Observations on the development ofLeishmania (L.) chagasiCunha and Chagas in the midgut of the sandfly vectorLutzomyia longipalpis(Lutz and Neiva)

Abstract

SUMMARY. Previous observations have shown that forms ofPromastigotes non infectants.

The life-cycle ofLeishmaniain the sandfly with special reference to the form infective to the vertebrate host

“…Lainson and Shaw's obser vations may explain the increase in infectivity with time reported by Sacks and Perkins (1985). The role of the « unproductive » line remains unexplained, nor is it known how long the non-dividing promastigotes can live, but Lainson and Shaw (1988) suggested they might play a role in creating suitable conditions for the line of metacyclic promastigotes. The report by Lainson and Shaw is the only one of division of the forms infective to the vertebrate.…”

“…In studies on the morphology of L. i. chagasi in Lu. longipalpis, Lainson and Shaw (1988) concluded that from 15-120 h after an infective bloodmeal there were two lines of parasite development. One was the transformation of amastigotes directly into metacyclic pro mastigotes which then divided producing more metacyclic promastigotes.…”

Development of Leishmania (Leishmania) infantum chagasi in Its Natural Sandfly Vector Lutzomyia longipalpis

“…22 In contrast, there are few published data relating to New World species; for example, there are only a few studies on L. infantum chagasi and L. mexicana in Lu. longipalpis 21,23,24 and L. amazonensis and L. braziliensis in Lu. migonei and Lu.…”

An ultrastructural study on the early development ofleishmania chagasi(kinetoplastida: trypanosomatidae) in its vectorlutzomyia longipalpis(diptera: psychodidae)

“…Measurements were made with an Olympus cameralucida, at the same magnification, and calculated as mean ± SD. Proportions of different mrophological forms were estimated by counting the numbers of individuals of each form and all the parasites in 5 microscopic fields (magnification = x 1,125) of Giemsa-smears of 6 separate flies (i. e. total of 30 microscopic fields) and calculating the respective percentages as described by Lainson and Shaw (1988).…”

“…Light microscopy investigations have shown that in the blood-meal, the amastigote enlarges and divides, at least once, before transforming into a dividing promasti gote (Shortt, 1928; Strangeways-Dixon and Lainson, 1966; and Lainson and Shaw, 1988). Recently, Lainson and Shaw (1988) suggested that the ingested amastigotes of Leish mania chagasi take two lines of development in its vector Lutzomyia longipalpis. Most amastigotes enlarge, divide and give rise to large promastigotes which fail to divide any further.…”