UI mastitis vaccine undergoes testing

Staphylococcus aureus isn't the most glamorous of microorganisms. It causes mastitis, the inflammation of cows' udders that can cripple milk production in a dairy. It also causes toxic shock syndrome and food poisoning in humans.

UI microbiologist Greg Bohach is working with Yong Ho Park, a colleague at Seoul National University in Korea, to test potential vaccines against staph bacteria.

Staph bacteria are able to suppress the body's normal immune response through the production of enterotoxins in an infection. The vaccine preparations under testing are enterotoxins that have been slightly altered to neutralize their poisonous qualities.

© Liz Kishimoto/The Spokesman-Review

UI microbiologist Greg Bohach has modified toxins to work as vaccines.

The researchers hope their altered proteins, which have been patented by the University of Idaho, will stimulate animals' immune systems. Some vaccines against staph are already on the market, but none have been able to provide complete immunity, Bohach said.

The mastitis riddle bears huge economic consequences, costing the U.S. dairy industry an estimated $1.5 billion to $2 billion a year.

ÒWe're really the first investigators to do a detailed study of how these toxins affect the immune systems of ruminants," Bohach said.

Bohach said understanding how staph bacteria can suppress immune systems could help unravel how diseases such as cancer and AIDS defeat the body's natural defenses.

The UI's cooperative arrangements to study the staph bacteria extend also to Washington State University. Bohach and fellow UI researchers Ken Bayles and Witold Ferens joined with WSU researchers Larry Fox, Bill Davis, and John Middleton to form the Staphylococcus Aureus Mastitis Research Institute.

Bohach's work has drawn more than $2 million in funding from United Dairymen of Idaho, the UI Agricultural Experiment Station, U.S. Department of Agriculture, and National Institutes of Health.