Don’t let the superbugs bite

But don't despair - we might be struggling but we are not beaten yet.

Evolution continues to be a bitch. Recently scientists gathered in Kensington, London, to have a good moan and to plan what can be done about it. “Superbugs and Superdrugs” is a great title for a meeting. Unfortunately the bugs seem to be more super than the drugs.

While that meeting went on, the US Centres for Disease Control and Prevention (CDC) issued a warning that we are entering a “nightmare” era. The CDC’s problem is a killer bacterium known as CRE, which is spreading in the US. Some strains of CRE are not only resistant to all antibiotics; they are also passing on that resistance to other bacteria, creating drug-resistant strains of E coli, for instance. On 11 March, Sally Davies, the UK government’s chief medical officer, asked the government to add the superbug problem to its “strategic risk register”, which highlights potentially catastrophic threats to the UK.

For a while, it all looked so good. When scientists discovered penicillin, then ever more weapons for our antibiotic arsenal, it seemed that bacteria had been defeated. The problem is, they fought back.

For all the worry over CRE, perhaps nowhere is this antibiotic resistance more evident than with tuberculosis. In the west, we won the war on TB so convincingly that receiving the BCG vaccine against it – once a waymark in British childhood – is no longer routine. Only in certain inner-city communities where migrant populations increase the likelihood of encountering the TB bacterium are children routinely immunised. However, in 2011, the World Health Organisation marked London out as the city with the highest TB infection rate in western Europe.

Many resistant bacteria originate in hospitals, where pharmaceutical regimes kill off the normal strains, making space in which bacteria that are naturally resistant can proliferate. Yet you can’t always blame the drugs. Research published at the end of February shows that drug resistance can arise even when the bacteria have never encountered a chemical meant to kill them.

In the study, E coli bacteria were made to suffer by exposing them to heat and restricting the nutrients in their environment. According to conventional wisdom, this should have kept proliferation in check – but it caused a spontaneous mutation that made the E coli resistant to rifampicin, one of the weapons in our antibiotic arsenal. What is worse is the observation that there was good reason for this mutation to arise: it made the stressful conditions more survivable. Bacteria with the mutation grew much faster.

Bacteria are survivors – if they can’t magic up a spontaneous mutation, they’ll pick one up in the street. A sampling of puddles in New Delhi showed that almost a third contain the genetic material that allows bacteria to produce an enzyme that destroys a swath of antibiotics. The NDM-1 gene is particularly evil. Its tricks include forcing itself into gut bacteria such as E coli that are incorporated into faeces; as a result, the resistant strains travel between hosts with ease.

Many infections involving a bacterium carrying NDM-1 are untreatable. GlaxoSmithKline is reportedly developing a drug to deal with it but it is years behind the curve. In the autumn, an EU project to mine the seabed for so far undiscovered antibiotics will start up, but it will take years for that, too, to bear fruit.

Let’s end on a positive note. Superbugs might be evolving in fiendish ways but they’re doing it blind and they’re up against evolution’s greatest invention – the human brain. We might be struggling but we are not beaten yet.

The EHEC bacteria. Image: Getty Images

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

This article first appeared in the 25 March 2013 issue of the New Statesman, After God
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The Earth moved: how we discovered ripples in space time

A new book charts the decades-long search to measure gravitational waves.

Monday 14 September 2015 was no ordinary day. At exactly 09:50:45 Universal Time, for one-fifth of a second, the Earth was stretched and squeezed by a tenth of a quintillionth of one per cent. Everything on the planet expanded and contracted as it did by one part in 1021 (1 followed by 21 noughts). It was proof that after a decades-long search, scientists had finally developed instruments sensitive enough to detect gravitational waves – ripples in space-time that were 10,000 times smaller than the nucleus of a hydrogen atom.

That at least begins to take care of when, where and what happened that Monday morning. In this engaging book the Dutch science writer Govert Schilling goes on to deal with the who and why by telling the tale of those involved in making what has been dubbed by some as “the discovery of the century” and the reason those unimaginably tiny ripples in space-time originated in a catastrophic event 1.3 billion years ago in a galaxy far, far away.

The “who” starts with a 36-year-old German physicist who in 1915 had just completed his masterwork, general relativity. In Albert Einstein’s new theory, gravity was due to the warping of space by the presence of mass. The Earth moves around the sun not because some mysterious invisible force pulls it, but because the warping of space tells matter how to move, while matter tells space how to curve. General relativity revealed that the familiar three-dimensions of space and the passage of time are not independent and absolute but are woven together into a four-dimensional fabric called space-time.

Einstein was fallible. Although vibrations in the fabric of space-time are a distinctive consequence of general relativity, Einstein wrote that “there are no gravitational waves”. He soon changed his mind; but the hunt for gravity waves using detectors in the lab would not begin until the late 1950s.

The Laser Interferometer Gravitational-wave Observatory, LIGO, was given the green light in 1990 by the US National Science Foundation, despite a $300 million price tag. By 2015 the project involved two similar detectors housed in facilities some 3,000 kilometres apart – one in Hanford, Washington State, the other in Livingston, Louisiana. A single detector would register microseismic events, such as passing cars; to exclude these false alarms, experimenters would take note only of events that showed up in both detectors within a few milliseconds of each other.

In the LIGO detectors, laser beams are fired along 4km-long L-shaped vacuum pipes and reflected from mirrors at each end. By analysing the light beams, it is possible to detect changes in the distance between the mirrors, which increases and decreases as space expands and contracts due to a passing gravitational wave. But the effect is tiny because gravity is a weak force and space-time is not easy to flex, bend, stretch or compress. A lot of energy is required for the tiniest ripples. Even pairs of stars orbiting each other don’t generate gravitational waves that LIGO can detect; but events involving black holes would.

Black holes, another prediction of general relativity, are the remnants of stars many times more massive than the sun. These stars burn brightly, and in their death throes, signalled by going supernova, their inner part collapses to form a black hole.

GW150914, the first gravitational wave detected by LIGO on 14 September 2015, was produced by the merger of two black holes that were 36 and 29 times as massive as the sun. As those two black holes orbited each other 1.3 billion years ago, they generated minute ripples in space-time that propagated with the speed of light. The waves carried away energy, causing the two holes to spiral ever closer, orbiting each other hundreds of times a second. As space-time was stretched and squeezed, the tiny perturbations grew into massive waves. When the two black holes collided and merged into one, a tsunami of gravitational waves was generated. These cataclysmic collisions happen less than once in a million years in our galaxy, but there are at least 100 billion galaxies in the observable universe.

“When I am judging a theory, I ask myself whether, if I were God, I would have arranged the world in such a way,” Einstein once confessed. Perhaps only he or Newton could get away with such a statement; the rest have to rely on the close relationship between theoretical insight and experimental scrutiny that lies at the heart of the scientific method. Wherever evidence can be coaxed out of nature, it corroborates or refutes a theory and serves as the sole arbiter of validity. Gravity waves are another tick for general relativity and the first direct proof of the existence of black holes; all other evidence has been circumstantial.

The hunt for gravity waves is over, but gravitational wave astronomy may help solve some mysteries that continue to baffle physicists: such as the nature of dark matter and dark energy, which together make up 96 per cent of the universe.

Ripples in Spacetime: Einstein, Gravitational Waves, and the Future of Astronomy
Govert Schilling
Harvard-Belknap, 340pp, £23.95

Manjit Kumar is the author of “Quantum: Einstein, Bohr and the Great Debate About the Nature of Reality” (Icon)

This article first appeared in the 17 August 2017 issue of the New Statesman, Trump goes nuclear