Detection and characterization of class 1 integrons among carbapenem-resistant isolates of Acinetobacter spp. in Malaysia
Wong Eng Hwa, Geetha Subramaniam, Parasakthi Navaratnam, Shamala Devi Sekaran
Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur; and School of Medicine and Health Sciences, Monash University, Sunway Campus, Petaling Jaya, Malaysia
Received: October 8, 2007 Revised: July 9, 2008 Accepted: September 22, 2008
Background and purpose:
To detect and characterize class 1 integrons among carbapenem-resistant strains of Acinetobacter spp. at University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia.
Thirty nine carbapenem-resistant Acinetobacter strains were obtained from UMMC from August 2003 to March 2004 and analyzed for the presence of blaIMP genes and class 1 integrons.
Class 1 integrons were detected in 31 of 39 strains. Two Acinetobacter calcoaceticus strains harbored an integron-borne blaIMP-4 metallo-β-lactamase, 1 of which was located on a 36-kb plasmid. Two different amplified products were found in the 31 isolates with 3 restriction pattern profiles 1, 2, and 3. Correlation was observed between carriage of class 1 integrons and genomic relatedness among these isolates, indicating that particular mechanisms of carbapenem resistance could have been acquired by genotypically distinct clinical isolates of Acinetobacter spp.
Although class 1 integrons are widely disseminated among clinical isolates of Acinetobacter spp. they do not play a major role in the spread of carbapenem resistance.
Acinetobacter; beta-lactamase IMP-4; Electrophoresis, gel, pulsed-field; Integrons
J Microbiol Immunol Infect. 2009;42:54-62.