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.
Vanessa Colimorio (left) and Sharon Kochlany (right) at a farm with their four-year-old twin daughters and one-year-old son. The kids share the same sperm donor.
Sharon Kochlany and Vanessa Colimorio's four-year-old twin girls had a classic school assignment recently: make a family tree. They drew themselves and their one-year-old brother branching off from their moms, with aunts, uncles, and grandparents forking off to the sides.
The recently-gained sovereignty of queer families stands to be lost if a consumer DNA test brings a stranger's identity out of the woodwork.
What you don't see in the invisible space between Kochlany and Colimorio, however, is the sperm donor they used to conceive all three children.
To look at a family tree like this is to see in its purest form that kinship can supersede biology—the boundaries of where this family starts and stops are clear to everyone in it, in spite of a third party's genetic involvement. This kind of self-definition has always been synonymous with LGBTQ families, especially those that rely on donor gametes (sperm or eggs) to exist.
But the world around them has changed quite suddenly: The recent consumer DNA testing boom has made it more complicated than ever for families built through reproductive technology—openly, not secretively—to maintain the strong sense of autonomy and privacy that can be crucial for their emotional security. Prospective parents and cryobanks are now mulling how best to bring a new generation of donor-conceived people into this world in a way that leaves open the choice to know more about their ancestry without obliterating an equally important choice: the right not to know about biological relatives.
For queer parents who have long fought for social acceptance, having a biological relationship to their children has been revolutionary, and using an unknown donor as a means to this end especially so. Getting help from a friend often comes with the expectation that the friend will also have social involvement in the family, which some people are comfortable with, but being able to access sperm from an unknown donor—which queer parents have only been able to openly do since the early 1980s—grants them the reproductive autonomy to create families seemingly on their own. That recently-gained sovereignty stands to be lost if a consumer DNA test brings a stranger's identity out of the woodwork.
At the same time, it's natural for donor-conceived people to want to know more about where they come from ethnically, even if they don't want to know the identity of their donor. As a donor-conceived person myself, I know my donor's self-reported ethnicity, but have often wondered how accurate it is.
Opening the Pandora's box of a consumer DNA test as a way to find out has always felt profoundly unappealing to me, however. Many people have accidentally learned they're donor-conceived by unwittingly using these tools, but I already know that about myself going in, and subsequently know I'll be connected to a large web of people whose existence I'm not interested in learning about. In addition to possibly identifying my anonymous donor, his family could also show up, along with any donor-siblings—other people with whom I share a donor. My single lesbian mom is enough for me, and the trade off to learn more about my ethnic ancestry has never seemed worth it.
In 1992, when I was born, no one was planning for how consumer DNA tests might upend or illuminate one's sense of self. But the donor community has always had to stay nimble with balancing privacy concerns and psychological well-being, so it should come as no surprise that figuring out how to do so in 2020 includes finding a way to offer ancestry insight while circumventing consumer DNA tests.
A New Paradigm
This is the rationale behind unprecedented industry news that LeapsMag can exclusively break: Within the next few weeks, California Cryobank, the largest cryobank in the country, will begin offering genetically-verified ancestry information on the free public part of every donor's anonymous profile in its database, something no other cryobanks yet offer (an exact launch date was not available at the time of publication). Currently, California Cryobank's donor profiles include a short self-reported list that might merely say, "Ancestry: German, Lebanese, Scottish."
The new information will be a report in pie chart form that details exactly what percentages of a donor's DNA come from up to 26 ethnicities—it's analogous to, but on a smaller scale than, the format offered by consumer DNA testing companies, and uses the same base technology that looks for single nucleotide polymorphisms in DNA that are associated with specific ethnicities. But crucially, because the donor takes the DNA test through California Cryobank, not a consumer-facing service, the information is not connected in a network to anyone else's DNA test. It's also taken before any offspring exist so there's no chance of revealing a donor-conceived person's identity this way.
Later, when a donor-conceived person is born, grows up, and wants information about their ethnicity from the donor side, all they need is their donor's anonymous ID number to look it up. The donor-conceived person never takes a genetic test, and therefore also can't accidentally find donor siblings this way. People who want to be connected to donor siblings can use a sibling registry where other people who want to be found share donor ID numbers and look for matches (this is something that's been available for decades, and remains so).
"With genetic testing, you have no control over who reaches out to you, and at what point in your life."
California Cryobank will require all new donors to consent to this extra level of genetic testing, setting a new standard for what information prospective parents and donor-conceived people can expect to have. In the immediate, this information will be most useful for prospective parents looking for donors with specific backgrounds, possibly ones similar to their own.
It's a solution that was actually hiding in plain sight. Two years ago, California Cryobank's partner Sema4, the company handling the genetic carrier testing that's used to screen for heritable diseases, started analyzing ethnic data in its samples. That extra information was being collected because it can help calculate a more accurate assessment of genetic risks that run in certain populations—like Ashkenazi Jews and Tay Sachs disease—than relying on oral family histories. Shortly after a plan to start collecting these extra data, Jamie Shamonki, chief medical officer of California Cryobank, realized the companies would be sitting on a goldmine for a different reason.
"I didn't want to use one of these genetic testing companies like Ancestry to accomplish this," says Shamonki. "The whole thing we're trying to accomplish is also privacy."
Consumer-facing DNA testing companies are not HIPAA compliant (whereas Sema4, which isn't direct-to-consumer, is HIPAA compliant), which means there are no legal privacy protections covering people who add their DNA to these databases. Although some companies, like 23andMe, allow users to opt-out of being connected with genetic relatives, the language can be confusing to navigate, requires a high level of knowledge and self-advocacy on the user's part, and, as an opt-out system, is not set up to protect the user from unwanted information by default; many unwittingly walk right into such information as a result.
Additionally, because consumer-facing DNA testing companies operate outside the legal purview that applies to other health care entities, like hospitals, even a person who does opt-out of being linked to genetic relatives is not protected in perpetuity from being re-identified in the future by a change in company policy. The safest option for people with privacy concerns is to stay out of these databases altogether.
For California Cryobank, the new information about donor heritage won't retroactively be added to older profiles in the system, so donor-conceived people who already exist won't benefit from the ancestry tool, but it'll be the new standard going forward. The company has about 500 available donors right now, many of which have been in their registry for a while; about 100 of those donors, all new, will have this ancestry data on their profiles.
Shamonki says it has taken about two years to get to the point of publicly including ancestry information on a donor's profile because it takes about nine months of medical and psychological screening for a donor to go from walking through the door to being added to their registry. The company wanted to wait to launch until it could offer this information for a significant number of donors. As more new donors come online under the new protocol, the number with ancestry information on their profiles will go up.
For Parents: An Unexpected Complication
While this change will no doubt be welcome progress for LGBTQ families contemplating parenthood, it'll never be possible to put this entire new order back in the box. What are such families who already have donor-conceived children losing in today's world of widespread consumer genetic testing?
Kochlany and Colimorio's twins aren't themselves much older than the moment at-home DNA testing really started to take off. They were born in 2015, and two years later the industry saw its most significant spike. By now, more than 26 million people's DNA is in databases like 23andMe and Ancestry; as a result, it's estimated that within a year, 90 percent of Americans of European descent will be identifiable through these consumer databases, by way of genetic third cousins, even if they didn't want to be found and never took the test themselves. This was the principle behind solving the Golden State Killer cold case.
The waning of privacy through consumer DNA testing fundamentally clashes with the priorities of the cyrobank industry, which has long sought to protect the privacy of donor-conceived people, even as open identification became standard. Since the 1980s, donors have been able to allow their identity to be released to any offspring who is at least 18 and wants the information. Lesbian moms pushed for this option early on so their children—who would obviously know they couldn't possibly be the biological product of both parents—would never feel cut off from the chance to know more about themselves. But importantly, the openness is not a two-way street: the donors can't ever ask for the identities of their offspring. It's the latter that consumer DNA testing really puts at stake.
"23andMe basically created the possibility that there will be donors who will have contact with their donor-conceived children, and that's not something that I think the donor community is comfortable with," says I. Glenn Cohen, director of Harvard Law School's Center for Health Law Policy, Biotechnology & Bioethics. "That's about the donor's autonomy, not the rearing parents' autonomy, or the donor-conceived child's autonomy."
Kochlany and Colimorio have an open identification donor and fully support their children reaching out to California Cryobank to get more information about him if they want to when they're 18, but having a singular name revealed isn't the same thing as having contact, nor is it the same thing as revealing a web of dozens of extended genetic relations. Their concern now is that if their kids participate in genetic testing, a stranger—someone they're careful to refer to as only "the donor" and never "dad"—will reach out to the children to begin some kind of relationship. They know other people who are contemplating giving their children DNA tests, and feel staunchly that it wouldn't be right for their family.
"With genetic testing, you have no control over who reaches out to you, and at what point in your life," Kochlany says. "[People] reaching out and trying to say, 'Hey I know who your dad is' throws a curveball. It's like, 'Wait, I never thought I had a dad.' It might put insecurities in their minds."
"We want them to have the opportunity to choose whether or not they want to reach out," Colimorio adds.
Kochlany says that when their twins are old enough to start asking questions, she and Colimorio plan to frame it like this: "The donor was kind of like a technology that helped us make you a person, and make sure that you exist," she says, role playing a conversation with their kids. "But it's not necessarily that you're looking to this person [for] support or love, or because you're missing a piece."
It's a line in the sand that's present even for couples still far off from conceiving. When Mallory Schwartz, a film and TV producer in Los Angeles, and Lauren Pietra, a marriage and family therapy associate (and Shamonki's step-daughter), talk about getting married someday, it's a package deal with talking about how they'll approach having kids. They feel there are too many variables and choices to make around family planning as a same-sex couple these days to not have those conversations simultaneously. Consumer DNA databases are already on their minds.
"It frustrates me that the DNA databases are just totally unregulated," says Schwartz. "I hope they are by the time we do this. I think everyone deserves a right to privacy when making your family [using a sperm donor]."
"I wouldn't want to create a world where people who are donor-conceived feel like they can't participate in this technology because they're trying to shut out [other] information."
On the prospect of having a donor relation pop up non-consensually for a future child, Pietra says, "I don't like it. It would be really disappointing if the child didn't want [contact], and unfortunately they're on the receiving end."
You can see how important preserving the right to keep this door closed is when you look at what's going on at The Sperm Bank of California. This pioneering cryobank was the first in the world to openly serve LGBTQ people and single women, and also the first to offer the open identification option when it opened in 1982, but not as many people are asking for their donor's identity as expected.
"We're finding a third of young people are coming forward for their donor's identity," says Alice Ruby, executive director. "We thought it would be a higher number." Viewed the other way, two-thirds of the donor-conceived people who could ethically get their donor's identity through The Sperm Bank of California are not asking the cryobank for it.
Ruby says that part of what historically made an open identification program appealing, rather than invasive or nerve-wracking, is how rigidly it's always been formatted around mutual consent, and protects against surprises for all parties. Those [donor-conceived people] who wanted more information were never barred from it, while those who wanted to remain in the dark could. No one group's wish eclipsed the other's. The potential breakdown of a system built around consent, expectations, and respect for privacy is why unregulated consumer DNA testing is most concerning to her as a path for connecting with genetic relatives.
For the last few decades in cryobanks around the world, the largest cohort of people seeking out donor sperm has been lesbian couples, followed by single women. For infertile heterosexual couples, the smallest client demographic, Ruby says donor sperm offers a solution to a medical problem, but in contrast, it historically "provided the ability for [lesbian] couples and single moms to have some reproductive autonomy." Yes, it was still a solution to a biological problem, but it was also a solution to a social one.
The Sperm Bank of California updated its registration forms to include language urging parents, donor-conceived people, and donors not to use consumer DNA tests, and to go through the cryobank if they, understandably, want to learn more about who they're connected to. But truthfully, there's not much else cryobanks can do to protect clients on any side of the donor transaction from surprise contact right now—especially not from relatives of the donor who may not even know someone in their family has donated sperm.
A Tricky Position
Personally, I've known I was donor-conceived from day one. It has never been a source of confusion, angst, or curiosity, and in fact has never loomed particularly large for me in any way. I see it merely as a type of reproductive technology—on par with in vitro fertilization—that enabled me to exist, and, now that I do exist, is irrelevant. Being confronted with my donor's identity or any donor siblings would make this fact of my conception bigger than I need it to be, as an adult with a full-blown identity derived from all of my other life experiences. But I still wonder about the minutiae of my ethnicity in much the same way as anyone else who wonders, and feel there's no safe way for me to find out without relinquishing some of my existential independence.
"People obviously want to participate in 23andMe and Ancestry because they're interested in knowing more about themselves," says Shamonki. "I wouldn't want to create a world where people who are donor-conceived feel like they can't participate in this technology because they're trying to shut out [other] information."
After all, it was the allure of that exact conceit—knowing more about oneself—that seemed to magnetically draw in millions of people to these tools in the first place. It's an experience that clearly taps into a population-wide psychic need, even—perhaps especially—if one's origins are a mystery.