Prevalence and Antimicrobial Susceptibility of Ceftiofur-Resistant Enterobacteriaceae in Raw Cow’s Milk and Kareish Cheese: Implications for Public Health

Abstract

Ceftiofur is primarily approved for the treatment of respiratory tract infections in foodproducing animals. The rise of ceftiofur resistance among Enterobacteriaceae has allegedlybeen attributed to the misuse and abuse of this popular antibiotic. In this study, we aimedto investigate the prevalence and antimicrobial susceptibility profiles of ceftiofur-resistantEnterobacteriaceae in raw milk and kareish cheese samples collected from Menoufiagovernorate, Egypt. A total of 80 samples, 40 each of raw cow’s milk and kareish cheese,were analyzed by enrichment in Enterobacteriaceae enrichment broth supplemented withceftiofur (8 µg/ml) and plated on violet, red bile glucose agar plates with ceftiofur (8µg/ml). The isolates were subjected to antimicrobial susceptibility testing against 10antibiotics. The study found that 90% of raw cow's milk samples and 95% of kareishcheese samples had ceftiofur-resistant Enterobacteriaceae. Higher resistance rates tocefepime (80.95%), cefotaxime (95.24%), and ceftriaxone (95.24%) were found amongraw milk isolates compared to ciprofloxacin (69.05%) and oxytetracycline (52.38%).Conversely, ceftazidime (14.29%), gentamicin (2.38%), meropenem (2.38%), and colistin(2.38%) showed lower resistance rates. Similarly, Enterobacteriaceae isolates of kareishcheese samples showed high resistance rates to cefepime (97.61%), ceftriaxone (78.57%),cefotaxime (71.43%), oxytetracycline (71.43%), and ciprofloxacin (69.05%), butlow resistance rates to gentamicin (11.90%) and ceftazidime (9.52%). No resistance wasobserved to meropenem and colistin. Our findings suggest that raw milk and karish cheesemay serve as potential reservoirs for the transmission of ceftiofur-resistantEnterobacteriaceae to humans. It is critical to monitor the frequency of ceftiofur-resistantbacteria in food items and modify the legislation controlling the use of ceftiofur in foodanimals.