scholarly journals A Novel Dual-Targeted α-Helical Peptide With Potent Antifungal Activity Against Fluconazole-Resistant Candida albicans Clinical Isolates

2020 ◽  
Vol 11 ◽  
Author(s):  
Yang Yang ◽  
Chenxi Wang ◽  
Nan Gao ◽  
Yinfeng Lyu ◽  
Licong Zhang ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Antifungal Activity ◽  
Clinical Isolates ◽  
Helical Peptide ◽  
Fluconazole Resistant

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 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 thymol against clinical isolates of fluconazole-sensitive and -resistant Candida albicans

2009 ◽  
Vol 58 (8) ◽  
pp. 1074-1079 ◽  
Author(s):  
Na Guo ◽  
Jingbo Liu ◽  
Xiuping Wu ◽  
Xingming Bi ◽  
Rizeng Meng ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Antifungal Activity ◽  
Concentration Index ◽  
Inhibitory Concentration ◽  
Clinical Isolates ◽  
Standard Strain ◽  
Antagonistic Action ◽  
Microdilution Method ◽  
Interaction Intensity

Thymol (THY) was found to have in vitro antifungal activity against 24 fluconazole (FLC)-resistant and 12 FLC-susceptible clinical isolates of Candida albicans, standard strain ATCC 10231 and one experimentally induced FLC-resistant C. albicans S-1. In addition, synergism was observed for clinical isolates of C. albicans with combinations of THY–FLC and THY–amphotericin B (AMB) evaluated by the chequerboard microdilution method. The interaction intensity was determined by spectrophotometry for the chequerboard assay, and the nature of the interactions was assessed using two non-parametric approaches [fractional inhibitory concentration index (FICI) and ΔE models]. The interaction between THY–FLC or THY–AMB in FLC-resistant and -susceptible strains of C. albicans showed a high percentage of synergism by the FICI method and the ΔE method. The ΔE model gave results consistent with FICI, and no antagonistic action was observed in the strains tested.

scholarly journals Synergistic mutual potentiation of antifungal activity of Zuccagnia punctata Cav. and Larrea nitida Cav. extracts in clinical isolates of Candida albicans and Candida glabrata

Phytomedicine ◽  
2015 ◽  
Vol 22 (6) ◽  
pp. 666-678 ◽  
Author(s):  
Estefanía Butassi ◽  
Laura A. Svetaz ◽  
Juan J. Ivancovich ◽  
Gabriela E. Feresin ◽  
Alejandro Tapia ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Antifungal Activity ◽  
Candida Glabrata ◽  
Clinical Isolates

scholarly journals Potent In Vitro Synergism of Fluconazole and Berberine Chloride against Clinical Isolates of Candida albicans Resistant to Fluconazole

2006 ◽  
Vol 50 (3) ◽  
pp. 1096-1099 ◽  
Author(s):  
Hua Quan ◽  
Ying-Ying Cao ◽  
Zheng Xu ◽  
Jing-Xia Zhao ◽  
Ping-Hui Gao ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Clinical Isolates ◽  
Antagonistic Action ◽  
Berberine Chloride ◽  
Agar Diffusion ◽  
Fungistatic Activity ◽  
Fluconazole Resistant ◽  
Time Kill ◽  
In Vitro Interaction

ABSTRACT In vitro interaction of fluconazole and berberine chloride was investigated against 40 fluconazole-resistant clinical isolates of Candida albicans. Synergism in fungistatic activity was found with the checkerboard microdilution assay. The findings of agar diffusion tests and time-kill curves confirmed the synergistic interaction, but no antagonistic action was observed.

scholarly journals Antifungal Activity of Aureobasidin A in Combination with Fluconazole against Fluconazole-Resistant Candida albicans 

2020 ◽  
Vol 6 (4) ◽  
pp. 285-291
Author(s):  
Shadi Alimehr ◽  
Masoomeh Shams-Ghahfarokhi ◽  
Mehdi Razzaghi Abyaneh ◽  
◽  
◽  
...  
Keyword(s):  
Candida Albicans ◽  
Antifungal Activity ◽  
Fluconazole Resistant ◽  
Aureobasidin A

scholarly journals Paradoxical antifungal activity and structural observations in biofilms formed by echinocandin-resistant Candida albicans clinical isolates

2013 ◽  
Vol 52 (2) ◽  
pp. 131-139 ◽  
Author(s):  
C. J. Walraven ◽  
S. M. Bernardo ◽  
N. P. Wiederhold ◽  
S. A. Lee
Keyword(s):  
Candida Albicans ◽  
Antifungal Activity ◽  
Clinical Isolates

scholarly journals A Gain-of-Function Mutation in the Transcription Factor Upc2p Causes Upregulation of Ergosterol Biosynthesis Genes and Increased Fluconazole Resistance in a Clinical Candida albicans Isolate

2008 ◽  
Vol 7 (7) ◽  
pp. 1180-1190 ◽  
Author(s):  
Nico Dunkel ◽  
Teresa T. Liu ◽  
Katherine S. Barker ◽  
Ramin Homayouni ◽  
Joachim Morschhäuser ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Candida Albicans ◽  
Clinical Isolates ◽  
Resistant Isolate ◽  
Ergosterol Biosynthesis ◽  
Gain Of Function ◽  
Zinc Cluster ◽  
Fluconazole Resistant ◽  
Lanosterol Demethylase

ABSTRACT In the pathogenic yeast Candida albicans, the zinc cluster transcription factor Upc2p has been shown to regulate the expression of ERG11 and other genes involved in ergosterol biosynthesis upon exposure to azole antifungals. ERG11 encodes lanosterol demethylase, the target enzyme of this antifungal class. Overexpression of UPC2 reduces azole susceptibility, whereas its disruption results in hypersusceptibility to azoles and reduced accumulation of exogenous sterols. Overexpression of ERG11 leads to the increased production of lanosterol demethylase, which contributes to azole resistance in clinical isolates of C. albicans, but the mechanism for this has yet to be determined. Using genome-wide gene expression profiling, we found UPC2 and other genes involved in ergosterol biosynthesis to be coordinately upregulated with ERG11 in a fluconazole-resistant clinical isolate compared with a matched susceptible isolate from the same patient. Sequence analysis of the UPC2 alleles of these isolates revealed that the resistant isolate contained a single-nucleotide substitution in one UPC2 allele that resulted in a G648D exchange in the encoded protein. Introduction of the mutated allele into a drug-susceptible strain resulted in constitutive upregulation of ERG11 and increased resistance to fluconazole. By comparing the gene expression profiles of the fluconazole-resistant isolate and of strains carrying wild-type and mutated UPC2 alleles, we identified target genes that are controlled by Upc2p. Here we show for the first time that a gain-of-function mutation in UPC2 leads to the increased expression of ERG11 and imparts resistance to fluconazole in clinical isolates of C. albicans.

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