Candida glabrata produces a melanin-like pigment that protects against stress conditions encountered during parasitism

2021 ◽  
Author(s):  
Rodrigo Almeida-Paes ◽  
Maria HG Figueiredo-Carvalho ◽  
Leandro BR da Silva ◽  
Gary Gerfen ◽  
Glauber R de S Araújo ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Chemical Treatment ◽  
Candida Glabrata ◽  
Minimal Medium ◽  
Antifungal Resistance ◽  
Stress Conditions ◽  
Biophysical Properties ◽  
Macrophage Killing

Aim: Melanin has been linked to pathogenesis in several fungi. They often produce melanin-like pigments in the presence of L-dihydroxyphenylalanine (L-DOPA), but this is poorly studied in Candida glabrata. Methods & materials: C. glabrata was grown in minimal medium with or without L-DOPA supplementation and submitted to a chemical treatment with denaturant and hot acid. Results: C. glabrata turned black when grown in the presence of L-DOPA, whereas cells grown without L-DOPA supplementation remained white. Biophysical properties demonstrated that the pigment was melanin. Melanized C. glabrata cells were effectively protected from azoles and amphotericin B, incubation at 42°C and macrophage killing. Conclusion: In the presence of L-DOPA, C. glabrata produces melanin, increases antifungal resistance and enhances host survival.

scholarly journals Enhanced Efflux Pump Activity in OldCandida glabrataCells

2018 ◽  
Vol 62 (3) ◽  
Author(s):  
Somanon Bhattacharya ◽  
Bettina C. Fries
Keyword(s):  
Amphotericin B ◽  
Abc Transporters ◽  
Resistant Strain ◽  
Candida Glabrata ◽  
Efflux Pump ◽  
Antifungal Resistance ◽  
Replicative Aging ◽  
Glucan Synthase ◽  
Content Type ◽  
Pump Activity

ABSTRACTWe investigated the effect of replicative aging on antifungal resistance inCandida glabrata. Our studies demonstrate significantly increased transcription of ABC transporters and efflux pump activity in old versus youngC. glabratacells of a fluconazole-sensitive and -resistant strain. In addition, higher tolerance to killing by micafungin and amphotericin B was noted and is associated with higher transcription of glucan synthase geneFKS1and lower ergosterol content in older cells.

scholarly journals Antifungal Resistance Pattern of Candida Species Isolated from High Vaginal Swabs of Women Attending a Hospital in Enugu State, Nigeria

2020 ◽  
pp. 62-72
Author(s):  
Joachim Ohiakwu Ezeadila ◽  
Ikechukwu Okoli ◽  
Christie Amaechi Oyeka
Keyword(s):  
Candida Albicans ◽  
Amphotericin B ◽  
Candida Tropicalis ◽  
Candida Species ◽  
Candida Glabrata ◽  
Candida Parapsilosis ◽  
Inhibition Zone ◽  
Candida Krusei ◽  
Antifungal Resistance ◽  
Resistance Pattern

There is an increase in non-albicans Candida (NAC) vulvovaginal candidiasis which is attributed to overuse of antifungal therapy and this has led to antifungal resistance. This study was aimed at determining the antifungal resistance pattern of some clinical isolates of Candida species. Eighty-eight (88) isolates were used which included Candida tropicalis (34), Candida Parapsilosis (21), Candida albicans (20), Candida krusei (7) and Candida glabrata (6). The drugs used were Fluconazole (25µg), Ketoconazole (10µg), Voriconazole (1µg), Nystatin (100Units), Amphotericin B (20µg), Flucytosine (1µg), Clotrimazole (10µg) and Itraconazole (50µg). The susceptibility testing was carried out using the M44-A standard method for yeast disk diffusion testing. Results showed that the percentages of Candida species resistant to Fluconazole, Ketoconazole, Voriconazole, Amphotericin B, Flucytosine, Clotrimazole and Itraconazole and Nystatin were 52.3%, 61.9%, 35.2%, 19.3%, 86.4%, 34.1%,  45.5% and 44.3%,  with inhibition zone diameters ≤14mm, ≤20mm, ≤13mm, <10mm, ≤11mm, ≤11mm, ≤13mm and no inhibition zone diameter respectively. Candida krusei was the most resistant species with 100% resistance to each of Fluconazole, Ketoconazole and Flucytosine. Candida tropicalis was the species with the highest susceptibility (79.4%) to Amphotericin B followed by Candida parapsilosis with inhibition zone diameters ≥15mm. While Candida glabrata showed 100% resistance to each of Flucytosine and Itraconazole, Candida albicans showed 100% resistance to Flucytosine only. Candida glabrata was the only Candida species with 0% resistance to Amphotericin B. The drug to which most of the Candida species were susceptible was Amphotericin B followed by Voriconazole while Flucytosine was the drug with the highest resistance followed by Ketoconazole and Fluconazole. The highest number of susceptible-dose dependent Candida isolates was observed with Ketoconazole (25%), followed by Clotrimazole and Itraconazole, each recording 23.9%. Based on the findings of the present study, Voriconazole is recommended for vaginal candidiasis especially in the study area and also especially for infections caused by Fluconazole-resistant Candida species. This suggests that routine sensitivity testing is pertinent to guiding the choice of antifungal therapy. Thus, indiscriminate use of antifungal drugs should be avoided to reduce the development and spread of resistance.

scholarly journals Vacuolar proton-translocating ATPase is required for antifungal resistance and virulence of Candida glabrata

PLoS ONE ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. e0210883 ◽  
Author(s):  
Asuka Minematsu ◽  
Taiga Miyazaki ◽  
Shintaro Shimamura ◽  
Hiroshi Nishikawa ◽  
Hironobu Nakayama ◽  
...  
Keyword(s):  
Candida Glabrata ◽  
Antifungal Resistance ◽  
Proton Translocating Atpase

scholarly journals Posaconazole Activity against Candida glabrata after Exposure to Caspofungin or Amphotericin B

2007 ◽  
Vol 52 (2) ◽  
pp. 513-517 ◽  
Author(s):  
Elisabetta Spreghini ◽  
Carmelo Massimo Maida ◽  
Maria Eleonora Milici ◽  
Giorgio Scalise ◽  
Francesco Barchiesi
Keyword(s):  
Cell Viability ◽  
Amphotericin B ◽  
Experimental Model ◽  
Induction Therapy ◽  
Candida Glabrata ◽  
Sequential Therapy ◽  
Yeast Cells ◽  
Fungal Burden ◽  
Therapeutic Advantage ◽  
Broth Dilution

ABSTRACT We evaluated the effects of sequential therapy with caspofungin (CAS) or amphotericin B (AMB) followed by posaconazole (POS) against Candida glabrata. The susceptibilities to POS of yeast cells pre-exposed to CAS or AMB were identical to those of untreated cells as shown by standard Clinical and Laboratory Standards Institute broth dilution, cell viability, and disk diffusion methods. We then investigated the activity of sequential regimens in an experimental model of disseminated candidiasis. CAS given at 1 mg/kg/day for 2 days followed by POS at either 15 or 30 mg/kg/day significantly reduced the counts compared to the controls, but this treatment was not superior to the use of CAS alone. Also, sequential regimens with AMB given at 1 mg/kg/day for 2 days followed by POS (AMB/POS) were effective at reducing the fungal burden against the controls. In addition, AMB/POS with both doses of the triazole were significantly more effective than AMB alone. Overall, our data showed that there is no therapeutic advantage in using CAS followed by POS, whereas an induction therapy with AMB followed by a maintenance regimen with POS might be a suitable strategy in managing C. glabrata infections.

Effect of antifungals on itraconazole resistant Candida glabrata

2010 ◽  
Vol 5 (3) ◽  
pp. 318-323 ◽  
Author(s):  
Soňa Kucharíková ◽  
Patrick Dijck ◽  
Magdaléna Lisalová ◽  
Helena Bujdáková
Keyword(s):  
Amphotericin B ◽  
Biofilm Formation ◽  
Candida Glabrata ◽  
Antifungal Agents ◽  
Inhibitory Concentration ◽  
Clinical Isolates ◽  
Azole Resistance ◽  
Low Concentrations ◽  
Reduction Assay ◽  
Very High

AbstractIn the last decade, infections caused by Candida glabrata have become more serious, particularly due to its decreased susceptibility to azole derivatives and its ability to form biofilm. Here we studied the resistance profile of 42 C. glabrata clinical isolates to different azoles, amphotericin B and echinocandins. This work was also focused on the ability to form biofilm which plays a role in the development of antifungal resistance. The minimal inhibitory concentration testing to antifungal agents was performed according to the CLSI (Clinical and Laboratory Standards Institute) M27-A3 protocol. Quantification of biofilm was done by XTT reduction assay. All C. glabrata clinical isolates were resistant to itraconazole and sixteen also showed resistance to fluconazole. All isolates remained susceptible to voriconazole. Amphotericin B was efficient in a concentration range of 0.125–1 mg/L. The most effective antifungal agents were micafungin and caspofungin with the MIC100 values of ≤0.0313–0.125 mg/L. Low concentrations of these agents reduced biofilm formation as well. Our results show that resistance of different C. glabrata strains is azole specific and therefore a single azole resistance cannot be assumed to indicate general azole resistance. Echinocandins proved to have very high efficacy against clinical C. glabrata strains including those with ability to form biofilm.

scholarly journals Activities of Flucytosine, Fluconazole, Amphotericin B, and Micafungin in a Murine Model of Disseminated Infection by Candida glabrata

2005 ◽  
Vol 49 (11) ◽  
pp. 4757-4759 ◽  
Author(s):  
Marçal Mariné ◽  
Carolina Serena ◽  
Belkys Fernández-Torres ◽  
F. Javier Pastor ◽  
Josep Guarro
Keyword(s):  
Amphotericin B ◽  
Murine Model ◽  
Candida Glabrata ◽  
Disseminated Infection ◽  
Tissue Burden

ABSTRACT We compared the efficacies of amphotericin B, fluconazole, flucytosine, and micafungin in a systemic murine infection by three isolates of Candida glabrata. Amphotericin B showed the best results, although none of the drugs dramatically reduced mortality or tissue burden in liver or spleen.

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