DeVeaux, Kunza, Murray Study E. coli in State Waters

Mines researchers have been testing toxin levels in South Dakota waterways in an effort to trace the extent and the origins.

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 presence of toxin genes in every other state where similar experiments were conducted only reached 30 percent. 

An additional $50,000 from the East Dakota Water Development District and the City of Sioux Falls is funding SD Mines research to help discover the magnitude of the problem and potential for super bugs to appear.

In Rapid City, Mines researchers found disease-causing traits from six testing sites in Rapid Creek, and research is continuing to gain a better understanding of the problem. 

Are all traits carried in the same bacterium, suggesting an immediate health concern, or do different bacteria have different traits, posing a future health risk? Is the primary cause related to fecal matter washing into the water after storms or is it so embedded in the ecosystem the problem is re-suspension?

Though answers remain elusive, the commitment to help ensure the public’s health is not. Kunza, DeVeaux, and Murray also presented at the South Dakota Public Health Association’s meeting in June.

Last edited 11/3/2016 9:04:35 PM

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