MOLECULAR SUBTYPES AND ANTIFUNGAL SUSCEPTIBILITIES OF SERIAL CRYPTOCOCCUS-NEOFORMANS ISOLATES IN HUMAN-IMMUNODEFICIENCY-VIRUS - ASSOCIATED CRYPTOCOCCOSIS

Serial isolates of Cryptococcus neofonnans from 33 human immunodeficie ncy virus-infected patients with cryptococcosis were analyzed to deter mine whether persistence might result from reinfection with a new cryp tococcal strain or acquisition of antifungal resistance, Isolates were subtyped by multilocus enzyme electrophoresis (MEE), electrophoretic karyotyping (EK), random-amplified polymorphic DNA (RAPD), and the CNR E-1 DNA probe, MICs of amphotericin B, fluconazole, and 5-fluorocytosi ne were determined, No changes in MEE or RAPD subtypes were detected i n serial isolates from any patient, Isolates from 8 patients (24%) sho wed alterations in EK only (mobility change in two or more bands) but not with any other subtyping method, MICs did not change significantly in isolates from 30 patients, In 1 case, the fluconazole MIC increase d stepwise over 18 months, suggesting development of resistance, These overall invariant subtyping and MIC results confirm previous studies suggesting that persistent cryptococcal infection is due to relapse ra ther than reinfection or antifungal drug resistance.