AUTHOR=Zhou Kai , Lokate Mariëtte , Deurenberg Ruud H. , Arends Jan , Lo-Ten Foe Jerome , Grundmann Hajo , Rossen John W. A. , Friedrich Alexander W. 

TITLE=Characterization of a CTX-M-15 Producing Klebsiella Pneumoniae Outbreak Strain Assigned to a Novel Sequence Type (1427)

JOURNAL=Frontiers in Microbiology

VOLUME=6

YEAR=2015

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2015.01250

DOI=10.3389/fmicb.2015.01250

ISSN=1664-302X

ABSTRACT=<p>Extended-spectrum -lactamase producing <italic>Klebsiella pneumoniae</italic> have emerged as one of the major nosocomial pathogens. Between July and September 2012, a CTX-M-15 producing <italic>K. pneumoniae</italic> caused an outbreak in a university hospital in the Netherlands. The outbreak isolates were characterized and assigned to a novel sequence type (ST1427). An epidemiological link between affected patients was supported by patient contact tracing and whole-genome phylogenetic analysis. Intra-strain polymorphism was detected among multiple isolates obtained from different body sites of the index patient, which may relate to antibiotic treatment and/or host adaptation. Environmental contamination caused by the outbreak clone was found in the patient rooms even on medical equipment. The novel clone was not closely related to any known endemic/epidemic clone, but carried a set of a plasmid-borne resistance genes [<italic>bla</italic><sub>CTX−M−15</sub>, <italic>bla</italic><sub>TEM−1</sub>, <italic>bla</italic><sub>OXA−1</sub>, <italic>aac(6</italic>′<italic>)-Ib</italic>-cr, <italic>qnrB1, tetA</italic>(A), <italic>aac(3)-II</italic>]. Analysis of its virulence factors revealed a previously uncharacterized capsular biosynthesis region and two uncharacterized fimbriae gene clusters, and suggested that the new clone was not hypervirulent. To our knowledge, this is the first outbreak report of <italic>K. pneumoniae</italic> ST1427, and our study could be of help to understand the features of this newly emerging clone.</p>