Lima José Bento Pereira, de Melo Nilson Vieira, Valle Denise
Laboratório de Fisiologia e Controle de Artrópodes Vetores, Departamento de Entomologia, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil.
Rev Inst Med Trop Sao Paulo. 2005 May-Jun;47(3):125-30. doi: 10.1590/s0036-46652005000300002. Epub 2005 Jul 12.
Resistance of the dengue vector to temephos stimulated its substitution for Bacillus thuringiensis var. israelensis (Bti) since 2001 in Brazil. The persistence of the two Bti formulations employed at that time by the Health Ministry, Vectobac G and Aquabac G, was assayed under laboratory and outdoor conditions. Both formulations were tested at 0.2 g/10 liters of water, the same concentration applied in the field for vector control. The tests were done against Ae. aegypti third instar larvae (Rockefeller strain). In the laboratory, Vectobac G and Aquabac G caused at least 95% mortality until 101 and 45 days after treatment, respectively. In the outdoor assays, test containers of different materials were treated with either formulation and placed in a shaded area. Larvae were introduced each 3-6 days and mortality was recorded 24 and 48 hours later. In the first set of assays, performed in June 2001, mortality levels of 70% or more were attained for 2-5 weeks for both formulations in all containers. The exception was for the iron one that rusted, resulting in low mortality after seven days. In the second set of assays (August 2001), 70% mortality was attained for just 1-2 weeks for all the containers and both formulations.
自2001年以来，登革热媒介对双硫磷产生抗性，促使巴西改用苏云金芽孢杆菌以色列变种（Bti）。当时卫生部使用的两种Bti制剂Vectobac G和Aquabac G，在实验室和室外条件下进行了持久性测定。两种制剂均以0.2克/10升水的浓度进行测试，这与现场用于病媒控制的浓度相同。测试针对埃及伊蚊三龄幼虫（洛克菲勒品系）进行。在实验室中，Vectobac G和Aquabac G分别在处理后101天和45天内导致至少95%的死亡率。在室外试验中，用不同材料制成的测试容器用任一制剂处理后，放置在阴凉处。每3至6天引入幼虫，并在24小时和48小时后记录死亡率。在2001年6月进行的第一组试验中，所有容器中的两种制剂在2至5周内死亡率达到70%或更高。唯一的例外是生锈的铁容器，七天后死亡率较低。在第二组试验（2001年8月）中，所有容器和两种制剂在1至2周内死亡率达到70%。
