scholarly journals Räuberische Pilze mit Anwendungspotenzial

BIOspektrum ◽  
2021 ◽  
Vol 27 (7) ◽  
pp. 686-689
Author(s):  
Valentin Wernet ◽  
Nicole Wernet ◽  
Reinhard Fischer
Keyword(s):  
Secondary Metabolites ◽  
Virulence Factors ◽  
Duddingtonia Flagrans ◽  
Interspecies Communication

AbstractNematode-trapping fungi, such as Duddingtonia flagrans, are fascinating carnivorous microorganisms. In a nutrient-rich environment they live as saprotrophs, but if nutrients are scarce and in the presence of nematodes, they can switch to a predatory lifestyle. The switch is characterized by the formation of complex, adhesive trap structures. The interaction requires a sophisticated interspecies communication with pheromones, secondary metabolites, and virulence factors.

scholarly journals Proteomic and Transcriptomic Analyses Provide Novel Insights into the Crucial Roles of Host-Induced Carbohydrate Metabolism Enzymes in Xanthomonas oryzae pv. oryzae Virulence and Rice-Xoo Interaction

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Guichun Wu ◽  
Yuqiang Zhang ◽  
Bo Wang ◽  
Kaihuai Li ◽  
Yuanlai Lou ◽  
...  
Keyword(s):  
Gene Expression ◽  
Signal Transduction ◽  
Amino Acids ◽  
Secondary Metabolites ◽  
Carbohydrate Metabolism ◽  
Virulence Factors ◽  
Global Gene Expression ◽  
Xanthomonas Oryzae ◽  
Oxidation Reduction ◽  
Phenylpropanoid Biosynthesis

Abstract Background Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial leaf blight, a devastating rice disease. The Xoo-rice interaction, wherein wide ranging host- and pathogen-derived proteins and genes wage molecular arms race, is a research hotspot. Hence, the identification of novel rice-induced Xoo virulence factors and characterization of their roles affecting rice global gene expression profiles will provide an integrated and better understanding of Xoo-rice interactions from the molecular perspective. Results Using comparative proteomics and an in vitro interaction system, we revealed that 5 protein spots from Xoo exhibited significantly different expression patterns (|fold change| > 1.5) at 3, 6, 12 h after susceptible rice leaf extract (RLX) treatment. MALDI-TOF MS analysis and pathogenicity tests showed that 4 host-induced proteins, including phosphohexose mutase, inositol monophosphatase, arginase and septum site-determining protein, affected Xoo virulence. Among them, mutants of two host-induced carbohydrate metabolism enzyme-encoding genes, ΔxanA and Δimp, elicited enhanced defense responses and nearly abolished Xoo virulence in rice. To decipher rice differentially expressed genes (DEGs) associated with xanA and imp, transcriptomic responses of ΔxanA-treated and Δimp-treated susceptible rice were compared to those in rice treated with PXO99A at 1 and 3 dpi. A total of 1521 and 227 DEGs were identified for PXO99A vs Δimp at 1 and 3 dpi, while for PXO99A vs ΔxanA, there were 131 and 106 DEGs, respectively. GO, KEGG and MapMan analyses revealed that the DEGs for PXO99A vs Δimp were mainly involved in photosynthesis, signal transduction, transcription, oxidation-reduction, hydrogen peroxide catabolism, ion transport, phenylpropanoid biosynthesis and metabolism of carbohydrates, lipids, amino acids, secondary metabolites, hormones, and nucleotides, while the DEGs from PXO99A vs ΔxanA were predominantly associated with photosynthesis, signal transduction, oxidation-reduction, phenylpropanoid biosynthesis, cytochrome P450 and metabolism of carbohydrates, lipids, amino acids, secondary metabolites and hormones. Although most pathways were associated with both the Δimp and ΔxanA treatments, the underlying genes were not the same. Conclusion Our study identified two novel host-induced virulence factors XanA and Imp in Xoo, and revealed their roles in global gene expression in susceptible rice. These results provide valuable insights into the molecular mechanisms of pathogen infection strategies and plant immunity.

scholarly journals Metabolomic Profiling of Burkholderia Cenocepacia in Synthetic Cystic Fibrosis Sputum Media Reveals Nutrient Environment-Specific Production of Virulence Factors

2021 ◽  
Author(s):  
Olakunle A. Jaiyesimi ◽  
Andrew C. McAvoy ◽  
David N. Fogg ◽  
Neha Garg
Keyword(s):  
Cystic Fibrosis ◽  
Quorum Sensing ◽  
Secondary Metabolites ◽  
Virulence Factors ◽  
Homoserine Lactone ◽  
Burkholderia Cenocepacia ◽  
Comparative Metabolomics ◽  
Nutrient Environment ◽  
Life Threatening ◽  
Future Work

Abstract Infections by Burkholderia cenocepacia lead to life-threatening disease in immunocompromised individuals, including those living with cystic fibrosis (CF). While genetic variation in various B. cenocepacia strains has been reported, it remains unclear how the chemical environment of CF lung influences the production of small molecule virulence factors by these strains. Here we compare metabolomes of three clinical B. cenocepacia strains in synthetic CF sputum media (SCFM2) and in a routine laboratory media (LB), in the presence and absence of the antibiotic trimethoprim. Using a mass spectrometry based untargeted metabolomics approach, we identify several compound classes which are differentially produced in SCFM2 compared to LB media, including siderophores, antimicrobials, quorum sensing signals, and various lipids. Furthermore, we describe that specific metabolites are induced by the antibiotic trimethoprim only in SCFM2 when compared to LB. Herein, C13-acyl-homoserine lactone, a quorum sensing signal previously not known to be produced by B. cenocepacia as well as pyochelin-type siderophores were exclusively detected during growth in SCFM2 in the presence of trimethoprim. The comparative metabolomics approach described in this study provides insight into environment-dependent production of secondary metabolites by B. cenocepacia strains and suggests future work which could identify personalized strain-specific regulatory mechanisms involved in production of secondary metabolites.

scholarly journals Gliotoxin, a known virulence factor in the major human pathogen Aspergillus fumigatus, is also biosynthesized by the non-pathogenic relative A. fischeri

2019 ◽  
Author(s):  
Sonja L. Knowles ◽  
Matthew E. Mead ◽  
Lilian Pereira Silva ◽  
Huzefa A. Raja ◽  
Jacob L. Steenwyk ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Aspergillus Fumigatus ◽  
Secondary Metabolite ◽  
Virulence Factors ◽  
Secondary Metabolite Production ◽  
Close Relative ◽  
Human Pathogen ◽  
Metabolite Production ◽  
Similarities And Differences ◽  
Close Relatives

ABSTRACTAspergillus fumigatus is a major opportunistic human pathogen. Multiple traits contribute to A. fumigatus pathogenicity, including its ability to produce specific secondary metabolites, such as gliotoxin. Gliotoxin is known to inhibit the host immune response, and genetic mutants that inactivate gliotoxin biosynthesis (or secondary metabolism in general) attenuate A. fumigatus virulence. The genome of A. fischeri, a very close non-pathogenic relative of A. fumigatus, contains a biosynthetic gene cluster that exhibits high sequence similarity to the A. fumigatus gliotoxin cluster. However, A. fischeri is not known to produce gliotoxin. To gain further insight into the similarities and differences between the major pathogen A. fumigatus and the non-pathogen A. fischeri, we examined whether A. fischeri strain NRRL 181 biosynthesizes gliotoxin and whether its production, and of secondary metabolites more generally, influence its virulence profile. We found that A. fischeri biosynthesizes gliotoxin in the same conditions as A. fumigatus. However, whereas loss of laeA, a master regulator of secondary metabolite production, has been previously shown to reduce the virulence of A. fumigatus, we found that laeA loss (and loss of secondary metabolite production, including gliotoxin) in A. fischeri does not influence its virulence. These results suggest that gliotoxin and secondary metabolite production are virulence factors in the genomic and phenotypic background of the major pathogen A. fumigatus but are much less important in the background of the non-pathogen A. fischeri. We submit that understanding the observed spectrum of pathogenicity across closely related pathogenic and non-pathogenic Aspergillus species will require detailed characterization of their biological, chemical, and genomic similarities and differences.IMPORTANCEAspergillus fumigatus is a major opportunistic fungal pathogen of humans but most of its close relatives are non-pathogenic. Why is that so? This important, yet largely unanswered, question can be addressed by examining how A. fumigatus and its non-pathogenic close relatives are similar or different with respect to virulence-associated traits. We investigated whether Aspergillus fischeri, a non-pathogenic close relative of A. fumigatus, can produce gliotoxin, a mycotoxin known to contribute to A. fumigatus virulence. We discovered that the non-pathogenic A. fischeri produces gliotoxin under the same conditions as the major pathogen A. fumigatus. However, we also discovered that, in contrast to what has been previously observed in A. fumigatus, loss of secondary metabolite, including gliotoxin, production in A. fischeri does not alter its virulence. Our results are consistent with the “cards of virulence” model of opportunistic fungal disease, where the ability to cause disease stems from the combination (“hand”) of individual virulence factors (“cards”), but not from individual factors per se.

scholarly journals Gliotoxin, a Known Virulence Factor in the Major Human Pathogen Aspergillus fumigatus, Is Also Biosynthesized by Its Nonpathogenic Relative Aspergillus fischeri

mBio ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Sonja L. Knowles ◽  
Matthew E. Mead ◽  
Lilian Pereira Silva ◽  
Huzefa A. Raja ◽  
Jacob L. Steenwyk ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Aspergillus Fumigatus ◽  
Secondary Metabolite ◽  
Virulence Factors ◽  
Secondary Metabolite Production ◽  
Human Pathogen ◽  
Content Type ◽  
Metabolite Production ◽  
Aspergillus Fischeri ◽  
Similarities And Differences

ABSTRACT Aspergillus fumigatus is a major opportunistic human pathogen. Multiple traits contribute to A. fumigatus pathogenicity, including its ability to produce specific secondary metabolites, such as gliotoxin. Gliotoxin is known to inhibit the host immune response, and genetic mutants that inactivate gliotoxin biosynthesis (or secondary metabolism in general) attenuate A. fumigatus virulence. The genome of Aspergillus fischeri, a very close nonpathogenic relative of A. fumigatus, contains a biosynthetic gene cluster that is homologous to the A. fumigatus gliotoxin cluster. However, A. fischeri is not known to produce gliotoxin. To gain further insight into the similarities and differences between the major pathogen A. fumigatus and the nonpathogen A. fischeri, we examined whether A. fischeri strain NRRL 181 biosynthesizes gliotoxin and whether the production of secondary metabolites influences the virulence profile of A. fischeri. We found that A. fischeri biosynthesizes gliotoxin under the same conditions as A. fumigatus. However, whereas loss of laeA, a master regulator of secondary metabolite production (including gliotoxin biosynthesis), has previously been shown to reduce A. fumigatus virulence, we found that laeA loss (and loss of secondary metabolite production) in A. fischeri does not influence its virulence. These results suggest that LaeA-regulated secondary metabolites are virulence factors in the genomic and phenotypic background of the major pathogen A. fumigatus but are much less important in the background of the nonpathogen A. fischeri. Understanding the observed spectrum of pathogenicity across closely related pathogenic and nonpathogenic Aspergillus species will require detailed characterization of their biological, chemical, and genomic similarities and differences. IMPORTANCE Aspergillus fumigatus is a major opportunistic fungal pathogen of humans, but most of its close relatives are nonpathogenic. Why is that so? This important, yet largely unanswered, question can be addressed by examining how A. fumigatus and its close nonpathogenic relatives are similar or different with respect to virulence-associated traits. We investigated whether Aspergillus fischeri, a nonpathogenic close relative of A. fumigatus, can produce gliotoxin, a mycotoxin known to contribute to A. fumigatus virulence. We discovered that the nonpathogenic A. fischeri produces gliotoxin under the same conditions as those of the major pathogen A. fumigatus. However, we also discovered that, in contrast to what has previously been observed in A. fumigatus, the loss of secondary metabolite production in A. fischeri does not alter its virulence. Our results are consistent with the “cards of virulence” model of opportunistic fungal disease, in which the ability to cause disease stems from the combination (“hand”) of virulence factors (“cards”) but not from individual factors per se.

scholarly journals Whole Genome Sequence of Alternaria alternata, the Causal Agent of Black Spot of Kiwifruit

2021 ◽  
Vol 12 ◽  
Author(s):  
Ke Huang ◽  
Jianming Tang ◽  
Yong Zou ◽  
Xiangcheng Sun ◽  
Jianbin Lan ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Virulence Factors ◽  
Genome Sequence ◽  
Alternaria Alternata ◽  
Black Spot ◽  
Transcriptional Regulators ◽  
Whole Genome Sequence ◽  
Economic Losses ◽  
Wide Range ◽  
Host Specific Toxins

Alternaria alternata is a pathogen in a wide range of agriculture crops and causes significant economic losses. A strain of A. alternata (Y784-BC03) was isolated and identified from “Hongyang” kiwifruit and demonstrated to cause black spot infections on fruits. The genome sequence of Y784-BC03 was obtained using Nanopore MinION technology. The assembled genome is composed of 33,869,130bp (32.30Mb) comprising 10 chromosomes and 11,954 genes. A total of 2,180 virulence factors were predicted to be present in the obtained genome sequence. The virulence factors comprised genes encoding secondary metabolites, including non-host-specific toxins, cell wall-degrading enzymes, and major transcriptional regulators. The predicted gene clusters encoding genes for the biosynthesis and export of secondary metabolites in the genome of Y784-BC03 were associated with non-host-specific toxins, including cercosporin, dothistromin, and versicolorin B. Major transcriptional regulators of different mycotoxin biosynthesis pathways were identified, including the transcriptional regulators, polyketide synthase, P450 monooxygenase, and major facilitator superfamily transporters.

scholarly journals Metabolomic profiling of Burkholderia cenocepacia in synthetic cystic fibrosis sputum medium reveals nutrient environment-specific production of virulence factors

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Olakunle A. Jaiyesimi ◽  
Andrew C. McAvoy ◽  
David N. Fogg ◽  
Neha Garg
Keyword(s):  
Cystic Fibrosis ◽  
Quorum Sensing ◽  
Secondary Metabolites ◽  
Virulence Factors ◽  
Homoserine Lactone ◽  
Burkholderia Cenocepacia ◽  
Combination Treatments ◽  
Comparative Metabolomics ◽  
Nutrient Environment ◽  
Future Work

AbstractInfections by Burkholderia cenocepacia lead to life-threatening disease in immunocompromised individuals, including those living with cystic fibrosis (CF). While genetic variation in various B. cenocepacia strains has been reported, it remains unclear how the chemical environment of CF lung influences the production of small molecule virulence factors by these strains. Here we compare metabolomes of three clinical B. cenocepacia strains in synthetic CF sputum medium (SCFM2) and in a routine laboratory medium (LB), in the presence and absence of the antibiotic trimethoprim. Using a mass spectrometry-based untargeted metabolomics approach, we identify several compound classes which are differentially produced in SCFM2 compared to LB media, including siderophores, antimicrobials, quorum sensing signals, and various lipids. Furthermore, we describe that specific metabolites are induced in the presence of the antibiotic trimethoprim only in SCFM2 when compared to LB. Herein, C13-acyl-homoserine lactone, a quorum sensing signal previously not known to be produced by B. cenocepacia as well as pyochelin-type siderophores were exclusively detected during growth in SCFM2 in the presence of trimethoprim. The comparative metabolomics approach described in this study provides insight into environment-dependent production of secondary metabolites by B. cenocepacia strains and suggests future work which could identify personalized strain-specific regulatory mechanisms involved in production of secondary metabolites. Investigations into whether antibiotics with different mechanisms of action induce similar metabolic alterations will inform development of combination treatments aimed at effective clearance of Burkholderia spp. pathogens.

Inhibition of Biofilm and Virulence Factors of Candida albicans by Partially Purified Secondary Metabolites of Streptomyces chrestomyceticus Strain ADP4

2018 ◽  
Vol 18 (11) ◽  
pp. 925-945 ◽  
Author(s):  
Vartika Srivastava ◽  
Rajeev K. Singla ◽  
Ashok K. Dubey
Keyword(s):  
Secondary Metabolites ◽  
Virulence Factors ◽  
Hydrolytic Enzymes ◽  
Docking Studies ◽  
Dilution Method ◽  
Aspartic Acid Residue ◽  
Chemical Profiling ◽  
Mechanistic Analysis ◽  
Vlife Mds ◽  
Diffusion Assay

Background: Despite several advancements in antifungal drug discovery, fungal diseases like Invasive Candidiasis (IC) still remain associated with high rates of morbidity and mortality worldwide. Thus there is an enormous need for anti-Candida drugs. Objective: The main objectives of the work included: 1. To investigate therapeutically significant classes of secondary metabolites produced by S. chrestomyceticus strain ADP4. 2. To investigate and analyze inhibition of significant virulence attributes of C. albicans, such as, biofilm and secretory hydrolytic enzymes by ADP4 secondary metabolites. 3. Mechanistic analysis of probable compounds for their site of action on Secretary Aspartyl Proteinase 3 (Sap3). Methods: Metabolite extract-SDB (MESDB) of S. chrestomyceticus strain ADP4 was fractionated on silica gel column chromatography. Fractions were analyzed for anti-Candida activity by disc diffusion assay. Active fractions were further purified by differential solvent treatment. MIC90 values were determined by broth dilution method. MFC was based on counting viable cells. Inhibition of yeast to hyphae transition and that of production of hydrolytic enzymes were estimated by plate assays. GC-MS of MESDB and Partially Purified Metabolite preparations (PPMs) was done. GRIP docking studies with Sap 3 of C. albicans was done using VLife MDS 4.6 software. Results: Chemical profiling showed that ADP4 secondary metabolites contained alkaloids, flavonoids, polyphenols, terpenoids and triterpenes. The MESDB and the PPMs showed low or no cytotoxicity but were able to effectively contain virulence attributes of Candida pathogen. Docking studies revealed that some of the probable compounds have affinity for aspartic acid residue in Sap3 enzyme of C. albicans. Conclusion: Secondary metabolite of strain ADP4 included important classes of therapeutically important compounds. Their anti-Candida activity was mediated by inhibition of critical virulence factors of the pathogen.

scholarly journals Safety Evaluation of Fermotein: Allergenicity, Mycotoxin Production, Biochemical Analyses and Microbiology of a Fungal Single-cell Protein Product

2020 ◽  
pp. 146-155
Author(s):  
Marjolein van der Spiegel ◽  
José J. van den Driessche ◽  
Elisa Leune ◽  
Lucie Pařenicová ◽  
Wim de Laat
Keyword(s):  
Heavy Metals ◽  
Secondary Metabolites ◽  
Single Cell ◽  
Virulence Factors ◽  
Cross Reactivity ◽  
Cell Protein ◽  
Food Allergens ◽  
Mycotoxin Production ◽  
Rhizomucor Pusillus ◽  
Antibiotic Synthesis

Aim: Single-cell proteins (SCPs) are considered as innovative and sustainable alternatives to animal-based products. Fermotein is an innovative SCP obtained from fermentation of the filamentous fungus Rhizomucor pusillus. The toxicity, capability to produce secondary metabolites and allergenic potential of this fungus has never been assessed before. Like other filamentous fungi, there is a lack of information on this species to assess its safety for human consumption. The objective of the current study was to investigate the safety of Fermotein and its source Rhizomucor pusillus regarding toxicity, capability to produce secondary metabolites and allergenicity. In addition, possible contaminants were also examined. Methodology: The genome of Rhizomucor pusillus was sequenced and annotated in order to screen for production of common mycotoxins, antibiotic synthesis pathways, mucormycosis-related virulence factors and in silico potential cross-reactivity with known food allergens. The presence of mycotoxins and allergens were validated by laboratory analysis. The level of RNA, heavy metals and microbiological contaminants were also determined.   Results: No mycotoxin production-related genes were identified in the genome of Rhizomucor pusillus nor were mycotoxins found in Fermotein. Six proteins present in Fermotein showed high homology with five known food allergens. No gene clusters were found that corresponded with antibiotic synthesis pathways. Although 10 proteins in the genome of Rhizomucor pusillus may represent mucormycosis-related virulence factors, no cases of mucormycosis after oral intake are reported. The level of heavy metals and microbiological contaminants were below legislative limits, whereas RNA content was 4.9 ± 0.2% of dry matter. Conclusion: No safety concerns were identified for Fermotein or its source Rhizomucor pusillus, except the potential for cross-reactivity with five known food allergens. This should be taken into account for communication with consumers. Information from the current study contributes to the body of evidence for determination of Qualified Presumption of Safety status of Rhizomucor pusillus.

Lycopene alleviates sulfamethoxazole-induced hepatotoxicity in grass carp (Ctenopharyngodon idellus) via suppression of oxidative stress, inflammation and apoptosis

2020 ◽  
Vol 11 (10) ◽  
pp. 8547-8559
Author(s):  
Hongjing Zhao ◽  
Yu Wang ◽  
Mengyao Mu ◽  
Menghao Guo ◽  
Hongxian Yu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Secondary Metabolites ◽  
Human Health ◽  
Grass Carp ◽  
Aquatic Environment ◽  
Ctenopharyngodon Idellus

Antibiotics are used worldwide to treat diseases in humans and other animals; most of them and their secondary metabolites are discharged into the aquatic environment, posing a serious threat to human health.

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