isolated from poultry intestine for potential probiotic use.

Background And Aim: To develop species-specific probiotics for poultry, it is ideal to obtain these probiotic microorganisms directly from the intestinal tract of broiler and egg-laying chicks in production environments to ensure adaptation to actual conditions. This study aimed to isolate lactic acid bacteria (LAB) from the intestinal tract of broiler and egg-laying chicks to determine their probiotic potential.

Materials And Methods: Twenty-five Ross-308 broilers and 25 Isa Brown egg-laying chicks were raised until days 42 and 120, respectively; they were housed in an individual poultry building. Lactic acid bacteria were isolated and identified from the small intestine mucus of broiler and layer chicks and then evaluated based on resistance to acidic pH levels, bile salt concentration, and antagonistic activity against wild strains of and spp. selected strains with probiotic potential were identified by polymerase chain reaction and confirmed by rDNA sequencing.

Results: One hundred and fifty Gram-positive isolates were obtained; 28% (42) were catalase and oxidase negative and biochemical identification was made by crystal system: 76.2% (32) spp., 16.6% (7) spp., and 7.2% (3) spp.; and evaluated for hemolysin production; tolerance to low pH and bile salts, and antagonistic potential were carried out. Molecular characterization yielded 56% (24) , and 44% (18) . About 81% (34) of strains were without vancomycin resistance genes criterion.

Conclusion: This study isolated and characterized 36 strains of LAB with probiotic qualities, from the intestines of broiler and egg-laying chicks, selecting , , and , as promising strains for further and research.