Infection

From ArticleWorld

An infection is not characterized just by the colonization itself, but also by a decrease in the host organism's function, as the infecting agents use the host's resources to survive and multiply and impair normal body functioning.

The infection can cause various affections, including infectious diseases, chronic wounds or gangrenes and, in more acute cases, death by organ failure or septic shock. However, the symptoms vary from one infectious agent to another. The organism does have its own defense system, the inflammation, but it is not always enough to fight the infection.

Colonization

There are several locations from which an infection may start. The most common is a wound infection, which involve replicating organism that can extend to nearby tissues. It is important to note that all multicellular organisms are, to some degree, colonized by other organisms like bacteria. However, many of them live in symbiotic relations with the host, or do not harm it in any way. For example, the anaerobic bacterias in the colon live in symbiosis, and some species of staphylococcus live under the skin but don't cause any harm.

The difference between colonization and infection is often debated, though the consensus seems to be that circumstances determine which happens. The species of staphylococcus that live under the skin are harmful under normal circumstances, but they can easily become pathogen under others. Some colonizations (like those by corynebacteria) affect wounds, but they prevent other pathogen bacteria to colonize or infect the wound.

Symptoms

An infection or a colonization greatly depends on a number of variables, including:

• The potential of the organism to cause harm
• The quantity of external agents entering the body
• The health of the host's immune system
• The route through which the pathogen enters the organism

The treatment varies greatly among the different cases of infections.