Selective Molecule Targets Chlamydia, Spares Beneficial Bacteria

Researchers from Umeå University and Michigan State University have identified a molecule capable of killing Chlamydia trachomatis bacteria while leaving beneficial bacteria unharmed. Chlamydia, the world’s most common bacterial sexually transmitted disease, affects an estimated 130 million people globally each year and can cause serious long-term health issues, including chronic pain, infertility, and complications during pregnancy and childbirth if left untreated.

Current treatments for chlamydia use broad-spectrum antibiotics that do not discriminate between harmful and health-promoting bacteria. As antibiotic resistance becomes more widespread, the need for more targeted therapies is urgent. "No one should have to live with chlamydia. But the problem is that the treatments we have today do not distinguish between dangerous and friendly bacteria. A growing problem is also that more and more bacteria are becoming resistant to today's broad-acting antibiotics," says Barbara Sixt, senior author of the study published in PLOS Biology.

Chlamydia trachomatis has unique properties, acting much like a virus by invading and reshaping human cells to create an environment for its own growth and reproduction. "We thought it could be possible to find a way to outsmart the bacterium's lifestyle by interfering with its special properties and its interactions with human cells," explains Magnus Ölander, the study’s first author.

To find molecules that could target chlamydia specifically, the team screened large collections of chemical compounds. They identified more than 60 potential candidates that could limit the bacterium’s growth in human cell cultures. After further testing, the researchers pinpointed a molecule that effectively inhibits the bacterium’s ability to produce fatty acids, which are essential for its survival and growth.

The discovery opens new possibilities for developing antibiotics that are both effective against chlamydia and gentle on the body’s beneficial bacteria and cells. "There is still a long way to go before we have a new treatment, but this finding may prove very important in developing new antibiotics that are both effective but at the same time gentle on the body,” adds Sixt.