The pathogen Candida albicans is pleiomorphic and grows in yeast and filamentous forms but the relationship between the regulation of different filamentous forms is unclear. BRG1 encodes a DNA binding protein which is an important regulator of morphology. Mutants lacking BRG1 grow as yeast under all conditions tested and over-expressing BRG1 drives hyphal growth even in the absence of inducing signals. A number of genetic mutants in repressors of filamentation form pseudohyphae under yeast conditions and some of these mutants can form hyphae under hypha-inducing conditions. This study examines the position of BRG1 in the regulatory networks that govern filamentation by examining the effect of over-expressing BRG1 in pseudohyphal mutants.
Globally, the occurrence of biofilm associated infection has become an alarming menace to the medical fraternity because the thick exopolysaccharide layer encasing the biofilms makes the biofilm producing pathogens inherently resistant to antibiotics. Candida albicans, the most common pathogen among Candida spp. is the causative agent for superficial and invasive candidiasis. The morphological phase switching from yeast to hyphal form is one of the virulent traits of C. albicans critical for its pathogenicity. Owing to the emergence of antifungal resistance among this opportunistic fungus, there is a dire need for improvised alternative antifungal agents. In the present study, we have evaluated a biosurfactant from a marine bacterium for its biofilm disruption ability against C. albicans. This biosurfactant had the potential to disrupt biofilms as well as to inhibit the morphological transition from yeast to hyphae. In addition, this biosurfactant showed enhance disruption of mixed species biofilms of C. albicans and Staphylococcus epidermidis when combined with DNase isolated from marine bacteria. From the results obtained, it is evident that the biosurfactant could act as a potential antibiofilm agent against drug resistant C. albicans strains.
- MeSH
- antifungální látky farmakologie MeSH
- Bacteria * enzymologie MeSH
- biofilmy * účinky léků MeSH
- Candida albicans * účinky léků MeSH
- deoxyribonukleasy * metabolismus MeSH
- hyfy MeSH
- kandidóza mikrobiologie MeSH
- lidé MeSH
- Staphylococcus epidermidis účinky léků MeSH
- vodní organismy * enzymologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The most recent genome-editing system called CRISPR-Cas9 (clustered regularly interspaced short palindromic repeat system with associated protein 9-nuclease) was employed to delete four non-essential genes (i.e., Caeco1, Caidh1, Carom2, and Cataf10) individually to establish their gene functionality annotations in pathogen Candida albicans. The biological roles of these genes were investigated with respect to the cell wall integrity and biogenesis, calcium/calcineurin pathways, susceptibility of mutants towards temperature, drugs and salts. All the mutants showed increased vulnerability compared to the wild-type background strain towards the cell wall-perturbing agents, (antifungal) drugs and salts. All the mutants also exhibited repressed and defective hyphal growth and smaller colony size than control CA14. The cell cycle of all the mutants decreased enormously except for those with Carom2 deletion. The budding index and budding size also increased for all mutants with altered bud shape. The disposition of the mutants towards cell wall-perturbing enzymes disclosed lower survival and more rapid cell wall lysis events than in wild types. The pathogenicity and virulence of the mutants was checked by adhesion assay, and strains lacking rom2 and eco1 were found to possess the least adhesion capacity, which is synonymous to their decreased pathogenicity and virulence.
- MeSH
- acetyltransferasy nedostatek genetika fyziologie MeSH
- antifungální látky farmakologie MeSH
- buněčná adheze MeSH
- buněčná stěna účinky léků MeSH
- buněčný cyklus MeSH
- Candida albicans účinky léků genetika patogenita fyziologie MeSH
- chitinasy farmakologie MeSH
- CRISPR-Cas systémy MeSH
- delece genu MeSH
- endo-1,3-beta-glukanasa farmakologie MeSH
- faktory asociované s proteinem vázajícím TATA box nedostatek genetika fyziologie MeSH
- fungální proteiny genetika fyziologie MeSH
- geny hub * MeSH
- hyfy růst a vývoj MeSH
- isocitrátdehydrogenasa nedostatek genetika fyziologie MeSH
- kationty farmakologie MeSH
- nepohlavní rozmnožování MeSH
- otevřené čtecí rámce MeSH
- poškození DNA MeSH
- vápník fyziologie MeSH
- virulence genetika MeSH
- Publikační typ
- časopisecké články MeSH
Arbuscular mycorrhizal (AM) fungi play a positive role in plant water relations, and the AM symbiosis is often cited as beneficial for overcoming drought stress of host plants. Nevertheless, water uptake via mycorrhizal hyphal networks has been little addressed experimentally, especially so through isotope tracing. In a greenhouse study conducted in two-compartment rhizoboxes, Medicago truncatula was planted in the primary compartment (PC), either inoculated with Rhizophagus irregularis or left uninoculated. Plant roots were either allowed to enter the secondary compartment (SC) or were restricted to the PC by root-excluding mesh. Substrate moisture was manipulated in the PC such that the plants were grown either in high moisture (15% of gravimetric water content, GWC) or low moisture (8% GWC). Meanwhile, the SC was maintained at 15% GWC throughout and served as a water source accessible (or not) by roots and/or hyphae. Water in the SC was labeled with deuterium (D) to quantify water uptake by the plants from the SC. Significantly, increased D incorporation into plants indicated higher water uptake by mycorrhizal plants when roots had access to the D source, but this was mainly explained by generally larger mycorrhizal root systems in proximity to the D source. On the other hand, AM fungal hyphae with access to the D source increased D incorporation into plants more than twofold compared to non-mycorrhizal plants. Despite this strong effect, water transport via AM fungal hyphae was low compared to the transpiration demand of the plants.
- MeSH
- Glomeromycota * MeSH
- hyfy MeSH
- kořeny rostlin MeSH
- mykorhiza * MeSH
- symbióza MeSH
- voda MeSH
- Publikační typ
- časopisecké články MeSH
Pythiosis is a harmful disease caused by Pythium insidiosum, an aquatic oomycete. Therapeutic protocols based on antifungal drugs are often ineffective because the cytoplasmic membrane of P. insidiosum does not contain ergosterol. Therefore, the treatment of pythiosis is still challenging, particularly making use of natural products and secondary metabolites from bacteria. In this study, xanthyletin and substances obtained from Pseudomonas stutzeri ST1302 and Klebsiella pneumoniae ST2501 exhibited anti-P. insidiosum activity and, moreover, xanthyletin was non-toxic against human cell lines. The hyphae of P. insidiosum treated with these three substances exhibited lysis holes on a rough surface and release of anamorphic material. Therefore, xanthyletin could be considered a promising alternative agent for treating cutaneous pythiosis in the near future.
- MeSH
- antifungální látky farmakologie MeSH
- antiparazitární látky farmakologie MeSH
- Bacteria chemie metabolismus MeSH
- buněčné linie MeSH
- fibroblasty účinky léků MeSH
- hyfy účinky léků ultrastruktura MeSH
- komplexní směsi MeSH
- kumariny farmakologie MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- Pythium účinky léků MeSH
- viabilita buněk účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The aim was to evaluate in vitro possible interactions, gene expression, and biofilm formation in species of Candida albicans, Streptococcus mitis, and Streptococcus sanguinis and their in vivo pathogenicity. The in vitro analysis evaluated the effects of S. mitis and S. sanguinis on C. albicans's biofilm formation by CFU count, filamentation capacity, and adhesion (ALS1, ALS3, HWP1) and transcriptional regulatory gene (BCR1, CPH1, EFG1) expression. In vivo studies evaluated the pathogenicity of the interaction of the microorganisms on Galleria mellonella, with analyses of the CFU per milliliter count and filamentation. In vitro results indicated that there was an observed decrease in CFU (79.4-71.5%) in multi-species biofilms. The interaction with S. mitis inhibited filamentation, which seems to increase its virulence factor with over-expression of genes ALS1, ALS3, and HWP1 as well the interaction with S. sanguinis as ALS3 and HWP1. S. mitis upregulated BRC1, CPH1, and EFG1. The histological images of in vivo study indicate an increase in the filamentation of C. albicans when in interaction with the other species. It was concluded that S. mitis interaction suggests increased virulence factors of C. albicans, with periods of lower virulence and proto-cooperation in the interaction with S. sanguinis.
- MeSH
- biofilmy růst a vývoj MeSH
- Candida albicans genetika růst a vývoj patogenita MeSH
- fungální proteiny genetika MeSH
- hyfy růst a vývoj MeSH
- kokultivační techniky MeSH
- larva mikrobiologie MeSH
- mikrobiální interakce fyziologie MeSH
- modely nemocí na zvířatech MeSH
- můry mikrobiologie MeSH
- počet mikrobiálních kolonií MeSH
- regulace genové exprese u hub MeSH
- Streptococcus mitis fyziologie MeSH
- Streptococcus fyziologie MeSH
- virulence genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Filamentous fungi that colonize microenvironments, such as animal or plant tissue or soil, must find optimal paths through their habitat, but the biological basis for negotiating growth in constrained environments is unknown. We used time-lapse live-cell imaging of Neurospora crassa in microfluidic environments to show how constraining geometries determine the intracellular processes responsible for fungal growth. We found that, if a hypha made contact with obstacles at acute angles, the Spitzenkörper (an assembly of vesicles) moved from the center of the apical dome closer to the obstacle, thus functioning as an internal gyroscope, which preserved the information regarding the initial growth direction. Additionally, the off-axis trajectory of the Spitzenkörper was tracked by microtubules exhibiting "cutting corner" patterns. By contrast, if a hypha made contact with an obstacle at near-orthogonal incidence, the directional memory was lost, due to the temporary collapse of the Spitzenkörper-microtubule system, followed by the formation of two "daughter" hyphae growing in opposite directions along the contour of the obstacle. Finally, a hypha passing a lateral opening in constraining channels continued to grow unperturbed, but a daughter hypha gradually branched into the opening and formed its own Spitzenkörper-microtubule system. These observations suggest that the Spitzenkörper-microtubule system is responsible for efficient space partitioning in microenvironments, but, in its absence during constraint-induced apical splitting and lateral branching, the directional memory is lost, and growth is driven solely by the isotropic turgor pressure. These results further our understanding of fungal growth in microenvironments relevant to environmental, industrial, and medical applications.
- MeSH
- časosběrné zobrazování MeSH
- hyfy růst a vývoj fyziologie MeSH
- mikrotubuly fyziologie MeSH
- Neurospora crassa růst a vývoj fyziologie MeSH
- optické zobrazování MeSH
- životní prostředí MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
The increasing use of plastics in human activities has resulted in an enormous amount of residues which became a matter of great environmental concern. Scientific studies on the microbial degradation of natural and synthetic molecules show the potential of fungal application on cleaning technologies. The biodegradation of PCL (polycaprolactone) and PVC (polyvinyl chloride) films by Aspergillus brasiliensis (ATCC 9642), Penicillium funiculosum (ATCC 11797), Chaetomium globosum (ATCC 16021), Trichoderma virens (ATCC 9645), and Paecilomyces variotii (ATCC 16023) was studied. According to ISO 846-1978-"Testing of Plastics - Influence of fungi and bacteria", samples of the studied polymers were inoculated with a mix suspension of 106 fungal inoculum and maintained in moisture glass chambers in a bacteriological incubator at 28 °C for 28 days. The samples were analyzed by means of morphological and color changes, mass loss, optical microscopy (OM), and scanning electron microscopy (SEM) after 28 days of culturing. After the incubation period, visual observations of the PCL films showed many micropores and cracks, pigmentation, surface erosion and hyphal adhesion on the sample surfaces, and a mass loss of up to 75%. On the contrary, there was no evidence of PVC biodegradation, such as changes in color and significant mass loss. Chaetomium globosum ATCC 16021 was a pioneer in the colonization and attack of PCL, resulting in significant mass losses. Although PVC was less attacked by the ascomycete, the polymer supported the adhesion and growth of its fertile structures (perithecia), suggesting the fungal potential to degrade both plastics.
Candida albicans is the main causative agent of vulvovaginal candidiasis (VVC), a common mycosis in women, relapses of which are difficult to manage due to biofilm formation. This study aimed at developing novel non-toxic compounds active against Candida spp. biofilms. We synthesised analogues of natural antifungal peptides LL-III (LL-III/43) and HAL-2 (peptide VIII) originally isolated from bee venoms and elucidated their structures by nuclear magnetic resonance spectroscopy. The haemolytic, cytotoxic, antifungal and anti-biofilm activities of LL-III/43 and peptide VIII were then tested. LL-III/43 and VIII showed moderate cytotoxicity to HUVEC-2 cells and had comparable inhibitory activity against C. albicans and non-albicans spp. The lowest minimum inhibitory concentration (MIC90) of LL-III/43 was observed towards Candida tropicalis (0.8 µM). That was 8-fold lower than that of antimycotic amphotericin B. Both peptides can be used to inhibit Candida spp. bio film f ormation. Biofilm inhibitory concentrations (BIC50) ranged from 0.9 to 58.6 µM and biofilm eradication concentrations (BEC50) for almost all tested Candida spp. strains ranged from 12.8 to 200 µM. Als o pro ven were the peptides' abilities to reduce the area colonised by biofilms , inhibit hyphae formation and permeabilise cell membranes in biofil ms . LL-III/43 and VIII are promising candidates for further development as therapeutics against VVC.
- MeSH
- amfotericin B farmakologie MeSH
- antifungální látky chemická syntéza farmakologie MeSH
- biofilmy účinky léků MeSH
- Candida účinky léků MeSH
- endoteliální buňky pupečníkové žíly (lidské) účinky léků MeSH
- hyfy účinky léků MeSH
- kandidóza vulvovaginální mikrobiologie MeSH
- kationické antimikrobiální peptidy chemická syntéza farmakologie MeSH
- kultivované buňky MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- včelí jedy chemie MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The genus Fuscoporia of the Hymenochaetaceae is characterized by resupinate to pileate basidiocarps, a dimitic hyphal system with fine crystal aggregates and encrusted generative hyphae in dissepiment edge and tube trama, the presence of hymenial setae, and hyaline, thin-walled, smooth basidiospores. Members of the F. contigua group are easy to distinguish from other species of Fuscoporia because of the moderately large pores, presence of mycelial setae, and large hymenial setae. Here, we explore phylogenetic relationships among 20 species of Fuscoporia based on examination of some 90 collections sampled worldwide. Seven new species are recognized in the F. contigua group-F. americana, F. centroamericana, F. costaricana, F. latispora, F. monticola, F. septiseta, and F. sinica-described from China, Costa Rica, Mexico, and the United States. Phylogenetic analyses inferred from DNA sequences of the nuc rDNA internal transcribed spacer (ITS1-5.8S-ITS2 = ITS), D1-D2 domains of nuc 28S rDNA (28S), and translation elongation factor EF-1 alpha (tef1) support the F. contigua group as one of two major clades within Fuscoporia comprising nine species worldwide.
