The resistance level shown by E. coli isolates originating from laying and broiler bird flocks from different farms in Nigeria

¹Department of Veterinary Microbiology, Faculty of Veterinary Medicine, University of Ibadan, Ibadan, Nigeria, ²Department of Pathobiology, School of Veterinary Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana

^&Corresponding author
Adelekan Oluseyi Okunlade, Department of Veterinary Microbiology, Faculty of Veterinary Medicine, University of Ibadan, Ibadan, Nigeria

To the editors of the Pan African Medical Journal    

In the scientific community, Escherichia coli (E. coli) have gained enough prominence and are considered the most studied bacteria in the world [1]. E. coli and the Enterobacteriaceae family have been included on a list of 12 bacterial families that pose major hazards to human health per the World Health Organization (WHO) classification [2]; demonstrating the organization's understanding of the gravity of antibiotic resistance. Antibiotic resistance in E. coli is a growing concern, and studies undertaken in a variety of settings have shed light on the problem. Distinct regional and national differences have been seen in the prevalence of ciprofloxacin-resistant Escherichia coli [2]. There should be great care and accountability in the use of antibiotics because of the link between antibiotic resistance and prescription overuse [3].

The usage of clinically relevant antibiotics in veterinary medicine and the declining availability of effective antimicrobial medications for the treatment of illnesses [4,5] only serve to exacerbate the situation. Historically, antibiotics have been of great significance in preserving a multitude of lives and mitigating sickness for a vast number of persons on a global scale [6]. For a variety of causes, drug-resistant forms of bacteria are more common in developing nations, reducing the efficacy of antimicrobials [7]. Chicken farmers in Nigeria and Ghana persist in the use of antibiotics in chicken feed or water for the purposes of prevention, treatment, and growth enhancement [8]. This practice has a substantial role in the development and spread of drug resistance.

This study determined the prevalence of antibiotic resistance in poultry fowl species and analyzed the pattern of resistance of Escherichia coli (E. coli) to commonly used antibiotics. A sample size of 300 avian specimens, which were deemed to be in apparent good health, was collected for the purpose of this study. The majority of the birds tested were laying birds, comprising 78.3% (235 out of 300) of the overall population. Of the total sample size of 300, the remaining 21.6% (65) were classified as broilers. The avian specimens exhibited a range of ages spanning from 16 to 22 weeks, whereas the collective sizes of the bird groups fluctuated between 300 and 600 individuals. The farms practiced an intensive management system with a deep litter option. Feeds are self-compounded with the addition of antibiotics in feed as prophylaxis. Samples were processed following standard microbiological procedures while isolates were identified using an Analytical Profile Index (API 20E kit (Biomerieux®, Inc. at 100 Rodolphe Street, Durham, North Carolina 27712, USA).

Antimicrobial susceptibility testing for a panel of 10 antibiotics was performed on the isolated organisms using the disc diffusion method. The antibiotics used in this study were septrin (25μg), chloramphenicol (30μg), sparfloxacin (5μg), ciprofloxacin (15μg), amoxicillin (30μg), augmentin (30μg), gentamicin (10μg), ofloxacin (5μg), pefloxacin (10μg) and streptomycin (30μg). The turbidity of each sample was calibrated to the 0.5 McFarland standard. The suspension of each isolate was evenly applied onto the surface of pre-prepared Mueller Hinton agar plates (Oxoid, Basingstoke, UK) using sterile swab sticks. A total of 185 Escherichia coli (E. coli) were isolated from the fecal samples of the avian specimens in the designated study areas. All of the E. coli isolates acquired showed resistance to many antibiotics, including ciprofloxacin (100%), pefloxacin (100%), augmentin (89%), amoxicillin (77%), streptomycin (67%), sparfloxacin (62%), gentamicin (58%) and chloramphenicol (56%). The findings indicate that 80%, 75%, and 50% of the isolates exhibited resistance to 5, 4, and 3 antibiotics, respectively (Table 1). Eighty percent (80%) of the E. coli bacteria studied showed resistance to several drugs, which is a major finding (Table 1).

Notably, these strains showed substantial resistance towards ciprofloxacin, pefloxacin, and augmentin (Table 1). The research findings indicate that there is a prevalence of 78% for E. coli and 80% for multidrug-resistant E. coli in both laying and broiler chickens. This aligns with the results reported by Adebowale et al. [9], who observed an 80% prevalence of E. coli and 56% prevalence of multidrug-resistant E. coli in a live bird market located in Abeokuta, Nigeria. The worldwide spread of E. coli strains that are resistant to many antimicrobials (multidrug-resistant, extensively drug-resistant, and pan-drug-resistant) is a major cause for alarm [10].

Conclusion    

The findings of this research indicate a significant level of antibiotic resistance in E. coli strains routinely seen in chicken populations in Nigeria. Antimicrobials are widely utilized in animals raised for human consumption as a means of reducing the prevalence of bacterial illnesses and increasing output. Numerous research studies have shown that the misuse and suboptimal utilization of antibiotics are pivotal variables contributing to the development of resistance. Limiting the use of antimicrobials in the context of animal husbandry is a long-term solution to the issue. Restricting the use of antibiotics for growth promotion via regulation is suggested, along with encouraging the use of probiotics.

Competing interests     

The authors declare no competing interests.

Authors' contributions     

Project conceptualization, data analysis, and result interpretation were performed by Adelekan Oluseyi Okunlade and Motolani Mary Akinpelu. Foluke Olajumoke Jemilehin and Akinlabi Oladele Ogunleye reviewed the manuscript. All the authors read and approved the final version of this manuscript.

Table     

Table 1: percentage multidrug resistance to E. coli

References