Paired fecal–carcass detection, serotype distribution, and antimicrobial resistance of Salmonella in slaughtered cattle in Algeria

Background and Aim: Salmonella is an important foodborne pathogen associated with livestock and contamination of meat during slaughter and processing. Cattle may harbor Salmonella without apparent clinical signs, creating opportunities for carcass contamination and subsequent entry into the food chain. This study aimed to determine the occurrence, serotype distribution, and antimicrobial resistance profiles of Salmonella recovered from paired fecal and carcass samples of slaughtered cattle in Algeria and to assess contamination patterns within paired samples. Materials and Methods: A cross-sectional study was conducted on 319 cattle at two slaughterhouses in Algiers, Algeria. Paired fecal and carcass samples were collected from each animal, yielding 638 samples. Salmonella isolation and identification were performed using bacteriological procedures, followed by serotyping of recovered isolates. Antimicrobial susceptibility was evaluated phenotypically against the antimicrobial agents included in the study, and multidrug resistance (MDR) was assessed. Results from paired fecal and carcass samples were compared to characterize the distribution of Salmonella at the animal level.