Transcript Ch 1 PPT

Main Themes in
Microbiology
Chapter 1
Humans are
outnumbered
• We have ~ 10 trillion cells in our
body
– We have 100 trillion foreign cells
in/on our body!!
– Tiny life forms are called
microorganisms
What is a
microorganism?
• Could be…
– Bacteria (E. coli)
– Viruses (Rabies)
– Protists
(Trypanosomes- sleeping sickness)
• Protozoa and algae
– Helminthes
• Worms
(beef tapeworm)
What is microbiology?
• Microbiology is a special area of
biology that deals with tiny life
forms not readily observed
without magnification
– Little guys are called?:
• Microorganisms
• Microbes
• Germs
• Bugs
Can I do this for a
living?
• Geomicrobiologist?
- roles of microbes in the
development of the earth’s
crust
• Marine microbiologist?
- study the oceans and its
smallest inhabitants
• Medical technologists?
- do tests to diagnose pathogenic
microbes and their diseases
• Nurse epidemiologists?
• - analyze the occurrence of
infectious diseases in hospitals
• Astrobiologist
- study the possibility of
organisms in space
What do we focus on?
• Genetics
• Physiology
– Appearance and survival
•
•
•
•
+ and – characteristics
Environmental interaction
Host interaction
Uses in industry/agriculture
How long have these
guys been around?
• Practically forever!
– Life on earth started 3.5 billion
years ago!
• Prokaryotes came first
• Then eukaryotes
Good or bad?
• Both!
• We’ve been using
microorganisms for thousands
of years!
Good Microbes
• Yeast (microscopic fungi) =
bread
• Penicillin (moldy bread) = first
aid
Biotechnology
• Industry applications
– Bacteria that can mine metals!
– Thiobacillus ferrooxidans takes mining
waste and makes pure copper as a waste
product
Genetic Engineering
• Manipulates genetics to make
new products and genetically
modified organisms
– Microbes can make drugs,
hormones, and enzymes
Bioremediation
• Fixing environmental problems
with microorganisms
• Cycloclasticus spirillensus is
one type of bacterium that can
break down oil residues
Bad Microbes
• Pathogens- agents that cause
disease
– Over 2000 types of microbes that
cause disease! (ex?)
– WHO says over 10 BILLION
infections caused by microbes
worldwide
Top Causes of Death in
US?
Bad microbes
• Malaria
– Actually a microbe (protist)
Malaria Prevention
• Malaria nets
cost $3-5
• 1/3 world
population
makes <$1/day
• Which kid will
sleep under the
net tonight?
The subtle side of
microbes
Associated with
• Gastric ulcers
– Heliobacter
• Cancer
– HPV
– Hepatitis viruses
• Type 1 Diabetes
– Coxsackievirus
• Schizophrenia
• MS
• OCD
• Coronary artery
disease
• Infertility
– Chlamydia
General Microbe
Characteristics?
• TINY
• Millimeters (mm), micrometers
(µm), and nanometers (nm)
3D Relative Size
• http://scaleofuniverse.com/
• Prokaryotic or eukaryotic?
• 1 or a few cells
• Free-living—live independently
• Parasitic—microbes harbored
and nourished inside host
• Could be viruses
– NOT ALIVE
– NOT CELLS
– Small amount of hereditary
material wrapped up in a protein
coating
– “Obligate intracellular parasites”
Rest of Class
• Lab Safety Sheets
• Textbooks
• Dirty Spot Lab Preview
Aseptic Technique
• Joseph Lister
• Goal: reduce microbes in a
medical setting and preventing
wound infections
– No handwashing prior to surgery
before Lister!!
–
Aseptic Technique
Videos
• https://www.youtube.com/watch
?v=gW_lTLUBfBY
• https://www.youtube.com/watch
?v=3k9v8akbfT8
Intro to Dirty Spot Lab
• HW: research the types of places that
microbes live and determine your choice
for swabbing.
•
Dry Run if time
Where does life come
from?
• Meat makes maggots
• Shrooms spring from spruce
• Rats from rotting refuse
Spontaneous Generation
• The idea that life can arise from
non-living matter
– Aka abiogenesis
• Competing theory—biogenesis
– Life can only arise from living
things of a similar nature
•
How can we prove or disprove this
hypothesis?
Francesco Redi (1668)
Hypothesis: Flies produce maggots
on meat. Lay small eggs
Set up a controlled experiment to
test his hypothesis
Found that by keeping flies away
from meat, no maggots appear
Variables
1. Controlled variables:
Jar, meat, location, temperature, time
2. Independent or Manipulative variable:
Gauze covering the meat jars
3. Dependant (responding) variable:
Whether maggots appear
John Needham – 1745
Hypothesis: spontaneous generation
occurs under the right conditions
– Boiled chicken broth and then sealed
flask (thought heat would kill)
– “Animalcules” swarmed after a few days
– Therefore, he felt his hypothesis was
right.
What was wrong with
Needham’s hypothesis?
He assumed all the animalcules
would be killed by heat
Louis Jablot
• Hypothesis: even microscopic
organisms must have parents
• Boiled hay infusions very similar
to Needham’s work
• However, his uncovered WAS
contaminated with growth
Lazzaro Spallanzani
• 1776
• Attempted to disprove Needham’s work.
• Took 4 flasks with broth in them
– Left open ?
• went cloudy
– Sealed but not boiled?
• went cloudy
– Boiled but left open
• went cloudy
– Sealed then boiled
• stayed clear
• Conclusion?
What would have been
Spallanzani’s hypothesis?
Microorganisms form not from air
but from other microorganisms.
When broth was boiled and then
sealed, no air could get in for
organisms to reproduce.
What was wrong with what
Spallanzani assumed?
No air
Pasteur’s broth in the curved necked flask
stayed sterile for years until he tilted it and
the airflow carried the microbes into the broth
Louis Pasteur - 1859
Tested Spallanzani’s work by using a
curved neck flask to prevent microbes
from entering flask but would let air in
Microbes collecting in bend
Boiled broth of control and experimental
flasks.
Result: No growth in curved neck flask.
Conclusion
Contamination is due to microbes
in the air.
Spontaneous generation theory
died here!!
John Tyndall
Heated hay infusions for various times.
Found 2 kinds of bacteria –
1. Those readily killed by heating
2. Heat resistant forms (endospores)
**Between 1875 – 1918, most of the
disease-causing bacteria were
identified.
The Microscope
• Antonie von Leeuwenhoek
1723)
•
•
Job?
Linen merchant why make a microscope?
(1632-
The Microscope
• Leeuwenhoek
looked at a
drop of water
and saw
moving things
– Called them
“animalcules”
• Bacteria and
protozoa
Intro to Hand Washing
Lab
The Pillar of Science:
The scientific method
• Origin in the 1600s…enough of
the superstition!!
https://www.youtube.com/watch?v=zrzMhU_4m-g
Scientific method
• NEEDS a testable hypothesis
• Use the deductive approach
– If…then
• Test, test, and retest that
hypothesis!
Know the jargon
• Hypothesis- tentative
explanation for what has been
observed
• Theory- very well supported
idea
– Many hypotheses and experiments
– NOT A “FACT”
• Law- principle of science
– Super accurate
Germ theory of disease
• Louis Pasteur
– Human diseases could
arise from infection
• Robert Koch
– Koch’s Postulates
• Verified germ theory
• Showed anthrax caused
by bacterium
Taxonomy
• What’s in a name?
• Taxonomy- formal system for
organizing, classifying, and
naming organisms
– Carl von Linnie
• Aka Carolus Linnaeus
• Standardized
– Keeps names short and consistent
– Binomial system of nomenclature
• Lichtenwalner meghan (print)
• Lichtenwalner meghan (written)
Phylogeny
• Natural relatedness of
organisms
– Related by evolution—theory that
all life descended, with
modification, from one common
ancestor
Evidence
• Morphology- similar structures
in organisms
• Physiology- similar functions of
organisms
• Genetics- similar DNA in
organisms
• Dumpy Kings Play Cards On Fat
Green Stools
•Domain
•Kingdom
•Phylum
•Class
•Order
•Family
•Genus
•Species
Kingdoms and Domains
• Originally, 2 kingdoms
– Plantae and Animalia
• Then 3 (Protista)
• …and 4 (Add the Bacteria—
kingdom Monera)
• …finally 5 (Fungi!)
1) Plantae
- mostly multicellular autotrophs
2) Animalia
- heterotrophs that can move
- multicellular eukaryotes
3) Protista
- single celled eukaryotes (catch all)
4) Fungi
- multicellular eukaryotes
- heterotrophs that don’t move
5) Monera
- not a kingdom anymore because of Bacteria and
Eubacteria Domain
5 kingdom system
• Associated with Robert
Whittaker
– Based on the morphology and
physiology-type of evidence
The domain system
• Now we look at molecular
biology
– How do DNA, proteins, rRNA
compare?
– Bacteria Kingdom split into two:
• Domain Bacteria
• Domain Archaea
3 domain system
• Domain eukarya—the
eukaryotes
• Domain archaea—prokaryotes
that live in extreme
environments
• Domain bacteria— “traditional”
prokaryotes
1)
2)
3)
4)
5)
6)
7)
Spreading heavy growth
Effuse
Filiform
Beaded
Echinulate
Arborescent
Rhizoidal
Test
On a piece of loose leaf
Write down 2 specific facts about
6 of the 9 Microbiologists
1)
2)
3)
4)
Oswald Avery
Robert Koch
Marcello Malpighi
Ilya Metchnikoff
5)
6)
7)
8)
9)
Joseph Lister
Theobald Smith
Dmitri Ivanowski
Rebecca Lancefield
Margaret Pittman