title: Identification of an integron containing the quinolone resistance gene qnrA1 in Shewanella xiamenensis.
abstract: This study investigated multidrug resistance in Shewanella xiamenensis isolated from an estuarine water sample in China during 2014. This strain displayed resistance or decreased susceptibility to ampicillin, aztreonam, cefepime, cefotaxime, chloramphenicol, ciprofloxacin, erythromycin, kanamycin and trimethoprim-sulfamethoxazole. The antimicrobial resistance genes aacA3, blaOXA-199, qnrA1 and sul1 were identified by PCR amplification and by sequencing. Pulsed-field gel electrophoresis and DNA hybridization experiments showed that the quinolone resistance gene qnrA1 was chromosomally located. qnrA1 was located in a complex class 1 integron, downstream from an ISCR1, and bracketed by two copies of qacEΔ1-sul1 genes. This integron is similar to In825 with four gene cassettes aacA3, catB11c, dfrA1z and aadA2az. An IS26-mel-mph2-IS26 structure was also detected in the flanking sequences, conferring resistance to macrolides. This is the first identification of the class 1 integron in S. xiamenensis. This is also the first identification of the qnrA1 gene and IS26-mediated macrolide resistance genes in S. xiamenensis. Presence of a variety of resistance genetic determinants in environmental S. xiamenensis suggests the possibility that this species may serve as a potential vehicle of antimicrobial resistance genes in aquatic environments.
authors: Center for Bioengineering and Biotechnology & State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China.
authors: Jing-yi
authors: JY
authors: Zhao
authors: Center for Bioengineering and Biotechnology & State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China.
authors: Xiao-dong
authors: XD
authors: Mu
authors: The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China.
authors: Yuan-qi
authors: YQ
authors: Zhu
authors: Center for Bioengineering and Biotechnology & State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China.
authors: Lijun
authors: L
authors: Xi
authors: Center for Bioengineering and Biotechnology & State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China zjxiao@upc.edu.cn.
authors: Zijun
authors: Z
authors: Xiao
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002681:China; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D063366:Estuaries; D005798:Genes, Bacterial; D032023:Integrons; D018942:Macrolides / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D010802:Phylogeny; D015363:Quinolones / Q000378:metabolism / Q000494:pharmacology*; D020592:Shewanella / Q000187:drug effects* / Q000235:genetics*; D014871:Water Microbiology
chemical_list: D000900:Anti-Bacterial Agents; D018942:Macrolides; D015363:Quinolones
keywords: IS26; Shewanella xiamenensis; antimicrobial resistance; blaOXA-199 gene; class 1 integron; qnrA1 gene