This article can be found in full length at www.jameswatts.co.uk – Only the introduction is shown here
Bacteria exist naturally on many biological surfaces, for example the skin or the lining of the intestines. Bacteria like these make up the body’s natural flora and have a range of symbiotic relationships; a good example would be the flora of the rumen in cattle which degrade food materials, providing energy for both the cattle and the bacteria. The three main types of symbiotic relationship are:
- Mutualism – Both members of the symbiotic relationship benefit
- Commensalism – No apparent harm/benefit occurs to either member of the relationship
- Parasitism – One member of the relationship is living at the expense of the other resulting in disease
The pathogenicity of a certain bacteria depends on its survival inside the host – how well is it able to resist or evade host defence mechanisms and immune response. The resulting disease/damage caused to tissue is due to either the pathogenicity of the bacteria or the immune response of the host itself.