Abstract
Because excessively high rates of false resistance have been encountered with the 10-μg amikacin disk in diffusion susceptibility tests, a study was performed to examine existing zone diameter interpretative criteria and to compare the accuracy of 10- and 30-μg amikacin disks by the error rate-bounded classification scheme. Although current zone diameter interpretative criteria eliminate false susceptibles, there is an unacceptably high rate of false resistants. This problem can be resolved in most instances by revising the zone diameter interpretative criteria for the 10-μg disk (resistant, ≤9 mm; indeterminate, 10 to 11 mm; susceptible, ≥12 mm) or, preferably, by replacing the 10-μg disk with a 30-μg disk and adopting new interpretative criteria (resistant, ≤14 mm; indeterminate, 15 to 16 mm; susceptible, ≥17 mm). Because of significant differences in performance among media, it is necessary to include Pseudomonas aeruginosa ATCC 27853 among controls routinely tested and to exclude from use lots of Mueller-Hinton agar yielding results outside the 75% tolerance (90% confidence) limits for amikacin.
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Selected References
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- Bauer A. W., Kirby W. M., Sherris J. C., Turck M. Antibiotic susceptibility testing by a standardized single disk method. Am J Clin Pathol. 1966 Apr;45(4):493–496. [PubMed] [Google Scholar]
- Garrod L. P., Waterworth P. M. Effect of medium composition on the apparent sensitivity of Pseudomonas aeruginosa to gentamicin. J Clin Pathol. 1969 Sep;22(5):534–538. doi: 10.1136/jcp.22.5.534. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Holmes R. K., Minshew B. H., Gould I. K., Sanford J. P. Resistance of Pseudomonas aeruginosa to gentamicin and related aminoglycoside antibiotics. Antimicrob Agents Chemother. 1974 Sep;6(3):253–262. doi: 10.1128/aac.6.3.253. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Klastersky J., Meunier-Carpentier F., Prevost J. M. Significance of antimicrobial synergism for the outcome of gram negative sepsis. Am J Med Sci. 1977 Mar-Apr;273(2):157–167. doi: 10.1097/00000441-197703000-00005. [DOI] [PubMed] [Google Scholar]
- Metzler C. M., DeHaan R. M. Susceptibility tests of anaerobic bacteria: statistical and clinical considerations. J Infect Dis. 1974 Dec;130(6):588–594. doi: 10.1093/infdis/130.6.588. [DOI] [PubMed] [Google Scholar]
- Minshew B. H., Pollock H. M., Schoenknecht F. D., Sherris J. C. Emergence in a burn center of populations of bacteria resistant to gentamicin, tobramycin, and amikacin: evidence for the need for changes in zone diameter interpretative standards. Antimicrob Agents Chemother. 1977 Dec;12(6):688–696. doi: 10.1128/aac.12.6.688. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Moellering R. C., Jr, Wennersten C., Kunz L. J., Poitras J. W. Resistance to gentamicin, tobramycin and amikacin among clinical isolates of bacteria. Am J Med. 1977 Jun;62(6):873–881. doi: 10.1016/0002-9343(77)90655-6. [DOI] [PubMed] [Google Scholar]
- Pollock H. M., Minshew B. H., Kenny M. A., Schoenknecht F. D. Effect of different lots of Mueller-Hinton agar on the interpretation of the gentamicin susceptibility of Pseudomonas aeruginosa. Antimicrob Agents Chemother. 1978 Sep;14(3):360–367. doi: 10.1128/aac.14.3.360. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Washington J. A., 2nd, Snyder R. J., Kohner P. C., Wiltse C. G., Ilstrup D. M., McCall J. T. Effect of cation content of agar on the activity of gentamicin, tobramycin, and amikacin against Pseudomonas aeruginosa. J Infect Dis. 1978 Feb;137(2):103–111. doi: 10.1093/infdis/137.2.103. [DOI] [PubMed] [Google Scholar]
- Waterworth P. M. Uniformity in sensitivity test media. J Antimicrob Chemother. 1978 Jan;4(1):4–6. doi: 10.1093/jac/4.1.4. [DOI] [PubMed] [Google Scholar]