Week
Weekly Topics
Chapters
1
Overview of Viruses,
Prokaryotic & Eukaryotic
Microorganisms
1-3
4-6
2
Microbial Metabolism &
Genetics
7-9
3
Physical & Chemical Control of
Microorganisms
11-13
4
Immune Responses to
14-16
Infection & Immunity Disorders
5
Assignments
SmartLabs
MCQ , Lab and
Reflection
Aseptic Techniques
Quiz (4-6)
MCQ , Lab and
Reflection
Staining
Quiz (7-9)
MCQ , Lab and
Reflection
Microbial Growth
Quiz (11-13)
Lab and
Reflection
Control of Microbial Growth
Midterm (Ch: 4-9,
11-16)
6
Identifying Pathogens &
Bacteria of Medical
Importance
17-19
7
Bacteria continued & Fungi of
Medical Importance
20-22
8
Parasites and Viruses
23-25
9
Group Presentations
10
Quiz/Exam
Blood
MCQ , Lab and
Reflection
ID of Unknown Bacteria
Quiz (17-19)
MCQ , Lab and
Reflection
Medical Microbiology
Quiz (20-22)
Lab and
Reflection
Final
(Ch: 17-25)
Welcome
To
Microbiology 112
Chapter 1
What is microbiology?
Microbial Diversity: 6 Types of Microbes
Reproductive spores
© Tom Volk
Janice Carr/CDC
© Charles Krebs Photography
Bacteria: Mycobacterium tuberculosis, a
Fungi: Thamnidium, a filamentous
Algae: desmids, Spirogyra filament, and diatoms
rod-shaped cell (15,500x).
fungus (400x)
(golden cells) (500x).
A single virus particle
CDC
© Yuuji Tsukii, Protist Information Server
CDC
Virus: Herpes simplex, cause of cold
Protozoa: A pair of Vorticella (500x), stalked cells
Helminths: Cysts of the parasitic roundworm,
sores (100,000x).
that feed by means of a whirling row of cilia.
Trichinella spiralis (250x) embedded in muscle.
4
Microbial Structure
• Two cell lines
– Prokaryote – lack nuclei and membrane-bound organelles
– Eukaryote –nucleus and membrane-bound organelles
• Viruses - Acellular
Examples?
(b) Virus Types
(a) Cell Types
Prokaryotic
Eukaryotic
Nucleus Mitochondria
Chromosome
Ribosomes
Envelope
Capsid
Ribosomes
Nucleic
acid
AIDS virus
Cell wall
Flagellum
Cell
membrane
Flagellum
Cell membrane
Bacterial virus
5
Microbial Dimensions
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Range
of
human
eye
1 mm
Reproductive structure
of bread mold
Louse
100 mm
Macroscopic
Nucleus
Colonial alga
(Pediastrum)
Range
of
light microscope
Amoeba
Red blood cell
White blood cell
10 mm
Most bacteria fall between 1 to 10 mm
in size
1 mm
Rod-shaped bacteria
(Escherichia coli)
Rickettsia bacteria
200 nm
Mycoplasma bacteria
100 nm
AIDS virus
Coccus-shaped bacteria
(Staphylococcus)
Poxvirus
Hepatitis B virus
Poliovirus
Range
10 nm
of
electron
microscope
Flagellum
Large protein
Diameter of DNA
1 nm
Require
special
microscopes
Amino acid
(small molecule)
0.1 nm
Hydrogen atom
(1 Angstrom)
Metric Scale
1,000
Log 10 of meters
3
100
10
1.
0
0
0,
0
0
0,
0
0
0,
0
0
2
1
0
–1
–2
–3
–4
–5
–6
–7
–8
–9
–10 –11
0
–12
6
Microbes & Infectious Diseases
Parasitic diseases 2.5%
• Pathogens: Microbes
that do harm
Miscellaneous 1.5%
• Nearly 2,000 different
microbes cause
diseases
5%
26%
7%
9%
11%
18%
17.5%
World-wide Disease Statistics-Deaths
Development of Aseptic Techniques
• The human body is a source of infection
– Joseph Lister – introduced aseptic techniques to
reduce microbes in medical settings and prevent
wound infections (1865)
• Involved disinfection of hands using chemicals prior to surgery
• Use of heat for sterilization
Robert Koch (1843-1910)
Germ Theory of Disease
• Established Koch’s
postulates - a sequence of
experimental steps that
verified the germ theory
• Identified cause of
anthrax, TB, and cholera
The Chemistry of Carbon and
Organic Compounds
• What is an organic chemical?
• 4 Major Biological Macromolecules?
– hint: think of food
10
Carbohydrates
• Sugars and polysaccharides
• General formula (CH2O)n
H
Aldehyde group
O
H
C1
H
HO
H
H
H
C2
C3
C4
C5
C6
H
O
H
C1
6
OH
H
CH2OH
5
H
O
H
H
4
OH
OH
H
1
HO OH
OH
H
3
H
H
2
OH
HO
HO
C2 OH
C3 H
6
CH2OH
O
5
H
HO
H
4
C4 H
OH
H
H
H
C5 OH
C6 OH
1
OH
3
H
H
Glucose
H OH
2
OH
C1 O
C2
HO
H
H
H
Ketone group
H
O
C3 H
C4 OH
C5 OH
C6 OH
O
6
HOCH2
OH
5
H
2
H
4
OH
H
Galactose
Fructose
2OH
HO CH
1
3
H
Carbohydrates
• Saccharide: simple carbohydrate
– Monosaccharide: 3-7 carbons
– Disaccharide: two monosaccharides
– Polysaccharide: five or more monosaccharides
O
O
O
O
Monosaccharide
O
Disaccharide
O
O
O
O
O
CH2
O
CH 2
O
O
O
Polysaccharide
Carbohydrates
• Functions – cell structure (cell walls), adhesion, and metabolism
6
CH2OH
H
OH
CH2OH
H
OH
O
O
H
H
H H
O 4 OH H 1 b
O 4 OH H 1Hb
4
1 b
4H
1 b
OH H H H H
OH H
H
O
O
O
H H
O
O
H
OH
CH2OH
H
OH
CH2OH
6
6
CH2OH
CH2OH
CH2OH
5
5
5
O
O
O
H H H
H H H
H
H H
4
1 a
4
1 a
4
1 a
O
O
O
O
OH H
OH H
OH H
3
H
2
OH
3
H
2
OH
3
H
2
OH
6
CH2OH
5
O
H
H H
4
1
O
OH
H
Branch
Branch
2
3
point
H O O
H 6 C OH
5
O
H
H H
4
1
O
OH H
H
bonds
3
H
(a) Cellulose
(b) Starch
2
OH
Lipids
• Long or complex, hydrophobic, C - H chains
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
H
H
H
H
H
H
H
H
H
O
C
HO
H
H
Linolenic acid, an unsaturated fatty acid
H
Triglycerides: 3 fatty acids bound to glycerol
• Triglycerides are used for energy storage
• Could be saturated or unsaturated
Fatty acids
1
Triglycerides
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
O
C
HO
H
Palmitic acid, a saturated fatty acid
2
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
H
H
H
H
H
H
H
H
H
O
C
HO
H
H
Linolenic acid, an unsaturated fatty acid
H
Phospholipids: glycerol with 2 fatty acids and
a phosphate group
• Bilayers of phospholipids form membranes
Variable alcohol group
Phosphate
R
O
O P O2
O
HCH H
HC
CH
Charged
head
Polar lipid molecule
Glycerol
Polar head
O
O
O C O C
Nonpolar
tails
HCH HCH
HCH HCH
Tail
Double
bond
Creates
a kink.
HCH HCH
HCH HCH
HCH HCH
HCH HCH
HCH HCH
HC
HCH
HCH
HCH
HCH
HCH
Water
1 Phospholipids in single layer
HCH
HCH
HCH
HCH
HCH
Water
H
Fatty acids
(a)
2 Phospholipid bilayer
(b)
Water
Proteins
• Predominant molecules in cells
• Monomer – amino acids – 20
• Polymer – peptide, polypeptide, protein
Amino Acids
• Amino acids vary
based on R group
• Primary
Structure
• Secondary
Structure
• Tertiary Structure
• Quaternary
Structure
Protein Structure
Nucleic Acids
• DNA and RNA
• Nucleotide monomer
N base
• DNA – deoxyribonucleic acid
– A,T,C,G – nitrogen bases
– Double helix
– Function – hereditary material
Pentose sugar
Phosphate
• RNA – ribonucleic acid
– A,U,C,G – nitrogen bases
– Function – organize protein
synthesis
nucleotide
Nucleic Acids
Backbone
Backbone
P
DNA
D
A
T
U
D
P
P
RNA
R
P
D
C
G
A
D
P
P
R
P
D
G
C
C
D
P
P
R
P
D
T
A
G
D
P
P
R
P
D
A
T
C
D
P
P
R
P
D
C
G
P
D
P
A
R
P
H bonds
ATP: The Energy Molecule of Cells
• Adenosine triphosphate
– Nucleotide - adenine, ribose, three phosphates
• Function - transfer and storage of energy
NH2
N
7
5
9
N
4 3
N
8
O
–O
P
O–
O
O
O
P O
P
O–
O–
O
6
CH2 O
OH OH
Adenosine
Adenosine diphosphate (ADP)
Adenosine triphosphate (ATP)
1N
2
Chapter 3: Tools of the Laboratory
Six “I’s”
0. Specimen Collection
?
Chapter 3: Tools of the Laboratory
Six “I’s”
0. Specimen Collection
1. Inoculation: growing sample with appropriate medium (limitations)
Chapter 3: Tools of the Laboratory
Six “I’s”
0. Specimen Collection
1. Inoculation: growing sample with appropriate medium (limitations)
2. Incubation: inoculated media placed in controlled environment
Chapter 3: Tools of the Laboratory
Six “I’s”
0. Specimen Collection
1. Inoculation: growing sample with appropriate medium (limitations)
2. Incubation: inoculated media placed in controlled environment
3. Isolation: separate individual microbes for pure culture
Pure culture
of bacteria
(from one colony)
Chapter 3: Tools of the Laboratory
Six “I’s”
0. Specimen Collection
1. Inoculation: growing sample with appropriate medium (limitations)
2. Incubation: inoculated media placed in controlled environment
3. Isolation: separate individual microbes for pure culture
4. Inspection: colony characteristics, microscopy
Chapter 3: Tools of the Laboratory
Six “I’s”
0. Specimen Collection
1. Inoculation: growing sample with appropriate medium (limitations)
2. Incubation: inoculated media placed in controlled environment
3. Isolation: separate individual microbes for pure culture
4. Inspection: colony characteristics, microscopy
5. Information Gathering: additional testing
Biochemical
tests
Drug
sensitivity
Immunologic tests
signs & symptoms
DNA
analysis
Chapter 3: Tools of the Laboratory
Six “I’s”
0. Specimen Collection
1. Inoculation: growing sample with appropriate medium (limitations)
2. Incubation: inoculated media placed in controlled environment
3. Isolation: separate individual microbes for pure culture
4. Inspection: colony characteristics, microscopy
5. Information Gathering: additional testing
6. Identification
Chapter 3: Tools of the Laboratory
Microscopy
Purpose?
Compound Light Microscope
Visible Light
(2000x)
Chapter 3: Tools of the Laboratory
Microscopy
All Three Same Organism
• Bright-field –specimen is darker than
surrounding field; live or
stained specimens
• Dark-field –illuminated specimens surrounded by
by dark field; live & unstained
specimens
• Phase-contrast – transforms changes in light
waves passing through the
specimen into image; intracellular
structures
Chapter 3: Tools of the Laboratory
Microscopy
Electron beam
100,000x
• Transmission electron microscopes
(TEM) – transmit electrons through the
specimen. Darker areas represent thicker,
denser parts and lighter areas indicate less
dense parts.
–
Viruses
image is of viral spheres
0.1 mm
650,000x
• Scanning electron microscopes (SEM) –
provide detailed three-dimensional view. SEM
bombards surface of a whole, metal-coated
specimen with electrons
Chapter 3: Tools of the Laboratory
All prepared slides are stained
Staining
(a) Simple Stains
© Harold J. Benson
Methylene blue
stain of Corynebacterium
(1,0003)
Visible Light
Chapter 3: Tools of the Laboratory
All prepared slides are stained
Staining
(a) Simple Stains
Methylene blue
stain of Corynebacterium
(1,0003)
Acid-fast stain
Red cells are acid-fast (hold dye).
Blue cells are non-acid-fast
(b) Differential Stains
Gram stain
Purple cells are gram-positive (thick cell wall).
Red cells are gram-negative
Spore stain, showing spores (green)
and vegetative cells (red)
Visible Light
Chapter 3: Tools of the Laboratory
All prepared slides are stained
Staining
(a) Simple Stains
Methylene blue
stain of Corynebacterium
(1,0003)
Acid-fast stain
Red cells are acid-fast (hold dye).
Blue cells are non-acid-fast
(b) Differential Stains
Visible Light
(c) Structural Stains
Gram stain
Purple cells are gram-positive (thick cell wall).
Red cells are gram-negative
India ink capsule stain of
Cryptococcus neoformans
Spore stain, showing spores (green) Flagellar stain of Proteus vulgaris.
and vegetative cells (red)
Note the fine fringe of flagella
Chapter 3: Tools of the Laboratory
Isolation
• If one bacterial cell is separated from others, it will
grow into a mound of cells— a colony
– A colony consists of one species (pure culture)
Mixture of cells in sample
Parent
cells
Separation of
cells by spreading
or dilution on agar
medium
Incubation
Microscopic view
Cellular level
Growth increases the
number of cells.
subculture from
one colony
Microbes become
visible as isolated
colonies containing
millions of cells.
Macroscopic view
Colony level
Chapter 3: Tools of the Laboratory
Isolation
Loop containing sample
– Streak plate
technique
1
2
3
4
5
(a) Steps in a Streak Plate; this one is a four-part or quadrant streak.
Loop containing sample
– Pour plate
technique
1
2
3
1
2
3
(c) Steps in Loop Dilution; also called a pour plate or serial dilution
– Spread plate
technique
1
(e) Steps in a Spread Plate
"Hockey stick"
2
Chapter 3: Tools of the Laboratory
Identification
• Biochemical tests to
determine an organism’s
chemical and metabolic
characteristics
Chapter 3: Tools of the Laboratory
Media
Chemical Content of Media
• General purpose media – grows a broad range of microbes
• Enriched media – contains complex organic substances required
by fastidious microbes (special requirements)
Chapter 3: Tools of the Laboratory
• pure culture= single species
• mixed culture= multiple species
• contaminants
Mixed
Contaminated
Pure
Chapter 3: Tools of the Laboratory
Media
Selective media:
Mixed sample
inhibit growth of some
microbes and encourage
growth of the desired
microbes
General-purpose
nonselective medium
(All species grow.)
Selective medium
(One species grows.)
Chapter 3: Tools of the Laboratory
Media
Differential media:
Mixed sample
displays visible differences
among microbes
General-purpose
nondifferential medium
(All species have a similar
appearance.)
Differential medium
(All three species grow but may
show different reactions.)
42
Chapter 3: Tools of the Laboratory
Media
aerobic
• Reducing medium –
contains a substance that
absorbs oxygen; used for
growing anaerobic bacteria
O2
anaerobic
O2