scholarly journals Synergistic Antifungal Activity of Chitosan with Fluconazole against Candida albicans, Candida tropicalis, and Fluconazole-Resistant Strains

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5114
Author(s):  
Wei-Hsuan Lo ◽  
Fu-Sheng Deng ◽  
Chih-Jung Chang ◽  
Ching-Hsuan Lin
Keyword(s):  
Candida Albicans ◽  
Antifungal Activity ◽  
Candida Tropicalis ◽  
Inhibitory Effect ◽  
Antifungal Drugs ◽  
Drug Resistant ◽  
Combinational Treatment ◽  
Fluconazole Resistant ◽  
Resistant Strains ◽  
Drug Resistant Strains

(1) Background: Few antifungal drugs are currently available, and drug-resistant strains have rapidly emerged. Thus, the aim of this study is to evaluate the effectiveness of the antifungal activity from a combinational treatment of chitosan with a clinical antifungal drug on Candida albicans and Candida tropicalis. (2) Methods: Minimum inhibitory concentration (MIC) tests, checkerboard assays, and disc assays were employed to determine the inhibitory effect of chitosan with or without other antifungal drugs on C. albicans and C. tropicalis. (3) Results: Treatment with chitosan in combination with fluconazole showed a great synergistic fungicidal effect against C. albicans and C. tropicalis, but an indifferent effect on antifungal activity when challenged with chitosan-amphotericin B or chitosan-caspofungin simultaneously. Furthermore, the combination of chitosan and fluconazole was effective against drug-resistant strains. (4) Conclusions: These findings provide strong evidence that chitosan in combination with fluconazole is a promising therapy against two Candida species and its drug-resistant strains.

scholarly journals Antifungal activity of MAF-1A peptide against Candida albicans

2021 ◽  
Author(s):  
Rong Cheng ◽  
Qiang Xu ◽  
Fangfang Hu ◽  
Hongling Li ◽  
Bin Yang ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Cell Membrane ◽  
Antifungal Drugs ◽  
Drug Resistant ◽  
Fluorescent Staining ◽  
Qrt Pcr ◽  
Major Threat ◽  
Antifungal Action ◽  
Resistant Strains ◽  
Drug Resistant Strains

AbstractInvasive candidiasis is a major threat to human health, and Candida albicans is the most common pathogenic species responsible for this condition. The incidence of drug-resistant strains of C. albicans is rising, necessitating the development of new antifungal drugs. Antimicrobial peptides (AMPs) have recently attracted attention due to their unique ability to evade the drug resistance of microorganisms. However, the mechanism of their activity has not yet been identified. The current study analyzed the mode of action of MAF-1A by confocal microscopy, scanning electron microscopy, fluorescent staining, flow cytometry, and qRT-PCR. The results indicate that MAF-1A disrupts the cell membrane of C. albicans and enters the cell where it binds and interacts with nucleic acids. qRT-PCR demonstrated that the expression of several sterol biosynthesis–related genes in C. albicans was increased after MAF-1A treatment. Together, these findings suggest that MAF-1A exerts antifungal action by affecting both the cell membrane and intracellular components. The antifungal mechanism of MAF-1A is unique, and its identification has great research and clinical significance.

scholarly journals Increase of Virulence and Its Phenotypic Traits in Drug-Resistant Strains of Candida albicans

2008 ◽  
Vol 52 (3) ◽  
pp. 927-936 ◽  
Author(s):  
Letizia Angiolella ◽  
Anna Rita Stringaro ◽  
Flavia De Bernardis ◽  
Brunella Posteraro ◽  
Mariantonietta Bonito ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Candida Albicans ◽  
Biological Properties ◽  
Antifungal Drugs ◽  
Infection Model ◽  
Phenotypic Traits ◽  
Homozygous Mutation ◽  
Drug Resistant ◽  
Resistant Strains ◽  
Drug Resistant Strains

ABSTRACT There is concern about the rise of antifungal drug resistance, but little is known about comparative biological properties and pathogenicity of drug-resistant strains. We generated fluconazole (FLC; CO23RFLC)- or micafungin (FK; CO23RFK)-resistant strains of Candida albicans by treating a FLC- and FK-susceptible strain of this fungus (CO23S) with stepwise-increasing concentrations of either drug. Molecular analyses showed that CO23RFLC had acquired markedly increased expression of the drug-resistance efflux pump encoded by the MDR1 gene, whereas CO23RFK had a homozygous mutation in the FSK1 gene. These genetic modifications did not alter to any extent the growth capacity of the drug-resistant strains in vitro, either at 28°C or at 37°C, but markedly increased their experimental pathogenicity in a systemic mouse infection model, as assessed by the overall mortality and target organ invasion. Interestingly, no apparent increase in the vaginopathic potential of the strains was observed with an estrogen-dependent rat vaginal infection. The increased pathogenicity of drug-resistant strains for systemic infection was associated with a number of biochemical and physiological changes, including (i) marked cellular alterations associated with a different expression and content of major cell wall polysaccharides, (ii) more rapid and extensive hypha formation in both liquid and solid media, and (iii) increased adherence to plastic and a propensity for biofilm formation. Overall, our data demonstrate that experimentally induced resistance to antifungal drugs, irrespective of drug family, can substantially divert C. albicans biology, affecting in particular biological properties of potential relevance for deep-seated candidiasis.

scholarly journals Antifungal Activity of Thai Cajuput Oil and Its Effect on Efflux-Pump Gene Expression in Fluconazole-Resistant Candida albicans Clinical Isolates

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Pitchayaphong Keereedach ◽  
Karnjana Hrimpeng ◽  
Khaemaporn Boonbumrung
Keyword(s):  
Gene Expression ◽  
Candida Albicans ◽  
Antifungal Activity ◽  
Efflux Pump ◽  
Clinical Problem ◽  
Antifungal Drugs ◽  
Clinical Isolates ◽  
Common Mechanism ◽  
Fluconazole Resistant ◽  
Resistant Strains

Candidiasis caused by the fluconazole-resistant opportunistic pathogen Candida albicans is an intractable clinical problem that threatens immunocompromised or normal individuals. The most common mechanism of fluconazole resistance in C. albicans is the failure of cells to accumulate the drug due to increased expression of the efflux proteins encoded by the CDR1, CDR2, and MDR1 genes. Because the number of current antifungal drugs is limited, it is necessary to develop new therapeutic strategies. This study aimed to evaluate the antifungal activity of Thai Cajuput oil, its synergism with fluconazole, and its effect on efflux-pump gene expression in fluconazole-resistant C. albicans clinical isolates. Thus, we first detected the efflux-pump genes in fourteen resistant strains by PCR. The frequencies of the CDR1, CDR2, and MDR1 genes were 68.75%, 62.5%, and 87.5%, respectively, and these efflux-pump genes were distributed in three distinct patterns. Subsequently, the antifungal activity of Thai Cajuput oil was assessed by broth macrodilution and its synergism with fluconazole was evaluated by the checkerboard assay. The changes in the expression levels of CDR1, CDR2, and MDR1 after treatment with Thai Cajuput oil were analyzed by qRT-PCR. The MICs and MFCs of Thai Cajuput oil ranged from 0.31 to 1.25 μl/ml and 0.63 to 1.25 μl/ml, respectively, and its activity was defined as fungicidal activity. The MICs of the combination of Thai Cajuput oil and fluconazole were much lower than the MICs of the individual drugs. Interestingly, sub-MICs of Thai Cajuput oil significantly reduced the MDR1 expression level in resistant strains P < 0.05 . Our study suggests that Thai Cajuput oil can be used to create new potential combination therapies to combat the antifungal resistance of C. albicans.

scholarly journals MONITORING THE RESISTANCE OF CLINICAL STRAINS OF CANDIDA YEAST TO FLUCONAZOLE (A BRIEF LITERATURE REVIEW)

2017 ◽  
pp. 70-74 ◽  
Author(s):  
T. M. Zheltikova
Keyword(s):  
Literature Review ◽  
Yeast Species ◽  
Geographical Location ◽  
Vulvovaginal Candidiasis ◽  
Drug Resistant ◽  
The Past ◽  
Fluconazole Resistant ◽  
Resistant Strains ◽  
The Moment ◽  
Drug Resistant Strains

The article analyzes the global and national research on the resistance of Candida yeasts to fluconazole. The studies demonstrate that the formation of resistance is determined by many factors: type of yeast, choice of the antimycotic medication, geographical location, etc. In addition, one can not disregard the socio-economic and even political causes. The frequency of detection of drug-resistant strains of different species of Candida yeast to fluconazole varies across different regions, between countries of the same region, and may vary from year to year within a country. In other words, the formation of yeast resistance/ susceptibility to fluconazole, and to other antifungals alike, is dynamic and may be reversible.Therefore, both global and national studies conducted over the past decades and devoted to the formation of resistance of Candida yeast to azoles, in particular, fluconazole, have shown that it is still the medication of choice for the treatment of candidiasis, including acute vulvovaginal candidiasis, as well as for relief and prevention of exacerbations of recurrent vulvovaginal candidiasis. C. krusei was and remains one of the most fluconazole-resistant yeast species. Other species, such as C. inconspicua and C. norvegensis, the number and incidence of which is too low for the moment to make any statistically valid conclusions, may in the future be added to the list. 

scholarly journals In Vitro Antifungal Activities of a Series of Dication-Substituted Carbazoles, Furans, and Benzimidazoles

1998 ◽  
Vol 42 (10) ◽  
pp. 2503-2510 ◽  
Author(s):  
Maurizio Del Poeta ◽  
Wiley A. Schell ◽  
Christine C. Dykstra ◽  
Susan K. Jones ◽  
Richard R. Tidwell ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Fusarium Solani ◽  
Antifungal Agents ◽  
Antifungal Drugs ◽  
Inhibitory Compounds ◽  
Wide Range ◽  
Fluconazole Resistant ◽  
Resistant Strains

ABSTRACT Aromatic dicationic compounds possess antimicrobial activity against a wide range of eucaryotic pathogens, and in the present study an examination of the structures-functions of a series of compounds against fungi was performed. Sixty-seven dicationic molecules were screened for their inhibitory and fungicidal activities againstCandida albicans and Cryptococcus neoformans. The MICs of a large number of compounds were comparable to those of the standard antifungal drugs amphotericin B and fluconazole. Unlike fluconazole, potent inhibitory compounds in this series were found to have excellent fungicidal activities. The MIC of one of the most potent compounds against C. albicans was 0.39 μg/ml, and it was the most potent compound against C. neoformans (MIC, ≤0.09 μg/ml). Selected compounds were also found to be active againstAspergillus fumigatus, Fusarium solani,Candida species other than C. albicans, and fluconazole-resistant strains of C. albicans and C. neoformans. Since some of these compounds have been safely given to animals, these classes of molecules have the potential to be developed as antifungal agents.

scholarly journals The Effects of Tormentic Acid and Extracts from Callistemon citrinus on Candida albicans and Candida tropicalis Growth and Inhibition of Ergosterol Biosynthesis in Candida albicans

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Chido Bvumbi ◽  
Godloves Fru Chi ◽  
Marc Y. Stevens ◽  
Molly Mombeshora ◽  
Stanley Mukanganyama
Keyword(s):  
Candida Albicans ◽  
Antifungal Activity ◽  
Candida Tropicalis ◽  
Methanol Extract ◽  
Fungal Infections ◽  
Water Extract ◽  
Antifungal Drugs ◽  
Ergosterol Content ◽  
Broth Microdilution Method ◽  
Tormentic Acid

Candida albicans and Candida tropicalis are the leading causes of human fungal infections worldwide. There is an increase in resistance of Candida pathogens to existing antifungal drugs leading to a need to find new sources of antifungal agents. Tormentic acid has been isolated from different plants including Callistemon citrinus and has been found to possess antimicrobial properties, including antifungal activity. The study aimed to determine the effects of tormentic and extracts from C. citrinus on C. albicans and C. tropicalis and a possible mode of action. The extracts and tormentic acid were screened for antifungal activity using the broth microdilution method. The growth of both species was inhibited by the extracts, and C. albicans was more susceptible to the extract compared to C. tropicalis. The growth of C. albicans was inhibited by 80% at 100 μg/ml of both the DCM: methanol extract and the ethanol: water extract. Tormentic acid reduced the growth of C. albicans by 72% at 100 μg/ml. The effects of the extracts and tormentic acid on ergosterol content in C. albicans were determined using a UV/Vis scanning spectrophotometer. At concentrations of tormentic acid of 25 μg/ml, 50 μg/ml, 100 μg/ml, and 200 μg/ml, the content of ergosterol was decreased by 22%, 36%, 48%, and 78%, respectively. Similarly, the DCM: methanol extract at 100 μg/ml and 200 μg/ml decreased the content by 78% and 88%, respectively. A dose-dependent decrease in ergosterol content was observed in cells exposed to miconazole with a 25 μg/ml concentration causing a 100% decrease in ergosterol content. Therefore, tormentic acid inhibits the synthesis of ergosterol in C. albicans. Modifications of the structure of tormentic acid to increase its antifungal potency may be explored in further studies.

Synergistic anticandidal activity of etomidate and azoles against clinical fluconazole-resistant Candida isolates

2019 ◽  
Vol 14 (17) ◽  
pp. 1477-1488 ◽  
Author(s):  
Lívia G do AV Sá ◽  
Cecília R da Silva ◽  
Rosana de S Campos ◽  
João B de A Neto ◽  
Letícia S Sampaio ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Antifungal Drugs ◽  
Planktonic Cells ◽  
Candida Spp ◽  
Flow Cytometric ◽  
Fluconazole Resistant ◽  
Anticandidal Activity ◽  
Checkerboard Assay ◽  
Resistant Strains ◽  
Radical Generation

Aim: The purpose of this study was to evaluate the effect of etomidate alone and in combination with azoles on resistant strains of Candida spp. in both planktonic cells and biofilms. Materials & methods: The antifungal activity of etomidate was assessed by the broth microdilution test; flow cytometric procedures to measure fungal viability, mitochondrial transmembrane potential, free radical generation and cell death; as well detection of DNA damage using the comet assay. The interaction between etomidate and antifungal drugs (itraconazole and fluconazole) was evaluated by the checkerboard assay. Results: Etomidate showed antifungal activity against resistant strains of Candida spp. in planktonic cells and biofilms. Etomidate also presented synergism with fluconazole and itraconazole in planktonic cells and biofilms. Conclusion: Etomidate showed antifungal activity against Candida spp., indicating that it is a possible therapeutic alternative.

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