Antimicrobial Resistance of Escherichia coli and Salmonella isolated from Raw Retail Broiler Chickens in Zambia

Abstract

Abstract Background Antimicrobial resistance (AMR) of foodborne pathogens is of public health concern, especially in developing countries like Zambia. This study was undertaken to determine the resistance profiles of Escherichia coli ( E. coli ) and Salmonella isolated from dressed broiler chickens purchased from open markets and supermarkets in Zambia.Results A total of 189 E. coli and five Salmonella isolates were isolated. Identification and confirmation of the isolates was done using Analytical Profile Index (API 20E) (Biomerieux ® ) and 16S rRNA sequencing. Antimicrobial susceptibility tests (AST) were performed using the Kirby Bauer disk diffusion technique using a panel of 10 different antibiotics and multiplex PCR was used to determine the presence of three target genes encoding for resistance: tetA, Sul1 and CTXM. AST results were entered and analyzed in WHONET 2018 software. A total of 189 E. coli and five Salmonella isolates were identified. Among the E. coli isolates, Tetracycline recorded the highest resistance of 79.4%, followed by Ampicillin 51.9%, Trimethoprim/Sulfamethoxazole 49.7%, Nalidixic Acid 24.3%, Chloramphenicol 16.4%, Cefotaxime 16.4%, Ciprofloxacin 10.1%, Colistin 7.4%, Amoxicillin/Clavulanic acid 6.9%, and Imipenem 1.1%. Two of the five Salmonella isolates were resistant to at least one antibiotic. Forty- seven (45.2%) of the isolates possessed at least one of the targeted resistance genes.Conclusion This study has demonstrated the presence of AMR E. coli and Salmonella on raw broiler chickens from both open markets and supermarkets. Such resistance is of public health concern and measures need to be put in place to regulate the use of these antimicrobials in poultry production.