A Century of Antibiotics
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We found ten drugs. The bacteria answered all ten.

A century of discovery, from Fleming's forgotten plate to the last drugs standing today, and how each one met its match.

Explore what's in the petri-dish to know more about the history of antibiotics.
An interactive infographic by Soumya.

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Found · 10 Resistance documented · 10
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How it was found

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Who
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Try it on a culture
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Where it came from
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The bacterium that beat it
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How it beat the drug
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What happened when it stopped working

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Today
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What it treated
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What the ten drugs bought

Ten compounds changed what it meant to survive an infection. For each one, bacteria answered — sometimes in decades, sometimes inside a year. Drag the playhead to watch both clocks run at once: discovery on the left of each lane, the first documented resistance on the right.

1 yr
Fastest resistance
6.5 yr
Median gap
13 yr
Class drought
Deaths from infectious disease, United States
Before
797 per 100k
After
36 per 100k
Maternal deaths in childbirth, United States
Before
582 per 100k
After
83 per 100k
Pneumococcal pneumonia, hospital fatality
Before
about 30%
After
about 5%
Before: 1900 · 1935 · pre-antibiotic era. After: 1980 · 1950 · with treatment.
≈200 million
Lives estimated saved by penicillin alone
It came from a mould on a plate a man forgot to clear away, and reached patients only because three other people spent eleven years making it into a drug.
Nine of ten
Of these drugs came out of soil, sewage or a mould
A Sardinian public health officer wondering about swimmers, a graduate student screening farm dirt, a missionary posting jungle soil home. The century's most useful medicines were found by people paying attention to ordinary things.
How long each drug held
Years between a drug entering use and the first documented resistance. Fastest at the top.
Methicillin
1 yr
1960 → 1961
Ceftriaxone
1 yr
1982 → 1983
Daptomycin
1 yr
2003 → 2004
Ciprofloxacin
3 yr
1987 → 1990
Streptomycin
4 yr
1943 → 1947
Tetracycline
9 yr
1950 → 1959
Imipenem
11 yr
1985 → 1996
Penicillin
12 yr
1928 → 1940
Vancomycin
30 yr
1958 → 1988
Colistin
56 yr
1959 → 2015
The answer arrives faster

Years from discovery to the first documented resistant strain, ordered by discovery date. Vancomycin and colistin are the outliers — both were held in reserve for decades before heavy use began, which is the whole point: resistance tracks use, not time.

The three drugs deliberately engineered against a known resistance mechanism — methicillin, ceftriaxone, daptomycin — were answered in one to two years each.

The supply ran out

Between ciprofloxacin in 1987 and linezolid in 2000, no genuinely new class arrived. The soil had been screened; the easy organisms had given up what they had.

That drought is what turns the timeline above from a story of trade-offs into a compounding problem. Resistance to an old drug matters much less when a new class is a decade away than when there is nothing behind it.

What rests on them
Caesarean sections, hip replacements, chemotherapy, transplants and intensive care all assume an infection can be stopped afterwards. The drugs are not only treatment; they are the condition for the rest of modern medicine.
Why it needs looking after
Resistance is the cost of use, not a failure of the drugs. In 2019 it was directly responsible for 1.27 million deaths, human consumption rose 46% between 2000 and 2018, and roughly two thirds of antibiotic tonnage still goes to livestock. Each of those is a decision, which means each can be decided differently.
Prescribing has tightened, farm use is falling in many countries, and new drugs are reaching patients again after a long gap. The century in this dish is mostly a record of what careful work bought.
Sources: Armstrong et al., JAMA 1999 · US Vital Statistics · GRAM study, The Lancet 2022 · Klein et al., PNAS 2021 · Van Boeckel et al. · WHO pipeline review
How antibiotics work

Four steps, in order. Tap through them.

One colony · millions of cells
The colony is not uniform.

Bacteria divide every twenty minutes or so, and copying errors happen. Long before any drug arrives, a few cells differ from the rest. One of them, by chance, already carries a trait that a future drug cannot get past.
The drug reaches every cell
It jams one machine the cell cannot do without.

Penicillin blocks wall-building, so the cell bursts under its own pressure. Streptomycin and tetracycline jam the ribosome, so no proteins get made. Ciprofloxacin stops DNA being copied. Colistin tears the outer membrane. Each target is something bacteria have and our cells do not, which is why the drug is safe for us.
Susceptible cells gone · one survivor
The drug does not create resistance. It clears the competition.

Everything the drug can reach dies. The cell that was already different is left standing in an empty dish, with all the food and none of the neighbours.
The same colony, a few hours later
The survivor rebuilds the colony in its own image.

Every descendant inherits the trait. Worse, the instructions often sit on a plasmid, a small loop of DNA that bacteria hand to each other, so resistance can cross to a different species entirely without either of them dividing.
Four ways they answer
Destroy the drug with an enzymePenicillin
Change the target so it no longer fitsStreptomycin
Pump it back out of the cellTetracycline
Coat the surface so it cannot landColistin
Drag the knob · tap a marker · ← →