Molecular characterization of carbapenem-resistant Klebsiella pneumoniae ST14 and ST512 causing bloodstream infections in ICU and surgery wards of a tertiary university hospital of Verona (northern Italy): co-production of KPC-3, OXA-48, and CTX-M-15 beta-lactamases

Klebsiella pneumoniae strain is an important opportunistic pathogen that causes severe nosocomial infections. In the present study a molecular characterization of carbapenem resistant K. pneumoniae, isolated from blood samples of hospitalized patients of Verona University Hospital, was performed. The simultaneous presence of SHV-1/CTX-M-15/KPC-3 and SHV-1/CTX-M-15/0XA-48 serin-beta-lactamases was ascertained in the 89% and 11% of K. pneumoniae ST512 and K. pneumoniae ST14, respectively. Molecular characterization of bla genes showed that bla(KPC-3) was found in Tn440 /a transposon with the tnpR, tnpA, ISKpn6, and ISKpn7 mobile elements whereas bla(CTX-M-15) was detected downstream ISEcp1 genetic element. A class 1 integron with a gene cassette of 780 bp corresponding to aadA2 gene was identified in 33 K. pneumoniae ST512 isolates. (C) 2019 Elsevier Inc. All rights reserved.