Phages, which are harmless viruses that destroy specific bacteria, are becoming useful tools to protect our food supply.
Every year, one in seven people in America comes down with a foodborne illness, typically caused by a bacterial pathogen, including E.Coli, listeria, salmonella, or campylobacter. That adds up to 48 million people, of which 120,000 are hospitalized and 3000 die, according to the Centers for Disease Control. And the variety of foods that can be contaminated with bacterial pathogens is growing too. In the 20th century, E.Coli and listeria lurked primarily within meat. Now they find their way into lettuce, spinach, and other leafy greens, causing periodic consumer scares and product recalls. Onions are the most recent suspected culprit of a nationwide salmonella outbreak.
Some of these incidents are almost inevitable because of how Mother Nature works, explains Divya Jaroni, associate professor of animal and food sciences at Oklahoma State University. These common foodborne pathogens come from the cattle's intestines when the animals shed them in their manure—and then they get washed into rivers and lakes, especially in heavy rains. When this water is later used to irrigate produce farms, the bugs end up on salad greens. Plus, many small farms do both—herd cattle and grow produce.
"Unfortunately for us, these pathogens are part of the microflora of the cows' intestinal tract," Jaroni says. "Some farmers may have an acre or two of cattle pastures, and an acre of a produce farm nearby, so it's easy for this water to contaminate the crops."
Food producers and packagers fight bacteria by potent chemicals, with chlorine being the go-to disinfectant. Cattle carcasses, for example, are typically washed by chlorine solutions as the animals' intestines are removed. Leafy greens are bathed in water with added chlorine solutions. However, because the same "bath" can be used for multiple veggie batches and chlorine evaporates over time, the later rounds may not kill all of the bacteria, sparing some. The natural and organic producers avoid chlorine, substituting it with lactic acid, a more holistic sanitizer, but even with all these efforts, some pathogens survive, sickening consumers and causing food recalls. As we farm more animals and grow more produce, while also striving to use fewer chemicals and more organic growing methods, it will be harder to control bacteria's spread.
"It took us a long time to convince the FDA phages were safe and efficient alternatives. But we had worked with them to gather all the data they needed, and the FDA was very supportive in the end."
Luckily, bacteria have their own killers. Called bacteriophages, or phages for short, they are viruses that prey on bacteria only. Under the electron microscope, they look like fantasy spaceships, with oblong bodies, spider-like legs and long tails. Much smaller than a bacterium, phages pierce the microbes' cells with their tails, sneak in and begin multiplying inside, eventually bursting the microbes open—and then proceed to infect more of them.
The best part is that these phages are harmless to humans. Moreover, recent research finds that millions of phages dwell on us and in us—in our nose, throat, skin and gut, protecting us from bacterial infections as part of our healthy microbiome. A recent study suggested that we absorb about 30 billion phages into our bodies on a daily basis. Now, ingeniously, they are starting to be deployed as anti-microbial agents in the food industry.
A Maryland-based phage research company called Intralytix is doing just that. Founded by Alexander Sulakvelidze, a microbiologist and epidemiologist who came to the United States from Tbilisi, the capital of Georgia, Intralytix makes and sells five different FDA-approved phage cocktails that work against some of the most notorious food pathogens: ListShield for Listeria, SalmoFresh for Salmonella, ShigaShield for Shigella, another foodborne bug, and EcoShield for E.coli, including the infamous strain that caused the Jack in the Box outbreak in 1993 that killed four children and sickened 732 people across four states. Last year, the FDA granted its approval to yet another Intralytix phage for managing Campylobacter contamination, named CampyShield. "We call it safety by nature," Sulakvelidze says.
Intralytix grows phages inside massive 1500-liter fermenters, feeding them bacterial "fodder."
Photo credit: Living Radiant Photography
Phage preparations are relatively straightforward to make. In nature, phages thrive in any body of water where bacteria live too, including rivers, lakes and bays. "I can dip a bucket into the Chesapeake Bay, and it will be full of all kinds of phages," Sulakvelidze says. "Sewage is another great place to look for specific phages of interest, because it's teeming with all sorts of bacteria—and therefore the viruses that prey on them."
In lab settings, Intralytix grows phages inside massive 1500-liter fermenters, feeding them bacterial "fodder." Once phages multiply enough, they are harvested, dispensed into containers and shipped to food producers who have adopted this disinfecting practice into their preparation process. Typically, it's done by computer-controlled sprayer systems that disperse mist-like phage preparations onto the food.
Unlike chemicals like chlorine or antibiotics, which kill a wide spectrum of bacteria, phages are more specialized, each feeding on specific microbial species. A phage that targets salmonella will not prey on listeria and vice versa. So food producers may sometimes use a combo of different phage preparations. Intralytix is continuously researching and testing new phages. With a contract from the National Institutes of Health, Intralytix is expanding its automated high-throughput robot that tests which phages work best against which bacteria, speeding up the development of the new phage cocktails.
Phages have other "talents." In her recent study, Jaroni found that phages have the ability to destroy bacterial biofilms—colonies of microorganisms that tend to grow on surfaces of the food processing equipment, surrounding themselves with protective coating that even very harsh chemicals can't crack.
"Phages are very clever," Jaroni says. "They produce enzymes that target the biofilms, and once they break through, they can reach the bacteria."
Convincing the FDA that phages were safe to use on food products was no easy feat, Sulakvelidze says. In his home country of Georgia, phages have been used as antimicrobial remedies for over a century, but the FDA was leery of using viruses as food safety agents. "It took us a long time to convince the FDA phages were safe and efficient alternatives," Sulakvelidze says. "But we had worked with them to gather all the data they needed, and the FDA was very supportive in the end."
The agency had granted Intralytix its first approval in 2006, and over the past 10 years, the company's sales increased by over 15-fold. "We currently sell to about 40 companies and are in discussions with several other large food producers," Sulakvelidze says. One indicator that the industry now understands and appreciates the science of phages was that his company was ranked as Top Food Safety Provider in 2021 by Food and Beverage Technology Review, he adds. Notably, phage sprays are kosher, halal and organic-certified.
Intralytix's phage cocktails to safeguard food from bacteria are approved for consumers in addition to food producers, but currently the company sells to food producers only. Selling retail requires different packaging like easy-to-use spray bottles and different marketing that would inform people about phages' antimicrobial qualities. But ultimately, giving people the ability to remove pathogens from their food with probiotic phage sprays is the goal, Sulakvelidze says.
It's not the company's only goal. Now Intralytix is going a step further, investigating phages' probiotic and therapeutic abilities. Because phages are highly specialized in the bacteria they target, they can be used to treat infections caused by specific pathogens while leaving the beneficial species of our microbiome intact. In an ongoing clinical trial with Mount Sinai, Intralytix is now investigating a potential phage treatment against a certain type of E. coli for patients with Crohn's disease, and is about to start another clinical trial for treating bacterial dysentery.
"Now that we have proved that phages are safe and effective against foodborne bacteria," Sulakvelidze says, "we are going to demonstrate their potential in therapeutic applications."
This article was first published by Leaps.org on October 27, 2021.
Sonja Bauman, 39, and Mariela Florez, 83, taking one of their regular walks in Plantation, Fla. The pair met through an online platform called Papa that provides "family on demand." (Photo by Sonja Bauman)
In 2020, Papa connected Bauman, the 39-year-old Floridian, with another woman in her mid-70s who lives alone and has very limited mobility. Bauman began driving her to doctor’s appointments and helping her with chores around the house. “When I’m not there, she doesn’t leave her apartment,” said Bauman. The two have gone to the gym together, and they walk slowly through the neighborhood, chatting so it feels less like exercise.
Parker was driven to start Papa by the problem of social isolation among seniors, exacerbated by the pandemic, but he believes users of all ages can benefit. “Many of our Pals feel more comfortable opening up with older members than their same-aged friends,” he said.
Other platforms aim for similar, in-person connections. Generation Tech unites teens with seniors for technology training. And Mon Ami, which provides case management software for aging and disability service providers, has an app that connects isolated older people with college-age volunteers.
Making new connections through video
Several new sites match you with strangers for real-time video chatting on various topics, such as finding common ground on political issues. Other video platforms focus on intergenerational connections.
S. Jay Olshansky, a gerontology professor at the University of Illinois-Chicago, recalls the first time he saw Hyunseung Lee, an 11-year-old from Seoul, through his computer screen. The kid was shy, but Olshansky, 67, encouraged him to ask questions. “Turns out, he was thirsting for this kind of interaction.”
They’d connected through Eldera, a platform that pairs mentors age 60 and up with mentees, using an algorithm, for video conversations. “The time and wisdom of older adults is the most important natural resource we can give future generations,” said Dana Griffin, Eldera's CEO. “Connecting through a screen is the opposite of social media.”
In weekly meetings, Olshansky noticed Lee’s unique interest in math. “There’s something special in you,” Olshansky told him. “How do we bring it to the surface?” He suggested Lee write a book on his favorite subject, and the preteen ran with it, cranking out 70 pages in two weeks. Lee has published his love letter to theorems on Amazon.
Hyunseung Lee, age 11, of Korea, and U.S. college professor Jay Olshanksy, 67, discuss math, strategy and Hyunsung's budding career as a book author during their video chats through a platform called Eldera. (Photo by Dana Palmer/Eldera)
Lee’s parents told Olshansky that their son has become more assertive — a recurring theme, Griffin said. “Confidence is the number one thing parents tell us about.” Since Eldera’s inception last year, the number of mentors has grown exponentially. Even so, Griffin said the waitlist for mentors typically numbers 200 kids.
Another site, Big and Mini, hosts video interactions between seniors and young adults; about 10,000 active users have joined since 2019, said co-founder Aditi Merchant.
Users often bring the benefits of their video interactions to their real-world relationships. Olshansky views Lee as an older version of his grandkids. “Eldera teaches me how to interact with them.” Lee, high on confidence, began instructing his classmates in math. Griffin noted that a group of Eldera mentors in Memphis, who met initially on Eldera, now take walks together in-person to trade ideas for helping each other’s Eldera kids solve problems in their schools and communities.
“We’ve evolved into a community for older adults who want to give back to the world,” said Griffin. Other new tools for connection take the form of virtual reality apps.
Connecting in virtual reality
During pandemic isolation, record numbers of people bought devices for virtual and augmented reality. Such gadgets can convince you that you’re hanging out with friends, even if they’re in another hemisphere. Lifelike simulations from miles away could be especially useful for meaningful interactions between people of different generations, since they’re often geographically segregated.
VR’s benefits require further study, but users report less social isolation and depression, according to MIT research. The immersive, 3-D experience is more compelling than FaceTime or Zoom. “It’s like the difference between a phone call and video call,” said Rick Robinson, Vice President of AARP’s Innovation Labs.
“When VR is designed right, the medium disappears,” said Jeremy Bailenson of Stanford.
Dana Pierce, a 56-year-old government employee in Indiana, got Meta's VR headset in May, 2021, thinking she’d enjoy it more than a new laptop. After many virtual group tours of exotic destinations, she has no regrets. Her adventures occur on Alcove, an app made by Robinson’s Innovation Labs. He co-created it with VR-company Rendever and sought input from people over age 50 to tailor it to their interests. “I’m an introvert,” said Pierce. “I’ve been more socially active since getting my headset than I am in real life.”
Tagging along with her to places like Paris are avatars representing real people around the world. She’s gotten to know VR users in their 70s, 80s and 90s, as well as younger people and some her own age. One is a new friend she plays chess with in relaxing nature settings. Another is her oldest son. He lives 90 minutes away but, earlier this year, Pierce welcomed him and his girlfriend to her virtual house on Alcove. They chatted in the living room decorated with family photos uploaded by Pierce. Then they took out a boat to go VR fishing — because why not — until 2 a.m.
“When VR is designed right, the medium disappears,” said Jeremy Bailenson, a communications professor who directs Stanford’s Virtual Human Interaction Lab. He’s teaching a class of 175 students entirely in VR. After months of covid isolation, the first time the class met, “there was a big catharsis. It really feels like you’re in a big crowd.” Like-minded people meet in VR for events such as comedy shows and creative writing meetups, while the Swedish pop group ABBA has performed this year as digital versions of themselves (“ABBA-tars”) during a virtual concert tour.
Karen Fingerman, a psychologist and director of the Texas Aging and Longevity Center at the University of Texas-Austin, supports the idea of VR for social connection, though she added that some people need it more than others. Hospitals and assisted-living facilities are using products such as Penumbra’s REAL I-Series and MyndVR to bring VR excursions to isolated patients and seniors. “If you’re in a bed or facility, this gives you something to talk about,” said Gita Barry, Penumbra’s executive vice president.
Pierce uses it on most days. She may see another adult son, who lives with her, less often as a result. But VR helps her manage real-world stressors, more than escaping them. After a long workday, she visits her back porch on Alcove, which overlooks a pond. “It’s my little retreat,” she said. “VR improves my mood. It’s added a lot to my life.”
Some seniors are using more than one technology. Olshansky and Lee discuss strategy while playing Internet chess. And Olshansky recently began using VR. He sees his sister, who lives far away, in a virtual beach house. “It’d be a great way to interact with Hyunseung,” he said. “I should get him a headset.”
A version of this article first appeared in The Washington Post on December 3, 2021.
