Antibiotic-Resistant Gonorrhea May Have Met Its Match

Reports of increasing cases of antibiotic-resistant gonorrhea are on the rise and in fact, the World Health Organization (WHO) has designated the infection as high priority as it poses a great public health threat. Hope may be on the horizon, however. Researchers from Imperial College London and the London School of Hygiene & Tropical Medicine have discovered that a new class of antibiotic is effective against Neisseria gonorrhoeae—the bacteria that cause gonorrhea infection—in lab studies, sparking new hope against yet another group of antibiotic-resistant bacteria.

Antibiotic overuse and misuse has contributed to the growing increase in antimicrobial resistance that has been growing across the world. One of the latest discoveries of bacteria developing resistance has been in Neisseria gonorrhoeae. When left untreated, infections caused by these bacteria can lead to “pelvic inflammatory disease, ectopic pregnancy and infertility, as well as an increased risk of HIV,” according to WHO. Researchers have discovered that the bacteria have progressively developed resistance to ciprofloxacin, as well as azithromycin. Perhaps most troubling are reports that the bacteria have also shown resistance to the extended-spectrum cephalosporins (ESCs), cefixime and ceftriaxone.

Now, for the first time, researchers have tested a new antibiotic against the bacteria. The antibiotic, closthioamide, was previously discovered in 2010. For their research, the scientists, “tested 149 samples of N. gonorrhoeae from hospital patients with infections in the throat, urethra, cervix and rectum,” according to a press release on the research. They found that closthioamide, in concentrations of 0.125mg/L, was effective against 146 of 149 samples. In addition, they found that the antibiotic was effective against “all of the samples provided by WHO which were known to be resistant to other antibiotics,” according to the press release. These findings mark a new step in the fight against gonorrhea infections; although the antibiotic has yet to be tested on animals and humans.

When speaking on the implications of these findings in the press release, co-lead author John Heap, PhD, stated, “The imminent threat of untreatable antibiotic-resistant infectious diseases, including gonorrhea, is a global problem, for which we urgently need new antibiotics. This new finding might help us take the lead in the arms race against antimicrobial resistance.” He added, “The next step will be to continue lab research to further assess the drug's safety and effectiveness. Despite showing tremendous promise, it will be a number of years before, and if, we can use the drug in real life human cases.”

Still, co-lead author Victoria Miari, MSc, PgDip, stated, “The results of our initial laboratory studies show that closthioamide has the potential to combat N. gonorrhoeae. Further research is needed, but its potential to successfully tackle this infection, as well as other bacteria, cannot be underestimated.”

According to the authors, closthioamide is the first of many undiscovered antibiotics that exist in nature; however, it is difficult to find these antibiotics and test them. Still the results of this study are promising, at least at the out-set, and news of a potential weapon against a drug-resistant threat is welcome news, regardless of how small or far off we will see the results.