Germ Tube Formation and Proteinase Activity of Candida albicans in Relation to Virulence for Mice

Okamoto, Kazumi; Ashimoto, Atsushi; Tanaka, Yoshinori; Hamada, Takeshi

doi:10.11150/kansenshogakuzasshi1970.67.466

Cited by 4 publications

(5 citation statements)

References 14 publications

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“…One of the key virulence determinants of Candida species is their ability to produce and secrete aspartyl proteases which digest a variety of host proteins. The virulence of these proteases has been demonstrated with animal experiments showing that the amount of protease is directly comparable with the pathogenicity of the strain (MacDonald and Odds, 1983;Kwong-Chung et al, 1985;Okamoto et al, 1993;Togni et al, 1994). Therefore, the higher rate of protease activity of C. albicans in comparison with other Candida species also suggests higher virulence.…”

Section: Virulence Factors Of Candidamentioning

confidence: 98%

Yeasts in Apical Periodontitis

Waltimo

Şen

Meurman

et al. 2003

Critical Reviews in Oral Biology & Medicine

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Microbiological reports of apical periodontitis have revealed that yeasts can be isolated from approximately 5-20% of infected root canals. They occur either in pure cultures or together with bacteria. Almost all isolated yeasts belong to the genus Candida, and the predominant species is C. albicans. Pheno- and genotypic profiles of C. albicans isolates show heterogeneity comparable with those of isolates from other oral sites. C. albicans expresses several virulence factors that are capable of infecting the dentin-pulp complex, including dentinal tubules. This causes, consequentially, an inflammatory response around the root apex, which suggests a pathogenic role for this organism in apical periodontitis. Yeasts are particularly associated with persistent root canal infections that do not respond favorably to conservative root canal therapy. This may be due to the resistance of all oral Candida species against a commonly used topical medicament, calcium hydroxide. However, other antimicrobial agents may offer alternative therapeutic approaches and improve the treatment of these persistent cases of apical periodontitis.

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Section: Virulence Factors Of Candidamentioning

confidence: 98%

Yeasts in Apical Periodontitis

Waltimo

Şen

Meurman

et al. 2003

Critical Reviews in Oral Biology & Medicine

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“…After that, at least 100 yeast cells from each well in three technical repetitions were counted using a Primo Star microscope (Zeiss, Oberkochen, Germany). The inhibition of the germ tubes was calculated using the formula of Okamoto et al [ 17 ]:

…”

Section: Methodsmentioning

confidence: 99%

2,4-Diacetylphloroglucinol Modulates Candida albicans Virulence

Stepanov

Poshvina

Vasilchenko

2022

JoF

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The dimorphic fungus Candida albicans is one of the most important opportunistic pathogens for humankind. The use of fungicides against Candida could be associated with sub-inhibitory effects, which are referred to as fungal stress responses and are undesirable for the host. In this work, we investigated the antifungal action of 2,4-diacetylphloroglucinol (2,4-DAPG) against Candida albicans ATCC 10231 with a focus on their biofilm-forming ability. We found that 2,4-DAPG was able to reduce the ability of Candida cells to form biofilms, but complete inhibition and eradication effects were not achieved. Furthermore, C. albicans cells in the adherent state were characterized by reduced susceptibility to 2,4-DAPG compared to planktonic cells. The investigation of the mechanisms that could explain the antibiofilm action of 2,4-DAPG revealed a reduction in the cell`s surface hydrophobicity and the inhibition of the yeast-to-hyphae transition. The inhibition of the Candida cells filamentation was accompanied by an increase in the expression of the NRG1 gene, which is a negative regulator of hyphal development. In addition, we microscopically visualized the treated biofilms and revealed numerous channels that were decorated with particles and localized on the hyphae. We assumed that these hyphal structures could be associated with the secretion of aspartyl proteases (Sap). The performed assessments revealed an increase in the activity of Sap, which was accompanied by an increase in the expression of the sap2 and sap4 genes. The antifungal action of 2,4-DAPG is known to be associated with affecting the permeability of cellular structures, which leads to H+ATPase malfunction and the disruption of mitochondrial respiration. The subsequent cytosol acidification and generation of ROS trigger the inhibition of Candida filamentation and activation of Sap production. The introduction of antioxidant Trolox simultaneously with 2,4-DAPG leads to a reduction in Sap production. Collectively, the obtained data indicate new aspects of the interaction of fungal cells with 2,4-DAPG, an antimicrobial metabolite of Pseudomonas spp.

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Section: Methodsmentioning

confidence: 99%

“…After that, at least 100 yeast cells from each well were counted with a light microscope (Primo Star, Zeiss, Germany), and germ tube inhibition was calculated by following the formula (Okamoto et al 1993 To evaluate hyphal growth of C. albicans ATCC 10231 strain on solid medium, 10 µL of inoculum suspension, adjusted to 10 6 CFU/mL was spotted on Spider agar plates containing different concentrations (from 7,5 to 120 µg/mL) of 2,4-DAPG. The plates were incubated for 4 days at 37ºC and the morphology of the fungal colony was observed using a stereomicroscope and photographed using a digital camera.…”

Section: The Effect Of 24-dapg On Germ Tube Formationmentioning

confidence: 99%

2,4-Diacetylphloroglucinol Against Candida albicans: Biofilm Formation, Aspartyl Protease Production and Ultrastructure Changes

Stepanov

Vasilchenko

2022

Preprint

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The dimorphic fungus Candida albicans is the one of the most important opportunistic pathogen of human. The use of fungicides against candida encounters sub-inhibitory effects, which are fungal stress response and undesirable for the host. In this work we investigated antifungal action of 2,4-diacetylphloroglucinol against Candida albicans ATCC 10231 with focus on they biofilm forming ability under the treatment.It was found that 2,4-DAPG reduced ability of candida cells to form biofilm, but complete inhibition or irradiation did not achieve. Moreover, Candida albicans cells in the adherent state have been characterized by reduced susceptibility to 2,4-DAPG comparing to planktonic cells.Investigation of mechanisms which could be explain the antibiofilm action of 2,4-DAPG has revealed the reduction in cell’s surface hydrophobicity and inhibition of yeast-to-hyphae transition. Biofilms formed under the sub-inhibitory concentrations of 2,4-DAPG were depleted in protein and carbohydrate content. Furthermore, we microscopically visualized the treated biofilms and have revealed numerous cannels localized on hyphae and associated with secretion of aspartyl proteases (Sap).We assumed what excretion of Sap is triggered by reactive oxygen generated upon affecting of mitochondrion respiration by 2,4-DAPG. Introducing of antioxidant Trolox simultaneously with 2,4-DAPG lead to reducing of Sap production. Thus, production of aspartyl proteases is a one of undesirable side effect of Candida albicans treatment, but using 2,4-DAPG in combination with antioxidants is the solution to overcome it.

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Germ Tube Formation and Proteinase Activity of Candida albicans in Relation to Virulence for Mice

Cited by 4 publications

References 14 publications

Yeasts in Apical Periodontitis

Yeasts in Apical Periodontitis

2,4-Diacetylphloroglucinol Modulates Candida albicans Virulence

2,4-Diacetylphloroglucinol Against Candida albicans: Biofilm Formation, Aspartyl Protease Production and Ultrastructure Changes

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