Antibiotic Resistance Explained

In any population, there will be variations. There will, of course, be the normal condition, which will be the most common. But then there will be conditions not too different from the norm, and these can be fairly common as well, but of course, not as common as the previous. And then there may be conditions very different from the usual, and these will typically be the most rare. Because of this variation, certain individuals will be more equipped to handle stresses than others. Let's just say we introduce a factor that kills all the bluish dots. Because there was variation, not all the dots were bluish, and therefore, some still remain. Now, think about the population of Europe during the Bubonic Plague, also known as the Black Plague. For the people who encountered and contracted the plague, over 90% of them died. This would be the normal, most common condition. But this meant that another 10% or so did not die despite coming in contact with the deadly plague. These people had a rare condition that allowed them to survive, and those who survived got to reproduce. If this condition that allowed them to survive was the result of their genetics, then this new population would be much more resilient to the plague, as nearly all of them would contain this new condition. Because of this, all subsequent outbreaks of the Bubonic Plague in Europe were far less damaging to the overall population, because the only people left were those who were naturally immune. Now, instead of people, think about a population of bacteria, and instead of a disease like the plague, think about antibiotics, designed to kill bacteria. Because there's a similar variation in the bacteria population, certain individuals will be more resilient. So, when exposing bacteria to antibiotics, instead of killing 100% of the bacteria, the antibiotic will kill something like 99.999% of the bacteria. Again, death is the normal condition. But that remaining 0.001% have a rare condition which allows them to survive even in the presence of antibiotics. So, when the remaining bacteria reproduce asexually, even if just a single bacterium remains, all of their offspring will contain the same genetic material that allowed the parent to survive. Meaning that once the population is fully recovered, all of the bacteria will be resilient, and the antibiotic will be less effective. This is antibiotic resistance. If this concept sounds familiar, it also goes by another, more general name, evolution. The ratio of traits in a population have changed to favor what was previously a rare condition. And now, the entire population has evolved to be more resilient. To kill this new population, you'll need to use even more antibiotics. Eventually, however, even extremely high concentrations of single antibiotics will be ineffective at killing significant numbers of bacteria, and you'll need to move on to a new antibiotic that's different enough from the previous one that they won't have a resilience to that one as well. But soon enough, the bacteria will grow resistant to this one the same way it did to the last one. This process of using new and different antibiotics against the same bacteria will continue until no more antibiotics are effective against it. And at this point, without effective ways at killing bacteria, many infections and diseases will become untreatable through medicine. If that doesn't sound too bad, let me again remind you of the bubonic plague. Today, we know that it's caused by the bacterium Yersinia pestis. The only way to treat any cases of it is with a mixture of different antibiotics. If our antibiotics become useless in fighting bacteria like this, the human population could again become vulnerable to huge pandemics. Europe alone lost over a third of its population to this single bacteria, and there's no telling how many lives could be lost today if another similar one with extreme antibiotic resistance was created. The only real ways to slow down the development of antibiotic resistance is to use less of them, and to instead either use other sterilization methods like heat or alcohol treatment, or to improve our personal immune systems to reduce the need for antibiotics. So maybe keep that in mind every time you use hand sanitizer just because you had to touch a doorknob, or buy soap with antibiotics mixed in, even though regular soap cleans your hands just as well. And ask yourself, what's more dangerous, a harmful bacteria that we can kill, or a slightly less harmful bacteria that we can't? I hope you enjoyed this video, and if you'd like to see others like it, please consider subscribing to my channel. If you have something you'd like me to make a Simply Put video about, let me hear it in the comments. I'm on Twitter, so follow me there for updates and such, and as always, I'll be back next week. Thanks for watching.