Carbapenemase typing and resistance profile of Enterobacteriaceae with reduced sensitivity to carbapenems in a Middle Eastern tertiary care center

Abstract

Objective: nowadays resistant bacteria represent worldwide a public health problem leading in some cases to a stalemate without any possible treatment. Therefore early detection and identification of carbapenemase producing gram-negative bacteria (GNB) is of crucial importance. Consequently we conducted a study in a tertiary care hospital to analyze the resistance phenotype of the carbapenem resistant GNB (CRGNB). Methods: we collected all the CRGNB from September 2014 till January 2016, we took randomly 40/126 strains and performed a sensitivity test in addition to a real time multiplex PCR to detect the exact carbapenemase coding genes (bla SPC , bla IMP1, bla VIM , bla NDM , bla KPC , et bla OXA-48). The studied strains were: Escherichia coli (70%), Klebsiella pneumonia (20%), Enterobacter aerogenes (2,5%), Enterobacter cloacae (2.5%) et Klebsiella oxytoca (2.5%). Results: 100% of the studied strains were intermediate or resistant to ertapenem, 85% intermediate or resistant to imipenem and/or meropenem. 33 / 40 strains (82.5%) are bla OXA-48 positive et one strain (2.5%) is bla NDM positive. the OXA-48 were urinary strains of E coli. 6 / 40 strains (15%) did not express carbapenemase genes in molecular studies. Conclusion: we note a marked emergence of CPGNB especially bla OXA-48 with high resistance pattern leading to narrow therapeutic options. This requires a rapid detection of such strains of GNB so that to initiate quickly the right preventive and therapeutic measures to avoid hospital epidemics with disastrous consequences.