Lots of microbes in this week’s Sunday Science: with new cures for Ebola, a “missing link” species, Lyme disease and the germ-free placenta. Also: giant frogs, robot cockroaches, why cats eat grass and how infidelity is linked to professional misconduct…

Where does the world’s largest frog rear its young? Most frogs just lay their eggs wherever is convenient. The Goliath frog, however, which clocks in at over 30 cm and 3.3 kg, actually appears to dig out its own nursery pools alongside riverbanks, which feat of strength may explain its large size. Not only that, but the adult frogs were observed guarding their tadpoles from predators. Original study here (open access).

Lyme disease, which is carried by parasitic ticks, may be three times more common in the UK than previously thought. Scientists estimate that diagnosed cases could top 8000 this year, compared to around 2000-3000 in previous years. Part of this is probably due to improved awareness amongst both the general public and the medical profession. I actually got this myself last summer – fortunately I got the characteristic bullseye rash and a swift course of antibiotics took care of the problem. However, it can cause very serious symptoms if left untreated, and not everybody gets the classic rash. There are calls to cull the booming population of deer, who carry the ticks, but they become immune to the disease so this may not be that effective. Global heating leading to warmer winters that do not kill off so many ticks is probably driving the increase in their numbers. Original study here (open access).

Some good news in the fight against a far more deadly disease – Ebola. People from people of the Democratic Republic of Congo have been suffering an outbreak for more than a year. This virus infection causes a haemorrhagic fever and has an extremely high mortality rate – two thirds of all people infected in the current outbreak have died. However, two new drugs have been shown to dramatically reduce the mortality rate in clinical trials that were so successful they were stopped early so that the drugs can be rolled out to treat patients now. The drugs are monoclonal antibodies; one derived from an Ebola survivor and another from experimental mice. An experimental vaccine has also been shown to reduce mortality, but not infection.

In a gargantuan effort, scientists have for the first time managed to isolate and grow a “missing link” microbe from deep-sea mud (it took them 12 years, to give you an idea…), imaged under the electron microscope. It’s actually two distinct species living closely together as symbionts and belongs to the Archaea, a group of single-celled organisms that superficially look like bacteria but are their own distinct domain of life. They were found on the seafloor at a deep-sea hydrothermal vent between Greenland and Norway called Loki’s castle. It’s particularly interesting because it contains many genes that belong to eukaryotes, the domain which contains all multicellular life. The study is not yet fully published but has generated a lot of excitement and can be found in pre-print version here.

There’s been increasing interest in the human microbiome, the microorganisms that naturally live in and on us, without doing any harm (and, indeed, in many cases, are essential for our healthy living). Most obviously, the billions of bacteria living in our gut help us access nutrients in our food and prevent colonisation by disease-causing bacteria. It was always thought, however, that the environment the fetus develops in is sterile, and that babies become colonised by microbes initially as they travel through the birth canal, and then by the outside world. Recently, there have been some studies suggesting the presence of a microbiome in the placenta, which seemed an utterly radical idea – one of the major functions of the placenta is to prevent microbes infecting the developing baby. But some studies found microbes in the placenta. It now seems that those were the result of contamination, or disease. A new and very rigorous, comprehensive study has now concluded (I think fairly reliably) that the placenta is microbe-free. The researchers were very rigorous about their controls – which enabled them to pinpoint a few examples of contamination. What I found eye-opening, as a former researcher, was that they found that so-called “sterile” DNA extraction kits were contaminated with microbes, and, in fact they “identified company-specific communities of bacteria from the genetic material extracted from the blank control samples.” [Italics mine]. Something to bear in mind for anyone relying on DNA extraction kits to test for the presence/absence of certain bacterial species! Original placenta study here (paywalled).

Researchers have developed a new “soft robot” that is also incredibly robust: the tiny thing can carry many times it’s own weight, scurry along rapidly, and even survive being stepped on. If it sounds like a cockroach, well, I have to tell you, it looks like one too. Original study here (paywalled) and snippet of the roboroach (please please call it that for real) here:

Europe has enough untapped onshore wind power potential to fulfil the entire global energy demands until 2050, according to a new study. This is even excluding the 54% of the land area surveyed that isn’t available for various reasons. Staggering, isn’t it? I had no idea there was that much potential capacity. Now, this would mean installing about another 11 million turbines (!) so that clearly isn’t going to happen, nor would we want it to – indeed this isn’t the aim of the study – but as an exercise in potential it’s very interesting, particularly as onshore wind is currently a cheap and mature renewable energy source. This is only onshore wind too – offshore capacity isn’t considered. So if we want to transition to a completely green energy supply across Europe (and, indeed, the globe), then with combined wind, solar and other renewables it’s not the insurmountable task it might at first seem. Original study here (paywalled).

If you’re a cat owner (or perhaps more accurately, servant) you may wonder why your cat eats grass – particularly as they often then vomit it back up. There’s lots of ideas why, but now it appears the mystery has finally been solved – because it helps expel intestinal parasites, or at least did so in a distant ancestor. Note however that they did not test the other common theory – that it helps cats expel hairballs.

And finally…as perhaps many of us suspected, people who are unfaithful to their partners are more likely to behave badly at work as well. I confess I didn’t go through this study in detail, which analysed groups of professionals who used the infamous Ashley Madison website, and linked them to various cases of professional misconduct, including complaints against police officers and financial misconduct for executives. Still, if you didn’t already have ample good reasons to believe the current Prime Minister of the United Kingdom and President of the United States can’t be trusted, you do now! Full study here (open access).


Featured image

Where the Loki Archaeota were discovered: on the seabed at the Mid-Atlantic Ridge near the hydrothermal vents Loki’s Castle.

CREDIT: Centre for Geobiology, Bergen, Norway, by R.B. Pedersen

Derived from here: https://www.eurekalert.org/multimedia/pub/91426.php


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