Australasian Science: Australia's authority on science since 1938

New Antibiotic Class Targets Multidrug-Resistant Bacteria

A new kind of antibiotic has been developed that could limit multidrug resistance by targeting and disrupting key elements in bacterial cells.

“The way most antibiotics stop key functions in bacteria is that they bind to the surface of an essential protein so that it is unable to perform its normal function,” said Prof Yaoqi Zhou of Griffith University’s Institute for Glycomics, who is a corresponding author of the research paper published in The FASEB Journal (https://goo.gl/S6b78p). “Our technique with this new anti­biotic approach is different. Instead of binding to the surface of the protein, we disrupt the structure of the protein, which stops it functioning.”

Zhou said this new approach is less susceptible to antibiotic resistance. “Indeed, while we saw 500-fold resistance develop to a commonly used antibiotic over 30 days, there was no resistance to our peptide antibiotic,” he said.

This new antibiotic peptide is also “narrow spectrum”, meaning it is highly specific in its targeting and only kills the disease-causing bacteria. Much of the bacteria in our bodies are good for us and this new approach will leave these “normal flora” unaffected.

“Using a peptide derived from the Helix 3 segment of the methionine aminopeptidase of Escherichia coli, we tested it on E. coli and showed it’s not only useful for inhibiting the growth of clinical strain E. coli but also the multidrug-resistant strain,” Zhou said.

“We did some computational studies to analyse why our peptide is able to disrupt the protein structure. My colleague A/Prof Kate Seib also tested our newly designed peptide against Neisseria gonorrhoeae, and found it inhibits the multidrug-resistant gonococcal strain as well.

“We can theoretically use the same technique to target cancer-causing proteins and viral proteins, so this will be a unique way to approach drug resistance in cancer patients. We’ve done an initial study on cancer cells and we do find it’s able to inhibit the growth of cancer cells. But there’s still a lot of work to do.”

As there has been little development of new natural antibiotics in the past 20 years, Zhou said the computational discovery of this type of structure-disrupting antibiotic could help combat multi-drug resistance in bacteria, and he was hopeful of taking it to clinical trials.