title: Prevalence of antibiotic resistance genes in bacterial communities associated with Cladophora glomerata mats along the nearshore of Lake Ontario.
abstract: The alga Cladophora glomerata can erupt in nuisance blooms throughout the lower Great Lakes. Since bacterial abundance increases with the emergence and decay of Cladophora, we investigated the prevalence of antibiotic resistance (ABR) in Cladophora-associated bacterial communities up-gradient and down-gradient from a large sewage treatment plant (STP) on Lake Ontario. Although STPs are well-known sources of ABR, we also expected detectable ABR from up-gradient wetland communities, since they receive surface run-off from urban and agricultural sources. Statistically significant differences in aquatic bacterial abundance and ABR were found between down-gradient beach samples and up-gradient coastal wetland samples (ANOVA, Holm-Sidak test, p < 0.05). Decaying and free-floating Cladophora sampled near the STP had the highest bacterial densities overall, including on ampicillin- and vancomycin-treated plates. However, quantitative polymerase chain reaction analysis of the ABR genes ampC, tetA, tetB, and vanA from environmental communities showed a different pattern. Some of the highest ABR gene levels occurred at the 2 coastal wetland sites (vanA). Overall, bacterial ABR profiles from environmental samples were distinguishable between living and decaying Cladophora, inferring that Cladophora may control bacterial ABR depending on its life-cycle stage. Our results also show how spatially and temporally dynamic ABR is in nearshore aquatic bacteria, which warrants further research.
authors.affiliation: a Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street N., Oshawa, ON L1H 7K4, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Ibsen
authors.affiliation: a Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street N., Oshawa, ON L1H 7K4, Canada.|b Department of Microbiology, University of Manitoba, 414E Buller Building, Winnipeg, MB R3T 2N2, Canada.|c Department of Chemical Biology and Therapeutics, IRC Building, Mail Stop: 1000, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors.forename: Dinesh M
authors.initials: DM
authors.lastname: Fernando
authors.affiliation: a Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street N., Oshawa, ON L1H 7K4, Canada.|b Department of Microbiology, University of Manitoba, 414E Buller Building, Winnipeg, MB R3T 2N2, Canada.
authors.forename: Ayush
authors.initials: A
authors.lastname: Kumar
authors.affiliation: a Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street N., Oshawa, ON L1H 7K4, Canada.
authors.forename: Andrea E
authors.initials: AE
authors.lastname: Kirkwood
mesh_terms: D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development; D000460:Chlorophyta / Q000382:microbiology*; D004352:Drug Resistance, Microbial / Q000235:genetics*; D005798:Genes, Bacterial; D060106:Lakes; D009864:Ontario; D014871:Water Microbiology
keywords: algal blooms; antibiotic resistance genes; bacteria; bactéries; eaux usées; fleurs d’eau; gènes de résistance aux antibiotiques; land-use; sewage; utilisation des terres