Acne is an unwelcome reality for 80 percent of us at some point in our lives, but researchers have discovered the secret to clear skin may be the kind of bacteria that’s taken up residence there.
According to findings published in the Journal of Investigative Dermatology today, certain strains of Propionibacterium acnes, a bacteria typically found in our pores, may actually protect skin from other strains of P. acnes that cause inflammation in the form of pimples.
Electron micrograph of bacteria-infecting viruses
Bacteria sometimes commit suicide for the good of the group. When a virus infects a bacterium, the cell kills itself rather than allow the virus to replicate inside it and spread to the surrounding bacteria.
The way this works is that when viruses aren’t around, the bacteria manufacture both a bacterial cyanide pill—a toxin molecule they could use to wipe themselves out if they come under attack—and an antitoxin molecule that keeps the toxin in check. When a virus infects the bacterium, the toxin is released, kills the bacterial cell, and prevents the virus from spreading to other cells. It’s bad for the individual bacterial cell but good for the community—and certainly bad for the infecting virus. Now researchers have found a virus that manipulates this mechanism for its own means, saving itself by keeping its host bacteria from cellular suicide.
This winter, an Arizona ski resort, Snowbowl, will be the first to use treated sewage water, and sewage water alone, to make manmade snow. Recycling’s usually a good thing, but opponents of the plan worry about chemicals left in the snow, and an August report by a civil and environmental engineer says that the recycled water, already used for irrigation in Flagstaff green spaces, may contain antibiotic-resistant bacteria.
Bacteria invisible to the naked eye find their way to many of the external surfaces of our bodies, including the naked eye. But the eye isn’t defenseless against this onslaught of microbes—researchers have found that it has special weapons for fighting back.
This fight happens at the surface of the cornea, the eye’s clear outer layer. New research published in the Journal of Clinical Investigation has found that keratin—a type of protein that gives structure to the cornea and other tissues like skin, teeth, hair, and mucous membranes—protects against bacteria. If the eye is like a fishbowl, it’s made of shards used for self-defense. Researchers say the new finding may lead to the creation of new kinds of antibiotics.
Plant researchers who want to study the roots of growing plants have a problem: Those roots are obscured by the soil in which the plant grows. But no more hiding. Now researchers have designed a transparent soil that lets them look at not only roots but also the microbes, good and bad, that colonize them.
Autoclaves—would you cook a turkey in this?
At Popular Science is a profile of food scientists given an impossible task: make year-old mashed potatoes taste good. Food that lasts a year on the shelf needs to be sterilized, and that is a battle against extremophiles. Our most effective weapon is a very blunt one—heat. 252 degrees Fahrenheit to be exact.
Writer Paul Adams tours a food science lab and gets a taste of “retort flavor” in his sterilized mashed potatoes. The unappetizing term refers to the retort, a machine that obliterates microbes and flavor in one fell (and very hot) swoop:
The potatoes look right, once we’ve fluffed them up a bit, but the wholesome earthy taste and smell of fresh potatoes is almost gone from the dish. In its place there’s a tired, wet-paper flavor with notes of old steam pipe. This side effect of confined high-heat cooking is known in the trade as “retort flavor.” Stuckey’s theory is that it’s just underlying parts of the flavor coming through. Before food is retorted, she says, the dank base notes present in it are masked in part “by the beautiful aromatic volatile notes that we take for granted. When the retort destroys these low-molecular-weight flavors, what’s left is the ugly insides.” Read More
Crawling my way to a healthier immune system.
Bacteria are practically everywhere around us, including on and inside you, but that is in many ways a good thing. For instance, having a diverse set of microbes living on your skin might help prevent allergies. A new study published in PNAS links two factors related to how microbes might affect our health: the observation that diversity of microbes on a person is related to the diversity of microbes in their environment, and the hygiene hypothesis, which suggests that the modern uptick in allergies and autoimmune diseases is caused by childhood under-exposure to bacteria.
For a while now, scientists have known that kids living on farms are less likely to have allergies or asthma. Being around livestock means the farm kids are also around a more diverse set of bacteria than city kids living in an apartment. In this new study, scientists swabbed the skin bacteria of 118 Finnish kids, some who lived in rural areas and some who lived in urban areas. They also tested the kids for levels of an antibody called IgE, high levels of which indicate hypersensitivity to allergens, or what is known as atopy. Lastly, they surveyed the parents about plant diversity around their homes.
It’s an exciting time for ecologists who study microbes. DNA sequencing has grown so cheap and fast that they can run around identifying bacteria living just about anywhere they can reach with a cotton swab. Turns out, bacteria are everywhere, even in the cleanest houses, and scientists are starting to wonder: do those bacteria in the home reflect the bacteria that live inside the inhabitants?
And if so, can they travel from person to person?
A small insight into this question came at one of the presentations at the International Human Microbiome Congress (covered by New Scientist in a short piece here). James Scott, who studies molecular genetics at the University of Toronto, reported that the gut microbes of babies, as found in their poop, were also in the dust in the babies’ homes. It’s not clear whether this means that bacteria in the dust are colonizing the babies or vice versa—or both—but it’s still something of a surprise. Gut microbes don’t seem like the sort to thrive outside the body, as they tend to require an oxygen-free environment. But maybe the gut bacteria in the dust are in a dormant form, waiting to be absorbed into a new gut before flowering into life again.
The corollary of this finding is that perhaps the other inhabitants of that home might pick up those microbes. Your gut microbiome, thus, would be closer to your roommates’ than to a stranger’s, something that would be easy to test with modern sequencing techniques. There’s also room to speculate that as we learn more about the microbiome’s relationship to disease, the swapping of microbes within a household could reveal an infectious component to illnesses that we don’t currently think of that way. It’s just a speculation now, but an interesting one.
The rise of antibiotic-resistant bacteria has got many experts predicting a future in which currently tractable diseases, like tuberculosis, became untreatable again. The popularity of modern antibiotics, ironically, is what is leading to their downfall: antibiotics in consumer products, like soaps, as well as the excessive use of antibiotics by people who have no bacterial infections, help select for strains of bacteria that don’t respond to drugs. Factory-farmed livestock, which receive tremendous doses of antibiotics in their feed, are also a likely breeding ground for resistant bacteria that could potentially infect humans.
Proponents of factory farming have scoffed at such claims [pdf], but now, scientists have provided definitive evidence that this happens: through genetic analysis, they found that a strain of MRSA, already resistant to one family of drugs, had hopped from people to farmed pigs, acquired resistance to another antibiotic being fed to the pigs, and then leapt back into humans, taking its new resistance with it. That strain, called MRSA ST398 or CC398, is now causing 1 out of 4 cases of MRSA in some regions of the Netherlands [pdf], where it arose, and it has also been found across the Atlantic in nearly half of the meat in US commerce. After this strain arose in 2004, the European Union began a ban the use of antibiotics in livestock feed. In the United States, however, where most of the antibiotics in circulation are being used in farming, no such regulation exists.
Image courtesy of wattpublishing / flickr
What’s the News: The bacterial hordes that call your mouth home—and yes, even if you brush rigorously, you’ve got ’em—are generally a pretty benign bunch. Mostly they just mooch around, snagging tastes of whatever you’re eating, but Streptococcus mutans, the bad boy that causes cavities, releases tooth-corroding acid whenever you eat sugar. Even mouthwash that kills everything it touches can’t save you from the ravages of S. mutans in the long term; it just grows back, along with the rest of your bacteria.
Scientists who study the mouth microbiome, however, think that a mouthwash that kills S. mutans and leaves the rest of the bacteria to take over S. mutans‘s real estate could spell the end of cavities. In a small clinical study last year, one team found that one application of the mouthwash knocked down S. mutans levels, and that harmless bacteria grew back in its place. If the mouthwash pans out, it could join the ranks of an emerging new type of treatment: better living through hacking the microbiome.