogenic bacteria and it may be used as a suitable candidate to control diseases.

Keywords

• lactobacillus
• Co-culture
• Co-Aggregation
• AFM microscopy