Pythium insidiosumkeratitis confirmed by DNA sequence analysis

Other characteristics consistent with this identification were colony morphology, optimal temperature of growth (35°C), hyphal diameter (4-6 mm), intercalary swellings in viable hyphae, vesicles at the end of spore discharge tubes, and spores germinating by means of germ tubes. 3 To confirm the identification, the internal transcribed spacer (ITS) region defined by primers TW81 and AB28 (incorporating ITS1, the 5.8S gene and ITS2) was amplified. A number of cases of human pythiosis have been reported, mostly subcutaneous infections and arteritis in thalassaemic patients in farming communities of South East Asia. 6 With respect to the eye, P insidiosum has been responsible for periorbital infections in Australia 7 and the USA 8 and corneal ulcers in Thailand, 6 Haiti, 9 and New Zealand. 10 Some patients have had no other medical history.