First report of novel genetic array aacA4-blaIMP-25-oxa30-catB3 and identification of novel metallo-β-lactamase gene blaIMP25: A Retrospective Study of antibiotic resistance surveillance on Psuedomonas aeruginosa in Guangzhou of South China, 2003-2007

Abstract

Carbapenem, imipenem and meropenem have been broadly prescribed contributing to the global occurrence and prevalence of carbapenem resistance in Psuedomonas aeruginosa, and the associated resistance genotypes remains clinically significant. A retrospective surveillance had been conducted on 499 P. aeruginosa isolates in South China during 2003-2007, including antimicrobial resistance and characterization of MBLs on carbapenem-resistant strains. One hundred and sixty-four out of 499 strains were carbapenem-resistant, with 11, 4 and 5 strains positive for blaIMP-9, blaIMP-25 and blaVIM-2, respectively. Sixteen out of 20 isolates were positive for intI1 and contained identical flanking regions (as indicated in KM384735), and all tested isolates containing the qacE△1-sul1 of the typical 3'-conserved region. A novel blaIMP-25 metallo-β-lactamase and a genetic array of aacA4-blaIMP-25-oxa30-catB3 have been discovered from this retrospective surveillance on antimicrobial resistance of P. aeruginosa.

Keywords: Carbapenem-resistant; Metallo-β-lactamase; P. aeruginosa; aacA4-blaIMP-25-oxa30-catB3; bla(IMP-25).