Bile tolerant Lactobacillus reuteri isolated from pig feces inhibits enteric bacterial pathogens and porcine rotavirus

Lactic acid producing bacterial strain Probio-16 was isolated from the swine excrements under anaerobic conditions and characterized by morphology and biochemical characteristics. The strain was further identified by 16S rRNA gene sequencing and phylogeneitc analysis. The antimicrobial activity of the strain was assayed by testing for growth inhibition of thirteen pathogenic microorganisms. The strain was tested for antiviral activity against porcine rotavirus in vitro in African green monkey epithelial cell line TF-104. Antibiotic susceptibility of the strain against 13 antibiotics was tested using disk diffusion method. Phenotypically and through 16S rRNA gene sequences, Probio-16 was identified and named as Lactobacillus reuteri Probio-16. This strain was resistant to pH 2.0, 5% porcine bile and exhibited antimicrobial activity against all the thirteen enteric bacterial pathogens tested. Probio-16 supernatant inhibited porcine rotavirus in vitro in TF-104 cell lines. Except for erythromycin and penicillin G at a concentration of 4 µg/ml, Probio-16 showed resistance to all other thirteen antibiotics tested. This study indicates L. reuteri Probio-16 as a novel strain with its tolerance to low pH and bile, antimicrobial activity, antibiotic resistance and antiviral activity against rotavirus, and an ideal probiotic candidate for animal and human application after the proper in vivo experiments.