The Accidental Discovery of Penicillin: How a P-Type Personality Changed History

Hi everyone, welcome to Cold-Knowledge Blind Box. Today we're talking about the story of penicillin.

Before we start, though, I want to briefly explain what "P person" means in my title.

The term comes from the MBTI personality test, and it refers to the "Perceiving" type. P people have a very clear trait: they lean toward staying open and flexible. They don't like over-planning or being too constrained, they'd rather go with the flow, and they adapt very well to surprises and change.

In short, P people don't schedule their lives too tightly. They prefer to "take it one step at a time," and they can spot and handle sudden situations quickly.

Did you know that many great discoveries in history are actually connected to this "P person" trait? The protagonist of today's story, Alexander Fleming, was a textbook P person. He was a scientist, but he was anything but rigorous, and he even had a bit of a mischievous streak.

But it was exactly this open, flexible personality, this sensitivity to accidents, that gave us penicillin, which has saved countless lives. And this miracle drug has profoundly shaped the course of human history.

Introduction: The Miracle Drug of the 20th Century

Penicillin has changed humanity no less than computers and the internet did. That reputation is well earned, because it saved the lives of countless soldiers on the battlefield.

After the Industrial Revolution, weapons changed dramatically. Humanity moved from the age of cold weapons to the age of hot weapons, and wounds from war became larger and deeper, which gave microbes better chances to multiply. So after World War I, people found that more soldiers died of infection after the war than died directly on the battlefield.

Against this backdrop, scientists poured their energy and time into the field of microbiology. But not every scientist was as lucky as our protagonist today, Alexander Fleming. You could say the birth of penicillin was largely a product of good fortune. More precisely, it was a lucky discovery brought about by a "P person" trait.

World War I and the Threat of Infection

In 1914, World War I broke out. People were terrified by the brutality of modern warfare. Soldiers no longer fought with swords and spears but with bullets and explosives. These hot weapons caused far more serious wounds, and the rotting of those wounds made infection much easier.

Alexander Fleming was serving as a military doctor at a field hospital in France at that time. He saw with his own eyes countless wounded soldiers who had barely escaped death on the battlefield, only to die of infection in the hospital.

The Path to Understanding Microbes

By the 20th century, people were already very familiar with microbes. As early as the 17th century, the Dutchman Antonie van Leeuwenhoek used a microscope he had built himself to see countless microorganisms in a drop of water. Later, in the 19th century, Louis Pasteur did in-depth research, and he is the founder of pasteurization, the method we often hear about. Humanity came to understand that the world is inhabited by a vast number of microbes, far more than we imagined.

These microbes exist almost everywhere. If our bodies are injured and the skin is broken, our biological barrier is damaged, and these microbes multiply rapidly in the wound, causing severe infection.

Before the 19th century, what surgeons feared most was not the failure of an operation, but the patient dying of infection after the skin had been cut open. Then, in 1865, the English surgeon Joseph Lister pointed out that surgery needed to be disinfected, and that the way to do it was with antiseptics. Patients treated with Lister's aseptic surgery had a much lower chance of infection.

But antiseptics could only serve as a preventive measure. Once a patient was already infected, using antiseptics at that point was useless. During World War I, Fleming used antiseptics to treat wounds, but the results were poor. Antiseptics are also toxic: they damage the body's own immune cells. This made Fleming realize that he had to find a weapon against bacteria that was more effective than antiseptics.

The First Stroke of Luck: The Discovery of Lysozyme

Fleming was very lucky. He soon discovered the first remarkable substance, and it came from his own nose.

In 1921, which was the third year after the war, Fleming caught a bad cold, but he kept working in the lab. He cultivated a lot of Staphylococcus aureus there. These bacteria were grown on a culture medium, and without any interference they would keep expanding their territory. In theory, the entire round culture medium should eventually be covered in Staphylococcus aureus.

The solid culture medium itself is transparent, but where Staphylococcus aureus has grown, it becomes cloudy. So scientists could tell whether an area had been taken over by bacteria by checking whether it was cloudy.

Fleming came to the lab with his bad cold, and I have no idea what he was thinking, but in a very mischievous way he took some of his own runny nose and put a drop onto the culture medium. Two weeks later, he was surprised to find that, apart from the spot where his nose had dripped, the rest of the culture medium was covered in bacteria.

What did this mean? Fleming thought it was probably because his nasal mucus contained a substance that killed bacteria. Scientists are scientists after all, and they are very sensitive to details. So he went on to run many other experiments with body fluids, and found that tears, saliva and most other body fluids have this kind of magical bacteria-killing substance. Other living things, like egg whites and fish roe, contain it too.

Fleming named this magical substance lysozyme. Before he discovered that egg white also contained lysozyme, he frantically asked his colleagues for their tears, which made his colleagues miserable. Later, Fleming solved the problem of the lysozyme source by using egg white, and then he dove headfirst into research.

That research went on for seven years, and the result disappointed everyone: lysozyme's antibacterial activity was very weak, and it had no effect on many pathogenic bacteria. Fleming had to give up his research on lysozyme.

The Second Stroke of Luck: The Accidental Discovery of Penicillin, and a P Person's Keen Insight

At the beginning, we mentioned that Fleming was very lucky. Although the outcome of the lysozyme discovery was only mediocre, it was born from one of Fleming's sudden flashes of inspiration, and this good luck was actually a groundwork laid for an even bigger stroke of luck later on.

In the summer of 1928, Fleming went on vacation with his family. He was away for several weeks and didn't return to his London lab until the end of August. And this is where our P-person trait comes in. P people usually aren't overly bound by strict experimental procedures. Before Fleming left, many of the bottles and jars in the lab had not been cleaned up according to standard procedure. Some cultures full of bacteria were just left sitting there.

I don't know whether Fleming did this on purpose or whether he was simply not following strict lab management rules. Either way, those culture dishes were left in the lab, unattended, before the vacation. If Fleming had been a strict J person (the "Judging" type), following the procedures and tidying up every day, then penicillin might never have been discovered.

The key is another P-person trait: a keen eye for unexpected situations. While he was cleaning up these cultures, his past experience let him notice a very important detail: some transparent circles had formed in one of the cultures. We explained earlier that transparency means no bacteria are growing, while cloudiness means the area has been taken over by bacteria. So it's obvious that the substance in the middle of those transparent circles has a bactericidal effect.

That's how Fleming discovered the mold, Penicillium. The mold is also a kind of microbe. The bacteria Fleming had been cultivating was a type of bacteria, and the Penicillium mold killed the Staphylococcus aureus.

The Struggle Between Microbes

It's not hard to guess the cause. When Fleming left, his culture dishes had no lids, and they contained water, so they easily grew mold.

Some Penicillium spores landed in them. The Penicillium multiplied and kept expanding its numbers, and it released a substance that inhibits bacterial growth: penicillin.

Because Penicillium can secrete penicillin, it can suppress the growth of other microbes, creating more resources and territory for itself. In the culture dishes, we could see that the staphylococci didn't dare to get close to the Penicillium. They got scared, so they gave up the space around the Penicillium, and a transparent ring formed.

This kind of struggle between microbes is called antibiosis, and it is the result of long-term biological evolution.

An Overlooked Discovery

Fleming was amazed by this discovery. He discovered penicillin in September 1928, and by June 1929 his paper had been published. It was a paper that would later earn a Nobel Prize, but unexpectedly, for the next ten years, nobody paid attention to it.

Then, in 1938, a team at Oxford University became interested in Fleming's research and decided to extract penicillin. In 1941, a policeman accidentally fell into a flower bed, and rose thorns scratched his eyes and face. The wound developed into sepsis, and even today, the mortality rate of sepsis is very high.

So the Oxford team gave the penicillin they had extracted to this patient. At first the results were very good, but the patient eventually died. It was not because of a problem with the penicillin, but because the amount of penicillin the lab had extracted was too small.

The Breakthrough in Industrial Production

Trying to produce drugs in a lab alone was completely impossible. They had to rely on modern pharmaceutical factories for mass production. Unfortunately, at that time Britain had been drawn into World War II, and the research team could not find a pharmaceutical company to work with them.

At the end of 1941, Japan launched a surprise attack on Pearl Harbor, and the United States officially entered the war. The Oxford team finally found hope in America. They persuaded the US government and made more people realize that penicillin would become a weapon on the battlefield. They partnered with American pharmaceutical companies and finally overcame the problem of low output.

Afterward, mass-produced penicillin rolled off the production lines and onto the battlefield. It became the most important weapon for the Allies after guns and cannons. Many wounded Allied soldiers recovered quickly and were able to return to the front within a few weeks. Penicillin played no small part in the Allied victory in World War II.

Fleming's Honors

Afterward, Fleming naturally became the center of attention. With the Nobel Prize behind him, in Michael Hart's book The 100: A Ranking of the Most Influential Persons in History, Fleming ranked 45th.

Just to give you a sense of how high his standing was, here are a few of the people ranked around 40th: at 40th, the ancient Greek philosopher Plato; at 42nd, the music giant Beethoven; at 43rd, Heisenberg, one of the founders of quantum mechanics.

The Arms Race Between Humans and Bacteria

With the birth of antibiotics, humanity officially entered an arms race with bacteria. I'm sure you've heard the term "superbug" before. It refers to bacteria that have developed resistance to antibiotics.

Antibiotics are a double-edged sword. Fleming may never have imagined that humans would keep working so hard to update and iterate antibiotics, and still fail to keep up with the speed at which bacteria evolve. Antibiotics saved countless lives from the brink of death, but at the same time, many people have died from superbug infections because of them.

Conclusion: The Lesson of the P Person

In the next episode, we'll talk about how superbugs came into being, and what the arms race between humans and bacteria looks like as a truly thrilling contest.

But today's story leaves us with an interesting lesson: sometimes, it is exactly the flexibility, openness and sensitivity to accidents that are characteristic of P people that lead to great discoveries. Of course, I'm not saying that rigorous scientific attitudes don't matter. What I'm saying is that keeping an open mind and a sharp eye for observation can sometimes bring wonderful surprises in the most unexpected places.

That's it for Cold-Knowledge Blind Box. See you next time.