Xanthothecium peruvianum isolated from human stratum corneum: A case report, characterisation and short review that suggest emendation of Arachnomyces peruvianus.

From stratum corneum samples of a palmar eczema, a fungus was isolated that developed white colonies with a yellowish dark reverse, suggestive of dermatophytes. The isolate produced numerous chlamydospores and sparse aleuroconidia, was resistant to cycloheximide, grew well on human stratum corneum samples and was positive in tests for urease production and hair perforation, but no dermatophyte could be identified. After several weeks, cleistothecia with delicate asci and disc-shaped ascospores were formed, suggesting Arachnomyces spp. The analyses of the ribosomal ITS and LSU (D1/D2 domains) nucleotide sequences proved a good match with the ex-type strain of Xanthothecium peruvianum (family Onygenaceae, order Onygenales), and LSU sequence showed 99% similarity with Arachnomyces glareosus. This is the first report of X. peruvianum isolated from human skin. The description of our isolate provides new information about this species and proposes its transfer to the genus Arachnomyces with the subsequent emendation of the description of Arachnomyces peruvianus. Morphologically and physiologically it mimics dermatophytes and other species of the genus Arachnomyces. Although the clinical situation did not suggest any relevance for A. peruvianus as a primary pathogen, this fungus may act as a secondary pathogen under suitable conditions due to its keratinolytic capacity.

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.

Emmonsiellopsis, a new genus related to the thermally dimorphic fungi of the family Ajellomycetaceae.

Two interesting fungi were isolated from fluvial sediments collected in the North of Spain. They were morphologically related to the thermally dimorphic fungi of the family Ajellomycetaceae, but the analysis of the internal transcribed spacer region of the rDNA, and the domains D1 and D2 of the 28S rRNA gene sequences confirmed that they were different from all the species described in that family. They were accommodated in the new genus Emmonsiellopsis as E. coralliformis sp. nov. and E. terrestris sp. nov. The two species are distinguished mainly by the maximum temper-ature of growth (up to 33 °C for E. coralliformis and to 42 °C for E. terrestris), the dendritic mycelium of E. coralliformis and the conidial ornamentation (verrucose in E. coralliformis and spinulose in E. terrestris). In addition, the phylogenetic data demonstrated that Ajellomyces griseus also represents a new genus within the Ajellomycetaceae, namely Helicocarpus. This new genus is easily distinguished by the lack of asexual morph, the production of brownish gymnothecial ascomata and oblate to lenticular, sparingly pitted ascospores. The proposal of both new genera was confirmed by the analysis of actin gene sequences.

Long-term storage of Ascosphaera aggregata and Ascosphaera apis, pathogens of the leafcutting bee (Megachile rotundata) and the honey bee (Apis mellifera).

Survival rates of Ascosphaera aggregata and Ascosphaera apis over the course of a year were tested using different storage treatments. For spores, the storage methods tested were freeze-drying and ultra-low temperatures, and for hyphae, freeze-drying, agar slants, and two methods of ultra-low temperatures. Spores of A. aggregata and A. apis stored well at -80 degrees C and after freeze-drying. A. aggregata hyphae did not store well under any of the methods tested while A. apis hyphae survived well using cryopreservation. Spores produced from cryopreserved A. apis hyphae were infective. Long-term storage of these two important fungal bee diseases is thus possible.

Morphology and development of the reticuloperidial ascomata of Auxarthron conjugatum.

Light and electron microscopy showed that the reticuloperidium of thick-walled hyphae, characteristic of the mature ascoma of Auxarthron conjugaturn, originated from branches that grew from the broad, gyre-like hyphal loops making up the ascomatal initials. Within the developing peridium, short, acropetally proliferating chains of prototunicate asci each arose from a single crozier and matured from base to tip. The walls of young asci were two-layered but evanesced as they matured with the outer layer dissolving before the inner one. Distal asci in some chains retained the inner wall, detached from adjacent asci by septum schizolysis and when transferred to fresh media produced germ tubes and mycelium. Ultraviolet epifluorescent staining with a DNA intercalator (Hoechst) indicated that these spore-like asci probably contained diploid nuclei. In normal asci, ascospores had an inner, electron lucent primary wall and a three-layered secondary wall. The deposition pattern of the middle layer of the secondary wall created the distinctive array of pits and ridges characteristic of the ascospores in this taxon. The production of ascospores, spore-like asci and arthroconidia, along with the tendency of ascospores to adhere in a mass, is interpreted as contributing to the reproductive flexibility and inoculum potential of A. conjugatum. In all respects the ascomata of A. conjugatum differed substantially from the morphologically similar taxon, Myxotrichum arcticum. These findings underscore the benefit of using DNA-based phylogenies in concert with cytological and ultrastructural observations for exploring selective pressures behind homoplasious characters and revealing novel structural features.

The role of pollen in chalkbrood disease in Apis mellifera: transmission and predisposing conditions.

Chalkbrood in honeybees (Apis mellifera L. Himenoptera: Apidae) is a fungal disease caused by Ascosphaera apis (Maassen ex Claussen) Olive and Spiltoir. This disease requires the presence of fungal spores and a predisposing condition in the susceptible brood for the disease to develop. In this study we examined the role of pollen in the development of chalkbrood disease under two experimental conditions: (i) pollen combs were transferred from infected to uninfected beehives and (ii) colonies were deprived of adequate pollen supplies to feed the brood. The results of both treatments confirmed that pollen is an element that should be taken into account when controlling this honeybee disease.

Experimental Infection of Snakes with Ophidiomyces ophiodiicola Causes Pathological Changes That Typify Snake Fungal Disease.

UNLABELLED: Snake fungal disease (SFD) is an emerging skin infection of wild snakes in eastern North America. The fungus Ophidiomyces ophiodiicola is frequently associated with the skin lesions that are characteristic of SFD, but a causal relationship between the fungus and the disease has not been established. We experimentally infected captive-bred corn snakes (Pantherophis guttatus) in the laboratory with pure cultures of O. ophiodiicola. All snakes in the infected group (n = 8) developed gross and microscopic lesions identical to those observed in wild snakes with SFD; snakes in the control group (n = 7) did not develop skin infections. Furthermore, the same strain of O. ophiodiicola used to inoculate snakes was recovered from lesions of all animals in the infected group, but no fungi were isolated from individuals in the control group. Monitoring progression of lesions throughout the experiment captured a range of presentations of SFD that have been described in wild snakes. The host response to the infection included marked recruitment of granulocytes to sites of fungal invasion, increased frequency of molting, and abnormal behaviors, such as anorexia and resting in conspicuous areas of enclosures. While these responses may help snakes to fight infection, they could also impact host fitness and may contribute to mortality in wild snakes with chronic O. ophiodiicola infection. This work provides a basis for understanding the pathogenicity of O. ophiodiicola and the ecology of SFD by using a model system that incorporates a host species that is easy to procure and maintain in the laboratory. IMPORTANCE: Skin infections in snakes, referred to as snake fungal disease (SFD), have been reported with increasing frequency in wild snakes in the eastern United States. While most of these infections are associated with the fungus Ophidiomyces ophiodiicola, there has been no conclusive evidence to implicate this fungus as a primary pathogen. Furthermore, it is not understood why the infections affect different host populations differently. Our experiment demonstrates that O. ophiodiicola is the causative agent of SFD and can elicit pathological changes that likely impact fitness of wild snakes. This information, and the laboratory model we describe, will be essential in addressing unresolved questions regarding disease ecology and outcomes of O. ophiodiicola infection and helping to conserve snake populations threatened by the disease. The SFD model of infection also offers utility for exploring larger concepts related to comparative fungal virulence, host response, and host-pathogen evolution.

Oxytetracycline as a predisposing condition for chalkbrood in honeybee.

Antibiotics, particularly oxytetracycline, have been discussed as a possible predisposing condition in the appearance of chalkbrood in the honeybee (Apis mellifera L.). Nevertheless, the scientific data to support this belief have been insufficient. We have developed a method to study the effects of this antibiotic as a predisposing factor under different circumstances. We conclude that oxytetracycline does not increase the risk of chalkbrood in susceptible worker brood in the short or mid-term.

Temperature dependent virulence of obligate and facultative fungal pathogens of honeybee brood.

Chalkbrood (Ascosphaera apis) and stonebrood (Aspergillus flavus) are well known fungal brood diseases of honeybees (Apis mellifera), but they have hardly been systematically studied because the difficulty of rearing larvae in vitro has precluded controlled experimentation. Chalkbrood is a chronic honeybee-specific disease that can persist in colonies for years, reducing both brood and honey production, whereas stonebrood is a rare facultative pathogen that also affects hosts other than honeybees and can likely survive outside insect hosts. Hive infection trials have indicated that accidental drops in comb temperature increase the prevalence of chalkbrood, but it has remained unclear whether virulence is directly temperature-dependent. We used a newly established in vitro rearing technique for honeybee larvae to test whether there are systematic temperature effects on mortality induced by controlled infections, and whether such effects differed between the two fungal pathogens. We found that increasing spore dosage at infection had a more dramatic effect on mortality from stonebrood compared to chalkbrood. In addition, a 24h cooling period after inoculation increased larval mortality from chalkbrood infection, whereas such a cooling period decreased mortality after stonebrood infection. These results raise interesting questions about honeybee defenses against obligate and facultative pathogens and about the extent to which stress factors in the host (dis)favor pathogens with lesser degrees of specialization.

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.

Exocellular proteases of Malbranchea gypsea and their role in keratin deterioration.

Malbranchea gypsea IMI 338,168 isolated from the soils of Keoladeo National Park, Bharatpur was studied for its ability to produce exocellular proteases on glucose-gelatin medium at pH 7; 28 degrees C. The fungus was observed to be a potent producer of such enzymes. Protease production was optimal at 15 days of incubation. Asparagine was repressive to protease expression. No relationship existed between the amount of enzyme production and increase in biomass. Exogenous sugars suppressed enzyme production in descending order as follows: glucose > mannose > maltose > arabinose > fructose. The enzymes expressed showed the ability to degrade three keratinous substrates tested. Buffalo skin was the most actively degraded substrate when exogenous glucose was present, and was also the most resistant to degradation in the absence of glucose. The rate of keratin deterioration was independent of enzyme activity. Production of protease enzymes especially keratinases is ecologically important in a place like a National Park because such enzymes degrade keratinous detritus derived from mammals and birds. Accumulation of such materials can be a cause of pollution and can provide a breeding spot for various types of pathogens.

Skin infection due to Geomyces pannorum var. pannorum.

Geomyces pannorum var. pannorum is an ubiquitous saprophytic fungus frequently isolated from the soil and from air samples. It has rarely been reported as an animal or plant pathogen and it is an occasional aetiological agent of superficial infection of skin and nails in humans. Here, we report a case of superficial infection of the skin due to this fungus in a healthy man. The patient was treated orally with terbinafine 250 mg daily and topic bifonazole with complete resolution in 2 months.

Onygenales (Eurotiomycetes, Ascomycota) queratinofílicos en suelos de establecimientos educacionales urbanos y rurales de la V Región, Chile / Queratinophilic onygenales (Eurotiomycetes, Ascomycota) in urban and rural soils of eduacational center of V Region, Chile

Con la finalidad de estudiar la presencia de Onygenales queratinofílicas potencialmente patógenas para el hombre y los animales, se analizaron mediante la técnica del anzuelo queratínico (Marzo – Diciembre, 2006), suelos de establecimientos educacionales urbanos y rurales de la V Región, Chile. Se colectaron un total de 64 muestras, de las cuales, la mitad se obtuvieron en Valparaíso-Viña del Mar (urbano) y la otra en Olmué-Limache (en zonas rurales). En zona urbana se aislaron 112 cepas (7 géneros y 12 especies) y en la rural 147 (11 géneros y 18 especies). Los géneros de mayor prevalencia en la zona urbana y rural en orden decreciente fueron: Chrysosporium y su teleomorfo 32 por ciento versus 45 por ciento; Keratinomyces y su teleomorfo, 26 por ciento y 16 por ciento; Microsporum y su teleomorfo 23 por ciento y 16 por ciento y Myceliophthora y su teleomorfo con un 13 y 10 por ciento. Amauroascus mutatus, Auxarthron umbrinum, Gymnoascus reessii, Chrysosporium charmichaelii, Ch. merdarium, Ch. tropicum, Geomyces pannorum var. pannorum fueron detectados sólo en la zona rural; mientras que Malbranchea flava sólo en la zona urbana. Mediante la técnica de Takashio, se pudo identificar separadamente las especies del complex Microsporum gypseum, determinándose que M. gypseum (Arthrodema gypseum) y M.fulvum (A. fulvum) obtuvieron una frecuencia de aislamiento similar en ambas zonas, siendo el primero un oportunista potencialmente patógeno para el hombre y los animales.

With the purpose of studying the presence of keratinophilic Onygenales that are potentially pathogenous for man and animal, urban and rural soils from educational centers in the V Region were examined with the keratinic bait technique (march-december 2006). A total of 64 samples were collected, 32 of them being from Valparaíso-Viña del Mar (urban) while the rest in Olmué-Limache (in rural zones). One hundred and twelve strains (7 genera and 12 species) were collected in the urban zone and 147 strains in the rural zone (11genera and 18 species). Genera with the highest prevalence both in the urban and the rural zones were, in decreasing order: Chrysosporium and its teleomorph 32 per cent vs. 45 per cent; Keratinomyces and its teleomorph 26 per cent and 16 per cent; Microsporum and its teleomorph 23 per cent and 16 per cent and Myceliophthora and its. teleomorph with 13 per cent and 10 per cent. Amauroascus mutatus, Auxarthron umbrinum, Gymnoascus reessii, Chrysosporium charmichaelii, Ch. merdarium, Ch.tropicum, Geomyces pannorum var. pannorum were detected only in the rural zone, whereas Malbranchea flava only in the urban zone. Species of the complex Microsporum gypseum, could be identified separately by means of the Takashio technique, coming to the conclusion that M. gypseum (Arthrodema gypseum) and M.fulvum (A. fulvum) achieved a similar frequency of isolation in both zones and that the former is a potentially opportunistic pathogen for man and animal.

Hongos geofílicos en la zona occidental de la región chaqueña (Argentina) / Geophilic fungi in western zone of Chaco Region, Argentina

Mediante las técnicas de Orr y de dilución, se estudiaron muestras de tierra de la zona occidental de la región chaqueña recogidas durante las estaciones de invierno y verano del año 2006. Mediante el anzuelo queratínico se aislaron 22 géneros y 25 especies fúngicas. Los Onygenales estuvieron representados con sólo 8 géneros, principalmente Chrysosporium indicum, Aphanoascus fulvescens y Myceliophthora vellerea, mientras en los no Onigenales, destacan: Paecilomyces lilacinus y Aspergillus fumigatus. En las muestras procesadas por dilución en PDA, se obtuvieron 24 géneros y 43 especies. Entre éstas, el género más frecuente y con mayor diversidad fue Aspergillus, siendo A. fumigatus la especie más representada, siguiendo en importancia los micelios hialinos y dematiáceos sin fructificar, los Penicillium del sub género Biverticillium y los Trichoderma de la sección Trichoderma. Se destaca la presencia de Corynascus verrucosus y C. setosus. Con ambas técnicas no se obtuvieron diferencias significativas respecto del número total de aislamientos entre invierno y verano.

Soil samples from the western zone of Chaco Region and collected during winter and summer of 2006 were studied by means of Orr and dilution techniques. Twenty two genera and 25 fungal species resulted with the use of the keratinic bait. Onygenales were represented by only 8 genera, mainly Chrysosporium indicum, Aphanoascus fulvescens and Myceliophtora vellerea, while Paecilomyces lilacinus and Aspergillus fumigates were present in the not Onygenales group. In samples processed by PDA dilution, 23 genera and 43 species were obtained. Among these, Aspergillus was the most frequent genus and which showed the highest diversity, being A. fumigatus the highest represented species, followed in importance by fructification-free hyaline and dematiaceous mycelia, Penicillium of the sub genus Biverticillium and Trichoderma from the Trichoderma section. The presence of Corynascus verrucosus and C. setosus is also pointed out. There were no significant differences detected under both techniques as regards the overall number of isolations within winter and summer.