Host Microbe Interactions: principles of disease Flashcards
What term is coined for living things living together?
Symbiosis
What flora do not cause disease under normal circumstances?
Normal flora
What flora Colonise for a brief time – does not last, normal flora
competes – may cause disease
Transient flora
What flora causes disease?
Pathogenic flora
What relationship occurs when there is mutual benefit?
Mutualism
What relationship does the Lactobacillus acidophilus and the adult vagina have?
Mutualism
What relationship does Staphylococcus epidermidis and the human skin have?
Commensalism
– Under normal circumstances does not cause harm
What relationship do pathogenic microbes have to its host?
Parasitism
What relationship Occurs when Host becomes predisposed to infection by otherwise harmless microbe? Such as in Candida albicans and the vagina?
Opportunism
What contributes to the manifestation of disease?
Factors of both the microbe, host and environment
Four things a microbe must do to cause disease (to be a pathogen):
• 1. Gain entry to a host – environment
• 2. Attach and multiply – microbial pathogenesis
• 3. Evade Host defences
– host susceptibility / immunity - tomorrow
• 4. Cause damage to tissues – microbial pathogenesis
What is the Period in which microbe attempts to evade host defenses and establish infection
Incubation period
Incubation period of chicken pox
2-3 weeks
Incubation period of pertussis (whopping cough)
7-10days
Incubation period of Covid 19
5-7 days
Summary of incubation periods
Chicken pox 2-3 weeks • Measles 8 – 14 days • Mumps 12 – 25 days •TB 4–12 weeks • Pertussis 7 – 10 days • Food poisoning 12 – 36 hrs • HIV/AIDS 3 weeks - years • Covid-19 5-7 days
What phase of disease is the Period of microbe multiplication
– Mild, non-specific symptoms
– Host defense may overcome infection at this point
Prodromal phase
What phase of disease depicted by Cell damage occurs
– Producing recognisable signs and symptoms
Acute or invasive phase
2 possible outcomes of disease development
Fulminating
Decline and convalescence
What phase of disease development is depicted by when Acute phase develops rapidly, Symptoms appear suddenly, Feature of a very virulent pathogen and has a Fatal outcome
Fulminanting
What phase is described by When host defense overcomes pathogen and Symptoms subside
Decline and convalescence
How does infectious disease become established?
- Gain entry to a host
- Attach and multiply
- Evade Host defences
- Cause damage to tissues
Give 3 reservoir of infection
Humans
Animals
Soil and water
What infection can you get from animals
Zoonoses
