Occurrence of Antibiotic Resistance Genes and Bacterial Markers in a Tropical River Receiving Hospital and Urban Wastewaters

• Published in: PloS one Vol. 11; no. 2; p. e0149211
• Main Authors: Devarajan, Naresh, Laffite, Amandine, Mulaji, Crispin Kyela, Otamonga, Jean-Paul, Mpiana, Pius Tshimankinda, Mubedi, Josué Ilunga, Prabakar, Kandasamy, Ibelings, Bastiaan Willem, Poté, John
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 24.02.2016; Public Library of Science (PLoS)
• Subjects: Abundance; Animals; Anti-Bacterial Agents; Antibiotic resistance; Antibiotics; Aquatic ecosystems; Bacteria; Bacteria - genetics; Bacterial genetics; Biology and Life Sciences; Chemistry; Contaminants; Contamination; Deoxyribonucleic acid; Developing countries; DNA; Drug resistance; Drug Resistance, Bacterial; E coli; Earth Sciences; Ecology and Environmental Sciences; Effluents; Engineering and Technology; Enterobacteriaceae; Environmental aspects; Environmental science; Escherichia coli; Fecal coliforms; Freshwater resources; Genes; Genes, Bacterial; India; Influence; Lakes; LDCs; Medical Waste; Medicine and Health Sciences; Metals; Microbial drug resistance; Outlets; Physical Sciences; Pseudomonas; Research and Analysis Methods; Risk factors; River basins; Rivers; Sediment load; Sediments; Studies; Tropical Climate; Veterinary medicine; Waste Water - microbiology; Wastewater; Water Microbiology; Water quality; India; Switzerland
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0149211

The occurrence of emerging biological contaminants including antibiotic resistance genes (ARGs) and Faecal Indicator Bacteria (FIB) is still little investigated in developing countries under tropical conditions. In this study, the total bacterial load, the abundance of FIB (E. coli and Enterococcus spp. (ENT)), Pseudomonas spp. and ARGs (blaTEM, blaCTX-M, blaSHV, blaNDM and aadA) were quantified using quantitative PCR in the total DNA extracted from the sediments recovered from hospital outlet pipes (HOP) and the Cauvery River Basin (CRB), Tiruchirappalli, Tamil Nadu, India. The abundance of bacterial marker genes were 120, 104 and 89 fold higher for the E. coli, Enterococcus spp. and Pseudomonas spp., respectively at HOP when compared with CRB. The ARGs aadA and blaTEM were most frequently detected in higher concentration than other ARGs at all the sampling sites. The ARGs blaSHV and blaNDM were identified in CRB sediments contaminated by hospital and urban wastewaters. The ARGs abundance strongly correlated (r ≥ 0.36, p < 0.05, n = 45) with total bacterial load and E. coli in the sediments, indicating a common origin and extant source of contamination. Tropical aquatic ecosystems receiving wastewaters can act as reservoir of ARGs, which could potentially be transferred to susceptible bacterial pathogens at these sites.