title: Complete genome sequence of Acinetobacter baumannii MDR-TJ and insights into its mechanism of antibiotic resistance.
abstract: OBJECTIVE
  To determine the genome sequence of Acinetobacter baumannii strain MDR-TJ and characterize the mechanisms of multidrug resistance in this strain.
  
  
  METHODS
  The whole-genome sequence was determined using Roche 454 GS FLX Titanium. Subsequently, the gaps were closed by sequencing PCR products. The genome of strain MDR-TJ was annotated using IMG ER, the RAST annotation server and the BASys bacterial annotation system. The comM gene of MDR-TJ was examined to identify a possible antibiotic resistance island. Based on the results of multilocus sequence typing, we investigated seven multidrug-resistant A. baumannii strains belonging to global clone 2 (GC2) isolated from Asia, Australia and Europe to determine the backbone shared by resistance islands of GC2 isolates.
  
  
  RESULTS
  The A. baumannii strain MDR-TJ genome consists of a circular chromosome and a plasmid, pABTJ1. Strain MDR-TJ was assigned to sequence type ST2. Strain MDR-TJ harbours a 41.6 kb resistance island designated RI(MDR-TJ), which can be derived from the backbone of Tn6167 through the insertion of a Tn6022 into the 3'-end of the tetA(B) gene. Comparative analysis showed that transposon Tn6022 and its truncated forms prevailed in the antibiotic resistance islands of GC2 isolates. The carbapenem resistance gene bla(OXA-23) carried by transposon Tn2009 is located on a putatively conjugative plasmid, pABTJ1.
  
  
  CONCLUSIONS
  A. baumannii strain MDR-TJ belongs to GC2 and is resistant to multiple antibiotics. A. baumannii MDR-TJ harbours a genomic resistance island that interrupts the comM gene. The carbapenem resistance of MDR-TJ is mediated by a putatively conjugative plasmid, pABTJ1.
authors.affiliation: Department of Biochemical Engineering, School of Chemical Engineering and Technology, Key Laboratory of Systems Bioengineering, Ministry of Education,  Tianjin University, Tianjin 300072,  China.
authors.forename: He
authors.initials: H
authors.lastname: Huang
authors.forename: Zhi-Liang
authors.initials: ZL
authors.lastname: Yang
authors.forename: Xiao-Meng
authors.initials: XM
authors.lastname: Wu
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
authors.forename: Yan-Jie
authors.initials: YJ
authors.lastname: Liu
authors.forename: Hao
authors.initials: H
authors.lastname: Luo
authors.forename: Xing
authors.initials: X
authors.lastname: Lv
authors.forename: Yi-Ru
authors.initials: YR
authors.lastname: Gan
authors.forename: Shi-Duo
authors.initials: SD
authors.lastname: Song
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
mesh_terms: D000151:Acinetobacter Infections / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001208:Asia; D001315:Australia; D004269:DNA, Bacterial / Q000737:chemistry* / Q000235:genetics*; D024881:Drug Resistance, Bacterial; D005060:Europe; D005798:Genes, Bacterial; D016680:Genome, Bacterial; D044404:Genomic Islands; D005838:Genotype; D006801:Humans; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D010957:Plasmids; D017422:Sequence Analysis, DNA
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial