- 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

antibiotic Flashcards by jood kh

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)

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Cell wall inhibitors
Protein synthesis inhibitors
DNA synthesis inhibitors
Anti-mycobacterial agents
Bactericidal
Bacteriostatic
are all under:

anti bacterial agents

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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

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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)

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cell wall synthesis inhibitors :
- these only affect — and not —-
- the 2 classes are:

bacteria
not mycoplasmas, chlamydiae or the host
b lactams ad glycopeptides

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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

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Standard penicillin
Anti-staphylococcal
Aminopenicillins
Anti-pseudomonal penicillins
are all types of:

penicillin
check structure 13

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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)

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glycopeptide resistance:
- exist primarily in —-
- resistance can transfer between —
- S. aureus with intermediate resistance to —- and both vancomycin and teicoplanin (GISA) have been discovered
- Cells contain VanR and VanS which detect —
- These activate VanH, VanA/B and VanX:
-VanH converts —- to —-
-VanA/B produces —- instead of —-
-VanX hydolyses —

enterococci ( VRE)
between species
vancomycin ( VISA)
vancomycin
pyruvate
lactate
D-ala-lactate
of D-ala-D-alanine
D-ala-D-alanine

vancomycin resistance could be due to – of the cell wall

thickening

inhibitors of protein sythesis are — and they have 5 classes of drugs which are:

bacteristatic
Aminoglycosides
Macrolides
Tetracyclines
Amphenicols
Oxazolidinones

Prokaryotic ribosomes are —
–> subunits are — and —
—> 30S ribosome has — RNA
—> 50S ribosome contains — and — RNA.
-Eukaryotic ribosomes are —
–> — and — subunits
—>Ribosomal RNA is — in eukaryotes (e.g. 18S versus 16S rRNA).

70S
30S and 50S
16S
23S and 5S
80S
40S and 60S
larger

aminoglycosides:
- amino sugars linked by — and these include :
- enter cell using —- transport system which are —- resistant
- — only
- causes — most frequent and is mild n reversible
- — which can be permanent
- —- restricts the use of aminoglycosides to serious infection

glycosidic bond as:
Gentamicin
Streptomycin
Amikacin
Neomycin
oxygen dependent transporter system
anaerobes
iv
nerphotoxisty
ototoxity ( aka death)
toxicity

macrolide: Erythromycin Clarithromycin Azithromycin Dirithromycin - ---- is a modified macrolide ( ketolide) - --- active - is --- - ---- in some species - used for

telithromycin orally bacteriostatic bactericidal respiratory infection

--- is a --- which contain a ---- ring w --- sugars attached ( check structure 44)

erythromycin macrolide multi-membered lactone ring with deoxy sugars attached

--- 2nd most prescribed antibiotic which is in a broad spectrum , used once a day for short treatment course and is orally active

azithromycin

----such as clindamycin and lincomycin have similar mechanism of action as macrolides -They are --- active -Active against ---- and ---

lincosamides orally gram +ve cocci n aerobes

streptogramins: - Quinupristin and dalfopristin used in --- (3:7 by weight) - Both bind to distinct sites on -- subunit - --- effect as each is ---- but combination is --- - Requires ---- daily ---infusions limiting its use

combination 50S synergic bacterstatic bactericidal multiple iv

- ---- can cause ventricular tachycardia when given with H1- antagonists such as astemizole or terfenadine. Both H1-antagonists have been removed from the market. - --- is poorly tolerated due to nausea and vomiting

macrolide ( macrolid toxicology ) ehtromycin

oxazolidiones: 1- --- : PO & iv preparations Good tissue penetration including CSF Activity against MRSA Can cause myelosuppression Anemia Thrombocytopenia Leucopenia Tedizolid 2- --- : Given as a phosphate pro-drug More potent than linezolid

linezolid tedizolid

---- are 4 fused cyclic ring which bind to ribosomes - selective for bacteria due to ---- - causing growing teeth to become --- and are contraindicated in --- and -- - resistance due to --- which reduces ---

tetracycline ( and also doxyclines ) transport mechanism stained yellow-brown children n preg women - pump -intracellular levels

basically the cell wall inhibitors either bind to alanine alanine or prevents binding

mechanism faction of tetracycline: - all inhibit ---- formation - Aminoglycosides & tetracyclines bind to -- -Macrolides, linezolid & streptogramins bind to --

ribosome complex 30s 50s check slides 52-53

protein synthesis inhibitors resistance mechanisms: 1-Decreased --- Aminoglycosides 2- --- pump Aminoglycosides Macrolides 3- ---- modifying enzymes (9+) which can acetylate, adenylate etc the antibiotic. Enzymes are specific for individual antibiotic 4- Target --- macrolides, lincosamides, streptogramin & linezolid (ribosomal RNA mutations)

permeability xenobiotic aminoglycoside mutation

--- is a cyclic lipopeptide -It binds to ---- causing --- resulting in an inability to synthesise proteins -It is ---- against ---

daptomycin bacterial mwmebanes deplorization bactericidal aerobic gram +ve

- televancin acts like ---

acts like vancomycin n daptomycin check structure 57

daptomycin resistance: -A 2005 report describes a patient with VRE treated with daptomycin. Failed to respond to daptomycin (resistant?) Patient responded to linezolid Evidence of alterations in daptomycin-resistant bacteria: increased --- increased --- surface charge resulting in reduced -- reduced --- capacities reduced --- .

fluidity positive drug binding permeabilizaion deploairzation

Quinolones (nalidixic acid) & fluoroquinolones (ciprofloxacin) Metronidazole is used for anaerobes Neither are used in children or during pregnancy Bactericidal at higher concentrations are all under:

inhibitors if dna synthesis

First Generation Quinolones : - ---- , 1962 Good Gram-Negative Rod efficacy, useful in UTI Second Generation Quinolones: ---- Aerobic Gram-Negative Rods & some Gram Positive Third Generation Quinolones : ---- Broad Spectrum Gram-ive Rod & Gram+ive Cocci Especially Pneumococcus coverage Fourth Generation Quinolones : ---- Very Broad spectrum & less resistance Gram-ive Rod, Gram+ive Cocci coverage & Anaerobes

nalidixic acid ciprofloxacin levofloxacin moxifloxaicin all of these are under fluroquilones and check slide 62 for structure

furoquiloes inhibit --- which is required for dna supercoiling - it also inhibits ---- - FQ are good ---- - they are well --- antibiotic but potential to cause --- and ---

dna gyrase dna type iv tipoisomerase oral bioavailibity well tolerated cause tendonopathy and tendon rupture. (Black box warning)

--- is a novel class of antibiotic inhibits --- and not a FQ , expected to be approved for ---- and ---

gepotidacin topoisomerase uti n gonorhea

Gram+ive rods Thick cell wall with 4 layers Innermost layer is peptidoglycan Outer layers are lipids are:

mycobacteria

anti mycobacterial agents: 1- --- : Rifampin, rifabutin and rifapentine 2- inhibits ---- 3- very important to treat --- and not uses as monotherpay 4- ---- :induces microsomal enzymes causing drug interactions Can cause hepatotoxicity, fever, orange urine

rifamycin DNA-dependent RNA polymerase tb rifampin

anti tb antibiotics: ---- inhibits synthesis of mycolic acids ----- inhibits transcription ---- inhibits synthesis of short-chain, fatty-acid precursors

Isoniazid (INH) Rifampin (RMP) Pyrazinamide (PZA)

adverse effects if antibiotic therapy :

The microbiome is the normal microbial flora found in humans Bacterial by-products influence health and disease What is a healthy microbiome? Gut micro-flora is disrupted by antibiotic therapy Leads to increased monosaccharides Facilitates growth of Salmonella enterica and Clostridium difficile Serious infections

healthy microbiome:

1014 bacteria and archaea of more than 1,000 species exist in the gut microbiome Associated with many illnesses Desire to exercise is due to microbiome Due to production of fatty acid amides that activate the endocannabinoid system Antibiotic therapy reduced exercise levels in mice Obesity is linked to microbiome (Schematic representation of the role of the gut microbiota in health and disease giving some examples of inputs and outputs. CVD=cardiovascular disease; IPA=indolepropionic acid; LPS=lipopolysaccharide; SCFA=short chain fatty acids; TMAO=trimethylamine N-oxide)

---- is a live faecal culture isolated from healthy volunteers. Approved by FDA (Dec 2022) for the prevention of recurrent C. difficle infection Single rectal administration post-antibiotic therapy 13% efficacy compared with placebo

rebyota check rest of slides especially slide 83