Tag Archives: microorganism

STD Awareness: Genetics and the Gonococcus

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Image: CDC

Ever since the discovery of effective antibacterial therapies less than a century ago, humans have been able to easily cure gonorrhea, the sexually transmitted scourge that laid waste to fallopian tubes and robbed newborns of vision. Most of us in the developed world have forgotten that this disease was once a leading cause of infertility in women and blindness in babies — and still is in much of the developing world.

Unfortunately, gonococci — the species of bacteria that cause gonorrhea — have been evolving resistance to every antibiotic we’ve thrown at them, including sulfonamides, penicillins, tetracyclines, macrolides, fluoroquinolones, and narrow-spectrum cephalosporins. We have one remaining first-line gonorrhea treatment left: extended-spectrum cephalosporins, which include cefixime, which is taken orally, and ceftriaxone, which is administered as a shot — and resistance is emerging to those drugs, as well.

Gonococci don’t swap potato salad recipes at family reunions — they swap genetic material!

The emergence of antibiotic-resistant gonorrhea is considered one of the most pressing problems in infectious disease — just two years ago, the Centers for Disease Control and Prevention named it an “urgent threat,” and indeed, gonorrhea seems to be evolving resistance to drugs at quite a rapid clip. Gonococci can acquire resistance to antibiotics in three ways.

First, a genetic mutation can endow bacteria with special antibiotic-fighting powers, making it harder for a drug like penicillin to attach to their cells and destroy them. Such a mutant is more likely to gain evolutionary traction if it finds itself in an antibiotic-drenched environment in which resistance to that drug allows it to “outcompete” other bacteria. Indeed, antibiotic resistance was first documented in the 1940s, just years after sulfonamides and penicillin were introduced as the first effective cures for gonorrhea. Continue reading →

STD Awareness: Gonorrhea, Women, and the Pre-Antibiotic Era

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Penicillin, the first cure for gonorrhea, was developed for mass production in the 1940s.

Penicillin, the first reliable cure for gonorrhea, was mass produced in the 1940s.

It’s Women’s History Month, a time to reflect on the achievements of women worldwide — like Margaret Sanger, Rosalind Franklin, and Florence Nightingale, or contemporary heroes like Wangari Maathai. But it may also be a time to examine some of the sadder aspects of womanhood, including the increased burden gonorrhea imposes on women. While gonorrhea is no picnic for anyone, it wreaks the most havoc in female reproductive tracts. In fact, before antibiotics, gonorrhea was a leading cause of infertility — one 19th century physician attributed 90 percent of female infertility to gonorrhea. Not only that, but the effects of gonorrhea could seriously reduce a woman’s overall quality of life.

With gonorrhea becoming more resistant to antibiotics, the CDC warns of a return to the pre-antibiotic era.

Gonorrhea is described by written records dating back hundreds of years B.C. Ancient Greeks treated it with cold baths, massage, “cooling” foods, and vinegar. In the Middle Ages, Persians might have recommended sleeping in a cool bed with a metal plate over the groin. A bit to the west, Arabs tried to cure gonorrhea with injections of vinegar into the urethra. Kings of medieval England might have had their gonorrhea treated with injections of breast milk, almond milk, sugar, and violet oil.

Although gonorrhea is as ancient an STD as they come, because women rarely have symptoms while men usually do, for much of history it was mostly discussed in terms of men. The name gonorrhea itself derives from the ancient Greek words for “seed flow” — gonorrhea was thought to be characterized by the leakage of semen from the penis. This confusion inspired many misguided notions throughout the millennia, such as the idea that almost all women carried gonorrhea and transmitted it to their unwitting male partners. Continue reading →

STD Awareness: The Latest on Gonorrhea

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Neisseria gonorrhoeae, the bacterium that gangs up on your body to give it gonorrhea. Image: CDC

Gonorrhea is that guy with the funny name who’s always up to something new and mischievous. Last year, the New England Journal of Medicine declared that it’s “time to sound the alarm” in response to emerging strains of gonorrhea that are increasingly resistant to antibiotics. Then, earlier this year, the medical journal JAMA reported the first North American sightings of gonorrhea that failed treatment with cefixime, one of the last drugs we have in our anti-gonorrhea arsenal. It’s a great time to be a gonococcus — the type of bacteria that causes gonorrhea — but the humans they infect probably don’t see it that way.

Last month, this bad boy rose to the top of the Most Wanted list when the Centers for Disease Control and Prevention proclaimed antibiotic-resistant gonorrhea an “urgent threat” — the highest threat level, which gonococci share with only two other bacteria types. To give you some context, the much more famous superbug MRSA was categorized as a “serious” threat, one notch below “urgent.”

Antibiotic-resistant gonorrhea is an “urgent” threat; meanwhile, researchers develop a gonorrhea vaccine that works — on mice.

Antibiotic-resistant gonorrhea is especially insidious for two reasons. One, gonorrhea often doesn’t have symptoms, which allows it to jump from one sexual partner to another, the hosts often none the wiser. Two, unless health care providers actually test the bug’s DNA, they have no way of knowing whether or not they’re dealing with a drug-resistant strain. This opens up the possibility for treatment failure — and for the antibiotic-resistant bacteria to be further propagated into the community.

The CDC estimates that the United States sees 246,000 cases of antibiotic-resistant gonorrhea infections annually — that’s about 30 percent of all gonorrhea infections in the country. For now, we seem to be able to cure them with higher doses or different combinations of drugs. So why does antibiotic-resistant gonorrhea deserve the “urgent” designation? While gonorrhea isn’t associated with a body count — unlike other drug-resistant pathogens, which collectively kill at least 23,000 Americans a year — it can have terrible consequences. Gonorrhea can cause pelvic inflammatory disease (PID) when it advances up the female reproductive tract, and epididymitis when it invades the male reproductive tract; both conditions can cause infertility. Also, gonorrhea infections make us more vulnerable to HIV. The CDC estimates that if the most resistant gonorrhea strain gains ground over the next decade, the country could see an additional 75,000 cases of PID, 15,000 cases of epididymitis, and 222 HIV infections, costing us $235 million. Continue reading →

STD Awareness: Will Gonorrhea Be Worse Than AIDS?

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A scanning electron micrograph of a colony of Neisseria gonorrhoeae, the bacteria that cause gonorrhea. Image: Portland State University

If you’ve been reading the news lately, you might have noticed an odd piece of reportage from CNBC, in which a naturopath claimed that antibiotic-resistant gonorrhea “might be a lot worse than AIDS” and might cause cases of sepsis that could kill “in a matter of days.” This quotation, uttered by a single naturopath, was then exaggerated in sources such as the United Kingdom’s Daily Mail, which ran the headline “Doctors warn that antibiotic-resistant strain of gonorrhea could be ‘worse than AIDS.'” In fact, the only person making this claim was one naturopath, not a doctor, and certainly not plural “doctors.”

There’s a lot to unpack here. First is the alarmism in the original CNBC article, and its dependence on an unreliable source. Second is the issue of antibiotic-resistant gonorrhea itself, which is a very serious public health problem. Thirdly, let’s look at the naturopath’s claim, which is that antibiotic-resistant gonorrhea could unleash a plague worse than AIDS and kill its victims in a matter of days.

Claims that antibiotic-resistant gonorrhea will be “worse than AIDS” are greatly exaggerated.

Alan Christianson, the naturopath behind the hyperbolic claims of super-virulent gonorrhea, does not seem to be an actual expert in infectious disease (his website lists “natural endocrinology” and “male menopause” among his specialties), nor is he a medical doctor. The article identifies him as a “doctor of naturopathic medicine,” but what does that mean?

Naturopaths are not medical doctors, and degrees in naturopathic medicine aren’t awarded by institutions accredited by the Association of Medical Colleges, the body that accredits medical schools. Naturopathy is a philosophy that is not generally supported by scientific evidence, but rather is based in “a belief in the healing power of nature,” according to the National Center for Complementary and Alternative Medicine. It was developed in the 1800s and today encompasses many modalities of alternative medicine, including homeopathy and herbalism. For these reasons, it is odd that a journalist quoted a naturopath on the potential of antibiotic-resistant gonorrhea rather than someone more qualified, such as a microbiologist or epidemiologist. Continue reading →

STD Awareness: An Update on Antibiotic-Resistant Gonorrhea

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Last year, we shared the fascinating and frightening story of the emergence of increasingly antibiotic-resistant gonorrhea, an STD caused by the gonococci bacteria. The sexually transmitted scourge, which we only so recently reined in with the development of antibiotics, has been performing some genetic gymnastics to defeat almost every drug we’ve thrown at it. We douse it with certain drugs, and the bacterium literally spits them back out at us, and it inactivates other drugs by snapping the active molecules in half. Sulfa drugs, penicillins, tetracyclines, fluoroquinolones — they all make a gonococcus heave a bored sigh. Luckily, cephalosporins were still an effective treatment, but recently there have been reports of stubborn gonorrhea infections caused by the latest and greatest (and some might say most hated) strain of gonococci.

The bacteria that cause gonorrhea continue to evolve, right under our noses!

Well, the story isn’t over — just like the bacteria that cause gonorrhea, the tale is rapidly evolving. The latest class of antibiotics that the gonococci are chipping away at is the cephalosporin family, which includes several chemically related drugs that work in similar ways — and that can likewise be defeated by microbes in similar ways. Cephalosporin-resistant gonorrhea was first reported in Japan and documented in a few European countries. The Japanese case that inspired the New England Journal of Medicine to declare last year that it was “time to sound the alarm” was an oral gonorrhea infection that was resistant to one member of the cephalosporin family: ceftriaxone.

Earlier this month, the prestigious medical journal JAMA reported the first North American sightings of gonorrhea that failed treatment with another cephalosporin: cefixime. Yeah, I know, you’d rather hear about Big Foot or UFO sightings, not evidence that something as real and unmythical as Gonorrhea 5.0 has landed in your back yard. Luckily, there’s plenty you can do to protect yourself from it, and we’ll tell you all about it toward the end of this article. (Spoiler alert: It involves using condoms!) Continue reading →

STD Awareness: Antibiotic-Resistant Syphilis

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Treponema pallidum under a microscope. Image: Dr. Edwin P. Ewing, Jr., CDC

The image to your right, with lively yellow splotches against a pale green background, is not a long-lost Jackson Pollack piece, and the dark squiggly lines aren’t strands of paint haphazardly splattered onto a canvas. In fact, those squiggly lines are magnified images of the spiral-shaped bacteria species Treponema pallidum. You might not have heard of T. pallidum, but you’ve probably heard of syphilis, the sexually transmitted disease (STD) that these bacteria cause. While syphilis isn’t as common as other STDs, like chlamydia and HPV, it’s still out there, and occasionally communities experience outbreaks. It’s always best for sexually active people to be screened for STDs and practice safer sex.

The evolution of syphilis strains that are resistant to certain antibiotics underscores the need to use antibiotics properly.

Syphilis can inflict serious long-term damage — in fact, before the introduction of antibiotics, syphilis was the worst STD out there! Known as the Great Pox when it descended upon Europe 500 years ago, it could cause large and painful boils. Eventually, natural selection led to T. pallidum’s evolution into a form with milder symptoms, which benefited the bacteria by enabling its less boil-ridden (and presumably more attractive) human hosts to spread it farther and wider. Nevertheless, the symptoms of syphilis, if present, still include infectious sores, and when the disease goes untreated, it can cause severe, possibly fatal, damage to the nervous system.

Back in the day, there were myriad inadequate “treatments” for syphilis, ranging from straight-up quackery to the use of partially effective but toxic chemicals such as mercury. But a century ago, in 1912, a new arsenic-based chemical called Neosalvarsan was hailed as a “magic bullet.” Unfortunately, this treatment took weeks or even more than a year to administer — and had dangerous side effects. Quack treatments continued to flourish, and it wasn’t until the widespread adoption of penicillin in the 1940s that an effective cure with few side effects was available.

But natural selection endures; in fact, by flooding T. pallidum’s habitat with certain antibiotics, we’ve created an environment that favors the organism’s evolution against us. While not as immediately threatening as antibiotic-resistant gonorrhea, syphilis has been quietly evolving resistance to some of the antibiotics we use to treat it. This underscores the importance of using antibiotics correctly and emphasizing safer-sex practices, such as using latex condoms during vaginal or anal intercourse and during oral contact with a penis. Continue reading →

Get Smart About Antibiotics!

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This week we celebrate Get Smart About Antibiotics Week. Antibiotics, or antimicrobials as they are also called, cure bacterial infections by killing bacteria or reducing their ability to reproduce so your own body’s immune system can overcome an infection. Penicillin was the first antibiotic, and was discovered in 1924 by Alexander Fleming. Since its widespread use, beginning in the 1940s, countless lives have been saved from devastating bacterial infections. Talk about a wonder drug!

Improper use of antibiotics can have dangerous consequences.

Since then, different types of antibiotics have been developed to combat many different types of infectious bacteria. Classes of antibiotics include penicillins, cephalosporins, macrolides, fluoroquinolones, aminoglycosides, and others. In each of these classes there are lots of different individual medications. (For example, cephalosporins include the drugs cephalexin, ceftriaxone, cefaclor, and others.) Some antibiotics are broad spectrum, which means they work on many different bacteria. Some are more narrow spectrum, used for specific bacteria.

Antibiotics only work for bacterial infections … not viral infections. They are ineffective at killing viruses. Viral infections include colds, flu, runny noses, most coughs and bronchitis, and sore throats unless they are caused by strep. Sexually transmitted viruses include human papillomavirus (HPV), herpes simplex virus, and HIV. Continue reading →