A yeast leading to widespread infection of laboratory mice was identified

A yeast leading to widespread infection of laboratory mice was identified from 26S rRNA gene sequences as with other members of the (species complex, nucleotide sequences from domains 1 and 2 of the 26S rRNA gene, the mitochondrial small-subunit rRNA gene, and the RNA polymerase II gene were phylogenetically analyzed. the exception of is a member of the (species Bay 65-1942 HCl complex. was first described as by van der Walt (17). Because the ascospore walls of this species are roughened as a result of surface ornamentation (5), van der Walt and Yarrow (18) concluded that was not typical of the smooth-spored sensu Rabbit polyclonal to PCSK5 stricto species and redescribed it as are phenotypically much like and were believed to represent the anamorphic states of this ascosporogenous species (4, 19, 20). Mendon?a-Hagler and Phaff (12) tested this possibility by measuring the extent of nuclear DNA complementarity among the four taxa. All four were reported to share 80% or greater nuclear DNA relatedness, leading Mendon?a-Hagler and Phaff (12) to propose that the four taxa represent the same species. Hurt (2) reexamined the nuclear DNA relatedness among the four taxa using a free-solution reassociation method rather than the filter-binding technique of Mendon?a-Hagler and Phaff (12). In contrast to the earlier results, Hurt (2) found only 20 to 56% nuclear DNA relatedness among the various pairings, which would suggest that the taxa represent four separate, but closely related, species. James et al. (3) compared the four taxa by phylogenetic analysis of the nucleotide sequences of the 18S rRNA gene, 26S D1 and D2 rRNA genes, and the mitochondrially encoded cytochrome oxidase II gene. These total outcomes once again recommended how the taxa represent four distinct but carefully related varieties, and because of this hereditary divergence, Wayne et al. (3) suggested reinstatement of so that as specific varieties. Recently, Kurtzman and Robnett (11) analyzed genus limitations in the complicated by multigene series evaluation. The ca. 80 varieties solved into 14 clades, that have been interpreted as genera, leading to redescriptions of some previously approved genera as well as the proposal of five fresh genera (8). Clade 2 through Bay 65-1942 HCl the analysis included many varieties of and which were phylogenetically unrelated to the sort varieties of their particular genera, aswell as varieties of the monotypic genera offers taxonomic priority, leading to the transfer of and additional clade 2 varieties to complicated and solved five clades by D1 and D2 26S rRNA gene series analysis, in keeping with the record of Wayne et al. (3). We additional compared these isolates by evaluation from the mitochondrial small-subunit rRNA RNA and gene polymerase II gene sequences. Analyses from the last two data models gave trees and shrubs congruent using the tree made of the D1 and D2 sequences, assisting the idea that are specific varieties. The analyses recognized yet another also, unknown species previously. Microscopic study of the ethnicities revealed that a number of strains from each one of these four clades shaped ascospores. As a result, we propose keeping the ascosporic areas of clade, receive for the phylogenetic trees and shrubs. RESULTS Initial recognition of yeasts from laboratory Bay 65-1942 HCl animals. In addition to the mice at the National Cancer Institute that were observed to have yeasts within the gastrointestinal tract, a line of knockout mice with a B6:129 background from that facility were shipped to another large research facility in another state for rederivation and Bay 65-1942 HCl eventual research. The mice were routinely maintained in a receiving and quarantine room. The gastrointestinal infection had not been seen at that research facility for many years. The transported infected mice were found to have gastric infection with chronic gastritis. DBA/2NCr mice placed in the same cage as infected null mice for 4 months also developed gastric infection. Histopathology. The histopathological gastric changes consisted of numerous but variable numbers of yeast-like organisms in gastric epithelial surface debris and along the surfaces of epithelial cells throughout all regions of the glandular stomach. Hematoxylin-eosin Bay 65-1942 HCl staining revealed that the organisms were small, approximately 3 m in diameter, spherical to ovoid yeast-like cells with a dark blue outer wall and some internal dot-like structures. These organisms were densely positive by periodic acid-Schiff staining. Chronic inflammation with lymphocytes or myeloid cells was observed in a minority of animals. However,.