Researchers Create New Antibiotic to Avoid Superbug Resistance

Investigators at the Royal Melbourne Institute of Technology (RMIT) have created a new type of antibiotic that can be rapidly re-engineered to avoid resistance by dangerous “superbugs,” according to research findings.

The investigators said 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 for different types of antimicrobial resistance.

The World Health Organization has called antimicrobial resistance “one of the top 10 global public health threats facing humanity,” making antibiotic development an urgent issue. Given that urgency, PhD candidate Priscila Cardoso and principal supervisor Céline Valéry, PhD, said their development was an exciting breakthrough.

Priscilicidin is a type of antimicrobial peptide, produced by all living organisms as the first defense against bacteria and viruses. After reviewing the literature on antimicrobial peptide molecular engineering, the investigators 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,” Valéry said in the press release. “In our case, only 20 designs were necessary to create an entire new family of antibiotics.”

Priscilicidin was based on a natural antibiotic peptide, which made it less likely to cause antimicrobial resistance compared to existing conventional antibiotics. Supervisor Charlotte Conn, PhD, noted that current natural antibiotics are expensive and difficult to make on a large scale, and they also break down quickly in the body.

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

The antibiotic was derived from Indolicidin, a natural antibiotic found in the immune systems of cows. The team’s research showed that Priscilicidin was highly active against resistant microbial strains, such as golden staph, E. coli bacteria, and candida fungi. It works by disturbing the membrane of the microbes, eventually killing the cell. Valéry said attacking this outer layer makes it more difficult for the bacteria to evolve and resist treatment.

Laboratory tests also showed that Priscilicidin had a similar antimicrobial activity as Indolicidin on common bacterial and fungal infections. Its molecules naturally self-assemble into hydrogel form, making it ideal for creating antibiotic gels and creams.

Valéry added that when new drugs are created, investigators need to consider the drug’s pharmaceutical formulation, including the drug’s form (capsule, cream, etc) and processes involved.

“The fact that 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,” Valéry said in the press release.

Although the team is predominantly investigating Priscilicidin for topical applications, they are not ruling out potential oral applications. Conn said in theory, Priscilicidin could be used for all means of administration, although none of them have been tested yet.

REFERENCE

Antibiotic innovation helps fight against superbugs. News release. RMIT University; February 7, 2023. Accessed February 10, 2023. https://www.rmit.edu.au/news/all-news/2023/feb/priscilicidin#:~:text=Priscilicidin%20was%20derived%20from%20Indolicidin,such%20as%20golden%20staph%2C%20E