Isolation and identification of potentially probiotic lactic acid bacteria for Holstein calves in the Mexican Plateau

Abstract

Neonate calves are continuously exposed to a wide range of microorganisms in the environment, including diarrhea-causing enteropathogens. Lactic acid bacteria (LAB) was isolated from the oral mucosa of calves, and colostrum and milk from Holstein cows, the strains identified and their resistance to acid pH and bile salts tested. Isolation was done on plated de Man-Rogosa-Sharpe agar. Once decontaminated, the LAB colonies were morphologically and biochemically characterized. Sixteen of the isolated bacterial strains were selected: 12 from oral mucosa, 2 from milk and 2 from colostrum. After testing for resistance to an acid environment (pH 4 and 4.5) and bile salts (0.3 and 1.5 g), the five most resistant species (pH 4 and 1.5 g bile salts) were identified with the API 50 CHL system: Leuconostoc mesenteroides, Pediococcus pentosaceus, Lactobacillus plantarum, Lactobacillus crispatus and Lactococcus lactis. These strains have probiotic potential in calves.