Outbreak of KPC-3-producing, and colistin-resistant, Klebsiella pneumoniae infections in two Sicilian hospitals

We report the first outbreak caused by colistin-resistant Klebsiella pneumoniae producing KPC-3 carbapenamase in two Italian hospitals. This spread occurred in 1 month, and was caused by eight colistin-resistant and carbapenem-resistant Klebsiella pneumoniae isolates from eight patients. A further three isolates were obtained from the intestinal tract and pharyngeal colonization. All isolates were multidrug-resistant (MDR), including being resistant to colistin, but they were susceptible to gentamicin and tigecycline. PCR detection showed that all isolates harboured the blaKPC-3 gene associated with blaSHV-11, blaTEM-1 and blaOXA-9. All K. pneumoniae isolates, genotyped by pulsed-field gel electrophoresis and multilocus sequence typing, belonged to the same sequence type (ST)258 clone. From our data and a review of the international literature, K. pneumoniae ST258 seems to be the most widespread genetic background for KPC dissemination in Europe.