Bacterial Anatomy And Physiology Flashcards
Capsule of bacteria is
Tough/well demarcated
Prevents phagocytosis by preventing Opsonization
Slime layer of bacteria is
Very Loose or undemarcated
Capsule and Slime layer both present in which organism
Streptococcus Salivaris
Organisms containing Capsule
Pretty and Nice Capsules
Streptococcus pneumoniae
Klebsiella pneumoniae
Bordetella pertussis
Vibrio Parahemolyticus
Clostridium perfringes
Yersinia pestis
Neisseria meningicoccus
Hemophilus influenza
Cryptococcus
Staphylococcus aureus
Bacillus anthracis
All capsules are made up of
Polysaccharides
Which bacteria capsules are not made up of Polysaccharides
Yersinia pestis - F1 PEPTIDE
B. Anthracis - Polypeptide
S. Pyogenes - Hyaluronic acid capsule
Which organism have microcapsule
S. Aureus
Demonstration of capsule is done by
Mc Fadyeans Reaction
Quellung Reaction/Neufeld Reaction
Mc Fadyean’s Reaction
Used for demonstration of Capsule
Add Polychrome Methylene blue - Purple color around capsule
Example - B. Anthracis
Quellung Reaction
For demonstration of capsule
Capsule Antigen + add Antisera - results in swelling around capsule
Example - Pneumococcus
3 A’s of Slime layer
Antibiotic resistance
Adherence
Anti phagocytic
Difference in thickness between gram Positive and Negative
Gram +ve - 100 layers thick
Gram -ve - 1-2 layer thickness
Difference in lipid content in Gram positive and negative
Gram Positive - 2-5%
Gram Negative - 15-50%
Composition of Gram Positive Cell wall
Peptidoglycan
Lipoproteins
Teichoic acid
Composition of cell wall of Gram negative organisms
Lipopolysaccharides
Lipoprotein
Peptidoglycan
Outer membrane, Periplasmic space and Porins are seen in cell wall of which organisms
Gram Negative organisms
Regions of Lipopolysaccharides
OPA
Region 1 - O antigen (Most variable)
Region 2 - Core Polysaccharide
Region 3 - Lipid A (endotoxin activities)
Composition of Tetrapeptide chain of Gram Positive Organisms
AGLA
Alanine
Glutamine
Lysine
Alanine
Pentapeptide mass bridge is seen in
Gram Positive Organisms
Demonstration of cell wall is done by
RMP Dr
Reaction with Antibody
Mechanical rupture of cell/Microdissection
Palsmolysis
Dr - Differential staining
Endotoxins are usually seen in which organisms
Gram negative Bacteria
Only gram Positive Organism containing Endotoxin
Listeria
Exotoxin can be seen in which organisms
Both gram Positive and Negative
Effect of heat on Endotoxin and Exotoxin
Endotoxin - Heat stable
Exotoxin - Heat liable
Endotoxins and Exotoxin are made up of
Endotoxin - Lipopolysaccharides
Exotoxin - Proteins
Antigenicity of Endotoxin and Exotoxin
Endotoxin - Low antigenicity
Exotoxin - High Antigenicity
Effect of Endotoxin and Exotoxin
Endotoxin - Constant effect
Exotoxin - Variable effect
Endotoxin and Exotoxin are released on
Endotoxin - released on lysis of cells
Exotoxin - released as secretions except Botulinum toxin
Which type of toxin is need in large amount to create efftects
Endotoxin
Types of L form
Stable L form
Unstable L form
Stable L form means
Unable to revert to original form
Ex - Mycoplasma
Unstable L form means
Lose their cell wall with penicillin
Can revert back to original form
Types of Unstable L forms
Protoplast - seen in gram Positive, entire cell wall is lost
Spheroplast - Gram negative, some part of cell wall remains
Ribosomes found in bacteria
70S (50S+30S)
Nucleus of bacteria contains
Single circular dsDNA
Which structure functions as respiratory unit in bacteria
Mesosomes
Mesosomes are prominent in gram Positive or negative
Gram Positive, seen in both
Antigen present in Flagella
H antigen
Endoflagella is seen in
Spirochetes
Origin - Periplasmic space
Parts of Flagella
Basal body
Hook
Filament
Classification of Flagella according to location
Monotrichous
Amphitrichous
Lophotrichous
Peritrichous
Examples of Monotrichous flagella
Vibrio Cholera
Pseudomonas
Example of Lophotrichous flagella
Helicobacter pylori
Example of Peritrichous Flagella
Proteus
E coli
Types of Motility
Tumbling - Listeria
Darting - Vibrio, Campylobacter
Corkscrew - Treponema
Twitching - Trichomonas vaginalis
Swarming
Falling leaf - Giardia Lamblia (Girata hua leaf)
Differential motility - motile at 22-25° and non motile at 37° - Yersinosis, Listeriosis
Examples of Swarming motility
PVCS
Proteus
Vibrio Parahemolyticus
C. Tetani, bacillus cereus
Serratia
Demonstration of Motility is done by
Hanging drop motility
Semi solid agar method - 0.5% Semi solid agar
Craiges tube
U tube
Stain and Microscope used to visualize Flagella
Leifson and Ryu stain
Dark Field Microscope
Functions of Fimbriae/Pili
Adhesion
Antigenic
Conjugation
Type 4 Pili - Helps in locomotion (Neisseria)
Spores forming organisms
Bacillus - Non bulging
Clostridium - Bulging
Types of Spores based on Location
Central
Subterminal
Terminal
Examples of Central Spores
B. Cereus
C. Bifermentans
Examples of subterminal spores
C. Tetani - Drumstick appearance
C. Tertium - tennis racket appearance
Parts of spore from innermost to outer
Core - Dipicolinic acid (makes it heat resistant)
Cortex
Coat (Chemical resistant)
Exosporium
Stains used for spores
Zeihl Neelsen Stain 0.5% H2SO4
Schaeffer and Fulton/Modified Ashby
Moeller stain
Only Prokaryote which lacks cell wall
Mycoplasma
Prokaryote having Sterols in cell membrane
Mycoplasma
Prokaryote lacking muramic acid in cell wall
Chlamydia
Cocci in clusters(Bunch of grapes)
Staphylococcus aureus
Cocci in chains
Streptococcus
Cocci in Pairs (Diplococci)
Pneumococcus
Lens shaped cocci
Neisseria Meningitidis
Kidney shaped cocci
Neisseria gonorrhea
Cocci in tetrads
Micrococcus
Spectacle like appearance
Enterococcus
Bacilli with Bamboo stick appearance
Bacillus anthracis
Diplobacilli
Klebsiella pneumoniae
Branching Filamentous Bacilli
Nocardia
Actinomyces
Curved bacilli
Vibrio
Bacters
Spiral bacilli
Spirochetes
Pleomorphic bacilli
H. Influenza
Brucella
Population doubling time of E.coli, M. TB and M. Leprae
E coli - 20 min
M Tb - 20hrs
M leprae - 20days
Capnophilic bacteria (CO2 loving)
Campylobacter
Examples of Obligate aerobes
M Tb
Legionella
Nocardia
Pseudomonas
Bacillus
Brucella
Bordetella
Examples of Obligate Anaerobes
Clostridium
Bacteroides
Actinomyces
Facultative anaerobes
Staphylococcus
Streptococcus
Enterobacteriacea
Hemophilus
Vibrio
Example of Acidophilic bacteria
Lactobacillus
Example of Alkalophiles
Vibrio
Bacteria classification according to temperature
Psychrophiles(less than 20)
Mesophiles
Thermophiles (55-80°)
Size of bacteria increase in which phase of Bacterial growth curve
Lag phase
Maximum size of bacteria is seen after which phase
At end of lag phase
In which phase bacteria are more susceptible to antibiotics
Log phase
Maximum metabolic activity is seen in which phase
Log phase
What happens in Stationary phase
STAB
Sporulation
Exotoxin
Antibiotic production
Bacteriocin production