Science news digest – 12th March 2013
In the science news this week, superbugs may prove major health risk, possible new bacteria group found in Antarctic lake, scientists grow a tooth from scratch, and finally… earthquake detected by satellite orbiting the Earth.
New wave of superbugs pose major threat, warns chief medical officer
Bacteria that are resistant to current antibiotics pose a “catastrophic threat” to the population, warned the chief medical officer for Britain in a report published this week.
If the use of antibiotics are not tightly regulated and no new ones are discovered, “we will find ourselves in a health system not dissimilar to the early 19th century at some point”, warned Dame Sally Davies.
New bacterial diseases are becoming increasingly more prevalent, and although the “superbugs”, MRSA and C difficile have been reduced in hospitals, there has been an alarming increase in other types of bacteria including new strains of E coli and Klebsiella, which causes pneumonia, reported the Guardian.
These bacteria, known as gram negative bacteria, are incredibly dangerous to older and frailer people, because they are found in the gut rather than on the skin, and are highly resistant to antibiotics.
As many as 5,000 people die each year in the UK from gram negative sepsis – where the bacteria gets into the bloodstream – and in half of these cases the bacteria is resistant to antibiotics.
"Antimicrobial resistance poses a catastrophic threat," said Davies. "If we don't act now, any one of us could go into hospital in 20 years for minor surgery and die because of an ordinary infection that can't be treated by antibiotics. And routine operations like hip replacements or organ transplants could be deadly because of the risk of infection.
"That's why governments and organisations across the world, including the World Health Organisation and G8, need to take this seriously."
There has been an 85% reduction in MRSA, meaning that even in the largest hospitals there are no more than two or three cases a year.
However, there are now 50 to 100 cases of gram negative bacteria infection for every MRSA case, according to Professor Mike Sharland from St George’s hospital in London, an advisor to the Department of Health on the use of antibiotics and antivirals in young people.
"This is your own gut bugs turning on you. Between 10% and 20% are resistant to drugs. We do not yet know why they are on the rise, although some hospital procedures, such as the use of catheters, may be implicated. Many are in the very young or older population," he said.
Davies suggests that in order to tackle this problem, the Government need to add drug resistant infections to the strategic risk register making it easier to raise as an issue abroad. She calls for action across a number of government departments, in particular the Department for Environment, Food and Rural Affairs, because of the use of antibiotics in farming.
Mystery bacteria found in Antarctica’s Lake Vostok
Water samples taken from Lake Vostok contain a bacterium that doesn’t seem to belong to any known bacterial groups, reported New Scientist, but it still remains to be seen whether this a new form of life.
The lake is under 3.5 kilometres of ice and has been cut off from the rest of the world since Antarctica froze over 14 million years ago.
In February 2012, Russian scientists drilled down to the lake, but there were concerns about possible contamination because the scientists used kerosene to lubricate the borehole, which had bacteria in it.
But this seems to have been avoided. When the drill reached the lake, it automatically withdrew in response to the pressure change. The lake water rushed up into the borehole, pushing the kerosene up, and then froze.
Sergey Bulat from the Petersburg Nuclear Physics Institute in Russia and colleagues have been studying the water which froze onto the drill bit since last May. However, the samples proved to be very dirty from the kerosene, and preliminary genetic analyses showed that the bacteria were from the drilling fluid and not the lake.
Bulat has now gone back to the DNA samples, and compared their DNA sequences to a database of known contaminants. He identified short fragments of DNA that belonged to 19 different known bacterial species.
"All of them proved to be contaminants, or bacteria from human skin," says Bulat.
However, the twentieth species appears to be more unusual. The genetic samples show less that 86 per cent similarity to the known major groups of bacteria. This could mean it belongs to an entirely new division, says Bulat, although he conceded it could just be a new species.
Tooth grown from scratch using gum cells
A team at King’s College London have grown a tooth by taking cells from adult human gum tissue and combining them with another type of cell from mice, reported the BBC.
The hope is that this technique could be used to replace missing teeth simply by growing them from the patient’s gum cells. Although this is likely to be many years away yet.
The researchers took epithelial cells from the gums of human patients, grew more of them in the lab, and then mixed them with mesenchyme cells from mice. The mesenchyme cells were cultured to be “inducing”, which means they instructed the epithelial cells to start growing into a tooth.
Transplanting the cell combination into mice, researchers were able to grow hybrid human/mouse teeth that had viable roots.
The next step will be to get an easily accessible source of human mesenchyme cells and to grow enough of them in order to make it a viable dental treatment.
Professor Paul Sharpe, who led the study, said that mesenchyme cells could be found in the pulp of wisdom teeth, but the difficulty had been getting hold of enough of them.
"This advance here is we have identified a cell population you could envisage using in the clinic. We are now working to try and identify a simple way of getting mesenchyme."
He added: "The next major challenge is to identify a way to culture adult human mesenchymal cells to be tooth-inducing, as at the moment we can only make embryonic mesenchymal cells do this."
Japan quake detected by satellite
The great Tohoku earthquake in Japan two years ago was detected by a satellite on the edge of the Earth’s atmosphere, the European Space Agency (ESA) have said.
The quake measured in at a massive 9.0 on the Richter scale, sending a ripple of sound through the atmosphere that was picked up by the Goce satellite, reported the BBC.
Its supersensitive instruments detected the wave as it passed through the thin atmosphere 255km above the surface of the Earth.