Types of transmission of an infectious disease
Direct - person to person
eg. HIV
Indirect - through air, ground
eg. Measles
Insect Vector - transmission from one person to another via organism
eg. Malaria
Koch’s postulates
Method of linking a set disease to a disease causing pathogen
- Organism present in diseased individual
- The microbes must be able to be isolated and grown in a pure culture
- Pure culture must induce disease when given to another individual
- The same microbes must be able to be isolated again and identified as the original species
Pasteur’s experiment
Pasteurisation
In the 1860’s Louis Pasture conducted his experiement on the swan neck flask, disproving spontaneous generation- developing germ theory
Method
- Fill two swan neck glasses with nutrient
- Heat and bend one of the flask necks into a swan shape
- Boil broths to kill any microbes
- Leave for several days
- Examine the growth of bacteria in each flask
Plant disease
Lemon Scented gum (Corymbia Citriodora)
Fungal Stem Canker
- gains access to inner layers of stem through damaged outer layers of bark
The tree’s defence - produces excess resinous sap at the wound site to expel the pathogen
Agriculture plant disease
Alternaria Stem Canker
Fungal pathogen that effects tomato plants.
Airborne or by infected soil.
Results in dying tissue and death of plant.
Animal disease
Classical Swine fever
Viral infection effecting pigs
Symptoms: high fever, huddling, cobsitipation and diarrhoea
Impacts: animal death, human illness, low grow rate, loss of fertility
