1418. Update of Trends in Klebsiella pneumoniae Carbapenemase Positive (KPC+) K. pneumoniae (KPN) in US Hospitals from the SENTRY Antimicrobial Surveillance Program
Session: Poster Abstract Session: Epidemiology of Multiple Drug-Resistant Gram Negative Rods
Saturday, October 20, 2012
Room: SDCC Poster Hall F-H

Background:

The emergence and spread of carbapenem-resistant KPN is a major public health concern.  We report an update of trends observed in KPC+ KPN in 2010 compared to 2007-2009 from SENTRY Antimicrobial Surveillance Program. 

Methods:

KPN clinical isolates were collected from geographically distributed US medical centers from 2007-2010, encompassing up to 35 states and 60 facilities.   Non-duplicate isolates were collected from blood (BSI), respiratory (RTI), skin and skin structure (SSSI), urinary (UTI), or other sites per protocol.  Susceptibility testing was performed by CLSI broth microdilution.  Isolates with imipenem (IMP) and/or meropenem (MER) MIC ≥ 2 g/ml were screened by PCR for carbapenemase genes (blaIMP, blaVIM, blaKPC, blaSME, blaGES, blaIMI, blaNMC-A, blaOXA-48).  Geographic regions were defined using US Census Regions.    

Results:

From 2007-2010, IMP or MER non-susceptibility was observed in 5.4% (173/3207) of KPN. blaKPC was the only carbapenemase gene identified in 154 (4.8%) isolates. For US regions combined, prevalence of KPC+ isolates were stable from 2007- 2009; 5.9% 2007, 4.9% 2008, 5.7% 2009 with a slight decrease in 2010 at 3.5% (p=0.035). The mid-Atlantic region overall had the highest occurrence of KPC at 23% (114/495), with yearly rate being > 20% from 2007 to 2009 and nearly 33% in 2009. However, percentage of KPC+ isolates decreased to 11% in 2010 (p= 0.002) in this region and reflected a decrease at 5 hospitals. The West South Central region had the second highest KPC prevalence overall (4.7%;17/365) with rates in 2010 at 9.4% (15/159) (p=0.001), due to isolates from Texas. Six of these 17 strains were indistinguishable by PFGE; including 2 from 2008 and 4 from 2010. The East North Central and South Atlantic regions had rates around 2% for 4-years combined. Overall rates in other areas were 1% or less. Of 154 KPC+ KPN, 70% (n=108) were from BSI, 15.6% (n=24) RTI, 12.3% (n=19) SSSI and 1.6% (n=3) UTI.  

Conclusion:                            

KPC continues to mediate carbapenem resistance among KPN in the US. BSI isolates comprise the majority of KPC+ KPN from this surveillance system. KPC prevalence rates remain highest in the mid-Atlantic region, but showed a significant decrease in 2010. Additionally, there was an increase of KPC+ KPN in Texas. Further evaluation to understand the change in rates is needed.

 

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)JMI Laboratories, Inc., North Liberty, IA, (3)Cepheid, Sunnyvale, CA, (4)Minnesota Department of Health, St. Paul, MN

Disclosures:

R. M. Kaiser, None

M. Castanheira, None

R. Jones, None

F. Tenover, None

R. Lynfield, None

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