title: The susceptibility of five African Anopheles species to Anabaena PCC 7120 expressing Bacillus thuringiensis subsp. israelensis mosquitocidal cry genes.
abstract: BACKGROUND
  Malaria, one of the leading causes of death in Africa, is transmitted by the bite of an infected female Anopheles mosquito. Problems associated with the development of resistance to chemical insecticides and concerns about the non-target effects and persistence of chemical insecticides have prompted the development of environmentally friendly mosquito control agents. The aim of this study was to evaluate the larvicidal activity of a genetically engineered cyanobacterium, Anabaena PCC 7120#11, against five African Anopheles species in laboratory bioassays.
  
  
  RESULTS
  There were significant differences in the susceptibility of the anopheline species to PCC 7120#11. The ranking of the larvicidal activity of PCC 7120#11 against species in the An. gambiae complex was: An. merus <An. arabiensis <An. gambiae <An. quadriannulatus, where < indicates a statistically lower LC₅₀. The LC₅₀ of PCC 7120#11 against the important malaria vectors An. gambiae and An. arabiensis was 12.3 × 10⁵ cells/ml and 8.10 × 105 cells/ml, respectively. PCC 7120#11 was not effective against An. funestus, with less than 50% mortality obtained at concentrations as high as 3.20 × 10⁷ cells/ml.
  
  
  CONCLUSIONS
  PCC 7120#11 exhibited good larvicidal activity against larvae of the An. gambiae complex, but relatively weak larvicidal activity against An. funestus. The study has highlighted the importance of evaluating a novel mosquitocidal agent against a range of malaria vectors so as to obtain a clear understanding of the agent's spectrum of activity and potential as a vector control agent.
authors.affiliation: School of Molecular and Cell Biology, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, South Africa. gustav.bouwer@wits.ac.za
authors.forename: Irene
authors.initials: I
authors.lastname: Ketseoglou
authors.forename: Gustav
authors.initials: G
authors.lastname: Bouwer
mesh_terms: D000349:Africa; D017033:Anabaena / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D000818:Animals; D000852:Anopheles / Q000187:drug effects* / Q000382:microbiology* / Q000502:physiology; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D004731:Endotoxins / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D006460:Hemolysin Proteins / Q000096:biosynthesis* / Q000235:genetics; D007814:Larva / Q000187:drug effects / Q000382:microbiology / Q000502:physiology; D009032:Mosquito Control / Q000379:methods; D010572:Pest Control, Biological / Q000379:methods; D016019:Survival Analysis
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis