Exogenous Scedosporium endophthalmitis in necrotizing anterior scleritis

F. Sánchez-Reus, M.A. Gil Arnal, N. Dominguez Agustin, Y. Gonzalez Atienza, R.M. Mocanu, M. Español Sabate, P. Coll Figa

Author address: 

Hospital Sant Pau, BARCELONA, Spain

Abstract: 

Objectives: To report a case of exogenous Scedosporium endophthalmitis in a patient with a surgically induced necrotizing anterior scleritis who underwent three scleral patch grafts. Case report: A 79-year-old woman presented with one-month history of ocular pain in her right eye without loss of visual acuity. Eighteen months prior to presentation she had undergone a bilateral pterygium excision. There was not other remarkable medical history. Ophthalmological examination with slit-lamp biomicroscopy showed a focal necrotic area in the nasal sclera of the right eye, no corneal infiltrates were present, no exudates in the anterior chamber were observed. Laboratory studies did not furnish evidence of any underlying autoimmune systemic disorder. Because of the necrotizing scleritis, a scleral patch graft was performed and topical and oral steroids started, but the graft failed within 1 month of surgery and a second scleral patch graft was needed and azathioprine added. However, the second patch graft failed again and a third scleral patch graft was carried out. Cyclophosphamide was added to the immunosuppressive therapy and oral voriconazole administrated for two weeks. Three months later, because of the progression of the illness, evisceration of the right eye was performed. Results: Microbiological cultures of the ocular samples collected during the three scleral grafting were negative and histopathological studies reported non-specific chronic inflammation and fibrosis. Pathologic sections of the eviscerated eye showed areas of acute and chronic inflammation with focal necrosis. Periodic acid-Schiff and Gomori methenamine silver stains revealed irregularly branched septate hyphae. Cultures of the eye samples revealed after 4 days the growth of numerous white cottony colonies that became brownish gray. Microscopic examination showed septate hyaline hyphae with brown ovoid unicellular conidia growing on a solitary conidiophore cell or laterally on hyphae. The fungus was morphologically identified as Scedosporium apiospermum, but sequence analysis of the ribosomal internal transcriber spacer region ITS1 and ITS2, showed a 99% homology with Pseudallescheria boydii (CBS 101724) and 98.6% with Scedosporium dehoogii (MUCL 20263). Discussion: Because recent molecular data have shown that the apparently single morphological species Pseudallescheria boydii includes eight different phylogenetic species and these species demonstrated different virulence in animals, morphological identification of these funguses will be confirmed by molecular methods, in order to know if the complex has different human virulence or antifungal resistance. The final characterization of our isolate needed the knowledge of the β -tubulin gene sequence. The probable final identification as S. dehoogii reinforces the experimental high virulence demonstrated for this species.
2009

abstract No: 

P157

Full conference title: 

4th Trends in Medical Mycology
    • TIMM 4th (2012)