Escherichia coli is present in the normal intestinal flora but some strains can cause intestinal and extraintestinal diseases, and research on its presence in food of animal origin is in the interests of public health. This study was designed to characterise E. coli strains according to their origin, their carriage of virulence genes specific for certain pathogroups, and phylogenetic group affiliation.

Escherichia coli is a widespread environmental pathogen frequently causing dairy cow mastitis. This bacterium is particularly capable of acquiring antimicrobial resistance, which can have severe impacts on animal food safety and human health. The objective of the study was to investigate antimicrobial resistance and genetic correlations of E. coli from dairy cow mastitis cases in northern China.

Objective: The increase and prevalence of multidrug-resistant bacteria in livestock animals are serious public health concerns. This study aimed to identify the presence of the blaTEM gene in extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli isolated from rectal swabs of apparently healthy pigs in Malang District, East Java, Indonesia. Materials and Methods: A total of 120 rectal swab samples were collected from the pigs. The rectal swabs were screened for the presence of E. coli using standard microbiological identifi¬cation procedures. The Kirby–Bauer disk diffusion method identified multidrug-resistant E. coli. Five different classes of antibiotics were used to identify multidrug-resistant isolates, including Ciprofloxacin, Trimethoprim, Tetracycline, Streptomycin, and Aztreonam. Multidrug-resistant E. coli isolates were characterized for the presence of ESBL using double-disk synergy test methods. The presence of blaTEM genes was determined using polymerase chain reaction methods. Results: The results of this study indicated that 107 (89.2%) out of 120 samples analyzed were positive for E. coli isolates. A total of 32 (29.9%) E. coli isolates were identified to be multidrug-re¬sistant and further subjected to molecular testing. The molecular analysis revealed (5; 15.6%) E. coli isolates to harbor the blaTEM gene. Conclusion: The results of this study revealed that pigs and products of pork origin must be considered a source of transmission of ESBL-producing E. coli to public health important under the food chain. [J Adv Vet Anim Res 2022; 9(3.000): 447-452]