Tuesday, July 26, 2022

Coronavirus jumped to humans at least twice at market in Wuhan, China

Studies describe not only where the COVID-19 pandemic began, but the likelihood that the causative SARS-CoV-2 virus made the leap from animal hosts to people multiple times

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - SAN DIEGO


In a pair of related studies, published July 26, 2022 online via First Release in Science, researchers at University of California San Diego, with colleagues on four continents, show that the origin of the COVID-19 pandemic in 2019 was at the Huanan Seafood Wholesale Market in Wuhan, China, and resulted from at least two instances of the SARS-CoV-2 virus jumping from live animal hosts to humans working or shopping there.

The findings, first reported in February after the papers were posted online as preprints awaiting peer review, garnered international attention, primarily focusing on identifying the market as the early epicenter of the COVID-19 pandemic. The World Health Organization estimates that there have been more than 566 million confirmed cases of COVID-19 worldwide and 6.3 million deaths since the pandemic was declared in early 2020.

“It’s vital that we know as much about the origin of COVID-19 as possible because only by understanding how pandemics get started can we hope to prevent them in the future,” said Joel O. Wertheim, PhD, associate professor in the Division of Infectious Diseases and Global Public Health at UC San Diego School of Medicine, and a co-author on both papers.

But elemental to understanding pandemic origins is pinpointing not just where, but how, a pathogen successfully jumps from a non-human animal host to human, known as a zoonotic event.

“I think there’s been consensus that this virus did in fact come from the Huanan Market, but a strong case for multiple introductions hasn’t been made by anyone else yet,” said Wertheim, senior author of the study that posits the SARS-CoV-2 virus, which causes COVID-19, jumped from animals to humans at least twice and perhaps as many as two dozen times.

According to researchers, two evolutionary branches of the virus were present early in the pandemic, differentiated only by two differences in nucleotides — the basic building blocks of DNA and RNA.

Lineage B, which included samples from people who worked at and visited the market, became globally dominant. Lineage A spread within China, and included samples from people pinpointed only to the vicinity the market. If the viruses in lineage A evolved from those in lineage B, or vice versa, Wertheim said this would suggest SARS-CoV-2 jumped only once from animals to humans.

But work by Wertheim and collaborators found that the earliest SARS-CoV-2 genomes were inconsistent with a single zoonotic jump into humans. Rather, the first zoonotic transmission likely occurred with lineage B viruses in late-November 2019 while the introduction of lineage A into humans likely occurred within weeks of the first event. Both strains were present at the market simultaneously.

Researchers arrived at this conclusion by deciphering the evolutionary rate of viral genomes to deduce whether or not the two lineages diverged from a single common ancestor in humans. They used a technique called molecular clock analysis and an epidemic simulation tool called FAVITES, invented by Wertheim team member Niema Moshiri, PhD, an assistant professor of computer science at Jacobs School of Engineering at UC San Diego and study co-author.

“None of this could have been done without FAVITES,” said Wertheim.

Validation

In February 2022, researchers at the Chinese Center for Disease Control and Prevention published a long-delayed analysis of genetic traces of the earliest environmental samples collected at the market two years earlier.

The samples were obtained after the first reports of a new, mysterious illness and after the market had already been shut down. The Huanan Seafood Wholesale Market in Wuhan is a so-called “wet market” where live animals are often slaughtered and sold for human consumption, including in some cases, wildlife.

However, no live wild mammals were left at the market after it was shut down. Instead, Chinese researchers swabbed walls, floors and other surfaces, tested meat still in freezers, sampled sewers and caught mice and stray cats and dogs around the market.

Their findings confirmed the not-yet-published predictions of Wertheim’s team that Lineage A was also at the market.

“We felt validated, but what we felt more was immense pressure because they beat our preprint to the punch by about 12 hours, and we could only discuss their findings in light of ours,” Wertheim said. “We were also shocked that they had been sitting on evidence for lineage A at the market for over a year without realizing its importance.”

The newly published data, said study authors, are powerful evidence that the two viral lineages evolved separately and that multiple spillover events occurred. The Wuhan market reportedly contained a robust live wild animal business, with snakes, badgers, muskrats, birds and raccoon dogs (a canid indigenous to Asia) and other species sold for food. Wertheim said he believes there were likely many viral introductions. At least two successfully made the animal-human leap; other viral strains went extinct.

“While I'm hesitant to call it proof, what we presented is the most comprehensive explanation for the SARS-CoV-2 genomic diversity at the outset of the pandemic,” Wertheim said. “There are really no other good explanations for both of these strains being at the market except for multiple jumps into humans.”

(The findings undercut a circulating and persistent theory that the SARS-CoV-2 virus escaped from the Wuhan Institute of Virology, located a few miles from the market.)

Jonathan E. Pekar, a doctoral student in Bioinformatics and Systems Biology who co-led the project with Wertheim and is lead author, said the pandemic was likely looming for years, awaiting only for the opportunity when humans would come into contact with an animal host capable of transmitting the virus.

“Everything complicated happened before that introduction,” Pekar said. “The last step is just extended contact and transmission from hosts to humans. At that point, it would actually be unusual to only have one introduction. We've seen this before with MERS-CoV (a similar zoonotic virus). We’ve seen it with humans giving SARS-CoV-2 to minks on farms and then minks giving it back to humans.

“This has happened before, and it's going to keep happening. Nature is a better lab than humans will ever be.”

The latest study continues a series of published papers by Wertheim and colleagues investigating and chronicling the origin and spread of COVID-19.

In September 2020, they published data explaining how the first, few cases of novel coronavirus in North America and Europe quickly spread due to insufficient testing and contact tracing. In March 2021, Wertheim, Pekar and colleagues characterized the brief time-period during which SARS-CoV-2 could have circulated undetected before the first human cases in Wuhan.

Co-authors of “The molecular epidemiology of multiple zoonotic origins of SARS-CoV-2” include: Andrew Magee, Karthik Gangavarapu and Marc A. Suchard, all at UCLA; Edyth Parker, Nathaniel L. Matteson, Mark Zeller, Joshua I. Levy and Kristian G. Andersen, all at The Scripps Research Institute; Katherine Izhikevich, Jennifer L. Havens and Tetyana I.Vasylyeva, all at UC San Diego; Lorena Mariana Malpica Serrano and Michael Worobey, both at University of Arizona; Alexander Crits-Christoph, Johns Hopkins Bloomberg School of Public Health; Jade C. Wang and Scott Hughes, both at New York City Department of Health; Jungmin Lee, Heedo Park, Man-Seong Park, Korea University; Katherine Ching Zi Yan and Raymond Tzer Pin Lin, all at National Centre for Infectious Diseases, Singapore; Mohd Noor Mat Isa and Yusuf Muhammad Noor, both at Malaysia Genome and Vaccine Institute; Robert F. Garry, Tulane University; Edward C. Holmes, University of Sydney, Australia; and Andrew Rambaut, University of Edinburgh.

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Study unveils first global dataset for SARS-CoV-2 infections in animals


Structured data on the virus in animals is essential to further our understanding of the COVID-19 pandemic and mitigate its spread at the human-animal interface, according to the authors of the paper published in Scientific Data


Peer-Reviewed Publication

COMPLEXITY SCIENCE HUB VIENNA

SARS-CoV-2 variants 

IMAGE: THE DIAGRAM SHOWS THE SARS-COV-2 VARIANTS IDENTIFIED IN THE DIFFERENT ANIMAL HOSTS. THE FIGURE DESCRIBES THE NUMBER OF EVENTS (ONE EVENT MAY INCLUDE ONE OR MORE CASES). view more 

CREDIT: NERPEL, A., YANG, L., SORGER, J. ET AL.

[Vienna, July 2022] In a pioneering initiative, a multidisciplinary Austrian team created the most comprehensive global dataset of SARS-CoV-2 infections in animals. Their findings were published Saturday, July 23, in the journal Scientific Data and the epidemiological information is available on a dashboard at https://vis.csh.ac.at/sars-ani/

“There was an urgent need for a global dataset on SARS-CoV-2 events in animals that can be easily imported, processed, and analyzed,” says Amélie Desvars-Larrive, the principal investigator of the study and a researcher at the Complexity Science Hub Vienna (CSH).

The initiative intends to facilitate One Health approaches on SARS-CoV-2. The idea is to create a collaborative approach that recognizes the interdependence of human, animal, and environmental health to obtain optimal health for all. 

“To tackle major threats to human health, we need integrated approaches,” points out Desvars-Larrive. “Although animals do not appear to play a significant role in the spread of COVID-19 among people currently, One Health tools that enable the integrative analysis and visualization of SARS-CoV-2 events are critical.” 

Two major animal health databases

For the past months, Desvars-Larrive and her team meticulously extracted, combined, and structured information on SARS-CoV-2 cases in animals. They included publicly available data from two major animal health databases: the Program for Monitoring Emerging Diseases (ProMED), a reporting system of the International Society for Infectious Diseases; and the World Animal Health Information System (WAHIS) of the World Organisation for Animal Health.

The unified dataset, called SARS-ANI, feeds a dashboard, which includes an overview of SARS-CoV-2 events in animals worldwide, stratified by species; clinical signs that were allegedly associated with the disease; control measures and outcomes; and a geographical overview of all events. The dashboard is linked to the live dataset available on GitHub.

Answers to current questions

The dataset can help answering some of the many questions regarding SARS-CoV-2 in animals, according to the authors. It shows, for instance, that the number of reported SARS-CoV-2 cases in animals is steadily increasing worldwide. A total of 704 events (one event can include one or more cases that are epidemiologically related) have been reported in 39 countries, across 27 animal species (as of July 25, 2022).

In addition, the team described a high diversity of SARS-CoV-2 variants in the animal hosts, especially in American mink and white-tailed deer. These variants show similarities with human variants. In terms of animal case fatality rates, they are relatively low.

An essential tool

Also, the dataset can be useful for estimating the impact of SARS-CoV-2 on pets, farm animals, wildlife, and conservation programs. In addition, scientists and policymakers can use it to develop guidelines for prevention, risk-based surveillance, and response to SARS-CoV-2.

“We believe the SARS-ANI dataset, with timely and reliable information, can assist in the development of national and international regulations and agreements aiming to reduce the risk of transmission at the human-animal interfaces,” declares Desvars-Larrive, who is also a professor in infection epidemiology at the University of Veterinary Medicine Vienna. 

The dataset – a joint effort by experts from CSH, University of Veterinary Medicine Vienna, and Wildlife Conservation Society – will be updated weekly for at least one year. “We also hope to receive new data from researchers around the world to develop it further and expand its use”, says Desvars-Larrive.

  

CAPTION

The SARS-ANI dashboard gives an easy-to-understand overview of specific aspects of SARS-CoV-2 events in animals and is publicly accessible at https://vis.csh.ac.at/sars-ani/

CREDIT

Nerpel, A., Yang, L., Sorger, J. et al.

The study SARS-ANI: a global open access dataset of reported SARS-CoV-2 events in animals by Afra Nerpel, Liuhuaying Yang, Johannes Sorger, Annemarie Käsbohrer, Chris Walzer, and Amélie Desvars-Larrive appeared in Scientific Data 9 (438) (2022). 

The SARS-ANI dashboard gives an easy-to-understand overview of specific aspects of SARS-CoV-2 events in animals and is publicly accessible at https://vis.csh.ac.at/sars-ani/


About CSH 

The mission of Complexity Science Hub Vienna is to host, educate, and inspire complex systems scientists dedicated to making sense of Big Data to boost science and society. Scientists at the Hub develop methods for the scientific, quantitative, and predictive understanding of complex systems.

The CSH is a joint initiative of AIT Austrian Institute of Technology, Central European University CEU, Danube University Krems, Graz University of Technology, IIASA, Medical University of Vienna, TU Wien, VetMedUni Vienna, Vienna University of Economics and Business, and Austrian Economic Chambers (WKO). 

https://www.csh.ac.at

 

Urban sites such as Berkeley and Brooklyn have their individual magnetic pulse

Multidisciplinary study uses magnetometers to investigate the magnetic fields of metropolitan areas


Peer-Reviewed Publication

JOHANNES GUTENBERG UNIVERSITAET MAIN

Magnetic fields occur wherever magnets are active. The Earth itself is surrounded by a magnetic field and its orientation can be readily determined using a compass, for example. Cities also have magnetic fields and can be clearly distinguished from each other thanks to their unique magnetic signatures. This is the conclusion of a multidisciplinary study comparing two US urban areas – Berkeley in California and Brooklyn Borough of New York City. Researchers from both the USA and Germany were tasked with continuously recording data over a four-week period, supplemented with additional measurements and analyses. "We found that these areas have what you could call an individual magnetic pulse," said Professor Dmitry Budker, a physicist working at Johannes Gutenberg University Mainz (JGU) and the Helmholtz Institute Mainz (HIM). Berkeley, interestingly, exhibits negligible magnetic field activity at night, while Brooklyn's magnetic activity remains at a high level overnight – confirming, as the team expected, that New York really is The City That Never Sleeps.

Experts from Mainz University contribute their knowledge in measuring magnetic fields to the comparison of urban settlements

The comparison of the two urban areas was preceded by an initial prototype study at Berkeley. Here, a line of the Bay Area Rapid Transit (BART) public transport system was identified as the dominant source of magnetic field activity during the daytime. "At Berkeley, we find a lot of different magnetic background signals during both the day and at night, but the main factor contributing to this is the BART system. When the line stops operating at night, this is reflected in our measurements," explained Professor Dmitry Budker. His research group has contributed to the project, notably through its expertise in using magnetometers to measure magnetic fields. At Mainz University, the team headed by Budker is mainly concerned with developing atomic magnetometry techniques to facilitate research into the fundamental questions of physics, such as the search for dark matter.

According to Budker, the multidisciplinary nature of cities is also of interest to the participating researchers at the Center for Urban Science and Progress at New York University. They want to learn more about how cities work, looking at various aspects such as energy efficiency, environmental pollution, and the social organization of a city.

Magnetometry and urban development

The recently published analysis is intended to provide a starting point for further research in this field and to lay the foundations for future developments. "It's a small study and we get the impression that we're only just scratching the surface," Budker added. "This type of investigation offers great potential and we hope that we can take it much further in the future," said the physicist.

"Apart from the anticipated result that 'New York never sleeps,' our measurements indicate that each city has distinct magnetic signatures that can, perhaps, be exploited for the analysis of anomalies in city operation and long-term trends of the development of cities," stated the authors in their paper published in the Journal of Applied Physics. The journal selected the study as its cover article.

Potential applications for magnetometry in urban studies include post-disaster assessments, monitoring of infrastructure such as bridges, and monitoring the stability of the power grid. The researchers pose an interesting multidisciplinary question that could be addressed in future: they wonder how and if an anomalous event, such as an epidemic or a pandemic, could influence an urban magnetic signature.

In addition to Dr. Arne Wickenbrock and Professor Dmitry Budker from Mainz, the study entitled "Do cities have a unique magnetic pulse?" also involved researchers from the Lawrence Berkeley National Laboratory, the University of California, Berkeley, the University of Delaware, and the Center for Urban Science and Progress in New York City.

 

Related links:
https://budker.uni-mainz.de/ – Budker Group at the JGU Institute of Physics ;
https://www.prisma.uni-mainz.de/ – PRISMA+ Cluster of Excellence ;
https://www.hi-mainz.de/ – Helmholtz Institute Mainz (HIM)
https://aip.scitation.org/action/showLargeCover?doi=10.1063%2Fjap.2022.131.issue-20 – Journal of Applied Physics cover

 

Read more:
https://www.uni-mainz.de/presse/aktuell/14970_ENG_HTML.php – press release "Worldwide coordinated search for dark matter" (20 Jan. 2022) ;
https://www.uni-mainz.de/presse/aktuell/14790_ENG_HTML.php – press release "Amplified signal and extreme sensitivity: on the trail of light dark matter particles" (15 Dec. 2021) ;
https://www.uni-mainz.de/presse/aktuell/14441_ENG_HTML.php – press release "Color centers in diamonds serve as gyroscopes" (6 Dec. 2021) ;
https://www.uni-mainz.de/presse/aktuell/13133_ENG_HTML.php – press release "Combined technique using diamond probes enables nanoscale imaging of magnetic vortex structures" (9 March 2021)

Brexit built borders inside British-European families, new report found

Brexit has had ‘real life consequences’ for those in mixed British-European families, says new research co-led by Lancaster University and the University of Birmingham.

Reports and Proceedings

LANCASTER UNIVERSITY

From joining different queues at airport security to holding different immigration status in their country of residence, the shift from a common status as EU citizens to family members having different rights to residence has evoked strong emotions.

Brexit has had ‘real life consequences’ for those in mixed British-European families, says new research co-led by Lancaster University and the University of Birmingham.

The study ‘British-European families after Brexit’, completed as part of the ESRC-funded project ‘Rebordering Britain and Britons after Brexit’, highlights how Brexit has introduced different rights and conditions concerning residence between spouses and partners, children and parents.

Many families worry about how these differences in status will impact on their future movements between the UK and EU.

Since the end of the Brexit transition period, moving from the UK to the EU has become more complex for such families. As British family members no longer have the right to freedom of movement, in the absence of work, their right to move and settle in the EU may be dependent on that of their EU family member(s).

Until recently, the ‘Surinder Singh’ route permitted foreign nationals to enter and settle in the UK on the basis that they were family members of a British citizen and living with them in an EU or EEA country or Switzerland prior to 31st December 2020.

The closing of this route after Brexit means that such families are no longer exempt from standard immigration controls and have to apply and pay for family visas before they can settle in the UK.

The new findings draw on responses to the ‘Migration and Citizenship after Brexit’ survey, the first major insight, by Lancaster University and the University of Birmingham, of how Brexit and the Covid-19 pandemic have impacted on the lives of those moving between the UK and EU.

Of the 2,024 survey respondents, 418 (21 per cent) British, EU/EEA and non-EU/EEA nationals living in the UK or the EU, identified they were part of a mixed-status family (families with at least one close member holding a different citizenship or migration status from the others).

Among them, the difference in status that Brexit had introduced was often presented as a cause for concern.

As one Hungarian woman, in her 40s living in the UK, explained, this had forced her: “To choose between me being a second-class citizen or my husband risking not being able to get permanent residency and risk being unable to receive pension.”

For British citizens living in the EU/EEA, concerns about the terms on which they would be able to return to the UK with non-British family members were a common response to the Brexit-borne differentiation of statuses with families.

As a British woman, in her 30s, living in France, said: “It means I can't leave for more than a few months if something happens to family overseas. My partner can't come to the UK without applying for a visa even to care for a relative. We're worried we'll get separated at the airport.”

Lead author of the report Dr Elena Zambelli, of Lancaster University, said: “Overall, the picture that emerges shows that, for some, Brexit introduced borders into their lives. Families that previously shared the rights to Free Movement within the EU, remade as mixed-status families with differentiated rights to mobility.

“For other families, who already had mixed migration statuses, Brexit deepened the impacts of the borders on their lives. This reveals further impacts of Brexit at the level of the family, making, fracturing and reconstituting their members’ ties within one or multiple countries and affecting their mobility and settlement options as a family.

“The survey showed their concerns are often accompanied by strong negative feelings, in consequence of Brexit finding themselves for the first time questioned about their entitlement to live and move in and out of their country of choice based on will and/or need.”

Other findings show:

  • ‘Family’ represents the main reason given by respondents who changed their country of residence since 2016, and its frequency was almost double that in the overall survey sample (+ 14%).
  • Three out of four respondents (75%) reported that, since the Brexit referendum, citizenship/migration status differences within their family had been an issue of concern; half (50%) relayed that these had affected their decisions to move or stay put.
  • For British citizens in the EU who secured temporary residence and EU citizens in the UK who secured pre-settled status under the Withdrawal Agreement, there remain lingering uncertainties as to what will happen when it lapses and what effects it will have on the mixed-status families they are part of.

The survey is part of a wider research project ‘Rebordering Britain and Britons after Brexit (MIGZEN)’ (www.migzen.net), led by Professor Michaela Benson at Lancaster University and Professor Nando Sigona at the University of Birmingham. The project is funded by UKRI Economic and Social Research Council as part of the ‘Governance After Brexit’ programme and explores the long-term impacts of Brexit and Britain’s shifting position on the world stage on migration to and from the UK.

The Rockefeller Foundation’s Pandemic Prevention Institute and the Pasteur Network partner to strengthen global disease surveillance

Business Announcement

INSTITUT PASTEUR

Washington, D.C., Paris | July 26, 2022 – The Rockefeller Foundation’s Pandemic Prevention Institute (PPI) and the Pasteur Network have signed a Memorandum of Understanding (MoU) to advance early detection and reporting for emerging and reemerging diseases and build a robust decentralized global surveillance network that strengthens local capacity for sharing high-quality data across countries. The collaboration aims to enhance the effectiveness of the Pandemic Prevention Institute and the Pasteur Network’s 33 member institutions in both addressing infectious diseases, such as COVID-19 and monkeypox, and informing interventions against them.

“Our work with the Pasteur Network will undoubtedly make a transformational impact on global health security, leveraging the ability to advance equitable data-sharing practices that will provide key stakeholders and decision-makers with timely, more accurate and relevant information to make critical health and policy decisions,” said Dr. Rick Bright, CEO of The Rockefeller Foundation’s Pandemic Prevention Institute. “Our collective aim is to advance access to pathogen surveillance, genomic sequencing, analytics, and data sharing tools in low- and middle-income countries and to foster sentinel laboratory networks for early disease detection.”

“This MoU is a major milestone in our collaboration with The Rockefeller Foundation and the PPI that could lead to significant impact in epidemic and pandemic preparedness. Together, the Pasteur Network and PPI are an effective combination of complementary talents and capacity to address global health threats said Dr. Amadou Sall, President of the Pasteur Network.

“We are proud to support this initiative. This important, historic partnership will provide much-needed support to capacity building and epidemic intelligence,” said Professor Stewart Cole, President of the Pasteur Network foundation that contributes to the Pasteur Network’s development.

Over the coming years, the partnership will focus primarily on the following areas:

  • Advancing global equitable data sharing to provide key stakeholders and decision-makers with an analytical toolset that leverages timely, more accurate and relevant data and information

  • Bolstering epidemiological and genomic surveillance in low- and middle-income countries to track emerging pathogen variants and transmission for real-time analyses, as well as advancing access to pathogen surveillance and analytical tools, such as digital apps

  • Enhancing discovery of emerging and reemerging high consequence pathogens, generating a diversity of essential disease surveillance data streams in areas such as zoonosis, anti-microbial resistance and water borne diseases

  • Building fit for purpose data analytics and disease discovery and forecasting systems, informed by the organizations’ partner networks, that are relevant, sustainable, and equitable at the local, state, and pan-regional level

The partnership will also focus on interdisciplinary research projects addressing the causes of outbreaks and epidemics. The combined networks will maintain local and regional structures to foster a permanent operational force and share technologies, systems, practices, and techniques with their networks.


###

About the Pasteur Network
Pasteur Network, previously known as the Institut Pasteur International Network, is a worldwide network of members which contribute to global health. This unique model of cooperation brings together, beyond the independent public or private structures that form the Network, a human and scientific community collectively mobilized for both local, regional and global health priorities. The members of Pasteur Network share the same mission to improve health through biomedical research, public health activities, training, and innovation. For more information, visit: https://pasteur-network.org/en/about/who-we-are/ and follow-on Linkedin: Pasteur Network and Twitter:@InstitutPasteur

About the Pandemic Prevention Institute
The Rockefeller Foundation’s Pandemic Prevention Institute (PPI) is mission-driven to contribute to the crucial work of building systems that detect, prevent and mitigate pandemic threats, leading to rapid, effective containment. PPI is pursuing its mission through the integration of cutting-edge technology and analytic approaches that turn data into action that drives life-saving decisions; a federated network of data users and holders with global representation; and collaborative leadership at the global level. For more information on partners, data solutions and more visit www.ppi.org and follow us on Twitter: @PPI_Insights and LinkedIn: The Pandemic Prevention Institute..

About The Rockefeller Foundation
The Rockefeller Foundation is a pioneering philanthropy built on collaborative partnerships at the frontiers of science, technology, and innovation to enable individuals, families, and communities to flourish. We work to promote the well-being of humanity and make opportunity universal.  Our focus is on scaling renewable energy for all, stimulating economic mobility, and ensuring equitable access to healthy and nutritious food.  For more information, sign up for our newsletter at rockefellerfoundation.org and follow us on Twitter @RockefellerFdn.

Wine-drinkers of the world rejoice! New research, led by UMass Amherst, finds key to billion-dollar problem

International research collaboration unlocks the mystery of Grapevine Trunk Diseases

Peer-Reviewed Publication

UNIVERSITY OF MASSACHUSETTS AMHERST

GTD’s cause in excess of $1.5 billion in losses annually. Barry Goodell enjoying the fruits of his research. 

IMAGE: GTD’S CAUSE IN EXCESS OF $1.5 BILLION IN LOSSES ANNUALLY. BARRY GOODELL ENJOYING THE FRUITS OF HIS RESEARCH. view more 

CREDIT: BARRY GOODELL

AMHERST, Mass. – Grapevine Trunk Diseases, or GTDs, are the bane of vineyard owners worldwide, and as of 2012, were responsible for more than $1.5 billion in annual economic damages. While researchers have long known that a host of pathogenic fungi combine to gang up on grapevines, the mechanics of how these GTD-causing fungi work has remained a mystery.

Recently, an international cohort of researchers, led by the University of Massachusetts Amherst, announced a previously unknown mechanism that is deployed by a group of pathogenic fungi working in concert and which are responsible for the death of the grapevines. Thankfully, it would seem that a fairly easy, cost-effective solution may be on the horizon.

GTDs have been known to devastate up to 30% of the vines in a single vineyard each year, and typically attack older, well-established vines. In California alone, annual GTD-related losses amount to 14% of the total value of the wine grapes produced.

GTD-causing fungi typically enter the vine’s system through pruning wounds and, once established, develop a rotting canker that gradually expands, dissolving the woody part of the vine from the inside out and killing the plant. It’s no easy feat to dissolve the tough cellulose and lignin framework that make up woody plants, but a consortium of fungi have figured out how to do it, perplexing scientists.

“The missing ingredient,” says Barry Goodell, professor of microbiology at UMass Amherst, and the paper’s senior author, “is an understanding of what very small compounds produced by the fungi are actually doing to the grapevines.” 

In particular, Goodell and his UMass Amherst colleagues and students, along with collaborating scientists from the University of Florence in Italy, the Université de Lorraine and the Université de Haute-Alsace, both in France, and the University of Concepción in Chile, as well as vineyard owners in both France and Italy, have discovered that some of the GTD-causing fungi produce different types of small compounds that are released into the wood of the vine. One of those compounds is responsible for reducing iron. Normally, we encounter iron as the chemical compound, Fe3+. Reducing iron from Fe3+ to Fe2+ sets the stage for some nasty grapevine problems.

“But that’s not the whole story,” Goodell says. “We also discovered that there’s another set of small compounds that are produced by other fungi in the consortia, and these compounds are really good at producing hydrogen peroxide. When hydrogen peroxide meets reduced iron—BOOM! – the reaction releases a host of oxygen radicals that damage the woody tissue causing an almost cancer-like disease.”

In short, different fungi, each producing one of the two types of small compounds needed for an extracellular bomb, figured out how to get together, mix their respective chemicals, and use them to blow apart the cellulose walls of the grapevine’s cells. Once the cell walls are breached, the fungi can feast on the sugar-rich fluid that once was the cellular structure supporting the vine’s own growth.

Luckily, there’s a potential fix, which is so common consumers probably eat it every morning with cereal: antioxidants and low-toxicity chelators. Often added to food products to preserve freshness, they also interrupt the production of reduced iron and hydrogen peroxide. They also scavenge the oxygen radicals the fungi produce. “In addition,” Goodell points out, “there are some select bacteria and fungi that produce these antioxidant and chelating compounds. Our research shows that we may be able to manage and stop GTDs through ‘bio-control’ treatments by increasing the natural presence of these antagonistic organisms on the vines.”

“Of course, there’s still work to be done,” says Goodell. “Vineyard pathologists need to test our research in the field, and other microbiologists will want to verify our work. But we already have colleagues as part of our larger team that are doing this, and we’re confident that this research represents a breakthrough in ways that we understand this devastating disease of vineyards and how to control that devastation.”

The research was recently published in the journals Fungal Biology and Frontiers in Plant Science, and was supported by the USDA-NIFA Hatch Multistate Program and the Microbiology Department at UMass, the French/European VitEST project and Laboratoire Vigne Biotechnologies et Environnement at University Haute-Alsace, and DAGRI at the University of Florence, Italy.

Contacts: Barry Goodell, bgoodell@umass.edu

                 Daegan Miller, drmiller@umass.edu