Identification and characterization of species-specific lactic acid bacteria for potential probiotic use in cattle

This study investigated lactic acid bacteria (LAB) isolated from bovine samples, and evaluated the colonization ability, fecal recovery and safety of one isolate with probiotic properties in a 15-day blind placebo study in calves. 104 LAB were assessed in-vitro for resistance to low pH, bile salts, aerobic incubation, and antimicrobial activity against Escherichia coli F5 and O157. Fourteen and 42 percent of the isolates had appropriate overall tolerance (growth rate >80% compared to controls) to pH 4 and 0.3% bile. The inhibitory effect of LAB supernatants on E. coli was associated to their low pH (r2 = 0.804, p < 0.001). The selected isolate (LPB80) was identified as Lactobacillus plantarum by 16S rRNA-PCR. LPB80 administration had no adverse effects. LPB80 was recovered from feces of treated and non-treated calves and from intestinal samples of treated calves. Results suggested that oral administration of LPB80 is safe and that LPB80 may colonize the intestinal tract of calves.