January 9, 2004. Copyright 2002. Graphic News. All rights reserved. New antibiotics could mimic viruses by Joanna Griffin LONDON, January 9, Graphic News: In an effort to counteract the problem of antibiotic resistance, scientists are turning to tiny viruses, known as bacteriophages, to attack bacteria and give them the equivalent of a nasty cold or worse! Researchers at Canadian biotechnology company PhageTech and McGill University in Montreal found that phage proteins that inhibit bacterial growth could be used to develop new drugs, according to the February edition of the journal Nature Biotechnology. Jing Liu and colleagues tested the bacterium Staphylococcus aureus -- the most common cause of food borne illness -- to identify both the harmful parts of the bacteriophage and the bacterial molecules targeted by the virus. The team identified 31 phage proteins that inhibit bacterial growth in S. aureus. They then used this information to identify drugs that affect the target in the same way as the phage proteins. Bacteriophages and other viruses cannot ÒliveÓ or reproduce without getting inside some living cell, whether itÕs a plant, animal, or bacteria. Over the course of evolution, phages have developed unique proteins that bind to and interact with critical cellular proteins in bacteria, shutting off key metabolic processes and hi-jacking bacteria to become factories to produce more phages. Looking like a multi-legged alien landing pod, the phage attaches to the surface of the much larger S. aureus. Once attached, the phage injects its DNA into the bacterium. The DNA instructs the bacterium to produce masses of new viruses. So many are produced that the S. aureus bursts and dies. The newly replicated phages then go on to attack more bacteria. The term ÒbacteriophageÓ dates back to 1917, when French microbiologist FŽlix dÕ Herelle first identified a virus that was parasitic on bacteria. But the application of bacteriophages to treat diseases such as staphylococcal infections, and neonatal sepsis, has been limited in the West, while in the former Soviet bloc such therapies have been widely used for decades. Today, the therapeutic use of bacteriophages is enjoying a renaissance. After penicillin revolutionised medicine in the mid-20th century, over-reliance on antibiotics led to complacency about alternatives and ultimately a host of multi-drug resistant ÒsuperbugsÓ -- the breeding of bacteria resistant to antibiotics. Though bacteriophages work by attacking only the bacterial host and will never have the widespread application of antibiotics, scientists believe that they may be the answer to one of modern medicineÕs most serious crises. /ENDS Source: Nature