CENTRO DE REFERENCIA PARA LACTOBACILOS
Unidad Ejecutora - UE
Screening of surface properties and antagonistic substances production by lactic acid bacteria isolated from the mammary gland of healthy and mastitic cows
MARIA CAROLINA ESPECHE; MARIA CLAUDIA OTERO; FERNANDO SESMA; MARIA ELENA FATIMA NADER-MACIAS
Año: 2008 p. 346 - 346
Bovine mastitis (BM) is a costly disease in dairy cattle production. The prevention andtreatment of mastitis is performed by applying antimicrobial products that negativelyaffect milk quality. In the last years, the use of probiotic microorganisms to preventinfections in humans and animals has being aggressively studied.Samples from teat canal andmilk (foremilk and stripping) were taken from healthy andmastitic mammary quarters. A screening of the surface properties and antagonisticsubstances production of lactic acid bacteria (LAB) isolated from the mammary gland wasperformed to select potential probiotic strains to prevent mastitis. Somatic cell count,physico-chemical and microbiological studies were carried out. Pre-selected microorganismswere genetically identified.Compared with stripping milk, foremilk showed lower levels of fat and higher levels ofpH, density, microorganism numbers, lower percentage of strains with mean and highhydrophobicity and mean autoaggregation and higher number of strains able to producehydrogen peroxide and bacteriocins. The other parameters analyzed were not statisticallysignificant. One hundred and two LAB strains were isolated. Most of them had low degreesof hydrophobicity and autoaggregation. No correlation between these properties wasfound. Antagonistic metabolites were mainly produced by strains isolated from healthyquarters. Most of the pre-selected strains were identified as Streptococcus bovis andWeissella paramesenteroides. Three bacteriocin-producers were found and their productspartially characterized.The results of this work are the basis for the further design of a specie-specific probioticproduct able to prevent BM.