The Wyeth pharmaceutical company announced on Thursday that it has federal approval for a new antibiotic. The drug, Tygacil, seems to be effective against a wide range of bacteria, including those with a developed resistance to conventional antibiotics. Wyeth calls it the first in a new class of medicines. What makes Tygacil so special?

A distinctive, dangling chemical chain. Tygacil is derived from the tetracycline family of antibiotics that's been around for decades. Like the tetracyclines, it works by clogging up the bacteria's ribosomes, the parts of the cell that produce new proteins. But when scientists at Wyeth added a little tail of glyco-amino acids to a familiar tetracycline called minocycline, they got a new and more powerful drug.

Tetracyclines used to be more potent than they are now. In the decades since tetracyclines hit the market, bacteria have evolved several kinds of resistance. Some bacteria, for example, produce a protein "pump" that sits on the membrane and flushes antibiotics out of the cell. Others make protective proteins that pull the antibiotic away from their ribosomes.

Tygacil appears to get around both of these obstacles. The bacterial pumps seem less able to push it around, and the protective proteins aren't as good at shaking it off the ribosome. As a result, Tygacil can be used to treat patients with certain drug-resistant infections.

Hope to here some more about it......zman