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

Abstract

Background Cryptococcus 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. Objectives We aim to investigate the molecular diversity of C. gattii isolates from strains isolated from 1995 to the present day from different continents. Method In 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. Results Genotyping 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. Conclusions The current study reveals the genetic diversity and new sequence types among strains from the C. gattii complex species.

Global Analyses of Multi-Locus Sequence Typing Data Reveal Geographic Differentiation, Hybridization, and Recombination in the Cryptococcus gattii Species Complex

“…As reported in the original literature [ 34 , 35 , 37 , 38 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 ], each of the four CGSC lineages (VGI, VGII, VGIII, and VGIV) in the IFMLST database are broadly distributed across multiple continents. However, the four lineages showed different patterns: the VGI lineage was recorded in 30 of the 45 countries with CGSC, followed by VGII (in 25 countries), VGIII lineage (in 11 countries), and VGIV lineage (in 9 countries).…”

“…A total of 1202 isolates from 31 studies were included in our meta-analyses of population geographic structures. Protocols for DNA extraction, amplification, sequencing, and allelic profiling as well as detailed descriptions of these isolates and their genotype data can be found in the original reports [ 34 , 35 , 37 , 38 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 ].…”

Antifungal susceptibility of the clinical and environmental strains of Cryptococcus gattii sensu lato in Taiwan

“…between species have been reported, 27,[33][34][35] they were not significant because of the limited number of strains studied. 36 Our results revealed differences in the antifungal susceptibility of C. gattii s.l. between the STs were significant (Table 3).…”

Cryptococcus neoformans Causing Meningoencephalitis in Adults and a Child from Lima, Peru: Genotypic Diversity and Antifungal Susceptibility

“…Even though acquired resistance to polyenes is uncommon in C. neoformans, a reduced susceptibility to drugs such as amphotericin B, after its use to treat cryptococcal meningitis, has been reported for more than two decades [70]. In addition, amphotericin B non-wild-type isolates were recently identified in five C. gattii VGI isolates from Australia, the Democratic Republic of Congo, Malaysia, and interestingly, Peru [71]. The identification of two VNI isolates that are in addition non-wildtype for 5-flucytosine draws attention.…”