Final material Flashcards
Antiseptic
antimicrobial agent intended for use on living tissue
disinfectant
antimicrobial agent intended for use on inanimate objects
antiseptics and disinfectants can be
selectively toxic:
-bacteriostatic
-bacteriaocidal
phenolics
-work by denaturing proteins to disrupt cell mem
-phenol (great starting point)
who invented phenol
Joseph Lister
examples of phenolics
cresol, xylenol, orthophenyphenol, lysol
alcohols
-denature protein, dissolve cell lipids
-ethanol (60-75%), isopropanol
Halogens
-iodine, chlorine
iodine is used
-clinically
-oxidizes cell components
-tinctures
-iodophors
tinctures
2% or more iodine in a H2O/ethanol solution of potassium iodide
iodophors
-completed iodine with organic carrier molecules
-H2O soluble, non-staining
-SLOW RELEASE IODINE
chlorine is used
environmentally
-chlorine gas
-sodium hypochlorite
-calcium hypochlorite
-hypochlorous acid (oxidizing agent)
heavy metals
-mercury, silver, zinc, copper, arsenic
-most multifactorial (can disrut cell wall, cell mem, can crosslink protein, disrupt nucleic acid)
silver nitrate
babys eyes
silver sulfadiazine
burn ointment
silver ions
in clothes, shoes
quaternary ammonium compounds
-detergents
-amphipathic
hydrophillic quaternary ammonium
- +charge to get close to - charge bacteria
hydrophobic quaternary ammonium compounds
stick to bacterial membrane
aldehyde
-complex w protein and nucleic acids
-formaldehyde, glutaraldehyde
things that can determine antimicrobial effectiveness
-cost
-odorless
-colorless
-water soluble
-stability
phenol coefficient
-compares new antimicrobial agent to phenol
-calculated by dividing the highest dilution of the agent that kills after 10 mins by the highest dilution of phenol that kills in ten mins
if > 1
antimicrobial is more effective than phenol
if = 1
same effectiveness as phenol
if < 1 `
less effective than phenol
growth inhibition tests
-looks for how long contact is necessary for antimicrobial to work
how to perform growth inhibition test
-add 100 microL of bacteria to tube that has 5mls of antimicrobial agent
-start timer as soon as you add bacteria
-transfer out 100 micro L into new tubes with nutrient broth at various time intervals
-you also need a control
antibiotics
-group of compounds originally produced by the metabolic reactions or microorganisms that kill or inhibit growth of other microbes
-can kill good and bad bacteria, can take a toll on good microbiome
mircoorganisms
bacteria: streptomyces and bacillus
broad spectrum
kill / inhibit both gram + and gram -
narrow spectrum
-kill / inhibit gram + or gram -
-can be more narrow than that: mycobacterium
antibiotic resistance
genetics, based on genes organisms have
different ways bacteria can be resistant
-organism lacks the target of antibiotic
-organism may be impermeable to antibiotic
-organism can alter the antibiotic
-organism can alter the target of the antibiotic
-organism can pump out the antibiotic
how can organisms pump out the antibiotic
eflux pumps
How does resistance occur
-overuse: not identifying agents of disease
-not finishing prescription
how to improve the problem of antibiotic resistance
-use other natural antimicrobial agents
-wash hands
-general education of people
-cycle the antibiotics used
kirby bauer method
-technique for antibiotic susceptibility
plate that kirby bauer method uses
-agar plate: Mueller-Hinton agar
-standardizes the results because of diffusion rate
-larger plate (15cm instead of 10cm): more surface area to see results better
how to perform the kirby bauer method
-get a confluent layer of bacteria onto the plate
-place antibiotic discs into the plate
-incubate
-measure diameter of zone of inhibition then look at catalog to give three numbers
antibiotic discs
-impregnated w specific antibiotics
-need to grow along with the bacteria to diffuse out of the disc
-each disc is a different antibiotic
3 numbers tell you
-susceptibility
-resistance
-intermediate range
