New drug to replace antibiotics

In a breakthrough, scientists have developed the first effective alternative to antibiotics that may aid the fight against drug-resistant infections.
In a small patient trial, the drug was shown to be effective at eradicating the superbug Methicillin-resistant Staphylococcus aureus (MRSA).
Researchers said it is unlikely that the infection could develop resistance against the new treatment, which is already available as a cream for skin infections.
They hope to develop a pill or an injectable version of the drug within five years.
The treatment marks "a new era in the fight against antibiotic-resistant bacteria," according to Mark Offerhaus, chief executive of the biotechnology company Micreos, which is behind the advance.

The treatment attacks infections in an entirely different way from conventional drugs and, unlike them, exclusively targets the Staphylococcus bacteria responsible for MRSA, and leaves other microbes unaffected.

The approach is inspired by naturally occurring viruses that attack bacteria using enzymes called endolysins. It uses a 'designer' endolysin, Staphefekt, which the scientists engineered to latch on to the surface of bacteria cells and tear them apart, 'The Times' reported.
"Endolysins exist in nature, but we've made a modified version that combines the bit that is best at binding to the bacteria with another bit that is best at killing it," said Bjorn Herpers, a clinical microbiologist, who tested the drug at the Public Health Laboratory in Kennemerland, the Netherlands.

Conventional antibiotics need to reach the inside of the cell to work, and part of the reason they are becoming less effective is that certain strains of bacteria, such as MRSA, have evolved impenetrable membranes.
By contrast, endolysins target basic building blocks on the outside of bacterial cells that are unlikely to change as infections genetically mutate over time.
Scientists believe that the results could mark the first of a wave of endolysin-based therapies for infections that conventional drugs are no longer able to treat.
About 80 per cent of gonorrhoea infections are resistant to frontline drugs, and multidrug-resistant salmonella, tuberculosis and E coli are regarded as significant threats.

Naturally occuring endolysins can attack all of these diseases, and the challenge is to create stable versions that can be packaged as drugs, researchers said.
The findings were presented at the Antibiotic Alternatives for the New Millennium conference here.