Experimental Susceptibility of Nyssomyia antunesi and Lutzomyia longipalpis (Psychodidae: Phlebotominae) to Leishmania ( Viannia ) lainsoni and L. ( V. ) lindenbergi (Trypanosomatidae: Leishmaniinae).

The present work assessed the experimental susceptibility of Nyssomyia antunesi and Lutzomyia longipalpis to Leishmania ( Viannia ) lainsoni and L. ( V .) lindenbergi . A L. ( Leishmania ) chagasi - Lu. longipalpis combination was used as a susceptible control. Wild-caught Ny. antunesi and laboratory-bred Lu. longipalpis were membrane-fed on blood with a 5 × 106 /mL log-phase promastigote culture suspension and dissected on days 2 and 8 post-blood meal (pbm) for analysis focused on the assessment of parasitoses, as well as placement and promastigote morphotyping. Survival curves were constructed. In all combinations, promastigotes were observed on day 8 pbm. For both Leishmania species, in Lu. longipalpis , the presence of parasites was observed up to the stomodeal valve, while in Ny. antunesi , the presence of parasites was observed up to the cardia. There were no significant differences in parasitosis between L. ( V. ) lainsoni and L. ( V. ) lindenbergi in either Ny. antunesi or Lu. longipalpis . Six morphological promastigote forms were distinguished in Giemsa-stained gut smears. The survival curves of all combinations decreased and were affected differently by several Lu. longipalpis -parasite combinations, as well with Lu. longipalpis -uninfected blood. These findings stress Lu. longipalpis as experimentally susceptible to Leishmania spp. and suggest the putative susceptibility of Ny. antunesi to L. ( V. ) lainsoni and L. ( V. ) lindenbergi .