Download Unit1 intro to micronotes

UNIT 1: INTRO TO
MICROBIOLOGY
"Thou shalt not be afraid for the terror by
night, nor for the arrow that flieth by day,
nor for the pestilence that walketh in
darkness....psalm 91
Microbiology
• Microbiology: study of microscopic
forms of life.
• Microorganism: minute living things
that individually are too
small to be seen with the naked eye.
BENIFICIAL ACTIVITIES OF
MICROORGANISMS:
1. forms the basis of food chain in
oceans, lakes and rivers.
2. Decomposition of sewage and solid
and industrial waste.
3. Used in synthesis of certain chemical
products such as alcohol,
acetone and drugs.
4. Makes vitamins in digestive tract of
humans.
microscope
5. Used in making foods such a pickles
cheeses, yogurt, alcoholic
beverages, ect.
6. Produce theraputic substances such
as growth hormone, insulin,
ect..
7. Incorporate nitrogen gas from air into
compounds in soil.
HARMUL EFFECTS:
1. Cause disease.
2. Food spoilage
HISTORY:
• 14th Century plague so severe Pope
consecrated the river Rhone at
Avignon so corpses flung in river might be
considered to have had
Christian burial.
• 1590: Janseen invented microscope
• 1665: Robert Hooke published book called
Micrographie which contained info on chemicals,
a description of microscope, and microscopic
illustrations. Showed that contained cork
compartments called cells.
•
•
Schleiden and Schwann: Cell Theory : all living
things composed of cells. ( based on Hooke's
observations)
1675: Van Leeuwenhook ( father microbiology)
made microscopes ( magnification 270X) and
proficient with them.
• Made detailed descriptions, of protozoa, bacteria,
yeast and algae.
• Observed microorganisms in cloudy water and
called them animalcules (1723 age 92) after his death
microbiology had a period of dormancy for 150 yrs
SPONTANEOUS GENERATION:
•
•
1.
2.
3.
4.
5.
Belief that some forms of life could arise
spontaneously from non-life.
Example: .
Flies from manure
maggots form rotting meat
rats from dirty towels
frogs and snakes from mud bottom of pond
sperm injected into cucumber...people
BIOGENESIS: living cells arise only from preexisting
living cells.
• 1668 Redi: Tried to disprove spontaneous
generation through experimentation using
Scientific method.
• 1748: Needham: reported that bacteria arose
spontaneously where no living forms
existed.
• 17th century bubonic plague caused collapse
of eastern Roman Empire ( 24 million deaths
in 6 yrs)
• 1760 Spallanzani: Questions Spontaneous
generation
• 1774 Joseph Priestly discovered Oxygen and
Lavoisier showed importance of oxygen to
life.
• 1789 Edward Jenner: develops
inoculation for small pox (
inoculation: variolation latin for small
pox).
• Before Jenner, Doctors would "Sow
pox" to help patients acquire immunity.
• llth century Chinese doctors would
make a powder from dried scabs of
victims with mild case of small pox and
then have healthy patient inhale
powder through straw... other would
rub scab powder into would…
• Problem was a weak acting germ in one
person might be virulent in another.
• 1831: 9 yr old boy sees a man mangled by
rabid wolf, goes home and
asks what
makes wolf go mad...father answered the
devil got into him....the boy was Louis
Pastuer...the quest begin
• 1858 Virchow: challenged spontaneous
generation , added to cell theory: all
organisms made of cells, cell simplest unit of
life.
• 1861: Pasteur : proved Biogenesis with swan
neck flask
experiment.
GOLDEN AGE OF
MICROBIOLOGY 1857-1914:
•
1857 Pasteur: discovered yeast caused
fermentation of wine.
• Pasteruization Pasteur found that bacteria could be
destroyed by heating the juice to a temperature o
f62.8 F for 30 min sets the foundation for the germ
theory
• GERM THOER Y OF DISEASE: infectious diseases
are caused by microorganisms.
• MI AM A: altered chemical quality of atmosphere.
Most scientist thought miasma caused disease.
• Mid 1600 Kircher observed microscopic worms in
plague victims.
• 1847 Semmelwies: performed autopsies on woman
who died of
childbed fever (1 in 4 giving birth in hospital died of
this uterine
infection as opposed to less than 1 % of those who
gave birth at home)... conclusion: doctors believed
the bloodier, crustier the lab coat..the better the
doctor...hence doctors performed
autopsies on dead women the went to labor ward to
deliver the
babies, transferring the infection.
• If wash hands in chlorine water it would cut down
on infection in maternity patients ....
• sad note Semmelwies died of childbed fever 1865.
• 1860 Joseph Lister: Used carbolic acid
treat surgical wounds(before this 8 out
of 10 surgery patients died of infection
termed surgical sepsis)( surgeon were
used to the nauseating stench of
putrefying flesh in the post surgical
ward) ( body cavity surgery
impossible except in direst
circumstances such as burst appendix
or ruptured spleen)
• 1876 Robert Koch: proved germ theory of
diseases ( Koch's Postulates)
• Koch also developed the solid medium: agar
( with help from lab assistant Fanny
Eishemius by using Japanese
seaweed (agar-agar) as solidifying agent....
• she used it in canning food.
• He perfected dyes in staining
microorganisms on glass and id bacillus
causing agent for tuberculosis
KOCH'S POSTULA TE:
1. microorganism must be identified in
infected organism. Must befound in every
case of disease that is checked.
2. Microorganisms must be isolated from
infected organism and grown in pure
culture (single organism, inject into animal
must come down with disease and must be
recovered)
3. Upon inoculation of microorganism into a
healthy organism, the microorganism from
the pure culture must cause the disease.
4. The same microorganism must be
recovered from the experimentally in lab
• 1798 Edward Jenner: first vaccination.
Used cowpox virus to infect a healthy
individual against small pox.
• The cowpox virus was called vaccinia
thus the name vaccination
1799 George Washington
• suffering from sore throat and respiratory infection
received state of the art medical treatment:
• given poisonous compound of mercury by mouth
and injections,
• forced to ingest poisonous white salt that made him
perspire and vomit.
• Caustic poltice were applied to body that made skin
blister,
• was forced to inhale vinegar vapor that burned lungs
and raised blisters inthroat.
• More that 5 pints of blood drained from his body....
All to no avail...he died shortly.
• "There are some remedies worse than the disease"
Publilis Syrus
Pasteur
• 1880 Pasteur; found principle behind how
vaccinationswork.
•
Found that bacteria causing cholera lost the ability
to cause disease.
• This was 1st vaccine made form germ that
caused disease rather than from a different but
closely related germ.
• 1881 Pasteur's Farm experiment with Anthrax ( 24
sheep, 1 goat, 6 cows vaccinated) equal number Not
vaccinated both groups exposed to Anthrax,
vaccinated animals survive, unvacinated all died)
• 1884 Pasteur develops rabies vaccine.
• Before this vaccination 100% mortality.
• Symptoms included fever, depression,
restlessness, uncontrollable excitement,
throat muscle convulsions, salivation, great
thirst, but smallest amount of water caused
more convulsions
• hence name hydrophobia.
• The virus cells were cultivated in the brains
of
healthy dogs by drilling hole into dog brain
and injecting with rabies virus.
• Diptheria (developed by Pasteur assistant)
and tetanus vaccines soon followed using
modified
forms of their toxins.
• 1885 Joseph Meister (boy) bitten by rabid
dog and gets vaccine (60 hr after bite) 14
doses in 10 days and survives.
Later in life Meister was gate keeper of
Pasteur Institute in Paris which houses crypt
of Pasteur.
• 1940 ,55 yrs after Pasteur saved his life Nazi
invaders demand Pasteur's crypt be opened
rather than doing so he commits suicide.
SYNTHEITIC DRUGS
• : Chemotherapeutic agents prepared
from chemicals in lab.
ANTIBIOTICS : chemicals produced
naturally from bacteria or fungi.
• 1910 Erhlich: Develops first
chemotherapeutic substance
discovered and evaluated and went on
the market.
• Was an arsenic compound called
Salvarsan which was used to treat
syphilis.
• 1928 Fleming: Agar plates inoculated
with Staplococcus aureus
were contaminated with Penicillium
notataum
• Named antibiotic penicillin.
• It was not isolated and put on the market until the
1940s
• 1st tested in 1941 on a 43 yr old police constable
who had been scratched near mouth by rose thorn
resulting in staphylococcus and Streptococcus
infections: multiple abscess of head and face, lungs
infected 1 eye removed, great pain, only hope was a
quick merciful death.
• Within one day of penicillin injection fever gone,
however penicillin lasted only a few days thus
doctors began filtering urine and collecting the
penicillin, the man continued to improve until penicillin
ran out, he then relapsed and died.
• 1929 Rene Dubos (father of antibiotics)
develops first antibiotic to treat cranberry
bog bacillus (CBB) but soon replaced by
Johannes Domask's Prontosil due to less
side effects.
• 1944 Albert Schatz: working for Selman
Waksman develops first successful antibiotic
to work against Tuberculosis...
• Waksman received Nobel prize for work not
Schatz.... THE DRUG WAS STREPTOMYCIN.
THE 3 BIG WONDER DRUGS:
• 1. STREPTOMYCIN,
• 2. PRONTOSIL
• 3. PENICILLIN
• 1954 Jonas Salks' Polio vaccine .
Back to the Future
• The war on disease was over!
• Antimicrobial drugs had won.
• Prontosil, penicillin, and streptomycin were
followed by more powerful drugs with
greater ability to wipe out pathogens.
• Laurie Garrett, in her encyclopedic work The
Coming Plague, says: "By 1965 more than
25,000 different antibiotic products had been
developed; physicians and scientists felt that
bacterial diseases, and the microbes
responsible, were no longer of great concern
or of .research interest."
• Twenty-nine years later Rachel Novak, in an article in
Science, would write, "Childbirth is a gamble with
death. Dental surgery potentially disabling.
• Even a facial boil can end in a trip to the morgue.
• " Alexander Tomasz, microbiologist at Rockefeller
University, recently confessed that we are on the
verge of a medical nightmare that would turn back
the clock to the days before antibiotics, when a
paper cut or a skinned knee could lead to fatal
infection.
• In U.S. hospitals, deaths from sepsis have increased
sevenfold in the last fifteen years.
• Deaths from infectious disease are up 58 percent
since 1980. Yet there are more antibiotics on the
market today than there ever have been.
• Why have infections, once again, become
untreatable?
Resistance
 The answer in a word is resistance.
 Microbes are finding ways to counteract or
neutralize the effects of antibiotics, rendering them
useless.
 Despite the more-than-160 different antibiotics, they
are variations of only fifteen major compounds and
five modes of action.
 The germs have found ways to foil these modes of
action. They are the ultimate survivors.
 .
Take penicillin for example
 It works by inactivating an enzyme that bacteria need
to make their cell wall.
 Without cell walls, bacteria cannot multiply and
cause infection.
 They have developed resistance to penicillin by
breaking it down before it can inactivate the cellwall-making enzyme or by making a new enzyme that
the penicillin cannot recognize. It took bacteria two
years to develop penicillin resistance.
 The miracle drug came into wide use in 1944, and
the first resistant pathogens were reported in 1946.
 By the late 1950s penicillin resistance was
widespread.
• Microbes have found ways of besting the
other antibiotics as well.
• Every germ has drug-resistant versions.
• The terrifying part is that some of them have
developed resistance to every known
antibiotic. They are untreatable!
• Presently these untreatables are restricted to
a group of bacteria called enterococcus.
• It is not a very common group and does its
infecting opportunistically, primarily in
hospitals among the sick and elderly—
people with compromised immune systems.
• It causes urinary tract and wound infections
and occasionally blood poisoning and
meningitis, where it is quickly fatal.