scholarly journals Antagonostic effectiveness of Macromycetes against Candida albicans strains and Issatchenkia orientalis

2021 ◽  
Vol 20 (1) ◽  
pp. e760
Author(s):  
Victor Barshteyn ◽  
Tetiana Krupodorova ◽  
Olena Pokas

The trend to search novel natural antifungal compounds has recently been increasing. Interspecific interactions between 30 Macromycetes species and fungal pathogens (Issatchenkia orientalis, Candida albicans strains) have been evaluated using dual culture plate assay. Interaction reactions between studied fungi were different: deadlock after mycelia contact or at a distance, overgrowth without initial deadlock, partial or complete replacement after initial deadlock with contact. Domination of replacement (78.7 %) of pathogenic fungi by Macromycetes was established. Complete replacement was almost twice more frequent (30.7 %) than partial replacement (19.3 %). These results clearly indicate effectiveness of Macromycetes against pathogenic fungi via contact antagonism. Strong antagonistic activity with high antagonistic index (AI) was established by xylotrophic species Ganoderma applanatum (AI = 22.5), Lentinula edodes (AI = 21.0), Flammulina velutipes, Irpiciporus litschaueri and Pleurotus ostreatus (AI = 20.5), leaf litter decay fungus Crinipellis schevczenkoi (AI = 21), and soil saprotroph   Lyophyllum shimeji (AI = 21).

2014 ◽  
Vol 40 (3) ◽  
pp. 212-220 ◽  
Author(s):  
Sinar David Granada García ◽  
Antoni Rueda Lorza ◽  
Carlos Alberto Peláez

Microorganisms for biological control are capable of producing active compounds that inhibit the development of phytopathogens, constituting a promising tool toob tain active principles that could replace synthetic pesticides. This study evaluatedtheability of severalpotentialbiocontrol microorganismsto produce active extracellular metabolites. In vitro antagonistic capability of 50 bacterial isolates from rhizospheric soils of "criolla" potato (Solanum phureja) was tested through dual culture in this plant with different plant pathogenic fungi and bacteria. Isolates that showed significantly higher antagonistic activity were fermented in liquid media and crude extracts from the supernatants had their biological activities assessed by optical density techniques. Inhibitory effecton tested pathogens was observed for concentrations between 0.5% and 1% of crude extracts. There was a correlation between the antimicrobial activity of extracts and the use of nutrient-rich media in bacteria fermentation. Using a bioguided method, a peptidic compound, active against Fusarium oxysporum, was obtained from the 7ANT04 strain (Pyrobaculum sp.). Analysis by nuclear magnetic resonance and liquid chromatography coupled to mass detector evidenced an 11-amino acid compound. Bioinformatic software using raw mass data confirmed the presence of a cyclic peptide conformed by 11 mostly non-standard amino acids.


mSphere ◽  
2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Eric H. Jung ◽  
David J. Meyers ◽  
Jürgen Bosch ◽  
Arturo Casadevall

ABSTRACTSimilarities in fungal and animal cells make antifungal discovery efforts more difficult than those for other classes of antimicrobial drugs. Currently, there are only three major classes of antifungal drugs used for the treatment of systemic fungal diseases: polyenes, azoles, and echinocandins. Even in situations where the offending fungal organism is susceptible to the available drugs, treatment courses can be lengthy and unsatisfactory, since eradication of infection is often very difficult, especially in individuals with impaired immunity. Consequently, there is a need for new and more effective antifungal drugs. We have identified compounds with significant antifungal activity in the Malaria Box (Medicines for Malaria Ventures, Geneva, Switzerland) that have higher efficacy than some of the currently used antifungal drugs. Our best candidate, MMV665943 (IUPAC name 4-[6-[[2-(4-aminophenyl)-3H-benzimidazol-5-yl]methyl]-1H-benzimidazol-2-yl]aniline), here referred to as DM262, showed 16- to 32-fold-higher activity than fluconazole againstCryptococcus neoformans. There was also significant antifungal activity in other fungal species with known antifungal resistance, such asLomentospora prolificansandCryptococcus gattii. Antifungal activity was also observed against a common fungus,Candida albicans. These results are important because they offer a potentially new class of antifungal drugs and the repurposing of currently available therapeutics.IMPORTANCEMuch like the recent increase in drug-resistant bacteria, there is a rise in antifungal-resistant strains of pathogenic fungi. There is a need for novel and more potent antifungal therapeutics. Consequently, we investigated a mixed library of drug-like and probe-like compounds with activity inPlasmodiumspp. for activity against two common fungal pathogens,Cryptococcus neoformansandCandida albicans, along with two less common pathogenic species,Lomentospora prolificansandCryptococcus gattii. We uncover a previously uncharacterized drug with higher broad-spectrum antifungal activity than some current treatments. Our findings may eventually lead to a compound added to the arsenal of antifungal therapeutics.


Author(s):  
Leenah Alaalm ◽  
Julia L. Crunden ◽  
Mark Butcher ◽  
Ulrike Obst ◽  
Ryann Whealy ◽  
...  

The highly conserved, ubiquitous molecular chaperone Hsp90 is a key regulator of cellular proteostasis and environmental stress responses. In human pathogenic fungi, which kill more than 1.6 million patients each year worldwide, Hsp90 governs cellular morphogenesis, drug resistance, and virulence. Yet, our understanding of the regulatory mechanisms governing fungal Hsp90 function remains sparse. Post-translational modifications are powerful components of nature’s toolbox to regulate protein abundance and function. Phosphorylation in particular is critical in many cellular signaling pathways and errant phosphorylation can have dire consequences for the cell. In the case of Hsp90, phosphorylation affects its stability and governs its interactions with co-chaperones and clients. Thereby modulating the cell’s ability to cope with environmental stress. Candida albicans, one of the leading human fungal pathogens, causes ~750,000 life-threatening invasive infections worldwide with unacceptably high mortality rates. Yet, it remains unknown if and how Hsp90 phosphorylation affects C. albicans virulence traits. Here, we show that phosphorylation of Hsp90 is critical for expression of virulence traits. We combined proteomics, molecular evolution analyses and structural modeling with molecular biology to characterize the role of Hsp90 phosphorylation in this non-model pathogen. We demonstrated that phosphorylation negatively affects key virulence traits, such as the thermal stress response, morphogenesis, and drug susceptibility. Our results provide the first record of a specific Hsp90 phosphorylation site acting as modulator of fungal virulence. Post-translational modifications of Hsp90 could prove valuable in future exploitations as antifungal drug targets.


2020 ◽  
Vol 17 (3) ◽  
pp. 527-535
Author(s):  
Nguyen Thi Van ◽  
Dinh Thi Ngoc Mai ◽  
Le Thi Hoang Yen ◽  
Nguyen Hong Minh ◽  
Nguyen Kim Nu Thao

Fungal diseases are a huge problem in agriculture, causing serious damage to annual crop yields worldwide. In order to control fungal pathogens in plants, using antagonistic microorganisms is a common approach, especially actinomycetes, as biocontrols considered to be very potential and safe for the environment. With the advantage of high levels of biodiversity, Vietnamese actinomycetes are of a valuable resource for finding strains that are capable of biocontrolling fungal pathogens in plants. Thus, in this study, 70 actinomycete strains were isolated from Cuc Phuong and Ba Be National Parks by four different isolation methods including rehydration centrifugation, sodium dodecyl sulfate – yeast extract, dry heating and dilution methods. Of these, 29 strains (41.4%) belong to rare actinomycete genera including Actinoplanes, Acrocarpospora, Dactylosporangium, Kineosporia, Micromonospora, Nocardia, Nocardiopsis and Pseudonocardia, which are rarely studied in Vietnam. Subsequently, 70 actinomycete strains were subjected to antagonistic activity assays against four highly pathogenic fungi in plants including Alternaria sp., Botrytis cinerea, Colletotrichum gloeosporioides and Phytophthora capsici. The results showed that 80.5% of Streptomyces and 31% of rare actinomyces could inhibit the growth of at least one of the four pathogenic fungal strains. Moreover, ten actinmomycete strains were found to be able to inhibit three types of tested fungal pathogens, simutaneously. Especially, four actinomycete strains (VTCC-A-828, VTCC-A-671, VTCC-A-605, and VTCC-A-69), having the highest antagonistic activity against four fungal pathogens Alternaria sp., Botrytis cinerea, Colletotrichum gloeosporioides and Phytophthora capsici, respectively, were selected. The results in this study indicate the great potential application for Vietnam's microorganisms in the field of plant protection.


2002 ◽  
Vol 48 (9) ◽  
pp. 772-786 ◽  
Author(s):  
Annette Krechel ◽  
Annekathrin Faupel ◽  
Johannes Hallmann ◽  
Andreas Ulrich ◽  
Gabriele Berg

To study the effect of microenvironments on potato-associated bacteria, the abundance and diversity of bacteria isolated from the rhizosphere, phyllosphere, endorhiza, and endosphere of field grown potato was analyzed. Culturable bacteria were obtained after plating on R2A medium. The endophytic populations averaged 103and 105CFU/g (fresh wt.) for the endosphere and endorhiza, respectively, which were lower than those for the ectophytic microenvironments, with 105and 107CFU/g (fresh wt.) for the phyllosphere and rhizosphere, respectively. The composition and richness of bacterial species was microenvironment-dependent. The occurrence and diversity of potato-associated bacteria was additionally monitored by a cultivation-independent approach using terminal restriction fragment length polymorphism analysis of 16S rDNA. The patterns obtained revealed a high heterogeneity of community composition and suggested the existence of microenvironment-specific communities. In an approach to measure the antagonistic potential of potato-associated bacteria, a total of 440 bacteria was screened by dual testing for in vitro antagonism towards the soilborne pathogens Verticillium dahliae and Rhizoctonia solani. The proportion of isolates with antagonistic activity was highest for the rhizosphere (10%), followed by the endorhiza (9%), phyllosphere (6%), and endosphere (5%). All 33 fungal antagonists were characterized by testing their in vitro antagonistic mechanisms, including their glucanolytic, chitinolytic, pectinolytic, cellulolytic, and proteolytic activity, and by their BOX-PCR fingerprints. In addition, they were screened for their biocontrol activity against Meloidogyne incognita. Overall, nine isolates belonging to Pseudomonas and Streptomyces species were found to control both fungal pathogens and M. incognita and were therefore considered as promising biological control agents. Key words: biocontrol, antagonistic potential, plant-associated bacteria.


2014 ◽  
Vol 13 (8) ◽  
pp. 950-957 ◽  
Author(s):  
Marc Swidergall ◽  
Joachim F. Ernst

ABSTRACTAntimicrobial peptides (AMPs) are key elements of innate immunity, which can directly kill multiple bacterial, viral, and fungal pathogens. The medically important fungusCandida albicanscolonizes different host niches as part of the normal human microbiota. Proliferation ofC. albicansis regulated through a complex balance of host immune defense mechanisms and fungal responses. Expression of AMPs against pathogenic fungi is differentially regulated and initiated by interactions of a variety of fungal pathogen-associated molecular patterns (PAMPs) with pattern recognition receptors (PRRs) on human cells. Inflammatory signaling and other environmental stimuli are also essential to control fungal proliferation and to prevent parasitism. To persist in the host,C. albicanshas developed a three-phase AMP evasion strategy, including secretion of peptide effectors, AMP efflux pumps, and regulation of signaling pathways. These mechanisms preventC. albicansfrom the antifungal activity of the major AMP classes, including cathelicidins, histatins, and defensins leading to a basal resistance. This minireview summarizes human AMP attack andC. albicansresistance mechanisms and current developments in the use of AMPs as antifungal agents.


2020 ◽  
Vol 22 (1) ◽  
Author(s):  
Yan Ramona ◽  
IDA BAGUS GEDE DARMAYASA ◽  
ANAK AGUNG NGURAH NARA KUSUMA ◽  
Martin Line

Abstract. Ramona Y, Darmayasa IBG, Kusuma AANN, Line MA. 2021. Diversity of biocontrol agents, isolated from several sources, inhibitory to several fungal plant pathogens. Biodiversitas 22: 298-303. This study investigated the inhibitory potential of diversity of antagonist bacteria residing in the rhizosphere zone and mature compost to counter fungal plant pathogens. Soils collected from rhizosphere of lettuce farms in Bali-Indonesia and Tasmania-Australia, mature compost, commercial biocontrol (Dipel®), and laboratory contaminants with significant inhibition against tested fungal pathogens were used as sources of antagonist bacteria. These antagonists were isolated by applying dilution and spread method on trypticase soya agar (TSA) or potato dextrose agar (PDA), and their ability to inhibit Sclerotinia minor, Sclerotinia sclerotiorum, Fusarium spp., and Rhizoctonia solani was assessed in dual culture assays. The results showed that 67 out of more than 100 isolates had antagonistic activity in vitro against at least one of tested fungal pathogens. In the preliminary identification, Bacillus spp. or Pseudomonas spp. were found to be pre-dominant isolates. Following screening studies in a non-replicated glasshouse experiment against S. minor and S. sclerotiorum, 8 of the most promising isolates were further identified using molecular methods based on their 16s rDNA sequences aligned with those deposited at the GeneBank. These 8 isolates were identified as Pseudomonas corrugata, Bacillus megaterium, Bacillus polymyxa, Bacillus mojavensis, Bacillus pumilus, Bacillus thuringiensis, Exiguobacterium acetylicum, and Chryseobacterium indologenes.


2019 ◽  
Vol 12 (2) ◽  
pp. 124-132
Author(s):  
Nia Safitri ◽  
Atria Martina ◽  
Rodesia Mustika Roza

Tanaman budi daya merupakan tanaman yang sering diserang oleh cendawan pathogen, sehingga mengakibatkan penurunan populasi dan produksi tanaman. Pengendalian hayati dengan cendawan antagonis merupakan salah satu metode yang paling efektif dan lebih ramah lingkungan dalam menekan pertumbuhan patogen tanaman. Penelitian ini bertujuan untuk menguji aktivitas antagonis cendawan isolat lokal Riau terhadap beberapa cendawan patogen pada tanaman budi daya. Uji antagonis dilakukan secara in vitro dengan metode dual culture menggunakan lima belas cendawan isolat lokal Riau terhadap Fusarium oxysporum f.sp. lycopersici, Ganoderma philippii, G. boninense, Rigidoporus microporus dan Colletotrichum sansevieria. Hasil penelitian menunjukkan bahwa Trichoderma sp. PNE 4 memiliki aktivitas antagonis tertinggi dan isolat FER C1 serta isolat LLB07 hanya memiliki aktivitas antagonis yang tinggi dalam menekan pertumbuhan cendawan patogen. Trichoderma sp. PNE 4 mampu menghambat pertumbuhan miselium F. oxysporum sebesar 85,30%, G. Philippii (100%), G. boninense (100%), dan C. sansevieria (100%). Isolat FER C1 hanya menghambat R. Microporus (50,39%) dan isolat LLB07 menghambat G. philippii (52,20%). Trichoderma sp. PNE 4 merupakan cendawan uji yang terpilih sebagai cendawan antagonis, karena memiliki kemampuan daya hambat  >70%.Abstract Cultivated plants are often attacked by pathogenic fungi resulting in a decline of population and crop production. Biocontrol with antagonistic fungi is one of the most effective and environmentally friendly methods in suppressing the growth of plant pathogens. This study aims to examine the antagonistic activity of local isolates fungi Riau against some pathogenic fungi on cultivated plants. The antagonistic test was performed in vitro by dual culture method using fifteen local isolates fungal Riau against Fusarium oxysporum f.sp. lycopersici, Ganoderma philippii, G. boninense, Rigidoporus microporus and Colletotrichum sansevieria. The results showed that Trichoderma sp. PNE 4 isolate exhibited highest activites and  FER C1 and LLB07 isolates exhibited high activities suppressed the growth of the fungal pathogen. Trichoderma sp. PNE 4 isolate inhibited mycelial growth F. oxysporum (85.30%), G. philippii (100%), G. boninense (100%) and C. sansevieria (100%). FER C1 isolate only inhibited R. microporus (50.39%), and LLB07 isolate inhibited G. philippii (52.20%). Trichoderma sp. PNE 4 isolate is test isolates as fungal antagonistic.


Author(s):  
ERIYANTO YUSNAWAN ◽  
ALFI INAYATI ◽  
YULIANTORO BALIADI

Abstract. Yusnawan E, Inayati A, Baliadi Y. 2019. Isolation of antagonistic fungi from rhizospheres and its biocontrol activity against different isolates of soil borne fungal pathogens infected legumes. Biodiversitas 20: 2048-2054. Soilborne diseases caused by Rhizoctonia solani and Fusarium sp. are biotic limits for legume production. Biological controls offer environmental friendly control for these pathogens. This study aimed to isolate and screen Trichoderma from different rhizospheres and to obtain effective Trichoderma isolates to suppress in vitro growth of the soil borne pathogens. The antagonistic inhibitory activity was performed by dual culture method. Seven out of forty indigenous Trichoderma isolates collected from East Java, Indonesia effectively suppressed the growth of different fungal isolates, namely Rhizoctonia solani (R.s1), R. solani (R.s2) as well as Fusarium sp. which infected soybean and mung bean. In vitro study showed different suppression of the pathogens on dual culture tests. The seven isolates inhibited the growth of R. solani (R.s1), R.solani (R.s2) and Fusarium sp. ranging from 90.0 to 99.6%, 72.8 to 82.4%, and 67.9 to 90.8%, respectively. Isolate origin and genetic variability of Trichoderma played an important role in the antagonistic activity. The fast-growing of selected Trichoderma showed their abilities for space occupation and nutrition competition, which involved in the antagonistic activity. The mycelial growth of Trichoderma over pathogens showed hyperparasitism mechanism. In addition, coiling of Trichoderma over hyphal pathogens was observed during microscopic observation. The seven Trichoderma isolates, therefore, are promising as biological control agents against the soil borne fungi infected legumes.


2010 ◽  
Vol 10 ◽  
pp. 760-765 ◽  
Author(s):  
S. C. Sati ◽  
P. Arya

The antagonistic activity of five aquatic hyphomycetes, viz.,Heliscus lugdunensis,Tetrachaetum elegans,Tetracladium breve,T. marchalianum, andT. nainitalense, against seven plant pathogenic fungi was studied using a dual culture technique. Inhibitory activity of tested aquatic hyphomycetes was determined by measuring the radial growth of plant pathogenic fungi on dual culture plates.Tetrachaetum elegansshowed antagonistic activity againstColletotrichum falcatum,Fusarium oxysporum,Pyricularia oryzae,Sclerotium sclerotiorum, andTilletia indicaHeliscus lugdunensisshowed antagonism against only two plant pathogenic fungi,Rhizoctonia solaniandColletotrichum falcatum.Tetracladium breve,T. marchalianum, andT. nainitalenseshowed no response towards tested plant pathogenic fungi.


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