Temporal pattern of Klebsiella pneumoniae carbapenemase (KPC) on surfaces of an intensive care unit of a large hospital

Background: Carbapenem-resistant Enterobacteriaceae are an increasing cause of healthcare-associated infections worldwide.Patients with infections caused by Klebsiella pneumoniae resistant to carbapenems (KPC) have significant increases in both allcausemortality and 30-day mortality. The aims of this study was to investigate the prevalence of KPC on environmental samplescollected during and after an outbreak caused by KPC in an intensive care unit (ICU) of a teaching hospital.Methods: Between 2010 and 2014 we conducted a total of 132 environmental monitoring campaigns from different criticalsurface of ICU ward in a Teaching Hospital Policlinico Umberto I. Samples were collected on surfaces in patient rooms and healthcare area. All samples were cultured and K. pneumoniae isolates were identified by standard microbiological techniques. Thepresumptive colonies were confirmed and tested for antibiotic resistance by an automated system. K. pneumoniae resitant tocarbapenems were tested for carbapenemase production by modified Hodge test.Results: A total of 2526 environmental samples were collected from November 2010 to July 2014. Of those, 111 resulted positivefor K. pneumoniae while KPC were 95 (85.6% of all K. pneumoniae, 3.8% of total samples). KPC was recovered in all patientrooms with similar proportion (5.1-5.6%) with the exception of patient 6 bed room where it was lower (2.4%). The pathogen wasnot recovered in rooms dedicated to healthcare personnel and doctors. Among surfaces, the highest proportion of KPC resulted onbedrail (6.8%), more than double than other surfaces. Washbasins had nearly half of samples KPC positive (1.2%).Conclusions: Despite previous studies suggested that environment plays a minor role in the transmission of carbapenem-resistantenterobacteriaceae, our data highlighted that surfaces represents a significant reservoir for KPC possibly supporting transientlycontamination of hands of healthcare workers in our ICU. Our results confirm that KPC are more likely found on surfaces closer tothe patient than on those situated further away.