Enrofloxacin residues in edible tissues of fish imported into Nigeria

Abstract

Drug resistance is a problem in the medical world today. It makes treatment difficult and void of expected results. Sub-lethal exposure to antibiotics is one of the major causes of drug resistance and the development of antibioticresistant strains of pathogenic organisms. This study explored the possibility of enrofloxacin residues in edible fish tissues from commonly imported and consumed fish species in Nigeria: Tilapia (Oreochromis niloticus), Horse mackerel (Trachurus murphyi), yellow croaker (Micropogonias furnieri), and Atlantic Mackerel (Scromber scombrus). Fish samples acquired from markets in Lagos were subjected to residue tests using the Green Spring® (Shenzhen Lvshiyuan Biotechnology Co. Ltd) Enzyme-Linked Immunosorbent Assay (ELISA) kit for Enrofloxacin. Randomly selected countries of import were; Argentina, Chile, China, Faroe Island, Iceland, Peru, and Uruguay. Results showed all studied samples having residues of enrofloxacin above internationally acceptable Maximum Residue Limits (MRLs). Croaker from Argentina recorded a significantly high residue level (0.650 ppm); Horse mackerel from Peru had the lowest residue level (0.12ppm). Indicating sub-lethal indirect exposure of consumers to enrofloxacin (none licenced aquaculture drug). Stringent attention is hereby recommended in investigating fish imports for antibiotic residues irrespective of the source to protect consumers' health.