Multi-drug resistant bacteria have caused enormous difficulties worldwide over the past few decades. Rather than address the root cause of the problem -- primarily, overuse and abuse of antibiotics -- scientists created new drugs which they hoped would be effective against the "super-bugs" such as meticillin-resistant staphylococcus aureus.

But, research published in the British medical journal The Lancet suggests that these harmful bacteria have already built up a resistance to the newest drugs.

Linezolid is a new antibiotic, which received approval from the U.S. Food and Drug Administration at the beginning of 2000. Ronald D. Gonzales of the University of Illinois College of Medicine at Chicago, and colleagues, studied its use in the treatment of bacterial infections caused by a strain of bacteria which has become resistant to the antibiotic vancomycin.

The investigators studied five patients who were admitted to one of three hospitals in the United States last year. In every case, linezolid was initially successful as a therapy. However, the enterococci bacteria causing the infection eventually became resistant to the new drug and in three cases the patients grew unresponsive to treatment.

The message is clear, bacteria are becoming resistant to new drugs even faster than they adapted to the older ones.

Perhaps the medical and pharmaceutical industry will be forced to look for new answers to this growing problem rather than continue to produce drug after drug.