Microbiology Exam Flashcards
(133 cards)
1
Q
Outline one important experiment that contributed towards disproving the theory of spontaneous generation. Outline two major discoveries or innovations from the “Golden Age of Microbiology”. Include in your answer the person responsible and approximate date.
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2
Q
Chains of cocci
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Streptococcus
3
Q
Rod-shaped
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Bacillus
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Q
Ribosomes slightly
smaller
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Prokaryotes
5
Q
Grape-like clusters
of cocci.
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Staphylococci
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Q
Ribosomes slightly
larger
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Eukaryotes
7
Q
Pseudomurein
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Archaea
8
Q
Non-cellular
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Viruses
9
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Eukaryotes
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Algae
10
Q
Define “glycocalyx”. Include in your answer two subcategories within that definition, and two examples of species that possess these structures. (5 marks)
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11
Q
Describe the role and structure of peptidoglycan. (6 marks)
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12
Q
Briefly compare and contrast ion-linked and ABC active transport systems. Preferably use diagrams. (6 marks)
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13
Q
Oxaloacetic acid +
Acetyl CoA
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Beginning of Krebs cycle
14
Q
Photosystem 1
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Generates ATP + NAPDH
15
Q
Excellent electron
acceptor
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Oxygen
16
Q
Describe five categories of aerobes and anaerobes. For your answer you are required to describe five categories in total, not five categories for each of aerobes and anaerobes. (5 marks)
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17
Q
Compare and contrast DNA replication and gene transcription. Include in your answer the roles of these processes in the life of a cell, and the essential elements of the mechanism.
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18
Q
What is wrong with the “Three Kingdoms Model” ?
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19
Q
Name a human disease caused by each of the following bacterial genera:
Yersinia: yersiniosis
Helicobacter: peritonitis, which is an infection of the peritoneum, or the lining of the abdominal cavity
Vibrio: Vibriosis
Clostridium: Clostridium difficile infection (CDI)
Bacillus: Bacillus anthracis
Streptococcus: treptococcal disease
Mycobacterium: Mycobacterium tuberculosis,
Neisseria: Meningitis
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20
Q
With respect to epidemiology, define the terms “incidence”, “prevalence” and “sporadic”.
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21
Q
Outline two major discoveries or innovations from the “Golden Age of Microbiology”. Include in your answer the date (i.e. year), and the person responsible.
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22
Q
3D fluorescence microscopy
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23
Q
Scanning tunnelling microscopy
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24
Q
Phase-contrast
microscopy
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Refraction
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Confocal
| microscopy
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Reduction of
| transmission.
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Basic dye
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Acidic dye
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30
Draw a diagram of the structure of the cell envelope of Gram-negative bacteria.
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31
How do bacteria move towards attractants and away from repellants?
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32
In relation to biochemistry, define the terms “oxidation” and “reduction”.
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33
Describe the growth phases of bacterial batch culture. Include in your answer a graph that incorporates “cell number” and “time information”.
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34
What happens at the DNA replication fork
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35
In terms of basic characteristics and large scale evolutionary history and diversity, how would you define:
a. fungi
b. protozoa c. algae?
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36
With respect to epidemiology, define the terms “incidence”, “prevalence” and “sporadic”.
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Sarcoptes scabiei -organism type, mode of transmission, common name of disease
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trachoma -organism type, mode of transmission, organism name
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Chicken pox -organism type, mode of transmission, organism name
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Tuberculosis -organism type, mode of transmission, organism name
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The flu-organism type, mode of transmission, organism name
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Hepatitis -organism type, mode of transmission, organism name
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Gonorrhea -organism type, mode of transmission, organism name
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Plasmodium falciparum -organism type, mode of transmission, common name
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Syphilis-organism type, mode of transmission, organism name
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Bordetella pertussis -organism type, mode of transmission, common name
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Tuberculosis - organism type, mode of transmission, organism name
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The flu- organism type, mode of transmission, organism name
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Rabies - organism type, mode of transmission, organism name
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HIV - organism type, mode of transmission, organism name
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51
Define the term “nosocomial infection”, and outline the four major classes of nosocomial infection, and
their importances.
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52
Outline the structure and function of IgG, IgM and IgA antibodies.
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53
Explain how the presence of algae can be pollution indicators.
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54
Compare and contrast the lytic and lysogenic life cycles of bacteriophage
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Outline the malaria parasite life cycle, using the above diagram as an aid. A good strategy to answer this quesiton may be to sketch a copy of the diagram and to add labels and additional explanatory notes.
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56
List key points of all the types of microscopy
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57
Four hundred and fifty bacterial cells are inoculated into liquid growth medium and incubated under suitable conditions for growth for six hours. At the end of that time there are 3 x 109 cells.
1. How many generations have elapsed? (this is not necessarily a whole number). (show working).
2. Provide an estimate of the generation time, but also indicate
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58
Outline the endosymbiotic theory, in the context of the 16s-RNA based universal evolutionary tree.
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59
Describe the purpose of, and procedure for, acid fast staining,
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60
Please explain, with the aid of a diagram, the basic structure of a Gram-negative bacterial cell. This
should include both the structure of the cell envelope, and also what is inside the cell.
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61
Compare and contrast phase contrast microscopy and dark field microscopy.
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Compare and contrast bright field microscopy and scanning electron microscopy. That answer should include but not be limited to the type of radiation used, the fundamentals of how the methods work,
the resolving powers, and the types of images produced.
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63
Please explain, with the aid of a diagram, the basic structure of a Gram-positive bacterial cell envelope.
This should include the names and descriptions of the important biochemicals.
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Describe the important differences between prokaryotes and eukaryotes.
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How do bacteria move towards attractants and away from repellants?
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Compare and contrast: 1. oxygenic (ie cyanobacterial and green plant) photosynthesis, and 2. cellular respiration. Include in your answer the roles of these processes in the cell, the main steps of the
processes, the reactants and the products
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67
Outline the differences between missense, nonsense and frameshift mutations. Include in your answer the general consequences of each class of mutation, in terms of the amino-acid sequence of the gene product.
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Outline the similarities of and differences of brown algae, red algae and green algae.
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Outline the lytic and lysogenic types of life cycles of bacteriophage
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Microbes in Our Lives
A few are pathogenic (disease-causing)
• Decompose organic waste
• Are producers in the ecosystem by photosynthesis
• Produce industrial chemicals such as ethanol and acetone
• Produce fermented foods such as vinegar, cheese, and bread
• Produce products used in manufacturing
(e.g., cellulase) and disease treatment (e.g., insulin)
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Archaea
Also prokaryotes
• Lack peptidoglycan
• Many live in extreme environments e.g.
• High salt concentrations
• Vey high temperatures (some can grow at >100oC).
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Fungi
Unicellular or multicellular eukaryotes
• Cell wall
• Chitin
• Use organic chemicals for energy
• Just like us i.e. they are not photosynthetic
• Typically live in soil but sometimes in other
environments
• Can sometimes cause disease.
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Protozoa
Diverse group
• Taxonomic dumping ground for unicellular
eukaryotes that are:
• Not fungi
• Not photosynthetic
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Algae
Also something of a taxonomic dumping ground, so
very diverse.
• Photosynthetic eukaryotes that are either
• Unicellular, or
• Multicellular but undifferentiated (cells largely the same, do not
have distinct tissues)– with seaweed as a prominent example.
• Essentially all marine or aquatic
• Cell wall composed of cellulose (like “normal” plants)
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Viruses
Very small
• Acellular (not cellular): genetic parasites
• Inert when outside host in form of virion (virus particle)
• Genetic material forces host to make more virus.
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Parasites
• In this context, am referring to organisms encompassed by the discipline of
parasitology.
• Poorly defined group – encompasses (nearly) every organism that causes
disease in humans that is not a bacterium, a virus, or a fungus.
• Overlaps with protozoa – protozoa that cause disease in humans are called
parasites and studied by parasitologists
• “Parasites” also includes parasitic worms (helminths), and some parasitic
arthropods such as mites (scabies), and lice.
• By convention, parasitic insects such as mosquitoes come under the discipline
of “medical entomology”, not parasitology (the distinction between
parasitology and medical entomology is somewhat blurry and artificial)
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Golden Age of Microbiology
1857-1914
• Pasteur’s work resulted in discoveries in:
• Microorganisms survival and reproduction
• Microorganisms and disease
• Immunity- created the first vaccines for rabies and anthrax
• Antimicrobial drugs
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Microbes Cause Disease
1867 – Joseph Lister used phenol to
prevent surgical wound infections
• Sprayed carbolic acid on surgical
instruments, wounds and dressings
• Reduced surgical mortality due to bacterial
infection
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Koch’s
Postulates
1. The microorganism must be found in abundance in all
organisms suffering from the disease, but should not
be found in healthy organisms.
2. The microorganism must be isolated from a diseased
organism and grown in pure culture.
3. The cultured microorganism should cause disease
when introduced into a healthy organism.
4. The microorganism must be re-isolated from the
inoculated, diseased experimental host and identified
as being identical to the original specific causative
agent.
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Some light microscopy variantsBrightfield (“normal”/default)
• Dark-field
• Phase contrast
• Differential interference contrast
• Fluorescence
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Fluorescence-based Microscopic Techniques
Fluorescent substances (fluorochromes) absorb light at
one wavelength (the excitation wavelength) and emit it
at another wavelength (the emission wavelength)
• In fluorescence microscopy, the excitation wavelength is
always UV light, which is invisible, so only light from the
fluorescent substance can be seen: allows visualization
of specific targets of interest.
• At its simplest, fluorescence microscopy is defined by
specimen preparation, not the microscope itself
(although a source of the excitation UV light needs to be
fitted)
• However, fluorescence techniques have also been
coupled with some specialised optics to e.g. yield 3D
images.
The specimen is “stained”
with a fluorescent stain that
specifically binds to a
diagnostic target of interest.
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Prokaryote
One circular chromosome, no
nuclear membrane
• No histones
• No organelles
• Bacteria: peptidoglycan cell walls
• Archaea: pseudomurein cell
walls
• Binary fission
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Eukaryote
• Paired chromosomes,
in nuclear membrane
• Histones
• Organelles
• cell walls if present:
polysaccharide
• Mitosis
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Prokaryote
Cells are smaller
• 1-10 µm in diameter
• No internal membrane
• Sterols are absent in
membrane of virtually all
prokaryotes
• Often Motile
• Flagella
• Ribosomes are slightly smaller
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Eukaryote
Cells are larger
• 10-100 µm in diameter
• Internal membranes that
compartmentalise their functions
• Golgi body, mitochondria, etc.
• Sterols in their cell membranes
• 5 to 25% of total lipids
• Mostly non-motile
• Ribosomes are slightly larger
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Gram Positive Cell Wall
Many layers of peptidoglycan, plus
• Teichoic acids
• Lipoteichoic acid-link to the plasma membrane
• Wall teichoic acid-link to peptidoglycan layers
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Gram Negative Cell Wall
Few layers of peptidoglycan
• In periplasm
• Outer membrane
• Lipoproteins, lipopolysaccharides, phospholipids
• Lipid A – endotoxin
• O polysaccharide – antigen
• Eg. E. coli O157:H7
• Porins (channels)
• Protect from phagocytosis, complement & antibiotics
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Energy & Carbon Source
Photoautotroph Light CO2
Cyanobacteria
plants, green,
purple bacteria
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Energy & Carbon Source
Photoheterotroph Light Organic compounds
Green, purple
nonsulfur bacteria
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Energy & Carbon Source
Chemoautotroph Chemical CO2
Iron-oxidizing
bacteria
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Chemoheterotroph Chemical Organic compounds
Fermentative
bacteria Animals,
protozoa, fungi,
bacteria
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Microbial Metabolism
Metabolism is the sum of the chemical reactions in an organism
• “Metabolism” : usually slightly more specific meaning, refers to chemical reactions that:
• Yield energy from nutrients, or
• Yield the precursors of larger molecules from nutrients, or
• Yield larger non-genetic molecules from smaller molecules (which are derived from
nutrients…)
It is not usually used to refer to phenomena such as DNA replication, transcription,
translation etc, the study of which is usually referred to as “molecular biology” – but the
boundaries between these fields are blurry
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The critical high energy compounds in
metabolism
These are compounds that can be used to power many different reactions.
• They are like the cell’s “money”.
• In general catabolic reactions are directed towards producing these compounds.
1.Nicotinamide adenine dinucleotide (NADH/NAD+) and relatives.
• The NADH form is a powerful reducing agent, while the NAD+ form is the oxidised form.
2.Adenosine triphosphate (ATP)
• If this is converted to adenosine diphosphate (ADP) plus phosphate, then energy is released.
• This reaction could probably also be classed formally as a redox reaction, but for
convenience/historical reasons, the conceptual framework that is used is that the third phosphate
is a “high energy phosphate” that is a source of energy.
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General outline of catabolism in a chemoheterotroph using
glucose or similar carbohydrate as an energy source.
Aerobic Respiration
Glycolysis
Krebs cycle (CAC)
Electron transport chain
O2 is final electron acceptor
Fermentation
Glycolysis
Fermentation
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Glycolysis
Usually the first stage of carbohydrate
metabolism
• Conversion of glucose (6 carbon compound) to
pyruvic acid (3 carbon compound) (also called
pyruvate)
2 X ATP + 2 X NADH + 1 X H2O produced from each
glucose molecule
No gaseous oxygen involved
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Krebs Cycle
Next stage after glycolysis
• Conversion of pyruvic acid to CO2 with formation of NADH
and similar reducing compound FADH2, as well as one ATP
• Involves another important high energy intermediate:
acetyl Coenzyme A (acetyl CoA) (higher energy than just
CoA)
• The essential logic:
• Step 1: one carbon of pyruvic acid’s 3 carbons is oxidised to CO2 and the
other two become the acetyl group in acetyl CoA. NADH formed as well
• Step 2: The acetyl group reacts with 4 carbon oxaloacetic acid to
become 6 carbon citric acid.
• Subsequent steps: Stepwise oxidation of citric acid back to oxaloacetic
acid, with generation of NADH, FADH2 and CO2
• This also does not involve molecular oxygen, but normally only exists in
organisms which use oxygen .
• Also called citric acid cycle or tricarboxylic cycle
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Electron Transport Chain
Purpose is to convert reducing power in NADH and
FADH2 into ATP, with O2 (i.e. oxygen in air) as terminal
electron acceptor (usually)
• Multi-step process mainly involving cytochromes
embedded in cytoplasmic membrane (or mitochondrial
membrane in eukaryotes)
• Mechanism is chemiosmosis.
• Redox reaction linked to pumping protons out of cell
• Creates energy store – gradient of proton concentration, into the cell.
• Movement of protons back into cell with gradient linked to
formation of ATP in membrane-bound ATP synthase.
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Batch Culture Phases (1)
Batch culture:
• Fresh liquid culture medium is
inoculated and incubated under
conditions that support growth,
with addition of more cells or
growth medium
• Lag Phase
• Little or no cell division
• Cell is adapting to environment
• Log Phase
• Cells are dividing at maximum speed for
species/medium/incubation conditions.
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Batch culture phases (2)
Stationary Phase
• Growth rate slows
• Nutrient exhaustion, accumulation of waste products,
pH non-optimal
• Death balances new cells
•Death or Decline Phase
• Deaths exceeds number of new cells
• Logarithmic decline
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Measuring Microbial Growth
Direct methods
• Plate counts
• Filtration
• Most probably number
• Direct microscopic count
•Indirect methods
• Turbidity
• Metabolic activity
• Dry weight
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Terminology
Antisepsis, Aseptic, -cide, -cidal, degerming, disinfection, pasteurisation, sanitization, -stasis, -static, sterilisation
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Commercial Sterilisation – killing of nearly everything, including most endospores
(Clostridium botulinum of particular concern)
Some endospores of thermophiles will survive – but will not germinate/grow at normal
food storage temperatures
Should not store canned food at temperatures >45oC.
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Chemical methods of microbial control:
Phenol
Phenolics
Alcohols
Halogens
Oxidizing agents
Surfactants
Heavy metals
Aldehydes
Gaseous agents
Enzymes
Antimicrobials
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• Genetics – the study of what genes do
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• Gene – a segment of DNA that encodes a functional
| product (usually a protein)
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Chromosome – a DNA molecule in a cell, that carries a
significant portion of the total DNA in the cell.
o Contains the genes
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DNA
Deoxyribonucleic acid
• Double helix associated with proteins
• Deoxyribose sugar and phosphate backbone
• 4 nucleotides
• Thymine (T)
• Adenine (A)
• Cytosine (C)
• Guanine (G)
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RNA
The “other” nucleic acid
• Ribonucleic Acid
• Ribose sugar (not deoxyribose which is in DNA)
• 4 nucleotides, containing the following bases:
o Uracil (U) (not Thymine which is in DNA)
o Adenine (A) (same as in DNA)
o Cytosine (C) (same as in DNA)
o Guanine (G) (same as in DNA)
• DNA is the definitive archive of genetic information
• RNA is multifunctional, but primarily involved in decoding of genetic information to become
amino acid sequence.
• 3 main types in the cell
• mRNA – Messenger RNA: intermediate in decoding of DNA sequence into amino-acid sequence (i.e protein)
tRNA –Transfer RNA: Structural and functional molecular that carries amino-acids and adds them to a growing protein chain
• rRNA – Ribosomal RNA: Structural and functional role in ribosomes that carry out protein synthesis.
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The Flow of Genetic Information
Parent cell - DNA to expression Genetic information is used within a cell to
produce the proteins needed for the cell to
function. Cell metabolizes and grows
Parent cell - DNA to recombination genetic information can be transferred between cells of the same generation to recombinant cell
Parent cell - replication Genetic information can
be transferred between
generations of cells Daughter cells
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A summary of events at the DNA replication fork:
1. Enzymes unwind the 1
parental double
helix.
2. Proteins stabilize the
unwound parental DNA.
3. The leading strand is
synthesized continuously
by DNA polymerase.
4. The lagging strand is
synthesized discontinuously.
Primase, an RNA polymerase,
synthesizes a short RNA
primer, which is then extended by
DNA polymerase.
5.DNA polymerase
digests RNA primer
and replaces it with DNA
6. DNA ligase joins
the discontinuous
fragments of the
lagging strand.
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Transcription
Genes (made of DNA) are transcribed into messenger RNA (mRNA)
• mRNA sequence: the RNA equivalent of the DNA sequence of the
coding strand of the gene.
• It is actually the non-coding strand that is read, and the complement
synthesised – which is the RNA version of the coding strand
• Transcription requires RNA polymerase & RNA nucleotides
• DNA “G”, “C” and “A” equivalent to RNA “G”, “C” and “A”
• DNA “T” equivalent to RNA “U” (the base is uracil).
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The Toyota Corolla of plasmid cloning
vectors: pUC19
Simple and highly effective – extremely heavily used with E. coli since early 1980s
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<2 kbp (2000 base
pairs)– very easy to
work with in test
tube, and get in and
out of cells.
Resistance gene:
confers resistance to
ampicillin, so cells
that contain the
vector can be
selected for
Indicator gene:
Makes colonies go blue on
X-gal medium: disrupted by
insertion of DNA.
Restriction enzyme
cleavage sites
for insertion of
foreign DNA
Origin of replication:
Stable replication in E. coli
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Carl Woese chose a superb evolutionary clock for his studies.
16s RNA
• Structural-functional RNA in ribosomes
• ~1500 bases
• Is found in all prokaryotes, and performs the same essential function in all prokaryotes.
• No selection for change: excellent for evolutionary studies.
• Its structure is maintained by internal base pairing.
• This means that a base change could disrupt pairing and impair function
• Really can only evolve in base-paired areas by very rare simultaneous errors that introduce complementary
changes at two different position.
• Base-paired parts evolve slowly enough to reveal very deep evolutionary history: can
reveal the most ancient evolutionary relationships.
• Unpaired parts (variable regions) evolve more quickly – can give more fine structure evolutionary
information.
• Now accepted as something close to definitive marker for evolution of all cellular life (is
18s RNA in eukaryotes)
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Cell type
Fungi
Eukaryotic
Sterols present
Glucans, mannans, chitin (no peptidoglycan)
Sexual and asexual reproductive spores
Limited to heterotrophic, aerobic, facultatively anaerobic
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Cell type
Bacteria
Prokaryotic
Sterols absent, except in mycoplasma
Peptidoglycan
Endospores (not for reproduction); some asexual reproductive spores
Heterotrophic, autotrophic, aerobic, facultatively anaerobic, anaerobic
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Lichens
• Combination of green alga or
(cyanobacterium) & a fungus
• Mutualistic relationship
• Both benefit
• Fungus provides nutrients, water, and protection
• Photosynthetic microbe provides carbohydrates and oxygen
• 3 morphological groups
• Crustose lichens
• Grow flush to surface
• Foliose lichens
• Leaf-like
• Fruticose lichens
• Finger-like projections
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Helminths (worms)
Multicellular eukaryotic animals. Not usually regarded as within the field of
microbiology
• Two divisions:
• Nematodes (roundworms)
• Platyhelminths (flatworms)
• Trematodes (flukes)
• Cestodes (tapeworms)
• Most produce eggs & have a larval stage
• The term “helminth’ is often regarded as being synonymous with “parasitic
worm”
• However, many close relatives of parasites are free living, and are also regarded as
helminths
• All parasitic worms are helminths, not all helminths are parasitic worms
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Characteristics of Viruses
• Viruses
• Minuscule, acellular, infectious agent having either DNA or RNA
• Cause infections of humans, animals, plants, and bacteria
• Cause most of the diseases that plague the industrialized world
• Cannot carry out any metabolic pathway
• Cannot reproduce independently
• Recruit the cell's metabolic pathways to increase their numbers
• Have extracellular and intracellular state
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Characteristics of Viruses
• Extracellular state
• Called virion
• Protein coat (capsid) surrounding nucleic acid
• Nucleic acid and capsid also called nucleocapsid
• Some have phospholipid envelope
• Outermost layer provides protection and recognition sites for host cells
• Intracellular state
• Capsid removed
• Virus exists as nucleic acid
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Growing Viruses in the Lab:
1. Bacteriophage
• Viruses that infect bacteria are known as bacteriophage
(“Bacteria eaters”)
• Can be grown either in suspensions of bacteria in liquid
media or in bacterial cultures on solid media
• If a lawn of bacteria are grown and then infected with a
bacteriophage plaques (clear zones on plate) will form
• The concentration of a bacteriophage suspension can be
measured in plaque forming units (pfu)
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Growing Viruses in the Lab:
2. Animal Viruses
• Animal viruses can be grown in one of three
ways:
• In living animals
• In embryonated eggs
• In cell cultures
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Prions
• Proteinaceous Infectious particle
• Inherited and transmissible by ingestion, transplant, and
surgical instruments
• Spongiform encephalopathies: Sheep scrapie, Creutzfeldt-Jakob
disease, mad cow disease
• PrPC: Normal cellular prion protein, on cell surface
• PrPSc: Scrapie protein; accumulates in brain cells,
forming plaques
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The Nature of Infectious Disease
• Causation of Disease: Etiology
• Exceptions to Koch's postulates
• Some pathogens can't be cultured in the laboratory
• Diseases caused by a combination of pathogens and other cofactors
• Ethical considerations prevent applying Koch's postulates to
pathogens that require a human host
• Difficulties in satisfying Koch's postulates
• Diseases can be caused by more than one pathogen
• Pathogens that are ignored as potential causes of disease
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Classifying Infectious Diseases
Occurrence of a Disease
• Incidence - Fraction of a population that contracts a
disease during a specific time
• Prevalence - Fraction of a population having a specific
disease at a given time
• Sporadic - Disease that occurs occasionally in a population
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Sporadic disease – Occurs occasionally
• Endemic disease – Constantly present in a population
• Epidemic disease – The occurrence of more cases of
disease than expected in a given area or among a specific
group of people over a particular period of time.
• Pandemic – Worldwide epidemic-influenza
• Herd immunity – Immunity in enough of the population
to prevent self-sustaining transmission.
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Transmission of Disease
Contact
• Direct: requires close association between infected and
susceptible host
• eg. Colds, Hepatitis, measles, STDs
• Indirect: spread by fomites
• Fomite: an inanimate object that
can spread disease
• eg. AIDS - syringe
• Droplet: transmission via airborne droplets
• cough, sneeze, laugh
• eg. Influenza, pneumonia, whooping cough
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Body’s Defences
Innate immunity:
First line of defense
-intact skin
-mucous membranes and their secretions
- normal microbiota
Second line of defense:
Phaocytes such as neutrophils, eosinophils, dendritic cells, macrophages, inflammation, fever, antimicrobial substances
Adaptive immunity - Third line of defense -specialised lymphocytes T cells and B cells, antibodies.
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Interferons
Small proteins produced by the host
• Three types
• Alpha interferon (IFN-α) & Beta interferon (IFN-β)
• Produced by virus-infected cells
• Produce antiviral proteins (AVPs)
• Gamma interferon (IFN-γ)
• Induce neutrophils & macrophages to kill bacteria
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Cytokines
• Soluble chemical messengers – small proteins (like hormones)
• Cell communication
• Only on cell that has a specific receptor
• Examples
• Interleukins (ILs): produced by white blood cells – mediate many functions
concerned with immunity
• Chemokines: induce migration of leucocytes
• Interferons: see two slides previous
• Tumour necrosis factor (TNF): complex functions, mainly related to mediating
inflammation
• Colony stimulating factor (CSF): Also complex functions, mainly concerned with
stimulation of growth of immune cells.
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B Lymphocytes (B Cells) and Antibodies
• Classes of antibodies
• IgM – first antibody produced
• IgG – most common and longest-lasting antibody
• IgA – associated with body secretions
• IgE – involved in response to parasitic infections and allergies
• IgD – exact function is not known
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```
GAMED”
IgG: 'G'eneric - common Abo
IgA: Secr'A'tory in breAst milk
IgM: i'Mmediate - first Abo made
IgE: all'E'rgy
IgD: 'D'on't worry about it; we 'D'on't
really know what this does.
```
A
132
```
Types of Adaptive Memory
• Naturally acquired active immunity
• Results from an infection
• Naturally acquired passive immunity
• Transfer of Ab from mother to infant
• Artificially acquired active immunity
• Injection of Ag (vaccination)
• Artificially acquired passive immunity
• Injection of Ab
```
A
133
```
There are 4 main types of vaccines:
• Live-attenuated vaccines
• Inactivated vaccines
• Subunit, recombinant, polysaccharide, and conjugate vaccines
• Toxoid vaccines
```
A
