High rate of colistin resistance among patients with carbapenem-resistant Klebsiella pneumoniae infection accounts for an excess of mortality.
Capone, A. 1; Giannella, M. 1; Fortini, D. 2; Giordano, A. 3; Meledandri, M. 4; Ballardini, M. 4; Venditti, M. 5; Bordi, E. 6; Capozzi, D. 7; Balice, M. P. 8; Tarasi, A. 9; Parisi, G. 10; Lappa, A. 10; Carattoli, A. 2; Petrosillo, N. 1; on behalf of the SEERBIO-GRAB network +; Canton, R.
[Article]
Clinical Microbiology & Infection.
19(1):E23-E30, January 2013.
(Format: HTML, PDF)
: Carbapenem-resistant Klebsiella pneumoniae (CR-KP) is becoming a common cause of healthcare-associated infection in Italy, with high morbidity and mortality. Prevalent CR-KP clones and resistance mechanisms vary between regions and over time. Therapeutic approaches and their impact on mortality have to be investigated. We performed a prospective study of patients with CR-KP isolation, hospitalized in nine hospitals of Rome, Italy, from December 2010 to May 2011, to describe the molecular epidemiology, antibiotic treatment and risk factors for mortality. Overall, 97 patients (60% male, median age 69 years) were enrolled. Strains producing blaKPC-3 were identified in 89 patients, blaVIM in three patients and blaCTX-M-15 plus porin defects in the remaining five patients. Inter-hospital spread of two major clones, ST512 and ST258, was found. Overall, 36.1% and 20.4% of strains were also resistant to colistin and tigecycline, respectively. Infection was diagnosed in 91 patients who received appropriate antibiotic treatment, combination therapy and removal of the infectious source in 73.6%, 59.3% and 28.5% of cases, respectively. Overall, 23 different antibiotic regimens were prescribed. In-hospital mortality was 25.8%. Multivariate analysis adjusted for appropriate treatment, combination therapy and infectious-source removal, showed that Charlson comorbidity score, intensive-care unit onset of infection, bacteraemia and infection due to a colistin-resistant CR-KP strain were independent risk factors for mortality. The spread of clones producing K. pneumoniae carbapenemases, mainly ST258, is currently the major cause of CR-KP infection in central Italy. We observed a high rate of resistance to colistin that is independently associated with worse outcome.
Copyright (C) 2013 Blackwell Publishing Ltd.