Parasite Kills Human Cells and Wears Their Remains As Disguise
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources.
Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content.
For decades scientists have been puzzled by a tiny parasite that affects millions worldwide, with the power to liquefy human organs and evade the immune system in ways that science hasn't been able to explain.
Now University of California, Davis microbiologist professor Katherine Ralston and her team, have uncovered its terrifying secret.
Entamoeba histolytica has the unusual ability to kill human cells and then wear them as a disguise to escape the immune defenses.
The research, the teams said, could pave the way for new treatments to stop the parasite once and for all.
Image shared on the UCDAVIS website shows E. histolytica (green) attacking human T-cells (white blood cells).
Image shared on the UCDAVIS website shows E. histolytica (green) attacking human T-cells (white blood cells).
Katherine Ralston
What Is Entamoeba histolytica?
Entamoeba histolytica is a single-celled parasite infects around 50 million people each year and claims some 70,000 lives annually.
Mostly encountered in developing countries with poor water sanitation, the shape-shifting amoeba typically enters a person's colon after ingesting contaminated food or water.
While, in most cases, such an infection causes nothing worse than diarrhea, they can sometimes become deadly.
Once inside the body, it chews in ulcers inside the colon, liquefying parts of the liver and invading the brain and lungs.
In developed countries like America, Entamoeba histolytica infections are rare, although they still account for at least five deaths per year. The parasite is usually brought into the U.S. by individuals who have picked up an infection abroad.
How Entamoeba histolytica Operates
Scientists used to believe that the parasite injected poison into human cells to kill them, but Ralston's research revealed a very different process.
Back in 2011, during her postdoctoral fellowship at the University of Virginia, Ralston observed the parasite under a microscope and found that it was actually taking bites out of human cells.
In a series of later studies, she discovered that this amoeba kills cells through a process called "trogocytosis"; after it's done chewing on human cells, it wears the remains as a disguise to trick the immune system into not fighting it.
What the Study Showed
While researchers have struggled to study this parasite effectively because of its massive genome, Ralston and her team have drafted an "RNAi library" that allows them to study each one of the parasite's 8,734 known genes to understand how it operates.
Using a gene-editing tool known as CRISPR, Ralston and her team aim to label proteins within the parasite with fluorescent markers. This should allow them to observe the interactions of said protiens under a microscope.
Gene editing may also allow to team to delete small parts of Entamoeba histolytica's genes and proteins to find which are crucial and how they could be targeted with drugs.
"We now see a light at the end of the tunnel, and we think this could be achievable," said study author and UC Davis biochemist Wesley Huang.
Do you have a tip on a health story that Newsweek should be covering? Do you have a question about parasites? Let us know via science@newsweek.com.
References
Bettadapur, A., Hunter, S. S., Suleiman, R. L., Ruyechan, M. C., Huang, W., Barbieri, C. G., Miller, H. W., Tam, T. S. Y., Settles, M. L., & Ralston, K. S. (2021). Establishment of quantitative RNAi-based forward genetics in Entamoeba histolytica and identification of genes required for growth. PLOS Pathogens, 17(11). https://doi.org/10.1371/journal.ppat.1010088
Huang, W., Ruyechan, M. C., & Ralston, K. S. (2025). Work with me here: Variations in genome content and emerging genetic tools in Entamoeba histolytica. Trends in Parasitology, 41(5), 401–415. https://doi.org/10.1016/j.pt.2025.03.010
Miller, H. W., Tam, T. S. Y., & Ralston, K. S. (2022). Entamoeba histolytica Develops Resistance to Complement Deposition and Lysis after Acquisition of Human Complement-Regulatory Proteins through Trogocytosis. mBio, 13(2). https://doi.org/10.1128/mbio.03163-21
Ralston, K. S., Solga, M. D., Mackey-Lawrence, N. M., Somlata, Bhattacharya, A., & Petri, W. A. (2014). Trogocytosis by Entamoeba histolytica contributes to cell killing and tissue invasion. Nature, 508(7497), 526–530. https://doi.org/10.1038/nature13242
Ruyechan, M. C., Huang, W., & Ralston, K. S. (2024). Cross-species protection suggests Entamoeba histolytica trogocytosis enables complement resistance through the transfer of negative regulators of complement activation (p. 2024.10.04.616735). bioRxiv. https://doi.org/10.1101/2024.10.04.616735
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Newsweek
an hour ago
- Newsweek
If You're Squeamish—Avoid These Dog Breeds
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. Dog owners can expect any breed to have bathroom accidents; it comes with the territory. However, those who are squeamish might want to avoid these six dog breeds that new research discovered are more susceptible to diarrhea. The study, published June 11 in PLOS One by Dan O'Neill from the United Kingdom's Royal Veterinary College and colleagues, analyzed veterinarian health records of over 2,250,000 dogs from 2019, revealing that about one in 12 dogs in the U.K. were diagnosed with acute diarrhea that year, or about 8.18 percent. The authors labeled this diagnosis as one of the most common clinical conditions in dogs viewed by primary veterinarians. Like humans, dogs can experience sudden loose or watery stools after food items and water pass too quickly through their gastrointestinal tract, an article from Cornell University College of Veterinary Medicine reported. Diarrhea can last anywhere from a few days to several weeks, affecting any breed. Six dog breeds—Maltese, Miniature Poodle, Cavapoo, German Shepherd, Yorkshire Terrier, and Cockapoo—were found to have the "highest annual incidence risk for acute diarrhea" when compared to crossbreeds. These dogs were significantly more likely to be diagnosed with diarrhea than generic crossbreeds. Meanwhile, Jack Russell terriers and Chihuahuas are less likely to be diagnosed with diarrhea. However, a dog's diet, exercise habits and an owner's likelihood of bringing their canine to the vet could affect whether those breeds have higher or lower predispositions to diarrhea, the authors wrote. A stock image of a small white and brown dog going to the bathroom outside in the grass. A stock image of a small white and brown dog going to the bathroom outside in the grass. Wavetop/Getty Images The study also found that age plays a role in the odds of a dog being diagnosed with acute diarrhea. The risk increases in dogs aged three and under, as well as adult dogs 9 years and older. The authors speculate that young, curious dogs scavenge and eat items they are not supposed to, leading to unpleasant accidents. While the older dogs with diarrhea could be due to an increase in medications or supplements they might need to take. The complications of aging. As time passes, dogs with diarrhea could experience dehydration. A dog's diarrhea could be a symptom of other health issues, which could require veterinary attention. Two-thirds of the appointments resulted in another diagnosis for the dog. This included 44 percent experiencing vomiting, 28 percent with a reduced appetite and 24 percent of dogs were lethargic, the study found. About 29 percent of all cases were classified as hemorrhagic, or bloody diarrhea. On the bright side, 80 percent of the canine owners who went to the vet for their dog's diarrhea did not require a second appointment. The study found most veterinarians treated diarrhea with probiotics, about 59 percent, dietary management (43 percent), antibiosis (38 percent), and maropitant (24 percent). The amount of antibiotics in treatment used raised concerns about "unnecessary antibiotic therapy" for acute diarrhea, as the authors stated that there have been years of recommendations to avoid high antibiotic use. Unnecessary use of antibiotics can lead to side effects, disrupt a dog's microbiome and could contribute to antibiotic resistance, an article from Visbiome Vet reported.
Newsweek
2 hours ago
- Newsweek
Inside Hospitals' Digital Command Centers
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. During the winter of 2023, staff at Children's Mercy Kansas City were waiting for the "surge": a dreaded period when viral illnesses like influenza and RSV abound, leading to an increase in hospital admissions. But as the winter bled into 2024, it became clear that something had changed. Children were still getting sick and requiring advanced medical care. However, staff at Children's Mercy weren't "feeling the angst" like they had in years past, according to Dr. Jennifer Watts, the hospital's associate chief medical officer of acute care and inpatient operations. The difference, Watts said, came from technology. That was the hospital's first year using GE HealthCare's Command Center software, a product that allows it to digitally monitor care delivery and track patients' progress throughout their stay. It's like the "NASA" control hub for the health system, Watts told Newsweek. During the first winter partnering with GE, Children's Mercy staff began asking, "Is the surge here?" "They just didn't feel it," Watts said. "We were able to prepare. We were able to have [sufficient] staff present. We got rid of the scramble that typically occurs when you don't prepare for things." Hospital staff inside Children's Mercy Kansas City's Patient Progression Hub, which uses GE Healthcare Command Center technology to paint a real-time picture of hospital happenings. Hospital staff inside Children's Mercy Kansas City's Patient Progression Hub, which uses GE Healthcare Command Center technology to paint a real-time picture of hospital happenings. Children's Mercy Kansas City Patient Progression Hub Children's Mercy is one of 300 hospitals around the world that use GE's Command Center technology. As hospitals across the U.S. face rising demand for their services—driven, in part, by sicker patients and an aging population—many are turning to these digital "command centers" to improve operational efficiency and polish the patient experience. Before developing a Patient Progression Hub, driven by GE's tech, Children's Mercy was still dealing with inefficient and outdated processes, according to Watts. Different departments were playing "phone tag" with one another to move patients through the hospital. Information was not centralized, and it was common to see staff with packets of papers in front of them, pinning memos on bulletin boards and communicating with fax machines. Within seven months of implementing the Command Center technology, the hospital saw an 86 percent reduction in admission delays and cut avoidable bed days by 24 percent—creating capacity for 300 more medical-surgical patients without expanding its facility. The tech sits atop hospitals' preexisting systems, like staffing platforms and electronic health records (EHRs), to generate a comprehensive, real-time picture of the hospital's caseload and available resources. "The software really helps connect the strategy to the day-to-day operations," Bree Bush, general manager of GE's Command Center, told Newsweek. Kristie Barazsu is the president and COO of Duke Health Lake Norman Hospital in Mooresville, North Carolina, and oversees patient flow for Duke Health, which stood up Command Center in 2019. During COVID-19, the health system could use the technology to understand where positive patients were located and deploy personal protective equipment (PPE) from its logistics center. Command Center also utilizes predictive analytics to help hospitals plan for the future. Duke uses it to forecast the area's census, analyzing overall demand by unit, patient population and information has informed the health system's staffing plan, allowing it to reduce reliance on costly, temporary travel labor—and reducing labor expenses by approximately $40 million to date, according to Barazsu. Rather than viewing the hospitals within Duke's system as independent entities, a tech Command Center has enabled leadership to get the full picture, she added. The system can now move patients from one hospital to another more quickly, allowing it to free up bed space and accept more transfers from other health systems. "We're not relying on word of mouth or pagers or systems that don't work well," Barazsu told Newsweek. "There's one source of truth." Staff coordinate care inside UMass Memorial Health's new Digital Hub. Staff coordinate care inside UMass Memorial Health's new Digital Hub. UMass Memorial Health While some health systems are partnering with a tech provider like GE, others are developing internal solutions to manage demand—and to keep tabs on a broadening menu of digital services. UMass Memorial Health has been on the forefront of the digital revolution, according to Dr. Eric Alper, its vice president, chief quality and chief clinical informatics officer. The health system was an early adopter of electronic intensive care unit (eICU) technology, which allows ICU staff to virtually connect with a critical care physician on overnight shifts. But a lot has changed since the advent of eICU tech about two decades ago, Alper told Newsweek. UMass Memorial used to run the service from a basement. Eventually it was supporting 150 critical care beds across the enterprise, and it was time for an upgrade. The health system recently stood up a new Digital Hub, a 20,000-square-foot home for its eICU services, and several other virtual programs, including interpreter services, remote video monitoring, mobile integrated health, "ED at Home," primary care and the Transfer and Access Center, which coordinates the comings and goings of patients across UMass Memorial hospitals. It might sound paradoxical to move virtual services to a physical location, but centralizing these operations has allowed for better communication, according to Alper, "We're collaborating more effectively by being in the same space, and that's allowing us to reduce some of the silos." An urgent care provider conducts a virtual visit from Sanford Health's Virtual Care Center. An urgent care provider conducts a virtual visit from Sanford Health's Virtual Care Center. Sanford Health Across the country in Sioux Falls, South Dakota, leaders at Sanford Health shared similar goals. The system stood up its own 60,000-square-foot Virtual Care Center in November, funded by a $350 million gift from its namesake Denny Sanford. In April, Newsweek followed up on the initiative with Dr. Dave Newman, Sanford's chief medical officer of virtual care. "One of the biggest things that the Virtual Care Center has done for Sanford is it emphasized the validity of virtual care and digital health," Newman told Newsweek. "The investment in the center and the space has shown that it's permanent, that this is what we're doing to help our patients, not just today or tomorrow but also 20 years from now." For Watts at Children's Mercy Kansas City, one incident stands out as a testament to the tech Command Center's importance. Anytime there is a mass casualty event, nearby hospitals need to prepare 20 percent of their beds to accept new patients. That's a challenge for most hospitals, given their daily capacity constraints—but when a shooter opened fire on the Kansas City Chiefs' Super Bowl parade in February 2024, Children's Mercy was able to respond. "This occurred a mile from our children's hospital, and we had no idea up front how many victims we would be receiving," Watts said, "but we were able to use the results of [Command Center predictive] modeling to get us to a point where, yes, we could take 20 percent of our beds and treat all of the victims that may be coming through our doors." She's excited to see hospitals' virtual command centers and digital services grow, saying, "I think we have opened the Pandora's box here."
New York Post
2 hours ago
- New York Post
Tropical fruit could be the answer to better heart health, new study suggests
Incorporating fruit every day is an important part of a balanced diet. But researchers believe that mangoes can particularly benefit heart health. A new study published in the Journal of the American Nutrition Association found that mango consumption has a 'significant' impact on cardio-metabolic responses and conditions in post-menopausal women. Post-menopause – the period when women do not have their menstrual cycle for at least 12 months after menopause – can increase the risk of conditions such as osteoporosis, obesity, depression and cardiovascular disease, according to experts. Researchers from the University of California, Davis, studied the effect of two weeks of mango intake at 330 grams per day in a group of 'relatively healthy' post-menopausal women with an overweight or obese BMI. 5 A new study found that mango consumption has a 'significant' impact on cardio-metabolic responses and conditions in post-menopausal women. Pixel-Shot – The study analyzed the impact of this diet on microvascular function and cardio-metabolic markers. Compared to two weeks without a daily serving of mango, the primary outcome did not detect a significant change in microvascular function, but did note that blood pressure and cholesterol levels were 'significantly reduced.' 'Two weeks of daily mango intake was associated with a significant decrease in multiple BP outcomes in a group of healthy postmenopausal women,' the researchers wrote in the publication. 'The glucose and insulin responses were also moderated after mango intake.' 5 The study analyzed the impact of this diet on microvascular function and cardio-metabolic markers. Pixelkram – The research was taken a step further with a small probe study that compared mango consumption to a calorically equivalent amount of white bread. In both groups, blood glucose levels rose after one hour, but were 'significantly less' after mango intake. Insulin levels also rose after one hour, yet remained elevated in those who consumed white bread. Researchers said this suggests a 'moderating effect of mangoes on glucose absorption and metabolism.' 5 The research was taken a step further with a small probe study that compared mango consumption to a calorically equivalent amount of white bread. Towfiqu Barbhuiya – The study concluded that further research using the amount of typical mango consumption over an extended period is necessary. The researchers noted the short length of mango intake as a study limitation. Registered dietitian nutritionist Lauri Wright, Ph.D., director of nutrition programs at the University of South Florida's College of Public Health, supported the addition of colorful fruit to the diet. 5 The study concluded that further research using the amount of typical mango consumption over an extended period is necessary. Vladimir Melnik – 'This small but intriguing study suggests that mangoes, already celebrated for their antioxidants and fiber, may also support vascular health in postmenopausal women,' she told Fox News Digital. (She was not involved in the new study.) 'After just two servings a day for several weeks, participants saw improvements in blood vessel function and reductions in cholesterol.' Although Wright is not calling mangoes a 'miracle cure,' she said these findings reinforce the idea that 'adding colorful, plant-based foods to your plate can have heart-protective benefits.' 5 Researchers said this suggests a 'moderating effect of mangoes on glucose absorption and metabolism.' aamulya – Mangoes offer a 'unique' mix of compounds, including mangiferin and quercetin, which can help reduce oxidative stress and inflammation, she said – conditions linked to heart disease. 'The takeaway? Enjoy mangoes as part of a varied, whole-food diet rich in fruits and vegetables,' Wright said. 'Mangoes are delicious and possibly heart-smart, so that's a win-win.'
