Heavy metals (Cu and Zn) contamination of pond sediment and co-occurrence of metal and antibiotic resistance in Escherichia coli from Nigerian aquaculture

Abstract

ABSTRACT Fish farms contribute to the problem of antibiotic resistance because of their therapeutic and prophylactic use of antibiotics and chemicals such as metals that can co-select for antibiotic resistance in bacteria. Very little is known about pond sediment contamination with metals and the co-selecting potentials of antimicrobials and chemicals used in aquaculture in developing countries. This study investigated pond sediment contamination with metals (Cu and Zn) and antimicrobial resistance profiles of Escherichia coli isolated from selected fish farms in South-West Nigeria. All isolated E. coli (n = 98) were metal-tolerant and showed resistance to at least one antibiotic. Significant correlations (p< 0.05, 0.01) were observed between concentrations of metals in pond sediment and phenotypic antibiotic resistance in E.coli. It is necessary to regulate the use of antibiotics and chemicals in aquaculture.