The Big Sioux River and Rapid Creek winding through
the heart of South Dakota’s two biggest cities transform into nature’s
playground during the summer months, but they are far from pristine. They are
among the nearly 70 percent of waterways on the state’s list of impaired bodies
that do not meet water-quality standards.
The Big Sioux has been on the list nearly two decades,
but until last year no one had sampled it for genes that can make the
often-harmless E. coli into a disease-causing pathogen, which sickens
around 95,000 Americans annually, according to the Centers for Disease Control.
Faculty researchers Dr. Lisa Kunza, an aquatic
ecologist, and Dr. Linda DeVeaux, a microbiologist and geneticist, both from
the South Dakota School of Mines & Technology Department of Chemistry &
Applied Biological Sciences, are searching for answers that could ultimately
improve public safety. Biomedical engineering doctoral student Kelsey Murray
has been assisting.
Their initial findings last spring caused alarm among
Sioux Falls city and county officials. Ninety-five percent of the samples
pulled from Skunk Creek and the Big Sioux, both in Sioux Falls, contained a
Shiga toxin gene that can turn E. coli into a dangerous strain. Intimin,
a gene that helps E. coli colonies embed themselves in the human gut and
thrive, was found in 100 percent of the samples.
In comparison, the prese...