Emergence and Clonal Spread of KPC-2 Producing Clinical Klebsiella Aerogenes Isolates From a Teaching Hospital in Tucuman, Argentina.

Abstract

IntroductionKlebsiella aerogenes is a nosocomial pathogen associated with drug resistance and healthcare-associated infections. We pursued this study to investigate an outbreak of clinical carbapenem-resistant K. aerogenes(CRKA) in an argentinian tertiary hospital which persisted for 4 months despite aggressive infection control measures. The primary goals aimed to evaluate the molecular characteristics and the clonal relationships among the CRKA isolates.MethodsWe characterized CRKA isolates by multiplex PCR and PFGE. The information was integrated with clinical and epidemiologic data.ResultsThe 14 CRKA strains were disseminated in an adult intensive care unit (50%) and five different wards. In patients who received antimicrobial treatment, 8 staggered to directed treatment, mainly with amikacin(6/8) and/or carbapenemes(5/8). The overall mortality was 42.8%, and the attributed mortality to CRKA infection was 21.4%, strains showed high rates of resistance to most of the antimicrobials without resistance to Amikacin and Tigecycline, and carried the blaKPC-2, blaSHV-2 and blaCTXM-15 genes. The PFGE indicated 2 distinct groups; 12/14 CRKA isolatesassociated with the dominant subgroup A and likely to be primarily responsible for the first isolation and subsequent dissemination in the hospital.ConclusionThe outbreak characteristics data showed prolonged hospitalization and previous use of broad-spectrum antibiotics as potential risk factors for the acquisition of CRKA.