[Determination of the minimum inhibitory concentration of fluconazole against Cryptococcus neoformans]. / Determinación de la concentración mínima inhibitoria de fluconazol frente a Cryptococcus neoformans.

The minimum inhibitory concentration of fluconozole was determined in 36 strains of Cryptococcus neoformans var. neoformans by a casitone broth microdilution method, taking into account that it is one of the most used antifungal agents in our country for the treatment of cryptococcal meningitis, the second opportunistic mycosis in order of frequency and that with the highest lethality among AIDS patients. The minimum inhibitory concentration of the studied strains ranged 0.125 to more than 64 micrograms/mL for a geometrical mean of 2.38 micrograms/mL. 50% of the strains were inhibited with 4 micrograms/mL and the least concentration that inhibited 90% was 16 micrograms/mL. It is stressed the importance of continuing this type of in vitro studies to detect the appearance of resistance of C. neoformans to antifungal agents.

[Minimum inhibitory concentration of amphotericin B in yeasts of medical interest]. / Determinación de la concentración mínima inhibitoria de anfotericina B en levaduras de interés médico.

In order to know the sensitivity of Candida and Crytococcus to amphotericin B, main drug for the treatment od systemic mycosis, it was determined the minimum inhibitory concentration (MIC) in 90 clinical isolates of Candida and Crytococcus by a micromethod for the broth dilution. According to the results, Crytococcus neoformas was more sensitive then Candida albicans (geometrical means 0.24 and 0.41 respectively). Only one resistant strain was found (CMI = 16 micrograms/mL), corresponding to the Candida krusei species. The introduction of this technique in the Mycology Laboratory of the "Pedro Kourí" Institute of Tropical Medicine will allow to establish the sensitivity patterns and to detect the possible appearance of resistance in the main species of pathogenic fungus for men in our environment.

[The identification of Cryptococcus neoformans var. neoformans in Cuban clinical isolates]. / Identificación de Cryptococcus neoformans var. neoformans en aislamientos clínicos cubanos.

50 strains of Cryptococcus neoformans of clinical origin were studied by using the canavanine-glycine-bromothymol blue (CGB) medium. 56% of the strains were isolated from AIDS patients, and 16% belonged to patients with kidney transplantation. 90% of the samples were obtained from the samples of cerebrospinal fluid, which corresponded to the classical form of presentation of cryptococcosis. All the strains were identified as C. neoformans var. neoformans, coinciding with previous reports made in Cuba. Knowing the varieties of C. neoformans, inferences can be drawn on the epidemiology, clinics and response to the treatment of cryptococcosis.