Cytocidal effects of Bacillus thuringiensis crystal protein against Leishmaniatropica

Leishmaniasis is an infectious disease that is caused by an obligate intracellular parasite which belongs to genus Leishmania, order Kinetoplastida. Using bio-microbial control agents as one of the alternative therapies for leishmaniasis infections has been developed. The aim of this study was to assess Bacillus thuringiensis crystal protein effects against Leishmania tropica parasite.

In this cross-sectional descriptive study, 47 B. thuringiensis isolates from soil samples in different regions of Fars province were collected based on the phenotypic characteristic, crystal toxin staining, and molecular identification. After enzyme digestion of toxin isolates using Proteinase K, their cytocidal effects on L. tropica were analyzed. The isolates with the most toxicity effect were identified by PCR.

Our results identified one isolate with the most cytocidal effect on L. tropica. The sb35 isolate crystalline toxin (Cry1) was the most effective toxin on Leishmania, showing the highest cytocidal effect (about 40%) at the concentration of 10-1 mg/ml. Cytopathic effects of promastigote treatment with crystallized toxins were observed as shrinking and inflammation.

Considering the results obtained in this study, using crystallized proteins of B. thuringiensis can be considered as an appropriate candidate for treating leishmaniasis by performing complementary studies