Skip to main content
Antimicrobial Agents and Chemotherapy logoLink to Antimicrobial Agents and Chemotherapy
. 1997 Mar;41(3):617–623. doi: 10.1128/aac.41.3.617

Antifungal drug susceptibilities of oral Candida dubliniensis isolates from human immunodeficiency virus (HIV)-infected and non-HIV-infected subjects and generation of stable fluconazole-resistant derivatives in vitro.

G P Moran 1, D J Sullivan 1, M C Henman 1, C E McCreary 1, B J Harrington 1, D B Shanley 1, D C Coleman 1
PMCID: PMC163761  PMID: 9056003

Abstract

Candida dubliniensis is a recently described species of Candida associated with oral candidiasis in human immunodeficiency virus (HIV)-infected individuals. Nineteen oral isolates of C. dubliniensis recovered from 10 HIV-positive and 4 HIV-negative individuals and one vaginal isolate from an additional HIV-negative subject were assessed for fluconazole susceptibility by broth microdilution (BMD), hyphal elongation assessment, and Etest. The susceptibilities of these 20 isolates to itraconazole and amphotericin B and of 10 isolates to ketoconazole were also determined by BMD only. Sixteen of the C. dubliniensis isolates were susceptible to fluconazole (MIC range, 0.125 to 1.0 microgram ml-1), and four (recovered from two AIDS patients) were fluconazole resistant (MIC range, 8 to 32 micrograms ml-1). Fluconazole susceptibility data obtained by hyphal elongation assessment correlated well with results obtained by BMD, but the corresponding Etest MIC results were one to four times higher. All of the isolates tested were found to be sensitive to itraconazole, ketoconazole, and amphotericin B. Sequential exposure of two fluconazole-sensitive (MIC, 0.5 microgram ml-1) C. dubliniensis isolates to increasing concentrations of fluconazole in agar medium resulted in the recovery of derivatives which expressed a stable fluconazole-resistant phenotype (BMD-determined MIC range, 16 to 64 micrograms ml-1), even after a minimum of 10 consecutive subcultures on drug-free medium and following prolonged storage at -70 degrees C. The clonal relationship between the parental isolates and their respective fluconazole-resistant derivatives was confirmed by genomic DNA fingerprinting and karyotype analysis. The results of this study demonstrate that C. dubliniensis is inherently susceptible to commonly used antifungal drugs, that fluconazole resistance does occur in clinical isolates, and that stable fluconazole resistance can be readily induced in vitro following exposure to the drug.

Full Text

The Full Text of this article is available as a PDF (139.8 KB).

Selected References

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

  1. Berrouane Y. F., Hollis R. J., Pfaller M. A. Strain variation among and antifungal susceptibilities of isolates of Candida krusei. J Clin Microbiol. 1996 Jul;34(7):1856–1858. doi: 10.1128/jcm.34.7.1856-1858.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Boerlin P., Boerlin-Petzold F., Durussel C., Addo M., Pagani J. L., Chave J. P., Bille J. Cluster of oral atypical Candida albicans isolates in a group of human immunodeficiency virus-positive drug users. J Clin Microbiol. 1995 May;33(5):1129–1135. doi: 10.1128/jcm.33.5.1129-1135.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Coleman D. C., Bennett D. E., Sullivan D. J., Gallagher P. J., Henman M. C., Shanley D. B., Russell R. J. Oral Candida in HIV infection and AIDS: new perspectives/new approaches. Crit Rev Microbiol. 1993;19(2):61–82. doi: 10.3109/10408419309113523. [DOI] [PubMed] [Google Scholar]
  4. Colombo A. L., Barchiesi F., McGough D. A., Rinaldi M. G. Comparison of Etest and National Committee for Clinical Laboratory Standards broth macrodilution method for azole antifungal susceptibility testing. J Clin Microbiol. 1995 Mar;33(3):535–540. doi: 10.1128/jcm.33.3.535-540.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Fisher-Hoch S. P., Hutwagner L. Opportunistic candidiasis: an epidemic of the 1980s. Clin Infect Dis. 1995 Oct;21(4):897–904. doi: 10.1093/clinids/21.4.897. [DOI] [PubMed] [Google Scholar]
  6. Galgiani J. N., Stevens D. A. Antimicrobial susceptibility testing of yeasts: a turbidimetric technique independent of inoculum size. Antimicrob Agents Chemother. 1976 Oct;10(4):721–728. doi: 10.1128/aac.10.4.721. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Gallagher P. J., Bennett D. E., Henman M. C., Russell R. J., Flint S. R., Shanley D. B., Coleman D. C. Reduced azole susceptibility of oral isolates of Candida albicans from HIV-positive patients and a derivative exhibiting colony morphology variation. J Gen Microbiol. 1992 Sep;138(9):1901–1911. doi: 10.1099/00221287-138-9-1901. [DOI] [PubMed] [Google Scholar]
  8. Hazen K. C. New and emerging yeast pathogens. Clin Microbiol Rev. 1995 Oct;8(4):462–478. doi: 10.1128/cmr.8.4.462. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Johnson E. M., Warnock D. W. Azole drug resistance in yeasts. J Antimicrob Chemother. 1995 Nov;36(5):751–755. doi: 10.1093/jac/36.5.751. [DOI] [PubMed] [Google Scholar]
  10. Lockhart S. R., Fritch J. J., Meier A. S., Schröppel K., Srikantha T., Galask R., Soll D. R. Colonizing populations of Candida albicans are clonal in origin but undergo microevolution through C1 fragment reorganization as demonstrated by DNA fingerprinting and C1 sequencing. J Clin Microbiol. 1995 Jun;33(6):1501–1509. doi: 10.1128/jcm.33.6.1501-1509.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. McCullough M. J., Ross B. C., Dwyer B. D., Reade P. C. Genotype and phenotype of oral Candida albicans from patients infected with the human immunodeficiency virus. Microbiology. 1994 May;140(Pt 5):1195–1202. doi: 10.1099/13500872-140-5-1195. [DOI] [PubMed] [Google Scholar]
  12. McCullough M., Ross B., Reade P. Characterization of genetically distinct subgroup of Candida albicans strains isolated from oral cavities of patients infected with human immunodeficiency virus. J Clin Microbiol. 1995 Mar;33(3):696–700. doi: 10.1128/jcm.33.3.696-700.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Pfaller M. A. Epidemiology and control of fungal infections. Clin Infect Dis. 1994 Aug;19 (Suppl 1):S8–13. doi: 10.1093/clinids/19.supplement_1.s8. [DOI] [PubMed] [Google Scholar]
  14. Pfaller M. A. Nosocomial candidiasis: emerging species, reservoirs, and modes of transmission. Clin Infect Dis. 1996 May;22 (Suppl 2):S89–S94. doi: 10.1093/clinids/22.supplement_2.s89. [DOI] [PubMed] [Google Scholar]
  15. Pfaller M., Wenzel R. Impact of the changing epidemiology of fungal infections in the 1990s. Eur J Clin Microbiol Infect Dis. 1992 Apr;11(4):287–291. doi: 10.1007/BF01962067. [DOI] [PubMed] [Google Scholar]
  16. Rex J. H., Cooper C. R., Jr, Merz W. G., Galgiani J. N., Anaissie E. J. Detection of amphotericin B-resistant Candida isolates in a broth-based system. Antimicrob Agents Chemother. 1995 Apr;39(4):906–909. doi: 10.1128/aac.39.4.906. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Rodriguez-Tudela J. L., Martinez-Suárez J. V. Defining conditions for microbroth antifungal susceptibility tests: influence of RPMI and RPMI-2% glucose on the selection of endpoint criteria. J Antimicrob Chemother. 1995 Jun;35(6):739–749. doi: 10.1093/jac/35.6.739. [DOI] [PubMed] [Google Scholar]
  18. Sanglard D., Kuchler K., Ischer F., Pagani J. L., Monod M., Bille J. Mechanisms of resistance to azole antifungal agents in Candida albicans isolates from AIDS patients involve specific multidrug transporters. Antimicrob Agents Chemother. 1995 Nov;39(11):2378–2386. doi: 10.1128/aac.39.11.2378. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Scherer S., Stevens D. A. A Candida albicans dispersed, repeated gene family and its epidemiologic applications. Proc Natl Acad Sci U S A. 1988 Mar;85(5):1452–1456. doi: 10.1073/pnas.85.5.1452. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Sullivan D. J., Henman M. C., Moran G. P., O'Neill L. C., Bennett D. E., Shanley D. B., Coleman D. C. Molecular genetic approaches to identification, epidemiology and taxonomy of non-albicans Candida species. J Med Microbiol. 1996 Jun;44(6):399–408. doi: 10.1099/00222615-44-6-399. [DOI] [PubMed] [Google Scholar]
  21. Sullivan D. J., Westerneng T. J., Haynes K. A., Bennett D. E., Coleman D. C. Candida dubliniensis sp. nov.: phenotypic and molecular characterization of a novel species associated with oral candidosis in HIV-infected individuals. Microbiology. 1995 Jul;141(Pt 7):1507–1521. doi: 10.1099/13500872-141-7-1507. [DOI] [PubMed] [Google Scholar]
  22. Sullivan D., Bennett D., Henman M., Harwood P., Flint S., Mulcahy F., Shanley D., Coleman D. Oligonucleotide fingerprinting of isolates of Candida species other than C. albicans and of atypical Candida species from human immunodeficiency virus-positive and AIDS patients. J Clin Microbiol. 1993 Aug;31(8):2124–2133. doi: 10.1128/jcm.31.8.2124-2133.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Sullivan D., Haynes K., Moran G., Shanley D., Coleman D. Persistence, replacement, and microevolution of Cryptococcus neoformans strains in recurrent meningitis in AIDS patients. J Clin Microbiol. 1996 Jul;34(7):1739–1744. doi: 10.1128/jcm.34.7.1739-1744.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Valentin A., Le Guennec R., Rodriguez E., Reynes J., Mallie M., Bastide J. M. Comparative resistance of Candida albicans clinical isolates to fluconazole and itraconazole in vitro and in vivo in a murine model. Antimicrob Agents Chemother. 1996 Jun;40(6):1342–1345. doi: 10.1128/aac.40.6.1342. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Vanden Bossche H., Marichal P., Gorrens J., Bellens D., Moereels H., Janssen P. A. Mutation in cytochrome P-450-dependent 14 alpha-demethylase results in decreased affinity for azole antifungals. Biochem Soc Trans. 1990 Feb;18(1):56–59. doi: 10.1042/bst0180056. [DOI] [PubMed] [Google Scholar]
  26. Vanden Bossche H., Marichal P., Odds F. C. Molecular mechanisms of drug resistance in fungi. Trends Microbiol. 1994 Oct;2(10):393–400. doi: 10.1016/0966-842x(94)90618-1. [DOI] [PubMed] [Google Scholar]
  27. Vazquez J. A., Beckley A., Sobel J. D., Zervos M. J. Comparison of restriction enzyme analysis and pulsed-field gradient gel electrophoresis as typing systems for Candida albicans. J Clin Microbiol. 1991 May;29(5):962–967. doi: 10.1128/jcm.29.5.962-967.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Warnock D. W. Azole drug resistance in Candida species. J Med Microbiol. 1992 Oct;37(4):225–226. doi: 10.1099/00222615-37-4-225. [DOI] [PubMed] [Google Scholar]

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

RESOURCES