Discovery of a sexual stage in Trichophyton onychocola, a presumed geophilic dermatophyte isolated from toenails of patients with a history of T. rubrum onychomycosis.

Trichophyton onychocola is a recently described geophilic dermatophyte that has been isolated from a toenail of Czech patient with a history of onychomycosis due to T. rubrum and clinical suspicion of relapse. In this study, we report a similar case from Denmark in an otherwise healthy 56-year-old man. The patient had a history of great toenail infection caused by T. rubrum in 2004 and presented with suspected relapse in 2011 and 2013. Trichophyton onychocola was the only microbial agent isolated at the second visit in 2013 and the identification was confirmed by DNA sequencing. Direct microscopic nail examination was positive for hyphae, however the etiological significance of T. onychocola was not supported by repeated isolation of the fungus. This new species may be an overlooked geophilic species due to the resemblance to some common species, for example, zoophilic T. interdigitale or some species of geophilic dermatophytes. We included differential diagnosis with phenotypically similar species; however, it is recommended that molecular methods are used for correct identification. The MAT locus of Danish strain was of opposite mating type than in the previously isolated Czech strain and the two isolates were successfully mated. The mating experiments with related heterothallic species T. thuringiense and Arthroderma melis were negative. The sexual state showed all typical signs of arthroderma-morph and is described by using optical as well as scanning electron microscopy. The sexual state was induced on a set of agar media, however low cultivation temperature and the presence of keratin source were crucial for the success rather than formulation of medium.

Aspergillus pragensis sp. nov. discovered during molecular reidentification of clinical isolates belonging to Aspergillus section Candidi.

The identity of nine clinical isolates recovered from Czech patients and presumptively identified as Aspergillus sp. section Candidi based on colony morphology was revised using sequences of ß-tubulin, calmodulin gene sequence, and internal transcribed spacer rDNA. Six isolates were from suspected and proven onychomycosis, one from otitis externa, and two associated with probable invasive aspergillosis. The results showed that one Aspergillus candidus isolate was the cause of otitis externa, and both isolates obtained from sputa of patients with probable invasive aspergillosis were reidentified as A. carneus (sect. Terrei) and A. flavus (sect. Flavi). Three isolates from nail scrapings were identified as A. tritici, a verified agent of nondermatophyte onychomycosis. One isolate from toenail was determined to be A. candidus and the two isolates belonged to a hitherto undescribed species, Aspergillus pragensis sp. nov. This species is well supported by phylogenetic analysis based on ß-tubulin and calmodulin gene and is distinguishable from other members of sect. Candidi by red-brown reverse on malt extract agar, slow growth on Czapek-Dox agar and inability to grow at 37°C. A secondary metabolite analysis was also provided with comparison of metabolite spectrum to other species. Section Candidi now encompasses five species for which a dichotomous key based on colony characteristics is provided. All clinical isolates were tested for susceptibilities to selected antifungal agents using the Etest and disc diffusion method. Overall sect. Candidi members are highly susceptible to common antifungals.

Trichophyton onychocola sp. nov. isolated from human nail.

A previously undescribed Trichophyton species was isolated from the nail of a 33-year-old man with a history of probable distal lateral subungual onychomycosis (without confirmation by mycological examination). The infection occurred for the first time five years earlier (in 2006) and affected the right great toenail, with complete clinical remission after treatment with ciclopirox olamine. This undescribed species was isolated during probable relapse in 2011, but its etiological significance was not confirmed, that is, direct microscopy was negative and additional clinical samples were not collected. The species is probably geophilic based on phylogenetic analysis (internal transcribed spacer [ITS] rDNA) and is most closely related to the anamorphic T. thuringiense, homothallic Arthroderma ciferrii (anamorph T. georgiae), and heterothallic A. melis. The new species is characterized by yellowish colonies, red reverse on several media, positive urease test, negative hair-perforation test, absence of growth at 34°C, absence of macroconidia, formation of one-celled clavate microconidia, and spiral hyphae. The species grows well on sterilized human hairs placed on agar medium without any additional nutrients and forms gymnothecium-like structures covered by peridial hyphae. The combination of unique micro- and macromorphological features and physiological and sequence data from four unlinked loci (ITS, benA, RPB2, and act1 gene) justified the proposal of a new species T. onychocola sp. nov.

Auxarthron ostraviense sp. nov., and A. umbrinum associated with non-dermatophytic onychomycosis.

Auxarthron is a genus within the Onygenales encompassing keratinophilic species with typical ascomata (gymnothecia) consisting of anastomosing network of thick-walled hyphae and small globose or oblate ascospores. No association of this genus with clinically relevant cases of human or animal infection has been reported. This paper describes the isolation of an undescribed Auxarthron species as an agent of proven onychomycosis affecting almost all fingernails in a man with psoriasis. The causality of the isolated fungus was verified by repeated sampling and direct microscopy revealing irregular septate hyphae. Based on micro- and macromorphological features and unique sequence data (ITS region, benA and RPB2 gene), the isolated fungus is proposed as the new species A. ostraviense. The sibling species of A. ostraviense, A. umbrinum, was isolated from three patients with suspected onychomycosis and a detailed clinical history is provided for one of these patients. All four isolates were tested for susceptibility to selected antifungal agents. Terbinafine and clotrimazole appear to be effective in vitro. The morphological identification of Auxarthron spp. is non-trivial, time-consuming and requires cultivation media other than Sabouraud glucose agar which is routinely used in dermatomycology.

Rare and new etiological agents revealed among 178 clinical Aspergillus strains obtained from Czech patients and characterized by molecular sequencing.

A collection of 178 Aspergillus isolates, recovered from Czech patients, mostly from 2007-2011, was subjected to multilocus DNA sequence typing using the ITS region, ß-tubulin, and calmodulin genes. An unusually wide spectrum of etiologic agents that included 36 species of Aspergillus is discussed in the context of recent taxonomic and clinical reports. Invasive aspergillosis (IA), onychomycosis, and otitis externa were the predominant clinical entities. Five cases due to species newly proven as etiologic agents of human mycoses, as well as cases with unique clinical manifestations caused by unusual agents are discussed in more detail. Three species (i.e., A. insulicola, A. westerdijkiae and A. tritici) were identified as the confirmed etiologic agents of non-dermatophytic onychomycosis. Emericella rugulosa was recovered from a premature newborn with a fatal necrotising disseminated infection and is reported for only the second time as the cause of IA. Furthermore, we document the first infection due to A. calidoustus in a patient with chronic granulomatous disease. The infection manifested as a latent brain aspergilloma with an unusual clinical-laboratory finding. In addition to the well-known agents of human mycosis, several rarely isolated or poorly documented species were identified. An undescribed cryptic species related to A. versicolor was found to be common among isolates linked to proven and probable onychomycosis. An isolate representing A. fresenii, or an unnamed sister species, were causal agents of otomycosis. Three well defined, and tentative new species belonging to section Cervini, Candidi and Aspergillus (Eurotium spp.), were associated with cases of probable onychomycosis.

[Fusarium as a cause of onychomycosis resistant to common antifungal therapy]. / Fusarium jako puvodce onychomykozy rezistentni k bezne antimykoticke terapii.

INTRODUCTION: Fusarium species are common soil saprophytes and plant pathogens. Members of the genus have been frequently reported as etiologic agents of opportunistic infections in humans and animals. We report six cases of confirmed or suspected onychomycosis caused by members of the genus Fusarium (F. solani and F. oxysporum species complexes). MATERIAL AND METHODS: The isolates were identified by rDNA ITS sequencing analysis. The EMBL accession numbers for the ITS are HE974453-HE974458. A disk diffusion method was used for in vitro susceptibility testing. Comparison of disks (ITEST) and Neo-Sensitabs tablets (Rosco) on a different media at two different temperatures (25 °C and 35 °C) was made. RESULTS: Six strains of Fusarium spp. (4 strains of F. solani and 2 strains of F. oxysporum) were isolated from patients with confirmed or suspected onychomycosis. Natamycin (pimaricin) was the only antifungal effective in vitro in all isolates tested. Variable susceptibility of the isolates was detected in amphotericin B, econazole and terbinafine. The remaining antifungals tested were not effective. The results varied depending on the culture medium and temperature for nystatin and econazole disks and amphotericin B and terbinafin tablets. CONCLUSION: It is important to adhere to recommended methods when testing in vitro susceptibility to antifungals in moulds. An incubation temperature of 35 °C is important for obtaining valid results in amphotericin B tablets (and probably also terbinafine ones). Determination of multidrug-resistant Fusarium spp. in onychomycosis make the choice of therapy difficult. Good clinical effect was recorded with nail plate ablation and subsequent local econazole therapy.

Phaeohyphomycosis and onychomycosis due to Chaetomium spp., including the first report of Chaetomium brasiliense infection.

Chaetomium species have been rarely described as aetiological agents of invasive and dermatomycotic infections in humans. The majority of cases have been reported within the last two decades. Treatment failed in most of these cases. In this paper we present two cases in which Chaetomium spp. can be clearly identified as an aetiological agent in pathological conditions. In the first report, we describe a new aetiological agent, Chaetomium brasiliense, which was implicated in a case of otitis externa in a patient with spinocellular carcinoma basis cranii. The patient had been repeatedly treated for relapsing otitis externa and had previously undergone surgery several times for otitis media. The fungal aetiology was confirmed by repeated positive culture and histologic studies. The second case involved onychomycosis with strikingly brown nail discoloration due to Chaetomium globosum in an otherwise healthy patient. The nail lesion was successfully cured by oral terbinafine. The determination of both species was supported by sequencing of rDNA regions. The morphological aspect of Chaetomium spp. identification is also discussed. In vitro antifungal susceptibility tests demonstrated that both isolates were susceptible to terbinafine and azole derivates except fluconazole. Amphotericin B was effective only against the C. brasiliense strain. We review the literature to summarize clinical presentations, histologic findings, and treatment strategies.

[Tinea capitis - a recurring problem]. / Tinea capitis - starronový problém.

In the first quarter of the 20th century, tinea capitis represented the most important dermatomycological diagnosis in Europe. For its significant social impacts (affecting children, potential permanent disfiguration), developed countries introduced strict anti-epidemic measures which, together with the discovery of griseofulvin in 1960, contributed to nearly complete eradication of the disease in Central Europe. Since 1980s, however, the incidence of tinea capitis has increased to become a serious medical problem both in America and in some parts of Europe. In the Czech Republic, as well as in the neighbouring countries, the main causative agent remains the zoophilic Microsporum canis. The main agent in the USA, the anthropophilic Trichophyton tonsurans, slowly migrates to the British Isles and Western Europe. Moreover, Trichophyton rubrum is a newly emerging pathogen. Because of different biological behaviour of the individual pathogens, both therapeutic approaches and preventive hygiene measures vary.