Antibiotic innovation helps fight against superbugs

Antibiotic innovation helps fight against superbugs

RMIT scientists have created a new type of antibiotic that can be rapidly re-engineered to avoid resistance by dangerous superbugs.

Developed by PhD candidate Priscila Cardoso and principal supervisor Dr Céline Valéry from the School of Health and Biosciences, the antibiotic has a simple design that allows it to be produced quickly and cost-effectively in a lab. 

Named Priscilicidin, the antibiotic’s amino acid building blocks are small, so it can be tailored to tackle different types of antimicrobial resistance.  

With the World Health Organization calling antimicrobial resistance "one of the top ten global public health threats facing humanity”, developing new antibiotics is more urgent than ever. 

Professor Charlotte Conn, one of Cardoso’s PhD supervisors, said given that urgency, Priscilicidin was an exciting breakthrough for public health. 

Priscilicidin is a type of antimicrobial peptide. These peptides are produced by all living organisms as the first defense against bacteria and viruses. 

Dr Céline Valéry with PhD candidate Priscila Cardoso wearing lab coats in their science lab. Priscila is holding a red folder. Dr Céline Valéry and PhD candidate Priscila Cardoso developed a new antimicrobial peptide called Priscilicidin. Credit: RMIT University

After reviewing the literature on antimicrobial peptide molecular engineering, the team designed and tested 20 short peptides before settling on Priscilicidin as the best candidate.

“The pharmaceutical industry generally tests thousands of compounds before getting a lead candidate. In our case, only 20 designs were necessary to create an entire new family of antibiotics,” Valéry said.

Conn said Priscilicidin was based on a natural antibiotic peptide, which made it less likely to cause antimicrobial resistance compared to existing conventional antibiotics.  

“Current natural antibiotics are expensive and difficult to make on a large scale. They also break down quickly in the body,” she said

“Priscilicidin combines the advantages of small molecular design, which means it’s quick and inexpensive to synthesise in a lab, with the advantages of natural antibiotics.”

Scientist Priscila Cardoso looking at a sample using a microscope. With antimicrobial resistance posing a big threat to global public health, developing new antibiotics is more urgent than ever. Credit: RMIT University

How does Priscilicidin work?

Priscilicidin was derived from Indolicidin, a natural antibiotic found in cows’ immune systems. 

The team’s research, published in January 2023 in the Women in Nanoscience 2022 special issue of Frontiers in Chemistry, showed Priscilicidin was highly active against resistant microbial strains such as golden staph, E. coli bacteria and candida fungi. 

Priscilicidin works by disturbing the membrane of the microbes, eventually killing the cell.  

“Attacking this outer layer makes it harder for the bacteria to evolve and resist treatment,” said Valéry. 

Lab tests showed Priscilicidin had a similar antimicrobial activity as Indolicidin on common bacterial and fungal infections.

Dr Céline Valéry using a pipette to inject a gel into a vial. Priscilicidin has a simple design that allows it to be produced quickly and cost-effectively in a lab. Credit: RMIT University

A new arsenal of topical and oral antibiotics

The team’s research shows Priscilicidin’s molecules naturally self-assemble into hydrogel form, making it ideal for creating antibiotic gels and creams. 

Valéry said when new drugs were created, scientists needed to consider the drug’s pharmaceutical formulation. 

This includes the drug’s form (capsule or cream, for example) and processes involved. Priscilicidin’s natural hydrogel form meant they can bypass some of that formulation process, Valéry said. 

“The fact we can control the viscosity of Priscilicidin means we can contemplate many applications as different products, diversifying the types of treatments to stop antimicrobial resistance,” she said.

While the team are predominantly investigating Priscilicidin for topical applications, they are not ruling out oral applications. 

“In theory, you could choose all means of administration for Priscilicidin, but none of them have been tested yet,” Conn said.

“We have an oral delivery technology at RMIT for protein and peptide drugs, which will allow antimicrobial peptides to be administered orally. We are currently looking at Priscilicidin as a candidate for this test.” 

A vial of Priscilicidin, an antimicrobial peptide, on a blue, gloved hand. Priscilicidin's molecules naturally self-assemble into hydrogel form, making it ideal for creating antibiotic gels and creams. Credit: RMIT University

“Rational design of potent ultrashort antimicrobial peptides with programmable assembly into nanostructured hydrogels" is published in Frontiers in Chemistry (DOI: 10.3389/fchem.2022.1009468).

This research was led by RMIT University in collaboration with CSIRO and Aikenhead Centre for Medical Discovery.

Co-authors are Priscila Cardoso, Samuel Appiah Danso, Andrew Hung, Chaitali Dekiwadia, Nimish Pradhan, Jamie Strachan, Brody McDonald, Kate Firipis, Jacinta F. White, Arturo Aburto-Medina, Charlotte E. Conn and Céline Valéry.

 

Story: Shu Shu Zheng

07 February 2023

Share

07 February 2023

Share

  • Research
  • STEM
  • Science and technology
Engage

Related News

RMIT students wearing navy lab coats and construction boots with their 3D printed coral structure.

Graphene oxide study strengthens the case for smart concrete

Engineers have added graphene oxide to cement mixture to make stronger 3D printed concrete that is easier to print, paving the way to create potential ‘smart’ walls that can monitor cracks.

news-feedstock-biochar-1220px.jpg

Aussie innovation turns waste into energy ‘gold’

New technology that turns waste into reusable goods for energy and agricultural applications is a step closer to commercialisation, following rigorous trials.

A person is on their bed in the dark with their knees bent towards their chest, clutching their face with their hands in distraught.

Sexual assault survivors deserve a gold standard reporting experience

A world-first report examining alternative ways for victim-survivors to report sexual assault says under-reporting could be reduced if moved away from law enforcement, but it will need greater support and funding to be sustainable and secure.

A bunch of teenagers taking a selfie with a smartphone.

Aussie teens are not actually selfie-obsessed

A new study zooming in on how smartphones influence our photography habits found Australians aged 20 to 40 years old take more selfies than teenagers and older Australians.

Show more
aboriginal flag
torres strait flag

Acknowledgement of Country

RMIT University acknowledges the people of the Woi wurrung and Boon wurrung language groups of the eastern Kulin Nation on whose unceded lands we conduct the business of the University. RMIT University respectfully acknowledges their Ancestors and Elders, past and present. RMIT also acknowledges the Traditional Custodians and their Ancestors of the lands and waters across Australia where we conduct our business - Artwork 'Luwaytini' by Mark Cleaver, Palawa.

More information