scholarly journals Diversity of Species and Susceptibility Phenotypes toward Commercially Available Fungicides of Cultivable Fungi Colonizing Bones of Ursus spelaeus on Display in Niedźwiedzia Cave (Kletno, Poland)

Diversity ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 224 ◽  
Author(s):  
Mariusz Dyląg ◽  
Artur Sawicki ◽  
Rafał Ogórek

Underground ecosystems are one of the most inhospitable places for microorganism development and function. Therefore, any organic matter located in these areas can stimulate fungal growth. The main purpose of this study was to find the best solution to effectively preserve (without relapses) paleolithic bones of cave bear (Ursus spelaeus) exhibited in cave without any negative influence on the cave environment. To achieve this aim, unambiguous identification of fungal species and its susceptibility tests toward fungicidal preparations were performed. Fungi were identified based on phenotypic tests and the internal transcribed spacer (ITS) region analysis. The antifungal activity of three preparations (Pufmax, Boramon and Devor Mousse) was evaluated by microdilution assay (protocol M38-A2) and spot tests assay. Phenotypic and molecular research showed that bones were colonized by 11 fungal species: Absidia glauca, Aspergillus fumigatus, Chrysosporium merdarium, Fusarium cerealis, Mortierella alpina, Mucor aligarensis, M. plumbeus, Penicillium chrysogenum, P. expansum, Sarocladium strictum and Scopulariopsis candida. All of the tested preparations were the most active against C. merdarium. In turn, M. plumbeus, M. aligarensis, M. alpina and A. glauca were the least susceptible. The highest antifungal activity was shown for Pufmax (minimum inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) values were in the range of 0.16–0.63% and 1.25–2.50%, respectively). The lowest fungicidal effect was observed for Boramon (MICs and MFCs in the range of 2.5–10% and 5–20%, respectively). Devor Mousse and Pufmax preparations showed fungicidal activity at the concentrations in the range of 1.25–5%. Susceptibility profiles were also confirmed based on spot tests assay. Our study allows for unambiguously identifying isolated fungi and assessing their susceptibility to commercially available fungicides, to prevent fungal outbreak.

2019 ◽  
Vol 10 (2) ◽  
pp. 1228-1232
Author(s):  
Shebi S ◽  
Geetha RV ◽  
Lakshmi Thangavelu Lakshmi Thangavelu

An antifungal medication, also known as an antimycotic medication, is a pharmaceutical fungicide or fungistatic used to treat and prevent mycoses such as athlete's foot, ringworm, candidiasis, serious systemic infections such as Cryptococcal meningitis, and others. In traditional medicine, extracts and essential oil from flowers and leaves are used in the belief they may be useful to treat a variety of fungal disorders. The aim of this study was to analyse the antimycotic properties of rosemary oil and its principal components. The Rosemary oil was screened for antifungal activity by the disc diffusion method. Activated cultures of Candida albicans in Sabouraud’s broth was adjusted to 0.5 McFarland standards [108cfu/ml]. 100 µl of the inoculum was introduced to molten Sabourauds dextrose agar and poured in the sterile Petri plates and allowed to set. Sterile filter paper discs (6.0 mm diameter) impregnated with 25µl, 50µl and 100µl /disc were placed on fungal seeded plates and incubated at 28oC for 48 hrs. Clear zones within which fungal growth was absent were measured and recorded as the diameter (mm) of complete growth inhibition. All the concentrations of the test solution inhibited the fungal species with varying degree of sensitivity. The extract showed good antifungal activity at different concentrations with a maximum zone of inhibition of 38 mm at concentration 100µl. This study provides a sample large enough to determine the antifungal properties of Rosemary oil and suggests further studies for possible therapeutic use.


2017 ◽  
pp. 261-269 ◽  
Author(s):  
Dragana Bjelic ◽  
Maja Ignjatov ◽  
Jelena Marinkovic ◽  
Nemanja Spremo ◽  
Maja Karaman ◽  
...  

Biocontrol using plant growth-promoting rhizobacteria (PGPR) represents an alternative approach to disease management, since PGPR are known to promote growth and reduce diseases in various crops. Among the different PGPR, members of the genus Bacillus are prefered for most biotechnological uses due to their capability to form extremely resistant spores and produce a wide variety of metabolites with antimicrobial activity. The objective of this research was to identify antagonistic bacteria for management of the plant diseases. Eleven isolates of Bacillus spp. were obtained from the soil samples collected from different localities in the Province of Vojvodina. The antifungal activity of bacterial isolates against five fungal species was examined using a dual plate assay. Bacillus isolates exhibited the highest antifungal activity against Fusarium proliferatum, Fusarium oxysporum f. sp. cepae and Alternaria padwickii, while they had the least antagonistic effect on Fusarium verticillioides and Fusarium graminearum. Molecular identification showed that effective bacterial isolates were identified as Bacillus safensis (B2), Bacillus pumilus (B3, B11), Bacillus subtilis (B5, B7) and Bacillus megaterium (B8, B9). The highest antagonistic activity was exhibited by isolates B5 (from 39% to 62% reduction in fungal growth) and B7 (from 40% to 71% reduction in fungal growth). These isolates of B. subtilis could be used as potential biocontrol agents of plant diseases.


PeerJ ◽  
2019 ◽  
Vol 6 ◽  
pp. e6237 ◽  
Author(s):  
Risto Vesala ◽  
Anni Harjuntausta ◽  
Anu Hakkarainen ◽  
Petri Rönnholm ◽  
Petri Pellikka ◽  
...  

BackgroundLarge and complex mounds built by termites of the genusMacrotermescharacterize many dry African landscapes, including the savannas, bushlands, and dry forests of the Tsavo Ecosystem in southern Kenya. The termites live in obligate symbiosis with filamentous fungi of the genusTermitomyces. The insects collect dead plant material from their environment and deposit it into their nests where indigestible cell wall compounds are effectively decomposed by the fungus. Above-ground mounds are built to enhance nest ventilation and to maintain nest interior microclimates favorable for fungal growth.ObjectivesIn Tsavo Ecosystem twoMacrotermesspecies associate with three differentTermitomycessymbionts, always with a monoculture of one fungal species within each termite nest. As mound architecture differs considerably both between and within termite species we explored potential relationships between nest thermoregulatory strategies and species identity of fungal symbionts.MethodsExternal dimensions were measured from 164Macrotermesmounds and the cultivatedTermitomycesspecies were identified by sequencing internal transcribed spacer (ITS) region of ribosomal DNA. We also recorded the annual temperature regimes of several termite mounds to determine relations between mound architecture and nest temperatures during different seasons.ResultsMound architecture had a major effect on nest temperatures. Relatively cool temperatures were always recorded from large mounds with open ventilation systems, while the internal temperatures of mounds with closed ventilation systems and small mounds with open ventilation systems were consistently higher. The distribution of the three fungal symbionts in different mounds was not random, with one fungal species confined to “hot nests.”ConclusionsOur results indicate that differentTermitomycesspecies have different temperature requirements, and that one of the cultivated species is relatively intolerant of low temperatures. The dominantMacrotermesspecies in our study area can clearly modify its mound architecture to meet the thermal requirements of several different symbionts. However, a treacherous balance seems to exist between symbiont identity and mound architecture, as the maintenance of the thermophilic fungal species obviously requires reduced mound architecture that, in turn, leads to inadequate gas exchange. Hence, our study concludes that while the limited ventilation capacity of small mounds sets strict limits to insect colony growth, in this case, improving nest ventilation would invariable lead to excessively low nest temperatures, with negative consequences to the symbiotic fungus.


2020 ◽  
Vol 14 (3) ◽  
pp. 1801-1808
Author(s):  
Nawaf I. Alshammari ◽  
Vajid N. Veettil ◽  
Abdel Moneim E. Sulieman ◽  
S.L. Stephenson

Environmental factors such as temperature and humidity directly affect the growth and fruit bodies of fungi. We studied the diversity of wood decaying fungal species, which have grown on same substrate in forest as well as laboratory environment. Ten specimens of fruit body of wood-decaying fungi and 24 random pieces of coarse wooden debris were collected from the forest of northwest Arkansas. The samples of coarse woody debris were incubated in laboratory-growth chambers for two months to promote the fungal growth. Fourty-two different species of wood-decay fungal isolates were recovered and identified by internal transcribed spacer (ITS) region sequencing. The isolates from the forest belonged to twenty-two different taxa whereas twenty taxonomic groups were reported from the growth compartments. Remarkably, data observed from two sets did not shared any taxon. These results indicated that environmental growth conditions play crucial role on fungal diversity even if grown on same substrates.


2019 ◽  
Vol 26 (6) ◽  
pp. 414-422
Author(s):  
Jia Liu ◽  
Ping Song ◽  
Jie Zhang ◽  
Ziyan Nangong ◽  
Xiaobei Liu ◽  
...  

Background: Genome sequence analysis (GenBank access No.: FN667742.1) shows that Xenorhabdus nematophila ATCC19061 contains one gene (Xn-cbp) encoding chitin binding protein (Xn-CBP). Objective: The present work aims to clarify the characteristics and function of Xn-CBP from X. nematophila HB310. Methods: In this study, the Xn-cbp gene was cloned and expressed in Escherichia coli BL21 (DE3). Substrate binding assays were performed to explain the ability of Xn-CBP combined with the polysaccharide. The insecticidal toxicity of Xn-CBP against the second-instar larvae of Helicoverpa armigera was determined by feeding method. Besides, the antifungal activity of Xn-CBP against Coniothyrium diplodiella, Verticillium dahlia, and Fusarium oxysporum was tested by spore germination assay and hyphal extension assay. Results: Xn-CBP encoded 199 amino acids with a calculated mass of 28 kDa, which contained a signal peptide and a chitin binding domain. The Bmax and Kd values of Xn-CBP to colloidal chitin were 2.46 and 4.08, respectively. Xn-CBP had insecticidal activity against the H. armigera with a growth inhibition rate of 84.08%. Xn-CBP had the highest spore germination inhibitory effect on C. diplodiella with the inhibition rate of 83.11%. The hyphal growth inhibition rate of Xn-CBP to F. oxysporum, 41.52%, was higher than the other two fungi. Conclusion: The Xn-CBP had the highest binding ability to colloidal chitin and it showed insecticidal activity and antifungal activity. The present study laid a foundation for further exploitation and utilization of X. nematophila.


2020 ◽  
Vol 20 (29) ◽  
pp. 2681-2691
Author(s):  
Athina Geronikaki ◽  
Victor Kartsev ◽  
Phaedra Eleftheriou ◽  
Anthi Petrou ◽  
Jasmina Glamočlija ◽  
...  

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.


Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jing Wang ◽  
Chaoyun Xu ◽  
Qiming Sun ◽  
Jinrong Xu ◽  
Yunrong Chai ◽  
...  

Abstract Background Microbiome interactions are important determinants for ecosystem functioning, stability, and health. In previous studies, it was often observed that bacteria suppress potentially pathogenic fungal species that are part of the same plant microbiota; however, the underlying microbe-microbe interplay remains mostly elusive. Here, we explored antagonistic interactions of the fungus Fusarium graminearum and bacterium Streptomyces hygroscopicus at the molecular level. Both are ubiquitous members of the healthy wheat microbiota; under dysbiosis, the fungus causes devastating diseases. Results In co-cultures, we found that Streptomyces alters the fungal acetylome leading to substantial induction of fungal autophagy. The bacterium secrets rapamycin to inactivate the target of rapamycin (TOR), which subsequently promotes the degradation of the fungal histone acetyltransferase Gcn5 through the 26S proteasome. Gcn5 negatively regulates fungal autophagy by acetylating the autophagy-related protein Atg8 at the lysine site K13 and blocking cellular relocalization of Atg8. Thus, degradation of Gcn5 triggered by rapamycin was found to reduce Atg8 acetylation, resulting in autophagy induction in F. graminearum. Conclusions Autophagy homeostasis plays an essential role in fungal growth and competition, as well as for virulence. Our work reveals a novel post-translational regulation of autophagy initiated by a bacterial antibiotic. Rapamycin was shown to be a powerful modulator of bacteria–fungi interactions with potential importance in explaining microbial homeostasis in healthy plant microbiomes. The autophagic process provides novel possibilities and targets to biologically control pathogens.


Antibiotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 31
Author(s):  
Magdaléna Kapustová ◽  
Giuseppe Granata ◽  
Edoardo Napoli ◽  
Andrea Puškárová ◽  
Mária Bučková ◽  
...  

Nanotechnology is a new frontier of this century that finds applications in various fields of science with important effects on our life and on the environment. Nanoencapsulation of bioactive compounds is a promising topic of nanotechnology. The excessive use of synthetic compounds with antifungal activity has led to the selection of resistant fungal species. In this context, the use of plant essential oils (EOs) with antifungal activity encapsulated in ecofriendly nanosystems could be a new and winning strategy to overcome the problem. We prepared nanoencapsules containing the essential oils of Origanum vulgare (OV) and Thymus capitatus (TC) by the nanoprecipitation method. The colloidal suspensions were characterized for size, polydispersity index (PDI), zeta potential, efficiency of encapsulation (EE) and loading capacity (LC). Finally, the essential oil nanosuspensions were assayed against a panel of fourteen fungal strains belonging to the Ascomycota and Basidiomycota phyla. Our results show that the nanosystems containing thyme and oregano essential oils were active against various fungal strains from natural environments and materials. In particular, the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values were two to four times lower than the pure essential oils. The aqueous, ecofriendly essential oil nanosuspensions with broad-spectrum antifungal activity could be a valid alternative to synthetic products, finding interesting applications in the agri-food and environmental fields.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ammarah Hami ◽  
Rovidha S. Rasool ◽  
Nisar A. Khan ◽  
Sheikh Mansoor ◽  
Mudasir A. Mir ◽  
...  

AbstractChilli (Capsicum annuum L.) is one of the most significant vegetable and spice crop. Wilt caused by Fusarium Sp. has emerged as a serious problem in chilli production. Internal transcribed spacer (ITS) region is widely used as a DNA barcoding marker to characterize the diversity and composition of Fusarium communities. ITS regions are heavily used in both molecular methods and ecological studies of fungi, because of its high degree of interspecific variability, conserved primer sites and multiple copy nature in the genome. In the present study we focused on morphological and molecular characterization of pathogen causing chilli wilt. Chilli plants were collected from four districts of Kashmir valley of Himalayan region. Pathogens were isolated from infected root and stem of the plants. Isolated pathogens were subjected to DNA extraction and PCR amplification. The amplified product was sequenced and three different wilt causing fungal isolates were obtained which are reported in the current investigation. In addition to Fusarium oxysporum and Fusarium solani, a new fungal species was found in association with the chilli wilt in Kashmir valley viz., Fusarium equiseti that has never been reported before from this region. The studies were confirmed by pathogenicity test and re-confirmation by DNA barcoding.


2021 ◽  
Vol 22 (14) ◽  
pp. 7715
Author(s):  
Grzegorz Czernel ◽  
Dominika Bloch ◽  
Arkadiusz Matwijczuk ◽  
Jolanta Cieśla ◽  
Monika Kędzierska-Matysek ◽  
...  

Silver nanoparticles (AgNPs) were synthesized using aqueous honey solutions with a concentration of 2%, 10%, and 20%—AgNPs-H2, AgNPs-H10, and AgNPs-H20. The reaction was conducted at 35 °C and 70 °C. Additionally, nanoparticles obtained with the citrate method (AgNPs-C), while amphotericin B (AmB) and fluconazole were used as controls. The presence and physicochemical properties of AgNPs was affirmed by analyzing the sample with ultraviolet–visible (UV–Vis) and fluorescence spectroscopy, scanning electron microscopy (SEM), and dynamic light scattering (DLS). The 20% honey solution caused an inhibition of the synthesis of nanoparticles at 35 °C. The antifungal activity of the AgNPs was evaluated using opportunistic human fungal pathogens Candida albicans and Candida parapsilosis. The antifungal effect was determined by the minimum inhibitory concentration (MIC) and disc diffusion assay. The highest activity in the MIC tests was observed in the AgNPs-H2 variant. AgNPs-H10 and AgNPs-H20 showed no activity or even stimulated fungal growth. The results of the Kirby–Bauer disc diffusion susceptibility test for C. parapsilosis strains indicated stronger antifungal activity of AgNPs-H than fluconazole. The study demonstrated that the antifungal activity of AgNPs is closely related to the concentration of honey used for the synthesis thereof.


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