scholarly journals The Mould War: Developing an Armamentarium against Fungal Pathogens Utilising Thymoquinone, Ocimene, and Miramistin within Bacterial Cellulose Matrices

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2654
Author(s):  
Sam Swingler ◽  
Abhishek Gupta ◽  
Hazel Gibson ◽  
Wayne Heaselgrave ◽  
Marek Kowalczuk ◽  
...  

An increase in antifungal resistance has seen a surge in fungal wound infections in patients who are immunocompromised resulting from chemotherapy, disease, and burns. Human pathogenic fungi are increasingly becoming resistant to a sparse repertoire of existing antifungal drugs, which has given rise to the need to develop novel treatments for potentially lethal infections. Bacterial cellulose (BC) produced by Gluconacetobacter xylinus has been shown to possess many properties that make it innately useful as a next-generation biopolymer to be utilised as a wound dressing. The current study demonstrates the creation of a pharmacologically active wound dressing by loading antifungal agents into a biopolymer hydrogel to produce a novel wound dressing. Amphotericin B is known to be highly hepatotoxic, which reduces its appeal as an antifungal drug, especially in patients who are immunocompromised. This, coupled with an increase in antifungal resistance, has seen a surge in fungal wound infections in patients who are immunodeficient due to chemotherapy, disease, or injury. Antifungal activity was conducted via Clinical & Laboratory Standards Institute (CLSI) M27, M38, M44, and M51 against Candida auris, Candida albicans, Aspergillus fumigatus, and Aspergillus niger. This study showed that thymoquinone has a comparable antifungal activity to amphotericin B with mean zones of inhibition of 21.425 ± 0.925 mm and 22.53 ± 0.969 mm, respectively. However, the mean survival rate of HEp-2 cells when treated with 50 mg/L amphotericin B was 29.25 ± 0.854% compared to 71.25 ± 1.797% when treated with 50 mg/L thymoquinone. Following cytotoxicity assays against HEp-2 cells, thymoquinone showed a 71.25 ± 3.594% cell survival, whereas amphotericin B had a mean cell survival rate of 29.25 ± 1.708%. The purpose of this study was to compare the efficacy of thymoquinone, ocimene, and miramistin against amphotericin B in the application of novel antifungal dressings.

2018 ◽  
Vol 5 (3) ◽  
pp. 171814 ◽  
Author(s):  
Chang Shu ◽  
Tengfei Li ◽  
Wen Yang ◽  
Duo Li ◽  
Shunli Ji ◽  
...  

The present work is focused on the design and development of novel amphotericin B (AmB)-conjugated biocompatible and biodegradable polypeptide hydrogels to improve the antifungal activity. Using three kinds of promoting self-assembly groups (2-naphthalene acetic acid (Nap), naproxen (Npx) and dexamethasone (Dex)) and polypeptide sequence (Phe-Phe-Asp-Lys-Tyr, FFDKY), we successfully synthesized the Nap-FFDK(AmB)Y gels, Npx-FFDK(AmB)Y gels and Dex-FFDK(AmB)Y gels. The AmB-conjugated hydrogelators are highly soluble in different aqueous solutions. The cryo-transmission electron microscopy and scanning electron microscopy micrographs of hydrogels afford nanofibres with a width of 20–50 nm. Powder X-ray diffraction analyses demonstrate that the crystalline structures of the AmB and Dex are changed into amorphous structures after the formation of hydrogels. Circular dichroism spectra of the solution of blank carriers and the corresponding drug deliveries further help elucidate the molecular arrangement in gel phase, indicating the existence of turn features. The in vitro drug releases suggest that the AmB-conjugated hydrogels are suitable as drug-controlled release vehicles for hydrophobic drugs. The antifungal effect of AmB-conjugated hydrogels significantly exhibits the antifungal activity against Candida albicans . The results of the present study indicated that the AmB-conjugated hydrogels are suitable carriers for poorly water soluble drugs and for enhancement of therapeutic efficacy of antifungal drugs.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Kelen Fátima Dalben Dota ◽  
Marcia Edilaine Lopes Consolaro ◽  
Terezinha Inez Estivalet Svidzinski ◽  
Marcos Luciano Bruschi

Propolis, a resinous compound produced byApis melliferaL. bees, is known to possess a variety of biological activities and is applied in the therapy of various infectious diseases. The aim of this study was to evaluate thein vitroantifungal activity of propolis ethanol extract (PE) and propolis microparticles (PMs) obtained from a sample of Brazilian propolis against clinical yeast isolates of importance in the vulvovaginal candidiasis (VVC). PE was used to prepare the microparticles. Yeast isolates (n=89), obtained from vaginal exudates of patients with VVC, were exposed to the PE and the PMs. Moreover, the main antifungal drugs used in the treatment of VVC (Fluconazole, Voriconazole, Itraconazole, Ketoconazole, Miconazole and Amphotericin B) were also tested. Minimum inhibitory concentration (MIC) was determined according to the standard broth microdilution method. SomeCandida albicansisolates showed resistance or dose-dependent susceptibility for the azolic drugs and Amphotericin B. Non-C. albicansisolates showed more resistance and dose-dependent susceptibility for the azolic drugs thanC. albicans. However, all of them were sensitive or dose-dependent susceptible for Amphotericin B. All yeasts were inhibited by PE and PMs, with small variation, independent of the species of yeast. The overall results provided important information for the potential application of PMs in the therapy of VVC and the possible prevention of the occurrence of new symptomatic episodes.


2007 ◽  
Vol 51 (4) ◽  
pp. 1500-1503 ◽  
Author(s):  
Mónica Azor ◽  
Josepa Gené ◽  
Josep Cano ◽  
Josep Guarro

ABSTRACT Eleven antifungal drugs were tested against representative isolates of the four phylogenetic clades of the Fusarium solani species complex obtained in a multilocus sequence analysis. They all showed very poor activity, with no differences among the clades. Amphotericin B was the most active drug.


2019 ◽  
Vol 16 (31) ◽  
pp. 12-17
Author(s):  
Gustavo Lima SOARES ◽  
Brenda Lavínia Calixto dos SANTOS ◽  
Brenna Ravena Araújo LUZ ◽  
Wylly Araújo de OLIVEIRA

Aspergillus species are a cause of a high number of fungal infections of difficult treatment, presenting an expressive number of deaths due to the complications in the severe cases of infection. The objective was to evaluate the antifungal action of carvacrol against Aspergillus species, as well as to evaluate the interactions when associated with amphotericin B or ketoconazole. The antifungal activity of carvacrol was evaluated by the broth microdilution method. The combinations of the substances were performed by the checkerboard methodology, to determine the Index of Fractional Inhibitory Concentration. Carvacrol showed antifungal activity against all Aspergillus strains used in the trials. In combinations of substances, only a combination of carvacrol and amphotericin B presented satisfactory results. Combinations of carvacrol and ketoconazole have not shown good. It is concluded that carvacrol is a good candidate for the antifungal drug because of its good activity against Aspergillus demonstrated in the present study, as well as in other studies in the literature. Their combination in vitro with amphotericin B or ketoconazole did not present any advantages over the use of antifungal drugs alone.


2013 ◽  
Vol 57 (8) ◽  
pp. 3681-3687 ◽  
Author(s):  
Samuel A. Siles ◽  
Anand Srinivasan ◽  
Christopher G. Pierce ◽  
José L. Lopez-Ribot ◽  
Anand K. Ramasubramanian

ABSTRACTCandida albicansis the most common etiologic agent of systemic fungal infections with unacceptably high mortality rates. The existing arsenal of antifungal drugs is very limited and is particularly ineffective againstC. albicansbiofilms. To address the unmet need for novel antifungals, particularly those active against biofilms, we have screened a small molecule library consisting of 1,200 off-patent drugs already approved by the Food and Drug Administration (FDA), the Prestwick Chemical Library, to identify inhibitors ofC. albicansbiofilm formation. According to their pharmacological applications that are currently known, we classified these bioactive compounds as antifungal drugs, as antimicrobials/antiseptics, or as miscellaneous drugs, which we considered to be drugs with no previously characterized antifungal activity. Using a 96-well microtiter plate-based high-content screening assay, we identified 38 pharmacologically active agents that inhibitC. albicansbiofilm formation. These drugs were subsequently tested for their potency and efficacy against preformed biofilms, and we identified three drugs with novel antifungal activity. Thus, repurposing FDA-approved drugs opens up a valuable new avenue for identification and potentially rapid development of antifungal agents, which are urgently needed.


2021 ◽  
Vol 7 (9) ◽  
pp. 718
Author(s):  
Monica Ganan ◽  
Silje B. Lorentzen ◽  
Peter Gaustad ◽  
Morten Sørlie

The development of yeast biofilms is a major problem due to their increased antifungal resistance, which leads to persistent infections with severe clinical implications. The high antifungal activity of well-characterized chitosan polymers makes them potential alternatives for treating yeast biofilms. The activity of a chito-oligosaccharide with a depolymerization degree (DPn) of 32 (C32) and a fraction of acetylation (FA) of 0.15 on Candida sp. biofilms was studied. The results showed a concentration-dependent reduction in the number of viable cells present in C. albicans, C. glabrata, and C. guillermondii preformed biofilms in the presence of C32, especially on intermediate and mature biofilms. A significant decrease in the metabolic activity of yeast biofilms treated with C32 was also observed. The antifungals fluconazole (Flu) and miconazole (Mcz) decreased the number of viable cells in preformed early biofilms, but not in the intermediate or mature biofilms. Contrary to Flu or Mcz, C32 also reduced the formation of new biofilms. Interestingly, a synergistic effect on yeast biofilm was observed when C32 and Flu/Mcz were used in combination. C32 has the potential to become an alternative therapeutic agent against Candida biofilms alone or in combination with antifungal drugs and this will reduce the use of antifungals and decrease antifungal resistance.


2007 ◽  
Vol 51 (4) ◽  
pp. 1573-1576 ◽  
Author(s):  
Vânia Lúcia Ribeiro da Matta ◽  
Márcia de Souza Carvalho Melhem ◽  
Arnaldo Lopes Colombo ◽  
Maria Luiza Moretti ◽  
Laura Rodero ◽  
...  

ABSTRACT In vitro susceptibility of 58 isolates of Pichia anomala to five antifungal drugs using two broth microdilution methods (CLSI and EUCAST) was analyzed. Low susceptibility to itraconazole was observed. Fluconazole, voriconazole, amphotericin B, and caspofungin showed good antifungal activity, although relatively high drug concentrations were necessary to inhibit the isolates.


2019 ◽  
Vol 15 (6) ◽  
pp. 648-658 ◽  
Author(s):  
Manzoor Ahmad Malik ◽  
Shabir Ahmad Lone ◽  
Parveez Gull ◽  
Ovas Ahmad Dar ◽  
Mohmmad Younus Wani ◽  
...  

Background: The increasing incidence of fungal infections, especially caused by Candida albicans, and their increasing drug resistance has drastically increased in recent years. Therefore, not only new drugs but also alternative treatment strategies are promptly required. Methods: We previously reported on the synergistic interaction of some azole and non-azole compounds with fluconazole for combination antifungal therapy. In this study, we synthesized some non-azole Schiff-base derivatives and evaluated their antifungal activity profile alone and in combination with the most commonly used antifungal drugs- fluconazole (FLC) and amphotericin B (AmB) against four drug susceptible, three FLC resistant and three AmB resistant clinically isolated Candida albicans strains. To further analyze the mechanism of antifungal action of these compounds, we quantified total sterol contents in FLC-susceptible and resistant C. albicans isolates. Results: A pyrimidine ring-containing derivative SB5 showed the most potent antifungal activity against all the tested strains. After combining these compounds with FLC and AmB, 76% combinations were either synergistic or additive while as the rest of the combinations were indifferent. Interestingly, none of the combinations was antagonistic, either with FLC or AmB. Results interpreted from fractional inhibitory concentration index (FICI) and isobolograms revealed 4-10-fold reduction in MIC values for synergistic combinations. These compounds also inhibit ergosterol biosynthesis in a concentration-dependent manner, supported by the results from docking studies. Conclusion: The results of the studies conducted advocate the potential of these compounds as new antifungal drugs. However, further studies are required to understand the other mechanisms and in vivo efficacy and toxicity of these compounds.


2020 ◽  
Vol 63 (2) ◽  
pp. 7-17
Author(s):  
Evelyn Rivera-Toledo ◽  
Alan Uriel Jiménez-Delgadillo ◽  
Patricia Manzano-Gayosso

The first compounds with specific antifungal activity were identified in the middle of the last century as a product of the secondary metabolism of bacteria of the order Actinomycetales, and their clinical use significantly diminished the morbidity and mortality associated with severe fungal infections. Many of such biosynthetic compounds are characterized by a chemical polygenic structure, with a variable number of carbon-carbon double bonds. Currently, besides polygenic antimycotics, there are other antifungal agents, such as the azole compounds, that have less toxicity in patients; however, cases of therapeutic failure with such compounds have been documented, therefore, the use of polygenics is still the best alternative in such cases. This review presents data about the properties and applications of antifungal-polygenic compounds using amphotericin B as a model. Key words: Amphotericin B; antifungal polyenes; ergosterol


Sign in / Sign up

Export Citation Format

Share Document