Three new species of the genus Ochroconis

Ochroconis bacilliformis, O. phaeophora and O. robusta, three novel species of the melanized genus Ochroconis (Sympoventuriaceae, Venturiales), are described, illustrated and distinguished phenotypically and molecularly from previously described species in the genus Ochroconis. Their potential significance for infection of cold-blooded vertebrates is discussed

One fungus, which genes?: development and assessment of universal primers for potential secondary fungal DNA barcodes

The aim of this study was to assess potential candidate gene regions and corresponding universal primer pairs as secondary DNA barcodes for the fungal kingdom, additional to ITS rDNA as primary barcode. Amplification efficiencies of 14 (partially) universal primer pairs targeting eight genetic markers were tested across > 1 500 species (1 931 strains or specimens) and the outcomes of almost twenty thousand (19 577) polymerase chain reactions were evaluated. We tested several well-known primer pairs that amplify: i) sections of the nuclear ribosomal RNA gene large subunit (D1-D2 domains of 26/28S); ii) the complete internal transcribed spacer region (ITS1/2); iii) partial beta-tubulin II (TUB2); iv) gamma-actin (ACT); v) translation elongation factor 1-alpha (TEF1 alpha); and vi) the second largest subunit of RNA-polymerase II (partial RPB2, section 5-6). Their PCR efficiencies were compared with novel candidate primers corresponding to: i) the fungal-specific translation elongation factor 3 (TEF3); ii) a small ribosomal protein necessary for t-RNA docking; iii) the 60S L10 (L1) RP; iv) DNA topoisomerase I (TOPI); v) phosphoglycerate kinase (PGK); vi) hypothetical protein LNS2; and vii) alternative sections of TEF1 alpha. Results showed that several gene sections are accessible to universal primers (or primers universal for phyla) yielding a single PCR-product. Barcode gap and multi-dimensional scaling analyses revealed that some of the tested candidate markers have universal properties providing adequate infra- and inter-specific variation that make them attractive barcodes for species identification. Among these gene sections, a novel high fidelity primer pair for TEF1 alpha, already widely used as a phylogenetic marker in mycology, has potential as a supplementary DNA barcode with superior resolution to ITS. Both TOPI and PGK show promise for the Ascomycota, while TOPI and LNS2 are attractive for the Pucciniomycotina, for which universal primers for ribosomal subunits often fail

Patterns of evolution in Ochroconis, a potential neurotroph

Ochroconis was one of numerous orphan-fungal groups in Hyphomycetes. Phylogenetic taxonomy using multi-gene analysis (nuLSU, nuSSU, mtSSU and RPB2) found that Ochroconis species were clustered within Sympoventuriaceae, Venturiales, Dothideomycetes. Species recognition by genealogical concordance concept using multi-gene analysis (nuSSU, ITS, nuLSU, ACT1, BT2 and TEF1) revealed that all investigated Ochroconis species were recognized and classified into two genera viz. Ochroconis (mesophile) and Verruconis (thermo-tolerant). Ochroconis consists of twenty two species viz. O. anellii, O. anomala, O. bacilliformis, O. constricta, O. cordanae, O. crassihumicola, O. gamsii, O. globalis, O. humicola, O. icarus, O. lascauxensis, O. longiphora, O. macrozamiae, O. minima, O. musae (mirabilis), O. olivacea, O. phaeophora, O. robusta, O. ramosa, O. sexualis, O. tshawytschae and O. verrucosa, and Verruconis consists of three species viz. V. calidifluminalis, V. gallopava and V. verruculosa. The thermo-tolerant and mesophilic species seemed to have specific pathological characters and antifungal susceptibility profiles. The phylogeny investigation also yielded remarkable results of re-identification of clinical strains, the best DNA barcoding candidate (ACT1) and the phylogenetically reliable markers (SSU, LSU and ITS). Furthermore, in ribosomal gene analyses of Ochroconis and Verruconis found that substitution pattern was carried on in accelerated rate, with transition bias at high divergent level and without the bias at the specific level

Ochroconis calidifluminalis, a Sibling of the Neurotropic Pathogen O. gallopava, Isolated from Hot Spring

Two strains resembling the neurotropic fungus Ochroconis gallopava were isolated from hot spring river water (IFM 54738 and IFM 54739). The isolates showed optimal growth at 42A degrees C, while the maximum growth temperature was 49A degrees C, thus having temperature relationships similar to those of O. gallopava. Colonies were light olive green, with a color change to dark reddish brown after several passages, which was also observed in O. gallopava. Conidia were indistinguishable from those of O. gallopava. The antifungal susceptibility profile of the isolates was also similar to that of O. gallopava, except for a lower susceptibility to micafungin. The two isolates had 100% homologous rRNA genes including the internal transcribed spacer (ITS) region and the D1/D2 region of the large subunit. The gene fragments, as O. gallopava, could be amplified with species-specific rDNA primers, and loop-mediated isothermal amplification designed for O. gallopava yielded positive results in the two isolates. However, homologies with O. gallopava in ITS and D1/D2 regions were 79.2 and 95.9%, respectively, widely exceeding generally accepted species boundaries. These differences were corroborated in virulence tested in experimental infection. The two isolates did not kill a mouse even until 28 days. However, mortalities of four O. gallopava strains ranged from 40 to 100%. The new isolates mainly affected the kidneys; whereas O. gallopava had a strong preference for the brain. We therefore propose a new species, Ochroconis calidifluminalis, for the two isolates

A multigene phylogeny reveals that Ochroconis belongs to the family Sympoventuriaceae (Venturiales, Dothideomycetes)

Ochroconis is a genus of ascomycete fungi that includes oligotrophic saprobes and some opportunistic species causing infections in vertebrates. The most important of these opportunists is the neurotropic species Ochroconis gallopava, which occurs in birds and occasionally in immunocompromised humans. Other Ochroconis species have been isolated from superficial infections of cats, dogs and fish. In their natural environment, these species are found in litter, soil, and on moist surfaces. Some thermophilic species have been isolated from hot springs, industrial effluents, and self-heated plant material. Although their ecology and epidemiology has been investigated, their classification within the ascomycetes is still unknown. Here, the phylogenetic placement of Ochroconis is investigated using a four-gene phylogeny (nuLSU, nuSSU, mtSSU and RPB2). The results show that Ochroconis and its recently described sister genus Verruconis belong to the order Venturiales (Dothideomycetes) and are nested within the Sympoventuriaceae, a family recently erected for a group of plant-saprobes or -pathogens sister to the Venturiaceae. They form a well-supported monophyletic group together with five species of the anamorphic genus Fusicladium isolated from leaf and needle litters

First report of subcutaneous phaeohyphomycosis caused by Ochroconis tshawytschae in an immunocompetent patient

We report the first case and clinical course of a case of human subcutaneous phaeohyphomycosis caused by Ochroconis tshawytschae, a rare fish pathogen. The diagnosis was based upon histopathological and mycological examinations of clinical samples. Identification of the etiologic agent was assessed on its phenotypic characteristics and subsequently, confirmed by molecular data. In vitro antifungal susceptibility of the isolate was investigated and a comparison was prepared of all of its features to those of its two most relevant related species, O. gallopava and O. humicola