Research Article

Genetic analysis of multidrug resistant Salmonella isolated from broiler chickens

Walid H. Hassan, Ahmed H. Abed, Abd El Rady Thabet and Eman A.M. El Nady
Department of Bacteriology, Mycology and Immunology, Faculty of Veterinary Medicine, Beni-Suef University.

Abstract

Salmonellosis is a major problem for the poultry industry, and this problem represents a critical food safety hazard. Resistance to antimicrobial agents within nontyphoidal Salmonellae is a serious problem. The present study aimed to analyze genetically some β-lactamase resistance genes and some virulence associated genes in Salmonella isolates from broiler chicken. Five hundred samples were collected from diseased broiler chickens of different ages (3-6 weeks) from different farms in Assiut Governorate in Egypt during the period from January 2015 to December 2015. Bacteriological examination showed that 26 Salmonella isolates were recovered with a prevalence rate of 5.2% Serotyping of Salmonella isolates showed that S. Enteritidis S. Typhimurium, and S. Kentuky were identified at rates of 50%, 30.8% and 19.2%, respectively. Results of antibiogram showed that 18 Salmonella isolates (92.3%) were multidrug resistant. All isolates were screened for the presence of 2 β-lactamase resistance genes (blaCTX and blaCMY) as well as 3 virulence genes (stn, invA and hilA) using multiplex PCR. The overall prevalences were 53.9% for blaCTX and 34.6% for blaCMY. Meanwhile, stn, invA and hilA genes were found in 96.2%, 100% and 84.7% of isolates, respectively.

Keywords

Multidrug resistance, Broiler chicken, Salmonellae, β-lactamases, stn, invA, hilA.