Download Scientists look to Australian frogs for new antibiotics ANSTO scientist

Scientists look to Australian frogs for new antibiotics
ANSTO scientist, Dr Anton Le Brun, is studying the skin secretions of Australian frogs in the search for
new antibiotics for treating infectious diseases.
Antibiotics are very useful for treating infections caused by bacteria. Different classes of antibiotics
kill bacteria by attacking different components of the cell; some antibiotics perforate the cell
membrane, some inhibit the function of essential enzymes in the bacteria, while others stop protein
synthesis within the bacterial cell.
While there are many antibiotics already available, many bacterial strains have become resistant to
the antibiotics that are regularly used against them. Examples of antibiotic-resistant infections
include strains of bacteria that cause golden staph, tuberculosis and gonorrhoea.
New antibiotics will be required to help treat infections now resistant to most of our current arsenal
of medications.
Together with scientists from the University of Melbourne, Le Brun is studying two anti-microbial
peptides from skin secretions of the green-eye tree frog (Litoria genimaculata) and the growling
grass frog (Litoria raniformis). Similar to some existing antibiotics, these peptides kill bacteria by
attacking the cell membrane of the microbe. These peptides may turn out to be promising new
antibiotics for treating drug-resistant infections.
The green-eyed tree frog. Credit: James Reardon
The growling grass frog. Credit: Grant Webster
To find out if these peptides can be developed into a new antibiotic, scientists want to know exactly
how the peptides interact with the cell membrane of the bacteria. Scientists also need to ensure the
peptides only kill bacterial cells and leave healthy human cells alone.
Scientists are using neutrons from ANSTO’s nuclear reactor to see how the frog peptides bind inside
the bacterial cell membranes. Using this technique, scientists hope to see where and how different
proteins, including the anti-microbial peptides, interact with the lipid bilayer of the bacterial cell
membrane.
References
http://www.ansto.gov.au/discovering_ansto/media_centre/discover_more_science_stories/science
stories/frogs_skin_giving_researchers_the_hop_on_bacteria