Antibiotic Resistance: When the Drugs Don’t Work

By Sophia Wolfram


‘It was a beautiful day, sun out and smiling innocently; finally something good after the shambles of a year 1940 had been thus far. I thought I’d better take advantage of this and went to do some gardening—finally cut that rose bush. A couple of days later, I felt the repercussions. The little thorn prick on my hand had become nastily infected and angry, that was when I called on the doctor’. *


From here Constable Albert Alexander only deteriorated further, developing sepsis, multiple abscesses and eventually losing an eye to infection. Due to his seemingly imminent defeat by the bacteria swarming his body, the doctors decided to experiment with their new wonder drug: an antibiotic. It turned out to be just that, Albert’s short term recovery being nothing short of miraculous. Unfortunately there was not enough antibiotic in that first batch to even cure one infection and Albert Alexander died, overwhelmed by the bacteria in his body.


This was the first time the world saw the power of antibiotics. Since then, we have honed our antibiotics into efficient, cheap and reliable ways of dealing with infection. This progress is phenomenal. However, with it also comes the misconception that antibiotics are a cover-all drug, and unfortunately, that is a very dangerous assumption to make.


At their core, antibiotics work by taking advantage of the differences between bacterial cells and our own, killing bacteria without harming us. It is an elegant solution to our age old bacterial problem. The issue now is that bacteria are becoming wise to antibiotics—they are becoming resistant. Resistance occurs when a genetic mutation in one bacterium causes a change in the specific structure or process which the antibiotic is targeting. (Mutations are common in bacteria, due to their simple genetic reproduction process.) The bacterium can now reproduce and spread unhindered. Having one mutant bacterium doesn’t sound too worrying—one cannot do much harm. However, bacteria have another secret weapon. Unlike viruses, bacteria can trade a small amount of DNA with each other in a process of plasmid exchange, known as ‘conjugation’. This means the mutation from one bacterium can end up manifesting in the entire bacterial population. Any bacteria that miss out on this mutation are easily killed by the antibiotic, leaving behind only the resistant population.


This is called ‘acquired’ resistance and it has the potential to completely undermine our hold over bacteria. Once a bacterial population is resistant to our antibiotics, we have almost no line of defence against them. The more we use a particular antibiotic, the more likely one lucky bacterium will develop resistance. Herein lies the problem: we have been dishing out antibiotics not only as a blanket treatment for possible infection, but also increasingly as a prophylactic treatment in both animals and humans. It is easy to see why this has happened, as antibiotics increase the lifespan of many animals, and therefore increase profits too. Unfortunately, when looked at on a national scale, the figures are shocking. In the US, approximately 70% of medically important antibiotics are bought for use in animals, working out at more than 8.5 million kg of antibiotics each year. If all it takes is a single bacterium mutation, it is easy to see why resistance is becoming such a major worry. When a mutation occurs in livestock, it can easily spread to humans through meat consumption, faecal fertilisers or contaminated surfaces. This is what is happening more and more.


Antibiotics are phenomenal because they carry very low risk whilst being highly effective. Though we have a variety of different ways that antibiotics act, there is a limit. Only 15 new antibiotics have been approved since 2000, dropping from 63 across the preceding 20 years. We are running out of ways we can target bacteria. If bacteria become resistant faster than we can produce new antibiotics, we are in trouble.


Source: CDC


If we look back at Albert Alexander’s story, it is clear how dangerous bacteria can be if we have nothing to fight against it. The great plague, TB, Leprosy and Cholera are all examples of diseases that current antibiotics have almost entirely wiped from living memory. However, if we refuse to ration our use of antibiotics, the human race could once again be defenceless against these horrific diseases. This is why we need to be more aware about antibiotic usage across the globe. Health organisations (the WHO, CDC, NIH), governments and doctors right down to an individual level need to be at the forefront of the solution to this crisis. Several bodies have set out goals to reduce antibiotic usage, for example, the UK government has aimed to reduce antibiotic use in livestock 25% by 2024. We still have time to solve this crisis, but only if we pay attention to the risks and start reducing our usage of antibiotics now.


Sources:

http://www.saveourantibiotics.org/media/1791/comparison-of-us-and-uk-farm-antibiotic-use.pdf

- *The realistic story of how Albert Alexander is debated; here I have used the more fanciful scratch on a rosebush for effect.