Klebsiella pneumoniae carbapenem producers in Intensive Care Unit. First results about clinical and environmental surveillance in teaching hospital "Umberto I", Rome

Background The aim of our study is to evaluate the effectiveness of epidemiological surveillance and prevention strategies of Klebsiella pneumoniae (KPC) infections in a teaching hospital in Rome. Methods An epidemic KPC cluster (8 cases) occurred in Nov 2010 in the Intensive Care Unit (ICU) of the teaching hospital “Umberto I” in Rome”, after that an epidemiological surveillance focused on patients, environment and KPC was activated. From Nov 2010 to Apr 2012; 251 patients were admitted in the ICU and 158 epidemiological investigations has been conducted in the hospital. Strains from clinical and environmental ICU samples were identified and characterized for antibiotic resistance through Vitek2 compact (BioMérieux Italia). Bacterial RNA was analyzed through real-time NucliSENS EasyQ KPC (BioMérieux Italia) to confirm KPC presence. Fifteen environmental strains have been characterized by Pulsed Field Gel Electrophoresis and PCR for KPC gene and matched with KPC clinical isolates. MultiLocus Sequence Typing was performed to link a clonal strain. Results We isolated 146 KPC strains from clinical ICU samples, and 69 from environmental ones (only 58 out of 69 KPC). Eleven out of fifteen (73% ) of the environmental strains showed the same PFGE profile of the clinical ones. The epidemic environmental clone has been identified as ST512 (clonal complex CC-258). This clone is persistent in the environment with the extension of the resistance to colistin. In the last 9 months of ICU surveillance we observed an 33.33% increase of KPC clinical isolations and a 8.33% decrease of environmental ones. The epidemiological survey showed widespread cases in the hospital. Conclusions In Europe 2010 will be remembered as the year in which extensive drug resistant carbapenem producers bacteria (XDR-KPC), including Klebsiella pneumoniae (KPC), attracted global attention. Our study highlights the central role of the traditional and molecular epidemiological approach to obtain a good risk management of hospital infection from bacteria XDR-KPC.