Abstract
We isolated 41 lactic acid bacterial strain from the feces of 6 Japanese brown calves and 6 Japanese black calves that were raised by nursing and mother/child separation techniques, respectively. Of the 41 lactic acid bacterial strains 28 were isolated from the Japanese black calves and 16 from the Japanese brown calves. The Lactobacillus strains were identified and compared on the basis of their biochemical characteristics, and the homology of the 500bp 16S rDNA sequence with that in the Lactobacillus strains was assessed using the International Nucleotide Sequence Database. Accordingly, 5 strains of Lactobacillus (L. fermentum,, L. reuteri,, L. salivarius, L. saerimneri, and L. amylovorus), and 2 Pediococcus strains (Pediococcus acidilactici, and P. pentosaceus) were isolated from the calves raised by nursing. In contrast, 4 Lactobacillus strains (L. salivarius, L. mucosae, L. reuteri, and L. oris strains) were isolated from calves raised by mother-child separation. The L. fermentum, L. saerimneri, L. amylovorus, P. acidilactici and P. pentosaceus strains, were isolated only from the calves raised by nursing, therefore, their mothers were thought to play an important role in the transmission of these strains. This was possible because of the high chances of contact between the mother and calf. Jong et al., (1999) reported that the L. amylovorus IMC-1 strain, isolated by Mutsu, et al., had antibiotic properties. The r-8 culture (L. amylovorus kumamoto [=JCM14931]) isolated from calves raised by nursing was centrifuged, and the supernatant was observed to significantly suppress the proliferation of Escherichia coli and Staphylococcus aureus (P<0.01). These results indicated that the r-8 strain could be a lactic acid bacterial strain that prevents bacterial infection in the intestinal tract of calves. We assume that the administration of the r-8 strain can prevent pathogenic entero bacterial infection in calves.
