Detection and enumeration of Leishmania in sand flies using agar-based media

An agar plating technique was used to determine the number of amastigotes ingested by Lutzomyia longipalpis fed on papules on Mesocricetus auratus caused by Leishmania mexicana amazonensis and on lesions on Mystromys albicaudatus caused by Leishmania braziliensis panamensis. The technique involved homogenizing sand flies after bloodfeeding on the infected animals and spreading the homogenate over the surface of agar plates. A great variation in the number of amastigotes ingested by individual sand flies was demonstrated. Not all amastigotes ingested developed anterior stomodeal infections.