Salivary gland antigens of laboratory-bred Phlebotomus sergenti and their immunogenicity in human volunteers in laboratory condition

To investigate Phlebotomus (P.) sergenti Parrot, 1917 (Diptera: Psychodidae) salivary gland antigens and their immune response in human. Methods: Human volunteers were exposed to sand flies' bites in the laboratory, and following each exposure the size of induration was recorded. The mean protein concentration of salivary gland lysate and specific anti-P. sergenti saliva IgG was measured. Sand fly salivary proteins were separated by SDS-PAGE and their immunoreactivity was examined by Western blotting assays. Results: Individuals exposed to P. sergenti salivary gland lysate for 8 months showed both antibody and delayed type hypersensitivity responses, although exposure for one month did not provoke any immune responses. The trend of antibody fluctuated during the exposure time and dropped by the end of antigen loading. The mean protein content was (0.36?0.08) ug in each pair salivary glands. Salivary gland lysate showed 11 to 12 major protein bands and 3 to 6 of them were immunoreactive. Conclusions: Our study showed that the salivary gland components of P. sergenti provoked both cellular and humoral immune responses in human. Furthermore, there are some immunogenic proteins in P. sergenti saliva which could be subjected for further investigation as vector-based vaccine candidate/s against anthroponotic cutaneous leishmaniasis.

Morphometric discrimination between females of two isomorphic sand fly species, Phlebotomus caucasicus and Phlebotomus mongolensis (Diptera: Phlebotominae) in endemic and non-endemic foci of zoonotic cutaneous leishmaniasis in Iran

Objective: To delineate reliable morphological characteristics for identifying and separating female Phlebotomus caucasicus and Phlebotomus mongolensis which exist sympatrically in the main foci of zoonotic cutaneous leishmaniasis in Iran. Methods: Sand flies were collected using sticky trap papers from active colonies of rodent burrows installed from 16 catching sites. Morphometric measurements were analyzed of 87 Phlebotomus caucasicus and 156 Phlebotomus mongolensis. Univariate and multivariate analysis were carried out to determine significant morphometric variables for discrimination of the two species. Finally, seven morphological characteristics of 65 female Phlebotomus caucasicus and 124 female Phlebotomus mongolensis were described. Results: Univariate and multivariate analyses of 10 morphometric variables via Discriminant Function Analysis (DFA) and Principal Component Analysis (PCA) showed that five morphometric variables had an accuracy of 100% for discriminating female Phlebotomus caucasicus and Phlebotomus mongolensis. Moreover, PCA revealed that the five morphometric variables with the highest loadings separated these two species. Morphological studies on antennal flagellum (and its associated structures) and mouth-parts of female specimens demonstrated significant differences in several structures. Conclusions: The results show that morphological and morphometrical features can be used to discriminate two female isomorphic species, Phlebotomus caucasicus and Phlebotomus mongolensis accurately.