Genotyping of Salmonella isolates from chickens and ducks and sequence analysis of two chicken isolates of Salmonella Enterica serovar Enteritidis

Abstract

Salmonella causes drastic losses in chicken and duck farms and is considered a major food-borne pathogen with public health concern. Out of 400 chicken and duck samples distributed as follows: (260 samples were collected from native species and 140 from imported species). Salmonella infection in local species represented 5.4% (14/260) and 3.6% (5/140) in imported poultry. A total seven Salmonella serotypes were obtained as follows: S. Enteritidis, S. Typhimurum, S. Kentuky, S. Virchow, S. Infantis, S. Remo, and S. Seremban by serotyping using the (Kauffmann–White scheme). In the same time, all the isolates were subjected to molecular identification by using five primers targeting (sefA, STM4495, ISR2-ISR3, ORF, and Hypothertical protein) which were specific for S. Enteritidis, S. Typhimurum, S. Infantis, S. Kentuky, and S. Virchow, respectively. Genotyping provided rapid, sensitive, and accurate method for Salmonella classification. Phylogenetic analysis was performed onto 2 strains of isolated Salmonella enteritidis (one isolated from imported chicks and the other one from local chicks based on sequencing of the PCR product of the sefA gene. The sequences showed close identity of local and imported isolates with other Salmonella reference strains in different countries. On conclusion, it is important to implement strict monitoring policy of Salmonella in imported and local poultry for prevention and control of Salmonella and formulation of effective vaccines to protect the poultry industry.