The Biology of Resistance
Today I am going to explain how antibiotic resistance works. More specifically, I want you to know what happens on a biological level in order to fully understand the process of this condition. Antibiotic resistance (ABR) is when a specific antibiotic has lost its effective power to kill bacteria and prevent that bacterium from spreading. The resistance of the bacterium to the antibiotic that used to be able to kill it is what the health community is referring to anytime ABR is mentioned. You might be wondering, “Well, how do those bacteria become resistant to the drug to begin with?” That’s an excellent question, and I can perfectly explain the phenomenon.
Believe it or not, there are some bacteria that naturally reject certain strands of antibiotic. In those cases, the antibiotic never stood a chance against the bacterium because the antibiotic’s effectiveness was always going to be denied. However, in the majority of most other cases, bacteria become resistant through one of two ways: (1) genetic mutation or (2) effects from other bacteria that are already resistant.
A mutation is when a specific bacterium alters its genetic material to completely change its identity. When a bacterium mutates, it blocks or inactivates the cell that the antibiotic was going to attack. When this happens, the antibiotic can’t reach its intended cell, and the mutated bacterium, which is now resistant, is left free to wander around the body. Another way that bacterium avoid the impact of antibiotics is through the release of enzymes. A bacterium will oftentimes release an enzyme that deactivates the potency of the antibiotic upon impact, or the enzyme will start a system within the bacterium that pumps the antibiotic right back out of the cells upon impact. In this case, the antibiotic reached the cells, but the bacterium outsmarted it. What makes these two cases particularly dangerous is not that there are one or two bacteria that block or inactivate one strand of antibiotics. What makes it dangerous is that these bacteria multiply, and they multiply quickly. So instead of there being one bacterium cell that was resistant, there are actually hundreds within a matter of minutes. The more these resistant bacteria reproduce, the more cells there are in your body that won’t be affected by that same antibiotic should you need to use it in the future.
When bacteria mate and share genetic material, the process is called conjugation. In conjugation, the sharing of genetic material includes the sharing of antibiotic resistance genes from one bacterium to the other. When this happens, then you have another entire strand of bacteria that has become resistant and is also multiplying at a rapid rate. This is how multiple types of bacteria begin reproducing hundreds of cells that are all resistant to the same drug. Sometimes, a virus can be responsible for the spreading of resistant genes. A virus that impacts a resistant cell will take the resistant genes with it. When that virus reaches a new cell, it releases the resistant genes into it, and thus, a virus has continued the spread of resistance. In less common cases, there are “naked” cells wandering around with no genetic material or makeup. These cells are free to acquire the genetic material of the cells around them. If the cells around them have resistant genes, then the naked cells will become resistant as well.
Antibiotic resistance on its surface seems like a very easy process. A person takes an antibiotic, some of the micro parts of the body become resistant to it, especially if that antibiotic is taken often and improperly, and then the body can no longer be healed by that medicine. However, it is actually a very complex system of transferring genetic material between cells and bacteria. ABR is entirely dependent on cell behavior and cell characteristics on a molecular level. The body works very hard to prevent this, but with millions of cells and bacteria, it’s not hard to see how antibiotic resistance has grown. Hopefully this educative post gives a better understanding of how ABR works, but more importantly, I hope it gives you a new appreciation for everything your body does to keep you healthy on a daily basis because it is fighting an uphill battle against ABR.
Sources:
http://emerald.tufts.edu/med/apua/about_issue/about_antibioticres.shtml
