NAU Undergrad Itching To Discover How Fleas Spread Plague

Health officials in the Four Corners region of the United States continue to wrestle with a persistent plague pandemic that has the potential to infect humans. Northern Arizona University (NAU) undergraduate Bret Clawson is tracking the plague in prairie dog populations to better understand the bacterium’s persistence and to prevent widespread outbreaks.

Learning more about the plague’s genetic structure

Clawson, a chemistry and biomedical science double major, collected two species of fleas that live on prairie dogs to learn more about the genetic structure of the plague. This research may provide insight into how fleas move in rodent populations. “Any population of rodents can have a plague outbreak,” Clawson said. “This research helps county health departments determine if insecticidal dustings are necessary and when to treat to minimize the likelihood of an outbreak.”

Between 1,000 and 2,000 cases of human plague are reported worldwide each year, and plague is present in wild rodent populations throughout the United States. And there may be a connection between rodent outbreaks and human infection—14 percent of human plague occurrences in the United States coincide with plague outbreaks in prairie dogs. “Previous studies have shown the greatest density of contemporary human cases of plague in the United States occurs in the Four Corners region,” Clawson said. “And prairie dog ranges overlap with the greatest concentration of plague cases.”

Tracing the plague from China around the world

Clawson’s research builds on the work of Paul Keim, NAU Regents' Professor of Biological Sciences and Director of NAU’s Center for Microbial Genetics and Genomics, and Dave Wagner, NAU Assistant Professor of Biological Sciences, who published a study that traced the plague from China along its path around the world. 

“I’ve benefitted from the individual mentorship of faculty members, and I’ve had exceptional opportunities.”

Keim and Wagner pinpointed the plague’s introduction to the western United States to the arrival of infected rats that scurried off ships in the ports of San Francisco more than a century ago. Clawson employed Keim and Wagner’s research methods of genome mapping to better understand how plague persists in the region.

Spreading the word about his research

Clawson has been selected to present his research findings at the National Conference for Undergraduate Research (NCUR) at the University of Wisconsin – La Crosse, April  11 to April 13, 2013.  In 2012 he earned the award for best undergraduate poster at the American Society for Microbiology’s Arizona and Nevada chapter conference. “I feel honored to be given the opportunity to present my work,” Clawson said. “One thing I took away from my past experiences was a great sense of pride for belonging to the scientific community.”

Clawson has been involved in every step of his undergraduate research project—from collecting the fleas to completing the genetic mapping—an opportunity he said makes his undergraduate experience at Northern Arizona University enriching and meaningful. “NAU has such a great environment for studying in the sciences,” Clawson said. “I’ve benefitted from the individual mentorship of faculty members, and I’ve had exceptional opportunities.”  Clawson said that he plans to apply the skills he gains at NAU toward a career in virology or endocrinology.

--Article adapted from NAU News