Term
| What 2 compounds does Haemophilus Influenzae require to grow? Accordingly what culture is used to grow it? |
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Definition
| Haemophilus Influenzae needs NAD and heme for growth, and thus it is grown on chocolate agar (denatured blood in the agar provides NAD and heme). |
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Term
| What does H. flu use to adhere, to evade Ig, and to evade phagocytosis? |
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Definition
| H. flu uses pili to adhere to epithelium, IgA protease to evade IgA, and capsule to evade phagocytosis. |
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Term
| What 2 parts of the H. flu cell body are recognized by the immune system? |
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Definition
- endotoxin (LPS) is recognized by TLR4 of the innate immune system
- the body can make antibodies against capsule
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Term
| Why are infants up to 6 months old protected against H. flu, but babies between 6 months and 3 years old unprotected from H. flu? |
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Definition
| Babies up to 6 months old are protected by their mothers' antibodies against H. flu. However kids generally younger than 3 are not able to mount a T cell dependent immune response. |
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Term
| How does the Hib vaccine also activate T cells to the polyribitol phosphate capsule of H. flu? |
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Definition
| The Hib vaccine presents the antigenic polysaccharide capsule conjugated to a protein that can be presented by APCs to T cells in order to activate T cells. |
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Term
| How do Neisseria meningitidis Gram stain, and what shape are they? |
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Definition
| Neisseria are the major pathogenic Gram- cocci. They look like kidney bean-shaped diplococci. |
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Term
| What kind of agar is Neisseria grown in, and how does it react to the oxidase test? |
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Definition
| Neisseria grows on chocolate agar, and it is oxidase positive. |
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Term
| What is constantly happening to the Neisseria cell wall that stimulates inflammation? |
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Definition
| It is constantly shedding/blebbing it's cell wall off releasing endotoxin. |
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Term
| In addition to pili, what other proteins does Neisseria use to adhere? |
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Definition
| Transmembrane Opa and Opc proteins. |
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Term
| How does dynamic surface protein variation affect Pili and Opa on Neisseria? |
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Definition
| Neisseria can antigenically vary (qualitative) their Pili to avoid stimulating the immune system, and they can turn Opa/Opc on and off to stick or not stick. |
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Term
| What compound does Neisseria, produce to make it look like human cells? When is its production a benefit, and when is it a disadvantage? |
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Definition
| Neisseria makes phosphorylcholine. It is a disadvantage in the serum where there is C-reactive protein to cause opsonization, but an advantage on respirator epithelium because there is no C-reactive protein there. |
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Term
| What aspect of Neisseria's genome determines whether phosphorylcholine is phase on or phase off? |
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Definition
| The polyG repeat in the coding sequence. |
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Term
| How do Listeria Gram stain, and what shape are they? |
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Definition
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Term
| How is Listeria acquired, and once it is in the body, why is it so difficult to clear? |
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Definition
| It is present in meats and cheeses (it can survive pasteurization), and it is difficult to clear because it is an intracellular pathogen. |
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Term
| What enzyme does Listeria use to get into cells, which to get out of the phagolysozome, and which does it use for actin nucleation? |
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Definition
To get into cells: Internalin
To get out of phagolysozome: Listeriolysin O
To cause actin nucleation: ActA |
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Term
| What immune response can work against Listeria? |
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Definition
| Cell-mediated CD4+, CD8+ T cells can recognize infected cells and kill them. |
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Term
| What bacteria is the leading cause of neonatal sepsis and meningitis? |
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Definition
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