scholarly journals Comparative systems analysis of the secretome of the opportunistic pathogen Aspergillus fumigatus and other Aspergillus species

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
R. P. Vivek-Ananth ◽  
Karthikeyan Mohanraj ◽  
Muralidharan Vandanashree ◽  
Anupam Jhingran ◽  
James P. Craig ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Systems Analysis ◽  
Opportunistic Pathogen ◽  
Aspergillus Species ◽  
Comparative Systems

scholarly journals Nitrogen, Iron and Zinc Acquisition: Key Nutrients to Aspergillus fumigatus Virulence

2021 ◽  
Vol 7 (7) ◽  
pp. 518
Author(s):  
Uxue Perez-Cuesta ◽  
Xabier Guruceaga ◽  
Saioa Cendon-Sanchez ◽  
Eduardo Pelegri-Martinez ◽  
Fernando L. Hernando ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Opportunistic Pathogen ◽  
Zinc Metabolism ◽  
Wide Field ◽  
Regulation Process ◽  
Number Of Genes ◽  
Iron And Zinc ◽  
Fungal Nutrition

Aspergillus fumigatus is a ubiquitous soil decomposer and an opportunistic pathogen that is characterized by its large metabolic machinery for acquiring nutrients from media. Lately, an ever-increasing number of genes involved in fungal nutrition has been associated with its virulence. Of these, nitrogen, iron, and zinc metabolism-related genes are particularly noteworthy, since 78% of them have a direct implication in virulence. In this review, we describe the sensing, uptake and regulation process of the acquisition of these nutrients, the connections between pathways and the virulence-implicated genes. Nevertheless, only 40% of the genes mentioned in this review have been assayed for roles in virulence, leaving a wide field of knowledge that remains uncertain and might offer new therapeutic and diagnostic targets.

scholarly journals Comparison of the Sensititre YeastOne and CLSI M38-A2 Microdilution Methods in Determining the Activity of Amphotericin B, Itraconazole, Voriconazole, and Posaconazole against Aspergillus Species

2018 ◽  
Vol 56 (10) ◽  
Author(s):  
Hsuan-Chen Wang ◽  
Ming-I Hsieh ◽  
Pui-Ching Choi ◽  
Chi-Jung Wu
Keyword(s):  
Aspergillus Fumigatus ◽  
Amphotericin B ◽  
Antifungal Agents ◽  
Susceptibility Testing ◽  
Geometric Mean ◽  
Antifungal Susceptibility ◽  
Reference Method ◽  
Aspergillus Species ◽  
Broth Microdilution ◽  
Content Type

ABSTRACT This study compared the YeastOne and reference CLSI M38-A2 broth microdilution methods for antifungal susceptibility testing of Aspergillus species. The MICs of antifungal agents were determined for 100 Aspergillus isolates, including 54 Aspergillus fumigatus (24 TR34/L98H isolates), 23 A. flavus, 13 A. terreus, and 10 A. niger isolates. The overall agreement (within 2 2-fold dilutions) between the two methods was 100%, 95%, 92%, and 90% for voriconazole, posaconazole, itraconazole, and amphotericin B, respectively. The voriconazole geometric mean (GM) MICs were nearly identical for all isolates using both methods, whereas the itraconazole and posaconazole GM MICs obtained using the YeastOne method were approximately 1 dilution lower than those obtained using the reference method. In contrast, the amphotericin B GM MIC obtained using the YeastOne method was 3.3-fold higher than that observed using the reference method. For the 24 A. fumigatus TR34/L98H isolates assayed, the categorical agreement (classified according to the CLSI epidemiological cutoff values) was 100%, 87.5%, and 83.3% for itraconazole, voriconazole, and posaconazole, respectively. For four A. niger isolates, the itraconazole MICs were >8 μg/ml using the M38-A2 method due to trailing growth, whereas the corresponding itraconazole MICs obtained using the YeastOne method were all ≤0.25 μg/ml without trailing growth. These data suggest that the YeastOne method can be used as an alternative for azole susceptibility testing of Aspergillus species and for detecting the A. fumigatus TR34/L98H isolates but that this method fails to detect A. niger isolates exhibiting trailing growth with itraconazole. Additionally, for isolates with azole MICs that approach or that are at susceptibility breakpoints or with high amphotericin B MICs detected using the YeastOne method, further MIC confirmation using the reference CLSI method is needed.

scholarly journals Nonribosomal Peptide Synthetase GenespesLandpes1Are Essential for Fumigaclavine C Production in Aspergillus fumigatus

2012 ◽  
Vol 78 (9) ◽  
pp. 3166-3176 ◽  
Author(s):  
Karen A. O'Hanlon ◽  
Lorna Gallagher ◽  
Markus Schrettl ◽  
Christoph Jöchl ◽  
Kevin Kavanagh ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Opportunistic Pathogen ◽  
Mass Spectrometry Analysis ◽  
Infection Model ◽  
Nonribosomal Peptide ◽  
Content Type ◽  
Spectrometry Analysis ◽  
Peptide Synthetases ◽  
Increased Sensitivity

ABSTRACTThe identity of metabolites encoded by the majority of nonribosomal peptide synthetases in the opportunistic pathogen,Aspergillus fumigatus, remains outstanding. We found that the nonribosomal peptide (NRP) synthetases PesL and Pes1 were essential for fumigaclavine C biosynthesis, the end product of the complex ergot alkaloid (EA) pathway inA. fumigatus. Deletion of eitherpesL(ΔpesL) orpes1(Δpes1) resulted in complete loss of fumigaclavine C biosynthesis, relatively increased production of fumitremorgins such as TR-2, fumitremorgin C and verruculogen, increased sensitivity to H2O2, and increased sensitivity to the antifungals, voriconazole, and amphotericin B. Deletion ofpesLresulted in severely reduced virulence in an invertebrate infection model (P< 0.001). These findings indicate that NRP synthesis plays an essential role in mediating the final prenylation step of the EA pathway, despite the apparent absence of NRP synthetases in the proposed EA biosynthetic cluster forA. fumigatus. Liquid chromatography/diode array detection/mass spectrometry analysis also revealed the presence of fumiquinazolines A to F in bothA. fumigatuswild-type and ΔpesLstrains. This observation suggests that alternative NRP synthetases can also function in fumiquinazoline biosynthesis, since PesL has been shown to mediate fumiquinazoline biosynthesisin vitro. Furthermore, we provide here the first direct link between EA biosynthesis and virulence, in agreement with the observed toxicity associated with EA exposure. Finally, we demonstrate a possible cluster cross-talk phenomenon, a theme which is beginning to emerge in the literature.

scholarly journals Gene Targeting in Aspergillus fumigatus by Homologous Recombination Is Facilitated in a Nonhomologous End- Joining-Deficient Genetic Background

2006 ◽  
Vol 5 (1) ◽  
pp. 212-215 ◽  
Author(s):  
Sven Krappmann ◽  
Christoph Sasse ◽  
Gerhard H. Braus
Keyword(s):  
Homologous Recombination ◽  
Aspergillus Fumigatus ◽  
Gene Targeting ◽  
Mutant Strain ◽  
Genetic Background ◽  
Opportunistic Pathogen ◽  
Nonhomologous End Joining ◽  
End Joining ◽  
Gene Encoding

ABSTRACT The akuA gene encoding the Ku70 component of the nonhomologous end-joining machinery was deleted in the opportunistic pathogen Aspergillus fumigatus. No obvious phenotype could be assessed for the corresponding mutant strain but relative frequencies of homologous recombination were increased as deduced from targeting the laccase-encoding abr2 gene.

scholarly journals Isolation and Molecular Characterization of Aspergillus fumigatus and Aspergillus flavus Isolated from Poultry Birds in Ado- Ekiti, Nigeria

2020 ◽  
pp. 31-44
Author(s):  
E. D. Fagbohun ◽  
K. J. Ayantola ◽  
A. J. Toyin-Famoroti
Keyword(s):  
Aspergillus Fumigatus ◽  
Molecular Characterization ◽  
Aspergillus Flavus ◽  
Clinical Signs ◽  
Signs And Symptoms ◽  
Aspergillus Species ◽  
Exercise Intolerance ◽  
State University ◽  
Poultry Farms

Aim: The study was carried out to isolate and identify Aspergillus species from commercial birds with suspected aspergillosis in the poultry farms within Ado Ekiti metropolis Nigeria.  Place and Period of Study: The study was carried out in the Department of Microbiology, Faculty of Science, Ekiti State University Ado Ekiti, Nigeria in August 2016. Methodology: A total of 35 sick/suspected birds were collected randomly from three poultry farms. At Ago-Aduloju poultry farms, 15 samples were randomly collected from 1000 birds while at Ekiti State University poultry farms, 10 samples were randomly collected from 500 birds. At Federal Polytechnic Ado Ekiti poultry farms, 10 samples were randomly collected from 700 birds. The bird’s selection was on the basis of clinical signs and symptoms such as difficulty in breathing, weight loss, drooping of wings and exercise intolerance. Swab samples were collected from each suspected/sick bird for mycological culture and molecular characterization of the isolates from each bird was carried out. The isolates were identified based on the color of the culture on Potato Dextrose Agar and microscopic examination. Molecular identification was done using 23S Ribosomal RNA Gene and Partial Sequence. Results: Six fungal strains that showed similar morphological and cultural characteristics of Aspergillus species were isolated. The isolates were coded ASP 1, ASP 2, ASP 3, ASP 4, ASP 5, and ASP 6. The identified organisms were; Aspergillus fumigatus qH 107 (ASP 1), Aspergillus fumigatus qH 107 (ASP 2), Aspergillus flavus M09 (ASP 3), Aspergillus flavus UOMS6 (ASP 4), Aspergillus fumigatus qH 107 (ASP 5), Aspergillus flavus qH 107 (ASP 6). Conclusion: It is evident that Aspergillus species were predominant in poultry farms selected in this study. Necessary precaution should be put in place to prevent the spread of aspergillosis. Poultry farmers are advised to avoid damp environments, moldy feeds, dry and dusty litters. Adequate ventilation should always be provided in poultry farms to prevent Aspergillosis.

scholarly journals Genetic Diversity and Dispersal of Aspergillus fumigatus in Arctic Soils

Genes ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 19
Author(s):  
Gregory A. Korfanty ◽  
Mykaelah Dixon ◽  
Haoran Jia ◽  
Heather Yoell ◽  
Jianping Xu
Keyword(s):  
Genetic Diversity ◽  
Aspergillus Fumigatus ◽  
Opportunistic Pathogen ◽  
Ecological Niches ◽  
Ecological Distribution ◽  
Resistant Genotype ◽  
Arctic Regions ◽  
Arctic Soils ◽  
The World ◽  
Geographic Regions

Aspergillus fumigatus is a saprophytic mold and an opportunistic pathogen with a broad geographic and ecological distribution. A. fumigatus is the most common etiological agent of aspergillosis, affecting over 8,000,000 individuals worldwide. Due to the rising number of infections and increasing reports of resistance to antifungal therapy, there is an urgent need to understand A. fumigatus populations from local to global levels. However, many geographic locations and ecological niches remain understudied, including soil environments from arctic regions. In this study, we isolated 32 and 52 A. fumigatus strains from soils in Iceland and the Northwest Territories of Canada (NWT), respectively. These isolates were genotyped at nine microsatellite loci and the genotypes were compared with each other and with those in other parts of the world. Though significantly differentiated from each other, our analyses revealed that A. fumigatus populations from Iceland and NWT contained evidence for both clonal and sexual reproductions, and shared many alleles with each other and with those collected from across Europe, Asia, and the Americas. Interestingly, we found one triazole-resistant strain containing the TR34 /L98H mutation in the cyp51A gene from NWT. This strain is closely related to a triazole-resistant genotype broadly distributed in India. Together, our results suggest that the northern soil populations of A. fumigatus are significantly influenced by those from other geographic regions.

scholarly journals tpo3 and dur3, Aspergillus fumigatus Plasma Membrane Regulators of Polyamines, Regulate Polyamine Homeostasis and Susceptibility to Itraconazole

2020 ◽  
Vol 11 ◽  
Author(s):  
Mingcong Chen ◽  
Guowei Zhong ◽  
Sha Wang ◽  
Jun Zhu ◽  
Lei Tang ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Plasma Membrane ◽  
Aspergillus Fumigatus ◽  
Drug Transport ◽  
Opportunistic Pathogen ◽  
Moderate Increase ◽  
High Concentration ◽  
Polyamine Biosynthesis ◽  
Drastic Increase ◽  
Polyamine Content

Aspergillus fumigatus is a well-known opportunistic pathogen that causes invasive aspergillosis (IA) infections, which have high mortality rates in immunosuppressed individuals. Long-term antifungal drug azole use in clinical treatment and agriculture results in loss of efficacy or drug resistance. Drug resistance is related to cellular metabolites and the corresponding gene transcription. In this study, through untargeted metabolomics and transcriptomics under itraconazole (ITC) treatment, we identified two plasma membrane-localized polyamine regulators tpo3 and dur3, which were important for polyamine homeostasis and susceptibility to ITC in A. fumigatus. In the absence of tpo3 and/or dur3, the levels of cytoplasmic polyamines had a moderate increase, which enhanced the tolerance of A. fumigatus to ITC. In comparison, overexpression of tpo3 or dur3 induced a drastic increase in polyamines, which increased the sensitivity of A. fumigatus to ITC. Further analysis revealed that polyamines concentration-dependently affected the susceptibility of A. fumigatus to ITC by scavenging reactive oxygen species (ROS) at a moderate concentration and promoting the production of ROS at a high concentration rather than regulating drug transport. Moreover, inhibition of polyamine biosynthesis reduced the intracellular polyamine content, resulted in accumulation of ROS and enhanced the antifungal activity of ITC. Interestingly, A. fumigatus produces much lower levels of ROS under voriconazole (VOC) treatment than under ITC-treatment. Accordingly, our study established the link among the polyamine regulators tpo3 and dur3, polyamine homeostasis, ROS content, and ITC susceptibility in A. fumigatus.

scholarly journals Global Sexual Fertility in the Opportunistic Pathogen Aspergillus fumigatus and Identification of New Supermater Strains

2020 ◽  
Vol 6 (4) ◽  
pp. 258
Author(s):  
Sameira S. Swilaiman ◽  
Céline M. O’Gorman ◽  
Wenyue Du ◽  
Janyce A. Sugui ◽  
Joanne Del Buono ◽  
...  
Keyword(s):  
Genetic Variation ◽  
High Temperature ◽  
Aspergillus Fumigatus ◽  
Opportunistic Pathogen ◽  
Sexual Cycle ◽  
Mating Types ◽  
Irish Population ◽  
Mating Partner ◽  
Ascospore Germination ◽  
Temperature Heat

A sexual cycle in Aspergillus fumigatus was first described in 2009 with isolates from Dublin, Ireland. However, the extent to which worldwide isolates can undergo sexual reproduction has remained unclear. In this study a global collection of 131 isolates was established with a near 1:1 ratio of mating types. All isolates were crossed to MAT1-1 or MAT1-2 Irish strains, and a subset of isolates from different continents were crossed together. Ninety seven percent of isolates were found to produce cleistothecia with at least one mating partner, showing that sexual fertility is not limited to the Irish population but is a characteristic of global A. fumigatus. However, large variation was seen in numbers of cleistothecia produced per cross, suggesting differences in the possibility for genetic exchange between strains in nature. The majority of crosses produced ascospores with >50% germination rates, but with wide variation evident. A high temperature heat shock was required to induce ascospore germination. Finally, a new set of highly fertile MAT1-1 and MAT1-2 supermater strains were identified and pyrimidine auxotrophs generated for community use. Results provide insights into the potential for the A. fumigatus sexual cycle to generate genetic variation and allow gene flow of medically important traits.

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