Outbreak of KPC-3-producing ST15 and ST348Klebsiella pneumoniaein a Portuguese hospital

Abstract

SUMMARYTo date, only a few sporadic cases of infections due toKlebsiella pneumoniaecarbapenemase (KPC) producers have been reported in Portugal. Here, we report for the first time an outbreak ofK. pneumoniaeKPC-3 producers in a tertiary-care hospital during 2013. Twenty-seven ertapenem-resistantK. pneumoniaewere identified in patients at a tertiary-care hospital during 2013 isolated predominantly from urine (48·1%) and blood (25·9%) cultures. All isolates were highly resistant toβ-lactam antibiotics and most showed intermediate resistance to imipenem. The more frequentβ-lactamases were TEM- (77·7%), CTX-M- (70·3%) and KPC-type (66·6%). KPC-3 was identified by sequencing. TheblaKPC−3gene was associated with an IncF plasmid, and efficiently transferred toE. coliJ53. Pulsed-field gel electrophoresis typing revealed three clusters of isolates which were further characterized by multi-locus sequence typing as ST11, ST15 and ST348. Ertapenem-resistant ST15 was already in circulation in the hospital, related to expression of OmpK36 modified porin, but the other two sequence types had not been previously found in the hospital. We conclude that the IncF plasmid mediated transfer of KPC-3 in the outbreak and that implementation of carbapenemase gene screening in isolates from patients on admission to hospital is advisable in order to control dissemination of these antimicrobial resistance elements.