Immunological separation of Entomophthorales genera

Human Pathogenic Entomophthorales

The pathogenic entomophthoralean fungi cause infection in insects and mammalian hosts. Basidiobolus and Conidiobolus species can be found in soil and insect, reptile, and amphibian droppings in tropical and subtropical areas. The life cycles of these fungi occur in these environments where infecting sticky conidia are developed. The infection is acquired by insect bite or contact with contaminated environments through open skin. Conidiobolus coronatus typically causes chronic rhinofacial disease in immunocompetent hosts, whereas some Conidiobolus species can be found in immunocompromised patients. Basidiobolus ranarum infection is restricted to subcutaneous tissues but may be involved in intestinal and disseminated infections. Its early diagnosis remains challenging due to clinical similarities to other intestinal diseases. Infected tissues characteristically display eosinophilic granulomas with the Splendore-Höeppli phenomenon. However, in immunocompromised patients, the above-mentioned inflammatory reaction is absent. Laboratory diagnosis includes wet mount, culture serological assays, and molecular methodologies. The management of entomophthoralean fungi relies on traditional antifungal therapies, such as potassium iodide (KI), amphotericin B, itraconazole, and ketoconazole, and surgery. These species are intrinsically resistant to some antifungals, prompting physicians to experiment with combinations of therapies. Research is needed to investigate the immunology of entomophthoralean fungi in infected hosts. The absence of an animal model and lack of funding severely limit research on these fungi.

Rhinoentomophthoromycosis due to Conidiobolus coronatus. A case report and an overview of the disease in India

Rhinoentomophthoromycosis due to Conidiobolus coronatus is a rare, chronic, granulomatous disease, occurring mainly in tropical Africa, South and Central America and south-east Asia, including India. We report a case of rhinoentomophthoromycosis in a 30-year-old male farmer, a resident of Gorakhpur city in Uttar Pradesh, which was diagnosed by histopathology and isolation C. coronatus in culture. The patient presented with a swollen nose with obstruction that had progressed slowly over one year. His nasal swelling was bilateral, diffuse, mildly tender, erythematous, non-pitting, with mucosal crusting and hypertrophy of inferior turbinates but no regional lympha-denopathy. A contrast-enhanced computed tomography (CECT) scan revealed bilateral pan-sinusitis with nasoethmoid polyposis. Culture of tissue from the nasal biopsy on Sabouraud glucose agar yielded multiple colonies of a mold with satellite smaller colonies at periphery. The isolate demonstrated the macroscopic and microscopic morphologic characteristics of C. coronatus. Its identity was further confirmed by direct DNA sequencing of internal transcribed spacer (ITS) and D1/D2 regions of rDNA. Haemotoxylin and eosin stained tissue sections of the skin biopsy revealed irregular epidermal acanthosis, marked inflammatory and granulomatous reaction with sparse, non-septate hyphae. The patient was treated successfully with a combination therapy of oral saturated potassium iodide solution, itraconazole, and intravenous infusion of amphotericin B. An overview of rhinoentomophthoromycosis cases reported to-date in India is presented.