Fig. 9
ISPsKD and ISPsOE L. donovani parasites survival in P. argentipes during the early midgut protease stress. Female P. argentipes were infected by feeding on human blood containing either of WT, ISP1KD, ISP1OE, ISP2KD and ISP2OE Leishmania parasites (~1 × 106 parasites/ml of human blood) and kept at 25 °C from 0 to 72 h after blood-feeding. a The early killing of WT, ISP1KD, ISP1OE, ISP2KD and ISP2OE Ld parasites inside the midgut of the sand fly. Trypan blue assay was used to monitored the viability of the parasites/gut, from the midgut infected with a different group of parasites (~106 amastigotes/ml), dissected at different time interval 0–72 h ABF. The visual examination of the dead and live parasites was determined by counting the parasites in Neubauer chamber of haemocytometer under a light microscope. The value represents the geometric mean of ± SD of 20 sand flies/group. The experiment was performed in triplicate. An asterisk (*) denotes P ≤ 0.05 as compared to WT. b WT, ISP1KD and ISP2KD infected female sand fly midguts were examined microscopically for infectivity. Intensities of infection were classified into three categories according to their intensity: light (< 100 parasites/gut), moderate (100–1000 parasites/gut) or heavy (> 1000 parasites/gut). Numbers above the bar indicate the number of dissected fully fed female sand flies for each group