Screenning of surface properties and antagonistis substances production of 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

VETERINARY MICROBIOLOGY

ELSEVIER SCIENCE BV

Lugar: Dusseldorf; Año: 2009 p. 346 - 357

0378-1135

Bovine mastitis is a costly disease in the dairy cattle. The prevention and treatment of mastitis is performed by applying antimicrobial products that affect negatively the milk quality. In the last years, the use of probiotic microorganisms to prevent infections in humans and animals is being strongly studied. Samples from teat canal and milk (foremilk and stripping) were taken from healthy and mastitic dairy cows. A screening of the surface properties and antagonistic substances production of lactic acid bacteria (LAB) isolated from the mammary gland was performed to select potentially probiotic strains to prevent mastitis. Somatic cell count (SCC), physico-chemical and microbiological studies were carried out. Pre-selected microorganisms were genetically identified... Compared with stripping, foremilk showed lower levels of fat and higher levels of pH, density, number of microorganisms, percentage of strains with mean and high hydrophobicty and mean autoaggregation and number of strains able to produce hydrogen peroxide and bacteriocins. The others parameters analyzed were not statistically significantly. A hundred and two LAB strains were isolated. Most of them had low degree of hydrophobicity and autoaggregation. No correlation between this both properties was found. Antagonistic metabolites were mainly produced by strains isolated from healthy animals. Most of the pre-selected strains were identified as Streptococcus bovis and Weissella paramesenteroides. Three bacteriocins-producers were found and their products partially characterized. The results of this work are the basis for the further design of a specie-specific probiotic product able to prevent bovine mastitis.