Gonorrhea's own enzyme triggers therapy against multidrug-resistant strains in lab tests

A team of scientists in the United Kingdom may have found a clever new way to outsmart superbugs — by turning one of their own tools against them.

Researchers at the Universities of Liverpool and Oxford have created a treatment that sneaks up on drug-resistant gonorrhea bacteria and activates right at their surface. In laboratory tests, it killed strains that no longer respond to ordinary antibiotics. The findings were published in the journal Proceedings of the National Academy of Sciences.

Gonorrhea is a sexually transmitted infection that affects millions of people worldwide. In the United Kingdom alone, it is the second most common bacterial STI. In recent years, the bacteria that cause it have grown increasingly resistant to the drugs used to treat them, leaving doctors with fewer options. Health experts call this a serious and growing public health challenge.

The new therapy works like a guided missile. Scientists combine an antibody — a type of protein that locks onto specific germs — with a powerful antimicrobial peptide, the part that actually kills the bacteria. The two are connected by a molecular linker that keeps the weapon inactive until it reaches its target.

Here is the clever part: the treatment borrows an enzyme that gonorrhea bacteria naturally produce. This enzyme, called IgA protease, is normally used by the bacteria to slip past the human immune system. But when the antibody attaches to the bacterial surface, the enzyme cuts the linker and releases the antimicrobial peptide exactly where it is needed. The bacteria basically activate their own destruction.

"By exploiting an enzyme that N. gonorrhoeae normally uses to evade the immune system, we've shown it is possible to trigger the release of an antimicrobial payload directly at the bacterial surface," said Dr. Hayley Lavender, a lecturer in microbial pathogenesis at the University of Liverpool.

Lab experiments showed the treatment killed multidrug-resistant gonorrhea while causing far less damage to human cells than traditional antibiotics might. The approach is similar to antibody-drug conjugates, which doctors already use to treat cancer by delivering powerful drugs directly to tumor cells.

The researchers say the platform could be redesigned to target other antibiotic-resistant bacteria that produce similar enzymes, potentially opening doors beyond gonorrhea. Professor Christoph Tang of the University of Oxford cautions that the work is still early. "The next steps will involve further optimization of the technology and detailed studies to evaluate safety and efficacy before any consideration of clinical testing," he said.

Still, the team sees this as a fundamentally different strategy — one that works with bacterial biology rather than against it, and that may help slow the rise of superbugs that no one can treat.