Brucellosis study targets cellular function

Photo: Washington State University

While brucellosis in the U.S. has been “essentially eradicated,” according to Washington State University researchers, the disease — in livestock and in people — remains a significant global concern.

Now, Washington State researchers have been awarded a $2.75 million grant to explore how bacterial proteins work together to cause one of the world’s most widespread zoonotic diseases.

Brucellosis is mainly caused by the bacterium Brucella abortus, and cattle are a primary host. (Other Brucella species of most concern include B. suis, primarily affecting swine and reindeer but also cattle and bison, and B. melitensis, which primarily affects goats but is not present in the U.S., according to USDA’s Animal & Plant Health Inspection Service, which operates the National Brucellosis Eradication Program.)

The NIH grant will focus on four of several proteins characterized in Brucella that are known to infiltrate host cells. The grant follows on research conducted in the Jean Celli lab that characterized a protein known as BspF that manipulates specific cell functions and steals nutrients required for the bacteria to grow and multiply.

Researchers will examine the individual functions of the select proteins and how they work together to help the infection persist.

“Understanding the way those bacteria function cannot be determined by one bacterial protein function; you need to know how they all work together,” said professor Jean Celli, of the WSU Paul G. Allen School for Global Health, whose lab was awarded the grant. “When you understand what host functions are required for the disease to develop, you can target those to prevent the disease from happening, but right now we need to find out how everything works.”

Celli said the research dollars may lead to ways to block the disease, by identifying and blocking of a step in the cellular processes that the bacterium is dependent on to grow.

While antibiotics can treat brucellosis and the disease has been “essentially eradicated in the U.S.” due to vaccine use in animals — as well as widespread milk pasteurization practices — the vaccine is not permitted for human use and the disease is endemic in much of the world, Washington State said.

“It’s not only a human health concern, it’s an animal health concern,” Celli said. “There is a big need to understand how this disease develops so we can find ways to mitigate it.”

Tim’s Take

Finding better treatments and preventions against brucellosis in human health may also lead to better ways of managing brucellosis in livestock — particularly in regions of the world where the disease is endemic — and wildlife, which can spread the disease to people and livestock, such as in the Greater Yellowstone Area (where it is present in bison and elk herds).