Emergence of blaKPC-containing Klebsiella pneumoniae in a long-term acute care hospital: a new challenge to our healthcare system.
OBJECTIVE
To characterize isolates of Klebsiella pneumoniae producing KPC carbapenemase (KPC-Kp) associated with an outbreak in a long-term acute care hospital (LTACH) in South Florida.


METHODS
During 21 March to 20 April 2008, 241 K. pneumoniae isolates detected at Integrated Regional Laboratories (Ft. Lauderdale, FL) for which the ertapenem MICs were > or =4 mg/L were studied. PCR, cloning and sequence analysis were used to detect bla(KPC) and to characterize the beta-lactamase and outer membrane proteins (Omps). The expression level of KPC enzymes was studied by immunoblotting. Genetic relatedness of isolates was investigated with rep-PCR and PFGE. Clinical records of patients were investigated.


RESULTS
Seven KPC-Kp strains were isolated from different patients located at a single LTACH, with a further three isolates being recovered from patients at different hospitals. All KPC-Kp isolates in patients from the LTACH and from one hospital patient were genetically related and shared PFGE patterns that clustered with known sequence type (ST) 258 strains. These strains were highly resistant to carbapenems (MICs > or = 32 mg/L) due to an increased level of KPC expression and loss of Omps. Rectal colonization was documented in all LTACH patients with KPC-Kp isolates. Treatment failures were common (crude mortality rate of 69%). Active surveillance and enhanced infection control practices terminated the KPC-Kp outbreak.


CONCLUSIONS
The detection of KPC-Kp in an LTACH represents a serious infection control and therapeutic challenge in a new clinical setting. The speed at which the epidemic of KPC-Kp is spreading in our healthcare system mandates urgent action.
Endimiani
Andrea
A
Research Service, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, 10701 East Boulevard, Cleveland, OH 44106, USA.
Depasquale
John M
JM
Forero
Sandra
S
Perez
Federico
F
Hujer
Andrea M
AM
Roberts-Pollack
Daneshia
D
Fiorella
Paul D
PD
Pickens
Nancy
N
Kitchel
Brandon
B
Casiano-Colón
Aida E
AE
Tenover
Fred C
FC
Bonomo
Robert A
RA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000145:classification / Q000235:genetics; D015373:Bacterial Typing Techniques; D016000:Cluster Analysis; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D000077727:Ertapenem; D005260:Female; D005431:Florida / Q000453:epidemiology; D006761:Hospitals; D006801:Humans; D015151:Immunoblotting; D007362:Intensive Care Units; D007710:Klebsiella Infections / Q000453:epidemiology* / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D008297:Male; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000145:classification / Q000235:genetics; D047090:beta-Lactams / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D047090:beta-Lactams; D001618:beta-Lactamases; C063912:carbapenemase; D000077727:Ertapenem