The effect of papain on some bacterial pathogens in poultry meat

Abstract

The poultry sector is a significant reservoir of antimicrobial-resistant (AMR) bacteria, posing a substantial threat to public health and food safety. This study quantified farm-level contamination in chickens and turkeys, characterized Escherichia coli and Salmonella spp. and their ESBL/carbapenemase encoding genes, and evaluated papain as a meat-preservation agent. A total of 442 samples (cloacal swabs, litter, water, feed, worker hands, meat, and organs) were collected from 12 chicken and 8 turkey farms. The total viable count (TVC), total coliform count (TCC) were enumerated. E. coli and Salmonella were isolated and tested by multiplex PCR for the detection of ESBL/carbapenemase encoding genes. Antimicrobial resistance (AMR) phenotypes and bla^CTX-M phylogeny were assessed. The effect of papain on chilled chicken meat (12 days) was assessed. The results indicated that microbial loads were higher in chicken than in turkey farms (p < 0.05). Chicken litter showed the highest counts (TVC 7.86 ± 0.25; TCC 6.38 ± 0.09 log10 CFU/g). In chickens, E. coli prevalence was 18.4% (50/272), varying by sample type (p < 0.001), and in turkeys, prevalence was 27.6% (47/170). The ESBL genes in chicken E. coli were bla^TEM 100%, bla^SHV 90%, bla^CTX-M 22%, and bla^OXA-1 10%; and the carbapenemases were bla^KPC 14%, bla^NDM 10%, and blaVIM 6%. Turkey E. coli carried bla^TEM (95.7%), bla^SHV (85%), bla^CTX-M (21.3%), bla^OXA-1 (4.3%), bla^KPC (10.6%), bla^NDM (10.6%, bla^VIM 6.4%. Salmonella occurred in 4.0% of chicken and 18.3% of turkey samples. Salmonella isolates with ESBLs from chickens had bla^TEM 100%, bla^CTX-M 9%, while bla^OXA-1 0%; in turkeys; bla^TEM 90%, and bla^OXA-1 3%. bla^KPC was absent in chickens but detected in 13% of turkey isolates. Phylogenetic analyses elucidate the potential transmission pathways. E. coli resisted ampicillin/sulbactam (65-67%); Salmonella resisted ceftriaxone (88-91%) and penicillin (82-86%). Papain significantly lowered TVC/TCC/TEC during storage, delaying spoilage. In conclusion, poultry farms, especially turkey farms, harbor multidrug-resistant E. coli and Salmonella with clinically important ESBL/carbapenemase genes. Prudent antibiotic use, strengthened biosecurity, and papain-based interventions can mitigate food-safety risks.