Susceptibility testing

The following sensitivity tests are routinely performed by the Regional Mycology Centre:

Yeasts

Fluconazole                          Itraconazole            Caspofungin
Amphotericin B                    Voriconazole            Flucytosine

Other drugs including micafungin and posaconazole are available upon request.

Synergy testing of 2 antifungal drugs, by the checkerboard technique, can also be performed on request.

Moulds

Itraconazole                    Amphotericin B      
Voriconazole                    Posaconazole

Other drugs including Micafungin and Caspofungin available upon request.

Susceptibility testing is recommended for:

• All life threatening fungal infections, to ensure that the optimal therapy is administered.
• Isolates from patients at increased risk of fungal infection, such as those infected with HIV, immunosuppressed or on ICU, so that appropriate antifungal therapy can be given.
• Mucosal candidiasis not responding to therapy.
• Clinically significant non-Candida albicans species due to increasing incidences of both infection and fluconazole resistance*.
• Rare pathogens because of an increased incidence of resistance and unpredictability of resistance patterns.

* Analysis shows that 21% of Candida spp. (n=841) we received in our laboratory during 2003/4, had an intermediate or resistant fluconazole MIC result. 2% of C. albicans and 19% C. tropicalis showed reduced susceptibility.