History of microbiogoy ppt

1. History of Microbiology
1. Before the discovery of microbes, reports were there
that some organisms are associated with diseases.
Lucretius (about 98-55 BC) and physician Giralomo
Fracastoro (1478-1553) suggested that diseases are
caused by invisible living creatures
2. Francesco Stelluti (Italian) was first to use microscopic
observation between 1625 to 1630 of bees and weevils
by the microscope provided by Gallileo
3. Microbiology the science of microbes got late start
when other branches were established because the tool
(microscope) to observe the very small group of
organism was not there. The existence of microbes was
reported in mid1600
4. Credit for this this momentous development goes to
two great scientists
Robert Hooke and Anton Von LeeuenHoek

2. Robert Hooke (1635-1703)
Curator of experiments of Royal Society of London He spent
much of his time in examining various materials under his
own compound microscope and published his reports in book
entitled Micrographia
Book contained detailed drawing of insects, their larve, eggs,
feathers, hairs, rocks and cork.
He was first to report Fungi
“Long Cylindrical transparent stalks not straight but a little
blended with weight of a round white knobs which grew on
top of each of them”
He suggested these knobs as common spore bearing cups of
common white mushroom. He suggested the
compartmentalization of structures in living systems, now
known as Cells

3. Anton Van Leeuwenhoek
Credit for discovery of microbes goes to Leeuwenhoek
Born in Delft in 1632and at age of 16 sent to Amsterdam to
apprentice in a draper shop to learn the technique and
appointed as cashier before returning to Delft
Although not attended any University but learned Mathematics
became a successful businessman, a surveyor and official wine
gauger for the town of Delft. Taking the last responsibility he
assayed all the wines entering the town and have
responsibilities to calibrate the vessels in which they were
transported. During this time the institutions were mostly
devoted to theology, law and philosophy
His main hobby was to construct Microscope and spent his
maximum life in making Microscopes and he was first to
observe microbes. His friend Renier de Graaf communicated
several works to Royal Society in England

4. Henary Oldenberg was the editor & was of opinion that
scientific informations should not have nationalistic
restrictions. So, Leeuenhoek was encouraged to communicate
his findings First report in Philosophical transaction dealt
with mouth parts, molds, eyes of bees, louse. Due to
Oldenbergs contact and translation of his work generated
interest in scientific world. He continuously send letters to
Royal Society and unanimously elected as fellow of Royal
Society. Over 200 of his letters have been preserved in the
Museum of Royal Society.
In 18th of his letter October 9th , 1676 first description of
unicellular organisms (Protozoa) and first report of small
microbe like bacteria was covered. He studied water from
fresh water lake, river, well, rain and sea. He termed these as
“animalcules” Most important was from human mouth, he
wrote in 1683.

5. He described rod shaped bacteria, spherical, cork
screw shaped bacterial forms.
His observation remained unconfirmed for many
years because no one was able to make the
microscopic observation of quality needed to observe
bacteria.
His microscope was send to Royal Society in London,
no body followed in Leeuenhoeks foot steps and the
branch of Microbiology remained dormant for many
years after his death

6. Microbiology study of microbial forms is multifaceted
discipline concerned with infectious diseases,
agricultural practices, sanitation and industrial
production of enzymes, chemicals
Microbes are unique models to study nutrition,
metabolism and genetics and used as instruments in
development of Biotechnology
Microbes have marked effect on course of human
population, history, strength of armies, out comes of
battles
Decline of Rome under emperor Justinian (AD 565) was
hastened by the epidemic of bubonic plague and
Smallpox. The people of Rome were decimated &
demoralized by the massive epidemic and as a result
were powerless against Barbarian hordes which
destroyed empire

7. Important diseases were Typhus, Plague, Small
pox, syphilis, cholera caused suffering and great
loss of human life
Population of Europe, N. America and Middle East
was about 100 millions when Plague (black death)
struck in 1936, Epidemic came down through “silk
road” to China, bringing Death to Asia, Mean time
spread to Europe and within a short period caused
loss of 25 million people in short time.
This caused population in check in 16 and 17th
century. Last great epidemic occurred in 1720 &
1722 in France

8. Appeared in India in 1892 & killed 6 million people
in India alone
During this time Napoleon began his retreat from
Moscow in 1312, most of his army became victim of
typhus, pneumonia, dysentery and other illness.
Diseases cold & deprivation all played leading roles
in his departure.
In 1813 again recruited new army of 5,00,000 young
warriors, huge population with unsanitary condt.
Rendered them susceptible to infectious diseases.
When faced allies at Leipzig, battle and diseases
reduced his army to approximately (5,00,000 to
1,76,000) causality of earlier battle 1,05,000 but
about 2,20,000 people were incapacitated by illness.
So, microbes were responsible for his defeat.

9. Status Prior to 1650
From dawn of civilization until middle of 19th century –
success in combating diseases, fight against destructive power,
harnessing fermenting ability Process of trial & error
Thoughts were influenced by Philosophers & supported by
Theory of Spontaneous generation supporting “Origin of
living organisms from inert organic material”
Aristotle (384-322 BC) & others wrote abundantly that Frogs
originated from damp earth, flies on decaying meat, mice on
grains
Giralomo Fracastoro suggested contagious is involved in
disease process
Scholars of

10. • 16th and 17th Century seeking logical
explanation to phenomenon in nature. None
of the explanations were obtained for
natural processes, when scientists especially
chemists clung to theory of chemical
instabilities & spontaneous generation.
• Van Helmont (1580- 1644) produced a recipe for
producing mice from soiled clothing and little
grain

11. Microbiology from 1650-1850
• 18th century age of enlighten during this time period
people questioned traditional doctrine. Biological
sciences get benefitted by the discovery of microscope
and realization that living system is composed of
individual units called as cells.
• Fabrication of microscope attributed to Dutch
Zacharium Jansssen and microscope was first time
used for biological material by Marcello Malpighii
and he can be considered as Father of Microscopic
Biology, contributed in discovery of capillaries and
understanding of embryonic processes

12. From Leeuenhoek to Pasteur
• Many experiments were conducted between (1725-1850)
• Many of the regarding the Theory of Spontaneous
Generation
• Francisco Redi 1627-1697 Italian physician published a
book in 1688 attacking theory of Spontaneous Generation
• He is most well known for his series of experiments,
published in 1668 as Esperienze Toronto alla Generazione
degl'Insetti (Experiments on the Generation of Insects),
which is regarded as one of the first steps in refuting
"spontaneous generation" - a theory also known as
Aristotelian abiogenesis. At the time, prevailing wisdom
was that maggots aformed naturally from rotting meat.
• Spontaneous Generation-The idea that organisms originate
directly from nonliving matter. "life from nonlife"
• abiogenisis - (a-not bio-life genesis-origin)

13. • Redi took six jars, which he divided in two groups of three:
• In one experiment, in the first jar of each group, he put an
unknown object; in the second, a dead fish; in the last, a
raw chunk of veal. Redi took the first group of three, and
covered the tops with fine gauze so that only air could get
into it. He left the other group of jars open. After several
days, he saw maggots appear on the objects in the open
jars, on which flies had been able to land, but not in the
gauze-covered jars.In the second Redi's experiment, meat
was kept in three jars. One of the jars was uncovered, and
two of the jars were covered, one with cork and the other
one with gauze. Flies could only enter the jar with the lid
off of it, and in this, maggots appeared. In the jar that were
covered with gauze, maggots stayed on the gauze and did
not live.
• He continued his experiments by capturing the maggots
and waiting for them to metamorphose, which they did,
becoming flies. Also, when dead flies or maggots were put
in sealed jars with dead animals or veal, no maggots
appeared, but when the same thing was done with living
flies, maggots did.

14. Lazzaro Spallanzani - One of the first to disprove
spontaneous generation. An Italian scientist who proved
microorganisms could be killed by boiling. (Italian 1767)
• 1768 Needham's experiment but removed all the air
from the flask. No growth occurred
• What causes microbes to form in decaying broth?
• Hypothesis: Microbes come from the air. Boiling will
kill microorganisms.
• Spallanzani put broth into four flasks
• Flask 1 was left open
• Flask 2 was sealed
• Flask 3 was boiled and then left open
• Flask 4 was boiled and then sealed

15. • Flask-2
• Sealed
• Turned cloudy
• Microbes were found
• Flask-3
• Boiled and left open
• Turned cloudy
• Microbes were found
• Flask-4
• Boiled and sealed
• Did not turn cloudy
• Microbes not found
• Spallanzani's Experiment Results
• What did Spallanzani's experiment show?
• Was his hypothesis correct or incorrect?

16. • John Needham added chicken broth to a flask
and boiled it. He then let it cool and waited.
Microbes grew, and he proposed it as an example
of spontaneous generation.
• In 1768,Lazzaro Spallanzani repeated Needham's
experiment but removed all the air from the
flask. No growth occurred.[5]
• In 1854, Heinrich Schröder (1810–1885)
and Theodor von Dusch, and in 1859, Schröder
alone, repeated the Helmholtz filtration
experiment[6] and showed that living particles can
be removed from air by filtering it through
cotton-wool.

17. Franz Schulze (1815-1873)
• German chemist took flask filled with vegetable infusion
closed with a cork to which 2 bend glass tubes were fitted
infusion was heated on sand bath & absorption bulb was
attached to tubes (one contained concentrated Sulfuric
acid and other a solution of potassium hydrate, everyday
he drew air through potash bulb & passed through the
acid bulb & flasks remained sterile for months A control
flask without acid sterilization of incoming air had visible
mold growth after few days. Sterilized flask when exposed
to air growth followed with in few days
• Conclusion Infusion could be sterilized & microbes could
be introduced through air

18. Research on Fermentation
• In many reports, the beginning of research on
fermentation and on the role of yeast is given as 1810,
when J. L. Gay-Lussac (1778–1850), on the basis of
detailed analyses, specified ethanol and CO2 as the
principal products of the decomposition of sugar
• The true beginnings of research on fermentation date to
around 1837, when three investigators independently
described many of the principal features of
yeast: Cagniard-Latour (1837) in France, and Schwann
(1837) andKützing (1837) in Germany. Microscopic studies
were the key to their scientific conclusions.

19. • Schwann observed beer Yeast consist of granules arranged
in rows & resembling fungi. He believed them as plants.
Gave the term Zuckerpilz (sugar fungus) from which the
term Saccharomyces was derived, N was essential for this
process. Another independent observation on fermentation
was by Friedrich Kuitzing suggested this process was
caused by living organisms. He also suggested different
types of fermentations are caused by different microbes.

20. Classification
• Linnaeus (1707-1775) was first to give classification system
in his book Systema Naturale (1743) Gave Binomial
Nomenclature, animalcules as infusoria Bacteria was
placed in the genus “Choas” emphasis was given on few
characteristics
• Adanson (1730) proposed Adansonian system of
classification, he gave equal weight to all characters
• Otto F Muller (1730-1784) animalcula et Marina published
posthumously (1786) 379 sp of bacteria He first time used
the term Vibrio & Monas

21. Medical Microbiology
• Enrico Acerbi (Italian in 1822) postulated that parasites
exists & capable to enter the body & their multiplication
caused Typhus fever
• Agostino Bassi (1835) advanced the theory on observation
on diseases of silk worm. Diseases caused death of worms
after death worms were covered with hard, white limy
substance. This was supposed to arise independently from
unknown factor. He found aseptic transfer of subcutaneous
material from sick silkworm to healthy worm resulted in
disease. Reported that disease was caused by a fungus
Botrytis bassiana
• Developed the concept that Contagion in different diseases
like Cholera, Plague, gangrene resulted from living
parasites

22. Edward Jenner (1749-1823)
• Published studies on the immunization of human against
Small pox. He observed that individuals routinely exposed
to cows often develops pustules on their hands & arms
similar to pustules of small pox. Infection of cowpox was
not fetal and cowpox infected ones were resistant to small
pox
• Jenner inoculated an 8 year old boy with material from
infected cowpox pustule on the hand of a milkmaid
pustules were developed at site of infection but quickly
recovered A challenge dose from active case of smallpox
was given and any symptom was not observed
• This was the first report of immunization

23. Microbiology after 1850 : Beginning of Modern
Microbiology
• Golden Age of Microbiology
• Later part of century no. of gifted scientists working
independently established areas now encompassed by the
term Microbiology
• During this period foundation of Immunology, medical
Microbiology, protozoology, systematics, fermentation,
mycology were set apart
• Up to 1860 doctrine of spontaneous generation was
accepted because chemists were infallible
• Louis Pasteur Brought revolution in the field of
Microbiology

24. Louis Pasteur (1822-1895)
• Chemist and genius scientist had unique ability to convince
and communicate to scientists and lay persons
• Disproved the theory of spontaneous generation
• Established immunology added a science
• Developed the concept of Fermentation
• Discovered Anaerobiosis
• Many microbiological techniques
Contributed in every branch of Microbiology
Pasteur School
Entered the controversy of Spontaneous Generation
Fermentations were caused by organic living beings which
reproduce and by vital activities generate observed chemical
changes. He suggested that germs are present in the air were
responsible for fermentation and are widely distributed in
nature. These germs are now a days termed as bacteria and
fungi

25. • Louis Pasteur- Notable Contributions
• 1857 – Lactic acid fermentation is due to a microorganism
• 1860 – Yeasts are involved in alcoholic fermentation
• 1861 – Disproved the theory of spontaneous generation
• 1861 – Introduction of the terms aerobic and anaerobic for yeasts. Production of
more alcohol in the absence of oxygen during sugar fermentation- The Pasteur
Effect
• 1862 – Proposed germ theory of disease
• 1867 – Pasteur devised the process of destroying bacteria known as
pasteurization.
• 1881 – Development of anthrax vaccine. Resolved Pebrine problem of silkworms.
• 1885 – Development of a special vaccine for rabies (the Pasteur treatment)
• Louis Pasteur, a French microbiologist, was born on December 27, 1822 in Dole,
France. He studied at the French school, the Ecole Normale Superieure.
• In 1848, he achieved distinction in organic chemistry for his discovery that tartaric
acid, a four carbon organic compound forms two different types of crystals. Using a
microscope, Pasteur successfully separated the crystals and developed a skill that
would aid his later studies of microorganisms.
• In 1854, at the young age of 32, he was appointed Professor of Chemistry at the
University of Lille in northern France. He died in 1895, at the age of 73.

26. • He designed aspirator filter system (aware that spun cotton
wool acts as effective filter for air borne microbe). He drew
air in huge amounts through spun cotton wool & dissolved
this in mixture of alcohol & ether. Microscopic examination
revealed large no. of small oval, round bodies
indistinguishable from germs previously described. Pasteur
noted that the no. of these organisms varied with temp.,
moisture and movement of air.
• T. Schwann 1837 demonstrated that yeasts were responsible
for formation of alcohol in wine & beer fermentation (before
Justin Leibig gave chemical theory of fermentation &
suggested that fermentation was result of normal chemical
decomposition of organic matter
• He was attracted and analyzed many fermentations and
suggested yeast was presented in all cases and responsible
for fermentations

27. • He suggested that when lactic or butyric acid was produced
bacteria was also present in addition to Yeast. Even when wine
turned bad Bacilli was present in addition to Yeast. He
suggested that sugar of ferment served as food for
microorganism
• He professed that each ferment was caused by a specific
organism which grows only when special requirement for its
growth is available. He made a defined medium containing
sugar and salts which was converted to alcohol and cell
material. Nitrogen was available to cells as Ammonium salts
• Observation served as basis for microbial physiology
Anaerobic & aerobic growth
Air requiring organisms are aerobes and scientists of middle of
19th century were of opinion microbes require oxygen He
observed that organisms involved in butyric acid fermentation
exists in anaerobic environment & observed their motility
under microscope. This motility ceases when cultures were
aerated. Finally he coined the term anaerobiosis

28. Disproved Spontaneous Generation
• Pasteur’s brilliance combined with his knowledge of
fermentation & he started working on fermentation According
to him entry of microbes to suitable media is responsible for
fermentation and prevented to enter fermentation was not
possible. For that he heated the flaks and after that placed
guncotton on top of flasks. Flasks remains uncontaminated
until the cotton was removed.
• He further invented a swan neck flask, thus allowed
unencumbered entrance of air, where all of the dust particle
and contaminants settled in the bend of neck
• Heated Flasks of this type remained clear and free of
fermentation until he broke off the neck. Flasks with broken
neck turned cloudy within few days. He explained that the
organisms capable of fermentation exists in air and when
precautions were taken to prevent the entry of to broth
fermentation did not occurred. He suggested different samples
contained different microbes

30. • He opened the flasks to different places- mountains, lakes,
attics, cellars and resealed the flasks . He showed that different
samples have varied population of microbes from place to
place
• He assured boiling of broth for 1 hr killed all living microbes
(eventually incorrect). This lead the proponents to attack
Pasteur. In fact some microbe not killed when broth was heated
for 1 hr (this is why his experiment succeeded with Yeast
extract and not with other broths
Ferdinand Cohn 1877 (1828-1898) published a paper on rod
shaped bacteria producing resting spores (endospore) resistant
to heat and can easily be identified under microscope. Spore
appeared as retractile objects under microscope His interest on
heat resistant bacteria emanated from emerging canning
industries which sought ways to prevent purification of foods.

31. Cohn
• Cohn described the entire life cycle of Bacillus
(vegetative cell → endospore → vegetative cell).
He
• is credited with the use of cotton plugs for closing
flasks and tubes to prevent the contamination of
• sterile culture media. In 1866, Cohn studied the
filamentous sulphur-oxidizing bacterium Beggiatoa
• mirabilis and was the first to identify the small
granules present in the cell that are of sulphur,
• produced from the oxidation of H2S.

32. • He found alkaline Hay infusion- difficult solution to sterilize-
contaminated with Bacillus subtilis – where spores are vheat
resistant. When transferred to fresh Hay infusion – spores
formed actively growing and dividing cells
• Solution to this problem presented by John Tyndall (1820-
1893) when he presented paper on Royal Society of London
1877. He recognized like Cohn infusion contained heat
resistant spores and spores germinate to vegetative cells
following brief exposure to heat & subsequent boiling killed
the veg. cells From this observation he developed technique
of alternating sequence of heat & growth this would kill the
bacteria if present. This technique of sterilization was
referred as tyndallization.
• The experiment of Pasteur & Tyndall demonstrated that
microbes do not arose independently.

33. • 1865 Napoleon III asked Pasteur to investigate the cause of
formation of bad wine & he suggested that this was caused by
specific organism & it was different from the agent of good
wine. He suggested that the grape juices be heated or
pasteurized to destroy resident population and resultant sol. If
inoculated with a proven producer produce good wine
• Working on butyric acid fermentation He studied Anthrax in
farm animals & demonstrated immunization is possible. He
also suggested that infection of Rabies settle in brain &nervous
system of animals and immunization is possible. He outlined
method for developing vaccine which could encounter harmful
effect of Rabies. In 1885 he reported a dog was protected from
infection by inoculation with an emulsion prepared from dried
spinal cord of Rabbit that had succumbed to disease and
developed vaccine

34. Robert Koch
• Anthrax a fatal disease of domestic animals caused economic
loss to farmers in late 19th century. Disease appeared in the
herd of Sheep or cattle without any apparent cause or source
• Before his work indications were there that Anthrax was
caused by a bacterium. Rod shaped bacterium appeared in the
blood of infected animal. One microbiologist transferred
anthrax by inoculating animals with dried or fresh blood
containing bacteria. But unable to prove that bacteria caused
the disease
• He quickly ruled out the idea of using sheep as experimental
organism because too expensive he used mice as model because
susceptible to Anthrax
• He took blood from infected animal and injected to healthy
mice. He repeated it several times and found each time mice
died if Anthrax. He found swollen spleen and presence of
Bacilli in both liver & spleen

35. • He started to culture Bacillus in broths without success
Finally he raised aqueous humor (liquid from eye ball) of
cow. He placed a drop of aqueous humor on thin glass cover
slip & inoculated it with a piece of infected spleen. He
inverted this cover slipover a depression slide to make
hanging drop
• He observed the growth of Bacilli as vegetative cells as before
many of them formed refractive spores. He inoculated a fresh
drop of humor and observed their germination into
vegetative cells. Once he was able to grow the infectious agent
outside the host Koch was aware how to proceed. He finally
discovered Koch’s postulates earlier given by Henle
• He used inoculation components as spores more spores he
used more quickly the mice died & once again Bacilli was
recovered from blood & spleen. Experiments proved that
microbes can cause infectious diseases

36. • Finally in 1884 Koch summarized his methods of proving that
a microbe is causative argent of infectious diseases, a method
known as Koch’s postulates
Koch’s postulates
1. Microbes must be demonstrable in all cases of diseases
2. Microbes can be isolated from diseased animal & can be
grown to pure culture
3. Microbes from this pure culture must cause the same disease
when inoculated to a healthy host
4. Experimentally infected animal must contain same microbe
By this time R Koch was recognized as leader of German school
of Microbiology in Berlin.
Technical advances in obtaining pure culture. He observed
unrefrigerated boiled potato developed various spots of
varying colours. Microscopic observations of these spots
revealed presence of bacteria – one spot was rods, another
spherical (coccus), one Yeast, separation of contaminants

38. From surface permitted growth of pure culture (single cell into
colony of many progeny cells). From these trials he developed
techniques which enabled microbe hunters to grow pure culture
of microbes
Koch used gelatin as solidifying agent to create a firm surface on
which to streak microbes. Gelatin was effective at room temp.
but liquefied at temp. above 30oC
Dr Walter Hess & his wife Fenny Hess introduced Agar as
solidifying agent (used to harden Jelly). Ideal solidifying agent
because after solidifying at 44oC it remains solid even at 70oC
Many of the bacterial agents causing infectious diseases were
discovered between 1877-1898. Pure culture technique led to a
major break through in this medical era. He also suggested a
colony arose from a single cell & developed streaking method
using using platinum loop, enable him to isolate pure culture. RJ
Petri 1887 an assistant of Koch developed Petri dishes, named
after discoverer and still to day used for culture. Design remain
unchanged except glass has been replaced by plastic

39. Elie Metchnikoff
Elie Metchnikoff, one of the associates of Louis Pasteur, was a Russian
zoologist who lived in Paris and did his work at the Institute Pasteur, France.
He was born in Kharkor priovince of Ukraine (USSR) in 1845. By the 1860s he
had completed his formal studies in Embryology from various Universities of
Kharkor, Russia, Germany and Italy. Metchnikoff coined the term
“phagocytosis” which literally means” the eating of cells”. In 1884, he published
account of phagocytosis, a defensive process in which the body’s white blood
cells (WBCs) engulf and destroy microorganisms. Thus, he formulated the
basic theory on which the science of immunology is founded: that the body is
protected from infection by leukocytes that engulf bacteria and other invading
organism (cellular immunity). He became an administrator to the Institute
Pasteur in 1888 and eventually became its director. He was awarded the Nobel
Prize in 1908. Metchnikoff’s notable contribution was on the Bacillus bulgaricus
therapy and his underlying concept of health. Metchnikoff belived that
streptococci and lactobacilli in yogurt assume residence in the intestine and
replace organisms that contribute to aging. Despite eating large quantities of
yogurt, Metchnikoff died an early death, in 1916, at age seventy-one.

40. List of Diseases & Inventors
Disease Causal organism Inventor
Anthrax Bacillus anthracis R Koch
Gonorrhea Neisseria gonorrhoeae Albert Neisser
Pyrrogenic Infection Staphylococcus aureus Alexender ogston
Tuberculosis Mycobacterium tuberculosis R Koch
Erysipelas Streptococcus pyrogenes FiedrichFehleisen
Diptheria Corynebacterium diptherae Theodor Klebs
Tetanus Clostridium tetani Arthur Nicolaier
Cholera Vibrio cholerae R Koch
Typhoid Salmonella typhae Georg Gaffky
Brucellosis Brucella melitensis David Bruce
Gastroenteritis Salmonella enteritidis August gaetner
Gas gangrene Clostridium perfringins Willium Welch
Bubonic plague Yersinia pestis Alexender Yersin
Botulism Clostridium botulinium Emile van ermengem
Dysentry Shigella dysenteriae Kiyoshi Shiga

41. Paul Ehrlich
• Another coworker of Koch lab contribution in immunology
and chemotherapy
• Suggested staining technique of bacteria in tissues where
bacterial cells absorb higher amount of dyes in comparison to
surrounding tissues
• He suggested that a toxic dye might destroy bacteria without
significant damage to host, reported that organic arsenicals
might be synthesized which could be harmless to animals but
toxic to invading parasites. Arsenicals (organic derivatives of
arsenic- a toxic element synthesized & used on Trypanosomal
infections on Rats. 606 th compound he synthesized was
found to be effective against Syphlis Spirocheate and gave the
term Magic Bullet
• In late 20 years Koch & his coworkers confirmed that
microbes were causative agent for a no. for a number oif
human & animal diseases

42. • John Snow, a British physician, traced the source of
cholera to the municipal water supply of London during
an 1854 outbreak. He reasoned that by avoiding the
contaminated water source,people could avoid the
disease.
• Snow’s recommendations were adopted and the
spread of disease was halted. Both Semmelweis and
Snow drew attention to the fact that a poison or unseen
object in the environment was responsible for the
disease, but the proof was still lacking.
• Joseph Lister in 1867, developed a system of antiseptic
surgery designed to prevent microorganisms from
entering wounds.

43. Joseph Lister
• Joseph Lister was born in 1827. He developed a system
of antiseptic surgery designed to prevent
microorganisms from entering wounds in 1867.
• In 1878, Lister studied the lactic acid fermentation of
milk and demonstrated the specific cause of milk
souring. He also developed a method for isolating a
pure culture of a bacterium, named as Bacterium lactis.
Because of his notable contribution-first introduction
of principles of sterile surgery in medical practice,
which was so far reaching in its effects—Lister will
always be known as the Father of antiseptic surgery.
• He died at the age of 85 in the year 1912.

44. • Chemical antiseptic originated with Joseph Lister 1827-1912 ,
English physician who employed carbolic acid for antisepsis
during surgery. Koch extended his work & deviced a method
for comparing efficiency of chemical antiseptics. He dried
cultures of bacteria generally anthrax spores. On a small
piece of silk thread which was then immersed in antiseptic
solution. At intervals thread was removed from antiseptic
solution washed with sterile water and placed in growth
medium to determine whether organism was still viable.
Koch found that carbolic acid was weak in its disinfecting
property and among all the chemicals he tested perchloride
of mercury was most effective. It destroyed bacterial spores
at high dilution & in the shortest period of time.
• Ferdinand Cohn in 1872 suggested that microbes are
involved in cycling all of all matters & this activity of
microbes in the biosphere allowed the reutilization of cellular
constituents

45. Martinus Beijerinck (1851-1931)
• A great Botanist as first to report the role of microbes in
cycling of matter.
• He introduced the concept of “enrichment cultures” ( a
method for isolation of microbes under any selected condition
such as salinity, osmolarity, temp, pH etc and isolated various
forms from natural environment. enrichment medium is
prepared with a defined chemical composition & inoculated
with soil or water rich in microbes.
• He discovered free living nitrogen fixing bacteria by
enrichment media devoid of nitrogen. Aerobic forms he named
as Azotobacterium. Studied Rhizobium Symbiotic nitrogen
fixer
• He described major group of bacteria. The luminous
bacterium Photobacterium, sulphate reducers (Desulfovibrio)

46. • Methane generating bacteria, Thiobacillus denitrificans
(denitrifying bacteria) He proposed the genus Lactobacillus
• Recognized existence of soluble living organisms he called as
“Contagium Vivum Fluidum” accepted as initial description
of Virus (TMV). He opened the concept of physiology,
ecology and Environmental Microbiology

47. Sergei Winogradsky (1856-1953)
• Born in Russia & witnessed the origin of Microbiology and
survived to see the age of even antibiotics Both Winogradsky &
Beijerinck spent time in the lab of great mycologist Sir Anton
de Bary (1831-1888). From his studied on Baggiatoa he
concluded that organism could utilize inorganic H2S as source
of energy & atmospheric CO2 as C source for synthesis of
cellular material. Named these organisms as orgoxydants &
opened the concept of Autotrophy
• After the death of de Bary he went to Zurich where he isolated
and clarified the role of nitrifying autotrophic bacteria
• He also suggested that Green & Purple Sulphur Bacteria could
oxidise H2Sto sulphate but not certain whether this process
was photosynthesis.
• He isolated N2 fixing anaerobic Clostridium pasteurianum

48. • At this time noted scientist & Noble Laureate Elie
Metchnikoff (1845-1916) carried a personal letter from
Pasteur to Zurich inviting Winogradsky to work at Pasteur
Institute
• Metchnikoff was discoverer of Phagocytosis & cellular
immunity
• He refuged the proposal & thought to return to Russia,
thus ending the first half of his illustrious scientific carrier
• He visited Paris in 1892 to represent Russia in 70th birthday
of Pasteur.
• After the revolution of Russia he migrated to Pasteur
institute & spent his life
• Specifdic role of blood in immune response better
understood throuh the work of Emil von Behring &
Shibasaburo Kitasato –he discovered that Tetanus is caused
by a bacterial toxin produced by Clostridium tetani

49. • He with von Behring demonstrated that rabbits
immunized with inactivated tetanus toxin (toxoid)
rendered immune to tetanus. Blood taken with
immunized one mixed with tetanus toxin
destroyed. More over when the immune serum
(serum blood minus cells & clotting factor ) was
injected to mice protected from tetanus. First
demonstration of passive immunization; immune
serum contains antitoxins, a blood protein which
specifically inactivates the toxin. Similar
experiment was performed against diptheria. He
made contribution for isolation of different
organisms from pond mud by technique Known as
Winogradsky column

50. Ronald Ross, an English physician working in the Far East in 1898
proved that mosquitoes were the vital link in malaria transmission. The
discovery earned him the 1902 Nobel Prize.
Another Englishman, David Bruce, isolated the cause of undulant fever.
Bruce also showed that tsetse flies transmit sleeping sickness.
A third British subject, Almroth Wright, described opsonins, the chemical
substances that promote phagocytosis in the body.
In 1897, the Tokyo physician Masaki Ogata reported that rat fleas
transmit bubonic plague. This discovery solved a centuries old mystery
of how plague spread.
A year later, Kiyoshi Shiga isolated the bacterium that causes bacterial
dysentery, an important intestinal disease. The organism was later
named Shigella.
The American microbiologists, Daniel E. Salmon and Theobald Smith,
were among the first to use heat killed bacteria for immunizations.

51. Salmon later studied swine plague and lent his name
to Salmonella, the cause of typhoid fever.
Smith showed that Texas fever, a disease of cattle, was
transmitted by ticks. The University of Chicago
pathologist Howard Taylor Rickkets located the agent of
Rocky Mountain spotted fever in the human bloodstream
and demonstrated its transmission via ticks.
Another American, William Welch, isolated the gas
gangrene bacillus at his laboratory at John Hopkins
University.
Walter Reed led a contingent to Cuba and pinpointed
mosquitoes as the insects involved in yellow fever
transmission.

52. Alexender Flamming
• Alexender Flamming a Scottish physician trained in
Microbiolgy was known for his work on host parasite
interaction. Fter world war I he studied the phenomenon of
phagocytosis & discovered a substance in tears, mucus and
body fluids which destroyed bacteria. A colleague of Flemming
named it as lysozyme- enzyme attacking bacterial cellwall
(peptidoglycan).
• While working on Staphylococcus variants a number of
culture plates were set apart on lab bench & examined these
plates were necessarily exposed to air became contaminated
with various microbes. It was noticed that around a large
colony of a contaminating mold the Staphylococcus colonies
became transparent & obviously under going lysis (Br. J Exp.
Pathology, 10: 226-236 , 1929) Industrial production started in
1942 by Florey & Chain

53. Paul Ehrlich in collaboration with Sakahiro Hata, discovered the
drug, Salvarsan, an arsenobenzol compound in 1910 for the
treatment of syphilis caused by Treponema pallidum.
Ehrlich laid important foundation of the era of chemotherapy which
is defined as the use of chemicals that selectively inhibit or kill
pathogens without causing damage to the victim.
Gerhard Domagk of Germany in 1935 reported that Prontosil, a red
dye used for staining leather, was active against pathogenic
streptococci and staphylococci in mice even though it had no
effect against the same infectious agent in the test tube.
The two French scientists Jacques and Therese Trefonel in the
same year showed that the compound Prontosil was broken down
within the body of the animal to sulphanilamide (sulpha drug)
which was the true active factor. Domagk was awarded Nobel Prize
in 1939 for the discovery of the first sulpha drug.

54. The credit for the discovery of the first”wonder drug”,
penicillin goes to a Scottish physician and bacteriologist,
Sir Alexander Fleming (Microfocus 1.7) in 1929 from the
mold Penicillium notatum. Fleming discovered the first
antibiotic which is a microbial product that can kill
susceptible microorganisms and inhibit their growth. Sir
Howard. W. Florey and Ernst B. Chain at Oxford
University in 1941 developed methods for industrial
production of penicillin in England. Fleming, Florey and
Chain shared the Nobel Prize in 1945 for the discovery
and production of penicillin.

55. • At the time of World War II (1939–44), S. A. Waksman of
Rutgers’ University, USA discovered another antibiotic,
streptomycin along with Albert Schatz in 1944 from an
actinomycete, Streptomyces griseus. Waksman received
the Nobel Prize in 1952 for his notable contribution and for
the discovery of streptomycin used in the treatment of
tuberculosis, a bacterial disease caused by Mycobacterium
tuberculosis, that had been discovered by Robert Koch in
1882. Dr. Paul R. Burkholder in 1947 isolated
chloramphenicol (chloromycetin) from Streptomyces
venezuelae. Dr. B.M. Dugger in 1945 Tetracyclin &1948
identified aureomycin from Streptomyces aureofaciens and
terramycin was discovered by Finlay, Hobby and
collaborators in 1950 from Streptomyces rimosus.
• Antibiotic production continues to be the important area of
industrial research. Currently, there are over 8000
antibiotics known, of which only a few are being used as
chemotherapeutic agents.

56. Viruses
• In 1892, D. Ivanovsky, a Russian scientist, had studied
tobacco mosaic disease, in which infected tobacco
plants develop a characteristic mosaic pattern of dark
and light spots. He found that the tobacco plant juice
retained its ability to cause infection even after it was
passed through a filter. The filtration technique used by
Ivanovsky would have filtered out all known bacteria,
and the fact that the filtered juice remained infectious
must have meant that something smaller than a
bacterium and invisible to the ordinary light
microscope was responsible for the disease. The
filterable agent—a virus

57. Six years later M. Beijerinck, a Dutch scientist, realized
the significance of Ivanovsky’s discovery& concluded
that tobacco mosaic disease was caused by a previously
undiscovered type of infective agent, a virus. In 1932,
Stanley moved to the Rockefeller Institute’s Division of
Plant Pathology in Princeton, New Jersey. He was
primarily interested in studying viruses. Viruses were
known to cause diseases in plants and animals, but little
was known about how they functioned. Stanley’s
assignment was to characterize viruses and determine
their composition and structure. Stanley began work on a
virus that had long been associated with the field of
virology He was aware of recent techniques used to
precipitate the tobacco mosaic virus (TMV) with common
chemicals. These results led him to believe that the virus
might be a protein susceptible to the reagents used in
protein chemistry

58. 1915–1917 D’Herelle and Twort discover bacterial viruses
1911 Rous discovers a virus that causes cancer in
chickens
1950 Lwoff Induces lysogenic bacteriophages
1952 Hershey and Chase show that bacteriophages inject
DNA into host cells
Zinder and Lederberg discover generalized transduction

59. • 1982 Stanley Prusiner isolates a protein from a slow
disease infection and suggests that it might direct its
own replication. He suggests the agent be termed a
prion.
• Barry Marshall demonstrates that a bacterium,
Helicobacter pylori, causes ulcers.