title: The profile of antibiotics resistance and integrons of extended-spectrum beta-lactamase producing thermotolerant coliforms isolated from the Yangtze River basin in Chongqing.
abstract: The spreading of extended-spectrum beta-lactamases (ESBL)-producing thermotolerant coliforms (TC) in the water environment is a threat to human health but little is known about ESBL-producing TCs in the Yangtze River. We received 319 ESBL-producing stains obtained from the Chongqing basin and we investigated antibiotic susceptibility, bla gene types and the presence of integrons and gene cassettes. 16.8% of TC isolates were ESBL-producing bacteria and bla(TEM+CTx-M) was the predominant ESBL type. 65.2% of isolates contained class 1 integrons, but only 3 carried intI 2. Gene cassettes were amplified and sequenced. aadA, drfA, cmlA, sat1, aar3 and two ORF cassettes were found. In conclusion, Yangtze River is heavily polluted by ESBL-producing TC bacteria and the combined bla gene type could enhance antibiotic resistance. Class 1 integrons were widespread in ESBL-producing isolates and play an important role in multi-drug resistance. Characterization of gene cassettes could reveal the dissemination of antibiotic resistance genes.
authors.affiliation: Department of Environmental Hygiene, School of Military Preventive Medicine, The Third Military Medical University, 30 Gaotanyan Street, Chongqing 400038, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Chen
authors.forename: Weiqun
authors.initials: W
authors.lastname: Shu
authors.forename: Xiaosong
authors.initials: X
authors.lastname: Chang
authors.forename: Ji-an
authors.initials: JA
authors.lastname: Chen
authors.forename: Yebin
authors.initials: Y
authors.lastname: Guo
authors.forename: Yao
authors.initials: Y
authors.lastname: Tan
mesh_terms: D001419:Bacteria / Q000145:classification / Q000187:drug effects* / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D002681:China; D016971:Citrobacter freundii / Q000187:drug effects / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics* / Q000502:physiology; D032023:Integrons / Q000235:genetics*; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000235:genetics; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D045483:Rivers / Q000382:microbiology; D044090:Serratia liquefaciens / Q000187:drug effects / Q000235:genetics; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D001618:beta-Lactamases