Multilocus sequence typing analysis reveals that Cryptococcus neoformans var. neoformans is a recombinant population.

Area of Science:

• Mycology
• Genetics
• Infectious Diseases

Background:

• Cryptococcus neoformans var. neoformans (serotype D) is a significant cause of cryptococcosis, particularly cutaneous forms.
• Its genotypic diversity and population structure remain poorly understood.
• This serotype is prevalent in Europe but less common globally.

Purpose of the Study:

• To investigate the genotypic diversity of clinical and environmental Cryptococcus neoformans var. neoformans isolates.
• To explore potential correlations between genotypes, geographical origin, and clinical manifestations.
• To compare the population structure of C. neoformans var. neoformans with C. neoformans var. grubii.

Main Methods:

• Molecular typing (MLST) was performed on 83 globally collected isolates.
• Phylogenetic and network analyses were used to assess population structure.
• Isolates were sourced from diverse clinical and environmental origins across multiple continents.

Main Results:

• All investigated isolates belonged to genotype VNIV.
• Multilocus sequence typing (MLST) analysis indicated a recombinant, rather than clonal, population structure.
• No significant correlation was found between MLST genotype, geographical origin, or clinical source.
• Distinct population structures were observed between C. neoformans var. neoformans and C. neoformans var. grubii.

Conclusions:

• Cryptococcus neoformans var. neoformans exhibits a recombinant population structure, not a clonal one.
• Geographical and clinical factors do not appear to drive specific MLST genotypes within this variety.
• Significant differences exist in population structure between C. neoformans var. neoformans and C. neoformans var. grubii.