Project description:BACKGROUND: Fusarium species are among the most common fungi present in the environment and some species have emerged as major opportunistic fungal infection in human. However, in immunocompromised hosts they can be virulent pathogens and can cause death. The pathogenesis of this infection relies on three factors: colonization, tissue damage, and immunosuppression. A novel Fusarium species is reported for the first time from keratitis in an agriculture worker who acquired the infection from plant material of maize. Maize plants are the natural host of this fungus where it causes stalk rot and seeding malformation under temperate and humid climatic conditions. The clinical manifestation, microbiological morphology, physiological features and molecular data are described. METHODS: Diagnosis was established by using polymerase chain reaction of fungal DNA followed by sequencing portions of translation elongation factor 1 alpha (TEF1 ?) and beta-tubulin (BT2) genes. Susceptibility profiles of this fungus were evaluated using CLSI broth microdilution method. RESULTS: The analyses of these two genes sequences support a novel opportunist with the designation Fusarium temperatum. Phylogenetic analyses showed that the reported clinical isolate was nested within the Fusarium fujikuroi species complex. Antifungal susceptibility testing demonstrated that the fungus had low MICs of micafungin (0.031 ?g/ml), posaconazole (0.25 ?g/ml) and amphotericin B (0.5 ?g/ml). CONCLUSION: The present case extends the significance of the genus Fusarium as agents of keratitis and underscores the utility of molecular verification of these emerging fungi in the human host.
Project description:Fusarium subglutinans and Fusarium temperatum are common maize pathogens that produce mycotoxins and cause plant disease. The ability of these species to produce beauvericin and fumonisin mycotoxins is not settled, as reports of toxin production are not concordant. Our objective was to clarify this situation by determining both the chemotypes and genotypes for strains from both species. We analyzed 25 strains from Argentina, 13 F. subglutinans and 12 F. temperatum strains, for toxin production by ultraperformance liquid chromatography mass spectrometry (UPLC-MS). We used new genome sequences from two strains of F. subglutinans and one strain of F. temperatum, plus genomes of other Fusarium species, to determine the presence of functional gene clusters for the synthesis of these toxins. None of the strains examined from either species produced fumonisins. These strains also lack Fum biosynthetic genes but retain homologs of some genes that flank the Fum cluster in Fusarium verticillioides None of the F. subglutinans strains we examined produced beauvericin although 9 of 12 F. temperatum strains did. A complete beauvericin (Bea) gene cluster was present in all three new genome sequences. The Bea1 gene was presumably functional in F. temperatum but was not functional in F. subglutinans due to a large insertion and multiple mutations that resulted in premature stop codons. The accumulation of only a few mutations expected to disrupt Bea1 suggests that the process of its inactivation is relatively recent. Thus, none of the strains of F. subglutinans or F. temperatum we examined produce fumonisins, and the strains of F. subglutinans examined also cannot produce beauvericin. Variation in the ability of strains of F. temperatum to produce beauvericin requires further study and could reflect the recent shared ancestry of these two species.IMPORTANCEFusarium subglutinans and F. temperatum are sister species and maize pathogens commonly isolated worldwide that can produce several mycotoxins and cause seedling disease, stalk rot, and ear rot. The ability of these species to produce beauvericin and fumonisin mycotoxins is not settled, as reports of toxin production are not concordant at the species level. Our results are consistent with previous reports that strains of F. subglutinans produce neither fumonisins nor beauvericin. The status of toxin production by F. temperatum needs further work. Our strains of F. temperatum did not produce fumonisins, while some strains produced beauvericin and others did not. These results enable more accurate risk assessments of potential mycotoxin contamination if strains of these species are present. The nature of the genetic inactivation of BEA1 is consistent with its relatively recent occurrence and the close phylogenetic relationship of the two sister species.
| S-EPMC7301838 | biostudies-literature
Project description:Fusarium subglutinans & Fusarium temperatum field populations GBS
Project description:Fusarium graminearum (F.g) is responsible for Fusarium head blight (FHB), which is a destructive disease of wheat that accumulates mycotoxin such as deoxynivalenol (DON) and makes its quality unsuitable for end use. Several FHB resistant varieties development is going on world-wide. However the complete understanding of wheat defence response, pathogen (Fusarium graminearum) disease development mechanism and the gene crosstalk between organisms is still unclear. In our study focused to analyse pathogen (F. graminearum) molecular action in different Fusarium head blight resistance cultivars during the disease development. To understand the Fusarium graminearum pathogen molecular reaction, microarray gene expression analysis was carried out by using Fusarium graminearum (8 x 15k) Agilent arrays at two time points (3 & 7 days after infection) on three wheat genotypes (Japanese landrace cv. Nobeokabouzu-komugi - highly resistant, Chinese cv. Sumai 3 - resistant and Australian cv. Gamenya - susceptible), which spikes infected by Fusarium graminearum ‘H-3’strain. During the disease development the pathogen biomass as well as the expression of Trichothecene biosynthesis involved genes (Tri genes) in three wheat cultivars was determined. In our material no relation between fungus biomass and the disease symptoms were observed, however, it showed relation with fungus virulence factors expression (Tri genes). For the first time, we report the nature of Fusarium graminearum gene expression in the FHB-highly resistant cv. Nobeokabouzu-komugi during the disease development stage and the possible underlying molecular response.
Project description:Fusarium subglutinans is a plant pathogenic fungus infecting cereal grain crops. In 2011, the species was divided in Fusarium temperatumsp. nov. and F. subglutinans sensu stricto. In order to determine the occurrence and significance of F. temperatum and F. subglutinans on maize, a monitoring of maize ears and stalks was carried out in Germany in 2017 and 2018. Species identification was conducted by analysis of the translation elongation factor 1α (TEF-1α) gene. Ninety-four isolates of F. temperatum and eight isolates of F. subglutinans were obtained during two years of monitoring from 60 sampling sites in nine federal states of Germany. Inoculation of maize ears revealed a superior aggressiveness for F. temperatum, followed by Fusarium graminearum, Fusarium verticillioides, and F. subglutinans. On maize stalks, F. graminearum was the most aggressive species while F. temperatum and F. subglutinans caused only small lesions. The optimal temperature for infection of maize ears with F. temperatum was 24 °C and 21 °C for F. subglutinans. All strains of F. temperatum and F. subglutinans were pathogenic on wheat and capable to cause moderate to severe head blight symptoms. The assessment of mycotoxin production of 60 strains of F. temperatum cultivated on rice revealed that all strains produced beauvericin, moniliformin, fusaric acid, and fusaproliferin. The results demonstrate a higher prevalence and aggressiveness of F. temperatum compared to F. subglutinans in German maize cultivation areas.
Project description:Genome-wide search for AreA-dependent and -independent nitrogen-regulated genes in Fusarium fujikuroi by cross-species hybridization with F. verticillioides microarrays. Keywords: glutamine treatmet Compare expression of genes of Fusarium fujikuroi wild-type and areA mutant strains responding to nitrogen limitation or sufficiency.