1. Steinernema carpocapsae Xenorhabdus nematophila Steinernema carpocapsae Xenorhabdus nematophila The bacterium Xenorhabdus nematophila as Dr. Jekyll: Mutualism with nematodes (Steinernema carpocapsae)

2. The bacterium Xenorhabdus nematophila as Mr. Hyde: pathogenesis against insects Xenorhabdus nematophila Manduca sexta (Tobacco hornworm)

3. As a microbiologist, my interest is in understanding the ways in which microbes, particularly bacteria, interact with other host organisms, a phenomenon known as symbiosis. In my lab, we study the bacterium Xenorhabdus nematophila, which interacts with two different host organisms in two very different ways. The bacterium associates with a microscopic worm called a nematode (Steinernema carpocapsae), which is found in soil and can infect caterpillars. Upon infection, the nematode releases its bacterial partner into the insect’s blood (called hemolymph), and the bacteria kill the insect and break down its tissues as a food source for both bacterial and nematode reproduction. When all of the nutrients are utilized, the bacteria colonize the nematodes once more and the nematode seeks out a new host insect. I am particularly interested how the bacterium regulates gene expression at various stages throughout the symbiotic cycle. Image from: Herbert and Goodrich-Blair. 2007. Nature Reviews Microbiology. 5, 634-646