Term
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Definition
| Rarely cause disease in healthy hosts, but regularly cause disease in compromised hosts. |
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Term
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Definition
| Rarely associate with a host except in the case of disease. |
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Term
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Definition
| Relative ability of organisms to cause infection and disease. |
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Term
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Definition
| Agent must be present in every case. Agent must be isolated from host and cultured. If agent is inoculated into a new host must produce disease. Same agent must be recovered from that new host. |
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Term
| Molecular Koch's Postulates |
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Definition
| Trait should be associated with more pathogenic strains. Inactivation of gene should eliminate or decrease virulence. When mutated gene is restored virulence should also be restored. |
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Term
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Definition
| Encounter, entry, colonization, multiplication, invasion/dissemination. |
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Term
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Definition
| When density reaches a threshold bacteria communicate with each other using small secreted molecules. They can then express virulence factors, form biofilms or become more resistant to antibiotics, depending on the species. |
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Term
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Definition
| LPS, expressed only on Gram neg. bacteria, binds TLR-4 and causes a wide range of cytokine and cell-induced inflammatory reactions, from fever to death. |
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Term
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Definition
| Both Gram pos and neg can make these, few broad classes exist, most important of which are pore-forming which lyse cells and enzymatic which enter cells and alter signaling or metabolism. |
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Term
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Definition
| Bacteria require iron to multiply in vivo. Siderophores are small molecules that bind iron and bring it back to the bacterium. Lactoferrin/transferrin binding proteins allow bacteria to acquire iron from host storage molecules. |
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