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Geographically structured populations of Cryptococcus neoformans Variety grubii in Asia correlate with HIV status and

Kantarawee Khayhan1, Ferry Hagen, Weihua Pan

  • 1Department of Microbiology and Parasitology, Faculty of Medical Sciences, University of Phayao, Phayao, Thailand ; CBS-KNAW Fungal Biodiversity Centre, Department of Yeast and Basidiomycete Research, Utrecht, The Netherlands ; Department of Internal Medicine and Infectious Diseases, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.

Plos One
|September 11, 2013
PubMed

Insights

Cryptococcosis, a fungal infection, is common in Asia, especially in HIV/AIDS patients. This study reveals limited genetic diversity in Asian Cryptococcus neoformans var. grubii, suggesting clonal reproduction and potential infection spread via immigrant workers.

Area of Science:

  • Medical Mycology
  • Population Genetics
  • Infectious Diseases

Background:

  • Cryptococcosis is a significant fungal infection in Asia, with 140,000 annual cases, predominantly in HIV/AIDS patients.
  • Cryptococcus neoformans variety grubii (serotype A) is the primary pathogen responsible for cryptococcosis in the region.

Purpose of the Study:

  • To analyze nucleotide polymorphisms and population genetics of Cryptococcus neoformans var. grubii isolates from 8 Asian countries.
  • To compare the genetic diversity and reproductive mode of the Asian population with global datasets.

Main Methods:

  • Multilocus sequence typing (MLST) using the ISHAM MLST consensus scheme was employed.
  • Analysis of 476 isolates of Cryptococcus neoformans var. grubii from diverse Asian geographical locations.

Main Results:

  • The Asian Cryptococcus neoformans var. grubii population exhibits limited genetic diversity and a predominantly clonal reproductive strategy compared to global data.
  • A correlation was identified between specific sequence types and isolates from HIV-negative patients.
  • High gene flow between Middle Eastern and Southeastern Asian populations suggests infection acquisition in Southeastern Asia by Middle Eastern immigrant workers.

Conclusions:

  • The Asian Cryptococcus neoformans var. grubii population is genetically less diverse and reproduces clonally.
  • Geographic distribution, sequence types, and HIV status are interconnected, with distinct patterns observed in HIV-negative individuals.
  • Evidence suggests that immigrant workers may contribute to the spread of cryptococcosis from Southeastern Asia to the Middle East.

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