Viruses & Bacteria Flashcards
What is infection?
The multiplication of a pathogenic microbe on or in a susceptible host with associated damage.
What causes infection?
Pathogenic microbes
Why are certain individuals more susceptible to certain infections?
Weakened immune systems Dietary deficiencies Poor living conditions Genetic predispositions Vaccinations Lifestyles
What can influence the outcome of an infection?
The host’s immune system
Which body system is effected
Whether drugs are used
What colour do Gran Negative bacteria stain?
Red
What colour do Gram positive bacteria stain?
Purple
What are the 4 steps in Gran staining?
1) Add Crystal violet
2) Add Iodine
3) Add Acetone/Methanol
4) Add red dye
Why would you use acid fast staining?
It allows us to see bacteria that do not react to Gram staining. eg Mycobacter in TB
What is a pathogen?
bacterium/virus/other microorganism that can cause disease
What is a non pathogen?
Bacterium that doesn’t cause disease
Why is the genome composition of a virus important?
Because RNA is less stable it is more likely to mutate
Why is whether a virus has an envelope important?
Because viruses with envelopes are more easily sterilised (because if the envelope is pierced the virus cannot survive)
What is a reservoir?
any person, animal, plant, soil, substance in which an infectious agent lives/multiplies
What is a source?
readily available form of infection agent
What are the modes of transition?
ingestion, inhalation, physical contact, inoculation, sexual transmission
