Abstract
Forty clinical isolates of Escherichia coli and 141 isolates of Klebsiella pneumoniae that either transferred ceftazidime resistance or showed sulbactam enhancement of oxyimino-beta-lactam susceptibility were tested by disk diffusion methodology for susceptibility to aztreonam, cefotaxime, ceftazidime, and cefoxitin. With standard 30 micrograms antibiotic disks, the fraction of these extended-spectrum beta-lactamase (ESBL)-producing isolates testing resistant by National Committee for Clinical Laboratory Standards criteria was lowest (24%) with cefotaxime disks. Forty percent of the E. coli and 29% of the K. pneumoniae isolates appeared susceptible with at least one oxyimino-beta-lactam disk. Ceftazidime and aztreonam disks were equivalent in differentiating ESBL production, and both were superior to cefotaxime disks. Over half the E. Coli and 29% of the K. pneumoniae isolates tested cefoxitin resistant. In 30 isolates, cefoxitin resistance was transmissible and due to a plasmid-mediated AmpC-type beta-lactamase. With a 5-micrograms ceftazidime disk, a breakpoint could be chosen with high sensitivity and specificity for ESBL-producing organisms. Present disk diffusion criteria underestimate the prevalence of ESBL-producing strains.
Full Text
The Full Text of this article is available as a PDF (252.4 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Arstila T., Jacoby G. A., Huovinen P. Evaluation of five different methods to prepare bacterial extracts for the identification of beta-lactamases by isoelectric focusing. J Antimicrob Chemother. 1993 Dec;32(6):809–816. doi: 10.1093/jac/32.6.809. [DOI] [PubMed] [Google Scholar]
- Bush K., Singer S. B. Biochemical characteristics of extended broad spectrum beta-lactamases. Infection. 1989 Nov-Dec;17(6):429–433. doi: 10.1007/BF01645566. [DOI] [PubMed] [Google Scholar]
- Coetzee J. N., Datta N., Hedges R. W. R factors from Proteus rettgeri. J Gen Microbiol. 1972 Oct;72(3):543–552. doi: 10.1099/00221287-72-3-543. [DOI] [PubMed] [Google Scholar]
- Jacoby G. A. Genetics of extended-spectrum beta-lactamases. Eur J Clin Microbiol Infect Dis. 1994;13 (Suppl 1):S2–11. doi: 10.1007/BF02390679. [DOI] [PubMed] [Google Scholar]
- Jacoby G. A., Medeiros A. A. More extended-spectrum beta-lactamases. Antimicrob Agents Chemother. 1991 Sep;35(9):1697–1704. doi: 10.1128/aac.35.9.1697. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jacoby G. A., Sutton L. Properties of plasmids responsible for production of extended-spectrum beta-lactamases. Antimicrob Agents Chemother. 1991 Jan;35(1):164–169. doi: 10.1128/aac.35.1.164. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Katsanis G. P., Spargo J., Ferraro M. J., Sutton L., Jacoby G. A. Detection of Klebsiella pneumoniae and Escherichia coli strains producing extended-spectrum beta-lactamases. J Clin Microbiol. 1994 Mar;32(3):691–696. doi: 10.1128/jcm.32.3.691-696.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Martínez-Martínez L., Hernández-Allés S., Albertí S., Tomás J. M., Benedi V. J., Jacoby G. A. In vivo selection of porin-deficient mutants of Klebsiella pneumoniae with increased resistance to cefoxitin and expanded-spectrum-cephalosporins. Antimicrob Agents Chemother. 1996 Feb;40(2):342–348. doi: 10.1128/aac.40.2.342. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mathew A., Harris A. M., Marshall M. J., Ross G. W. The use of analytical isoelectric focusing for detection and identification of beta-lactamases. J Gen Microbiol. 1975 May;88(1):169–178. doi: 10.1099/00221287-88-1-169. [DOI] [PubMed] [Google Scholar]
- Medeiros A. A., Cohenford M., Jacoby G. A. Five novel plasmid-determined beta-lactamases. Antimicrob Agents Chemother. 1985 May;27(5):715–719. doi: 10.1128/aac.27.5.715. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Meyer K. S., Urban C., Eagan J. A., Berger B. J., Rahal J. J. Nosocomial outbreak of Klebsiella infection resistant to late-generation cephalosporins. Ann Intern Med. 1993 Sep 1;119(5):353–358. doi: 10.7326/0003-4819-119-5-199309010-00001. [DOI] [PubMed] [Google Scholar]
- Normark S., Grundström T., Bergström S. Susceptibility to penicillins and cephalosporins in beta-lactamase producing strains of E. coli and relative amount of beta-lactamase produced from these strains. Scand J Infect Dis Suppl. 1980;Suppl 25:23–29. [PubMed] [Google Scholar]
- Payne D. J., Amyes S. G. Transferable resistance to extended-spectrum beta-lactams: a major threat or a minor inconvenience? J Antimicrob Chemother. 1991 Mar;27(3):255–261. doi: 10.1093/jac/27.3.255. [DOI] [PubMed] [Google Scholar]
- Philippon A., Labia R., Jacoby G. Extended-spectrum beta-lactamases. Antimicrob Agents Chemother. 1989 Aug;33(8):1131–1136. doi: 10.1128/aac.33.8.1131. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Takahashi I., Sawai T., Ando T., Yamagishi S. Cefoxitin resistance by a chromosomal cephalosporinase in Escherichia coli. J Antibiot (Tokyo) 1980 Sep;33(9):1037–1042. doi: 10.7164/antibiotics.33.1037. [DOI] [PubMed] [Google Scholar]