Carbapenem-resistant Klebsiella pneumoniae infections in a Greek intensive care unit: Molecular characterisation and treatment challenges.

Abstract

Acquisition of carbapenemase-producing Klebsiella pneumoniae (CP-Kp) strains poses a major threat to critically ill patients. The objectives of this study were to describe the epidemiology of CP-Kp isolates as well as the clinical outcome associated with the corresponding infections and to identify risk factors for mortality of intensive care unit (ICU) patients in a Greek hospital. A prospective, observational study was conducted in a nine-bed general ICU over a 2-year period (April 2010-March 2012). Imipenem-resistant K. pneumoniae isolates recovered from clinical samples of ICU patients were prospectively collected and studied for the presence of carbapenemases. Isolates were submitted to molecular typing using pulsed-field gel electrophoresis (PFGE). In total, 61 CP-Kp isolates (48 KPC-producers and 13 VIM-producers) were recovered from 58 ICU patients. The majority of KPC-producers were classified into a single PFGE type, indicating potent clonal dissemination. Among the 32 infected patients, bacteraemia was diagnosed in 16. Tigecycline+colistin was the most common combination antimicrobial regimen. Infection-attributable mortality was 43.8%. Regarding mortality risk factors, non-survivors were older (P=0.080), all of them presented with septic shock (P=0.010) and they had higher Sepsis-related Organ Failure Assessment (SOFA) scores at infection onset (P=0.004) compared with survivors. Appropriate definitive treatment and combination regimens were not associated with patient survival. In conclusion, CP-Kp infections are associated with limited treatment options and high in-hospital mortality. Effective measures for preventing dissemination of respective isolates in the hospital setting are required.