Anti-Candida albicansaction of the glyco-protein complex purified from metabolites of gut bacteriumRaoultella ornithinolyticaisolated from earthwormsDendrobaena veneta

Autophagy of Candida albicans cells after the action of earthworm Venetin-1 nanoparticle with protease inhibitor activity

The present studies show the effect of the Venetin-1 protein-polysaccharide complex obtained from the coelomic fluid of the earthworm Dendrobaena veneta on Candida albicans cells. They are a continuation of research on the mechanisms of action, cellular targets, and modes of cell death. After the action of Venetin-1, a reduced survival rate of the yeast cells was noted. The cells were observed to be enlarged compared to the controls and deformed. In addition, an increase in the number of cells with clearly enlarged vacuoles was noted. The detected autophagy process was confirmed using differential interference contrast, fluorescence microscopy, and transmission electron microscopy. Autophagic vesicles were best visible after incubation of fungus cells with the Venetin-1 complex at a concentration of 50 and 100 µg mL-1. The changes in the vacuoles were accompanied by changes in the size of mitochondria, which is probably related to the previously documented oxidative stress. The aggregation properties of Venetin-1 were characterized. Based on the results of the zeta potential at the Venetin-1/KCl interface, the pHiep = 4 point was determined, i.e. the zeta potential becomes positive above pH = 4 and is negative below this value, which may affect the electrostatic interactions with other particles surrounding Venetin-1.

Atypical changes in Candida albicans cells treated with the Venetin-1 complex from earthworm coelomic fluid

In the present research, the effect of a protein-polysaccharide complex Venetin-1 obtained from the coelomic fluid of Dendrobaena veneta earthworm on Candida albicans cells was characterized. The compound destroyed fungal cells without showing cytotoxicity to human skin fibroblasts, which was demonstrated in earlier studies. Since it had an effect on the fungal cell wall and membrane, this complex was compared with the known antifungal antibiotic fluconazole. Both preparations disturbed the division of yeast cells and resulted in the formation of aggregates and chains of unseparated cells, which was illustrated by staining with fluorochromes. Fluorescent staining of the cell wall with Calcofluor white facilitated comparison of the types of aggregates formed after the action of both substances. The analysis performed with the use of Congo red showed that Venetin-1 exposed deeper layers of the cell wall, whereas no such effect was visible after the use of fluconazole. The FTIR analysis confirmed changes in the mannoprotein layer of the cell wall after the application of the Venetin-1 complex. Staining with Rhodamine 123 and the use of flow cytometry allowed comparison of changes in the mitochondria. Significantly elongated mitochondria were observed after the Venetin-1 application, but not after the application of the classic antibiotic. Phase contrast microscopy revealed vacuole enlargement after the Venetin-1 application. The flow cytometry analysis of C. albicans cells treated with Venetin-1 and fluconazole showed that both substances caused a significant decrease in cell viability.

Novel Venetin-1 nanoparticle from earthworm coelomic fluid as a promising agent for the treatment of non-small cell lung cancer

The present research shows the antitumor activity of a protein-polysaccharide complex Venetin-1 obtained from the coelomic fluid of Dendrobaena veneta earthworms against A549 cancer cells. The investigations are a continuation of experiments on the antitumor activity of coelomic fluid obtained from this species. The Venetin-1 nanoparticle was obtained after thermal treatment of the coelomic fluid, separation from coelomocytes, filtration, and lyophilization. The preparation showed a selective effect on cancer cells, whereas normal cells were unaffected. Venetin-1 was effective against the lung cancer cells at doses of 31.3 and 62.5 µg/ml, and the results were imaged using light microscopy and scanning electron microscopy (SEM). The cells died mainly via the apoptosis pathway. Necrotic cells appeared sporadically in the microscopic view. SEM imaging revealed complete destruction of the A549 cells after the incubation with Venetin-1. The atomic force microscopy (AFM) analyses showed changes in the topography, peak force error images, and Young's modulus (elasticity) of the A549 cells after the incubation with Venetin-1. The transmission electron cryomicroscopy (Cryo-TEM) analysis indicated a polymeric nature of the analyzed preparation. The samples of Venetin-1 showed a very homogeneous size profile with the microparticle size of approximately 58.23 nm. A significant decrease in Venetin-1 binding to sphingomyelin was observed. Venetin-1 lost its pore-forming activity or deactivation of the pore-forming activity occurred. This confirms the absence of hemolytic capacity of Venetin-1 towards red blood cells. The conducted analyses show the suitability of the obtained complex for biomedical research. The next step will consist in analyses of the effect of Venetin-1 on the immune system in mice.

Antifungal Activity of Earthworm Coelomic Fluid Obtained from Eisenia andrei, Dendrobaena veneta and Allolobophora chlorotica on Six Species of Phytopathogenic Fungi

The functioning of soil ecosystems greatly depends on the interactions occurring between soil biota communities. It is well known that earthworms are an important soil component that substantially affects its function, including their meaningful impact on the development of different phytopathogenic soil fungi. Phytopathogenic fungi are responsible for crop disease and cause great economic damage. It has previously been established that earthworms’ coelomic fluid can suppress the growth of phytopathogenic fungi, but the exact molecular mechanism is unknown. The present study aimed at broadening the proof of this observed phenomenon by investigating the effects of the coelomic fluid extract of three different earthworm species (Eisenia andrei, Dendrobaena veneta and Allolobophora chlorotica) on the growth of six different phytopathogenic fungi species (Berkeleyomyces basicola, Fusarium culmorum, Globisporangium irregulare, Rhizoctonia solani, Macrophomina phaseolina, and Sclerotinia sclerotiorum). Coelomic fluid extract was obtained by electrostimulation or usage of extraction buffer (only in case of A. chlorotica) and prepared in three different concentrations by diluting the obtained coelomic fluid with physiological saline. The coelomic fluid extract of the three investigated earthworm species had an inhibitory effect on the growth of all six phytopathogenic fungi species. The greatest inhibitory effect was achieved with the E. andrei coelomic fluid extract reducing the growth of R. solani fungi. The findings of this research confirm the antifungal activity of coelomic fluid obtained from earthworm species belonging to different ecological categories and may be of potential use in crop protection against phytopathogenic fungi.

Post-epizootic microbiome associations across communities of neotropical amphibians

Microbiome-pathogen interactions are increasingly recognized as an important element of host immunity. While these host-level interactions will have consequences for community disease dynamics, the factors which influence host microbiomes at larger scales are poorly understood. We here describe landscape-scale pathogen-microbiome associations within the context of post-epizootic amphibian chytridiomycosis, a disease caused by the panzootic chytrid fungus Batrachochytrium dendrobatidis. We undertook a survey of Neotropical amphibians across altitudinal gradients in Ecuador ~30 years following the observed amphibian declines and collected skin swab-samples which were metabarcoded using both fungal (ITS-2) and bacterial (r16S) amplicons. The data revealed marked variation in patterns of both B. dendrobatidis infection and microbiome structure that are associated with host life history. Stream breeding amphibians were most likely to be infected with B. dendrobatidis. This increased probability of infection was further associated with increased abundance and diversity of non-Batrachochytrium chytrid fungi in the skin and environmental microbiome. We also show that increased alpha diversity and the relative abundance of fungi are lower in the skin microbiome of adult stream amphibians compared to adult pond-breeding amphibians, an association not seen for bacteria. Finally, stream tadpoles exhibit lower proportions of predicted protective microbial taxa than pond tadpoles, suggesting reduced biotic resistance. Our analyses show that host breeding ecology strongly shapes pathogen-microbiome associations at a landscape scale, a trait that may influence resilience in the face of emerging infectious diseases.

Candida albicans cell wall as a target of action for the protein-carbohydrate fraction from coelomic fluid of Dendrobaena veneta

The protein-polysaccharide fraction (AAF) isolated from the coelomic fluid of the earthworm Dendrobaena veneta destroys C. albicans cells by changing their morphology, disrupting cell division, and leading to cell death. Morphological changes in C. albicans cells induced by treatment with AAF were documented using DIC, SEM, and AFM. Congo Red staining showed that the fungal wall structure was changed after incubation with AAF. The effect on C. albicans cell walls was shown by AFM analysis of the surface roughness of fungal cell walls and changes in the wall thickness were visualized using Cryo-SEM. The FTIR analysis of C. albicans cells incubated with AAF indicated attachment of protein or peptide compounds to the fungal walls. The intact LC-ESI-MS analysis allowed accurate determination of the masses of molecules present in AAF. As shown by the chromatographic study, the fraction does not cross biological membranes. The Cryo-TEM analysis of AAF demonstrated the ability of smaller subunits to combine into larger agglomerates. AAF is thermally stable, which was confirmed by Raman spectroscopy. AAF can be considered as a potential antifungal antibiotic with activity against clinical C. albicans strains.

Sida hermaphrodita seeds as the source of anti - Candida albicans activity

Sida hermaphrodita is a perennial herbaceous plant with potential economic importance; however, there is no information about its antimicrobial properties. The aim of our study was to analyze the morphology and metabolic activity of Candida albicans cells after exposure to the extract from S. hermaphrodita seeds, determine its cytotoxicity against human skin fibroblasts and carry out chemical analysis of the extract. Microscopic analysis showed that the crude seed extract (CSE) caused a significant decrease in the metabolic activity of fungal cells, clear cell deformation, and budding disturbances. The analysis of cytotoxicity showed no influence of the extract on the fibroblasts. The CSE and seed extract after dialysis (DSE) were analyzed using electrophoretic, chromatographic, and spectroscopic methods. SDS-PAGE electrophoresis showed the presence of proteins and carbohydrate compounds in the extract. The Raman spectroscopy analysis of the DSE confirmed the presence of proteins, while FTIR analyses revealed the occurrence of albumin-type proteins. The NMR and GC-MS analyses showed the presence of carbohydrates in the seed extract. The MALDI and ESI LC-MS/MS analysis of the CSE and the DSE fractions revealed the occurrence of vicilin-type and plant lipid transfer proteins. The seed extract is a promising formulation to use in C. albicans infections.

Anti-Candida albicans effect of the protein-carbohydrate fraction obtained from the coelomic fluid of earthworm Dendrobaena veneta

An antifungal active fraction (AAF) from the coelomic fluid (CF) of the earthworm Dendrobaena veneta was isolated. The aim of the study was to analyze the antifungal activity of the AAF and to carry out chemical characterization of the fraction. The active fraction showed antifungal activity against a clinical C. albicans isolate, C. albicans ATCC 10231, and C. krusei ATCC 6258. It effectively reduced the metabolic activity of C. albicans cells and influenced their morphology after 48 hours of incubation. Scanning electron microscopy (SEM) images revealed loss of integrity of the cell wall induced by the active fraction. Calcofluor White staining showed changes in the structure of the C. albicans cell wall induced by the AAF. The fungal cells died via apoptosis and necrosis after the treatment with the studied fraction. Electrophoresis under native conditions revealed the presence of two compounds in the AAF, while SDS/PAGE gel electrophoresis showed several protein and carbohydrate compounds. The active fraction was analyzed using Raman spectroscopy, MALDI TOF/TOF, and ESI LC-MS. The Raman analysis confirmed the presence of proteins and determined their secondary structure. The MALDI TOF/TOF analysis facilitated detection of four main compounds with a mass of 7694.9 m/z, 12292.3 m/z, 21628.3 m/z, and 42923.2 m/z in the analyzed fraction. The presence of carbohydrate compounds in the preparation was confirmed by nuclear magnetic resonance (NMR) and gas chromatography (GC-MS). The ATR-FTIR spectrum of the AAF exhibited high similarity to the spectrum of egg white lysozyme. The AAF showed no endotoxicity and cytotoxicity towards normal skin fibroblasts (HSF); therefore, it can be used for the treatment of skin and mucous membrane candidiasis in the future. Given its efficient and selective action, the fraction seems to be a promising preparation with antifungal activity against C. albicans.

Antimycobacterial action of a new glycolipid-peptide complex obtained from extracellular metabolites of Raoultella ornithinolytica

In this paper, an antimycobacterial component of extracellular metabolites of a gut bacterium Raoultella ornithinolytica from D. veneta earthworms was isolated and its antimycobacterial action was tested using Mycobacterium smegmatis. After incubation with the complex obtained, formation of pores and furrows in cell walls was observed using microscopic techniques. The cells lost their shape, stuck together and formed clusters. Surface-enhanced Raman spectroscopy analysis showed that, after incubation, the complex was attached to the cell walls of the Mycobacterium. Analyses of the component performed with Fourier transform infrared spectroscopy demonstrated high similarity to a bacteriocin nisin, but energy dispersive X-ray spectroscopy analysis revealed differences in the elemental composition of this antimicrobial peptide. The component with antimycobacterial activity was identified using mass spectrometry techniques as a glycolipid-peptide complex. As it exhibits no cytotoxicity on normal human fibroblasts, the glycolipid-peptide complex appears to be a promising compound for investigations of its activity against pathogenic mycobacteria.

Impact of multi-metals (Cd, Pb and Zn) exposure on the physiology of the yeast Pichia kudriavzevii

Metal contamination of the environment is frequently associated to the presence of two or more metals. This work aimed to study the impact of a mixture of metals (Cd, Pb and Zn) on the physiology of the non-conventional yeast Pichia kudriavzevii. The incubation of yeast cells with 5 mg/l Cd, 10 mg/l Pb and 5 mg/l Zn, for 6 h, induced a loss of metabolic activity (assessed by FUN-1 staining) and proliferation capacity (evaluated by a clonogenic assay), with a small loss of membrane integrity (measured by trypan blue exclusion assay). The staining of yeast cells with calcofluor white revealed that no modification of chitin deposition pattern occurred during the exposure to metal mixture. Extending for 24 h, the exposure of yeast cells to metal mixture provoked a loss of membrane integrity, which was accompanied by the leakage of intracellular components. A marked loss of the metabolic activity and the loss of proliferation capacity were also observed. The analysis of the impact of a single metal has shown that, under the conditions studied, Pb was the metal responsible for the toxic effect observed in the metal mixture. Intracellular accumulation of Pb seems to be correlated with the metals' toxic effects observed.

Analysis of antifungal and anticancer effects of the extract from Pelargonium zonale

The extract from Pelargonium zonale stalks exhibits activity against Candida albicans and exerts an effect on the HeLa cell line. The action against C. albicans cells was analysed using light, CLSM, SEM, and TEM microscopes. The observations indicate that the extract influenced fungal cell morphology and cell metabolic activity. The morphological changes include cell wall damage, deformations of cell surfaces, and abnormalities in fungal cell shape and size. Cells of C. albicans treated with the extract exhibited disturbances in the budding pattern and a tendency to form agglomerates and multicellular chains. The P. zonale extract caused a significant decrease in the metabolic activity of C. albicans cells. Cells died via both apoptosis and necrosis. The antitumor activity of the extract was analysed using the MTT assay. The P. zonale extract exhibited minor cytotoxicity against the HeLa cell line but a dose-dependent cytopathic effect was noticed. The P. zonale extract is a promising source for the isolation of antifungal and anticancer compounds.

Antifungal and anticancer effects of a polysaccharide-protein complex from the gut bacterium Raoultella ornithinolytica isolated from the earthworm Dendrobaena veneta

The polysaccharide-protein complex (PPC) isolated from metabolites of gut bacteria Raoultella ornithinolytica from Dendrobaena veneta earthworms exhibits activity against Candida albicans, in breast ductal carcinoma (line T47D) and in the endometrioid ovarian cancer line (TOV-112D) in vitro. The action against C. albicans was analyzed using light, SEM, TEM, and AFM microscopes. The changes observed indicated two directions of the action of the complex, that is, disturbance of metabolic activity and cell wall damage. The PPC is an adhesion-promoting complex inducing death of C. albicans cells by necrosis. Owing to its significant effect on C. albicans, the complex is a promising source of antifungal compounds. The PPC showed a minimal cytotoxic effect against human skin fibroblasts; however, the cytotoxicity against the T47D line was determined at 20% and 15% against the TOV-112D line. The action of the PPC against the T47D line exerted a cytopathic effect, whereas in the TOV-112D line, it caused a reduction in the cell number. The PPC induced death of tumor cells by apoptosis and necrosis. In view of the negligible cytotoxicity on fibroblasts, the PPC will be subjected to chemical modifications to increase its antitumor activity for prospective medical applications.