In vitro susceptibility of Cryptococcus neoformans clinical isolates from Egypt to seven antifungal drugs

Abstract

The in vitro susceptibility of 29 clinical isolates of Cryptococcus neoformans to fluconazole, miconazole, itraconazole, ketoconazole, flucytosine, nystatin and amphotericin B was tested by broth and colorimetric microdilution methods. Most of the isolates showed uniform patterns of susceptibility to the used antifungal agents. Only three isolates exhibited resistance [fourfold or greater rise in the minimum inhibitory concentrations (MICs)] to the tested antifungal drugs. The MIC50 and MIC90 were 0.5-8 mg l(-1) for 5-flucytosine, 0.2-8.25 mg l(-1) for nystatin, 0.5-16 mg l(-1) for fluconazole and 0.2-12.5 mg l(-1) for miconazole. However, MIC50 and MIC90 were in narrow range for the clinical yeast isolates in both methods used and showed 0.5-1 mg l(-1) for amphotericin B and 0.016-0.25 mg l(-1) for both ketoconazole and itraconazole. The combination of fluconazole plus flucytosine showed greater synergistic and fungicidal activity compared with that of fluconazole plus amphotericin B or the use of individual drugs.

Clinical Study on the Efficacy and Safety of Intravenous Itraconazole Infusion for the Treatment of Invasive Fungal Infection in China

“…However, itraconazole has been successfully used in the primary prevention of this infection (38). In vitro tests have reported disparate results of its activity against this fungi (13,39). Nevertheless, in the present series, 3 of 5 infected patients, who mostly suffered from pulmonary infections responded.…”

Flucytosine and cryptococcosis: time to urgently address the worldwide accessibility of a 50-year-old antifungal

“…40 High-level resistance to flucytosine (MIC ≥32 mg/L) remained essentially unchanged at 1%–2% over the entire study period, 40 consistent with results from smaller studies from Spain, Egypt and South America. 41,42,44 However, interestingly, full susceptibility to flucytosine (MIC ≤4 mg/L) ranged from 35% in North America to 68% in Latin America. 40 North American isolates were considerably less susceptible to both flucytosine and fluconazole compared with other geographical regions, 40 although susceptibilities in North America isolates increased over time (for flucytosine, from 34% in 1990–1994 to 66% in 2000–2004).…”