Virus Trained to Kill Bacteria
Scientists have stumbled upon a new way for coping with drug-resistant bacteria. The discovery involves bacteriophages, viruses that infect bacteria. While working on an unrelated project, phages were found to contain genes that allow them to quickly change their proteins to bind to different cell receptors. This means that phages can be engineered to treat bacterial infections that have become resistant to antibiotics.
Expert Quote: "This serendipitous finding underscores the importance of basic research. With our increased understanding of how bacteriophages work, we can potentially tailor these viruses to infect and destroy bacteria that have mutated and become drug-resistant." (Anthony Fauci, Director of the National Institute of Allergy and Infectious Diseases NIH)
Our Comments: Not all good medical research is done by design. Some is by serendipity, pure good luck. A celebrated example of serendipity took place in 1928 at St. Mary's Hospital in London. While studying staph bacteria, the physician Alexander Fleming happened to noticed that on a dish of agar on which he had been growing germs, near some mold, the germs were less common. He grew more of the mold, named it penicillin from its Latin name Penicillium, and found it was effective against a number of bacteria, including those that cause anthrax, diphtheria, and meningitis.
Although unforeseen findings often crop up in medical research, it is only the well-prepared mind that is capable of grasping the significance of the totally unexpected finding, and Fleming was fully prepared to capitalize upon it. During the First World War, Fleming had treated wounded soldiers and seen for himself that there was no effective way of treating many infections. After the war, Fleming was determined to find a better way of killing germs, and he did, by accident.
Scientists Discover Potential New Way to Control Drug-Resistant Bacteria
Based on an improved understanding of bacteriophages - viruses that infect bacteria - scientists reporting in the Sept. 23 issue of the journal Nature believe they have discovered a potential new way to control drug-resistant bacteria, an increasingly worrisome public health problem.
The new research, funded by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, found that bacteriophages contain genes that allow them to quickly change their proteins to bind to different cell receptors. The researchers, who encountered this genetic property while working on an unrelated project, believe that this discovery could lead to the use of genetically engineered phages to treat bacterial infections that have become resistant to antibiotics.
"This serendipitous finding underscores the importance of basic research," says Anthony S. Fauci, M.D., director of NIAID. "With our increased understanding of how bacteriophages work, we can potentially tailor these viruses to infect and destroy bacteria that have mutated and become drug-resistant."
"This powerful and innovative research opens up numerous possibilities for developing drugs and vaccines that can control resistant bacteria, which are a growing public health concern," says David L. Klein, Ph.D., who oversees bacterial respiratory disease research at NIAID. "The introduction of bacteriophages may also lead to a unique approach against biodefense-related pathogens."
The discovery was made by researchers at the University of California Los Angeles led by Jeffery F. Miller, Ph.D., professor and chair of microbiology, immunology and molecular genetics. Dr. Miller's team found that the genome of the phage that infects Bordetella bronchiseptica, a relative of the bacterium that causes whooping cough, contains a series of genes that change the part of the virus that binds to the bacterial cell. These genes allow the phage to rapidly evolve new variants that can recognize and attack bacteria that may have become resistant to the previous phage.
"Phage therapy has been practiced for nearly a hundred years in parts of the world, and even in the United States in the first half of the 20th century," says Dr. Miller. "But now we think we can engineer bacteriophages to function as 'dynamic' anti-microbial agents. This could provide us with a renewable resource of smart antibiotics for treating bacterial diseases."
Dr. Miller says that he and his team are continuing to study this genetic mechanism to learn more about its biochemical properties and to determine whether higher forms of life have similar classes of genes. He believes that, in time, they will be able to use the knowledge gleaned from this discovery to generate proteins in the laboratory that will bind to almost any molecule of interest.
Source: National Institutes of Health press release, September 23, 2004
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