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75 Cards in this Set
- Front
- Back
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agents that are "selectively" toxic for bacteria (either killing them or inhibiting their growth without harm to patient
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antibiotics
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kills bacteria
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bacterrcidal
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inhibits growth of bacteria
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bacteristatic
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name some ways of clarifying antimicrobial agents
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1 origin
2. agents 3. chemical structure 4. target site/activity (selective toxicity) |
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natural products of fungi, actinomycetes, and bacteria which kill or inhibit growth of microbes
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antibiotic (origin)
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what are some examples of antibiotics
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penecillin
cephalosporin tetracyclin |
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what are some synthetic compounds of antibiotics
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trimethoprim
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what are some antibiotic producing microbes
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gm + rods
fungi actinomycetes |
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what gm + rods microbes produce antibiotics
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bacillus subtilis
bacillus polymyxa |
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wwhat sntibiotic is produced by bacillus subtilis
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bacitracin
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what antibiotic is produced by bacillis polymyxa
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polymyxa
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what fungi microbes produce antibiotics
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penicillin notatum
cephalosporium spp |
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what antibiotic is produced by penicillin notatum
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penicillin
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what antibiotic is produced by cephalosporium spp
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cephalothin
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what actinomycetes produces antibiotics
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streptomyces:
- venezuelae - griseus - nodosus micromonospora purpurea |
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what antibiotic is produced by streptomyces venezuelae
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chloramphenicol
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what antibiotic is produced by streptomyces griseus
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streptomycin
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what antibiotic is produced by streptomyces nodosus
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amphotericin B
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what antibiotic is produced by micromonospora purpurea
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gentamycin
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what common chemical structure do all antibacterials have
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beta lactam ring (monobactam)
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what are some chemical structures of antibacterials
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monobactam
carbapenems cephamycins |
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what is the target site of activity for antibiotics cell wall synthesis
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mammalian cells lack cell wall
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what is the target site of activity for antibiotics protein synthesis
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ribosome (gentamycin)
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what is the target site of activity for antibiotics in nucleic acid synthesis
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dna
rna |
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what is the target site of activity for antibiotics with cell membrane function
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?
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relatively easy to develop and find low toxicitu because prokaryotic cells are very different from host cells
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antibacterial
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more difficult to develop because eucaryotic cells resemble human cells
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antihelminthic
antiprotozoan antifungal |
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most difficult to develop becuase viruse reproduces using host cell enzymes and machinery
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antivirals
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effective against many different types of bacteria (gm + and +)
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broad spectrum (ex. tetracycline)
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effective against a subset of bacteria (either gm - or +)
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narrow spectrum (ex. penicillin, isoniazid- mycobacterium only)
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how do antimicrobial mechanisms of action inhibit cell wall synthesis
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interfere with peptidohlycan synthesis
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what is the result of antimicrobial interference with peptidoglycan synthesis
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- results in cell lysis
- low toxicity ex. penicillin and vancomycin |
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what arw some beta lactam antibiotics
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penecillin
caphalosporins carbapenems monobactams cephamycin |
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what is PBP
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penicillin binding protein
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enzymes involved in cross linking bacterial cell wall components
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PBP
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what is the determinant factor in the spectrum of activity in antibiotics
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whether they bind to PBPs in the org
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t or f, different bacteria may have different PBPs
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true
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give some examples of penicillin
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penecillin G & V
nafcillin, methicillin ampicillin, Amoxicillin carbenicillin, ticarcillin pipercallin, azlocillin |
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what is the beta lactamase benzylpenicillin used for
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pharyngitis
pneumonia meningitis endocarditis |
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what is the penecillin beta lactamase fluclox/cloxacillin used for
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skin
soft tissue joint bone |
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what is the penecillin beta lactamase amp/amoxycillin used for
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uti
enteric fever bone meningitis epi |
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what is the penecillin beta lactamase azlo/piperacillin used for
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p. aeroginosa and other g + rods
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what is the caphalosporin beta lactamase cephalexin used for
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uti
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what is the caphalosporin beta lactamase cefuroxime
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uti, lrti
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what is the caphalosporin beta lactamase cetriaxone used for
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meningitis
joint bone |
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what is the caphalosporin beta lactamase ceftazidime
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p. aeruginosa and other G - rods
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what is the caphalosporin beta lactamase ceforaxime
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men
lrti uti abdominal sepsis |
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what is the carbapenems beta lactamase imipenem
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p. aeruginosa and other gm - rods
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what are some beta lactamase inhibitors
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clavulanic acid
sulnactam tazobactam |
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- used with amoxycillin (augmentin)
- used with ticarcillin (timentin) |
clavulanic acid
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used with amoxycillin
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augmentin
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used with ticarcillin
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timentin
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used with ampicillin
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sulbactam
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used with piperacillin (tazocin)
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tazobactam
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what is the outcome of antibiotics inhibiting protein synthesis by interfering with procaryotic (70s) ribosomes also found in mitochondria
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- most have broad spectrum of activity
- tetracycline, chloramphenicol, erythromycin, streptomycin |
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what agents bind to 70s ribosome
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aminoglycosides
tetracyclines macrolides lincosamide chloramphenical |
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when dealing with antimicrobial mode of action, what happens when there is injury to plasma membrane
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- loss or metabolites and or cell lysis
- many polypeptide antibiotics - ex. polymyxin B (antibacterial) or miconazole (antifungal) |
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causes changes in membrane permeability
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injury to plasma membrane
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what is the effect of inhibition of nucleic acid synthesis
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it interferes with DNA replication and transcription
- may be toxic to humam cells - ex. rifampin and quinolones |
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inhibition that involves the competitive inhibition of key enzymes
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inhibition of synthesis of essential metabolites
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what is meant by drug resistance
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prevent entry
alter binding site inactivate drug |
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can be destroyed by bate lactamase produced by resistant bacterial strains
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penicillins (penicillinase)
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may develop from mutation leading to modified porins
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resistance
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has a beta lactam component which binds strongly to be lactamases inhibiting their activity
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clavulnic acids
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what are some safety concerns with the use of antimicrobials
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- toxicity
- interactions with other meds - hypersensitivity reactions - fetal damge/risk to pregnant women - antibiotic resistance |
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causes kidney damage and liver damage
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antimicrobial toxicity
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may neutralize effectiveness of contraceptive pills
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interaction with other meds
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anaphylactic reactions to penicillin
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hypersensitivity
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when dealing with fetal damage/risk to pregnant women, what drug causes discoloration of teeth in children and may cause liver damage in pregnant women
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tetracycline
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when dealing with fetal damage/risk to pregnant women, what drug causes cartilage damage
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fluroquinolones
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what are some methods of antimicrobial susceptibility testing
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1. dilution methods
2. disc diffusion method |
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how many dilution methods are used in dilution method
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2
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- provides minimum inhibitory concentration (MIC) results
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dilution method
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with broth macrodilution (tube dilution) test, what broth is used
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mueller hinton broth
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what plate is used in broth microdilution test
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microtiter plate
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