Detection of multidrug-resistant Pseudomonas aeruginosa harboring blaGES-1 and blaGES-11 in Recife, Brazil

Introduction: Pseudomonas aeruginosa, an important pathogen globally, presents several resistance mechanisms. This study aimed to investigate the presence of bla(GES) in clinical isolates of Pseudomonas aeruginosa obtained from various clinical specimens from patients admitted to three different hospitals in Recife, Brazil. The Guiana extended spectrum beta-lactamase (GES) enzymes are responsible for conferring broad spectrum resistance to beta-lactam drugs, including the carbapenems. Methods: A total of 100 carbapenem-resistant P. aeruginosa isolates underwent polymerase chain reaction (PCR) testing to identify bla(GES), bla(KPC), bla(SPM-1), bla(IMP), and bla(VIM). Additionally, PCR products positive for bla GES were sequenced. The clonal profiles of these same isolates were then determined by means of enterobacterial repetitive intergenic consensus (ERIC)-PCR analysis. Results: PCR analysis revealed that four isolates harbored bla GES; DNA sequencing showed that two harbored bla(GES-1) and two bla(GES-11). Beta-lactamase genes bla(SPM-1), bla(IMP), bla(VIM), and bla KPC were investigated; none of these genes was detected. Automated susceptibility testing methods (Vitek (R) 2, bioMerieux) showed that the bla(GES-1) - positive isolates were only susceptible to polymyxin B. The patterns obtained with ERIC-PCR methods showed clonal relationship between the two isolates that harbored bla(GES-11), whereas different clonal profiles were found in the isolates harboring bla(GES-1). Conclusions: We detected the presence of bacterial isolates positive for two different variants of the enzyme GES in three different hospitals from Recife, Brazil. These enzymes have a great capacity for dissemination among Gram-negative bacteria and confer broad-spectrum resistance to betalactam antibiotics and to the carbapenems.