An evaluation of the impact of abattoir processing on the levels of spp. and on broiler carcasses.

BACKGROUND

Twenty years since the monitoring of foodborne diseases started in the EU and United Kingdom, infection is still the most reported zoonosis. One of the crucial reasons for this is thought to be an increase in virulent strains in the chicken meat as a consequence of insufficient and/or inadequate controls on farm and during chicken slaughter and processing. This study aimed to investigate the impact of abattoir processing on the levels of spp. and on broiler carcasses, including the effect of hot water carcass immersion and ultrasound intervention, the abattoir's compliance with process hygiene criteria (PHC) and antimicrobial resistance in spp. strains.

METHODS

Neck skin samples ( = 270) were taken from seven broiler batches over seven sampling days in one abattoir, immediately after defeathering, evisceration, hot water immersion/ultrasound intervention and air-chilling (40 samples per day/batch). Quantification of spp. and was performed based on ISO methods following spp. confirmation on the MALDI-TOFF and PCR. Antimicrobial susceptibility testing of spp. was performed via disc diffusion method using EUCAST guidelines.

RESULTS

was confirmed in 93.7%, in 1.1% and spp. in 1.9% of samples. Abattoir processing significantly reduced final carcass microbial load, with an overall reduction in and levels of 1.14 log and 1.43 log, respectively. Hot water immersion and ultrasound intervention substantially decreased levels by 0.85 log and levels by 0.82 log. The abattoir was found unsatisfactory regarding compliance with PHC for levels within the sampling window, but satisfactory when the new proposed PHC for levels was applied. Antimicrobial resistance was found in isolates from all seven chicken batches, and 48.7% of isolates showed resistance to at least one antibiotic. Most isolates exhibited resistance to tetracycline (45%), nalidixic acid (41%), and ciprofloxacin (39%). Multidrug resistance was found in 2.7% of isolates, with combined resistance to ciprofloxacin, erythromycin and tetracycline in 1.6% of isolates.

CONCLUSION

This study confirmed significant reduction of microbial load on chicken carcasses during abattoir processing, with an emphasis on the importance of using interventions in meat industry. The prevalence of resistance to ciprofloxacin and tetracycline is not declining in spp. on chicken meat, despite antimicrobial stewardship initiatives, and the presence of multidrug resistant strains may be of public health concern.