Closthioamide, discovered in 2010, might eventually offer an alternative for current drugs that are becoming less effective against gonorrhoea.
The World Health Organisation (WHO) has estimated that 700,000 people around the world die annually from drug-resistant infections. It also listed drug-resistant gonorrhoea, a sexually transmitted disease caused by the Neisseria gonorrhoeae bacterium, as a high priority infection that poses a great threat to human health.
Antimicrobial resistance occurs when a strain of bacteria evolves to resist each consecutive treatment, until no treatments are left, leaving these so-called superbugs incurable. Antibiotics have become less effective against certain bacteria, including N. gonorrhoeae, largely due to overuse and misuse of antimicrobials.
Some strains of N. gonorrhoeae are now currently untreatable due to the lack of alternative treatments. The standard WHO recommended treatment combines the antibiotics ceftriaxone and azithromycin, but without treatment, gonorrhoea infection can lead to pelvic inflammatory disease and infertility in adults, and vision damage in babies when passed from the mother during childbirth.
Now, for the first time, researchers from Imperial College London and the London School of Hygiene & Tropical Medicine have tested the new antibiotic, closthioamide, on gonorrhoea samples in the laboratory.
The researchers tested 149 samples of N. gonorrhoeae from hospital patients with infections in the throat, urethra, cervix and rectum. They found that at very low amounts (0.125mg/L), closthioamide was effective against 146 of 149 samples taken from patients, and against all of the samples provided by WHO which were known to be resistant to other antibiotics.
Although still yet to be tested on animals and humans, the researchers have said that the antibiotic could be an exciting new step in the fight against the disease. The paper is published in the journal, Antimicrobial Agents and Chemotherapy.
Dr John Heap, lead author from Imperial’s Department of Life Sciences, explained, ‘The imminent threat of untreatable antibiotic-resistant infectious diseases, including gonorrhoea, 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.’
