blaVIM and blaIMP Genes Detection in Isolates of Carbapenem Resistant P. aeruginosa of Hospitalized Patients in Two Hospitals in Iran

Abstract

<strong><em>Background & objective</em></strong><em>:</em> Beta-lactam antibiotics resistance specifically Imipenem and Meropenem, the last choices of treatment, causes fatal events in patients with <em>P.aeruginosa</em> infection. The aim of this study was to detect the VIM and IMP of metallo-beta-lactamase genes in 103 isolates of <em>P. aeruginosa </em>in two Iranian hospitals.<br /> <strong><em>Methods</em></strong><strong><em>: </em></strong>In this study, we evaluated the susceptibility of <em>P. aeruginosa</em> to a range of β-lactam antibiotics using disk diffusion method as a standard biochemical test. Combined disk test of Imipenem (IMP) and Imipenem plus Ethylenediaminetetraacetic acid (EDTA) was performed as a phenotypic method to find metallo-beta-lactamase producing isolates.Using conventional PCR method; we evaluated VIM and IMP of metallo-beta-lactamase (MBL) genes in 103 isolates of <em>P.aeruginosa</em>.<br /> <strong><em>Results</em></strong><strong><em>:</em></strong> Twenty six (25.2%) out of 103 isolates were resistant to Imipenem and 26 (25.2%) to Meropenem. Among 26 Imipenem and Meropenem-resistant strains (25.2%), 19 cases (73.0%) were MBL producing. Using PCR method, we detected the bla_VIMand bla_IMPgenes in 6 (5.8%) and 2(1.9%) of 19 MBL producing isolates, respectively. <br /> <strong><em>Conclusions: </em></strong>Evaluation of these carbepenemases genes improve epidemiologic researches and also, can be used as a diagnostic tool for discriminating between antibiotics resistant and sensitive strains of <em>P.aeruginosa</em> as well as follow-up the patients after treatment.