April 26, 2023
Hosted By Dr. Kasie Raymann
Kissing bugs vector the eukaryotic parasite Trypanosoma cruzi, the causative agent of Chagas’ disease. This neglected tropical disease affects millions of people and kills an estimated 10,000 people annually, making it one of, if not the most medically significant insect-vectored diseases in the Americas. Kissing bugs feed exclusively on vertebrate blood, during which time they can acquire the parasite from an infected host. Like all other obligately and exclusively hematophagous insects, kissing bugs require bacteria for successful development. Unlike most other obligately and exclusively hematophagous insects, the bacterial symbionts of kissing bugs are extracellular, residing in the midgut, and are acquired environmentally each generation. This arrangement can be exploited to generate axenic (bacteria-free) kissing bugs through surface sterilization of eggs, and manipulation of the microbiome through introduction of specific microbes via a blood meal. We have leveraged this system to explore what bacteria make suitable symbionts of kissing bugs. Our results suggest that while several bacteria can function as symbionts, some species are much better suited than others, while some species are incapable of functioning as symbionts. Functional symbionts must provision the host with B vitamins that are depauperate in vertebrate blood, but this alone is insufficient for proper host development. In this talk I will discuss our lab’s work in understanding how successful kissing bug symbionts support host biology beyond provisioning of B vitamins, as well as recent advances in our understanding of the interactions between the kissing bug and T. cruzi.