Rapid Assays for Specific Detection of Fungi of Scopulariopsis and Microascus Genera and Scopulariopsis brevicaulis Species

Abstract

PurposeFungi of Scopulariopsis and Microascus genera cause a wide range of infections, with S. brevicaulis being the most prevalent aetiological agent of mould onychomycosis. Proper identification of these pathogens requires sporulating culture, which considerably delays the diagnosis. So far, sequencing of rDNA regions of clinical isolates has produced ambiguous results due to the lack of reference sequences in publicly available databases. Thus, there is a clear need for the development of new molecular methods that would provide simple, rapid and highly specific identification of Scopulariopsis and Microascus species. The objective of this study was to develop simple and fast assays based on PCR and real-time PCR for specific detection of fungi from Scopulariopsis and Microascus genera, and separately, S. brevicaulis species.MethodsOn the basis of alignment of β-tubulin gene sequences, Microascus/Scopulariopsis-specific primers were designed and S. brevicaulis-specific primers were reevaluated. DNA from cultured fungal isolates, extracted in a two-step procedure, was used in Microascus/Scopulariopsis-specific and S. brevicaulis-specific PCR and real-time PCR followed by electrophoresis or melting temperature analysis, respectively.ResultsThe specificity of the assays was confirmed, as positive results were obtained only for Scopulariopsis spp. and Microascus spp. isolates tested in Microascus/Scopulariopsis-specific assay, and only for S. brevicaulis and S. koningii (syn. S. brevicaulis) isolates in a S. brevicaulis-specific assay, respectively, and no positive results were obtained neither for other moulds, dermatophytes, yeast-like fungi, nor for human DNA.ConclusionsThe developed assays enable fast and unambiguous identification of Microascus spp. and Scopulariopsis spp. pathogens.

Rapid and Visual RPA-Cas12a Fluorescence Assay for Accurate Detection of Dermatophytes in Cats and Dogs

“…Additionally, it has been reported that for Wood’s lamp examination, only 50% of M. canis infections can be detected, while most other dermatophytes (such as T. mentagrophytes ) do not produce fluorescence [ 34 ]. Another common diagnostic method in clinical practice is a direct microscopic examination, which could be a simple and rapid way to screen for microconidia and hyphae, however, only >85% of cases can be accurately diagnosed [ 3 ]. Importantly, the professional requirements for the microscopic examination have high professional requirements.…”

“…Importantly, the professional requirements for the microscopic examination have high professional requirements. In addition, time-consuming and demanding (about 1–2 weeks) are two recognized disadvantages of fungal culture, which can delay the diagnostic outcome and treatment [ 3 ]. Molecular tools are increasingly used in the laboratory for fungal identification.…”

“…The most common dermatophytes in cats and dogs are Microsporum canis (zoophilic) and Trichophyton mentagrophytes (zoophilic and anthropophilic) [ 2 ]. In cats, 98% of dermatophytosis cases are caused by M. canis [ 3 ]. Dermatophytosis is transmitted by animal-to-animal or animal-to-environment contact with infectious substances (i.e., spores, hyphae) [ 2 ].…”

In Vitro Inhibiting Effects of Three Fungal Species on Eggs of Donkey Gastrointestinal Strongyles

“…Finally, S. brevicaulis is a keratinolytic and chitin-degrading mold widely distributed in the soil, plant materials, skin, and feathers [ 38 ]. It is considered a common contaminant species, but it can cause infections in humans, in which it may be responsible for endocarditis [ 39 ], onychomycosis [ 40 ], and keratitis [ 41 ].…”

Isolation of Scopulariopsis brevicaulis from Wistar Rats

“…belongs to the ascomycete family Microascaceae and is a ubiquitous, saprobic mold found worldwide in soil, plant debris, wood, paper, animal matter, air, and moist indoor environments (Abbott et al 1998;Anandan et al 2008). The genus Scopulariopsis, and predominantly S.brevicaulis, is known to be an opportunistic pathogen that is thought to cause invasive (immunocompetent and immunosuppressed patients) and noninvasive infections such as, onychomycosis, keratitis, conjunctivitis, endocarditis, and disseminated in animals and humans (Ragge et al 1990;Tosti et al 1996;Iwen et al 2012;Cawcutt et al 2015;Kordalewska et al 2016;Hampson et al 2019).…”