New antibiotic works against superbugs

May 21 2006

A new antibiotic with the ability to fight drug-resistant superbugs has been developed by researchers at drug company Merck's research laboratories in New Jersey.

The new class of antibiotic has a natural base and is called platensimycin and could be the answer to bacteria such as Methicillin-Resistant Staphylococcus Aureus (MRSA) and Enterococcus, which have proved resistant to even the most powerful modern antibiotics such as vancomycin.

The drug is in the earliest stages of development but, if it passes the required clinical trials, it will be only the third entirely new anti-bacterial to be reach the clinic stage in the last 40 years.

Most of the antibiotics in current use were discovered in the 1940s and 50s and work by interfering with the formation of a bacterium's walls, proteins or DNA, so that it cannot reproduce and spread.

Over the years scientists have managed to subtlety alter the molecular structures of existing antibiotics in order help them retain their ability to work against resistant bacteria but this process has a limited life.

As bacteria reproduce, their DNA mutates, which can make them immune to the interference of drugs and as many doctors predicted the possible overuse of and limited choice of antibiotics in the past few decades, has encouraged the growth in the number of pathogenic bacteria that have developed resistance to them.

Platensimycin, is an antimicrobial compound produced by a bacterium called Streptomyces platensis and has a the ability to destroy the super bugs.

The antibiotic was discovered by screening 250,000 extracts from drug-producing micro-organisms found in soil collected in South Africa.

Platensimycin is a molecule produced by Streptomyces platensis, a fungus-like bacterium, and does not work in the same way as older antibiotics.

It has an inhibiting effect on an enzyme called FabF, which is used in the formation of fatty acids in bacterial cells which are the crucial building blocks of cell membranes and surfaces for bacteria.

The synthetic compounds isoniazid and triclosan have the same effect and have been widely used but other fungus-derived anti-bacterial compounds have been abandoned after failing the long process of testing and clinical trials required for any new drug.

Dr. Jun Wang and colleagues, found in an experiment on mice infected with Staphylococcus aureus that platensimycin destroyed the bacteria with no toxic side-effects and demonstrated a potent, broad-spectrum effect against multiple microbes.