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49 Cards in this Set
- Front
- Back
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how do microbes adhere to a surface
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use adhesins
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what type of bacteria have fimbriae
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gram negative
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with what do fimbrial adhesins interact with
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glycolipids of host epithelial cells
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what type of gram negative adhesin is located directly on the cell surface
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invasin - recognize integrins
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what is the receptor for gram positive bacteria
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fibronectin (coats the mucosal surface of epithelial cells)
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why is gram negative pneumonia more prevalent in hospitalized patients
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because fibronectin (gram positive) is displaced, integrin ratio is increased
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what constituent of plasma is in very little supply to allow bacterial growth
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free iron
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what do bacterium secrete to sequester iron
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chelators
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what kind of bacteria secrete toxins that destroy RBC to scavenge iron from them
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streptococci
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brucella abortus symptoms in humans vs cattle
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human - systemic infection
cattle - aborts fetus |
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what is the best way of preventing against the complement system
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preventing its activation
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what is one major way mentioned that this happens in bacteria
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masking surface proteins that would activate the cascade
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what are the activators respectively for gram positive and gram negative bacteria
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teichoic acid and lipopolysaccharides
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what are two types of bacteria that do this
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meningiococci and pneumococci
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what sugar helps to inactivate complement
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salic acid
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how do meningiococci prevent complement activation
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coat themselves in IgA antibodies that do not activate cascade
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how does HSV avoid complement
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envelope glycoprotein that binds C3b, preventing activation
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how do gram negative salmonella and e. coli prevent complement activation
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do not prevent activation, but prevent membrane attack complex from binding to outer bacterial membrane
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how does bordell apertussis inhibit neutrophil motility
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secretes AMP to inhibitory evels
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how does group A strep inactivate chemotaxis
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C5a peptidase creation
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leukocidins
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produced by some bacteria to kill neutrophils and macrophages
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what do capsules do for immunity
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prevent phagocytosis by macrophages until opsonizing agent is added
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how do encapsulated bacteria avoid phagocytosis
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secrete protein A which reduces opsinization
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how does l. monocytgenes escape from phagocytic vesicle
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secretes listeriolysin that forms pores in vesicle
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what protozoa is resistant to lysosomal enzymes
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leishmania
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how does legionella inhibit the oxidative pathway of phagosomes
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inhibiting the hexose monophosphate shunt and oxygen consumption in neutrophils
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how is bacterial uptake of microbes performed
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binding to specific external receptors
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what microbe family resides in neutrophils
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ehrlichia
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what histopathology is common for viruses that lyse host cells
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synctia and multinucleated giant cells
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what bacteria form host cytoskeleton bridges to other bacteria
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shigella and l. monocytogenes
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what does HIV infect
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CD4+ cells, induces collapse of the immune system
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is measels immunosuppressive
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yes
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immunesupression can also result from what
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inhibition of the synthesis of cytokines of the function of cytokines
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what antigen presenting step is destroyed by some pathogens
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MHC class i or II function
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what do superantigens stimulate
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nonspecific T cell response
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nonspecific t cell response
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activation of T cells by streptococci against a large variety of microbes, causes toxic cascade of cytokines
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where do superantigens bind
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MHC molecule and T cell receptor
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what is one of the best examples of antigenic variation
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trypanosomes, trypanosoma brucei
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what type of protein coat undergoes changes during infection
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variable surface glycoprotein
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what undergoes periodic changes in gonococcus that change surface proteins
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pilin
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how does the influenza virus change presentations
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gradually over the course of an epidemic season
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when does antigenic drift occur
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2-3 years
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antigenic shifts
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every 10 years or so
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the above antigenic changes involve what proteins
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hemagglutinin and nuraminidase
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hemagglutinin
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binds cell surface receptors
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nuraminidase
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changes cell receptors
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what type of antibody can h. influenzae inactivate
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IgA
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what does staphylokinase do
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cleaves plasminogen in plasmin, degrades IGG and C3b
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what bacteria produces gastric adenocarcinomas
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h. pylori
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