Antibiotic-resistant gonorrhea discovered; are ‘superbug’ chlamydia, syphilis strains next?

A new strain of antibiotic-resistant gonorrhea should be enough to scare anyone who’s playing the field without full protection. But the worries might not stop there. Like gonorrhea, chlamydia and syphilis are sexually transmitted diseases that are caused by bacteria. And anytime you have a bacterial disease, there’s at least some chance that the germs could eventually find a way to outsmart antibiotics.

So what are the odds that chlamydia or syphilis could turn into the next super germs?

Drug-resistant chlamydia--Chlamydia trachomatis in full--would be a big-time public health disaster. The Centers for Disease Control and Prevention estimates that there are nearly 3 million cases of chlamydia infections in the U.S. each year. And that’s at a time when the disease is relatively easy to treat with antibiotics such as azithromycin or doxycycline. Although most infected people don’t have symptoms, chlamydia can cause pelvic inflammatory disease in women, which can lead to chronic pain and infertility.

Although chlamydia could in theory become resistant to common antibiotics, the biology of the germ generally makes it slow to pick up new tricks, says Daniel Rockey, a professor of bacteriology at Oregon State University. As Rockey explains, chlamydia is very different from the gonorrhea germ, a shifty microbe that constantly reinvents itself by eagerly stealing DNA from other bacteria. This sort of rapid evolution in action gave it a huge advantage in the fight against antibiotics.


Chlamydia, in contrast, is a relatively stable germ that doesn’t change its genetic code willy-nilly. This means that it’s slow to adapt to new threats, including antibiotics. As Rockey and colleagues recently noted in the journal Future Microbiology, there have been a few reports of drug-resistant chlamydia in the lab, but the problematic germs have yet to show up in humans. Considering how quickly and easily chlamydia spreads, we should be grateful. Because, as Rockey puts it, “if [drug resistant chlamydia] ever does get into the population, all bets are off.”

Treponema pallidum--the bacterium that causes syphilis--is another germ that’s (thankfully) slow to change. But some strains are already showing resistance to oral, easy-to-take drugs such as erythromycin, says Lola Stamm, an associate professor of epidemiology at the University of North Carolina’s Gillings School of Global Public Health. For now, penicillin injected into the muscles is still an effective treatment. “If it ever gets resistant to penicillin, that would be a scary day,” Stamm says. “We don’t have a lot of other options.”

Syphilis--a serious disease that can cause widespread damage if left untreated--is rare in this country; the CDC says there were about 36,000 cases in 2006. But Stamm says that an outbreak in Shanghai and other parts of China in 2010 underscores the potential for future trouble.

As long as people are having sex--and as long as bacteria are looking for their own way to perpetuate the species--antibiotic-resistant STDs will be a problem. Whether or not the threat stops with gonorrhea, let’s be careful out there.