Identification of CTX-M15-, SHV-28-producing Klebsiella pneumoniae ST15 as an epidemic clone in the Copenhagen area using a semi-automated Rep-PCR typing assay

• Published in: European journal of clinical microbiology & infectious diseases Vol. 30; no. 6; pp. 773 - 778
• Main Authors: Nielsen, J. B., Skov, M. N., Jørgensen, R. L., Heltberg, O., Hansen, D. S., Schønning, K.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01-06-2011; Springer Nature B.V
• Subjects: Automation; Bacterial Typing Techniques; beta-Lactamases - biosynthesis; beta-Lactamases - genetics; Biomedical and Life Sciences; Biomedicine; Cross Infection - epidemiology; Cross Infection - microbiology; Denmark - epidemiology; Disease control; Disease Outbreaks; DNA, Bacterial - genetics; E coli; Electrophoresis, Gel, Pulsed-Field; Epidemics; Genotype; Humans; Internal Medicine; Investigations; Klebsiella Infections - epidemiology; Klebsiella Infections - microbiology; Klebsiella pneumoniae - classification; Klebsiella pneumoniae - enzymology; Klebsiella pneumoniae - isolation & purification; Laboratories; Medical Microbiology; Molecular Typing; Outbreaks; Polymerase chain reaction; Polymerase Chain Reaction - methods; Repetitive Sequences, Nucleic Acid - genetics; Denmark; Hvidovre Hospital; Epidemic Clone; Outbreak Strain; Copenhagen Area; Cefpodoxime
• ISSN: 0934-9723; 1435-4373
• DOI: 10.1007/s10096-011-1153-x

Rapid molecular typing methods can be a valuable aid in the investigation of suspected outbreaks. We used a semi-automated repetitive sequence-based polymerase chain reaction (Rep-PCR) typing assay and pulsed field gel electrophoresis (PFGE) to investigate the relationship between local
Klebsiella pneumoniae
(
K. pneumoniae
) producing extended spectrum β-lactamases (ESBLs) and their relation to recognized Danish outbreak strains. PFGE and Rep-PCR produced similar clustering among isolates. Individual isolates from each cluster were further characterized by PCR amplification and sequencing of
bla
TEM
,
bla
SHV
, and
bla
CTX-M
, and multilocus sequence typing (MLST). Thirty-five out of 52 ESBL-producing
K. pneumoniae
isolates were ST15 and
bla
CTX-M15
,
bla
SHV-28
, and
bla
TEM-1
positive by PCR. Ten out of 52 were ST16 and tested positive for
bla
CTX-M15
,
bla
SHV-1
, and
bla
TEM-1
. Isolates from previously recognized hospital outbreaks were also ST15 and PCR positive for
bla
CTX-M15
,
bla
SHV-28
, and
bla
TEM-1
, and typed within the main cluster by both Rep-PCR and PFGE. In conclusion,
K. pneumoniae
ST15 containing
bla
CTX-M15
and
bla
SHV-28
constitutes an epidemic clone in the Copenhagen area and this clone can be rapidly recognized by semi-automated Rep-PCR.