scholarly journals Synergy of Nitric Oxide and Azoles againstCandida Species In Vitro

1998 ◽  
Vol 42 (9) ◽  
pp. 2342-2346 ◽  
Author(s):  
Gail E. McElhaney-Feser ◽  
Robert E. Raulli ◽  
Ronald L. Cihlar
Keyword(s):  
Nitric Oxide ◽  
Candida Albicans ◽  
Half Life ◽  
Inhibitory Concentration ◽  
Therapeutic Strategies ◽  
Fractional Inhibitory Concentration ◽  
Concentration Indices

ABSTRACT The candidacidal activity of nitric oxide (NO) as delivered by a class of compounds termed diazeniumdiolates has been investigated. Diazeniumdiolates are stable agents capable of releasing NO in a biologically usable form at a predicted rate, and three such compounds were examined for activity. One compound, (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (DETA-NO), proved to be most suitable for examining NO activity due to its relatively long half-life (20 h) and because of limited candidacidal activity of the uncomplexed DETA nucleophile. DETA-NO was active against six species of Candida for which the MICs necessary to inhibit 50% growth (MIC50s) ranged from 0.25 to 1.0 mg/ml. C. parapsilosis and C. kruseiwere the most susceptible to the compound. In addition to a determination of NO effects alone, the complex was utilized to investigate the synergistic potential of released NO in combination with ketoconazole, fluconazole, and miconazole. Activity was investigated in vitro against representative strains of Candida albicans, C. krusei, C. parapsilosis,C. tropicalis, C. glabrata, and C. dubliniensis. Determination of MIC50, MIC80 and MICs indicated that DETA-NO inhibits all strains tested, with strains of C. parapsilosis and C. krusei being consistently the most sensitive. The combination of DETA-NO with each azole was synergistic against all strains tested as measured by fractional inhibitory concentration indices that ranged from 0.1222 to 0.4583. The data suggest that DETA-NO or compounds with similar properties may be useful in the development of new therapeutic strategies for treatment of Candida infections.

scholarly journals IN VITRO ANTIFUNGAL ACTIVITY OF TIMOL AND CARVACROL ON CANDIDA SPECIES

2019 ◽  
Vol 4 ◽  
Author(s):  
Luciana Thaís Rangel Souza ◽  
Cecília Correia Costa ◽  
Mateus Cardoso Oliveira ◽  
Isabel Celeste Caires Pereira Gusmão
Keyword(s):  
Candida Albicans ◽  
Antifungal Activity ◽  
Inhibitory Concentration ◽  
Candida Krusei ◽  
Minimum Fungicidal Concentration ◽  
Sabouraud Agar ◽  
In Vitro Antifungal Activity

Aim: to evaluate the in vitro action of thymol and carvacrol against the yeasts of Candida albicans ATCC10231 and Candida krusei ATCC34135. Method: A laboratory study was performed to evaluate antifungal activity. The characterization of the Minimal Inhibitory Concentration (MIC) of the thymol essential oil was carried out using the technique where the microdilution is performed, in which a plate containing 96 wells is used. The determination of the Minimum Fungicidal Concentration (MFC) was performed by dripping 10 μL of each of the concentrations evaluated on Sabouraud agar plates. Results: The MIC of thymol and carvacrol for C. albicans was 40 μg/mL and for Candida krusei it did not present antifungal activity. While the MIC of nystatin was 0.03mg for both species with thymol and carvacrol. Conclusion: Thymol presented satisfactory antifungal activity against the pathogens studied, but carvacrol did not present antifungal activity.

scholarly journals Antifungi Effect of Keghenyat Leaves Fraction (Acmella uliginosa) In Vitro Study

2017 ◽  
Vol 1 (1) ◽  
pp. 1-7
Author(s):  
Agustina Septi Hijir ◽  
Salni Salni ◽  
Joko Marwoto ◽  
Triwani Triwani ◽  
Sri Nita ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Minimum Inhibitory Concentration ◽  
Reproductive Tract ◽  
Inhibitory Concentration ◽  
In Vitro Study ◽  
Vitro Study ◽  
Alternative Medicines ◽  
Post Hoc

Introduction Candida is a yeast fungus classes most commonly found in the oral cavity, gastrointestinal tract, reproductive tract and skin, especially the species Candida albicans. Alternative medicines such as herbs are easily available and affordable by the community, such as keghenyat leaves (Acmella uliginosa). Aim of StudyTo determine the activity of Keghenyat leaves fraction (Acmella uliginosa) compared to Nystatin against Candida albicans in vitro. MethodsIn vitro study was held in Laboratory of Genetics and Biotechnology Department of Biology, Faculty of Science and Medical Faculty, Sriwijaya University in December 2015 and January 2016. Research stages: extraction, fractionation, sensitivity test using Nystatin and Candida albicans, fractions antifungal activity test, the determination of minimum inhibitory concentration (MIC), bioautografi test and determination of compound classes. One final stages of testing the active fraction Keghenyat leaves (Acmella uliginosa) with Nystatin. Data were analyzed using ANOVA and Post Hoc Duncan test and linear regression using SPSS 20. ResultsHexane faction of Keghenyat leaves (Acmella uliginosa) is active against the fungus Candida albicans, has a Minimum Inhibitory Concentration (MIC) of 0.625% (6250μl) against the fungus Candida albicans antifungal contain active compounds that terpenoids and flavonoids, amounting to 84.68 mg / ml equivalent to 1 mg / ml Nystatin against the fungus Candida albicans. ConclusionThere is a significance different MIC between hexane fraction of Keghenyat leaves (Acmella uliginosa) and Nystatin, Nystatin have more high activity.

scholarly journals Biofabricated Silver Nanoparticles Synergistically Activate Amphotericin B Against Mature Biofilm Forms of Candida Albicans

2017 ◽  
Vol 4 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Shivkrupa D. Halbandge ◽  
Supriya P. Mortale ◽  
Sankunny Mohan Karuppayil
Keyword(s):  
Silver Nanoparticles ◽  
Candida Albicans ◽  
Amphotericin B ◽  
Hemolytic Activity ◽  
Biofilm Formation ◽  
Inhibitory Concentration ◽  
Fungal Infections ◽  
Fractional Inhibitory Concentration ◽  
Planktonic Growth ◽  
Concentration Indices

Background: Biofilm formation by Candida albicans is a significant clinical challenge. Fungal biofilms are resistant to most of the currently available antifungal agents. Amphotericin-B (AmB) is an antifungal agent used for the treatment of systematic fungal infections but it is well known for its toxicities and side-effects. Novel approaches are needed to treat these infections that can reduce its toxicities. Objectives: Current study aims to evaluate the efficacy of silver nanoparticles (SNPs) alone and in combination with AmB against growth and biofilm formation in C. albicans. Methods: Combinations of SNP-AmB were tested against planktonic growth and biofilm formation in vitro. Micro broth dilution method was used to study planktonic growth and biofilm formation. The fractional inhibitory concentration indices (FICI) were calculated by using a checkerboard format. Biofilm formation was analyzed by using XTT-metabolic assay. Results: MIC of AmB for developing biofilm was lowered by 16 fold in combination with SNPs. The calculated fractional inhibitory concentration indices were 0.1875 suggesting that this interaction is synergistic. Similarly, the mature biofilms were significantly prevented by SNPs-AmB combination. This interaction was synergistic. Furthermore, interaction between SNPs and AmB against planktonic growth was additive. Hemolytic activity assay was carried out on these drugs and combinations. Drug required for inhibition alone as well as in combination did not exhibit hemolytic activity. Conclusion: The combinations with SNPs lead to decreases in the dosage of AmB required for anti-Candida activity. SNPs-AmB combination could be an effective strategy against biofilm formed by C. albicans.

In vitro synergy of eugenol and methyleugenol with fluconazole against clinical Candida isolates

2010 ◽  
Vol 59 (10) ◽  
pp. 1178-1184 ◽  
Author(s):  
Aijaz Ahmad ◽  
Amber Khan ◽  
Luqman Ahmad Khan ◽  
Nikhat Manzoor
Keyword(s):  
Inhibitory Concentration ◽  
High Sensitivity ◽  
Antagonistic Activity ◽  
Fractional Inhibitory Concentration ◽  
Antifungal Drug Resistance ◽  
Naturally Occurring ◽  
Opportunistic Pathogenic ◽  
Concentration Indices ◽  
Compromised Patients

The species Candida is a group of opportunistic pathogenic commensals in immune-compromised patients. Treatment of Candida infections is becoming increasingly difficult due to antifungal drug resistance, especially with fluconazole (FLC), which is a commonly used azole. In the present study the in vitro antifungal activity of eugenol (EUG) and methyleugenol (MEUG) alone and in combination against 64 FLC-sensitive and 34 FLC-resistant clinical Candida isolates is highlighted. All the strains were susceptible to both the naturally occurring phenyl propanoids. The nature of the interaction was studied from fractional inhibitory concentration indices (FICIs) for both EUG plus FLC, and MEUG plus FLC combinations calculated from chequerboard microdilution assays. FICI values depicted a high synergism of FLC with both compounds, which was greatest with MEUG. FLC-resistant Candida isolates showed high sensitivity to both compounds. No antagonistic activity was seen in the strains tested in the present study. From these results we suggest that EUG and MEUG have great potential as antifungals, and that FLC can be supplemented with EUG and MEUG to treat FLC-resistant Candida infections.

Comparison of methodologies for synergism testing of drug combinations against resistant strains of Pseudomonas aeruginosa.

1996 ◽  
Vol 40 (3) ◽  
pp. 677-683 ◽  
Author(s):  
D M Cappelletty ◽  
M J Rybak
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Clinical Isolate ◽  
Inhibitory Concentration ◽  
Laboratory Strain ◽  
Fractional Inhibitory Concentration ◽  
Beta Lactam ◽  
Beta Lactams ◽  
Drug Concentrations ◽  
Concentration Indices

The purpose of this study was to determine if synergism was maintained for various combinations of beta-lactams with an aminoglycoside against four clinical strains and one laboratory strain of Pseudomonas aeruginosa which were resistant, according to the MICs, to the beta-lactams and/or aminoglycoside. The results from both the checkerboard and killing curve methodologies were compared. The laboratory strain (ATCC 27853) was manipulated in vitro by serial passage onto agar containing increasing concentrations of each antibiotic to select for resistance. One clinical isolate (R61) was also serially passed to raise the MIC of piperacillin from 128 to 1,024 micrograms/ml. The fractional inhibitory concentration indices for all isolates indicated indifference for all combination therapies, with values ranging from 0.6 to 3. In contrast, killing curve results for all isolates demonstrated synergism with drug concentrations at either one-fourth or one-half the MIC for each organism. The MIC of piperacillin for the laboratory-manipulated clinical isolate R61 was 1,024 micrograms/ml, and synergism was still observed with concentrations of one-half the MIC of piperacillin and amikacin. For clinical isolate R166, which was beta-lactam and tobramycin resistant, synergism continued to be demonstrated with concentrations of tobramycin (1/16 MIC) in combination with piperacillin and cefepime at 1/2 the MIC. The results of this study indicate that against P. aeruginosa, synergism is observed in spite of resistance to beta-lactams and/or aminoglycosides. Synergism appears to be maintained even at very high MICs (piperacillin, 1,024 micrograms/ml; tobramycin, 128 micrograms/ml) with drug concentrations within achievable therapeutic ranges. With current definitions of synergism there was a complete lack of correlation between the results obtained by the checkerboard and killing curve methodologies, with the fractional inhibitory concentration indices showing indifference and killing curves resulting in synergism. The methodologies and definitions of synergism or antagonism are variable and not standardized and should be reevaluated.

scholarly journals Effect of hydroalcoholic leaves extract of Datura stramonium on pathogenic Candida albicans

2015 ◽  
Vol 39 (2) ◽  
pp. 55-61
Author(s):  
Ali Y. Salman
Keyword(s):  
Candida Albicans ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Datura Stramonium ◽  
In Vitro Test ◽  
In Vivo Test ◽  
Vitro Test

      This research aimed at studying the effect of different concentration of hydroalcoholic leaves extract of Datura stramonium concentration against pathogenic Candida albicans isolated from clinical cases of diarrhea in cows and dogs in Baghdad province. Hydroalcoholic extract of the leaves of Datura stramonium were prepared in different concentrations for In vitro and In vivo study against Candida albicans. In vitro test includes the determination of minimum inhibitory concentration 50, 25, 12.5, 6.25, 3.12 and 1.75mg/1ml), and it was found that the minimum inhibitory concentration was 3.12 mg/1ml. Whereas the in vivo test was performed for the determination of sensitivity test of Candida albicans in concentration of plant 10, 15 and 20 mg/1ml which was compared with same concentration of Nystatin. The study was performed in seven groups of mice according to different concentrations. The infective dose of Candida albicans was 1X108, which was proved by histopathology changes after eight day. The result obtained from invivo study revealed that after the end of the therapeutic period that lasted for 8 days. Confirm the efficacy of Datura stramonium extract at 20% as a treatment for mice infected with Candida albicans.

scholarly journals Synergistic activity of azoles with amiodarone against clinically resistant Candida albicans tested by chequerboard and time–kill methods

2008 ◽  
Vol 57 (4) ◽  
pp. 457-462 ◽  
Author(s):  
Qiongjie Guo ◽  
Shujuan Sun ◽  
Jinlong Yu ◽  
Yan Li ◽  
Lili Cao
Keyword(s):  
Candida Albicans ◽  
Inhibitory Concentration ◽  
Systemic Disease ◽  
Synergistic Activity ◽  
Synergistic Interactions ◽  
Colony Counting ◽  
Reduction Assay ◽  
Time Kill ◽  
Concentration Indices

Candida albicans is the most common candidal pathogen, causing serious systemic disease in immunocompromised patients. Azoles are widely applied and largely effective; however, they are generally fungistatic and clinically resistant isolates are emerging increasingly. The present study provided in vitro evidence using a chequerboard technique that amiodarone is strongly synergistic with azoles against resistant C. albicans, with mean fractional inhibitory concentration indices of 0.01 and high-percentage synergistic interactions of 1250 %. A time–kill study performed by both colony counting and a colorimetric reduction assay confirmed the synergistic interaction, with a ≥2 log10 decrease in c.f.u. ml−1 compared with the corresponding azoles alone. These results suggest the possibility of supplementing azoles with amiodarone to treat resistant C. albicans infections.

scholarly journals In vitro synergy of isavuconazole in combination with colistin against Candida auris

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Patrick Schwarz ◽  
Anne-Laure Bidaud ◽  
Eric Dannaoui
Keyword(s):  
Response Surface ◽  
Surface Analysis ◽  
Concentration Index ◽  
Inhibitory Concentration ◽  
Response Surface Analysis ◽  
Fractional Inhibitory Concentration ◽  
Candida Auris ◽  
Fractional Inhibitory Concentration Index ◽  
Agar Diffusion

AbstractThe in vitro interactions of isavuconazole with colistin were evaluated against 15 clinical Candida auris isolates by a microdilution checkerboard technique based on the EUCAST reference method for antifungal susceptibility testing and by agar diffusion using isavuconazole gradient concentration strips with or without colistin incorporated RPMI agar. Interpretation of the checkerboard results was done by the fractional inhibitory concentration index and by response surface analysis based on the Bliss model. By checkerboard, combination was synergistic for 93% of the isolates when interpretation of the data was done by fractional inhibitory concentration index, and for 80% of the isolates by response surface analysis interpretation. By agar diffusion test, although all MICs in combination decreased compared to isavuconazole alone, only 13% of the isolates met the definition of synergy. Essential agreement of EUCAST and gradient concentration strip MICs at +/− 2 log2 dilutions was 93.3%. Antagonistic interactions were never observed for any technique or interpretation model used.

A Simple Silicon Based Nitric Oxide Sensor

1999 ◽  
Author(s):  
Marcelo Bariatto ◽  
Rogerio Furlan ◽  
Koiti Arakai ◽  
Jorge J. Santiago-Aviles
Keyword(s):  
Nitric Oxide ◽  
Amperometric Detection ◽  
Cellular Level ◽  
High Yield ◽  
Sensor Calibration ◽  
Nitric Oxide Sensor ◽  
Sensor Configuration

Abstract Nitric oxide (NO) is known to mediate many beneficial physiology processes, motivating its detection in vivo as well as in vitro. Electrochemical detection provides the required cellular level determination of NO among several other techniques. In this work, electrochemical micro-sensors for both types of detection, in vivo and in vitro, were developed, exploring the silicon planar technology, which presents high yield and reliability and also permits batch fabrication. The developed in vitro sensor features eight detection sites (10 μm × 10 μm microelectrodes), for determination of nitric oxide spatial distribution or multi-species analysis. Different electrochemical methods were applied to provide sensor calibration and chemical reproducibility. For in vivo analysis, the designed structures have a needle shape (40 μm thick) and they were silicon micro-machined by using plasma etching or etch stop techniques. Different configurations were designed and implemented, containing a number of detection microelectrodes that vary from 2 to 10. The amperometric detection of both nitric oxide and nitride (NO2−) — a molecule that causes an interference — were investigated by using the in vitro micro-sensor configuration. The need of a cationic exchanger (Nafion) was demonstrated in order to provide selectivity to NO for low concentrations. Also, the developed sensor has a sensitivity of 500 A/M.cm2 and a detection limit of 10 μM.

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