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Hours after a wastewater
system failure at Indiana’s largest hog farm
dumped 50,000 gallons of raw sewage into a tributary
of the state’s most scenic waterway on April
4—the latest in a series of damaging spills
at Pohlmann Farms—Wabash student scientists
were on the scene. The Indiana Department of Environmental
Management (IDEM) responded to the massive fish
kill, and TV news carried images of the ecological
calamity across the region. But Wabash students
were tracking two less visible and more persistent
menaces.
For the past two years under
the direction of biology professor Shivi Selvaratnam,
Maury Raycroft ’03, Andrew Smithka ’03,
and Peter Murage ’03 have been sampling Sugar
Creek sediment and studying PCB (polychlorinated
biphenyl) contamination in the creek and the presence
of bacteria that degrades the known carcinogen.
Dave Kunberger ’02, Paul Drambarean ’05
and seniors Wes Ket and Marty Dado have been working
with Selvaratnam to study the presence and growth
of antibiotic-resistant bacteria caused by treated
hog waste entering the creek.
It’s hard to imagine more
relevant research. Doctors fear that overuse of
antibiotics is creating a growing population of
bacteria increasingly resistant to medicine’s
limited range of antibiotics. At the same time,
repairing the damage spread by agricultural run-off
to wetlands and waterways has mobilized some of
the nation’s largest environmental projects,
including those run by Smithsonian Institute ecologist
and Wabash alumnus Dennis Whigham ’66. Selvaratnam’s
research projects combines these hot environmental
topics and puts them under the microscope. The professor/student
collaboration is breaking new ground in the state.
“As far as I know, no one else has studied
these particular issues in the same way we are,”
Selvaratnum says. “IDEM has looked at PCB
contamination of Sugar Creek, but not at the microbial
community level.”
What they’ve found thus
far is alarming. Long before the massive spill,
and sampling for one year from three sites—one
upstream from the hog farm, one near the farm’s
wastewater outlet on Little Sugar Creek, and one
farther downstream—the scientists’ results
indicated increased numbers of bacteria resistant
to antibiotics, with the highest concentration at
the site nearest the wastewater outlet. Eighty percent
of these bacteria are resistant to multiple antibiotics.
What this means for people and
animals in Sugar Creek is speculation, Selvaratnam
says—no studies have been done to establish
correlation between increased bacteria in the creek
and human health problems. But she admits she will
not allow her children to play there.
If a human health risk was established,
it would be something like this: you accidentally
ingest creek water or it makes contact with a skin
sore or cut, allowing bacteria into your system.
“Most of these bacteria
are fecal pathogens that cause diseases like diarrhea,”
the professor says. “If it’s not treatable
by antibiotics, you could pick up from Sugar Creek
something that’s hard to treat.
“You also have to
ask, ‘What are these antibiotic-resistant
bacteria doing to other species in the ecosystem?’
They could pose a problem for other organisms, or
could transfer their antibiotic resistance to indigenous
bacteria.”
And as they work their way through
the food chain—a fish ingests the bacteria,
a bird eats the fish—the bacteria could be
carried far from the petri dish Sugar Creek has
become.
This summer, Selvaratnam, [biology
professor] Aus Brooks, and their students will study
the interaction between the bacteria and algae in
the creek.
“The question we haven’t
been able to answer is how long these antibiotic
resistant bacteria stay around,” Selvaratnam
says.
Kier Marshall ’04 is testing
one theory—that these bacteria are harbored
by algae growing on rocks. The algae may provide
suitable habitat for the bacteria to grow and possibly
reproduce.
Selvaratnam is submited a paper
for publication, and in May she and her students
presented their preliminary results at the national
meeting of the American Society for Microbiology
in Washington, D.C. She also hopes that recent calls
from reporters and IDEM will spread word of the
potential health hazard of these agricultural practices.
Her goal for the PCB project
is more ambitious.
“People know there are PCBs
in Sugar Creek—anyone who can read the fish
advisory signs along its banks knows that,”
Selvaratnam says. She hopes to be able to study
how the concentrations of these carcinogens can
be reduced.
“I’m hoping
in the next year to be able to work with small microcosms—bring
samples of the sediment in to the lab, add PCB-degrading
bacteria and see what happens.”
“Doing Science”
Whether or not the public responds
to Selvaratnam’s research, the benefits for
Wabash students have been immediate.
“I wanted to get
field experience, to work on something that might
help people,” says Raycroft. “I’ve
learned a lot. You get a lot of freedom to put your
own twist on things.
Dado declares: “You get
a chance to screw it up!”
Dado recalls a stretch of two
months when he and Ket struggled without any clear
results from their experiment. “It forced
us to sit down and actually think about what we
were doing wrong, and how we could fix it,”
Dado says.
“They develop independent
thinking,” Selvaratnam says. “And now
these guys can troubleshoot, just as scientists
do.”
“Doing research,
I found out that in science you’ll have some
success, but it’s going to be three times
more work than you thought it would be,” Raycroft
says. “But it’s also more rewarding.
When you do a lab for class, it’s all been
done before. But with research projects like these,
we’re doing something that’s our own,
something that can be useful.”
“Being able to do
so much here put me far ahead when I applied to
graduate school this year,” adds Raycroft,
who enters the PhD program at Notre Dame this fall.
“They look at the research I’ve done
and are impressed.”
Medical school-bound senior Wes
Ket, who served an internship at IDEM before his
research with Selvaratnum, sees the research broadening
the factors he’ll consider when he begins
diagnosing patients.
“I’ll certainly
be more aware and open to the possibility that environmental
influences may be more of a factor in the patients
I treat.”
Passing it on
Most scientific studies last for
years and engage a steady stream of student researchers,
another plus for Wabash students. New researchers
must be introduced to the project, and there’s
nothing like teaching the next crew to imbed what
“veteran” student researchers have learned.
“Maury worked with
me for two years, then mentored Wes and Marty, and
now they’re all mentoring the next group,”
Selvaratnam says. “These “veterans”
teach the new guys and the techniques and work with
them n the projects. I think that’s an important
experience for them. It’s similar to a grad
school approach, but it works well for my lab.”
The design of the new science
building makes for frequent collaboration, not only
between professors and student researchers, but
between students and professors working on different
projects. This year Selvaratnam, David Polley, and
Richard Nelson convened bi-weekly floor meetings
on the second floor’s “serendipitous’
space, bringing the professors and student researchers
together to talk about their projects, learn about
the others’, and exchange ideas.
“These meetings have helped
us become a community of learners,” Selveratnum
says. “The students feel comfortable seeking
help from any of us.”.
“We could never do
this in Thomas labs,” Selvaratnam concludes.
“The new building creates a space where science
students and professors collaborate more freely,
where students always have each other to hang out
with— a place to talk and be excited about
science.”
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