Microbes And Disease Flashcards
Define disease
Any disorder that produces symptoms and is not the result of an injury
Define infection
Disease caused by spread of pathogenic microbes
Name 6 ways a pathogen can be transmitted
Touch
Body fluid
Waste
Food
Surfaces
Air
Define a bacteria
A single celled microbe that can be harmless, beneficial or pathogenic
What are the shapes of bacteria?
Spherical (cocci), rod (bacilli), spiral and other
What is a spirochete?
Thin, flexible, spiral-shaped bacteria
Live in mud and animal GI
E.g. leptospira
What is a ribrios?
Comma shaped bacteria
Can be anaerobic
E.g. vibrio cholerae
Give an example of an aerobic rod/cocci.
Bordatella pertussis
Eschericha coli
What is a pyogenic cocci?
Sphere shaped bacteria that causes pus
E.g. staph. Aureus
What is an endospore-forming bacteria?
A bacteria that forms endospores (dormant state of the bacteria) which are highly resistant and live on after the bacteria is dead. They are highly transmissible.
E.g. clostridium botulism
What is a virus?
Simple, smallest microbe which aims to reproduce
Needs a host
How does a virus reproduce?
Invades host cell
Uses cell reproduction mechanisms to copy its own DNA
Leaves cell either by lysis or budding
What is cell lysis?
Bursting of the cell resulting in cell death
What is budding in terms of viruses?
Virus pushes against cell membrane causing it to envelope the virus into a package
What is an enveloped virus?
Virus which has left the host cell via budding
This gives it protection against the hosts immune system
E.g. coronavirus
What is a non-enveloped virus?
Leaves the cell via lysis
Does not survive for long outside the body and is susceptible to temperature changes
E.g. norovirus
What is a fungi?
Group of spore-producing organisms that can live anywhere and colonise
Infect humans via skin contact or inhalation of spores
May be opportunistic (when immunity is weak) or primary (occurs in normal immunity)
Can cause local and systemic infections
What is a mould?
A fungus which has many cells that form long threads (hyphae)
What is a yeast?
A fungus which is a single, round cell
What is a parasite?
An organism which lives on another and uses it for food
Protozoa: single-cell, in gut, amoeba
Helminth: large, multi-celled, in organs, tapeworm
Ectoparasite: can cause disease in own right, scabies
