Abstract
The susceptibility of Pseudomonas aeruginosa to imipenem has been shown to vary according to zinc concentration in the media. MICs of imipenem for 68 unique clinical isolates of P. aeruginosa were determined in media supplemented with zinc at concentrations between 0.5 and 6.0 micrograms/ml. In agar containing up to 3 micrograms of zinc/ml, 75 to 82% of the strains were susceptible to imipenem at an MIC of < or = 4 micrograms/ml. In agar supplemented to contain 6 micrograms of zinc/ml, however, only 40% of the strains were susceptible to imipenem. Manufacturers should ensure that the concentration of zinc in commercial media is below 3 micrograms/ml to avoid false classification of isolates as resistant to imipenem.
Full Text
The Full Text of this article is available as a PDF (68.2 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Baron E. J., Hindler J. A. Bioactivity of imipenem as a function of medium, time, and temperature. Antimicrob Agents Chemother. 1984 Jun;25(6):781–782. doi: 10.1128/aac.25.6.781. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cooper G. L., Louie A., Baltch A. L., Chu R. C., Smith R. P., Ritz W. J., Michelsen P. Influence of zinc on Pseudomonas aeruginosa susceptibilities to imipenem. J Clin Microbiol. 1993 Sep;31(9):2366–2370. doi: 10.1128/jcm.31.9.2366-2370.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Daly J. S., Deluca B. A., Hebert S. R., Dodge R. A., Soja D. T. Imipenem stability in a predried susceptibility panel. J Clin Microbiol. 1994 Oct;32(10):2584–2587. doi: 10.1128/jcm.32.10.2584-2587.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gaynes R. P., Culver D. H. Resistance to imipenem among selected gram-negative bacilli in the United States. Infect Control Hosp Epidemiol. 1992 Jan;13(1):10–14. doi: 10.1086/646417. [DOI] [PubMed] [Google Scholar]
- Grist R. External factors affecting imipenem performance in dried microdilution MIC plates. J Clin Microbiol. 1992 Feb;30(2):535–536. doi: 10.1128/jcm.30.2.535-536.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McMaster D., McCrum E., Patterson C. C., Kerr M. M., O'Reilly D., Evans A. E., Love A. H. Serum copper and zinc in random samples of the population of Northern Ireland. Am J Clin Nutr. 1992 Aug;56(2):440–446. doi: 10.1093/ajcn/56.2.440. [DOI] [PubMed] [Google Scholar]
- O'Rourke E. J., Lambert K. G., Parsonnet K. C., Macone A. B., Goldmann D. A. False resistance to imipenem with a microdilution susceptibility testing system. J Clin Microbiol. 1991 Apr;29(4):827–829. doi: 10.1128/jcm.29.4.827-829.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- White R. L., Kays M. B., Friedrich L. V., Brown E. W., Koonce J. R. Pseudoresistance of Pseudomonas aeruginosa resulting from degradation of imipenem in an automated susceptibility testing system with predried panels. J Clin Microbiol. 1991 Feb;29(2):398–400. doi: 10.1128/jcm.29.2.398-400.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]