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Journal of Industrial Microbiology &... Jan 1998The production of mycotoxins by Alternaria alternata in cellulosic ceiling tiles was examined with thin-layer chromatography and high-performance liquid chromatography...
The production of mycotoxins by Alternaria alternata in cellulosic ceiling tiles was examined with thin-layer chromatography and high-performance liquid chromatography procedures. Alternariol and alternariol monomethyl ether were found in ceiling tile extracts, whereas extracts of control rice cultures of all three isolates produced these mycotoxins plus altenuene and altertoxin I. Extensive fungal growth and mycotoxin production occurred in the ceiling tiles at relative humidities of 84-89% and 97%.
Topics: Air Microbiology; Alternaria; Benz(a)Anthracenes; Cellulose; Chromatography, High Pressure Liquid; Chromatography, Thin Layer; Lactones; Mutagens; Mycotoxins; Perylene; Sick Building Syndrome
PubMed: 9523456
DOI: 10.1038/sj.jim.2900477 -
Biomolecules Jan 2020The fungus, is considered to be a potential agent for the biocontrol of perennial sowthistle (). A new chlorinated xanthone, methyl...
The fungus, is considered to be a potential agent for the biocontrol of perennial sowthistle (). A new chlorinated xanthone, methyl 8-hydroxy-3-methyl-4-chloro-9-oxo-9-xanthene-1-carboxylate () and a new benzophenone derivative, 5-chloromoniliphenone (), were isolated together with eleven structurally related compounds (-) from the solid culture of the fungus, which is used for the production of bioherbicidal inoculum of . Their structures were determined by spectroscopic (mostly by NMR and MS) methods. Alternethanoxins A and B, which were reported in earlier, were re-identified as moniliphenone and pinselin, respectively. The isolated compounds were tested for phytotoxic, antimicrobial, insecticidal, cytotoxic and esterase-inhibition activities. They did not demonstrate high phytotoxicity (lesions up to 2.5 mm in diameter/length at a concentration of 2 mg/mL) when tested on leaf disks/segments of perennial sowthistle () and couch grass (). They did not possess acute toxicity to , and showed moderate to low cytotoxicity (IC > 25 µg/mL) for U937 and K562 tumor cell lines. However, chloromonilicin and methyl 3,8-dihydroxy-6-methyl-4-chloro-9-oxo-9-xanthene-1-carboxylate () were shown to have antimicrobial properties with MIC 0.5-5 µg/disc. Compound and chloromonilinic acid B were found to have contact insecticidal activity to wheat aphid () at 1 mg/mL. Compounds and methyl 3,8-dihydroxy-6-methyl-9-oxo-9-xanthene-1-carboxylate displayed selective carboxylesterase inhibition activity at concentration of 100 µg/mL. Therefore, the waste solid substrate for production of spores can be re-utilized for the isolation of a number of valuable natural products.
Topics: Alternaria; Anti-Bacterial Agents; Benzophenones; Benzopyrans; Magnetic Resonance Spectroscopy; Molecular Structure; Secondary Metabolism; Xanthones
PubMed: 31947939
DOI: 10.3390/biom10010081 -
Food Microbiology Aug 2021Tomato fruit is susceptible to Alternaria spp. spoilage, which poses a health risk due to their mycotoxin production. Biopreservation relies on the use of whole...
Tomato fruit is susceptible to Alternaria spp. spoilage, which poses a health risk due to their mycotoxin production. Biopreservation relies on the use of whole microorganisms or their metabolites to manage spoilage microorganisms including filamentous fungi. However, the use of treatments at fungistatic level might activate intracellular pathways, which can cause an increment in mycotoxin accumulation. The objective of this work was to evaluate the effect of two strains of Debaryomyces hansenii and the antifungal protein PgAFP at 10 and 40 μg/mL. Both growth and production of two of the most common mycotoxins (tenuazonic acid and alternariol monomethyl ether) by Alternaria tenuissima sp.-grp. and Alternaria arborescens sp.-grp. on a tomato-based matrix, were analysed at 12 °C. Additionally, the impact of these biocontrol agents on the stress-related RHO1 gene expression was assessed. All treatments reduced mycotoxin accumulation (from 27 to 92% of inhibition). Their mode of action against Alternaria spp. in tomato seems unrelated to damages to fungal cell wall integrity at the genomic level. Therefore, the two D. hansenii strains (CECT 10352 and CECT 10353) and the antifungal protein PgAFP at 10 μg/mL are suggested as biocontrol strategies in tomato fruit at postharvest stage.
Topics: Alternaria; Debaryomyces; Fruit; Fungal Proteins; Fungicides, Industrial; Mycotoxins; Plant Diseases
PubMed: 33653520
DOI: 10.1016/j.fm.2021.103741 -
Journal of Natural Medicines Jun 2019Endophytic fungi have been shown in recent years to produce a series of bioactive secondary metabolites. Several endophytic fungi were isolated from the fresh wild body...
Endophytic fungi have been shown in recent years to produce a series of bioactive secondary metabolites. Several endophytic fungi were isolated from the fresh wild body of Phellinus igniarius, and initially evaluated for their antimicrobial activity. Among which, Shm-1 extract showed moderate inhibitory activity against Clavibacter michiganense and the fungus was identified to be Alternaria alternata Shm-1 through the comparison of morphological characteristics and the sequence of the rDNA ITS with those of other Alternaria species. A new 2H-benzindazole derivative, alterindazolin A (1), has been isolated from cultures of the endophyte Alternaria alternata Shm-1. Its structure was characterized as 1-benzyl-5-p-hydroxy-phenyloxygen-benz[e]indazole by spectroscopic data analysis including 1D NMR, 2D NMR and MS spectrum.
Topics: Alternaria; Endophytes; Fruit; Humans; Molecular Structure
PubMed: 30868543
DOI: 10.1007/s11418-019-01291-x -
Genome Biology and Evolution Dec 2019Horizontal gene transfer (HGT) has been identified as an important source of genomic innovation in fungi. However, how HGT drove the evolution of Alternaria alternata, a...
Horizontal gene transfer (HGT) has been identified as an important source of genomic innovation in fungi. However, how HGT drove the evolution of Alternaria alternata, a necrotrophic fungus which can be ubiquitously isolated from soil and various plants and decaying plant materials is largely known. In this study, we identified 12 protein-encoding genes that are likely acquired from lineages outside Pezizomycotina. Phylogenetic trees and approximately unbiased comparative topology tests strongly supported the evolutionary origin of these genes. According to their predicted functions, these HGT candidates are involved in nitrogen and carbohydrate metabolism. Especially, five genes of them were likely transferred as a physically linked cluster from Tremellales (Basidiomycota). Functionally knocking out the five-gene cluster in an A. alternata isolate causing citrus brown spot resulted in an 80% decrease in asexual spore production in the deletion mutant. We further knocked out each of these five genes in this cluster and the resultant single-gene deletion mutants exhibited a various degree of reduction in spore production. Except for conidiation, functions of these genes associated with vegetative growth, stress tolerance, and virulence are very limited. Our results provide new evidence that HGT has played important roles over the course of the evolution of filamentous fungi.
Topics: Alternaria; Ascomycota; Basidiomycota; Citrus; Evolution, Molecular; Fungal Proteins; Gene Deletion; Gene Transfer, Horizontal; Multigene Family; Phylogeny; Plant Diseases; Spores, Fungal
PubMed: 31764979
DOI: 10.1093/gbe/evz257 -
Phytochemical Analysis : PCA Apr 2022In addition to the mycotoxin swainsonine, the locoweed endophytic fungus Alternaria oxytropis (Pleosporaceae) also produces a series of rarely reported, highly...
UPLC-Q-TOF-MS/MS analysis of the guaiane sesquiterpenoids oxytropiols A-J and detection of undescribed analogues from the locoweed endophytic fungus Alternaria oxytropis (Pleosporaceae).
INTRODUCTION
In addition to the mycotoxin swainsonine, the locoweed endophytic fungus Alternaria oxytropis (Pleosporaceae) also produces a series of rarely reported, highly oxygenated bicyclic guaiane sesquiterpenoids. Few investigations on the electrospray tandem mass fragmentation pattern of this sesquiterpenoid have been reported.
OBJECTIVES
We aimed to analyze and detect new guaiane sesquiterpenoid analogues from crude extracts of the locoweed endophytic fungus A. oxytropis by UPLC-Q-TOF-MS/MS experiments.
MATERIALS AND METHODS
Oxytropiols A-J (1-10) and the extract of the locoweed endophytic fungus A. oxytropis were analyzed by UPLC-Q-TOF-MS/MS in positive mode.
RESULTS
Typical neutral losses, McLafferty rearrangement, 1,2-rearrangement, and 1,3-rearrangement were considered to be the main fragmentation patterns for the [M + H] /[M + Na] ions of 1-10 by UPLC-Q-TOF-MS/MS experiments, and possible fragmentation pathways of 1-10 were suggested. A unique and undescribed analogue named oxytropiol K (11) was found in the extract based on UPLC-Q-TOF-MS/MS analysis. Compound 11 was isolated and elucidated by NMR spectrometry, and its UPLC-Q-TOF-MS/MS analysis was consistent with the fragmentation pathways of 1-10.
CONCLUSION
The results further support that UPLC-Q-TOF-MS/MS is a powerful and sensitive tool for the characterization of known compounds (dereplication) and the detection of new analogues from crude extracts and imply that the locoweed endophytic fungus A. oxytropis, with few chemical investigations, is an important resource for undescribed metabolites.
Topics: Alternaria; Chromatography, High Pressure Liquid; Oxytropis; Sesquiterpenes; Sesquiterpenes, Guaiane; Tandem Mass Spectrometry
PubMed: 34755399
DOI: 10.1002/pca.3092 -
Mycoses Feb 2020Cutaneous phaeohyphomycosis is an emerging disease in immunocompromised patients, being Alternaria one of the most common genera reported as a causative agent. Species...
BACKGROUND
Cutaneous phaeohyphomycosis is an emerging disease in immunocompromised patients, being Alternaria one of the most common genera reported as a causative agent. Species identification is not carried out mainly due to the complexity of the genus. Analysis of the ITS barcode has become standard for fungal identification, but in Alternaria it is only able to discriminate among species-groups or sections.
METHODS
We present three cases of cutaneous infection caused by Alternaria isolates morphologically identified as belonging to section Infectoriae. They have been morphologically characterised and phylogenetically delineated with five molecular markers (ITS, ATPase, gapdh, rpb2 and tef1).
RESULTS
Mycotic infections have been diagnosed by repeated cultures and histopathological examination in two of the cases. The polyphasic approach has allowed to delineate three new species of Alternaria section Infectoriae, that is A anthropophila, A atrobrunnea and A guarroi. ATPase has been the only locus able to discriminate most of the species (29 out of 31) currently sequenced in this section, including A infectoria the commonest reported species causing alternariosis. Susceptibility test showed different antifungal patterns for the three species, although terbinafine was the most active in vitro drug against these fungi.
CONCLUSIONS
The ATPase gene is recommended as an alternative barcode locus to identify Alternaria clinical isolates in section Infectoriae. Our results reinforce the relevance of identification of Alternaria isolates at the species level and the necessity to carry out antifungal susceptibility testing to determine the most adequate drug for treatment.
Topics: Adenocarcinoma; Aged; Alternaria; Alternariosis; Antifungal Agents; Bayes Theorem; Consensus Sequence; Female; Humans; Immunosuppressive Agents; Likelihood Functions; Lung Transplantation; Male; Middle Aged; Myocardial Ischemia; Phenotype; Phylogeny; Prostatic Neoplasms; Sequence Alignment; Skin Ulcer; Transplantation Immunology
PubMed: 31651065
DOI: 10.1111/myc.13026 -
Transplant Infectious Disease : An... Jun 2010Alternaria species are members of a heterogeneous group of dematiaceous fungi that rarely cause opportunistic infections in transplant recipients. During a 20-year...
Alternaria species are members of a heterogeneous group of dematiaceous fungi that rarely cause opportunistic infections in transplant recipients. During a 20-year period from 1989 to 2008, 8 solid organ transplant recipients (63% males; median age, 48 years) developed Alternaria species infections at the Mayo Clinic. All patients were highly immunocompromised as evidenced by their receipt of multiple transplants, treatment of acute and chronic allograft rejection, and occurrence of other opportunistic infections. All patients presented with non-tender erythematous or violaceous skin papules, nodules, or pustules in exposed areas of the extremities. No case of visceral dissemination was observed. Itraconazole was the most common drug used for treatment, although voriconazole, posaconazole, and caspofungin could potentially be useful based on our limited clinical data and in vitro antifungal susceptibility testing. One patient was treated with voriconazole, while another patient who was refractory to itraconazole had rapid resolution of lesions after the addition of caspofungin. Attempts at antifungal therapy alone were unsuccessful; all patients eventually required surgical excision of lesions. In conclusion, Alternaria species are rare but increasingly recognized opportunistic infections among highly immunocompromised transplant recipients. Wide excisional surgery combined with prolonged systemic antifungal therapy and reduction in immunosuppressive regimens provided the best chance of cure. Although itraconazole remains the most common drug for treatment, this case series highlights the potential clinical utility of caspofungin, voriconazole, and posaconazole as alternative regimens.
Topics: Adult; Alternaria; Antifungal Agents; Azoles; Caspofungin; Dermatomycoses; Echinocandins; Female; Humans; Lipopeptides; Male; Middle Aged; Opportunistic Infections; Organ Transplantation
PubMed: 20002611
DOI: 10.1111/j.1399-3062.2009.00482.x -
PloS One 2021The buttonwood (Conocarpus erectus L.) is a mangrove shrub belonging to Combretaceae family. It mostly grows on the shorelines of tropical and subtropical regions in the...
Molecular characterization of leaf spot caused by Alternaria alternata on buttonwood (Conocarpus erectus L.) and determination of pathogenicity by a novel disease rating scale.
The buttonwood (Conocarpus erectus L.) is a mangrove shrub belonging to Combretaceae family. It mostly grows on the shorelines of tropical and subtropical regions in the world. It was introduced to Lasbela University of Water, Agriculture & Marine Sciences (LUWMS), Uthal, Baluchistan as an ornamental plant as it grows well under harsh, temperate and saline conditions. During a routine survey, typical leaf spot symptoms were observed on the leaves of buttonwood plants. A disease severity scale for alternaria leaf spot of buttonwood was developed for the first time through this study. Disease severity according to the scale was 38.97%. The microscopic characterizations was accomplished for the identification of Alternaria alternata and Koch's postulates were employed to determine the pathogenicity. For molecular identification, 650 bp internal transcribed spacer (ITS) regions (ITS1, 5.8s and ITS2) were amplified from three representative isolates (LUAWMS1, LUAWMS2 and LUAWMS3) through polymerase chain reaction (PCR). The nucleotide sequences from ITS regions of the isolates were submitted to NCBI with GenBank accession numbers MW585375, MW585376 and MW585377, respectively. The phylogenetic tree of 22 A. alternata isolates was computed and representative isolates exhibited 99.98% genetic similarity with mangroves ecosystem isolates. This study reports the incidence of alternaria leaf spot of buttonwood at LUWMS for the first time. It is suspected that the disease may spread further. Therefore, effective management strategies should be opted to halt the further spread of the disease.
Topics: Alternaria; Combretaceae; DNA, Fungal; Phylogeny; Plant Diseases; Plant Leaves
PubMed: 33984023
DOI: 10.1371/journal.pone.0251471 -
Phytopathology Dec 2015Fruit rot caused by Alternaria spp. is one of the most important factors affecting the postharvest quality and shelf life of blueberry fruit. The aims of this study were...
Fruit rot caused by Alternaria spp. is one of the most important factors affecting the postharvest quality and shelf life of blueberry fruit. The aims of this study were to characterize Alternaria isolates using morphological and molecular approaches and test their pathogenicity to blueberry fruit. Alternaria spp. isolates were collected from decayed blueberry fruit in the Central Valley of California during 2012 and 2013. In total, 283 isolates were obtained and five species of Alternaria, including Alternaria alternata, A. tenuissima, A. arborescens, A. infectoria, and A. rosae, were identified based on DNA sequences of the plasma membrane ATPase, Alt a1 and Calmodulin gene regions in combination with morphological characters of the culture and sporulation. Of the 283 isolates, 61.5% were identified as A. alternata, 32.9% were A. arborescens, 5.0% were A. tenuissima, and only one isolate of A. infectoria and one isolate of A. rosae were found. These fungi were able to grow at temperatures from 0 to 35°C, and mycelial growth was arrested at 40°C. Optimal radial growth occurred between 20 to 30°C. Pathogenicity tests showed that all five Alternaria spp. were pathogenic on blueberry fruit at 0, 4, and 20°C, with A. alternata, A. arborescens, and A. tenuissima being the most virulent species, followed by A. infectoria and A. rosae. Previously A. tenuissima has been reported to be the primary cause of Alternaria fruit rot of blueberry worldwide. Our results indicated that the species composition of Alternaria responsible for Alternaria fruit rot in blueberry can be dependent on geographical region. A. alternata, A. arborescens, A. infectoria, and A. rosae are reported for the first time on blueberry in California. This is also the first report of A. infectoria and A. rosae infecting blueberry fruit.
Topics: Alternaria; Blueberry Plants; Fruit; Phylogeny; Spores, Fungal; Temperature; Virulence
PubMed: 26267542
DOI: 10.1094/PHYTO-05-15-0122-R