/ 29 January 2014

Dead zebras could be the key to anthrax treatment

Zebra carcasses could hold the cure to anthrax bacteria infections.
Zebra carcasses could hold the cure to anthrax bacteria infections.

Zebra carcasses in Etosha National Park in Namibia may open up new ways to detect and treat anthax poisoning, according to researchers. While the bacterium that causes anthrax can be found naturally in soil and commonly affects animals, it can also be used as a biological weapon.

"If a bioterrorist attack were to happen, Bacillus anthracis, the bacteria that causes anthrax, would be one of the biological agents most likely to be used," says the United States's Centre for Disease Control and Prevention. In fact, last week there were two separate anthrax scares at the South African National Roads Agency Limited's offices in Centurion.

But a virus discovered in the bodies of zebras that died of anthrax could hold the key to treating those infected with the anthrax bacteria.

"The first thing the team noticed was that the virus was a voracious predator of the anthrax bacterium," said Holly Ganz, a research scientist at the University of California and first author on the paper, which appeared in scientific journal PLOS One this week.  The newly discovered virus, named Bacillus phage Tsamsa, is a bacteriophage, which literally means "bacteria eater".

"Bacteriophages are often highly specific to a particular strain of bacteria," the University of California says in the report, "and when they were first discovered in the early 20th century there was strong interest in them as antimicrobial agent [something which kills micro-organisms, such as bacteria]. But the discovery of penicillin and other antibiotics eclipsed phage treatments in the West."

But the overuse of antibiotics is giving rise to drug-resistant microbes and super bugs. Alexander Fleming, credited with the discover of penicillin, said in his 1945 Nobel Prize acceptance speech: "The time may come when penicillin can be bought by anyone in the shops. Then there is the danger that the ignorant man may easily under-dose himself and by exposing his microbes to non-lethal quantities of the drug make them resistant. Here is a hypothetical illustration. Mr X has a sore throat. He buys some penicillin and gives himself, not enough to kill the streptococci but enough to educate them to resist penicillin. He then infects his wife. Mrs X gets pneumonia and is treated with penicillin. As the streptococci are now resistant to penicillin the treatment fails. Mrs X dies. Who is primarily responsible for Mr. X's death?"

Ganz said: "With growing concerns about antibiotic resistance and superbugs, people are coming back to look at phages." Part of the reason is that bacteriophages target specific bacteria, rather than antibiotics which can be quite indiscriminate.