Week 4 Flashcards
Describe the classification of Bacteria
- prokaryote
- single-celled
- lack of membrane-bound organelles
- typically classified phenotypically by morphology and biochemistry
Describe the classification of Fungi
- eukaryote
- membrane-bound organelles
- enzymatically diverse
- bound by cell membrane
- single-celled yeast
- multicellular mould (filamentous fungi)
Describe the classification of Parasites
- eukaryotes
- complex life cycles
- protozoa and helminths (worms)
Describe the classification of Viruses
- non-living
- comprised of nucleic acid (DNA or RNA)
- surrounded by a protein coat (capsid)
- classified based on shape and structure
- described as intracellular parasites
Describe the classification of Prions
- non-living
- comprised of protein
- most resistant because they are not metabolically active
Define commensalism and give an example
The host is neither harmed nor benefited, microbes benefit
E.g. staphylococcus aureus
What are 3 reservoir types for infectious agents and give an example of each
Humans - old or young
Animals - rodents/chickens
Environment - still water, soil
What does biofilm provide physical protection against for pathogens?
- immune evasion
- antibiotic treatment
- mechanical/shearing forces
- temperature changes
- disinfection
What are the portals of exit ?
- Oral cavity
- Anus
- Eyes
- Ears
- Urethra
- Nasal cavity
- Vagina
- Access device
What are the three ways transmission of infectious diseases occur?
Contact - Direct & indirect (fomites)
Vectors - mechanical (flies), biological (mosquitos with malaria)
Common vehicle - airborne, waterborne, foodborne
What are the portals of entry?
- New portal - devices
- traumatic injury
- vector bites
Who is a susceptible host ?
- Extremes of age
- Immunocompromised (suppression)
- Co-morbidities (obesity, COPD)
- Genetic pre-disposition
- Malnutrition
- Medical procedures
- Anatomical defects (heart valves)
- Healthcare workers
How to interrupt the chain of infection: infectious agent
- identify the infectious agent
- timely identification
- accurate id
- antimicrobial stewardship (narrow spectrum, dosage, education)
- treatment (antibiotics, antivirals, symptomatic treatment
How to interrupt the chain of infection: reservoir
- hand hygiene
- clean water
- general hygiene
- containment
- nutrition
How to interrupt the chain of infection: Portal of exit
- face masks (N95 - fit tested, surgical mask)
- quarantine
- wound dressings
- respiratory etiquette
- sewage treatment
How to interrupt the chain of infection: mode of transmission
- containment
- negative pressure
- social distancing
- protective clothing
- insecticides
- surface disinfection
How to interrupt the chain of infection: portal of entry
- safe sharps use
- safety goggles
- hand hygiene
- food prep
- aseptic non touch technique
- wiping direction
- gloves
How to interrupt the chain of infection: susceptible host
- vaccination
- nutrition
- education
- access to healthcare
- hand hygiene
- manage comorbid conditions
