, TABLE OF CONTENTS
Module 1: Introduction to Microbiology
Lesson 1: Bacterial Structure...................................................................................................................................................... 1
Lesson 2: Bacterial Growth Curve .............................................................................................................................................. 2
Lesson 3: Bacterial Identification ................................................................................................................................................ 2
Lesson 4: Cultural And Physiological Characteristics .................................................................................................................. 6
Lesson 5: Physiological Characteristics ...................................................................................................................................... 7
Lesson 6: Specimen Collection, Transport And Processing Of Clinical Specimens ...................................................................... 9
Module 2: Gram Positive & Gram-Negative Cocci
Lesson 1: Staphylococci ........................................................................................................................................................... 13
Lesson 2: Streptococci .............................................................................................................................................................. 16
Lesson 3: Gram Negative Cocci ................................................................................................................................................ 20
Module 3: Gram Positive Spore Forming and Non-Sporeforming Bacilli
Lesson 1: Gram Positive Bacili Spore Forming .......................................................................................................................... 24
Lesson 2: Bacillus Species........................................................................................................................................................ 24
Lesson 3: Clostridium Species .................................................................................................................................................. 25
Lesson 4: Gram Positive Bacilli - Non-Spore Formers ............................................................................................................... 27
Lesson 5: Clostridum Species ................................................................................................................................................... 27
Lesson 6: Erysipelothrix Rhusiopathiae ..................................................................................................................................... 31
Lesson 7: Listeria Monocytogenes ............................................................................................................................................ 31
Lesson 8: Lactobacillus Acidophilus .......................................................................................................................................... 31
Module 4: Acid Fast and Partially Acid-Fast Gram-Positive Bacilli
Lesson 1: Mycobacterium Tuberculosis ..................................................................................................................................... 32
Lesson 2: Complexes Of Mycobacteria ..................................................................................................................................... 34
Lesson 3: Atypical Mycobacteria ............................................................................................................................................... 34
Lesson 4: Mycobacterium Leprae.............................................................................................................................................. 36
Lesson 5: Fungi-Like Bacteria - Non-Spore Forming, Branching Aerobic Actinomycetes ............................................................ 36
Module 5: Gram Negative Bacilli: Family Enterobacteriacaeae
Lesson 1: Enterobacteriaceae ................................................................................................................................................... 39
Lesson 2: Kesh (Klebsiella-Enterobacter-Serratia-Hafnia) ......................................................................................................... 40
Lesson 3: Salmonella................................................................................................................................................................ 41
Lesson 4: Shigella .................................................................................................................................................................... 42
Lesson 5: Citrobacter ................................................................................................................................................................ 43
Lesson 6: Proteus-Providencia-Morganella (PPM)..................................................................................................................... 43
Lesson 7: Yersinia .................................................................................................................................................................... 44
Lesson 8: Plesiomonas Shigelloides ......................................................................................................................................... 44
Module 6: Family Vibrionaceae and Non-Fermenting Gram-Negative Bacilli
Lesson 1: Non-Fermentative Gram-Negative Bacilli ................................................................................................................... 46
Lesson 2: Family Vibrionaceae ................................................................................................................................................. 48
Lesson 3: Chromobacterium Violaceum .................................................................................................................................... 49
Module 7: Gram-Negative Bacilli and Coccibacilli: Campylobacter and Haemophilus
Lesson 1: Campylobacter.......................................................................................................................................................... 51
Lesson 2: Small Pleomorphic Gram-Negative Bacilli.................................................................................................................. 52
Module 8: Gram-Negative Coccobacilli: Optimally Recovered on Special Media
Lesson 1: Bordetella ................................................................................................................................................................. 55
Lesson 2: Francisella ................................................................................................................................................................ 55
Lesson 3: Brucella .................................................................................................................................................................... 56
Lesson 4: Legionella ................................................................................................................................................................. 57
Module 9: Anaerobic Bacteriology
Lesson 1: Obligate Anaerobes .................................................................................................................................................. 58
Module 10: Spirochetes, Obligate Intracellular and Nonculturable Bacterial Agents, Miscellaneous Pathogenic Bacteria, and Fungi-
like Bacteria
Lesson 1: Spirochetes............................................................................................................................................................... 60
Lesson 2: Obligate Intracellular And Nonculturable Bacterial Agents ......................................................................................... 62
Lesson 3: Miscellaneous Pathogenic Bacteria ........................................................................................................................... 64
Lesson 4: Fungi-Like Bacteria ................................................................................................................................................... 65
FOR PERSONAL USE ONLY
, MODULE 1: INTRODUCTION TO MICROBIOLOGY
o For immunogenic induces TNF-alpha, IL-attachment
OUTLINE
o Protects against mechanical disruption of the cell
I Bacterial Structure
A Cellular Appendages o PEPTIDOGLYCAN/MUREIN LAYER (main compo)
II Bacterial Growth ▪ Gram (+) cell wall - thicker
A Stages of Bacterial Growth ▪ Chemical composition: N-acetylglucosamine and
B Cell Morphology N-acetylmuramic acid
C Morphologic Forms of Bacteria ▪ Teichoic acid - negatively charged; regulate
D Arrangement of Bacteria movement of cations
E Motility ▪ Impermeable to alcohol
F Staining
o For ACID FAST ORGANISMS (Mycolic acid)
i Gram Stain
ii Acid-Fast Stain ▪ Present in murein layer of Mycobacterium spp
iii Other Stains o Functions for acid fastness; resistance to drying and
III Bacterial Identification chemicals
A Agar ▪ Gram (-) cell wall - thinner
B Methods of Obtaining Pure Isolated Colonies ▪ Permeable to alcohol
C Classification Of Culture Media ▪ With protein, phospholipids and
i According to Consistency lipopolysaccharides
ii According to Composition
▪ NO TEICHOIC ACID
iii According to How the Medium Is Disposed
iv According to How the Medium Is Used o 3 Regions of Lipopolysaccharide (LPS)
v Antibiotic Susceptibility Agar ▪ Lipid A - major constituents
D Techniques Of Inoculation ▪ Core polysaccharide
E Bacterial Colony ▪ Antigenic O - specific polysaccharide
i Types Of Colonies ▪ FUNCTION: to evade phagocytosis
IV Cultural and Physiological Characteristics ▪ NO CELL WALL: Mycoplasma and Ureaplasma
A According to Nutritional Requirement 3. Cytoplasmic/Metachromatic granules
B According to Oxygen Requirement
o For food reserves
C According to Carbon Dioxide Requirement
D According to Temperature Requirement o Examples:
E According to PH Requirement ▪ Babes - Ernst bodies - Corynebacterium
F According to Moisture diphtheriae
G According to Salt Concentration ▪ Much granules - Mycobacterium
H According to Osmotic Pressure ▪ Bipolar granules - Yersinia pestis
I According to Pressure Requirement ▪ Sulfur granules - Nocardia and Actinomyces
V Specimen Collection, Transport & Processing of Clinical
Specimens
A Transport Of Specimens A. CELLULAR APPENDAGES
B Specimen Preservation 1. Capsule
C Specimen Storage o THICK, slimy gelatinous compound surrounding cell
D Specimen Preparation wall
E Ways To Facilitate Anaerobic Cultivation o Outermost layer
F Criteria For Specimen Rejection o Prevents/inhibits phagocytosis
G Clinical Specimens
i Blood o BEST DEMONSTRATED:
ii CSF ▪ Negative staining
iii Throat and Nasopharyngeal Swab ▪ Neufeld Quellung
iv Stool o POLYSACCHARIDE CAPSULE - Clostridium
v Urine perfringens & Neisseria meningitidis
vi Genital Tract Specimens o D-GLUTAMATE CAPSULE - Bacillus anthracis
vii Sputum NOTE: Most microorganism with capsule are pathogenic;
viii Body Fluids Capsulated organism usually are not flagellated
ix Tissues and Biopsies
x Hair, Nails or Skin Scrapings 2. Nucleus (Nucleoid region)
H Significance o Contains hereditary materials
o No nuclear membrane so nuclear material are
scattered in the cytoplasm which are referred to as
I. BACTERIAL STRUCTURE nucleoids
1. Outer Membrane 3. Plasmids
o Also called Cell Membrane, Plasma membrane, o DNA molecule that can replicate independently,
Cytoplasmic membrane, Plasmalemma double-stranded, in many cases CIRCULAR
o First part of bacterial structure o Extrachromosomal DNA carries an antibiotic gene
o Surrounds cytoplasm ▪ SMALL PLASMID - resistant to tetracycline &
o Only found in gram-negative bacteria chloramphenicol
o Chemical composition: lipopolysaccharide ▪ LARGE PLASMID - resistant to beta-lactams
(phospholipid bilayer) (Penicillin)
o Functions: 4. Fimbriae (Fimbria)/Pili (PIlus)
▪ Serve as primary permeability barriers to o SHORT, Hairlike, extend from cell membrane into the
hydrophilic and hydrophobic compounds external environment
- Acts as osmotic barrier o Produced by GRAM NEGATIVE (E. coli)
▪ Regulates transport of solute across membrane o Composed of chemical variations of protein (Pilin)
▪ Carrier for enzymes, phosphorylation, DNA o 2 TYPES OF PILI:
replication, Penicillin Bound Protein (PBPs) ▪ Common Pili - for attachment
▪ Site of energy synthesis ▪ Sex Pili - producing/transfer genetic material and
o Semipermeable only when the cell is ALIVE/LIVING important in medical dx.
▪ if the cell dies, permeability loses. 5. Flagella (Flagellum)
2. Cell wall o For motility: slender, whiplike structure
o Site of the antibiotic function o Motility is the best at 25 C (room temperature)
o Attachment of flagella and pili o Component: Flagellin
o Cell shape and protection from osmotic damage o Bacilli and Spirilli are MOTILE
FOR PERSONAL USE ONLY 1
, o Used in classification of bacteria Ex. Botulism/diphtheria
o Axial filaments or periplasmic flagella is spiral toxin/TSS
organisms Enterotoxin - damages Uses aqueous extract of
o Classifications of location of flagella cells of GIT - S. aureus and blood cells of horse shoe
▪ Atrichous - no flagellum E. coli crabs (+) result: Clumping
▪ Monotrichous - one flagellum at ONE END (ex. Neurotoxin - interferes with
Vibrio and Pseudo) nerve impulses
▪ Amphitrichous - one or group of flagella on BOTH Coagulase
ENDS (ex. C. jejuni) • Toxoids
▪ Lophotrichous - group of flagella at BOTH or ONE o non - poisonous form of toxins which can be used for
END/S (ex. S. maltophilia) vaccination.
▪ Peritrichous - entire surface (E. coli) o Ways of converting toxins to toxoid:
▪ By aging
▪ By exposure to heat
▪ By exposure to 50% alcohol
II. BACTERIAL GROWTH CURVE
• Generation time found to vary in different organisms
o S. aureus - 30 minutes
o M. tuberculosis - 18 hours
o T. pallidum - 33 hours
o E. coli - 20 minutes
o Demonstration
▪ Hanging Drop Method • Generation time/Doubling time - time interval until the
▪ Semi-solid - SIM completion of the next division
▪ Leifson stain • Time required to double its population
o Motility
▪ Gliding motility - Capnocytophaga A. STAGES OF BACTERIAL GROWTH
▪ Darting - Campylobacter 1. Lag Phase/Adjustment Phase (4 hours)
▪ Tumbling - Listeria o Initial phase
▪ Twitching - Kingella kingae o Detoxifying medium
▪ Shooting stars - Vibrio cholerae o Turning on enzymes to utilize medium
▪ Corkscrew - Spiral organisms o Number of cells at beginning equal number cells at the
6. Endospore end of lag phase
o responsible for substantial metabolic and structural 2. Log Phase/Exponential Phase (10 hours)
changes in the bacterial cell o Rapid exponential growth
o Keratin like coat (dipicolinic acid) o Enters an active stage of growth
o NOT all bacteria possessed spores. If no spore - o Bacterial division at constant rate
Vegetative o Cellular production is most active during this period
o Formed after stationary phase 3. Stationary phase/Plateau (1-2 days)
o Must be autoclaved in order to kill the spore o Nutrients are limited and used up
o Produced by GRAM (+) only, which are Clostridium o New cells equal the number of dying cells
and Bacillus o Dead debris starting to accumulate
o Resistant structures which enable bacteria to stand o They die due to:
with drying, heat, chemical agents ▪ Lack of food
o Responsible for perpetuation and NOT FOR ▪ Accumulation of toxins/dead debris
MULTIPLICATION ▪ Development of unfavourable pH
o Chemical composition: Calcium dipicolinate 4. Death phase/Stage of decline
o Classification of spores o Complete cessation of multiplication
▪ Terminal spore - Clostridium tetani
▪ Subterminal spore - Clostridium botulinum III. BACTERIAL IDENTIFICATION
▪ Central spore - Bacillus anthracis Macroscopic Examination
o Staining • Scan to see if the specimen submitted is acceptable or not
▪ Schaeffer-Fulton - green (due to malachite green) • Example: If the px submitted a Sputum specimen, and
EXOTOXINS ENDOTOXINS you scan to see that there is more saliva than sputum, ask
Does not require cell death Requires cell death the px to collect another sample = unacceptable
Excreted by living bacteria Liberated by cell walls Microscopic Examination
cells when disintegrated • 2 general ways of observing microorganism under the
Heat labile (60 C) Heat stable (60 C) microscope
Highly toxic/highly potent Weakly toxic / less potent 1. Living State
Highly antigenic Not antigenic a. Wet Mount (shape and arrangement)
Produce by GRAM (+) - Same as performing fecalysis
Produce by GRAM (-)
except Listeria - On a slide, place a drop of distilled water,
Lipopolysaccharide in instead of stool, place 2-3 drops of bacterial
Protein in nature
nature colonies, then emulsify with the coverslip,
Cannot be converted to then examine under the microscope
Can be converted to toxoid b. Hanging Drop
toxoid
Not acted upon by - Best way to observe the motility
Acted upon by enzymes 2. Fixed State
enzymes
Stimulates antitoxin Stimulates antitoxin ▪ Adhere the organism on the slide and apply the
production - YES production - NO stain
Limulus Lysate Test - ▪ More specific than Wet Mount
Gram (-) produce exotoxin:
detect ENDOTOXIN in
Vibrio and E. coli
body fluids Other forms of Examination
1. Manual
FOR PERSONAL USE ONLY 2
Module 1: Introduction to Microbiology
Lesson 1: Bacterial Structure...................................................................................................................................................... 1
Lesson 2: Bacterial Growth Curve .............................................................................................................................................. 2
Lesson 3: Bacterial Identification ................................................................................................................................................ 2
Lesson 4: Cultural And Physiological Characteristics .................................................................................................................. 6
Lesson 5: Physiological Characteristics ...................................................................................................................................... 7
Lesson 6: Specimen Collection, Transport And Processing Of Clinical Specimens ...................................................................... 9
Module 2: Gram Positive & Gram-Negative Cocci
Lesson 1: Staphylococci ........................................................................................................................................................... 13
Lesson 2: Streptococci .............................................................................................................................................................. 16
Lesson 3: Gram Negative Cocci ................................................................................................................................................ 20
Module 3: Gram Positive Spore Forming and Non-Sporeforming Bacilli
Lesson 1: Gram Positive Bacili Spore Forming .......................................................................................................................... 24
Lesson 2: Bacillus Species........................................................................................................................................................ 24
Lesson 3: Clostridium Species .................................................................................................................................................. 25
Lesson 4: Gram Positive Bacilli - Non-Spore Formers ............................................................................................................... 27
Lesson 5: Clostridum Species ................................................................................................................................................... 27
Lesson 6: Erysipelothrix Rhusiopathiae ..................................................................................................................................... 31
Lesson 7: Listeria Monocytogenes ............................................................................................................................................ 31
Lesson 8: Lactobacillus Acidophilus .......................................................................................................................................... 31
Module 4: Acid Fast and Partially Acid-Fast Gram-Positive Bacilli
Lesson 1: Mycobacterium Tuberculosis ..................................................................................................................................... 32
Lesson 2: Complexes Of Mycobacteria ..................................................................................................................................... 34
Lesson 3: Atypical Mycobacteria ............................................................................................................................................... 34
Lesson 4: Mycobacterium Leprae.............................................................................................................................................. 36
Lesson 5: Fungi-Like Bacteria - Non-Spore Forming, Branching Aerobic Actinomycetes ............................................................ 36
Module 5: Gram Negative Bacilli: Family Enterobacteriacaeae
Lesson 1: Enterobacteriaceae ................................................................................................................................................... 39
Lesson 2: Kesh (Klebsiella-Enterobacter-Serratia-Hafnia) ......................................................................................................... 40
Lesson 3: Salmonella................................................................................................................................................................ 41
Lesson 4: Shigella .................................................................................................................................................................... 42
Lesson 5: Citrobacter ................................................................................................................................................................ 43
Lesson 6: Proteus-Providencia-Morganella (PPM)..................................................................................................................... 43
Lesson 7: Yersinia .................................................................................................................................................................... 44
Lesson 8: Plesiomonas Shigelloides ......................................................................................................................................... 44
Module 6: Family Vibrionaceae and Non-Fermenting Gram-Negative Bacilli
Lesson 1: Non-Fermentative Gram-Negative Bacilli ................................................................................................................... 46
Lesson 2: Family Vibrionaceae ................................................................................................................................................. 48
Lesson 3: Chromobacterium Violaceum .................................................................................................................................... 49
Module 7: Gram-Negative Bacilli and Coccibacilli: Campylobacter and Haemophilus
Lesson 1: Campylobacter.......................................................................................................................................................... 51
Lesson 2: Small Pleomorphic Gram-Negative Bacilli.................................................................................................................. 52
Module 8: Gram-Negative Coccobacilli: Optimally Recovered on Special Media
Lesson 1: Bordetella ................................................................................................................................................................. 55
Lesson 2: Francisella ................................................................................................................................................................ 55
Lesson 3: Brucella .................................................................................................................................................................... 56
Lesson 4: Legionella ................................................................................................................................................................. 57
Module 9: Anaerobic Bacteriology
Lesson 1: Obligate Anaerobes .................................................................................................................................................. 58
Module 10: Spirochetes, Obligate Intracellular and Nonculturable Bacterial Agents, Miscellaneous Pathogenic Bacteria, and Fungi-
like Bacteria
Lesson 1: Spirochetes............................................................................................................................................................... 60
Lesson 2: Obligate Intracellular And Nonculturable Bacterial Agents ......................................................................................... 62
Lesson 3: Miscellaneous Pathogenic Bacteria ........................................................................................................................... 64
Lesson 4: Fungi-Like Bacteria ................................................................................................................................................... 65
FOR PERSONAL USE ONLY
, MODULE 1: INTRODUCTION TO MICROBIOLOGY
o For immunogenic induces TNF-alpha, IL-attachment
OUTLINE
o Protects against mechanical disruption of the cell
I Bacterial Structure
A Cellular Appendages o PEPTIDOGLYCAN/MUREIN LAYER (main compo)
II Bacterial Growth ▪ Gram (+) cell wall - thicker
A Stages of Bacterial Growth ▪ Chemical composition: N-acetylglucosamine and
B Cell Morphology N-acetylmuramic acid
C Morphologic Forms of Bacteria ▪ Teichoic acid - negatively charged; regulate
D Arrangement of Bacteria movement of cations
E Motility ▪ Impermeable to alcohol
F Staining
o For ACID FAST ORGANISMS (Mycolic acid)
i Gram Stain
ii Acid-Fast Stain ▪ Present in murein layer of Mycobacterium spp
iii Other Stains o Functions for acid fastness; resistance to drying and
III Bacterial Identification chemicals
A Agar ▪ Gram (-) cell wall - thinner
B Methods of Obtaining Pure Isolated Colonies ▪ Permeable to alcohol
C Classification Of Culture Media ▪ With protein, phospholipids and
i According to Consistency lipopolysaccharides
ii According to Composition
▪ NO TEICHOIC ACID
iii According to How the Medium Is Disposed
iv According to How the Medium Is Used o 3 Regions of Lipopolysaccharide (LPS)
v Antibiotic Susceptibility Agar ▪ Lipid A - major constituents
D Techniques Of Inoculation ▪ Core polysaccharide
E Bacterial Colony ▪ Antigenic O - specific polysaccharide
i Types Of Colonies ▪ FUNCTION: to evade phagocytosis
IV Cultural and Physiological Characteristics ▪ NO CELL WALL: Mycoplasma and Ureaplasma
A According to Nutritional Requirement 3. Cytoplasmic/Metachromatic granules
B According to Oxygen Requirement
o For food reserves
C According to Carbon Dioxide Requirement
D According to Temperature Requirement o Examples:
E According to PH Requirement ▪ Babes - Ernst bodies - Corynebacterium
F According to Moisture diphtheriae
G According to Salt Concentration ▪ Much granules - Mycobacterium
H According to Osmotic Pressure ▪ Bipolar granules - Yersinia pestis
I According to Pressure Requirement ▪ Sulfur granules - Nocardia and Actinomyces
V Specimen Collection, Transport & Processing of Clinical
Specimens
A Transport Of Specimens A. CELLULAR APPENDAGES
B Specimen Preservation 1. Capsule
C Specimen Storage o THICK, slimy gelatinous compound surrounding cell
D Specimen Preparation wall
E Ways To Facilitate Anaerobic Cultivation o Outermost layer
F Criteria For Specimen Rejection o Prevents/inhibits phagocytosis
G Clinical Specimens
i Blood o BEST DEMONSTRATED:
ii CSF ▪ Negative staining
iii Throat and Nasopharyngeal Swab ▪ Neufeld Quellung
iv Stool o POLYSACCHARIDE CAPSULE - Clostridium
v Urine perfringens & Neisseria meningitidis
vi Genital Tract Specimens o D-GLUTAMATE CAPSULE - Bacillus anthracis
vii Sputum NOTE: Most microorganism with capsule are pathogenic;
viii Body Fluids Capsulated organism usually are not flagellated
ix Tissues and Biopsies
x Hair, Nails or Skin Scrapings 2. Nucleus (Nucleoid region)
H Significance o Contains hereditary materials
o No nuclear membrane so nuclear material are
scattered in the cytoplasm which are referred to as
I. BACTERIAL STRUCTURE nucleoids
1. Outer Membrane 3. Plasmids
o Also called Cell Membrane, Plasma membrane, o DNA molecule that can replicate independently,
Cytoplasmic membrane, Plasmalemma double-stranded, in many cases CIRCULAR
o First part of bacterial structure o Extrachromosomal DNA carries an antibiotic gene
o Surrounds cytoplasm ▪ SMALL PLASMID - resistant to tetracycline &
o Only found in gram-negative bacteria chloramphenicol
o Chemical composition: lipopolysaccharide ▪ LARGE PLASMID - resistant to beta-lactams
(phospholipid bilayer) (Penicillin)
o Functions: 4. Fimbriae (Fimbria)/Pili (PIlus)
▪ Serve as primary permeability barriers to o SHORT, Hairlike, extend from cell membrane into the
hydrophilic and hydrophobic compounds external environment
- Acts as osmotic barrier o Produced by GRAM NEGATIVE (E. coli)
▪ Regulates transport of solute across membrane o Composed of chemical variations of protein (Pilin)
▪ Carrier for enzymes, phosphorylation, DNA o 2 TYPES OF PILI:
replication, Penicillin Bound Protein (PBPs) ▪ Common Pili - for attachment
▪ Site of energy synthesis ▪ Sex Pili - producing/transfer genetic material and
o Semipermeable only when the cell is ALIVE/LIVING important in medical dx.
▪ if the cell dies, permeability loses. 5. Flagella (Flagellum)
2. Cell wall o For motility: slender, whiplike structure
o Site of the antibiotic function o Motility is the best at 25 C (room temperature)
o Attachment of flagella and pili o Component: Flagellin
o Cell shape and protection from osmotic damage o Bacilli and Spirilli are MOTILE
FOR PERSONAL USE ONLY 1
, o Used in classification of bacteria Ex. Botulism/diphtheria
o Axial filaments or periplasmic flagella is spiral toxin/TSS
organisms Enterotoxin - damages Uses aqueous extract of
o Classifications of location of flagella cells of GIT - S. aureus and blood cells of horse shoe
▪ Atrichous - no flagellum E. coli crabs (+) result: Clumping
▪ Monotrichous - one flagellum at ONE END (ex. Neurotoxin - interferes with
Vibrio and Pseudo) nerve impulses
▪ Amphitrichous - one or group of flagella on BOTH Coagulase
ENDS (ex. C. jejuni) • Toxoids
▪ Lophotrichous - group of flagella at BOTH or ONE o non - poisonous form of toxins which can be used for
END/S (ex. S. maltophilia) vaccination.
▪ Peritrichous - entire surface (E. coli) o Ways of converting toxins to toxoid:
▪ By aging
▪ By exposure to heat
▪ By exposure to 50% alcohol
II. BACTERIAL GROWTH CURVE
• Generation time found to vary in different organisms
o S. aureus - 30 minutes
o M. tuberculosis - 18 hours
o T. pallidum - 33 hours
o E. coli - 20 minutes
o Demonstration
▪ Hanging Drop Method • Generation time/Doubling time - time interval until the
▪ Semi-solid - SIM completion of the next division
▪ Leifson stain • Time required to double its population
o Motility
▪ Gliding motility - Capnocytophaga A. STAGES OF BACTERIAL GROWTH
▪ Darting - Campylobacter 1. Lag Phase/Adjustment Phase (4 hours)
▪ Tumbling - Listeria o Initial phase
▪ Twitching - Kingella kingae o Detoxifying medium
▪ Shooting stars - Vibrio cholerae o Turning on enzymes to utilize medium
▪ Corkscrew - Spiral organisms o Number of cells at beginning equal number cells at the
6. Endospore end of lag phase
o responsible for substantial metabolic and structural 2. Log Phase/Exponential Phase (10 hours)
changes in the bacterial cell o Rapid exponential growth
o Keratin like coat (dipicolinic acid) o Enters an active stage of growth
o NOT all bacteria possessed spores. If no spore - o Bacterial division at constant rate
Vegetative o Cellular production is most active during this period
o Formed after stationary phase 3. Stationary phase/Plateau (1-2 days)
o Must be autoclaved in order to kill the spore o Nutrients are limited and used up
o Produced by GRAM (+) only, which are Clostridium o New cells equal the number of dying cells
and Bacillus o Dead debris starting to accumulate
o Resistant structures which enable bacteria to stand o They die due to:
with drying, heat, chemical agents ▪ Lack of food
o Responsible for perpetuation and NOT FOR ▪ Accumulation of toxins/dead debris
MULTIPLICATION ▪ Development of unfavourable pH
o Chemical composition: Calcium dipicolinate 4. Death phase/Stage of decline
o Classification of spores o Complete cessation of multiplication
▪ Terminal spore - Clostridium tetani
▪ Subterminal spore - Clostridium botulinum III. BACTERIAL IDENTIFICATION
▪ Central spore - Bacillus anthracis Macroscopic Examination
o Staining • Scan to see if the specimen submitted is acceptable or not
▪ Schaeffer-Fulton - green (due to malachite green) • Example: If the px submitted a Sputum specimen, and
EXOTOXINS ENDOTOXINS you scan to see that there is more saliva than sputum, ask
Does not require cell death Requires cell death the px to collect another sample = unacceptable
Excreted by living bacteria Liberated by cell walls Microscopic Examination
cells when disintegrated • 2 general ways of observing microorganism under the
Heat labile (60 C) Heat stable (60 C) microscope
Highly toxic/highly potent Weakly toxic / less potent 1. Living State
Highly antigenic Not antigenic a. Wet Mount (shape and arrangement)
Produce by GRAM (+) - Same as performing fecalysis
Produce by GRAM (-)
except Listeria - On a slide, place a drop of distilled water,
Lipopolysaccharide in instead of stool, place 2-3 drops of bacterial
Protein in nature
nature colonies, then emulsify with the coverslip,
Cannot be converted to then examine under the microscope
Can be converted to toxoid b. Hanging Drop
toxoid
Not acted upon by - Best way to observe the motility
Acted upon by enzymes 2. Fixed State
enzymes
Stimulates antitoxin Stimulates antitoxin ▪ Adhere the organism on the slide and apply the
production - YES production - NO stain
Limulus Lysate Test - ▪ More specific than Wet Mount
Gram (-) produce exotoxin:
detect ENDOTOXIN in
Vibrio and E. coli
body fluids Other forms of Examination
1. Manual
FOR PERSONAL USE ONLY 2
