Search results for "Candida albicans."

Tribolium castaneum immune defense genes are differentially expressed in response to Bacillus thuringiensis toxins sharing common receptor molecules …

2015

In Tribolium castaneum larvae we have demonstrated by RNA interference knockdown that the Bacillus thuringiensis Cry3Ba toxin receptors Cadherin-like and Sodium solute symporter proteins are also functional receptors of the less active Cry3Aa toxin. Differences in susceptibility to B. thuringiensis infection might not only rely on toxin-receptor interaction but also on host defense mechanisms. We compared the expression of the immune related genes encoding Apolipophorin-III and two antimicrobial peptides, Defensin3 and Defensin2 after B. thuringiensis challenge. All three genes were up-regulated following Cry3Ba spore-crystal intoxication whereas only Defensins gene expression was induced u…

In vitro differentiation of murine hematopoietic progenitor cells toward the myeloid lineage occurs in response to Staphylococcus aureus and yeast sp…

2013

We have studied the effect of inactivated microbial stimuli (Candida albicans, Candida glabrata, Saccharomyces boulardii, and Staphylococcus aureus) on the in vitro differentiation of lineage negative (Lin−) hematopoietic progenitor mouse cells. Purified Lin− progenitors were co-cultured for 7 days with the stimuli, and cell differentiation was determined by flow cytometry analysis. All the stimuli assayed caused differentiation toward the myeloid lineage. S. boulardii and particularly C. glabrata were the stimuli that induced in a minor extent differentiation of Lin− cells, as the major population of differentiated cells corresponded to monocytes, whereas C. albicans and S. aureus induced …

Novel aspect of amphotericin B action: accumulation in human monocytes potentiates killing of phagocytosed Candida albicans.

1994

The influence of low doses of amphotericin B on the capacity of human monocytes to kill Candida albicans was investigated. Killing rates were quantified by a novel flow cytometric assay and were found to be 37% +/- 3% (standard error of the mean) after 3 h. Preincubation of monocytes for 6 to 20 h with low concentrations of amphotericin B (0.2 microgram/ml) resulted in a markedly augmented fungicidal capacity. Enhancement of killing was 80% +/- 11% (standard error of the mean) over that by the controls. This effect did not appear to be due to amphotericin B-dependent monocyte activation; the respiratory burst and expression of human leukocyte antigen-DR were unaltered, and no stimulation of…

In vitro anti-biofilm activity of Boswellia spp. oleogum resin essential oils

2009

Aims:  To evaluate the anti-biofilm activity of the commercially available essential oils from two Boswellia species. Methods and Results:  The susceptibility of staphylococcal and Candida albicans biofilms was determined by methyltiazotetrazolium (MTT) staining. At concentrations ranging from 217·3 μg ml−1 (25% v/v) to 6·8 μg ml−1 (0·75% v/v), the essential oil of Boswellia papyrifera showed considerable activity against both Staphylococcus epidermidis DSM 3269 and Staphylococcus aureus ATCC 29213 biofilms. The anti-microbial efficacy of this oil against S. epidermidis RP62A biofilms was also tested using live/dead staining in combination with fluorescence microscopy, and we observed that …

4-Diazopyrazole Derivatives as Potential New Antibiofilm Agents

2008

<i>Background:</i> The recognition that chronic infections and infections associated with medical devices are biofilm related has been the impulse for investigating the antibiofilm properties of some diazopyrazoles biologically active as antimicrobials. <i>Methods:</i> The susceptibility of staphylococcal biofilms was determined at concentrations ranging from 25 to 1.5 µg/ml using crystal violet and methylthiazotetrazolium (MTT) staining. In the case of <i>Candida albicans,</i> we first assessed the anti-germ tube formation effect of 4-NO<sub>2</sub> (compound 1c) and then we evaluated its antibiofilm activity at concentrations ranging from 10…

Role of IFN-gamma in immune responses to Candida albicans infections

2014

Candida albicans is the most frequent etiologic agent that causes opportunistic fungal infections called candidiasis, a disease whose systemic manifestation could prove fatal and whose incidence is increasing as a result of an expanding immunocompromised population. Here we review the role of interferon-gamma (IFN-γ) in host protection against invasive candidiasis. This cytokine plays an essential role in both the innate and adaptive arms of the immune response to candidiasis. We focus on recent progress on host-pathogen interactions leading to the production of IFN-γ by host cells. IFN-γ is produced by CD4 Th1, CD8, γδ T, and natural killer (NK) cells, essentially in response to both IL-12…

Candida albicans: to be or not to be recognized by TLR4? Response to “Both TLR2 and TLR4 are involved in the recognition of Candida albicans” by M.G.…

2006

Initial steps of wall protoplast regeneration in Candida albicans

1997

Summary Cell wall regeneration of individual Candida albicans yeast and mycelial protoplasts was studied with confocal and electron microscopy using polyclonal antibodies and leetins. Quantitative measurements of the fluorescence emitted by individual protoplasts during the process of regeneration indicate that chitin is the first polymer to be laid down, whereas β(1,3)- and β(1,6)glucan are incorporated at a later stage. Mannoproteins were found on the surface of fresh protoplasts and those newly synthesized were then deposited with time. During the first steps of wall regeneration, the proteins that interacted covalently with chitin or glucan were different, but the same species were foun…

Use of a Genetically Engineered Strain To Evaluate the Pathogenic Potential of Yeast Cell and Filamentous Forms duringCandida albicansSystemic Infect…

2007

ABSTRACTThe pathogenesis ofCandida albicanssystemic infection is complex and results from the balance between its intrinsic virulence attributes and the host immune responses. Morphogenetic transitions between yeast cell and filamentous forms are considered one of the main virulence attributes inC. albicans. We have examined the pathogenesis of a genetically engineeredC. albicansstrain in which morphogenetic conversions can be externally manipulated in immunodeficient mice; these included B-cell deficient, nude (T cell deficient), SCID (lacking both functional T and B cells), and DBA/2N (C5 deficient with impaired neutrophil activity) mice. We also tested mice severely immunosuppressed by c…

From attachment to damage: defined genes of Candida albicans mediate adhesion, invasion and damage during interaction with oral epithelial cells.

2010

Candida albicans frequently causes superficial infections by invading and damaging epithelial cells, but may also cause systemic infections by penetrating through epithelial barriers. C. albicans is an unusual pathogen because it can invade epithelial cells via two distinct mechanisms: induced endocytosis, analogous to facultative intracellular enteropathogenic bacteria, and active penetration, similar to plant pathogenic fungi. Here we investigated the molecular basis of C. albicans epithelial interactions. By systematically assessing the contributions of defined fungal pathways and factors to different stages of epithelial interactions, we provide an expansive portrait of the processes an…