Ungual hyalohyphomycosis caused by Fusarium proliferatum in an immunocompetent patient

Possibly the first case of onychomycosis by Fusarium lactis: Case presentation and literature review of onychomycosis by Fusarium species

Fusarium species (spp.) is frequently found in soil and plant residues and on plant bodies in all climatic zones worldwide. Although there have been few reports of onychomycosis caused by Fusarium spp., it is characterized by drug sensitivity and other characteristics. Here, we report what may be the first case of onychomycosis caused by Fusarium lactis. We analyzed the mycology and characterized previously reported cases of onychomycosis caused by Fusarium spp. A 73-year-old otherwise healthy woman presented with discoloration and thickening of her right thumbnail with paronychia. Direct microscopy revealed unevenly swollen hyphae, and a Grocott-stained nail specimen showed septate hyphae. Based on the morphological features and gene analysis of fungus isolated from the nail, we diagnosed onychomycosis caused by F. lactis belonging to Fusarium fujikuroi species complex. Partial nail removal and topical application of 1% luliconazole solution resolved the condition in 6 months. Minimum inhibitory concentrations for isolated F. lactis showed high sensitivity to luliconazole but not itraconazole or terbinafine. The isolated F. lactis was temperature-sensitive. A search of the literature revealed 57 cases of onychomycosis caused by Fusarium spp. with delineated clinical characteristics. Since those cases were investigated using morphological and/or molecular methods, we analyzed them by species complex as well as species. Onychomycosis caused by Fusarium spp. is predominantly found on the big toe, with Fusarium solani species complex and Fusarium oxysporum species complex accounting for over 70% of cases. Infection of only one digit with paronychia is a characteristic clinical manifestation of onychomycosis caused by Fusarium spp. Since there has been an increase in instances of molecular determination of Fusarium spp., it is deemed necessary to clarify its clinical and fungal nature. Due to its characteristic drug sensitivity and temperature-sensitive nature, new treatments are expected to be developed.

Detection of 2-ethyl-1-hexanol and its modulating effect in biofilm of Fusarium oxysporum

In immunocompetent individuals, Fusarium spp. stands out as the causative agent of onychomycosis, among the non-dermatophyte molds. Despite evidence indicating that Fusarium oxysporum organizes itself in the form of a biofilm causing onychomycosis, there is little literature on the etiopathogenesis of the biofilm on the nail, specifically the signaling molecules present, known as quorum sensing (QS). Thus, this study detected the presence of a molecule related to QS from the ex vivo biofilm of F. oxysporum on human nail and investigated its effect on preformed biofilm in vitro. The detection and physicochemical characterization of a QS molecule, from the extracellular matrix (ECM), was carried out by Fourier transform infrared (FTIR) spectroscopy with an attenuated total reflectance (ATR) accessory and by headspace gas chromatography coupled to mass spectrometry (GC-MS) analyses. Determination of viable cells, cell activity, total biomass, ECM components and scanning electron microscopy (SEM) were performed to evaluate the influence of the QS molecule on the in vitro biofilm of F. oxysporum. The beginning, in the ex vivo biofilm of F. oxysporum on human nails, the volatile organic compound 2-ethyl-1-hexanol (2EH) was detected as a component of QS. Thereafter in vitro analyses, synthetic 2EH was able to modulate the biofilm by stimulating its filament, increasing total biomass and ECM production in terms of total carbohydrates, but with a reduction in total proteins and nucleic acids. We thus evidence, for the first time, the presence of 2EH in the biofilm of F. oxysporum, developed on the human nail, and the in vitro action of this compound as a QS molecule.

A Case of Laying Hens Mycosis Caused by Fusarium proliferatum

In this article, we present the first case report of a chicken mycosis caused by F. proliferatum occurred on a private farm in the Russian Federation. Lesions on the skin of the legs and scallops were reported. The object of this study was samples of feed and pathological material from sick hens-layers. Mycological analysis included determination of the total number of fungi (TNF) and identification and determination of the toxicity and pathogenicity of the isolates. The identification of the isolate was carried out taking into account direct microscopy, morphological features, and the method of molecular genetic analysis. Microscopic fungi of the genus Penicillium and Rhizopus were isolated by mycological analysis of the feed. The test feed was nontoxic. Mycological examination of pathological material (scrapings from the combs and affected legs) identified an isolate of Fusarium proliferatum, which showed toxicity on biological objects (protozoa, rabbits) and pathogenicity (white mice). Dermal application of F. proliferatum suspension was accompanied by reddening of the rabbit skin. Intraperitoneal injection of fungal spores caused mycosis in white mice. Polymerase chain reaction (PCR) made it possible to identify this type of microscopic fungus (F. proliferatum) with high accuracy in the samples under study. The research results allow us to consider F. proliferatum as a cause of poultry disease against the background of predisposing factors in the form of desquamation of the stratum corneum of the skin against the background of immunosuppression and metabolic disorders caused by an imbalance in the diet.

Efficacy of Propolis Gel on Mature Biofilm Formed by Neocosmospora keratoplastica Isolated from Onychomycosis

This article describes Neocosmospora keratoplastica as an etiological onychomycosis agent. Ex vivo studies were initially performed to demonstrate the ability of this species to grow and form a well-organized characteristic biofilm on sterilized healthy nails. Based on the history of excellent results, both for antifungal and antibiofilm, of propolis resin gum, we evaluated its activity using artificially formed biofilm. In vitro, the minimal biofilm eradication concentration of the propolis extract (PE) was 375 µg of total polyphenol content (TPC) per mL, while for the propolis gel (PG) it was 450 µg of TPC per mL. In biofilm exposed to the propolis products, a decrease in hyphae and conidia was evident, accompanied by a disorganization of the extracellular matrix. Additionally, this low concentration of PE was able to significantly reduce the number of colony-forming units and the metabolic activity. Furthermore, the treatment of a 15-year nail infection due to N. keratoplastica was carried out exclusively using a topical treatment with a gel containing propolis (30%) with a daily dosage. This treatment achieved complete remission of the onychomycosis in 12 months. It is important to point out that some inconveniences previously reported by other patients treated with propolis extract were eliminated, increasing adherence to treatment.

Ungual hyalohyphomycosis caused by Fusarium cugenangense

Fusarium onychomycosis is uncommon in the temperate climate zone of Japan. Based on the morphological characteristics and a gene analysis, we diagnosed a patient with ungual hyalohyphomycosis caused by Fusarium cugenangense belonging to the F oxysporum complex. This intractable disease was cured by 6-month treatment with efinaconazole 10% solution.

Non-dermatophyte Mould Onychomycosis in Japan

The incidence of non-dermatophyte mould onychomycosis has been increasing worldwide for the past several decades, but it is not well recognized in Japan. Recent molecular techniques and phylogenetic analyses contributed to the identification of uncommon and emerging species. We came across 13 (0.5%) cases of non-dermatophyte onychomycosis among a total of 2,591 onychomycosis cases in 106,703 outpatients during the past 5 years (January 2015-December 2019). The cases included 5 patients with Aspergillus species, 4 patients with Fusarium species, and one patient each with Scopulariopsis brevicaulis and Botryosphaeria dothidea, respectively. Botryosphaeria dothidea is closely related phylogenetically to Neoscytalidium dimidiatum. In Japan, at the time of writing this report, there are 26 reported cases of ungual aspergillosis and 18 cases of hyalohyphomycosis caused by Fusarium species. We summarize these cases and report the symptoms and mycological features.

Epidemiological survey of onychomycosis pathogens in Japan by real-time PCR

In Japan, an epidemiological survey of onychomycosis pathogens was performed using culture methods; however, the positive culture rate was 40% or less. As part of an epidemiological survey of dermatomycoses in Japan, we overcame this low positive rate by employing a real-time polymerase chain reaction (PCR) assay that allowed rapid and accurate detection and identification. In 2011, nail specimens were collected from patients at nine institutes in various prefectures in Japan and diagnosed as onychomycosis. For the detection and identification of the main pathogens causing onychomycosis, we performed real-time PCR using specific TaqMan® MGB probes and primer sets. Of the 496 onychomycosis samples, real-time PCR detected 382 cases (77.0%) caused by Trichophyton rubrum; 74 cases (15.0%) caused by Trichophyton interdigitale; and eight cases (1.6%) caused by Candida albicans. The real-time PCR positive rate was 96.2%. The most frequent pathogen was T. rubrum throughout life, with the number of patients affected peaking in the range of 60 to 69 years of age and no significant differences in the composition of causative pathogens by sex. We were able to detect and identify pathogens from almost all specimens and succeeded in analyzing the pathogens involved in onychomycosis cases in Japan. These data confirmed that our real-time PCR method was effective for detecting and identifying the main fungal pathogens from onychomycosis specimens.