Occurrence of Campylobacter, Listeria monocytogenes, and extended-spectrum beta-lactamase Escherichia coli in slaughterhouses before and after cleaning and disinfection

Summary

To prevent foodborne illness, adequate cleaning and disinfection (C&D) is essential to remove pathogenic bacteria from the slaughter environment. The aim of this study was to determine the presence of Campylobacter spp., Listeria monocytogenes, and extended-spectrum beta-lactamase-producing Escherichia coli (ESBL E. coli) before and after C&D in slaughterhouses. Samples from food- and non-food contact surfaces taken before and after C&D in one red meat and one poultry slaughterhouse were analyzed for the target bacteria. Whole-genome sequencing and antimicrobial susceptibility testing were performed. In total, 484 samples were analyzed. Campylobacter spp. were isolated from 13.0% to 15.5% of samples before C&D in the red meat and poultry slaughterhouse, respectively. Listeria monocytogenes was isolated before C&D in 12.5% and 5.2% of samples in the red meat and poultry slaughterhouse, respectively. It was noted that C. jejuni was detected on multiple surfaces and that L. monocytogenes showed potential persistence in one slaughterhouse. After C&D, L. monocytogenes was found in one sample. ESBL E. coli was not detected either before or after C&D. These findings show the possibility to remove pathogenic bacteria from slaughter and meat processing facilities, but also indicate that deficiencies in slaughter hygiene pose a risk of cross-contamination of meat.