Laboratory of Medical Entomology, René Rachou Institute-FIOCRUZ, Minas Gerais, Brazil.
PLoS Negl Trop Dis. 2020 Oct 14;14(10):e0008666. doi: 10.1371/journal.pntd.0008666. eCollection 2020 Oct.
The microbial consortium associated with sandflies has gained relevance, with its composition shifting throughout distinct developmental stages, being strongly influenced by the surroundings and food sources. The bacterial components of the microbiota can interfere with Leishmania development inside the sandfly vector. Microbiota diversity and host-microbiota-pathogen interactions regarding New World sandfly species have yet to be thoroughly studied, particularly in Lutzomyia longipalpis, the primary vector of visceral leishmaniasis in Brazil.The native microbiota of different developmental stages and physiological conditions of Lu. longipalpis (Lapinha Cave), was described by culturing and 16s rRNA gene sequencing. The 16s rRNA sequencing of culture-dependent revealed 13 distinct bacterial genera (Bacillus, Enterococcus, Erwinia, Enterobacter, Escherichia, Klebsiella, Lysinibacillus, Pseudocitrobacter, Providencia, Pseudomonas, Serratia, Staphylococcus and Solibacillus). The in vitro and in vivo effects of each one of the 13 native bacteria from the Lu. longipalpis were analyzed by co-cultivation with promastigotes of L.i. chagasi, L. major, L. amazonensis, and L. braziliensis. After 24 h of co-cultivation, a growth reduction observed in all parasite species. When the parasites were co-cultivated with Lysinibacillus, all parasites of L. infantum chagasi and L. amazonensis died within 24 hours. In the in vivo co-infection of L.chagasi, L. major and L. amazonensis with the genera Lysinibacillus, Pseudocitrobacter and Serratia it was possible to observe a significant difference between the groups co-infected with the bacterial genera and the control group.These findings suggest that symbiont bacteria (Lysinibacillus, Serratia, and Pseudocitrobacter) are potential candidates for paratransgenic or biological control. Further studies are needed to identify the nature of the effector molecules involved in reducing the vector competence for Leishmania.
与沙蝇相关的微生物群落已经引起了人们的关注，其组成在不同的发育阶段发生变化，强烈受到周围环境和食物来源的影响。微生物群落中的细菌成分可以干扰利什曼原虫在沙蝇媒介体内的发育。尚未对新世界沙蝇物种的微生物群落多样性和宿主-微生物-病原体相互作用进行彻底研究，特别是在巴西内脏利什曼病的主要媒介卢氏长须沙蝇（Lutzomyia longipalpis）中。通过培养和 16s rRNA 基因测序，对不同发育阶段和生理条件下的 Lu. longipalpis（拉皮纳洞穴）的原生微生物群落进行了描述。培养依赖性 16s rRNA 测序揭示了 13 个不同的细菌属（芽孢杆菌、肠球菌、欧文氏菌、肠杆菌、大肠杆菌、克雷伯氏菌、Lysinibacillus、Pseudocitrobacter、普罗维登斯菌、假单胞菌、沙雷氏菌、葡萄球菌和 Solibacillus）。通过与 L.i. chagasi、L. major、L. amazonensis 和 L. braziliensis 的前鞭毛体共培养，分析了 Lu. longipalpis 中 13 种本土细菌中的每一种的体外和体内效应。共培养 24 小时后，所有寄生虫物种的生长均受到抑制。当寄生虫与 Lysinibacillus 共培养时，所有 L. infantum chagasi 和 L. amazonensis 的寄生虫在 24 小时内死亡。在 L.chagasi、L. major 和 L. amazonensis 的体内共感染中，与 Lysinibacillus、Pseudocitrobacter 和 Serratia 属共同感染的组与对照组之间观察到显著差异。这些发现表明，共生细菌（Lysinibacillus、Serratia 和 Pseudocitrobacter）是转基因或生物防治的潜在候选者。需要进一步研究以确定参与降低媒介对利什曼原虫易感性的效应分子的性质。
