The Acinetobacter baumannii ATPase gene in diverse strains is frequently occupied by integrated genomic islands

Abstract number: P2025

Shaikh F., Spence R.P., Levi K., Towner K.J., Rajakumar K.

Objectives: To determine if the ATPase gene of genetically diverse A. baumannii strains harbour integrated genomic islands.

Methods: RAPD-PCR was used to investigate the genetic diversity of fifty A. baumannii strains that were originally isolated from various clinical specimens. PCR-based interrogation was used to identify strains with a presumed disrupted ATPase gene. PCR mapping and chromosome walking were then used to provide definitive evidence of the presence of ATPase-borne, chromosomally integrated, genomic islands in these strains. An ATPase-specific yeast capture vector was constructed to enable cloning and characterisation of selected elements.

Results: RAPD-PCR analysis demonstrated that the strains examined possessed substantial genetic diversity. Forty one of fifty strains tested contained a disrupted ATPase gene. Of 15 island-bearing strains subjected to further analysis, 8 were found to contain elements with ends matching one (2 strains) or both (6 strains) extremities of AbaR1, the first A. baumannii resistance island to be described; the remaining 7 strains possessed islands with ends distinct to those of AbaR1. Using a recombination-based yeast capture system, we have cloned the integrated element present within the ATPase gene of A. baumannii strain A14. In an E. coli background, this element confers resistance to ampicillin, chloramphenicol and gentamicin, making it only the second known A. baumannii resistance island to be reported.

Conclusions: The ATPase gene of A. baumannii strains is frequently occupied by genomic islands. Preliminary data suggest that in addition to AbaR1-related islands, other distinct entities may also be capable of targeting this integration locus.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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