Medical and Veterinary Entomology (2001) 15, 281-286

P. Volf, M. Svobodová and E. Dvoráková (2001)
Bloodmeal digestion and Leishmania major infections in Phlebotomus duboscqi: effect of carbohydrates inhibiting midgut lectin activity
Medical and Veterinary Entomology 15 (3), 281-286
Abstract: The carbohydrates galactosamine and heparin, previously shown to inhibit phlebotomine lectin activity in vitro, were fed to the sandfly Phlebotomus duboscqi Neveu-Lemaire (Diptera: Psychodidae) with blood, and the effects on mortality, fecundity, protease activity and susceptibility to Leishmania major Yakimoff and Schokhor (Kinetoplastida: Trypanosomatidae) were studied. Previous study revealed that galactosamine considerably enhanced the establishment of L. major infection in P. duboscqi and significantly increased parasite loads in late infections. This work demonstrates a similar but less pronounced effect of heparin. Heparin increased infection rates and parasite loads 3 and 9 days post-feeding but did not affect the location of Leishmania promastigotes and their anterior migration. Galactosamine supplement caused pronounced changes in bloodmeal digestion. It abolished the activity of alkaline proteases and trypsin, caused premature defecation of bloodmeal, increased mortality of female sandflies in days 1–4 post-feeding and decreased their fecundity. Heparin had a less pronounced effect on sandfly physiology. It lowered trypsin activity 12 and 72 h post-bloodmeal but did not alter defecation, mortality and oviposition. The data suggest that the enhancing effect of these carbohydrates on Leishmania infections in sandfly midgut could be explained by their interference with midgut proteases. The study supports the hypothesis that proteolytic activities of midgut proteases strongly influence the vector competence of sandflies.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Petr Volf

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Phlebotomus duboscqi