Experimental effect of feeding on ricinus communis and bougainvillea glabra on the development of the sand fly phlebotomus papatasi [diptera: psychodidae] from Egypt

Plants are promising sources of agents useful for the control of vectors of human diseases including leishmaniasis. The effect of Ricinus communis [Euphorbiaceae] and Bougainvillea glabra [Nyctaginaceae] on transmission of leishmaniasis was investigated using them as diets for Phlebotomus papalasi to monitor their effect on life-history traits. P. papatasi were allowed to feed separately on both plants then offered a blood-meal. Fed-females were observed daily for egg-laying and subsequent developmental stages. P. papatasi was able to feed on B. glabra [29.41% females and 46.30% males] and R. communis [5.80% females and 10.43% males]. 34.28% of females died within 24-48 hours post-feeding on R. communis, whereas, it was 16.5% in females fed on B. glabra. Overall fecundity of surviving females was reduced compared to controls, reared on standard laboratory diet; however there was no effect on the sex ratio of progeny. Female P. papatasi in the control group had significantly longer life span compared to plant-fed group. Feeding on these plants not only decreased sand fly survival rates but incurred negative effects on fecundity. Findings indicate that planting high densities of R. communis and B. glabra in sand flies-endemic areas will reduce population sizes and reduce the risk of Leishmania major infections

Evaluation of preservation methods and simulated multiple infection on the fidelity of real-time PCR detection of Leishmania DNA

To detail the evaluation of a real-time polymerase chain reaction [PCR]-based approach to Leishmania detection. Also to test the fidelity of PCR diagnostics in a series of experiments mimicking infection by two species of Leishmania. Leishmania major [a causal agent of cutaneous leishmaniasis] infected Phlebotomus papatasi sandflies were generated to test the effect of four preservation methods on the fidelity of real-time PCR detection of Leishmania DNA. There was no effect of preservation methods on the sensitivity or specificity of two different assays. The ability of these assays to correctly diagnose cases of multiple infection was tested with artificial double infections created by combining DNA from pairs of Leishmania species [L, major, L. tropica and L, panamensis]. One assay failed to properly diagnose certain double infections but overall the PCR methodologies were robust. These findings provide important reassurances for subsequent real world investigations of Leishmania in vector, reservoir and human populations