search
for
 About Bioline  All Journals  Testimonials  Membership  News  Donations


Memórias do Instituto Oswaldo Cruz
Fundação Oswaldo Cruz, Fiocruz
ISSN: 1678-8060
EISSN: 1678-8060
Vol. 105, No. 8, 2010, pp. 993-1000
Bioline Code: oc10171
Full paper language: English
Document type: Research Article
Document available free of charge

Memórias do Instituto Oswaldo Cruz, Vol. 105, No. 8, 2010, pp. 993-1000

 en Cryptococcus neoformans check for this species in other resources var. grubii - Pathogenicity of environmental isolates correlated to virulence factors, susceptibility to fluconazole and molecular profile
Pedroso, Reginaldo S.; Lavrador, Marco A. S.; Ferreira, Joseane C.; Candido, Regina C. & Maffei, Claudia M. L.

Abstract

The pathogenicity of Cryptococcus neoformans check for this species in other resources is heterogeneous and is associated with the expression of viru- lence factors. This study aimed to correlate the pathogenicity of C. neoformans var. grubii in BALB/c mice with in vitro virulence factors, fluconazole minimal inhibitory concentrations (MICs) and molecular profiles, before and after animal passage. Ten environmental isolates and one ATCC strain of C. neoformans var. grubii mating type α were evaluated. Most isolates (91%) killed 50% or more of the infected animals by day 24 postinfection and were recovered from the lungs and brains of surviving animals on days 7 and 14 postinfection. The burden of yeast in the lungs was more variable than that in the brain. The differences in the expression of virulence factors (growth at 37º C, presence and size of the capsule and production of melanin, urease, proteinase and phospholipase) by most isolates pre and postpassage in animals were not statistically significant. The fluconazole MICs in postpassaged lines differed by a one-dilution from the MIC of the corresponding prepassaged line for six isolates. Using molecular typing [polymerase chain reaction-fingerprinting with (GACA)4 and M13], eight isolates were identified as VNI and three as VNII. We concluded that different isolates with the same molecular and phenotypic profiles, including isolates that are markedly hypervirulent, span a wide range of virulence and there were no changes in virulence factors in the postpassaged lines when compared with the corresponding nonpassaged lines.

Keywords
Cryptococcus neoformans - virulence factors - pathogenicity - molecular typing

 
© Copyright © 2010 - Instituto Oswaldo Cruz - Fiocruz
Alternative site location: http://memorias.ioc.fiocruz.br

Home Faq Resources Email Bioline
© Bioline International, 1989 - 2017, Site last up-dated on 16-Oct-2017.
Site created and maintained by the Reference Center on Environmental Information, CRIA, Brazil
System hosted by the Internet Data Center of Rede Nacional de Ensino e Pesquisa, RNP, Brazil