Don’t Flush Your Kitty Litter! Toxoplasmosis Is a Growing Threat to Sea Otters and Other Marine Mammals

Sea otter in water with an overlay of Toxoplasma gondii oocysts.

Southern sea otters (Enhydra lutris nereis), endangered marine mammals along California’s coastlines, are facing an unexpected threat. The menace comes not from pollution, habitat loss or natural predators, but from a microscopic enemy—Toxoplasma gondii (T. gondii). This protozoan parasite, typically associated with domestic cats, has found its way into marine ecosystems with sometimes deadly consequences for sea otters. Recently, scientists identified transmission of virulent, atypical strains of T. gondii from terrestrial felids to sea otters along the southern California coast, with lethal consequences (1).

Understanding T. gondii and Its Hosts

T. gondii is a versatile parasite that can infect nearly all warm-blooded animals, including humans and marine mammals. However, the T. gondii lifecycle depends upon felids (e.g., domestic cats and their wild relatives) who serve as definitive hosts. It is in their intestines that the parasite completes its sexual reproductive stage. The resulting oocysts are excreted in the animals’ feces. T. gondii oocysts exhibit remarkable resilience, surviving in soil, freshwater and seawater for extended periods. They are even resistant to standard wastewater treatment processes, which means oocysts in cat waste disposed of by flushing will pass through the treatment plant and be discharged into the environment. ​(2,3).

Oocysts can also be washed from soil contaminated with cat waste and carried via storm drains and rivers into the ocean, dispersing them into coastal waters. Once there, the oocysts settle on kelp or in sediments where they can be picked up by marine invertebrates like snails, mussels and clams. Marine mammals such as sea otters become infected when they consume these contaminated invertebrates. Otters can also ingest oocysts during grooming sessions​ (1,3).

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Tardigrade Proteins Might Solve the Cold Chain Problem for Biologics

image depicting a microscopic tardigrade

Some of our most advanced medicines today rely on components derived from living organisms. These therapeutics, called biologics, include things like vaccines, blood products like Human Blood Clotting Factor VIII (FVIII), antibodies and stem cells. Biologics are incredibly temperature sensitive, which means they need to be kept cold during production, transport and storage, a process collectively called the cold chain. The stringent transport and storage temperature requirements for biologics create a barrier to accessing these lifesaving options; particularly for those in remote or underdeveloped regions, where maintaining a cold chain is logistically difficult and costly.

But what if we could break the cold chain? Inspired by one of the most resilient creatures on Earth – the tardigrade – scientists at the University of Wyoming are exploring ways to do just that.

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Mpox—The Latest Zoonotic Virus Making Headlines

Mpox (formerly known as Monkeypox; 1) has been making the news lately. The declaration by the WHO Director-General naming mpox a public health emergency of international concern (PHEIC; 2) has a lot of people wondering what it is, how it spreads and how concerned they should be. Understandably, we are all a little jumpy when we start hearing about a new viral disease, but the virus that causes mpox (monkeypox virus) isn’t new.

Artists rendering of monkeypox on a torso.

A member of the Poxviridae family, the monkeypox virus is closely related to the variola virus that causes smallpox; however, monkeypox causes milder symptoms and is less fatal (1). While the virus gained its unfortunate name from its discovery in monkeys in 1958 (3), the original source of the disease remains unknown. The virus exists in a wide range of mammals including rodents, anteaters, hedgehogs, prairie dogs, squirrels and shrews (4) and can spread to humans through close contact with an infected individual or animal. Symptoms can include fever, headache, muscle and back pain, swollen lymph nodes, chills and exhaustion (3). The most distinguishing symptom is the blister-like rash.

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The Battle of Shiloh’s Angel’s Glow: Fact, Civil War Legend or Modern Myth? 

It sounds like the script for a Hollywood movie. The story, first appearing in 2001, begins with a purported civil war legend from the Battle of Shiloh. The legend said that the wounds of some soldiers glowed (faintly) in the dark. Soldiers with these glowing wounds were more apt to survive, giving the phenomenon the name “Angels Glow”. The story ends with two curious teenagers solving the mystery using their science fair project. They identify infection by the bioluminescent bacteria Photorhabdus luminescens (formerly Xenorhabdus luminescens) as the likely cause of the glowing wounds. P. luminescens produces bacteriocins (antimicrobial peptides), which the teenagers attribute to helping keep other infections at bay, resulting in the improved survival rate for the soldiers whose wounds glowed.

The teenagers win. The mystery is solved. The credits roll. 

Except life (and science) is rarely as simple as a summer block buster. 

Cannon at sunset on a civil war battlefield
The Battle of Shiloh took place in Hardin County Tennessee on April 6th and 7th, 1862.
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Mind Control, Mutilation and Death. The Fungal Fate That Lurks in Waiting for Emerging Periodical Cicadas

For the first time since Thomas Jefferson was president, broods of 13- and 17-year periodical cicadas are emerging from the ground at the same time. The fate that awaits some of these periodic cicadas—a fungal infection that hijacks their behavior and destroys their genitalia — sounds like the script of a bad zombie horror film. The culprit (or villain) is the entomopathogenic fungus Massospora cicadina.  

An adult red eyed 17-year periodical cicada sits on a leaf

While most entomopathogens kill their host before releasing their infectious spores, M. cicadina is one of the few species that increase spore dispersal by hijacking their host’s behavior and keeping them alive while sporulating (1). The manner it uses to do this is both gruesome and fascinating. If you can stomach some details of insect sex and dismemberment, read on.

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Measles and Immunosuppression—When Getting Well Means You Can Still Get Sick

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In 2000 measles was officially declared eliminated in the United States (1), meaning there had been no disease transmission for over 12 months. Unfortunately it was not gone for good. So far in 2024 there have been 8 outbreaks and 131 cases. Ninety of these case (69%) are associated with an outbreak and seventy (53%) have resulted in hospitalization (as of May 2, 2024; 2).  

Help in Limiting a Dangerous Childhood Disease

Before the development of a vaccine in the 1960s, measles was practically a childhood rite of passage. This common childhood disease is not without teeth however. One out of every 20 children with measles develops pneumonia, 1 out of every 1,000 develops encephalitis (swelling of the brain), and 1 to 3 of every 1,000 dies from respiratory and neurological complications (3). Between the years of 1958 and 1962, the US averaged 503,282 reported cases of measles (4). The first measles vaccine was licensed in the U.S. by John Enders in 1963, and not surprisingly, after the measles vaccine became widely used, the number of cases of measles plummeted. By 1970, there were under 1,000 cases (2).

Decreased Childhood Mortality from Other Infectious Diseases—An Unexpected Benefit

What was surprising was that with the disappearance of this childhood disease, the number of childhood deaths from all infectious diseases dropped dramatically. As vaccination programs were instituted in England and parts of Europe, the same phenomenon was observed. Reduction or elimination of measles-related illness and death alone can’t explain the size of the decrease in childhood mortality. Although measles infection is associated with suppression of the immune system that will make the host vulnerable to other infections, these side effects were assumed to be short lived. In reality, the drop in mortality from infectious diseases following vaccination for measles lasted for years, not months (5).

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Discovery of Protein Involved in TDP-43 Cytoplasmic Re-Localization Points to Potential Gene Therapy for ALS and FTD

A mouse stands on test tubes next to graphic of DNA double helix.

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are fatal and rapidly progress as neurodegenerative diseases. While inherited mutations can cause both conditions, they mostly appear sporadically in individuals without a known family history. Despite affecting different neurons, both diseases share a common hallmark: the pathogenic buildup of abnormal nuclear TAR-binding protein 43 (TDP-43) in the cytoplasm of affected motor neuron cells. Current theories propose that this cytoplasmic re-localization triggers toxic phosphorylation and fragmentation of TDP-43. Concurrently, a decrease of TDP-43 in the nucleus diminishes TDP-43-related physiological nuclear functions, contributing to the diseases’ progression (1).

Although this cytoplasmic accumulation of TDP-43 plays a significant role in the pathogenesis of ALS and FTD, the cellular mechanisms involved in the re-localization of TDP-43 to the cytoplasm is not known (2). A team of Australian neuroscientists led by Dr. Lars Ittner believe that they have found part of the answer for sporadic forms of the diseases. They identified novel interactions between pathogenic or dysfunctional forms of TDP-43 and the 14.3.3ɵ isoform of the cytoplasmic protein 14-3-3. By targeting this interaction with an AAV-based gene therapy vector, they were able to block and even partially reverse neurodegeneration in ALS/FTD mouse models.  

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Dynein Motor Proteins Could Be the Moving Power Behind Cancer Metastasis

3D Cancer Cell

“The cancer has spread.” are perhaps some of the most frightening words for anyone touched by cancer. It means that cancer cells have migrated away from the primary tumor, invaded health tissues and firmed secondary tumors. Called metastasis, this event is the deadliest feature of any type of cancer (1). The cellular mechanisms that play a role in metastasis could serve as powerful therapeutic targets. Unfortunately, understanding of these mechanisms is limited. However, some studies have suggested a link between the dysregulation of microtubule motors and cancer progression. A new study by a team from Penn State has revealed that the motor protein dynein plays a pivotal role in the movement of metastatic breast cancer cells through two model systems simulating soft tissues (1).

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Cyanobacteria Identified as Cause of Elephant Mass Mortality Event

The largest contiguous population of elephants in Africa lives in the Kavango-Zambezi Trans Frontier Conservation Area (KAZA TFCA) which encompasses parts of Botswana Zimbabwe, Zambia, Angola and Namibia. Within KAZA, nearly 90% of the elephant population is concentrated in Botswana (58%) and Zimbabwe (29%). In June of 2020, over 300 elephants were found dead in Botswana under mysterious circumstances. Less than two months later—in a span of only 27 days—34 more elephant deaths were reported in neighboring Zimbabwe. The news of these mass mortality events was both notable and concerning given the importance of the KAZA elephant metapopulation to species conservation.

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Uncovering the Neuroscience of Imagination Using a Virtual Reality World for Rats

Imagination is often considered a uniquely human trait. Simply put, it is what allows us to think about things that aren’t happening in that moment, and it plays an integral part in our day-to-day lives. We use it when we think through our calendar for the day, consider restaurant options for dinner, or visualize the best route. It turns out this trait might not be as unique to humans as we thought. In fact, a study published in Science suggests that we might share this ability with rats (1).

Rats are the most divisive of rodents. Some people see disease-carrying scourges; some see intelligent, affectionate creatures with larger-than-life personalities; and still others simply can’t get past their bare tails and small eyes. Love them or hate them, science has shown that there is more to these creatures than meets the eye. They are intelligent, ticklish and empathetic; and the study in Science suggests, imaginative.

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