A jogger found the bloodstained and filthy body of Kristopher Olinger by the side of the road one September morning in 1997. The last time anyone saw the 17-year-old from Pacific Grove, CA was at midnight, when he went out to photograph the ocean for a school project. The police investigation determined that he had been carjacked, kidnapped, and stabbed. His abductors drove him to a dirt turnout along a deserted coastal road and threw him over a 15-foot cliff into the ocean below. Olinger spent the next hour climbing back up the cliff, only to expire at the top from his multiple knife wounds.
Huh, I guess we took a little break there for a while. Sorry about that. We don’t even have a good excuse for why we haven’t been updating. It’s not like we had a death in the family, or a medical crises. We didn’t even go on vacation. Well, here’s a cute picture of a dog in a sleeping bag:
All better now?
Anyway, on to what I really wanted to talk about today: Antibiotic resistant superbugs!
The CDC recently sent out a press release calling for immediate action to halt the spread of antibiotic-resistant bacteria that they’re calling CRE. The acronym stands for Carbapenem-Resistant Enterobacteriaceae, or in plain English, bacterial strains that normally live in our intestines but can wreak havoc when they get into the blood, bladder, or in wounds, and have acquired the ability to withstand our most-effective antibiotics. Apparently these antibiotic-resistant strains have been on the rise for about 10 years now, but they are finally becoming widespread and are incredibly lethal, killing about half of those who are infected. These strains do not pose a great threat to an average, healthy person who spends little time in the hospital, but can be very dangerous to your elderly grandmother, or anyone staying in a hospital or long-term care facility.
But now I will get to what I really really want to talk about today: The image that accompanies the CDC press release. It’s a backlit agar plate, held by blue-gloved disembodied hands. The bacteria growing on the plate makes four unusual clover leaf shapes. Somehow the picture comes across as threatening, even though few people know what those clover leafs actually mean. I have an advanced degree in microbiology and I still had to look it up.
Turns out that cloverleaf plate is the end result of a Modified Hodge Test, which is really just an adaptation of the cloverleaf test developed by Kjellander and Myrbäch back in 1964. The test tells you whether or not a certain bacterial strain is secreting an enzyme that can break down a specific antibiotic, which tells you if it is resistant to that antibiotic. If your strain makes a nice, well-defined clover leaf shape, then it is resistant to the antibiotic. If the plate looks more like a dark circle with a cross through it, then the strain is susceptible to the drug.
How does it work? Well, first you cover the plate with a solution of garden-variety E. coli. Why E. coli? This bacteria is susceptible to the antibiotic and makes a yellowish lawn all over the plate, except for a circle around the little white disk, which is impregnated with the antibiotic. The antibiotic from the disc seeps into the surrounding agar and prevents any E. coli from growing there. Next, you streak a line of a bacteria that is resistant to the antibiotic coming out from the white disc, as well as a strain that is susceptible. These are the positive and negative controls, respectively. Then, you streak a line of your unknown bacteria. I think the CDC did this part twice so that the plates would look like luck four-leaf clovers, instead of the three-leaf ones, but it does look nifty, so I suppose you can’t blame them. Then, you culture the plates at around 98 degrees and see what grows.
First of all, the E. coli will grow everywhere, except for where there are antibiotics leeching into the agar. The other bacterial strains that produce the antibiotic-eating enzymes will be surrounded by E. coli growth, since the enzymes make the agar safe for the E. coli This creates the round leaf shape. Strains that are susceptible to the antibiotic and do not make these enzymes will grow poorly next to the disk, and will not be surrounded by E. coli, so the dark (bacteria-free) part will look more like a piece of pie.
And that’s why that picture of the cloverleaf plate is so scary, but it shows several strains of bacteria that are circulating in our hospitals that don’t give a *bleep* about our antibiotics. Even scarier, is that these bacteria have the potential to spread the genes for these antibiotic-eating enzymes to other bacteria, which could results in all sorts of new, deadly “superbugs.”
What can YOU do about CRE? Unfortunately, not much. The responsibility is going to fall on the hospitals to institute stricter cleaning regimes and isolation of CRE-positive patients to prevent its spread. Also, public health labs will need to do more antibiotic resistance testing (AKA Clover leaf plates!) to find the CRE-resistant strains, track their movement, and to make sure that they are not treated with useless antibiotics.
BUT! You can act wisely toward the bacterial strains that are still susceptible to antibiotics.
-ALWAYS finish ALL of your prescribed antibiotics.
-NEVER take antibiotics for a viral infection – and don’t pester your doctor about it, because sometimes they give out antibiotics just because they’re tired of being hounded when whiny kids have ear aches.
-Buy organic meats and dairy products that do not come from animals that have been treated with unnecessary, constant antibiotics.
-Do not buy antibacterial soaps or other antibacterial products. The antibiotic in these products does not make you any safer, and tends to accumulate in the environment, where bacteria form a resistance to it. If you much, alcohol-based hand sanitizer is ok.
The superbugs may still win in the end, but at least we can stave off their dominion for as long as possible…
2012 was the year of peak Zombie. The Walking Dead TV show first aired in late 2010, and zombies started to get hot in 2011. In May 2011, the normally tight-laced CDC even put out a press release highlighting the importance of disaster preparation using the Zombie Apocalypse as an example. In 2012, The Walking Dead season 3 set viewing records, and inspired zombie pub crawls and zombie fun runs. But how long can zombie hysteria last? There are more zombie movies set to be released In 2013, but as with vampires, eventually the public will tire of zombies and will move on to some other mythical creature. Perhaps minotaurs will be next? Or unicorns?
But while everyone’s attention is focused on zombies, I’d like to point out examples of so-called “zombies” in nature – no, not the undead, brain-eating kind that are transformed by a zombie virus, but people whose minds are being controlled in much more subtle and insidious ways.
1. Nails and teeth would be the first things to fall off of a decaying body, which would make a zombie pretty innocuous. Sure, it would be pretty traumatic to have a zombie gumming your arm, or pawing at your chest, but without nails to scratch, or teeth to bite, how would they pass on the virus?
2. As top predators, zombies would occupy a higher trophic level than us, and would need to eat a lot of humans to keep up their energy needs. How could they hunt down enough humans, especially when there are large zombie hoards? It just doesn’t make thermodynamic sense. The caveat to this idea though is that if they’re cold blooded and if they aren’t trying to support an energy-sucking brain, like humans do, then they may be able to survive on fewer calories per day.
3. Within a few days of death, a zombie would become a bloated, decomposing, maggot-ridden bag of gas. The human body is full of nutrients, and insects and bacteria make pretty quick work of defenseless human flesh. A zombie would be a puddle goo in no time.
4. Don’t tell PETA, but zombies would be vegan. It makes more sense for zombies to eat grass and weeds than brrrraiinnns because digesting meat requires teeth to chew the flesh and organs to make protein-dissolving enzymes. Since they don’t have a working digestive track, they would instead make use of their native bacterial populations to break down plant matter and to generate the amino acids and vitamins they would need to wander around and scare people.
5. Dogs and other predators would eat them. Sure, they’re made of rotting meat, but my well-fed Chihuahua-mix will drag month-old avocado rinds from my compost pile to nibble on, so I imagine if there were packs of abandoned pets they would start hunting down zombies for dinner. Lions, tigers, bears, ostriches and other large predators could also take a bite out of the zombie population. Literally.
Did you know that the United States is part of an international Outer Space Treaty? Formally (and wordily) called “Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies,” the treaty establishes the foundation of Space Law. Basically the idea is that no country can put nuclear weapons into orbit or establish a military base on the moon (Sorry Newt Gingrich!) Also everyone should maintain the integrity and cleanliness of Outer Space, since it is not owned by any one country, and must be preserved for Science.
With that goal in mind, NASA has a Planetary Protection Officer that consults with engineers to ensure that equipment sent from Earth is suitably decontaminated before launch. Capsules that are sent into the void of space have little risk of contaminating another heavenly body, and have more relaxed decon standards. Rovers have much more strict requirements.
Still, each type of machine has a certain allowable amount of organisms that tag along – kind of like the amount of spiders and dog hairs allowed in sausage. Total sterility is impossible, but the engineers try to keep the number of organisms to a minimum. Some parts can be autoclaved – put in a pressure cooker that kill organisms with heat and pressure. More delicate equipment is wiped down with alcohol.
The Mars Curiosity Rover was clean and all set to fly when engineers decided to tweak the packing on the drill bits that the rover will use to drill into the Martian terrain. Concerned that a rocky landing might damage the bit-grabbing mechanism, they pre-loaded one of the bits onto the drill to make sure that it would be ready to go, even if it couldn’t load the bit mechanically. Unfortunately, these engineers failed to tell the Planetary Protection Officer, and the drill was sealed up without being properly cleaned.
Since Curiosity is mainly traveling through dry, rocky areas, there may be little risk of contaminating Mars with our Earth bugs. After analyzing the exposure risk, the Planetary Protection Officer decided that the only real concern would be in Curiosity found water. Since liquid water in required for all Earth life forms, a bacteria that jumped ship in the Martian desert is probably a goner, but one that takes up residence in a pond just might survive.
The odds of Curiosity finding water in the cold, dry Gale Crater where it landed are pretty low. However, can you imagine being the engineer that would have to steer away from the water in the event that you did find it? I don’t know if I would have that kind of self-control.
Perhaps I’m being optimistic, but I would be shocked if organisms from the earth survived on the edges of this drill despite the harsh UV light, the dryness of the environment, the freezing temperatures and lack of air pressure. The bacteria that are tagging along are probably from humans – we are walking bacteria bags, after all – and are happier hanging around a warm, moist body than in the harsh rocky environment of Mars. As long as one of the NASA employees didn’t have a nasty case of Deinococcus radiodurans, I can’t imagine that the rover was contaminated with anything that would set up shop on Mars.
In the event that we did collect bacteria from Mars that we had previously planted there, then wouldn’t we be able to figure that out? Yes, it would be devastating to set up cultures from some precious Mars soil and realize that you had grown E. coli or even a common soil microorganism. But with genetic tests you could determine if the organisms are recently from Earth or if there really are similar microbes growing on Mars.
Of course, it’s never wise to bet against the bacteria. So far we’ve found organisms in almost every place we’ve looked, including ice cores in Antarctica and in boiling geysers. We’ve also found them in the
Atacama desert, which is the most Mars-like environment you can find without leaving earth. So it’s certainly smart to be as clean as possible. You never know what kind of organisms might survive an interplanetary round-trip.
For any independent, heterosexual woman, this news might be terrifying: semen contains a protein that could potentially be messing with your mind. Well, at least it’s messing with llama minds.
A recent study that was published online in PNAS (which if you sound out the journal name is very appropriate for this subject) found that a protein in llama semen, when injected into the female animal’s bloodstream, causes ovulation with no “physical activity” required. The responsible protein in the semen is one that they’ve known about for decades, called nerve growth factor, or NGF, but no one knew that it had these stimulatory powers. NGF is found in all sorts of animals and functions in the brain to keep neurons alive and kicking.
Researchers think that the NGF protein travels to the llama’s hypothalamus and pituitary gland in the brain and tells it to start pumping out the hormones that cause ovulation.
(Ok, so before I get into the nuts (ha!) and bolts of this post, I just have to point out that Greg Adams and his colleagues at the University of Saskatchewan collected semen using an “artificial llama vagina.” Can you imagine Adam’s grad students explaining that to their grandmothers when asked what they do in the lab? The llamas are lucky compared to the bulls in the experiment, however, whose semen was collected using “electroejaculation.”)
Fortunately for humans, llamas are “induced ovulators” which means that they only drop an egg when they have sex (or when a scientist doses it with semen extract). Humans and many other animals are “spontaneous ovulators” which is a misleading term for females that release eggs on a regular schedule.
While human women do not ovulate on command, it’s still possible that NGF is having an effect on a women’s cycle, and slightly altering the timing of ovulation. The researchers next step is to look at NGF in human couples. They think that the protein may play a role in fertility and want to see if men with low NGF have a hard time impregnating women.
In cows, at least (also spontaneous ovulators), NGF from regular doses of semen causes the female’s reproductive system to pump out higher levels of hormones that help the cow not to miscarry. If the same effect happens in humans, then couples should continue “baby dancing” even after the woman is pregnant.
All of this is still speculation in animals that are not llamas, camels, cows and mice, but NGF is found in the semen of ALL animals that scientists have examined, and in high concentrations. Contrary to “biology according to Todd Akin,” it’s likely that the presence of this protein in semen evolved to improve the odds of insemination.
Finally, the researchers also think that NGF may be one reason why the rhythm method is such an ineffective way of not getting pregnant. If NGF from sperm is altering a women’s cycle then it will be especially hard to track it and limit sex to “non-fertile” times. According to the Planned Parenthood website, one in four couples who practice the rhythm method will get pregnant each year.