Friday, January 29, 1999 Published at 04:49 GMT
New drug to beat 'superbugs'
Bacteria can change form in just a few years
American scientists say they have made a breakthrough in combating bacterial "superbugs" that build up resistance to drugs.
Pharmaceutical giant Merck and Co Inc says it has successfully redesigned a drug to block the mechanism used by certain bacteria to fight off penicillin-type antibiotics.
It has not yet been used on humans, but has been tested on monkeys without causing dangerous side effects.
Doctors say 70% of bacteria involved in infections that people get in hospitals are now resistant to at least one antibiotic.
Last year the Institute of Medicine noted that 90% of all strains of staphylococcus aureus, the most common cause of infections, some of them deadly, are now resistant to penicillin.
The breakthrough may make it possible to bring some penicillin-type antibiotics back into use against bugs that have built up defences against them.
The new drug, called by its experimental name L-786,392, targets a bacterial protein known as PBP2a, short for penicillin-binding protein.
It is found in drug-resistant staphylococci and enterococci, and blocks the chemical doorways that penicillin usually uses to get into and kill bacteria.
The scientists first developed the technique of neutralising the resistance mechanism a few years ago, but they had to go back to the drawing board when the drugs caused harmful side effects.