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

Getty
Show Hide image

Not just a one-quack mind: ducks are capable of abstract thought

Newborn ducklings can differentiate between objects that are the same and objects that are different, causing scientists to rethink the place of abstract thinking.

There’s a particular loftiness to abstract thought. British philosopher and leading Enlightenment thinker John Locke asserted that “brutes abstract not” – by which he meant anything which doesn’t fall under the supreme-all-mighty-greater-than-everything category of Homo sapiens was most probably unequipped to deal with the headiness and complexities of abstract thinking.

Intelligence parameters tail-ended by “bird-brained” or “Einstein” tend to place the ability to think in abstract ways at the Einstein end of the spectrum. However, in light of some recent research coming out of the University of Oxford, it seems that the cognitive abilities of our feathery counterparts have been underestimated.

In a study published in Science, led by Alex Kacelnik – a professor of behavioural psychology – a group of ducklings demonstrated the ability to think abstractly within hours of being hatched, distinguishing the concepts of “same” and “different” with success.

Young ducklings generally become accustomed to their mother’s features via a process called imprinting – a learning mechanism that helps them identify the individual traits of their mothers. Kacelnik said: “Adult female ducks look very similar to each other, so recognising one’s mother is very difficult. Ducklings see their mothers from different angles, distances, light conditions, etc, so their brains use every possible source of information to avoid errors, and abstracting some properties helps in this job.”

It’s this hypothesised abstracting of some properties that led Kacelnik to believe that there must be more going on with the ducklings beyond their imprinting of sensory inputs such as shapes, colours or sounds.

The ability to differentiate the same from the different has previously been used as means to reveal the brain’s capacity to deal with abstract properties, and has been shown in other birds and mammals, such as parrots, pigeons, bees and monkeys. For the most part, these animals were trained, given guidance on how to determine sameness and differences between objects.

What makes Kacelnik’s ducklings special then, as the research showed, was that they were given no training at all in learning the relations between objects which are the same and object which are different.

“Other animals can be trained to respond to abstract relations such as same or different, but not after a single exposure and without reinforcement,” said Kacelnik.

Along with his fellow researcher Antone Martinho III, Kacelnik hatched and domesticated mallard ducklings and then threw them straight into an experiment. The ducklings were presented pairs of objects – either identical or different in shape or colour – to see whether they could find links and relations between the pairs.

The initial pairs they were presented served as the imprinting ones; it would be the characteristics of these pairs which the ducklings would first learn. The initial pairs involved red cones and red cylinders which the ducklings were left to observe and assimilate into their minds for 25 minutes. They were then exposed to a range of different pairs of objects: red pyramid and red pyramid, red cylinder and red cube.

What Kacelnik and his research partner found was that the ducklings weren’t imprinting the individual features of the objects but the relations between them; it’s why of the 76 ducklings that were experimented with, 68 per cent tended to move towards the new pairs which were identical to the very first pairs they were exposed to.

Put simply, if they initially imprinted an identical pair of objects, they were more likely to favour a second pair of identical objects, but if they initially imprinted a pair of objects that were different, they would favour a second pair of differing objects similar to the first.

The results from the experiment seem to highlight a misunderstanding of the advanced nature of this type of conceptual thought process. As science journalist Ed Yong suggests, there could be, “different levels of abstract concepts, from simple ones that young birds can quickly learn after limited experience, to complex ones that adult birds can cope with”.

Though the research doesn’t in any way assume or point towards intelligence in ducklings to rival that of humans, it seems that the growth in scientific literature on the topic continues to refute the notions that human being as somehow superior. Kacelnik told me: “The last few decades of comparative cognition research have destroyed many claims about human uniqueness and this trend is likely to continue.”