SELECTION OF LACTOBACILLI FOR CHICKEN PROBIOTIC ADJUNCTS

During inhibitory activity screening of 296 strains of lactic acid bac teria from the gastro-intestinal tract of chicks, 77 strains showed in hibition against enteric indicator strains (Salmonella enteritidis and Escherichia coli). Eight different strains identified as Lactobacillu s salivarius were selected for the following attributes: their ability to inhibit all the indicator strains; a high adhesion efficiency to t he epithelial cells of chickens and also their resistance to a number of antibiotics, monensin, bile salts and pH 3.0. The inhibitory action was not affected by the addition of catalase and no inhibition was de tected after neutralizing the supernatant culture fluid. The competiti veness of the most promising strains, Lact. salivarius CTC2183 and CTC 2197, was assessed in chicken feed mixture and in vivo. It was conclud ed that both strains were capable of becoming predominant over the ind igenous flora in the incubated chicken feed mixture. In vivo tests sho wed that Lact. salivarius CTC2197 was able to colonize and overcome La ct. salivarius CTC2183 and the indigenous flora in the crop and caecum of the inoculated chicks.