The key to creating the next generation of antibiotics could lie in horse dung, according to researchers at ETH Zurich and the University of Bonn. Jim Drury reports.
Horse manure......it has a potent smell and is a useful fertiliser....now it's helping chemists on the scent of an antibiotic breakthrough. An ETH Zurich team, led by researcher Andreas Essig, discovered a new compound called copsin in the common inky cap mushroom that grows on manure. In tests the protein killed various lab-cultivated bacteria. SOUNDBITE (English) ANDREAS ESSIG, POST DOCTORAL RESEARCHER AT ETH ZURICH, SAYING: "Horse dung is a very rich substrate that harbours a diversity of micro-organisms, including fungi and bacteria. Now these micro-organisms are in a constant competition for nutrients and space and it's therefore very likely to find potent antibiotics in such an environment." Working with University of Bonn biologists, Pauli Kallio and colleagues cultivated the fungus in a laboratory. SOUNDBITE (English) OR PAULIO KALLIO, SENIOR SCIENTIST AT ETH ZURICH, SAYING: "Here we are growing Pichia pastoris, which is a methylotrophic yeast and in this yeast we are producing copsin, so this is a long process." The process takes five days but in lab tests showed impressive results. SOUNDBITE (English) ANDREAS ESSIG, POST DOCTORAL RESEARCHER AT ETH ZURICH, SAYING: "Copsin kills bacteria by binding to an essential cell wall building block. The cell wall you can consider like the achilles heel of bacteria, so when you disrupt the cell wall synthesis bacteria usually dies rapidly." Essig says copsin's inherent stability is crucial. It can survive extreme temperatures and exposure to acid or aggressive enzymes. This could make it useful in the food industry, because it kills pathogens like Listeria, which cause food poisoning. But it's the possibility of copsin's potential use as an antibiotic that's giving chemists the potential whiff of success.