M7 Flashcards
7.2 path types
how could we define health? when would we use this def?
how could we define disease? what are the issues surrounding this def?
- WHO: โa state of complete mental physical and social wellbeing, and not merely the absence of disease or infirmityโ (at the beginning of long responses!)
- Any condition that adversely affects the function of any part of a living thing (key issue is for eg braces could also be a โdiseaseโ with this def = broad + imprecise)
7.2 path types
what are the diff pathogen types? (6)
can you give an example of each pathgn?
Prion - BSE prion
Virus - HPV (human polio virus)
Bacteria - Mycobacterium tuberculosis
Protozoa - Plasmodium sp.
Fungi - Tinea pedis
Macro-parasite - tapeworms
7.2 path types
what disease is associated with each of these pathogens?
1) A prion
2) HPV
3) Mycobacterium tuberculosis
4) Plasmodium sp.
5) Tinea pedis
6) Tapeworms
1) CJD (Creutzfeldt-Jakob disease), or aka BSE, or aka mad cow disease
2) Polio
3) Tuberculosis
4) Malaria
5) Tinea (athleteโs ๐ฆถ)
6) Tapeworm disease
7.2 path types
prions - living/non-living, characteristics, relative size, explain the example
eg
Incurable disease transmitted by eating nerve tissue from infected animals - prion proteins are not digested in the gut and can enter the bloodstream, eventually reaching the brain. (holes in the brain?)
7.2 path types
viruses - living/non-living, characteristics, relative size, explain the example
Highly contagious via the โfaecal-oralโ route - virus normally attacks cells in the digestive tract โ billions of viral particles present in faeces of infected people. Poor personal hygiene + sub-standard sewerage system = contaminated water + food supply = disease becomes endemic.
7.2 path types
bac - living/non-living, characteristics, relative size, explain the example
characteristics - unicellular, prokaryotic, microscopic pathogens with a single loop of double stranded DNA
size
up to 100 um
7.2 path types
protozoa - living/non-living, characteristics, relative size, explain the example
size: 50-150 um
7.2 path types
fungi - living/non-living, characteristics, relative size, explain the example
size: 4 ฮผm (unicellular)
7.2 path types
macroparasites - living/non-living, characteristics, relative size, explain the example
7.2 path types
- size of a prion?
- description? (super brief)
- transmitted by eating ____ tissue of an infected animal
- how to describe mad cow disease?
10nm
defective form of proteinโฆ
nerve
fatal neurological disease
7.2 path types
- size of a virus?
- ___-cellular
<500 nm
non-cellular (NOT LIVING)
7.2 path types
HOW PATH TYPES ARE ALL AN UPGRADED AND MORE COMPLEX VERSION further down the list?
- prions: non-living, no DNA or RNA
- viruses: non-living, but do have DNA, RNA, protective coating of protein
- bacteria: unicellular, prokary, single loop of double stranded DNA
- protozoa: unicellular but EUKARY
- fungi: unicellular or MULTICELLULAR, eukary
- macro: multicellular, eukary, seen with naked eye
7.2 path types
how does malaria (a protozoan) infect ๐คต๐ป?
travels to humanโs LIVER to grow + multiply, then travels to BLOODSTREAM to infect + DESTROY RBCs
7.3 named epid trans
what is the structure of the Zaire ebolavirus?
most fatal (contains 7 distinct proteins of large molecules arranged in a long, braided strand of negative RNA)
7.3 named epid trans
what are the key symptoms of EVD?
- incub period 2-21 days
7.3 named epid trans
what are some adaptations EV has had to assist entry + transmission?
RNA virus -> high mutation rate
- early 2014, Ebola virus picked up a mutation called A82V, which made it worse at infecting bat cells, but 2x better at infecting human ones
7.3 named epid trans
is there a treatment for ebola?
no cure, patients supported w/ oral + intravenous fluids
- 2016: successful highly protective rVSV-ZEBOV vaccine
- mAbs (monoclonal antibodies) bind to a portion of the Ebola virusโs surface called the glycoprotein, which prevents the virus from entering a personโs cells
7.3 named epid trans
what is the mortality rate?
Killed 11,300 out of 28,600 infections
fatality rate 50%
7.3 named epid trans
Are there any strategies to prevent this disease from becoming an epidemic again in the future? (2)
- Targeted programmes for behaviour change (ie convince people to stop eating wild primates)
- Vaccine development (ie vaccinating health care workers as a preventative measure)
7.4 micr ๐ฆ test exp
risk 1
how would you mitigate it?
microbes from ๐ฆ samples ingested in body, causing illness
(breathing in microbes, microbes getting into cuts in skin)
PPE (๐งค, ๐ท, ๐ฅฝs) + NOT OPENING the agar plate once it has been sealed
7.4 micr ๐ฆ test exp
risk 2
how would you mitigate it?
Burns on hands (or other parts of the body, eg hair) caused by placing hands into spirit lamp or overflowing boiled water
- Use test tube tongs and angle the test tube opening away from the body, continuously moving through the flame
- Tie ๐ฑ๐ปโโ๏ธ back
7.5 types of transmission
what is a vector?
a living organism that carries a disease causing agent from one host to another in the life cycle of a pathogen
- mech trans = vect. not infected themselves
- biolog trans = when the pathogen reproduces within the vect. (animal)
7.6 koch + pasteur
when talking about Kโs postulates, word to use is?
microbes
7.6 koch + pasteur
what are Pโs contributions? (3)
- Disproved spontaneous generation
- Developed worldโs first attenuated vaccine (anthrax, ๐ cholera, rabies) + est. principle of immunity
- Invented pasteurisation (heating -> KILL THEM MICROBES)
7.7 ๐๐๐๐ + ๐๐ diseases
what are some key facts about panama disease?
assess the threat?
High rates of transmission, no cure, no resistant ๐ varieties
80% of global production is under threat from Panama disease
SIGNIFICANT THREAT to banana industry/production
7.7 ๐๐๐๐ + ๐๐ diseases
general causes of infectious diseases in plants + animals (4)
- Increased movement of human populations
- Loss of genetic diversity - monoculture, cloning practices, selective breeding
- Increase in โhobby farmsโ
- Pesticide resistance
7.7 ๐๐๐๐ + ๐๐ diseases
NDV effect?
- can typically kill 80% of unprotected poultry in rural areas, thus constraining large-scale expansions of the poultry industry in these regions
7.7 ๐๐๐๐ + ๐๐ diseases
FMD effect?
- entire herds destroyed to contain outbreak
- projected that a 12 month outbreak of FMD in Australia would result in a loss totalling $16bil -> bc trigger export bans, reduce meat quality, reduce financial return to producers
7.8 path adaptns
what are the pathogens youโll be focusing on for this dp? what groups are they in?
- Yersinia pestis (bacteria)
- Measles virus
- Giardia (protozoa)
- Tapeworms (macro)
7.8 path adaptns
YersP, entry adap?
Pili and fimbriae - extensions on the bacteria which bind to the host cellโs receptor proteins that are matching
7.8 path adaptns
YersP, transm adap? (2)
- Use of a vector (flea) to transmit pathogen to host
- When Yersinia pestis infects a flea, production of biofilm inside the fleaโs foregut starves the flea which makes it bite repeatedly - helps bacteria be spread via regurgitation into the wound at next feeding on host
7.8 path adaptns
Measles adaps?
Entry
Has 2 important proteins on its surface
- H protein - able to attach to receptors found on human cells
- F protein - gives virus ability to fuse with host cellโs plasma membrane, allowing viral DNA to enter host cell
โ increased ability of virus to enter human cells
7.8 path adaptns
GiardDuo adaps?
Transmission
- When in the external environment, Giardia can switch to a cyst form that is more durable
- Cyst form allows them to survive outside the intestines for months
- Once inside a host, the cysts dissolve and the parasites are released
7.8 path adaptns
apart from its โentryโ adaptation, what is the tapewormโs โtransmissionโ adaptation?
Tapeworms made up of many sections, each of which contain reproductive organs
These sections can release lots of eggs that end up in the hostโs faeces
7.9 plant resp: fungal, viral
P.cinnamomic symptoms/imp
- damages ALL parts of plant: wilted/yellowing leaves, stunted growth, coloured cankers
- 1970s destroyed >282,000 ha of E.marginate in WA
7.9 plant resp: fungal, viral
what is the significance of ^ lignin prod. for E.cal? like, how does it actually help instead of โkeeps the plant aliveโ?
- Lignin plays a role in protecting the cellulose cell wall of plant cells from damage by pathogens
forming a physical barrier that is impervious to the pathogen