Poisoning Microbe Targeted in New Studies
By Marcia Wood
July 10, 2001
If a microbe can somehow cling to a
food surface, it might be able to start a successful invasion. Now,
Agricultural Research Service scientists
are snooping into the secret tricks that food-poisoning organisms use when they
grab onto chicken skin, for instance. Their studies may lead to new, safe, and
effective ways to thwart pathogenic microorganisms such as
Campylobacter. That microbe causes an estimated 2 million illnesses,
10,000 hospitalizations and 100 deaths a year in this country.
Microbiologist Robert E. Mandrell and colleagues at the
ARS Food Safety and
Health Research Unit in Albany, Calif., are spying on Campylobacter
jejuni, the most troublesome of the Campylobacter species. They want
to determine how the microbes genes interact with molecules known as
Preliminary experiments by Mandrells team at the
ARS Western Regional Research Center in
Albany are revealing details about two kinds of chicken-skin molecules that
likely serve as receptors. The molecules are proteins called proteoglycans and
fat-containing compounds called phospholipids.
In a test with 12 Campylobacter strains, the researchers found that
all of the strains bound to proteoglycans within about two minutes. In about 20
minutes, the Campylobacters formed large colonies. In another test, the
scientists showed that eight of nine Campylobacter strains, when exposed
to a mixture of chicken-skin phospholipids, bound to a phospholipid known as
Other scientists have already speculated that proteins or fats in meats may
act as receptors. The Albany investigations provide new evidence that
proteoglycans and phospholipids probably play that role in poultry and show the
speed with which the microbe can attach to receptors that it apparently
Mandrell did the work with Anna H. Bates, David L. Brandon, Gary A. McDonald
and William Miller, of the Albany team, and with Amy O. Charkowski, now at the
University of Wisconsin, Madison.
An article in the July issue of the agencys Agricultural Research magazine
tells more and can be viewed on the World Wide Web.
ARS is the U.S. Department of
Agricultures chief scientific research agency.