Leishmania amazonensis: Chemotaxic and osmotaxic responses in promastigotes and their probable role in development in the phlebotomine gut

Studying taxis in real time using optical tweezers: Applications for Leishmania amazonensis parasites

“…However, if one needs more sensitivity it is possible to average the time over long periods in order to detect small changes in the parasite behavior, but at the cost of losing real time observations. We should also bear in mind that standard chemotaxis capillar studies wait for about 1 h [Barros et al, 2006]. Bray (1983) was the first to propose that leishmania could perform chemotaxis.…”

“…Bleul et al (1996), Nagasawa et al (1996) and Nelson et al (1975) are among the most cited reports in this area. For parasites there are more studies on the chemotaxis of bacteria than that of protozoa [Blair, 1999;Rao et al, 2008;Barros et al, 2006]. Some methods are commonly used to study microorganism chemotaxis.…”

“…Another methodology, introduced by Barros et al (2006) to study the chemotaxis of leishmania, was based on measurement of the mean time of straight line movement. Movement in a straight line is defined here as the absence of abrupt changes of direction.…”

Reactivation of flagellar motility in demembranated Leishmania reveals role of cAMP in flagellar wave reversal to ciliary waveform

“…The molecular mechanism of how the flagellum of trypanosomes sense and respond to changes in surrounding microenvironment remains unresolved40. Figure 7 shows a diagrammatic representation of the possible mechanistic events that take place when a Leishmania parasite encounters any change in its immediate surrounding environment841.…”

“…This ensures the proper positioning of the parasites to be transmitted by the insect’s bite and is possibly directed by chemotaxis8. Once the promastigotes are transferred to the mammalian host, the vigorous and unusual oscillations of flagellar tip invades the macrophages, reorienting the parasite and damaging the macrophage plasma membrane2.…”