Περίληψη:
Objectives: Global dissemination of KPC-type carbapenemases is mainly
associated with the spread of high-risk clones of Klebsiella pneumoniae
and of KPC-encoding plasmids. In this study, we explored the population
structure of KPC-encoding plasmids from the recent epidemics of
KPC-producing K. pneumoniae (KPC-Kp) in Greece and Italy, the two major
European endemic settings.
Methods:Thirty-four non-replicate clinical strains of KPC-Kp
representative of the early phases (2008-11) of the Greek
(naEuroS=aEuroS22) and Italian (naEuroS=aEuroS12) epidemics were
studied. Isolates were typed by MLST, and bla(KPC)-carrying plasmids
were characterized by S1 profiling, PCR-based replicon typing and RFLP.
Transfer experiments by conjugation or transformation were carried out
with Escherichia coli recipients. Eleven plasmids, representative of all
different restriction profiles, were completely sequenced.
Results:The representative Greek strains belonged to 14 sequence types
(STs), with a predominance of ST258. The representative Italian strains
belonged to three STs, with a predominance of clonal complex 258 (ST258,
ST512). The 34 strains carried plasmids of variable size (78-166 kb),
either with bla(KPC-2) or bla(KPC-3) gene embedded in a Tn4401a
transposon. Plasmids from Greek strains were mostly of a single RFLP
type (A) and resembled the archetypal pKpQIL KPC-encoding plasmid, while
plasmids from Italian strains belonged to a more heterogeneous
population, showing five RFLP profiles (A, C-F). Types A and C resembled
pKpQIL or deletion derivatives thereof, while types D-F included
plasmids with hybrid structures between pKpQIL, pKPN3 and pKPN101-IT.
Conclusions:pKpQIL-like plasmids played a major role in the
dissemination of bla(KPC) in Greece and Italy, but evolved with
different dynamics in these endemic settings.
Συγγραφείς:
Papagiannitsis, Costas C.
Di Pilato, Vincenzo
Giani, Tommaso and
Giakkoupi, Panagiota
Riccobono, Eleonora
Landini, Giulia and
Miriagou, Vivi
Vatopoulos, Alkiviadis C.
Rossolini, Gian Maria
