Evaluation and characterization of sources of tranmission farm to table Salmonella spp. to bovine carcasses

In this study, it was aimed to determine the transmission sources, characterisation of serotypes and antibiotic resistance profiles of Salmonella spp. using samples taken from cattle slaughterhouses and meat integrated facilities in the Marmara Region. Within the scope of the study, a total of 336 swab samples were collected between November 2021 and September 2023. Of these samples, 179 were taken from carcass surfaces and 157 were taken from food contact surfaces. Sampling and analyses were performed in accordance with ISO 18593:2018 and ISO 6579-1 standards. Pre-enrichment, selective enrichment and biochemical confirmation steps were applied in the isolation process; suspicious colonies were confirmed by molecular analysis method. Serotyping procedures were completed in Salmonella spp. positive samples and antibiotic resistance profiles were evaluated by disc diffusion method. Antibiotic susceptibility and resistance rates of different serotypes were analysed according to the European Society for Clinical Microbiology and Infectious Diseases (EUCAST) and CLSI criteria. The results revealed that the prevalence of Salmonella spp. varied in samples from slaughterhouses and meat integrated facilities. Salmonella spp. was detected in 0.44% of the samples taken from slaughterhouses, while Salmonella spp. was not detected in the samples taken from meat integrated facilities. Antibiotic resistance analyses showed that the isolate had high resistance rates against antibiotics such as Amoxicillin-Clavulanic Acid, Pefloxacin, Tetracycline, Chloramphenicol. Salmonella Typhimurium isolate was found to have multiple antibiotic resistance. The results obtained provide important information on the presence and antibiotic resistance of Salmonella spp.in cattle slaughterhouses and meat integrated facilities in the region. It is thought that these findings can be a guide for improving food safety standards and developing strategies for the control of Salmonella spp. The study contributes to the formulation of policies to reduce public health risks caused by foodborne pathogens