Effect of a Probiotic on Gut Colonization and Tissue Invasion by Salmonella Enteritidis in Broiler Chickens

Abstract

Introduction: Salmonella enteritidis (SE) is reported to be among the leading agents of food-borne human illnesses which are often transferred via consumption of contaminated poultry products. Probiotics are live microbial feed supplements which could decrease the intestinal infection of salmonellae by competitive-exclusion phenomenon. The objective of the present study was to evaluate the effect of a probiotic based on Lactobacillus, Bifidiobacter and Enterococcus spp. on gut colonization and tissue invasion of SE in broiler chickens.

Methods: One hundred and twenty-eight day-old chicks were divided by a completely randomization into four treatments (T1-T4) each with four replicates of eight birds. The chicks in T1 and T2 received water contained 120 mg/l probiotic during the experiment, but those in T3 and T4 were given pure water. At the second day, the chicks in T1 and T3 were challenged by introducing seeder chicks inoculated with 1.5×105 cfu SE one day before. At the 3rd , 5th , 7th  and 21st days, samples were obtained from cecum and liver, and examined for SE isolation.

Results: The chicks did not experience any clinical signs or mortality. The seeder chicks were infected over the experiment. Cecal colonization of SE was not influenced by probiotic significantlyc, but SE isolation from liver samples showed nearly 55% decrease.

Conclusion: Addition of probiotic to the water of newly-hatched chicks could be useful from a clinical viewpoint, but sanitation considerations in parent flocks and their offspring is more important.