Multi-drug Resistant Escherichia Coli from Poultry: A Potential Source of Antimicrobial Resistance Spread in Poultry Farm Environment

Background: Escherichia coli is known to inhabit the gastrointestinal tract of poultry and other animals. E. coli infection can cause major economic losses in poultry production. The development of resistance to the commonly used antimicrobials in the treatment of such infection can be a setback in the poultry sector. Objective: This study was carried out to determine the antibiotic resistance profile of E. coli isolated from chickens in Imo State, Nigeria. Materials and Methods: Twelve poultry farms were selected across the 3 senatorial zones of the state using purposive random sampling. A total of 120 cloacal samples were collected from chickens using sterile swabs. The samples were streaked onto MacConkey agar (MCA) and incubated at 37o C overnight. Pink colonies on the MCA were streaked onto eosin-methylene blue agar, incubated for 24 hours at 37o C, and confirmed by indole, methyl red, Voges-Proskauer, and citrate (IMVIC) tests. Antimicrobial susceptibility test was carried out using disc diffusion technique, and the inhibition zone diameter was measured and recorded as resistant or susceptible. Results: Twenty isolates out of the 120 samples were identified as E. coli. Twenty isolates were highly resistant to 5 antibiotics out of 10 antibiotics used. Antibiotic resistance patterns were as follows: amoxicillin (AMP) (95%), cephalothin (CEP) (90%), nalidixic acid (NA) (85%), trimethoprim (SXT) (85%), cefoperazone (PEF) (80%), ampicillin (AMP) (70%) ofloxacin (OFX) (15%), ciprofloxacin (CIP) (10%), gentamicin (CN) (10%), and streptomycin (S) (10%). Sixteen resistance patterns were recorded with AMC-SXT-AMP-CEP-NA-PEF being the most prevalent. Conclusion: This study shows that multi-drug resistant E. coli strains are present in poultry farms in Imo State.