Probiotic properties of vaginal lactic acid bacteria to prevent metritis in cattle

AIMS: The isolation of bovine vaginal lactic acid bacteria (LAB) and the screening of their beneficial properties to select those that could be used as probiotics in the prevention of bovine metritis were performed. METHODS AND RESULTS: Out of 76 Lactobacillus sp. and seven Streptococcus sp. strains, a small number showed high- and medium hydrophobicity when the microbial adhesion to hydrocarbons method (MATH) was applied. In the agar plate diffusion test, a large number of strains inhibited vaginal bovine Escherichia coli 99/14 and human E. coli. This inhibition was due to acid. Only a few strains inhibited Actinomyces pyogenes 96/393, a pathogen isolated from bovine metritis. This inhibition remained after neutralization. The taxonomic identification of the selected strains was carried out by an amplified ribosomal DNA restriction analysis (ARDRA). Most of the strains were identified as Lactobacillus fermentum, a few as Lactobacillus gasseri and one as Lactobacillus rhamnosus. CONCLUSIONS: Bovine vaginal lactobacilli strains have differential surface properties. The strains selected are capable of inhibiting specific metritis pathogens. SIGNIFICANCE AND IMPACT OF THE STUDY: Our results can be applied for future studies to design a probiotic product to prevent metritis in dairy postpartum cows.