Molecular Aspects of Parasite-Vector and Vector-Host Interactions in Leishmaniasis

Abstract

Leishmania-sand fly interactions are reviewed in the context of the potential barriers to the complete development of the parasite that exist within the midgut environment of phlebotomine flies and the molecular adaptations that the parasite has evolved that permit the development of transmissible infections to proceed. Cell surface and secreted phosphoglycans protect the parasite from the proteolytic activities of the blood-fed midgut, mediate attachment to the gut wall in order to maintain infection during excretion of the bloodmeal, and contribute to the formation of a biological plug in the anterior gut that may promote transmission by bite. The importance of vector saliva in modulating the host response to transmitted parasites is also reviewed.

Infecção natural de Lutzomyia longipalpis por Leishmania sp. em Teresina, Piauí, Brasil

“…As demais amostras positivas apresentaram ambas as formas nas regiões do piloro, íleo e papila retal, ou seja, porções do trato digestivo posterior. Os resultados obtidos neste estudo são discordantes de outros que relataram a presença de formas procíclicas na porção anterior do estômago e nectomonadas no estômago, cárdia e válvula do esôfago 5,6 .…”

“…Realizou-se dissecação de, em média, dez fêmeas por captura. O trato digestivo e a cabeça foram retirados e observados para verificar a presença de formas evolutivas de Leishmania, segundo nomenclatura utilizada por Walters et al 5 e Sacks & Kamhawi 6 . A taxonomia dos insetos foi realizada de acordo com seus caracteres morfológicos 7 .…”

An in vitro system for developmental and genetic studies of Leishmania donovani phosphoglycans

“…1B), consistent with similar studies with promastigotes of L. major (data not shown). Maintenance of stationary phase viability is critical, since promastigotes differentiate in stationary phase to the infective metacyclic form of the parasite [3,31]. In contrast, the viability of LdB amastigotes decreased more substantially in stationary phase, dropping to less than 90% after 2 days (Fig.…”

Impact of Phlebotomine Sand Flies on U.S. Military Operations at Tallil Air Base, Iraq: 2. Temporal and Geographic Distribution of Sand Flies

“…P. sergenti and P. papatasi are almost certainly the primary vectors of Leishmania tropica (Wright) and Leishmania major Yakimoff & Schokhor, respectively (Al-Azawi and Abul-Hab 1977, KillickKendrick et al 1985, Al-Zahrani et al 1988, KillickKendrick 1990. Sukkar (1978) suggested that P. papatasi was also the primary vector of visceral leishmaniasis [Leishmania donovani (Laveran & Mesnil) and/or Leishmania infantum Nicolle]; however, P. papatasi is a restricted vector and is incapable of transmitting any species of Leishmania other than L. major (Sacks and Kamhawi 2001). Killick-Kendrick (1990) reported that data from Li-Ren et al (1986) indicated that P. alexandri should be considered a potential vector of visceral leishmaniasis in Iraq.…”