IgA gene expression and quantification of cecal IgA+, IgM+, and CD4+ cells in chickens treated with EFAL41 and infected with Salmonella Enteritidis

•IgA gene expression and quantification of mucous IgA+, IgM+ and CD4+ lymphocytes.•Cecal samples were processed by qRT-PCR, immunohistochemistry and flow cytometry.•Enterococcus faecium AL41 has immunomodulatory effect against salmonella. IgA gene expression and quantification of mucous IgA+, IgM+ and CD4+ lymphocytes in the cecum of chicks was studied by qRT-PCR, immunohistochemistry and flow cytometry. A total of 220 1-day-old Salmonella-free chicks of Cobb 500 were divided into four groups (n=55). Group 1 served as control (C), group 2 was pretreated with probiotic bacterial strain Enterococus faecium AL41 (EFAL41), group 3 was infected with Salmonella Enteritidis PT4 (SE), and group 4 was pretreated with E. faecium AL41 and subsequently challenged with Salmonella Enteritidis PT4 (EFAL41+SE). The relative mRNA expression of IgA was upregulated in the EFAL41 group (P