Advertisement

Mycopathologia

, Volume 145, Issue 3, pp 131–135 | Cite as

Comparative Study of Agar Diffusion Test and the NCCLS Macrobroth Method for In Vitro Susceptibility Testing of Candida spp.

  • Luciana Maria Faiad Soni
  • Marcelo Nascimento Burattini
  • Antonio Carlos Campos Pignatari
  • Olga Fischman Gompertz
  • Arnaldo Lopes Colombo
Article

Abstract

We performed a prospective double-blind study to evaluate the correlation between inhibition zones obtained by a disk-diffusion test, using Neo-sensitabs of fluconazole (Rosco Diagnostica), and the MICs generated by the NCCLS macrobroth dilution assay. Eighty clinical isolates, representing 5 of the clinically relevant species of Candida, were tested simultaneously by both methods. A clear inverse correlation was found between the results obtained by both tests (r = −0.69). In addition, there was high degree of agreement between methods in the identification of susceptible isolates. However, the resistance definition by disk-diffusion test had a positive predictive value of only 17%. Our data support the hypothesis that Rosco Fluconazole Neo-sensitabs have potential as a screening test for the identification of Candida isolates susceptible to fluconazole. Resistant isolates should be further investigated by standardized broth procedures.

Candida resistance susceptibility testing 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Beck-Sagué M, Jarvis WR. Secular trends in the epidemiology of nosocomial fungal infections in the United States, 1980– 1990. J Infect Dis 1993; 167: 1247–1251.PubMedGoogle Scholar
  2. 2.
    Rex JH, Pfaller MA, Rinaldi MG, Polak A, Galgiani JN. Antifungal susceptibility testing. Clin Microbiol Rev 1993; 6: 367–381.PubMedGoogle Scholar
  3. 3.
    National Committee For Clinical Laboratory Standards. Reference Method for Broth Dilution Antifungal Susceptibility Testing of Yeasts; Approved Standard M27-A. Wayne, Pa, National Committee for Clinical Laboratory Standards. 1997; 17(9): 1–8.Google Scholar
  4. 4.
    Pfaller MA, Bale M, Buschelman B, Lancaster M, Espinel-Ingroff A, Rex JH, Rinaldi MG, Cooper CR, McGinnis MR. Quality control guidelines for National Committee for Clinical Laboratory Standards recommended broth macrodilution testing of amphotericin B, fluconazole, and flucytosine. J Clin Microbiol 1995; 33: 1104–1107.PubMedGoogle Scholar
  5. 5.
    Rex JH, Pfaller MA, Galgiani JN, Bartlett MS, Espinel-Ingroff A, Ghannoum MA, Lancaster M, Odds FC, Rinaldi MG, Walsh TJ, Barry AL. Development of interpretative breakpoints for antifungal susceptibility testing: conceptual framework and analysis of in vitro-in vivo correlation data for fluconazole, itraconazole, and Candida infections. Clin Infect Dis 1997; 24: 235–247.PubMedGoogle Scholar
  6. 6.
    Pfaller MA, Barry AL. Evaluation of a novel colorimetric broth microdilution method for antifungal susceptibility testing of yeast isolates. J Clin Microbiol 1994; 1992–1996.Google Scholar
  7. 7.
    Tiballi RN, He X, Zarins LT, Revankar SG, Kauffman CA. Use of a colorimetric system for yeast susceptibility testing. J Clin Microbiol 1995; 33: 915–917.PubMedGoogle Scholar
  8. 8.
    Colombo AL, Barchiesi F, McGough DA, Fothergill AW, Rinaldi MG. Evaluation of the Etest system versus a microtitre broth method for antifungal susceptibility testing of yeasts against fluconazole and itraconazole. J Antimicrob Chemother 995; 36: 93–100.Google Scholar
  9. 9.
    Colombo AL, Barchiesi F, McGough DA, Rinaldi MG. Comparison of Etest and National Committee for Clinical Laboratory Standards broth macrodilution method for azole antifungal susceptibility testing. J Clin Microbiol 1995; 33: 535–540.PubMedGoogle Scholar
  10. 10.
    National Committee for Clinical Laboratory Standards. Performance standards for antimicrobial disk susceptibility tests-fifth edition; Approved standard.-A5. National Committee for Clinical Laboratory Standards, Viii anova, Pa, 993.Google Scholar
  11. 11.
    Casals JB, Pringler N. Antibacterial/antifungal sensitivity testing using Neo-Sensitabs, Rosco Diagnostica, Taastrup, Denmark, 1991, 55–58.Google Scholar
  12. 12.
    Sandven P., Bjørneklett A, Maeland A. Susceptibilities of Norwegian Candida albicans strains to fluconazole: Emergence of resistance. Antimicrob Agents Chemother 1993; 37: 2443–2448.PubMedGoogle Scholar
  13. 13.
    Espinel-Ingroff A, Steele-Moore L, Galgiani JN. Evaluation of 80% inhibition standards for determination of fluconazole minimum inhibitory concentrations in three laboratories. Diagn Microbiol Infect Dis 1994; 20: 81–86.PubMedCrossRefGoogle Scholar
  14. 14.
    Barry AL, Brown SD. Fluconazole disk diffusion procedure for determining susceptibility of Candida species. J Clin Microbiol 1996; 34: 2154–2157.PubMedGoogle Scholar

Copyright information

© Kluwer Academic Publishers 1999

Authors and Affiliations

  • Luciana Maria Faiad Soni
    • 1
  • Marcelo Nascimento Burattini
    • 1
  • Antonio Carlos Campos Pignatari
    • 1
  • Olga Fischman Gompertz
    • 2
  • Arnaldo Lopes Colombo
    • 1
  1. 1.Division of Infectious DiseasesEscola Paulista de Medicina – UNIFESPSão PauloBrazil
  2. 2.Division of Cellular BiologyEscola Paulista de Medicina – UNIFESPSão PauloBrazil

Personalised recommendations