Title: Environmental resistome risks of wastewaters and aquatic environments deciphered by shotgun metagenomic assembly

Biography:

MD Ekwanzala is PhD candidate in the Water Research Unit of Tshwane University of Technology (Pretoria, South Africa). He holds a Baccalaureus in Technology in Biotechnology (Vaal University of Technology) and a Master of Technology in Water Science and Technology (TUT). His PhD project uses genomics and metagenomics approaches to track and characterize environmental resistome. In this project, they made use of whole genome and shotgun metagenomics sequencing to track and characterize South African hospital wastewater, municipal wastewater (in-fluent and effluent), activated sludge, surface water and benthic sediment. Concurrently, they are using an Ultra-Performance Liquid Chromatography System hyphenated with a Waters Synapt G2 instrument combined with a quadrupole time-of-flight mass spectrometer (UHPLC-QTOF-MS) to quantify most prescribed antibiotics.

Abstract

In this paper, we deciphered the core resistome disseminating from hospital wastewater to the aquatic environment by characterising the resistome, plasmidome, mobilome and virulome using metagenomic analysis. This study also elucidated different environmental resistome risks using shotgun-metagenomic assembly. The results showed that clinically relevant taxa were found in assessed matrices (Salmonella spp., Acinetobacter spp, Escherichia-Shigella spp., Pseudomonas spp., Staphylococcus spp. and Vibrio spp.). For the plasmidome, we found 249 core plasmidome sequences that were shared among all assessed matrices. The core mobilome of 2 424 mobile genetic elements shared among all assessed matrices was found. Regarding the virulome, we found 148 core virulence factors shared among all assessed samples, and the core virulome content was consistently shared across the most abundant bacterial genera. Although influent of wastewater showed considerable higher relative bacterial abundance (P = 0.008), hospital wastewater showed significant higher environmental resistome risk scores against all other assessed matrices, with an average of 46.34% (P = 0.001). These results suggest hospital wastewater, effluent and sewage sludge should be subjected to stringent mitigating measures to minimise such dissemination.