bacteria

1. 1
BACTERIA
Chapter 20.2

2. Agenda
 November 10 – Day 4
 Bacteria Notes
 Bacterial Disease Poster Project
2

3. 3
This is a
pore in
human skin
and the
yellow
spheres are
bacteria

4. 4
Clean skin has about 20 million
bacteria per square inch

5. 5
Evolution/Classification
 Prokaryotes
 The oldest fossils known, nearly 3.5 billion
years old, are fossils of bacteria-like
organisms.
 Evolution has yielded many species
adapted to survive where no other
organisms can.
 Grouped based on:
 Structure, physiology, molecular Composition,
reaction to specific types of stain (Gram
Positive/Gram Negative).
 Eubacteria= Germs/bacteria
 Archaebacteria

6. 6
Kingdom Archaebacteria
 First discovered in extreme environments
 Methanogens: Harvest energy by
converting H2 and CO2 into methane gas
 Anaerobic, live in intestinal tracts
 Extreme halophiles: Salt loving, live in
Great Salt Lake, and Dead sea.
 Thermoacidophiles: Live in acid
environments and high temps.
 Hot Springs, volcanic vents

7.  Depending on the
species, bacteria
can be aerobic
which means they
require oxygen to
live
or
anaerobic which
means oxygen is
deadly to them.
Green patches are green sulfur
bacteria. The rust patches are
colonies of purple non sulfur
bacteria. The red patches are
purple sulfur bacteria.

8. 8
Chemosynthetic bacteria use the
sulfur in the “smoke” for energy
to make ATP.

9. 9
The red color of this snow is due to a blue-green bacteria

10. 10
Kingdom Eubacteria
 Can have one of three basic shapes
1.Bacilli – rod-shaped
2.Spirilla – spiral-shaped
3.Cocci – sphere-shaped
•Strepto – in chains
•Staphylo – grape-like
clusters
•Diplo – pairs
o Can live in colonies

11. 11
BACTERIA PICS

12. 12
Bacillus
bacteria
are rod
shaped

13. 13
Coccus
bacteria
are ball
shaped

14. 14
Spirillium bacteria have a corkscrew shape

15. 15
Diplo-bacteria
occur in pairs,
such as the
diplococcus
bacteria that
causes
gonorrhea

16. 16
Staphylo -
occur in
clumps, such as
this
staphylococcus
that causes
infections of
cuts

17. 17
Strepto- occur
in chains of
bacteria, such
as this
streptococcus
bacteria that
causes some
types of sore
throats

18. Cyanobacteria
You may have seen
them as "green slime"
in your aquarium or in
a pond.
Cyanobacteria can do
"modern
photosynthesis", which
is the kind that makes
oxygen from water. All
plants do this kind of
photosynthesis and
inherited the ability
from the cyanobacteria.

19.  The Gram stain, which divides most
clinically significant bacteria into two main
groups, is the first step in bacterial
identification.
 Bacteria stained purple/violet are Gram +
- their cell walls have thick peptidoglycan.
 Bacteria stained pink are Gram – - Their
cell walls have thin peptidoglycan and
lipopolysaccharides.

20. 20
STRUCTURE OF BACTERIA
Structure Function
Cell Wall Protects and gives shape
Outer
Membrane
Protects against antibodies (Gram Neg. Only)
Cell
Membrane
Regulates movement of materials, contains
enzymes important to cellular respiration
Cytoplasm Contains DNA, ribosomes, essential compounds
Chromosome Carries genetic information
Plasmid Contains some genes obtained through
recombination
Capsule &
Slime Layer
Protects the cell and assist in attaching cell to
other surfaces
Endospore Protects cell against harsh environments
Pilus Assists the cell in attaching to other cells
Flagellum Moves the cell

21. 21
No Nucleus-DNA in Cytoplasm

22. 22
Eubacteria - Nutrition and Growth
 Heterotrophic or Autotrophic
 Some are Photoautotrophs – Use sunlight for Energy
 Some are Chemoautotrophs.
 Many are Obligate Anaerobes. (live w/o O2)
 Ex. Clostridium tetani – Tetanus
 Some are Faculatative Anaerobes (can live w/ or w/o
O2)
 Ex. Escherichia Coli
 Some are Obligate Aerobes (need O2 to survive)
 Ex.) Mycobacterium tuberculosis

23. 23
REPRODUCTION
IN
BACTERIA

24. 24
BACTERIA REPRODUCES
BY FISSION
First the chromosomal DNA
makes a copy
The DNA replicates

25. 25
NEXT THE CYTOPLASM
AND CELL DIVIDES
The two resulting cells are
exactly the same

26. 26
In addition to
the large
chromosomal
DNA, bacteria
have many
small loops of
DNA called
Plasmids

27.  Bacteria can reproduce sexually -
conjugation or asexually - binary fission.

28. 28
CONJUGATION

29. 19.3 Diseases Caused by
Bacteria
Key Concepts:
1. How do Bacteria cause disease?
2. How can Bacterial growth be
controlled?
Vocabulary: Pathogen, Vaccine,
Antibiotic
29

30. Microorganisms Cause Disease
 The Who
 Louis Pasteur – French Chemist
 Disproved Theory of Spontaneous
Generation
 Chapter 1 – What is it?
 Germ Theory of Disease
 Observed and hypothesized that
microorganisms caused infection and
disease
 Encouraged doctors and surgeons to
sanitize and sterilize themselves and
equipment
30

31. Microorganisms Cause Disease
 The How
 Some Bacteria need room to grow and
reproduce, in order to do so, they destroy
living tissue for food
 Other types of bacteria create toxins during
growth and development which can destroy
living tissue
 Disease results when bacteria interfere with
an organisms ability to function properly.
31

32. 32
Bacteria and Disease
Disease Pathogen Areas
affected
Mode of
transmission
Botulism Clostridium botulinum Nerves Improperly
preserved food
Cholera Vibrio cholerae Intestine Contaminated water
Dental Caries Streptococcus mutans,
sanguis, salivarius
Teeth Environment to
mouth
Gonorrhea Neisseria gonorrhoeae Urethra,
fallopian
Sexual contact
Rocky
Mountain SF
Rickettsia recketsii Blood,
skin
Tick bite
Strep throat Streptococcus pyogenes URT,
blood,
skin
Sneezes, coughs,
etc.
Tetanus Costridium tetani Nerves Contaminated
wounds
Tuberculosis Mycobacterium tuberculosis Lung,
bones
coughs

33. 33
Helicobacter
pylori
is the
pathogenic
bacteria
that can
causes ulcers

34. 34
Leprosy is a
bacterial
infection
that
decreases
blood flow to
the
extremities
resulting in
the
deterioration
of toes, ears,
the nose and
the fingers.

35. 35
BOTULISM

36. 36
ROCKY MOUNTAIN SF

37. 37
LYME DISEASE
Berrelia burgdorferi Affects
Skin and
joints
Transmitted
by a Tick
bite

38. 38
Salmonella Affects the
Intestine
Transmitted
through
contaminated
food and water

39. 39
STREP THROAT

40. 40
TUBERCULOSIS

41. 41
Common Antibiotics
Antibiotic Mechanism Target bacteria
Penicillin Inhibits cell wall synthesis Gram Positive
Ampicillin Inhibits cell wall synthesis Broad spectrum
Bacitracin Inhibits cell wall synthesis Gram Positive – Skin
Ointment
Cephalosporin Inhibits cell wall synthesis Gram Positive
Tetracycline Inhibits Protein Synthesis Broad spectrum
Streptomycin Inhibits Protein Synthesis Gram Neg. tuberculosis
Sulfa drug Inhibits cell metabolism Bacterial meningitis,
UTI
Rifampin Inhibits RNA synthesis Gram Pos., some Neg.
Quinolines Inhibits DNA Synthesis UTI

42. Antibiotics
 Anti – against
 Bio- life
 = against life, so antibiotics will only kill
living things, which means they are
ineffective against viruses (which aren’t
alive)
 How do they work?
 They block the growth and reproduction of
bacteria
42

43. Vaccines
 An injection of a weakened of killed pathogen
 Prompts the body to begin the primary
immune response
 What is the Primary Immune Response?
 Secondary Immune response is then
activated
 What is the Secondary Immune Response?
 Once the person comes in contact with the
bacteria for a 2nd time, they will have
antibodies ready and present to fight the
disease
43

44. How to kill Bacteria
 Sterilization by Heat – Most bacteria can not
survive high temperatures, so pathogens
will be killed by exposure to high heat
 Disinfectants – chemical solutions that kill
pathogens
 Food Storage/Processing –
 Refrigerator storage slows bacterial reproduction
 Boiling, Frying, Steaming – heat food to the
point at which bacteria will be killed
 Preserved food – use of vinegar, salt and sugar
to prevent food from spoiling due to bacterial
contamination
44

45. 45
Some Final Information
 Because antibiotics have been overused,
many diseases that were once easy to
treat are becoming more difficult to
treat. MRSA
 Some Bacteria are Useful
 Ex. Producing and Processing food
 Breaking down dead organic material
 Make unripened cheese like ricotta and
cottage by breaking down the protein in
milk.