Cryptococcal meningitis in non-HIV patients in the State of Amazonas, Northern Brazil

Cryptococcosis is a life-threatening fungal infection caused by the Cryptococcus neoformans/Cryptococcus gattii species complex. Most cases are recorded in patients suffering from HIV/AIDS (human immunodeficiency virus/acquired immunodeficiency syndrome). However, this infection also occurs in non-HIV patients with a proportion of 10-30% of all cases. The study aimed at the clinical and molecular characterization of non-HIV patients diagnosed with cryptococcosis at the Tropical Medicine Foundation (FMT-HVD) from July 2016 to June 2019. Medical records of respective patients were analyzed to describe the course of cryptococcosis in non-HIV patients. In addition, multi-locus sequence typing (MLST) was applied to identify the sequence types of the isolated Cryptococcus strains, to perform phylogenetic analysis, and to evaluate the isolates' genetic relationship to global reference strains. Antifungal susceptibility profiles to amphotericin B, fluconazole, and itraconazole were assessed by broth microdilution. From a total of 7 patients, 4 were female, the age range varied between 10 and 53 years (median of 36.3 years). Cryptococcal meningitis was the common clinical manifestation (100%). The period between onset of symptoms and confirmed diagnosis ranged from 15 to 730 days (mean value of 172.9 days), and the observed mortality was 57.1%. Of note, comorbidities of the assessed cryptococcosis patients comprised hypertension, diabetes mellitus, and intestinal tuberculosis. Genotyping applying PCR-RFLP of the URA5 gene identified all clinical isolates as C. gattii genotype VGII. Using MLST, it was possible to discriminate the sequence types ST20 (n = 4), ST5 (n = 3), and the newly identified sequence type ST560 (n = 1). The antifungals amphotericin B, fluconazole, and itraconazole showed satisfactory inhibitory activity (microdilution test) against all C. gattii VGII strains.