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61 Cards in this Set
- Front
- Back
name 4 virulence factors of bacteria
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fimbriae and pillia
flagella secretion of toxins and enzymes invasion |
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what do fimbriae and pilli do?
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they allow bacteria to attach to certian sites in our body so they are not washed away
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what do flagella do?
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allow bacteria to swim and survive
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poisoning is an example of what kind of virulence factor?
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secretion of enzymes and toxins
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name 2 diseases associated with bacterial invasion of cells
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salmonella (in the intestine)
tuberculosis (in the lungs) |
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gram positive bacteria have ___ peptidoglycan and their stain is ___ coloured
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gram positive bacteria have thick peptidoglycan and their stain is purple coloured
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gram negative bacteria have ___ peptidoglycan and their stain is ___ coloured
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gram negative bacteria have thin peptidoglycan and their stain is pink coloured
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gram negative bacteria dont have a thick peptidoglycan layer. What layer do they have instead and what 2 things does this layer contain?
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gram negative bacteria have an outer layer which contains porins and lipopolysaccharides
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where are techoic acids found?
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on the cell wall (thick peptidoglycan) of the gram positive bacteria
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what is the gram negative alternative to techoic acids?
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lipopolysaccharides
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what are the 3 ways selective toxicity is produces
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1. disrupting bacterial cell wall
2. targeting unique bacterial enzymes 3. disrupting bacterial protein synthesis |
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what tequnique will provide the best basis for selection of therapy?
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culturing bacteria to identify it
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define bacteriostatic and bacteriocidal
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bacteriostatic antibiotics stop the growth and replication of bacteria, and the immune system can deal will the rest
bacteriocidal kill the bacteria |
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t/f MBC is usually lower than MIC
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false. min bacteriocidal concentration is usually higher than min inhibitory concentration
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name 5 infections which require special selection of antibiotics to penetrate the site of action
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meningitis
UTI osteomylitis abcesses otitis media |
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mengitis requires antibiotics that can penetrate the ____
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meninges
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what is the most common kind of UTI? (general)
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the kind that occurs when bladder is infected during catheterizations
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osteomylitis is an infection of the?
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BONE
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why are abcesses difficult to treat with antibiotics?
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because they are poorly perfused with blood
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otitis media is an infection of the? why is it difficult to treat
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ear infection! difficult to treat because antibiotics cannot penetrate the inner ear
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name 4 conditions where its better to treat with bacteriocidal than bacteriostatic antibiotics. Why?
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1. AIDS
2. organ transplant 3. cancer chemotherapy 4. being old all 4 of these have compromised immune systems. this means that bacteriostatic is not that effecive. bacteriocidal is necessary |
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what are 6 complications of antibiotic therapy? BRASSD
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Bone marrow toxicity
Resistance Allergy Serum Sickness SUperinfection Destruction of normal bacterial flora |
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what are 3 symptoms of bone marrow toxicity
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sore throat, bruising, fatigue
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What are the three ways a bacteria can acquire antibiotic resistance?
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1. reduction of drug at the site of target
2. increased drug inactivation 3. alteration of bacterial target |
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what are two ways a bacteria can reduce the amount of drug at the site of target, to acquire resistance
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1. uptake less and less of the drug
2. use efflux pumps to kick out the drug |
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give an example of an enzyme that a bacteria can produce to inactivate a drug
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some bacteria can produce beta lactamase, which inactivates beta lactams such as penicilllin and cephalasmporam
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how can bacteria alter a target to acquire resistance?
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bacteria can mutate a site of target such that antiobiotics cant bind to the target
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what is the most common antibiotic allergy?
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penicillin
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most fatal antibiotic allergic reaction occur long/soon after dosage
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soon after dosage. 20 minutes in fact
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how would you treat an antibiotic allergic reaction
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antihistamine and epinephrine
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what is serum sickness
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the body identifies an antibiotic as harmful and produces an immune system mediated allergic reaction
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what takes longer to develop, serum sickness or allergy?
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serum sickness. allergy takes 20 minutes, serum sickness takes 20 days
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how would you treat serum sickenss
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antihistamines, analgesics, and corticosteroids
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how does superinfection occur?
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when broad spectrum antibiotics kill bacteria and normal intestinal bacterial flora, then new drug resistant bacterial flora show up, which can cause problems
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there are 3 consequences associated with normal bacterial flora destruction what are they?
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1. loss of vitamin K. NBF produce this vitamin. warfarin needs this vitamin or else there are bleeding side effects
2. they contribute to first pass metabolism. this can cause drug toxicity 3. they contribute to enterohepatic recycling. this can cause lower drug plasma levels such as oral contraceptives |
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what bacteria formed mold which contained penecillin?
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staphylococci
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what are the two targets of penicillin (PBPs) and what do they do?
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1. transpeptidase enzymes form cross links betweek peptidoglycans on the cell wall. penicillin inhibits this
2. autolysins degrade peptidoglycans on the cell wall. penicillin activates this |
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are penicillins bacteriocidal or static?
what is the net effect of penicillin use on a bacteria? |
penicillins are bacteriocidal.
they disrupt cell wall synthesis, degrade the cell wall, cause the cell to take up too much water, so it lyses and dies |
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t/f penicillins are active only against bacteria that are growing and dividing
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true
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penicillins are more effective against gram positive/negative bacteria, why?
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gram positive bacteria because they do not have an outer membrane
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what are 3 ways penicillin can gain resistance?
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1. inability to reach target
2. inactivation 3. mutation of PBPs that make them have a low affinity for penicillin |
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what are the 4 classes of penicillins?
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1. narrow spectrum penicillins
2. narrow spectrum penicillinase resistant penicillins 3. broad spectrum penicillins 4. extended spectrum penicillins |
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narrow spectrum penicillins
a) gram positive or negative destroying? b) administration? c) treat what two diseases? |
destroy gram positive
administered via IV treat meningitis and pneumonia |
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narrow spectrum penicillinase resistant penicillins
a) gram positive or negative destroying b) non susceptible to what enzyme? c) effective against what specific bacteria? d) less effective against _____ producing bacteria |
a) gram positive destroying
b) non susceptible to beta lactamase c) effective against staphlocuccus d) less effective against non penicillinase producing bacteria |
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broad spectrum penicillins
a) gram positive or gram negative destroying? why? b ) resistant to beta lactamases? |
a) both. because they can penetrate outer membrane of gram negative bacteria
b) no, they are readily inactivated by beta lactamases |
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extended spectrum penicillins
a) difference between this and broad spectrum? |
a) although they attack both gram negative and positive, AND are readily inactivated by beta lactamases, extended spectrum penicillins can destroy pseudomonas aeruginosa
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___ have the exact same mech of action as penicillin
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cephelasporins
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as we move from 1st to 4th generation, what happens to cephelasprorin characteristics
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1. increased activity against gram negative bacteria
2. increased resistance to beta lactamases 3. increased ability to penetrate cerebral spinal fluid |
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what is the best alternative to penicillin?
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cephelasporins
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what drug is used to treat infections cause by MRSA
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vancomycin
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what is vancomycin mech of action?
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binds to precursors of cell wall synthesis to disrupt the transglycosylation step in cross bridge synthesis
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____ infusion of vancomycin causes ______
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rapid infusion of vancomycin causes red person syndrome
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what is tetracycline mech of action
what spectrum is it bacteriocidal/bacteriostatic? |
it inhibits protein synthesis by binding to ribosomes
it is broad spectrum it is bacteriostatic |
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name 1 adverse effect of tetracycline
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photosensitivity
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what are macrolide mech of action
what spectrum are they bacteriocidal/bacteriostatic? |
they inhibit protein synthesis
they are broad spectrum they are bacteriostatic macrolides are the same as tetracycline except their adverse effects |
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1 adverse effect of macrolides?
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QT interval prolongation
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oxazolidinones
mech of action? spectrum? bacteriostatic/bacteriocidal? what do they treat? |
they inhibit protein synthesis
they are narrow spectrum agaignst gram positive only they are bacteriostatic the treat MRSA and VRE (vanamycin resistant enterococci) |
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aminoglycosides
a) spectrum bacteriostatic/bacteriocidal? |
narrow spectrum
they are BACTERIOCIDAL |
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sulfonamides and trimethoprim
a) mech of action b) bacteriostatic/bacteriocidal? c) treatment of what? |
a) block folic acid synthesis
b) bacteriocidal c) treatment of UTIs |
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Both ___ and ____ lead to photosensitivity
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both tetracycline and sulfonamides/trimethoprim
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what is the primary treatment for treating tuberculosis?
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isoniazid
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