Tag Archives: microbes

STD Awareness: Is Mouthwash a Match for Gonorrhea’s Superpowers?

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Since the 1930s, we’ve enjoyed around eight decades of easily cured gonorrhea — at least in places with easy access to antibiotics — but experts fear those days are numbered. In the past year or so, cases of untreatable gonorrhea have occasionally made headlines.

Thanks to the powers of evolution, some bacteria have acquired the multiple genes necessary to withstand the onslaught of the pills and shots administered by doctors. Gonococci, the bacteria that cause gonorrhea, are starting to win this “arms race” with humans, whose antibiotic arsenals are losing effectiveness. And with gonorrhea on the rise, gonococci may be evolving at an ever-quickening clip.

In 1879, Listerine claimed to cure gonorrhea. Today, scientists are finally testing that claim. We await the results.

Oral Gonorrhea: The Silent Scourge

Many experts believe oral gonorrhea is a key driver of antibiotic resistance. These infections usually don’t cause symptoms, and without symptoms people usually don’t seek treatment. Without treatment, gonococci can hang out in a throat for up to three months.

After transmission by oral sex — and possibly even by kissing  — gonococci can set up camp in the throat, which is an ideal environment for acquiring antibiotic resistance. They might not be causing symptoms, but they’re not sitting there twiddling their thumbs, either. If there’s one thing gonococci love to do, it’s collecting genes like some of us collect trading cards, and the throat is a gathering place for closely related bacteria species that hand out antibiotic-resistance genes for their expanding collections.

Gonococci can easily scavenge DNA from their surroundings — say, from a dead bacterium — and patch long segments of these genes into their own DNA, creating genetic hybrids between themselves and other organisms. Last month, scientists from Indiana University caught this phenomenon on video for the first time.

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STD Awareness: UK Announces “Worst-Ever” Case of Gonorrhea

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In late March, the BBC reported a story that was widely repeated in headlines across the world: “Man has ‘world’s worst’ super-gonorrhoea.”

The article told the story of a British man whose symptoms started in early 2018, about a month after he had picked up the bug during a visit to Southeast Asia. Once back home, his doctors were unable to cure it with the standard combination of azithromycin and ceftriaxone — “the first time the infection cannot be cured with first choice antibiotics,” the author wrote.

In most of the world, we don’t have a good picture of antibiotic resistance in gonorrhea.

Actually, a similar case of multidrug-resistant gonorrhea had been documented in the United Kingdom in late 2014, as noted in the New England Journal of Medicine. It was the first verified case to fail to be cured by the azithromycin/ceftriaxone combo — the infection didn’t go away until after the patient was given a double dose of both antibiotics, but by then it had been 112 days and the infection could have cleared on its own. By July 2017, the World Health Organization (WHO) had noted that there had been multiple documented cases of gonorrhea that were “untreatable by all known antibiotics.”

What was different about the man in the BBC story was that his case of ceftriaxone-resistant gonorrhea had a higher level of azithromycin resistance than those that came before. While it may not have truly been the first case of multidrug-resistant gonorrhea that couldn’t be treated with the standard dual therapy of azithromycin and ceftriaxone, it was the “most serious.” Continue reading →

STD Awareness: Is Gonorrhea Becoming “Impossible” to Treat?

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Image: National Institute of Allergy and Infectious Disease

Health authorities have been worried about it for a long time now, and we’ve been following it on our blog since 2012. The boogeyman? Antibiotic-resistant gonorrhea, a strain of the sexually transmitted bacteria that is becoming more and more difficult to treat. Higher doses of the drug will be needed to cure stubborn cases of gonorrhea — until the doses can no longer be increased. Then, untreatable gonorrhea could be a reality.

“Little now stands between us and untreatable gonorrhea.”

The World Health Organization (WHO), in a press release last month, finally used the word “impossible” when describing treatment of antibiotic-resistant gonorrhea, referring to documented cases of gonorrhea that were “untreatable by all known antibiotics.” Worse, these cases are thought to be the proverbial “tip of the iceberg,” as there aren’t good data on antibiotic-resistant gonorrhea in many developing countries, where gonorrhea is more prevalent and epidemics could be spreading under the radar. Adding to this problem is the fact that gonorrhea rates are climbing worldwide, which is thought to be due to a number of factors, including the decline in condom use, the frequent absence of symptoms, inadequate treatment, and increasing urbanization and travel.

What will happen if gonorrhea can’t be cured? Your infection could clear up on its own, after a lengthy battle with your immune system, but we don’t know a lot about how long this could take (weeks? months? never?). Unfortunately, despite your immune system’s best efforts, gonorrhea doesn’t go out without a fight. Gonorrhea can lead to pelvic inflammatory disease, which can cause tissue damage to the reproductive organs resulting in infertility, ectopic pregnancy, and chronic pain. It can also cause scarring that blocks sperm’s movement out of the testes, resulting in epididymitis, which is associated with infertility, chronic scrotal pain, and testicular shrinkage. Furthermore, gonorrhea increases risk for HIV transmission and can be passed to a baby during childbirth. The CDC estimates that, in the United States alone, untreatable gonorrhea could cause 75,000 cases of pelvic inflammatory disease, 15,000 cases of epididymitis, and 222 extra HIV infections over a 10-year period. Worldwide, where gonorrhea and HIV disproportionately affect developing countries, these problems could get even more out of control. Continue reading →

STD Awareness: Fully Antibiotic-Resistant Gonorrhea Is on the Horizon

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shot-in-armWe’ve been anticipating its arrival for years now, but earlier this fall, the Centers for Disease Control and Prevention (CDC) finally made an announcement: Cases of gonorrhea resistant to the last drugs we use to cure it are emerging.

Over the years, gonorrhea has evolved resistance to every drug we’ve thrown at it — sulfonamides, penicillins, tetracyclines, macrolides, fluoroquinolones, and narrow-spectrum cephalosporins. The last line of defense we have is a one-two punch of a pair of antibiotics: azithromycin and ceftriaxone. By using two drugs, we can delay the inevitable evolution of antibiotic resistance by attacking the bacteria in two vulnerable locations, rather than just one, making it more difficult for the bug to mount a defense and pass on its superior survival skills to subsequent generations.

Prevention is paramount: Stop the spread of antibiotic resistance by practicing safer sex!

Unfortunately, we could only stave off the inevitable for so long. At their conference in September, the CDC announced a cluster of gonorrhea infections that are highly resistant to azithromycin, and that fall prey only to high doses of ceftriaxone. As gonorrhea’s tolerance to ceftriaxone increases, the infection will get more and more difficult to cure.

This cluster of drug-resistant cases was identified in Honolulu in April and May of this year, with five infections showing “dramatic” resistance to azithromycin, as well as reduced vulnerability to ceftriaxone. The good news is that these cases were cured with higher-than-usual doses of antibiotics, but the bad news is that dosages can only climb so high before a drug is no longer considered to be an effective treatment. Continue reading →

STD Awareness: Gonorrhea’s Ever-Growing Resistance to Antibiotics

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Gonococci, the bacteria that cause gonorrhea.

Ever since the advent of effective antibacterial therapies less than a century ago, humans with access to these drugs can easily cure gonorrhea. 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 — sulfa drugs and antibiotics not only erased these infections from our bodies, they also erased memories of gonorrhea’s dangers from our collective consciousness.

There are two drugs remaining to treat gonorrhea, and resistance to them is climbing higher as the years march on.

Unfortunately, thanks to their talent for genetic gymnastics, gonococci, the bacteria that cause gonorrhea, have been evolving resistance to every drug we’ve thrown at them — to tetracycline, to penicillin, and more recently to fluoroquinolones. One class of antibiotics remains to treat gonorrhea: cephalosporins. In 2013, Centers for Disease Control and Prevention (CDC) Director Tom Frieden warned that we could find ourselves in a “post-antibiotic era” – unless we take precautions. And, just two weeks ago, the latest study from the CDC’s Gonococcal Isolate Surveillance Project sounded the alarm that the post-antibiotic era is drawing ever closer, especially when it comes to gonorrhea.

Azithromycin and ceftriaxone, the two drugs that are used in combination to deliver a one-two punch to invading gonococci, are the best antibiotics remaining in our arsenal. Azithromycin is taken by mouth, while ceftriaxone is administered by a shot, and when taken together they team up to target different weak points in gonococci’s armor. Azithromycin interferes with the bacteria’s ability to make proteins, shutting the cells down, while ceftriaxone causes the cell wall to fall apart. However, the gonococci can acquire resistance. For example, in the case of azithromycin, a resistant bacterium can spit out the drug before it has a chance to kill it, or it can change the shape of its protein-making apparatus such that the drug can’t attach to it.  Continue reading →

Teen Talk: What Is Kissing Disease?

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kissing diseaseIf you’re a total dork like me, you might have some plush microbes hanging out on your desk or in your bedroom. The one that represents Epstein-Barr virus is especially adorable (look to your right and try not to coo in delight!). I just want to grab it, cuddle up to it, and fall asleep in its pillowy purple-pink embrace.

In reality, Epstein-Barr virus, or EBV for short, is not the most warm-and-fuzzy microbe of the bunch. I’d way rather have a cold. Why? Because EBV causes mono, which is more whimsically known as the kissing disease. And, despite that cute moniker, kissing disease can be most unpleasant.

Take it from one mono survivor: “Mono stinks!”

First, an explanation of why mono is also called the kissing disease. Merely being in the presence of someone with mono won’t put you at risk, even if you’re both in the same room — you need to be actively swapping spit with them to be exposed to the virus. Kissing is probably the most famous way for two people to exchange saliva, but sharing cups, eating utensils, or toothbrushes can do it, too. After exposure to the virus, symptoms could show up in 4 to 6 weeks.

Second, an explanation of why mono can be so terrible. While not all teenagers and young adults who are infected with EBV will develop symptoms, those who do probably won’t enjoy the experience. Symptoms include extreme fatigue, head and body aches, sore throat, and fever. It’s bad enough to have those symptoms for a few days, but mono might seem to go on and on with no end in sight. Most people are better in 2 to 4 weeks, but even then it could take another few weeks to get back to 100 percent. And some unlucky people can experience these symptoms for six months or even longer! In addition to these nasty symptoms, serious complications are possible. Continue reading →

STD Awareness: Ceftriaxone-Resistant Gonorrhea

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Nestled in the throat of a Japanese woman was a collection of clones that scientists abducted from their temporary habitat and christened H041 — a humdrum moniker for a strain of bacteria that would burn headlines in medical journals. Though the bacteria never caused symptoms in their host, they lingered in her throat from at least January until April of 2009, when a swab finally tested negative. Rather than succumbing to repeated bombardment by an antibiotic called ceftriaxone, the infection probably just went away on its own — as oral gonorrhea infections tend to do.

Resistance to ceftriaxone, our last good gonorrhea drug, has been reported in Japan, Australia, Sweden, France, and Spain.

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.” 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. Resistance to cefixime was first documented in 1999, leaving ceftriaxone as our best remaining option, and the CDC’s first choice for treating gonorrhea. There are no good alternatives to ceftriaxone remaining, which is why reports of ceftriaxone-resistant gonorrhea are so deeply troubling.

What made H041 special was that it was the first extensively drug-resistant strain of Neisseria gonorrhoeae, the bacteria that cause gonorrhea. With an unusually high level of resistance to ceftriaxone — four to eight times higher than the previous record holder — the strain was also resistant to a slew of other antibiotics: penicillin and its relatives, fluoroquinolones, macrolides, tetracycline, trimethoprim-sulfamethoxazole, chloramphenicol, nitrofurantoin, cefpodoxime, cefixime, ciprofloxacin, and levofloxacin — and had reduced susceptibility to azithromycin to boot.

Another thing that made H041 special — as special as clones can be, anyway — is that it never reappeared. After its discovery, researchers in Kyoto and Osaka intensified their surveillance, trying to uncover it again and track its spread through the population. However, their search for H041 turned up empty handed. But other ceftriaxone-resistant strains have been documented around the world. Continue reading →