Abstract
BackgroundTo study the molecular characteristics of a long-term, low frequency outbreak of bla KPC-2 in a low prevalence setting involving the hospital environment.Methodology/Principal FindingsKPC-producing bacteria were screened by selective chromogenic agar and Real-Time PCR. The presence of antibiotic resistance genes was ascribed by PCRs and subsequent sequencing, and the KPC-producing isolates were phylogenetically typed using PFGE and multi-locus sequence typing. Bla KPC-2-plasmids were identified and analysed by S1-nuclease-PFGE hybridization and PCR based replicon typing. A ∼97 kb IncFII plasmid was seen to carry bla KPC-2 in all of the clinical isolates, in one of the isolates recovered from screened patients (1/136), and in the Klebsiella pneumoniae and Enterobacter asburiae isolates recovered from the environment (sinks) in one intensive care unit. The K. pneumoniae strain ST258 was identified in 6 out of 7 patients. An intergenus spread to E. asburiae and an interspecies spread to two different K. pneumoniae clones (ST27 and ST461) of the bla KPC-2 plasmid was discovered. K. pneumoniae ST258 and genetically related E. asburiae strains were found in isolates of both human and environmental origins.Conclusions/SignificanceWe document a clonal transmission of the K. pneumoniae ST258 strain, and an intergenus plasmid diffusion of the IncFII plasmid carrying bla KPC-2 in this outbreak. A major reservoir in the patient population could not be unveiled. However, the identification of a persisting environmental reservoir of strains with molecular determinants linked to human isolates, suggests a possible role of the environment in the maintenance of this long-term outbreak.
Highlights
The Klebsiella pneumoniae carbapenemase (KPC) was first identified in the USA in a Klebsiella pneumoniae isolate dated from 1996[1] and has subsequently been reported worldwide.[2]
With respect to K. pneumoniae, multilocus sequence typing (MLST) has shown that the global dissemination of KPC-producing K. pneumoniae is dominated by isolates belonging to a hyperepidemic clonal complex including sequence type (ST) 258.[4] the dissemination and outbreaks of KPC seems to be associated with specific clones several reports are describing outbreaks where several clones and different species are involved [5,6] as well as individual patients containing different species harbouring blaKPC.[7,8,9]
Clinical cases Six KPC-producing K. pneumoniae isolates from clinical samples were recovered in Sørlandet Hospital (SH) from November 2007 to April 2010 (Table 1 and Table 2)
Summary
The Klebsiella pneumoniae carbapenemase (KPC) was first identified in the USA in a Klebsiella pneumoniae isolate dated from 1996[1] and has subsequently been reported worldwide.[2]. In Norway, the first case of K. pneumoniae with KPC was associated with import from Greece in 2007 at a hospital in the southern part of Norway.[10] Subsequently, five additional clinical isolates were identified at the same hospital and a nearby hospital from patients with no recent history of travel or hospitalisation abroad. In this study we describe this long-term outbreak with regards to the molecular characteristics of these isolates, plasmid content and dissemination, and the identification of KPCproducing isolates in the hospital environment. To study the molecular characteristics of a long-term, low frequency outbreak of blaKPC-2 in a low prevalence setting involving the hospital environment
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
