1. Complete genome sequence of hypervirulent and outbreak-associated Acinetobacter baumannii strain LAC-4: epidemiology, resistance genetic determinants and potential virulence factors.
- Author
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Ou HY, Kuang SN, He X, Molgora BM, Ewing PJ, Deng Z, Osby M, Chen W, and Xu HH
- Subjects
- Acinetobacter Infections genetics, Acinetobacter Infections microbiology, Acinetobacter baumannii classification, Acinetobacter baumannii isolation & purification, Base Sequence, Chromosomes, Bacterial genetics, Computer Simulation, DNA Transposable Elements genetics, Drug Resistance, Microbial genetics, Genetic Loci, Genomic Islands genetics, Genomics, Humans, Los Angeles epidemiology, Molecular Sequence Data, Multilocus Sequence Typing, Mutagenesis, Insertional genetics, Phylogeny, Polymerase Chain Reaction, Virulence genetics, Acinetobacter Infections epidemiology, Acinetobacter baumannii genetics, Acinetobacter baumannii pathogenicity, Disease Outbreaks, Drug Resistance, Multiple genetics, Genome, Bacterial, Sequence Analysis, DNA, Virulence Factors genetics
- Abstract
Acinetobacter baumannii is an important human pathogen due to its multi-drug resistance. In this study, the genome of an ST10 outbreak A. baumannii isolate LAC-4 was completely sequenced to better understand its epidemiology, antibiotic resistance genetic determinants and potential virulence factors. Compared with 20 other complete genomes of A. baumannii, LAC-4 genome harbors at least 12 copies of five distinct insertion sequences. It contains 12 and 14 copies of two novel IS elements, ISAba25 and ISAba26, respectively. Additionally, three novel composite transposons were identified: Tn6250, Tn6251 and Tn6252, two of which contain resistance genes. The antibiotic resistance genetic determinants on the LAC-4 genome correlate well with observed antimicrobial susceptibility patterns. Moreover, twelve genomic islands (GI) were identified in LAC-4 genome. Among them, the 33.4-kb GI12 contains a large number of genes which constitute the K (capsule) locus. LAC-4 harbors several unique putative virulence factor loci. Furthermore, LAC-4 and all 19 other outbreak isolates were found to harbor a heme oxygenase gene (hemO)-containing gene cluster. The sequencing of the first complete genome of an ST10 A. baumannii clinical strain should accelerate our understanding of the epidemiology, mechanisms of resistance and virulence of A. baumannii.
- Published
- 2015
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