Cunninghamella species are mainly soil fungi of the Mediterranean and subtropical zones, and less commonly found in temperate regions. The genus contains seven species. However, C.bertholletiae is the only species known to cause disease in man and animals.Cunninghamella is an opportunistic fungus seen to affect diabetics and immunocompromised individuals. It can present as rhinocerebral, pulmonary, cutaneoarticular or disseminated forms.
Literature review did not reveal any case report of Cunninghamella spinosum causing ocular involvement till date. We report a rare case of corneal ulcer caused by Cunninghamella spinosum.
A 54-year-old male presented with history of injury to the left eye with a stick 11 days ago. He complained of diminution of vision, pain, redness, watering and discharge from the left eye, five days after the injury. He was not a diabetic and there was no history suggestive of immunocompromised state. His visual acuity in left eye at presentation was hand movements. Anterior segment examination revealed a corneal ulcer with infiltrate measuring 7 × 8 mm involving central and paracentral zone of the cornea. [Figs. 1 and 2] There was no hypopyon, satellite lesions or endothelial plaque. Anterior chamber showed grade 3 reaction.
Corneal scrapings were done from the active edges of the ulcer and smears were sent for Gram stain, Giemsa stain and potassium hydroxide (KOH) mount. Material was also inoculated onto culture plates for bacterial, fungal and Acanthamoeba culture. Gram stain revealed the fungal hyphae [Fig. 3]. Sample sent for mycological processing and direct microscopy revealed broad hyaline, aseptate, branching, and filamentous fungi suggestive of zygomycete [Fig. 4]. Culture grew Cunninghamella spinosum.
The patient was started on G. Ciprofloxacin, Natamycin 5%, Fluconazole 0.3%, Atropine 1%and oral Ketoconazole 200 mg B.D. ×2 weeks. He was put on topical and systemic antiglaucoma medication for the management of secondary glaucoma. Patient was on regular follow-up and the ulcer healed well. His final best corrected visual acuity after 2 months was 6/36 in the left eye with macular grade corneal opacity [Fig. 5].
The genus Cunninghamella is characterized by white to gray, rapidly growing colonies, producing erect, straight, branching sporangiophores ending in globose or pyriform-shaped vesicles from which several one-celled, globose to ovoid, echinulate or smooth-walled swollen sporangiola attached by denticles develop.
C.bertholletiae causes infections in immunocompromised patients leading to devastating results and it is known to cause infection in the bone marrow transplant patients, pneumonia and mucormycosis.
We report this rare case of fungal corneal ulcer by this opportunistic fungus C. spinosum in a patient who was not immunocompromised. It is important to note that the species C.spinosum is not known to affect human race. Although most of the systemic conditions caused by this cunninghamella species are known to cause devastating results, our patient responded well to Natamycin and Azole antifungal agents.
1. Weitzman I, Crist MY. Studies with clinical isolates of Cunninghamella. I. Mating behaviour Mycologia. 1979;71:1024–33
2. Weitzman I, Crist MY. Studies with clinical isolates of Cunninghamella. II. Physiological and morphological studies Mycologia. 1980;72:661–9
3. Rippon JW. Mycosis: ZygomycosisMedical Mycology 19883rd Ed Philadelphia W.B.: Saunders Co
4. Garey KW, Pendland SL, Huynh VT, Bunch TH, Jensen GM, Pursell KJ. Cunninghamellabertholletiae infection in a bone marrow transplant patient: Amphotericin lung penetration, MIC determinations, and review of the literature Pharmacotherapy. 2001;21:855–60