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Population diversity and virulence characteristics of Cryptococcus neoformans/C. gattii species complexes isolated during the pre-HIV-pandemic era.
Pharkjaksu, Sujiraphong; Kwon-Chung, Kyung J; Bennett, John E; Ngamskulrungroj, Popchai.
Afiliación
  • Pharkjaksu S; Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok Noi, Bangkok, Thailand.
  • Kwon-Chung KJ; Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
  • Bennett JE; Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
  • Ngamskulrungroj P; Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok Noi, Bangkok, Thailand.
PLoS Negl Trop Dis ; 14(10): e0008651, 2020 10.
Article en En | MEDLINE | ID: mdl-33017391
Cryptococcosis has become a major global health problem since the advent of the HIV pandemic in 1980s. Although its molecular epidemiology is well-defined, using isolates recovered since then, no pre-HIV-pandemic era epidemiological data exist. We conducted a molecular epidemiological study using 228 isolates of the C. neoformans/C. gattii species complexes isolated before 1975. Genotypes were determined by URA5 restriction fragment length polymorphism analysis and multi-locus sequence typing. Population genetics were defined by nucleotide diversity measurements, neutrality tests, and recombination analysis. Growth at 37°C, melanin synthesis, capsule production, and urease activity as virulence factors were quantified. The pre-HIV-pandemic isolates consisted of 186 (81.5%) clinical, 35 (15.4%) environmental, and 7 (3.1%) veterinary isolates. Of those, 204 (89.5%) belonged to C. neoformans VNI (64.0%), VNII (14.9%) and VNIV (10.5%) while 24 (10.5%) belonged to C. gattii VGIII (7.5%), VGI (2.6%) and VGII (0.5%). Among the 47 sequence types (STs) identified, one of VNII and 8 of VNIV were novel. ST5/VNI (23.0%) in C. neoformans and ST75/VGIII (25.0%) in C. gattii were the most common STs in both species complexes. Among C. neoformans, VNIV had the highest genetic diversity (Hd = 0.926) and the minimum recombination events (Rm = 10), and clinical isolates had less genetic diversity (Hd = 0.866) than environmental (Hd = 0.889) and veterinary isolates (Hd = 0.900). Among C. gattii, VGI had a higher nucleotide diversity (π = 0.01436) than in VGIII (π = 0.00328). The high-virulence genotypes (ST5/VNI and VGIIIa/serotype B) did not produce higher virulence factors levels than other genotypes. Overall, high genetic variability and recombination rates were found for the pre-HIV-pandemic era among strains of the C. neoformans/C. gattii species complexes. Whole genome analysis and in vivo virulence studies would clarify the evolution of the genetic diversity and/or virulence of isolates of the C. neoformans/C. gattii species complexes during the pre- and post-HIV-pandemic eras.
Asunto(s)

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Cryptococcus neoformans / Cryptococcus gattii / Genética de Población Tipo de estudio: Prognostic_studies Límite: Animals / Humans País/Región como asunto: America do norte / Asia / Europa Idioma: En Revista: PLoS Negl Trop Dis Asunto de la revista: MEDICINA TROPICAL Año: 2020 Tipo del documento: Article País de afiliación: Tailandia Pais de publicación: Estados Unidos

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Cryptococcus neoformans / Cryptococcus gattii / Genética de Población Tipo de estudio: Prognostic_studies Límite: Animals / Humans País/Región como asunto: America do norte / Asia / Europa Idioma: En Revista: PLoS Negl Trop Dis Asunto de la revista: MEDICINA TROPICAL Año: 2020 Tipo del documento: Article País de afiliación: Tailandia Pais de publicación: Estados Unidos