Pathogenesis is disease. Normal flora are part of host's normal microbial community.
Primary pathogens infect healthy hosts. Opportunistic pathogens infect compromised hosts. Virulence is a quantifiable measure of pathogenicity. Parasites do not kill the host. Parasite: consume host resources at host expense. A parasite is an organism that lives in or on the living tissue of a host organism at the expense of that host, but without immediately killing the host. The biological interaction between the host and the parasite is called parasitism.
Parasitism is a type of symbiosis, by one definition, although another definition of symbiosis excludes parasitism, since certain types of DNA, such as transposable elements and B chromosomes, may also be considered as parasites of the host genome. Some organisms are parasitic only during a part of their lifecycle. Many cuckoos, for example, are brood parasites: their young are parasitic on the host species, but adult cuckoos fend for themselves.
|Anthroponosis||Disease with humans as only vertebrate hosts.|
|Zoonosis||Disease transmitted among wild animals (reservoir hosts) and humans.|
|Reservoir Host||Wild animal that maintains infection in nature.|
|Procyclic||Related to the beginning of the parasite's life cycle.|
|Metacyclic||Related to the infective stage of the parasite's life cycle.|
|VSG||Variable surface glycoprotein|
|ESAG||Expression site associated glyocoprotein|
|COG||A bluster of orthologous genes (COG).|
|3-Way COG||A 3-Way COG is orthologous between three species.|
|2-Way COG||A 2-way COG is orthologous between two species. .|
|Synteny||A phenomenon where a COG consists of five or more genes.|