Wednesday, November 18, 2020

Valuing 'natural capital' vital to avoid next pandemic, global experts warn

Every economic decision needs to take natural capital into account to avoid an even bigger catastrophe than the current pandemic, says Emory disease ecologist Thomas Gillespie.

By Carol Clark

Pandemics will emerge more often, kill more people than COVID-19 and do even more damage to the world economy unless urgent steps are taken to address risk drivers such as deforestation, warns a major new report on biodiversity and pandemics. 

The report, entitled “Escaping the Era of Pandemics,” was made public by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), which includes United Nations members from more than 100 governments. The report is the result of an urgent workshop organized by the IPBES. The workshop brought together 22 experts to evaluate scientific evidence and make recommendations to control and prevent future pandemics, detailed in the report, which IPBES members will now consider whether to endorse. 

“The two biggest driving forces for pandemics are forest degradation and industrial animal production,” says Thomas Gillespie, an associate professor in Emory’s Department of Environmental Sciences and Rollins School of Public Health, who served as a scientific peer reviewer for the report. “Greater management and surveillance of wet markets, where live animals are sold, is also important.” 

Every major economic decision, Gillespie warns, needs to take into account what he calls “natural capital” in order to avoid even bigger catastrophes than the current pandemic. 

The economic costs of a major pandemic are 100 times the estimated costs of prevention, the report notes. It recommends government policy changes to reduce globalized agricultural expansion and the types of trade that have led to pandemics. Some of the possible measures it cites are taxing meat consumption and livestock production and reforming financial aid for land use to consider risks to biodiversity and health. 

Like all pandemics, the emergence of the novel coronavirus was driven entirely by human activities, the report states. The authors estimate that another 1.7 million currently “undiscovered” viruses exist in mammals and birds — and nearly half of them may have the potential to infect people. 

National governments need to incorporate a “One Health” approach — considering the deep connections between the health of people, domesticated animals, wildlife and ecosystems — to build pandemic control and prevention efforts, the report adds. 

Thomas Gillespie in 2018 with famed primatologist Jane Goodall. He is working with the Jane Goodall Institute on a One Health project in Tanzania's Gombe National Park.

Gillespie is a disease ecologist who helped pioneer the “One Health” approach to protect humans, ecosystems and biodiversity. His projects in Africa, including collaborating with Jane Goodall at Gombe National Park in Tanzania, are focused on helping farmers subsisting amid fragmented forests co-exist with primates and other wildlife in ways that minimize the risk of pathogen exchange between species, known as “spillover.” HIV, for instance, spilled over from chimpanzees to humans. Infectious disease and deforestation are the two biggest challenges facing chimpanzees at Gombe today, according to a newly published study led by Goodall and co-authored by Gillespie. 

The Gillespie Lab has a similar project in Costa Rica, focused on bats in fragmented natural ecosystems.

Now, Gillespie finds himself virtually managing his lab’s field projects while also advising global policymakers. “More people are listening,” Gillespie says. “This pandemic has fueled awareness that a One Health approach applied on a grand scale is vital to both local and global economies.” 

In the following Q&A, Gillespie explains the seismic shifts he says are needed to protect global health and economies against the impacts of pandemics. 

What do you mean exactly by “natural capital”? 

Natural capital consists of ecosystems of nature that sustain us. Human activity has driven an overall global decline in natural resources of 40 percent per capita in just over 20 years. Our economies, our health and our well-being are all built upon natural capital. 

There is growing recognition that we are totally dependent on the natural capital of our planet and that perpetual economic growth is not sustainable. We’ve had a false sense that we can simply measure the success of countries and policies through gross domestic product and economic growth, even when it means we are taking loans from nature that we have no capacity to repay. 

The rising risks of pandemics has caught the attention of people who are in charge of economies because COVID-19 is immediately affecting bottom lines. Every country is feeling the pain simultaneously, at both individual and national levels. 

Is it possible for human development and conservation to co-exist? 

When people talk about development from an economic standpoint it involves conversion of natural resources for profit, often by degradation of ecosystems via mining, timber cutting, oil extraction or clearing for cash crops. But when we talk about development from a sustainability perspective, we’re talking about improving the quality of human life. 

Use of the word “development” in these different ways can lead to a great deal of confusion. The urgency of the coronavirus pandemic is helping to break the silos down so that people from both camps can come together to think about solutions. There is growing recognition that instead of just considering whether a land-use project will impact a certain endangered species, we need to have mechanisms to evaluate more broadly how projects may impact the health of wildlife, people and an entire ecosystem. 

Right now, those profiting from economic development are not the ones paying the costs. The data shows very clearly that you can have a high GDP (gross domestic product) and also have plenty of poor people and a large proportion of a population struggling to survive. There is not a clear linkage between gains in the stock market and the quality of life for the average citizen. 

How does climate change fit into this “One Health” approach? 

Although many have rallied behind mitigating and adapting to climate change, it’s just one of the troubling vital signs of the planet. Climate change, biodiversity loss and the ever-increasing risks of pandemics are all symptoms of the same illness — our disconnect with nature and associated unsustainable norms. 

We’ve long needed to bring together climate scientists, disease ecologists and policymakers from agriculture, financial and environmental systems to tackle the illness instead of just having them all separately focus on individual symptoms. This shift is occurring, discussions are happening. The challenges are enormous, but at least now everyone has come together at the same table to try to work toward solutions. 

What are some examples of individual countries taking on these challenges? 

U.S. President-elect Joe Biden has vowed to rejoin the Paris Agreement for carbon reductions and set a 2050 carbon neutrality target. That holds huge implications for global climate diplomacy and will also create opportunities to rally behind shared solutions to prevent future pandemics and to safeguard the planet’s ecosystem services upon which our collective future depends. 

Some governments are beginning to remove environmentally harmful subsidies and redirecting incentives for a green recovery. In fact, New Zealand, Scotland and Iceland are recasting their entire economic frameworks to officially prioritize human well-being and planetary health over GDP. 

New Zealand developed a “Living Standards Framework” to set its budget. Bhutan now shapes policy to advance what it calls its “Gross Happiness Indicator.” Similarly, the world’s largest sovereign wealth fund — the Norwegian Government Pension Fund — has divested from 32 companies involved in unsustainable palm oil production. 

These kinds of initiatives are leading the way to build a better future together.


Bat ecology in the era of pandemics

Great apes and COVID-19: Experts raise the alarm for endangered species

Spillover: Why germs jump species from animals to people

Wednesday, November 11, 2020

Major review of plants' role in antibacterial activity clears new paths for drug discovery

"If ever there was a time to cultivate our knowledge and tap into the chemical power of plants, this is it," says ethnobotanist Cassandra Quave, noting that two in five plants are currently estimated to be threatened with extinction as a result of destruction of the natural world. (Getty Images)

By Carol Clark

Scientists have compiled the first comprehensive review of plant natural products that play a role in antibacterial activity, to serve as a guide in the search for new drugs to combat antibiotic-resistant pathogens. 

Chemical Reviews published the work by researchers at Emory University, which includes 459 plant natural products that met rigorous criteria for demonstrating antibacterial activity. The review is also deposited on the Shared Platform for Antibiotic Research and Knowledge (SPARK), sponsored by Pew Charitable Trusts. 

“We hope that chemists and pharmacology researchers will use our review as a guide to dig deeper into the promising potential of many plant compounds,” says Cassandra Quave, senior author of the review and associate professor in Emory’s Center for the Study of Human Health and Emory School of Medicine’s Department of Dermatology. Quave is also a member of the Emory Antibiotic Resistance Center. 

In the United States, at least 2.8 million people get antibiotic-resistant infections each year and more than 35,000 people die from them, according to the Centers for Disease Control and Prevention. 

“If ever there was a time to cultivate our knowledge and tap into the chemical power of plants, this is it,” Quave says. “We’re seeing a rise in antimicrobial resistance across the globe. And, at the same time, we’re also losing vast amounts of plant biodiversity.” 

Two in five plants are currently estimated to be threatened with extinction, according to the State of the World’s Plants and Fungi Report, published in 2020 by the Royal Botanic Gardens, Kew. 

Quave is a leader in the field of medical ethnobotany, studying how Indigenous people incorporate plants in healing practices to uncover promising candidates for new drugs. The Quave lab has identified compounds from plants such as the Brazilian peppertree, the American beautyberry and the European chestnut that inhibit dangerous antibiotic-resistant bacteria. Her lab found, for instance, that triterpenoid acids from the Brazilian peppertree “disarm” methicillin-resistant Staphylococcus aureus, known as MRSA, by blocking its ability to produce toxins. 

The first antibiotic, penicillin, was derived from microbes in mold that kill bacteria. Since then, scientists have found other microorganisms that live in soil that are easy to grow in a laboratory setting and can kill pathogens resistant to some drugs. The ability of bacteria to continue to evolve resistance, however, is outpacing the ability to generate effective drugs from these sources. 

“One obstacle to plant natural products making it into the new drug pipeline is the complexity of the discovery process,” Quave says. “You have to identify a promising plant candidate, tease through the hundreds of chemicals contained within a particular plant to identify the active compound, and then isolate enough of this compound to do experiments on it. It’s not nearly as easy as sequencing a soil microbe and growing up a big vat of it to conduct experiments.” 

Tapping the knowledge of traditional people who have used plants for centuries to treat infections offers valuable clues for where to focus research, she adds. 

“In recent decades, interest has grown in investigating plants as potential drug candidates,” Quave says. “Technologies have improved to more easily access and study bioactive molecules within plants. And more papers are being published that follow standardized procedures for evaluation of antimicrobial activities among plant compounds.” 

For the current review, the Quave lab looked at nearly 200 papers published between 2012 and 2019 that met strict standardization criteria for authenticating plant-derived compounds that significantly inhibited antibacterial activity. The co-authors spanned undergraduates who conducted the initial literature reviews to graduate students and scientists specialized in biology, chemistry, pharmacology and/or botany. 

The 459 compounds included in the review encompass a diverse range of species — including those from commonly known plant families such as citrus, daisies, beans and mint. The compounds fall into three major classes of chemicals: About half are phenolic derivatives, around 25 percent are terpenoids, nearly 6 percent are alkaloids and the remainder are classified as other metabolites. 

The co-authors selected 183 of the compounds and provided further discussion of their antibacterial activity, biosynthesis, chemical structure, mechanism of action and their potential as antibiotics. 

“These are all compounds as they appear in nature, not synthesized or derivatized by chemists,” Quave explains. “We wanted to provide a systematic overview that brings promising drug candidates to the forefront, opening up new chemical space for discovery. Our review can serve as a starting point for chemists to consider whether they could possibly optimize any of these compounds to become scaffolds for antibiotic treatments.” 

Co-authors of the review include the following members of the Quave lab: Gina Porras, a post-doctoral fellow specialized in natural products chemistry; François Chassagne, a post-doctoral fellow and a pharmacologist; James Lyles, an associate academic research scientist and analytical chemist; Lewis Marquez, a graduate student of pharmacology; Micah Dettweiler, a former research specialist in the lab who is now a graduate student in agronomy at the University of Florida; Akram Salam, a graduate student of pharmacology; Tharanga Samarakoon, a botanist and collections manager of the Emory University Herbarium; Sarah Shabih, an Emory senior majoring in human health; and Darya Farrokhi, who graduated from Emory in 2020 with a degree in biology. 

The work was supported by the National Institute of Allergy and Infectious Disease, the National Center for Complementary and Integrative Health, Emory University and The Jones Center at Ichauway in Georgia.


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