Latest Antibiotic Already Becoming Ineffective

The April 14, 2001 issue of The Lancet reports that the latest antibiotic designed to work against antibiotic-resistant bacteria is starting to become ineffective. The researchers report that the resistant bacteria are adapting to the new drug and developing resistance to it as well.

The new drug, linezolid, is just over a year old and was designed to replace vancomycin, the previous drug that was designed to fight antibiotic-resistant bacteria. Lead researcher Dr. John P. Quinn, of the University of Illinois College of Medicine in Chicago, found five cases of linezolid-resistant infection in the last 3 months of 2000. All five cases had been treated with long courses of the drug which increases the chances that resistance will occur. Three of the five cases had initially improved on linezolid but later developed resistance to it. According to Quinn, he and his colleagues have come up with an novel approach to taking care of patients with bacterial infections; they actually test bacterial samples to see whether the samples will respond to the drug rather than simply throw antibiotics at every problem they find.

Bacteria, like other living things, have an inborn, innate ability to adapt to their environment. When they are repeatedly exposed to antibiotics they are able to change themselves to avoid the effects of the drugs designed to kill them.