Mordant: It is a substance which facilitates the reaction of the primary stain with the material to be stained. It combines with the stain and then facilitate the reaction. Basic mordant reacts with acidic stain and acidic mordant react swith basic stain. Decolorizer : It is a chemical added in differential staining procedure to selectively remove the stain from the materials that are not intended to be stained. Pathogen : Organism that causes disease
Virulence : Degree of pathogenicity depends on
in causing disease which
toxin production and invasiveness. Invasiveness : The ability to penetrate in to the tissues, overcome the host defense, multiply and disseminate widely. Toxicity: The capacity to damage the tissues. Opportunistic : Normally harmless organism causing disease during lowered host resistance. Infection: The result of breakdown in the host-parasite relationship and follows when the balance is tipped in favor of the parasite.