Mod 7 IQ 9 Flashcards
prion
does not contain DNA or RNA
mostly attacks brain or nerve cells
Virus
Non-cellular contains DNA, RNA, and protein coats
require a living host to replicate
Bacteria
Prokaryotic cell divides quickly and / or produces toxins
Protozoans
Eukaryotic cell (single-celled organism)
Fungi
Eukaryotic cell
with cell wall spreads via spore or rapid division
some infect external skin and nails, while others enter the host’s body
How pathogens cause disease
- Enter the host through a certain part of the body
- Reach their target site or niche in the body
- Attach to or invade the target site they are trying to infect so that they are not dislodged
- Multiply rapidly
- Obtain their nutrients from the host
- Avoid and survive the attack by the host’s natural defense mechanisms
- Have enough virulence and virulent pathogen only needs ( a virulent pathogen only needs to be present in small amounts
- Exit infected host to spread to an uninfected host
What are prions
Prions are infectious agents that consist only of protein they have no nucleic acid and therefore referred to as non-cellular pathogens
In animals
Bovine spongiform encephalopathy (BSE) or the Mad cow disease
Humans
(TSE) transmissible spongiform encephalopathy which causes brain damage
What are viruses
Viruses are microscopic pathogens a typical virus has a small piece of genetic material. Viruses are also referred to as non- cellular pathogens. Viruses are technically not living they have nucleic acid (DNA or RNA). On its own viruses are harmless however if they enter a living cell and start replicating they can cause disease due to viruses’ possessing the ability to replicate at an extraordinary rate and can mutate and evolve
Viruses can infect all types of living things including animals and plants to microorganisms such as bacteria
Rotavirus refers to a group of double-stranded RNA viruses
What is an example of a virus
Rotavirus
it causes diarrhea and gastroenteritis mainly in children between six months and two years old
Transmitted by person to person contact
what is an infectious disease
caused by the invasion of the body by a disease-causing agent (usually microscopic life-form)
what is a non-infectious disease
Do NOT involve a pathogen, and cannot be contagious
What are bacteria
Bacteria are prokaryotic, unicellular microorganisms DNA is contained in a single loop. Some bacteria have an additional circle of genetic material called a plasmid. Not all bacteria are cause disease only 1% do
What is an example of a bacteria
An example of bacteria os campylobacter which causes food poisoning and transmitted through indirect contact occurs when contaminated food is eaten can also be transmitted from raw meat
What are protozoans
Protozoans are eukaryotic macro organisms with DNA organized in a nucleus
What is an example of protozoa
The plasmodium protozoan which causes malaria which is vector transmitted from person to person or female mosquitos
What are fungi
Fungi are eukaryotic organisms, they include yeasts. molds and corps destroying rusts and smuts some fungi cause disease
What is an example of a fungi
Trichophyton fungi cause athlete’s foot
what are macroparasites
Microparasites are microorganisms that can cause disease. They include roundworms, flatworms, and flukes as well arthropods like ticks, mites, lice, and fleas
What is an example of macroparasite
Cestodes or tapeworms cause infection of the digestive tract it is caused by undercooked meat, food, and water with tapeworm eggs and larvae
What is an epidemic
is the rapid spread of infectious disease to a large number of people in a particular population in a particular population in a relatively short period of time.
What is a pandemic
an outbreak of a disease over a whole country or on a global scale
What do the factors that increase the exposure to pathogens and causes the spread of disease include
a continual source of disease which called the reservoir
When humans or animals are in close proximity with one another
Social and environmental factors such as contaminated water supply
Poor sanitation facilities and lack of access to affordable vaccines
Environmental factors include climate change Asia research found that the virus was spread by ticks and the habitat expanded due to global warming
global travel which helps the spread of disease. For example Severe Acute Respiratory Syndrome (SARS) a disease that causes pneumonia which first appeared in China later was found in several countries around the world the next year.
What is direct contact
Direct contact between people (through, touch, saliva mucus, contaminated blood or other bodily fluids)
when an individual coughs and sneezes and small droplets of mucus, which may contain pathogens
sexually transmitted diseases) to unborn children through the placenta
What is indirect contact
Airborne transmission of droplets respiratory pathogens are usually transmitted through the air
from contaminated objects such as door handles, bedding, towels or contaminated blood products and medical supplies
contaminated food and drinking water
presence of faeces
infected animal e.g. from handling contaminated animal products
What is vector transmission
Vector transmission can be mechanical or biological. Mechanical vector transmission involves an animal carrying pathogen from one host to another without being infected itself. For example, a fly lands faeces and later transmits bacteria from faeces to food. Humans eat food, resulting in diarrhoea or dysentery. Biological vectors include insects and other arthropods
What are Koch’s four postulates
- It must be shown that the microorganism believed to be the cause of the disease is always present in diseased organisms
- The microorganism must be isolated and grown in pure culture that is a culture only containing that microorganism
- Microorganisms from the pure culture, when injected into a healthy organism without the disease, must produce disease
- Microorganisms isolated from the experimental organisms, growth in pure culture, and compared with the microorganisms in the original culture, are shown to be identical
What was the effect of Pastuer’s Work
Pasteur discovered that microbes were responsible for the sourcing of alcohol and developed the process called pasteurization
Pasteur’s work also led to the development of vaccinations for fowl cholera, anthrax, and rabies
What is named plant disease
Golden potato cyst nematode Macroparasites Microscopic, soil-borne plants which feed on the roots of potato plants and are a serious threat to Australia’s potato industry
What is named animal disease
Foot mouth disease in cattle whichin 2001 outbreak caused the loss of $19 billion pounds in the UK
