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Peterson S.W.,Bacterial Foodborne Pathogens and Mycology Research Unit
PloS one | Year: 2013

During the course of mold surveys, a set of Talaromyces isolates were obtained that did not fit any described species. Phenotypic examination of these isolates showed that they were similar to T. piceus but differed in some growth characteristics. Multilocus DNA sequence data were obtained for the new isolates and some related species in the broader, more inclusive clade, and the data were analyzed using genealogical concordance. The new isolates are described as Talaromyces columbinus. From analysis of the related species, Penicillium rugulosum var. atricolum is given species status in Talaromyces as T. atricola. Penicillium tardum and P. chrysitis were showed to be synonyms of T. rugulosus. Penicillium scorteum and T. phialosporus were showed to be conspecific and under the rule of priority T. scorteus is the proper name for isolates previously known as T. phialosporus. Talaromyces wortmanii was showed to be distinct from Penicillium concavorugulosum and T. variabilis but the relationship of the latter two species remains unresolved. Examination of ITS sequences from GenBank showed that T. columbinus has previously been reported from human lung infections under the name Penicillium piceum.

Naumann T.A.,Bacterial Foodborne Pathogens and Mycology Research Unit | Price N.P.J.,Renewable Product Technology Research Unit
Molecular Plant Pathology | Year: 2012

Plant class IV chitinases have a small amino-terminal chitin-binding domain and a larger chitinase domain, and are involved in plant defence against fungal infection. Our previous work on the chitinases ChitA and ChitB from the model monocotyledon Zea mays showed that the chitin-binding domain is removed by secreted fungal proteases called fungalysins. In this article, we extend this work to dicotyledons. The effects of fungalysin-like proteases on four class IV chitinases from the model dicotyledon Arabidopsis thaliana were analysed. Four Arabidopsis chitinases were heterologously expressed in Pichia pastoris, purified and shown to have chitinase activity against a chitohexaose (dp6) substrate. The incubation of these four chitinases with Fv-cmp, a fungalysin protease secreted by Fusarium verticillioides, resulted in the truncation of AtchitIV3 and AtchitIV5. Moreover, incubation with secreted proteins from Alternaria brassicae, a pathogen of A.thaliana and brassica crops, also led to a similar truncation of AtchitIV3 and AtchitIV4. Our finding that class IV chitinases from both dicotyledons (A.thaliana) and monocotyledons (Z.mays) are truncated by proteases secreted by specialized pathogens of each plant suggests that this may be a general mechanism of plant-fungal pathogenicity. © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

Aoki T.,Japan National Institute of Agrobiological Science | Scandiani M.M.,Laboratorio Agricola Rio Parana | O'Donnell K.,Bacterial Foodborne Pathogens and Mycology Research Unit
Mycoscience | Year: 2012

A novel soybean sudden death syndrome (SDS) pathogen from Argentina and Brazil is formally described herein as Fusarium crassistipitatum based on detailed phenotypic analyses of macro- and microscopic characters and phylogenetic analyses of multilocus DNA sequence data. Fusarium crassistipitatum can be distinguished from the other soybean SDS and bean (Phaseolus/Vigna) root rot pathogens (BRR) phenotypically by the production of yellowish colonies on PDA; and tall, stout, and mostly unbranched conidiophores with a thick-walled base, which form multiseptate conidia apically. Phylogenetic species recognition based on genealogical concordance of a six-gene dataset strongly supported the reciprocal monophyly of F. crassistipitatum with respect to the other SDS and BRR pathogens. Isolates of F. crassistipitatum were able to induce typical SDS foliar and root rot symptoms on soybean that were indistinguishable from those caused by three other SDS pathogens (i. e., F. virguliforme, F. brasiliense, and F. tucumaniae) on susceptible cultivars A-6445RG and N-4613RG in a pathogenicity experiment. © 2011 The Mycological Society of Japan and Springer.

Hubka V.,Academy of Sciences of the Czech Republic | Hubka V.,Charles University | Kolarik M.,Charles University | Kubatova A.,Charles University | Peterson S.W.,Bacterial Foodborne Pathogens and Mycology Research Unit
Mycologia | Year: 2013

Aspergillus section Aspergillus contains economically important, xerophilic fungi that are widely distributed in nature and the human environment and are known for their ability to grow on substrates with low water activity. The taxa were revised based on sequence data from four loci, PCR fingerprinting, micro- and macromorphology, and physiology. The number of taxa was reduced to 17 species, all of which can be distinguished with sequence data from either the caM or RPB2 locus. The original description of A. proliferans was supplemented by a description of its teleomorph. This species seems to be relatively common and often has been confused with A. glaucus. In addition, green sporulating isolates of A. niveoglaucus isolated from food and several other substrates are indistinguishable in phenotype from A. glaucus. A dichotomous key based on ascospore size and ornamentation and the ability to grow at specific combinations of temperature and water activity is provided for identification of species. In response to recent changes in the botanical code, we transferred the Eurotium species to Aspergillus and selected one name for each species. © 2013 by The Mycological Society of America.

Ward T.J.,Bacterial Foodborne Pathogens and Mycology Research Unit | Usgaard T.,Bacterial Foodborne Pathogens and Mycology Research Unit | Evans P.,Food Safety and Inspection Service
Applied and Environmental Microbiology | Year: 2010

A 30-probe assay was developed for simultaneous classification of Listeria monocytogenes isolates by lineage(I to IV) major serogroup (4b1/2b1/2aand 1/2c) and epidemic clone (EC) type (ECI ECIa ECII and ECIII). The assay was designed to facilitate rapid strain characterization and the integration of subtype data into risk-based inspection programs. © 2010, American Society for Microbiology.

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