Isoeugenol Affects Expression Pattern of Conidial Hydrophobin Gene RodA and Transcriptional Regulators MedA and SomA Responsible for Adherence and Biofilm Formation in Aspergillus fumigatus

Abstract Aspergillus fumigatus is one of the major pathogenic fungal species, causing life-threatening infections. Due to a limited spectrum of available antifungals, exploration of new drug targets as well as potential antifungal molecules has become pertinent. Rodlet layer plays an important role in adherence of fungal conidia to hydrophobic cell surfaces in host, which also leads to A. fumigatus biofilm formation, contributing factor to fungal pathogenicity. From decades, natural sources have been known for the development of new active molecules. The present study investigates effect of isoeugenol on genes responsible for hydrophobins (RodA), adhesion as well as biofilm formation (MedA and SomA) of A. fumigatus. Minimum inhibitory concentrations (MIC and IC50) of isoeugenol against A. fumigatus were determined using broth microdilution assay. The IC50 results showed reduced hydrophobicity and biofilm formation after treatment with the compound and electron micrograph data corroborated these findings. The qRT-PCR showed a significant downregulation of genes RodA, MedA, SomA and pksP involved in hydrophobicity and biofilm formation. SwissADME studies potentiated drug-like propensity for isoeugenol which formed four hydrogen bonds with low binding energy (-4.54 Kcal/mol) at the catalytic site of RodA protein studied via AutoDock4. Hence, the findings conclude that isoeugenol inhibits conidial hydrophobicity and biofilm formation of A. fumigatus and further investigations are warranted in this direction.

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Substituted 6,7-dimethoxy-5-oxo-2,3,5,9b-tetrahydrothiazolo[2,3-a]isoindole- 3-1,1-dioxide Derivatives with Antimicrobial Activity and Docking Assisted Prediction of the Mechanism of their Antibacterial and Antifungal Properties

Current Topics in Medicinal Chemistry ◽

10.2174/1568026620666200922114735 ◽

2020 ◽

Vol 20 (29) ◽

pp. 2681-2691

Author(s):

Athina Geronikaki ◽

Victor Kartsev ◽

Phaedra Eleftheriou ◽

Anthi Petrou ◽

Jasmina Glamočlija ◽

...

Keyword(s):

Antimicrobial Activity ◽

Antifungal Activity ◽

Drug Targets ◽

Bacterial Species ◽

Pharmaceutical Research ◽

Docking Studies ◽

Fungal Species ◽

Docking Analysis ◽

E Coli ◽

Antibacterial And Antifungal

Background: Although a great number of the targets of antimicrobial therapy have been achieved, it remains among the first fields of pharmaceutical research, mainly because of the development of resistant strains. Docking analysis may be an important tool in the research for the development of more effective agents against specific drug targets or multi-target agents 1-3. Methods: In the present study, based on docking analysis, ten tetrahydrothiazolo[2,3-a]isoindole derivatives were chosen for the evaluation of the antimicrobial activity. Results: All compounds showed antibacterial activity against eight Gram-positive and Gram-negative bacterial species being, in some cases, more potent than ampicillin and streptomycin against all species. The most sensitive bacteria appeared to be S. aureus and En. Cloacae, while M. flavus, E. coli and P. aeruginosa were the most resistant ones. The compounds were also tested for their antifungal activity against eight fungal species. All compounds exhibited good antifungal activity better than reference drugs bifonazole (1.4 – 41 folds) and ketoconazole (1.1 – 406 folds) against all fungal species. In order to elucidate the mechanism of action, docking studies on different antimicrobial targets were performed. Conclusion: According to docking analysis, the antifungal activity can be explained by the inhibition of the CYP51 enzyme for most compounds with a better correlation of the results obtained for the P.v.c. strain (linear regression between estimated binding Energy and log(1/MIC) with R 2 =0.867 and p=0.000091 or R 2 = 0.924, p= 0.000036, when compound 3 is excluded.

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Aspergillus fumigatus, One Uninucleate Species with Disparate Offspring

Journal of Fungi ◽

10.3390/jof7010030 ◽

2021 ◽

Vol 7 (1) ◽

pp. 30

Author(s):

François Danion ◽

Norman van Rhijn ◽

Alexandre C. Dufour ◽

Rachel Legendre ◽

Odile Sismeiro ◽

...

Keyword(s):

Respiratory Tract ◽

Aspergillus Fumigatus ◽

Filamentous Fungus ◽

Fungal Species ◽

Conidial Germination ◽

Biological Cycle ◽

Gene Deletions ◽

Airborne Conidia ◽

Nutritional Environment ◽

Germination Parameters

Establishment of a fungal infection due to Aspergillus fumigatus relies on the efficient germination of the airborne conidia once they penetrate the respiratory tract. However, the features of conidial germination have been poorly explored and understood in this fungal species as well as in other species of filamentous fungi. We show here that the germination of A. fumigatus is asynchronous. If the nutritional environment and extensive gene deletions can modify the germination parameters for A. fumigatus, the asynchrony is maintained in all germinative conditions tested. Even though the causes for this asynchrony of conidial germination remain unknown, asynchrony is essential for the completion of the biological cycle of this filamentous fungus.

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Antimicrobial and Immunomodulating Activities of Two Endemic Nepeta Species and Their Major Iridoids Isolated from Natural Sources

Pharmaceuticals ◽

10.3390/ph14050414 ◽

2021 ◽

Vol 14 (5) ◽

pp. 414

Author(s):

Neda Aničić ◽

Uroš Gašić ◽

Feng Lu ◽

Ana Ćirić ◽

Marija Ivanov ◽

...

Keyword(s):

Biofilm Formation ◽

Food Industry ◽

Balkan Peninsula ◽

Antimicrobial Activities ◽

Natural Sources ◽

E Coli ◽

Food Borne ◽

Metabolite Profiles ◽

Aspergillus Sp ◽

First Time

Two Balkan Peninsula endemics, Nepeta rtanjensis and N. argolica subsp. argolica, both characterized by specialized metabolite profiles predominated by iridoids and phenolics, are differentiated according to the stereochemistry of major iridoid aglycone nepetalactone (NL). For the first time, the present study provides a comparative analysis of antimicrobial and immunomodulating activities of the two Nepeta species and their major iridoids isolated from natural sources—cis,trans-NL, trans,cis-NL, and 1,5,9-epideoxyloganic acid (1,5,9-eDLA), as well as of phenolic acid rosmarinic acid (RA). Methanol extracts and pure iridoids displayed excellent antimicrobial activity against eight strains of bacteria and seven strains of fungi. They were especially potent against food-borne pathogens such as L. monocytogenes, E. coli, S. aureus, Penicillium sp., and Aspergillus sp. Targeted iridoids were efficient agents in preventing biofilm formation of resistant P. aeruginosa strain, and they displayed additive antimicrobial interaction. Iridoids are, to a great extent, responsible for the prominent antimicrobial activities of the two Nepeta species, although are probably minor contributors to the moderate immunomodulatory effects. The analyzed iridoids and RA, individually or in mixtures, have the potential to be used in the pharmaceutical industry as potent antimicrobials, and in the food industry to increase the shelf life and safety of food products.

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Dectin-2-Targeted Antifungal Liposomes Exhibit Enhanced Efficacy

mSphere ◽

10.1128/msphere.00715-19 ◽

2019 ◽

Vol 4 (5) ◽

Cited By ~ 1

Author(s):

Suresh Ambati ◽

Emma C. Ellis ◽

Jianfeng Lin ◽

Xiaorong Lin ◽

Zachary A. Lewis ◽

...

Keyword(s):

Candida Albicans ◽

Aspergillus Fumigatus ◽

Effective Dose ◽

Cryptococcus Neoformans ◽

Amphotericin B ◽

Antifungal Drugs ◽

Extracellular Matrices ◽

Content Type ◽

Order Of Magnitude ◽

Life Threatening

ABSTRACT Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus cause life-threatening candidiasis, cryptococcosis, and aspergillosis, resulting in several hundred thousand deaths annually. The patients at the greatest risk of developing these life-threatening invasive fungal infections have weakened immune systems. The vulnerable population is increasing due to rising numbers of immunocompromised individuals as a result of HIV infection or immunosuppressed individuals receiving anticancer therapies and/or stem cell or organ transplants. While patients are treated with antifungals such as amphotericin B, all antifungals have serious limitations due to lack of sufficient fungicidal effect and/or host toxicity. Even with treatment, 1-year survival rates are low. We explored methods of increasing drug effectiveness by designing fungicide-loaded liposomes specifically targeted to fungal cells. Most pathogenic fungi are encased in cell walls and exopolysaccharide matrices rich in mannans. Dectin-2 is a mammalian innate immune membrane receptor that binds as a dimer to mannans and signals fungal infection. We coated amphotericin-loaded liposomes with monomers of Dectin-2’s mannan-binding domain, sDectin-2. sDectin monomers were free to float in the lipid membrane and form dimers that bind mannan substrates. sDectin-2-coated liposomes bound orders of magnitude more efficiently to the extracellular matrices of several developmental stages of C. albicans, C. neoformans, and A. fumigatus than untargeted control liposomes. Dectin-2-coated amphotericin B-loaded liposomes reduced the growth and viability of all three species more than an order of magnitude more efficiently than untargeted control liposomes and dramatically decreased the effective dose. Future efforts focus on examining pan-antifungal targeted liposomal drugs in animal models of fungal diseases. IMPORTANCE Invasive fungal diseases caused by Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus have mortality rates ranging from 10 to 95%. Individual patient costs may exceed $100,000 in the United States. All antifungals in current use have serious limitations due to host toxicity and/or insufficient fungal cell killing that results in recurrent infections. Few new antifungal drugs have been introduced in the last 2 decades. Hence, there is a critical need for improved antifungal therapeutics. By targeting antifungal-loaded liposomes to α-mannans in the extracellular matrices secreted by these fungi, we dramatically reduced the effective dose of drug. Dectin-2-coated liposomes loaded with amphotericin B bound 50- to 150-fold more strongly to C. albicans, C. neoformans, and A. fumigatus than untargeted liposomes and killed these fungi more than an order of magnitude more efficiently. Targeting drug-loaded liposomes specifically to fungal cells has the potential to greatly enhance the efficacy of most antifungal drugs.

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Prevalence of Aspergillus fumigatus and other fungal species in the sputum of adult patients with cystic fibrosis

Mycoses ◽

10.1046/j.1439-0507.2003.00830.x ◽

2003 ◽

Vol 46 (1-2) ◽

pp. 19-23 ◽

Cited By ~ 134

Author(s):

N. Bakare ◽

V. Rickerts ◽

J. Bargon ◽

G. Just-Nübling

Keyword(s):

Cystic Fibrosis ◽

Aspergillus Fumigatus ◽

Fungal Species ◽

Adult Patients

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Crystal structure of an Lrs14-like archaeal biofilm regulator fromSulfolobus acidocaldarius

Acta Crystallographica Section D Structural Biology ◽

10.1107/s2059798318014146 ◽

2018 ◽

Vol 74 (11) ◽

pp. 1105-1114

Author(s):

Marian S. Vogt ◽

Simon L. Völpel ◽

Sonja-Verena Albers ◽

Lars-Oliver Essen ◽

Ankan Banerjee

Keyword(s):

Crystal Structure ◽

Biofilm Formation ◽

Coiled Coil ◽

Transcriptional Regulators ◽

Bioinformatic Analysis ◽

Considerable Degree ◽

Sulfolobus Acidocaldarius ◽

Asymmetric Unit ◽

Winged Helix ◽

Structural Differences

The small winged helix–turn–helix (wHTH) proteins of the Lrs14 family are major transcriptional regulators and act as archaeal biofilm regulators (AbfRs) in the crenarchaeoteSulfolobus acidocaldarius. Here, the first crystal structure of an AbfR ortholog, AbfR2, the deletion of which is known to impair biofilm formation, is presented. Like most other wHTH orthologs, AbfR2 is dimeric in solution as well as in its 2.45 Å resolution crystal structure. Given the presence of three independent AbfR2 dimers in the asymmetric unit, the crystal structure shows a considerable degree of conformational variation within the dimer, the antiparallel orientations of which are stabilized by coiled-coil interaction between H4 helices. Conserved anchor interactions between helices H0 and H4 of AbfR2 further contribute to dimer stabilization. The combined structural and bioinformatic analysis reveals cluster-specific structural differences between different members of the Lrs14 protein family.

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Chromatin profiling reveals genome stability heterogeneity in clinical isolates of the human pathogen Aspergillus fumigatus

10.1101/2021.04.19.440431 ◽

2021 ◽

Author(s):

Ana Cristina Colabardini ◽

Fang Wang ◽

Zhengqiang Miao ◽

Lakhansing Pardeshi ◽

Clara Valero ◽

...

Keyword(s):

Aspergillus Fumigatus ◽

Genome Stability ◽

Genome Instability ◽

Invasive Pulmonary Aspergillosis ◽

Biosynthetic Gene Cluster ◽

Clinical Isolates ◽

Immunosuppressed Patients ◽

Life Threatening ◽

Metabolites Production ◽

Chromatin Profiling

Invasive Pulmonary aspergillosis is a life-threatening infection in immunosuppressed patients caused by the filamentous fungus Aspergillus fumigatus. Chromatin structure regulation is important for genome stability maintenance and has the potential to lead to genome rearrangements driving differences in virulence and pathogenesis of different A. fumigatus isolates. Here, we compared the chromatin activities of the most investigated clinical isolates Af293 and CEA17 and uncovered striking differences in the number, locations and expression of transposable elements. We found evidence for higher genome instability in Af293 as compared to CEA17 and identified a spontaneous Af293 variant that exhibits gross chromosomal alterations including the loss of a 320 kb long segment in chromosome VIII and the amplification of a biosynthetic gene cluster. As a consequence of these re-arrangements, the variant shows increased secondary metabolites production, growth and virulence. Our work emphasizes genome stability heterogeneity as an evolutionary driver of A. fumigatus fitness and virulence.

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Microbial Warfare on Three Fronts: Mixed Biofilm of Aspergillus fumigatus and Staphylococcus aureus on Primary Cultures of Human Limbo-Corneal Fibroblasts

Frontiers in Cellular and Infection Microbiology ◽

10.3389/fcimb.2021.646054 ◽

2021 ◽

Vol 11 ◽

Author(s):

Adrián Ramírez-Granillo ◽

Luis Antonio Bautista-Hernández ◽

Víctor Manuel Bautista-De Lucío ◽

Fátima Sofía Magaña-Guerrero ◽

Alfredo Domínguez-López ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Aspergillus Fumigatus ◽

Biofilm Formation ◽

Primary Cultures ◽

Morphological Characterization ◽

Fibroblast Culture ◽

Bacterial Biofilm ◽

Corneal Fibroblast ◽

Corneal Fibroblasts ◽

Fibroblast Monolayer

BackgroundCoinfections with fungi and bacteria in ocular pathologies are increasing at an alarming rate. Two of the main etiologic agents of infections on the corneal surface, such as Aspergillus fumigatus and Staphylococcus aureus, can form a biofilm. However, mixed fungal–bacterial biofilms are rarely reported in ocular infections. The implementation of cell cultures as a study model related to biofilm microbial keratitis will allow understanding the pathogenesis in the cornea. The cornea maintains a pathogen-free ocular surface in which human limbo-corneal fibroblast cells are part of its cell regeneration process. There are no reports of biofilm formation assays on limbo-corneal fibroblasts, as well as their behavior with a polymicrobial infection.ObjectiveTo determine the capacity of biofilm formation during this fungal–bacterial interaction on primary limbo-corneal fibroblast monolayers.ResultsThe biofilm on the limbo-corneal fibroblast culture was analyzed by assessing biomass production and determining metabolic activity. Furthermore, the mixed biofilm effect on this cell culture was observed with several microscopy techniques. The single and mixed biofilm was higher on the limbo-corneal fibroblast monolayer than on abiotic surfaces. The A. fumigatus biofilm on the human limbo-corneal fibroblast culture showed a considerable decrease compared to the S. aureus biofilm on the limbo-corneal fibroblast monolayer. Moreover, the mixed biofilm had a lower density than that of the single biofilm. Antibiosis between A. fumigatus and S. aureus persisted during the challenge to limbo-corneal fibroblasts, but it seems that the fungus was more effectively inhibited.ConclusionThis is the first report of mixed fungal–bacterial biofilm production and morphological characterization on the limbo-corneal fibroblast monolayer. Three antibiosis behaviors were observed between fungi, bacteria, and limbo-corneal fibroblasts. The mycophagy effect over A. fumigatus by S. aureus was exacerbated on the limbo-corneal fibroblast monolayer. During fungal–bacterial interactions, it appears that limbo-corneal fibroblasts showed some phagocytic activity, demonstrating tripartite relationships during coinfection.

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PRESENTATION PATTERN AND FUNGAL AGENTS SPECTRUM CAUSING OTOMMYCOSIS

Asian Journal of Pharmaceutical and Clinical Research ◽

10.22159/ajpcr.2017.v11i1.24368 ◽

2018 ◽

Vol 11 (1) ◽

pp. 408

Author(s):

Kassim Dekhil

Keyword(s):

Candida Albicans ◽

Aspergillus Niger ◽

Aspergillus Fumigatus ◽

Influencing Factors ◽

Aspergillus Flavus ◽

Species Distribution ◽

Alternaria Alternata ◽

Otitis Externa ◽

Fungal Species ◽

The Public

Objective: This study was aimed to identify the public pattern of presentation, influencing factors, and sort the fungal species, distribution of sex of patients with otomycosis.Results: The predominant complaints were pruritus and found in 76 patients (88.73%), discomfort and pain found in 62 patients (72.09%), aural fullness in 48 patients (55.81%), tinnitus in 34 patients (39.53%), hearing impairment in 50 cases (58.31%), ear discharge in 22 patients (25.58%), and most of the symptoms seen in 36 patients (68.14%). The results showed a total of eight fungal species belong to six different genera, namely, Aspergillus, Candida, Penicillium, Rhizopus, Alternaria, and Cephalosporium were isolated during this study. Among identified fungi, Aspergillus niger was found to be the most prevalent fungal species with 35.71% followed by Candida albicans (27.55%), Aspergillus flavus (10.20%), Aspergillus fumigatus (8.16), Penicillium digitatum (6.12%) and Cephalosporium species (4.08%), and Rhizopus species (5.1%), while Alternaria alternata had the lowest percentage (6.54%).Conclusion: Otomycosis/mycotic otitis externa is still a common problem and there is a rise in the occurrence of otomycosis in latest years, especially in tropical and subtropical humid climates.

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