The history of microbiology is littered juicy anecdotes and larger-than-life characters. But as well as sharing the "classic" history of microbiology, I also want to pitch the story from a new perspective, that might offer some lessons for the current microbial challenges we're facing.
Part 1. The classics: A round-up of the biggest names in microbiology
Let's start in Delft. On a pre-COVID trip to the Netherlands, I made a nerdy pilgrimage to the Old Church in the medieval city of Delft, to visit the tomb of Antoni van Leeuwenhoek. Widely regarded as the Father of Microbiology, von Leeuwenhoek spent the 1670s peering through the lenses of his remarkable home-made microscopes. He is credited as the first person to observe and document bacteria (which he called "animalcules"). And protozoa. And sperm cells. And red blood cells. And the list goes on…
The first observation of any microorganism was recorded less than a decade previously: Robert Hooke, Fellow of the Royal Society in England, published his observations of the fungus mucor in the seminal text Micrographia. In contrast, however, van Leeuwenhoek refused to publish his methods for producing his world-class lenses, and real scientific progress in observing and characterising microbes died with these two men for over 150 years.
And so on to France in the 1860s. Louis Pasteur's work using bespoke swan-necked glass flasks demonstrated that, once boiled, broth remained sterile until coming into contact with dust from the air. This ground-breaking finding refuted once and for all the previously accepted theory of spontaneous generation: that living microorganisms could arise spontaneously from non-living material. Pasteur's insight that heat kills microbes also led to his patented method of pasteurisation, which has since been adopted worldwide as a way to safely preserve food and drink.
Across the border in Germany, Robert Koch vied with Pasteur for microbiological glory, with the two men competing neck-and-neck to identify the bacteria responsible for anthrax and cholera. Koch's germ theory led him to formulate his now infamous postulates: a set of criteria demonstrating the causal link between microorganisms and disease.
These now-obvious revelations heralded lifesaving changes in medical practice and disease prevention. At the Glasgow Royal Infirmary in the 1860s, Joseph Lister pioneered sterile surgery, using carbolic acid to decontaminate his hands, surgical instruments and patients' wounds. And even simple hand-washing was first acknowledged as a good idea: the Hungarian obstetrician Ignaz Semmelweis demonstrated a dramatic reduction in maternal mortality once he and his colleagues started washing their hands before seeing patients.
But we've skipped a step. Long before the world understood where microbes come from and how they cause disease, there were efforts to prevent illnesses that were obviously spreading from person to person. And so, in 1796, Englishman Edward Jenner famously inoculated eight-year-old James Phipps by rubbing a dairymaid's cowpox scab into a cut in the boy's arm. The procedure conferred protection against both cowpox and the related but much deadlier smallpox, and so the legacy of vaccination was born.
Jumping ahead now, to London in 1928, when Scottish physician Alexander Fleming serendipitously forgot to throw away some agar plates before leaving his lab for a family holiday. On his return, he found the plates contaminated with mould, and made the curious observation that a bacteria-free halo had appeared around the fungus. He purified the Penicillium mould, and discovered that the antibiotic substance it produced was capable of killing the bacteria responsible for scarlet fever, diphtheria and gonorrhoea. The rest, as they say, is history.
Part 2. The other version: Re-framing the history of microbiology
Except that it isn't. Not the whole history, anyway. Now, I don't mean to undermine the contributions of these great men. But that's just it. They're men. And white. And European. And all working across a period of less than 300 years. Looking a bit deeper, we find that this classic history ignores the work of ancient civilizations, women, and non-white pioneers. It also frames microbiologists as valiant knights, and microbes as brutish villains to be vanquished. As is often the case, the truth is a little more nuanced.
Take Edward Jenner, for example: long before the Father of Vaccinology pioneered cowpox inoculation, so-called variolation (inoculation with smallpox pus or scabs) was practiced in China and India, with some sources claiming this method was introduced as early as 100 BC. Indeed, the introduction of variolation to the Western world appears to date to the often-forgotten Onesimus, an African slave living in Boston, Massachusetts. At the height of a local smallpox outbreak in 1721, Onesimus informed his master of the variolation method that he had witnessed in Africa, leading to the first inoculation trial in America. The trial's success was reported to the Royal Society in London, 50 years before Jenner's cowpox vaccination.
Or what about Robert Koch? It is well-documented that Koch spent many frustrating years failing to culture his beloved microbes on gelatin. His unpaid assistant, illustrator and cook, Fanny Hesse, suggested that he use agar instead. Her advice was crucial to Koch ultimately identifying the mycobacterium responsible for tuberculosis, but (as was so often the case for women in science) her contribution went uncredited in Koch's publications.
And then there's Ruth Ella Moore, the first African-American woman to earn a PhD in natural sciences in 1933. This fact serves as a stark reminder that, throughout the years spanning van Leeuwenhoek's work in the 1670s to Fleming's in the 1920s, a significant proportion of women and non-white people were denied the opportunity to study, let alone practice, science and medicine.
And now for the biggest re-framing of all: microbes themselves. Bugs aren't the villains that history positions them as, and doctors and scientists aren't always the heroes. Don't get me wrong - clean drinking water and vaccination are the twin interventions credited with saving more human lives than any other, due to the prevention of diseases caused by microbes. But it's so much more complicated than that. Take Fleming's mould: the history of antibiotics long pre-dates human evolution, with soil-dwelling fungi producing chemicals to keep competing bacteria in check. Our own history as a species is inextricably entwined with microbes - from the endosymbiotic bacteria that became our mitochondria, to the millions of commensals we rely on to digest our food and fend off harmful pathogens. Or the microbes needed to make wine and cheese (shudder the thought of a world without those fungal friends). And simply look to germ-free mice as a reminder that a microbe-free world is problematic, leading to immunological and other health problems. Microbes are frequently kind and suddenly cruel; capricious, devastating, indispensable, and endlessly captivating.
We've come so far from van Leeuwenhoek's lenses. As genomic sequencing technologies have rapidly improved in throughput, cost and availability, microbial ecosystems are being increasingly well-characterised. And a stark story is unfolding: our microbiota are changing, perhaps with long-lasting and far-reaching consequences. We have clobbered our native flora with antibiotics, antiseptics, and changes in our diet and environments. We have deforested our guts, and association studies have linked such microbiome changes to increases in obesity, cancer, autoimmune diseases and even mental health problems. It's not just a reduction in microbial diversity, but a shift too, with a rise in infections due to antibiotic-resistant pathogens and opportunists like Clostridium difficile.
As doctors, we are well-placed to address some of these challenges. We need to be champions of antibiotic stewardship and infection control, to help fend off antibiotic resistance. We need to engage with new insights into microbial ecology, and advocate for a healthier microbiome through interventions like breastfeeding and dietary change. And we need to communicate this narrative more effectively to our patients. By reframing the history of microbes, we can strive to change the future.
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