Molecular screening of resistant and virulent genes in salmonella enteritidis and salmonella typhimurium from poultry in Khyber Pakhtunkhwa

Abstract

The current study was conducted to investigate the prevalence of Salmonella and its dominant serovars, S. Enteritidis and S. Typhimurium by phenotypic and molecular characterization in poultry. We reported the antimicrobial resistance profile, biofilm formation and presence of resistant and virulent genes of S. Enteritidis and S. Typhimurium of poultry origin in Peshawar. A total of 310 liver samples were collected from morbid and dead birds and processed both by direct plating and selective enrichment methods. Over all prevalence of Salmonella was found to be 21.6% in poultry liver. PCR based molecular screening of Salmonella isolates through serovar specific genes revealed that S. Enteritidis (74.11%) and S. Typhymurium (18.8%) were the most prevalent serovars. Salmonella isolates were found highly resistant to Tetracycline, Oxytetracycline, Nalidixic acid, Doxycycline, Sulfamethoxazole and Erythromycin. While susceptibility of Salmonella isolates was noted against Ceftriaxone, Cefotaxime, Meropenem, Amikacin, Norfloxacin and Ceftazidime. The prevalence of MDR strains were found to be 93.3% of the total isolates while 14.4% isolates were ESBLs producers. The most prevalent resistant genes in Salmonella were sul1 (98.8%), sul2 (97.6%), gyrA (95.2%), strB and CTX-M (80%). Four virulent genes i.e. SpaN, CsgA, SipA and MsgA were present in more than 80% of isolated strains of Salmonella. Hence, it was concluded that poultry birds in the Peshawar region are carrier of highly resistant and virulent S. Enteritidis and S. Typhimurium strains and are a potential public health risk. A routine surveillance and a regulated antimicrobial application are required for control and prevention of the current situation in the poultry.