This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow E-mail this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Wirth, M. C.
Right arrow Articles by Berry, C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Wirth, M. C.
Right arrow Articles by Berry, C.
Agricola
Right arrow Articles by Wirth, M. C.
Right arrow Articles by Berry, C.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, October 2007, p. 6066-6071, Vol. 73, No. 19
0099-2240/07/$08.00+0     doi:10.1128/AEM.00654-07
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Mtx Toxins Synergize Bacillus sphaericus and Cry11Aa against Susceptible and Insecticide-Resistant Culex quinquefasciatus Larvae{triangledown}

Margaret C. Wirth,1* Yangkun Yang,2 William E. Walton,1 Brian A. Federici,1,3 and Colin Berry2

Department of Entomology, University of California, Riverside, California 92521,1 Cardiff School of Biosciences, Cardiff University, Cardiff, Wales, United Kingdom,2 Interdepartmental Graduate Programs in Microbiology and Genetics, Genomics and Bioinformatics, University of California, Riverside, California 925213

Received 22 March 2007/ Accepted 6 August 2007

Two mosquitocidal toxins (Mtx) of Bacillus sphaericus, which are produced during vegetative growth, were investigated for their potential to increase toxicity and reduce the expression of insecticide resistance through their interactions with other mosquitocidal proteins. Mtx-1 and Mtx-2 were fused with glutathione S-transferase and produced in Escherichia coli, after which lyophilized powders of these fusions were assayed against Culex quinquefasciatus larvae. Both Mtx proteins showed a high level of activity against susceptible C. quinquefasciatus mosquitoes, with 50% lethal concentrations (LC50) of Mtx-1 and Mtx-2 of 0.246 and 4.13 µg/ml, respectively. The LC50s were 0.406 to 0.430 µg/ml when Mtx-1 or Mtx-2 was mixed with B. sphaericus, and synergy improved activity and reduced resistance levels. When the proteins were combined with a recombinant Bacillus thuringiensis strain that produces Cry11Aa, the mixtures were highly active against Cry11A-resistant larvae and resistance was also reduced. The mixture of two Mtx toxins and B. sphaericus was 10 times more active against susceptible mosquitoes than B. sphaericus alone, demonstrating the influence of relatively low concentrations of these toxins. These results show that, similar to Cyt toxins from B. thuringiensis subsp. israelensis, Mtx toxins can increase the toxicity of other mosquitocidal proteins and may be useful for both increasing the activity of commercial bacterial larvicides and managing potential resistance to these substances among mosquito populations.

* Corresponding author. Mailing address: Department of Entomology, University of California, Riverside, CA 92521. Phone: (951) 827-3918. Fax: (951) 827-3086. E-mail: mcwirth{at}mail.ucr.edu

{triangledown} Published ahead of print on 17 August 2007.

Applied and Environmental Microbiology, October 2007, p. 6066-6071, Vol. 73, No. 19
0099-2240/07/$08.00+0     doi:10.1128/AEM.00654-07
Copyright © 2007, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • de Melo, J. V., Jones, G. W., Berry, C., Vasconcelos, R. H. T., de Oliveira, C. M. F., Furtado, A. F., Peixoto, C. A., Silva-Filha, M. H. N. L. (2009). Cytopathological Effects of Bacillus sphaericus Cry48Aa/Cry49Aa Toxin on Binary Toxin-Susceptible and -Resistant Culex quinquefasciatus Larvae. Appl. Environ. Microbiol. 75: 4782-4789 [Abstract] [Full Text]  
  • Chalegre, K. D. d. M., Romao, T. P., Amorim, L. B., Anastacio, D. B., de Barros, R. A., de Oliveira, C. M. F., Regis, L., de-Melo-Neto, O. P., Silva-Filha, M. H. N. L. (2009). Detection of an Allele Conferring Resistance to Bacillus sphaericus Binary Toxin in Culex quinquefasciatus Populations by Molecular Screening. Appl. Environ. Microbiol. 75: 1044-1049 [Abstract] [Full Text]  


Copyright © 2010 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»