Quantification of Salmonella transfer in cross-contamination scenarios found in chicken slaughterhouses

Chicken are among the main reservoirs of Salmonella, and slaughterhouses have been identified as key sites for cross-contamination of this pathogen. This study aimed to quantify the transfer rate of Salmonella in different cross-contamination scenarios found in chicken slaughterhouses. To this end, a pool of Salmonella spp. Was inoculated onto chicken carcasses and thighs, reaching out concentrations of 2-5 log₁₀ CFU/g. After inoculation, carcasses and thighs were used to reproduce four cross-contamination scenarios based on industrial reality as follows: 1. Transfer of Salmonella from chicken carcasses to stainless steel and polyethylene surfaces; 2. Transfer of Salmonella between hanging chicken carcasses; 3. Transfer of Salmonella from stainless steel surfaces to chicken carcasses, and 4. Transfer of Salmonella from thighs to stainless steel and polyethylene surfaces. The results showed that the transfer rates (TR) of Salmonella on the chicken carcass to stainless steel and polyethylene were 25.77 ± 22.63% and 24.71 ± 13.93%, respectively, while the TR between hanged chicken carcasses was 5.11 ± 1.71%. When sliding carcasses through a stainless steel ramp, 41.47 ± 1.32% of the Salmonella present on the ramp adhered to the chicken carcasses, and the greater transfer seems to be linked to the wet surfaces. The transfer rates from the thighs to the stainless steel and polyethylene were 1.81 ± 0.66% and 9.0 ± 1.34%, respectively. Cross-contamination occurred regardless of the sample weight, time of contact, and amount of inoculum.