title: Characterization of IS26-composite transposons and multidrug resistance in conjugative plasmids from Enterobacter cloacae.
abstract: SHV-12 is the most widespread resistance determinant of Enterobacter cloacae in Taiwan; however, blaSHV-12 has rarely been mobilized. Six multidrug-resistant E. cloacae isolates were collected. After conjugal transfer, plasmid profiling and analysis of incompatibility groups was performed to characterize the genetic context of blaSHV-12 -containing fragments. The presence of mobile genetic elements was demonstrated by PCR, cloning, sequencing and bioinformatics analyses. Four different β-lactamase genes (blaTEM-1 , blaSHV-12 , blaCTX-M-3 and/or blaCTX-M-14 ) were observed in the conjugative plasmids belonging to the IncHI2 (n = 4), IncI1 or IncP incompatibility groups. The IS26-blaSHV-12 -IS26 locus was located in five different genetic environments. A novel structural organization of a class 1 integron with the aac(6')-IIc cassette truncated by IS26 was identified in one isolate. Thus, blaSHV-12 was obtained from different plasmids through IS26-mediated homologous recombination. IS26 plays a vital role in the distribution of mobile resistance elements between different plasmids found in multidrug-resistant E. cloacae isolates.
authors.affiliation: Division of Infectious Disease, Department of Internal Medicine, Tungs' Taichung Metro Harbor Hospital, Taichung.
authors.forename: Chih-Ming
authors.initials: CM
authors.lastname: Chen
authors.affiliation: Departments of Medical Research.|Intensive Care Medicine, Chi-Mei Medical Center, Yungkang City, Tainan.|Department of Medicine, Taipei Medical University, Taipei.
authors.forename: Wen-Liang
authors.initials: WL
authors.lastname: Yu
authors.affiliation: Division of Infectious Disease, Chang Bing Show Chwan Memorial Hospital, Changhua County.
authors.forename: Mei
authors.initials: M
authors.lastname: Huang
authors.affiliation: Institute of Medical Science and Department of Microbiology, China Medical University and Hospital, Taichung, Taiwan.
authors.forename: Jau-Jin
authors.initials: JJ
authors.lastname: Liu
authors.affiliation: Institute of Medical Science and Department of Microbiology, China Medical University and Hospital, Taichung, Taiwan.
authors.forename: I-Chien
authors.initials: IC
authors.lastname: Chen
authors.affiliation: Institute of Medical Science and Department of Microbiology, China Medical University and Hospital, Taichung, Taiwan.
authors.forename: Huei-Fen
authors.initials: HF
authors.lastname: Chen
authors.affiliation: Institute of Medical Science and Department of Microbiology, China Medical University and Hospital, Taichung, Taiwan.
authors.forename: Lii-Tzu
authors.initials: LT
authors.lastname: Wu
mesh_terms: D003001:Cloning, Molecular; D003227:Conjugation, Genetic; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial; D016972:Enterobacter cloacae / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000382:microbiology; D019143:Evolution, Molecular; D022761:Gene Transfer, Horizontal; D059765:Homologous Recombination; D006801:Humans; D032023:Integrons; D010957:Plasmids / Q000032:analysis* / Q000145:classification; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013624:Taiwan; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D001618:beta-Lactamases
keywords: Enterobacter cloacae; IS26-blaSHV-12-IS26 locus; blaSHV-12; homologous recombination