Evaluating the presentation of blaCTX-M, blaTEM, and blaSHV resistance genes in Escherichia coli isolated from animal food sources in Tonekabon city and determination of their antibiotic resistance profile

prevalence of E. coli which produces broad spectrum Beta-lactamases in the category of animals like sheep as well as the risk of its transmission to humans have become a significant concern during recent years. The purpose of the research was to study the presence of genes blaCTX-M , blaTEM and blaSHV in E.coli isolates derived from lamb meat in butcheries of Tonekabon city, and to determine the anti-biotic resistance pattern of these isolates. 50 samples of lamb meat were randomly collected from butcheries of Tonekabon city and were transferred to laboratory under sterile conditions. The presence of studied genes was examined using PCR technique and proprietary primers. Anti-biotic sensitivity test was conducted using Kirby’s disk diffusion method. Among obtained isolates, 30 isolates were identified as E. coli. All 30 isolated (100%) carried the blaCTX-M gene and lacked blaSHV. blaCTX-M was identified in 7 isolates (23.3%). 7 samples (23.3%) were positive for both blaCTX-M and blaTFM. The analysis of anti-biotic resistance showed that the isolates were resistant against amoxicillin-clavulanic (86/7%), doxycycline and cephadol (10%) and tetracycline (6/7%). On the other hand, all 30 isolates (100%) were susceptible to cefotaxime and ceftazidime, and 28 isolates were susceptible to ceftriaxone. Isolates susceptible to antibiotics which carrying resistant genes, probably have the potential to become resistant against them. Thus logical usage of antibiotics should be considered more than before.