THE DETECTION OF RELATIVE mRNA EXPRESSION OF CYTOKINE IN CHICKENS AFTER Enterococcus faecium EF55 ADMINISTRATION AND Salmonella enterica Enteritidis INFECTION

Abstract

Summary: Quantitative RT-PCR was used to determine the mRNA expression of pro-inflammatory cytokines IL-15, IL-17, IL-18, LITAF, iNOS, and LyTact chemokine at the caecum and spleen of experimentally infected chicks with S. enterica serovar Enteritidis SE147 preventively treated with Enterococcus faecium EF55. One-day-old ROSS 308 female chicks (100) were randomly divided into 4 groups (n=25). The chicks of the probiotic (EF) and Salmonella+ probiotic (EFSE) groups received per os E. faecium EF55 (109 CFU/day) from 1 to 7 days of the experiment. The birds of the Salmonella (SE) and EFSE groups were perorally infected with Salmonella Enteritidis SE147 in a single dose (108 CFU) on Day 4 of the experiment. The preventive administration of E. faecium EF55 showed higher, however no significant, mRNA levels of studied proinflammatory cytokines and LyTact chemokine except of iNOS in caecum of EFSE experimental group of chicks mainly at Day 1 after S. Enteritidis SE147 infection compared to other groups. In contrast, the dynamics of cytokine/chemokine gene specific responses in caecum are not correlated with responses in the spleen.