Science Seeks Germs
To Kill Other Germs

GRIFFIN, Ga. —(AP)— The nation's scientists are taking aim at the bugs in beef and chicken that make people sick by wiping them out in the bowels of animals before they are slaughtered.

They didn't have to go far to find their exterminators. In one method, other bacteria were fit to handle the task.

"We've concentrated on the end product of food so long when we should be looking at how to stop it from being contaminated in the first place," said Lester Crawford, director of the Center for Food and Nutritional Quality at Georgetown University in Washington.

Salmonella, campylobacter and toxic forms of E. coli all get their start in animal intestines. They can spill out in the slaughterhouse and make their way into food.

Currently, slaughtered chickens are sprayed with chlorine and quick-chilled to slow or halt the spread of bacteria. Inspectors also touch, sniff and sometimes test animal carcasses for contamination. Another method, in which bacteria are killed with zaps of radiation, has run into political opposition from anti-technology activists.

At a lab in Griffin, food scientist Michael Doyle looked inside a cow's stomach for a way to kill E. coli 0157:H7, the mutant microbe blamed in the recall of 25 million pounds of ground beef over the summer.

Doyle found that several types of bacteria inside cattle make their own repellent against E. coli. So he took those bacteria from cattle manure and tissue, grew them in the lab and fed them to calves in their milk.

The bacteria not only wiped out E. coli in one group of calves within three weeks, it also kept it from invading a second group, said Doyle, who runs the University of Georgia Center for Food Safety and Quality Enhancement.

Doyle hopes his work will lead to a product that could be fed to cattle to clean them out before they are sent to slaughter. He wants to get the product to market within three years, at a cost of about $1 per animal.

"This type of technology is exactly what we need if we are going to keep the bacteria out of the food supply," said Caroline Smith Dewaal, director of food safety for the Center for Science in the Public Interest, a consumer activist group opposed to most technological programs.

Several researchers are working on a similar concept for chickens.

A new oral vaccine aimed at cutting down salmonella infections from eggs and poultry could be available for farmers by early next year. It would cost less than a penny per bird.

Developed by biologist Roy Curtiss III of Washington University in St. Louis, the vaccine is a weakened form of salmonella that allows the bird's defenses to fight off infections.

Scientists at the U.S. Department of Agriculture's Research Service in College Station, Texas, also have patented a mixture of bacteria from a chicken's gut that wards off salmonella in chicks.

The mixture is now being sold overseas. The approach is awaiting approval in the United States from the Food and Drug Administration.

In Canada, Andy Potter and his colleagues at the nonprofit Veterinary Infectious Disease Organization are also working on an E. coli vaccine for chickens. They hope eventually to develop a ``super vaccine'' that can also fight salmonella and campylobacter.

"Food safety begins when the animal is born," Potter said.

Many types of E. coli are present in humans and animals and aid digestion. But the toxic form _ E. coli 0157:H7 _ serves no purpose. Neither does salmonella or campylobacter.

Killing bacteria inside animals isn't foolproof. Doyle, for example, still has to find out how long his method will keep E. coli at bay and whether the bacteria will interfere with other animal antibiotics.