Prevalence and antimicrobial resistance of Salmonella spp. isolated from chicken meat in upper northeastern Thailand

Abstract

Foodborne disease associated with Salmonella spp. occurs in some parts of the world, including Thailand. The present study aimed to determine prevalence, antimicrobial resistance, and serotypes of Salmonella spp. isolated from chicken meat in upper northeastern Thailand. A total of 326 swab samples of fresh chicken meat were collected from wet markets in Khon Kaen, U-don Thani, Nong Khai, Loei, Kalasin, Maha Sarakham, and Bueng Kan Provinces, northeastern Thailand, between August and November 2019. All samples were analyzed for Salmonella spp. using the ISO 6579:2002/AMD 1:2007 method. The isolates were tested for antimicrobial susceptibility using the Kirby-Bauer method, and the serotypes of isolates positive were identified. The overall prevalence of Salmonella spp. isolated from chicken meat was 36.2% (118/326), and prevalence in the provinces was as follows: U-don Thani, 70.9%; Bueng Kan, 66.67%; Khon Kaen, 45.9%; Kalasin, 31.25%; Nong Khai, 29.8%; Maha Sarakham, 26.42% and Loei, 12.5%. Resistance was highest for nalidixic acid at 31%, followed by ampicillin (24%), tetracycline (19%), sulfamethoxazole trimethoprim (8%), norfloxacin (5%), ciprofloxacin (4%), amoxicillin (4%), and chloramphenicol (1%). However, all isolates were susceptible to ceftazidime. Twenty-seven serotypes were detected, with the Corvallis, Singapore, Kentucky and Agona serotypes being the most common. Salmonella spp. were detected in a large percentage of the swab samples of chicken meat in every city, indicating a high level of contamination of chicken meat. Given the high resistance of Salmonella strains to some antibiotics, it may be beneficial to find other drugs for salmonellosis treatment and to use antibiotics more wisely.