OREGON STATE UNIVERSITY

college of science

Toxic algal blooms behind Klamath River dams create health risks far downstream

CORVALLIS, Ore. – A new study has found that toxic algal blooms in reservoirs on the Klamath River can travel more than 180 miles downriver in a few days, survive passage through hydroelectric turbines and create unsafe water conditions on lower parts of the river in northern California.

Water-borne algal blooms can accumulate to concentrations that can pose health risks to people, pets and wildlife, and improved monitoring and public health outreach is needed to address this issue, researchers said.

The frequency, duration and magnitude of harmful algal blooms appear to be increasing.

The findings were made by researchers from Oregon State University, based on data from an extensive survey of the Klamath River in 2012, and just published in Harmful Algae, a professional journal.

The toxins may be a special concern if they are bioaccumulated in some animal species, such as freshwater mussels in which the level of the toxin can be more than 100 times higher than ambient concentrations.

“It’s clear that these harmful algal blooms can travel long distances on the river, delivering toxins to areas that are presently underappreciated, such as coastal margins,” said Timothy Otten, an OSU postdoctoral scholar in the OSU College of Science and College of Agricultural Sciences.

“And the blooms are dynamic, since they can move up and down in the water column and are physically distributed throughout the reservoir,” he said. “This means you can’t just measure water in one place and at one time and adequately estimate the public health risk.”

Microcystis is a seasonal blue-green cyanobacterium found around the world, preferring warm waters in lakes and reservoirs. Some strains are toxic, others are not. Its magnitude and persistence may increase with global climate change, researchers say, and it can cause a range of health issues, including liver damage, rashes, gastrointestinal illness, and other concerns. The toxin is not destroyed by boiling, making it unique from many other biological drinking water contaminants.

Improved awareness of the ability of blooms to travel significant distances downstream, and communication based on that, would help better inform the public, the OSU scientists said. But individual knowledge and awareness would also help.

“On a lake or river, if you see a green band along the shore or green scum on the surface, the water may not be safe to recreate in,” Otten said. “Because this problem is so diffuse, it's often not possible to put up posters or signs everywhere that there’s a problem in real-time, so people need to learn what to watch for.  Just as with poison ivy or oak, the general public needs to learn to recognize what these hazards look like, and know to avoid them in order to safeguard their own health.”

In this and other recent research, the OSU scientists have also developed genetic tools that can help identify problems with Microcystis, more quickly and at lower cost than some older methods. But those tools have not yet been widely adopted by the monitoring community.

“Right now, some lakes are not sampled at all for algal blooms, so we don’t really know if there’s a problem or not,” said Theo Dreher, the Pernot Professor and former chair of the Department of Microbiology in the OSU College of Science and College of Agricultural Sciences. “There’s no doubt we could use improved monitoring in highly used lakes and reservoirs, or in rivers downstream of them when toxic blooms are found.”

In this study, researchers found that intensive blooms of Microcystis in Iron Gate Reservoir on the Klamath River were the primary source of toxic algae observed downstream. They used genetic tracking technology to establish what many may have suspected when observing Microcystis in the lower reaches of the Klamath River. This transport of algae has been very little studied, even though it’s likely common.

The possible removal of dams on the Klamath River after 2020 may ultimately help mitigate this problem, the researchers said. Their study found no evidence of endemic Microcystis populations in the flowing regions of the Klamath River, both upstream and downstream of the Copco and Iron Gate reservoirs.

The problem with these bacteria is national and global in scope, especially in summer.

There are more than 123,000 lakes greater than 10 acres in size across the United States, and based on an EPA National Lakes Assessment, at least one-third may contain toxin-producing cyanobacteria. Dams, rising temperatures and atmospheric carbon dioxide concentrations, extreme weather and increased runoff of nutrients from urban and agricultural lands are all compounding the problem.

Many large, eutrophic lakes such as Lake Erie are plagued each year by algal blooms so massive that they are visible from outer space. Dogs have died from drinking contaminated water, and sea otter deaths in Monterey Bay have been attributed to eating shellfish contaminated with toxin produced by Microsystis.

This study was supported by Pacificorp, the OSU Agricultural Experiment Station and the Mabel E. Pernot Trust.

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Tim Otten, 541-737-1796

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Toxic algal bloom
Toxic algal bloom

View of “nature as capital” uses economic value to help achieve a sustainable future

CORVALLIS, Ore. – Researchers today outlined in a series of reports how governments, organizations and corporations are successfully moving away from short-term exploitation of the natural world and embracing a long-term vision of “nature as capital” – the ultimate world bank upon which the health and prosperity of humans and the planet depend.

The reports, published in the Proceedings of the National Academy of Sciences, suggest that significant progress has been made in the past decade, and that people, policy-makers and leaders around the world are beginning to understand ecosystem services as far more than a tree to cut or fish to harvest.

“Valuing nature means understanding the myriad ways in which our communities, health and economies depend on ecosystems,” said Jane Lubchenco, a distinguished professor at Oregon State University, former director of the National Oceanic and Atmospheric Administration, and co-leader of this group of studies.

“There is now broad appreciation of nature’s values and we are learning how to incorporate that knowledge into policy and management decisions by governments, financial institutions and businesses,” she said. “In 10 years we’ve gone from very little specific understanding to powerful examples, where working with nature is benefitting people now and in the future.”

The stakes are high. The world’s gross domestic product has increased nearly 60 times since the start of the Industrial Revolution, the researchers point out, allowing a dramatic increase in the standard of living even as Earth’s population surged.

But with global environmental threats in the future and a world population that may approach 10 billion by 2100, the health of nature will literally become a life-support system that no longer can tolerate short-term production and consumption at the expense of natural stewardship. Disasters such as the 2010 Deepwater Horizon oil spill are being evaluated not just based on the immediate damage, but also the long-term costs such as lost water filtration, hunting and fishing.

Scientists say that just in recent years, we may be turning the corner toward approaches that could help the planet and all its natural inhabitants to live long and prosper.

In the U.S., some coastal restoration practices gained support as more people understood their additional value for carbon sequestration and storage. In Denver, a water board provided $32 million for forest restoration work to avoid damage to water quality caused by large wildfires.

Costa Rica has transformed itself from having the world’s highest deforestation rate to one of the few countries with net reforestation. South Africa has linked development and ecosystem service planning to better allocate water, reduce poverty and avoid disasters. China is creating a network of “ecosystem function conservation areas” that focus conservation in areas with a high return on investment. In the Brazilian Amazon, environmental protection has helped reduce the incidence of malaria, acute respiratory infection and diarrhea.

The researchers said that sometimes, but not always, it can help to literally translate ecosystem services into a dollar value – what something is worth, and what would it cost if we lost it. Such approaches have helped set the stage for cap-and-trade of carbon emissions, taxes on activities with negative ecosystem impacts, and certification systems to help inform consumers and realign incentives in the private sector.

One notable success story, outlined today in a different publication co-authored by Lubchenco in the journal Oceanography, is fisheries policy and marine management in the U.S. and European Union.

The approach incorporates a commitment to end overfishing, complete with time tables and strict accountability, plus the option of using rights-based approaches to fishery management. In the U.S., these are called “catch shares,” and they give fishermen a say in the present and a stake in the future, within scientifically determined limits. Catch shares, plus the mandate to end overfishing, are turning fisheries around, to the benefit of fishermen, consumers and ecosystems. 

This approach has transformed U.S. fisheries. For example, the number of overfished stocks in U.S. federal fisheries has plummeted from 92 stocks in 2000 to 37 in 2014.  The number of stocks that were previously depleted and have now recovered to a point where they can be fished sustainably has increased dramatically, from zero in 2000 to 37 in 2014.

Elsewhere in the world, other rights-based approaches to fisheries are also ending overfishing and protecting biodiversity.  For example, so-called ‘TURF reserves’ combine an exclusive right to fish in a particular area with no-take marine reserves.  Under this system, fully protected marine reserves provide a wide range of ecological benefits while helping to produce larger and more diverse fish species that can “seed” the areas around the reserve. Those areas can then be fished, using science-based harvest levels, by fishermen who have exclusive rights to certain areas, and gain a personal interest in protecting the sustainability of the system.

Such an approach can help protect natural systems in perpetuity while promoting economic health, and may be especially critical for food security in parts of the developing world, where nearly three billion people depend on fish for at least 20 percent of their animal protein intake.

“The challenges in fishery management are significant, but we also have good news to celebrate,” Lubchenco said. “We can end overfishing at the same time we return fisheries to profitability and sustainability.

“Much work remains to be done,” Lubchenco said. “Our global economic, political and social systems depend on the world’s natural resources, but many policy decisions do not yet explicitly incorporate natural capital into the decision-making process. However, these new results from around the world show what works. The real opportunity is widespread adoption of these ideas and approaches.”

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Jane Lubchenco, 541-737-5337

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Rice terraces
Rice terrace in China

Decades of research yield natural dairy thickener with probiotic potential

CORVALLIS, Ore. – Microbiologists at Oregon State University have discovered and helped patent and commercialize a new type of dairy or food thickener, which may add probiotic characteristics to the products in which it’s used.

The thickener is now in commercial use, and OSU officials say it may have a significant impact in major industries. The global market for polymers such as this approaches $7 billion, and there are estimates the U.S. spends up to $120 billion a year on probiotic products such as yogurt, sour cream and buttermilk.

The new product is produced by a natural bacterium that was isolated in Oregon. It’s the result of decades of research, beginning in the early 1990s when a novel polymer with an ability to rapidly thicken milk was discovered by an OSU microbiologist. The polymer is known as Ropy 352 and produced by a non-disease-causing bacterium.

“This is one of many naturally occurring, non-disease-causing bacterial strains my research program isolated and studied for years,” said Janine Trempy, an OSU microbiologist. “We discovered that this bacterium had a brand-new, never-before reported grouping of genes that code for a unique polymer that naturally thickens milk. In basic research, we’ve also broadened our understanding of how and why non-disease-causing bacteria produce polymers.”

This polymer appears to give fermented foods a smooth, thick, creamy property, and may initially find uses in sour cream, yogurt, kefir, buttermilk, cream cheese and artisan soft cheeses. Composed of natural compounds, it offers a slightly sweet property and may improve the sensory characteristics of low-fat or no-fat foods. And unlike other polymers that are now commonly used as thickeners, it may add probiotic characteristics to foods, with associated health benefits.

“There are actually very few new, non-disease-causing bacterial strains that produce unique polymers with characteristics desirable and safe for food products,” Trempy said. “In the case of a dairy thickener, for instance, a bacterium such as Ropy 352 ferments the sugar in the milk and produces a substance that changes the milk’s properties.”

These are chemical processes driven by naturally occurring bacteria that do not cause disease in humans, Trempy said, but instead may contribute to human health through their probiotic potential.

One of the most common polymers, xanthum gum, has been in use since 1969 and is found in a huge range of food products, from canned foods to ice cream, pharmaceuticals and beauty products. Xanthum gum is “generally recognized as safe” by the FDA, but is derived from a bacterium known to be a plant pathogen and suspected of causing digestive distress or being “pyrogenic,” or fever-inducing.

Trempy’s research program has determined the new polymer will thicken whole and non-fat milk, lactose-free milk, coconut milk, rice milk, and other products designed for use in either dieting or gaining weight. Beyond that, the polymer may have a wide range of applications such as thickening of pharmaceuticals, nutraceuticals, fruit juices, cosmetics and personal care products.

In their broader uses, microbial polymers are used for food production, chemical production, detergents, cosmetics, paints, pesticides, fertilizers, film formers, lubricants, explosives, pharmaceutical production and waste treatment.

OSU recently agreed to a non-exclusive license for the patented Ropy 352 technology to a global market leader for dairy starter cultures. It’s also available for further licensing through OSU’s Office of Commercialization and Corporate Development.

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Janine Trempy, 541-737-4441

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Food thickener
Dairy thickener

Licensing agreement reached on brilliant new blue pigment discovered by happy accident

CORVALLIS, Ore. – A brilliant new blue pigment – discovered serendipitously by Oregon State University chemists in 2009 – is now reaching the marketplace, where it will be used in a wide range of coatings and plastics.

The commercial development has solved a quest that began thousands of years ago, and captured the imagination of ancient Egyptians, the Han dynasty in China, Mayan cultures and others – to develop a near-perfect blue pigment.

It happened accidently.

OSU chemist Mas Subramanian and his team were experimenting with new materials that could be used in electronics applications and they mixed manganese oxide – which is black in color – with other chemicals and heated them in a furnace to nearly 2,000 degrees Fahrenheit. One of their samples turned out to be a vivid blue. Oregon State graduate student Andrew Smith initially made these samples to study their electrical properties.

“It was serendipity, actually; a happy, accidental discovery,” Subramanian said.

The new pigment is formed by a unique crystal structure that allows the manganese ions to absorb red and green wavelengths of light, while only reflecting blue. The vibrant blue is so durable, and its compounds are so stable – even in oil and water – that the color does not fade.

These characteristics make the new pigment versatile for a variety of commercial products. Used in paints, for example, they can help keep buildings cool by reflecting infrared light. Better yet, Subramanian said, none of the pigment’s ingredients are toxic.

OSU has reached an exclusive licensing agreement for the pigment, which is known as “YInMn” blue, with The Shepherd Color Company. It will be used in a wide range of coatings and plastics.

“This new blue pigment is a sign that there are new pigments to be discovered in the inorganic pigments family,” said Geoffrey T. Peake, research and development manager for The Shepherd Color Company. Commercial quantities of the pigment will be available later this year, he added.

The lack of toxic materials is critical, Subramanian pointed out, and a hallmark of the new pigment.

“The basic crystal structure we’re using for these pigments was known before, but no one had ever considered using it for any commercial purpose, including pigments,” Subramanian said.  “Ever since the early Egyptians developed some of the first blue pigments, the pigment industry has been struggling to address problems with safety, toxicity and durability.”

Another commercial use of the product – in addition to coatings and plastics, may be in roofing materials. The new pigment is a “cool blue” compound that has infrared reflectivity of about 40 percent – much high than other blue pigments – and could be used in the blue roofing movement.

“The more we discover about the pigment, the more interesting it gets,” said, Subramanian, who is the Milton Harris Professor of Materials Science in the OSU College of Science.  “We already knew it had advantages of being more durable, safe and fairly easy to produce. Now it also appears to be a new candidate for energy efficiency.”

In addition to testing the blue pigment for other applications, Subramanian is attempting to discover new pigments by creating intentional laboratory “accidents.” His original work was funded by the National Science Foundation.

“Who knows what we may find?,” he said.

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Mas Subramanian, 541-737-8235, mas.subramanian@oregonstate.edu

New zebrafish model should speed research on parasite that causes toxoplasmosis

 

The study this story is based on is available online: http://bit.ly/1e2jPlB

CORVALLIS, Ore. – Researchers at Oregon State University have found a method to speed the search for new therapies to treat toxoplasmosis – by successfully infecting zebrafish with Toxoplasma gondii.

The findings were just published in the Journal of Fish Diseases, in work supported by the Tartar Foundation and the National Institutes of Health.

T. gondii, a protozoan parasite, can infect a wide range of hosts, and is one of the most prevalent parasites in the world. It has been estimated to infect about one-third of the human race. Treatment can be difficult because parasites often have biologic similarities to the hosts they infect.

Zebrafish have been found in recent years to be an excellent model for biomedical research because they reproduce rapidly, bear many similarities to human genetics and biological systems, and can be used in “high throughput” technologies to literally test hundreds of compounds in a fairly short period of time.

“This advance may provide a very efficient tool for the discovery of new therapies for this parasitic infection,” said Justin Sanders, an OSU postdoctoral fellow and lead author on the study. “With it we should be able to more easily screen a large library of compounds, at much less expense, and look at things that are unknown or have never been considered as a possible treatment.”

Although it infects many animals, T. gondii infection has never been observed prior to this in fish. But the OSU researchers found that by raising the temperature of the water in which zebrafish lived to a warmer-than-normal 98.6 degrees, or the temperature of a human body, they could become infected with the parasite but also survive.

T. gondii affects a wide range of mammals and birds, and cats are actually one of the most routine hosts,” said Michael Kent, a professor of microbiology in the OSU College of Science. “It can cause congenital defects, which is one reason that pregnant women are told not to clean the catbox. Many people become infected for life. These chronic infections can cause serious eye disease and can be fatal to people with weakened immune systems.

“New therapies would clearly be of value, and now we have a better way to find them,” he said.

This work was done in collaboration with researchers from the University of Chicago, Albert Einstein College of Medicine, and the U.S. Department of Agriculture.

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Michael Kent, 541-737-8652

Disrupted biological clock linked to Alzheimer’s disease

CORVALLIS, Ore. – New research has identified some of the processes by which molecules associated with neurological diseases can disrupt the biological clock, interfere with sleep and activity patterns, and set the stage for a spiral of health concerns that can include a decreased lifespan and Alzheimer’s disease.

The research was published in Neurobiology of Disease by scientists from Oregon State University and the Oregon Health & Science University, in work supported by the National Institutes of Health.

Previous studies have shown that disruption of the biological clock – the natural pattern of day-night activity that’s genetically controlled in many animals – can cause neurodegeneration, loss of motor function and early death.

The newest results help outline the molecular mechanisms involved, and show how proteins associated with neurological disease can diminish the biological clock function and ultimately lead to very serious health problems, including severe cognitive deterioration. It also confirms that these risks increase significantly with age.

"The molecular basis underlying biological clock deficits in Alzheimer's disease has been difficult to tease out," said Matthew Blake, an OSU faculty research assistant and author of the study. "Only recently have we been able to utilize our model system to accurately dissect this mechanism."

This research was done with fruit flies, which have many genes and biological processes that are similar or identical to those of humans, retained through millions of years of evolution. Circadian clocks are so essential to health that they are found throughout the nervous system and peripheral organs.

Proper function of circadian rhythms has been shown to affect everything from sleep to stress reaction, feeding patterns, DNA repair, fertility and even the effectiveness of medications.

“Alzheimer’s disease has always been of interest in this research, because sleep disruption is one of its earliest symptoms, and almost everyone with Alzheimer’s has some sleep problems,” said Jadwiga Giebultowicz, corresponding author of this study, a professor in the Department of Integrative Biology in the OSU College of Science, and expert on the biological and genetic underpinnings of the biological clock.

“This research adds more support to the hypothesis that neurological damage is a circular process that, in turn, causes more disruption of the biological clock,” Giebultowicz said. “We’ve identified a new player in this process, a fragment of the amyloid precursor protein called AICD, that is able to enter the nucleus of cells and interfere with central clock function.”

One known cause of Alzheimer’s disease is cleavage of an amyloid precursor protein, which creates a peptide that’s toxic to neurons. An enzyme involved is elevated in Alzheimer’s patients. This study took that process further and showed that increased production of the enzyme, which in flies is called dBACE, reduced the expression of a core clock protein.

The results suggest that dBACE acts via dAICD to cause the disruption of the biological clock and loss of daily sleep and activity cycles. This disruptive process was much more severe in older flies.

“A general message from this is that normal day-night, sleep and activity cycles are important,” Giebultowicz said.

“There’s evidence that proper sleep allows neuronal repair activity and the maintenance of neuronal health,” she said. “Since neuronal damage is a destructive process that can build on itself once it begins, it’s important that sleep issues should be taken seriously by people and their doctors, especially as they age.”

Molecular clock oscillations decline with age, Giebultowicz said, and finding ways to help maintain or restore them might form the basis for a possible therapy to reduce or prevent the associated health problems.

Collaborators on this research included Eileen Chow in the Department of Integrative Biology at OSU, and Doris Kretzschmar at the Oregon Institute of Occupational Health Sciences, an international expert in the use of fruit flies as a model for neurodegenerative diseases.

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Jadwiga Giebultowicz, 541-737-5530

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Drosophila melanogaster
Fruit fly

A mile deep, ocean fish facing health impacts from human pollution

CORVALLIS, Ore. – Deep-water marine fish living on the continental slopes at depths from 2,000 feet to one mile have liver pathologies, tumors and other health problems that may be linked to human-caused  pollution, one of the first studies of its type has found.

The research, conducted in the Bay of Biscay west of France, also discovered the first case of a deep water fish species with an “intersex” condition, a blend of male and female sex organs. The sampling was done in an area with no apparent point-source pollution, and appears to reflect general ocean conditions.

The findings have been published in Marine Environmental Research, by scientists from Oregon State University; the Centre for Environment, Fisheries and Aquaculture Science in the United Kingdom; and other agencies. It was supported by the European Union.

The research is of particular interest, OSU researchers said, when contrasted to other studies done several years ago in national parks of the American West, which also found significant pollution and fish health impacts, including male fish that had been “feminized” and developed eggs.

“In areas ranging from pristine, high mountain lakes of the United States to ocean waters off the coasts of France and Spain, we’ve now found evidence of possible human-caused pollution that’s bad enough to have pathological impacts on fish,” said Michael Kent, a professor of microbiology in the OSU College of Science, co-author on both these research projects and an international expert on fish disease.

“Deep in the ocean one might have thought that the level of contamination and its biological impact would be less,” Kent said. “That may not be the case. The pathological changes we’re seeing are clearly the type associated with exposure to toxins and carcinogens.”

However, linking these changes in the deep water fish to pollution is preliminary at this time, the researchers said, because these same changes may also be caused by naturally-occurring compounds. Follow up chemical analyses would provide more conclusive links with the pathological changes and man’s activity, they said.

Few, if any health surveys of this type have been done on the fish living on the continental slopes, the researchers said. Most past studies have looked only at their parasite fauna, not more internal biological problems such as liver damage. The issues are important, however, since there’s growing interest in these areas as a fisheries resource, as other fisheries on the shallower continental shelf become depleted.

As the sea deepens along these continental slopes, it’s been known that it can act as a sink for heavy metal contaminants such as mercury, cadmium and lead, and organic contaminants such as PCBs and pesticides. Some of the “intersex” fish that have been discovered elsewhere are also believed to have mutated sex organs caused by “endocrine disrupting chemicals” that can mimic estrogens.

In this study, the health concerns identified were found in black scabbardfish, orange roughy, greater forkbeard and other less-well-known species, and included a wide range of degenerative and inflammatory lesions that indicate a host response to pathogens, as well as natural cell turnover. The fish that live in these deep water, sloping regions usually grow slowly, live near the seafloor, and mature at a relatively old age. Some can live to be 100 years old.

Partly because of that longevity, the fish have the capacity to bioaccumulate toxicants, which the researchers said in their report “may be a significant human health issue if those species are destined for human consumption.” Organic pollutants in such species may be 10-17 times higher than those found in fish from the continental shelf, the study noted, with the highest level of contaminants in the deepest-dwelling fish.

However, most of those contaminants migrate to the liver and gonads of such fish, which would make their muscle tissue comparatively less toxic, and “generally not high enough for human health concern,” the researchers wrote.

The corresponding author on this study was Stephen Feist at the Centre for Environment, Fisheries and Aquaculture Science in Weymouth, England.

In the previous research done in the American West, scientists found toxic contamination from pesticides, the burning of fossil fuels, agriculture, industrial operations and other sources, which primarily found their way into high mountain lakes through air pollution. Pesticide pollution, in particular, was pervasive.

Together, the two studies suggest that fish from some of the most remote parts of the planet, from high mountains to deep ocean, may be impacted by toxicants, Kent said.

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Michael Kent, 541-737-8652

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Testicle with egg
Trout testicle with egg

Genetic discovery may offer new avenue of attack against schistosomiasis

CORVALLIS, Ore. – Researchers at Oregon State University have discovered a group of genes in one species of snail that provide a natural resistance to the flatworm parasite that causes schistosomiasis, and opens the door to possible new drugs or ways to break the transmission cycle of this debilitating disease.

Schistosomiasis infects more than 200 million people in more than 70 countries, and is most common in areas with poor sanitation. It can cause chronic, lifelong disability, beginning with gastrointestinal problems and sometimes leading to liver damage, kidney failure, infertility and bladder cancer.

Schistosomisasis, which is native to Africa but has now spread around the world, has been called a neglected global pandemic. Its impact on human health rivals that of malaria.

However, the circular transmission of this complex disease depends upon spending some time as an infection in aquatic snails, where the number of parasites is greatly magnified. Snails may therefore offer a key opportunity to break the cycle of transmission.

The findings about this genetic discovery were just published in PLOS Genetics, by researchers from OSU and the Universite de Perpignan Via Domitia in France. The work was supported by the National Institutes of Health.

“We’ve found a new class of previously unknown genes that appear to control the ability to resist schistosomes,” said Michael Blouin, a professor of integrative biology in the OSU College of Science. “It was found that a dominant genetic allele in this region conveys an eight-fold decrease in the risk of schistosomiasis infection.

“These genes are the type that, in other animal species, help to recognize pathogens and trigger an immune response,” Blouin said. “This is important new information. With further research we’ll learn more about the exact genetics and molecules that are involved as the parasite interacts with the host.”

There are two possible applications of these results that could be pursued in an effort to treat or control this disease, the researchers said. One would be development of new drugs, which could be important - right now only a single medication, praziquantel, exists to help treat the disease. With its increasingly widespread use, resistance to that drug is possible.

Alternatively, researchers might attempt to insert these parasite-resistant genes into the species of snails that most commonly transmit schistosomiasis.

“There are ways to drive new genes into a population,” said Jacob Tennessen, an OSU postdoctoral research associate and lead author on this study.

This is already being tried for some other diseases, the scientists noted, such as in mosquitos that transmit malaria. Modifying snail populations to be resistant is currently not practical, they said, but identifying new genes that control resistance to the parasite is a critical first step.

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Michael Blouin, 541-737-2362

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Resisting schistosomiasis
Schistosomiasis resistance

Trematode eggs
Trematode eggs

Global warming to increase ocean upwelling, but fisheries impact uncertain

CORVALLIS, Ore. – A report to be published Thursday in the journal Nature suggests that global warming may increase upwelling in several ocean current systems around the world by the end of this century, especially at high latitudes, and will cause major changes in marine biodiversity.

Since upwelling of colder, nutrient-rich water is a driving force behind marine productivity, one possibility may be enhancement of some of the world’s most important fisheries.

However, solar heating due to greenhouse warming may also increase the persistence of “stratification,” or the horizontal layering of ocean water of different temperatures. The result could be a warm, near-surface layer and a deep, cold layer.

If this happens to a significant extent, it could increase global hypoxic, or low-oxygen events, decouple upwelling from the supply of nutrient-rich water, and pose a significant threat to the global function of fisheries and marine ecosystems.

The projected increase in upwelling, in other words, appears clear and definitive. But researchers say its biological impact is far less obvious, which is a significant concern.

These upwelling systems cover less than 2 percent of the ocean surface, but contribute 7 percent to global marine primary production, and 20 percent of global fish catches.

“Our modeling indicates that normally weaker upwelling toward the polar ends of upwelling-dominated regions will strengthen,” said Bruce Menge, the Wayne and Gladys Valley Professor of Marine Biology in the College of Science at Oregon State University, and co-author of the report.

“Ordinarily, you would expect that an increase in upwelling would mean an increase in marine coastal productivity, and that might happen,” Menge said.

“However, a thicker and warmer top later, and more stratified ocean waters may put the cold, nutrient-rich waters too deep for upwelling to bring them up, and reduce the ability of upwelling to energize the coastal ocean food web,” he said. “This could have a very negative impact on marine production and fisheries.”

The findings were made by researchers from OSU and Northeastern University, in work supported by that university and the National Science Foundation.

Another possibility, the study concluded, are changes in the frequency or severity of low-oxygen, or “hypoxic” events such as those that have plagued the Pacific Northwest in the past decade. Depending on where the layers of warm and cold water end up, as well as local subsea terrain and currents, the hypoxic events could become either less common or more severe. In a hypoxic event, microbial decay of phytoplankton blooms uses up the available oxygen, causes hypoxia, and often leads to a die-off of fish and other marine organisms.

Among the findings of the study:

  • The change in upwelling may be more pronounced in the Southern Hemisphere, due to the local influences of land masses, coastline, water depth and other issues.
  • Major current systems will be affected off the western coasts of North America, South America, Africa and parts of Europe.
  • The general increase in upwelling is going to be driven by a strengthening of alongshore winds, due to a differential in land and ocean heating.
  • At high, but not low latitudes, the upwelling season will start earlier, last longer and be more intense.
  • At tropical and sub-tropical latitudes, upwelling will become almost a year-round phenomenon.
  • The findings are consistent with different research which shows that coastal upwelling has intensified over the past 60 years.
  • Impacts on the California Current System are expected to be less pronounced because of other climatic forces at work, such as the Pacific Decadal Oscillation, the El Nino-Southern Oscillation, and the North Pacific Gyre Oscillation.

Researchers said that by understanding these climate-mediated “hotspots” in upwelling, and how they will change in the future, it may be possible to better manage productive fisheries and coastal ecosystems around the world.

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Bruce Menge, 541-737-5358

Unwanted impact of antibiotics broader, more complex than previously known

CORVALLIS, Ore. – Researchers at Oregon State University have discovered that antibiotics have an impact on the microorganisms that live in an animal’s gut that’s more broad and complex than previously known.

The findings help to better explain some of the damage these medications can do, and set the stage for new ways to study and offset those impacts.

The work was published online in the journal Gut, in research supported by Oregon State University, the Medical Research Foundation of Oregon and the National Institutes of Health.

Researchers have known for some time that antibiotics can have unwanted side effects, especially in disrupting the natural and beneficial microbiota of the gastrointestinal system. But the new study helps explain in much more detail why that is happening, and also suggests that powerful, long-term antibiotic use can have even more far-reaching effects.

Scientists now suspect that antibiotic use, and especially overuse, can have unwanted effects on everything from the immune system to glucose metabolism, food absorption, obesity, stress and behavior.

The issues are rising in importance, since 40 percent of all adults and 70 percent of all children take one or more antibiotics every year, not to mention their use in billions of food animals. Although when used properly antibiotics can help treat life-threatening bacterial infections, more than 10 percent of people who receive the medications can suffer from adverse side effects.

“Just in the past decade a whole new universe has opened up about the far-reaching effects of antibiotic use, and now we’re exploring it,” said Andrey Morgun, an assistant professor in the OSU College of Pharmacy. “The study of microbiota is just exploding. Nothing we find would surprise me at this point.”

This research used a “cocktail” of four antibiotics frequently given to laboratory animals, and studied the impacts.

“Prior to this most people thought antibiotics only depleted microbiota and diminished several important immune functions that take place in the gut,” Morgun said. “Actually that’s only about one-third of the picture. They also kill intestinal epithelium. Destruction of the intestinal epithelium is important because this is the site of nutrient absorption, part of our immune system and it has other biological functions that play a role in human health.”

The research also found that antibiotics and antibiotic-resistant microbes caused significant changes in mitochondrial function, which in turn can lead to more epithelial cell death. That antibiotics have special impacts on the mitochondria of cells is both important and interesting, said Morgun, who was a co-leader of this study with Dr. Natalia Shulzhenko, a researcher in the OSU College of Veterinary Medicine who has an M.D. from Kharkiv Medical University.

Mitochondria plays a major role in cell signaling, growth and energy production, and for good health they need to function properly.

But the relationship of antibiotics to mitochondria may go back a long way. In evolution, mitochondria descended from bacteria, which were some of the earliest life forms, and different bacteria competed with each other for survival. That an antibiotic would still selectively attack the portion of a cell that most closely resembles bacteria may be a throwback to that ingrained sense of competition and the very evolution of life.

Morgun and Schulzhenko’s research group also found that one of the genes affected by antibiotic treatment is critical to the communication between the host and microbe.

“When the host microbe communication system gets out of balance it can lead to a chain of seemingly unrelated problems,” Morgun said.

Digestive dysfunction is near the top of the list, with antibiotic use linked to such issues as diarrhea and ulcerative colitis. But new research is also finding links to obesity, food absorption, depression, immune function, sepsis, allergies and asthma.

This research also developed a new bioinformatics approach named “transkingdom network interrogation” to studying microbiota, which could help further speed the study of any alterations of host microbiota interactions and antibiotic impact. This could aid the search for new probiotics to help offset antibiotic effects, and conceivably lead to systems that would diagnose a person’s microbiome, identify deficiencies and then address them in a precise and individual way. 

Healthy microbiota may also be another way to address growing problems with antibiotic resistance, Morgun said. Instead of trying to kill the “bad” bacteria causing an illness, a healthy and functioning microbiota may be able to outcompete the unwanted microbes and improve immune function.

Collaborators on this research were from the OSU College of Pharmacy; OSU College of Veterinary Medicine; OSU College of Science; the National Cancer Institute; University of British Columbia; University of Maryland School of Medicine; and the National Institutes of Health.

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Andrey Morgun, 541-737-8047