Brucellosis vaccine, diagnostics research progressing at UW

University of Wyoming scientist Gerry Andrews is not wearing the starched white laboratory coat one might expect. Nor is he partaking in his typical daily routine, weaving from one station to the next, pipette in hand.

Today, Andrews leans back in his desk chair, comfortable in a pair of jeans and button-down shirt, with his hands crossed over a knee. Despite the absence of the lab coat and test tube, Andrews exudes the level-headed, analytic patience of a scientist as he discusses the time-intensive process of his team's research.

"You have to do it systematically. We have enough data I feel comfortable moving forward, but we have a long way to go," says Andrews, leaning forward in his chair. "Animal work takes a lot of time, you know."

Andrews knows very well. He has been researching elk brucellosis vaccines and diagnostics since 2005. Andrews, an assistant professor in the College of Agriculture's Department of Veterinary Sciences, and his team hope their research will eventually lead to better diagnostic methods and possibly a more effective vaccine for brucellosis in elk, cattle and other animals.

Brucellosis has been a prominent problem for Wyoming and its livestock industry. In 2004, when two herds of cattle were infected with Brucella abortus in western Wyoming, most likely due to contact with nearby feed-ground elk, the state lost its brucellosis-free status for two years. B. abortus is the species of bacterium that can cause elk, bison and domestic cattle to abort.

A new diagnostics method or vaccine could help those researching brucellosis, and it could ultimately help ranchers, wildlife managers and others control the disease.

This is where Andrews and his team come in.

When he began working on the project in 2005, Andrews was aware of the need for better diagnostics methods and a better brucellosis vaccine. "Depending on the success of the research, developing better diagnostics should help wildlife managers streamline brucellosis process management. A new, effective vaccine would also most certainly contribute," he said.

In addition, the new diagnostic tool or vaccine would provide to ranchers a sense of psychological security. "The rancher won't be worried when he or she sees elk mingling with livestock if the cattle are immune and the elk are as well," Andrews speculated.

The research could be useful for diagnostics and vaccines in both cattle and wildlife. Furthermore, Andrews said, if disease eradication is the ultimate goal, then the most aggressive approach--vaccinating both cattle and wildlife--would probably be the best option.

While Andrews, the blue jean optimist, considers this ultimate goal a possibility, Andrews, the test tube scientist, knows the research team still has a long road to travel.

Before they could consider developing better diagnostics or a new vaccine, Andrews and his team first had to understand the bacterial virulence genes involved in the disease. Using a gene discovery approach called In vivo-induced antigen technology (IVIAT), they identified a set of genes that is up-regulated, or turned on, by the Brucella bacterium when it's inside the host.

Jack Leonhardt, who was raised on a ranch near Cowley in Wyoming's Big Horn Basin, worked under Andrews while finishing his bachelor's degree in microbiology last spring, and he is continuing his studies in the lab as a master's degree student.

"I enjoy applying the technology I learned about in classes, and I have found working with brucellosis in the laboratory relates back to my ranch work," Leonhardt said. "I did not think going into microbiology would tie into ranching, but it's kind of ironic I am still indirectly working with cattle."

Andrews said major goals are to evaluate the proteins for their potential use as diagnostic targets and for the possibility of their use in a vaccine.

Last year, Andrews' team began evaluating the effectiveness of three of the 10 proteins they identified using IVIAT as vaccine candidates in laboratory mice infected with B. abortus Strain 19 (this strain has been used for elk but is not very effective).

One particular protein, which Andrews fondly referred to as "our favorite," showed significantly more rapid clearance of B. abortus Strain 19 and significantly reduced bacterial load in the rodents injected with the protein than those that were not. Andrews said the next step is to try combinations of the different proteins and to characterize how animals respond to them immunologically.

These proteins, Andrews said, may also be used as predictors of brucellosis in diagnostics work. In essence, by simply dripping an animal's blood onto a new diagnostic device, researchers would be able to use the proteins in the blood to identify a brucellosis-positive or vaccination-positive animal.

So why aren't researchers and wildlife managers using this diagnostic tool or trying new vaccines on elk?

Time is one factor, but Andrews also cites other issues affecting the pace of the research.

UW has only a biosafety level 2 lab, but a BSL-3 lab with animal capabilities is required for the next step in the research, which involves infecting vaccinated rodents with wild-type strains rather than B. abortus Strain 19. Working with wild-type brucellosis requires a BSL-3 lab suitable for work with infectious agents that may cause serious or potentially lethal diseases as a result of exposure.

Groundbreaking for the new $25 million BSL-3 lab took place in June, and the project should be com

plete within two years. So, for now, Andrews and his team will travel to Colorado State University in Fort Collins, Colo., which has an animal BSL-3 lab, for the next step in their research.

Andrews said there is very little genetic-discovery-based brucellosis research happening elsewhere in the country. Instead, research is concentrated on improving RB51, the current vaccine used for cattle that is only about 70-percent effective. The Andrews team is not working to improve the current vaccine but is rather trying to develop a new one.

Leaning back in his chair, he says, "It's going to take time and patience."

The full story and photos, in addition to stories on other research and activities in the College of Agriculture, are in the fall 2009 edition of Ag News at www.uwyo.edu/uwexpstn/AGNEWS/AGNEWS_main.htm.

Posted on Wednesday, October 28, 2009