Enterobacteriaceae and Salmonella contamination of wild boar (Sus scrofa) carcasses: comparison between different sampling strategies.

ABSTRACT

During 2020, a total of 64 wild boar carcasses were tested for Enterobacteriaceae count (EBC), Salmonella and Yersinia enterocolitica in the abdominal region (i) within 5 h after hunting in the game collection point and (ii) before dressing and processing in the game-handling establishment (GHE) (49 carcasses-average time interval between (i) and (ii) 4.3 days). Because of COVID-19 restrictions, 15 carcasses were transported to a near slaughterhouse (average time interval between (i) and (ii) 2.3 days). Mesenteric lymph nodes (MLNs) were collected and tested for Salmonella and Y. enterocolitica. Results are shown in relation to sampling A (49 carcasses-GHE) and sampling B (15 carcasses-slaughterhouse). Sampling A EBC median values were (i) 2.51 log10 CFU/cm2 and (ii) 2.79 log10 CFU/cm2. EBC increase between (i) and (ii) was statistically significant (p = 0.001). Salmonella prevalence on carcasses varied from (i) 2.0 to (ii) 6.1%. Sampling B EBC median values were (i) 3.1 log10 CFU/cm2 and (ii) 3.32 log10 CFU/cm2. EBC increase between (i) and (ii) was not statistically significant (p = 0.191). Salmonella prevalence on carcasses varied from (i) 6.7 to (ii) 0.0%. The prevalence (sampling A + B) of lymphatic Salmonella carriers was 7.8% (5/64). From carcasses and/or MNLs, the serovars Enteritidis, Typhimurium, Agama, Zaiman and Diarizonae O50 (z) were detected. Y. enterocolitica was never isolated. Long chilling periods prior to wild game processing should be avoided, and carcasses should be tested at GHE rather than after shooting to proper reflect the microbial load of wild boar meat entering the food chain.