The determination and comparing of antibiotic resistance in Escherichia coli isolated from chicken meat with colibacillosis and apparently healthy flocks

Hanieh Shafiei ¹ (Shahrekord Branch, Islamic Azad University)
Majid Gholami-Ahangaran ² (Department of Poultry Diseases, Veterinary Medicine Faculty, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran)
Asiye Ahmadi-Dastgerdi ³ (Department of Food Science and Technology, Ardestan Branch, Islamic Azad University, Ardestan, Iran)

Submited date : 2023-05-01 accepted date : 2023-07-25

Keywords: Chicken Meat, Escherichia coli, Antibiogram, resistance genes,

Abstract :

In this study, for detecting of resistance genes to fluoroquinolones and sulfonamides, 50 bacterial strains were isolated from broiler chickens with pericarditis and perihepatitis and E. coli colonies were confirmed by microbial and biochemical tests. Then, the resistance of the strains to the commercial antibiotics (Enrofloxacin and sulfonamide + trimethoprim) was evaluated by the conventional antibiogram method. In addition, the bacterial genome was extracted by boiling method and the qnrA and sul1 genes were amplified with specific primers to evaluate antibiotic resistance against fluoroquinolones and sulfonamides. After confirming the bacteria and performing an antibiogram, the strains isolated from chickens with a history of colibacillosis showed the lowest antibiotic resistance to gentamicin (7%) and the highest resistance to tetracycline (71%). In this study, 59.5% of these strains showed resistance to at least two antibiotics, and about 9.5% of the strains showed resistance to all 13 antibiotics used in the antibiogram test. Also, the electrophoresis of the PCR product of the strains isolated from chickens with a history of colibacillosis showed that 10 and 15 and one strain out of the 42 investigated strains were able to amplify fragments of 822, 670 and 286 base pairs, respectively, carrying the gene Sul1, qnrA and Act (3)-IV. In other words, 23.8% of strains contained Sul1 gene, 35.7% of strains contained qnrA gene and 2.4% of strains carried Act (3)-IV gene. Therefore, according to the growing trend of antibiotic resistance, it is necessary to prevent the disease from entering the farm by following the proper principles of nutrition and health. Also, by timely vaccination, it is possible to prevent poultry from contracting infectious diseases to a large extent, so that we can reduce the use of different antibiotics and move towards the production of antibiotic-free products.