Transcript history - West Campus | Pima Community College, Tucson

HISTORY AND SCOPE OF
MICROBIOLOGY
History
• 1665 Robert Hooke observed
living plant tissues (20X
mag.)
• “Little boxes” or Cells
• Used simple magnifying lens
• Suggested all living things
are made of cells
Hooke's Microscope
1665
Antonie van Leeuwenhoek
was inspired by this
publication
Antonie van Leeuwenhoek
(1677) (“layu-wen-hook”)
–First observation of living cells
(200-300X mag.)
–“Animalcules”
–Single lens Microscope (Self
made)—simple microscope
–Tooth plaque
–Rain water
–Diarrheal feces
Antonie van Leeuwenhoek
• Bacteria
• Protozoa
• Sperm cells
• Blood cells
• Microscopic
worms
Antonie van Leeuwenhoek’s
microscope
3-4” microscope
Required good
lighting and
patience
Spontaneous Generation
• The idea that life could arise
spontaneously from nonliving
matter
–Ex: Toads and Mice could arise
from soil
th
–Until the 18 century this
believe existed
History (cont.)
• 1668 Francesco
Redi
st
–1 one to
disprove
spontaneous
generation
Francesco Redi’s experiments
with meat
uncovered
covered
Maggots
No maggots
Disproved that maggots arise from decaying meat!!
British clergyman John Needham’s
experiments (1745)
• Proved (??) spontaneous generation
in chicken broth
• Heated Nutrient Fluids and poured
them into covered flasks
Hot Mutton
gravy
Turbid
broth
“...my phial swarm’d with life...”
Italian priest Lazzaro
Spallanzani (1765)
• Similar to Needham’s
Experiments
• He showed that heating a
sealed flask of meat broth
prevented growth of organism
• Skeptics claimed—lack of O2
prevented growth!!
The Golden Age of
Microbiology!
•Louis Pasteur (finally disproved
spontaneous generation after many years
of debate)
•Robert Koch (proof of germ theory)
•Other pioneers in Microbiology
Pasteur—Father of
microbiology
•1857- Louis Pasteur saves France’s wine
industry
•Napoleon III begged Pasteur (a chemist
by training) to help solve a problem
•Sailors were mutinying b/c their wine
was spoiling after only a few weeks at sea
•Pasteur armed with his trusty
microscope accepted the challenge
Luis Pasteur
Louis Pasteur (1861)
–Spontaneous Generation finally
disproved
–Boiled broth in long-s-shaped necked
flasks (unsealed)
• Remained sterile
• Proved that microorganisms are
present in air, but air does not create
microbes
–Beginning of the golden age of
microbiology
Swan neck flask experiment disproved spontaneous generation(1861)
History (cont.)
• 1861 Pasteur
–Proved Microorganisms are present in
nonliving matter
–Microbes can be destroyed by heat
• Aseptic Technique
• Fermentation mediated by yeast, not air
–Pasteurization to prevent wine and beer
spoilage (by bacteria)
1857-Louis Pasteur saves
France’s wine
1)Good wine contained yeast
2)Sour wine contained bacterium (Bacteria
that use alcohol and produce acetic acid spoil wine by turning it to
vinegar (acetic acid).
3)He reasoned that if wine is heated to
destroy the harmful bacteria it
wouldn’t spoil (process known as
Pasteur’s Tomb in the Crypt of the Pasteur Institute in Paris
Germ Theory of Disease
• Pasteur proposed that wine
spoiling in an analogy for
disease (bacterial growth made the
wine “sick”)
• He hypothesized in 1857 that
microorganisms are responsible
for infectious diseases
Edward Jenner (country doctor)
– Milkmaid didn’t get smallpox b/c they
contracted the milder form of cowpox
– Immune system cannot distinguish btw
cowpox/smallpox
– Scratched a farmboy w/ a needle bearing
fluid from cowpox
– Small pox Vaccine
- -Vacca-cow
- Vaccination w/ cowpox provided
immunity for smallpox
Immunity
Protection from a
disease from
vaccination
Robert Koch (1843-1910)
• German country physician who developed
microbiology into a science
• Developed pure culture techniques (used
potato slices to grow bacteria) developed agar later on
• Proof of the germ theory
• Work with anthrax
• Koch’s postulates
Bacillus anthracis
Pure Culture Key to Studying
Microbes
Definition: Pure culture is a
population of organism, all of which
are the progeny of a single organism
-In nature, microbes almost never
occur as pure cultures
AGAR
•Is a complex polysaccharide derived from
seaweed
•Was suggested by Fannie Hesse wife of
Koch’s co-worker Walther Hesse
•“why do your jellies and pudding stay solid in warm weather”?
•AGAR-AGAR had been used as a gelling
agent in Asia for centuries
•Fannie learned to use AGAR-AGAR from a
Dutch neighbor in New York who spent time in
Asia
Koch’s postulates
1)Specific microorganism is present in all
cases of the disease
2)Organism can be obtained in pure
culture outside of the host
3)Organism when re-inoculated into host
causes the same symptoms
4)Organism can be isolated in pure culture
from experimentally infected host
Koch’s findings
Koch and his coworkers discovered that
bacteria caused
•TUBERCULOSIS
•CHOLERA
•DIPTHERIA
•TYPHOID FEVER
•GONORRHEA
•PNEUMONIA
Hungarian doctor Ignaz
Semmelweis
(1818-1865)
• Taught medicine in Vienna
• No one connected germs w/
disease yet
• Puerperal fever “childbirth fever”
caused 25-30% mortality
• Nearby obstetric hospital had
only a 2% death rate
Ignaz Semmelweis (cont.)
• He made some observations
• Medical Students working on
cadavers moved from the
dissecting room to the maternity
ward
• Midwives
–Stayed only in maternity ward
Ignaz Semmelweis (cont.)
• Ordered students to wash
hands and medical
instruments in chlorinated
lime
• Mortality dropped to 1.3%
• By 1848, 0% mortality
Paul Ehrlich-hospital
dermatologist
• ChemotherapyTreatment using
chemical substances
• 1910 Paul Ehrlich
-”Magic bullet”
–Salvarsan (arsenic
derivative)
• Preparation 606
–Syphilis
Alexander Fleming –scottish
researcher--1928
• Discovered Penicillin (fungus) by
accident
• Was convinced that nasal mucus
had antibacterial effects
• Left his Staphylococcus culture on
an agar plate for 2 weeks-went on
vacation-came back &found mold
on his plate which prevented
bacterial growth (a mycology lab
underneath him had this rare spore drift)
Founders of Microbiology
(Review)
•First observed microbes—
Leeuwenhoek
•Proved living cells can arise only from
other living cells---Pasteur
•Confirmed the Germ Theory of Disease
--Koch
Scope of microbiology
Microbiology
• Bacteria
• Fungi
• Viruses
• Immunology
Bacteria
• Medical importance
–Gastroenteritis
–Syphilis
–Tetanus
–Lyme disease
–Plague
Bacteria (cont.)
• Industrial importance
–Food supplements
•Amino acids & Vitamins
–Organic solvents
•Acetone
Bacteria (cont.)
• Pharmaceutical
importance
–Antibiotics
•polymyxin
–Hormones
•Insulin
Biotechnology and
Recombinant DNA
• Biotechnology:
–The use of microorganisms, cells, or
cell components to make a product
–Foods, antibiotics, vitamins, enzymes
• Recombinant DNA Technology:
–Insertion or modification of genes to
produce desired proteins
Figure 9.1.1
Bacteria (cont.)
• Environmental importance
–Biodegradation
•Oil spills
•Wastewater treatment
Figure 9.1.2
Gram positive
S. aureus
Gram negative
E. coli
Fungi
• Medical importance
–Valley fever
–Candidiasis
–Athlete's foot
Fungi (cont.)
• Industrial importance
–Fermentation
•Wine
•Beer
•Bread
Fungi (cont.)
• Pharmaceutical importance
–Antibiotics
•Penicillin
Fungi (cont.)
• Environmental importance
–Wastewater treatment
–Degradation of complex
organic matter
•Lignin in wood
Viruses
• Medical importance
–HIV
–Influenza
–Rabies
–Common cold
Viruses
• Genetic engineering
–“Gene shuttles”
–Treatment of some genetic
disorders
DNA can be inserted into a
• Microinjection
cell by:
• Gene gun
Figure 9.6 & 7
Viruses (cont.)
• Environmental importance
–Unknown
ADENOVIRUS
HERPESVIRUS
Emerging Infectious Diseases
• West Nile encephalitis
–West Nile Virus
–First diagnosed in the West
Nile region of Uganda in
1937.
Emerging Infectious Diseases
• Bovine Spongiform Encephalopathy
– Prion (infectious proteinaceous material)
– Also causes Creutzfeldt-Jakob disease
(CJD)
– New-variant CJD in humans related to
cattle fed sheep offal for protein.
Emerging Infectious Diseases
• Escherichia coli O57:H7
–Toxin-producing strain of
E. coli
–Fist seen in 1982
–Leading cause of diarrhea
worldwide.
Emerging Infectious Diseases
• Invasive group A
Streptococcus
–Rapidly growing bacteria
cause extensive tissue
damage.
–Increased incidence since
1995
Emerging Infectious Diseases
• Ebola hemorrhagic fever
–Ebola virus
–Causes fever, hemorrhaging,
and blood clotting
–First identified near Ebola
River, Congo
–Outbreak every few years
Emerging Infectious Diseases
• Hantavirus pulmonary syndrome
– Hantavirus
– Fist identified in 1951 in Korea as cause
of hemorrhagic fever and named for
Hantaan River
– A new disease involving respiratory
symptoms was seen in the U.S. in 1995
– The U.S. virus, called Hantavirus Sin
Nombre virus, probably came to the U.S.
with rats around 1900
Emerging Infectious Diseases
• Acquired immunodeficiency syndrome
(AIDS)
– Human immunodeficiency virus (HIV)
– First identified in 1981.
– Worldwide epidemic infecting 40 million
people; 14,000 new infections everyday.
– Sexually transmitted disease affecting males
and females.
– In the U.S., HIV/AIDS in people 13-24
years of age: 44% are female and 63% are
African American.
Emerging Infectious Diseases
• Anthrax
– Bacillus anthracis
– In 1877, Koch proved B. anthracis causes
anthrax.
– Veterinarians and agricultural workers are
at risk of cutaneous anthrax.
– In 2001, dissemination of B. anthracis
via mail infected 22 people.