Occurrence and Antimicrobial Resistance of Salmonella spp. and Escherichia coli Isolates in Apparently Healthy Slaughtered Cattle, Sheep and Goats in East Azarbaijan Province

Background: The increasing prevalence of antimicrobial resistance bacteria in meat-producing animals, especially ruminants, represents a major problem for human and veterinary medicine and also could increase the patients' morbidity and mortality. Objectives: The current study aimed to identify the occurrence and antimicrobial susceptibility pattern of Salmonella spp. and Escherichia coli isolated from slaughtered ruminants in East-Azarbaijan province. Materials and Methods: In this study 160 samples (40 sheep, 40 goats and 80 cattle) were examined to isolate the enteric pathogens. The antibiotic resistance was determined by Kirby-Bauer disc diffusion method using 12 antibiotics. Results: A total of one hundred and twenty bacteria were obtained and most of these isolates belonged to these following genera: Escherichia coli (25%), Proteus (18.8%), Salmonella spp. (8.8 %), Pseudomonas spp. (7.5%) and Yersinia spp. (6.3%). Eight (57.1%) of 14 Salmonella spp. isolates and 26 (65%) of 40 E. coli isolates showed resistance to more than four antibiotics, called multiple antibiotic resistance (MAR). Conclusions: Overall, the obtained results emphasize the need for a surveillance and monitoring system to emerge drug resistance in all pathogenic microorganisms in ruminant and other animals.