New Preclinical Study Points to Alternative Approach for Tackling Antibiotic-Resistant STIs

New Preclinical Study Points to Alternative Approach for Tackling Antibiotic-Resistant STIs

(IN BRIEF) Researchers at the University of Liverpool and the University of Oxford have developed an experimental targeted therapy designed to kill antibiotic-resistant Neisseria gonorrhoeae, the bacterium that causes gonorrhoea. The approach uses an antibody-drug conjugate made up of an antibody, a molecular linker and an antimicrobial peptide. The antibody directs the treatment to the bacterium, while one of the pathogen’s own enzymes, IgA protease, activates the antimicrobial payload at the bacterial surface. In laboratory tests, the therapy killed a multidrug-resistant gonococcal strain resistant to current first-line antibiotics. The researchers also found that attaching the antimicrobial peptide to the antibody reduced toxicity in tested human cell types while maintaining antibacterial activity. The work remains at a preclinical stage. The therapy has not yet been tested in humans, and further research is needed to assess safety, efficacy, delivery and the potential for bacterial resistance.

(PRESS RELEASE) LIVERPOOL, 29-Jul-2026 — /EuropaWire/ — Researchers at the University of Liverpool and the University of Oxford have developed a targeted experimental approach that could help tackle antibiotic-resistant strains of Neisseria gonorrhoeae, the bacterium responsible for gonorrhoea.

The study, published in PNAS, describes a new antibody-drug conjugate designed to deliver an antimicrobial payload directly to the surface of the bacterium while reducing potential harm to human cells.

In laboratory testing, the therapy successfully killed a multidrug-resistant strain of N. gonorrhoeae, including a strain resistant to current first-line antibiotics.

The researchers said the findings point to a possible new strategy for addressing drug-resistant bacterial infections, although the work remains at an early preclinical stage and further research is required before any testing in humans.

Gonorrhoea is the second most common bacterial sexually transmitted infection in the United Kingdom.

Health experts have warned that antimicrobial resistance in gonorrhoea has increased in recent years, narrowing the range of effective treatment options.

The research team developed a targeted delivery system made up of an antibody, a specially engineered molecular linker and a potent antimicrobial peptide.

The antibody directs the treatment specifically to N. gonorrhoeae.

The antimicrobial component remains inactive until it reaches the bacterial surface.

A key feature of the approach is that it uses one of the bacterium’s own enzymes, known as an IgA protease, to activate the treatment.

After the antibody binds to the bacterial surface, the enzyme cuts the linker and releases the antimicrobial peptide directly at the site where it is needed.

Dr Hayley Lavender, Lecturer in Microbial Pathogenesis at the University of Liverpool, said antibiotic-resistant gonorrhoea is an urgent and growing public health challenge.

She said the research team aimed to develop a way to deliver a powerful antimicrobial agent specifically to the bacteria while reducing the risk of damaging human cells.

Lavender added that by exploiting an enzyme normally used by N. gonorrhoeae to evade the immune system, the researchers showed that an antimicrobial payload could be released directly at the bacterial surface.

In laboratory experiments, the antibody-drug conjugate killed a multidrug-resistant gonococcal strain.

The researchers also found that attaching the antimicrobial peptide to the antibody substantially reduced toxicity in the human cell types tested, while preserving antibacterial activity.

The findings suggest that antibody-drug conjugates, already widely used in cancer treatment, could potentially be adapted for use against bacterial infections.

The researchers said the platform’s modular structure may eventually allow the system to be redesigned to target other antibiotic-resistant bacteria that produce similar enzymes.

However, the authors stressed that the work is still in its early stages.

The therapy has not been tested in humans, and further preclinical research is needed to evaluate its safety, effectiveness and delivery.

Additional studies will also be required to assess whether bacteria could develop resistance to the approach over time.

Professor Christoph Tang, Professor of Cellular Pathology at the University of Oxford, said the results are encouraging but remain preclinical.

He said the next steps will include further optimisation of the technology and detailed studies to evaluate safety and efficacy before clinical testing can be considered.

The researchers said the study demonstrates a fundamentally different approach from conventional antibiotics.

Instead of acting broadly, the method exploits specific bacterial biology to trigger highly targeted drug activation at the pathogen’s surface.

The paper, “An antibody–drug conjugate active against antibiotic-resistant Neisseria gonorrhoeae”, was published in PNAS.

Media Contact:

pressoffice@liverpool.ac.uk

SOURCE: University of Liverpool