As she walks into her microbiology laboratory at Oregon State University, Kate Field hands her graduate student a Ziploc bag full of tubes of fecal samples. "These are just in from New Zealand," she says with a smile. For just being handed what essentially amounts to a bag of poop, her graduate student seems pretty excited as well. Now, the student's job is to test whether the genetic markers Field has developed can reliably identify what type of animal produced the sample. "Right now they're working pretty well," Field says.
Field is developing a number of PCR-based methods to track fecal contamination culprits. She pulls out a figure of a host clade with dozens of branches to demonstrate the variety of species-specific microbial markers from Bacteroides bacteria, including cat, pig, elk, and human. Her assays look for the presence of particular ribosomal RNA sequences within groups of anaerobic bacteria that ...
