G. G. Jackson The pathogenesis of bacterial infection defines the dynamics at an interface of ecologic association of bacteria and host. First, it occurs at the portal of initial contact with a per missive target cell. The infected cell provides either a passive or a specific receptor for the bacterium or its products, to gether with ligands and an environment of helper and inhibiting factors. The result is bacterial replication to produce an im balance of a potentially commensal relation which, under other defined conditions, would be optimal for the survival of both the host and bacterial...