Microorganisms which cause disease are called pathogens
A disease suggests a malfunction of body or mind which has an adverse effect on good health.
For a micro organism to be a pathogen it must:
- gain entry to the host
- colonise the tissues of the host
- resist the defences of the host
- cause damage to the host tissues
Pathogens include bacteria, viruses and fungi.
If a pathogen gets into the host and colonises its tissue it results in an infection. Disease occurs when an infection leads to…