title: Hospital Effluents Are One of Several Sources of Metal, Antibiotic Resistance Genes, and Bacterial Markers Disseminated in Sub-Saharan Urban Rivers.
abstract: Data concerning the occurrence of emerging biological contaminants such as antibiotic resistance genes (ARGs) and fecal indicator bacteria (FIB) in aquatic environments in Sub-Saharan African countries is limited. On the other hand, antibiotic resistance remains a worldwide problem which may pose serious potential risks to human and animal health. Consequently, there is a growing number of reports concerning the prevalence and dissemination of these contaminants into various environmental compartments. Sediments provide the opportunity to reconstruct the pollution history and evaluate impacts so this study investigates the abundance and distribution of toxic metals, FIB, and ARGs released from hospital effluent wastewaters and their presence in river sediments receiving systems. ARGs (bla TEM, bla CTX-M, bla SHV, and aadA), total bacterial load, and selected bacterial species FIB [Escherichia coli, Enterococcus (ENT)] and species (Psd) were quantified by targeting species specific genes using quantitative PCR (qPCR) in total DNA extracted from the sediments recovered from 4 hospital outlet pipes (HOP) and their river receiving systems in the City of Kinshasa in the Democratic Republic of the Congo. The results highlight the great concentration of toxic metals in HOP, reaching the values (in mg kg(-1)) of 47.9 (Cr), 213.6 (Cu), 1434.4 (Zn), 2.6 (Cd), 281.5 (Pb), and 13.6 (Hg). The results also highlight the highest (P < 0.05) values of 16S rRNA, FIB, and ARGs copy numbers in all sampling sites including upstream (control site), discharge point, and downstream of receiving rivers, indicating that the hospital effluent water is not an exclusive source of the biological contaminants entering the urban rivers. Significant correlation were observed between (i) all analyzed ARGs and total bacterial load (16S rRNA) 0.51 to 0.72 (p < 0.001, n = 65); (ii) ARGs (except bla TEM) and FIB and Psd 0.57 < r < 0.82 (p < 0.001, n = 65); and (iii) ARGs (except bla TEM) and toxic metals (Cd, Cr, Cu, and Zn) 0.44 to 0.72, (p < 0.001, n = 65). These findings demonstrate that several sources including hospital and urban wastewaters contribute to the spread of toxic metals and biological emerging contaminants in aquatic ecosystems.
authors: Faculty of Science, Earth and Environmental Science Section, F.-A. Forel Institute and Institute of Environmental Sciences, University of Geneva Geneva, Switzerland.
authors: Amandine
authors: A
authors: Laffite
authors: Department of Chemistry, Faculty of Science, University of Kinshasa Kinshasa, Democratic Republic of the Congo.
authors: Pitchouna I
authors: PI
authors: Kilunga
authors: Département de Géographie-Science de l'Environnement, Faculté des Sciences, Université Pédagogique Nationale Kinshasa, Democratic Republic of the Congo.
authors: John M
authors: JM
authors: Kayembe
authors: Faculty of Science, Earth and Environmental Science Section, F.-A. Forel Institute and Institute of Environmental Sciences, University of Geneva Geneva, Switzerland.
authors: Naresh
authors: N
authors: Devarajan
authors: Department of Chemistry, Faculty of Science, University of Kinshasa Kinshasa, Democratic Republic of the Congo.
authors: Crispin K
authors: CK
authors: Mulaji
authors: Faculty of Science, Earth and Environmental Science Section, F.-A. Forel Institute and Institute of Environmental Sciences, University of GenevaGeneva, Switzerland; enviroSPACE Lab., Institute for Environmental Sciences, University of GenevaGeneva, Switzerland; United Nations Environment Programme, Division of Early Warning and Assessment, Global Resource Information Database - Geneva, International Environment HouseGeneva, Switzerland.
authors: Gregory
authors: G
authors: Giuliani
authors: Faculty of Science, Earth and Environmental Science Section, F.-A. Forel Institute and Institute of Environmental Sciences, University of Geneva Geneva, Switzerland.
authors: Vera I
authors: VI
authors: Slaveykova
authors: Faculty of Science, Earth and Environmental Science Section, F.-A. Forel Institute and Institute of Environmental Sciences, University of GenevaGeneva, Switzerland; Department of Chemistry, Faculty of Science, University of KinshasaKinshasa, Democratic Republic of the Congo; Département de Géographie-Science de l'Environnement, Faculté des Sciences, Université Pédagogique NationaleKinshasa, Democratic Republic of the Congo.
authors: John
authors: J
authors: Poté
keywords: Sub-Saharan Africa; antibiotic resistance genes; fecal indicator bacteria; hospital and urban wastewater; sediment receiving system; toxic metals; tropical conditions; water pollution