Experimental evolution to increase the efficacy of the entomopathogenic fungus Beauveria bassiana against malaria mosquitoes: effects on mycelial growth and virulence

Entomopathogenic fungi such as Beauveria bassiana are currently considered as a potential control agent for malaria mosquitoes. The success of such strategies depends among others on the efficacy of the fungus to kill its hosts. As B. bassiana can use various resources for growth and reproduction, increasing the dependency on mosquitoes as a nutritional source may be instrumental for reaching this goal. Passage of entomopathogenic fungi through an insect host has been shown to increase its virulence. We evaluated the virulence, fungal outgrowth, mycelial growth rate, and sporulation rate of two B. bassiana isolates (Bb1520 and Bb8028) that underwent 10 consecutive selection cycles through malaria mosquitoes (Anopheles coluzzii) using an experimental evolution approach. This cycling resulted in an altered capacity of evolved B. Bassiana lineages to grow on different substrates while maintaining the ability to kill insects. Notably, however, there were no significant changes in virulence ...

昆虫病原真菌（Entomopathogenic fungi）如球孢白僵菌（Beauveria bassiana），目前被视为防治传疟蚊子的潜在防控药剂。此类防控策略的成功与否，除其他影响因素外，取决于真菌杀灭宿主的效力。由于球孢白僵菌可利用多种资源完成生长与繁殖，增强其对蚊子作为营养来源的依赖性，或有助于达成这一防控目标。已有研究证实，昆虫病原真菌经昆虫宿主传代可提升其毒力。本研究采用实验进化方法，对两株球孢白僵菌菌株（Bb1520与Bb8028）开展了连续10次通过传疟蚊子科鲁兹按蚊（Anopheles coluzzii）的选择传代实验，随后评估了其毒力、菌体增殖、菌丝生长速率及产孢率。经此类循环传代后，进化获得的球孢白僵菌谱系在不同培养基质上的生长能力发生了改变，但仍保留了杀灭昆虫的能力。然而值得注意的是，其毒力并未出现显著变化……