Laboratório de Biologia Molecular de Insetos, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ, Brazil.
Mosquitos Vetores: Endossimbiontes e Interação Patógeno-Vetor, Instituto René Rachou, Fiocruz, Belo Horizonte, MG, Brazil.
Parasit Vectors. 2021 Jan 6;14(1):21. doi: 10.1186/s13071-020-04465-9.
Aedes aegypti control programs have failed to restrain mosquito population expansion and, consequently, the spread of diseases such as dengue, Zika, and Chikungunya. Wolbachia infection of mosquitoes is a new and promising complementary tool for the control of arbovirus transmission. The use of Wolbachia-infected mosquitoes, mass reared using human blood, is currently being tested in several countries. However, the use of human blood for mass rearing mosquitoes, and thus expansion of this strategy, is problematic. With the aim of overcoming this problem, we tested the effect of different types of blood source on the fitness parameters of female Ae. aegypti and the Wolbachia titer over generations to be able to guarantee the suitability of an alternative source to human blood for mass rearing Wolbachia-infected mosquitoes.
We investigated and compared essential parameters of the vector capacity of laboratory strains of Ae. aegypti with and without Wolbachia that fed on blood of different types of host (human, guinea pig, and mouse). The parameters analyzed were fecundity, fertility, pupation dynamics, and adult survival. Also, we tested whether it is possible to maintain mosquitoes with Wolbachia on mouse blood over generations without losing the bacterium titer.
The average number of eggs per female, egg viability and pupation dynamics in the Wolbachia-infected mosquito (wMelBr) strain were similar, regardless of the blood source. The F1 progenies of females that fed on mouse blood or human blood were analyzed. The longevity of males was lower than that of females. F1 female survival differed depending on the presence of Wolbachia in the mother. In subsequent generations analyzed up until F35, the relative Wolbachia density was even higher when mosquitoes fed on mouse blood in comparison to human blood.
Taken together, our results provide no evidence that the different types of blood influenced the fitness of the Wolbachia-infected mosquitoes. The presence of the bacterium in the colonies of Wolbachia-infected Ae. aegypti after 35 generations under the conditions evaluated indicates that they can be maintained on mouse blood. Based on these results, we show that it is possible to use mouse blood to feed female mosquitoes when using human blood for this purpose is problematic.
埃及伊蚊控制计划未能抑制蚊子种群的扩张，因此登革热、寨卡和基孔肯雅热等疾病仍在传播。蚊子感染沃尔巴克氏体是控制虫媒病毒传播的一种新的、有前途的补充手段。目前，正在几个国家测试使用大量用人血饲养的感染沃尔巴克氏体的蚊子。然而，用人血大量饲养蚊子，从而扩大这一策略，存在问题。为了克服这个问题，我们测试了不同类型的血液来源对雌性埃及伊蚊的适应度参数和沃尔巴克氏体滴度的影响，以确保一种替代人类血液的来源能够适合大规模饲养感染沃尔巴克氏体的蚊子。
我们调查并比较了携带和不携带沃尔巴克氏体的实验室埃及伊蚊的媒介容量的基本参数，这些蚊子以不同类型的宿主（人、豚鼠和小鼠）的血液为食。分析的参数包括产卵量、生育率、蛹化动态和成虫存活率。我们还测试了是否可以在没有失去细菌滴度的情况下，在几代内用小鼠血液维持携带沃尔巴克氏体的蚊子。
无论血液来源如何，感染沃尔巴克氏体的蚊子（wMelBr 株）的平均产卵数、卵的活力和蛹化动态都相似。分析了以小鼠血液或人血为食的雌性后代 F1。雄性的寿命低于雌性。F1 雌性的存活率取决于母体中沃尔巴克氏体的存在。在分析到 F35 的后续几代中，与用人血相比，用鼠血喂养的蚊子中的相对沃尔巴克氏体密度更高。
总的来说，我们的结果没有证据表明不同类型的血液影响感染沃尔巴克氏体的蚊子的适应度。在所评估的条件下，35 代后，感染沃尔巴克氏体的埃及伊蚊的菌落中仍存在细菌，表明它们可以用鼠血维持。基于这些结果，我们表明，当用人血喂养雌性蚊子存在问题时，可以使用鼠血。
