How do antibiotics work?
Thanks to @seasofme for this subject. Go and read her beautiful poems about life and love. You won't be disappointed. In fact, you'll be inspired.
This is an important question because of what's happening today. By this I mean the fact that the antibiotics that are available are no longer capable of killing bacteria that have become immune. How does that happen? The answer is evolution. It's been happening since the beginning of life on the planet Earth.
An antibiotic is a chemical that can kill infectious bacteria. We would probably not be here if it weren't for these marvelous chemical agents. Before antibiotics, a simple infection would kill most people. In fact, infections killed almost anyone who got injured, especially soldiers fighting in wars before WW II. Think of it this way. A soldier in the Civil War would get shot. The lead musket ball would pass through his jacket and shirt and carry bacteria into the wound. If not cleaned out within a short period of time, the bacteria would multiply and result in an infection that could not be stopped. This is how many wounded soldiers died.
The first effective antibiotic was penicillin, which was discovered accidently by a Scottish scientist, Alexander Fleming in 1928. Yes, there were other antibiotics before this, but penicillin was the first most effective chemical antibiotic and it held this status for quite some time.
How does penicillin work? Penicillin is a chemical associated with a fungus. Its core structure is responsible for the antimicrobial action. The way this works is that penicillin interferes with a bacteria's ability to make its cell membrane. Without a cell membrane a bacteria is incapable of reproducing or infecting anything. Penicillin inhibits the formation of peptidoglycan cross-links in the bacteria's cell wall by interfering with an enzyme needed for this cross-linking process. Without this the bacteria is essentially dead. This is a simple explanation for a much more complicated process.
There are several penicillin antibiotics. They all have a common chemical structure and only differ by a side chain. The core structure is a beta-lactam ring. The original penicillin had this core structure with a benzyl group as its side chain. I'm relating this so that you realize the penicillin is a generic name for a family of antibiotics.
At first, penicillin was produced from cultures of the fungus that produces it metabolically. What this means is that when the fungus gets growth-stressed it forms penicillin as a bi-product. So, manufacturing penicillin requires stressing the fungus' growth on a constant basis. Eventually, penicillin and its derivatives were created by synthetic methods. Needless to say, penicillin saved many lives in WW II. It also cured my rheumatic fever, which is a streptococcus infection of the heart valve.
But, this is not the end of the story. Medical research has created many different and more effective antibiotics. The main reason that this is necessary is because bacteria evolve and eventually become immune to antibiotics. There are hundreds of these chemical agents and they work by different mechanisms. Examples that you may be familiar with include Erythromycin, Streptomycin, Neomycin, Methicillin and etc. The list goes on and on. Unfortunately, misuse of antibiotics (doctors prescribe them for diseases that are viral, not bacterial; use in cattle, chicken and hog mass production, and in ointments and soap) has created infectious bacteria strains that are immune to almost all antibiotics. This is a serious problem. We could end up back in the eighteenth century where there was no practical way to cure an infection.
One of the strains of bacteria that medical professionals are concerned with is MRSA or Methicillin-resistant Staphylococcus aureus. An infection with this bad boy is very difficult to treat. Often the only course of action is amputation. Many of these antibiotic resistant bacteria are found in hospitals and nursing homes. It makes one think about going to a hospital for something routine. You could get sick there.
Fortunately, there are many new antibiotics in the pipeline, but they have to go through testing protocols in order to become commercially available. This takes time. So, don't get a MRSA infection until they come up with a solution to this serious problem.
Thanks for reading.