1350. Trends in Klebsiella pneumoniae carbapenemase positive (KPC+) K. pneumoniae in USA Hospitals: Report from the 2007-2009 from the SENTRY Antimicrobial Surveillance Program. 
Session: Oral Abstract Session: The Menace of Klebsiella pneumoniae Carbapenemase (KPC)-Producing Organisms
Saturday, October 22, 2011: 3:00 PM
Room: 157ABC


Carbapenem-resistant K. pneumoniae (KPN) has been an increasing concern worldwide, including in the USA.  We evaluated trends in KPC+ KPN from 2007-2009 among isolates from SENTRY Antimicrobial Surveillance Program. 


KPN clinical isolates were collected from a total of 42 USA medical centers from 2007-2009.   Non-duplicate isolates were studied from blood (BSI), respiratory (RTI), skin and skin structure (SSSI), or other sites per protocol.  Susceptibility testing was performed by CLSI broth microdilution.  Isolates with imipenem and/or meropenem MIC ≥ 2 µg/ml were screened by PCR for various carbapenemase genes (blaIMP, blaVIM, blaKPC, blaSME, blaGES, blaIMI, blaNMC-A, blaOXA-48).  Geographic regions were defined using USA Census Regions.    


Of 2049 KPN isolates, 127 (6.2%) showed carbapenem resistance.  blaKPC was identified in 112 (5.5%) isolates over the 3 years.  No other carbapenemase genes were identified. For USA regions combined, prevalence rates of KPC+ isolates were 5.9% in 2007, 4.7% in 2008, and 5.7% in 2009.  The highest rates were in the Mid-Atlantic Region at 28.3% (n=96) with a fluctuating trend over time, (29% in 2007, 22% in 2008, and 33% in 2009), but a slight increase from 2007 vs. 2009 (p= 0.61).  The East North Central region had the second highest rate at 2.4% (n=8) with a slightly increasing trend, nil in 2007, 3.1% (n=3) in 2008, and 3.8% (n=5) in 2009 (p=0.06).  Rates for other regions ranged from 0% to only 1.8%.  Of 112 KPC+ KPN, 63% (n=71) were from BSI, 17% (n=19) RTI, 12% (n=13) SSSI and 8% (n=9) other.  The highest percentage of KPC+ isolates by infection site were from SSSI (12%; 13/108), followed by RTI (7.9%; 19/240), and BSI (4.7%; 71/1504).


KPC+ KPN prevalence rates were highest in the mid-Atlantic region, consistent with prior reports.  Overall USA KPC rates were stable across the monitored years; however, some regions appear to show an increasing trend. Other carbapenamase genes are not yet observed. Skin and skin structure sites were important sources of KPC+ organisms. It will be important to monitor changing epidemiology among carbapenemase-producing organisms to guide prevention and treatment strategies. 


Subject Category: A. Antimicrobial agents and Resistance

Robyn M. Kaiser, MD, MPH1, Mariana Castanheira, PhD2, Ronald Jones, MD2, Fred Tenover, Ph.D. D(ABMM)3 and Ruth Lynfield, MD4, (1)Univ. of Minnesota Med. Ctr., Minneapolis, MN, (2)Microbiology, JMI Laboratories, North Liberty, IA, (3)Antibiotic Resistance Working Group, IDSA, Sunnyvale, CA, (4)Antibiotic Resistance Working Group, IDSA, St. Paul, MN


R. M. Kaiser, None

M. Castanheira, None

R. Jones, None

F. Tenover, None

R. Lynfield, None

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