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University Center, VA, United States

Kerrigan L.,10801 University Blvd | Nims R.W.,RMC Pharmaceutical Solutions Inc.
Regenerative Medicine

Authentication of human tissues, cell lines and primary cell cultures (including stem cell preparations) used as therapeutic modalities is often performed using phenotyping and technologies capable of assessing identity to the species level (e.g., isoenzyme analysis and/or karyotyping). This authentication paradigm alone cannot provide assurance that the correct human cell preparation is administered, so careful labeling and tracking of cells from the donor, during manufacture and as part of the final product are also employed. Precise, accurate identification of human cells to the individual donor level could, however, significantly reduce the risks of exposing human subjects to misidentified cells. The availability of a standardized method for achieving this will provide a way to improve the safety profile of human cell-based products by providing assurance that a given lot of cells originated from the intended donor and were not inadvertently mixed or replaced with cells from other donors. In support of this goal, an international team of scientists has prepared a consensus standard on authentication of human cells using short tandem repeat profiling. Associated with the standard itself will be the establishment and maintenance of a public database of short tandem repeat profiles for commonly used cell lines. © 2011 Future Medicine Ltd. Source

Suh S.-O.,10801 University Blvd | Zhou J.J.,10801 University Blvd
Antonie van Leeuwenhoek, International Journal of General and Molecular Microbiology

Three ascosporogenous yeast strains were isolated from the gut of the passalid beetle, Odontotaenius disjunctus, inhabiting on rotten oak trees. DNA sequence comparison and other taxonomic characteristics identified the strains as a novel species in the genus Kazachstania. The name Kazachstania intestinalis sp. nov. (type strain EH085 T = ATCC MYA-4658 T = CBS 11839 T) is proposed for the strains. The yeast is homothallic, producing persistent asci with 1-4 spheroidal ascospores. Molecular phylogeny from ribosomal RNA gene sequences placed this novel species on the basal lineage of a clade including Kazachstania lodderae, Kazachstania exigua, Kazachstania martiniae, and other related Kazachstania spp., but none of those species was a close sister to K. intestinalis. © 2011 Springer Science+Business Media B.V. Source

Ogataea (Hansenula) polymorpha and related yeasts were studied to clarify their taxonomy and phylogenetic relationships. The molecular analyses based on ribosomal DNA sequences revealed that (1) ATCC 14755, type strain of Pichia angusta, is phylogenetically distinguished from the majority of O. polymorpha strains including ATCC 34438T (=NRRL Y-5445T=CBS 4732 T), type of the species; (2) Ogataea thermophila is conspecific to O. polymorpha; and (3) two of the strains, ATCC 26012 and ATCC 58401, are a novel Candida species closely related to O. polymorpha. The conclusions were also supported by physiological characteristics and other taxonomic features of these strains. Therefore, we propose here two novel species, Ogataea angusta comb. nov. (ATCC 14755T=CBS 7073T=NRRL Y-2214T) and Candida parapolymorpha sp. nov. (ATCC 26012T=NRRL Y-7560 T), and conclude that O. thermophila is a synonym of O. polymorpha. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved. Source

Houseknecht J.L.,10801 University Blvd | Suh S.-O.,10801 University Blvd | Zhou J.J.,10801 University Blvd
Fungal Biology

Living stock cultures with constant phenotypes and genotypes are required for a wide range of research and industrial applications; however, long-term, stable preservation of fastidious Phytophthora strains has been challenging. In this study, we systematically evaluated different cryopreservation treatments to identify and clarify freezing, thawing, and other conditions appropriate for long-term maintenance. Optimal preservation conditions were largely strain-specific, with robust strains remaining fully viable and the fastidious yielding lower recovery under all test conditions. Nevertheless, several procedures were shown to be generally applicable for effective cryopreservation of most Phytophthora organisms. Fastidious strains retained higher viability following the -1 °C min-1 freezing protocol (Mr Frosty's) than either of two widely used programmed freezing procedures. Revival was higher when frozen mycelium plugs were thawed at 37 °C for 2 min or 25 °C for 5 min, while lower viability was apparent for fastidious strains thawed at 55 °C for 1.5 min. Among 15 cryoprotective solutions assessed, 5 % dimethyl sulfoxide produced the highest viability for all fastidious strains. The effect of prefreeze and postfreeze treatments on revival was mild, if any, and strain-dependent. This study has generated reliable, practical, long-term preservation solutions applicable to a majority of Phytophthora species. It also has revealed a need for in-depth physiological and morphological investigations to further enhance the preservation methods for fastidious strains. © 2012 The British Mycological Society. Source

Suh S.-O.,10801 University Blvd | Maslov D.A.,University of California at Riverside | Molestina R.E.,10801 University Blvd | Zhou J.J.,10801 University Blvd
Antonie van Leeuwenhoek, International Journal of General and Molecular Microbiology

Two strains of a basidiomycetous yeast were derived from an insect trypanosomatid culture isolated from the intestine of a plant bug, Collaria oleosa (Heteroptera: Miridae), collected in Costa Rica. The yeast did not form ballistoconidia but reproduced only by budding. Teliospores were not observed in individual and crossed cultures of each strain. Morphological and other taxonomic characteristics of the yeast were similar to those of the species in the polyphyletic genus Rhodotorula. However, molecular phylogeny inferred from the internal transcribed spacers and D1/D2 region of the large subunit rRNA gene showed that the strains represent a new species placed among the smut fungi in the family Ustilentylomataceae, which includes Aurantiosporium subnitens, Fulvisporium restifaciens, Ustilentyloma fluitans, and Rhodotorula hordea. Given the well distinguished phylogenetic position of this novel species within the Ustilentylomataceae, we propose Microbotryozyma collariae gen. nov., sp. nov. to accommodate the yeast isolated from C. oleosa, with strain American Type Culture Collection MYA-4666 T (= PRA303-1S = CBS 12537) designated as the type strain. © 2012 Springer Science+Business Media B.V. Source

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