Occurrence of haemolytic Escherichia coli, antimicrobials residue in cultured Clarias gariepinus and assessment of antimicrobial use among catfish farmers in Kano metropolis, Nigeria

Abstract

Antibiotics have been utilized as both antibacterials and growth-promoting agents, although their residues have been reported to be hazardous to both animals and humans. This study aimed to determine the presence of drug resistant haemolytic Escherichia coli in cultured African catfish, detect chloramphenicol and furaltadone residues in fish-fillets, and assess knowledge, attitude and practice of fish farmers on antimicrobial usage. Liver and fillets samples (N=400) from 10 commercial fish farms (n=40) were examined. Isolates were identified after Grams’ staining using conventional biochemical tests. Antimicrobial susceptibility was tested using Kirby-Bauer disc diffusion technique and results were interpreted using clinical laboratory standard institute(CLSI) guide. Detection of drug residues was done using high performance liquid chromatography (HPLC). Antimicrobial use (knowledge, attitude and practice) of fish farmers were assessed usingsemi-structured questionnaire. Haemolytic E. coli (69.3) were isolated and 63 % were observed to be resistant to chloramphenicol, furaltadone, gentamicin, amoxicillin, erythromycin, tetracycline, penicillin, streptomycin, nitrofurantoin and doxycycline. Chloramphenicol and furaltadone residues were not detected in all the samples. Most fish farmers 18 (60%) lack knowledge of antimicrobial resistance and withdrawal period 22 (73.3 %). Their sources of information on antimicrobial usage are co-farmers, drug-vendors and internet. In this study from cultured Clarias gariepinus the occurrence of haemolytic E. coli was 69.3 % and that of chloramphenicol, furaltadone and their metabolites was zero. The E. coli isolated were resistant to at least 4 of the 10 antimicrobials tested.