8/10/2023 0 Comments Cryptococcus neoformans india ink![]() gattii infections in the US Pacific Northwest with more than 60 cases between 20 ( 20). Following this outbreak, since 2004, it has been observed an increasing incidence of C. A clonal predominant strain (VGIIa) could be responsible, but reasons for its dissemination remain unclear. Unlike endemic cases in Australia, infected patients presented with respiratory syndrome and seemed to have underlying conditions associated with immunosuppression. gattii emerged in British Columbia and caused an unprecedented outbreak in Vancouver island with more than 200 cases in 9 years ( 47). However, many laboratories did not differentiate routinely the two species until recently. Then an endemic focus was noted in the arboriginal community in North Australia and in Papua New Guinea since 1990 ( 45, 149, 150). Distribution of each genotype was variable between each region. gattii was initially confined to tropical and subtropical regions (Australia, Brazil, southern California, Thailand, Vietnam, Hawaii, Central Africa) with sporadic cases of meningoencephalitis among otherwise healthy individuals ( 70). gattii can be present in export trees and woody products. Some native and domestic animals are also affected ( 66).ĭistribution of C. The soil can be contaminated near from trees surroundings. Since the description of an ecological niche from Eucalyptus trees, the fungus has been isolated in more than 50 species of trees and their hollows ( 159). ![]() gattii(serotype B) was reported from Eucalyptus trees in 1990 by Ellis and Pfeiffer in Australia, it confirmed an unusually high incidence of C. isolated a different strain of Cryptococcus with unique elongated cells, which culture did not differ from typical C. gattii was recorded from a Congolese Bantu boy with meningitis in 1970 ( 48). neoformans approximately 50 million years ago ( 112). Phylogenic studies showed a divergence of C. neoformans) have been recently described in patients with cryptococcosis without known risk factors ( 24, 73). Furthermore, autoantibody against GM-CSF ( C. Some cases occur in otherwise healthy patients with possible single-gene errors of immunity in the IL-12/IFNγ axis. Use of corticosteroids or others immunosuppressive drugs are frequently reported in association with others risk factors ( 122). Other predisposing factors such as solid organ transplant are listed in Table 2( 73). Nowadays, HIV represents the major risk factor (more than 50% of cases in the Western world while in Sub-Saharan Africa cryptococcosis is almost exclusively observed in HIV-infected patients). Patients with T-cell mediated immunodeficiency are at greatest risk for cryptococcal infections. Thanks to the introduction of highly active antiretroviral therapy (HAART), the rate of cryptococcosis has declined significantly in developed countries in the past few years with an increase of cryptococcosis in HIV-negative patients ( 131). However, this infection has emerged as a major cause of mortality among persons who do not have access to HAART in developing countries. One million cases are reported each year in Sub-Saharan Africa, with more than 600 000 deaths/year in HIV-infected patients ( 123). In 1990’s, 80% of cryptococcosis occurred in patients with AIDS ( 39). With the emergence of AIDS, the yeast gained increasing medical importance. However, cryptococcosis was rare before 1980’s ( 36, 132). neoformans exposition is frequent as 80% of adults have antibodies directed against C. VGII genotype can be further divided into three subtypes: VGIIa, VGIIb, VGIIc. gattii can be divised into four genotypes: VGI, VGII, VGIII, VGIV. These species are characterized by distinct geographic distribution, host preference clinical presentation and therapeutic recommendations. C. neoformans variety grubii corresponds to serogroup A and C. neoformans variety neoformans is serogoup D ( Table 1) ( 24, 36). Two Cryptococcus species are pathogenic in humans: C. Polysaccharide capsule and melanin are virulence factors. Cryptococcus spp.is a basidiomycetous yeast.
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