Unit 3 Bacterial Pathogenesis Flashcards
Processes used by pathogens to produce disease
Pathogenesis
These are pathogen products that enhance bacteria’s ability to cause disease
Virulence factors
Do all species have the same virulence factors?
No. Different species have different virulence factors. Depends upon genome
Some of the first virulence factors that a host will encounter are
Attachment factors
Is there only one attachment factors per microbe?
No there are many.
Attachment factors on bacteria bind to these large plasma glycoprotein in the plasma and extracellular matri
Fibronectin
The attachment proteins are fibronectin binding proteins
These are attachment factors with a specialized pili that has an adhesive tip (tips are specific, pili not)
These are various surface associated molecules
There are also specialized proteins for attachment
Fimbrae
Capsules, slime layers
S-layer, wall surface proteins
These attachment factors are short and numerous
These attachment factors are long and there are just one of them, allowing them to attach to each other
Fimbrae
Pili
Which help prevent phagocytosis in addition to aiding in attachment, capsules or slime layers?
Capsules
These type of virulence factors are part of the cell wall structure and induce inflammatory responses after cell death. Not protein. They typically require high amounts to cause harm.
Endotoxins
These virulence factors are proteins that are released outside of the producing cell.
Exotoxins
These endotoxins are found on gram negative cells
Which part of it is the disease causing part?
Lipoplysaccharides (LPS)
Lipid A
These endotoxins are found on gram-positive cells.
Lipoteichoic acids (LTA)
This type of exotoxin acts on cell membranes, typically punching holes in it causing fluid to rush in and bursting.
They can also be enzymes which digest phospholipids, destroy membrane and cause lysing
Cytolysins
This type of exotoxin nonspecifically stimulate T cells to secrete large amounts of cytokines
Superantigens
This type of exotoxin has 2 subunits, one which binds the the host cell and the other that has a negative action inside of the cell by having enzymatic activity
A-B toxins
Which subunit of the A-B toxins binds to the host cell receptor? It only goes in the host cell if it triggers endocytosis, otherwise it doesn’t
Which has a negative action inside of the cell?
B binds to the receptor
A has negative action inside of the cell
These are communication chemicals whose release is triggered by superantigens. Causes too much information, interference occurs, causing inflammation (fever/ shock)
Cytokines
This is one example of shock that occurs in vagina via staphylococcus aureus
Toxic Shock
This bacteria is the cause of diptheria, respiratory illness that sprends via the aerosol route
Corynebacterium diptheriae
What type of toxin is Corynebacterium diptheriae?
How does it enter the host cell via the receptor (which are plentiful on the cell because they are in the heart and kidney)
This forms a ___
A-B toxin (exotoxin)
Endocytosis
Endosome
In the endocytosis of diptheria bacteria, how is the B subunit recept released from the the receptor in the endosome?
What forms, which the A subunit ultimately goes through?
Acidification
A channel
What does corynebacterium diptheriae inactivate by release of A subunit into the cytoplasm?
What does it abolish?
So the cell can’t make ____ in the heart and kidneys
Translation factor EF2
Translation
Proteins
What is the white stuff that forms on tonsils in diptharia?
It can grow and block access of the airway
Pseudomembrane
What is used to treat diptharia (antibodies which bind the toxin before it binds the cell)?
Antitoxin
This is the causative agent of whooping cough
What type of toxin?
What type of proteins does it interrupt?
This releases too much_____, causing ______
Pertussis toxin
AB toxin, aerosol route
G proteins
cAMP
inbalanced water and ion concentration
Does the whooping cough vaccine ensure lifelong immunity?
Is it more deadly in adults or infants?
No. Wears off over time. Have to get it again.
Infants.
This bacteria works similarly to pertussis but in the digestive tract.
Cholera toxin.
Stimulates G protein releasing cAMP causing H2O and ion imbalance
Where is cholera a problem?
Where there is no sewage or water treatment (fecal matter gets into water supply)
What does cholera cause?
Diahrrea via hypertonic cells and dehydration.
This toxin stops protein synthesis differently than diptheria, causes breakdown of RNA component of the ribosome
Shiga Toxin
Shiga toxin was long associated with _____ then became associated with ______
What occurred?
Dysentary
E. coli
Conjugation (copying over of plasmids)
Why is the shiga toxin dangerous?
What is it especially dangerous to?
Where does it cause harm?
It affects cells that line the endothelium (blood vessels)
Capillaries, which are one layer thick, repair can’t occur, hemorrhages occur
Kidneys
Who is the shiga toxin especially deadly to?
Young and elderly
This bacteria produces botulism, usually via contaminated food for adults.
Clostidium botulinum
Botulism interferes with chemical messaging that causes our muscles to contract, what neurotransmitter does it affect?
Acetylcholine
The A part of botulism interferes with what proteins which cause the secretion of acetylcholine?
What does this cause?
SNARE proteins
Flaccid paralysis
Botulism and tetanus have what type of toxin?
What about cholera?
Diptheria, shiga are this type
Neurotoxin (interferes with nervous system)
Enterotoxin (interferes with digestive system)
Cytotoxins (they target cells)
How is botulism normally spread?
Food (canned food) where they grow anaerobically (don’t eat weird cans)
Also can be spread via honey, never give it to infants. Oil too.
This is a common soil microbe.
What does the vaccine protect us against?
It is also commonly called
Tetanus
The toxin, gives us inactivated version of it.
Lockjaw
This disease works by preventing the release of inhibitory GABA and glycine NTs, resulting in spastic paralysis (overstimulation)
Tetanus
What population usually dies from tetanus?
Infants, birthed in unsterile environments
These exotoxins are made by the bacteria and work and the plasma membrane of cells, often forming pores or degrading phospholipids
Cytolysins
These are a classic example of cytolysins, they lyse red blood cells.
They are produced if a microbe lacks a particular nutrient, which in this case is _____
Hemolysins
Iron
This lysis pattern has greenish tinge around the colony, means there is an incomplete breakdown of red blood cells
Alpha hemolysis
This lysis pattern has bright areas around the colonies, signifies complete breakdown
Beta Hemolysis
This lysis pattern has nothing happening around the colonies, no lysis at all
Gamma Hemolysis
Streptococcus pyogenes causes strep throat and has what lysis pattern?
Beta Hemolysis
This bacterial toxin is a pore forming cytolysin that binds to a membrane and forms a pore for calcium influx. It triggers apoptosis.
Whats a mircobe example of this?
Alpha toxin
Staphylococcus Aureus
This additional toxin of staphylococcus aureus forms pores for the entry of toxin.
What type of cell does it target in our bodies?
What does it disrupt, leading to apoptosis?
PV leukocidin
Mitochondrial membrane
White blood cells (leukocydes)