A stealth fungus has decimated North American bats but scientists may be a step closer to treating white-nose syndrome
Creationism's malevolent designer seems to be in two minds about bats.
On the one hand it gives them a super-duper immune system that means they can harbour viruses like the corona viruses, one of which became SARS-CoV-2 that caused COVID-19; on the other hand, it designs a nasty fungus that is currently decimating populations of bat in North America, against which even their super-duper, intelligently [sic] designed immune system is ineffective.
The fungus, known to science as Pseudogymnoascus destructans, which causes the disease known as white-nose syndrome, is an invasive organism that uses various strategies to invade the skin of hibernating bats with deadly consequences. It was first detected in a New York cave in 2006.
Tell me all about the fungus Pseudogymnoascus destructans, its origins and its effect on hibernating bats, please. Pseudogymnoascus destructans: Overview and OriginsNow two scientists at the University of Wisconsin-Madison have worked out how the fungus evades the bats' immune system, which was supposedly intelligently [sic] designed to protect the bat from organisms such as fungi that the same designer intelligently [sic] designed to harm them.
Pseudogymnoascus destructans (formerly known as Geomyces destructans) is a psychrophilic (cold-loving) fungus that causes a devastating disease known as White-nose Syndrome (WNS) in hibernating bats. This fungus thrives in cold and humid environments, typical of the caves and mines where bats hibernate.
Origins
- Discovery: P. destructans was first identified in North America in 2006, although it was later determined to be an invasive species from Europe or Asia, where bats have co-evolved with the fungus and exhibit some resistance.
- Spread: The exact mechanism of its introduction to North America is unknown, but it is speculated that it could have been transported by humans, possibly via contaminated clothing or equipment used in caves.
White-nose Syndrome (WNS)
White-nose Syndrome is named for the characteristic white fungal growth observed on the muzzles, ears, and wings of affected bats. The disease has a profound impact on bat populations, particularly in North America.
Symptoms and Pathology
- Physical Symptoms: Bats with WNS exhibit white fungal growth, tissue damage, and severe wing degradation.
- Behavioral Changes: Infected bats display unusual behavior, such as flying outside during the day in winter, when they should be hibernating.
- Physiological Effects: The fungus invades and disrupts the bat's skin, particularly the wings, which are crucial for maintaining water balance, temperature regulation, and flight. This leads to dehydration, electrolyte imbalance, and ultimately, starvation as bats wake frequently during hibernation, depleting their fat reserves.
Impact on Bat Populations
The impact of P. destructans on hibernating bat populations is profound and multifaceted:
- Mortality Rates: WNS has led to mortality rates exceeding 90% in some bat colonies. Species such as the little brown bat (Myotis lucifugus), the northern long-eared bat (Myotis septentrionalis), and the tricolored bat (Perimyotis subflavus) have been particularly affected.
- Ecological Consequences: Bats play a crucial role in ecosystems as insect predators. The decline in bat populations due to WNS has potential ripple effects on insect populations and agricultural pest control.
Geographic Spread
Since its discovery in New York in 2006, WNS has spread rapidly across the United States and Canada. The fungus has been confirmed in numerous states and provinces, with the disease continuing to expand its range.
Research and Conservation Efforts
Researchers are actively studying P. destructans and WNS to understand the fungus’s biology, the disease’s progression, and potential mitigation strategies:
- Surveillance and Monitoring: Ongoing efforts to monitor bat populations and the spread of WNS are critical for managing the disease.
- Conservation Strategies: Efforts include habitat protection, captive breeding programs, and public education to minimize human spread of the fungus.
- Treatment and Mitigation: Scientists are exploring potential treatments, such as antifungal agents and probiotics, to protect bats. Additionally, managing hibernacula environments to reduce fungal growth is being investigated.
Conclusion
Pseudogymnoascus destructans and the associated White-nose Syndrome represent a significant threat to hibernating bat populations, particularly in North America. Understanding the origins, pathology, and impact of this fungus is crucial for developing effective conservation strategies to protect these vital creatures and the ecological roles they fulfill.
The fungus's secret, which should thrill devotees of creationism's putative divine malevolence with its sheer malevolent brilliance, is that it thrives in cold conditions so is able to infect the surface layer of skin cells while the bat is hibernating, during which its body temperature drops to a little above the ambient temperature in the cave. The fungal spores also have a coating of melanin, which means they avoid detection by the immune system.
But, even if the bat's first line of defence detects the spores inside the skin cells, the normal response, where the cell self-destructs to expose the infection to cells of the immune system, is inhibited by the spores, which then survive periods of arousal when the bat's body temperature rises and the immune system would normally be more effective. They can then germinate and invade deeper layers of tissues when the bat hibernates again.
The scientists' findings are the subject of a paper in Science and of a news release from the University of Wisconsin-Madison:
A stealth fungus has decimated North American bats but scientists may be a step closer to treating white-nose syndrome
An invasive fungus that colonizes the skin of hibernating bats with deadly consequences is a stealthy invader that uses multiple strategies to slip into the small mammals’ skin cells and quietly manipulate them to aid its own survival. The fungus, which causes the disease white-nose syndrome, has devastated several North American species over the last 18 years.
Scientists have learned much about the fungus, Pseudogymnoascus destructans, since it was first documented in a New York cave in 2006, including where it thrives, its distribution, and clinical features. But exactly how the fungus initiates its infection has remained a “black box — a big mystery,” says Bruce Klein, a professor of pediatrics, medicine and medical microbiology and immunology at the University of Wisconsin–Madison.
That dearth of understanding has made it challenging to develop countermeasures to treat or prevent infections.
Now, Klein and Marcos Isidoro-Ayza, a PhD candidate at Klein’s lab, have for the first time been able to study in detail how the fungus gains entry and covertly hijacks cells called keratinocytes at the surface of bats’ skin.
The feat is detailed in the July 12, 2024, issue of Science.
The researchers found that P. destructans uses infected cells as a refuge and prevents the cells from dying, which in turn thwarts the bats’ immune system and allows the microbial invader to continue growing and slip into more cells.
To do so, Klein and Isidoro-Ayza created the first-ever keratinocyte cell line from the skin of a little brown bat. Further, they successfully mimicked the conditions of hibernation, which are marked by wide body temperature fluctuations that accompany periods of torpor — when the animals’ metabolism slows and body temperature drops — and arousal.
This is crucial to understanding P. destructans infections because the cold-loving fungus gains its foothold during the chilly conditions of torpor and is able to persist during arousal, when the bats’ body temperature increases.
Klein and Isidoro-Ayza have already identified how the fungus gains its stealth entry into cells: by co-opting a protein on their surface called epidermal growth factor receptor, or EGFR. Mutations in the same receptor in human cells drive certain lung cancers and these cancers are treated with an existing drug called gefitinib, opening the possibility it could be used to treat or prevent white-nose syndrome.
Remarkably, when we inhibited the receptor with this drug, we stopped the infection. This is an FDA-approved drug that could potentially be used in the future for the treatment of susceptible bat species.
Marcos Isidoro-Ayza, first-author.
Department of Pediatrics, Medicine and Medical Microbiology and Immunology
School of Medicine and Public Health
University of Wisconsin–Madison, Madison, WI, USA.
While EGFR’s precise role in infection is not yet completely clear, Klein and Isidoro-Ayza have learned much about how the fungus works.
Its initial entry occurs during torpor, when bats’ immune systems are dormant and their body temperature is in an ideal range for P. destructans to germinate and grow. During torpor, the fungus penetrates bats’ skin cells with its hyphae — slender filaments through which it grows and gathers nutrients — without breaking the cells’ membranes. Doing so would trigger the cells’ death and expose the fungus to the bats’ immune system.
Klein and Isidoro-Ayza also found that the fungus employs multiple strategies that allow it to continue its invasion during periods of arousal, despite the bats’ higher body temperatures and reactivated immune system.
First, during arousal periods, the fungus manipulates the cells so they engulf the fungus in a process known as endocytosis, rather than the fungus using its hyphae to penetrate the cell.
Second, they found that the fungus spores — microscopic particles by which it reproduces — are coated in a layer of melanin that protects them from the cells’ strategies for killing invading microbes.
P. destructans' final infection strategy is to block apoptosis, also known as programmed cell death, which is a defense mechanism cells use to expose pathogens so immune cells can root them out and destroy them.That allows the spore to survive that period of arousal, and when the bat goes back into torpor, the spores inside of its cells start germinating again and keep colonizing the skin. By not killing the cells, the fungus can linger in the tissue and go into deeper layers of the skin
Marcos Isidoro-Ayza.
With this new knowledge in hand, the researchers are hopeful that treatments and a potential vaccine are closer to becoming reality.
These findings are just one product of a collaboration between Klein and Isidoro-Ayza and scientists at the U.S. Fish and Wildlife Service and U.S. Geological Survey’s National Wildlife Health Center in Madison. The effort received $2 million in funding from the National Science Foundation and Paul G. Allen Family Foundation in 2023 to search for better insight into how P. destructans causes infection and develop treatment and prevention strategies against white-nose syndrome.
The research is valuable not only for the conservation of bats, which provide a number of benefits including as pollinators and insect predators, but because fungal pathogens are a growing problem for many species.
There are fungal diseases causing epidemics and pandemics in different types of organisms, including plants, invertebrate animals, amphibians, reptiles and bats, so, any mechanism that we discover or better understand in this disease could have implications for the conservation of other species too.
Marcos Isidoro-Ayza.
AbstractThe evolutionary explanation for this fungus is quite easy to see. The environment of the body of a hibernating bat for a fungus which had evolved to survive in cold caves and feed off organic matter is plain to see. All that was needed to make it even more successful was a mechanism for evading the bat's immune system and this was provided by a melanin-coated spore and a way of inhibiting cell apoptosis. A few chance mutations each gave the fungus an advantage over that which went before, and the organism was able to exploit the new niche the hibernating bats presented.
Millions of hibernating bats across North America have died from white-nose syndrome (WNS), an emerging disease caused by a psychrophilic (cold-loving) fungus, Pseudogymnoascus destructans, that invades their skin. Mechanisms of P. destructans invasion of bat epidermis remain obscure. Guided by our in vivo observations, we modeled hibernation with a newly generated little brown bat (Myotis lucifugus) keratinocyte cell line. We uncovered the stealth intracellular lifestyle of P. destructans, which inhibits apoptosis of keratinocytes and spreads through the cells by two epidermal growth factor receptor (EGFR)–dependent mechanisms: active penetration during torpor and induced endocytosis during arousal. Melanin of endocytosed P. destructans blocks endolysosomal maturation, facilitating P. destructans survival and germination after return to torpor. Blockade of EGFR aborts P. destructans entry into keratinocytes.
Marcos Isidoro-Ayza, Bruce S. Klein
Pathogenic strategies of Pseudogymnoascus destructans during torpor and arousal of hibernating bats. Science 385, 194-200 (2024). DOI:10.1126/science.adn5606
© 2024 The Authors
Published by American Association for the Advancement of Science.
Reprinted with kind permission under License #5827590907811.
What isn't easy to see is why a supposedly omnibenevolent god goes to such extremes to increase the suffering in the world and why, in this particular case, having designed a better immune system for bats than the one it gave to most other animals, it should then design something that ingeniously evades it, unless it just enjoys watching its creation suffer.
And yet creationists still manage to fool themselves into believing the notion of intelligent design is rational science.
The Unintelligent Designer: Refuting The Intelligent Design Hoax
The Malevolent Designer: Why Nature's God is Not Good
Illustrated by Catherine Webber-Hounslow.
The creator is unable to make up its mind and gave Bats a superior immune system and yet it has also chosen to afflict Bats with this fungus. Yes its contradictory and doesn't make sense. Its having an arms race with itself. The only way that this contradiction can make sense if this is the work of one and the same being, is if this being has a split personality. As I said before, this being has a Jekyll and Hyde personality, and He doesn't need a chemical potion to turn into Mr. Hyde
ReplyDeleteAs the Bible says God kills and makes alive, He hurts and He heals, He makes peace and creates evil, calamity, catastrophe, disaster, woe, depending on which Biblical translation is used. The great philosopher Karl Jung stated that the Bible God is both good and evil, and that evil should be integrated to God's attributes. Read Karl Jung on the book of Job.Karl Jung is a lot wiser than any of these Fundamentalists and Creationists. Dr. Jekyll and Mr. Hyde the novel appeared in 1886, but God as Dr. Jekyll and Mr. Hyde is the original, primeval Dr. Jekyll and Mr. Hyde.