Clinical and epidemiological study of an outbreak of KPC-producing Klebsiella pneumoniae infection in Buenos Aires, Argentina

Introduction: KPC-producing Klebsiella pneumoniae (Kpn-KPC) is an emerging pathogen, with a high capacity of nosocomial spread. The aim of this study was to describe the clinical and epidemiological characteristics of a nosocomial outbreak of Kpn-KPC in Buenos Aires, Argentina. Methods: Prospective and descriptive study. We recorded clinical and epidemiological characteristics of patients with Kpn-KPC infection (august 2009 to july 2010). Antimicrobial susceptibility was performed by disk-diffusion antibiogram and an automated method (bioMerieux Vitek (R) 2 C). Screening for K. pneumoniae carbapenemase (KPC) was performed with the 3-aminophenyl-boronic acid (APB) test inhibition and its presence was confirmed by PCR. Molecular typing of isolates was performed by pulsed field gel electrophoresis (PFGE). Results: Twenty seven patients were infected by KPC producing K. pneumoniae (surgical care unit: n = 8; medical care unit: n = 6; intensive care unit [ICU]): n = 5; emergency care unit: n = 4; and other: n = 4). All Kpn-KPC isolates belonged to a single clonal type (ST258). Site of infection: urinary tract (63%), respiratory tract (15%), intra-abdominal (15%), bloodstream (7%) and bone (4%). All Kpn-KPC isolates were only susceptible to tigecycline and colistin. Inappropriate empirical treatment: 63%. Specific treatment for Kpn-KPC infection: colistin (74%), tigecycline (4%) and tigecycline + colistin (22%).Global mortality: 59% (attributable mortality: 26%). Positive surveillance cultures (swabs): 7/70(10%). Conclusions: We described the emergence of a nosocomial outbreak of Kpn-KPC in Buenos Aires, with a high capacity for dissemination and a high mortality rate. The implementation of infection control measures is essential to reduce the nosocomial spread of Kpn-KPC. (C) 2011 Elsevier Espana, S.L. All rights reserved.