Recently we have heard a lot about viruses and the whole world has realized how dangerous they can be. But what about bacteria? With antibiotic resistance on the rise, bacteria can soon bring us more difficult problems to solve. What is antibiotic resistance and what can we do to fight it?
THE SNEAKY BACTERIA
As you can probably deduce, antibiotic resistance is bacteria’s ability to avoid being killed by antibiotics. According to natural selection, when antibiotics are given to a patient, many bacteria won’t survive because they don’t have such resistance. However, some of them have plasmids or other mechanisms which allow them to survive the ‘attack’. Those bacteria will then reproduce and new, usually more aggressive treatments will be necessary to kill them. Some bacteria can even spread resistance to other cells which don’t have such characteristics yet. So, what is it exactly that makes bacteria antibiotic resistant?
MECHANISMS OF RESISTANCE
Let’s take a closer look at the science behind antibiotic resistance in bacteria. The following examples are the most common ways in which those prokaryotic organisms fight against available medicines:
– preventing antibiotic from entering a cell in the first place, thanks to, for example, the outer membrane
– using pumps inside a cell to get rid of antibiotic
– using different enzymes to change or destroy drug
– developing new processes that don’t involve antibiotic’s target
– changing receptors so that antibiotic can’t attach to the membrane
Quite clever, isn’t it? Wait until you hear about spreading resistance from one bacterium to the other!
‘I WILL HELP YOU OUT’- SAID ONE CELL TO THE OTHER
The theory of natural selection says that bacteria can’t just develop resistance to antibiotics. What it means is that when a drug is given to a colony of bacterial cells, those which already don’t have this characteristic, can’t suddenly acquire it from within their cells. However, they can get the required gene for resistance from other bacteria which do have it. The following mechanisms are the 3 main ways in which those genes can be transferred between cells:
transduction: happens in the presence of bacteriophages (viruses which can invade bacteria). Once a phage invades a bacterium which carries resistance, it can transfer its DNA with resistance to another bacterium when it connects to it.
conjugation: plasmids with resistance can transfer from one cell to the other when they connect with pili
transformation: when a bacterium with antibiotic resistance dies and its contents are released to the extracellular space, other bacteria can pick up that DNA and confer resistance in that way
WHAT PROBLEMS DOES ANTIBIOTIC RESISTANCE POSE TO US?
There has been a global increase in the use of antibiotics when such treatment is not even appropriate (for example for viral infections). This is one of the contributing factors for the formation of ‘superbugs’; bacteria which are resistant to most available treatments. That’s why patients who catch such infections have a very low chance of recovery. There is a desperate need for solutions to this problem because we don’t have many ways to stop the spread of superbugs which means that we are soon likely to see an increase in infections caused by them. The good news is that not all antibiotic resistant bacteria are immediately superbugs. On the other hand, it is still not excellent news because to treat infections with bacteria resistant to the first-line treatment, we need to use more aggressive antibiotics which contribute to longer recovery time and more side effects. I think that it should convince most of us to start taking this problem seriously.
FIGHTING WITH RESISTANCE
Prevention is key when we talk about ways in which we can reduce antibiotic resistance. All of us can adhere to general advice of WHO and doctors and contribute to a positive change in that way. First of all, we should reduce the amount of antibiotics. When we have a viral infection, antibiotics are not going to help so we shouldn’t ask our doctor to prescribe them. If we do have to take them, we should do it for as long as our doctor tells us to. Some people stop treatment as soons as they feel better, but it doesn’t mean that the infection is completely eradicated. Reduction in antibiotic use in the livestock will also help as the resistant bacteria won’t spread via food.
I hope this article made you more aware of this pressing issue in medicine. If you are interested in getting to know more, check out the following resources:
– “The Scientist Speaks” podcast on Spotify, Tackling Antibiotic Resistance: Viruses to the Rescue
– World Antimicrobial Awareness Week
– This Podcast Will Kill You
Cedars Sinai. “Articles.” Cedars-Sinai, www.cedars-sinai.org/health-library/diseases-and-conditions/a/antibiotic-resistance.html.
Centers for Disease Control and Prevention. “How Antibiotic Resistance Happens.” Centers for Disease Control and Prevention, 20 Mar. 2019, www.cdc.gov/drugresistance/about/how-resistance-happens.html.
Khan Academy. “Genetic Variation in Prokaryotes.” Khan Academy, 2018, www.khanacademy.org/science/ap-biology/gene-expression-and-regulation/mutations-ap/a/genetic-variation-in-prokaryotes.
Nineham, Laura. “Antibiotic Resistance.” The Medic Portal, 17 Nov. 2020, www.themedicportal.com/application-guide/medical-school-interview/nhs-hot-topics/antibiotic-resistance/.
Tosh, Pritish K. “Protect Yourself from Superbugs.” Mayo Clinic, 2018, www.mayoclinic.org/diseases-conditions/infectious-diseases/expert-answers/superbugs/faq-20129283.
World Health Organization. “Antibiotic Resistance.” World Health Organization, WHO, 31 July 2020, www.who.int/news-room/fact-sheets/detail/antibiotic-resistance.