Australian scientists in major breakthrough for alternative to antibiotics

Posted by AFN Staff Writers on 31st July 2012

Australian scientists have discovered the structure and operating procedures of a powerful anti-bacterial killer that could replace antibiotics. The invention has wide implications for the food industry around the world.

Researchers from Australia’s Monash University, working with the Rockefeller University and the University of Maryland, have published research detailing how the bacteriophage lysin, PlyC, can kill bacteria.

Bacteriophages are viruses that can attack bacteria using proteins called lysins.

The technology has been investigated since before 1919; however it was mostly abandoned with the development of antibiotics in World War Two. Since then, antibiotics have become the standard treatment against bacteria, in both humans and livestock.

Food Implications

The use of antibiotics on animals, particularly those farmed in close quarters, such as chicken, prawn and pigs, as well as dairy and feed-lot beef, are used to control disease and the nutritional well being of the animals.

However, there is increasing concern that excessive exposure to antibiotics can cause the weakening of immunity and disease resistance in people. Consumers can absorb antibiotics from their use in the food chain.

The recent developments in understanding the PlyC bacteriophage could prove an important step in replacing antibiotics.

Food Standards Australia New Zealand has recently been considering the use of bacteriophages as processing aids to reduce food poisoning.

Monash University Developments

Associate Professor Buckle said the PlyC, which attacks the streptococci bacteria, was a very promising target for the future development of new drugs.

“PlyC, in its purified form, has been shown to be 100 times more efficient at killing certain bacteria than any other lysin to date even faster than household bleach,” said study co-author Ashley Buckle from Monash University.

First identified in 1925, PlyC was purified in the 1960s by study author Vince Fischetti, professor from Rockefeller, but its atomic structure proved elusive until now.

In collaboration with Fischetti (Rockefeller) and Dan Nelson (Maryland), Monash researchers James Whisstock, Ashley Buckle and Sheena McGowan, have spent the last six years deciphering the atomic structure of PlyC, to better understand its remarkable anti-bacterial properties.

McGowan said PlyC looked a little like a spaceship.

“PlyC is actually made from nine separate protein ‘parts’ that assemble to form a very effective bacterial killing machine. It actually resembles a flying saucer carrying two warheads.”

The bacteriophage could revolutionise medical treatment, not only in human therapy but in livestock treatment as well.

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