Angeliki Mavroidi
General Hospital of Nea Ionia, Greece
Title: Changing Characteristics of Colistin-Resistant Carbapenemase-producing Klebsiella pneumoniae from Bloodstream Infections
Biography
Biography: Angeliki Mavroidi
Abstract
Colistin is often used as salvage therapy for the treatment of infections caused by multidrug-resistant K.pneumoniae. The aim of the present study was the determination of colistin resistance rates among carbapenemase-producing (CP Kp) and the characterisation of colistin-resistant (COL-R) CP Kp recovered from bloodstream infections during May 2011 - December 2015 in a Greek hospital. Identification of the isolates to the species level and antibiotic susceptibility testing were performed by the MicroScan ® (Siemens Healthcare, PA, USA). The MICs of imipenem, meropenem and colistin were additionally determined by the Etest method, according to the interpretive criteria of the Clinical and Laboratory Standards Institute (CLSI, 2014). Phenotypic screening for carbapenemase production was performed by the modified Hodge test and the boronic acid/EDTA combined-disk test. DNA extraction was performed using the QIAcube (Qiagen, Düsseldof, Germany). Carbapenemase-encoding genes were detected by PCR. During the study period, COL-R represented 30% of 95 CP Kp isolates, while a rapid increase was observed in the incidence of COL-R CP Kp from 2014 to 2015 (25% to 55%, respectively). The majority of COL-R CP Kp (69%) was recovered from patients in the ICU. The COL-R CP Kp carried the blaKPC (n=16), blaOXA-48 (n=9), blaOXA-48+blaNDM (n=3) and blaNDM (n=1) genes. The first COL-R CP Kp carrying the blaOXA-48 and blaNDM were isolated on February 2015. The alarming increase in the colistin resistance rates and the spread of different carbamenemase genes among CP Kp recovered from bloodstream infections further complicates the therapy and infection control measures for combating this organism.