Immunogenetics applied to control salmonellosis in chicken: a review

Salmonella infection is an important risk to public health, as newly hatched chicks are very sensitive to Salmonella and the infection transfers to humans through contaminated meat and eggs. Vaccination and antibiotic treatment are common strategies to control salmonellosis. However, it is doubtful whether these strategies succeed, because immune functions depend on the activity of several genes. Genetic improvement of the immune system is an effective method to control salmonellosis. There is genetic variation among breeds and individuals inside breeds in terms of resistance to infection. Genes responsible for resistance to disease can be identified through quantitative trait loci and gene expression analysis. High-throughput technologies assist us to detect single nucleotide polymorphisms (SNPs) and to analyse the regulation of several genes simultaneously. By now, several SNPs have been detected in the chicken genome that influence the function of immune genes. Additionally, the expression level of genes varies during infection depending on the breed and age of chicken and environmental conditions. This review summarizes the results of previous studies on the identification of genes and gene regulation during Salmonella infection in chickens