(B and C) Capsule thickness (B) and yeast cell diameter (C) of 50 individual cells from eight randomly selected clinical isolates grown in CIM-20 versus DMEM broth
(B and C) Capsule thickness (B) and yeast cell diameter (C) of 50 individual cells from eight randomly selected clinical isolates grown in CIM-20 versus DMEM broth. DMEM induced occasional irregular, elongated cells in some strains. Scale bars = 30 m. Download FIG?S1, TIF file, 11.9 MB. Copyright ? 2018 Fernandes et al. This content is distributed under the terms of the Creative Commons Attribution 4.0 International license. TABLE?S2. Statistical significance for all those associations tested in this study. Download Table?S2, XLSX file, 0.1 MB. Copyright ? 2018 Fernandes et al. This content is distributed under the terms of the Creative Commons Attribution 4.0 International license. ABSTRACT Pathogenic species of cause hundreds of thousands of deaths annually. Considerable phenotypic variation is usually exhibited during contamination, including increased capsule size, Galactose 1-phosphate Potassium salt capsule shedding, giant cells (15?m), and micro cells (1?m). We examined 70 clinical isolates of and from HIV/AIDS patients in Botswana to determine whether the capacity to produce morphological variants was associated with clinical Galactose 1-phosphate Potassium salt parameters. Isolates were cultured under conditions designed to simulate stresses. Substantial variance was seen across morphological and clinical data. Giant cells were more common in while micro cells and shed capsule occurred in only. Phenotypic variables fell into two groups associated with differing symptoms. The production of large phenotypes (greater cell and capsule size and giant cells) was associated with higher CD4 count and was negatively correlated with intracranial pressure indicators, suggesting that these are induced in early stage contamination. Small phenotypes (micro cells and shed capsule) were associated with lower CD4 counts, negatively correlated with meningeal inflammation indicators, and positively correlated with intracranial pressure indicators, suggesting that they are produced later during contamination and may contribute to immune suppression and promote proliferation and dissemination. These styles persisted at the species level, indicating that they were not driven by association with particular species. Isolates possessing giant cells, micro cells, and shed capsule were rare, but strikingly, they were associated with patient death (contamination. species, is currently ranked as one of the three most common life-threatening opportunistic infections in individuals with HIV/AIDS worldwide (1, 2). The health burden is particularly high in the developing world, and it is difficult to resolve despite current best antifungal therapy (2, 3). Of annual cryptococcus-related deaths, 75% occur in sub-Saharan Africa where cryptococcal disease presents in 15 to 30% of HIV/AIDS patients and is associated with 70% mortality at 3?months (4, 5). neoformansis the major cause of disease in immunocompromised individuals, while species in the gattiicomplex tend to infect immunocompetent individuals (6). However, complex species are progressively being recognized in HIV/AIDS patients, particularly and yeast cells generally possess a thick capsule that Galactose 1-phosphate Potassium salt is considered the major virulence factor, although this can be thin or even absent in clinical samples (11). The capsule protects the cell from phagocytosis and from reactive oxygen species damage (12, 13). Shed extracellular capsule is usually thought to impair the host immune response, leading to macrophage dysfunction and cell death (14). Capsule size varies greatly among strains and dramatically increases in response to environmental stresses, including host contamination (15). Cryptococcal cells can also change in size during contamination (16), and various studies have emphasized the plasticity of the cryptococcal genome (17,C20). Individual strains can give rise to variant populations, including giant cells with cell body larger than 15?m and micro cells with cell body smaller than 1?m in diameter (21, 22). These phenotypes are frequently observed and are likely to be important in human contamination (21, 23,C25). Capsule and cell size, and the production of variants, can be experimentally modulated by simulating host-specific conditions and differ between species (26). Here, we examine capsule and cell size variance in a collection of clinical isolates taken from HIV patients in Botswana, comprising 53?isolates across four molecular genotypes (VNI, Mouse monoclonal to EGF VNII, VNBI, and VNBII), 16?(VGIV) isolates, and a single (VGI) isolate. We present significant correlations between species, phenotype, and clinical end result, explore phenotypic differences between and that might reflect their differing pathogenesis, and show that the capacity for variance may be associated with higher virulence. RESULTS Botswanan clinical isolates have high levels of genetic diversity. Multilocus Galactose 1-phosphate Potassium salt sequence typing (MLST) analysis divided the 70 isolates into different major species and genotypes. The collection comprised 53?isolates, including genotypes VNI (= 17; 24.3%), VNII (= 2; 2.9%), VNBI (= 25; 35.7%), and VNBII (= 9; 12.9%), 17?species complex isolates, including (= 1; 1.4%), and (= 16; 22.9%). For simplicity, we have excluded the single isolate from statistical analysis. Across the collection there were 16 allele types (ATs), 12 ATs, 16 ATs, 16 ATs, 14 ATs, 21 ATs, and.