Episode 93: Emma Wilson talks about Toxoplasma gondii infection and its consequences

Our guest today is Dr. Emma Wilson, a researcher who has spent the past 15 years studying Toxoplasma gondii, a protozoan parasite that infects about a third of the world’s population. She is a native of Scotland and a professor of biomedical science at the University of California, Riverside. Toxoplasma gondii is a single-celled organism found in all mammals. The primary focus of Emma’s research is the immune response in the brain following Toxoplasma gondii infection. Her 2016 research paper in the online journal PLOS Pathogens connected the Toxoplasma gondii to brain dysfunction. Show notes: [00:03:05] Emma begins the interview taking about growing up was born in Glasgow with parents who were in the acting business. [00:03:38] Emma shares how her father advised her to keep all of her doors open, which lead her as a youth to pursue everything she found interesting. [00:04:30] Dawn asks if Emma decided to major in ecology in an effort to help save the rainforests. [00:05:28] Ken asks about Emma’s experience with a “proverbial crazy professor” who showed her a room full of rattlesnakes and how that experience led to Emma’s curiosity in immunology. [00:06:54] Ken asks whether if it’s that she was paid to stand out in the bush so that mosquitos could feast upon her during a research trip to Tanzania. [00:08:16] Ken asks if Emma’s experience in Africa was limited to mosquitos or if she was able to see some of the impressive wildlife there. [00:09:26] Emma discusses her experiences after her research trip to Africa and her decision to pursue work in immunology at Dr. William Harnett’s lab at the University of Strathclyde. [00:10:32] Dawn asks about the research Emma did in Harnett’s lab. [00:11:46] Dawn mentions that Emma had the opportunity to attend a conference in Philadelphia where she met many interesting people. She goes on to ask about the conference and how she ended up spending the next five and a half years at the University of Pennsylvania. [00:13:52] Dawn mentions another conference Emma was able to attend, this one in California, where she stood out for asking so many questions. Dawn asks about how this led her to go to work at University of California, Riverside. [00:16:50] Ken mentions that the primary focus of Emma’s research at Riverside is the immune response in the brain following Toxoplasma gondii infection, further mentioning that in an episode of the podcast “This Week in Parasitism” Dr. Dickson Despommier referred to Toxoplasma gondii as the most successful parasite on Earth. Ken asks Emma to give an overview of what Toxoplasma gondii is and does. [00:18:58] Dawn asks why Toxoplasma gondii has such a high infection rate in countries such as France and Brazil, where close to 80 percent of people are infected. In the U.S., only 15 to 30 percent of people are infected. [00:20:49] Ken mentions that Eskimos, who’s traditional diet is rich in raw meat, have an almost 100 percent infection rate. [00:21:19] Ken asks how the Toxoplasma parasite prevents digestion in the stomach. [00:23:12] Emma discusses how most cases of Toxoplasma in healthy adults present little to no consequences of infection, but that congenitally infected children or people who are immunocompromised can have serious consequences. [00:25:33] Ken asks how an immunocompetent individual keeps the infection at bay and if there is any risk associated with that constantly active immune response in the brain to this infection. [00:27:32] Ken explains that cats are the only definitive host of the toxoplasmosis parasite because it can only complete its sexual reproduction cycle in the gut of a cat. He goes on to explain that cats eat rats, and sometimes rats eat cat feces, which infects the rats with Toxoplasma gondii, When the cats eat these rats the cats perpetuate the cycle. Ken asks Emma to explain how the infection changes the fundamental fear response in rodents that they naturally have ...