title: Conjugal transfer of a toxin-coding megaplasmid from Bacillus thuringiensis subsp. israelensis to mosquitocidal strains of Bacillus sphaericus.
abstract: Both Bacillus sphaericus and Bacillus thuringiensis subsp. israelensis produce mosquitocidal toxins during sporulation and are extensively used in the field for control of mosquito populations. All the known toxins of the latter organism are known to be encoded on a large plasmid, pBtoxis. In an attempt to combine the best properties of the two bacteria, an erythromycin resistance-marked pBtoxis plasmid was transferred to B. sphaericus by a mating technique. The resulting transconjugant bacteria were significantly more toxic to Aedes aegypti mosquitoes and were able to overcome resistance to B. sphaericus in a resistant colony of Culex quinquefasciatus, apparently due to the production of Cry11A but not Cry4A or Cry4B. The stability of the plasmid in the B. sphaericus host was moderate during vegetative growth, but segregational instability was observed, which led to substantial rates of plasmid loss during sporulation.
authors.affiliation: Cardiff School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3US, United Kingdom.
authors.forename: Katherine
authors.initials: K
authors.lastname: Gammon
authors.forename: Gareth W
authors.initials: GW
authors.lastname: Jones
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Hope
authors.forename: Cláudia M F
authors.initials: CM
authors.lastname: de Oliveira
authors.forename: Lêda
authors.initials: L
authors.lastname: Regis
authors.forename: Maria Helena N L
authors.initials: MH
authors.lastname: Silva Filha
authors.forename: Brian N
authors.initials: BN
authors.lastname: Dancer
authors.forename: Colin
authors.initials: C
authors.lastname: Berry
mesh_terms: D000330:Aedes / Q000254:growth & development / Q000382:microbiology; D000818:Animals; D001407:Bacillus / Q000145:classification / Q000235:genetics* / Q000254:growth & development; D001413:Bacillus thuringiensis / Q000235:genetics*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics*; D001427:Bacterial Toxins / Q000235:genetics*; D003227:Conjugation, Genetic; D003465:Culex / Q000254:growth & development / Q000382:microbiology; D004731:Endotoxins / Q000235:genetics*; D006460:Hemolysin Proteins; D007305:Insecticide Resistance; D007814:Larva / Q000382:microbiology; D010572:Pest Control, Biological; D010957:Plasmids / Q000235:genetics*; D013171:Spores, Bacterial / Q000254:growth & development
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis