The photo is the work of postdoctoral research associate Christoph Schaudinn of the USC Center for Biofilms.  A native of Germany, Schaudinn earned his Ph.D. in microbiology from Humboldt University in Berlin before joining Bill Costerton’s research team in late 2004. 

Schaudinn specializes in capturing the microbiological world through the use of electron and laser microscopes.  Together with research associate Amita Gorur, he hopes to use his images to illuminate the secret life of biofilms in the context of their environment, namely our mouths. 

“When you study a frog, the frog is in the pond, the pond is part of an environment, of course, it is normal.  But microbiologists sometimes forget this; they focus on their issue and forget the rest.  We want to study the bacteria in their natural environment,” says Schaudinn.

Studying them in their natural environment is slightly more complex than it sounds.  To view bacteria with an electron microscope, specimens must be fixed and embedded in resin then cut into sections no more than 60 to 80 nanometers thick, roughly the width of a human hair.

In addition, since bacteria are mostly made of lighter elements such as carbon, sulfur and nitrogen, to see them in the electron microscope’s tube, they must be attached to heavier, radioactive elements such as uranium. 

“This all sounds very unhealthy, but the uranium never leaves the tube.  There are a lot of very old microscopy scientists,” jokes Schaudinn.

For Gorur, who completed her microbiology training at Madurai Kamaraj University in southern India, the opportunity to truly observe bacteria as they respond to each other, their host’s immune system and other stimuli is intriguing. 

“There are a lot of variables in this.  Every person is different.  Oral hygiene is different— what part of the world you come from, what disorders and diseases exist—so many factors come into play,” says Gorur.

The oral cavity as seen through Schaudinn’s images is a remarkable world teeming with life.  In this microbial ecosystem—scientists have identified 347 subgingival species of bacteria and around 500 total in the human oral cavity—there is a staggering array of activity taking place.

Like the primordial bacteria of Earth’s pre-Cambrian beginnings, biofilms in the oral cavity live in a nutrient rich, but hostile and volatile environment.   Clinging to the surface of teeth and tissue, biofilm bacteria must compete with other bacteria, fend off the human immune system, recover from daily attacks by brush and floss, and occasionally thwart the best efforts of our own alumni.

“We’ve looked at images with endodontists, and you could see the bacteria hiding in the dentin tubules.  They’ve cleaned up the area clinically, but their instruments can’t reach these bacteria,” says Gorur. 

While that visual representation served its purpose, Gorur and Schaudinn are preparing to embark upon a project that may provide more substantial information and maybe, one day, more effective biofilm management techniques.

Combining the images with data collected from the patient—health history, immunological markers, hygiene habits and other relevant information—the duo hope to draw comparisons between biofilms and environment.  If that sounds a little vague, it’s by design.