16th October 2008, first period, year 8 biology. I don’t remember many of my high school lessons but this one I will never forget. Trundling in on a typical Thursday morning, I took my seat, ready to spend the next hour perfecting my ability to text under the desk. That was until Miss Taylor walked in, a stack of weird-looking, circular plates under her arm.
“Ok class, today’s assignment is to go to the bathroom… and not wash your hands”.
Thirty faces looked back at her. Their expressions varying from shock and astonishment to disgust or confusion. She smiled at our silence before going on to explain the day’s experiment.
“Today I’m going to show you why you should always wash your hands after going to bathroom and why you must always cover your mouth before coughing or sneezing”.
She then handed us three of the strange plates and asked us to perform three tasks:
- The first was to go to bathroom and without washing our hands, place one hand on to a plate.
- The second was to then wash our hands and place a now clean hand on to a plate.
- Finally she asked us to cough on the last plate before sealing all three and taking them back to the classroom.
A few days later, in our next biology lesson, we eagerly came in to find three plates sat on our desks. Miss Taylor explained to us how the plates contained a substance called agar. Agar is a good source of nutrients and when stored at the right temperature, agar plates encourage the growth of bacteria. The three plates that sat in front of me looked a little like the ones below:
If anything drilled in to me the importance of hand washing, it was those plates. I was amazed by how much bacteria could be found on my hands despite me being a pretty hygienic person (well, as hygienic as any high schooler can be). The next week we did a similar experiment taking swabs from the tables, from soil and from our clothes. Every single plate we generated grew bacteria, but if there are so many micro-organisms in our environment, why don’t we get constantly sick?
Well for one, not all bacteria are bad for us. Some in fact are beneficial and can break down nutrients for us that our own bodies can’t digest. They can also compete with so called ‘bad’ bacteria (better known as pathogens) for the nutrients they need to survive. Any pathogenic bacteria that do make it into the body also have to fight off our immune system. Thankfully, many of these harmful bacteria never even get close due to inventions such as anti-bacterial hand wash or surface cleaners that have become common place in many house-holds.
Despite that, some bacterial pathogens do manage to colonise our bodies and make us ill. In the developed world at least, this isn’t a major problem. A simple trip to the doctors can result in some antibiotics which will kill off the bacteria and get rid of that nasty infection. Thanks to antibiotics, we live in an era where surgery survival rates are through the roof and a simple E.coli infection won’t kill us. Unfortunately, this age may soon be at an end.
When antibiotics first came on to the market, they were hailed as the “magic bullet” that would end the terror of bacterial infections. In those days, a simple cut or routine surgery could lead to death if the wound became infected with bacteria. Now those days seem like the dark ages but if things don’t change, they could become a reality once again.
Antibiotics are drugs that kill bacteria. Although there are lots of different species of bacteria, antibiotics tend to target functions or specific parts of the bacteria that are conserved across these species. This means that a single antibiotic can target a wide range of different bacterial infections. The problem is that bacteria are getting smarter. Antibiotics are becoming ineffective against many forms of bacteria because the bacteria are evolving new ways to evade them. This leads to the development of ‘Superbugs’ which can’t be treated with common antibiotics. The World Health Organisation (WHO) has described the problem of antibiotic resistance as a ‘serious threat’ and this is due, in large, to the overuse of antibiotics and natural selection.
Natural selection occurs via the random mutation of individuals in a population. If a particular mutation is advantageous, those with the mutation are more likely to survive and pass that advantage on to their offspring. This causes the mutation to eventually spread throughout the population. The same thing is occurring in bacteria. One bacterium may have a chance mutation that leads to antibiotic resistance. Usually it would take a long time for ‘selection’ to run its course and for this mutation to become a common feature of the population. The overuse of antibiotics however is speeding things up.
In the image above, if the red bacteria had a mutation that made them resistant to antibiotics, in a normal environment, it would take a long time for that mutation to be selected and for the red population to grow and outcompete the yellow population. If we add antibiotics however, we markedly speed up the process of selection. Almost everything but the red bacteria are killed allowing the red bacteria to grow and reproduce without competition. If these red bacteria are pathogenic, you could become really sick and may not have any treatment options.
The biggest problem with antibiotic resistance is how fast it spreads. Bacteria have a really cool trick up their sleeves. As well as passing on advantageous traits to their offspring, they can also pass them on to other nearby bacteria in a process known as lateral gene transfer. This means that antibiotic resistance can spread rapidly through a species but it can also be passed on to other species of bacteria.
Since the first antibiotic was discovered in 1928, antibiotics have been misused in a number of ways including:
- Over or incorrect prescription by doctors.
- Incorrect use by patients (Skipping doses, not completing the course etc.).
- Overuse in animals and farming.
This had led to the emergence of numerous superbugs, like the well known superbug MRSA, which pose a real threat to human health.
Maybe you’re reading this thinking I’m taking about years in the future. “Antibiotic resistance won’t affect me, there are plenty of different antibiotics out there, you’re over reacting”….. I wish that were so. The last new class of antibiotic was discovered in 1987. That’s right… 30 years ago. And scientists are running out of ideas to create new ones. Below is a quote from the WHO and a scary one at that:
A post-antibiotic era – in which common infections and minor injuries can kill – far from being an apocalyptic fantasy, is instead a very real possibility for the 21st Century.
As of 2016, there were approximately 480,000 cases of multidrug resistant tuberculosis per year and this number will no doubt continue to rise. What’s more, people with MRSA (an antibiotic resistant bacteria) are 64% more likely to die than those infected with the non-resistant form. On top of those two cases of resistance, resistance has also been reported in malaria, E.coli infections and sexually transmitted diseases such as Gonorrhea to name but a few. I’m sure you’ll agree that these are terrifying statistics. So what can we do?
This is a global problem that requires a global effort to overcome but here are a few simple steps that we can all do on a personal level to prevent the spread of antibiotic resistance:
- Always take antibiotics exactly as prescribed by your doctor. This means always finishing the course even if you feel better and never deliberately skipping doses.
- Never ‘save’ antibiotics from previous infections or borrow antibiotics from friends and family. Antibiotics are only effective against bacterial infections. If your doctor is reluctant to prescribe them they probably suspect you are infected with a virus and as such antibiotics would be ineffective.
- Colds and the flu (viral infections) cannot be treated with antibiotics! Do not ask your doctor for antibiotics if you have either of these illnesses.
- Ensure your friends and family also understand the importance of the correct use of antibiotics. This is a problem that needs tackling from all angles! You can make a difference.
Thank you for taking the time to read this post. This is a very concerning issue that requires as much attention as possible so if you have any questions, please feel free to comment below and I will try my best to answer them.
All of the statistics used in this post were taken from the 2016 World Health Organisation report on antimicrobial resistance.
(MRSA- Methicillin-Resistant Staphylococcus Aureus)
And for more information on the matter, please check out these other great sources: