Molecular characterisation of carbapenem-resistant Acinetobacter baumannii isolates from intensive care unit in a hospital, Bogota, Columbia

Abstract number: P1673

Saavedra S., Hernández J., Murcia M., Gualteros S., Arias G., Ortiz L., Leal A., Saavedra C.

Objectives: Typing molecular from isolates carbapenem-resistant Acinetobacter baumannii and to detected microbiological and molecular ocurrence from carbapenemases.

Methods: One hundred thirty two isolates carbapenem-resistant A. baumannii from ICU of twelve hospital in Bogotá were collected from 2005 to 2006. The isolates were re-identificated with API 20NE (bioMérieux) and the confirmation of minimum inhibitory concentrations (MICs) of imipenem and meropenem were determined with Etest (AB Biodisk). For detection of metallo-carbapenemases we used MBL Etest strip and gene identification from metallo and oxa-type carbapenemases was by PCR. Amplification products were evaluated by sequentiation.

The characterisation molecular by assessment the relatedness of the isolates was realised by pulsed-field gel electrophoresis (PFGE) of ApaI-digest genomic DNA. The cluster analysis was realised with Fingerprinting II software (Bio-Rad).

Results: All Isolates were resistant to meropenem with MIC > 32 mg/mL and 131 resistant to imipinem with MIC > 32 mg/mL and one isolate showed had intermediate resistant with MIC 8 mg/mL. From isolates studied only thirty isolates were positive for detection MBL for E-test but neither had VIM or IMP genes by PCR. PCR detection from OXA-carbapenemases gene suggested presence from gene blaOXA-51-like in all isolates. In another hand we founded blaOXA-23-like in 129 isolates, blaOXA-24-like only in one isolate and in the case blaOXA-58-like none amplificated. Sequencing from amplification products confirmed the presence from OXA-72 carbapenemase in one isolate and OXA-23 carbapenemase in the others isolates.

Typing results showed presence a predominant clone conformed by 88 isolates from all hospitals, the others isolates were distributed the following form 3 clones had 2, 5 and 6 isolates each one and two clones conformed by 3 isolates and finally, 14 isolates unique fingerprints.

Conclusions: our results indicate the ocurrence from a predominant clone from A. baumannii Carbapenems resistant, this clone were disseminated in all ICU Hospitals from Bogotá studied.

Carbapenemase OXA-23 was the most frecuently founded in our isolates, while OXA 72 was detected in only one intermediate resistant isolate to Imipenem, this is the fist report from this class from OXA-types Carbapenemases from Colombia.

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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