Investigation of presence and antibiotic susceptibility of Salmonella spp. in beef obtained from Istanbul

Salmonella is an important pathogen causing foodborne illness cases and outbreaks in many regions of the world. The fact that Salmonella serotypes have developed resistance to various antibiotics today poses a concern in the treatment of serious disease cases where the use of antibiotics is necessary. This study was conducted to determine the presence and antibiotic susceptibility of Salmonella spp. in beef and ground beef obtained from various butchers and markets operating in the European and Asian sides of Istanbul. The sample of the study consisted of 167 raw beef samples (86 of which were cut into morsel-sized pieces) and 36 raw ground beef samples. ISO 6579-1 classical culture method was used to analyze a total of 203 samples. As a result, Salmonella spp. was detected in 4 (2.4%) of the beef samples and 2 (5.6%) of the ground beef samples, and a total of 9 Salmonella strains were isolated. The isolates obtained were confirmed by molecular method and serotyped. Antibiotic tests were performed by disk-diffusion method and the sensitivity of 9 Salmonella serotypes [Eko, Enteritidis, Reading, Telaviv, Infantis, Typhimurium (2), and Anatum (2)] to ampicillin, amoxicillin-clavulanic acid, cefotaxime, cefoxitin, imipenem, chloramphenicol, ciprofloxacin, gentamicin, streptomycin, tetracycline and trimethoprim-sulphametoxazole antibiotics were examined. While all isolates were found to be intermediate resistant to streptomycin, Salmonella Enteritidis was determined to be intermediate resistant to ciprofloxacin as well as streptomycin. Additionally, two serotypes (Typhimurium and Anatum) isolated from one of the beef cut into morsel-sized piece samples were found resistant to ampicillin and tetracycline. The emergence of antibiotic-resistant Salmonella strains in recent years indicates an important public health problem. It is considered important to increase awareness of rational drug use in both human medicine and veterinary medicine.