Impact of anthropogenic activities on the occurrence and distribution of toxic metals, extending-spectra β-lactamases and carbapenem resistance in sub-Saharan African urban rivers
The occurrence and dissemination of toxic metals, antibiotic resistant bacteria and their resistance genes (ARGs) in the aquatic ecosystems of sub-Saharan African countries are still understudied, despite their potential to threat human health and aquatic organisms. In this context, the co-contamination and seasonal distribution of toxic metals and ARGs in river sediments receiving untreated urban sewages and hospital effluents from Kinshasa, the capital city of the Democratic Republic of the Congo were investigated. ARGs including β-lactam resistance (blaCTX-M and blaSHV), carbapenem resistance (blaVIM, blaIMP, blaKPC, blaOXA-48 and blaNDM) and total bacterial load were quantified by using quantitative polymerase chain reaction (qPCR) in total DNA extracted from sediment. The results highlight (i) strong pollution of rivers by toxic metals correlating with high abundance of 16S rRNA bacteria and ARGs copy numbers, (ii) multidiffuse pollution originating from human activity contributing to the spread of toxic metals and ARGs into the urban rivers.
Authors recommend the prudence and regulation for the use of antimicrobials for both human and animal medicine, to limit the spread of ARGs and bacteria multiresistant in the environment and the urgent need of access to safe drinking water.18 May 2020