Indian Journal of Medical Microbiology Medknow Publications on behalf of Indian Association of Medical Microbiology ISSN: 0255-0857 EISSN: 1998-3646 Vol. 28, Num. 4, 2010, pp. 414-415

Indian Journal of Medical Microbiology, Vol. 28, No. 4, October-December, 2010, pp. 414-415

Correspondence

Keratomycosis due to Scedosporium apiospermum

R Nath¹, RN Gogoi², L Saikia¹

¹ Department of Microbiology, Assam Medical College and Hospital, Dibrugarh, India
² Department of Ophthalmology, Assam Medical College and Hospital, Dibrugarh, India
Correspondence Address:
R Nath, Department of Microbiology, Assam Medical College and Hospital, Dibrugarh, India
reema_44@rediff.com

Date of Submission: 25-Jan-2010
Date of Acceptance: 08-Jul-2010

Code Number: mb10126

PMID: 20966590
DOI: 10.4103/0255-0857.71811

Dear Editor,

Mycotic keratitis is an important ophthalmic problem in the developing world. Besides the common fungi Aspergillus and Fusarium,^[1] many more fungi are also being recognized as causes of keratomycosis, Scedosporium apiospermum is one of them. ^[2],[3],[4] Treatment of these keratomycosis cases is difficult due to resistance of this fungus to various antifungal agents. ^{[2],[3],[4],[5]} In this letter, we report two cases of keratomycosis by Scedosporium apiospermum.

A 48-year-old housewife came with an ulcer in the left cornea following a paddy leaf injury three months back. [Figure - 1].Visual acuity was perception of light positive in the affected eye. Slit-lamp biomicroscopic examination revealed a perforated paracentral circular corneal ulcer of 4 mm in diameter with anterior synechiae of the iris and a hypopyon (2 mm). Five percent natamycin at hourly interval for 7 days and at two-hourly interval thereafter for 15 days were already given without any response. Another 47-year-old patient, farmer, presented with an ulcer in the right central cornea following an injury by a paddy leaf 20 days back. The visual acuity of the right eye was finger counting positive at a distance of three metres. There was an irregular shaped superficial corneal ulcer with a 2 mm hypopyon. Corneal scrapings were inoculated into blood agar; Sabouraud's dextrose agar with chloramphenicol in a row of C-shaped streaks, directly examined with 10% potassium hydroxide (KOH), which revealed abundant septate hyaline hyphae with the characteristic ovoid conidia in the first case and abundant septate hyaline hyphae in the second case. Culture yielded growth of the same fungus in Sabouraud's dextrose agar as well as in blood agar in all the C-streaks [Figure - 2]a and b. In blood agar medium at 37°C, it showed good growth in 48 hours. No bacterial growth was detected. Identification was made from typical colonies growing after two days as well as slide culture in potato dextrose agar, which showed septate hyaline hyphae with numerous single-celled, pale-brown, broadly clavate to ovoid conidia [Figure - 3]. The culture was identified as Scedosporium apiospermum. The patients were put on itraconazole (1%) eye drops at hourly interval to start with for seven days and thereafter at two-hourly interval. Oral fluconazole 200 mg was given daily for two weeks and thereafter 150 mg daily for two weeks. Both the patients gradually responded. In the first patient, the ulcer healed with an opacity in six weeks but the visual acuity did not improve. The second patient responded with decrease of congestion and hypopyon decreased in size after 10 days of therapy. Visual acuity improved to 6/24 after eight weeks.

Azoles are often cited as agents of choice for this fungus. ^[5] Both our cases responded with decreased inflammation within 10 days with topical itraconazole and oral fluconazole. The treatment strategy varies in different case reports. Topical (1%) and oral voriconazole (200 mg/day) therapy proved to be efficacious in several reports with or without surgical intervention like debridement, keratectomy and penetrating keratoplasty. ^[4] Good response is also reported with debridement and amphotericin B therapy, in spite of in vitro resistance to amphotericin B, itraconazole, and ketoconazole. ^[4] Early identification of the species and cautious antifungal therapy depending on clinical response can be helpful in the treatment of unusual fungal keratitis cases like Scedosporium keratitis.

Acknowledgement

Authors acknowledge the financial grant by Indian Council of Medical Research for a study on microbial agents of corneal ulcers.

References

Copyright 2010 - Indian Journal of Medical Microbiology

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