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Please use this identifier to cite or link to this item: http://hdl.handle.net/1807/3559

Title: Histopathological and ultrastructural effects of δ-endotoxins of Bacillus thuringiensis serovar israelensis in the midgut of Simulium pertinax larvae (Diptera, Simuliidae)
Authors: Cavados, C.F.G.
Majerowicz, S.
Chaves, J.Q.
Araújo-Coutinho, C.J.P.C.
Rabinovitch, L.
Keywords: Tropical Diseases
Bacillus thuringiensis serovar israelensis - Simulium pertinax - midgut - histopathology - ultrastructure oc04106
Issue Date: Aug-2004
Publisher: Fundação Oswaldo Cruz, Fiocruz
Citation: Memórias do Instituto Oswaldo Cruz 99(5)
Abstract: The bacterium Bacillus thuringiensis (Bt) produces parasporal crystals containing δ-endotoxins responsible for selective insecticidal activity on larvae. Upon ingestion, these crystals are solubilized in the midgut lumen and converted into active toxins that bind to receptors present on the microvilli causing serious damage to the epithelial columnar cells. We investigated the effect of these endotoxins on larvae of the Simulium pertinax, a common black fly in Brazil, using several concentrations during 4 h of the serovar israelensis strain IPS-82 (LFB-FIOCRUZ 584), serotype H-14 type strain of the Institute Pasteur, Paris. Light and electron microscope observations revealed, by time and endotoxin concentration, increasing damages of the larvae midgut epithelium. The most characteristic effects were midgut columnar cell vacuolization, microvilli damages, epithelium cell contents passing into the midgut lumen and finally the cell death. This article is the first report of the histopathological effects of the Bti endotoxins in the midgut of S. pertinax larvae and the data obtained may contribute to a better understanding of the mode of action of this bacterial strain used as bioinsecticide against black fly larvae.
URI: http://bioline.utsc.utoronto.ca/archive/00002412/01/oc04106.pdf
Other Identifiers: http://bioline.utsc.utoronto.ca/archive/00002412/
Appears in Collections:Bioline International Legacy Collection

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