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Beltsville, MD, United States

Peterson S.W.,National United University | Jurjevic Z.,EMSL Analytical Inc. | Frisvad J.C.,Technical University of Denmark
PLoS ONE | Year: 2015

A set of isolates very similar to or potentially conspecific with an unidentified Penicillium isolate NRRL 735, was assembled using a BLAST search of ITS similarity among described (GenBank) and undescribed Penicillium isolates in our laboratories. DNA was amplified from six loci of the assembled isolates and sequenced. Two species in section Cinnamopurpurea are self-compatible sexual species, but the asexual species had polymorphic loci suggestive of sexual reproduction and variation in conidium size suggestive of ploidy level differences typical of heterothallism. Accordingly we use genealogical concordance analysis, a technique valid only in heterothallic organisms, for putatively asexual species. Seven new species were revealed in the analysis and are described here. Extrolite analysis showed that two of the new species, P. colei and P. monsserratidens produce the mycotoxin citreoviridin that has demonstrated pharmacological activity against human lung tumors. These isolates could provide leads in pharmaceutical research.

Kozak-Muiznieks N.A.,Centers for Disease Control and Prevention | Lucas C.E.,Centers for Disease Control and Prevention | Brown E.,Centers for Disease Control and Prevention | Pondo T.,Centers for Disease Control and Prevention | And 4 more authors.
Journal of Clinical Microbiology | Year: 2014

Since the establishment of sequence-based typing as the gold standard for DNA-based typing of Legionella pneumophila, the Legionella laboratory at the Centers for Disease Control and Prevention (CDC) has conducted routine sequence-based typing (SBT) analysis of all incoming L. pneumophila serogroup 1 (Lp1) isolates to identify potential links between cases and to better understand genetic diversity and clonal expansion among L. pneumophila bacteria. Retrospective genotyping of Lp1 isolates from sporadic cases and Legionnaires' disease (LD) outbreaks deposited into the CDC reference collection since 1982 has been completed. For this study, we compared the distribution of sequence types (STs) among Lp1 isolates implicated in 26 outbreaks in the United States, 571 clinical isolates from sporadic cases of LD in the United States, and 149 environmental isolates with no known association with LD. The Lp1 isolates under study had been deposited into our collection between 1982 and 2012. We identified 17 outbreak-associated STs, 153 sporadic STs, and 49 environmental STs. We observed that Lp1 STs from outbreaks and sporadic cases are more similar to each other than either group is to environmental STs. The most frequent ST for both sporadic and environmental isolates was ST1, accounting for 25% and 49% of the total number of isolates, respectively. The STs shared by both outbreak-associated and sporadic Lp1 included ST1, ST35, ST36, ST37, and ST222. The STs most commonly found in sporadic and outbreak-associated Lp1 populations may have an increased ability to cause disease and thus may require special attention when detected.Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Mejia L.C.,U.S. Department of Agriculture | Mejia L.C.,Rutgers University | Mejia L.C.,Smithsonian Tropical Research Institute | Castlebury L.A.,U.S. Department of Agriculture | And 3 more authors.
Studies in Mycology | Year: 2011

Members of the genus Plagiostoma inhabit leaves, stems, twigs, and branches of woody and herbaceous plants predominantly in the temperate Northern Hemisphere. An account of all known species of Plagiostoma including Cryptodiaporthe is presented based on analyses of morphological, cultural, and DNA sequence data. Multigene phylogenetic analyses of DNA sequences from four genes (β-tubulin, ITS, rpb2, and tef1-α) revealed eight previously undescribed phylogenetic species and an association between a clade composed of 11 species of Plagiostoma and the host family Salicaceae. In this paper these eight new species of Plagiostoma are described, four species are redescribed, and four new combinations are proposed. A key to the 25 accepted species of Plagiostoma based on host, shape, and size of perithecia, perithecial arrangement in the host, and microscopic characteristics of the asci and ascospores is provided. Disposition of additional names in Cryptodiaporthe and Plagiostoma is also discussed. © 2011 by the CBS Fungal Biodiversity Centre.

Woudenberg J.H.C.,Fungal Biodiversity Center | Woudenberg J.H.C.,Laboratory of Phytopathology | van der Merwe N.A.,University of Pretoria | Jurjevic T.,EMSL Analytical Inc. | And 4 more authors.
Fungal Genetics and Biology | Year: 2015

Alternaria spp. from sect. Alternaria are frequently associated with hypersensitivity pneumonitis, asthma and allergic fungal rhinitis and sinusitis. Since Alternaria is omnipresent in the outdoor environment, it is thought that the indoor spore concentration is mainly influenced by the outdoor spore concentration. However, few studies have investigated indoor Alternaria isolates, or attempted a phylogeographic or population genetic approach to investigate their movement. Therefore, the aim of the current study was to investigate the molecular diversity of indoor Alternaria isolates in the USA, and to test for recombination, using these approaches. Alternaria isolates collected throughout the USA were identified using ITS, gapdh and endoPG gene sequencing. This was followed by genotyping and population genetic inference of isolates belonging to Alternaria sect. Alternaria together with 37 reference isolates, using five microsatellite markers. Phylogenetic analyses revealed that species of Alternaria sect. Alternaria represented 98% (153 isolates) of the indoor isolates collected throughout the USA, of which 137 isolates could be assigned to A. alternata, 15 to the A. arborescens species complex and a single isolate to A. burnsii. The remaining 2% (3 isolates) represented sect. Infectoriae (single isolate) and sect. Pseudoulocladium (2 isolates). Population assignment analyses of the 137 A. alternata isolates suggested that subpopulations did not exist within the sample. The A. alternata isolates were thus divided into four artificial subpopulations to represent four quadrants of the USA. Forty-four isolates representing the south-western quadrant displayed the highest level of uniqueness based on private alleles, while the highest level of gene flow was detected between the south-eastern (32 isolates) and south-western quadrants. Genotypic diversity was high for all quadrants, and a test for linkage disequilibrium suggested that A. alternata has a cryptic sexual cycle. These statistics could be correlated with environmental factors, suggesting that indoor A. alternata isolates, although extremely diverse, have a continental distribution and high levels of gene flow over the continent. © 2015 The Authors.

Walker D.M.,Rutgers University | Walker D.M.,U.S. Department of Agriculture | Castlebury L.A.,U.S. Department of Agriculture | Rossman A.Y.,U.S. Department of Agriculture | And 2 more authors.
Mycologia | Year: 2010

Species of Gnomoniopsis are leaf-and stem-inhabiting pyrenomycetes that infect plants in Fagaceae, Onagraceae and Rosaceae. Morphology and analyses of DNA sequences from three ribosomal DNA and protein coding regions, namely β-tubulin, translation elongation factor 1α (tef-1α) and the ITS region including ITS1, 5.8S rDNA and ITS2, were used to define species in Gnomoniopsis. Secondary structural alignment of the ITS region across four genera in Gnomoniaceae was used to increase the potential number of homologous positions in the ITS alignment. Ascospore isolates were grown from newly collected specimens. Type specimens were compared with these specimens to determine their identity. In this paper a recent concept of Gnomoniopsis is confirmed with phylogenetic resolution of additional species. Four new combinations and one new species are proposed. Nine species are described and illustrated, and a key is provided to the 13 species currently recognized in Gnomoniopsis. © 2010 by The Mycological Society of America.

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