Antimicrobial Genes Expression in Heterophils of Aseel

Abstract

Salmonellosis is one of the most common infections in the chicken, and also the most important source of human food-borne infection. Heterophils are the predominate granulocyte in chicken expressing a variety of pathogen-associated molecular patterns (PAMPs) in killing the microbes via cationic antimicrobial peptides, such as beta-defensins that are capable of a broad spectrum of antimicrobial activity. Thus, the Toll-like receptors (TLRs) and beta-defensins are the major component of the heterophil antimicrobial arsenal. Aseel is considered to be robust and hardy in terms of disease resistance, but the immuno-genetic basis has not been investigated enough. The expression of the 14 Avian beta-defensins (AvBDs) and chicken Toll-like receptors (chTLRs) 1, 2, 3, 4, 5, 7, 15 and 21 were detectable in the heterophils. In spite of the efforts in prophylactic measures, vaccination and use of antibiotics, eradication of salmonellae from poultry stocks has not been very successful. An alternative approach chTLRs and beta defensin genes can be used as molecular markers in the selection of more resistant chicken lines.