Bacteria discovery could lead to antibiotics alternatives

(Press-News.org) Scientists have discovered an Achilles heel within our cells that bacteria are able to exploit to cause and spread infection.

The researchers say their findings could lead to the development of new anti-infective drugs as alternatives to antibiotics whose overuse has led to resistance.

University of Manchester researchers studied Listeria – a potentially deadly group of bacteria that can cause listeriosis in humans when digested – and found they are able to spread infection by hitching a ride on a naturally occurring protein called calpain.

"Bacteria produce a number of chemicals that allow them to invade a host and to establish an infection," said lead researcher Dr David Brough, who is based in Manchester's Faculty of Life Sciences.

"The chemicals produced depend upon many factors, such as the species of bacteria, the type of host, and also whether the infection grows inside or outside a cell.

"We have investigated the growth of Listeria, a pathogenic bacterium that grows inside cells. An essential step for its growth, and thus the infection, is the bacteria's ability to move from within one compartment in a cell to another.

"We discovered that in order for this particular type of bacteria to move and to grow some of the host cells biology is exploited, a protein called calpain. Without calpain the bacteria cannot move within the cell and so do not grow.

"This discovery highlights the possibility of using drugs against these host proteins to block infections, potentially reducing the need to use antibiotics."

The study, funded by the Wellcome Trust, is published in the PLoS ONE journal.

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Notes for editors:

A copy of the paper, 'Inhibition of Calpain blocks phagosomal escape of Listeria monocytogenes,' by David Brough et al, published in PLoS One, is available on request.

About the Wellcome Trust:

The Wellcome Trust is a global charitable foundation dedicated to achieving extraordinary improvements in human and animal health. It supports the brightest minds in biomedical research and the medical humanities. The Trust's breadth of support includes public engagement, education and the application of research to improve health. It is independent of both political and commercial interests. www.wellcome.ac.uk

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