Changes

==Replication==

==Replication==

The lifespan of bacteria differs from that of viruses in that it includes a colonization phase

The lifespan of bacteria differs from that of viruses in that it includes a '''colonization''' phase, which occurs on epithelial surfaces.  As bacteria are capable of self-replication (i.e. they don't require host cellular machinery), this colonization phase allows them to develop a highly skilled and lethal army before invading the body.  Once invasion occurs, spread can occur via the vascular or lymphatic systems.  The pathogenesis of a particular strain of bacteria very much depends upon its location in the body: "''Streptococcus pneumoniae'' in the lung causes pneumonia...whereas in the blood it causes a rapidly fatal systemic illness, pneumoncoccal sepsis." (Murphy, et al, 43)

==Prevention and control==

==Prevention and control==