Klebsiella pneumoniae Antimicrobial Drug Resistance, United States, 1998–2010

Guillermo V. Sanchez, Ronald N. Master, Richard B. Clark, Madiha Fyyaz, Padmaraj Duvvuri, Gupta Ekta, and Jose Bordon

Author affiliations: Author affiliations: George Washington University, Washington, DC, USA (G.V. Sanchez); Quest Diagnostics Nichols Institute, Chantilly, Virginia, USA (R.N. Master, R.B. Clark); Providence Hospital, Washington (M. Fyyaz, P. Duvvuri, G. Ekta, J. Bordon)

Abstract

We studied antimicrobial-resistant Klebsiella pneumoniae for 1998–2010 by using data from The Surveillance Network. Susceptibility results (n = 3,132,354) demonstrated significant increases in resistance to all antimicrobial drugs studied, except tetracycline. Cross-resistance among carbapenem-resistant K. pneumoniae was lower for tetracycline and amikacin.

Klebsiella spp. are among the most common pathogens isolated in intensive care units (ICUs), and K. pneumoniae is the most frequently encountered carbapenemase-producing Enterobacteriaceae (1). Increasing antimicrobial drug resistance, including carbapenem-resistant K. pneumoniae (CRKP), accounts for substantial increases in illness and death (1). Few antimicrobial therapy options exist for infections caused by CRKP (2).
The emergence of K. pneumoniae resistance to carbapenems is well documented (3). However, few studies have analyzed the trends and prevalence of in vitro K. pneumoniae antimicrobial drug resistance since carbapenem resistance emerged in the United States during the late 1990s (4). Furthermore, few investigations have examined antimicrobial drug resistance with regard to specimen source or cross-resistance patterns among CRKP.
We examined the prevalence of K. pneumoniae antimicrobial drug resistance in US inpatients using a large national surveillance system. Our objectives were to analyze K. pneumoniae antimicrobial drug resistance among US inpatients, resistance patterns by specimen source, and cross-resistance among imipenem-resistant K. pneumoniae isolates.