Students Analyze River Levels of E. coli

“Community awareness of water issues is high at this time, and our students are participating in research that is addressing a contemporary issue.” — Tim Keeton

<em>From left: Hannah Jeffery and Austin Desmarais.<br><br></em>From left: Hannah Jeffery and Austin Desmarais.

Since 2006, Tim Keeton and microbiology students at Alma College have tested the distribution of antibiotic genes in the environment. Over the last two years, the research has expanded to test river levels for E. coli, the bacterium commonly found in the lower intestine of warm-blooded organisms.

Their research is of particular interest to City of Alma officials and citizens, who are concerned about the rising levels of antibiotics, E. coli and nutrients in the Pine River. Evidence of this contamination has been seen in huge growths of algae that have appeared in the river during the summer months.

Sourcing E. coli

The question for the researchers: What is the source of the E. coli? Tests conducted by Alma College students during the summer of 2016 were designed to determine the percentage of E. coli coming from human sources, like leaking septic tanks, vs. animal sources, such as agricultural runoff from farms.

“Animal feeding operations use a lot of antibiotics,” says Keeton, associate professor of biology. “We are interested in the impact these operations have on the environment. We believe that agricultural runoff through field tile systems is adding disproportionate amounts of antibiotic genes and E. coli levels to the river and its tributaries.”

<em>Tim Keeton<br><br></em>Tim Keeton

Lab Work Detects Bacteria

The Gratiot Area Water Authority, which provides drinking water for both Alma and nearby St. Louis, gets about 25 percent of its water from the Pine River. The water is treated, but the more contaminants found in the water, the more the water has to be treated.

In their research, the students go to various sites along the Pine River, other streams and drainage ditches, collect water and sediment samples and then test the samples to determine their concentrations. As part of the laboratory work, the students perform a quantitative PCR assay, or polymerase chain reaction, a process used in molecular biology that determines the detection of bacteria from humans, cattle and other animal sources.

“We look at the genetics of bacteria to determine who hosted it,” says Keeton. “Bacterium from a human differs from bacterium from a cow.”

<em>Students collect samples from the Pine River.<br><br></em>Students collect samples from the Pine River.

Real-world Science

This research is valuable to students because it exposes them to applied molecular and microbial science in a real-world setting, says Keeton.

“They learn laboratory techniques, such as DNA fingerprinting, and they have opportunities to meet city officials who are concerned about the quality of their community’s drinking water,” he says. “Community awareness of water issues is high at this time, and our students are participating in research that is addressing a contemporary issue.”

The results of their research will be shared with the Alma community.

Story published on August 09, 2016