title: Mtx toxins from Lysinibacillus sphaericus enhance mosquitocidal cry-toxin activity and suppress cry-resistance in Culex quinquefasciatus.
abstract: The interaction of Mtx toxins from Lysinibacillus sphaericus (formerly Bacillus sphaericus) with Bacillus thuringiensis subsp. israelensis Cry toxins and the influence of such interactions on Cry-resistance were evaluated in susceptible and Cry-resistant Culex quinquefasciatus larvae. Mtx-1 and Mtx-2 were observed to be active against both susceptible and resistant mosquitoes; however varying levels of cross-resistance toward Mtx toxins were observed in the resistant mosquitoes. A 1:1 mixture of either Mtx-1 or Mtx-2 with different Cry toxins generally showed moderate synergism, but some combinations were highly toxic to resistant larvae and suppressed resistance. Toxin synergy has been demonstrated to be a powerful tool for enhancing activity and managing Cry-resistance in mosquitoes, thus Mtx toxins may be useful as components of engineered bacterial larvicides.
authors.affiliation: Department of Entomology, University of California, Riverside, CA 92521, United States. Electronic address: mcwirth@ucr.edu.
authors.forename: Margaret C
authors.initials: MC
authors.lastname: Wirth
authors.affiliation: Cardiff School of Biosciences, Cardiff University, Cardiff Wales CF10 3AT, United Kingdom.
authors.forename: Colin
authors.initials: C
authors.lastname: Berry
authors.affiliation: Department of Entomology, University of California, Riverside, CA 92521, United States.
authors.forename: William E
authors.initials: WE
authors.lastname: Walton
authors.affiliation: Department of Entomology, University of California, Riverside, CA 92521, United States; Interdepartmental Graduate Programs in Microbiology and Genetics, Genomics and Bioinformatics University of California, Riverside, CA 92521, United States.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Federici
mesh_terms: D000818:Animals; D001407:Bacillus / Q000737:chemistry*; D001426:Bacterial Proteins / Q000633:toxicity*; D003465:Culex / Q000382:microbiology*; D004731:Endotoxins / Q000633:toxicity; D006460:Hemolysin Proteins / Q000633:toxicity; D007305:Insecticide Resistance / Q000502:physiology*; D010572:Pest Control, Biological / Q000379:methods*
chemical_list: D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins
keywords: Cry toxins; Mtx toxins; Resistance; Resistance Management; Synergy