Wirth M C, Federici B A, Walton W E
Department of Entomology, University of California, Riverside, California 92521, USA.
Appl Environ Microbiol. 2000 Mar;66(3):1093-7. doi: 10.1128/AEM.66.3.1093-1097.2000.
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.
球形芽孢杆菌是一种杀蚊细菌，最近被开发为一种商业杀幼虫剂，在全球范围内用于控制害虫和媒介蚊子。虽然球形芽孢杆菌对库蚊和按蚊幼虫具有高度活性，但对重要的媒介物种埃及伊蚊几乎无毒。在本研究中，我们评估了苏云金芽孢杆菌以色列亚种的溶细胞蛋白Cyt1A增强球形芽孢杆菌对埃及伊蚊毒性的能力。对这两种物质的各种组合进行了评估，结果均显示出高毒性。球形芽孢杆菌与Cyt1A的比例为10:1时，对埃及伊蚊的毒性比单独使用球形芽孢杆菌高3600倍。统计分析表明，这种高活性是由于Cyt1A毒素与球形芽孢杆菌之间的协同作用。这些结果表明，Cyt1A可能有助于扩大球形芽孢杆菌的宿主范围。
