Chlamydospore formation is a characteristic of many fungal species, among them the closely related human-pathogenic dimorphic yeasts Candida albicans and C. dubliniensis. Whereas function and regulation of filamentation are well-studied in these species, the basis of chlamydospore formation is mostly unknown. Here, we investigate the contribution of environmental and genetic factors and identif...

The regulation of morphogenesis in the human fungal pathogen Candida albicans is under investigation to better understand how the switch between budding and hyphal growth is linked to virulence. Therefore, in this study we examined the ability of C. albicans to undergo a distinct type of morphogenesis to form large thick-walled chlamydospores whose role in infection is unclear, but they act as ...

Formation of chlamydospores by Candida albicans was an established medical diagnostic test to confirm candidiasis before the molecular era. However, the functional role and pathological relevance of this in vitro morphological transition to pathogenesis in vivo remain unclear. We compared the physical properties of in vitro-induced chlamydospores with those of large C. albicans cells purified b...

Clonostachys rosea is a potential biocontrol fungus that can produce highly resistant chlamydospores under specific conditions. To investigate the genes related to chlamydospore formation, we identified reliable reference genes for quantification of gene expression in C. rosea 67-1 during sporulation. In this study, nine reference genes, actin (ACT), elongation factor 1 (EF1), glyceraldehyde-3-...

Early log phase yeast cells of Candida albicans transformed into suspensor cells and chlamydospores when streaked on washed agar without added nutrients. The transformation was apparently a result of endogenous metabolism since starved yeast cells did not form chlamydospores. Addition of glucose (5 mg/ml) to washed agar completely suppressed chlamydospore formation. Size of inoculum and age of ...

A variety of analytical techniques was employed to study the composition of the chlamydospore of Candida albicans. The outer, thin, electron-transparent layer was found to be composed of glucan, together with a small amount of chitin. The inner, thick, electron-dense layer is proteinaceous. The central structure is composed largely of ribonucleic acid and lipid globules. In addition to being ac...

The ultrastructure of Phanerochaete chrysosporium hyphae from pellets in submerged liquid cultures was investigated in order to learn more about the interrelation between fungal architecture and manganese peroxidase (MnP) production. At day 2 of cultivation, some subapical regions of hyphae in the outer and middle zones of the pellet initiated differentiation into intercalary thick-walled chlam...

Candida albicans and Candida dubliniensis are pathogenic fungi that are highly related but differ in virulence and in some phenotypic traits. During in vitro growth on certain nutrient-poor media, C. albicans and C. dubliniensis are the only yeast species which are able to produce chlamydospores, large thick-walled cells of unknown function. Interestingly, only C. dubliniensis forms pseudohypha...

Isolates of Candida dubliniensis may be misidentified as Candida albicans in microbiological laboratories if only the germ tube and/or the chlamydospore test is used for identification to the species level. In this study, we have evaluated the efficacy of tobacco agar for the differentiation of C. dubliniensis from C. albicans. On this medium at 28 degrees C, all 30 C. dubliniensis isolates pro...

The formation of chlamydospores of Phytophthora parsiana, a newly described high temperature tolerant pathogen of woody plants, were investigated in culture media and in infected roots of susceptible host plants. Different solid agar media and cleared V-8 juice broth were inoculated with different isolates of P. parsiana and incubated for four days at room temperature before they were transferr...