title: Cyt1A from Bacillus thuringiensis synergizes activity of Bacillus sphaericus against Aedes aegypti (Diptera: Culicidae).
abstract: Bacillus sphaericus is a mosquitocidal bacterium recently developed as a commercial larvicide that is used worldwide to control pestiferous and vector mosquitoes. Whereas B. sphaericus is highly active against larvae of Culex and Anopheles mosquitoes, it is virtually nontoxic to Aedes aegypti, an important vector species. In the present study, we evaluated the capacity of the cytolytic protein Cyt1A from Bacillus thuringiensis subsp. israelensis to enhance the toxicity of B. sphaericus toward A. aegypti. Various combinations of these two materials were evaluated, and all were highly toxic. A ratio of 10:1 of B. sphaericus to Cyt1A was 3, 600-fold more toxic to A. aegypti than B. sphaericus alone. Statistical analysis showed this high activity was due to synergism between the Cyt1A toxin and B. sphaericus. These results suggest that Cyt1A could be useful in expanding the host range of B. sphaericus.
authors.affiliation: Department of Entomology, University of California, Riverside, California 92521, USA. mcwirth@mail.ucr.edu
authors.forename: M C
authors.initials: MC
authors.lastname: Wirth
authors.forename: B A
authors.initials: BA
authors.lastname: Federici
authors.forename: W E
authors.initials: WE
authors.lastname: Walton
mesh_terms: D000330:Aedes / Q000187:drug effects*; D000818:Animals; D001407:Bacillus / Q000378:metabolism*; D001413:Bacillus thuringiensis / Q000378:metabolism; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000494:pharmacology*; D001427:Bacterial Toxins; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004731:Endotoxins / Q000494:pharmacology*; D006460:Hemolysin Proteins; D007306:Insecticides / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects; D009032:Mosquito Control / Q000379:methods*; D010572:Pest Control, Biological / Q000379:methods*; D013045:Species Specificity
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D007306:Insecticides; C030956:insecticidal crystal protein, Bacillus Thuringiensis