OMIG, Abstract 3
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Diagnosis of Microsporidial Keratitis by Polymerase Chain Reaction
G.A.K. Reddy1, P.K. Balne1, K Gaje1, P Garg2
1Jhaveri Microbiology Centre, Hyderabad Eye Research Foundation, L.V. Prasad Eye Institute, Hyderabad, India,
2Cornea and Anterior Segment Services, L.V. Prasad Eye Institute, Hyderabad, India.
Purpose: To evaluate the Polymerase Chain Reaction (PCR) for the diagnosis of microsporidial keratitis.
Methods: Thirty patients with microbial keratitis between June 2008 and December 2008 were included in the study. Corneal scrapings were collected for direct microscopic examination, culture and for microsporidial PCR. Primers for PCR was designed from small subunit rRNA of microsporidia (Forward: 5’ CACCAGGTTGATTCTGCC 3’ and reverse: 5’ GTGACGGGCGGTGTGTAC 3’). PCR was satnderdized using American Type Culture collection strains of E. hellem (ATCC 50504), E cuniculi (ATCC 50789), E. intestinalis (ATCC 50651) and Vittaforma corneae (ATCC 50505)
Results: PCR was positive for microsporidia in 10 of 30 patients and culture was negative for bacteria, fungi and Acanthamoeba in all the 10 patients. Microsporidial spores were detected by potassium hydroxide with calcoflour white preparation (KOH+CFW) in all the 10 patients (100%), by Gram stain in 5/7 (71.4%), by Giemsa stain in 1/2 (50 %) and by 1% acid fast stain in 7/8 (87.5%) patients. In the remaining 20 patients, 10 patients showed fungal growth, 8 patients showed bacterial growth and 2 patients showed Acanthamoeba growth and all these 20 patients were negative for microsporidial PCR.
Conclusions: PCR is highly sensitive for the diagnosis of keratitis caused by microsporidia.
Disclosure Code: N