Rumi and Pasteurized Kareish Cheeses Are a Source of β-Lactam-Resistant Salmonella in the Nile Delta Region of Egypt: Insights into Their Incidence, AMR Pattern, Genotypic Determinants of Virulence and β-Lactam Resistance.

The spread of superbugs in dairy products can jeopardize global public health. To date, information on the incidence rates of virulent and β-lactams-resistant (BLR) Salmonella in cheeses from rural areas of Egypt has been lacking. Biochemical, serological, antibiotic susceptibility, and multiplex PCR (M-PCR) tests were performed to identify and characterize Salmonella isolates. In this study, 44 (15.71%) Salmonella isolates of eight different serotypes were recovered from 280 samples of Rumi and pasteurized Kariesh cheeses across the Nile Delta region of Egypt. The most predominant serotypes were S . Typhimurium, S . Enteritidis, and S . Infantis. The virulence genes ( invA , stn , and hilA ) were identified in all isolates. However, spvC was only detected in S . Typhimurium. The highest resistance was developed against Erythromycin and Clindamycin (90.91%), followed by Ceftazidime and Cephalothin (84.09%). Meropenem and colistin were the most effective antibiotics. A high proportion (79.55%) of multi-drug resistance (MDR) isolates carried narrow spectrum (NS), extended-spectrum (ES), and AmpC-BLR genes. The bla OXA-1 , bla OXA-2 , bla TEM-1 , bla CTX-M , bla CMY-1 , and bla CMY-2 BLR genes were positive in 37.04%, 29.63%, 25.93%, 14.81%, 37.04%, and 3.70% of isolates, respectively. In conclusion, a high prevalence of virulence and BLR genes harboring Salmonella strains in Egyptian cheeses is considered a great threat to public health.