The present study aimed to establish a simple method to yield large amounts of Leishmania tropica amastigote-like forms in axenic cultures and to compare the superoxide dismutase (SOD) and glutathione peroxidase (GPX) enzymes at different stages of L. tropica. Different culture conditions were tested to find the optimum condition of axenic amastigotes generation. Superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities were determined at logarithmic and stationary phases and axenic amastigote stage of the parasite. A high proportion (88%) of amastigote-like forms of L. tropica was observed in BHI medium supplemented with 20% FCS, pH 4.5, and incubated at 37ºC with 5% CO2. The results showed that SOD activity was at the lowest level in the logarithmic phase of promastigotes and increased towards the stationary phase of promastigotes and amastigote stage. The results showed that the optimum condition for differentiation of L. tropica promastigotes to axenic amastigotes was BHI medium containing 20% FCS at pH 4.5, incubated at 37ºC in the presence of 5% CO2. It seems that SOD, but not GPX is a major determinant of intracellular survival of the parasite.

Cryptosporidiosis is a zoonotic protozoan disease of worldwide distribution, affecting a wide range of vertebrate hosts. Most data on the biology, distribution pattern, pathology and prevalence of cryptosporidial infection in farm animals is restricted to cattle, sheep and goats. Limited data is available in other domestic herbivores including camel. Numerous camels (Camelus dromedarius) are raised in the semi-arid regions of Iran. Although camel is acknowledged as a potential source of contamination, little is known with regards to the prevalence of Cryptosporidium in this population except a case report on the occurrence of this infection in a bactrian camel (Camelus bactrianus) in China. This investigation was undertaken to determine the prevalence of Cryptosporidium infection in camels (C. dromedarius) from Najaf-Abad slaughterhouse, Isfahan Province, central part of Iran. Out of 103 faecal samples from 63 adult males and 40 adult females, 2-14 years old, 39 (37.9%) were found positive for oocysts. No significant differences were observed between males and females, and among different age groups. There was also no significant difference among infection intensity in different age groups. This is the first report of Cryptosporidium infection in camels from this country.