Emergence of blaVEB and blaGES among VIM-producing Pseudomonas aeruginosa clinical isolates in Alexandria, Egypt.

Thirty-three Pseudomonas aeruginosa isolates, resistant to one or more β-lactams, were included in this study. Identification of tested strains was confirmed using MALDI-TOF/MS. Phenotypic and genotypic β-lactamase patterns were investigated. Most of the isolates were resistant to carbapenems (32 out of 33) and to the extended-spectrum cephalosporins (ESC) (30 out of 33). Phenotypically, the production of extended-spectrum beta-lactamase (ESBL), metallo-β-lactamases (MBL), and carbapenemases was detected in 10, 23, and 9 isolates, respectively. However, AmpC hyperproduction was not phenotypically detected among all isolates. Genotypically, ESBL and MBL encoding genes were detected in 23 and 27 isolates, respectively. Altogether 27 strains were detected as blaVIM positive and 16 strains carried blaOXA-10 gene. To the best of our knowledge, this is the first report of P. aeruginosa clinical isolates harboring blaVEB together with blaGES in Egypt, where 5 of our 30 ESC-resistant isolates showed this genotype. Our results confirmed that resistance of P. aeruginosa isolates to β-lactam antibiotics is mediated via multiple β-lactamases belonging to different molecular classes. To the best of our knowledge, this is the first report of blaVEB among P. aeruginosa clinical isolates from Egypt. Ten isolates harbored blaVEB and five of them co-harbored blaVEB together with blaGES, blaVIM, and blaOXA-10.