Penicillin: An Accidental Discovery That Saved Billions

Penicillin is an antibiotic used to fight off many different types of bacteria. Before the introduction of penicillin and antibiotics there were no known effective treatments against bacterial infections. Today, there are many different strains of penicillin, some are natural while others are synthetic. Penicillin has saved the lives of thousands of people.

Alexander Flemming first discovered Penicillin in 1929. He was a bacteriologist, who was working with staphylococci when he discovered the effects of penicillin. He had left his culture of staphylococci over a course of a few works and when he returned, he noticed that there was a fungal contaminant, Penicillium notatum, which stopped the growth of the staphylococci. Penicillin affects the cell wall of the bacteria or rather inhibits the proteins which cross link peptidoglycan in cell wall production. Penicillin directly interferes with the synthesis of peptidoglycan in bacterial cell walls. When the bacterial cells grow the cell walls will burst. Penicillin can only affect peptidoglycan during the growing period of the cell. Peptidoglycan that are already cross linked will not have damage due to penicillin. (Lobanovska, 2017)

Penicillin generally affects gram positive bacteria. Gram positive bacteria have two layers; a thick peptidoglycan layer and cell membrane. Gram negative bacteria prevent penicillin from attacking because they have a liposaccharide layer and protein layer which protect the peptidoglycan. The structure of penicillin has three parts to it which include a free carboxyl acid group, one or more substituted amino acids side chains, and a fused beta-lactam structure. The free carboxyl acid group is an organic compound that contains a carboxyl group which is -COOH. A lactam is a cyclic amide, which is formed from an amino carboxylic acid, and a beta-lactam is a ring that consists of a four-membered lactam where the nitrogen is attached to the beta carbon. (Shelton, 2013) Another way to view the structure of penicillin is as two amino acids that are covalently bonded.

One of the most effective types of Penicillin is Penicillin-G which contains an ethyl phenyl group. Although it is one of the most effective, it still has many cons associated with it. Along with only working on gram positive bacteria, penicillin-G is broken down in the stomach which contains gastric acid and it is poorly and irregularly absorbed into bloodstream. In order to fight against these problems, the amino acid chains allow electron-attracting groups to attach to them which ultimately prevent the damages due to acid. If a bulky group attaches to the amino acids, this group can provide steric hinderance which will block enzymes from attaching to the penicillin which would deactivate the penicillin. In order to fight against Gram negative bacteria, if the polarity of penicillin is increased there is an increase of activity against the gram-negative bacteria. (Libretexts, 2019)

Bacteria have become resilient to penicillin. They can become resilient in a few different ways such as developing enzymes called penicillinases which can be transported to other bacteria through an exchange of material between to bacteria cells. Doctors try to minimize the use of penicillin in cases that the patient does not need penicillin to prevent things like this from happening. (Amasino, 2017) Penicillin can also have side effects which include confusion, abdominal pain, easy bruising, bleeding and allergic reactions. (Ogbru, 2019) People who are allergic to penicillin class of antibiotics can have anywhere from minor symptoms which include itchiness or redness to major symptoms that includes loss of consciousness or an anaphylactic reaction. (Healthwise Staff, 2018)

Penicillin is considered a “wonder drug” because it has helped resolve diseases such as strep throat which was once deadly but no can easily be cured. It also is has the ability to destroy multiplying bacterial cells but does not change the biochemistry of human cells. (American Chemical Society National Historic Chemical Landmarks, 2008) The first trials of penicillin on humans were very successful. This success lead to treating soldiers in WWII. This launched a race between companies to mass produce penicillin. The key in mass producing Penicillin was using deep-tank fermentation which the company Pfizer had figured out. The Pfizer company had earlier successes with things such as creating a candy flavored medicine that patients would gladly take instead of the original bitter antiparasitic drug santonin that would treat malady or intestinal worms.

Pfizer entered the race to mass produce penicillin and produced five times the amount of penicillin that was originally predicted. The procedure used to make Penicillin began with taking a sterile form of the mold and placing it in a big fermenter tank which contained corn steep liquor, milk sugar, salts and minerals. The mold was then allowed to grow for a period from two to four days. The Penicillin was then extracted from the broth, purified, freezed and then dehydrated to form the drug. Scientists learned that if the normal yellow color that penicillin had meant it had impurities. This procedure mass produced Penicillin to save thousands of lives. (American Chemical Society National Historic Chemical Landmarks, 2008)

Penicillin has directly impacted almost everyone’s lives. According to the mortality data, 18% of deaths in America were caused by some sort of respiratory tract. If pneumonia is left untreated it can kill the host but with treatment can be cured within a few weeks. Cuts and scratches used to be life threatening because of the infection that normally followed them. With proper bandaging, infections can now be avoided but if one were to get an infection we know have penicillin and other antibiotics to fight of these infections. In third world countries, they do not have the resources or money that the United States and several other countries have. A woman giving birth in countries without penicillin or other antibiotics face many threats. 10% of maternal deaths are caused by bacterial infections and a many of these children die to due infections. (ReAct, 2018)

Penicillin was an innovation that has helped saved thousands of lives and cure many diseases. Infections that were once deadly can now be cured with this antibiotic. Penicillin was accidentally discovered, and many companies had problems figuring out how to mass produce this drug at first, but Penicillin is now widely available. It is still affective against most bacteria even though some have gained a resistance to Penicillin. This antibiotic was helpful back in WWII and is still helpful today.