Shousun C. Szu a scientist at the national institutes of Health says the best way to prevent people from being poisoned by deadly E.coli would be to vaccinate all infants against the bacteria. Vaccines for people and for cattle are just two approaches under development to prevent or treat food poisoning by the strain E.coli

Efforts to develop drugs and vaccines for people also face barriers. Because outbreaks are rare and sporadic for instance, it would be difficult to test such treatments in clinical trials. E.coli causes 75000 cases of infection and 61 deaths in the United States each year, according to a 1999 estimate by the centers for disease control and prevention posted on the web site.

Antibiotics the usual treatment for bacterial infection, only make things worse by killing the bacteria and releasing more of their toxin, the sole treatment shown to reduce the severity of kidney problems was intravenous fluids. An experimental approach is to feed cows sodium chlorate, a chemical used in the pulp and paper industry. This idea takes advantage of the fact that O157 has an enzyme that allows it to survive without oxygen, which is not true for most desirable bacteria. That enzyme will convert sodium chlorate to sodium chlorite, which poisons the pathogen.

Experts say multiple approaches might be used in parallel, because no single approach works perfectly. So we are left with prevention, prevention and prevention, preventing the contamination from ever occurring.

As few as 10 E.coli bacteria can make someone ill. The bacteria release one or two potent toxins that cause bloody diarrhea. In 15 percent of children younger than 10 and more rarely for adults, the infection causes hemolytic uremic syndrome, in which red blood cells are destroyed and the kidneys fail. In a small percentage of such cases, the syndrome proves fatal.

E-Coli Vaccines

Szu of the health institutes and colleagues have developed a vaccine made up of complex sugar that is on the surface of the bacteria, the very O-type polysaccharide that gives O157 its name.
The sugar is linked to a protein taken from another bacterium to make it more potent in stimulating the immune system. Szu and collaborators have tested the vaccine on adult volunteers and on children 2 to 5 years old.
The volunteers were not exposed to O157- that would be unethical – but they developed antibodies to it. Moreover, when the bacteria were exposed in the laboratory to blood samples from vaccinated people, the microbes were killed.
The vaccine is years from the market. The cattle vaccine developed by Bioniche is based on the work of B. Brett Finlay of the University of British Colombia, who helped discover how O157 bacteria attach themselves to the cattle intestines, where that can then multiply.
The bacteria use a type of microscopic syringe to shoot proteins into the cells lining the intestine, and the cells erect a protein pedestal, to which the bacteria can blind.
The bioniche vaccine consists of proteins involved in the attachment.
The idea is that the cow’s immune system would make antibodies to attack the proteins, thereby blocking the attachment.
The bacteria could still pass through the cow and into manure. But if they could not colonize, their levels should remain low.
Tests at the University of Nebraska found that the vaccine reduced by 70 percent the number of cows shedding O157 into their manure.