Introduction to Biology
February 16, 2018
When you hear the word “Antibiotic” the first thing that pops into your mind is probably Penicillin. Penicillin is the most famous and most used antibiotic and as such others don’t get the recognition they deserve. The word “antibiotic” comes from two root words: the prefix “anti-” means to fight or oppose and the word “bio” means life. So in essence, “antibiotic” means to fight/oppose life, which is what they do. They kill harmful bacteria without damaging the human body. They do this by affecting only the areas that bacteria have that human cells don’t, primarily a cell wall. Antibiotics have been used for a long time and people in ancient times used plants and chemicals from animals to treat diseases without fully knowing what exactly they were doing. But, despite antibiotic’s ability to kill dangerous bacteria, they do have their own problems.
In the modern era there are well over a hundred different antibiotics. I find this amazing because antibiotics have only been around since the beginning of the 20th Century (1900s) and despite the progress scientists have made, there is still so much more to be discovered. Because there are so many antibiotics, there are several different ways to classify them. The most common way is to break them up into groups by antibiotic “ancestor” or parent. There are two examples listed. The first one breaks antibiotics into eight categories or classes. These eight categories are: Penicillins, Cephalosporins, Fluoroquinolones, Aminoglycosides, Monobactams, Carbapenems, Macrolides, and Others. Under the heading of Others there is vancomycin, rifampin, linezolid, and tetracycline. A common thing with antibiotics is that most of these “families” have a common suffix.
There is another system that splits these up into only six classes.2 These classes are: Penicillins, Cephalosporins, Aminoglycosides, Tetracyclines, Macrolides, and Fluoroquinolones. There are some similarities between these two systems but there are also some differences. This classification is different because it collapses the Monobactam, Carbapenems, and “Others” categories and takes tetracycline from “Others” and makes it its own category. Some antibiotics are put into a group called “beta-lactam antibiotic”. Beta-lactam antibiotics have something that is called a beta-lactam ring in the molecular structure. These antibiotics are penicillin, carbapenems, cephalosporins, and monobactams.
The first scientifically documented antibiotic was penicillin. Penicillin was accidently discovered by Alexander Fleming. Fleming was a biologist that, at the time of his discovery, worked at St. Mary’s Hospital in London looking for a bacteria-killing substance. He, in September of 1928, walked in to his lab and saw a petri plate that had a curious white fluffy mold growing on it. The petri plate was most likely contaminated by a spore from a nearby lab wh...