6: Killing Bacteria II Flashcards
Borrelia Burgdoferi
Lyme disease
North East US
Trepomeia Pallidum
sexual or congenital origin grows only in humans and rabit testes causes shphillis 2 negatives... like Gram neg axial fillament (flagella that starts in periplasmic space instead of outside) contortion of whole cell for movement very small genome spiral shape
Terpomeia Pallidum History
syphilis given to Columbus’ crew by native americans
south america syphilis caused european syphilis
Pros and cons to small genome
con: limited number of environments it can live in
pro: requires less nrg for replication
Tuskegee Syphillis Experiment
Trepomenia Pallidum
625 black men enrolled 1932-1972
not treated… researchers observed them dying
lead to having “informed consent”
Subspecies of Treponema
pallidum (syphilis)
pertenue (Yaws)
Syphilis
Primary
Secondary
Tertiary
Primary Syphilis
direct sexual contact with infectious lesion
lesion appears 3-90 days after contact
chancer: lesion
Secondary Syphilis
4-10 weeks after exposure
rash
Tertiary Syphilis
3-15 yrs after exposure
soft tummor like inflamations in skin and bone
Congenital Syphilis
early (first year)L rash, fever, neurosyphyilis, pnemonitis)
Late: saddle nose deformation, saber shit
Yaws
tropical skin infection
subspecies T. pallidum pertenue
Disk Diffusion
place filter disc satuared with compound on lawn of bacteria
more clearing… bigger zone of clearance, more effective
Kirby-bauer
subset of disk diffusion tests
Surfacants
DON’T kill bacteria
DISLODGE bacteria
soap and detergent
Acid aninonic sanitizers
Quats
Acid aninonic sanitizers
aninoic react with plasma membranes
non-toxic, non-corrosive
Quats
wuaternary ammonium compounds
good antimicrobial
ineffective afainst pseudomonads
antimicrobial soap
soap plus another compound
Chemical Food Preservation
Don’t kill bacteria
inhibit bacterial growth
organic acids and salts
sulfer dioxides
potassium sorbate/sodium benzoate
Sodium nitrate and nitrite
organic acids and salts
chem
easily metabolized by us… but also bacteria… so least effective but best for body
sulfer dioxides
Wine… used by Homer
kind of distasteful and toxic, but good in small amounts
potassium sorbate/sodium benzoate
perserves acidic foods from molds
cheese and soda
not metabolized well, but not dangerous… build up
Sodium nitrate and nitrite
Slim jims
can become carcinogen if eaten too much… liver cancer
alcohols
kill bacteria (bacteriacidal)
denature proteins in large enough concs
requires water for activity!
advantages of alcohol
cheap
leaves no residue… good for surfaces
disadvantages of alcohol
skin drying
doesn’t kill spores and non-enveloped viruses (colds… flu IS enveloped)
overuse of ethanol in hospitals
killed everything but. C. difficile… spike in it since it ad less competetion and had better chance of transmission
concentrations of alcohol that don’t work at any exposure time
100%… need water!
40% (what we drink)
2 things to consider with effectivness of alcohol
concentration
exposure time
why do we need water with alcohol
water breaks hydrogen bonds
best alcohol conc
65-70%
Halogens
bacteriacidal Chlorine Bleach Iodine (fluoridation of water)
Iodine tincture
mix iodine with alcohol and 10% water to make iodine more soluble… its pretty insoluble by itself
iodine not toxic to human tissue
iodine can be used to sterilize water
skin and wound antiseptic
Chlorine
most effective… but damaging to host
gas react with water to make hypoclorous acid… strong oxidizer
Bleach
destroys tissue
10% bleach is great surface disinfectant
Heavy Metals
KILL bacteria
combine with sulfylhydril groups in protiens… denaturation
silver, copper, mercury, zinc… oldest…water and why we thrown coins into fountains
Silver nitrate sollution
put in babies eyes to prevent gonorrhoea which causes blindness
copper and mercury chloride
less used bc toxinc to humans
Aldehydes
kill bacteria… and ppl
covalently link to proteins and destroy function
formaldehyde
formalin
Glutraldehyde
formaldehyde
crosslink with proteins
preserve appearance… changes composition… toxic
good for bio spills… sterlization… destroys bio things that we don’t want… vat of flu
formalin
great disinfectant
sample preservation
Glutraldehyde
sterilize medical instruments
mixture of Glutraldehyde and formaldehyde
prep cells for microscopy
chemiical sterlization
kill everything in the room
closed chamber
ethlene oxide
chlorine dioxide
formalin gas
vaporous hydrogen peroxide
ethlene oxide
react with side groups of bioc chems
has a VERY reactive oxygen that does this
oxidizes pretty much anything
sterlizer… kills everything
fumigant (termites)
chlorine dioxide
drinking water
most to least resistant microbes
Prions Endospores of Bacteria Mycobacteria Cysts of Protozoa Vegetative Protozoa Gram-neg Bacteria Fungi (most fungal spores too) Viruses w/o envelopes Gram Positive Bacteria Viruses w/ lipid envelopes
another way to kill bacteria
mutations
mutations
permanent change in primary sequence of DNA
change in one strand… eventually subsequent replication leads to a base change
matter in the CODING sequence!!!!!
nonsense mutations
early stop codon
often lethal
missence mutations
change in coding sequence… different amino acid
sometimes lethal
sometimes has phenotype
frame shift mutation
add or remove 1-2 nucleotides
shift how codons are read
change sequence of protein
may mean stop codon not read as stop codon… more amino acids added than there should be
where do mutations matter (what sequence)
the CODING sequence
you can get away with mutations in the non-coding sequence
How mutations happen
polymerase mistakes
UV light
Mutagenic Agents
polymerase mistakes
has proofreading capability… but still makes mistakes
1:10,000 base pairs
UV Light
Thymine dimers
T-T can pair with G… single base pair deletion… change in sequence (replace with single cytosine)
frame shift and/or missence
Mutagenic Agents
chemical agents tht react with DNA and cause improper base pairing
