106: Creepy dreadful wonderful parasites (and a few bacteria) with Bobbi Pritt

Julie’s Biggest Takeaways:

Parasites are incredibly varied in many characteristics, including their size! Some are microscopic, while others are macroscopic and can be seen with the naked eye. Not just small macroscopic, although some worms at 35 cm can be considered quite large. Some tapeworms can reach 50 feet!

Bobbi Pritt’s blog started as an exercise to share the cases she observed while a student at the London School of Tropical Medicine. She wanted to share these cases with students back at the Mayo Clinic, but found the audience grew to include clinical parasitologists, microbiologists, and parasite-interested people worldwide. Part of its success relies on its succinctness: a short, digestible case study with the minimum information needed to make a diagnosis.

Pritt’s research focuses on developing molecular tests to detect microorganism RNA or DNA. Molecular tests can be used as a complementary diagnostic test or as the primary test, which can give healthcare workers definitive information to make therapeutic decisions much more quickly than a test that requires culturing the microorganism.

A new bacterium that causes Lyme disease, Borellia mayonii, was found because the molecular tests that detect Borellia burgdorferi are flexible enough to detect multiple species and can differentiate between the different types of organisms. It was an astute technologist working at the bench who recognized the readout was slightly different than

We did a tick drag, taking a white cloth and dragging it through vegetation. The Ixodes ticks that transmit Lyme disease will think the sheet is a host and will grab onto the sheet, allowing easy collection of a large number of ticks to test for bacterial presence.

One of the outstanding questions in parasitology is the relationship of Blastocystis (formerly known as Blastocystis hominis but may actually be several species) to human health. Blastocystis lives in the intestinal tract and may cause irritable bowel-like syndrome. Definitive evidence on whether Blastocystis causes intestinal disease has yet to be presented, and there is a lot of opportunity for research in this area.

Links for this Episode:

• Take the MTM Listener survey (~3 min.)
• Creepy Dreadful Wonderful Parasites (Bobbi Pritt’s blog)
• ParasiteGal: Bobbi Pritt on Twitter
• Pritt B.S. et al. Identification of a Novel Pathogenic Borrelia species causing Lyme borreliosis with unusually high spirochaetaemia: a descriptive study. Lancet Infectious Disease. 2016.
• MTM Episode: Biofilms and Metagenomic Diagnostics in Clinical Infections with Robin Patel
• HOM Tidbit: Patrick Manson. On the Guinea Worm. British Medical Journal.
• Bobbi on This Week in Parasitism (TWiP)