mod 7 Flashcards
1
Q
Prion
A
- Non living
- Defective protein
- Doesn’t contain DNA/RNA
- Molecular level low nm
- Mad-cow disease
- Creutzfeldt-Jakob disease
2
Q
Virus
A
- Non living
- Non cellular
- Contains DNA/RNA
- Requires host to replicate
- Less then 500 nm
- COVID-19
- HIV
3
Q
Bacteria
A
- Living
- Unicellular, prokaryotic
- Cell Wall
- Reproduce via binary fission
- Tuberculosis
- Salmonella
4
Q
Protozoan
A
- Living
- Eukaryotic Multicellular
- Complex life style
- 50-150 micrometers
- Asexual reproduction
- Malaria
5
Q
Fungi
A
- Living
- Eukaryotic, some unicellular most multicellular
- size varies from um to nm
- Reproduce through spores
- Athletes foot
Stem rust
6
Q
Macroparasite
A
- Living
- Eukaryotic multicellular
- External parasites - ectoparasites
- Internal parasites - endoparasites
- mm to metres
- Tapeworm
7
Q
Epidemic
A
- An outbreak of an infectious disease within a defined area or population at the same time. Zaire ebolavirus 2014-2016 in West Africa, transmitted by fruit bats and direct contact.
8
Q
Pandemic
A
The spread of an infectious disease across a continent or worldwide. COVID-19 2020-2023.
9
Q
Direct Transmission
A
- Person to person through exchanges of bodily fluids eg touching, kissing, sexual contact, biting.
- Droplet spread caused by talking, coughing, sneezing.
10
Q
Indirect Transmission
A
- Airborne transmission
- Contaminated Objects which contains pathogens on its surface
- Food and drinking water
- Animal to person contact including scratch or bite from animals
- Vector borne - spread by blood sucking insects
11
Q
Robert Koch
A
- Hypothesised that specific pathogens cause specific disease
- Experimented the spread of specific pathogen caused diseases through sheep
Kock postulates - Pathogen must be found in all animals suffering from same disease
- Pathogen must be isolated from a diseased animal and grown in pure culture.
- Cultured pathogen should cause disease when introduced to healthy animal
- Pathogen must be re-isolated from the infected animal.
12
Q
Louis Pasteur
A
- Disproved spontaneous generation (belief that life spontaneously generated)
Done via swan-neck experiment, where nutrient broth was placed in a swan neck flask and a broken neck flask exposing broth to the air. After boiling to eliminate pathogens, after a while microbial growth was observed only in the broken neck flask, proving that microbes are airborne. - Developed world’s first attenuated vaccine (anthrax)
- Demonstrated fermentation was caused by living organisms
- Invented pasteurization
13
Q
Plant disease example
A
- Fire blight
- Destructive plant disease affecting pome fruit worldwide
- Caused by bacterium Erwinia amylovora, exists in all pome fruit producing countries except Japan and Australia, due to strict quarantine measures.
- Attacks all parts of pome plants. Infection results in tissue death and bacterial ooze droplets on infected tissue.
- Transmission via rain, wind, insects and pruning tools.
- Melbourne’s Royal Botanic Garden’s Outbreak in 1997 causing 20 million dollars lost in revenue, resulting in quarantine measures.
- Prevention includes on-farm biosecurity and ensuring all staff and visitors participate in hygiene practices.
14
Q
Animal disease example
A
- Foot and mouth disease (FMD V)
- Contagious Viral infection impacting cloven-hoofed animals such as cows.
- Virus can survive in many environments including live animals, meat and dairy products. Thus it poses great risk to livestock raised in agricultural production. Currently excluded from Australia due to detailed response plans and arrangements, particularly its strict quarantine measures.
- Causes blisters fevers and blisters in the mouth and hooves of infected animals. While recovery rates are high, infected animals are left weak and debilitated, destroying herds.
- Potential breakouts of FMD V would cost billions of dollars of agricultural damage in Australia, thus it is imperative that Australia remains FMD V free, by incorporating biosecurity and assuring hygienic practices.
- 2001 UK outbreak, where importation restrictions caused a 19 billion dollar loss in exportation.
15
Q
Malaria Adaptation
A
- Caused by 4 parasitic protozoan species of Plasmodium, where Plasmodium Falciparum is the main contribution to mortality.
- At each life stage of the plasmodium species, different antigen molecules are produced preventing host from launching immune response
- When inside red blood cells, Plasmodium produce adhesion proteins which surface on the red blood cell, interfering with the movement through capillaries, thus facilitating reproduction and survival of the parasite.
- Before the adaptive immune system can respond to foreign adhesion proteins, plasmodium alters adhesion proteins on RBC, protecting them against immune system
- While in human liver cells, Plasmodium kills cells, causing separation between surrounding cells, emerging gaps through which parasites move to infect other liver cells. Parasites also accumulate calcium ions from liver cells, used to block presentation of antigens, thus avoiding immune system.
