The End of Antibiotics Is Upon Us

Yeah, you read that right. And no, this is not a joke. Bacteria have once again outsmarted us, so to speak. They have developed a way to be resistant to all of our main antibiotics, and the worst part is that it’s easily passed on to other bacteria of a different species.

Just to give you a general idea of what I’m going to talk about, here are some really interesting facts. For those of you who didn’t already know, bacteria dominate our planet. They are half of the world’s biomass (total mass of living things), and that is pretty astonishing, considering you can’t even see them with your naked eye. They have been around for 3.5 billion years and can grow anywhere (they’ve been found growing in every environment from Antarctica to hot springs). Another thing you might be interested to know is that you have 1013 cells in your body. A lot right? There are 1014 (that’s the number 10 with 14 more zeros behind it!) microbial cells in your body. They outnumber your own cells! I don’t know about you, but I find that really amazing. And relating back to the antibiotic issue, here’s something I bet you didn’t know; some bacteria had resistance to penicillin before it was distributed to the public. They are always one step ahead of us, and now with antibiotic misuse, humans are signing their own death wish.

Now I’m going to explain how this has happened, if you’re interested. Simple terms will be used, so no need to freak out and click the back button, but if you’re not that concerned about the process, just scroll down to the second last paragraph for other important information. So, basically what’s happened is a bacterium (bacterium is singular, bacteria is plural) was living in India in the sewer (as bacteria do, because they live everywhere). It was exposed to waste from hospitals, waste from households, and many other things, as you’d expect. Most importantly, the bacterium was exposed to antibiotics, like the ones most commonly used in hospitals. Normally, antibiotics kill bacteria, but this one gained resistance. It could have created the resistance itself (through spontaneous mutations in its DNA, for example) or it could have gained it from another bacterium, by means which I shall explain now as it is important later too.

Bacteria can share DNA. Some people call it “bacteria sex”. They have a single circular chromosome (for those who don’t know, that’s made of DNA), but some bacteria also have smaller extra “chromosomes” called plasmids, which can encode for many things, including antibiotic resistance. By complicated means (shown in the picture), they can transfer this plasmid to other bacteria, while keeping a copy themselves, which means both bacteria now have genes that can code for resistance against that particular antibiotic. Therefore, the bacterium living in the sewer that I mentioned before could have obtained resistance from another bacterium. It would be rather common for bacteria to develop some sort of resistance, especially in wastewater coming from a hospital, since so many drugs and antibiotics are used there. Similar situations of “super bugs” happen in the actual hospitals too.

So now we have a bacterium living in the sewer with some extra DNA that allows it to be resistant to one antibiotic. Doesn’t sound that interesting, I know. But, once other bacteria gain resistance to other antibiotics and share that new DNA with our original bacterium, it therefore can gain more resistance to other antibiotics. Let’s say this happens. Now the bacterium has a lot of extra DNA that allows it to survive when those antibiotics are present. By other genetic processes that I won’t explain here, all of that new DNA can be put into one single plasmid that encodes for resistance for all of those antibiotics, so the bacterium can easily transfer it to other bacteria to allow them to survive in those conditions too.

I know what you’re thinking. Big deal, we have one bacterium living in the sewers of India that’s resistant to all of the antibiotics. But in India, due to low levels of hygiene, dirty water seeps everywhere, and that’s how our bacterium can spread. It is easily able to come into contact with a human and infect them, especially since India is overcrowded. That person can now infect someone else, and this continues on and on and on. People travel to India, come into contact with someone who is infected or a contaminated water supply, and they bring the bacteria back home with them, only to infect more people (the main discoveries of this plasmid have been in India and Europe, though it has now reached every country in the world).

And to make matters worse, this bacterial plasmid can be passed on (via “bacteria sex”) to so many different species of bacteria, like E. coli (a bacteria almost everyone has heard about. Some strains can cause serious food poisoning), Neisseria gonorrhoeae (causes gonorrhoea), Neisseria meningitides (causes meningitis) and Klebsiella pneumoniae (the bacteria scientists first discovered the resistance plasmid in, and it causes pneumonia), which means that when these bacteria are causing disease, they will be very difficult to kill, if not impossible. Though, don’t get the idea that bacteria only cause disease, as there are so many bacteria that you couldn’t live without, so do be grateful for them.

What can we do about this? Well, not much, really. Unless scientists can come up with a new antibiotic of some sort, or some other form of treatment for these “super bugs”, then humans don’t stand a chance. But even then, they’ll probably just quickly develop resistance to it anyway. Of course, you can take preventative measures, like using your antibiotics correctly, cleaning and disinfecting things appropriately, and just being aware in general (and spreading that awareness to your friends and family). It doesn’t take much to wash your hands when suitable or avoiding something that might make you sick. Most of it is common sense, and it all helps lower the risk. But, we need to come up with other options, because once we can’t use antibiotics, we really have nothing else left to defend against bacteria and their diseases.

References

Most information was gained from lectures and laboratory classes from a Microbiology and Immunology (and Genetics) course at a University.

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