Geographically structured populations of Cryptococcus neoformans Variety grubii in Asia correlate with HIV status and show a clonal population structure.

Contains fulltext : 125490.pdf (publisher's version ) (Open Access)Cryptococcosis is an important fungal disease in Asia with an estimated 140,000 new infections annually the majority of which occurs in patients suffering from HIV/AIDS. Cryptococcus neoformans variety grubii (serotype A) is the major causative agent of this disease. In the present study, multilocus sequence typing (MLST) using the ISHAM MLST consensus scheme for the C. neoformans/C. gattii species complex was used to analyse nucleotide polymorphisms among 476 isolates of this pathogen obtained from 8 Asian countries. Population genetic analysis showed that the Asian C. neoformans var. grubii population shows limited genetic diversity and demonstrates a largely clonal mode of reproduction when compared with the global MLST dataset. HIV-status, sequence types and geography were found to be confounded. However, a correlation between sequence types and isolates from HIV-negative patients was observed among the Asian isolates. Observations of high gene flow between the Middle Eastern and the Southeastern Asian populations suggest that immigrant workers in the Middle East were originally infected in Southeastern Asia

Consensus multi-locus sequence typing scheme for Cryptococcus neoformans and Cryptococcus gattii

This communication describes the consensus multi-locus typing scheme established by the Cryptococcal Working Group I (Genotyping of Cryptococcus neoformans and C. gattii) of the International Society for Human and Animal Mycology (ISHAM) using seven unlinked genetic loci for global strain genotyping. These genetic loci include the housekeeping genes CAP59,GPD1, LAC1, PLB1, SOD1, URA5 and the IGS1 region. Allele and sequence type information are accessible at http://www.mlst.net/