Outbreak of Klebsiella pneumoniae producing a new carbapenem-hydrolyzing class A beta-lactamase, KPC-3, in a New York Medical Center.
From April 2000 to April 2001, 24 patients in intensive care units at Tisch Hospital, New York, N.Y., were infected or colonized by carbapenem-resistant Klebsiella pneumoniae. Pulsed-field gel electrophoresis identified a predominant outbreak strain, but other resistant strains were also recovered. Three representatives of the outbreak strain from separate patients were studied in detail. All were resistant or had reduced susceptibility to imipenem, meropenem, ceftazidime, piperacillin-tazobactam, and gentamicin but remained fully susceptible to tetracycline. PCR amplified a blaKPC allele encoding a novel variant, KPC-3, with a His(272)-->Tyr substitution not found in KPC-2; other carbapenemase genes were absent. In the outbreak strain, KPC-3 was encoded by a 75-kb plasmid, which was transferred in vitro by electroporation and conjugation. The isolates lacked the OmpK35 porin but expressed OmpK36, implying reduced permeability as a cofactor in resistance. This is the third KPC carbapenem-hydrolyzing beta-lactamase variant to have been reported in members of the Enterobacteriaceae, with others reported from the East Coast of the United States. Although producers of these enzymes remain rare, the progress of this enzyme group merits monitoring.
Woodford
Neil
N
Antibiotic resistance Monitoring and Reference Laboratory, Specialist and Reference Microbiology Division-Colindale, Health Protection Agency, London, United Kingdom. neil.woodford@hpa.org.uk
Tierno
Philip M
PM
Young
Katherine
K
Tysall
Luke
L
Palepou
Marie-France I
MF
Ward
Elaina
E
Painter
Ronald E
RE
Suber
Deborah F
DF
Shungu
Daniel
D
Silver
Lynn L
LL
Inglima
Kenneth
K
Kornblum
John
J
Livermore
David M
DM
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis; D001426:Bacterial Proteins / Q000235:genetics; D015780:Carbapenems / Q000378:metabolism; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology*; D004196:Disease Outbreaks; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D005964:Glucosyltransferases / Q000235:genetics; D006801:Humans; D007525:Isoelectric Focusing; D007710:Klebsiella Infections / Q000453:epidemiology / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000201:enzymology* / Q000235:genetics; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D009519:New York City / Q000453:epidemiology; D010957:Plasmids / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D015780:Carbapenems; D005964:Glucosyltransferases; C430063:WaaE protein, Klebsiella pneumoniae; D001618:beta-Lactamases; C495220:beta-lactamase KPC-3, Klebsiella pneumoniae