Background. The incidence of cryptococcosis has increased over the past 30 years as the result of the AIDS pandemia and immunossuppresive treatments. It has been reported the presence of resistant strains in vitro to antifungal drugs. The proposed correlation between minimum inhibitory concentration (MIC) of the isolated C. neoformans strains and the clinical course is still controversial. The aim of this study was to determine the correlation between the MICs of fluconazole and amphotericin B for C. neoformans and the clinical course of cryptococcal meningitis in AIDS patients.
Methods. We performed a prospective study between 2009 y 2010 in the Infectious Diseases Hospital (Montevideo,Uruguay) that enrolled 33 patients that met the inclusion criteria (adults, HIV positive, cryptococcalmeningitis confirmed by isolation of the strain of cerebroespinal fluid). The study was approved by theethics committee of the participating institution.The identification of the strains was performed by phenotipic studies. All of isolates belongued to C.neoformans var neoformans. Susceptibility to fluconazol and amphotericin B determined by the CLSI brothmicrodilution metodology.
Results. Sample characteristics: of the 33 patients 21 were male, all had CD4‚Č§200/mm3, 9 had biochemical andcytological study of cerebrospinal fluid tests. 24 wrere already had a diagnose of AIDS and were noreceiving HAART. 4 patients died during hospitalization for reasons related to cryptococcal meningitis.
The study of antifungal susceptibility showed MICs of o, 25 - 4ŌÖg /ml to fluconazole and 0,03-0,5ug/ml in the amphotericin B. Therefore, no strain showed in vitro resistance to any of the antifungal agent tested and futhermore, no established relation between MICs and clinical outcome.
Conclusion. Determining the susceptibility to antifungal shows no strains of C. neoformans resistant or clinicalproblems related to resistance. No relationship was found between clinical outcome and antifungal MICsand all the strains in vitro since all strains were susceptible. Severe immune deterioration due to theabsence to HAART seems to be the most important determinant for the development of the lifethreatening cryptococcosis in this population.