Superficial properties of Lactic Bacteria (BL) isolated from bovine milk in dairy herds of Córdoba.

PELLEGRINO, M.; ESPECHE, C; VISSIO, C.; LARRIESTRA, A.; BOGNI, C.; NADER-MACIAS, MEF

Rosario

Congreso; V Congreso Argentino de Microbiologia General (SAMIGE); 2008

SAMIGE

Mastitis, defined as the inflammation of mammary gland, is included among the prevalent diseases of the dairy cattle. The traditional strategies to prevent the disease are often costly and with adverse effects. The use of BL with beneficial properties for intramammary administration in cows during the dried period, would constitute an alternative method for the control of the disease together with the application of preventive measures. On the other hand, the specificity of species of the indigenous microbiota is an important characteristic to promote the settling of an ecological specific niche, like bovine mammary gland. The aim of the present work was to realize the isolation, phenotypical identification and the determination of superficial properties of BL isolated from bovine mammary gland, for potential incorporation in a probitic product of local application. A total of 51 milk samples were collected from cows in lactation belonging to 8 dairy herds from the south of the province of Córdoba. The herds were visited once during August - October, 2007. The 17.6 % and 43.1 % of the samples were coming from cows with clinical and subclinical mastitis respectively, whereas 39.3 % was obtained of healthy animals. The samples were place in selective culture medium for BL's isolation, of which there 117 BL were isolated and identified by phenotypical tests. Most of the strains (47.87 %) were isolated from healthy quarters, while 38.46 % of quarters with subclinical mastitis and the rest from quarters with clinical signs of mastitis. There were studied the superficial properties of BL isolated by the determination of hidrofobicity (MATH with hexadecan) and of auto aggregation, which allow to predict its capacity of adhesion to epithelia. The majority of the strains isolated independently of the condition of the quarters showed low hidrofobicity (94 %) and lower capacity of auto aggregation (100 %). Nevertheless strains with median and high hidrofobicity (7) were isolated from healthy quarters (5), subclinical mastitis quarters (2) and none of them from clinical mastitis quarters. There was not correlation between both properties analyzed (Coefficient of Pearson's correlation: 0.136). The low hidrofobicity and the capacity of auto aggregation would be a characteristic of the BL isolated from this particular ecological niche. We are working on the determination of mastitis pathogens inhibition to complete the report of the beneficial properties. These results will allow advance in the selection of microorganisms that would be included in a probiotic veterinary product of local application for the prevention of bovine mastitis.