Epidemics of vector-borne pathogens have dramatically changed in recent years, as we have witnessed the introduction of Zika and West Nile viruses in the US, Crimean-Congo hemorrhagic fever in south-western Europe, and the continuous emergence of Lyme disease throughout the Northeast of the USA and central Europe. Ticks are the most important vectors for infectious diseases in the northern hemisphere and second after mosquitoes worldwide. As a result, there is an increasing public health interest in tick-borne pathogens.
We study ticks and tick-borne pathogens with a special emphasis on Borrelia burgdorferi, the agent of Lyme disease. B. burgdorferi has a complex life cycle that involves two very distinct milieus, the tick mid gut and the vertebrate host. In order to survive, Borrelia tightly regulates the expression of numerous genes. Nonetheless, little is known about the sensing mechanisms by which the spirochete accomplishes this adaptation. Notably, B. burgdorferi requires cholesterol to grow but cannot synthesize it. The spirochete uptakes cholesterol from the host to makeup cholesterol glycolipids (CGal and ACGal), which are major lipid components of the spirochete membrane. These, cholesterol glycolipids sort themselves out in the membrane to form microdomains, also known as lipid rafts, which have a subset of specific proteins involved in important biological processes including sensing, signaling and protein trafficking.
As medical entomologists we are interested in surveillance, prevention and control of vector-borne diseases. One aspect that is under studied is how tick-borne pathogens and members of the tick’s microbiome interact and whether these interactions shape the ability of the tick to transmit and acquire pathogens.
