scholarly journals Derivatives of the antimalarial drug mefloquine are broad spectrum antifungal molecules with activity against drug-resistant clinical isolates

2019 ◽  
Author(s):  
Marhiah C. Montoya ◽  
Sarah Beattie ◽  
Kathryn M. Alden ◽  
Damian J. Krysan
Keyword(s):  
Antifungal Activity ◽  
Mechanism Of Action ◽  
Broad Spectrum ◽  
Fungal Infections ◽  
Clinical Isolates ◽  
In Vitro Toxicity ◽  
Drug Resistant ◽  
Candida Auris ◽  
Recent Emergence ◽  
Derivatives Of

ABSTRACTThe antifungal pharmacopeia is critically small, particularly in light of the recent emergence of multi-drug-resistant pathogens such as Candida auris. Herein, we report that derivatives of the anti-malarial drug mefloquine have broad spectrum antifungal activity against pathogenic yeasts and molds. In addition, the mefloquine derivatives have activity against clinical isolates that are resistant to one or more of the three classes of drugs currently used to treat invasive fungal infections, indicating that they have a novel mechanism of action. Importantly, the in vitro toxicity profiles using human cell lines indicate that the mefloquine derivatives are very similar to the parent mefloquine despite being up to 64-fold more active against fungal cells. In addition to direct antifungal activity, sub-inhibitory concentrations of the mefloquine derivatives inhibit the expression of virulence traits including filamentation in C. albicans and capsule formation/melanization in C. neoformans. Mode/mechanism of action experiments indicate that the mefloquine derivatives interfere with both mitochondrial and vacuolar function as part of a multi-target mechanism of action. The broad-spectrum scope of activity, blood-brain-barrier penetration, and large number of previously synthesized analogs available combine to support the further optimization and development of the antifungal activity of this general class of drug-like molecules.

scholarly journals Derivatives of the Antimalarial Drug Mefloquine Are Broad-Spectrum Antifungal Molecules with Activity against Drug-Resistant Clinical Isolates

2020 ◽  
Vol 64 (3) ◽  
Author(s):  
Marhiah C. Montoya ◽  
Sarah Beattie ◽  
Kathryn M. Alden ◽  
Damian J. Krysan
Keyword(s):  
Antifungal Activity ◽  
Mechanism Of Action ◽  
Broad Spectrum ◽  
Antimalarial Drug ◽  
Fungal Infections ◽  
Antifungal Drugs ◽  
Clinical Isolates ◽  
Content Type ◽  
Recent Emergence ◽  
Derivatives Of

ABSTRACT The antifungal pharmacopeia is critically small, particularly in light of the recent emergence of multidrug-resistant pathogens, such as Candida auris. Here, we report that derivatives of the antimalarial drug mefloquine have broad-spectrum antifungal activity against pathogenic yeasts and molds. In addition, the mefloquine derivatives have activity against clinical isolates that are resistant to one or more of the three classes of antifungal drugs currently used to treat invasive fungal infections, indicating that they have a novel mechanism of action. Importantly, the in vitro toxicity profiles obtained using human cell lines indicated that the toxicity profiles of the mefloquine derivatives are very similar to those of the parent mefloquine, despite being up to 64-fold more active against fungal cells. In addition to direct antifungal activity, subinhibitory concentrations of the mefloquine derivatives inhibited the expression of virulence traits, including filamentation in Candida albicans and capsule formation/melanization in Cryptococcus neoformans. Mode/mechanism-of-action experiments indicated that the mefloquine derivatives interfere with both mitochondrial and vacuolar function as part of a multitarget mechanism of action. The broad-spectrum scope of activity, blood-brain barrier penetration, and large number of previously synthesized analogs available combine to support the further optimization and development of the antifungal activity of this general class of drug-like molecules.

scholarly journals Impact of antifungal resistance in Australia

2007 ◽  
Vol 28 (4) ◽  
pp. 174 ◽  
Author(s):  
David Ellis ◽  
Tania Sorrell ◽  
Sharon Chen
Keyword(s):  
Antifungal Activity ◽  
Selection Pressure ◽  
Opportunistic Infections ◽  
Fungal Infections ◽  
Fungal Species ◽  
Antifungal Drugs ◽  
Drug Resistant ◽  
Populations At Risk ◽  
Complete Resistance ◽  
Major Increase

The last two to three decades have seen a major increase in invasive fungal infections (IFIs), a small, but increasing proportion of which are caused by pathogens with partial or complete resistance to antifungal drugs. The increase in IFIs has largely been associated with the increase in immunocompromised and critically ill patients. Opportunistic infections with relatively drug-resistant environmental fungi account for much of the resistance. In addition, amongst the only fungal species to colonise humans, Candida, two species that are resistant (C. krusei) or relatively resistant (C. glabrata) to fluconazole have emerged. In part this is explained by the selection pressure exerted by widespread use of fluconazole. Together with the introduction of new antifungal drugs with selective and/or variable antifungal activity, these changes have stimulated interest in understanding mechanisms and origins of resistance, the identification of resistance in the laboratory and its relationship to clinical outcomes, and in surveillance of clinical isolates and populations at risk of IFIs.

scholarly journals Non-toxic Cobalt(III) Schiff Base Complexes with Broad Spectrum Antifungal Activity

2020 ◽  
Author(s):  
Angelo Frei ◽  
A. Paden King ◽  
Gabrielle J. Lowe ◽  
Amy K. Cain ◽  
Francesca L. Short ◽  
...  
Keyword(s):  
Schiff Base ◽  
Antifungal Activity ◽  
Broad Spectrum ◽  
Bacterial Infections ◽  
Fungal Infections ◽  
Antifungal Drugs ◽  
New Drugs ◽  
Schiff Base Complexes ◽  
In Vivo Studies

Resistance to currently available antifungal drugs has quietly been on the rise but overshadowed by the alarming spread of antibacterial resistance. There is a striking lack of attention to the threat of drug resistant fungal infections, with only a handful of new drugs currently in development. Given that metal complexes have proven to be useful new chemotypes in the fight against diseases such as cancer, malaria, and bacterial infections, it stands to reason to explore their possible utility in treating fungal infections. Herein we report a series of cobalt(III) Schiff base complexes with broad spectrum antifungal activity. Some of these complexes (1-3) show minimum inhibitory concentrations (MIC) in the low micro- to nanomolar range against a series of Candida and Cryptococcus yeasts. Additionally, we demonstrate that these compounds show no cytotoxicity against both bacterial and human cells. Finally, we report first in vivo toxicity data on these compounds in Galleria mellonella, showing that doses as high as 266 mg/kg are tolerated without adverse effects, paving the way for further in vivo studies of these complexes. <br>

scholarly journals Evaluation of bisphenylthiazoles as a promising class for combating multidrug-resistant fungal infections

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0258465
Author(s):  
Mohamed Hagras ◽  
Nader S. Abutaleb ◽  
Ahmed M. Sayed ◽  
Ehab A. Salama ◽  
Mohamed N. Seleem ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Antifungal Activity ◽  
Amphotericin B ◽  
Antifungal Agent ◽  
Fungal Infections ◽  
Multidrug Resistant ◽  
Candida Auris ◽  
Conformationally Restricted ◽  
Normal Human

To minimize the intrinsic toxicity of the antibacterial agent hydrazinyloxadiazole 1, the hydrazine moiety was replaced with ethylenediamine (compound 7). This replacement generated a potent antifungal agent with no antibacterial activity. Notably, use of a 1,2-diaminocyclohexane moiety, as a conformationally-restricted isostere for ethylenediamine, potentiated the antifungal activity in both the cis and trans forms of N-(5-(2-([1,1’-biphenyl]-4-yl)-4-methylthiazol-5-yl)-1,3,4-oxadiazol-2-yl)cyclohexane-1,2-diamine (compounds 16 and 17). Both compounds 16 and 17 were void of any antibacterial activity; nonetheless, they showed equipotent antifungal activity in vitro to that of the most potent approved antifungal agent, amphotericin B. The promising antifungal effects of compounds 16 and 17 were maintained when assessed against an additional panel of 26 yeast and mold clinical isolates, including the Candida auris and C. krusei. Furthermore, compound 17 showed superior activity to amphotericin B in vitro against Candida glabrata and Cryptococcus gattii. Additionally, neither compound inhibited the normal human microbiota, and both possessed excellent safety profiles and were 16 times more tolerable than amphotericin B.

scholarly journals Toxoflavin Produced byBurkholderia gladiolifromLycoris aureaIs a New Broad-Spectrum Fungicide

2019 ◽  
Vol 85 (9) ◽  
Author(s):  
Xiaodan Li ◽  
Yikui Li ◽  
Ren Wang ◽  
Qizhi Wang ◽  
Ling Lu
Keyword(s):  
Antifungal Activity ◽  
Broad Spectrum ◽  
Fungal Pathogens ◽  
Antifungal Agents ◽  
Fungal Infections ◽  
Endophytic Bacterium ◽  
Content Type ◽  
Burkholderia Gladioli ◽  
Lycoris Aurea ◽  
Resistant Mutants

ABSTRACTFungal infections not only cause extensive agricultural damage but also result in serious diseases in the immunodeficient populations of human beings. Moreover, the increasing emergence of drug resistance has led to a decrease in the efficacy of current antifungals. Thus, screening of new antifungal agents is imperative in the fight against antifungal drug resistance. In this study, we show that an endophytic bacterium,Burkholderia gladioliHDXY-02, isolated from the medicinal plantLycoris aurea, showed broad-spectrum antifungal activity against plant and human fungal pathogens. An antifungal ability assay indicated that the bioactive component was produced from strain HDXY-02 having an extracellular secreted component with a molecular weight lower than 1,000 Da. In addition, we found that this new antifungal could be produced effectively by liquid fermentation of HDXY-02. Furthermore, the purified component contributing to the antifungal activity was identified to be toxoflavin, a yellow compound possessing a pyrimido[5,4-e][1,2,4]triazine ring.In vitrobioactivity studies demonstrated that purified toxoflavin fromB. gladioliHDXY-02 cultures had a significant antifungal activity against the human fungal pathogenAspergillus fumigatus, resulting in abolished germination of conidia. More importantly, the growth inhibition by toxoflavin was observed in both wild-type and drug-resistant mutants (cyp51Aand non-cyp51A) ofA. fumigatus. Finally, an optimized protocol for the large-scale production of toxoflavin (1,533 mg/liter) has been developed. Taken together, our findings provide a promising biosynthetic resource for producing a new antifungal reagent, toxoflavin, from isolates of the endophytic bacteriumB. gladioli.IMPORTANCEHuman fungal infections are a growing problem associated with increased morbidity and mortality. Moreover, a growing number of antifungal-resistant fungal isolates have been reported over the past decade. Thus, the need for novel antifungal agents is imperative. In this study, we show that an endophytic bacterium,Burkholderia gladioli, isolated from the medicinal plantLycoris aurea, is able to abundantly secrete a compound, toxoflavin, which has a strong fungicidal activity not only against plant fungal pathogens but also against human fungal pathogensAspergillus fumigatusandCandida albicans,Cryptococcus neoformans, and the model filamentous fungusAspergillus nidulans. More importantly, toxoflavin also displays an efficacious inhibitory effect against azole antifungal-resistant mutants ofA. fumigatus. Consequently, our findings provide a promising approach to abundantly produce toxoflavin, which has novel broad-spectrum antifungal activity, especially against those currently problematic drug-resistant isolates.

scholarly journals Clinical Epidemiology and Risk Factors of Candida auris Bloodstream Infection in Trauma Patients

2020 ◽  
Vol 41 (S1) ◽  
pp. s168-s168
Author(s):  
Omika Katoch ◽  
Vijeta Bajpai ◽  
Surbhi Khurana ◽  
Sonal Katyal ◽  
Purva Mathur
Keyword(s):  
Risk Factors ◽  
Broad Spectrum ◽  
Clinical Epidemiology ◽  
Fungal Infections ◽  
Major Surgery ◽  
Trauma Patients ◽  
Candida Auris ◽  
Becton Dickinson ◽  
Broad Spectrum Antibiotics ◽  
Hospital Acquired

Background: Candidiasis caused by Candida auris is one of the most serious hospital-acquired infection. Initially, Candida auris was reported to cause local infections; later, invasive candidasis was also reported in which the bloodstream, the central nervous system, kidneys, liver eyes, etc, are invaded. In this study, we evaluated the clinical epidemiology and risk factors in patients hospitalized to trauma center. Methods: This study was conducted at JPN Apex Trauma Centre of All India Institute of Medical Sciences, New Delhi, which is a 169-bed hospital. All patients who were identified to have candidemia due to C. auris over a period of 5 years from January 2012 to December 2016 were included. Blood samples were collected in BAC-T-Alert bottles (Bio Merieux, Durham, NC) and isolates were identified up to the species level by the VITEK 2 (version 8.01, BioMerieux). Conventional identification was performed by observing color development on CHROMagar (Becton Dickinson, Franklin Lakes, NJ). The demographic and clinical data of patients were collected from the hospital information system. Results: Over a period of 5 years, 20 patients admitted to our trauma hospital developed candidemia due to Candida auris. Among them, men were predominant (95%), and the mean (SD) age of the patients was 33 (+15) years. Among these patients, 80% were in hospitalized and 20% were follow-up patients. The median of the total length of stay in the hospital was 34 days (range, 7–122). All of the patients were on mechanical ventilation; 65% patients were catheterized and 75% patients had central line placed. Head injury was the major cause of trauma followed by abdomen, chest, and spine. The overall mortality rate was 40%. Most of the patients (65%) who developed Candida auris infection were immunocompromised. The different comorbidities present were hypertension (35%), diabetes (15%), renal disease (10%), and hepatitis C (5%). Broad-spectrum antibiotics were given: amoxicillin-clavulanate was given to 65% of patients; cefoperazone sulbactam was given to 30% of patients; chloroamphenicol, amicillin-sulbactam, or clindamycin was given to 10% of patients. Antifungal agents like fluconazole or caspofungin were given to 5% of patients. Major surgeries like cranioplasty were performed in 58% of patients. Pancreatectomy, laparotomy, and endoscopic necrosectomy were performed in 42% of patients. Conclusions:Candida auris is one of the dreaded and most commonly spread hospital-acquired fungal infections, especially in immunocompromised patients. Broad-spectrum antibiotics use, major surgery, and invasive devices were the most common risk factors for acquiring Candida auris infection.Funding: NoneDisclosures: None

scholarly journals Antifungal In Vitro Activity of Pilosulin- and Ponericin-Like Peptides from the Giant Ant Dinoponera quadriceps and Synergistic Effects with Antimycotic Drugs

Antibiotics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 354 ◽  
Author(s):  
Hilania Valéria Dodou Lima ◽  
Carolina Sidrim de Paula Cavalcante ◽  
Gandhi Rádis-Baptista
Keyword(s):  
Antifungal Activity ◽  
Antimicrobial Peptides ◽  
Broad Spectrum ◽  
Culture Medium ◽  
Fungal Infections ◽  
Synergistic Effects ◽  
Antifungal Drugs ◽  
Clinical Strain ◽  
Onset Of Action

Venoms from ants comprise a rich source of bioactive peptides, including antimicrobial peptides. From the proteome and peptidome of the giant ant Dinoponera quadriceps venom, members of five known classes of antimicrobial peptides were disclosed (e.g., dermaseptin-, defensin-, ICK-, pilosulin- and ponericin-like types). Based on comparative analysis, these family members have structural determinants that indicate they could display antimicrobial activities. In previous works, pilosulin- and ponericin-like peptides were demonstrated to be active against bacteria, fungi, and parasites. Herein, the antifungal activity of ponericin- and pilosulin-like peptides were assessed, aiming at the expansion of the knowledge about AMPs in predatory ants and the development of new microbicide strategies to deal with difficult-to-treat fungal infections. Synthetic pilosulin- (Dq-2562, Dq-1503, and Dq-1319) and ponericin-like (Dq-3162) peptides were evaluated for their fungicide and fungistatic activities against different species of Candida, including a drug-resistant clinical strain. The MICs and MLCs were determined for all peptides individually and in combination with general antifungal drugs by the microdilution method. The time-kill kinetic curves were set up by means of a luminescent reagent, of which the light signal is proportional to the number of viable cells. The candicidal synergism observed by the combination of subinhibitory concentrations of peptides and general antimycotic drugs were quantified by the checkerboard test and fluorescent dye permeation assay. The influence of ergosterol on the antifungal activity was verified by supplementation of culture medium. The pilosulin- (Dq-2562 and Dq-1503) and ponericin-like (Dq-3162) were the most active peptides, displaying a broad spectrum of antifungal activity in vitro, with MICs in the range of 0.625 to 10 µM. The combination of peptides and conventional antimycotic drugs displayed a synergistic reduction in the MIC values of individual peptides and drugs, while soluble ergosterol in the culture medium increased the MICs. The fungicide and fungistatic activity of the individual peptides and peptides in combination with antimycotics were time-dependent with a rapid onset of action and long-lasting effect, which involved membrane disruption as an underlying mechanism of their action. Altogether, pilosulin- and ponericin-like peptides from the giant ant D. quadriceps venom display a broad-spectrum of candicidal activity, what allows their inclusion in the row of the antifungal peptides and gives support for further studies on the development of strategies to fight candidiasis.

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