PDF(Pubmed)
Abstract：
The entomopathogenic fungus Beauveria bassiana provides an eco-friendly substitute to chemical insecticides for mosquito control. Nevertheless, its widespread application has been hindered by its comparatively slow efficacy in eliminating mosquitoes. To augment the potency of B. bassiana against Aedes mosquitoes, a novel recombinant strain, Bb-Cyt1Aa, was developed by incorporating the Bacillus thuringiensis toxin gene Cyt1Aa into B. bassiana. The virulence of Bb-Cyt1Aa was evaluated against Aedes aegypti and Aedes albopictus using insect bioassays. Compared to the wild-type (WT) strain, the median lethal time (LT50) for A. aegypti larvae infected with Bb-Cyt1Aa decreased by 33.3% at a concentration of 1 × 108 conidia/mL and by 22.2% at 1 × 107 conidia/mL. The LT50 for A. aegypti adults infected with Bb-Cyt1Aa through conidia ingestion was reduced by 37.5% at 1 × 108 conidia/mL and by 33.3% at 1 × 107 conidia/mL. Likewise, the LT50 for A. aegypti adults infected with Bb-Cyt1Aa through cuticle contact decreased by 33.3% and 30.8% at the same concentrations, respectively. Furthermore, the Bb-Cyt1Aa strain also demonstrated increased toxicity against both larval and adult A. albopictus, when compared to the WT strain. In conclusion, our study demonstrated that the expression of B. thuringiensis toxin Cyt1Aa in B. bassiana enhanced its virulence against Aedes mosquitoes. This suggests that B. bassiana expressing Cyt1Aa has potential value for use in mosquito control.
OBJECTIVE: Beauveria bassiana is a naturally occurring fungus that can be utilized as a bioinsecticide against mosquitoes. Cyt1Aa is a delta-endotoxin protein produced by Bacillus thuringiensis that exhibits specific and potent insecticidal activity against mosquitoes. In our study, the expression of this toxin Cyt1Aa in B. bassiana enhances the virulence of B. bassiana against Aedes aegypti and Aedes albopictus, thereby increasing their effectiveness in killing mosquitoes. This novel strain can be used alongside chemical insecticides to reduce dependence on harmful chemicals, thereby minimizing negative impacts on the environment and human health. Additionally, the potential resistance of B. bassiana against mosquitoes in the future could be overcome by acquiring novel combinations of exogenous toxin genes. The presence of B. bassiana that expresses Cyt1Aa is of significant importance in mosquito control as it enhances genetic diversity, creates novel virulent strains, and contributes to the development of safer and more sustainable methods of mosquito control.
OBJECTIVE: Beauveria bassiana is a naturally occurring fungus that can be utilized as a bioinsecticide against mosquitoes. Cyt1Aa is a delta-endotoxin protein produced by Bacillus thuringiensis that exhibits specific and potent insecticidal activity against mosquitoes. In our study, the expression of this toxin Cyt1Aa in B. bassiana enhances the virulence of B. bassiana against Aedes aegypti and Aedes albopictus, thereby increasing their effectiveness in killing mosquitoes. This novel strain can be used alongside chemical insecticides to reduce dependence on harmful chemicals, thereby minimizing negative impacts on the environment and human health. Additionally, the potential resistance of B. bassiana against mosquitoes in the future could be overcome by acquiring novel combinations of exogenous toxin genes. The presence of B. bassiana that expresses Cyt1Aa is of significant importance in mosquito control as it enhances genetic diversity, creates novel virulent strains, and contributes to the development of safer and more sustainable methods of mosquito control.
摘要：
昆虫病原真菌球孢白僵菌为化学杀虫剂提供了一种生态友好的替代品，用于控制蚊子。然而，其消灭蚊子的功效相对较慢，阻碍了其广泛应用。为了增强巴氏杆菌对抗伊蚊的效力，一种新的重组菌株，Bb-Cyt1Aa,是通过将苏云金芽孢杆菌毒素基因Cyt1Aa整合到玄武岩中而开发的。使用昆虫生物测定法评估了Bb-Cyt1Aa对埃及伊蚊和白纹伊蚊的毒力。与野生型（WT）菌株相比，感染Bb-Cyt1Aa的埃及伊蚊幼虫的中位致死时间（LT50）在1×108分生孢子/mL时减少了33.3％，在1×107分生孢子/mL时减少了22.2％。通过分生孢子摄入感染Bb-Cyt1Aa的埃及伊蚊的LT50在1×108分生孢子/mL时降低了37.5％，在1×107分生孢子/mL时降低了33.3％。同样，在相同浓度下，通过角质层接触感染Bb-Cyt1Aa的埃及伊蚊成虫的LT50下降了33.3%和30.8%，分别。此外，Bb-Cyt1Aa菌株对幼虫和成虫的毒性也增加，当与WT菌株相比时。总之,我们的研究表明，苏云金芽孢杆菌毒素Cyt1Aa的表达增强了其对伊蚊的毒力。这表明表达Cyt1Aa的球孢芽孢杆菌具有用于蚊子控制的潜在价值。
目的：球孢白僵菌是一种天然存在的真菌，可用作抗蚊子的生物杀虫剂。Cyt1Aa是由苏云金芽孢杆菌产生的δ-内毒素蛋白,其对蚊子表现出特异性和有效的杀虫活性。在我们的研究中,这种毒素Cyt1Aa在球孢芽孢杆菌中的表达增强了球孢芽孢杆菌对埃及伊蚊和白纹伊蚊的毒力，从而提高了它们杀死蚊子的效力。这种新型菌株可以与化学杀虫剂一起使用，以减少对有害化学物质的依赖。从而最大限度地减少对环境和人类健康的负面影响。此外,通过获得外源毒素基因的新组合，可以克服未来对蚊子的潜在抗性。表达Cyt1Aa的球孢芽孢杆菌的存在在蚊子控制中具有重要意义，因为它增强了遗传多样性。创造了新的毒株，并有助于发展更安全和更可持续的蚊子控制方法。
目的：球孢白僵菌是一种天然存在的真菌，可用作抗蚊子的生物杀虫剂。Cyt1Aa是由苏云金芽孢杆菌产生的δ-内毒素蛋白,其对蚊子表现出特异性和有效的杀虫活性。在我们的研究中,这种毒素Cyt1Aa在球孢芽孢杆菌中的表达增强了球孢芽孢杆菌对埃及伊蚊和白纹伊蚊的毒力，从而提高了它们杀死蚊子的效力。这种新型菌株可以与化学杀虫剂一起使用，以减少对有害化学物质的依赖。从而最大限度地减少对环境和人类健康的负面影响。此外,通过获得外源毒素基因的新组合，可以克服未来对蚊子的潜在抗性。表达Cyt1Aa的球孢芽孢杆菌的存在在蚊子控制中具有重要意义，因为它增强了遗传多样性。创造了新的毒株，并有助于发展更安全和更可持续的蚊子控制方法。
