Survey of prevalence of tet(A) and class 1 Integron genes in tetracycline-resistant Escherichia coli isolated from lesions of colibacillosis

Antibiotics have long been the first line of defense against Escherichia coli infection, but they have lost their potency as the bacteria become increasingly resistant to treatment. The aim of this study was to evaluate the resistance to tetracyclines and the prevalence of tetA and integron class I resistance genes in E. coli isolated from broilers with colibacillosis. In this study, 96.6 % of Escherichia coli isolates resistant to one or both tetracycline antibiotics were studied. Experimental results showed that 98.2 % of tetracycline-resistant Escherichia coli bacteria isolated from lesions of colibacillosis carry tetA. The prevalence of class I integron gene was 98.2%. Also, 96.5% of the isolates of this bacterium carried both genes. Considering the results, the prevalence of tetA and integron class 1 genes in this study was significantly higher than other studies. This difference could indicate high antibiotic resistance in poultry farms in this region which emphasizes the need for cautious use of tetracyclines in poultry production to reduce the prevalence of E. coli resistant to these antibiotics.