1. History of Microbiology
Dr. Debalina Basu

5. Aristotle Proposed the theory of spontaneous generation
Also called abiogenesis
Idea that living things can arise from nonliving matter
Idea lasted almost 2000 years

6. John Needham
By 1745 an English scientist used microscopic observations to support the theory of abiogenesis.
To test the theory he boiled meat broth for several minutes in a loosely sealed flask. ( allow to cool down the flask)
Immediately after boiling he saw under the microscope that the broth had no living things.
After a few days he examined the flask and found microrganism.

7. John Needham Abiogenesis
Microorganisms

8. Disproving Spontaneous Generation

9. Francesco Redi (1668)
In 1668, Francesco Redi, an Italian physician, did an experiment with flies and wide-mouth jars containing meat

10. Redi’s Experiment Redi used open & closed flasks which contained meat.
His hypothesis was that rotten meat does not turn into flies.
He observed these flasks to see in which one(s) maggots would develop.

11. Redi’s (1626-1697) Experiments
Evidence against spontaneous generation: 1. Unsealed – maggots on meat 2. Sealed – no maggots on meat 3. Gauze – few maggots on gauze, none on meat

12. Redi’s Findings
He found that if a flask was closed with a lid so adult flies could not get in, no maggots developed on the rotting meat within.
In a flask without a lid, maggots soon were seen in the meat because adult flies had laid eggs and more adult flies soon appeared.

13. Anton Van Leeuwenhoek First person to see bacteria
Single lens microscope

14. Early Compound Microscope
beautifully crafted but had severe chromatic distortion

16. Simple microscopes gave better resolution
Spermatozoa from man & dog
Leeuwenhoek
1678

17. Louis Pasteur ( )

18. Pasteur's Experiment
Hypothesis: Microbes come from cells of organisms on dust particles in the air; not the air itself.
Pasteur put broth into several special S-shaped flasks
Each flask was boiled and placed at various locations

19. Pasteur's Experiment - Step 1
S-shaped Flask
Filled with broth
The special shaped was
intended to trap any dust particles containing
bacteria

20. Pasteur's Experiment - Step 2
Flasks boiled
Microbes Killed

21. Pasteur's Experiment - Step 3
Flask left at various locations
Did not turn cloudy
Microbes not found
Notice the dust that collected in the neck of the flask

23. The Theory of Biogenesis
Pasteur’s S-shaped flask kept microbes out but let air in.
Proved microbes only come from other microbes (life from life) - biogenesis

25. The Theory of Biogenesis 1864
Pasteur’s S-shaped flask kept microbes out but let air in.
Proved microbes only come from other microbes (life from life) - biogenesis

26. GOLDEN AGE OF MICROBIOLOGY
The period from 1860 to 1900 is often named the Golden Age of Microbiology. During this period, rapid advances, spear-headed by Louis Pasteur and Robert Koch, led to the establishment of microbiology as a science.

28. The Golden Age of Microbiology (1857-1914)
Many disease producing organisms were discovered
Microbial metabolism studies undertaken
Microbiological techniques refined
A better understanding of the role of immunity and ways to control and prevent infection by microbes

30. History: Joseph Lister
1867 Antiseptic Surgery( Carbolic acid- Phenol)

31. Joseph Lister,  (1827 –1912), was a British surgeon and a pioneer of antiseptic surgery.
He promoted the idea of sterile surgery while working at the Glasgow Royal Infirmary. Lister successfully introduced carbolic acid (now known as phenol) to sterilise surgical instruments and to clean wounds.
Lister's work led to a reduction in post-operative infections and made surgery safer for patients, distinguishing him as the "father of modern surgery

32. Other evidences Joseph Lister:
provided indirect evidence that microorganisms were the causal agents of disease
developed a system of surgery designed to prevent microorganisms from entering wounds as well as methods for treating instruments and surgical dressings
his patients had fewer postoperative infections

33. Joseph Lister
Joseph Lister was known as the ‘father of antiseptic surgery’ during the 19th century. He was always interested in surgery at a young age (
In the 1840s, operations became more common. Most were successful, but soon after the patient would die from an infection called ward fever. The reason was unclear, but it was believed that it had something to do with the air. In 1864, he read Pasteur’s work on micro-organisms and decided to experiment using one of Pasteur’s techniques. He decided to use a chemical to destroy germs that entered the body through open wounds (
That same year, Lister read in the newspaper that the treatment of sewage with a chemical called carbolic acid had led to a reduction of diseases among the people of England. He then developed a successful method of using this chemical during operations to apply to wounds, spray in the air, and sterilize instruments. This process was very effective and the rate of infection dramatically reduced in the patients treated. Operations could now be carried out safely. Even though his antiseptic method was later replaced by the use of aesepsis, his work marked the beginning for a new era (

34. Joseph Lister Social Impacts:
Lister’s antiseptic method helped recover patients dying from ward fever.
Antiseptic method was used in many hospitals.
The rate of infection and death rate of many patients were dramatically reduced (
The mouthwash, Listerine, was named after him for his work in antisepsis (

35. Germ Theory of Disease
Causal relationship between microbes and disease
Disinfection controls surgical infection
Microbes cause disease

36. Germ Theory of Disease
Robert Koch first developed relationship between microorganisms and disease
Developed Koch’s Postulates for testing relationship
Discovered cause of anthrax and tuberculosis

37. Germ Theory of Disease
Observation on causative agents of potato blight and diseases of silkworms led to hypothesis
Formalized through work of Pasteur and Koch (and others) led to theory that germs or microorganisms may cause disease

38. Germ Theory of Disease Koch’s Postulates:
Same microorganism must be observed in every instance of disease
Organism must be isolated from diseased host and grown in pure culture
Specific disease must be reproduced when pure culture is reintroduced into host

40. Robert Koch Confirmed germ theory Discovered cause of Developed
anthrax
cholera
tuberculosis
Developed
pure culture techniques
staining techniques
solid media

41. Rules to prove an organism causes a disease
Koch’s postulates
Rules to prove an organism causes a disease
Organism consistently isolated from diseased individuals
Organism cultivated in pure form
Signs and symptoms induced after inoculation
Same organism isolated from experimentally infected individual

42. History 1929 Discovery of Penicillin (first antibiotic)
Alexander Fleming

43. Alexander Fleming ( ( (

44. Alexander Fleming
Right after Paul Ehrlich had discovered a cure for syphilis, which was a drug named salvarsan, another scientist was so enthusiastic about finding a new drug that treats small wounds and infections for soldiers during World War I (
This scientist was named Alexander Fleming and was the founder of penicillin. It was during 1922 when Fleming was wondering if there were ways of killing strong bacteria and tried many experiments to prove it true. One day while working with some harmful bacteria, some mucous from Fleming’s nose, which had a chemical called lysozyme, had dropped on to one of his Petri dishes and had destroyed most of the bacteria on it (
This had assured him that there were ways to kill strong bacteria.
In 1928 as Fleming was going through some Petri dishes, he had found one particular dish that had the Staphylococcus aureus mold but was completely wiped off from one whole section from another mold that was in the Penicillium mold family. This mold happened to have antibacterial chemicals that were able to clean off all the bad mold on the Petri dish. This mold was later called penicillin from Fleming because of its strong antibacterial powers found in the Penicillium mold (

45. Alexander Fleming Social Impacts: Political Impact:
Penicillin was able to cure diphtheria, gangrene, pneumonia, syphilis, and tuberculosis.
Was able to cure bacterial infections and major/minor wounds during World War II. (
Political Impact:
Because Fleming had found penicillin, which was a mass production during the World War II ( it had saved lives of the soldiers who had minor injuries during that time.

46. ALEXANDER FLEMING
In 1928 Fleming observed that the growth of the bacterium staphyloccus aureus was inhibited in the areas surrounding the colony of a mold that had contaminated a Petri plate. The mold was identified as Penicillium notatum, and its active compound was named penicillin.

47. There are two types of microorganisms:
Prokaryotes
have a relatively simple morphology and lack a true membrane-bound nucleus
Eukaryotes
are morphologically complex and have a true, membrane-bound nucleus

49. Innoculation: Producing a pure culture
Culturing Microbes
Innoculation: Producing a pure culture
Introduce bacteria into a growth medium using “aseptic technique” to prevent contamination. Tools: Bunsen burner, loop. Needle, etc.

50. Innoculation: Producing a pure culture
Introduce bacteria into a growth medium using “aseptic technique” to prevent contamination. Tools: Bunsen burner, loop. Needle, etc.

51. Isolation: Colony on media, one kind of microbe, pure culture

52. Isolation: Colony on media, one kind of microbe, pure culture – Streak Plates

53. Incubation: Allow organisms to grow under the optimal conditions
Temperature, with or without oxygen etc
Candle jar reduces oxygen

55. World War I
World War I was a war that took place during the early 20th century between 1914 – This war was also considered and named as the Great War (
Social Problems:
-Diseases, injuries and psychological disorders had a big outbreak during World War I.
-Syphilis was very common for women during those times and Spanish Flu had increased severely. (
Political Problem:
-The war initially started because Austria’s Hungary archduke Franz Ferdinand and his wife were assassinated on Serbian ground. This led Austria into an angry reaction and had declared war with Serbia (

56. Paul Ehrlich (http://www.nndb.com/people/238/000086977/)(

57. Paul Ehrlich
Paul Ehrlich was a doctor during the mid 19th century and early 20th century ( bio.html). After his studies, he went to research more about how some cells had an attraction to certain chemicals. As time went on, Ehrlich got more interested in finding the cure for “sleeping sickness.” He worked hard to find a chemical less stronger than Atoxyl because, even though it worked fine, it was an arsenic compound, which was poisonous. Ehrlich tried to find many alternatives for Atoxyl, more than 900, but later went back to #606. As he tested this alternative again with his colleague, they discovered that it didn’t work with the sleeping disease, but worked with a newly discovered disease called syphilis ( This 606th drug had cured the infectious disease among most of the black Americans (
Social Impact:
During World War I, there was a social disturbance which started a widespread of syphilis among people. With the discovery of a cure for syphilis, it treated the many people who were affected with the disease (

64. Ilya Ilyich Mechnikov, Nobel Prize in Physiology 1908

65. Ilya Ilyich Mechnikov (Russian: Илья́ Ильи́ч Ме́чников, also written as Élie Metchnikoff; 15 May [O.S. 3 May] 1845 – 15 July 1916) was a Russian zoologist best known for his pioneering research in immunology.[1][2][3]
In particular, he is credited with the discovery of phagocytes (macrophages) in This discovery turned out to be the major defence mechanism in innate immunity.[4] He and Paul Ehrlich were jointly awarded the 1908 Nobel Prize in Physiology or Medicine "in recognition of their work on immunity".[

66. The innate immune system, also known as the non-specific immune system or in-born immunity system,[1] is an important subsystem of the overall immune system that comprises the cells and mechanisms involved in the defense of the host from infection by other organisms. The cells of the innate system recognize and respond to pathogens in a similar way, but, unlike the adaptive immune system, the system does not provide long-lasting immunity to the host.[2] Innate immune systems are the first and immediate line of defense against infection, all classes of plant and animal life are endowed with.

76. Thank you