*1Ojja, C. V., 2Amosun, E. A., and 3Ochi, E. B.
1,2Avian Medicine Programme, Pan African University Life and Earth Sciences Institute (Including Health and Agriculture), University of Ibadan, Ibadan, Nigeria
2Department of Microbiology and Parasitology, Faculty of Veterinary Medicine, University of Ibadan, Ibadan, Nigeria
3Department of Clinical Studies, School of Veterinary Medicine, University of Juba, Juba, South Sudan *Correspondence to: ojja.christopher@paulesi.org.ng; vukenichris170@gmail.com; +211923419563
Abstract:
Background: Antibiotics are significant for improving the health and productivity of chickens, but overuse and misuse of antibiotics have led to the development of antimicrobial resistance (AMR), which has resulted in ineffective treatment of infectious diseases with associated mortality in chicken and potential spread of AMR pathogens to humans. The objective of the study was to evaluate the AMR profiles of Enterobacteriaceae from faecal samples of laying chicken in Ibadan, southwestern Nigeria.
Methodology: This was a cross-sectional study of 200 apparently healthy laying hens from 10 selected local government areas of Ibadan, Nigeria, and from which cloacal samples were collected for isolation of Enterobacteriaceae. Samples were first inoculated on tryptone soy broth (TSB) for enrichment and then sub-cultured on MacConkey agar plates. Presumptive Escherichia coli isolates were sub-cultured on Eosin Methylene Blue (EMB) agar and greenish metallic sheen colonies on EMB agar were identified as E. coli by colony morphology and Gram stain microscopy. Commercial API (Analytical Profile Index) kit was used to confirm the identity of the Enterobacteriaceae isolates. Antimicrobial susceptibility testing of the isolates was performed by the disc diffusion technique and result interpreted using the guideline of Clinical and Laboratory Standards Institute. Data were analysed on STATA and p<0.05 was considered statistical significance.
Results: The results showed that out of 200 chicken samples, 190 were cultured positive, giving a colonization rate of 95.0%, with 287 Enterobacteriaceae isolates. Escherichia coli (59.6%), Enterobacter spp., (27.9%), and Klebsiella pneumoniae (12.5%) were the bacterial isolates identified. For antibiotic susceptibility, E. coli had sensitivity rate of 78.2% to ciprofloxacin, 73.4% to ofloxacin, 71.8% to sparfloxacin, and 70.9% to pefloxacin, and resistant rates to cotrimoxazole of 73.4%, streptomycin 65.4%, and other antibiotics 63.7%. Klebsiella pneumoniae was sensitive to gentamicin (33.3%), ofloxacin (33.3%), and ciprofloxacin, but resistant to other antibiotics. Enterobacter spp. was sensitive to amoxicillin-clavulanic acid (93.8%), pefloxacin, and streptomycin (70.3%), but resistant to ofloxacin (100.0%), cotrimoxazole (84.5%), chloramphenicol (68.8%), gentamicin (64.1%), amoxicillin (60.9%) and ciprofloxacin (60.9%). A total of 29 resistance patterns were observed in 50 resistant Enterobacteriaceae isolates with 12 MDR patterns observed in 54.0% (n=27) of the isolates.
Conclusion: This study reports faecal Enterobacteriaceae colonization rate of 95% of commercial poultry chicken in Ibadan, southwest Nigeria, belonging to three members of the family Enterobacteriaceae, with high MDR patterns. The high AMR rates can lead to ineffective treatment of infectious diseases in chicken, with associated mortality and a potential source for transmission of AMR pathogens to humans.
Keywords: Antimicrobial resistance, Enterobacteriaceae, Laying chicken, Ibadan, Nigeria
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