High-frequency switching of colony morphology in Candida albicans

Science ◽  
1985 ◽  
Vol 230 (4726) ◽  
pp. 666-669 ◽  
Author(s):  
B Slutsky ◽  
J Buffo ◽  
D. Soll
Keyword(s):  
Candida Albicans ◽  
High Frequency ◽  
Colony Morphology

Ultrastructural Changes of Candida albicans Species Induced by the Presence of Sodium Diclofenac

2017 ◽  
Vol 68 (11) ◽  
pp. 2566-2569 ◽  
Author(s):  
Elena Rusu ◽  
Ionela Sarbu ◽  
Magdalena Mitache ◽  
Horatiu Moldovan ◽  
Carmen Ioana Biris ◽  
...  
Keyword(s):  
Candida Albicans ◽  
High Frequency ◽  
Fungal Infections ◽  
Diagnostic Methods ◽  
Ultrastructural Changes ◽  
Frequency Of Occurrence ◽  
Medical Treatments ◽  
Sodium Diclofenac ◽  
Cell Wall Disruption ◽  
Candidiasis Treatment

The high frequency of occurrence of candidiasis as well as high mortality of patients with immunosuppression cause a tendency toward better understanding of Candida albicans species virulence factors and developing sensitive and specific diagnostic methods, and appropriate strategies of candidiasis treatment. In recent decades the incidence of fungal infections has alarming increases because of advanced medical treatments. In this study was analyzed possible ultrastructural changes of the species C. albicans cells following treatment with sodium diclofenac at various concentrations. Following treatment of C. albicans cells with sodium diclofenac 1 mM and 2 mM changes in the plasmalemma can be noticed, changes in the density of cell wall, disruption and necrotic appearance of the cytoplasm.

Farnesol restores wild-type colony morphology to 96% of Candida albicans colony morphology variants recovered following treatment with mutagens

Genome ◽  
2006 ◽  
Vol 49 (4) ◽  
pp. 346-353 ◽  
Author(s):  
Ellen C Jensen ◽  
Jacob M Hornby ◽  
Nicole E Pagliaccetti ◽  
Chuleeon M Wolter ◽  
Kenneth W Nickerson ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Quorum Sensing ◽  
Environmental Conditions ◽  
Budding Yeast ◽  
Colony Morphology ◽  
Morphological Transition ◽  
Strongly Correlated ◽  
Wild Type ◽  
Hyphal Morphology

Candida albicans is a diploid fungus that undergoes a morphological transition between budding yeast, hyphal, and pseudohyphal forms. The morphological transition is strongly correlated with virulence and is regulated in part by quorum sensing. Candida albicans produces and secretes farnesol that regulates the yeast to mycelia morphological transition. Mutants that fail to synthesize or respond to farnesol could be locked in the filamentous mode. To test this hypothesis, a collection of C. albicans mutants were isolated that have altered colony morphologies indicative of the presence of hyphal cells under environmental conditions where C. albicans normally grows only as yeasts. All mutants were characterized for their ability to respond to farnesol. Of these, 95.9% fully or partially reverted to wild-type morphology on yeast malt (YM) agar plates supplemented with farnesol. All mutants that respond to farnesol regained their hyphal morphology when restreaked on YM plates without farnesol. The observation that farnesol remedial mutants are so common (95.9%) relative to mutants that fail to respond to farnesol (4.1%) suggests that farnesol activates and (or) induces a pathway that can override many of the morphogenesis defects in these mutants. Additionally, 9 mutants chosen at random were screened for farnesol production. Two mutants failed to produce detectable levels of farnesol.Key words: farnesol-remedial mutants, farnesol-sensing mutants, farnesol-synthesis mutants, quorum sensing, Candida albicans, morphological transition.

scholarly journals ACandida albicansCRISPR system permits genetic engineering of essential genes and gene families

2015 ◽  
Vol 1 (3) ◽  
pp. e1500248 ◽  
Author(s):  
Valmik K. Vyas ◽  
M. Inmaculada Barrasa ◽  
Gerald R. Fink
Keyword(s):  
Candida Albicans ◽  
Genetic Engineering ◽  
High Frequency ◽  
Target Genes ◽  
Gene Families ◽  
Induced Mutations ◽  
Pathogenic Yeast ◽  
Crispr System ◽  
Gene Knockouts ◽  
Major Impediment

Candida albicansis a pathogenic yeast that causes mucosal and systematic infections with high mortality. The absence of facile molecular genetics has been a major impediment to analysis of pathogenesis. The lack of meiosis coupled with the absence of plasmids makes genetic engineering cumbersome, especially for essential functions and gene families. We describe aC. albicansCRISPR system that overcomes many of the obstacles to genetic engineering in this organism. The high frequency with which CRISPR-induced mutations can be directed to target genes enables easy isolation of homozygous gene knockouts, even without selection. Moreover, the system permits the creation of strains with mutations in multiple genes, gene families, and genes that encode essential functions. This CRISPR system is also effective in a fresh clinical isolate of undetermined ploidy. Our method transforms the ability to manipulate the genome ofCandidaand provides a new window into the biology of this pathogen.

scholarly journals High-Frequency Rugose Exopolysaccharide Production by Vibrio cholerae

2002 ◽  
Vol 68 (11) ◽  
pp. 5773-5778 ◽  
Author(s):  
Afsar Ali ◽  
Mohammed H. Rashid ◽  
David K. R. Karaolis
Keyword(s):  
Vibrio Cholerae ◽  
High Frequency ◽  
Biofilm Formation ◽  
Colony Morphology ◽  
Exopolysaccharide Production ◽  
Clinical Strains ◽  
Environmental Survival ◽  
El Tor

ABSTRACT Vibrio cholerae can shift to a “rugose” phenotype, thereby producing copious exopolysaccharide (EPS), which promotes its environmental survival and persistence. We report conditions that promote high-frequency rugose EPS production (HFRP), whereby cells switch at high frequency (up to 80%) to rugose EPS production. HFRP appeared to be more common in clinical strains, as HFRP was found in 6 of 19 clinical strains (32%) (including classical, El Tor, and non-O1 strains) but in only 1 of 16 environmental strains (6%). Differences were found between strains in rugose colony morphology, conditions promoting HFRP, the frequency of rugose-to-smooth (R-S) cell reversion, and biofilm formation. We propose that rugose EPS and HFRP provide an evolutionary and adaptive advantage to specific epidemic V. cholerae strains for increased persistence in the environment.

scholarly journals High-frequency switching in Candida albicans.

1992 ◽  
Vol 5 (2) ◽  
pp. 183-203 ◽  
Author(s):  
D R Soll
Keyword(s):  
Candida Albicans ◽  
High Frequency ◽  
Molecular Mechanisms ◽  
Phenotypic Variability ◽  
Epigenetic Mechanism ◽  
Cell Phenotype ◽  
Wall Structures ◽  
Specific Antigens ◽  
Unique Cell ◽  
System Switching

Most strains of Candida albicans are capable of switching frequently and reversibly between a number of phenotypes distinguishable by colony morphology. A number of different switching systems have been defined according to the limited set of phenotypes in each switching repertoire, and each strain appears to possess a single system. Switching can affect many aspects of cellular physiology and morphology and appears to be a second level of phenotypic variability superimposed upon the bud-hypha transition. The most dramatic switching system so far identified is the "white-opaque transition." This system dramatizes the extraordinary effects switching can have on the budding cell phenotype, including the synthesis of opaque-specific antigens, the expression of white-specific and opaque-specific genes, and the genesis of unique cell wall structures. Switching has been demonstrated to occur at sites of infection and between episodes of recurrent vaginitis, and it may function to generate variability in commensal and infecting populations for adaptive reasons. Although the molecular mechanisms involved in the switch event are not understood, recent approaches to its elucidation are discussed and an epigenetic mechanism is proposed.

scholarly journals High-Frequency Genetic Contents Variations in Clinical Candida albicans Isolates

2011 ◽  
Vol 34 (5) ◽  
pp. 624-631 ◽  
Author(s):  
Feng Yang ◽  
Tian-Hua Yan ◽  
Elena Rustchenko ◽  
Ping-Hui Gao ◽  
Yan Wang ◽  
...  
Keyword(s):  
Candida Albicans ◽  
High Frequency

scholarly journals Development of autonomously replicating plasmids for Candida albicans.

1987 ◽  
Vol 7 (1) ◽  
pp. 209-217 ◽  
Author(s):  
M B Kurtz ◽  
M W Cortelyou ◽  
S M Miller ◽  
M Lai ◽  
D R Kirsch
Keyword(s):  
Molecular Weight ◽  
Candida Albicans ◽  
High Molecular Weight ◽  
High Frequency ◽  
Tandem Repeats ◽  
Southern Hybridization ◽  
Autonomously Replicating Sequence ◽  
Multiple Copies ◽  
Total Dna ◽  
Orthogonal Field

A pool of Candida albicans RsaI fragments cloned onto a vector containing pBR322 sequences and the Candida ADE2 gene was used to transform a Candida ade2 mutant to adenine protrophy. A potential autonomously replicating sequence (ARS) in Candida DNA was identified by two criteria: instability of the selectable marker in the absence of selection and the presence of free plasmid in total DNA preparations. Plasmids carrying the ARS transformed C. albicans at a high frequency (200 to 1,000 ADE+ transformants per microgram of DNA), and Southern hybridization analysis of these transformants indicated that multiple copies of the plasmid sequences were present and that, although they were present in high-molecular-weight molecules, these sequences had not undergone rearrangement. Orthogonal field alternation gel electrophoresis indicated that the high-molecular-weight transforming sequences were not associated with any chromosome. The simplest interpretation to account for these data is that the transforming sequences are present as oligomers consisting of head-to-tail tandem repeats. The transformed strains occasionally yield stable segregants in which the transforming sequences are integrated into the chromosome as repeats. The Candida sequence responsible for the ARS phenotype was limited to a single 0.35-kilobase RsaI fragment which is present in one copy per haploid genome.

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