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PloS One 2020Airborne fungi are associated with upper and lower airway inflammatory diseases. Alternaria is commonly found in nasal secretions and induces the production of chemical...
Airborne fungi are associated with upper and lower airway inflammatory diseases. Alternaria is commonly found in nasal secretions and induces the production of chemical mediators from sinonasal mucosa. This study aimed to establish an Alternaria-induced chronic rhinosinusitis (CRS) mouse model and determine the influence of host allergic background on the immunopathological characteristics of CRS. BALB/c mice were used for establishing the CRS model. Alternaria was intranasally instilled for 8 or 16 weeks with or without ovalbumin (OVA) presensitization. Total serum IgE and Alternaria-specific IgE levels were measured by enzyme-linked immunosorbent assay (ELISA). Interleukin (IL)-4, IL-10, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α levels in nasal lavage fluid (NLF) and splenocytes were measured by ELISA and their mRNAs and levels of associated transcription factors in sinonasal mucosa were determined with quantitative reverse-transcriptase polymerase chain reaction (RT-PCR). Hematoxylin-eosin staining and periodic acid-Schiff staining were performed to evaluate histological changes. Total serum IgE was increased in both allergic and non-allergic CRS. IL-4 was strongly expressed in NLF in both allergic and non-allergic CRS at 16 weeks and not only eosinophils but also neutrophils were increased in NLF of non-allergic CRS mice. The levels of Th1, Th2, and Treg cytokines and transcription factor mRNAs were significantly increased in sinonasal mucosa of non-allergic CRS mice. Both inflammatory cell infiltration and goblet cell hyperplasia were increased in CRS mice. Repeated intranasal instillation of Alternaria results in sinonasal inflammation with inflammatory cell infiltration. The sinonasal mucosal immune responses against Alternaria were shown to differ depending on the host allergic background.
Topics: Alternaria; Animals; Chronic Disease; Disease Models, Animal; Female; Immunoglobulin E; Interleukin-10; Interleukin-4; Mice; Mice, Inbred BALB C; Nasal Lavage Fluid; Nasal Mucosa; RNA, Messenger; Rhinitis; Sinusitis; Spleen; Transcription Factors; Tumor Necrosis Factor-alpha
PubMed: 32544181
DOI: 10.1371/journal.pone.0234731 -
Molecules (Basel, Switzerland) Apr 2022A series of 30 succinate dehydrogenase inhibitors (SDHIs) of 4-amino coumarin-based derivatives were designed and synthesized. According to the analysis of fungicidal...
A series of 30 succinate dehydrogenase inhibitors (SDHIs) of 4-amino coumarin-based derivatives were designed and synthesized. According to the analysis of fungicidal activity in vitro, most of the compounds expressed broad-spectrum antifungal activity against four plant pathogenic fungi ( and ) using the mycelium growth inhibition method. The results showed that compounds with the group of 2-ene-3-methyl-butyl and with the group of 2-bromo-1-oxo-hexyl displayed excellent activity against and , with EC values of 92~145 μg/mL. Molecular docking showed that the inhibitor was completely locked into the cavity of SDH, forming a conventional hydrogen bond interacting with the amino acid residue TYR58. The present work indicates that these derivatives would serve as novel potential fungicides targeting SDH.
Topics: Alternaria; Aminocoumarins; Antifungal Agents; Botrytis; Coumarins; Fungicides, Industrial; Molecular Docking Simulation; Structure-Activity Relationship
PubMed: 35566096
DOI: 10.3390/molecules27092738 -
Fungal Biology Apr 2022Alternaria rot has been recently described as an emerging fungal disease of citrus causing significant damage in California groves. A survey was conducted to determine...
Alternaria rot has been recently described as an emerging fungal disease of citrus causing significant damage in California groves. A survey was conducted to determine latent infections on fruits, twigs, and leaves and investigate their seasonal patterns during 2019 and 2020. On fruits, latent infections were more associated with the stem end than with the stylar end, except during spring when a significantly high percentage of flowers (86%) had latent infections. Latent infections on twigs varied markedly between years (28% in 2019 and 9.5% in 2020), while Alternaria spp. were also recovered from citrus leaves. Alternaria isolates collected during the survey were identified based on multigene sequence analysis, confirming that Alternaria alternata and Alternaria arborescens are the two species associated with infections of citrus fruits. Of the 23 isolates, 19 were identified as A. alternata and demonstrated the dominance of this species over A. arborescens. Isolates representing populations of these two species were selected as representative isolates for physiological and morphological studies. A. alternata and A. arborescens showed similar conidial dimensions but differed in the number of conidia produced. Growth rates demonstrated that A. alternata grows faster than A. arborescens at all the temperatures evaluated, except at 25 and 35 °C. The growth patterns were similar for both species. The sporulation rate of the Alternaria isolates was influenced differently by temperature. This parameter also influenced conidial germination and appressorium formation, and no significant differences were observed between Alternaria species. Pathogenicity and aggressiveness tests on detached fruit demonstrated the ability of A. alternata and A. arborescens to cause internal lesions and produce fruit drop in the orchards with no quantitative differences between them (disease severity indexes of 58 and 68%, respectively). The fungicide sensitivity tests showed that DMI fungicides are the most effective fungicides in reducing mycelial growth. The SDHI fungicides had intermediate activity against the mycelial growth but also suppressed spore germination. The spore germination assay suggested that some of the isolates included in this study might have some level of resistance to QoI and SDHI fungicides. The findings of this study provide new information about the pathogens associated with the excessive fruit drop recently observed in some California citrus groves.
Topics: Alternaria; Citrus; Fruit; Fungicides, Industrial; Spores, Fungal; Virulence
PubMed: 35314059
DOI: 10.1016/j.funbio.2022.02.003 -
Scientific Reports Aug 2021Early blight (EB) caused by Alternaria linariae or Alternaria solani and leaf blight (LB) caused by A. alternata are economically important diseases of tomato and...
Early blight (EB) caused by Alternaria linariae or Alternaria solani and leaf blight (LB) caused by A. alternata are economically important diseases of tomato and potato. Little is known about the genetic diversity and population structure of these pathogens in the United States. A total of 214 isolates of A. alternata (n = 61), A. linariae (n = 96), and A. solani (n = 57) were collected from tomato and potato in North Carolina and Wisconsin and grouped into populations based on geographic locations and tomato varieties. We exploited 220 single nucleotide polymorphisms derived from DNA sequences of 10 microsatellite loci to analyse the population genetic structure between species and between populations within species and infer the mode of reproduction. High genetic variation and genotypic diversity were observed in all the populations analysed. The null hypothesis of the clonality test based on the index of association [Formula: see text] was rejected, and equal frequencies of mating types under random mating were detected in some studied populations of Alternaria spp., suggesting that recombination can play an important role in the evolution of these pathogens. Most genetic differences were found between species, and the results showed three distinct genetic clusters corresponding to the three Alternaria spp. We found no evidence for clustering of geographic location populations or tomato variety populations. Analyses of molecular variance revealed high (> 85%) genetic variation within individuals in a population, confirming a lack of population subdivision within species. Alternaria linariae populations harboured more multilocus genotypes (MLGs) than A. alternata and A. solani populations and shared the same MLG between populations within a species, which was suggestive of gene flow and population expansion. Although both A. linariae and A. solani can cause EB on tomatoes and potatoes, these two species are genetically differentiated. Our results provide new insights into the evolution and structure of Alternaria spp. and can lead to new directions in optimizing management strategies to mitigate the impact of these pathogens on tomato and potato production in North Carolina and Wisconsin.
Topics: Alternaria; Base Sequence; Discriminant Analysis; Genes, Mating Type, Fungal; Genetic Variation; Genotype; Geography; Linkage Disequilibrium; Solanum lycopersicum; Microsatellite Repeats; North Carolina; Nucleotides; Polymorphism, Single Nucleotide; Principal Component Analysis; Probability; Solanum tuberosum; Wisconsin
PubMed: 34426589
DOI: 10.1038/s41598-021-95486-6 -
Toxins Sep 2021fungi dominate the grain microbiota in many regions of the world; therefore, the detection of species that are able to produce mycotoxins has received much attention. A...
fungi dominate the grain microbiota in many regions of the world; therefore, the detection of species that are able to produce mycotoxins has received much attention. A total of 178 grain samples of wheat, barley and oat obtained from the Urals and West Siberia regions of Russia in 2017-2019 were included in the study. Grain contamination with fungi belonging to sections and was analysed using qPCR with specific primers. The occurrence of four mycotoxins produced by , AOH, AME, TEN, and TeA, was defined by HPLC-MS/MS. DNA was found in all analysed grain samples. The prevalence of DNA of sect. fungi (range 53 × 10-21,731 × 10 pg/ng) over the DNA of sect. (range 11 × 10‒4237 × 10 pg/ng) in the grain samples was revealed. Sixty-two percent of grain samples were contaminated by at least two mycotoxins. The combination of TEN and TeA was found most often. Eight percent of grain samples were contaminated by all four mycotoxins, and only 3% of samples were free from the analysed secondary toxic metabolites. The amounts varied in a range of 2-53 µg/kg for AOH, 3-56 µg/kg for AME, 3-131 µg/kg for TEN and 9-15,000 µg/kg for TeA. To our knowledge, a new global maximum level of natural contamination of wheat grain with TeA was detected. A positive correlation between the amount of DNA from sect. and TeA was observed. The significant effects of cereal species and geographic origin of samples on the amounts of DNA and mycotoxins of spp. in grain were revealed. Barley was the most heavily contaminated with fungi belonging to both sections. The content of AOH in oat grain was, on average, higher than that found in wheat and barley. The content of TEN in the grain of barley was lower than that in wheat and similar to that in oat. The content of TeA did not depend on the cereal crop. The effect of weather conditions (summer temperature and rainfall) on the final fungal and mycotoxin contamination of grain was discussed. The frequent co-occurrence of different fungi and their mycotoxins in grain indicates the need for further studies investigating this issue.
Topics: Alternaria; Avena; DNA, Fungal; Edible Grain; Food Contamination; Hordeum; Mycotoxins; Russia; Triticum; Weather
PubMed: 34678974
DOI: 10.3390/toxins13100681 -
Basic & Clinical Pharmacology &... Dec 2016The mycotoxin alternariol (AOH) is produced by Alternaria fungi. It occurs naturally in foodstuffs and is frequently found as contaminant in fruit and grain products.... (Review)
Review
The mycotoxin alternariol (AOH) is produced by Alternaria fungi. It occurs naturally in foodstuffs and is frequently found as contaminant in fruit and grain products. Most information regarding AOH toxicity and the potential mechanisms involved comes from in vitro studies, as only very limited in vivo studies have been performed. AOH forms reactive oxygen species (ROS) and interacts with DNA topoisomerase, thereby generating both single (SSB)- and double-strand DNA beaks (DSB). This triggers various DNA damage response pathways. AOH causes a marked reduction in proliferation in mammalian cells due to cell cycle arrest often in the G /M-phase. After an additional inhibition of cytokinesis, cells with abnormal nuclei as well as polyploidy are reported. In macrophages, AOH may increase autophagic activity and induce senescence. Furthermore, AOH is found to change the morphology and phenotype of various human macrophage cell models. Studies so far indicate that the AOH-induced effects are primarily a result of DSB via its effects on topoisomerase activity. Thus, most probably there will be a threshold for the AOH-induced effects, typically seen in the 5-10 μM range. These in vitro mechanistic studies further support the in vivo studies suggesting low acute toxicity. However, a decreased immune response to infections and/or a disturbed balance of the adaptive immune system when exposed together with other mycotoxins cannot be excluded. This hypothesis needs to be further explored with proper in vivo studies.
Topics: Alternaria; Animals; Autophagy; Cell Proliferation; Cytokinesis; DNA Breaks; DNA Breaks, Double-Stranded; Environmental Pollutants; Food Contamination; Humans; Immunity, Innate; Lactones; Macrophages; Mutagens; Mycotoxins; Reactive Oxygen Species
PubMed: 27341187
DOI: 10.1111/bcpt.12635 -
Plant Disease Apr 2021The fungal genus consists of highly diverse species. They can be isolated readily from soil, water, and many plants, and even from animals and humans. is a...
The fungal genus consists of highly diverse species. They can be isolated readily from soil, water, and many plants, and even from animals and humans. is a small-spored species of section . It has been reported as a pathogen, an endophyte, and a saprophyte, and can also be found in indoor air. It causes cumin blight, a destructive disease on cumin (), and also causes other serious diseases, such as pumpkin seed rot, date palm leaf spot, wheat leaf spot, and gray spot of . In this study, we sequenced and assembled the first genome of isolate CBS 107.38. The draft genome can be used as a reference for the further study of related pathogens and comparative genomics of species.
Topics: Alternaria; Apiaceae; Cuminum; Genomics
PubMed: 32990522
DOI: 10.1094/PDIS-02-20-0224-A -
Pest Management Science Sep 2021Alternaria species are well-known aggressive pathogens that are widespread globally and warmer temperatures caused by climate change might increase their abundance more... (Review)
Review
Alternaria species are well-known aggressive pathogens that are widespread globally and warmer temperatures caused by climate change might increase their abundance more drastically. Early blight (EB) disease, caused mainly by Alternaria solani, and brown spot, caused by Alternaria alternata, are major concerns in potato, tomato and eggplant production. The development of EB is strongly linked to varieties, crop development stages, environmental factors, cultivation and field management. Several forecasting models for pesticide application to control EB were created in the last century and more recent scientific advances have included modern breeding technology to detect resistant genes and precision agriculture with hyperspectral sensors to pinpoint damage locations on plants. This paper presents an overview of the EB disease and provides an evaluation of recent scientific advances to control the disease. First of all, we describe the outline of this disease, encompassing biological cycles of the Alternaria genus, favorite climate and soil conditions as well as resistant plant species. Second, versatile management practices to minimize the effect of this pathogen at field level are discussed, covering their limitations and pitfalls. A better understanding of the underlying factors of this disease and the potential of novel research can contribute to implementing integrated pest management systems for an ecofriendly farming system. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Topics: Agriculture; Alternaria; Pest Control; Plant Breeding; Plant Diseases
PubMed: 33538396
DOI: 10.1002/ps.6320 -
Biomedica : Revista Del Instituto... Aug 2023Fungal genera Alternaria and Fusarium include human and plant pathogenic species. Several antifungals have been used for their control, but excessive use has contributed...
In vitro and Quantitative and Structure Activity Relationship (QSAR) evaluation of the antifungal activity of terpenoid constituents of essential oils against Alternaria alternata and Fusarium oxysporum.
INTRODUCTION
Fungal genera Alternaria and Fusarium include human and plant pathogenic species. Several antifungals have been used for their control, but excessive use has contributed to resistance development in pathogens. An alternative to searching for and developing new antifungal agents is using essential oils and their main components, which have biological activities of interest in medicine and food production.
OBJECTIVE
To evaluate in vitro and in silico the antifungal activities of terpenoids against Alternaria alternata and Fusarium oxysporum.
MATERIALS AND METHODS
The minimum inhibitory concentration and minimum fungicidal concentration values of 27 constituents of essential oils used against Alternaria alternata and Fusarium oxysporum were evaluated in vitro. In addition, using genetic algorithms, quantitative models of the structure-activity relationship were used to identify the structural and physicochemical properties related to antifungal activity.
RESULTS
The evaluated compounds proved to be effective antifungals. Thymol was the most active with a minimum inhibitory concentration of 91.6 ± 28.8 μg/ml for A. alternata and F. oxysporum. Quantitative structure-activity relationship models revealed the octanolwater cleavage ratio as the molecular property, and the phenols as the main functional group contributing to antifungal activity.
CONCLUSION
Terpenoids exhibit relevant antifungal activities that should be incorporated into the study of medicinal chemistry. Inclusion of in silico assays in the in vitro evaluation is a valuable tool in the search for and rational design of terpene derivatives as new potential antifungal agents.
Topics: Humans; Quantitative Structure-Activity Relationship; Antifungal Agents; Alternaria; Fusarium; Oils, Volatile; Terpenes
PubMed: 37721910
DOI: 10.7705/biomedica.6883 -
Toxins Jun 2017Occurrence of toxigenic molds and mycotoxins on dried fruits is a worldwide problem, but limited information is available in China. A total of 220 dried fruits (raisins,...
Occurrence of toxigenic molds and mycotoxins on dried fruits is a worldwide problem, but limited information is available in China. A total of 220 dried fruits (raisins, dried apricots, dates and wolfberries) purchased from China were analyzed for 17 mycotoxins (i.e., toxins, ochratoxin A (OTA), patulin (PAT) and trichothecenes) by UPLC-MS/MS, combined with a single-step cleanup. The result showed that at least one mycotoxin was detected in 142 samples (64.6%). The lowest incidence of contaminated samples was observed in dried apricots (48.2%), and the highest incidence in dried wolfberries (83.3%). The toxins seemed to be the major problem in dried fruits, rather than OTA or PAT. Tenuazonic acid (TeA) was the predominant mycotoxin, in both frequency and concentration, ranging from 6.9 to 5665.3 μg kg, followed by tentoxin (TEN; 20.5%), and mycophenolic acid (MPA; 19.5%). Moreover, raisins are more likely to be contaminated with OTA than the other dried fruits. Penicillic acid (PA) was detected only in dried dates, and PAT was detected only in one apricot sample. In addition, our results also showed that the simultaneous presence of 2-4 mycotoxins was observed in 31.4% of dried fruits. TeA and TEN were the most frequent combination, detected in 29 (13.2%) samples, followed by TeA and MPA with a prevalence of 11.4%. Therefore, the results of this survey suggest the need for wider monitoring on the contamination of these mycotoxins, especially toxins in agro-products, and indicate the importance of setting a maximum limit for toxins in China.
Topics: Alternaria; China; Environmental Monitoring; Food Contamination; Fruit; Magnoliopsida; Mycotoxins
PubMed: 28672847
DOI: 10.3390/toxins9070200