Epidemiological study on multidrug-resistant Pseudomonas aeruginosa clinical isolates in Vietnam

The emergence of multidrug-resistant (MDR) Pseudomonas aeruginosa isolates, which are resistant to all beta-lactams, aminoglycosides, and fluoroquinolones, is a serious medical problem worldwide. In this study, 40 multidrug-resistant Pseudomonas aeruginosa isolates were obtained in a medical setting to perform an epidemiological study in Vietnam. Of them, 25 isolates harbored metallo-beta-lactamase encoding genes, including blaIMP-7, blaIMP-26, blaIMP-51 and blaNDM-1. The blaIMP-51 was a novel IMP variant and IMP-51 had an amino acid substitution (Ser262Gly) compared with IMP-7. E. coli expressing blaIMP-51 was significantly resistant to cefotaxime, meropenem and moxalactam, compared with E. coli expressing blaIMP-7. The amino acid residue at the position 262 was located near the active site, proximal to the H263 Zn(II) ligand. Phylogenic analysis constructed from the SNP concatemers revealed that 15, 4 and 4 isolates belonged ST235, ST310 and ST773, respectively.