13
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Horizontal gene transfer in a polyclonal outbreak of carbapenem-resistant Acinetobacter baumannii.

      Journal of Clinical Microbiology

      Acinetobacter Infections, epidemiology, microbiology, Acinetobacter baumannii, classification, drug effects, genetics, Anti-Bacterial Agents, pharmacology, Australia, Bacterial Proteins, Carbapenems, Disease Outbreaks, Drug Resistance, Bacterial, Gene Transfer, Horizontal, Humans, Molecular Sequence Data, Sequence Analysis, DNA

      Read this article at

      ScienceOpenPublisherPMC
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          In the last few years, phenotypically carbapenem resistant Acinetobacter strains have been identified throughout the world, including in many of the hospitals and intensive care units (ICUs) of Australia. Genotyping of Australian ICU outbreak-associated isolates by pulsed-field gel electrophoresis of whole genomic DNA indicated that different strains were cocirculating within one hospital. The carbapenem-resistant phenotype of these and other Australian isolates was found to be due to carbapenem-hydrolyzing activity associated with the presence of the blaOXA-23 gene. In all resistant strains examined, the blaOXA-23 gene was adjacent to the insertion sequence ISAba1 in a structure that has been found in Acinetobacter baumannii strains of a similar phenotype from around the world; blaOXA-51-like genes were also found in all A. baumannii strains but were not consistently associated with ISAba1, which is believed to provide the promoter required for expression of linked antibiotic resistance genes. Most isolates were also found to contain additional antibiotic resistance genes within the cassette arrays of class 1 integrons. The same cassette arrays, in addition to the ISAba1-blaOXA-23 structure, were found within unrelated strains, but no common plasmid carrying these accessory genetic elements could be identified. It therefore appears that antibiotic resistance genes are readily exchanged between cocirculating strains in epidemics of phenotypically indistinguishable organisms. Epidemiological investigation of major outbreaks should include whole-genome typing as well as analysis of potentially transmissible resistance genes and their vehicles.

          Related collections

          Author and article information

          Journal
          10.1128/JCM.01971-06
          1829019
          17108068

          Comments

          Comment on this article