In vitro susceptibility of Malassezia furfur to antifungal compounds from HIV-positive and negative patients

Abstract

Malassezia is a genus of lipophilic and lipid-dependent yeast. Despite being part of skin microbiota, it can produce local and systemic opportunistic infections. Azole and amphotericin B antifungals are the main treatment to eradicate the disease. Given the difficulty for in vitro growth, no susceptibility tests are standardized; therefore, little is known about antifungal susceptibility patterns. Although Human Immunodeficiency Virus (HIV) seropositive patients have a higher concentration of Malassezia yeasts in the skin, no difference in antifungal resistance patterns has been sought compared to the seronegative population. Therefore, we compared susceptibility patterns in 20 isolates of Malassezia furfur in HIV-positive and negative populations, comparing the Epsilon Test technique with the reference method Broth Microdilution Test. Isolates showed a high Minimum Inhibitory Concentration to amphotericin B, while itraconazole is the antifungal, to which all isolates are most sensitive. As for HIV status, only itraconazole showed a statistical difference between seropositive and negative. None of the antifungals proved to be compared using the techniques in the study; hence more studies need to be performed.