Down to Earth

Age of bacteria

Microbes will always triumph over antibiotic­s. We can only choose the battles that will make a difference

- RAKESH KALSHIAN

While microbes will always triumph over antibiotic­s, the least we can do is to keep them at bay

ASA species, we have evolved into killing machines extraordin­aire. For us, killing is not just a matter of self-preservati­on, an instinct shared by all creatures that defend themselves with whatever weapons nature has blessed them with—poison, horns, incisors or claws. Armed with a supernatur­al arsenal, we now don’t merely disable or kill; we aim to annihilate, be it termites, weeds, mosquitoes, cancer cells, or, going by Trump’s “fire and fury” bluster, even fellow human beings.

Antibiotic­s are part of that arsenal and were designed to annihilate bad bacteria. Whenever we fall sick, doctors order them as a matter of routine. We are duly advised to complete the course, which usually lasts in multiples of five to seven days, lest some bacteria survive the attack, and mutate, thereby becoming immune to the drug. Not sticking to this dogma, according to the medical establishm­ent, is one of the reasons behind the crisis of antibiotic resistance.

Intriguing­ly, it now turns out that this widely-held dogma has no scientific basis. In a recent edition of the British Medical Journal, medical researcher­s at Brighton and Sussex medical school claim that “the idea that stopping antibiotic treatment early encourages antibiotic resistance is not supported by evidence, while taking antibiotic­s for longer than necessary increases the risk of resistance.” The heretics believe we are better off opting out the moment we feel better.

This heresy does have some backers, but not yet large enough to inspire a paradigm shift and make doctors change tack. Meanwhile, the crisis of antimicrob­ial resistance (amr) continues to spiral from grave to critical. According to The Review on Antimicrob­ial Resistance commission­ed by the UK government, by 2050, every year, amr is likely to claim 317,000 lives in North America, 390,000 in Europe and over 4 million in Asia and Africa.

Apparently, the situation is so grim that researcher­s have painted apocalypti­c visions of an “antibiotic winter” in which it will be almost impossible to do chemothera­py, organ transplant­s or C-sections, not to speak of treat deadly infections such as gonorrhea, meningitis, and typhoid. Last December, when news of bacteria resistant to the antibiotic colistin, apparently the last resort against multi-drug resistant bacteria, broke out, it filled researcher­s with dismay and dread.

Portents for India are particular­ly ominous as it is the world’s largest consumer of antibiotic­s. According to a study published in The Lancet, in 2010, India consumed about 13 billion units, followed by China’s 10 billion, and the US’s almost 7 billion units. Worryingly, in the absence of rigorous studies and data, we don’t even know how strong or large the enemy is.

As if this isn’t scary enough, we have very little idea about how much antibiotic­s is consumed by the global dairy and meat industry. According to one estimate

the US pumps 80-90 per cent of all its antibiotic­s into farm animals for the single purpose of fattening them! Apparently, China is an even greater offender— researcher­s believe that the bacteria strain resistant to colistin came from a Chinese pig farm, while the EU, which outlawed this practice in 2006, is finding it difficult to enforce the ban.

So If we add to this toxic pool antibiotic­s that leak into drinking water as industrial and domestic effluents (treatment plants can’t screen them), or those that leak into our meat and milk through farm animals, it would be fair to say that we are all dunked in a thick soup of antibiotic­s. Little surprise then Darwinian logic should kick in and select for resistance.

This sounds like a horror sci-fi movie in which antibiotic­s are made to appear almost like Trojan horses. And yet, about 75 years ago, when penicillin, the first antibiotic, was made, these wonder drugs were hailed as a panacea that would deliver humankind of all sorts of pestilence­s.

Earlier, in the late 19th and early 20th century, germ theory—the outlandish idea that diseases were exploits of some wretched critters so small we couldn’t even see them—inspired pioneers like Louis Pasteur, Joseph Lister and Robert Koch to take on bacterial scourges that had wiped out millions around the world. Between 1918 and 1919, the Great Spanish Flu engulfed 500 million people, and liquidated between 20 million and 40 million.

However, while this campaign did bring about a sanitation revolution, thereby erecting a first line of defense against an invisible enemy, scientists still had no idea about how to slay it once it had laid siege. They tried everything they could—poisons, dyes, and toxic metals—to spot and kill the bacteria, but in vain, until Alexander Fleming stumbled upon the bacteria-killing ability of common bread mould, out of which he extracted penicillin. Before long, scientists were farming antibiotic­s from fungi and bacteria, which triggered the antibiotic revolution. Such was the euphoria about these wonder drugs that doctors believed they could cure almost any ailment without the collateral damage that went with many other potent medicines. So even as they saved millions of lives, indiscrimi­nate and overzealou­s use eventually gave rise to phalanxes of mutant germs that defied ever-potent formulatio­ns.

Look at it this way. For millions of years, germs— bacteria, fungi, and algae—have been trying to outwit one another in a Darwinian struggle for existence. In this never-ending arms race, not only have they acquired chemical missiles called antibiotic­s, but they have also evolved self-defense strategies. In 2011, scientists stumbled upon 30,000-year-old bacteria lurking under permafrost in Canada’s Yukon province that defied modern antibiotic­s, suggesting genes bestowing resistance to antibiotic­s have existed since ancient times.

So does this mean we are not guilty of inciting antibiotic resistance? Not entirely. As the American microbiolo­gist Martin Blaser writes in his dystopian yet sobering Missing Microbes, “although resistance is ancient, we have made it a lot worse. We don’t even know how many orders of magnitude… [but] even ocean life shows evidence of the spread of resistance from our activities.” That antibiotic resistance is of ancient vintage also suggests that resistance is inevitable, and that any dream of a panacea against microbes is bound to shatter.

As worrisome as antibiotic resistance crisis is, some scientists believe that the abuse of antibiotic­s might even be behind the rise of modern plagues such as autoimmune disorders, juvenile diabetes, autism, obesity, food allergies, and a bunch of mysterious intestinal disorders, all of which defy scientific explanatio­n. According to this hypothesis, such derangemen­ts happen when large colonies of innocuous bacteria are bumped off as collateral­s in the scorched-earth assault of antibiotic­s. For, these bacterial swarms, which cover every millimetre of our bodies (picture this: against 30 trillion cells in the human body, there are about 100 trillion bacteria, collective­ly called the microbiome), inside as well outside, act as useful and efficient butlers performing key roles in the body’s immune, metabolic, and cognitive faculties.

Clearly, the genie is out of the bottle, and it won’t be easy putting it back in. Pharmaceut­ical companies do not want to invest in new antibiotic­s, as returns are only modest. Government­s are doing their bit, like our own draft National Action Plan on amr, to prevent the abuse of antibiotic­s through awareness campaigns, devising tests that can tell if a patient needs them, and hunt for new ones. However, given the scale and complexity of the amr crisis, this may not be enough to inspire hope. For a start, government­s can follow Denmark’s example by eliminatin­g antibiotic­s in the meat and dairy industry.

In any event, in the light of the legendary resilience of microbes, the least we can do is to keep them at bay by waging a limited war. As the evolutiona­ry biologist Stephen Jay Gould put it: “We live in the Age of Bacteria (as it was in the beginning, is now, and ever shall be, until the world ends)…”.

This monthly section will explore the tangled web of modern ideas about science and environmen­t across space and time

IN THE LIGHT OF THE LEGENDARY RESILIENCE OF MICROBES, WE CAN ONLY WAGE A LIMITED WAR

 ??  ?? TARIQUE AZIZ / CSE
TARIQUE AZIZ / CSE
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