Nav: Home

Swine coronavirus replicates in human cells

October 14, 2020

New research from the University of North Carolina at Chapel Hill suggests that a strain of coronavirus that has recently alarmed the swine industry may have the potential to spread to humans as well.

The coronavirus strain, known as swine acute diarrhea syndrome coronavirus (SADS-CoV), emerged from bats and has infected swine herds throughout China since it was first discovered in 2016. Outbreaks of such an illness have the potential to wreak economic havoc in many countries across the globe that rely on the pork industry.

The virus' potential threat to people was demonstrated in lab tests that revealed SADS-CoV efficiently replicated in human liver and gut cells, as well as airway cells. The findings were published Oct. 12 in PNAS.

Though it is in the same family of viruses as the betacoronavirus SARS-CoV-2, which causes the respiratory illness COVID-19 in humans, SADS-CoV is an alphacoronavirus that causes gastrointestinal illness in swine. The virus causes severe diarrhea and vomiting and has been especially deadly to young piglets.

SADS-COV is also distinct from two circulating common cold alphacoronaviruses in humans, HCoV-229E and HCoV-NL63.

"While many investigators focus on the emergent potential of the betacoronaviruses like SARS and MERS, actually the alphacoronaviruses may prove equally prominent -- if not greater -- concerns to human health, given their potential to rapidly jump between species," said Ralph Baric, professor of epidemiology at UNC-Chapel Hill Gillings School of Global Public Health.

While SADS-CoV has not been known to affect humans to-date, the COVID-19 pandemic serves as a potent reminder that many coronavirus strains found in animals have the potential to infect humans as well - an effect known as spillover.

The Baric lab worked with Caitlin Edwards, a research specialist and master of public health student at UNC-Chapel Hill, on the study which suggests humans may be susceptible to spillover of SADS-CoV.

Edwards, the study's first author, tested several types of cells by infecting them with a synthetic form of SADS-CoV to understand just how high the risk of cross-species contamination could be.

Evidence from the study indicates that a wide range of mammalian cells, including primary human lung and intestinal cells, are susceptible to infection. According to Edwards, SADS-CoV shows a higher rate of growth in intestinal cells found in the human gut, unlike SARS-CoV-2, which primarily infects lung cells.

Cross-protective herd immunity often prevents humans from contracting many coronaviruses found in animals. However, results from the testing done by Edwards and her team suggest that humans have not yet developed such immunity to SADS-CoV.

"SADS-CoV is derived from bat coronaviruses called HKU2, which is a heterogenous group of viruses with a worldwide distribution," Edwards said. "It is impossible to predict if this virus, or a closely related HKU2 bat strain, could emerge and infect human populations. However, the broad host range of SADS-CoV, coupled with an ability to replicate in primary human lung and enteric cells, demonstrates potential risk for future emergence events in human and animal populations."

In response to these findings, Edwards and colleagues tested the broad-spectrum antiviral remdesivir as a potential method of treatment for the infection.

Working with Gilead Sciences, remdesivir was developed by the Baric Lab to combat all known coronaviruses, including SADS-CoV. It is currently being used to treat COVID-19 infections in humans, including the United States president. Preliminary results from this study show that it has robust activity against SADS-CoV, though Edwards cautions that more testing is necessary on additional cell types and in animals to confirm these findings.

"Promising data with remdesivir provides a potential treatment option in the case of a human spillover event," she said. "We recommend that both swine workers and the swine population be continually monitored for indications of SADS-CoV infections to prevent outbreaks and massive economic losses."

SADS-CoV could also pose a threat to the U.S. economy, which was third in global pork production in 2019. In 2012, the U.S. pork industry was devastated by different swine coronavirus that emerged from China.

"Not surprisingly, we are currently looking for partners to investigate the potential of SADS-CoV vaccine candidates to protect swine," Baric said. "While surveillance and early separation of infected piglets from sows provide an opportunity to mitigate larger outbreaks and the potential for spillover into humans, vaccines may be key for limiting global spread and human emergence events in the future."
-end-
Other members of the Department of Epidemiology involved in the study include Boyd Yount, Assistant Professor Rachel Graham, PhD; Sarah Leist, PhD; Yixuan Hou, PhD; Associate Professor Amy Sims, PhD; Jesica Swanstrom, Trevor Scobey, Michelle Cooley and Caroline Currie.

University of North Carolina at Chapel Hill

Related Coronavirus Articles:

App analyzes coronavirus genome on a smartphone
A team led by Garvan's Dr Ira Deveson developed the app 'Genopo' that can analyse the coronavirus genome on a portable Android device.
Hypercoagulability in patients with coronavirus disease (COVID-19)
In this AJR article, 82 patients with COVID-19 who underwent abdominal ultrasound or CT were retrospectively compared with 82 patients without COVID-19 for thromboembolism and solid-organ infarction.
Evaporation critical to coronavirus transmission as weather changes
As COVID-19 cases continue to rise, it is increasingly urgent to understand how climate impacts the spread of the coronavirus, particularly as winter virus infections are more common and the northern hemisphere will soon see cooler temperatures.
People with 'silent' COVID-19 have as much coronavirus as those with symptoms
People with 'silent' COVID-19 infection have as much coronavirus in their noses and throats as those with symptoms, reveals research published online in the journal Thorax.
Exercise hormone may modulate genes associated with replication of novel coronavirus
Brazilian researchers observed that in uninfected adipocytes, the hormone irisin altered the expression of genes that regulate ACE-2, which encodes a protein to which the virus binds in order to invade human cells.
Despite coronavirus: Social contacts increase again
Arrange a get-together with friends, enjoy life out in the fresh air: Despite the corona pandemic, everyday life is returning to normal.
How coronavirus took hold in North America and in Europe
Early interventions were effective at stamping out coronavirus infections before they spread, according to a study published in the journal Science.
NSAIDs not associated with more severe coronavirus disease, study finds
The use of non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and diclofenac, is not associated with any adverse effects in people who have tested positive for COVID-19, according to a new study published September 8 in PLOS Medicine by Anton Pottegård of the University of Southern Denmark and colleagues from Aarhus University Hospital and the Danish Medicines Agency.
Cellular roadmaps predict body's coronavirus vulnerability
New research from Cornell University developed potential roadmaps for how the coronavirus infects organs and identifies what molecular factors could help facilitate or restrict infection.
New method of detecting illnesses including coronavirus and cystic fibrosis
A new and quicker method of diagnosing diseases in patients has been created by researchers.
More Coronavirus News and Coronavirus Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Sound And Silence
Sound surrounds us, from cacophony even to silence. But depending on how we hear, the world can be a different auditory experience for each of us. This hour, TED speakers explore the science of sound. Guests on the show include NPR All Things Considered host Mary Louise Kelly, neuroscientist Jim Hudspeth, writer Rebecca Knill, and sound designer Dallas Taylor.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

Kittens Kick The Giggly Blue Robot All Summer
With the recent passing of Ruth Bader Ginsburg, there's been a lot of debate about how much power the Supreme Court should really have. We think of the Supreme Court justices as all-powerful beings, issuing momentous rulings from on high. But they haven't always been so, you know, supreme. On this episode, we go all the way back to the case that, in a lot of ways, started it all.  Support Radiolab by becoming a member today at Radiolab.org/donate.