Effect of Salmonella enterica serovar Enteritidis infection on egg production and immune response of the laying duck

Laying rate and egg quality are also decreased after SE infection (PP+, CD4+, CD8+) display the opposite trend. Expression profiles of immune response genes were also investigated in the reproductive tract of SE-infected ducks using qRT-PCR analysis, revealing that a number of immune genes, including toll-like receptors (TLR2, TLR4-5, TLR15, TLR21), NOD-like receptors (NOD1, NLRX1, NLRP12), avian β-defensins (AvβD4-5, AvβD7, AvβD12), cytokines (IL-6, IL-1β, IFN-γ), and MyD88 are upregulated in the reproductive tracts of SE-infected ducks (all P<0.05), whereas TLR3, TLR7, NLRC3, NLRC5 and TNF-α are significantly downregulated in these animals.