Evaluation of Antibiotic Resistance in Escherichia coli Isolates Obtained from Broiler Chicken Flocks at Young Ages in Kermanshah Province

Document Type : Research Paper


1 Department of Animal and Poultry Health and Nutrition, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.

2 Department of Veterinary, Agriculture Faculty, Kermanshah Branch, Islamic Azad university, Kermanshah, Iran.

3 Institute of Biomedical Research, University of Tehran, Tehran, Iran.


Introduction: The widespread use of antibiotics for growth promotion or therapeutic purposes in poultry farming has led to increased antibiotic resistance. Escherichia coli is one of the gastrointestinal bacteria capable of transferring resistance genes and causing antibiotic resistance in humans and poultry. Evaluating antibiotic resistance in poultry flocks can provide researchers with a clear picture of the health status of poultry flocks and the human community. Methods: This study was conducted on 60 broiler chicken flocks aged 1 to 28 days. These flocks had no history of antibiotic use. In the laboratory, after necropsy, sampling was carried out from five chicken pieces in each flock. After confirming the diagnosis and purification of E. coli using biochemical methods, antibiotic sensitivity testing against 19 antibiotics was performed using the disc diffusion method, following the CLSI guidelines. Results: Out of 300 samples collected, 270 (90%) isolates of E. coli were obtained. In this study, the sensitivity of antibiotics was as follows: fosfomycin (100%), lincomycin (94.81%), neomycin (48.52%), amoxicillin (48.15%), norfloxacin (41.48%), thiamphenicol (38.52%), enrofloxacin (38.52%), sulfamethoxazole (36.66%), florfenicol (31.85%), tilmycosin (31.85%), danofloxacin (30%), flumequine (25.19%), difloxacin (21.85%), chlortetracycline (16.66%), trimethoprim (16.66%), doxycycline (11.85%), erythromycin (10%), tylosin (1.48%), and colistin (0%). Additionally, resistance was observed only against tylosin (91.85%). No multiple resistance was observed among the isolated strains, and at least sensitivity to two antibiotics was detected in all samples. Conclusion: The findings of this research indicate that the level of antibiotic resistance in broiler chicken flocks at young ages in the Kermanshah region is low. However, the sensitivity rate to 17 antibiotics is less than 50%, demonstrating a relatively high level of sensitivity in poultry at these ages.


Main Subjects

  1. Xiong, W., Wang, Y., Sun, Y., Ma, L., Zeng, Q., Jiang, X., ... & Zhang, T. (2018). Antibiotic-mediated changes in the fecal microbiome of broiler chickens define the incidence of antibiotic resistance genes. Microbiome6(1), 1-11.
  2. Muhammad, J., Khan, S., Su, J. Q., Hesham, A. E. L., Ditta, A., Nawab, J., & Ali, A. (2020). Antibiotics in poultry manure and their associated health issues: a systematic review. Journal of Soils and Sediments20, 486-497.
  3. Samad, A. (2022). Antibiotics resistance in poultry and its solution. Devotion Journal of Community Service3(10), 999-1020.
  4. Gadde, U., Kim, W. H., Oh, S. T., & Lillehoj, H. S. (2017). Alternatives to antibiotics for maximizing growth performance and feed efficiency in poultry: a review. Animal health research reviews18(1), 26-45.
  5. Hardiati, A., Safika, S., Wibawan, I. W. T., Indrawati, A., & Pasaribu, F. H. (2021). Isolation and detection of antibiotics resistance genes of Escherichia coli from broiler farms in Sukabumi, Indonesia. Journal of advanced veterinary and animal research8(1), 84.
  6. Mehdi, Y., Létourneau-Montminy, M. P., Gaucher, M. L., Chorfi, Y., Suresh, G., Rouissi, T., ... & Godbout, S. (2018). Use of antibiotics in broiler production: Global impacts and alternatives. Animal nutrition4(2), 170-178.
  7. Yang, Y., Ashworth, A. J., Willett, C., Cook, K., Upadhyay, A., Owens, P. R., ... & Moore Jr, P. A. (2019). Review of antibiotic resistance, ecology, dissemination, and mitigation in US broiler poultry systems. Frontiers in Microbiology10, 2639.
  8. Rothrock Jr, M. J., Hiett, K. L., Guard, J. Y., & Jackson, C. R. (2016). Antibiotic resistance patterns of major zoonotic pathogens from all‐natural, antibiotic‐free, pasture‐raised broiler flocks in the Southeastern United States.Journal of Environmental Quality45(2), 593-603.
  9. Roth, N., Käsbohrer, A., Mayrhofer, S., Zitz, U., Hofacre, C., & Domig, K. J. (2019). The application of antibiotics in broiler production and the resulting antibiotic resistance in Escherichia coli: A global overview. Poultry science98(4), 1791-1804.
  10. Sarker, M. S., Mannan, M. S., Ali, M. Y., Bayzid, M., Ahad, A., & Bupasha, Z. B. (2019). Antibiotic resistance of Escherichia coli isolated from broilers sold at live bird markets in Chattogram, Bangladesh. Journal of Advanced Veterinary and Animal Research6(3), 272.
  11. Humphries, R. M., Abbott, A. N., & Hindler, J. A. (2019). Understanding and addressing CLSI breakpoint revisions: a primer for clinical laboratories. Journal of Clinical Microbiology57(6), 10-1128.
  12. Montoro-Dasí, L., Villagrá, A., Sevilla-Navarro, S., Pérez-Gracia, M. T., Vega, S., & Marín, C. (2020). The dynamic of antibiotic resistance in commensal Escherichia coli throughout the growing period in broiler chickens: fast-growing vs. slow-growing breeds. Poultry Science99(3), 1591-1597.
  13. Madadi, M. S., Ghaniei, A., Zare, P., & Isakakroudi, N. (2014). Antimicrobial susceptibility pattern of Escherichia coli isolates to antibacterial agents in Urmia, Iran. Int J Basic Sci Res3, 695-697.
  14. Azizpour, A. (2022). Determination of antibiotic resistance patterns of Escherichia coli strains to twenty antibiotics used in the Iran. Journal of Sabzevar University of Medical Sciences29(1), 101-114.
  15. Khoshkhoo, P.H., Peighambari, S.M. (2005). Drug resistance patterns and plasmid profiles of Escherichia coli isolated from cases of avian colibacillosis. 60(2), 97-105.
  16. Azizpour, A., Saidi Namin, V. (2018). Investigating antibiotic resistance patterns in Escherichia coli isolated from broiler chickens with colibacillosis against ten common antibiotics in Iran's poultry industry. 14(4), 2345-2352.
  17. Haghighi Khoshkho, P., Alinejad, I. (2010). Antibacterial resistance patterns in Escherichia coli isolated from broiler chickens with colibacillosis in Golestan province. Journal of Veterinary Clinical Research, 1, 39-47.
  18. Pourhossein, Z., Asadpour, L., Habibollahi, H., & Shafighi, T. (2023). Evaluation of resistance to colistin and aminoglycosides in Escherichia coli isolated from broilers in Guilan province. New Findings in Veterinary Microbiology6(1), 76-84.

Articles in Press, Accepted Manuscript
Available Online from 13 March 2024
  • Receive Date: 13 February 2024
  • Revise Date: 12 March 2024
  • Accept Date: 13 March 2024