Having worms can be good for the gut

Parasitic worms may hold the secret to soothing inflamed bowels.

In studies of mice and people, parasitic worms shifted the balance of bacteria in the intestines and calmed inflammation, researchers report online April 14 in Science. Learning how worms manipulate microbes and the immune system may help scientists devise ways to do the same without infecting people with parasites.

Previous research has indicated that worm infections can influence people’s fertility (SN Online: 11/19/15), as well as their susceptibility to other parasite infections (SN: 10/5/13, p. 17) and to allergies (SN: 1/29/11, p. 26). Inflammatory bowel diseases also are less common in parts of the world where many people are infected with parasitic worms.
P’ng Loke, a parasite immunologist at New York University School of Medicine, and colleagues explored how worms might protect against Crohn’s disease. The team studied mice with mutations in the Nod2 gene. Mutations in the human version of the gene are associated with Crohn’s in some people.

The mutant mice develop damage in their small intestines similar to that seen in some Crohn’s patients. Cells in the mice’s intestines don’t make much mucus, and more Bacteroides vulgatus bacteria grow in their intestines than in the guts of normal mice. Loke and colleagues previously discovered that having too much of that type of bacteria leads to inflammation that can damage the intestines.
In the new study, the researchers infected the mice with either a whipworm (Trichuris muris) or a corkscrew-shaped worm (Heligmosomoides polygyrus). Worm-infected mice made more mucus than uninfected mutant mice did. The parasitized mice also had less B. vulgatus and more bacteria from the Clostridiales family. Clostridiales bacteria may help protect against inflammation.
“Although we already knew that worms could alter the intestinal flora, they show that these types of changes can be very beneficial,” says Joel Weinstock, an immune parasitologist at Tufts University Medical Center in Boston.

Both the increased mucus and the shift in bacteria populations are due to what’s called the type 2 immune response, the researchers found. Worm infections trigger immune cells called T helper cells to release chemicals called interleukin-4 and interleukin-13. Those chemicals stimulate mucus production. The mucus then feeds the Clostridiales bacteria, allowing them to outcompete the Bacteroidales bacteria. It’s still unclear how the mucus encourages growth of one type of bacteria over another, Loke says.

Blocking interleukin-13 prevented the mucus production boost and the shift in bacteria mix, indicating that the worms work through the immune system. But giving interleukin-4 and interleukin-13 to uninfected mice could alter the mucus and bacterial balance without worms’ help, the researchers discovered.

Loke and colleagues also wanted to know if worms affect people’s gut microbes. So the researchers took fecal samples from people in Malaysia who were infected with parasitic worms.

After taking a deworming drug, the people had less Clostridiales and more Bacteriodales bacteria than before. That shift in bacteria was associated with a drop in the number of Trichuris trichiura whipworm eggs in the people’s feces, indicating that getting rid of worms may have negative consequences for some people.

Having data from humans is important because sometimes results in mice don’t hold up in people, says Aaron Blackwell, a human biologist at the University of California, Santa Barbara. “It’s nice to show that it’s consistent in humans.”

Worms probably do other things to limit inflammation as well, Weinstock says. If scientists can figure out what those things are, “studying these worms and how they do it may very well lead to the development of new drugs.”

Riding roller coasters might help dislodge kidney stones

Passing a kidney stone is not exactly rocket science, but it could get a boost from Space Mountain.

It seems that shaking, twisting and diving from on high could help small stones dislodge themselves from the kidney’s inner maze of tubules. Or so say two researchers who rode the Big Thunder Mountain Railroad roller coaster at Disney’s Magic Kingdom in Orlando, Fla., 20 times with a fake kidney tucked inside a backpack.

The researchers, from Michigan State University College of Osteopathic Medicine in East Lansing, planned the study after several of their patients returned from the theme park announcing they had passed a kidney stone. Finally, one patient reported passing three stones, each one after a ride on a roller coaster.
“Three consecutive rides, three stones — that was too much to ignore,” says David Wartinger, a kidney specialist who conducted the study with Marc Mitchell, his chief resident at the time.
Since neither of the two had kidney stones themselves, the pair 3-D printed a life-size plastic replica of the branching interior of a human kidney. Then they inserted three stones and human urine into the model. The stones were of the size that usually pass on their own, generally smaller in diameter than a grain of rice. After arriving at the park, Wartinger and Mitchell sought permission from guest services to do the research, fearing that two men with a backpack boarding the same ride over and over might strike workers as suspect.
“Luckily, the first person we talked to in an official capacity had just passed a kidney stone,” Wartinger says. “He told us he would help however we needed.”

Even when a stone is small, its journey through the urinary tract can be excruciating. In the United States alone, more than 1.6 million people each year experience kidney stones painful enough to send them to the emergency room. Larger stones — say, the size of a Tic Tac — can be treated with sound waves that break the stones into smaller pieces that can pass.

For the backpack kidney, the rear of the train was the place to be. About 64 percent of the stones in the model kidney cleared out after a spin in the rear car. Only about 17 percent passed after a single ride in the front car, the researchers report in the October Journal of the American Osteopathic Association.

Wartinger thinks that a coaster with more vibration and less heart-pounding speed would be better at coaxing a stone on its way.

The preliminary study doesn’t show whether real kidneys would yield their stones to Disney magic. Wartinger says a human study would be easy and inexpensive, but for now, it’s probably wise to check with a doctor before taking the plunge.

Fleeting dead zones can muck with seafloor life for decades

Short bouts of suffocating conditions can desolate swaths of seafloor for decades, new research suggests. That devastation could spread in the future, as rising temperatures and agricultural runoff enlarge oxygen-poor dead zones in the world’s oceans.

Monitoring sections of the Black Sea, researchers discovered that even days-long periods of low oxygen drove out animals and altered microbial communities. Those ecosystem changes slow decomposition that normally recycles plant and animal matter back into the ecosystem after organisms die, resulting in more organic matter accumulating in seafloor sediments, the researchers report February 10 in Science Advances.
Carbon is included among that organic matter. Over a long enough period of time, the increased carbon burial could help offset a small fraction of carbon emitted by human activities such as fossil fuel burning, says study coauthor Antje Boetius, a marine biologist at the Max Planck Institute for Marine Microbiology in Bremen, Germany. That silver lining comes at a cost, though. “It means your ecosystem is fully declining,” she says.

“We need to pay more attention to the bottom of the ocean,” says Lisa Levin, a biological oceanographer at the Scripps Institution of Oceanography in La Jolla, Calif. “There’s a lot happening down there.” The new work shows that scientists need to consider oxygen conditions when tracking how carbon moves around the environment, says Levin, who was not involved in the research.
Some oxygen-poor, or hypoxic, waters form naturally, such as the suffocating conditions caused by a lack of churning in the deep realms of the Black Sea (SN Online: 10/9/15). Other regions lose their oxygen to human activities; fertilizer washing in from farms nourishes algal blooms, for example, and the bacteria that later decompose that algal influx suck up oxygen. Rising sea-surface temperatures could worsen these problems by decreasing the amount of dissolved oxygen that water can hold and making it harder for ocean layers to mix, as warmer waters remain on top (SN: 3/5/16, p. 11).
Scientists have noticed increased carbon burial in hypoxic waters before. The mechanism behind that increase was unclear, though. Boetius and colleagues headed out to the Black Sea, the world’s largest oxygen-poor body of water, and studied sites along a 40-kilometer-long stretch of seafloor. (Military activities in the region following Russia’s annexation of Crimea limited where the researchers could study, Boetius says.) Some sites were always flush with oxygen, some occasionally suffered a few days of low oxygen, and others were permanently oxygen-free.

The ecological difference between the sites was stark. In oxygen-rich waters, animals such as fish and starfish flourished, and little organic matter was deposited on the seafloor. In areas with perpetually or sporadically low oxygen, the researchers reported that oxygen-dependent animals were nowhere to be seen, and organic matter burial rates were 50 percent higher.

Bottom-dwelling animals are particularly important, the researchers observed, helping recycle organic matter by eating larger bits of debris sinking from the surface ocean and by mixing oxygen into sediments during scavenging. What’s more, the researchers found that the microbial community in oxygen-poor waters shifted toward those microbes that don’t depend on oxygen to live. Such microbes further limit decomposition by producing sulfur-bearing compounds that make organic matter harder to break down.

Depending on the size of the area affected, animals could take years or decades to return to previously hypoxic waters, Boetius says. Some of the studied sites experienced low-oxygen conditions for only a few days a year yet remained barren even when oxygen returned. The absence of animals prolongs the effects of hypoxic conditions beyond the times when oxygen is scarce, she says.

Stunning images reveal glacial landscapes under the oceans

The footprints of long-gone glaciers and icebergs are now frozen in time in a stunning new collection of images of Earth’s seafloor.

The Atlas of Submarine Glacial Landforms is a comprehensive, high-resolution atlas of underwater landscapes that have been shaped by glaciers, largely in polar and subpolar regions, and provides a comparative look at how glaciers, ice and related climate shifts transform Earth. Kelly Hogan, a marine geophysicist with the British Antarctic Survey and an editor of the atlas, presented it April 26 in Vienna at a meeting of the European Geosciences Union.
Most of the more than 200 images were generated from research vessels using multibeam bathymetry, which renders the seafloor surface in 3-D, exposing a region’s glacial history. For example, the distinctive asymmetry of 20,000-year-old glacial deposits called drumlins in the Gulf of Bothnia, between Finland and Sweden, suggests that ice flowed south, toward a larger glacier in the Baltic Sea.

Other images reveal the tracks of icebergs that once plowed and scribbled the ocean floor, such as those seen in the Barents Sea in the Arctic Ocean. The tracks may look random, but they tell tales of past currents and water depth.

In all, the seafloor depicted in the atlas covers an area about the size of Great Britain. But the real impact of the project goes beyond individual images, Hogan says. She expects that scholars exploring glacial history, researchers predicting future ice behavior and climate scientists are among those who will keep a copy close at hand.

Neandertal kids were a lot like kids today — at least in how they grew

A Neandertal child whose partial skeleton dates to around 49,000 years ago grew at the same pace as children do today, with a couple of exceptions. Growth of the child’s spine and brain lagged, a new study finds.

It’s unclear, though, whether developmental slowing in those parts of the body applied only to Neandertals or to Stone Age Homo sapiens as well. If so, environmental conditions at the time — which are currently hard to specify — may have reduced the pace of physical development similarly in both Homo species.
This ancient youngster died at 7.7 years of age, say paleoanthropologist Antonio Rosas of the National Museum of Natural Sciences in Madrid and colleagues. The scientists estimated the child’s age by counting microscopic enamel layers that accumulated daily as a molar tooth formed.

Previous excavations uncovered the child’s remains, as well as fossils of 12 other Neandertals, at a cave site in northwestern Spain called El Sidrόn.

Much — but not all —of the Neandertal child’s skeleton had matured to a point expected for present-day youngsters of the same age, the scientists report in the Sept. 22 Science. But bones at the top and in the middle of the spine had not fully fused, corresponding to a stage of development typical of 4- to 6- year-olds today. Also, the ancient child’s brain was still growing at an age when living humans’ brains have nearly or fully reached adult size. Signs of bone tissue being reshaped on the inner surface of the child’s braincase pointed to ongoing brain expansion. Rosas’ team calculated that the youngster’s brain volume was about 87.5 percent of that expected, on average, for Neandertal adults.

Neandertals’ slightly larger brains relative to people today may have required more energy, and thus more time, to grow, the researchers suggest. And they suspect that the growth of Neandertals’ bigger torsos, and perhaps spinal cords, slowed the extinct species’ backbone development in late childhood.

Rosas’ new study “reinforces what should have been apparent for some time — that Neandertal growth rates and patterns, except for those related to well-known differences in [skeletal shape], rarely differ from modern human variations,” says paleoanthropologist Erik Trinkaus of Washington University in St. Louis.

But researchers need to compare the El Sidrόn child to fossils of H. sapiens youngsters from the same time or later in the Stone Age, Trinkaus adds. Relative to kids today, ancient human youth may display slower growth rates comparable to those of the Neandertal child, he suspects.

Trio wins physics Nobel Prize for gravitational wave detection

Subtle cosmic vibrations kicked up by swirling black holes have captured the public imagination — and the minds of the physics Nobel Prize committee members, too.

Three scientists who laid the groundwork for the first direct detection of gravitational waves have won the Nobel Prize in physics. Rainer Weiss of MIT, and Kip Thorne and Barry Barish, both of Caltech, will share the 9-million-Swedish-kronor (about $1.1 million) prize, with half going to Weiss and the remainder split between Thorne and Barish.
Though researchers often wait decades for Nobel recognition, the observation of gravitational waves was so monumental that the scientists were honored less than two years after the discovery’s announcement.

“These detections were so compelling and earth shattering…. Why wait?” says Clifford Will of the University of Florida in Gainesville, who was not directly involved with the discovery. “It’s fabulous. Absolutely fabulous.”

Weiss, Thorne and Barish are pioneers of the Laser Interferometer Gravitational Wave Observatory, or LIGO. On February 11, 2016, LIGO scientists announced they had spotted gravitational waves produced by a pair of merging black holes. This first-ever detection generated a frenzy of excitement among physicists and garnered front-page headlines around the world.

LIGO’s observation of gravitational waves directly confirmed a 100-year-old prediction of Einstein’s general theory of relativity — that rapidly accelerating massive objects stretch and squeeze spacetime, producing ripples that travel outward from the source (SN: 3/5/16, p. 22).
“If Einstein was still alive, it would be absolutely wonderful to go to him and tell him about the discovery. He would be very pleased, I’m sure of it,” Weiss said during a news conference at MIT a few hours after he got word of the win. “But then to tell him what the discovery was, that it was a black hole, he would have been absolutely flabbergasted because he didn’t believe in them.”

As enthusiastic team members clad in LIGO-themed T-shirts celebrated the discovery, Weiss stressed that the discovery was a group effort. “I’m a symbol of that. It’s not all on my shoulders, this thing,” he said, citing the large collaboration of scientists whose work led up to LIGO’s detection.

Physicists anticipate that LIGO will spark an entirely new field of astronomy, in which scientists survey the universe by feeling for its tremors. “It will allow us to see the parts of the universe that were not revealed to us before,” says LIGO team member Carlos Lousto of the Rochester Institute of Technology in New York.

LIGO’s first incarnation, which officially began collecting data in 2002 and ran intermittently until 2010, yielded no hints of gravitational waves. After years of upgrades, the souped-up detectors, known as Advanced LIGO, began searching for spacetime ripples in 2015. Almost as soon as the detectors were turned on — even before scientific data-taking had formally begun — scientists detected the minuscule undulations of their first black hole collision. Those ripples, spotted on September 14, 2015, journeyed to Earth from 1.3 billion light-years away, where they were produced by two colossal black holes that spiraled inward and merged into one (SN: 3/5/16, p. 6).

Quivers from those converging black holes, when converted into an audio signal, made a tell-tale sound called a “chirp,” reminiscent of a bird’s cry. The particulars of that signature reveal details of the collision. “The beauty of the symphony is in what you can extract from the tiny wiggles, or the wiggles on tops of wiggles, in that signal,” Thorne said at an Oct. 3 news conference at Caltech.
Since that first detection, scientists have observed three more black hole collisions. And additional gravitational ripples may already be in the bag: It’s rumored that LIGO scientists have also detected a smashup of neutron stars (SN Online: 8/25/17). In fact, Weiss teased an announcement to come on October 16.

An astounding feat of engineering, LIGO consists of two enormous L-shaped detectors that stretch across the wooded landscape of Livingston, La., and the desert of Hanford, Wash. Each detector boasts two 4-kilometer-long arms through which laser light bounces back and forth between mirrors.

Gravitational waves passing through a detector stretch one arm while shortening the other. LIGO compares the arms’ sizes using the laser light to measure length differences a tiny fraction of the size of a proton. Gravitational waves should produce signals in the two distant detectors nearly simultaneously, helping scientists to rule out spurious signals that can be caused by events as mundane as a truck bouncing along nearby.

“LIGO is probably one of the best and most amazing instruments ever built by mankind,” Barish said at the Caltech news conference. But building it was a risky endeavor: No one had previously attempted anything like it, and no one could say for sure whether the effort would succeed. “What’s fundamental is you have to be willing to take risks to do great things,” Barish said.

In August, LIGO’s two detectors teamed up with the similarly designed Virgo detector near Pisa, Italy (SN Online: 8/1/17). The latest gravitational wave sighting, made on August 14, showed up in all three detectors almost simultaneously, which allowed scientists to pinpoint the region of space in which the black holes resided more precisely than ever before (SN Online: 9/27/17).

Weiss spent decades on the project, beginning with nascent scribbles on scraps of paper and early prototypes. In the 1960s, Weiss came up with the idea for a laser gravitational wave detector while teaching a class on general relativity. (Other researchers had independently proposed the technique as well.) He refined that idea and built a small, prototype detector, establishing the basic blueprint that would eventually evolve into LIGO.
Inspired by a conversation with Weiss, Thorne, who had been studying theoretical aspects of gravitational waves, assembled a team to work on the technique at Caltech in the ’70s. (Thorne was a 1958 semifinalist in the Science Talent Search, a program of the Society for Science & the Public, which publishes Science News.)

Another LIGO founder, Ronald Drever, died in March. Drever, who had been working on gravitational wave detectors at the University of Glasgow, joined Thorne at Caltech in 1979. Weiss and Drever each worked individually on prototypes, before Weiss officially teamed up with Thorne and Drever in 1984 to create LIGO (SN: 3/5/16, p. 24). Drever did live to hear of the first detection, Will says, but “it’s sad that he didn’t live to see it all.”

Barish joined the project later, becoming director of LIGO in 1994. He stayed in that role for more than 10 years, elevating LIGO from scientists’ daydreams into reality. Barish oversaw construction and commissioning of the detectors, as well as initial gravitational wave searches. “He entered the experiment in a crucial moment, when it was necessary to bring the experiment to a different level, make it a big collaboration,” says Alessandra Buonanno of the Max Planck Institute for Gravitational Physics in Potsdam, Germany.

Speculation that LIGO would nab a Nobel began as soon as the discovery was announced. So the collaboration was not surprised by the honor. “We were certainly expecting this to happen,” says LIGO team member Manuela Campanelli of the Rochester Institute of Technology. Still, the lack of surprise didn’t dampen the mood of festivity. “I feel in a dream,” says Buonanno.

LIGO and Virgo are currently in a shutdown period while scientists tinker with the detectors to improve their sensitivity. The gravitational wave hunt will resume next year. Besides black hole mergers and neutron star smashups, in the future, scientists might also spot waves from an exploding star, known as a supernova. Upcoming detectors might sense trembles generated in the Big Bang, providing a glimpse of the universe’s beginnings.

And scientists may even find new phenomena that they haven’t predicted. “I await expectantly some huge surprises in the coming years,” Thorne said.

In the deep ocean, these bacteria play a key role in trapping carbon

A mysterious group of microbes may be controlling the fate of carbon in the dark depths of the world’s oceans.

Nitrospinae bacteria, which use the nitrogen compound nitrite to “fix” inorganic carbon dioxide into sugars and other compounds for food and reproduction, are responsible for 15 to 45 percent of such carbon fixation in the western North Atlantic Ocean, researchers report in the Nov. 24 Science. If these microbes are present in similar abundances around the world — and some data suggest that the bacteria are — those rates may be global, the team adds.
The total amount of carbon that Nitrospinae fix is small when compared with carbon fixation on land by organisms such as plants or in the sunlit part of the ocean, says Maria Pachiadaki, a microbial ecologist at Bigelow Laboratory for Ocean Sciences in East Boothbay, Maine, who is lead author on the new study. “But it seems to be of major importance to the productivity and health of the 90 percent of the ocean that is too deep and too dark for photosynthesis.” These bacteria likely form the base of the food web in much of this enigmatic realm, she says.

Oceans cover more than two-thirds of Earth’s surface, and most of those waters are in the dark. In the shallow, sunlit part of the ocean, microscopic organisms called phytoplankton fix carbon dioxide through photosynthesis. But in the deep ocean where sunlight doesn’t penetrate, microbes that use chemical energy derived from compounds such as ammonium or hydrogen sulfide are the engines of that part of the carbon cycle.

Little has been known about which microbes are primarily responsible for this dark ocean carbon fixation. The likeliest candidates were a group of ammonium-oxidizing archaea (single-celled organisms similar to bacteria) known as Thaumarchaeota because they are the most abundant microbes in the dark ocean.

But there was no direct proof that these archaea are the main fixers in those waters, says Pachiadaki. In fact, previous studies of carbon fixation in these depths suggested that ammonium-oxidizers weren’t performing the task quickly enough to match observations, she says. “The energy gained from ammonium oxidation is not enough to explain the amount of the carbon fixed in the dark ocean.”
She and colleagues suspected that a different group of microbes might be bearing the brunt of the task. Nitrospinae bacteria that use the chemical compound nitrite were known to be abundant in at least some parts of the dark ocean, but the microbes weren’t well studied. So Pachiadaki’s team analyzed 3,463 genomes, or genetic blueprints, of single-celled organisms found in 39 seawater samples collected in the western North Atlantic Ocean, at depths ranging from “twilight” regions below about 200 meters to the ocean’s deepest zone below 9,000 meters. The team identified Nitrospinae as the most abundant bacteria, particularly in the twilight zone. Although still less abundant than the ammonium-oxidizing Thaumarchaeota, the nitrite-oxidizers are much more efficient at fixing carbon, requiring only a tiny amount of available nitrite.

And although scientists knew that these bacteria use nitrite to produce energy, the new study showed that the compound is the primary source of energy for the microbes. Marine microbiologist Frank Stewart of Georgia Tech in Atlanta says the study “exemplifies how advances in genomic methods can generate hypotheses about metabolism and ecology.” These findings suggest that scientists need to rethink how energy and materials cycle in the dark ocean, he says. “While this ocean realm remains underexplored, studies like this are models for how to close our knowledge gap.”

Babies’ kicks in the womb are good for their bones

One of the strangest things about growing a human being inside your body is the alien sensation of his movements. It’s wild to realize that these internal jabs and pushes are the work of someone else’s nervous system, skeleton and muscles. Someone with his own distinct, mysterious agenda that often includes taekwondoing your uterus as you try to sleep.

Around the 10-week mark, babies start to bend their heads and necks, followed by full-body wiggles, limb movement and breathing around 15 weeks. These earliest movements are usually undetectable by pregnant women, particularly first-timers who may not recognize the flutters until 16 to 25 weeks of pregnancy. These movements can be exciting and bizarre, not to mention uncomfortable. But for the developing baby, these kicks are really important, helping to sculpt muscles, bones and joints.
While pregnant women can certainly sense a jab, scientists have largely been left in the dark about how normal fetuses move. “It’s extremely difficult to investigate fetal movements in detail in humans,” says Stefaan Verbruggen, a bioengineer formerly at Imperial College London who recently moved to Columbia University in New York.

Now, using relatively new MRI measurements of entire fetuses wiggling in utero, researchers have tracked these kicks across women’s pregnancies. The results, published January 24 in the Journal of the Royal Society Interface, offer the clearest look yet at fetal kicking and provide hints about why these moves are so important.
Along with bioengineer Niamh Nowlan, of ICL, and colleagues, Verbruggen analyzed videos of fetal kicks caught on MRI scans. These scans, from multiple pregnant women, included clear leg kicks at 20, 25, 30 and 35 weeks gestation. Other MRI scans provided anatomical details about bones, joints and leg sizes. With sophisticated math and computational models, the researchers could estimate the strengths of the kicks, as well as the mechanical effects, such as stresses and strains, that those kicks put on fetal bones and joints.
Kicks ramped up and became more forceful from 20 to 30 weeks, the researchers found. During this time, kicks shifted the wall of the uterus by about 11 millimeters on average, the team found. But by 35 weeks, kick force had declined, and the uterus moved less with each kick, only about 4 millimeters on average. (By this stage, things are getting pretty tight and tissues might be stretched taut, so this decrease makes sense.) Yet even with this apparent drop in force, the stresses experienced by the fetus during kicks kept increasing, even until 35 weeks. Increasing pressure on the leg bones and joints probably help the fetus grow, the researchers write.

Other work has found that the mechanical effects of movement can stimulate bone growth, which is why weight-bearing exercises, such as brisk walking and step aerobics, are often recommended for people with osteoporosis. In animal studies, stationary chick and mouse fetuses have abnormal bones and joints, suggesting that movement is crucial to proper development.

The results highlight the importance of the right kinds of movements for fetuses’ growth. Babies born prematurely can sometimes have joint disorders. It’s possible that bone growth and joints are affected when babies finish developing in an environment dominated by gravity, instead of the springy, tight confines of a uterus. Even in utero position might have an effect. Head-up breech babies, for instance, have a higher risk of a certain hip disorder, a link that hints at a relationship between an altered kicking ground and development. In fact, the researchers are now looking at the relationship between fetal movements and skeletal stress and strain in these select groups.

Mechanical forces in utero might have long-lasting repercussions. Abnormal joint shapes are thought to increase the risk of osteoarthritis, says Verbruggen, “which means that how you move in the womb before you’re even born can affect your health much later in life.”

There’s a lot more work to do before scientists fully understand the effects of fetal movements, especially those in less than ideal circumstances. But by putting hard numbers to squirmy wiggles, this new study is kicking things off right.

SpaceX just launched its biggest rocket for the first time

It’s another record for SpaceX. At 3:50 p.m. Eastern on February 6, the private spaceflight company launched the Falcon Heavy rocket for the first time.

The Heavy — essentially three SpaceX Falcon 9 rocket boosters strapped together — is the most powerful rocket launched since the Saturn V, which shot astronauts to the moon during the Apollo program. SpaceX hopes to use the Heavy to send humans into space. The company is developing another rocket, dubbed the BFR, to eventually send people to Mars.
Another first for this launch: the synchronized return of two of the boosters. (The third, from the center core, didn’t descend properly, and instead of landing on a droneship, it hit the ocean at 300 mph.) Part of SpaceX’s program is to reuse rockets, which brings down the cost of space launches. The company has successfully landed the cores of its Falcon 9 rockets 21 times and reflew a rocket six times. The company landed a previously used rocket for the first time in March.

But the cargo for today’s launch is aimed at another planet. The rocket carried SpaceX CEO Elon Musk’s red Tesla Roadster with “Space Oddity” by David Bowie playing on the stereo. It is now heading toward Mars.

“I love the thought of a car drifting apparently endlessly through space and perhaps being discovered by an alien race millions of years in the future,” Musk tweeted in December.
Editor’s note: This story was updated on February 7 to update the status of the booster landings, and again on February 9 to correct the rocket that SpaceX hopes to use to send people to Mars. The company intends to use its BFR rocket, not the Falcon Heavy.

U.S. cases of a deadly fungus nearly doubled in recent years

A fungus that recently evolved to infect humans is spreading rapidly in health care facilities in the United States and becoming harder to treat, a study from the U.S. Centers for Disease Control and Prevention finds.

Candida auris infections were first detected in the United States in 2013. Each year since, the number of people infected — though still small — has increased dramatically. In 2016, the fungus sickened 53 people. In 2021, the deadly fungus infected 1,471 people, nearly twice the 756 cases from the year before, researchers report March 21 in Annals of Internal Medicine. What’s more, the team found, the fungus is becoming resistant to antifungal drugs.
The rise of cases and antifungal resistance is “concerning,” says microbiologist and immunologist Arturo Casadevall, who studies fungal infections. “You worry because [the study] is telling you what could be a harbinger of things to come.” Casadevall, of Johns Hopkins Bloomberg School of Public Health, was not involved in the CDC study.

In tests of people at high risk of infection, researchers also found 4,041 individuals who carried the fungus in 2021 but were not sick at the time. A small percentage of carriers may later get sick from the fungus, says Meghan Lyman, a medical epidemiologist in the CDC’s Mycotic Diseases Branch in Atlanta, possibly developing bloodstream infections that carry a high risk of death.

Starting in 2012, C. auris infections popped up suddenly in hospitals on three continents, probably evolving to grow at human body temperature as a result of climate change (SN: 7/26/19). The fungus, typically detected through blood or urine tests, usually infects people in health care settings such as hospitals, rehabilitation facilities and long-term care homes. Because people who get infected are often already sick, it can be hard to tell whether symptoms such as fevers are from the existing illness or an infection.
Those most at risk of infection include people who are ill; those who have catheters, breathing or feeding tubes or other invasive medical devices; and those who have repeated or long stays in health care facilities. Healthy people are usually not infected but can spread the fungus to others by contact with contaminated surfaces, including gowns and gloves worn by health care workers, Lyman says.

Growing drug resistance
Infections can be treated with antifungal drugs. But Lyman and colleagues found that the fungus is becoming resistant to an important class of such medications called echinocandins. These drugs are used as both the first line and the last line of defense against C. auris, says Casadevall.

Before 2020, six people were known to have echinocandin-resistant infections and four other people had infections resistant to all three class of existing antifungal drugs. That resistance developed during treatment using echinocandin. None of those cases passed the resistant strain to others. But in 2021, 19 people were diagnosed with echinocandin-resistant infections and seven with infections resistant to multiple drugs.

More concerning, one outbreak in Washington, D.C., and another in Texas suggested people could transmit the drug-resistant infections to each other. “Patients who had never been on echinocandins were getting these resistant strains,” Lyman says.

Some health care facilities have been able to identify cases early and prevent outbreaks. “We’re obviously very concerned,” Lyman says, “but we are encouraged by these facilities that have had success at containing it.” Using those facilities’ infection control measures may help limit cases of C. auris, she says, as well as reducing spread other fungal, bacterial and viral pathogens.