antibiotic Flashcards
gram +ve is characterised by —- cell wall which is composed of layers of —–
gram -ve contain —- outer membrane that is — with —–
thick
peptidoglycan
lipopoly-saccharide
lipid bilayer
aqueoes channels ( porins)
Cell wall inhibitors
Protein synthesis inhibitors
DNA synthesis inhibitors
Anti-mycobacterial agents
Bactericidal
Bacteriostatic
are all under:
anti bacterial agents
in anti microbial resistance :
1- —- degradation aka —-
2- mutations in —– aka
3- reduced —- especially in –
4- —- pumps includes:
enzymatic
b lactamases
drug target
penicillin binding proteins
permeability
gram -ve bacteria
xenobiotic includes:
MexB (b-lactams)
MexY (aminoglycosides) in Gram-ive bacteria
WHO essential medicines:
- —- antibiotic selected
- access: these are antibiotics that have a — potential for resistance and should be — available everywhere.
- watch : These antibiotics have a —- potential for resistance and should not be — treatment except for specific indications.
- RESERVE: . These antibiotics that are kept for — cases of —- organisms and are drugs of last resort.
39
low
freely
high
first line
life treating
multi resistant
( check slide 8 , 9 for structure of cell wall sooo important)
cell wall synthesis inhibitors :
- these only affect — and not —-
- the 2 classes are:
- bacteria
- not mycoplasmas, chlamydiae or the host
- b lactams ad glycopeptides
- b lactams are defined by the presence of — ad the four types are:
- b lactam ring
- types are:
1-Penicillins
2-Cephalosporins
3-Carbapenems
4-Monobactams
check the structure of b lactam ring slide 12
Standard penicillin
Anti-staphylococcal
Aminopenicillins
Anti-pseudomonal penicillins
are all types of:
penicillin
check structure 13
1- standard pencilling:
- originally isolated from —
- penicillin g aka — is only —
- penicillin V is stable in — and used —
- used to treat infection from:
2- Anti-staphylococcal penicillin:
- these are resistant to —
- principle agent is:
- used to treat:
Penicillium notatum
benzylpenicillin)
iv
acid
orally
infections from :
Streptococci
Meningococci
Syphilis
resistant to degredation
methicillin
staphylocococcal infection
3- aminopencilin :
- contain an —
- —- and —- are 2nd most prescribed antibiotics
- not effective against —
- enhanced activity against —
- used for:
4- Anti-pseudomonal penicillins:
- —– : Carbenicillin & ticarcillin
- —- : Piperacillin, azlocillin & mezlocillin
- not active against —
- similar to — except w enhanced activity against —-
amino group
Ampicillin and amoxicillin
staphylococci
gram -ve infection
used for:
-H. influenza
-E. coli
-Salmonella & Shigella
Carboxypenicillins
Ureidopenicillins
staphylococci
aminopencillin
Pseudomonas aeruginosa
cephalosporin :
- First isolated in 1945 from a — (Cephalosporium acremonium)
- Cephamycins are related molecules from —.
- — activity increases and — activity decreases from 1st-3rd generation
-Similar profile and mechanism of action as —
mould
streptomyces
anti gram -ve
anti staphyloccoal
penicillin
cephalosporins ( other b lactam antibiotic) and generations:
1st generation:
- —-
- —– (most used cephalosporin)
2nd generation:
-Activity against —
- —
3rd generation:
- Increased activity against —
- —-
4th generation:
- Improved —
- —-
5th generation (definition is fluid):
- —–activity
- —
Streptococci, staphylococci & E. coli
cephazolin
H. influenzae & B. fragilis
cefaclor
gram -ve bacteria
Cefotaxime & cefixime
gram +ve activity
cefapime
Anti-pseudomonal activity
cefaroline
action of penicillin:
- acts as a mimetic of — the natural substrate of —- ( penicillin biding protein )
- irreversibly inhibits —- by preventing —-
- leads to increased secretion of —- which is an inhibitor of —-
- Uninhibited autolysin leads to — of bacteria
Ala-Ala
traspeptidase ( basically its a pbp and its the one causing crosslink)
transpeptidase
cell wall cross linking
lipoteichoic acid
autolysin
lysis
adverse effects of b lactam :
- very — toxicity may cause — due to disturbance in —
- —- which are rare
- penicillin causes —- in 2% of patients which is due to reaction of —- as: penicillenic acid with proteins to form an antigen , Only 10% cross-reaction with cephalosporins
- — w cephradine
low
diarreha
normal gut flora
seizures
allergic reaction
penicillin metabolites
nerphotoxity
- b lactamase hydrolyses —
- some antibiotics are resistant to b lactamase as –
- Type I chromosomal b-lactamase is specific for — (cephalosporinase)
b lactam ring
methicillin
cephaloporin
b lactamase inhibitors:
- These are b-lactams without —- such as:
- thet covelantly bind to —
- they don’t inhibit —
antimicrobial activity
-as:
Clavulanate
Sulbactam
Tazobactam
b lactamase
cephalosporinase
check slide 24 pls
combination therapy:
b lactamase inhibitors are used in combination w — as:
Amoxicillin-clavulanate (po)
Ampicillin-sulbactam (iv)
Ticarcillin-clavulanate (iv)
Piperacillin-tazobactam (iv)
b lactam antibiotc
methillin resistance is due to —
the — codes for variant — with — affinity for b lactams
— takes over cell wall synthesis in the presence of methicillin
mecA
mecA
variant penicillin binding protein (PBP 2a) which is basically a mutation in transpeptidase
low
PBP 2a
glycopeptides:
- —- is a (1.5kDa) glycopeptide antibiotic made by Streptomyces orientalis
- Introduced in 1965 for resistant Staph
- Only effective against — infection
- Given by — infusion or — for GI infection
- Effective in —-
vancomycin ( basically in vanocmycin when it binds to alanine alanine the traspeptidase won’t be able to bind)
gram +ve
iv
orally
MRSA
Teicoplanin
Telavancin (Lipoglycopeptide)
Oritavancin
Dalbavancin
Similar mechanism of action to vancomycin
More renal toxicity with televancin
are all examples of:
glycopeptides
( check structure slide 29,30)