Cutaneous Phaeohyphomycosis Caused by Alternaria alternata Unresponsive to Itraconazole Treatment

Unusual location of cutaneous alternariosis in an immunocompetent patient

Alternaria is a dematiaceous fungus ubiquitously found in nature. It can cause infections, especially in immunocompromised patients. We report a periorbital location of Alternaria infection in an immunocompetent woman with a confusing clinical presentation. The diagnosis was confirmed by a cutaneous biopsy of the cheek. PCR sequencing identified Aternaria alternata species. The evolution was fatal despite antifungal treatment.

Novel cases of cutaneous phaeohyphomycosis by Alternaria alstromeriae, Epicoccum tritici and Phialemonium obovatum from North India

BACKGROUND

A growing number of non-dermatophytic moulds and yeasts with the ability to act as human pathogens are reported every year. Dematiaceous fungi cause phaeohyphomycosis which encompasses a broad spectrum of diseases ranging from superficial (cutaneous and subcutaneous) to disseminated infections. Such fungal infections are responsible for causing significant morbidity and mortality, frequently in immunocompromised patients and rarely in immunocompetent patients.

OBJECTIVES

To investigate the prevalence of cutaneous mycosis in Jammu district (India) and to isolate and identify the recovered causal agents from the affected skin of the patients.

METHODS

For direct microscopy, 10% KOH was used. Skin samples were collected carefully from the affected areas of suspected patients, followed by the isolation and identification of the causal agents by cultural examination, morphological examination and ITS sequencing.

RESULTS

Herein, we report and describe three new cases of cutaneous phaeohyphomycosis from District Jammu of Union Territory Jammu and Kashmir, India. The age of the patients under study ranged from 17 to 42 years and the duration of infection from 1 to 2 years. The etiological agents that were recovered from the patients under study were Alternaria alstromeriae, Epicoccum tritici and Phialemonium obovatum. These dematiaceous fungal species were isolated from the skin specimen of immunocompetent hosts.

CONCLUSION

Among the three isolated etiological agents, two (Alternaria alstromeriae, Epicoccum tritici) represent new global records and one (Phialemonium obovatum) new record to India as causal agents of cutaneous phaeohyphomycosis. Careful microscopic and mycological examination form the basis of correct diagnosis of such fungal infections in the absence of simple and reliable laboratory tests (serologic or antigen tests).

Computational identification and antifungal bioassay reveals phytosterols as potential inhibitor of Alternaria arborescens

Alternaria arborescens is a major pathogen for crops like tomato, tangerine and so on and its control is mostly dependent on the application of chemical agents. Plants as the sources of natural products are very attractive option for developing eco-friendly and natural antifungal agents. In this study, we modeled three-dimensional structure of chorismate synthase (CS) enzyme from A. arborescens. Docking studies of phytosterols, namely, γ-sitosterol and β-sitosterol, with CS showed them to be potential inhibitor of CS. To explore the stability and conformational flexibility of all the AaCS complex systems, molecular dynamics simulations were performed. None of the putative inhibitors as well as β- and γ-sitosterol showed interaction with the FMNH₂ binding pocket of the tomato CS (major host of A. arborescens) indicating their suitability as antifungal compounds inhibiting the shikimate pathway without causing any harm to the host. An in vivo antifungal bioassay showed a significant reduction in fungal growth in the presence of β-sitosterol (500 ppm) which resulted in ∼23% and ∼17% reduction in fungal fresh and dry weight, respectively, at 8 days after inoculation. This study provides experimental evidence establishing natural sterols like β-sitosterol can be useful in curbing A. arborescens damage in an eco-friendly manner.Communicated by Ramaswamy H. Sarma.

Cutaneous infection by different Alternaria species in a liver transplant recipient

Fungal invasive infections are rare in general population but are an emergent cause of infection in the immunocompromized population, especially in the solid organ transplant recipients. Herein the authors report a clinical case of a liver transplanted patient suffering a cutaneous co-existent infection with A. alternata as well as A. infectoria.

To our knowledge this is the first case of cutaneous concomitant infection due to those two species reported not only in Portugal but also worldwide. The patient was treated with surgical excision of the lesions and oral itraconazol without relapse.