A Triad of Public Health Risks: Microbial Contamination, Antimicrobial Resistance, and Drug Residues in Backyard Slaughtered Broiler Meat in Ethiopia

Abstract

ABSTRACT Chicken meat is a favored traditional dish in Ethiopia and is widely consumed globally, but it carries risks of contamination with microbial hazards and antimicrobial residues. This study analyzed 120 broiler carcass samples from farms practicing backyard slaughtering to assess microbial load, occurrence of Campylobacter, E. coli O157:H7, and Salmonella, and to detect antimicrobial resistance and drug residues. The Antimicrobial Resistance (AMR) profile was determined using the VITEK 2XL system, while the detection and quantification of antimicrobial residues were performed by Ultra‐High Performance Liquid Chromatography coupled with a Triple Quadrupole Mass Spectrometer (UHPLC–MS/MS). Results showed that all tested samples were found positive for at least one bacterial pathogen. The overall prevalence was 62.5% for Campylobacter , 22.5% for E. coli O157:H7, and 16.7% for Salmonella . The contamination levels for all tested microbial groups exceeded the limit of Ethiopian standard requirements. Specifically, E. coli and total aerobic bacteria were found in all samples (100%), followed by coliforms in 114 (95%) and S. aureus in 105 (87.5%) of the samples. Among the isolated bacteria, 40.7% of E. coli O157:H7 and 65% of Salmonella isolates were multi‐drug resistant (MDR). Three Salmonella isolates were extensively drug‐resistant (XDR) and one was pan‐drug resistant (PDR). Antimicrobial residue analysis detected enrofloxacin in 25% of samples, oxytetracycline in 18.3%, and sulfadiazine in 3.3%, with a substantial proportion (21.67%) exceeding established EU maximum residue limits. The observed contamination, AMR, and drug residue levels are attributable to unregulated slaughter and widespread drug use in broilers, which necessitate implementation of safety procedures and rational use of antimicrobials.