Comparison of Salmonella spp. Contamination and Antimicrobial Resistance Patterns between Two Pig Slaughterhouse Models

Objective: To compare the Salmonella spp. contamination and antimicrobial resistance (AMR) patterns between two pig slaughterhouse models, Materials and Methods: Three hundred sixty pig fecal samples and 360 pork samples were collected from one Hazard Analysis and Critical Control Point (HACCP) standard slaughterhouse and one poor hygiene practice (PHP) slaughterhouse (180 pig fecal samples and 180 pork samples were collected from each slaughterhouse) in Khon Kaen province during 2017-2018 (n=720). All samples were purified and serotype identified. The positive Salmonella spp. isolates were then tested for their antimicrobial susceptibility against ampicillin, ciprofloxacin, chloramphenicol, nalidixic acid, streptomycin, sulfamethoxazole-trimethoprim, tetracycline, and colistin. Results: There were 230 Salmonella spp. isolates purified from the total of samples (n=720); 39.17% Salmonella spp. were isolated from pig fecal samples (141/360) and 24.72% from pork (89/360). The fecal and pork isolates from the HACCP slaughterhouse were 30.56% (110/360) and 6.39% (23/360), whereas the fecal and pork isolates from PHP slaughterhouse were 8.61% (31/360) and 18.33% (66/360), respectively. The most predominant serotype was the Enterica type I 4,[5],12:i:-. Conclusion: After the statistical analyzed between two slaughterhouses, the results demonstrated that the HACCP standard slaughterhouse could reduce the proportion of serotype numbers of Salmonella spp., and stop some AMR spreading from pigs to pork, but the PHP slaughterhouse increased the proportion of positive Salmonella and serotype numbers from pigs to pork.