A monitoring report for Salmonella spp. in an HACCP standard pig slaughterhouse

Abstract

To monitor the prevalence of Salmonella spp. in a Hazard Analysis and Critical Control Point (HACCP) standard
pork slaughterhouse, a comprehensive inspection of an HACCP slaughterhouse was carried out. One hundred and
eighty pairs of fecal and pork samples (n=360) and 65 pairs of important hygiene samples from the before and after
working area (n=130) were collected, isolated and serotype identified, in an HACCP standard slaughterhouse in
northeast Thailand. These isolates were then antimicrobial susceptibility tested against ampicillin, ciprofloxacin,
chloramphenicol, nalidixic acid, streptomycin, tetracycline, sulfamethoxazole/trimethoprim, and colistin. As a result,
there were 61.11% Salmonella spp. isolated from total fecal samples (110/180), 12.78% of pork (23/180) and 6.15% from
hygiene test (8/130), and the most common antimicrobial resistance was against ampicillin, streptomycin, and
tetracycline. The PFGE result shows the Salmonella isolates of pork were contaminated from their own farm, and these
dominant isolates can be sorted into 3 major sources with high similarity. Furthermore, nine fecal and ten pork
Salmonella spp. isolates shared the same serotype and PFGE pattern in the paired samples of the dual positive fecal and
carcass isolates from the total 180 pairs. The relativity rate of Salmonella spp. isolates from feces to pork was 5.00% (9
pairs of 180 pairs). In conclusion, there is a low rate of Salmonella spp. from farm via direct slaughter contamination,
and the most reported cases could be from cross-contamination during the next process of transporting and storage.
More work should be carried out focusing on improving meat production, transportation, and storage.