6.1 Viruses  (Page 3/15)

Fighting bacteria with viruses

The emergence of superbugs, or multidrug resistant bacteria , has become a major challenge for pharmaceutical companies and a serious health-care problem. According to a 2013 report by the US Centers for Disease Control and Prevention (CDC), more than 2 million people are infected with drug-resistant bacteria in the US annually, resulting in at least 23,000 deaths. US Department of Health and Human Services, Centers for Disease Control and Prevention. “Antibiotic Resistance Threats in the United States, 2013.” http://www.cdc.gov/drugresistance/pdf/ar-threats-2013-508.pdf (accessed September 22, 2015). The continued use and overuse of antibiotics will likely lead to the evolution of even more drug-resistant strains.

One potential solution is the use of phage therapy , a procedure that uses bacteria-killing viruses (bacteriophages) to treat bacterial infections. Phage therapy is not a new idea. The discovery of bacteriophages dates back to the early 20th century, and phage therapy was first used in Europe in 1915 by the English bacteriologist Frederick Twort . M. Clokie et al. “Phages in Nature.” Bacteriophage 1, no. 1 (2011): 31–45. However, the subsequent discovery of penicillin and other antibiotics led to the near abandonment of this form of therapy, except in the former Soviet Union and a few countries in Eastern Europe. Interest in phage therapy outside of the countries of the former Soviet Union is only recently re-emerging because of the rise in antibiotic-resistant bacteria. A. Sulakvelidze et al. “Bacteriophage Therapy.” Antimicrobial Agents and Chemotherapy 45, no. 3 (2001): 649–659.

Phage therapy has some advantages over antibiotics in that phages kill only one specific bacterium, whereas antibiotics kill not only the pathogen but also beneficial bacteria of the normal microbiota. Development of new antibiotics is also expensive for drug companies and for patients, especially for those who live in countries with high poverty rates.

Phages have also been used to prevent food spoilage. In 2006, the US Food and Drug Administration approved the use of a solution containing six bacteriophages that can be sprayed on lunch meats such as bologna, ham, and turkey to kill Listeria monocytogenes , a bacterium responsible for listeriosis, a form of food poisoning. Some consumers have concerns about the use of phages on foods, however, especially given the rising popularity of organic products. Foods that have been treated with phages must declare “ bacteriophage preparation ” in the list of ingredients or include a label declaring that the meat has been “treated with antimicrobial solution to reduce microorganisms.” US Food and Drug Administration. “FDA Approval of Listeria -specific Bacteriophage Preparation on Ready-to-Eat (RTE) Meat and Poultry Products.” http://www.fda.gov/food/ingredientspackaginglabeling/ucm083572.htm (accessed September 22, 2015).