THURSDAY, Aug. 22, 2002 (HealthDayNews) -- Two teams of scientists are developing powerful new drugs for the fight against anthrax and other bioterrorism threats.
Scientists at Rockefeller University in New York City announced in today's issue of Nature that they have developed a new antibiotic that not only attacks anthrax spores, but also can detect them.
And a second team of scientists was to report today at the American Chemical Society's annual meeting that a compound taken from baker's yeast also shows promise in protecting against anthrax infection.
The Rockefeller scientists extracted a "killer protein" called PlyG lysin from a virus that infects bacillus anthracis. Three-quarters of the mice who were injected with the protein survived a lethal infection of a bacterium closely related to anthracis.
In nature, the virus invades anthrax bacterium and replicates inside it. When it's time to exit the bacterium, the virus produces an enzyme called lysin that chews through the cell wall of its host, The New York Times reports today. As the Rockefeller University biologists demonstrated, the enzyme can also destroy the cell wall when injected from the outside.
The real treatment value of the drug is that it may destroy resistant strains of the organism.
"One of the problems in infectious disease today is antibiotic resistance, and the problem is that bugs are evolving faster than new drugs can fight them," says Gary Ostroff, lead author of the second anthrax study being presented at the Chemical Society meeting.
Two antibiotics, penicillin and ciprofloxacin (cipro), have been effective against the strain of anthrax found in the United States last fall, but there is continued concern that bioterrorists might engineer and unleash new strains of the bacteria that are resistant to existing antibiotics.
The drug reported in Nature binds to vital "molecular building blocks" in the bacterium's cell wall, making it almost impossible for strains to elude it.
The drug has the added benefit of aiding in the detection of anthrax spores. When the anthrax cells break open, they release a molecule that can be detected with a hand-held device within minutes, the Times reports. Currently, detecting anthrax spores is a time-consuming, laborious procedure, as evidenced by the events of last October.
The other potential anthrax combatant is called WGP Beta Glucan, and a form of it is already being used for other purposes. In laboratory tests, the compound greatly increased the survival rate of mice infected with lethal anthrax spores. The compound may have a prophylactic as well as a therapeutic role to play.
WBP Beta Glucan is a patented form of beta 1,3-glucan, which is derived from the cell wall of baker's yeast. A less potent version of the compound is already available as a nutritional supplement (Imucell) used to enhance general immune system function, so it's likely the pill form currently being tested will pass safety hurdles. Nevertheless, the new pill still needs to go through the full drug development process before it can be approved for use against anthrax and is more than two years away from being marketed, according to Biopolymer Engineering, the company that conducted the study.
"Just like with infectious disease, it's enhancing the innate immune system's ability to do its job," says Ostroff, vice president of research and development at Biopolymer Engineering.
Hopefully, the compound under development will also have an effect with resistant bacteria.
"We have been able to demonstrate with the injectable form of the drug [an earlier version] that it can stimulate the immune system to kill resistant bacteria," Ostroff says.
Both anthrax drugs have a long way to go before they reach the market. However, once they do, there may be other applications as well.
WGP Beta Glucan enhanced the rate of restoration of white blood cell counts in irradiated mice, indicating it might hold promise in helping cancer patients having chemotherapy, radiation and immunotherapy. It may also play a role in protecting against radiation and chemical warfare.
The viral protein reported in Nature may have similar applications related to biowarfare, according to the Times.
What To Do
For more on bioterrorism, visit Center for Civilian Biodefense Studies or the American Medical Association
