High Concentrations of Quinolones Residues found in Eggs from Poultry Farms in Kaduna, Nigeria.

Eggs are the major product generated from layer poultry production systems and are readily processed for consumption and sold to meet public demand. However, antimicrobial usage during production results in residues accumulating in poultry eggs. Thus, it is necessary to monitor and ensure that poultry eggs are safe for human consumption, with no antibiotic residues that can lead to allergic reactions/intoxication or development of antimicrobial resistance. Forty-five (45) farms around Kaduna metropolis, Nigeria were sampled for table eggs alongside a structured questionnaire to consider operation systems (cage or floor), stocking system (all-in-all-out or multiple batches), and location, along with egg producer sizes as either small-, medium-, or large-scale producers. A total of 450 fresh eggs were collated and analyzed using Enzyme-Linked Immunosorbent Assay. The result overall, showed a high prevalence (95.6%) of samples positive for quinolone residues with highest levels of 10,185.5 ng/ml and 5,519ng/ml from two farms (4.4%). These levels are higher than the Maximum Residue Limits (MRL) for edible tissue set by regulatory agencies, including the European Union and U.S. Department of Agriculture (100 ng/ml=100 mg/l). Thirty-three (33) samples from 33 farms (73.3%) overall had residue levels higher than the MRL, 10 farms (22.2%) had residue levels ranging between 2.5 ng/ml – 94.5 ng/ml, while only two farms had undetectable limits of less than 2.5ng/ml. No specific association was found for any of the assessed production factors. Quinolones are antibiotics used both in veterinary and human medicine, thus, their usage must comply with set safety criteria. Consequently, the presence of quinolones in poultry eggs may result in the transmission, to humans, of resistant bacteria and residues of fluoroquinolone active metabolites harmful to human health.