Surveillance and Molecular Epidemiology of Klebsiella pneumoniae Isolates That Produce Carbapenemases: First Report of OXA-48-Like Enzymes in North America

Abstract

ABSTRACTA study was designed to characterize nonrepeat isolates of carbapenemase-producingK. pneumoniaeobtained from the SMART worldwide surveillance program during 2008 and 2009. Characterization was done by PCR and sequencing forblaVIM,blaIMP,blaNDM,blaOXA,blaKPC, and plasmid-mediated quinolone resistance and virulence factors (VFs). Genetic relatedness was determined with pulsed-field gel electrophoresis (PFGE) using XbaI and multilocus sequence typing. A total of 110 isolates were included; 47 possess genes that encodeK. pneumoniaecarbapenemases (KPCs), 26 NDMs, 19 VIMs, 13 OXA-48-like, and 5 imipenems (IMPs). We identified 3 different major sequence types (STs) among 65% of the isolates (i.e., ST11 [n= 11], ST147 [n= 23], and ST258 [n= 38]). ST11 and ST147, producing OXA-48-like and NDMs, were found in Argentina, Turkey, Greece, Italy, and India; ST258, producing KPCs, was present in the United States, Israel, Greece, and Puerto Rico. The major STs consisted of up to 4 different pulsotypes, and each pulsotype had a specific geographical distribution. A new ST, named ST903, withblaIMP-26, was identified in the Philippines, while twoblaOXA-48-positive isolates were detected in the United States. There were no significant differences in the distribution of the VFs between the isolates; all were positive forfimH,mrkD,wabG, andureA. This is the first report of OXA-48-like enzymes in North America. Our study highlights the importance of surveillance programs using molecular techniques as powerful tools to identify the importance of international sequence types.