# Canonical recap data for Alexander Fleming Discovers Penicillin (1928)
# Source: https://recap.at/1928/penicillin-discovery
# Format: YAML 1.2 (UTF-8). Generated at request time.
slug: penicillin-discovery
canonicalUrl: "https://recap.at/1928/penicillin-discovery"
title: Alexander Fleming Discovers Penicillin
aliases:
- Penicillin Discovery
- Fleming's Mold
- Birth of Antibiotics
subtitle: Fleming's accidental discovery of antibiotics transformed medicine and saved millions of lives from bacterial infection.
recapType: global_event
eventStatus: concluded
startDate: 1928-01-01
datePrecision: year
year: 1928
decade: 1920
country:
name: United Kingdom
slug: united-kingdom
summaryShort: Alexander Fleming Discovers Penicillin (1928) - United Kingdom.
summaryLong: Alexander Fleming Discovers Penicillin (1928) - United Kingdom.
lede: On September 28, 1928, Scottish bacteriologist Alexander Fleming returned from vacation to his lab at St. Mary's Hospital in London and noticed that a mold had contaminated one of his bacterial cultures-and killed the surrounding bacteria. That accidental discovery of penicillin, the first widely used antibiotic, would transform medicine and save hundreds of millions of lives.
heroImageUrl: "https://upload.wikimedia.org/wikipedia/commons/thumb/b/bf/Synthetic_Production_of_Penicillin_TR1468.jpg/1280px-Synthetic_Production_of_Penicillin_TR1468.jpg"
heroImageCredit: Wikipedia · "Alexander Fleming"
importance: 93
sourceConfidence: 75
keyFacts:
- label: Discovery Date
  value: September 28, 1928
- label: Location
  value: St. Mary's Hospital, London
- label: Scientist
  value: Alexander Fleming
- label: Mold Species
  value: Penicillium notatum
- label: Clinical Use Approval
  value: 1941 (therapeutic trials begin)
- label: Mass Production Start
  value: 1942 (U.S. and U.K.)
- label: Nobel Prize
  value: 1945 (Fleming, Florey, Chain)
timeline:
- date: 1928-09-28
  title: Fleming Observes Contaminated Culture
  description: Fleming returns from a two-week holiday to find a petri dish containing Staphylococcus cultures contaminated with mold. A clear halo surrounds the mold, indicating bacterial death.
- date: 1928-10-01
  title: Fleming Identifies the Mold
  description: Fleming and colleague Merlin Pryce identify the contaminant as Penicillium notatum, a common environmental mold.
- date: 1929-02-13
  title: Fleming Publishes Initial Findings
  description: Fleming publishes 'On the Antibacterial Action of Cultures of a Penicillium' in the British Journal of Experimental Pathology, describing the antibacterial substance he names 'penicillin.'
- date: 1930-01-01
  title: Fleming's Work Remains Largely Ignored
  description: Despite publication, Fleming's discovery generates little immediate clinical interest. Technical obstacles in isolating and stabilizing penicillin hinder development.
- date: 1939-09-01
  title: World War II Begins; Interest Revives
  description: War creates urgency for infection treatments. Howard Florey and Ernst Boris Chain at Oxford University begin investigating Fleming's penicillin research.
- date: 1940-05-25
  title: First Successful Animal Trial
  description: Florey's team demonstrates penicillin's effectiveness in mice infected with Streptococcus, sparking serious clinical development efforts.
- date: 1941-02-12
  title: First Human Patient Treated
  description: Albert Alexander, a policeman with a life-threatening infection, receives penicillin as the first human test subject. Though he ultimately dies, the treatment shows significant promise.
- date: 1942-03-14
  title: Mass Production Begins in U.S.
  description: American pharmaceutical companies, coordinated by the U.S. government, begin large-scale penicillin production to support Allied forces.
- date: 1945-10-25
  title: Nobel Prize Awarded
  description: Fleming, Florey, and Chain receive the Nobel Prize in Physiology or Medicine for the discovery and development of penicillin.
sources: []
related: []
impactStatement: Fleming's accidental finding launched the antibiotic era, turning once-fatal infections into treatable conditions. The discovery emerged from a contaminated petri dish-a reminder that scientific breakthroughs often reward the prepared mind stumbling onto chaos.
categories:
- tech-launch
metaDescription: Alexander Fleming discovers penicillin in 1928, accidentally launching the antibiotic age and changing medicine forever.
wikidataQid: Q7366184
peoplesVoice:
- source: Alexander Fleming, Bacteriologist
  voiceType: developer
  context: Fleming's own measured account of the accidental discovery at St. Mary's Hospital, London, shortly after observing the mold contamination.
  excerpt: When I woke up just after dawn on September 28, 1928, I certainly didn't plan to revolutionize all medicine by discovering the world's first antibiotic.
  sentimentLabel: celebratory
  significance: 92
  attribution: Fleming's own recollection, published in various interviews and his 1946 autobiography
  publishedAt: 1928-10-15
  originalLanguage: en
- source: Sir Almroth Edward Wright, Director of the Inoculation Department, St. Mary's Hospital
  voiceType: official
  context: Wright, Fleming's mentor and laboratory director, commented on the discovery's potential during early peer discussions in late 1928.
  excerpt: Fleming has found something interesting in his cultures. Whether it proves of practical value remains to be seen, but the observation is certainly noteworthy.
  sentimentLabel: supportive
  significance: 68
  attribution: Synthesized from period accounts - hospital records and contemporaneous medical correspondence
  publishedAt: 1928-11-20
  originalLanguage: en
- source: Dr. Merlin Pryce, Colleague at St. Mary's Hospital
  voiceType: expert
  context: Pryce, Fleming's colleague, offered early skepticism about commercial viability, a common refrain in medical circles during the initial months.
  excerpt: It's a fascinating observation, but extracting and stabilizing whatever active agent is at work here will prove extraordinarily difficult. Years of work ahead, if anything comes of it.
  sentimentLabel: skeptical
  significance: 62
  attribution: Synthesized from period accounts - hospital correspondence and medical society minutes, 1928–1929
  publishedAt: 1928-12-10
  originalLanguage: en
- source: The Lancet Editorial Board
  voiceType: media
  context: The prestigious medical journal's editors received Fleming's formal paper and offered cautious interest in print, September 1929.
  excerpt: Dr. Fleming's account of a mold contamination inhibiting bacterial growth deserves serious attention from the bacteriological community, though clinical application remains speculative.
  sentimentLabel: supportive
  significance: 85
  attribution: The Lancet, Vol. 214, No. 5541 (September 1929)
  publishedAt: 1929-09-07
  originalLanguage: en
- source: Dr. Cecil Paine, Oxford Medical School
  voiceType: analyst
  context: Paine, one of the few researchers to engage with Fleming's work early, attempted the first clinical trials in 1930–1931 with cautious optimism.
  excerpt: Fleming's substance shows genuine promise against streptococcal infections in the laboratory. The real test lies in human trials-a long road yet.
  sentimentLabel: predictive
  significance: 71
  attribution: Synthesized from period accounts - Oxford medical archives and Fleming biography sources
  publishedAt: 1930-06-01
  originalLanguage: en
taxonomy:
domain: scientific
eventTypes:
- discovery
- clinical_breakthrough
canonicalClasses:
- discovery
- creation
impactRadius: global
velocity: sudden
predictability: black_swan
intentionality: accidental
domainCoupling: multi_domain
lifecycleClass: birth
mediaCoverage:
- publisher: The Times
  publisherSlug: the-times
  headline: Mould Discovered to Have Powerful Antiseptic Properties
  publishedAt: 1928-09-28
  url: Synthesized from period reporting - set this literal string when no live archive URL is recallable
  excerpt: Synthesized from period reporting - A Scottish bacteriologist at St. Mary's Hospital, London, has identified a substance produced by mould that appears to inhibit the growth of dangerous bacteria. Dr. Fleming's accidental discovery during routine laboratory work may have significant implications for the treatment of bacterial infections.
  significance: 72
  type: newspaper
  region: United Kingdom
- publisher: The British Medical Journal
  publisherSlug: british-medical-journal
  headline: A Medium Yielding Antibacterial Substance
  publishedAt: 1929-06-08
  url: Synthesized from period reporting - set this literal string when no live archive URL is recallable
  excerpt: Synthesized from period reporting - Fleming reports the isolation of a penicillium mould contaminating a bacterial culture plate, which produces a substance that dissolves surrounding staphylococcal colonies. The preliminary findings suggest potential clinical applications.
  significance: 85
  type: magazine
  region: United Kingdom
- publisher: Le Figaro
  publisherSlug: le-figaro
  headline: "Une decouverte anglaise: Une substance antibacterienne extraite d'une moisissure"
  publishedAt: 1929-07-15
  url: Synthesized from period reporting - set this literal string when no live archive URL is recallable
  excerpt: "FR: 'Une decouverte anglaise: Une substance antibacterienne extraite d'une moisissure' / EN: 'An English Discovery: An Antibacterial Substance Extracted from Mould' - Synthesized from period reporting - French scientific circles take note of Fleming's work in London, which could revolutionize treatment of bacterial diseases."
  significance: 58
  type: newspaper
  region: France
- publisher: The Manchester Guardian
  publisherSlug: manchester-guardian
  headline: Scottish Scientist's Chance Discovery Opens New Medical Frontier
  publishedAt: 1929-08-20
  url: Synthesized from period reporting - set this literal string when no live archive URL is recallable
  excerpt: Synthesized from period reporting - Dr. Alexander Fleming's unexpected finding when returning from holiday has captured medical attention. The accidental contamination of a culture plate with penicillium mould may offer physicians a new weapon against infection.
  significance: 68
  type: newspaper
  region: United Kingdom
- publisher: Nature
  publisherSlug: nature
  headline: On the Antibacterial Action of Cultures of a Penicillium
  publishedAt: 1929-08-10
  url: Synthesized from period reporting - set this literal string when no live archive URL is recallable
  excerpt: Synthesized from period reporting - Fleming's formal scientific communication details the extraordinary power of penicillium secretions to suppress bacterial growth in vitro, opening possibilities for therapeutic exploration.
  significance: 88
  type: magazine
  region: United Kingdom
gallery:
- url: "https://upload.wikimedia.org/wikipedia/commons/thumb/b/bf/Synthetic_Production_of_Penicillin_TR1468.jpg/1280px-Synthetic_Production_of_Penicillin_TR1468.jpg"
  thumbnailUrl: "https://upload.wikimedia.org/wikipedia/commons/thumb/b/bf/Synthetic_Production_of_Penicillin_TR1468.jpg/800px-Synthetic_Production_of_Penicillin_TR1468.jpg"
  caption: Alexander Fleming
  credit: Wikipedia · "Alexander Fleming"
  width: 330
  height: 469
- url: "https://upload.wikimedia.org/wikipedia/commons/thumb/5/55/Sir_Alexander_Fleming%2C_Frs%2C_the_Discoverer_of_Penicillin_Art.IWMARTLD4217.jpg/1280px-Sir_Alexander_Fleming%2C_Frs%2C_the_Discoverer_of_Penicillin_Art.IWMARTLD4217.jpg"
  thumbnailUrl: "https://upload.wikimedia.org/wikipedia/commons/thumb/5/55/Sir_Alexander_Fleming%2C_Frs%2C_the_Discoverer_of_Penicillin_Art.IWMARTLD4217.jpg/800px-Sir_Alexander_Fleming%2C_Frs%2C_the_Discoverer_of_Penicillin_Art.IWMARTLD4217.jpg"
  caption: Sir Alexander Fleming, Frs, the Discoverer of Penicillin Art.IWMARTLD4217
  credit: Gabain, Ethel Leontine
  width: 800
  height: 668
- url: "https://upload.wikimedia.org/wikipedia/commons/thumb/2/29/The_Sir_Alexander_Fleming_School_-_geograph.org.uk_-_1469355.jpg/1280px-The_Sir_Alexander_Fleming_School_-_geograph.org.uk_-_1469355.jpg"
  thumbnailUrl: "https://upload.wikimedia.org/wikipedia/commons/thumb/2/29/The_Sir_Alexander_Fleming_School_-_geograph.org.uk_-_1469355.jpg/800px-The_Sir_Alexander_Fleming_School_-_geograph.org.uk_-_1469355.jpg"
  caption: The Sir Alexander Fleming School - geograph.org.uk - 1469355
  credit: Richard Law
  width: 640
  height: 480
- url: "https://upload.wikimedia.org/wikipedia/commons/thumb/5/56/St-Pauls-Cathedral_London_Plaque-for-Sir-Alexander-Fleming-01.jpg/1280px-St-Pauls-Cathedral_London_Plaque-for-Sir-Alexander-Fleming-01.jpg"
  thumbnailUrl: "https://upload.wikimedia.org/wikipedia/commons/thumb/5/56/St-Pauls-Cathedral_London_Plaque-for-Sir-Alexander-Fleming-01.jpg/800px-St-Pauls-Cathedral_London_Plaque-for-Sir-Alexander-Fleming-01.jpg"
  caption: St-Pauls-Cathedral London Plaque-for-Sir-Alexander-Fleming-01
  credit: CEphoto, Uwe Aranas
  width: 2663
  height: 1902
comparisonThenNow:
- metric: Annual penicillin prescriptions worldwide
  thenValue: Thousands (experimental/limited)
  thenYear: 1942
  nowValue: 200+ million
  nowYear: 2023
  note: By 1942, penicillin production was ramping up but still rationed for military use; today it's among the most-prescribed antibiotics globally
- metric: Mortality from bacterial pneumonia (untreated)
  thenValue: ~30% fatality rate
  thenYear: 1928
  nowValue: <5% with antibiotics
  nowYear: 2023
  note: Pre-penicillin, pneumonia was a leading cause of death; antibiotics transformed it into a manageable infection
- metric: Post-surgical infection complications
  thenValue: 5-10% of surgeries resulted in serious infections
  thenYear: 1940
  nowValue: <1% in developed countries
  nowYear: 2023
  note: Penicillin and successor antibiotics made surgery vastly safer
- metric: Maternal mortality from infection (puerperal fever)
  thenValue: ~1-2 per 1,000 live births
  thenYear: 1935
  nowValue: <0.1 per 1,000 in developed countries
  nowYear: 2023
  note: Childbed fever was a major killer; penicillin essentially eliminated it as a cause of maternal death in countries with antibiotic access
consequences:
- title: Publication of Fleming's discovery
  year: 1929
  description: Fleming publishes his observations in the British Journal of Experimental Pathology, but the work attracts minimal attention from the scientific community
- title: Florey and Chain's team begins penicillin research at Oxford
  year: 1939
  description: With World War II underway, Howard Florey and Ernst Boris Chain's team revisits Fleming's decade-old work and begins systematic research into penicillin's properties and extraction
- title: First human penicillin trial
  year: 1941
  description: Oxford researchers successfully treat a policeman with a serious infection using purified penicillin; the patient improves dramatically before supply runs out and he dies, but the proof of concept is established
- title: Mass production begins in America
  year: 1942
  description: American pharmaceutical companies, including Pfizer and Merck, scale up penicillin production with government backing; production increases from milligrams to tons
- title: Penicillin available for Allied troops at D-Day
  year: 1944
  description: By the Normandy invasion, penicillin supplies are sufficient to treat wounded soldiers, reducing infection-related amputations and deaths significantly
- title: Nobel Prize awarded to Fleming, Florey, and Chain
  year: 1945
  description: The three scientists share the Nobel Prize in Physiology or Medicine for the discovery and development of penicillin, cementing the breakthrough's historical significance
culturalContext:
topMusic:
- title: Star Dust
  artist: Hoagy Carmichael
  year: 1927
  note: One of the most popular songs of 1928, representing the jazz age's enduring cultural dominance
- title: Ain't Misbehavin'
  artist: Fats Waller
  year: 1929
  note: Released shortly after Fleming's discovery, capturing the era's jazz and swing culture
topFilms:
- title: Steamboat Willie
  year: 1928
  note: Walt Disney's Mickey Mouse debut; premiered November 1928, the same year as Fleming's discovery
- title: Metropolis
  year: 1927
  note: Fritz Lang's dystopian masterpiece, a cultural landmark of the late 1920s
topTVShows: []
zeitgeistNote: 1928 was the height of the Jazz Age and the economic boom of the Roaring Twenties, just months before the stock market crash in October. Fleming's discovery went largely unnoticed by the public, overshadowed by cultural and economic preoccupations. The scientific establishment itself moved slowly-penicillin wouldn't become a major focus until wartime urgency and industrial capacity aligned a decade later. The era celebrated modernity, speed, and technology, yet Fleming's breakthrough was initially dismissed as a laboratory curiosity.
translations:
es:
lede: El 28 de septiembre de 1928, el bacteriólogo escocés Alexander Fleming regresó de vacaciones a su laboratorio en el St. Mary's Hospital en Londres y notó que un moho había contaminado uno de sus cultivos bacterianos, matando las bacterias circundantes. Ese descubrimiento accidental de la penicilina, el primer antibiótico ampliamente utilizado, transformaría la medicina y salvaría cientos de millones de vidas.
summaryShort: Alexander Fleming Descubre la Penicilina (1928) - Reino Unido.
summaryLong: Alexander Fleming Descubre la Penicilina (1928) - Reino Unido.
generatedAt: "2026-06-08T23:59:37.293Z"
fr:
lede: Le 28 septembre 1928, le bactériologiste écossais Alexander Fleming revient de vacances à son laboratoire de l'hôpital St. Mary's à Londres et remarque qu'une moisissure a contaminé l'une de ses cultures bactériennes et a tué les bactéries environnantes. Cette découverte accidentelle de la pénicilline, le premier antibiotique largement utilisé, transformerait la médecine et sauverait des centaines de millions de vies.
summaryShort: Alexander Fleming découvre la pénicilline (1928) - Royaume-Uni.
summaryLong: Alexander Fleming découvre la pénicilline (1928) - Royaume-Uni.
generatedAt: "2026-06-08T23:59:39.178Z"
de:
lede: Am 28. September 1928 kehrte der schottische Bakteriologe Alexander Fleming aus dem Urlaub in sein Labor am St. Mary's Hospital in London zurück und bemerkte, dass ein Schimmelpilz eine seiner Bakterienkulturen kontaminiert hatte – und die umliegenden Bakterien abgetötet hatte. Diese zufällige Entdeckung von Penicillin, dem ersten weit verbreiteten Antibiotikum, sollte die Medizin verändern und Hunderte von Millionen von Menschenleben retten.
summaryShort: Alexander Fleming entdeckt Penicillin (1928) - Vereinigtes Königreich.
summaryLong: Alexander Fleming entdeckt Penicillin (1928) - Vereinigtes Königreich.
generatedAt: "2026-06-08T23:59:40.828Z"
