Use of Bacillus thuringiensis israelensis for Onchocerciasis Control in West Africa

Guillet, Pierre; Kurtak, Daniel C.; Philippon, Bernard; Meyer, Rolf

doi:10.1007/978-94-011-5967-8_11

Cited by 38 publications

(32 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Bti is highly effective in mosquito control, but even though it has been extensively used for Ͼ20 years, insect resistance in field populations has not been observed (3,4). The high efficacy of Bti is because of the production of multiple toxins with different modes of action.…”

Section: Discussionmentioning

confidence: 99%

“…A major threat to the use of Bt is the appearance of insect resistance, which has been documented in lepidopteran insects (2); however, no resistance has been observed in the field in mosquito species controlled with Bti (3,4). In contrast, resistant mosquito populations have been selected in the field with Bacillus sphaericus, another mosquitocidal bacterium that produces another toxin, Bin (5).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Bacillus thuringiensis subsp. israelensis Cyt1Aa synergizes Cry11Aa toxin by functioning as a membrane-bound receptor

Pérez

Fernández

Sun

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

219

212

View full text Add to dashboard Cite

Bacillus thuringiensis subsp. israelensis produces crystal proteins, Cry (4Aa, 4Ba, 10Aa, and 11Aa) and Cyt (1Aa and 2Ba) proteins, toxic to mosquito vectors of human diseases. Cyt1Aa overcomes insect resistance to Cry11Aa and Cry4 toxins and synergizes the toxicity of these toxins. However, the molecular mechanism of synergism remains unsolved. Here, we provide evidence that Cyt1Aa functions as a receptor of Cry11Aa. Sequential-binding analysis of Cyt1Aa and Cry11Aa revealed that Cyt1Aa binding to Aedes aegypti brush border membrane vesicles enhanced the binding of biotinylated-Cry11Aa. The Cyt1Aa-and Cry11Aa-binding epitopes were mapped by means of the yeast two-hybrid system, peptide arrays, and heterologous competition assays with synthetic peptides. Two exposed regions in Cyt1Aa, loop ␤6-␣E and part of ␤7, bind Cry11Aa. On the other side, Cry11Aa binds Cyt1Aa proteins by means of domain II-loop ␣8 and ␤-4, which are also involved in midgut receptor interaction. Characterization of single-point mutations in Cry11Aa and Cyt1Aa revealed key Cry11Aa (S259 and E266) and Cyt1Aa (K198, E204 and K225) residues involved in the interaction of both proteins and in synergism. Additionally, a Cyt1Aa loop ␤6-␣E mutant (K198A) with enhanced synergism to Cry11Aa was isolated. Data provided here strongly indicates that Cyt1Aa synergizes or suppresses resistance to Cry11Aa toxin by functioning as a membrane-bound receptor. Bacillus thuringiensis subsp. israelensis is a highly effective pathogenic bacterium because it produces a toxin and also its functional receptor, promoting toxin binding to the target membrane and causing toxicity.receptor interaction ͉ binding epitopes ͉ insect resistance ͉ mode of action

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Bacillus thuringiensis subsp. israelensis Cyt1Aa synergizes Cry11Aa toxin by functioning as a membrane-bound receptor

Pérez

Fernández

Sun

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

219

212

View full text Add to dashboard Cite

show abstract

“…B. thuringiensis subsp. israelensis has been used in the field for nearly 20 years with no development of insect resistance (7,11).…”

mentioning

confidence: 99%

Diversity of Bacillus thuringiensis Strains from Latin America with Insecticidal Activity against Different Mosquito Species

Ibarra

Rincón

Ordúz

et al. 2003

Appl Environ Microbiol

135

View full text Add to dashboard Cite

The characterization of selected Bacillus thuringiensis strains isolated from different Latin America countries is presented. Characterization was based on their insecticidal activity against Aedes aegypti, Culex quinquefasciatus, and Anopheles albimanus larvae, scanning electron microscopy, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and plasmid profiles as well as PCR analysis using novel general and specific primers for cry and cyt genes encoding proteins active against mosquitoes (cyt1, cyt2, cry2, cry4A, cry4B, cry10, cry11, cry17, cry19, cry24, cry25, cry27, cry29, cry30, cry32, cry39, and cry40). Strains LBIT315, LBIT348, and IB604 showed threefold higher mosquitocidal activity against A. aegypti and C. quinquefasciatus larvae than B. thuringiensis subsp. israelensis and displayed high similarities with the B. thuringiensis subsp. israelensis used in this study with regard to protein and plasmid profiles and the presence of cry genes. Strain 147-8906 has activity against A. aegypti similar to that of B. thuringiensis subsp. israelensis but has different protein and plasmid profiles. This strain, harboring cry11, cry30, cyt1, and cyt2 genes, could be relevant for future resistance management interventions. Finally, the PCR screening strategy presented here led us to identify a putative novel cry11B gene.

show abstract

“…israelensis (Bti), Wrst found in the Negev Desert (Goldberg and Margalit, 1977) has come to be used extensively for the control of larvae of pest and vector black Xies and mosquitoes around the world, providing both medical and environmental beneWt (Lacey and Undeen, 1986). An outstanding success in cooperation between industry and a governmental organization to achieve those beneWts is the World Health Organization's Onchocerciasis Control Programme wherein Bti applications comprise up to 50% of all insecticide applications (Guillet et al, 1990).…”

Section: Bacillus Thuringiensis Changes the Paradigmmentioning

confidence: 99%

From Metchnikoff to Monsanto and beyond: The path of microbial control

Lord

2005

Journal of Invertebrate Pathology

142

View full text Add to dashboard Cite

In 125 years since MetchnikoV proposed the use of Metarhizium anisopliae to control the wheat cockchafer and brought about the Wrst Weld trials, microbial control has progressed from the application of naturalists' observations to biotechnology and precision delivery. This review highlights major milestones in its evolution and presents a perspective on its current direction. Fungal pathogens, the most eye-catching agents, dominated the early period, but major mycological control eVorts for chinch bugs and citrus pests in the US had questionable success, and interest waned. The discoveries of Bacillus popilliae and Bacillus thuringiensis began the era of practical and commercially viable microbial control. A program to control the Japanese beetle in the US led to the discovery of both B. popilliae and Steinernema glaseri, the Wrst nematode used as a microbial control agent. Viral insect control became practical in the latter half of the 20th century, and the Wrst registration was obtained with the Heliothis nuclear polyhedrosis virus in 1975. Now strategies are shifting for microbial control. While Bt transgenic crops are now planted on millions of hectares, the successes of more narrowly deWned microbial control are mainly in small niches. Commercial enthusiasm for traditional microbial control agents has been unsteady in recent years. The prospects of microbial insecticide use on vast areas of major crops are now viewed more realistically. Regulatory constraints, activist resistance, benign and eYcacious chemicals, and limited research funding all drive changes in focus. Emphasis is shifting to monitoring, conservation, integration with chemical pesticides, and selection of favorable venues such as organic agriculture and countries that have low costs, mild regulatory climates, modest chemical inputs, and small scale farming. Published by Elsevier Inc.

show abstract

Use of Bacillus thuringiensis israelensis for Onchocerciasis Control in West Africa

Cited by 38 publications

References 6 publications

Bacillus thuringiensis subsp. israelensis Cyt1Aa synergizes Cry11Aa toxin by functioning as a membrane-bound receptor

Bacillus thuringiensis subsp. israelensis Cyt1Aa synergizes Cry11Aa toxin by functioning as a membrane-bound receptor

Diversity of Bacillus thuringiensis Strains from Latin America with Insecticidal Activity against Different Mosquito Species

From Metchnikoff to Monsanto and beyond: The path of microbial control

Contact Info

Product

Resources

About