21-year retrospective study of the prevalence of Scopulariopsis brevicaulis in patients suspected of superficial mycoses

Cutaneous Hyalohyphomycosis and Its Atypical Clinical Presentations in Immunosuppressed Patients

There has been a substantial increase in the number of cases of invasive fungal infections worldwide, which is associated with a growing number of immunosuppressed patients and a rise in antifungal resistance. Some fungi that were previously considered harmless to humans have become emerging pathogens. One of them is Purpureocillium lilacinum, a ubiquitous filamentous fungus commonly found in the environment, especially in the air and soil. P. lilacinum belongs to a bigger group of hyaline fungi that cause hyalohyphomycosis, a fungal infection caused by fungi with colorless hyphae. Although this is a heterogeneous group of fungi, there are similarities regarding their ubiquity, ways of transmission, affected patients, and difficulties in diagnostics and treatment. In hyalohyphomycosis, the skin is one of the most affected organs, which is why the involvement of dermatologists is crucial for the initial assessment, since the timely recognition and early diagnosis of this condition can prevent life-threatening infections and death. In this review, we covered cutaneous hyalohyphomycosis caused by P. lilacinum and other fungi in the same group, including Fusarium, Penicilium, Scedosporium, Scopulariopsis, Acremonium, and Trichoderma genera.

Identification of Zoophilic Dermatophytes Using MALDI-TOF Mass Spectrometry

Dermatophytoses represent a major health burden in animals and man. Zoophilic dermatophytes usually show a high specificity to their original animal host but a zoonotic transmission is increasingly recorded. In humans, these infections elicit highly inflammatory skin lesions requiring prolonged therapy even in the immunocompetent patient. The correct identification of the causative agent is often crucial to initiate a targeted and effective therapy. To that end, matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) represents a promising tool. The objective of this study was to evaluate the reliability of species identification of zoophilic dermatophytes using MALDI-TOF MS. The investigation of isolates from veterinary clinical samples suspicious of dermatophytoses suggests a good MALDI-TOF MS based identification of the most common zoophilic dermatophyte Microsporum canis. Trichophyton (T.) spp. usually achieved scores only around the cutoff value for secure species identification because of a small number of reference spectra. Moreover, these results need to be interpreted with caution due to the close taxonomic relationship of dermatophytes being reflected in very similar spectra. In our study, the analysis of 50 clinical samples of hedgehogs revealed no correct identification using the provided databases, nor for zoophilic neither for geophilic causative agents. After DNA sequencing, adaptation of sample processing and an individual extension of the in-house database, acceptable identification scores were achieved (T. erinacei and Arthroderma spp., respectively). A score-oriented distance dendrogram revealed clustering of geophilic isolates of four different species of the genus Arthroderma and underlined the close relationship of the important zoophilic agents T. erinacei, T. verrucosum and T. benhamiae by forming a subclade within a larger cluster including different dermatophytes. Taken together, MALDI-TOF MS proofed suitable for the identification of zoophilic dermatophytes provided fresh cultures are used and the reference library was previously extended with spectra of laboratory-relevant species. Performing independent molecular methods, such as sequencing, is strongly recommended to substantiate the findings from morphologic and MALDI-TOF MS analyses, especially for uncommon causative agents.

Current knowledge on the etiology and epidemiology of Scopulariopsis infections

Scopulariopsis is a common fungus in the environment, characterized by its intrinsic resistance to the available antifungal drugs. Around 70 cases of infection by this fungus have been described in the literature. Pulmonary and disseminated infections are the most common and their treatment is difficult; therefore, very diverse approaches have been taken, with varied results. A successful outcome has been reported in only a few cases, generally attributed to a multitreatment strategy combining medical and surgical procedures that ultimately led to the resection of the infected tissue if possible, identification of the mould, and an aggressive long-term antifungal therapy. Although most of the infections are caused by Scopulariopsis brevicaulis, a few other species have also been linked to these cases, although molecular evidence has not been proven for all of them. On this basis, more knowledge on the epidemiology, presentation, diagnosis, treatment, and prognosis of these unusual infections would improve their management. This review aims to compile the current data on Scopulariopsis infections.

PCR-RFLP assays for species-specific identification of fungi belonging to Scopulariopsis and related genera

Fungi of the Scopulariopsis genus, commonly found in the environment, are opportunistic pathogens that can cause various types of human infections. So far, no efficient molecular method has been developed for species differentiation among Scopulariopsis and related genera. In order to advance this field, we have evaluated performance of polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assays, based on cytochrome c oxidase subunit 1 and β-tubulin genes. The assays resulted in 2-10 restriction patterns, depending on the gene amplified and restriction enzyme applied. Pooled analysis of the patterns allowed to propose an algorithm, that can be successfully used for an accurate species-specific identification of 21 species of the Scopulariopsis-like fungi.