Gonorrhoea - a commonly transmitted disease is turning incurable over the increased antibiotic resistance, warn UK doctors.
The Health Protection Agency told doctors that the antibiotic normally used to treat gonorrhoea is no longer effective because the sexually transmitted disease is now largely resistant to it, the BBC reported.
For now, doctors must stop using the usual treatment cefixime and instead use two more powerful antibiotics. One is a pill and the other a jab.
The HPA say the change is necessary because of increasing resistance.
Tests on samples taken from patients and grown in the laboratory showed reduced susceptibility to the usual antibiotic cefixime in nearly 20 percent of cases in 2010, compared with just 10percent of cases in 2009.
As recently as 2005, no gonorrhoea bacteria with reduced susceptibility to cefixime could be found in the UK.
The bacterium that causes the infection - Neisseria gonorrhoeae - has an unusual ability to adapt itself and has gained resistance, or reduced susceptibility, to a growing list of antibiotics - first penicillin itself, then tetracyclines, ciprofloxacin and now cefixime.
"Our lab tests have shown a dramatic reduction in the sensitivity of the drug we were using as the main treatment for gonorrhoea. This presents the very real threat of untreatable gonorrhoea in the future," said Prof Cathy Ison, a gonorrhoea expert at England's HPA.
"We were so worried by the results we were seeing that we recommended that guidelines on the treatment of gonorrhoea were revised in May this year, to recommend a more effective drug.
"But this won't solve the problem, as history tells us that resistance to this therapy will develop too. In the absence of any new alternative treatments for when this happens, we will face a situation where gonorrhoea cannot be cured," he added.