Researchers from University College Cork (UCC) believe they have made a breakthrough in the fight against superbugs, which cause havoc in Irish hospitals due to their growing resistance to antibiotics.

The researchers have developed new molecules that have been shown to dramatically improve the effectiveness of existing antibiotics against superbugs, and which will help address the growing problem of antimicrobial resistance.

The significant threat posed by resistant microbes to human health has been highlighted by several international bodies, including the World Health Organisation.

Many bacteria have developed resistance to current antibiotics by producing biofilms which shield them against the effects of the antibiotic. The new molecules interfere with the bacteria and prevent it from producing the biofilm in the first place.

Individual bacteria communicate with one another by producing so-called “signal molecules”. Different strains use different signal molecules to communicate with each other, similar to the various languages spoken by humans.

Dr Tim O’Sullivan, who spearheaded the research, said his team analysed the signal molecules and then made molecular mimics which effectively end up confusing the bacteria and prevent them from launching their resistance countermeasures.

The antibiotic is then able to treat the infection as normal. The new molecules were shown to make existing antibiotics 16 times more effective.

Cystic fibrosis

Dr O’Sullivan said the molecules were tested on two bugs, including burkholderia cepacia, which is a bacteria found in the lungs. It can be fatal to individuals with cystic fibrosis, who are also “particularly susceptible” to it.

“The lungs produce mucus which makes them an environment that is suited to bacterial infection,” he said. “Lungs are prone to getting repeated infections which inevitably, through evolution and so on, means the person is more likely to develop resistance.”

Dr O’Sullivan said the research was designed to show proof of concept, which means it may be possible to treat other infections with it.

“By virtue of the fact that you can demonstrate it in these strains, it’s potentially applicable to other strains of bacteria and other types of infections,” he said.

“As more microbes develop resistance to current antibiotics, and relatively few new antibiotics are coming to market, we need to identify new ways of dealing with resistant infections. The approach outlined in our work has significant potential.”

Potential targets

Research is ongoing within the team on further improving their new molecules and identifying additional strains of bacteria as potential targets.

The research, which was published in the journal Future Medicinal Chemistry, was carried out by Conor Horgan, a postgraduate researcher, and Dr Pavan Kumar, a Marie Sklodowska-Curie postdoctoral fellow.

The discovery grew out of an international collaboration with Dr Pol Huedo and microbiologists at the Autonomous University of Barcelona.