Fungal keratitis due to Schizophyllum commune: an emerging pathogenic fungus

Abstract

Fungal keratitis due to Schizophyllum commune is very rare. In this study, we report the clinical and microbiological profile of five patients with fungal keratitis due to S. commune. Direct microscopic examination of corneal scrapings from all five patients showed septate branching hyaline fungal filaments. Similarly, in all five patients Sabouraud dextrose agar (SDA) plates inoculated with corneal scrapings showed white, cottony colonies on the second day of incubation. Lactophenol cotton blue stained wet preparation of 7-day-old colonies on SDA revealed clamp connections and no spores. The fungus was identified by its characteristic clamp connections, fan-shaped bracket fruiting body with pinkish-grey longitudinally split-radiating gills. The phenotypic identification of one of the five isolates further conformed by ITS sequencing. Treatment outcome was available for two of the five patients; in these two patients, the keratitis resolved with topical natamycin.

Eosinophilic plasmacytic conjunctivitis concurrent with gingival fistula caused by Schizophyllum commune in a captive cheetah (Acinonyx jubatus)

“…After the diagnosis of an S. commune infection, responses to antifungal drugs such as itraconazole and pimaricin (natamycin) are reportedly good in humans and animals [7] , [9] , [10] , [14] ; the present case also responded well to this treatment regimen, despite the animal's reaction to itraconazole. In the present case, signs of a return to estrus were apparent, and we repeatedly observed the cheetah rubbing her face against deadwood.…”

“…The characteristic associated clinical features include eosinophilic inflammation, allergic bronchopulmonary mycosis (ABPM) [2], [11], allergic fungal rhinosinusitis (AFRS) [12] and mucoid impaction of the bronchi (MIB) [3], [11]. Fungal keratitis has also recently been described [13], [14], and invasion of the lung, brain, and palate have been reported in both immunocompromised and immunocompetent patients [15].…”

“…Two were canine cases involving osteomyelitis [6] , [7] , one was a canine case involving subcutaneous granuloma and pneumonia [5] , and recently lethal systemic invasion of the eyes, lung, heart, and lymph node was described in a harbor seal [8] . There are some reports of good responses to antifungal drugs and/or corticosteroids in humans [9] , [10] , [12] , [14] and dogs [7] . However, it is very difficult to diagnose an S. commune infection because the clinical signs of ABPM are nonspecific; thus, differentiating the condition from other allergic diseases is problematic [16] .…”

Traumatic implantation keratitis caused by Schizophyllum commune in Central India

“…First case of S. commune was reported by Kligman et al in 1950 in a case of onychomycosis [ 8 ]. Since then, S. commune has been isolated from patients with pulmonary disease, atypical meningitis, cerebral abscess, and chronic sinusitis from different parts of the world but very few cases were reported as traumatic implantation keratitis [ 9 ]. Management of fungal keratitis largely involves a decision on which antifungal to use and the route of administration of antifungal drug.…”

Schizophyllum spp. in Covid-19- A Series of Ten Cases from a Tertiary Care Hospital of Central India.

“…This fungus is rarely reported in humans because it is difficult to diagnose in many clinical settings. It has been recognized as the etiological agent of a variety of hypersensitivity disorders, such as allergic sinusitis, bronchopulmonary mycoses, chronic eosinophilic pneumonia, and of invasive infections such as fatal disseminated infections involving the lungs, orbit, and brain [4,5].…”