Consider the case of penicillin. For decades, it has been prescribed by many physicians for every sniffle and sneeze, even when the source of the problem was a virus. To make matters worse, antimicrobials have been introduced into hand creams, household cleansers, livestock feed. Not long ago, the fda's Center for Veterinary Medicine announced plans to withdraw approval of the use of fluoroquinolones in poultry feed. Of particular concern was campylobacter, a common cause of diarrheal disease.
Overuse is just part of the problem, however.
The evolution of resistance really goes into fast-forward when patients with serious diseases like malaria and TB do not follow doctor's orders, often because they are poor and cannot afford a full course of medication. Instead, they take just enough medication to alleviate their symptoms but not enough to rid their system of the original infection. The current attack against resistant strains is multipronged. Some microbiologists are trying to re-engineer the older generation of miracle drugs to get around the mechanisms of resistance. Tetracycline, which kills bacteria by disabling a cellular structure known as the ribosome, is the target of one such effort.