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Let's Talk Parasites

Isaure de Buron, biology professor

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Biology professor Isaure de Buron does not want this article to be about her. She wants it to be about her field of study: parasitology.

Forget the childhood in Brittany, the windsurfing in Montpellier, the Fulbright in the Czech Republic. Let’s not bother with the prestigious publications, the fellowships, the major contributions to science. Let’s talk parasites.

“Parasites are cool creatures!” de Buron laughs. “You automatically think disease, but really their biology is fascinating.”

She flashes a broad, knowing smile: She is used to the layman’s apprehension, accustomed to having to convince the outsider. What she may not know is that her enthusiasm for creatures most of us try to avoid is catching. When she proposes a movement in defense of parasites, she’s still smiling, tongue planted firmly in cheek, but the point is taken. Maybe parasites can actually be, well, interesting.

For starters, de Buron notes, parasites are highly successful creatures. Although we may think of them as shameless freeloaders who hitch rides and sponge meals, your average parasite has to work mighty hard just to stay alive.

The environments parasites inhabit are extremely inhospitable, often harboring cells whose role is to kill them. Some parasites require living in up to three or four different hosts before reaching their definitive host, the one in which they will reach maturity and reproduce. In human terms, that’s like having to first live in an ocean, then in a volcano and then on the moon – just in order to have kids.

What especially interests de Buron are the methods parasites employ in order to survive the various threats to their existence. Some will cloak their identities, camouflage themselves, to confuse the host’s defense system. Others will attack and infect the very cells that should kill them. Still others will modify the behavior of a host so as to favor their own survival.

Lest we get to thinking these critters are incredibly crafty, de Buron notes that parasites don’t adopt these tactics on purpose, but by way of natural selection. Every host, “even the tiniest mosquito,” has a defense system which fights parasites. Those that survive the defense system will reproduce and pass their genes on, which will in turn provoke the host defense system to adopt another tactic, which will in turn weed out ineffectual parasite genes, and so on.

In the parlance of parasitology, this is known as an “arms race,” and because it means that parasites and their hosts prompt each other to constantly upgrade their genetic weaponry, in de Buron’s view it is not too much to say that parasites are agents of evolution.

Certainly parasites are well-adapted to their environment. Whether we like it or not, they have done remarkably well.

“They are everywhere,” de Buron observes. “If someone says, ‘There are no parasites in this area,’ you have to ask, ‘Are there any parasitologists in this area?’”

De Buron knows whereof she speaks: When she arrived in Charleston eight years ago, the general thought was that marine parasites, the ones she now studies, were not especially worthy of attention in Lowcountry waters. But the simple fact of the matter was that nobody had looked hard enough. Extensive research had been logged north of Cape Hatteras, and in the Gulf of Mexico, but data concerning the waters in between were markedly scant. When de Buron came to Charleston, the biological richness of the local estuarine systems astounded her. Where there is life, of course, there are parasites.

It turns out that Charleston’s local waters are so plentiful with (all kinds of) life, “we need 20 more parasitologists to study it all!”

Don’t let that keep you out of the water. She is quick to point out that the presence of parasites usually indicates that an ecosystem is healthy. Parasites are not ancillary to the local biodiversity, but part of it.

In the absence of 20 more parasitologists to study them, de Buron puts in more than her share of hours at her lab at Fort Johnson on James Island, poring over tissue samples, collecting data, exploring the ins and outs of marine-parasite life in collaboration with the S.C. Department of Natural Resources. At the DNR lab, the atmosphere is lively with scientific pursuit; colleagues and students regularly bring de Buron specimens and questions. Currently her focus is divided between the parasitic worms living in Southern flounder and the spotted sea trout. She has (or “we have,” she will insist, with a generous nod to the work of her College students) discovered and described numerous species previously unknown to science. With each new species arises a tantalizing new batch of questions: How do the worms survive? What do they do to their fish host? What is their impact on the larger fish population?

De Buron welcomes the unknowns. Apart from general mirth, curiosity is perhaps her most salient quality. As a child growing up on the coast of Brittany, she was encouraged to ask questions, and to look for answers.

“It started with holes in the sand,” she says. “Just looking to see what was there.”

Instead of a television, her family kept stacks upon stacks of books and cultivated an atmosphere of inquiry, so it’s no surprise that a sense of wonder has inspired and informed her work from the outset.

“I ask so many questions,” she laughs, “some people probably think of me as a pain in the neck.”

The pain-in-the-neck part is hard to imagine, but as a seeker of new points of view, new angles, it’s true she does like to ask questions. When asked if she thinks a person is born with curiosity, her first response is, “What do you think?”

Just in case people aren’t born with it, de Buron encourages her students to ask questions. She doesn’t worry that she might not know the answer: The asking of the question itself represents progress. What might be another professor’s dread– not knowing the answer to a student question – is, to her, a challenge. If I don’t know the answer, her logic goes, let’s find the answer, together. In such a way the learning process becomes interactive, a two-way street, and builds on itself.

Since her arrival at the College in 2001, demand for the courses she teaches has significantly increased. Formerly, most of the students who signed up for courses in parasitology were pre-med students looking to get a jump on med-school topics. Now the course attracts students from a variety of disciplines.

True to form, de Buron hesitates to take full credit for the expanding interest. She links it to the fact that she has brought studies in ecology, studies of the parasite’s place in the broader world, to the course.

In any case, her approach seems to be working. More than a few of her students have made significant contributions to the parasitology field and published in highly regarded journals. The fact that she still calls on some of her former students as collaborators testifies to her talent as much as it does to theirs, even if she won’t put it that way. As de Buron sees it, her primary role as a teacher is to inspire interest in a field of study that is often overlooked. It’s safe to say she’s doing that – and a whole lot more.

Parasites may not be glamorous, but they are intriguing. Marvels of adaptation and survival, they are everywhere, and always will be. In the words of de Buron’s screensaver, installed by a former student as a token of appreciation, “PARASITES RULE!”

– Charlie Geer ’94