Send to

Choose Destination
Emerg Infect Dis. 2013 Nov;19(11):1803-10. doi: 10.3201/eid1911.121470.

CTX-M β-lactamase-producing Klebsiella pneumoniae in suburban New York City, New York, USA.


CTX-M extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae isolates are infrequently reported in the United States. In this study, we analyzed nonduplicate ESBL-producing K. pneumoniae and Escherichia coli clinical isolates collected during 2005-2012 at a tertiary care medical center in suburban New York City, USA, for the presence of blaCTX-M, blaSHV, blaTEM, and blaKPC genes. Despite a high prevalence of blaCTX-M genes in ESBL-producing E. coli since 2005, blaCTX-M genes were not detected in K. pneumoniae until 2009. The prevalence of CTX-M-producing K. pneumoniae increased significantly over time from 1.7% during 2005-2009 to 26.4% during 2010-2012 (p<0.0001). CTX-M-15 was the dominant CTX-M genotype. Pulsed-field gel electrophoresis and multilocus sequence typing revealed high genetic heterogeneities in CTX-M-producing K. pneumoniae isolates. This study demonstrates the recent emergence and polyclonal spread of multidrug resistant CTX-M-producing K. pneumoniae isolates among patients in a hospital setting in the United States.


Escherichia coli; Klebsiella pneumoniae; antimicrobial resistance; bacteria; beta-lactamases CTX-M-15; extended-spectrum beta-lactamases; multilocus sequence typing; pulsed-field gel electrophoresis

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for CDC-NCEZID Icon for PubMed Central
Loading ...
Support Center