What is the LD50 of a pathogen?
the amount required to kill 50% of organisms (measures virulence)
secreted from bacteria to affect host somewhere else
intrinsically part of host, but removed and secreted to host for toxic effects
Hemolysis test: tests for what type of toxicity?
Three possible results of hemolysis test
α: partial hemolysis, leaves green edge
β: total hemolysis, large missing area
γ: culture grows but no hemolysis
Describe AB toxins: type and action
Action: B unit Binds to host cell and A unit carries out toxic Action
Flacid paralysis cause and example
Inhibits ACh at NMJ
Spacstic paralysis cause and example
inhibits glycine release on inhibitory neuron, does not allow relaxation
What is a super antigen?
One that stimulates the specific immune system more than it should in a nonspecific manner. Leads to large amounts of inflammation
What are the three parts of an endotoxin?
2. Core polysaccharide
3. O-specific polysaccharide
What is the toxic part of an endotoxin?
What is the function of the O-specific polysaccharide of an endotoxin clinically?
unique to organism, identifiable in lab setting
Which is more toxic: endotoxin or exotoxin?
3 types of hypersensitivity immune responses
T2: antibodies against pathogen also attack host
T3: WBCs pull pathogens out of tissue to attack in dangerous areas like capillaries
The innate immune system counts on these molecules to be present on pathogens
PAMPs--pathogen associated molecular patterns
These protein components of serum may bind to pathogens and help facilitate their phagocytosis
mediate early cellular response to viral infections
Differentiation of immune system cells
These cells respond immediately to infection
These cells are recruited by mircophages at the beginning of infection
What is the purpose of the complement system?
to control inflammation
Produced by infected cells to recruit immune cell response
Which cells are responsible for initiating the adaptive immune response?
phagocytes from innate response
Cells responsible for bringing antigens to T-cells
Antigent Presenting Cells
Immune system produces these in response to antigens perceived as dangerous
Two types of immunity
Active: host body initiates an immune response
Passive: antibodies are transferred from another person (either transfusion or from mother)