title: Escherichia coli out in the cold: Dissemination of human-derived bacteria into the Antarctic microbiome.
abstract: Discharge of untreated sewage into Antarctic environments presents a risk of introducing non-native microorganisms, but until now, adverse consequences have not been conclusively identified. Here we show that sewage disposal introduces human derived Escherichia coli carrying mobile genetic elements and virulence traits with the potential to affect the diversity and evolution of native Antarctic microbial communities. We compared E. coli recovered from environmental and animal sources in Antarctica to a reference collection of E. coli from humans and non-Antarctic animals. The distribution of phylogenetic groups and frequency of 11 virulence factors amongst the Antarctic isolates were characteristic of E. coli strains more commonly associated with humans. The rapidly emerging E. coli ST131 and ST95 clones were found amongst the Antarctic isolates, and ST95 was the predominant E. coli recovered from Weddell seals. Class 1 integrons were found in 15% of the Antarctic E. coli with 4 of 5 identified gene cassette arrays containing antibiotic resistance genes matching those common in clinical contexts. Disposing untreated sewage into the Antarctic environment does disseminate non-native microorganisms, but the extent of this impact and implications for Antarctic ecosystem health are, as yet, poorly understood.
authors.affiliation: Biological Sciences, Faculty of Science and Engineering, Macquarie University, North Ryde, NSW 2109, Australia. Electronic address: michelle.power@mq.edu.au.
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Power
authors.affiliation: Division of Evolution, Ecology and Genetics, Research School of Biology, The Australian National University, 116 Daley Road, Acton, ACT 2601, Australia. Electronic address: angelingifta.robinson@anu.edu.au.
authors.forename: Angelingifta
authors.initials: A
authors.lastname: Samuel
authors.affiliation: Queensland University of Technology, Science and Engineering Faculty, School of Earth, Environmental and Biological Sciences, GPO Box 2434, Brisbane, QLD 4001, Australia; JJSC Consulting Ltd., 16 Mullacor St., Ferny Grove, QLD 4055, Australia. Electronic address: smithjj16@tpg.com.au.
authors.forename: James J
authors.initials: JJ
authors.lastname: Smith
authors.affiliation: Antarctic Conservation and Management, Australian Antarctic Division, 203 Channel Highway, Kingston, Tasmania 7050, Australia. Electronic address: jonny.stark@aad.gov.au.
authors.forename: Jonathon S
authors.initials: JS
authors.lastname: Stark
authors.affiliation: Biological Sciences, Faculty of Science and Engineering, Macquarie University, North Ryde, NSW 2109, Australia.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Gillings
authors.affiliation: Division of Evolution, Ecology and Genetics, Research School of Biology, The Australian National University, 116 Daley Road, Acton, ACT 2601, Australia. Electronic address: david.gordon@anu.edu.au.
authors.forename: David M
authors.initials: DM
authors.lastname: Gordon
mesh_terms: D000818:Animals; D000864:Antarctic Regions; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000382:microbiology* / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000235:genetics; D006801:Humans; D032023:Integrons; D064307:Microbiota; D010802:Phylogeny; D012722:Sewage / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D012722:Sewage
keywords: Class 1 integron; Human impacts; ST131; ST95; Sewage; Wildlife