TITLE:
Low Prevalence of the Genetic Determinants of OXA-1 and AAC (6’) Resistance in Escherichia coli Isolated from Broiler Chicken Droppings in Azaguié, Côte d’Ivoire: A Surveillance Study
AUTHORS:
Kpandji Isidore Kouadio, Eric Joël Tahou, Messou Anicet-Charles Assoua, Aurelie Mirabelle Touvoli, Assanvo Simon-Pierre N’Guetta, Kouadio Nathalie Guessennd
KEYWORDS:
Broiler Chickens, Escherichia coli, OXA-1, AAC (6), Côte d’Ivoire
JOURNAL NAME:
Journal of Biosciences and Medicines,
Vol.14 No.11,
November
4,
2026
ABSTRACT: Background: The rise in avian antibiotic resistance poses a major risk to public health. In Côte d’Ivoire, surveillance studies on the genetic determinants of resistance in avian Escherichia coli remain limited. Objective: The aim of this surveillance study is to assess the prevalence of the OXA-1 and AAC (6’) resistance genes in E. coli strains isolated from broiler chicken droppings in the town of Azaguié, Côte d’Ivoire. Methods: A cross-sectional collection of droppings samples was conducted at 14 broiler farms from June 24 to 26, 2024. After isolating and identifying E. coli strains, susceptibility testing for seven antibiotics was performed using the antibiotic disk diffusion method on agar medium, followed by testing for extended-spectrum beta-lactamase (ESBL) production using the double synergy method. Conventional PCR was performed to detect the OXA-1 and AAC (6’) genetic determinants and class 1 integrons (Int 1). Results: A total of 57 strains of E. coli were isolated. They showed complete susceptibility to beta-lactams (AMC, ceftriaxone, cefotaxime, ceftazidime), 17.54% resistance to gentamicin, 45.61% resistance to nalidixic acid, and 100% resistance to colistin. Molecular analysis of resistant E. coli strains revealed the presence of the oxa-1 and aac (6) genes in 12.50% and 25% of the isolates, respectively, with a significant co-occurrence of the two genes (p = 0.00988). Furthermore, molecular analysis revealed the presence of class 1 integrons (Int 1) at a rate of 70.83%, with no significant association with the blaOXA-1 gene (p = 0.47) or the aac (6’) gene (p = 0.321). Conclusion: This study revealed low prevalences of resistance determinants. However, the high prevalence of class 1 integrons (Int 1) suggests a potential risk of resistance spreading in poultry farms in the Azaguié area, hence the need to continue surveillance within a “One Health” framework to prevent the emergence and spread of antibiotic resistance.