16S rRNA PCR for differentiation of pathogenic and non-pathogenic leptospira isolates.

PURPOSE: To determine the risk factors, microbiological features, clinical features and other epidemiological characteristics of Nocardia keratitis seen at a tertiary eye care centre in south India. METHODS: We evaluated 31 patients with Nocardia keratitis seen over two years, from September 1999 to September 2001. Corneal scrapings were subjected to microscopy and culture using standard protocols. RESULTS: Out of 2184 corneal ulcers cultured, 31(1.42%) were found to be Nocardia asteroides. All 31(100%) were detected correctly by 10% potassium hydroxide wet mount preparation. The highest percentage of isolates was susceptible to gentamicin (100%) followed by ciprofloxacin(93.55%). Twenty four (77.42%) patients were from rural areas; 22(70.97%) were agricultural workers; 29(93.55%) had history of trauma; 2(6.45%) had previous ocular surgery; 28(90.32%) had ocular injury with soil and sand; and 22(70.97%) had ocular injury while working in the agricultural fields. Ten (32.26%) patients presented at our institute between 15 to 35 days of onset of illness, 26(83.87%) had previous medical treatment, and 15(48.39%) patients had used traditional eye medicines. The average age of the patients was 46.16 years, with a range of 11 to 75 years. No seasonal variation was observed. CONCLUSIONS: A high index of suspicion of Nocardia infection should exist in patients with a history of trauma to the eye by soil or sand. The organisms are sensitive to commonly used topical ocular antibiotics.