We (the human race) may be about to lose the ‘magic bullets’ that protect us from everything that nature has to throw at us, plunging us back into dark, dark times. Probably. At this point, the doctors reading this will have guessed what this is about. The antibiotic apocalypse. Antibiotics are magical drugs, chemicals that can throw back almost any bacterial infection in the blink of an eye and leave us unharmed. Never again must we fear a sore throat or open cut, for no more might they cause sudden death. We have these ‘magic bullets’ (a term coined by the pioneers of antibiotics themselves) that save us from the endless dangers of soil and dirty water and even air. But those magic bullets might be about to backfire on us.
But first, some back story.
For all of history, the germs have been out to get us. Since the dawn of time, bacteria and viruses and other nasty critters have thought our bodies would make a nice house. In particular, they thought it would be good for them to spread into our vital organs, multiply into a visible lump and start secreting toxins. From their point of view, this is like moving into a house and putting in some furniture. From our point of view, they kill us. Which isn’t very good. So we developed the immune system. And by ‘we’, I mean most animal life. Cats and dogs and elephants and people and worms all have basically the same immune response. Which(by the way) is really cool. Here’s how it works.
When something bad enters your body (through a cut or through a face hole) it is detected pretty soon by the immune system. The skin is actually the first line of defence, but as those of you who have ever got sick will know, it doesn’t keep everything out. So then the body dispatches an initial wave – B cells and neutrophils.
B cells are like intelligence agents – they lock onto the antigen (nasty thing) and read the proteins on the outside of the cell. They then rush back to the bone marrow (HQ). In the bone marrow, there are millions of other B cells – memory cells. This is the data bank of the immune system. Each memory cell contains specific instructions on the proteins needed to destroy that antigen. While the B cells are doing their thing, the neutrophils are going around being like tanks. They literally eat the antigens – absorb them and dissolve them. Those guys can actually shut down most infections on their own, but sometimes they need backup. That’s where T cells come in.
The T cell response is triggered by the B cells – they are specific, trained fighters. Compared to the neutrophils, they are snipers rather than tanks. They have outer shells that are tailored to lock onto the antigen and wipe it out. Then the neutrophils can mopup the dead bodies. Coool. Through this mechanism, the immune system can wipe out most small scale infections in a matter of weeks. But the system is slow-moving, and if the antigens are good at growing and moving really fast, the germs can beat them to the punch. This is where you get killer diseases from – things like the black death, malaria, syphilis or anthrax. But also things like a sore throat or an infected cut can let in horrible diseases (with names like staphylococcus aureus) that do things like this. Which aren’t very nice. And even in the 1900s, these diseases were a serious threat to life and limb. George Washington, who had the best medical care on Earth, probably died of a sore throat. So the race was on. To find a drug that could kill these horrible diseases in their tracks. And I think we all know who got there first. The good man, Alexander Fleming. We all know this story. Fleming, who was studying staphylococcus, left a petri dish unattended and found a mysterious mould growing on it. The mould was preventing the bacteria growing near it, so Fleming isolated the chemical used by the mould. Thus was penicillin, the first magic bullet, was created. And so began the antibiotic age. And at the same time, we passed the beginning of the end. The fact was, antibiotics could cure lots of bacterial diseases quickly and easily. All of them, in fact. At the point where the industrial production of penicillin was ironed out and large-scale production began, there was nothing it couldn’t cure. And more and more and more of theses magic bullets were discovered (in fact, we found 25 new ones last month – in soil!), giving us an entire magic machine gun-worth of protection against the dark forces that haunted us for so long.
So we used them, and used them, and used them. Chances are, you’ve been given antibiotics in your life for something that your body would handle just fine on it’s own. But the magic bullets were quicker, so we took them. And in doing so, hurried our own doom closer and closer. The problem with germs (I mean, one of the problems with germs) is that they make babies really fast.
A common E. Coli bacterium splits in half every 20 minutes – so the size of the colony will double in size every 20 minutes. But if you copy the same strand of DNA that fast, there will be copying errors. There will be mutations. And when you have mutations in a bacterial population, you will have tough ones. On average, a single round of antibiotics will kill 90% of a given bacteria in a Petri dish (in the body, it can be less). If you use another round, then in theory you end up with only 1% of the original population.
Only you don’t. About 10% of the bacteria will be immune to the antibiotic. They will survive the first round, and the second round, and the third round after that. And then they grow, and you have a colony of bacteria that are resistant to the initial antibiotic. But that’s OK, because we have loads of antibiotics. Right? Nuh-uh. If you take the rule of thumb that 10% of a population is resistant to the antibiotic in question, 5 or 6 rounds of different antibiotics is in fact enough to essentially obliterate the population, leaving the immune system to clear up.
6 rounds of antibiotics will leave you with only 0.001% of the initial population – pretty insignificant by any standard. But that 0.0001% is resistant to all 6 antibiotics. And if the immune system doesn’t take out those few bacteria, they will reproduce and come back with a vengeance. If that 0.0001% were all E. Coli, it would take all of 39 years for the infection to reach 100% of pre-antibiotic levels. Which is a while. But that’s not the point.
The massive use of antibiotics in hospitals – only one or two types, rather than our hypothesized 6 – has led to the evolution of some nasty critters. The most well-know of these is MRSA.
It’s our old friend, staphylococcus aureus. It’s been hit with so many rounds of methicillin (a common antibiotic) that in a hospital, chances are you’ll find MRSA rather than standard SA. Which is a really big problem – our main weapon against staphylococcus is suddenly useless. A magic bullet broke.
And if one can break, who’s to say if all of them can break?
I’m not saying that suddenly, all of our magic bullets will explode and leave us exposed to the millions of bacterial infections lurking in the shadows. It might not happen – we could develop other techniques to stop infection, or find new antibiotics. The weapon we have against the hordes might be a torch, and will last against the dark for millenia.
Or it might be a candle. And some day the candle will be extinguished, and we will all be left to face the dark.