is an opportunistic fungal pathogen that causes infections mainly in immunosuppressed individuals, such as transplant recipients.
This study investigated the effects of rapamycin, an ...immunosuppressant drug, on the cellular organization, biophysical characteristics, and main virulence factors of
.
Morphological, structural, physicochemical and biophysical analyses of cells and secreted polysaccharides of the reference H99
strain were investigated under the effect of subinhibitory concentrations of rapamycin.
Rapamycin at a minimum inhibitory concentration of 2.5 μM reduced
cell viability by 53%, decreased capsule, increased cell size, chitin and lipid body formation, and changed peptidase and urease activity.
Further studies are needed to assess how rapamycin affects the virulence factors and pathogenicity of
Cryptococcosis is a fungal infection caused by a type of fungus called
. Among the
group,
is often linked to fungal infections in people who have a weak immune system (known as being immunosuppressed). The main aim of this work was to look at the effect of an immunosuppressant called rapamycin, which is commonly used to prevent organ transplant rejection, on the ability of
to cause infection. The results showed that this drug stopped the growth of the fungus, dampening its ability to cause disease.
Discovery of novel anticandidal agents with clarified mechanisms of action, could be a rationalist approach against diverse pathogenic fungal strains due to the rise of resistance to existing drugs. ...In support to this hypothesis, in this paper, a series of benzimidazole-oxadiazole compounds were synthesized and subjected to antifungal activity evaluation. In vitro activity assays indicated that some of the compounds exhibited moderate to potent antifungal activities against tested
species when compared positive control amphotericin B and ketoconazole. The most active compounds
and
were evaluated in terms of inhibitory activity upon ergosterol biosynthesis by an LC-MS-MS method and it was determined that they inhibited ergosterol synthesis concentration dependently. Docking studies examining interactions between most active compounds and lanosterol 14-α-demethylase also supported the in vitro results.
Systemic fungal infections caused by filamentous fungi, particularly in the immunocompromised population, represent a serious threat to public health. The increase in resistant strains to classic ...antifungal drugs, especially azoles, is a global health problem, with some infections becoming almost impossible to treat. Furthermore, the emergence of new multidrug-resistant fungal species, such as Scedosporium spp. and Fusarium spp., as etiological agents, poses a challenge in treatment. On the other hand, superficial fungal infections caused by dermatophytes have a high incidence rate, affecting approximately 20 to 30% of the healthy human population. Therefore, the discovery and development of new broad-spectrum antifungal compounds able to modulate and/or eradicate antifungal resistance have become an essential and urgent task. Taking into account that thioxanthones are privileged structures and bioisosteres of xanthones, three thioxanthones were synthesized and, subsequently, their activity as potential agents against filamentous fungi was evaluated. A minimum inhibitory concentration and minimum lethal concentration was tested against clinically relevant species using the broth microdilution method. The derivatives were synthesized through aromatic nucleophilic substitution reactions using a chlorinated thioxanthone and a primary amine as the building blocks. This showed interesting results against most of the isolates tested, including intrinsically resistant strains or those that acquired resistance to fluconazole or other azoles; among the tested compounds, one of the thioxanthone showed more promising activity. These findings highlight the potential value of thioxanthone derivatives as new models for antifungal agents for the treatment of systemic and superficial fungal infections.
This work aims to explore the capacity of a
(later heterotypic synonym of
) strain named XT1 CECT 8661 against the necrotrophic plant pathogen
and to identify the compounds responsible for its ...activity. Q_TOF electrospray mass spectrometry analysis allows us to detect several lipopeptides - surfactin, bacillomycin, and fengycin - in XT1 cultures.
antibiosis studies demonstrated the efficiency of the lipopeptide fraction for the inhibition of fungal growth. In fact, microscopy studies (SEM/TEM) revealed, an alteration of the morphology of the phytopathogen in interaction with lipopeptides, with resistance structures appearing in the early stages of growth of the fungus. Our studies, carried out with tomatoes, grapes, and strawberries have demonstrated the efficiency of
XT1 CECT 8661 lipopeptides against
infection and it capability to trigger the antioxidant activity in fruit. Overall, the results of this study highlight the potential of lipopeptides of this strain as an effective biological control agent against the colonisation of
.
Antimicrobial peptides (AMPs) are essential components of immune defenses of multicellular organisms and are currently in development as anti-infective drugs. AMPs have been classically assumed to ...have broad-spectrum activity and simple kinetics, but recent evidence suggests an unexpected degree of specificity and a high capacity for synergies. Deeper evaluation of the molecular evolution and population genetics of AMP genes reveals more evidence for adaptive maintenance of polymorphism in AMP genes than has previously been appreciated, as well as adaptive loss of AMP activity. AMPs exhibit pharmacodynamic properties that reduce the evolution of resistance in target microbes, and AMPs may synergize with one another and with conventional antibiotics. Both of these properties make AMPs attractive for translational applications. However, if AMPs are to be used clinically, it is crucial to understand their natural biology in order to lessen the risk of collateral harm and avoid the crisis of resistance now facing conventional antibiotics.
Penicillium digitatum is a destructive post-harvest pathogen of citrus fruit during storage and marketing. The aim of this study is to evaluate the activity of the natural polyphenolic compounds, ...tannins, on P. digitatum. Tannins acted against P. digitatum by inhibiting its mycelial growth and spore germination. In vivo tests showed that tannins significantly (P < 0.05) decrease the disease symptoms of P. digitatum in artificially inoculated citrus fruit. Storage tests also showed that tannins reduce the disease severity of green mold on citrus fruit by 70%. To determine the antifungal mechanism of tannins on P. digitatum, we evaluated the integrity of the cell wall and the permeability of the membrane. The disruption of cell wall and the plasma membrane caused leakage of the intracellular contents, such as sugars. These findings suggest that the cell wall of P. digitatum is the target for tannins and that they can potentially be used as an alternative to control citrus green mold.
•Spore germination of P. digitatum is inhibited by tannins.•Tannins reduce disease severity on citrus fruit.•Tannins disrupt cell wall and the plasma membrane of the pathogen.
Although the antibacterial properties of MXene nanosheets containing Ti3C2Tx are known, their antifungal properties have not been well studied. Herein, we present for the first time a report on the ...antifungal properties of Ti3C2Tx MXene. The Ti3C2Tx MXene was obtained by first exfoliating MAX phase of Ti3AlC2 with concentrated hydrofluoric acid, then the Ti3C2Tx was intercalated and deliminated by ethanol treatment and ultrasonication process. The delaminated Ti3C2Tx MXene nanosheets (d-Ti3C2Tx) were characterized using field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX), X-ray diffraction spectroscopy (XRD), and Raman spectroscopy. It was found that Ti3C2Tx MXene was characterized by lamellar structure alternating with layers of Ti, Al and C. The EDX results revealed that the delaminated Ti3C2Tx MXene nanosheets were composed of Ti, C, Si, O, F, and a trace amount of Al. The XRD and Raman spectra further indicated the elimination of Al and the formation of two-dimensional Ti3C2Tx MXene nanosheets. The antifungal activity of the delaminated Ti3C2Tx MXene was determined against Trichoderma reesei using the modified agar disc method. Observation using inverted phase contrastmicroscopy revealed inhibited fungus growth with the absence of hyphae around the discs treated wtih MXene. The surrounding of the control groups without an inclusion of MXene was found with large number of hyphae and spores. In addition, the spores of the fungi treated with the samples containing d-Ti3C2Tx MXene nanosheets did not germinate even after 11 days of culture. The results demonstrated disruption to the hemispheric structural formation of fungi colony, inhibition of hyphae growth and cell damage for fungi grown on the d-Ti3C2Tx MXene nanosheets. These new findings suggest that d-Ti3C2Tx MXene nanosheets developed in this work could be a promising anti-fungi material.
•The first report on the antifungal properties of d-Ti3C2Tx MXene nanosheets.•The interlayer distance of d-Ti3C2Tx MXene nanosheets can be easily expanded by ethanol.•The d-Ti3C2Tx MXene nanosheets were characterized by lamellar structure with alternating layers of Ti, Al, and C.•d-Ti3C2Tx MXene nanosheets inhibit the growth of mycelium and spore germination of trichoderma reesei.
Antifungal activities of plant-beneficial
Bacillus
have been widely studied in recent years. Numerous studies have studied the antifungal mechanisms of soluble non-volatile bioactive compounds such ...as lipopeptides and proteins produced by
Bacillus
against soil-borne diseases. However, the antagonistic mechanisms of volatile organic compounds (VOCs) from
Bacillus
against airborne phytopathogens are still largely unknown, and the function of
Alternaria solani
pathogenic genes has not been well identified. Here, we first isolated a
Bacillus
strain with strong antifungal activity and finally identified it as
B. subtilis
ZD01. Then, the antagonistic mechanisms of VOCs produced by strain ZD01, against
A. solani
, an airborne fungal pathogen that can cause early blight diseases of potato, were studied. We showed that VOCs produced by strain ZD01 can reduce the colony size and mycelial penetration and can cause serious morphological changes of
A. solani
. Scanning electron microscope (SEM) observation showed that VOCs released by ZD01 could cause more flaccid and gapped hyphae of
A. solani
. Also, we found that VOCs produced by ZD01 can inhibit the conidia germination and reduce the lesion areas and number of
A. solani in vivo
significantly. Meanwhile, based on gas chromatography/mass spectrometry (GC/MS) analysis, 29 volatile compounds produced by strain ZD01 were identified. Out of 29 identified VOCs, 9 VOCs showed complete growth inhibition activities against
A. solani
. Moreover, we identified two virulence-associated genes (
slt2
and
sod
) in
A. solani
.
slt2
is a key gene that regulates the mycelial growth, penetration, sporulation, and virulence
in vivo
in
A. solani
. In addition,
sod
plays a significant role in the SOD synthetic pathway in
A. solani
. Results from qRT-PCR showed that the transcriptional expression of these two genes was down-regulated after being treated by VOCs produced by ZD01. These results are useful for a better understanding of the biocontrol mechanism of
Bacillus
and offer a potential method for potato early blight disease control.
Microorganisms living inside plants can promote plant growth and health, but their genomic and functional diversity remain largely elusive. Here, metagenomics and network inference show that fungal ...infection of plant roots enriched for Chitinophagaceae and Flavobacteriaceae in the root endosphere and for chitinase genes and various unknown biosynthetic gene clusters encoding the production of nonribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs). After strain-level genome reconstruction, a consortium of
and
was designed that consistently suppressed fungal root disease. Site-directed mutagenesis then revealed that a previously unidentified NRPS-PKS gene cluster from
was essential for disease suppression by the endophytic consortium. Our results highlight that endophytic root microbiomes harbor a wealth of as yet unknown functional traits that, in concert, can protect the plant inside out.
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