|Dunne, W. Michael|
Submitted to: Journal of Clinical Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/19/2008
Publication Date: 1/1/2009
Citation: Marschall, J., Tibbetts, R.J., Dunne, W., Frye, J.G., Fraser, V.J., Warren, D.K. 2009. Presence of the KPC carbapenemase gene in Enterobacteriaceae causing bacteremia, and the correlation with in vitro carbapenem susceptibility. Journal of Clinical Microbiology. 47(1):239-241. Interpretive Summary: Resistance to beta-lactam antibiotics is increasingly found in a number of bacterial isolates recovered from patients in the US which are associated with clinical disease. This resistance may result in difficult to treat infections and/or increases in morbidity or mortality. Therefore a study was initiated to screen bacterial clinical isolates for resistance and to determine the mechanisms causing resistance. During six months, we obtained 243 Enterobacteriaceae isolates from patients with Gram-negative bacteremia at a 1250-bed teaching hospital in St. Louis, Missouri. These isolates were then screened for the presence of blaKPC which is a gene associated with resistance in the carbapenem class of antimicrobials. Three (1.2%) of 243 isolates were positive for the beta-lactamase gene blaKPC as determined by PCR amplification and sequence analysis. The blaKPC positive bacteria were Klebsiella pneumoniae, Enterobacter cloacae, and Proteus mirabilis. These results indicate that resistance to carbepenems occours among the Enterobacteriacia. Additionally, clinical isolates of these Gram-negative bacteria should be screened for resistance to this class of antimicrobial in order to optimize therapy.
Technical Abstract: During six months, we obtained Enterobacteriaceae isolates from patients with Gram-negative bacteremia at a 1250-bed teaching hospital in St. Louis, Missouri, and compared carbapenem susceptibility with the presence of blaKPC, a transferable carbapenemase gene. Three (1.2%) out of 243 isolates were blaKPC-positive. Ertapenem non-susceptibility had a low positive predictive value.