In this study, we employed a combination of genome mining and heteronuclear single quantum coherence (HSQC)-based small molecule accurate recognition technology (SMART) technology to search for fernane-type triterpenoids. Initially, potential endophytic fungi were identified through genome mining. Subsequently, fine fractions containing various fernane-type triterpenoids were selected using HSQC data collection and SMART prediction. These triterpenoids were then obtained through targeted isolation and identification. Finally, their antifungal activity was evaluated. As a result, three fernane-type triterpenoids, including two novel compounds, along with two new sesquiterpenes and four known compounds were isolated from one potential strain, Diaporthe discoidispora. Their structures were elucidated through analysis of high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) and nuclear magnetic resonance (NMR) spectroscopic data. The absolute configurations were determined using single-crystal X-ray diffraction analysis and electron capture detector (ECD) analysis. Compound 3 exhibited moderate antifungal activity against Candida albicans CMCC 98001 and Aspergillus niger.
Triterpenes/isolation & purification* ; Antifungal Agents/isolation & purification* ; Molecular Structure ; Candida albicans/drug effects* ; Ascomycota/genetics* ; Magnetic Resonance Spectroscopy ; Aspergillus niger/drug effects* ; Genome, Fungal ; Microbial Sensitivity Tests

Humans ; Candida albicans/genetics* ; CARD Signaling Adaptor Proteins/genetics* ; Mutation ; Encephalomyelitis

This study aimed to explore the mechanism of n-butanol alcohol extract of Baitouweng Decoction(BAEB) in the treatment of vulvovaginal candidiasis(VVC) in mice based on the negative regulation of NLRP3 inflammasome via PKCδ/NLRC4/IL-1Ra axis. In the experiment, female C57BL/6 mice were divided randomly into the following six groups: a blank control group, a VVC model group, high-, medium-, and low-dose BAEB groups(80, 40, and 20 mg·kg~(-1)), and a fluconazole group(20 mg·kg~(-1)). The VVC model was induced in mice except for those in the blank control group by the estrogen dependence method. After modeling, no treatment was carried out in the blank control group. The mice in the high-, medium-, and low-dose BAEB groups were treated with BAEB at 80, 40, and 20 mg·kg~(-1), respectively, and those in the fluconazole group were treated with fluconazole at 20 mg·kg~(-1). The mice in the VVC model group received the same volume of normal saline. The general state and body weight of mice in each group were observed every day, and the morphological changes of Candida albicans in the vaginal lavage of mice were examined by Gram staining. The fungal load in the vaginal lavage of mice was detected by microdilution assay. After the mice were killed, the degree of neutrophil infiltration in the vaginal lavage was detected by Papanicolaou staining. The content of inflammatory cytokines interleukin(IL)-1β, IL-18, and lactate dehydrogenase(LDH) in the vaginal lavage was tested by enzyme-linked immunosorbent assay(ELISA), and vaginal histopathology was analyzed by hematoxylin-eosin(HE) staining. The expression and distribution of NLRP3, PKCδ, pNLRC4, and IL-1Ra in vaginal tissues were measured by immunohistochemistry(IHC), and the expression and distribution of pNLRC4 and IL-1Ra in vaginal tissues were detected by immunofluorescence(IF). The protein expression of NLRP3, PKCδ, pNLRC4, and IL-1Ra was detected by Western blot(WB), and the mRNA expression of NLRP3, PKCδ, pNLRC4, and IL-1Ra was detected by qRT-PCR. The results showed that compared with the blank control group, the VVC model group showed redness, edema, and white secretions in the vagina. Compared with the VVC model group, the BAEB groups showed improved general state of VVC mice. As revealed by Gram staining, Papanicolaou staining, microdilution assay, and HE staining, compared with the blank control group, the VVC model group showed a large number of hyphae, neutrophils infiltration, and increased fungal load in the vaginal lavage, destroyed vaginal mucosa, and infiltration of a large number of inflammatory cells. BAEB could reduce the transformation of C. albicans from yeast to hyphae. High-dose BAEB could significantly reduce neutrophil infiltration and fungal load. Low-and medium-dose BAEB could reduce the da-mage to the vaginal tissue, while high-dose BAEB could restore the damaged vaginal tissues to normal levels. ELISA results showed that the content of inflammatory cytokines IL-1β, IL-18, and LDH in the VVC model group significantly increased compared with that in the blank control group, and the content of IL-1β, IL-18 and LDH in the medium-and high-dose BAEB groups was significantly reduced compared with that in the VVC model group. WB and qRT-PCR results showed that compared with the blank control group, the VVC model group showed reduced protein and mRNA expression of PKCδ, pNLRC4, and IL-1Ra in vaginal tissues of mice and increased protein and mRNA expression of NLRP3. Compared with the VVC model group, the medium-and high-dose BAEB groups showed up-regulated protein and mRNA expression of PKCδ, pNLRC4, and IL-1Ra in vaginal tissues and inhibited protein and mRNA expression of NLRP3 in vaginal tissues. This study indicated that the therapeutic effect of BAEB on VVC mice was presumably related to the negative regulation of NLRP3 inflammasome by promoting PKCδ/NLRC4/IL-1Ra axis.
Female ; Animals ; Humans ; Mice ; Candidiasis, Vulvovaginal/drug therapy* ; Inflammasomes/genetics* ; Interleukin-18 ; NLR Family, Pyrin Domain-Containing 3 Protein/genetics* ; 1-Butanol/pharmacology* ; Fluconazole/therapeutic use* ; Interleukin 1 Receptor Antagonist Protein/therapeutic use* ; Mice, Inbred C57BL ; Candida albicans ; Cytokines ; Drugs, Chinese Herbal/pharmacology* ; Ethanol ; RNA, Messenger ; Calcium-Binding Proteins/therapeutic use*

The aim of this paper was to investigate the effect of berberine hydrochloride on the cell wall integrity of Candida albicans hypha. The minimal inhibitory concentration(MIC) of berberine hydrochloride against clinical and standard C. albicans strains was detected by micro liquid-based dilution method; the effect of berberine hydrochloride on the colony formation of C. albicans SC5314 was investigated by spot assay; the effect of berberine hydrochloride on the metabolism of C. albicans SC5314 hypha was checked by XTT reduction assay, and the viability of C. albicans SC5314 hypha was tested by fluorescent staining assay. The effect of berberine hydrochloride on the morphology of C. albicans SC5314 hypha was examined by scanning electron microscope. The changes in the cell wall of C. albicans SC5314 hypha after berberine hydrochloride treatment were detected by transmission electron microscopy. The effect of berberine hydrochloride on β-glucan from C. albicans SC5314 was detected by flow cytometry. The effect of berberine hydrochloride on hypha-specific gene ECE1 and β-glucan synthase genes FKS1 and FKS2 in C. albicans was examined by qRT-PCR. The results showed that berberine hydrochloride showed a strong inhibitory effect on both clinical and standard strains of C. albicans, and the MIC was 64-128 μg·mL~(-1). Spot assay, XTT redunction assay and fluorescent staining assay showed that with the increase of berberine hydrochloride concentration, the viability of C. albicans SC5314 gradually decreased. The transmission electron microscopy scanning assay showed that this compound could cause cell wall damage of C. albicans. The flow cytometry analysis showed the exposure degree of C. albicans β-glucan. The qRT-PCR further showed that berberine hydrochloride could significantly down-regulate hypha-specific gene ECE1 and β-glucan synthase-related gene FKS1 and FKS2. In conclusion, this compound can down-regulate C. albicans and β-glucan synthase-related gene expressions, so as to destroy the cell wall structure of C. albicans, expose β-glucan and damage the integrity of the wall.
Antifungal Agents/pharmacology* ; Berberine/pharmacology* ; Candida albicans/genetics* ; Cell Wall ; Hyphae ; Microbial Sensitivity Tests

This study explored the mechanism of Sanhuang Decoction(SHD) in treating dextran sulfate sodium(DSS)-induced ulcerative colitis(UC) in mice with Candida albicans(Ca) colonization via high-throughput transcriptome sequencing. Specifically, the animal model was established by oral administration of 3.0% DSS for 7 days followed by intragastrical administration of Ca suspension at 1.0 × 10~8 cells for 4 days and then the mice were treated with SHD enema for 7 days. Afterwards, the general signs were observed and the disease activity index(DAI) was recorded every day. After mice were sacrificed, colon length and colon mucosa damage index(CMDI) were determined and the histomorphology was observed with the HE staining method. The fungal loads of feces were detected with the plate method. Anti-saccharomyces cerevisiae antibody(ASCA) and β-1,3-glucan in serum, and TNF-α, IL-1β, and IL-6 in serum and colon were detected by ELISA. High-throughput RNA sequencing method was adopted to identify transcriptome of colon tissues from the control, model and SHD(15.0 g·kg~(-1)) groups. Differentially expressed genes(DEGs) among groups were screened and the GO and KEGG pathway enrichment analysis of the DEGs was performed. The expression levels of NLRP3, ASC, caspase-1, and IL-1β genes related to the NOD-like receptor signaling pathway which involved 9 DEGs, were examined by qRT-PCR and Western blot. The results demonstrated that SHD improved the general signs, decreased DAI and Ca loads of feaces, alleviated colon edema, erosion, and shortening, and lowered the content of β-1,3-glucan in serum and TNF-α, IL-1β, and IL-6 in serum and colon tissues of mice. Transcriptome sequencing revealed 383 DEGs between SHD and model groups, which were mainly involved in the biological processes of immune system, response to bacterium, and innate immune response. They were mainly enriched in the NOD-like signaling pathway, cytokine-cytokine interaction pathway, and retinol metabolism pathway. Moreover, SHD down-regulated the mRNA and protein levels of NLRP3, caspase-1, and IL-1β. In a word, SHD ameliorates DSS-induced UC in mice colonized with Ca, which probably relates to its regulation of NOD-like receptor signaling pathway.
Animals ; Candida albicans/genetics* ; Colitis, Ulcerative/genetics* ; Colon ; Dextran Sulfate/toxicity* ; Disease Models, Animal ; Drugs, Chinese Herbal ; High-Throughput Nucleotide Sequencing ; Mice ; Transcriptome

Antifungal drug resistance is a significant clinical problem, and antifungal agents that can evade resistance are urgently needed. In infective niches, resistant organisms often co-existed with sensitive ones, or a subpopulation of antibiotic-susceptible organisms may evolve into resistant ones during antibiotic treatment and eventually dominate the whole population. In this study, we established a co-culture assay in which an azole-resistant Candida albicans strain was mixed with a susceptible strain labeled with green fluorescent protein to mimic in vivo conditions and screen for antifungal drugs. Fluconazole was used as a positive control to verify the validity of this co-culture assay. Five natural molecules exhibited antifungal activity against both susceptible and resistant C. albicans. Two of these compounds, retigeric acid B (RAB) and riccardin D (RD), preferentially inhibited C. albicans strains in which the efflux pump MDR1 was activated. This selectivity was attributed to greater intracellular accumulation of the drugs in the resistant strains. Changes in sterol and lipid compositions were observed in the resistant strains compared to the susceptible strain, and might increase cell permeability to RAB and RD. In addition, RAB and RD interfered with the sterol pathway, further aggregating the decrease in ergosterol in the sterol synthesis pathway in the MDR1-activated strains. Our findings here provide an alternative for combating resistant pathogenic fungi.
ATP-Binding Cassette Transporters ; genetics ; metabolism ; Antifungal Agents ; chemistry ; metabolism ; pharmacology ; Azoles ; pharmacology ; Biosynthetic Pathways ; drug effects ; genetics ; Candida albicans ; chemistry ; drug effects ; metabolism ; Cell Membrane ; chemistry ; metabolism ; Coculture Techniques ; Drug Resistance, Fungal ; drug effects ; Ergosterol ; metabolism ; Fungal Proteins ; genetics ; metabolism ; Lipids ; chemistry ; Molecular Structure ; Permeability ; Phenyl Ethers ; chemistry ; metabolism ; pharmacology ; Sterols ; chemistry ; metabolism ; Stilbenes ; chemistry ; metabolism ; pharmacology ; Triterpenes ; chemistry ; metabolism ; pharmacology

The aim of this paper was to investigate the inhibitory effect of extract of Coptidis Rhizoma(ECR) on invasion of Candida albicans hyphae in vitro.XTT reduction method was used to evaluate the metabolic activity of C.albicans.The colony edge growth of C.albicans was observed by solid medium.The growth of C.albicans hyphae was determined on semi-solid medium.The morphology and viability changes of C.albicans hyphae were assessed by scanning electron microscope and fluorescence microscope.qRT-PCR method was used to detect the ALS3 and SSA1 expression of C.albicans invasin genes.The results showed that the metabolic viability by XTT method detected that the activity of C.albicans was gradually decreased under the intervention of 64,128 and 256 mg·L-1 of ECR respectively.128,256 mg·L-1 of ECR significantly inhibited colony folds and wrinkles on solid medium and the hyphal invasion in semi-solid medium.Scanning electron microscopy and fluorescence microscopy showed that 128,256 mg·L-1 of ECR could inhibit the formation of C.albicans hyphae.qRT-PCR results showed that the expression of invasin gene ALS3 and SSA1 was down-regulated,and especially 256 mg·L-1 of ECR could down-regulate the two genes expression by 4.8,1.68 times respectively.This study showed that ECR can affect the invasiveness of C.albicans by inhibiting the growth of hyphae and the expression of invasin.
Adenosine Triphosphatases ; genetics ; Candida albicans ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Fungal Proteins ; genetics ; Gene Expression Regulation, Fungal ; HSP70 Heat-Shock Proteins ; genetics ; Hyphae ; drug effects ; ultrastructure ; Microscopy, Electron, Scanning

OBJECTIVE: To evaluate the efficacy of cis-2-dodecenoic acid (BDSF) in the treatment and prevention of vaginal candidiasis in vivo. METHODS: The activities of different concentrations of BDSF against the virulence factors of Candida albicans (C. albicans) were determined in vitro. An experimental mouse model of Candida vaginitis was treated with 250 μmol/L BDSF. Treatment efficiency was evaluated in accordance with vaginal fungal burden and inflammation symptoms. RESULTS: In vitro experiments indicated that BDSF attenuated the adhesion and damage of C. albicans to epithelial cells by decreasing phospholipase secretion and blocking filament formation. Treatment with 30 μmol/L BDSF reduced the adhesion and damage of C. albicans to epithelial cells by 36.9% and 42.3%, respectively. Treatment with 200 μmol/L BDSF completely inhibited phospholipase activity. In vivo mouse experiments demonstrated that BDSF could effectively eliminate vaginal infection and relieve inflammatory symptoms. Four days of treatment with 250 μmol/L BDSF reduced vaginal fungal loads by 6-fold and depressed inflammation. Moreover, BDSF treatment decreased the expression levels of the inflammatory chemokine-associated genes MCP-1 and IGFBP3 by 2.5- and 2-fold, respectively. CONCLUSION BDSF is a novel alternative drug that can efficiently control vaginal candidiasis by inhibiting the virulence factors of C. albicans.
Animals ; Candida albicans ; drug effects ; metabolism ; pathogenicity ; physiology ; Candidiasis, Vulvovaginal ; drug therapy ; genetics ; immunology ; microbiology ; Chemokine CCL2 ; genetics ; immunology ; Disease Models, Animal ; Fatty Acids, Monounsaturated ; administration & dosage ; Female ; Fungal Proteins ; genetics ; metabolism ; Humans ; Insulin-Like Growth Factor Binding Protein 3 ; genetics ; immunology ; Mice ; Virulence ; drug effects ; Virulence Factors ; genetics ; metabolism

The hyphal development of Candida albicans (C. albicans) has been considered as an essential virulent factor for host cell damage. However, the missing link between hyphae and virulence of C. albicans is also been discovered. Here, we identified that the null mutants of ERG3 and ERG11, two key genes in ergosterol biosynthesis pathway, can form typical hyphae but failed to cause the oral mucosal infection in vitro and in vivo for the first time. In particular, the erg3Δ/Δ and erg11Δ/Δ strains co-cultured with epithelial cells significantly reduced the adhesion, damage, and cytokine (interleukin-1α (IL-1α)) production, whereas the invasion was not affected in vitro. Importantly, they were incapable of extensive hyphal invasion, formation of micro-abscesses, and tongue epithelium damage compared to wild type due to the decrease of the colonization and epithelial infection area in a murine oropharyngeal candidiasis model. The fluconazole (FLC), an antifungal targeted at ergosterol biosynthesis, relieved the epithelial infection of C. albicansin vitro and in vivo even under non-growth inhibitory dosage confirming the virulent contribution of ergosterol biosynthesis pathway. The erg3Δ/Δ and erg11Δ/Δ strains were cleared by macrophages similar to wild type, whereas their virulence factors including agglutinin-like sequence 1 (Als1), secreted aspartyl proteinase 6 (Sap6), and hyphal wall protein-1 (Hwp1) were significantly reduced indicated that the non-toxicity might not result from the change on immune tolerance but the defective virulence. The incapacity of erg3Δ/Δ and erg11Δ/Δ in epithelial infection highlights the contribution of ergosterol biosynthesis pathway to C. albicans pathogenesis and fluconazole can not only eliminate the fungal pathogens but also reduced their virulence even at low dosage.
Animals ; Antifungal Agents ; pharmacology ; Candida albicans ; drug effects ; genetics ; pathogenicity ; Candidiasis, Oral ; drug therapy ; genetics ; microbiology ; Fluconazole ; pharmacology ; Genes, Fungal ; genetics ; Mice ; Microscopy, Electron, Scanning ; Potassium Channels ; genetics ; Virulence

BACKGROUNDCandida albicans (C. albicans) can become a pathogen causing superficial as well as life-threatening systemic infections, especially in immunocompromised patients. Many phenotypic attributes contribute to its capacity to colonize human organs. In our study, 93 C. albicans isolates from patients of various candidiasis in a hospital of China were surveyed. We aimed to investigate the white-opaque (WO) switching competence, drug sensitivity, and virulence of mating type-like (MTL) a/α isolates.

METHODSInternal transcribed spacer (ITS) gene and the MTL configuration were detected in all the isolates by reverse transcription-polymerase chain reaction. White/opaque phenotype and doubling time of cell growth were determined. The minimum inhibitory concentrations of antifungal agent were measured using broth microdilution method.

RESULTSSixty-four isolates (69.6%) were classified to serotype A, 19 (20.6%) to serotype B, and 9 (9.8%) to serotype C. Moreover, phylogenetic analysis showed that these isolates were divided into four different subgroups of ITS genotypes. Most of our clinical isolates were MTL a/α type, while 6.8% remained MTL a or MTLα type. The frequency of opaque phenotype was 71.0% (66 isolates). Following the guidelines of Clinical and Laboratory Standards Institute M27-A3, all isolates were susceptible to caspofungin and a few (0.6-3.2%) of them showed resistance against amphotericin B, flucytosine, fluconazole, itraconazole, and voriconazole.

CONCLUSIONSFrom these analyses, there were comparatively more C. albicans strains classified into serotype B, and the frequency of opaque phase strains was significant in the clinical isolates from China. Genetic, phenotypic, or drug susceptibility patterns were not significantly different from previous studies. MTL a/α isolates could also undergo WO switching which facilitates their survival.

Amphotericin B ; pharmacology ; Antifungal Agents ; pharmacology ; Candida albicans ; classification ; drug effects ; genetics ; Fluconazole ; pharmacology ; Genotype ; Humans ; Microbial Sensitivity Tests ; Phylogeny