• Scientists learn about the wide variety of viroids and viroid-like entities

    green flat oblong leaf plant on close up photography
    Photo by Pixabay on Pexels.com

    To recognize and understand viroids and viroid-like covalently closed circular RNAs, a team of researchers from the National Library of Medicine (NLM) and partnering university research institutes have created a computer pipeline. Compared to linear RNA, this kind of single-stranded RNA forms a continuous, covalently closed circle. The journal Cell reported the findings.

    Viroids are the smallest and most basic known infectious agents. They are circular RNAs with just 250–400 nucleotides. They had been thought to solely infect plants, up until now. The lack of knowledge about the diversity of viroid and viroid-like RNAs encouraged researchers to learn more about these sub-viral agents and their potential prevalence in various environments and hosts.

    Researchers discovered 11,378 viroid-like cccRNAs spanning 4,409 species-level clusters by examining a collection of 5,131 metatranscriptomes and 1,344 plant transcriptomes. Comparing this discovery to the previously reported viroid-like elements, there was a five-fold increase.


    Researchers found that this unique family of pathogens is widespread in all sorts of habitats and hosts, similar to the more well-known RNA viruses, and is not restricted in its spread to a few plants as was initially assumed. Additionally, completely unknown viral types were discovered, and distant relatives of the human Hepatitis Delta Virus (Hepatitis D) were found, providing insight into the origin of this important human illness.

    Eugene V. Koonin, Ph.D., a co-author of the paper and a senior investigator in the Computational Biology Branch of NLM’s Intramural Research Program, stated that this work opens up new paths for researchers worldwide.  He said they are working on some follow-up investigations.


    Benjamin D. Lee et al. (2023). Mining metatranscriptomes reveals a vast world of viroid-like circular RNAs, CellDOI: 10.1016/j.cell.2022.12.039


  • The development of artificial human skin offers the path for new treatments for skin cancer

    By Juliana Casagrande Tavoloni Braga, Mariana Petaccia Macedo, Clovis Pinto, João Duprat, MariaDirlei Begnami, Giovanni Pellacani, Gisele Gargantini Rezze – (2013). “Learning Reflectance Confocal Microscopy of Melanocytic Skin Lesions through Histopathologic Transversal Sections”. PLoS ONE 8 (12): e81205. DOI:10.1371/journal.pone.0081205. ISSN 1932-6203.-“This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.”, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=87004389

    A study team from the University of Copenhagen was able to stop invasive development in a skin cancer model by utilizing artificial human skin.

    The study, which examines what exactly occurs when a cell transforms into a cancer cell, has been published in Science Signaling.

    The researchers have been investigating the so-called TGF beta pathway, one of the cell’s signaling mechanisms. This pathway, which regulates things like cell proliferation and cell division, is essential for the communication between the cell and its environment. The cell may develop into a cancer cell and invade the surrounding tissue if these systems are compromised according to Professor and Team Lead Hans Wandall from the University of Copenhagen’s Department of Cellular and Molecular Medicine.

    Your skin cells won’t just randomly begin to infiltrate the hypo-dermis and cause havoc under normal conditions. They will instead create a fresh layer of skin. However, when cancerous cells appear, the skin’s layers’ boundaries are no longer respected, and the cells begin to invade one another. This type of growth is invasive.

    In their research on the TGF beta pathway, Hans Wandall and his colleagues developed strategies for preventing invasive development, which helped to reduce the invasive growth of skin cancer.

    Drugs that can disrupt these signaling pathways are currently available, and they might be tested. In this study, they have employed several of them said Sally Dabelsteen, an associate professor and co-author of the study from the School of Dentistry.

    Dr. Zilu Ye and Professor Jesper V. Olsen from the Faculty of Health and Medical Sciences’ Novo Nordisk Foundation Center for Protein Research collaborated with Hans Wandall and Sally Dabelsteen on this project.

    Some of these medications have previously undergone testing on humans, while others are now undergoing testing in relation to several other cancers. Additionally, they might be examined especially for skin cancer.

    Human skin cells that have been genetically altered are employed as the artificial skin in this latest study. On collagen-rich subcutaneous tissue, skin cells are generated. The cells proliferate in layers as a result, exactly like the skin of a human body.

    The skin model, also known as artificial skin, enables researchers to introduce artificial genetic modifications very fast, which gives insight into the processes that promote skin growth and regeneration. This is in contrast to mouse models.

    In this method, not just skin cancer but also other skin conditions may be reproduced and their progression can be tracked.

    The researchers have overcome the potentially problematic question of whether the outcomes of experiments on mouse models can be translated to human tissue by employing fake human skin. Most of these research were conducted in the past using mice as models. Instead, because the artificial skin brings us closer to the reality of humans, the researchers can now draw the conclusion that these compounds likely are not dangerous and might be used in practice.

    The researchers’ synthetic skin is similar to the skin used to test cosmetics in the European Union, which outlawed animal testing in 2004. Hans Wandall notes that using artificial skin does not enable scientists to examine a drug’s impact on a complete organism. Since the middle of the 1980s, cosmetics businesses have employed skin models similar to the one presented here.

    The researchers may examine the effect focusing on the specific organ—the skin—and then they earn experiences with regard to how chemicals work, while they strive to discover whether it can harm the structure of the skin and the healthy skin cells.


    Zilu Ye et al. (2022). Characterization of TGF-β signaling in a human organotypic skin model reveals that loss of TGF-βRII induces invasive tissue growth, Science Signaling (2022) DOI: 10.1126/scisignal.abo2206


  • ‘Monster’ 2.7-kilogram cane toad discovered by park rangers in Australia

    An Australian park ranger holds a 2.7-kilogram cane toad that was discovered in Queensland’s Conway National Park.

    An invasive “giant” cane toad, a warty brown animal the length of a human arm and weighing 2.7 kilograms, was found in the wilds of a coastal park in Australia and subsequently killed by park rangers.

    Wildlife workers in Queensland’s Conway National Park saw the toad after being forced to stop their vehicle by a snake crossing the road.

    Last week, ranger Kylee Gray stumbled upon a cane toad and was shocked by how large and heavy it was.

    She explained that large cane toads consume a wide variety of insects, reptiles, and even small mammals.

    They removed and euthanized the animal.

    The introduction of cane toads to Queensland in 1935 to combat the cane bug had catastrophic effects on native fauna.

    The Queensland Department of Environment and Science released a statement speculating that the toad’s weight of 2.7 kilograms (almost the weight of a newborn human infant) may be a world record.

    The department has described it as a “monster,” and has suggested that it may be shown at the Queensland Museum.

    Rangers concluded it was female based on its size.

    Age is unknown; however, Gray noted that wild frogs and toads can live up to 15 years.

    Cane toads are so toxic that some of their predators have gone extinct in certain areas, and females can lay up to 30,000 eggs in a single season.



  • Carnivorous pitcher plant’s successful heterotrophic way of getting food is to eat the waste of other animals

    By Karelj – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=49667833

    Dr. Alastair Robinson, Manager Biodiversity Services at Royal Botanic Gardens Victoria, and colleagues in Western Australia, Queensland, Malaysia, and Germany have shown in a study released today in the Annals of Botany that some Nepenthes, known as the tropical pitcher plants, obtain more nitrogen and, by extension, nutrients, from mammal droppings than those that capture insects.

    Dr. Robinson claims that a small number of species of Nepenthes have adapted to eating animal waste instead of meat.

  • The United States has a shorter average pregnancy duration compared to Europe

    an expected mother rubbing holding her baby bump
    Photo by Pavel Danilyuk on Pexels.com

    In the United States, where mother and newborn mortality rates are far higher than in Europe and other developed countries, maternal health outcomes continue to worsen. Researchers from Boston University School of Public Health (BUSPH) and the Beth Israel Deaconess Medical Center (BIDMC), which is affiliated with Harvard Medical School, are leading a new study that sheds light on how hospital organizational structures and staffing within US maternity care may impact the birthing process and potentially contribute to unfavorable birth outcomes.

    The study, which was published in the journal PLOS ONE, examined the gestational age distribution and timing of home and hospital births in three high-income nations: the US, which follows a model of maternity care that mainly depends on obstetricians and clinical interventions, and England and the Netherlands, which rely mainly on midwives who offer low-intervention maternity care.

    The study demonstrates that US pregnancies, on average, are shorter than pregnancies in England and the Netherlands, and that the average length of US pregnancies continuously decreased by more than half a week between 1990 and 2020, from 39.1 weeks to 38.5 weeks. Compared to 44 percent of births in the Netherlands and 40 percent of births in England, just 23 percent of US births took place at 40 weeks or more in 2020. In all three nations, the gestational age distribution for in-home deliveries was the same.

    The researchers limited the study to hospital-based vaginal deliveries without procedures like induction or labor augmentation that might potentially change the timing. They also looked at the birth time by hour of the day for home and hospital-based vaginal births in all three nations.

    Births at home and in hospitals were placed at comparable periods of the day in England and the Netherlands, peaking between one and six in the morning.

    The timing of births in the US, however, was noticeably different between the two settings: home births peaked at the same time as home births in other nations. Conversely, hospital-based births—even those without interventions that would have changed the normal pattern of timing—most frequently took place between 8 a.m. to 5 p.m., the usual workday for clinical personnel.

    The publication is the first international study comparing gestational age and birth timing in three high-income countries utilizing big datasets; the majority of other studies have concentrated on data from specific hospitals or nations. The authors claim their findings indicate the US maternity care models might benefit from an organizational change that places less focus on active, clinical management of labor and allows the birthing process to take a natural course. This is because England and the Netherlands have better birthing outcomes than the US.

    According to Dr. Eugene Declercq, professor of community health sciences at BUSPH and research leader, this multi-country analysis demonstrates that the US is an exception in gestational age distribution and timing of low-intervention hospital deliveries.  Hospital staffing and operational strategies should more closely follow the natural patterns of birth timing and gestational age rather than attempting to make birth timing match organizational demands, according to nations with better maternity outcomes than the US.

    The study examined population-based birth data from all three nations that were publicly available and nationally representative, including information on more than 3.8 million births in the US, 156,000 births in the Netherlands in 2014, and more than 56,000 births in England between 2008 and 2010. For births that took place between 37 and 42 weeks, the researchers compared the timing of births at home and in hospitals.

    According to study senior author Dr. Neel Shah, chief medical officer of Maven Clinic and a visiting scientist at BIDMC, every system is ideally built to produce the results that it gets. The maternal health system in the US has to be designed with more consideration given to its disturbingly low outcomes. The research demonstrates that American hospitals may be built with the convenience of doctors and nurses in consideration more so than the needs of women giving birth when compared to other high-income nations.


    Declercq E, Wolterink A, Rowe R, de Jonge A, De Vries R, Nieuwenhuijze M, et al. (2023) The natural pattern of birth timing and gestational age in the U.S. compared to England, and the Netherlands. PLoS ONE 18(1): e0278856. https://doi.org/10.1371/journal.pone.0278856


  • The deep-sea eelpout Pyrolycus jaco was discovered by Scripps Oceanography researchers

    Pyrolycus jaco, a recently discovered species of eelpout, is the light purple fish in the lower left of this image. It is seen here at the Jacó Scar hydrothermal seep among mussels and tubeworms. Image credit: ROV SuBastian/Schmidt Ocean Institute.

    A new species of fish belonging to the eelpout family was found by a team of researchers led by the Scripps Institution of Oceanography at UC San Diego. It resides in the eastern Pacific Ocean off Costa Rica.

    The first fish species to be identified from the hydrothermal seep location known as Jacó Scar, which is situated on Costa Rica’s Pacific coast, is the newly discovered species named Pyrolycus jaco. The little eel-like fish, which is about 6 inches long and has a pale pink to lavender body, has been spotted nestled among tubeworms at depths of 1,750 to 1,800 meters. The study was released in the journal Zootaxa on January 19 and describes the new species.

    Ben Frable, the main author and collection manager of the Marine Vertebrate Collection at Scripps Oceanography, said that is a really intriguing and distinctive tiny fish, so we called it after the unique place and city of Jacó in Costa Rica. This finding is a remarkable illustration of how far collaborative research can go, made possible by previous expeditions and discoveries made by Scripps marine scientists over the years.

    Eelpouts are ray-finned fish that have unusual eel-shaped bodies. Some species also have mouths that appear to be “pouting,” making them easy to identify. There are about 300 species of eelpouts that have been identified, some of which may be found directly off the coast of California.

    With the discovery of Pyrolycus jaco, there are now 13 species of eelpout known to exist in the world, all of which may be found on hydrothermal vents or methane seeps, which are microbe-driven ecosystems that run on chemicals from the Earth’s crust rather than sunlight. Natural gas and other compounds come out of the seafloor as methane seeps at the same cold temperature as the water around them. A geyser-like eruption of chemical-rich water with temperatures exceeding 400°C (752°F) occurs at hydrothermal vents. Only four other eelpout species are known to live on hydrothermal vents in the Pacific Ocean, where the new species joins them.

    The Jacó Scar methane seep is a harsh area with hydrothermal vent-like features, including high temperatures up to 5.2°C (41.4°F), which is several degrees warmer than the surrounding areas in the deep sea. Pyrolycus jaco is the first eelpout species to be observed there. Due to this seemingly minor variation, Jacó Scar appears to be a sanctuary for several creatures that usually only exist at hydrothermal vents, in contrast to nearby methane seeps.

    The new species may also be clearly identified from closely related species by changes in its body size, such as a reduced head length, and in the amount of bones and sensory pores that are distributed throughout its body.

    When researchers from the University of Costa Rica and Scripps Oceanography first found the Jacó Scar site in 2009, Lisa Levin, Greg Rouse, and other scientists saw the fish for the first time. They saw many eelpouts swimming among the tubeworms while using the Human Occupied Vehicle (HOV) Alvin of the Woods Hole Oceanographic Institution. The researchers continued to investigate this distinctive ecosystem over succeeding research cruises, including the use of high-resolution video by the Schmidt Ocean Institute’s remotely operated vehicle (ROV) SuBastian in 2019. To date, they have characterized 24 new invertebrate species from Jacó Scar alone, mostly tiny worms.

    The current research was based on four eelpout specimens obtained by HOV Alvin in 2018. Three of the specimens are now on display: two are at Scripps Oceanography’s Marine Vertebrate Collection, one is at the University of Costa Rica’s Ichthyology Collection, and the fourth is in Copenhagen.

    According to Frable, the original scientific publication documenting Jacó Scar did not classify the fish to the species level because the major objective was to document the existence of this rare seep-vent ‘hybrid’ habitat. Later, in 2021, while working on a more thorough species inventory, Charlotte Seid of Scripps Oceanography requested Frable to identify the eelpout. In order to get more information on the possible species, Frable got in touch with Peter Rask Møller, a famous eelpout expert and curator at the Natural History Museum of Denmark. He identified it right away as being new and belonging to the Pyrolycus genus, which is Latin for “fire wolf.” Then Frable, Seid, and Møller collaborated with Allison Bronson, a Cal Poly Humboldt expert in CT scanning, to create a 3D digital X-ray that could be used to study the bones without damaging the specimens.

    The researchers emphasized in the Zootaxa report that this new species finding demonstrates the richness of unique biodiversity at the Costa Rican methane seeps.

    According to Seid, collection manager of the Benthic Invertebrate Collection at Scripps Oceanography, this eelpout finding is just one illustration of how exceptional this specific environment is, and by extension, other deep-sea habitats that they have not even identified yet. The researchers have been visiting various locations for years, and the Jacó Scar research site is simply one of the many things they continue to learn about. This report emphasizes the need for further deep-sea habitat exploration and conservation, as well as the technologies required to fully research them.


    FRABLE, BENJAMIN & Seid, Charlotte & BRONSON, ALLISON & Moller, Peter. (2023). A new deep-sea eelpout of the genus Pyrolycus (Teleostei: Zoarcidae) associated with a hydrothermal seep on the Pacific margin of Costa Rica. Zootaxa. 5230. 79-89. 10.11646/zootaxa.5230.1.5.


  • The gut and mouth microbiomes and how they are passed from person to person

    Image by Arek Socha from Pixabay

    Human health can greatly benefit from the microbiome’s presence. It’s crucial to the proper functioning of several bodily systems, including the digestive and immune ones. However, our understanding of the acquisition and transmission of the bacteria and other microorganisms that make up the microbiome is quite limited.

    Nicola Segata and colleagues from the Department of Cellular, Computational, and Integrative Biology at the University of Trento and the European Institute of Oncology conducted a global study on the acquisition of health-associated bacteria that aimed to clarify this problem. The study, the results of which appeared in Nature, featured researchers from eighteen different universities in different parts of the world. Mireia Valles-Colomer, a postdoctoral researcher at the UniTrento’s Segata Lab, is the work’s primary author.

    As far as studies on the spread of human microbes go, this one easily tops them all in terms of size and variety. Researchers studied the ways in which bacteria may be passed down via generations (vertical transmission) and in close social relationships such as between spouses or friends (horizontal transmission). Over the course of 20 countries and across all continents, researchers evaluated over 9,000 samples of stool and saliva.

    The study first verified the long-lasting and initial transfer of the gut microbiota at birth. There is evidence that bacteria carried over from the mother’s microbiome can be found in the bodies of the elderly. However, many typical adult bacterial species are absent in babies, leading investigators to believe that humans acquire these bacteria later in life. The research demonstrated that humans pick up bacteria via their social connections, such as those between romantic partners, those who share a home, and those who regularly spend time together.

    The study’s authors also found that the transmission of the mouth microbiome differs significantly from that of the gut microbiome. In fact, the bacteria found in saliva are spread far more often, especially through horizontal contact. There is only a small chance of bacteria being passed on from mother to child during birth, but the longer two individuals stay close together, the more likely it is that they will transfer bacteria.

    After studying the transmission of over 800 different types of bacteria, Mireia Valles-Colomer concluded that depending on the lifestyle and relationship dynamics, they discovered evidence of widespread sharing of gut and mouth microbiome. The findings point to the fact that social interactions do influence the make-up of our microbiomes. Furthermore, researchers have discovered that certain bacteria, particularly those that survive better outside of the human body, are transferred far more frequently than others. Some of these bacteria are so new that scientists don’t even know what they’re called. Since researchers still don’t know a lot about the microbiome’s transmission mechanisms and how it impacts human health, this creates motivation to explore them more thoroughly.

    Nicola Segata stated that as adults, the majority of the microbiome we carry comes from the persons we spend the most time with. There is a rough correlation between the number of bacteria shared and the length of time people spend together, such as when roommates or romantic partners share living quarters.

    Bacteria can spread even with short, casual encounters. Segata added that since various non-communicable illnesses (such as cardiovascular diseases, diabetes, or cancer) are partly connected to an altered composition of the microbiome, the transmission of the microbiome has important consequences for human health.  Showing that the human microbiome may be passed from person to person raises the possibility that some diseases previously thought to be non-communicable may, in fact, be contagious. More research into the microbiome’s contagious nature will help us better understand the variables that put us at risk for certain diseases and may one day lead to the development of medicines that might reduce those risks.


    Valles-Colomer, M., Blanco-Míguez, A., Manghi, P. et al. The person-to-person transmission landscape of the gut and oral microbiomes. Nature (2023). https://doi.org/10.1038/s41586-022-05620-1


  • Many frog species are affected by a deadly pathogen, but the effects vary by species

    closeup photo of blue frog on green surface
    Photo by Thierry Fillieul on Pexels.com

    A new study conducted by scientists at Western Sydney University examines a deadly fungal infection that is causing significant biological disturbance for frogs and evaluates how reactions vary across species.

    The study, which was published in Functional Ecology, analyzed the chytrid fungal infection, which is responsible for the decline of at least 501 amphibian species and is often regarded as the most devastating single disease on biodiversity.

    Dr. Nicholas Wu of the University of Hawkesbury’s Institute for the Environment, who authored the paper, claims that chytridiomycosis is responsible for the biggest loss of biodiversity due to a single illness; however, it is unknown if frogs infected with this fungus show the same symptoms.

    According to Dr. Wu, using a meta-analytic method, the study demonstrated there are significant similarities in symptoms across frog species that offer a clearer understanding of the cause of the disease and, thus, mortality.

    For the sake of conservation, it is possible to rely on these symptoms to predict how frogs that have not been exposed to chytrid could espond if they become infected. Swabbing a wild frog that appears ill and then determining the pathogen load allows researchers to make judgments about the frog’s condition in lieu of any direct experimental testing.

    According to the results, hosts may only experience skin disturbance and changes in immune response at low pathogen load, but at high pathogen load, they will undergo changes in reproduction and body condition.

    Dr. Wu noted that meta-analytic techniques might be a beneficial tool for better understanding disease dynamics in an ecological setting, especially in context of the increasing number of emerging infectious illnesses.

    Emerging infectious diseases are a major factor in the decreasing trend of animal and plant species across the planet. There are a lot of things in the environment and there are variances between the host and the pathogen, so how species react to infectious diseases is all over the place.

    Understanding the similarities in trait sensitivity can provide light on the effects of illness and aid in wildlife management. Different ‘traits’ associated to an animal’s fitness, such as physical condition, reproduction, or metabolic rate, may be more susceptible to pathogen load.


    Nicholas C. Wu, Pathogen load predicts host functional disruption: A meta‐analysis of an amphibian fungal panzootic, Functional Ecology (2023). DOI: 10.1111/1365-2435.14245


  • An updated taxonomy and description of a new species of the New Zealand gecko genus Hoplodactylus

    Scientists from the University of Otago have described a new species of New Zealand gecko by utilizing a new method to analyze ancient DNA.

    This unique species, once known as Duvaucel’s gecko, is now recognized in te reo Māori language as te mokomoko a Tohu. Its 600 or so mature individuals are restricted to the islands of Ngwhatu-kai-ponu (Brothers) and Kuru Pongi (Trios) in Cook Strait (Hoplodactylus tohu).

    Researcher Lachie Scarsbrook, who directed the study at the University of Otago’s Department of Zoology, says that while these geckos and the Duvaucel’s gecko found on islands off the northeastern coast of North Island were once thought to be the same species, scientists have known for a long time that there are differences between these southern and northern lineages.

    According to Mr. Scarsbrook, the geckos of the Brothers and Trios Islands are smaller, have distinct colors and patterns on their bodies, and exhibit unique genetic markers, all of which are essential to designate a new species.

    The researchers didn’t know how different the mainland populations of the North and South Islands were until they utilized ancient DNA techniques to recreate their diversity, which had been lost to extinction. More over five million years, to be precise.

    This article, published in the journal Zootaxa, explains te mokomoko a Tohu, which was made possible by a new way of collecting genomes from small bones without damaging them in the process.

    The two tiny populations on the Brothers and Trios Islands, as well as those recently translocated to Mana Island, are currently the only known examples of Hoplodactylus tohu, Mr. Scarsbrook explains.

    Because of this, the IUCN Red List has reclassified both the Duvaucel’s gecko and the te mokomoko a Tohu as critically endangered.

    Although these islands have served as a refuge from certain rodents and other invasive predators for ages, the consequences of climate change and the incursion of predators pose serious threats to the continued existence of te mokomoko a Tohu.

    Dr. Sharon Barcello-Gemmel, Rangatira of Te Ātiawa o Te Waka-a-Māui Trust, the iwi with mana whenua over the Ngāwhatu-kai-ponu Islands, generously suggested the species epithet tohu.

    Her tupuna, Hone Kākahi, also known as Tohu Kākahi, was a pioneering pacifist whose efforts in the decades before the invasion of Parihaka are honored by her name.

    Tohu was captured and then made his way to Dunedin on a sea voyage that took him from Whakatū (Nelson) via the Ngawhatu Islands and over the whole ancient and modern range of te mokomoko a Tohu.

    Mr. Scarsbrook, who is finishing up his DPhil at Oxford, adds that working with the local iwi to describe this new species has been an extensive and highly fulfilling process.

    The researchers intend to emphasize the value of iwi involvement and collaboration in science by giving this species a te reo Māori scientific and common name: te mokomoko a Tohu (Hoplodactylus tohu).

    He also noted how the process brought to light the differences between te reo Māori and the standards for scientific naming set down in the International Code of Zoological Nomenclature (ICZN).

    Taxonomy has the capacity to either prevent or expedite the extinction of a species because of the lasting impact of the scientific names given to them. The researchers want to see te mokomoko a Tohu included into the expanding discussion throughout the world about the need to loosen up taxonomic terminology.

    The researchers go on to say that more research utilizing these innovative methods is desperately needed to support evidence-based conservation management, which in turn would lead to successful kaitiaki [guardian] practices, which would ensure the survival of te mokomoko a Tohu.

    If scientists, conservationists, and Tangata Whenua don’t know what kinds of animals exist, they can’t hope to preserve them from extinction, as Mr. Scarsbrook puts it.

    Ancient DNA study on Hoplodactylus geckos has barely scraped the surface of what researchers know about gecko, skink, frog, and tuatara diversity in Aotearoa at the time of human settlement and how it has altered since then.


    Lachie Scarsbrook et al, Revision of the New Zealand gecko genus Hoplodactylus, with the description of a new species, Zootaxa (2023). DOI: 10.11646/zootaxa.5228.3.3


  • Fever following cancer treatment may be facilitated by mucus-eating gut bacteria

    Neutrophils. By Dr Graham Beards – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=20521666

    Neutropenia is the depletion of neutrophils, a type of white blood cell, which is a typical side effect of cytotoxic cancer treatments like chemotherapy and radiation. Patients with severe neutropenia often experience fever. The mucus-degrading commensal bacterium Akkermansia muciniphila was identified as the possible causative agent of this fever, according to research published on November 16 in Science Translational Medicine. The results of this study demonstrate that these microbes reduce the thickness of the mucus layer in mice, leaving the animals more susceptible to secondary bacterial infections; this finding may lead to strategies for preventing treatment-induced fevers in humans.

    Scientists have found connections between changes in gut microbiota and neutropenic fever, suggesting that infections arising in the gut can be a key source of bacterial infections in the blood. To learn more about this connection, s cientists at the University of Texas MD Anderson Cancer Center studied fecal samples from 119 patients having stem cell transplantation, a process that is followed by radiation and chemotherapy. Many patients who experienced fever during the first few days of neutropenia were shown to have a higher relative abundance of A. muciniphila and Bacteroides species in their gut. These bacteria are able to break down mucin, an important part of the mucus layer.

    Thereafter, researchers looked into whether or not mice’s microbiomes are affected by radiation therapy or chemotherapy. Finding that the mice group exposed to these radiation therapy began eating less food encouraged the researchers to undertake a third experimental part of the study, as loss of appetite is a common side effect of cancer treatments. Microbiomes of healthy mice that were not given cytotoxic cancer treatment but were placed on a calorie-restricted diet were studied in the third group. Compared to control mice, Akkermansia and Bacteroides levels increased six days after radiation or chemotherapy, or after one week on the restriction diet. Histological examinations demonstrated that along with these alterations in the composition of the microbiome, the mucus layer in the colon became noticeably thinner.

    MD Anderson researcher Jennifer Karmouch, a co-author of the study, explains that a decreased mucus layer in the intestine makes it more likely for bacteria to enter the bloodstream and cause infection. That’s why the team believes some patients spike a fever in the first place.

    Karmouch and colleagues wanted to know if they could stop Akkermansia from proliferating and stop the subsequent reduction in the thickness of the colonic mucus layer. They did this by administering one of two medications to mice. Azithromycin, an antibiotic that specifically targets Akkermansia, was given to some of the mice, while others were given propionate, a metabolite that has been observed to be deficient in the colonic lumen of calorie-restricted mice. The group also found that propionate inhibits mucin consumption by Akkermansia in an in vitro experiment.

    The mucus layer in the colons of irradiated mice was maintained by both therapies. As the FDA currently does not recommend azithromycin for cancer patients, propionate may provide some hope, as Karmouch suggests. Karmouch said that she and her team are trying to figure out how to deliver it more directly to the colon because the metabolite’s low absorbability limits its potential clinical application.

    More than half of the patients who developed a neutropenic fever had higher-than-average levels of Akkermansia in their gut microbiomes, but the study shows that Akkermansia levels alone cannot predict if a patient with neutropenia will develop fever, as some cancer patients with fevers had low Akkermansia counts. Karmouch speculates that there may be functional variations between A. muciniphila strains, and that this may affect the bacteria’s ability to thin mucus.

    There could be other factors to take into account, though. The work demonstrates a really fascinating link, says Ami Bhatt, a microbiome scientist at Stanford University. However, she adds, it does not prove that Akkermansia is essential or sufficient for the thinning of the mucus, and other mucin-degrading organisms can occupy that niche.  While Bhatt did not contribute to this study, she is on the scientific advisory board of Cantata Bio, a startup focused on infectious diseases, and has worked with one of the coauthors in the past.

    Nevertheless, as Bhatt notes, this study adds to the growing body of evidence that the gut microbiota affects the possibility of potential pathobionts making it into the blood system and causing illnesses.


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