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roundtable: the evolving enemy Watch Show 4:
"The Evolutionary Arms Race"
on PBS
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bottle of prescription antibiotics
In the battle against infectious disease, humankind has inadvertently given rise to deadly enemies. Antibiotic resistance is a stunning example of evolution by natural selection. Bacteria with traits that allow them to survive the onslaught of drugs can thrive, re-ignite infections, and launch to new hosts on a cough. Evolution generates a medical arms race. The bad news is that bacteria -- with their fast doubling times and ability to swap genes like trading cards -- evolve quickly. The good news is that in the 150 years since Darwin, we have grown to understand the rules of the race. But can we win this war?
  panelists
Tamar Barlam
  George Beran
  Stuar Levy
  Stephen Palumbi
  Question submittal is now closed. Please go to the forums to read our panelists' answers to the user questions.
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Stuart B. LevyStuart B. Levy, professor of medicine and of molecular biology and microbiology, is the Director of the Center for Adaptation Genetics and Drug Resistance at Tufts University School of Medicine and staff physician at the New England Medical Center. He is president of the international organization Alliance for the Prudent Use of Antibiotics and author of The Antibiotic Paradox: How Miracle Drugs Are Destroying the Miracle (1992). He is chief scientific officer of Paratek Pharmaceuticals, Inc.

People should realize that although antibiotics are needed to control bacterial infections, they can have broad, undesirable effects. They can produce long-lasting change in the kinds and proportions of bacteria not only in the treated individual, but also in the environment and in other people. For example, it's been shown that when one member of a household chronically takes an antibiotic, such as to treat acne, the concentration of antibiotic-resistant bacteria on the skin of family members rises. Similarly, heavy use of antibiotics in hospitals, day care centers, and farms (where the drugs are often given to livestock for non-medicinal purposes) increases the levels of resistant bacteria. And international travel has spread antibiotic resistance without regard to borders.

A number of corrective measures can be taken right now. Farmers should be helped to find inexpensive alternatives for encouraging animal growth rather than using antibiotics at low levels. The public can wash raw fruit and vegetables thoroughly to clear off both resistant bacteria and possible antibiotic residues. When they receive prescriptions for antibiotics, they should complete the full course of therapy (so that all pathogenic bacteria die). Consumers should not demand antibiotics for colds or other viral infections. They can continue to put antibiotic ointments on small cuts, but they should think twice about routinely using hand lotions and a proliferation of other products now imbued with antibacterial chemicals. When possible, physicians should prescribe an antibiotic targeted specifically to that microbe instead of having to choose a broad-spectrum product.
Overall reversal of the bacterial resistance problem will require public health officials, physicians, farmers, and others to think about the effects of antibiotics in new ways. The time has come for global society to accept bacteria as normal, generally beneficial components of the world and not try to eliminate them -- except when they give rise to disease. Let's revive the drug-susceptible bacteria to out-compete the drug-resistant ones.
(Boldface added.)
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