In vitro cultivation of axenic amastigotes and the comparison of antioxidant enzymes at different stages of Leishmania tropica

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.

Comparison of three methods for diagnosis of cutaneous leishmaniasis.

BACKGROUND: Leishmaniasis is one of the infectious parasitic diseases of highest incidence in the world. Cutaneous Leishmaniasis (CL) has long been reported in Shiraz, Southern Iran. There is a need to find a sensitive and specific method for treatment and control of the disease. METHODS: We have compared the sensitivity of the conventional methods microscopy and cultivation of lesion scrapes against PCR amplification of parasite kinetoplast DNA from these samples. The samples (n=219) were obtained from the patients clinically suspected of CL. The smears were stained with Giemsa for microscopy and cultured in Novy-Nicolle-McNeal (NNN) blood agar for promastigote growth. For PCR, the dry smears were scraped off the slides and DNA was extracted. RESULTS: The positive rates from 219 specimens were 76.71%, 50.68%, and 93.61% for microscopy, cultivation, and PCR, respectively. The highest correlation was found between PCR and microscopy method (P=0.014). In PCR assay, 95.61%, 3.9%, and 0.49% of the samples were identified as Leishmania major, L. tropica, and dermatropic L. infantum, respectively. CONCLUSION: The PCR method appears to be the most sensitive for the diagnosis of CL and is valuable for identifying the other species of Leishmania with confusing dermatropic signs.

Chrysomya bezziana as a Causative Agent of Human Myiasis in Fars Province, Southern Iran.

Myiasis is the invasion of body tissues of humans or animals by the larvae of the Diptera or two-winged flies. The various forms of myiasis may be classified from clinical or entomological point. This study describes the existence of Chrysomya bezziana (Diptera: Calliphoridae) cases as a causative agent of myiasis in 18 and 87 year-old men in two different regions in Fars Province. To our knowledge, this is the first observation of mentioned species in this province.

Characterization of Leishmania isolated from unhealed lesions caused by leishmanization

Leishmania parasites were isolated after 13 and 8 years from the unhealed lesions of 2 soldiers who had been immunized against leishmaniasis during the war between Iraq and the Islamic Republic of Iran. Isoenzyme characterization on these isolates using 11 enzyme systems was carried out and the results were compared with the enzyme profiles of the original isolates of L. major used for leishmanization. Minor enzymatic differences in glucose-6-phosphate dehyrognase and phosphoglucomutase were observed but otherwise the strains appeared unchanged