Latest news with #Entamoebahistolytica
Global News
13 hours ago
- Health
- Global News
More E. coli cases believed to be connected to popular Calgary restaurant
The number of laboratory confirmed cases of E. coli and a rare parasite, believed to be connected to a popular Calgary-area restaurant, continues to grow. In an email to Global News, Alberta Health Services said there has been an increase in people calling Health Link (811) reporting symptoms of gastrointestinal illness after eating at the Saskatoon Farm, about 20 minutes southeast of Calgary, earlier this month. View image in full screen Alberta Health Services is now asking anyone who had something to eat or drink at the Saskatoon Farm between July 1 and 18 to call 811 to arrange to get tested for E. coli. Global News While AHS hasn't divulged how may calls it has received, it confirms there have now been 26 probable cases of E. coli confirmed by laboratory testing. Story continues below advertisement That's an increase from the 18 cases confirmed on Friday, July 25, 2025, by AHS Medical Officer of Health Dr. Francesco Rizzuti. AHS said the number of people testing positive for the parasite, Entamoeba histolytica, has also increased, with nine of those who tested positive for E. coli also testing positive. That's up from the three cases provided in a media briefing on Friday. AHS said a number of other pathogens, including norovirus and rotavirus, have also been identified in the laboratory testing, but it has yet to be determined if they can be linked to the Saskatoon Farm as both norovirus and rotavirus are commonly associated with gastrointestinal illness. Get weekly health news Receive the latest medical news and health information delivered to you every Sunday. Sign up for weekly health newsletter Sign Up By providing your email address, you have read and agree to Global News' Terms and Conditions and Privacy Policy There has also been one additional person who required hospitalization, bringing the total number to three, although two have since been discharged. View image in full screen The Saskatoon Farm is located a 20 minute drive southeast of Calgary and is a popular destination for Saskatoon berry picking, a farmers market and a restaurant. Global News AHS has also expanded the timeframe for people who consumed water, beverages or food at the Saskatoon Farm to get tested for any of the identified pathogens, even if they have not developed any symptoms. Story continues below advertisement Anyone who dined at the restaurant between July 1 and July 18 is now being asked to call 811 (Health Link) to make arrangements to get tested. The previous timeframe was July 1 to 16. View image in full screen AHS has identified the Saskatoon Farm's water system as the most likely source of the outbreak of gastrointestinal illness and is asking anyone who dined there between July 1 and 18 to call 811 to arrange to get tested. Global News AHS investigators have identified the Saskatoon Farm's water system as the most likely cause of the outbreak. Even though the Saskatoon Farm has switched to a different water source that has been confirmed to be safe for human consumption, Rizzuti said there is ongoing testing being done and the restaurant will remain closed until AHS inspectors and medical officers of health determine there is no more risk to the public. Health Canada defines E. coli as a bacteria that can be spread through contact with infected people, animals, food and surfaces — including undercooked, unpasteurized, contaminated or untreated water, foods and other liquids that have come into contact with the feces of infected animals or people. Story continues below advertisement The improper handling of infected food can also cause cross-contamination of other foods. People who become infected with the parasite E. histolytica can also develop a severe gastrointestinal illness called amoebiasis weeks to months after infection. While none of the people confirmed to be infected with the parasite have tested positive for amoebiasis, Rizutti said, in some rare cases it can lead to other infections outside of the gastrointestinal system, including the heart, liver and lungs. The symptoms of amoebiasis, said Rizutti, may not show up for weeks or even months after the initial infection, which is why AHS is asking people who dined at the Saskatoon Farm between July 1 and 16 to call 811 to arrange to get tested. According to Health Canada, people who test positive for E. histolytica can be treated with a variety of drugs but the extent of treatment depends on whether the parasite is isolated to the gastrointestinal system or has spread to other organs.
Time of India
22-07-2025
- Health
- Time of India
Why should you avoid eating raw salads in monsoons?
Monsoons bring with them a wave of happiness as well as agony. This is because despite the respite from summer heat this season brings, it also brings in a wave of infections and ailments that can easily take a toll on health and well-being. This happens due to the humid weather, which makes it favorable for the bacteria and parasites to thrive and grow. This is why eating mindfully in this season is essential. While there's no denying that raw salads are usually a great option for health and nutrition, consuming them during the rainy season can do more harm than good. Here's why health experts advise limiting or avoiding raw salads in monsoons. Higher Risk of Bacterial Contamination: Raw vegetables used in salads—like lettuce, tomatoes, cucumbers, and spinach—are often contaminated with bacteria such as E. coli, Salmonella, and Listeria during the monsoon due to muddy water and poor washing practices. These pathogens thrive in warm, moist environments and can cause severe stomach infections. Washed But Not Safe Even thorough washing may not remove all microbes, especially when water quality is poor. According to a study published in the International Journal of Food Microbiology, even clean-looking produce can carry harmful microorganisms if they were irrigated with contaminated water or handled without hygiene. The monsoon season exacerbates this problem. Risk of Parasitic Infections: Many raw vegetables carry microscopic parasites like Giardia lamblia and Entamoeba histolytica, which are particularly active during monsoon. These can cause prolonged digestive issues, including diarrhea, bloating, and abdominal cramps. Cooking vegetables helps kill these organisms, but raw salads leave you exposed. Weakening Digestive Fire (Agni) According to Ayurveda, the monsoon season weakens digestive strength, or 'Agni.' Raw salads, being fibrous and cooling in nature, are harder to digest during this time. This can result in indigestion, gas, and discomfort. Lightly sautéed or steamed vegetables are preferred to support the digestive system. Food Spoilage Is Faster in Humidity Monsoon humidity accelerates spoilage. Pre-cut salads sold outside or stored for long durations can become stale quickly and harbor mold or fungus. A study in the Journal of Food Protection revealed that pre-prepared salads had higher microbial loads in humid conditions, especially if stored at improper temperatures.
Newsweek
13-05-2025
- Health
- Newsweek
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@ 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). 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. 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). 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. 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.
Yahoo
12-05-2025
- Health
- Yahoo
This parasite rips apart human cells and wears them as disguises
Entamoeba histolytica is a particularly tenacious parasite. The single-celled amoeba generally arrives in the colon after contaminated water and food is ingested—most often in places with poor sanitation infrastructure. Although the majority of the 50 million people who contract it each year suffer from little more than diarrhea, around 50,000–100,000 of them don't survive the encounter. In those cases, E. histolytica chews ulcers into the colon walls before moving on to melt away parts of the liver. From there, the amoeba spreads into the lungs and brain, where its destruction ultimately proves fatal. For decades, E. histolytica has stumped researchers struggling to explain how the parasite so successfully evades the immune system. But after about two decades of research, a team of microbiologists have finally determined E. histolytica's gnarly strategy: The parasite has a tendency to cloak itself in remnants of dead human cells as a disguise against the body's immune system. Now, microbiologists think they have a plan to fight back. Their amoeba battle strategy is detailed in a study published in the May issue of Trends in Parasitology. 'All parasites are understudied, but E. histolytica is especially enigmatic,' University of California, Davis microbiologist Katherine Ralston explained in a university profile on May 12. 'It can kill anything you throw at it, any kind of human cell.' Ralston is the new paper's first author, but she first began studying E. histolytica during her postdoctoral fellowship in 2011. 'You could see little parts of the human cell being broken off,' Ralston said of her very first encounter with the parasite. In 2014, she published her initial findings in Nature on the process, known as trogocytosis. 'This was important [to discover],' she said. 'To devise new therapies or vaccines, you really need to know how E. histolytica damages tissue.' It didn't take long for Ralston to see firsthand how the amoeba can become an absolutely voracious and impatient menace. E. histolytica doesn't consume cells as much as it takes bites out of them as it travels through organs. These wounded cells are left to leak out its contents as E. histolytica moves on to its next targets—hence its name. Histolytica translates to 'tissue-dissolving.' In 2022, Ralston discovered a major reason behind the parasite's tenacity: the amoeba develops an ability to evade a crucial part of the human immune system known as complement proteins. These proteins are vital to identifying and eradicating foreign cells. To escape them, E. histolytica ingests specific proteins from human cell outer membranes, then places those proteins on its own outer surface. Two of those molecules block those important compliment proteins from attaching themselves and fighting back. Essentially, E. histolytica wears chunks of human cells as a disguise against its host's immune system. However, yet another complication to taming E. histolytica remained—its complexity. The pathogen's genomic sequence is five times larger than salmonella's and 2,500 times larger than HIV's. While scientists sequenced E. histolytica's genomic sequence in 2005, it took eight years for researchers to analyze the bioinformation thoroughly enough to identify a potential breakthrough in controlling the parasite. In 2013, a separate study indicated E. histolytic displayed a cellular process known as RNA inhibition (RNAi) to control its gene expression. Fast forward another eight years, when Ralston's team created an RNAi library that finally allowed experts to selectively inhibit each of the parasite's 8,734 genes. Ralston's latest study presents one of the most promising steps yet in combatting E. histolytic: a battle plan. The team proposes combining their RNAi library with CRISPR gene-editing technology in order to label certain amoeba proteins with fluorescent markers. Researchers can then watch how E. histolytica interacts with the proteins before altering or deleting various proteins and genes. From there, they may be able to identify which portions are crucial to the amoeba's proliferation and disguise. By eventually targeting these with tailored drugs, researchers could soon halt E. histolytica's rampage. 'We now see a light at the end of the tunnel, and we think this could be achievable,' said Wesley Huang, one of the new study's co-authors along with Maura Ruyechan. With nearly all the pieces in place, scientists are another step closer to developing vaccines and drug regimens to take on E. histolytica. Despite their size, dealing with microscopic problems like this one often takes years to accomplish. 'Science is a process of building,' said Ralston. 'You have to build one tool upon another, until you're finally ready to discover new treatments.'
