Scientists target receptors in new anthrax treatment
people suffering from anthrax poisoning, which could overcome the
problem of antibiotic resistance that is becoming increasingly
common in southern and Eastern Europe and Africa.
Researchers could also use the discovery to design more effective antibiotics against the bacterium, Bacillus anthracis. Such information is especially valuable because the anthrax bacterium is widely regarded as a potential bioterrorism weapon.
The US and Canadian researchers said that this approach could also be used to stop other deadly invaders such as SARS, influenza and Aids.
The study focuses on a blocker that binds to the receptors in the body where anthrax attaches. The theory is that by using receptors as the target rather than the toxin itself should overcome any resistance to the antibiotic.
They tested the inhibitor in rats, discovering that the best design was a polyvalent inhibitor, a model that displays multiple copies of receptor-binding peptides.
The design allowed the binding of multiple sites becoming more potent than inhibitors that bind to a single site.
Results from the six animals injected with the polyvalent inhibitor appeared to be protected from anthrax, with no signs of any side effects.
"We believe that combining the inhibitor with antibiotic therapy may increase the chance of survival for people who become infected with anthrax by neutralising the toxin," said Dr Ravi Kane, Rensselaer Polytechnic Institute in New York.
The issue of concern at the moment stems from current antibiotic use for treating anthrax. Pathogens can mutate and develop resistance to these treatments, rendering them ineffective.
In addition, with anthrax, there is concern that individuals could intentionally alter the toxin in the lab to make it resistant to current treatments, making it an even more deadly bioterrorism agent.
Inhalation anthrax still has a fatality rate of 75 per cent even after antibiotics are given.
To get an idea of its threat, spores of the bacterium Bacillus anthracis is considered to be one of the top (CDC Category A) biothreat agents by the US government.
The bacteria secrete toxins that paralyse the immune system, damage tissues and lead to death.
