title: Functional metagenomic analysis reveals rivers are a reservoir for diverse antibiotic resistance genes.
abstract: The environment harbours a significant diversity of uncultured bacteria and a potential source of novel and extant resistance genes which may recombine with clinically important bacteria disseminated into environmental reservoirs. There is evidence that pollution can select for resistance due to the aggregation of adaptive genes on mobile elements. The aim of this study was to establish the impact of waste water treatment plant (WWTP) effluent disposal to a river by using culture independent methods to study diversity of resistance genes downstream of the WWTP in comparison to upstream. Metagenomic libraries were constructed in Escherichia coli and screened for phenotypic resistance to amikacin, gentamicin, neomycin, ampicillin and ciprofloxacin. Resistance genes were identified by using transposon mutagenesis. A significant increase downstream of the WWTP was observed in the number of phenotypic resistant clones recovered in metagenomic libraries. Common β-lactamases such as blaTEM were recovered as well as a diverse range of acetyltransferases and unusual transporter genes, with evidence for newly emerging resistance mechanisms. The similarities of the predicted proteins to known sequences suggested origins of genes from a very diverse range of bacteria. The study suggests that waste water disposal increases the reservoir of resistance mechanisms in the environment either by addition of resistance genes or by input of agents selective for resistant phenotypes.
authors.affiliation: School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom.
authors.forename: G C A
authors.initials: GC
authors.lastname: Amos
authors.affiliation: School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom.
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Health Protection Agency, West Midlands Public Health Laboratory, Heart of England NHS Foundation Trust, Bordesley Green East, Birmingham, United Kingdom; Institute of Microbiology and Infection, Biosciences, University of Birmingham, Birmingham, United Kingdom.
authors.forename: P M
authors.initials: PM
authors.lastname: Hawkey
authors.affiliation: School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom.
authors.forename: W H
authors.initials: WH
authors.lastname: Gaze
authors.affiliation: School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom. Electronic address: E.M.H.Wellington@warwick.ac.uk.
authors.forename: E M
authors.initials: EM
authors.lastname: Wellington
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001483:Base Sequence; D016000:Cluster Analysis; D004352:Drug Resistance, Microbial / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D015723:Gene Library; D014644:Genetic Variation; D056186:Metagenomics / Q000379:methods*; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010802:Phylogeny; D045483:Rivers / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D062065:Wastewater / Q000382:microbiology*; D014871:Water Microbiology; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D062065:Wastewater; D001618:beta-Lactamases
keywords: Antibiotic resistance; Environmental resistance; Functional metagenomics; Sewage; Waste water