Medical Microbiology

  1. effects of temperature on effectivness
    • increase temperature increases efficiancy
    • increases energy and they "bash" into each other
    • denatures
  2. effects of increased volume
    increased volume increases killing effect
  3. effects of exposure rate
    prolonged application can kill more
  4. Cleanliness principle
    • clean surface first
    • rid of organic matter
    • disinfectants work better
  5. Ideal disinfectant
    • no such thing
    • bad for us as well - we don't want to kill everything
    • too expensive
  6. soaps and detergents
    • polar at one end non polar at the other end -like aphospholps
    • emulsfied ... cleanliness effect
    • disrupts membranes and impars proteins
  7. Organic acids and bases
    change pH (enzymes can't function)
  8. Heavy metals:
    Ag, Cu, Hg, Se
    interact with amino, sulfy hydryls groups n proteins (substute groups in nucleic acids)
  9. Halogens:
    • binds to proteins
    • iodophors -organic molecule attached to iodine
    • acts like a detergent
  10. halogens:
    • chlorine bleach
    • strong oxidizer
    • effective but inactivated by organic matter
    • destroys bonds between monomers
  11. Alcohols
    • denatures proteins; disrupts cell membranes
    • -best mixed with water
    • -disinfect, not sterilize (drys to fast)
  12. alcohols:
    • denature proteins
    • action not impaired by presense of organic materials
  13. Hydrogen peroxide
    • oxidizing agent
    • form free radicals
  14. Alkylating agents
    add functional groups to macromolectules
  15. formaldehyde
    inactive viruses, toxins
  16. ethylene oxide
    gas sterilization
  17. Dry heat:
    • slowly oxidizes molecule
    • -requires higher temperatures
    • -takes long
  18. Moist heat
    • denature proteins - breaks hydrogen bonds
    • quicker - water distributes heat better
    • -molecules banging around more
  19. pasturization
    • slows microbial growth on food - to extend shelf life
    • bacteria still exists but as long as we don't overload out system can control them
  20. Radiation:
    UV light
    • low energy
    • not oxidizing
    • breaks hydrogen bonds
    • ---have to overwhelm them to make them base pair with themselves
  21. ionizing radiation
    • high energy
    • oxidizing
    • needs an electron so it goes takes one from another and then they need an electron and it's a chain reaction
  22. radiation:
    • lower energy
    • more efficeintly passed through water molecules
    • won't kill endospores -water isn't part of their system
  23. Filtration
    required pores smaller than pathogen
  24. Thermal death point
    temperature that kills all bacteria in 24 hours
  25. thermal death time
    time to kill all bacteria in a culture at a specific temperature
  26. Phenol coefficient
    • compare all disinfectants performance with phenol when conditions are identical
    • estimate killing powe and come up with a ratio
    • 1=phenol
    • <1=better than phenol
    • >1=less than phenol
  27. Filter paper method of evaluating disinfectants
    disks get saturated with disinfectant and placed on a medium that was innoculated ad let the bacteria grow
  28. Use dilution for evaluationg disinfectants
    • make seial dilutions of disinfectant
    • take a bead that was contaminated with bacteria
    • place 1 bead in each dilution for a certain amount of time
    • take them out and inset in a broth
    • and see if anything grows
  29. Inhibition of cell synthesis
    • inhibits formation of new peptidoglycon layer
    • -can't grow and can't repair damage with long term use
    • resistance is common
  30. disrupt membrane function
    resistance in some classes
  31. inhibition of protein synthesis
    • targeting or taking advantage of the fact that prokaryote and eukaryotes are different enough to effect one instead of the other
    • attacks small ribosomes by altering target site
  32. inhibiting of nucleic acid synthesis
    • atacks enxymes involed
    • attacks ones unique to the bacteria
    • fast acting because RNA is constantly being made
    • broad spectrum: we have different enzymes than the bacteria but all bacteria have the same enzyme
  33. competitive inhibition enzymes
    • competes for the active site on an enzyme
    • so the substrate can't
    • have to have a higher amount it than the substrate
  34. Broad spectrum
    • prokaryotic specific
    • works on a wide range of groups
    • cons: we have good microbes within us they could kill
    • selective for resistance: killing for one genes while other may not have that gene
  35. narrow spectrum
    • works on a narrow range
    • specific bacterium
    • used most often when: don't know what the bacterium is and the patient is dying
  36. Chemotherapy index
    • ratio of toxis dosage level vs. therapeutic dosage level
    • max tolerance dose
    • min dose that cures dz

    • 1=close to killing yourself
    • 100=a lot safer
    • >1=suicide
  37. mutualism
    both benefit
  38. commensalism
    • host benefits
    • no positive or negative effect on virus
  39. parasitism
    • virus benefits
    • host is harmed
  40. resident
    • found in one spot
    • we expect to find it there
  41. transient
    don't expect to find it there
  42. opportunist
    take advantage of a situation

    • immunocompromised
    • introduced into unusual body site
    • disturbed microbiota
  43. opportunist:
    • body already is fighting a dz
    • stress - depresses immune system
    • chemothereapy
  44. opportunist:
    disturbed microbiota
    • where you expect to find them
    • keeping each colony in check
    • 1 or 2 or more colonies removed leave a chance open for other colonies to be introduced or already existing colonies take over
  45. how microbes cause dz
    • infect: -gain acces - adhere to cell surface - or invade tissues - multiply
    • produce toxins
    • use energy and monomers from host -decreasing host growth and repair
  46. Sterilize
    to free from living microorganisms by the use of physical or chemical agents, depriving thm of the ability to reproduce
  47. disinfect
    the act of freeing something from infections by destroying harmful microorganism
  48. antiseptic
    free of living microorganisms
  49. sanitizer
    a substance of preparation for killing germs
  50. bacteriostatic
    inhibition of the growth of bacteria withou destruction
  51. bactericidal
    destroying bacteria
  52. germicidal
    any substance that kills germs or other microorganisms
  53. viricidal
    an agent that inhibits or destroys viruses
  54. fungistatic
    capable of inhibiting the growth and reproduction fo fngi without destroying them
  55. fungicidal
    destroying fungi
  56. sprocidal
    tending to kill spores
Card Set
Medical Microbiology
exam 2 need to knows