Vector-host-parasite inter-relationships in leishmaniasis. I. The effect of Leishmania parasites on rate of digestion of blood proteins from various vertebrate hosts by the sand fly Phlebotomus langeroni (Diptera: Psychodidae).

Protein digestion in the gut of Phlebotomus langeroni (Nitzulescu) was studied at four subsequent 24 hour intervals post feeding on human, dog (Canis familiaris), rat (Rattus rattus) and turkey (Melagris gallopava) bloods with and without Leishmania infantum or L. major promastigotes. Most of the proteins of the studied blood meals were digested within 96 hours. The percent of blood proteins digested in the first 48 hours was higher than in the second 48 hours in all cases of the studied blood meals except the normal blood of the turkey in which the ratio of the digested blood proteins in the two periods was 1:1. During the first 48 hours, the percent of the digested blood proteins was lower than normal in the presence of L. infantum in case of human and dog blood meals. The reverse was true in case of the rat and turkey blood meals in the presence of L. infantum and in the blood meals from each of the four vertebrate hosts in the presence of L. major. The significance of these findings in considering L. infantum as a natural parasite of P. langeroni in El Agamy focus was discussed.