Emydomyces testavorans, a New Genus and Species of Onygenalean Fungus Isolated from Shell Lesions of Freshwater Aquatic Turtles.

The fungal order Onygenales includes many pathogens of humans and animals, and recent studies have shown some onygenalean fungi to be significant emerging pathogens of reptiles. Although many of these fungi have similar morphological features in histologic tissue sections, recent molecular analyses have revealed a genetically complex and diverse group of reptile pathogens comprising several genera, most notably Nannizziopsis, Ophidiomyces, and Paranannizziopsis Infections by members of these genera have been previously reported in a variety of reptile species, including crocodilians, lizards, snakes, and tuataras, with negative impacts on conservation efforts for some reptiles. Despite the well-documented pathogenicity of these fungi in all other extant reptile lineages, infection has not yet been reported in aquatic turtles. In this study, we report the isolation of an onygenalean fungus associated with shell lesions in freshwater aquatic turtles. The morphologic and genetic characteristics of multiple isolates (n = 21) are described and illustrated. Based on these features and results of a multigene phylogenetic analysis, a new genus and species, Emydomyces testavorans, are proposed for these fungi isolated from turtle shell lesions.

Spore morphology and ultrastructure of an Ascosphaera apis strain from the honeybees (Apis mellifera) in southwest China.

Ascosphaera apis is an intestinally infective, spore-forming, filamentous fungus that infects honeybees and causes deadly chalkbrood disease. Although A. apis has been known for 60 y, little is known about the ultrastructure of the spores. In this study, the fine morphology and ultrastructure of an isolate, A. apis CQ1 from southwest China, was comprehensively identified by transmission electron microscopy, confocal laser scanning microscopy, scanning electron microscopy, and optical microscopy. The high sequence similarity and phylogenetic data based on nuc rDNA ITS1-5.8S-ITS2 (ITS) supported the hypothesis that the CQ1 strain is a new member of the A. apis species. Morphological observation indicated that the mature spores are long ovals with an average size of 2 × 1.2 µm and are tightly packed inside spherical spore balls. More than 10 spore balls that were 8-16 µm in diameter were wrapped and formed a spherical, nearly hyaline spore cyst of 50-60 µm in diameter. Ultrastructural analysis showed that mature spores have two nuclei with distinctly different sizes. A large nucleus with double nuclear membranes was found in the center of the spore, whereas the small nucleus was only one-fifth of the large nucleus volume and was located near the end of the spore. Numerous ribosomes filled the cytoplasm, and many mitochondria with well-defined structures were arranged along the inner spore wall. The spore wall consists of an electron-dense outer surface layer, an electron-lucent layer, and an inner plasma membrane. Chitin is the major component of the spore wall. The germinated spore was observed as an empty spore coat, whereas the protoplasts, including the nuclei, mitochondria, and ribosomes, had been discharged. In addition to these typical fungal spore organelles, an unknown electron-dense regular structure might be the growing mycelium, which was arranged close to the inner spore wall and almost covered the entire wall area.

Xerotolerant fungi in house dust: taxonomy of Spiromastix, Pseudospiromastix and Sigleria gen. nov. in Spiromastigaceae (Onygenales, Eurotiomycetes).

During a global investigation of fungi in house dust, we isolated six novel arthroconidial fungi. Phylogenies from combined analysis of nuc rDNA 18S, 28S and internal transcribed spacers sequences demonstrated that these fungi and two species preserved in culture collections represent undescribed species of Spiromastigaceae, Onygenales. Seven of the eight species lacked sexual states and only characters of asexual states and growth rates on different media could be used to characterize them. The eighth species produced ascomata only on water agar. We introduce six new species and one new combination in Spiromastix and validate the recently proposed family Spiromastigaceae, genus Pseudospiromastix and combination Ps. tentaculata. The new genus Sigleria is proposed for two new species that differ from Spiromastix by conidiophore branching patterns, slower growth and a limited ability to utilize nitrate as a sole N source. A key to the three genera of Spiromastigaceae, Spiromastix, Pseudospiromastix and Sigleria, is provided. Phylogenetic analyses support the placement of Spiromastigaceae within Onygenales.

Halophilic and thermotolerant Gymnoascus species from several special environments, China.

This study introduces three new Gymnoascus species (Gymnoascaceae, Onygenales), G. halophilus, G. stercorarius and G. thermotolerans, isolated from sediments in Chaka Salt Lake, compost and cornfield soil, respectively, in China, based on a polyphasic characterization including morphology, physiology and molecular phylogeny. Phylogenetic relationships were assessed based on the nuclear internal transcribed spacer (ITS = ITS1 + 5.8S + ITS2) region and a combined multilocus alignment of the ITS, 18S subunit rRNA gene and 28S subunit rRNA genes. Our study identified phylogenetic and phenotypic characters that differentiated the three new species from known species in the genus. Salinity and temperature tolerance tests revealed that G. halophilus was an obligate halophile while G. stercorarius and G. thermotolerans were halotolerant and thermotolerant. A key to accepted species of Gymnoascus is provided.

Onychomycosis caused by Onychocola canadensis: the first report in Estonia and lessons to learn.

We report the first case of onychomycosis caused by Onychocola canadensis in Estonia. We believe that the number of nail infections caused by this fungus is underestimated due to the current diagnostic algorithm of non-dermatophytic onychomycosis. The need to define categories and criteria for 'proven' and 'probable' non-dermatophyte mold infections to promote more extensive studies in the future is also discussed.

Isolation and characterization of a new fungal genus and species, Aphanoascella galapagosensis, from carapace keratitis of a Galapagos tortoise (Chelonoidis nigra microphyes).

A new fungal genus and species, Aphanoascella galapagosensis, recovered from carapace keratitis in a Galapagos tortoise residing in a south Texas zoological collection, is characterized and described. The presence of a pale peridium composed of textura epidermoidea surrounded by scarce Hülle cell-like chlamydospores, and the characteristic reticulate ascospores with an equatorial rim separates it from other genera within the Onygenales. The phylogenetic tree inferred from the analysis of D1/D2 sequences demonstrates that this fungus represents a new lineage within that order. As D1/D2 and ITS sequence data also shows a further separation of Aphanoascus spp. into two monophyletic groups, we propose to retain the generic name Keratinophyton for species whose ascospores are pitted and display a conspicuous equatorial rim, and thereby propose new combinations in this genus for four Aphanoascus species.

Remispora spitsbergenensis sp. nov., a marine lignicolous ascomycete from Svalbard, Norway.

Abstract: Remispora was established for R. maritima, a fungus with globose/subglobose, lightly colored and coriaceous ascomata; deliquescing asci; ellipsoidal ascospores; and bipolar, pleomorphic ascospore appendages. Seven species currently are included in Remispora: R crispa, R. galerita, R maritima, R. minuta, R. pilleata, R. quadriremis and R stellata. Variations on ascospore appendages can be observed in Remispora. In general the appendage is exosporic in nature and comprises an amorphous, electron-transparent matrix, and a fibrous, electron-dense component. An eighth Remispora species, R. spitsbergenensis sp. nov., is described here, discovered from washed-up wood collected at the shore of Longyearbyen, Svalbard, Norway. Ascospore appendages of R. spitsbergenensis appear as fibrous strands and amorphic material under the scanning electron microscope, which are characteristic of a Remispora species. Remispora spitsbergenensis resembles R. quadriremis and R. stellata because all possess four or more ascospore appendages at one end. Remispora spitsbergenensis possesses consistently four polar appendages at each end in contrast to six in R. stellata. Also ascospore appendages of R. spitsbergenensis are ribbon-like, compared with the obclavate, curved and attenuate appendages in R. quadriremis and R. stellata. A key for the identification of the eight Remispora species is provided.

Bat white-nose syndrome: an emerging fungal pathogen?

White-nose syndrome (WNS) is a condition associated with an unprecedented bat mortality event in the northeastern United States. Since the winter of 2006*2007, bat declines exceeding 75% have been observed at surveyed hibernacula. Affected bats often present with visually striking white fungal growth on their muzzles, ears, and/or wing membranes. Direct microscopy and culture analyses demonstrated that the skin of WNS-affected bats is colonized by a psychrophilic fungus that is phylogenetically related to Geomyces spp. but with a conidial morphology distinct from characterized members of this genus. This report characterizes the cutaneous fungal infection associated with WNS.

Evaluation of the vital staining method for Lacazia loboi through the experimental inoculation of BALB/c mice.

The viability of the currently unculturable fungal pathogen Lacazia loboi can be determined by means of fluorescein diacetate-ethidium bromide (FD-EB) staining. This technique can be used in experimental study of the mycosis, in attempts to cultivate the fungus and in attempts to gauge the success of therapies. In the present study, the potential applications of FD-EB vital staining were studied using a proposed murine experimental model of lobomycosis. BALB/c mice were inoculated in the footpads with an L. loboi suspension that appeared in FD-EB staining to have lost viability after being held for 15 days at room temperature, whereas a control group of mice was inoculated with apparently viable fungi. The animals were killed after 1, 2, 4, 6, 8, 11 and 13 months. Both inoculated footpads were excised, one for determination of viability and the other for histological examination. In the group injected with nonviable material, no active infection was noted; inoculation sites showed small quantities of macrophage-laden infiltrate and no viable fungal cells. In the control group, the infection progressed with exuberant infiltrates surrounding copious fungal growth, most of which consisted of cells staining as viable in FD-EB. These results suggest that the FD-EB vital staining is a sensitive and specific method that can reliably be used for viability determination in L. loboi.