GENETIC IDENTIFICATION OF POTENTIALLY PROBIOTIC Lactobacillus TO PREVENT BOVINE METRITIS

OTERO, M. CLAUDIA; CALLEGARI, M. LUISA; MORELLI, LORENZO; NADER-MACÍAS, M. ELENA

Tucumán, Argentina

Jornada; XXIII Jornadas de la Sociedad de Biología de Tucumán.; 2006

Bovine metritis and antibiotic treatments cause adverse effects on the dairy cows health and on the quality of the milk. Our objective is to the selection of probiotic Lactobacillus to prevent the bacterial colonization and metritis. The identification of Lactobacillus isolates by conventional biochemical tests is usually applied but with some limitations. The molecular biology analysis has been shown to be a rapid, cost-effective and highly discriminatory method for the identification of lactic acid bacteria. The objetive of this work was to identify genetically Lactobacillus strains isolated from the bovine vaginal tract by the Amplified 16s rDNA Restriction Analysis. The ability to produce CO2 from glucose, to grow in MRS-Vancomycin and to ferment ribose, were tested to classify lactobacilli into metabolic groups. The DNA extraction and the amplification was carried out by micro LYSIS reagent and Mega Mix reagent (LABOGEN SRL) with P0 and P6 primers. The restriction enzimes used were: Sau 3AI, Hinf I, Dra I and Hinc II. These profiles were compared with those obtained by computer analysis of the restriction sites in the 16S rDNA sequences. Most of the strains were identified as L. fermentum, a few as L. gasseri and one as L. rhamnosus. These results agree with those obtained from phenotypic methods (API CH 50) for the strains belonging to the species L. fermentum and L. rhamnosus. Those microorganisms phenotypically classified as L. acidophilus were identified as L. gasseri. One strain showed a restriction profile that does not agree with any theoretical profiles, but identified as L. delbrueckii subsp. delbrueckii by fermentative profile. The correct genetic identification is a fundamental step for the vaginal Lactobacillus strains to be considered for their probiotic use to prevent bovine metritis.