Prevalence of Extended Spectrum Β-Lactamase (ESBL) Producing Escherichia coli and Molecular Characterization of ESBL, Carbapenemases, and Blacmy2 Genes in Broilers and Humans at Menoufia Governorate, Egypt

Antibiotic resistance is a serious worldwide problem threatening human health and life. Poultry, especially broilers, represent a major source of ESBL-producing E. coli due to the extensive use of antibiotics during their production. This study investigated the prevalence of ESBL-EC in broilers, the surrounding environment, and humans, as well as the occurrence of ESBLs, carbapenemases, and bla CMY2 genes. 249 samples were included in that study: 130 broiler cloacal swabs, 54 environmental samples, and 65 human samples. All samples were grown on Macconkey broth, then cultured on EMB containing cefotaxime sodium. Suspected E. coli isolates were identified and confirmed biochemically by IMVIC tests. The disc diffusion method was used to determine the antibiotic susceptibility pattern of E. coli isolates grown on EMB with cefotaxime. PCR was performed for the amplification of ESBLs, carbapenemases, and bla CMY2 genes. Our results revealed that ESBL-EC was isolated from 180 (72.3%) of the 249 collected samples. The prevalence of ESBL-producing E. coli was as follows: 85.4%, 46.3%, and 67.7% in broiler cloacal swabs, environmental samples, and human samples, respectively. Among 188 E. coli isolates grown on EMB containing cefotaxime, 187 were resistant to CTX, 170 to CAZ, 166 to FEP, and 146 to FOX. PCR amplification showed that the predominant gene was bla TEM , which was detected in 98% of the amplified isolates, followed by bla CTX-M (88%). Bla KPC wasn't detected in any isolates. Many gene combinations were detected, and the most common one was bla TEM with bla CTX-M , which was detected in 24 (48%) of the 50 isolates.