Micro-CT visualization of a promastigote secretory gel (PSG) and parasite plug in the digestive tract of the sand fly Lutzomyia longipalpis infected with Leishmania mexicana

Leishmaniasis is a debilitating disease of the tropics, subtropics and southern Europe caused by Leishmania parasites that are transmitted during blood feeding phlebotomine sand flies (Diptera: Psychodidae). Using non-invasive micro-computed tomography, we were able to visualize impact laboratory model infection Lutzomyia longipalpis with mexicana its response second meal. For first time show in 3D plug promastigote secretory gel (PSG) distended midgut whole infected measure volume relation midgut. We also degree opening stomodeal valve demonstrate extension PSG into pharynx. Although our pilot study could only examine few flies, it supports hypothesis second, non-infected, meal enhances parasite transmission as showed thoracic PSG-parasite after was, on average, more than twice did not have