Skip to main content
NCBI home page
Antimicrobial Agents and Chemotherapy logoLink to Antimicrobial Agents and Chemotherapy
. 1978 Oct;14(4):517–530. doi: 10.1128/aac.14.4.517

Disk Agar Diffusion Susceptibility Testing of Yeasts

Michael A Saubolle 1,†, Paul D Hoeprich 1
PMCID: PMC352501  PMID: 568910

Abstract

A disk agar diffusion method was developed for testing the susceptibility of rapidly growing yeasts in vitro. A totally defined, completely synthetic agar culture medium (synthetic amino acid medium, fungal) and clinical isolates of Candida spp. and Torulopsis glabrata were used. Turbidimetric adjustment of cell suspensions resulted in standard, reproducible inocula, which gave sharp, clear zones of inhibition when applied by an agar overlay method. Optimal disk loads were determined for amphotericin B, amphotericin B methyl ester, 5-fluorocytosine, clotrimazole, and miconazole. Disk potencies were stable over a 2-month period when stored in a vacuum desiccator at −30°C. Using an error ratebounded classification, the zones of inhibition were correlated with both broth dilution and agar dilution minimum inhibitory concentrations (MICs). With amphotericin B and amphotericin B methyl ester, all isolates were susceptible, yielding zone diameters which clustered within 5 mm. Overall correlations between zone diameters and broth dilution MICs with 5-fluorocytosine, miconazole, and clotrimazole were 97, 96, and 82% (excluding T. glabrata), respectively; correlations of zone diameters with agar dilution MICs were 96, 92, and 88%, respectively. Disk diffusion susceptibility testing of yeasts appears to be generally applicable. However, when results are equivocal, quantitative test methods should be used.

Full text

PDF
517

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Barry A. L., Garcia F., Thrupp L. D. An improved single-disk method for testing the antibiotic susceptibility of rapidly-growing pathogens. Am J Clin Pathol. 1970 Feb;53(2):149–158. doi: 10.1093/ajcp/53.2.149. [DOI] [PubMed] [Google Scholar]
  2. Bennett J. E. Chemotherapy of systemic mycoses (first of two parts). N Engl J Med. 1974 Jan 3;290(1):30–32. doi: 10.1056/NEJM197401032900107. [DOI] [PubMed] [Google Scholar]
  3. Block E. R., Jennings A. E., Bennett J. E. Variables influencing susceptibility testing of Cryptococcus neoformans to 5-fluorocytosine. Antimicrob Agents Chemother. 1973 Oct;4(4):392–395. doi: 10.1128/aac.4.4.392. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Burgess M. A., Bodey G. P. Clotrimazole (Bay b 5097): in vitro and clinical pharmacological studies. Antimicrob Agents Chemother. 1972 Dec;2(6):423–426. doi: 10.1128/aac.2.6.423. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Drouhet E. Basic mechanisms of antifungal chemotherapy. Mod Treat. 1970 May;7(3):539–564. [PubMed] [Google Scholar]
  6. Godefroi E. F., Heeres J., Van Cutsem J., Janssen P. A. The preparation and antimycotic properties of derivatives of 1-phenethylimidazole. J Med Chem. 1969 Sep;12(5):784–791. doi: 10.1021/jm00305a014. [DOI] [PubMed] [Google Scholar]
  7. Griffith L. J., Mullins C. G. Drug resistance as influenced by inactivated sensitivity discs. Appl Microbiol. 1968 Apr;16(4):656–658. doi: 10.1128/am.16.4.656-658.1968. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Hamilton-Miller J. M. A comparative in vitro study of amphotericin B 1 clotrimazole and 5-fluorocytosine against clinically isolated yeasts. Sabouraudia. 1972 Nov;10(3):276–283. [PubMed] [Google Scholar]
  9. Hoeprich P. D. Chemotherapy of systemic fungal diseases. Annu Rev Pharmacol Toxicol. 1978;18:205–231. doi: 10.1146/annurev.pa.18.040178.001225. [DOI] [PubMed] [Google Scholar]
  10. Hoeprich P. D., Finn P. D. Obfuscation of the activity of antifungal antimicrobics by culture media. J Infect Dis. 1972 Oct;126(4):353–361. doi: 10.1093/infdis/126.4.353. [DOI] [PubMed] [Google Scholar]
  11. Hoeprich P. D., Huston A. C. Effect of culture media on the antifungal activity of miconazole and amphotericin B methyl ester. J Infect Dis. 1976 Oct;134(4):336–341. doi: 10.1093/infdis/134.4.336. [DOI] [PubMed] [Google Scholar]
  12. Hoeprich P. D., Huston A. C. Susceptibility of coccidioides immitis, Candida albicans, and Cryptococcus neoformans to amphotericin B, flucytosine, and clotrimazole. J Infect Dis. 1975 Aug;132(2):133–141. doi: 10.1093/infdis/132.2.133. [DOI] [PubMed] [Google Scholar]
  13. Holt R. J., Newman R. L. Laboratory assessment of the antimycotic drug clotrimazole. J Clin Pathol. 1972 Dec;25(12):1089–1097. doi: 10.1136/jcp.25.12.1089. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Holt R. J., Newman R. L. The antimycotic activity of 5-fluorocytosine. J Clin Pathol. 1973 Mar;26(3):167–174. doi: 10.1136/jcp.26.3.167. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Holt R. J. Recent developments in antimycotic chemotherapy. Infection. 1974;2(2):95–107. doi: 10.1007/BF01642028. [DOI] [PubMed] [Google Scholar]
  16. Howarth W. R., Tewari R. P., Solotorovsky M. Comparative in vitro antifungal activity of amphotericin B and amphotericin B methyl ester. Antimicrob Agents Chemother. 1975 Jan;7(1):58–63. doi: 10.1128/aac.7.1.58. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Krick J. A., Remington J. S. Editoral: Treatment of fungal infections. Arch Intern Med. 1975 Feb;135(2):344–346. [PubMed] [Google Scholar]
  18. LINTON A. H. Interpreting antibiotic sensitivity tests. J Med Lab Technol. 1961 Jan;18:1–20. [PubMed] [Google Scholar]
  19. Marks M. I., Steer P., Eickhoff T. C. In vitro sensitivity of Torulopsis glabrata to amphotericin B, 5-fluorocytosine, and clotrimazole (Bay 5097). Appl Microbiol. 1971 Jul;22(1):93–95. doi: 10.1128/am.22.1.93-95.1971. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. 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]
  21. Normark S., Schönebeck J. In vitro studies of 5-fluorocytosine resistance in Candida albicans and Torulopsis glabrata. Antimicrob Agents Chemother. 1972 Sep;2(3):114–121. doi: 10.1128/aac.2.3.114. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. SEABURY J. H., DASCOMB H. E. Experience with amphotericin B for the treatment of systemic mycoses. AMA Arch Intern Med. 1958 Dec;102(6):960–976. doi: 10.1001/archinte.1958.00260230106014. [DOI] [PubMed] [Google Scholar]
  23. Schär G., Kayser F. H., Dupont M. C. Antimicrobial activity of econazole and miconazole in vitro and in experimental candidiasis and aspergillosis. Chemotherapy. 1976;22(3-4):211–220. doi: 10.1159/000221928. [DOI] [PubMed] [Google Scholar]
  24. Schönebeck J., Anséhn S. 5-Fluorocytosine resistance in candida spp. and Torulopsis glabrata. Sabouraudia. 1973 Mar;11(1):10–20. doi: 10.1080/00362177385190041. [DOI] [PubMed] [Google Scholar]
  25. Shadomy S. Further in vitro studies with 5-fluorocytosine. Infect Immun. 1970 Oct;2(4):484–488. doi: 10.1128/iai.2.4.484-488.1970. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Shadomy S. In vitro antifungal activity of clotrimazole (Bay b 5097). Infect Immun. 1971 Aug;4(2):143–148. doi: 10.1128/iai.4.2.143-148.1971. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Shadomy S. In vitro studies with 5-fluorocytosine. Appl Microbiol. 1969 Jun;17(6):871–877. doi: 10.1128/am.17.6.871-877.1969. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Shadomy S., Kirchoff C. B., Ingroff A. E. In vitro activity of 5-fluorocytosine against Candida and Torulopsis species. Antimicrob Agents Chemother. 1973 Jan;3(1):9–14. doi: 10.1128/aac.3.1.9. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Shadomy S., Paxton L., Espinel-Ingroff A., Shadomy H. J. In vitro studies with miconazole and miconazole nitrate. J Antimicrob Chemother. 1977 Mar;3(2):147–152. doi: 10.1093/jac/3.2.147. [DOI] [PubMed] [Google Scholar]
  30. Toala P., Schroeder S. A., Daly A. K., Finland M. Candida at Boston City Hospital. Clinical and epidemiological characteristics and susceptibility to eight antimicrobial agents. Arch Intern Med. 1970 Dec;126(6):983–989. doi: 10.1001/archinte.126.6.983. [DOI] [PubMed] [Google Scholar]
  31. Utz C. J., Shadomy S. Antifungal activity of 5-fluorocytosine as measured by disk diffusion susceptibility testing. J Infect Dis. 1977 Jun;135(6):970–974. doi: 10.1093/infdis/135.6.970. [DOI] [PubMed] [Google Scholar]
  32. Van Cutsem J. M., Thienpont D. Miconazole, a broad-spectrum antimycotic agent with antibacterial activity. Chemotherapy. 1972;17(6):392–404. doi: 10.1159/000220875. [DOI] [PubMed] [Google Scholar]
  33. Waitz J. A., Moss E. L., Weinstein M. J. Chemotherapeutic evaluation of clotrimazole (Bay b 5097, 1 (o-chloro- - -diphenylbenzyl) imidazole). Appl Microbiol. 1971 Nov;22(5):891–898. doi: 10.1128/am.22.5.891-898.1971. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Wickerham L. J., Burton K. A. Carbon Assimilation Tests for the Classification of Yeasts. J Bacteriol. 1948 Sep;56(3):363–371. doi: 10.1128/jb.56.3.363-371.1948. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Antimicrobial Agents and Chemotherapy are provided here courtesy of American Society for Microbiology (ASM)

RESOURCES