Multilocus sequence typing of strains from the Cryptococcus gattii species complex from different continents

• DOI: 10.1111/myc.13389
• Publication Date: 2021-11-02T12:18:08Z
• Authors: Virginie Bellet; Frédéric Roger; Donika Krasteva; Tiphany Gouveia; Pascal Drakulovski; Cyril Pottier; Sébastien Bertout
• Keywords: 0301 basic medicine; 0303 health sciences; 03 medical and health sciences; Genotype; Flucytosine; Humans; Cryptococcus gattii; Cryptococcosis; Mycological Typing Techniques; Fluconazole; Multilocus Sequence Typing; 3. Good health

AbstractBackgroundCryptococcus neoformans and Cryptococcus gattii species complexes are pathogens causing cryptococcal meningitis, a fungal infection that leads to death unless treated. Worldwide, it is estimated to kill over 180,000 individuals annually.ObjectivesWe aim to investigate the molecular diversity of C. gattii isolates from strains isolated from 1995 to the present day from different continents.MethodIn this study, we analysed the molecular diversity by MLST and antifungal susceptibility by using the broth microdilution method according to the CLSI M27‐A4 protocol of a total of 26 strains from Cryptococcus gattii species complex from both clinical and environmental sources.ResultsGenotyping showed that most of the strains (17/26; 65.4%) belonged to serotype B and were distributed between three genotypes: VGI (13/17; 76.5%), VGII (3/17; 17.6%) and VGVI (1/17; 5.9%). The serotype C strains (9/26; 34.6%) were distributed between the VGIII (1/9; 11.1%) and VGIV (8/9; 88.9%) genotypes. The 26 strains belonged to 17 different MLST subtypes, and we highlight four new MLST genotypes (ST553, 554, 555 and 556). The two environmental strains were identified as serotype B and genotype VGI, but were of ST 51 and 154. All isolates have wild‐type MIC of fluconazole and flucytosine. Regarding amphotericin B, five VGI strains showed MICs to AMB equal to 1 µg/ml, and according to the ECV for these genotypes, they were considered non‐wild‐type strains.ConclusionsThe current study reveals the genetic diversity and new sequence types among strains from the C. gattii complex species.