In search of 'wee beasties'
Sept. 29, 2004
By Gigi Marino
When most people look at a newly clean counter, they see just that. But not Margot Vigeant. This assistant professor of chemical engineering may not see the wee beasties flagellating merrily along, but she knows they are there. "Basically, if you have any surface that is wet for any length of time, from a few minutes up to a few hours," she says, "it will be covered with bacteria."
Vigeant is an expert in bacterial adhesion. She studies the ubiquitous E. coli, which can be found everywhere from the human colon to culinary tools (in unsanitary conditions). These bacteria have flagella, whiplike appendages that propel them through their microscopic worlds.
Vigeant says that people tend not to study bacteria with flagella because their ability to swim can complicate the research. But their ability to do a St. Vitus' dance through liquid environments is exactly what interests her.
"I'm trying to understand the fundamental properties of bacteria and the fluid they swim in," she says. "For instance, what happens when you add soap? Do they come off? Stay off? Come back?"
What she has found will not please obsessive-compulsives. Soap dispels the bacteria. "But if you rinse, they come back and stick," Vigeant says. "It's annoying." She's careful not to extrapolate her findings to bacteria on the hands — the experiments she's doing in the lab are conducted on glass.
But Vigeant points out that the ramifications could be important, especially in the medical community, where keeping items sterile is vital. "The idea is to find out specifically what's happening on a molecular basis." To do so, she has collaborated with colleagues to build a precise instrument — a total internal reflection aqueous fluorescent microscope.
"There aren't a lot of them in the world," she says. Students from the physics department designed the fiber optics for the light beam, mechanical engineers helped with the hardware, and chemical engineers completed the final alignment, allowing users to track bacterial movement within nanometers (other microscopes track within 500 nanometers).
"It's really neat to work in a place where we can pull from different resources and build something like this," she says.
Vigeant, who has been at Bucknell for five years, involves students in every aspect of her work. Students work on real projects, which they post online. In the last semester, the student website elicited calls from C.S.I. Miami and Schick.
"It's been fun for me," says Vigeant. "It tells me that we're going in the right direction."
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Gigi Marino is editor of Bucknell World, the university's alumni magazine.
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