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Activity of voriconazole against Candida albicans and Candida krusei isolated since 1984
1Department of Pathology, Division of Microbiology, Northwestern University Medical School, Chicago, IL 60611, USA.
Abstract:
With the recent dramatic rise in fluconazole use, there has been an increase in Candida species resistant to that agent. This has led to the clinical development of newer triazoles such as voriconazole that have greater potency and a broader spectrum of activity. We therefore hypothesized that fluconazole-resistant Candida albicans and Candida krusei would be susceptible to voriconazole. Susceptibility testing was performed on 205 isolates of C. albicans collected from 1984 to 1995, and on C. albicans and C. krusei that were identified as fluconazole resistant since 1995. The anti fungal agents used were amphotericin B, 5-flucytosine, itraconazole, ketoconazole, fluconazole and voriconazole. Three C. albicans and 26 C. krusei isolates had a minimum inhibitory concentration (MIC) >/=20 mg/l and were defined as fluconazole resistant. Of these, 28 isolates were susceptible to 2 mg/l) but all were susceptible to
Insights
Voriconazole demonstrates effectiveness against fluconazole-resistant Candida albicans and Candida krusei. This new triazole antifungal agent shows promise for treating infections caused by these drug-resistant fungal species.
Area of Science:
- Mycology
- Infectious Diseases
- Antimicrobial Resistance
Background:
- Rising fluconazole resistance in Candida species necessitates alternative antifungal treatments.
- Emergence of drug-resistant fungal infections poses a significant clinical challenge.
Purpose of the Study:
- To evaluate the in vitro susceptibility of fluconazole-resistant Candida albicans and Candida krusei to voriconazole.
- To compare voriconazole's efficacy against resistant strains with existing antifungals.
Main Methods:
- Antifungal susceptibility testing was conducted on 205 Candida albicans isolates (1984-1995) and fluconazole-resistant C. albicans and C. krusei isolates identified post-1995.
- Minimum Inhibitory Concentrations (MICs) were determined for amphotericin B, 5-flucytosine, itraconazole, ketoconazole, fluconazole, and voriconazole.
Main Results:
- Twenty-nine fluconazole-resistant isolates (3 C. albicans, 26 C. krusei) were tested against voriconazole.
- 28 of these isolates were susceptible to voriconazole (MIC ≤ 2.5 mg/l), with a mean MIC of 0.78 mg/l.
- All ten amphotericin B-resistant C. krusei strains were susceptible to voriconazole.
Conclusions:
- Voriconazole exhibits potent activity against fluconazole-resistant Candida albicans and Candida krusei.
- The higher potency of voriconazole suggests its potential utility in treating infections caused by fluconazole- and amphotericin B-resistant Candida species.