scholarly journals Differential Activities of Newer Antifungal Agents against Candida albicans and Candida parapsilosis Biofilms

2007 ◽  
Vol 52 (1) ◽  
pp. 357-360 ◽  
Author(s):  
Αspasia Katragkou ◽  
Athanasios Chatzimoschou ◽  
Maria Simitsopoulou ◽  
Maria Dalakiouridou ◽  
Eudoxia Diza-Mataftsi ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Antifungal Agents ◽  
Candida Parapsilosis ◽  
Planktonic Cells

ABSTRACT The activities of voriconazole, posaconazole, caspofungin, and anidulafungin against Candida albicans and Candida parapsilosis biofilms were evaluated. In contrast to planktonic cells, the MICs for voriconazole and posaconazole for the biofilms of the two species were high (≥256 and >64 mg/liter, respectively) but relatively low for the echinocandins caspofungin and anidulafungin (≤1 and ≤2 mg/liter, respectively).

scholarly journals The Antimicrobial Peptides P-113Du and P-113Tri Function against Candida albicans

2016 ◽  
Vol 60 (10) ◽  
pp. 6369-6373 ◽  
Author(s):  
Guan-Yu Lin ◽  
Hsueh-Fen Chen ◽  
Yao-Peng Xue ◽  
Ying-Chieh Yeh ◽  
Chia-Lu Chen ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Antifungal Activity ◽  
Antimicrobial Peptides ◽  
Antifungal Agents ◽  
Low Ph ◽  
Planktonic Cells ◽  
Content Type ◽  
Peptide Derivatives ◽  
Helix Conformation ◽  
Α Helix

ABSTRACTTwo antimicrobial P-113 peptide derivatives, P-113Du and P-113Tri, were investigated in this study. Notably, P-113Du and P-113Tri contained significant fractions of α-helix conformation and were less sensitive to high salt and low pH than P-113. Moreover, compared to P-113, these peptides exhibited increased antifungal activity against planktonic cells, biofilm cells, and clinical isolates ofCandida albicansand non-albicans Candidaspp. These results suggest that P-113Du and P-113Tri are promising candidates for development as novel antifungal agents.

scholarly journals In vitroactivities of antifungals alone and in combination with tigecycline againstCandida albicansbiofilms

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5263 ◽  
Author(s):  
Mayram Hacioglu ◽  
Ayse Seher Birteksoz Tan ◽  
Sibel Dosler ◽  
Nese Inan ◽  
Gulten Otuk
Keyword(s):  
Candida Albicans ◽  
Amphotericin B ◽  
Biofilm Formation ◽  
Antifungal Agents ◽  
Synergistic Effects ◽  
Planktonic Cells ◽  
Effective Agent ◽  
Highly Active ◽  
Highly Effective ◽  
Anti Fungal

BackgroundCandidamay form biofilms, which are thought to underlie the most recalcitrant infections.MethodsIn this study, activities of antifungal agents alone and in combination with tigecycline against planktonic cells and mature and developing biofilms ofCandida albicansisolates were evaluated.ResultsAmphotericin B and echinocandins were found to be the most effective agents against mature biofilms, whereas the least effective agent was fluconazole. Furthermore, the most effective anti-fungal monotherapies against biofilm formation were amphotericin B and anidulafungin, and the least effective monotherapy was itraconazole. The combination of tigecycline and amphotericin B yielded synergistic effects, whereas combinations containing itraconazole yielded antagonist effects against planktonic cells. The combination of tigecycline and caspofungin exhibited maximum efficacy against mature biofilms, whereas combinations containing itraconazole exhibited minimal effects. Combinations of tigecycline with amphotericin B or anidulafungin were highly effective againstC. albicansbiofilm formation.DiscussionIn summary, tigecycline was highly active againstC. albicansparticularly when combined with amphotericin B and echinocandins.

scholarly journals Activities of Triazole-Echinocandin Combinations against Candida Species in Biofilms and as Planktonic Cells

2011 ◽  
Vol 55 (5) ◽  
pp. 1968-1974 ◽  
Author(s):  
Athanasios Chatzimoschou ◽  
Αspasia Katragkou ◽  
Maria Simitsopoulou ◽  
Charalampos Antachopoulos ◽  
Elpiniki Georgiadou ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Biofilm Formation ◽  
Candida Parapsilosis ◽  
Planktonic Cells ◽  
Simultaneous Treatment ◽  
Content Type ◽  
Antagonistic Effects ◽  
Independence Model ◽  
Agent Interactions ◽  
Bliss Independence

ABSTRACTBiofilm formation complicates the treatment of various infections caused byCandidaspecies. We investigated the effects of simultaneous or sequential combinations of two triazoles, voriconazole (VRC) and posaconazole (PSC), with two echinocandins, anidulafungin (AND) and caspofungin (CAS), againstCandida albicansandCandida parapsilosisbiofilms in comparison to their planktonic counterparts. Antifungal activity was assessed by the 2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]2H-tetrazolium-5-carboxanilide (XTT) metabolic assay. Antifungal-agent interactions were analyzed by the Bliss independence model in the simultaneous-treatment studies and by analysis of variance (ANOVA) in the sequential-treatment studies. AgainstC. albicansplanktonic cells, the simultaneous combination of PSC (32 to 128 mg/liter) and CAS (0.008 to 0.25 mg/liter) was synergistic; the combinations of PSC (128 to 1,024 mg/liter) with AND (0.03 to 0.5 mg/liter) and VRC (32 to 512 mg/liter) with AND (0.008 to 0.03 mg/liter) were antagonistic. AgainstC. parapsilosisplanktonic cells, the interaction between VRC (32 to 1,024 mg/liter) and CAS (1 to 16 mg/liter) was antagonistic. All simultaneous antifungal combinations demonstrated indifferent interactions against biofilms of bothCandidaspecies. Damage to biofilms of both species increased (P< 0.01) in the presence of subinhibitory concentrations of echinocandins (0.008 to 0.064 mg/liter), followed by the addition of PSC (512 mg/liter forC. albicansand 64 to 512 mg/liter forC. parapsilosis) or VRC (256 to 512 mg/liter forC. albicansand 512 mg/liter forC. parapsilosis). Triazole-echinocandin combinations do not appear to produce antagonistic effects againstCandidasp. biofilms, while various significant interactions occur with their planktonic counterparts.

scholarly journals Absence of Amphotericin B-Tolerant Persister Cells in Biofilms of Some Candida Species

2008 ◽  
Vol 52 (5) ◽  
pp. 1884-1887 ◽  
Author(s):  
Rawya S. Al-Dhaheri ◽  
L. Julia Douglas
Keyword(s):  
Drug Resistance ◽  
Candida Albicans ◽  
Amphotericin B ◽  
Candida Glabrata ◽  
Candida Parapsilosis ◽  
Candida Krusei ◽  
Cell Populations ◽  
Planktonic Cells ◽  
Persister Cells ◽  
Tolerant Cell

ABSTRACT Biofilms and planktonic cells of five Candida species were surveyed for the presence of persister (drug-tolerant) cell populations after exposure to amphotericin B. None of the planktonic cultures (exponential or stationary phase) contained persister cells. However, persisters were found in biofilms of one of two strains of Candida albicans tested and in biofilms of Candida krusei and Candida parapsilosis, but not in biofilms of Candida glabrata or Candida tropicalis. These results suggest that persister cells cannot solely account for drug resistance in Candida biofilms.

scholarly journals In VitroAnalyses of the Effects of Heparin and Parabens on Candida albicans Biofilms and Planktonic Cells

2011 ◽  
Vol 56 (1) ◽  
pp. 148-153 ◽  
Author(s):  
Marisa H. Miceli ◽  
Stella M. Bernardo ◽  
T. S. Neil Ku ◽  
Carla Walraven ◽  
Samuel A. Lee
Keyword(s):  
Candida Albicans ◽  
Metabolic Activity ◽  
Biofilm Formation ◽  
High Dose ◽  
Dependent Manner ◽  
Planktonic Cells ◽  
Content Type ◽  
Heparin Sodium ◽  
The Individual

ABSTRACTInfections and thromboses are the most common complications associated with central venous catheters. Suggested strategies for prevention and management of these complications include the use of heparin-coated catheters, heparin locks, and antimicrobial lock therapy. However, the effects of heparin onCandida albicansbiofilms and planktonic cells have not been previously studied. Therefore, we sought to determine thein vitroeffect of a heparin sodium preparation (HP) on biofilms and planktonic cells ofC. albicans. Because HP contains two preservatives, methyl paraben (MP) and propyl paraben (PP), these compounds and heparin sodium without preservatives (Pure-H) were also tested individually. The metabolic activity of the mature biofilm after treatment was assessed using XTT [2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction and microscopy. Pure-H, MP, and PP caused up to 75, 85, and 60% reductions of metabolic activity of the mature preformedC. albicansbiofilms, respectively. Maximal efficacy against the mature biofilm was observed with HP (up to 90%) compared to the individual compounds (P< 0.0001). Pure-H, MP, and PP each inhibitedC. albicansbiofilm formation up to 90%. A complete inhibition of biofilm formation was observed with HP at 5,000 U/ml and higher. When tested against planktonic cells, each compound inhibited growth in a dose-dependent manner. These data indicated that HP, MP, PP, and Pure-H havein vitroantifungal activity againstC. albicansmature biofilms, formation of biofilms, and planktonic cells. Investigation of high-dose heparin-based strategies (e.g., heparin locks) in combination with traditional antifungal agents for the treatment and/or prevention ofC. albicansbiofilms is warranted.

scholarly journals Sublethal Injury and Resuscitation of Candida albicans after Amphotericin B Treatment

2003 ◽  
Vol 47 (4) ◽  
pp. 1200-1206 ◽  
Author(s):  
Robert S. Liao ◽  
Robert P. Rennie ◽  
James A. Talbot
Keyword(s):  
Cell Death ◽  
Candida Albicans ◽  
Amphotericin B ◽  
Antifungal Agents ◽  
Sybr Green ◽  
Sequential Treatment ◽  
Tetrazolium Salt ◽  
Fungal Cell ◽  
Sublethal Injury

ABSTRACT Amphotericin B treatment was previously shown to inhibit Candida albicans reproduction and reduce the fluorescence of vitality-specific dyes without causing a corresponding increase in the fluorescence of the mortality-specific dyes bis-(1,3-dibutylbarbituric acid)trimethine oxonol and SYBR Green Ι. In the present study, we have confirmed these results and have shown that the numbers of CFU are reduced by 99.9% by treatment with 0.5 μg of amphotericin B per ml for 10 h at 35°C. This reduction was not due to fungal cell death. First, the level of reduction of the tetrazolium salt 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide increased in the presence of concentrations of amphotericin B that caused greater than 90% reductions in the numbers of CFU. Second, fungal cells treated with amphotericin B at a concentration of 0.5 μg/ml were resuscitated by further incubation at 22°C for 15 h in the continued presence of amphotericin B. Third, recovery of the ability to replicate was prevented by sequential treatment with 20 μg of miconazole per ml, which also increased the fluorescence of mortality-specific dyes to near the maximal levels achieved with 0.9 μg of amphotericin B per ml. Sequential treatment with fluconazole and flucytosine did not increase the levels of staining with the mortality-specific dyes. Itraconazole was less effective than ketoconazole, which was less effective than miconazole. The practice of equating the loss of the capacity of C. albicans to form colonies with fungal cell death may give incorrect results in assays with amphotericin B, and the results of assays with caution with other antifungal agents that are lipophilic or that possess significant postantifungal effects may need to be interpreted.

scholarly journals Kinetic characterisation and inhibitor sensitivity of Candida albicans and Candida auris recombinant AOX expressed in a self-assembled proteoliposome system

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alice C. Copsey ◽  
Mario R. O. Barsottini ◽  
Benjamin May ◽  
Fei Xu ◽  
Mary S. Albury ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Future Development ◽  
Therapeutic Target ◽  
Fungicide Resistance ◽  
Alternative Oxidase ◽  
Antifungal Agents ◽  
Candida Auris ◽  
Novel Treatments ◽  
Membrane Bound ◽  
Self Assembled

AbstractCandidemia caused by Candida spp. is a serious threat in hospital settings being a major cause of acquired infection and death and a possible contributor to Covid-19 mortality. Candidemia incidence has been rising worldwide following increases in fungicide-resistant pathogens highlighting the need for more effective antifungal agents with novel modes of action. The membrane-bound enzyme alternative oxidase (AOX) promotes fungicide resistance and is absent in humans making it a desirable therapeutic target. However, the lipophilic nature of the AOX substrate (ubiquinol-10) has hindered its kinetic characterisation in physiologically-relevant conditions. Here, we present the purification and expression of recombinant AOXs from C. albicans and C. auris in a self-assembled proteoliposome (PL) system. Kinetic parameters (Km and Vmax) with respect to ubiquinol-10 have been determined. The PL system has also been employed in dose–response assays with novel AOX inhibitors. Such information is critical for the future development of novel treatments for Candidemia.

scholarly journals CaNdt80 Is Involved in Drug Resistance in Candida albicans by Regulating CDR1

2004 ◽  
Vol 48 (12) ◽  
pp. 4505-4512 ◽  
Author(s):  
Chia-Geun Chen ◽  
Yun-Liang Yang ◽  
Hsin-I Shih ◽  
Chia-Li Su ◽  
Hsiu-Jung Lo
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Drug Resistance ◽  
Candida Albicans ◽  
Type Strain ◽  
Antifungal Agents ◽  
Wild Type Strain ◽  
Efflux Pump ◽  
Antifungal Drugs ◽  
Galactosidase Activity ◽  
Wild Type

ABSTRACT Overexpression of CDR1, an efflux pump, is one of the major mechanisms contributing to drug resistance in Candida albicans. CDR1 p-lacZ was constructed and transformed into a Saccharomyces cerevisiae strain so that the lacZ gene could be used as the reporter to monitor the activity of the CDR1 promoter. Overexpression of CaNDT80, the C. albicans homolog of S. cerevisiae NDT80, increases the β-galactosidase activity of the CDR1 p-lacZ construct in S. cerevisiae. Furthermore, mutations in CaNDT80 abolish the induction of CDR1 expression by antifungal agents in C. albicans. Consistently, the Candt80/Candt80 mutant is also more susceptible to antifungal drugs than the wild-type strain. Thus, the gene for CaNdt80 may be the first gene among the regulatory factors involved in drug resistance in C. albicans whose function has been identified.

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