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International Journal of Food... Mar 2012Blueberries are traditionally consumed in North America, some European countries and Japan. In Argentina, the blueberry crop is profitable because production starts in...
Blueberries are traditionally consumed in North America, some European countries and Japan. In Argentina, the blueberry crop is profitable because production starts in November, when the northern hemisphere lacks fresh fruit. Fungal contaminants can grow and produce mycotoxins in fresh fruit. The aims of this work were to identify the main genera of the mycobiota of blueberries grown in Argentina and to determine the toxicogenic potential, pathogenicity and host specificity of the species isolated. The genus Alternaria was the main component of the blueberry mycobiota (95%); minor proportions of Phoma spp. (4%) and Penicillium spp. (1%) were also isolated. According to their sporulation patterns, 127 Alternaria isolates belonged to the Alternaria tenuissima species-group, 5 to the Alternaria alternata species-group and 2 to the Alternaria arborescens species-group. The last mentioned species-group was not isolated at 5°C. Of the 134 isolates, 61% were toxicogenic in autoclaved rice; 97% of these produced alternariol (AOH) in a range from 0.14 to 119.18 mg/kg, 95% produced alternariol methylether (AME) in a range from 1.23 to 901.74 mg/kg and 65% produced tenuazonic acid (TA) in a range from 0.13 to 2778 mg/kg. Fifty two isolates co-produced the three mycotoxins. According to the size of the lesion that they caused on blueberries, the isolates were classified as slightly pathogenic, moderately pathogenic and very pathogenic. No significant differences in pathogenicity were found on different blueberry varieties. In this work, high incidence and toxicogenic potential of the Alternaria isolates from blueberries were demonstrated. Thus, more studies should be done to evaluate the health risk posed by the presence of the Alternaria toxins in blueberries and in the manufactured by-products.
Topics: Alternaria; Argentina; Blueberry Plants; Food Storage; Mycotoxins
PubMed: 22285534
DOI: 10.1016/j.ijfoodmicro.2012.01.004 -
BMC Genomics Mar 2015Alternaria is considered one of the most common saprophytic fungal genera on the planet. It is comprised of many species that exhibit a necrotrophic phytopathogenic...
BACKGROUND
Alternaria is considered one of the most common saprophytic fungal genera on the planet. It is comprised of many species that exhibit a necrotrophic phytopathogenic lifestyle. Several species are clinically associated with allergic respiratory disorders although rarely found to cause invasive infections in humans. Finally, Alternaria spp. are among the most well known producers of diverse fungal secondary metabolites, especially toxins.
DESCRIPTION
We have recently sequenced and annotated the genomes of 25 Alternaria spp. including but not limited to many necrotrophic plant pathogens such as A. brassicicola (a pathogen of Brassicaceous crops like cabbage and canola) and A. solani (a major pathogen of Solanaceous plants like potato and tomato), and several saprophytes that cause allergy in human such as A. alternata isolates. These genomes were annotated and compared. Multiple genetic differences were found in the context of plant and human pathogenicity, notably the pro-inflammatory potential of A. alternata. The Alternaria genomes database was built to provide a public platform to access the whole genome sequences, genome annotations, and comparative genomics data of these species. Genome annotation and comparison were performed using a pipeline that integrated multiple computational and comparative genomics tools. Alternaria genome sequences together with their annotation and comparison data were ported to Ensembl database schemas using a self-developed tool (EnsImport). Collectively, data are currently hosted using a customized installation of the Ensembl genome browser platform.
CONCLUSION
Recent efforts in fungal genome sequencing have facilitated the studies of the molecular basis of fungal pathogenicity as a whole system. The Alternaria genomes database provides a comprehensive resource of genomics and comparative data of an important saprophytic and plant/human pathogenic fungal genus. The database will be updated regularly with new genomes when they become available. The Alternaria genomes database is freely available for non-profit use at http://alternaria.vbi.vt.edu .
Topics: Allergens; Alternaria; Databases, Genetic; Genome, Fungal
PubMed: 25887485
DOI: 10.1186/s12864-015-1430-7 -
Scientific Reports Nov 2023Alternaria, a cosmopolitan fungal genus is a dominant member of the grapevine (Vitis vinifera) microbiome. Several Alternaria species are known to produce a variety of...
Alternaria, a cosmopolitan fungal genus is a dominant member of the grapevine (Vitis vinifera) microbiome. Several Alternaria species are known to produce a variety of secondary metabolites, which are particularly relevant to plant protection and food safety in field crops. According to previous findings, the majority of Alternaria species inhabiting grapevine belong to Alternaria sect. Alternaria. However, the phylogenetic diversity and secondary metabolite production of the distinct Alternaria species has remained unclear. In this study, our aim was to examine the genetic and metabolic diversity of endophytic Alternaria isolates associated with the above-ground tissues of the grapevine. Altogether, 270 Alternaria isolates were collected from asymptomatic leaves and grape clusters of different grapevine varieties in the Eger wine region of Hungary. After analyses of the nuclear ribosomal DNA internal transcribed spacer (ITS) and RNA polymerase second largest subunit (rpb2) sequences, 170 isolates were chosen for further analyses. Sequences of the Alternaria major allergen gene (Alt a 1), endopolygalacturonase (endoPG), OPA10-2, and KOG1058 were also included in the phylogenetic analyses. Identification of secondary metabolites and metabolite profiling of the isolates were performed using high-performance liquid chromatography (HPLC)-high-resolution tandem mass spectrometry (HR-MS/MS). The multilocus phylogeny results revealed two distinct groups in grapevine, namely A. alternata and the A. arborescens species complex (AASC). Eight main metabolites were identified in all collected Alternaria isolates, regardless of their affiliation to the species and lineages. Multivariate analyses of untargeted metabolites found no clear separations; however, a partial least squares-discriminant analysis model was able to successfully discriminate between the metabolic datasets from isolates belonging to the AASC and A. alternata. By conducting univariate analysis based on the discriminant ability of the metabolites, we also identified several features exhibiting large and significant variation between A. alternata and the AASC. The separation of these groups may suggest functional differences, which may also play a role in the functioning of the plant microbiome.
Topics: Alternaria; Phylogeny; Vitis; Tandem Mass Spectrometry; Wine
PubMed: 37935846
DOI: 10.1038/s41598-023-46020-3 -
Microbiological Research 2008Alternaria jesenskae sp. nov. recovered from seeds of a shrubby perennial plant Fumana procumbens (Cistaceae) in Slovakia is described and illustrated. The new taxon can...
Alternaria jesenskae sp. nov. recovered from seeds of a shrubby perennial plant Fumana procumbens (Cistaceae) in Slovakia is described and illustrated. The new taxon can be clearly separated from the other related large-spored and filament-beaked Alternaria species based on sequences of the ITS1, 5.8S and ITS2 region as well as by its distinctive morphology. Even though the molecular data have shown close relatedness with A. multirostrata, the new species is morphologically most similar to A. tomatophila distinguished primarily by the pronounced colony pigmentation, conidial septation and beak branching.
Topics: Alternaria; Cistaceae; DNA, Fungal; DNA, Ribosomal; DNA, Ribosomal Spacer; Molecular Sequence Data; Phylogeny; RNA, Ribosomal, 18S; RNA, Ribosomal, 5.8S; Seeds; Slovakia
PubMed: 16793249
DOI: 10.1016/j.micres.2006.05.004 -
Plant Disease Jan 2022
Topics: Alternaria; Brassicaceae; China; Plant Diseases
PubMed: 34132598
DOI: 10.1094/PDIS-04-21-0767-PDN -
Microbial Pathogenesis Dec 2023Black rot, caused by Alternaria radicina, seriously endangers carrots throughout the growing season, affecting both leaves and fleshy roots. In this study, we sequenced...
Black rot, caused by Alternaria radicina, seriously endangers carrots throughout the growing season, affecting both leaves and fleshy roots. In this study, we sequenced and assembled the genome of the A. radicina isolate CBR2. The genome was 34.6 Mb in size and consisted of 6 scaffolds. The sequence information provided in this genome will be used as a reference for further comparative genomics analysis of Alternaria species and will contribute to disease control in carrot production.
Topics: Daucus carota; Alternaria
PubMed: 37871854
DOI: 10.1016/j.micpath.2023.106421 -
Applied Microbiology and Biotechnology Jul 2012Due to its potential in preventing or slowing the occurrence of many diseases, resveratrol (3,5,4'-trihydroxystilbene) has attracted great research interest. The...
Due to its potential in preventing or slowing the occurrence of many diseases, resveratrol (3,5,4'-trihydroxystilbene) has attracted great research interest. The objective of this study was to identify microorganisms from selected plants that produce resveratrol and to optimize the conditions for resveratrol production. Endophytes from Merlot wine grapes (Vitis vinifera L. cv. Merlot), wild Vitis (Vitis quinquangularis Rehd.), and Japanese knotweed (Polygonum cuspidatum Siebold & Zucc.) were isolated, and their abilities to produce resveratrol were evaluated. A total of 65 isolates were obtained and 21 produced resveratrol (6-123 μg/L) in liquid culture. The resveratrol-producing isolates belonged to seven genera, Botryosphaeria, Penicillium, Cephalosporium, Aspergillus, Geotrichum, Mucor, and Alternaria. The resveratrol-producing capability decreased or was completely lost in most isolates after three rounds of subculture. It was found that only the strain Alternaria sp. MG1 (isolated from cob of Merlot using GA1 medium) had stable and high resveratrol-producing capability in all subcultures. During liquid cultivation of Alternaria sp. MG1 in potato dextrose medium, the synthesis of resveratrol began on the first day, increased to peak levels on day 7, and then decreased sharply thereafter. Cell growth increased during cultivation and reached a stable and high level of biomass after 5 days. The best fermentation conditions for resveratrol production in liquid cultures of Alternaria sp. MG1 were an inoculum size of 6 %, a medium volume of 125 mL in a 250-mL flask, a rotation speed of 101 rpm, and a temperature of 27 °C.
Topics: Alternaria; Antioxidants; Culture Media; DNA, Fungal; Endophytes; Fallopia japonica; Fermentation; Molecular Sequence Data; Resveratrol; Sequence Analysis, DNA; Stilbenes; Vitis
PubMed: 22526800
DOI: 10.1007/s00253-012-4045-9 -
BMC Infectious Diseases Mar 2022Fungal infection secondary to a penetrating plant thorn injury in upper extremities is infrequently reported especially in immunocompetent hosts. Alternaria is a...
BACKGROUND
Fungal infection secondary to a penetrating plant thorn injury in upper extremities is infrequently reported especially in immunocompetent hosts. Alternaria is a dematicaceous hyphomycete, commonly found in decay and plant pathogens, and Alternaria alternata has been regarded as the most frequent species among more than 400 s of its species. This case is the first report of thorn-induced Alternaria alternata infection of the hand in an immunocompetent host.
CASE PRESENTATION
A 47-year-old male patient was admitted to our institution with persistent pain and swelling of the right hand even after a prior surgical removal of a previous thorn injury. Upon impression of abscess, chronic extensor tenosynovitis, and septic arthritis at the 3rd metacarpophalangeal joint based on advanced imaging, the patient underwent surgical incision and drainage. Intraoperative culture, biopsy, and gene molecular sequencing results revealed fungal infection with Alternaria alternata. Postoperatively, the patient was treated with oral itraconazole (200 mg q 12 h) for nine consecutive months.
CONCLUSIONS
We report the first case of chronic extensor tenosynovitis and septic arthritis of the hand with Alternaria alternata after a thorn injury in an immunocompetent host. Despite rare incidences of fungal extensor tenosynovitis and septic arthritis, the current case strongly suggests a careful examination of social history and surgical debridement along with a prolonged use of appropriate anti-fungal agents in thorn injuries.
Topics: Alternaria; Hand; Humans; Male; Middle Aged; Tenosynovitis; Upper Extremity
PubMed: 35351014
DOI: 10.1186/s12879-022-07280-y -
Rapid Communications in Mass... Oct 2015Many species of Alternaria damage important agricultural crops, including small grains and tomatoes. These fungi can produce a variety of secondary metabolites, some of...
RATIONALE
Many species of Alternaria damage important agricultural crops, including small grains and tomatoes. These fungi can produce a variety of secondary metabolites, some of which are toxic to humans and animals. Interest in screening for conjugated or 'modified' mycotoxins has increased because of their tendency to evade traditional analytical screening methods. Two sulfoconjugated Alternaria toxins have been reported and the potential exists for many more.
METHODS
One hundred and forty-eight Canadian strains of Alternaria spp., about half of them isolated from grain, were grown on Potato Dextrose Agar in Petri dishes for 7 days. Plugs of each strain were removed, extracted and screened by a rapid liquid chromatography (LC)/data-dependent tandem mass spectrometry (MS(2)) method in negative electrospray ionization mode. Data generated on an Orbitrap Q-Exactive mass spectrometer was processed by post-acquisition neutral loss filtering (NLF). Seven isolates that produced sulfoconjugates of known Alternaria toxins were selected for growth on three additional types of fermentation media.
RESULTS
Collision-induced dissociation of sulfoconjugated ions displayed a distinctive neutral loss of SO3 (79.957 Da) that was detected in the MS(2) datasets using post-acquisition NLF. A total of 108 of the 148 isolates screened produced sulfoconjugated metabolites on agar plates. Analysis of the seven isolates grown in liquid culture, on rice and Cheerios, led to the discovery of six new, two previously reported and 30 unidentified sulfoconjugated compounds.
CONCLUSIONS
NLF of HRMS(2) data from an Orbitrap Q-Exactive is a powerful tool for the rapid discovery of sulfoconjugated fungal metabolites. This technique could also be applied to the detection of other important conjugated mycotoxins such as glucosides. The majority of the Canadian isolates of Alternaria spp. studied produced sulfoconjugated metabolites, some of which had no known 'free' Alternaria precursor metabolite, indicating that they are possibly new metabolites. The advantage of sulfoconjugation to Alternaria spp. is unknown, and warrants further study into the mechanisms behind the sulfur assimilatory pathways.
Topics: Alternaria; Chromatography, Liquid; Edible Grain; Metabolome; Spectrometry, Mass, Electrospray Ionization; Sulfur Compounds
PubMed: 26331931
DOI: 10.1002/rcm.7286 -
Food Additives & Contaminants. Part A,... May 2019In the present investigation, fresh and dried tomato samples from markets and packinghouses located in Apulia region (southern Italy) were analysed for Alternaria...
In the present investigation, fresh and dried tomato samples from markets and packinghouses located in Apulia region (southern Italy) were analysed for Alternaria toxins. All samples proved to be contaminated by tenuazonic acid (TeA); in particular, dried tomatoes were contaminated in the range 425-81,592 µg/kg, while fresh tomatoes were in the range 11-4560 µg/kg. The second most abundant toxin was alternariol monomethyl ether (AME), followed by tentoxin (TEN) and alternariol (AOH). Overall dried tomatoes were more contaminated than fresh ones, although this seemed not directly related to the presence of sodium chloride, utilized in the drying process. Five representative Alternaria isolates within those collected from samples proved to be one Alternaria arborescens (A215) and four Alternaria alternata. Within the latter species, one strain belonged to morphotype tenuissima (A216), and three to alternata (A214, A217 and A218). They were confirmed to produce TeA, AOH, and AME in vitro. This study demonstrates the possible risk for consumers' health related to the consumption of contaminated fresh and dried tomatoes, and thus the need for suitable control strategies.
Topics: Alternaria; Food Contamination; Italy; Solanum lycopersicum; Toxins, Biological
PubMed: 30943118
DOI: 10.1080/19440049.2019.1588998