EMERGENCE OF CO-CARBAPENEMASE GENES, BLA(OXA23), BLA(VIM) AND BLA(NDM) IN CARBAPENEMRESISTANT ACINETOBACTER BAUMANNII CLINICAL ISOLATES.

Abstract

This study investigated presence of carbapenemase genes among carbapenem-resistant Acinetobacter baumannii (CRAB) clinical isolates and their clonal relationships. Fifty-six CRAB isolates were collected from patients admitted to Hua Hin Hospital, Prachuap Khiri Khan, Thailand. PCR amplification and DNA sequencing were used to identify blaOXA23, blaOXA40, blaOXA58, blaVIM, blaSIM and blaNDM. Clonal relationship was explored using repetitive element palindromic (REP)-PCR. Plasmid profiling was obtained from EcoRI-digested fragments. The CRAB isolates were classified by REP-PCR into 12 groups, with 71% belonging to group I, which was associated with the presence of blaOXA23. Co-existence of blaOXA23 + blaVIM2 (n = 20), blaOXA23 + blaNDM1 (n = 2), blaVIM2 + blaNDM1 (n = 1), and blaOXA23 + blaVIM2 + blaNDM1 (n = 1) were discovered. The emergence of CRAB carrying multiple types of carbapenemase genes (the first such report in Thailand) is a worrying phenomenon and public health measures should be put in place to prevent any serious nosocomial infection and to contain the spread of such CRAB genotypes.