Nigrospora oryzae Pulmonary Infection in a Bronchogenic Cancer: an Opportunistic Invader?

Abstract

The genus Nigrospora is a cosmopolitan dematiaceous ascomycetes fungus which inhabits the soil and includes both entomopathogenic and phytopathogenic properties. Among the evolving species of Nigrospora, the frequently isolated are Nigrospora sphaerica (N. sphaerica) and Nigrospora oryzae (N. oryzae). N. sphaerica has been implicated in human infections like corneal ulcer, onychomycosis, respiratory allergies, deep mycoses, and skin infections in both immunocompetent and immunocompromised individuals, whereas N. oryzae is an established plant pathogen and the only reported human association is its isolation from human superficial skin scrapings. Here, we report a case of pulmonary infection by N. oryzae in a 55-year-old male with a neoplasm of squamous cell origin and diffuse skeletal metastasis. Bronchoalveolar lavage and biopsies of lung tissue demonstrated branching septate hyphae and extensive tumor necrosis and malignant cells, respectively. Fungal culture and molecular sequencing established N. oryzae as the etiological agent. The patient was treated with itraconazole and palliative radiotherapy. Due to the poor compliance and unfavorable effects of treatments, the patient opted for alternative therapies and succumbed due to ongoing invasive pathogenesis. To the best of our knowledge, this is the first communication describing a dematiaceous mold N. oryzae causing opportunistic pulmonary infection in a lung neoplasm along with antifungal susceptibility data against seven antifungal drugs using the reference CLSI method.