This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Coudron, P. E.
Right arrow Articles by Climo, M. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Coudron, P. E.
Right arrow Articles by Climo, M. W.

 Previous Article  |  Next Article 

Journal of Clinical Microbiology, February 2003, p. 772-777, Vol. 41, No. 2
0095-1137/03/$08.00+0     DOI: 10.1128/JCM.41.2.772-777.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

Occurrence of Extended-Spectrum and AmpC Beta-Lactamases in Bloodstream Isolates of Klebsiella pneumoniae: Isolates Harbor Plasmid-Mediated FOX-5 and ACT-1 AmpC Beta-Lactamases

Philip E. Coudron,1* Nancy D. Hanson,2 and Michael W. Climo3

Pathology and Laboratory Medicine Service/113,1 Department of Medicine, McGuire Veterans Affairs Medical Center, Richmond, Virginia 23249-0001,3 Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, Nebraska 681782

Received 12 August 2002/ Returned for modification 4 October 2002/ Accepted 12 November 2002

We tested 190 Klebsiella pneumoniae bloodstream isolates recovered from 189 patients in 30 U.S. hospitals in 23 states to determine the occurrence of extended-spectrum ß-lactamase (ESBL) and AmpC ß-lactamase producers. Based on growth inhibition by clavulanic acid by disk and MIC test methods, 18 (9.5%) of the isolates produced ESBLs. Although the disk diffusion method with standard breakpoints identified 28 cefoxitin-nonsusceptible isolates, only 5 (18%) of these were confirmed as AmpC producers. Of two AmpC confirmatory tests, the three-dimensional extract test was easier to perform than was the double-disk approximation test using a novel inhibitor, Syn2190. Three of the five AmpC producers carried the blaFOX-5 gene, while the other two isolates harbored the blaACT-1 gene. All AmpC genes were transferable. In vitro susceptibility testing with standard inocula showed that all five AmpC-producing strains were susceptible to cefepime, imipenem, and ertapenem but that with a high inoculum, more of these strains were susceptible to the carbapenems than to cefepime. All but 1 of 14 screen-positive AmpC nonproducers (and ESBL nonproducers) were susceptible to ceftriaxone and cefepime at the standard inoculum as were 6 of 6 isolates that were randomly selected and tested with a high inoculum. These results indicate that (i) a significant number of K. pneumoniae bloodstream isolates harbor ESBL or AmpC ß-lactamases, (ii) confirmatory tests are necessary to identify true AmpC producers, and (iii) in vitro, carbapenems are active against AmpC-producing strains of K. pneumoniae.

* Corresponding author. Mailing address: Pathology & Laboratory Medicine Service/113, McGuire Veterans Affairs Medical Center, 1201 Broad Rock Blvd., Richmond, VA 23249-0001. Phone: (804) 675-5809. Fax: (804) 675-5518. E-mail: Philip.Coudron{at}med.va.gov.

Journal of Clinical Microbiology, February 2003, p. 772-777, Vol. 41, No. 2
0095-1137/03/$08.00+0     DOI: 10.1128/JCM.41.2.772-777.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Jacoby, G. A. (2009). AmpC {beta}-Lactamases. Clin. Microbiol. Rev. 22: 161-182 [Abstract] [Full Text]  
  • Empel, J., Baraniak, A., Literacka, E., Mrowka, A., Fiett, J., Sadowy, E., Hryniewicz, W., Gniadkowski, M., and the Beta-PL Study Group, (2008). Molecular Survey of {beta}-Lactamases Conferring Resistance to Newer {beta}-Lactams in Enterobacteriaceae Isolates from Polish Hospitals. Antimicrob. Agents Chemother. 52: 2449-2454 [Abstract] [Full Text]  
  • Tan, T Y, Ng, S Y, Teo, L, Koh, Y, Teok, C H (2008). Detection of plasmid-mediated AmpC in Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis. J. Clin. Pathol. 61: 642-644 [Abstract] [Full Text]  
  • Scheetz, M. H., Hurt, K. M., Noskin, G. A., Oliphant, C. M. (2006). Applying antimicrobial pharmacodynamics to resistant gram-negative pathogens.. Am J Health Syst Pharm 63: 1346-1360 [Abstract] [Full Text]  
  • Coudron, P. E. (2005). Inhibitor-Based Methods for Detection of Plasmid-Mediated AmpC {beta}-Lactamases in Klebsiella spp., Escherichia coli, and Proteus mirabilis. J. Clin. Microbiol. 43: 4163-4167 [Abstract] [Full Text]  
  • Black, J. A., Thomson, K. S., Buynak, J. D., Pitout, J. D. D. (2005). Evaluation of {beta}-Lactamase Inhibitors in Disk Tests for Detection of Plasmid-Mediated AmpC {beta}-Lactamases in Well-Characterized Clinical Strains of Klebsiella spp.. J. Clin. Microbiol. 43: 4168-4171 [Abstract] [Full Text]  
  • Black, J. A., Moland, E. S., Thomson, K. S. (2005). AmpC Disk Test for Detection of Plasmid-Mediated AmpC {beta}-Lactamases in Enterobacteriaceae Lacking Chromosomal AmpC {beta}-Lactamases. J. Clin. Microbiol. 43: 3110-3113 [Abstract] [Full Text]  
  • Kang, C.-I., Pai, H., Kim, S.-H., Kim, H.-B., Kim, E.-C., Oh, M.-d., Choe, K.-W. (2004). Cefepime and the inoculum effect in tests with Klebsiella pneumoniae producing plasmid-mediated AmpC-type {beta}-lactamase. J Antimicrob Chemother 54: 1130-1133 [Abstract] [Full Text]  
  • Literacka, E., Empel, J., Baraniak, A., Sadowy, E., Hryniewicz, W., Gniadkowski, M. (2004). Four Variants of the Citrobacter freundii AmpC-Type Cephalosporinases, Including Novel Enzymes CMY-14 and CMY-15, in a Proteus mirabilis Clone Widespread in Poland. Antimicrob. Agents Chemother. 48: 4136-4143 [Abstract] [Full Text]  
  • Nasim, K., Elsayed, S., Pitout, J. D. D., Conly, J., Church, D. L., Gregson, D. B. (2004). New Method for Laboratory Detection of AmpC {beta}-Lactamases in Escherichia coli and Klebsiella pneumoniae. J. Clin. Microbiol. 42: 4799-4802 [Abstract] [Full Text]  
  • Black, J. A., Thomson, K. S., Pitout, J. D. D. (2004). Use of {beta}-Lactamase Inhibitors in Disk Tests To Detect Plasmid-Mediated AmpC {beta}-Lactamases. J. Clin. Microbiol. 42: 2203-2206 [Abstract] [Full Text]  
  • Alvarez, M., Tran, J. H., Chow, N., Jacoby, G. A. (2004). Epidemiology of Conjugative Plasmid-Mediated AmpC {beta}-Lactamases in the United States. Antimicrob. Agents Chemother. 48: 533-537 [Abstract] [Full Text]  
  • Hanson, N. D. (2003). AmpC {beta}-lactamases: what do we need to know for the future?. J Antimicrob Chemother 52: 2-4 [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»