Download Pathogens and Disease

Pathogens and Disease - The Search for Better Health
Linked to part 1 – What is a healthy organism?

Discuss the difficulties of defining the terms ‘health’ and ‘disease’

Outline how the function of genes, mitosis, cell differentiation and specialization assist in the maintenance of health
Linked to part 2 – Over 3000 years ago the Chinese and Hebrews were advocating cleanliness in food, water and personal
hygiene

distinguish between infectious and non-infectious disease

explain why cleanliness in food, water and personal hygiene practices assist in control of disease

identify the conditions under which an organism is described as a pathogen
Linked to part 3 – During the second half of the nineteenth century, the work of Pasteur and Koch and other scientists stimulated
the search for microbes as a cause of disease

describe the contribution of Pasteur and Koch to our understanding of infectious diseases

distinguish between:
o prions
o viruses
o bacteria
o protozoans
o fungi
o macro-parasites
and name one example of a disease caused by each type of pathogen
Linked to part 7 – Increased understanding had led to the development of a wide range of strategies to prevent and control
disease

discuss the role of quarantine in preventing the spread of disease and plants and animals into Australia or across regions of
Australia

explain how one of the following strategies has controlled and/or prevented disease:
o public health programs
o pesticides
o genetic engineering to produce disease-resistant plants and animals
Definition of Health:
How do our bodies help to keep us healthy?
Definition of Disease:
Non-infection Disease:
Infectious Disease:
Characteristics of Pathogens:
Personal Hygiene
•Cleanliness prevents _________________ of items that could come in contact with our body by stopping
them from ______________ the body.
•For a long time humans have realized the important of cleanliness in maintaining __________.
•The Ancient Romans built ____________ to remove human wastes away from their homes. (Pathogens
live off the nutrients)
•The Chinese and Hebrews undertook ____________ lifestyles even 3,000 years ago.
•Today we wash our hands before eating, cook food properly, treat our sewage, provide uncontaminated
drinking water for everyone, hold our hand over our mouth when we cough, cover open sores and so on.
Quarantine in Australia
•The Australian Quarantine and Inspection Service (________) helps to prevent the spread of disease
____________ and ________________ Australia.
•Upon entering Australia, all plant and animals products are kept in strict quarantine and must be declared
at ____________________ in order for this to take place.
•This protects _____________ Australian flora and fauna as well as the health of the _____________
inhabitants.
•Fruit and vegetables cannot be carried through parts of Victoria, NSW, Queensland and South Australia
in order to prevent disease moving from one state to the next.
Genetic engineering and disease resistance
•_______________ organisms are being produced with a variety of ___________ qualities for their
particular species. One aspect of genetic _________________ is to produce organisms with increased
_________________ to disease.
•A genetically engineered striped bass is being developed with insect genes in order to _____________
disease resistance.
•A tomato is being developed with resistance to bacteria.
Louise Pasteur
•Pasteur was a French chemist who discovered that ‘germs’ or ________________ were the cause of
_______________ disease.
•He studied soured wine and found that it contained small rod like ____________ as well as the yeast that
was found alone in non-soured wine.
•Previously people thought maggots came to be _________________.He disproved the theory of
‘spontaneous generation’ supporting the cell theory showing that new cells were produced from existing
cells.
•He produced a technique of heating fluid to 550C for 30 minutes to kill microorganisms responsible for
souring it. This became known as Pasteurization and is still used today.
Robert Koch
•A physician who discovered that micro-organisms are present in every ______ with an infectious disease.
•Worked initially with ______________ – a bacteria killing many sheep and cattle.
•Wrote a list of criteria needed to prove a particular organism caused a particular disease – known as
Koch’s _______________.
1.The organism responsible for the disease must always be _____________ when the disease occurs
2.The organism must be _______________ from the host and grown in _______ cultures in the laboratory
3.Organisms from this pure culture can be inoculated (injected) into healthy organisms that then produce
the disease
4.The organism must them be re-isolated, grown again in pure culture and compared with the first
organism that was originally isolated
Macroparasites
•Macroparasites can be seen with the ____________ eye
•__________________ live inside a host and include tapeworm in mammals
•__________________ live on the outside of the host and include tics, fleas, and mites in mammals
•Aphids are ectoparasites that live on plants by tapping into the sugar carried in the ____________
Fungi
•Eukaryotic organisms that can be unicellular (yeast) or multicellular (mushrooms). They can be
__________________ (living on a host) or ______________________ (living on dead material)
•Examples include tinea (athletes foot) in humans and mildew in plants. Fungal spores cause this in plants.
Protozoans
•Protozoans are microscopic single cells eukaryotes of which only a few are pathogens.
•Examples include _______________ and amoebic dysentery.
Bacteria
•Prokaryotes with no membrane bound organelles and a single strand of _________. Approximately 0.5 –
5.0 µm in size.
•Most are actually _____________ to our everyday lives, a few are harmful such as ____________,
_____________ and ________________ in animals and __________ _________ in plants.
•Bacteria produce ________________ as waste products that harm the host. Bacteria are classified by
their shape.
Draw in some different shaped bacteria:
Viruses
•Non _____________ protein coated package of DNA approximately 30-300 µm in size.
•Discovered in the last 50 years due to the development of the ________________ microscope.
•Uses the host __________ to reproduce its own __________ and in doing so ___________ the hosts cell.
•Examples include _______________ in mammals and _____________ mosaic virus in plants.
Draw a virus:
Prions
•Prions are __________________ that manage to produce themselves in their host.
•The proteins are abnormally folded and then have the ability to infect other proteins so that they also fold
abnormally.
•They have no ________________ material in them.
•They attack the ___________ causing small holes. Humans and animals alike suffer dizziness, nausia and
seizures which eventually lead to death.
•Examples include ‘mad cow’ or BSE (Bovine ______________ encephalitis) disease in cattle and
________ (Creutzfeld-Jacob Disease) in humans.
•Infection is caused by eating neural tissue