Prevalence and Antimicrobial-Resistant Patterns of Non-typhoidal Salmonella in Good Agricultural Practice Certified Broiler Farms and Poultry Slaughterhouses in an Intensive Farming Area in Upper Northern Part of Thailand

Abstract

Non-typhoidal Salmonella (NTS) is still one of the most infectious foodborne pathogens causing problematic health issues worldwide in both human and veterinary medicine. Poultry meat was one of the important sources of NTS spreading and tended to be highly resistant to antibiotics. The aim of this study was to determine the prevalence, serotypes, and antimicrobial-resistant patterns of Salmonella circulating in broiler farms and poultry slaughterhouses in an intensive farming area in the upper northern part of Thailand from August to October 2019. Fifty samples of boot swabs were collected from 50 broiler farms, 50 cecal samples, and 250 neck skin samples from slaughterhouses. Salmonella was identified by culture method and serum-agglutination and antimicrobial susceptibility testing was tested using the automated VITEK-2 compact system. This study's total prevalence of Salmonella was 53.71% (n=188/350). We found that 53% (159/300) of cecal and neck skins samples were collected from slaughterhouses and 58% (29/50) of boot swabs collected from broiler farms were positive for NTS. Twenty-four serotypes of NTS were identified, the most encountered was S. Kentucky. The antimicrobial-resistant patterns showed that all the strains were non-susceptible to amikacin, cefalexin, cephalothin, and gentamicin and were susceptible to imipenem, neomycin, and nitrofurantoin. The NTS prevalence in samples from broiler farms was slightly higher than in poultry slaughterhouses indicating that there was contamination in the farming and slaughtering process. Therefore, both hygienic measurements in poultry production and antimicrobial usage in the poultry industry should be considered.