Dissemination of metallo-β-lactamase-producing Pseudomonas aeruginosa of sequence type 235 in Asian countries

Abstract

Objectives: To investigate the epidemiological traits of metallo-b-lactamase (MBL)-producing Pseudomonas aeruginosa (MPPA) clinical isolates collected by the Asian Network for Surveillance of Resistant Pathogens (ANSORP). Methods:Atotal of16MPPAclinical isolateswerecollected fromsix Asian countries in2000to2009byANSORP.The MBLgenewasdetected byPCRamplification. The genetic organization of the class1integroncarrying theMBLgene cassettewas investigated by PCR mapping and sequencing. Southern blotting, repetitive sequence-based PCR and multilocus sequence typing (MLST) experiments were performed to characterize the isolates. Results: PCR and sequencing experiments detected the blaVIM-2(n=12), blaVIM-3(n=1), blaIMP-6(n=2) and blaIMP-26(n=1) genes. The MBL genes were located on the chromosome in all isolates except one. Furthermore, all the MBL genes were located in a class 1 integron. All the MPPA isolates from Malaysia, Thailand, Sri Lanka and Korea were identified as sequence type (ST) 235 by MLST. Three VIM-2-producing isolates fromIndia were identified as ST773, and one isolate harbouring VIM-3 from Taiwan was identified as ST298. Conclusions: P. aeruginosa ST235might play a role in dissemination of MBL genes in Asian countries. © The Author 2013. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.