Such quick resistance epitomizes the dilemma of antibiotics development: Drugs cost hundreds of millions of dollars and take at least a decade to develop, and then become increasingly less effective. (see 'Renewing the Fight Against Bacteria,').
In the past, a classic screening approach, which tests in vitro the inhibitory effect of synthetic and natural compounds or extracts, led to the discovery of many current antibacterial drugs. Linezolid, for example, was developed in this way: thousands of compounds were reviewed to find one that kills bacteria. Today, this method yields few, novel, promising structures. The related method of developing second and third generation drugs based on existing pharmaceuticals is no longer considered an option because cross resistance reduces the effectiveness of macrolides (based on erythromycin), rifapentine (based on penicillin), and carbapenems (based on imipenim).
Some pharmaceutical companies are turning to new approaches to find anti-biotics that will elude resistance. Many are ...
