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

Abstract

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 bla_VIM positive and 16 strains carried bla_OXA-10 gene. To the best of our knowledge, this is the first report of P. aeruginosa clinical isolates harboring bla_VEB together with bla_GES 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 bla_VEB among P. aeruginosa clinical isolates from Egypt. Ten isolates harbored bla_VEB and five of them co-harbored bla_VEB together with bla_GES, bla_VIM, and bla_OXA-10.

Keywords: ESBL; MALDI-TOF/MS; carbapenemases; β-lactamases.