Nav: Home

Dermal disruption: Amphibian skin bacteria is more diverse in cold, variable environments

February 21, 2019

Amphibians are victims of lethal skin-disease epidemics. In the first global-scale study, researchers from 31 universities and research centers, including the Smithsonian Tropical Research Institute (STRI), collected skin bacteria from more than 2,300 healthy frogs and salamanders from 12 countries to describe microbes on a wide range of host animals to improve knowledge of the distribution of frog-skin bacteria, known to be important in maintaining amphibian health.

Based on samples of 205 different species of amphibians, the team concluded that an animal's environment, especially the temperature, plays a big role in which bacteria live on its skin. Their most striking result, published in Nature Ecology and Evolution, was that amphibian skin microbes are more diverse in areas with cold winters and variable temperatures. This was unexpected because most animals and plants are more diverse in the tropics.

"Finding higher overall diversity of these skin bacteria in temperate areas was a surprise, and then it became our task to explain why," said Jordan Kueneman, a STRI postdoctoral research fellow who led the study.

The study was the culmination of many projects; several big research teams that focus on amphibian decline in the U.S., Germany, Panama and Madagascar joined groups spanning the continents to collect samples and interpret the results. "Our intention was to unify people from different disciplines around a common problem, so that we could share data and ideas, to explore new questions and solve new problems as they arise," Kueneman said.

Previous studies showed that there were some rules of thumb about free living bacteria in different places across the globe, and the team wondered if there were similar rules about bacteria on the skin of a host animal. They also wondered about interactions between amphibian genes and the bacteria living on their skin and whether predicted gene function changes from place to place.

They found that fast-growing bacteria may take over in warm climates, driving diversity down. However, in more variable environments, such as temperate climates, different kinds of bacteria could be favored during different annual temperature regimes. For example, bacteria that can survive cold in a dormant state could remain on the amphibians, which could help explain the higher microbial diversity observed in these environments. Higher dormancy gene abundance was observed on amphibians in more variable climates.

Because the American bullfrog (Lithobates catesbeianus) lives around the globe, they sampled it at different sites to better understand the effects of the environment on a single host. This is uniquely possible with this species due to novel introductions, linked with frog leg consumption. "Unfortunately, this species is also a tolerant reservoir and amplifier for frog fungal disease," Kueneman said.

Their work is leading to an understanding of the role of microbes in amphibian health and to insights for the use of beneficial microbes to promote frog recovery and prevent disease epidemics in the field. This study highlights the way a team of scientists from different fields can come together to study frog skin ecology, which may inform probiotic treatments for sick amphibians and bioaugmentation methods, introducing specific bacteria with the intention of influencing the living system to improve frog health in the future.

With funds from the Simons Foundation, Kueneman is working broadly on terrestrial tropical microbiology. He says that it is imperative to build robust datasets including tropical microbes to better understand their role in host health, host adaptation, co-evolution and biogeography of animals, plants and their symbionts. Passionate about his work, he emphasizes the potential to use beneficial microbes to solve environmental problems and to promote health and wellbeing of humans, animals and plants.
-end-
Kueneman, J.G., Bletz, M.C., McKenzie, V.J. et al. 2019. Community richness of amphibian skin bacteria correlates with bioclimate at the global scale. Nature Ecology and Evolution, https://doi.org/10.1038/s41559-019-0798-1

Smithsonian Tropical Research Institute

Related Bacteria Articles:

Conducting shell for bacteria
Under anaerobic conditions, certain bacteria can produce electricity. This behavior can be exploited in microbial fuel cells, with a special focus on wastewater treatment schemes.
Controlling bacteria's necessary evil
Until now, scientists have only had a murky understanding of how these relationships arise.
Bacteria take a deadly risk to survive
Bacteria need mutations -- changes in their DNA code -- to survive under difficult circumstances.
How bacteria hunt other bacteria
A bacterial species that hunts other bacteria has attracted interest as a potential antibiotic, but exactly how this predator tracks down its prey has not been clear.
Chlamydia: How bacteria take over control
To survive in human cells, chlamydiae have a lot of tricks in store.
Stress may protect -- at least in bacteria
Antibiotics harm bacteria and stress them. Trimethoprim, an antibiotic, inhibits the growth of the bacterium Escherichia coli and induces a stress response.
'Pulling' bacteria out of blood
Magnets instead of antibiotics could provide a possible new treatment method for blood infection.
New findings detail how beneficial bacteria in the nose suppress pathogenic bacteria
Staphylococcus aureus is a common colonizer of the human body.
Understanding your bacteria
New insight into bacterial cell division could lead to advancements in the fight against harmful bacteria.
Bacteria are individualists
Cells respond differently to lack of nutrients.

Related Bacteria Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Changing The World
What does it take to change the world for the better? This hour, TED speakers explore ideas on activism—what motivates it, why it matters, and how each of us can make a difference. Guests include civil rights activist Ruby Sales, labor leader and civil rights activist Dolores Huerta, author Jeremy Heimans, "craftivist" Sarah Corbett, and designer and futurist Angela Oguntala.
Now Playing: Science for the People

#520 A Closer Look at Objectivism
This week we broach the topic of Objectivism. We'll be speaking with Keith Lockitch, senior fellow at the Ayn Rand Institute, about the philosophy of Objectivism as it's taught through Ayn Rand's writings. Then we'll speak with Denise Cummins, cognitive scientist, author and fellow at the Association for Psychological Science, about the impact of Objectivist ideology on society. Related links: This is what happens when you take Ayn Rand seriously Another Critic Who Doesn’t Care What Rand Thought or Why She Thought It, Only That She’s Wrong Quote is from "A Companion to Ayn Rand"