Antibiotic Residues in Broiler Chicken Liver Tissues and Resistance Profiles of isolated Bacteria: Findings and implications on one Health

Antibiotic residues may be found in food of animal origin and pose a risk to human health. This study detected antibiotic residues in chicken liver tissues and assessed the resistance profiles of bacteria isolated from the chicken liver tissues in Ishaka-Bushenyi municipality, Uganda. A cross-sectional study was conducted from March 2023 to November 2023 in which 20 broiler liver samples were collected from Ishaka-Bushenyi municipality markets in Western Uganda. The liver samples underwent a microbiological analysis to test for the presence of antibiotic residues, isolation of bacteria and determination of their resistance profiles to antibiotics. Overall, 20% of the samples tested against E. coli ATCC 25922 from Ishaka were positive for antibiotic residues while 10% from Bushenyi were positive for antibiotic residues. All the samples (100%) tested against S. aureus ATCC 25923 were positive for the presence of antibiotic residues from both Ishaka and Bushenyi. We isolated E. coli (45%), Klebsiella spp (35%) and S. aureus (20%). All the three bacteria were 100% resistant to metronidazole. Among the detected isolates, 88.9% of E. coli, 100% of S. aureus isolates, and 85.7% of Klebsiella spp. were susceptible to meropenem. This study revealed that broiler chicken samples collected from Ishaka and Bushenyi markets contained antibiotic residues. Consequently, the isolated pathogens from the broiler chicken samples showed high resistance to antibiotics that are commonly used in humans. There is a need to restrict the use of antibiotics in food-producing animals like broiler chickens because humans end up consuming antibiotic residues.