July 11,2011—, 2011 -- Scientists have discovered a new strain of gonorrhea-causing bacteria in Japan that is resistant to available treatments.
Since the 1940s, the sexually transmitted disease known as "the clap" has been easily treated with antibiotics. But the new strain of Neisseria gonorrhoeae has genetically mutated to evade cephalosporins -- the only antibiotics still effective against the infection.
"This is both an alarming and a predictable discovery," lead researcher Magnus Unemo, professor at the Swedish Reference Laboratory for Pathogenic Neisseria in Örebro, Sweden, said in a statement. "Since antibiotics became the standard treatment for gonorrhea in the 1940s, this bacterium has shown a remarkable capacity to develop resistance mechanisms to all drugs introduced to control it."
The discovery, announced by Unemo at the International Society for Sexually Transmitted Disease Research meeting in Quebec City, Canada, could hail gonorrhea's transition from treatable STD to global public health threat.
"While it is still too early to assess if this new strain has become widespread, the history of newly emergent resistance in the bacterium suggests that it may spread rapidly unless new drugs and effective treatment programs are developed," Unemo said in a statement.
Cephalosporin-resistant Neisseria gonorrhoeae joins methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci in a sinister class of bacteria known as superbugs. But unlike hospital-acquired MRSA and VRE, which spread where antibiotic use runs high and immune defenses run low, super gonorrhea could spread anywhere.
"This report points out that antibiotic resistance is occurring not only in hospitals, but out in the community," said Dr. William Schaffner, chair of preventive medicine at Vanderbilt University Medical Center in Nashville, Tenn. And while the strain was disovered in Kyoto, Japan, antibiotic-resistant bacteria "don't need a passport."
Antibiotic resistance is not a new phenomenon -- even for Neisseria gonorrhoeae, which developed resistance to several other antibiotics used before cephalosporins.
"We were concerned about this 20 years ago and combated that very effectively," said Schaffner, explaining how gonorrhea treatments have evolved alongside the bacteria. "But if you have a strain that's completely resistant to antibiotics, you have to very quickly develop strategies to recognize the resistant strain and alternative treatment regimens."
Such tests and new treatments could be developed, Schaffner said, but they would likely be more expensive. Amid cutbacks across all facets of research, pharmaceutical companies are investing less in the quest for new antibiotics, he said.
With an estimated 700,000 new cases each year in the U.S. alone, gonorrhea is one of the most common STDs. It spreads through direct contact with the penis, vagina, mouth or anus, and can also be transmitted from mom to baby during delivery.
But only 50 percent of infected women and less than five percent of infected men develop symptoms, such as a burning sensation and discharge. Left untreated, the infection can spread to the skin, blood and other organs causing pain, infertility and even death.
A July 8, 2011, report from the U.S. Centers for Disease Control and Prevention urged doctors to be on the lookout for gonorrhea resistant to cephalosporins, and to report cases promptly.
The new superbug serves as a reminder that antibiotic resistance is a problem that spreads beyond hospital and nursing home walls.
"We need to implement a program so that pharmaceutical companies are motivated financially to pursue research in developing antibiotics," Schaffner said. "And both the public and professional have to be much more rigorous in their expectations and use of antibiotics."