Chapter 1
History of Microbiology
Today’s Class
• General Information
• Course Outline
• Lab and Lab Schedule
• Chapter #1 Almco’s Fundamentals of
Microbiology J.C. Pommerville
– Microbiology: Then and Now
Books
• Alcamo’s Fundamentals of Microbiology
• Lab manual: Leboffe, M. and Pierce, B.
Microbiology Laboratory Theory and
Application
Instructor
• Thomas Graham
• Background 15 years Health Canada
– Escherichia coli O157:H7 and other VTEC
– Salmonella and Campylobacter
– Master’s Thesis on Listeria monocytogenes
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thomas.graham@lethbridgecollege.ab.ca
Best way to get hold of me is through Email.
I will set-up regular office schedule.
I check my Email every day.
WebCT post all information there as well
(hopefully).
Course Outline
• The class is broken down into three
sections
• After each section there will be an exam
• Two midterms and one final
• Also, during class there will be two
assignments
– Assignment #1 will be on describing a
infectious bacterial pathogen.
– Assignment #2 Group presentation on fungal,
parasitic or viral infections in humans.
Lab Schedule
• No, there is no lab this week (orientation, safety
and microscopy).
• Two lab assignments (handouts).
• You must have a lab coat you can ask Cherie if
there are any left for sale CB4002.
• Miss 2 labs and you will fail unless you have a
medical reason.
• Marking sheet will be provided you are
responsible for bring them to each lab.
• Must go down to maintenance and have your
card swiped to get access to the lab.
Do you have any questions?
• Speak now or forever hold your peace!!!
• What are your majors (ie are you all nurses ?)
• Major problem in Microbiology is learning all the
new terms.
Chapter 1
Alcamo’s
Microbiology: Then and Now
Microorganisms
• Microorganisms are ubiquitous (every where)
throughout the world.
– Antarctica, tallest mountain and deepest part
of the sea.
• Microorganisms are defined as any organism
too small to be visible to the naked eye (not
really true mushrooms).
• Most microorganisms are harmless and wide
variety are beneficial to life and without them we
would be soon be over run with dead plant and
animal material.
Microorganisms
• They produce around 50% of the oxygen that
we breath.
• However, when people hear the words viruses,
parasites and bacteria they automatically think
of infection and disease.
• The pathogens (any microbe that causes
disease) have caused a number of major
epidemics plague, cholera and small-pox,
influenza, AIDs.
Tragedy In Eyam
• 1665 – 1666
• A tailor brought some plague infected fleas in
cloth to the village.
• Soon the village had its first cases of the plague.
• The village folks decided to stay in their village
to insure that the other villages did not get
infected.
• 260 of 350 died
Nursery Rhyme
• A ring-a-ring of rosies (rose colored blotches)
• A pocketful of posies (flowers used to lessen
the stench of the dead)
• A tishoo! A tishoo! (sneezing)
• We all fall down. (death)
THE BEGINNINGS OF MICROBIOLOGY
• Robert Hooke, 1665
– Published “Micrographia”
– Developed first microscope
– Sliced a cork and observed it’s micro structure he called
“cella”
– Poor magnification 25 x
• Anton van Leeuwenhoek, 1674
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Developed a lens system from ground glass
Magnify up to 300 times
Looked at water, tooth scum and faeces
He described “Animalcules” tiny animals
Looked at teeth scum and suggested that the population
of animalcules on your teeth was larger then the people
in many big cities
Anton van Leeuwenhoek, 1674
Leeuwenhoek’s Lens System
The Transition Period
Does Life Generate Itself Spontaneously?
• Basis of the doctrine of spontaneous generation.
• Aristotle fourth century B.C. suggested that
flies, worms and other small animals arose
spontaneously from decaying material without
parents.
• Jan Baptista van Helmont 1600’s observed rats
that originated from wheat bran and old rags
and no parents.
Spontaneous Generation
• Others saw worms produced from rotting meat
and frogs produced from slime.
• The only one who did not believe these ideas
was Leeuwenhoek who had observed tiny eggs
with his special microscope.
• Fransesco Redi's, 1668 set out to dispute the idea of
spontaneous generation
Redi’s Experiment
• He set-up a number of experiments where he
covered some jars of meat with fine lace cloth
to prevent flies from entering and laying eggs.
• In these jars there were no maggots.
• In other jars he did not cover he found maggots.
• He suggested that the only way that this could
happen was due to flies laying invisible eggs
that hatched and gave rise too maggots.
Francesco Redi
This was the beginnings of experimental science
• Needham's, 1748 had objections
– He had followed Redi’s method but used boiled gravy and a cork in jar
– His however gave rise to the “animalcules”
– He was rewarded with a membership in the Royal Society of London for
disproving Redi
– It was actually one of the first documented experimental errors
(contamination of the cork).
• Spallanzani's, 1767 criticized Needham’s work
– Spallanzani boiled meat and vegetable broth for long periods
– He then made 3 flasks; one open to the air, 1 corked like Needham’s and
the last flame sealed the neck of the flasks
– The first two grew “animalcules” the last one did not.
• Needham countered by saying Spallanzani had killed the vital
life force by over heating and sealing the jars from the life giving
air.
Finally Louis Pasteur Ended the Debate
• He developed an elaborate experiment using four
different flasks.
• One was left open to the air.
• One was sealed by melting the glass.
• One had an open tube with heat that would sterilize
the air.
• The final tube had a long bent neck which prevented
microbes from reaching the broth.
Read The MicroInquiry 1
Alcamo’s Fundamentals of
Microbiology Pg 12-13
The Idea That Microorganisms May be the
Cause of Disease
• Edward Jenner’s, 1798
– Developed an inoculation against smallpox that
interrupted transmission of the disease.
– First vaccination procedure.
– He had no idea what caused smallpox or the mode of
transmission.
• Ignaz Semmelweis, 1847
– Many pregnant women were dying of puerperal
(childbed) fever a blood poisoning resulting from bacterial
infection of the uterus.
– He determined that student physicians would come from
autopsies to delivering babies.
– He first suggested hand scrubbing chlorine and lime.
– Amount of deaths dropped dramatically.
Epidemiology – scientific study from which health
problems are identified, including source, cause and
mode of transmission
• Semmelweis may have used epidemiology first
John Snow, 1854 took it to a new level.
• Snow used it during an Cholera outbreak in
London.
• Interviewed rich and poor the sick and healthy
people.
• Plotted locations of each cholera case.
John Snow
• Traced source of outbreak to sewage
contaminated water pumps in the streets.
• Identified drinking water as the source
without isolating the causative agent.
• He ordered the removal of the handles off
of all public water pumps.
Spatial Association Between E. coli O157 Infection and
Cattle Density in Ontario (1990 - 1998)
N
N
Cattle - Pop ratio (%)
no cattle
low (0 .1 - 9.57)
median (9.58 - 80.42)
high (80.43 - 104.40)
very high (104.41 - 272.93)
VTEC 1990 - 1998 (rate /100,000 pop.)
low (0 - 2.73)
median (2.74 - 5.14)
high (5.15 - 6.60)
very high (6.61 - 8.26)
Ottawa
Ottawa
#
#
L. H uron
L. Huron
Walkerton
a
%
a$
%
a
%
a
%
#
L. O ntario
#
L. O ntario
Toronto
Toronto
L. Erie
L. Erie
Cases of human O157:H7 infections
Cattle density (Cattle to Human population ratio)
Michel et al. (1999)
Health Canada
Santé Canada
The Classical Golden Age
of Microbiology
(1854 – 1914)
Germs Cause Infectious Disease
• Louis Pasteur proposes that germs cause
infectious disease.
• First he was asked to determine why wine went
sour by a local merchant.
• 1857 Pasteur found that wine was produced
from the fermentation grape juice by
microorganisms (yeast), not the breakdown of
chemicals in grapes, as was believed at the
time.
Louis Pasteur
• He proved this by removing all the yeast from
the wine. This stopped fermentation.
• Then he returned the yeast and fermentation
resumed.
• He also showed that the souring of the wine
was the result of bacterial contamination.
Microorganisms were small reproducing factories.
• From the wine work Pasteur’s wrote a paper in 1857 and in
it proposed that germs were related to human illness and
formulated the germ theory of disease.
• Germ Theory Of Disease: stated that microorganisms are
responsible for many diseases.
• He also suggested in the same paper, that to control the
souring of wine, that had initially lead to this work, a wine
maker would only need to heat the wine to kill the bacteria
and the wine would be fine.
• This process was accepted and was termed pasteurization
many years later.
Pasteur’s work Contributes To Disease
Identification and Control
• In 1859 Louis Pasteur’s daughter Jeanne died of typhoid
and this lead him to focus most of his work in to controlling
diseases.
• He demonstrated that bacterial broth of Cholera inoculations
made animals ill but was unable to show the true causative
agent.
• His critics had claimed that the toxins in the broth had
caused the animals to be sick not the bacteria.
• In 1865, his two year old daughter Camille died of blood
poisoning.
Silkworms
• In 1865, Pasteur turned to looking at Pebrine a disease
in silkworms to isolate disease.
• In this work he isolated a protozoan as the cause of the
silkworm disease.
• By changing feed and separating the health silkworms
from sick Pasteur he stopped the spread of the disease
and saved the silkworm industry in France.
• However, at the age of twelve Pasteur’s third daughter
Cecille died of typhoid disease.
• This lead Pasteur to work on human diseases.
Hansen, Obermeier, Cohn and Lister
• Pasteur work stimulated other researchers to look at
microorganisms as disease causing agents.
• Gerhard Hansen identified bacteria in leprosy patients.
• Otto Obermeier described bacteria in the blood of relapsing
fever patients.
• Ferinand Cohn discovered that bacteria could divide into large
numbers (replication).
• Joseph Lister
– suggested that gangrene was caused by bacteria.
– To block transmission of disease during surgery he used carbolic acid to
clean wounds and surgical equipment.
Robert Koch
• Robert Koch focused on anthrax.
• Anthrax was a deadly bacterial disease that was
killing a large number of cattle and sheep in
Germany.
• Koch set-up a lab in his house to do his studies.
• In 1875, Koch injected mice with blood from an
infected sheep and the mice died.
• He noted at autopsies the mice had died from
the same disease as the sheep.
Koch
• He was able to isolate a rod shaped bacteria from the
blood of an ox’s eye.
• From hours of tedious observations of these bacteria
he observed that these bacteria multiplied into tangled
threads then formed into highly resistant spores.
• He took some of the spores and injected them into
mice.
• The infected mice soon showed the signs of anthrax.
• Following autopsies he was able to see swarms of the
same bacilli in the blood of these mice
Koch Postulates
Koch’s Postulates
• Koch procedures became known as “The Koch
Postulates”.
• These procedure gave a procedure that can be used
to identify and isolate germs from infectious disease.
• Therefore, can relate specific organisms to a specific
disease.
• This method of pathogen detection is still used today.
Koch Developed Pure Culture Techniques for Isolating Bacteria
• Koch developed a cultivation technique using sliced potatoes.
• He noticed that he could get small masses of bacteria on the potato
which he termed colonies.
• Colonies – are viable mass of microorganisms, usually of a single
type.
• He soon added gelatin to broth and made it solid.
• He inoculated it with bacteria and next day he could see colonies.
• This lead him to develop a pure culture method.
• Pure Culture – an accumulation of one type of microorganism
formed by the growth of colonies of that organism
Pure Culture Inoculation
• Koch now could quickly get pure cultures to
inoculate into animals to test for infection.
• In 1881, Koch published his methods for pure
culture.
• Koch received a letter of congratulations from
Pasteur who had never been able to isolate
infectious bacteria.
Agar and Petri Dish
• Koch did not like the gelatin he had used as a solidifying agent.
• Turn liquid at high temperatures and by chemicals produced by
the microorganisms.
• A wife of one of Koch’s associates had suggested the use of a
seaweed extract (agar) as a solidifying agent.
• Fanny Eilshemius had used agar as a jelling agent for her jams
and jellies.
• Today it is still the most used solidifying agents for culture
media.
• Petri dishes were also invented by an assistant of Koch named
Julius Petri.
Competition fuels the study of infectious disease
Pasteur and Koch
• Pasteur lab: focused on infection and immunity.
• Anthrax (1878)
• Anthrax showed that chickens did not become infected by anthrax because
their body temperature was 42ºC.
• but did if their temperature was cooled to 37ºC.
• Cholera (1880)
• Developed a weakened bacteria that does not cause chicken cholera.
• He injected the weaken bacteria into chickens and then treated them with
the lethal strain of cholera bacteria.
• The chickens did not develop disease..
• lead to the principles for vaccination
Koch
• Koch lab: focused on isolation, culture, and
identification.
• Isolated the causative agent for caused
tuberculosis, typhoid, and diphtheria bacilli.
• Kitasato a scientist working in Koch’s lab
isolated tetanus bacillus Clostridium tetani.
Pasteur
• Elie Metchnikoff working in Pasteur’s lab
discovered phagocytes an immunological
defensive process were white blood cells
engulf and destroy microorganisms.
• **1885 Pasteur successfully immunized a small
boy, Joseph Meister, infected with rabies with
bits of tissue isolated from the brain of a rabid
animal.
Other Global Pioneers Contribute to Microbiology
• Nicolle - showed that lice transmitted typhus.
• Calmette - developed immunization process for tuberculosis.
• Bordet – isolated pertussis bacillus.
• Pfeiffer – identified the cause of meningitis.
• Ehrlich – working on syphilis developed first synthetic drug “magic
bullet” out of arsenic.
• Ross – mosquitoes caused malaria.
• Bruce – tsetse flies cause sleeping sickness.
Microbes represent a diverse group of organisms
• Fungi
• Protista
• Bacteria
• Viruses
Fungi
• Mushrooms, puffballs, truffles, molds and
yeasts.
• 70,000 species.
• May be as many as 1.5 million species because
most have not been discovered.
• Grow best in warm, moist places.
Fungi
• Secrete enzymes that breaks down nutrients,
therefore, grow on food source.
• Produce useful products.
– Antibiotics like penicillin
• Used by food and alcohol industry.
• Together with bacteria play a major role in
decomposing dead matter.
Protista
• Single-celled protozoa and algae.
• 200,000 species.
• Some can be free-living others need plant or
animal hosts.
• Locomotion is achieved by flagella, cilia or
crawling.
Protista
• Protista obtain food by absorbing from
surroundings or by eating small animals and plants.
• Algae make their own food through photosynthesis.
• Most protozoa are important as food for other
animals (snails, clams, and Sponge Bob Square
Pants).
• However, some cause disease
– Malaria
– Sleeping sickness
– Diarrhea
Bacteria
• 10 million species and billions that have not yet been
discovered.
• Simple singled-celled organisms that do not have a
nucleus.
• Divided into two groups
– Eubacteria
– Archaea
• Three shapes
– Bacillus (rod shaped)
– Coccus (spherical)
– Spirillium (spiral)
Bacteria
• Decomposers sewage treatment.
• Food industry yoghurt and cheese.
• However, also responsible for food spoilage.
• A number are pathogenic
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Tuberculosis
Typhoid
Plague
Hamburger Disease
Etc.
Viruses
• 3,600 known types of viruses.
• Structurally simpler than all other microbes.
• Not true cells.
• Core of nucleic acid (DNA or RNA) surrounded by a protein
coat.
• Features used to identify viruses
– Nucleic acid type, size, shape and biological properties
• Small number cause human disease
– Smallpox, polio, measles, flu, AIDs and SARs are some
examples
THE SECOND GOLDEN AGE OF
MICROBIOLOGY (1943-1970)
• Development of Genetics depended on work with
microorganisms.
• In 1943 Salvador Luria and Max Dulbruck used
Escherichia coli to show that bacteria can form
spontaneous mutations that generates resistance to
viral infection to bacteria phage.
• This research also showed other researchers that
bacteria, especially E. coli, were excellent model
systems for studying general principles of genetics.
MICROBIOLOGY (1943-1970)
• Beadle and Tatum used fungus, Neurospora, to show
that one gene codes for one enzyme.
• 1953 Hersey and Chase showed that DNA was the
substance of genetic material using bacteria viruses
(bacteriaphage).
• Watson and Crick worked out the structure of DNA
New Microscopes Opened Up New Worlds
• New type of microscope was developed.
• Electron microscope could magnify objects 1000 times better
then the light microscope.
• This allowed researchers to see that bacteria were actually
cellular like other microbes.
• However, they were organized differently than other microbes.
• Allowed researchers to classify two types of cellular
organizations:
– Eukaryotic cells
• DNA surrounded by a membrane envelope = cell nucleus
• Karyotic with nut
– Prokaryotic cells
• DNA not surrounded by an envelope
• Without nut
Chemotherapy and antibiotic are used to combat
infectious disease.
• After the relationship between microorganisms and
disease was established the search for substances
to destroy them took off.
• Chemotherapy – treatment of disease with
chemical substances.
• Synthetic drugs – prepared from chemicals in a lab.
• Paul Ehrlich, 1910 synthesized the first synthetic
drug.
Synthetic Drugs
• Ehrlich, said that his chemical was the “magic bullet”.
• It was derived from arsenic.
• Ehrlich showed that it was very effective at curing syphilis.
• The chemical was called salvasan (Gave salvation to syphilis
suffers).
• Soon more drugs were synthesized that could destroy
microorganisms.
• A large number of these were made from derivatives of
clothing dyes.
A Fortunate Accident
• Alexander Fleming, 1929, left bacterial plates on
bench and left for a two week holiday.
• When he returned he found that a mold (Penicillium)
had killed some of the bacteria that were near to it.
• Fleming then set out to find out what had occurred.
• He soon had developed an assay for the detection of
the antimicrobial substance from Penicilium.
• He termed this new substance penicillin.
Antibiotics
• Florey and Chain, 1940 purified large amounts of penicillin
and carried out trials to show the antimicrobial potential of
penicillin.
• Gerhard Domagk, 1932, discovered the first sulfa drugs
that prevented the production of folic acid in bacteria.
• Selman Waksman discovered actinomycin and
streptomycin he called these two new substances
“Antibiotics”.
• Antibiotics: Are defined as any chemicals produced
naturally from bacteria and fungi that act against other
microorganisms.
Antibiotics
• The research into antibiotics took off in
World War II to help treat infections in war
casualties.
• In 1969, the US Surgeon General declared
that it was time to close the book on
infectious diseases.
• However, many of the drug companies who
were making a lot of money from these
antibiotic drugs.
• Had failed to mentioning one little problem.
• Many of the bacteria were starting to show
signs of resistance to the antibiotics, as
early as the 1950’s
End of the Second Golden Age
• Near the end of the 1960’s many believed that the
antibiotics would soon bring an end to the age of
infectious disease.
• This lead to a decrease in research funding for
microbiology.
• Researcher’s started to take all the information
learned from bacteria research and apply it to
research on animals.
The Third Golden Age of Microbiology (Now)
• Again Microbiology finds itself in the front lines of
research.
• A lot of this is due to biotechnology research era.
• Allows for the complete DNA sequencing of bacterial
genomes (Genomics).
– Development of microarrays.
• Also, infectious diseases are still around and are
getting a little nasty.
– More than a 11 million people die from tuberculosis, malaria,
lower respiratory infections and diarrheal diseases each
year.
Microbiology Challenges
• Antibiotic resistance
– Increasing inability to treat infections.
– More and more pathogens are becoming resistant to
antibiotic antimicrobial drugs.
– “Superbugs” MRSA, VRSA, others?
– One bonus is microbial genomics.
– Knowing the genes may be able to developed treatments to
attach bugs.
– Also vaccination development.
Emerging and Reemerging Diseases
• Emerging diseases are the diseases that we have
never seen before.
– AIDs, hantavirus pulmonary syndrome, Lyme
disease, Mad Cow and SARs.
• Reemerging diseases the ones that have been seen
before but are again having a resurgence (usually due
to antibiotic resistance).
– Cholera, Tuberculosis, Dengue fever, West Nile
Bioterrorism
• Bioterrorism – use of biological agents to cause
death and disease on large populations.
• Small Pox, Anthrax, Plague
• On the positive sides to this has focused a lot of
funding dollars back into research of infectious
microorganisms and molecular epidemiology.