Antimicrobial Agents Flashcards by Jean-Luc Banks

which are 30S inhibitors?

aminoglycosides

- tetracyclines

How well did you know this?

Not at all

Perfectly

which are 50S inhibitors?

chloramphenicol
macrolides
lincosamides
streptogramins
oxazolidinones
CLOMS

How well did you know this?

Not at all

Perfectly

aminoglycosides bacteriostatic/cidal

bactericidal

How well did you know this?

Not at all

Perfectly

aminoglycosides used best against

gram negative rods

How well did you know this?

Not at all

Perfectly

aminoglycosides mechanism of action

disrupt LPS in outer membrane

How well did you know this?

Not at all

Perfectly

examples of aminoglycosides

streptomycin
gentamycin

S AND G IN aminoGlycoSide

How well did you know this?

Not at all

Perfectly

aminoglycosides don’t work well against

anaerobes are intrinsically resistant

How well did you know this?

Not at all

Perfectly

aminoglycosides and pH

reduced activity at low pH

How well did you know this?

Not at all

Perfectly

enzymatically inactivate aminoglycosides

modification by phosphorylation, adenylation or acetylation
enzymes encoded on mobile genetic elements

How well did you know this?

Not at all

Perfectly

alter drug target aminoglycosides

methylation of rRNA

- mutation of ribosomal protein

How well did you know this?

Not at all

Perfectly

alter drug exposure aminoglycosides

decreased uptake nonspecific

- increased efflux (P. aeruginosa)

How well did you know this?

Not at all

Perfectly

aminoglycosides and beta lactams

beta lactams pre-weaken structure of bacterial envelope

- allows amino glycoside to get in

How well did you know this?

Not at all

Perfectly

tetracycline bacteriostatic/cidal

bacteriostatic

How well did you know this?

Not at all

Perfectly

tetracycline used against

gram positives
gram negatives
mycoplasma
intracellular bacteria

How well did you know this?

Not at all

Perfectly

tetracycline examples

tetracycline
doxycycline

CYCLINES

How well did you know this?

Not at all

Perfectly

which has troubles with divalent cations

tetracycline

- divalent cations inhibit absorption of drug in GI tract

How well did you know this?

Not at all

Perfectly

which has contraindications

tetracycline
in pregnancy
young children
inhibition of bone growth
discoloration of teeth

How well did you know this?

Not at all

Perfectly

tetracycline and beta lactamases

avoid!
beta lactams will only work on actively dividing cells
static interferes with the cidal activity

How well did you know this?

Not at all

Perfectly

tetracycline alter drug exposure

lots of efflux pumps

- most are effective against tetracycline itself

How well did you know this?

Not at all

Perfectly

tetracycline alter drug target

ribosome protection proteins

- bind to ribosome and displace drug from binding site

How well did you know this?

Not at all

Perfectly

chloramphenicol bacteriostatic/cidal

bacteriostatic
cidal against important encapsulated organisms
broad spectrum
synthetic

How well did you know this?

Not at all

Perfectly

chloramphenicol and ribosome

binds 50S bacterial

- but not 60S human

How well did you know this?

Not at all

Perfectly

chloramphenicol enzymatically inactivate drug

modified by acetyl transferases

How well did you know this?

Not at all

Perfectly

macrolides bacteriostatic/cidal

bacteriostatic

macrolides work best against

- gram positives - Chlamydia gram negative POSITIVE THAT LIAR GAVE ME CHLAMYDIA WHEN HE ASSURED ME HE WAS NEGATIVE LIE FROM MACROLIDE

macrolides examples

- erythromycin - azithromycin RO to RO

lincosamides bacteriostatic/cidal

- bacteriostatic

lincosamides work best against

- gram positive and gram negatives | - anaerobes

lincosamides example

- clindamycin LINC TO CLIN

lincosamides used well against what pathogen

- C. diff associated pseudomembranous colitis

streptogramins A and B individually

- individually bacteriostatic

streptogramins A and B together

- bactericidal together

streptogramin A works against which process

- peptide bond formation

streptogramin B works against which process

- chain elongation

MLSB

- resistance to macrolides, lincosamides, and streptogrammin B

MLSB resistance

- cross resistance due to similar mechanisms of action

MlSB alter drug target

- ribosome methylation by erm genes

erm genes stand for

- erythromycin ribosome methylation genes

erm expression

- constitute or inducible

determine inducible clindamycin resistance

- use D test | - makes it look like a D on the plate

Oxazolidinones bacteriostatic/cidal

- bacteriostatic

Oxazolidinones work best against

- gram positives that are resistant to other antibiotics

Oxazolidinones bind to

- 23S in 50S subunit

Oxazolidinones cross resistance

- no cross resistance with other protein synthesis inhibitors

Oxazolidinones example

- linezolid ZOLID ZOLID

Oxazolidinones alter drug target

mutations in 23S rRNA

folate synthesis inhibitors

- trimethoprim | - sulfonamides

RNA synthesis inhibitors

- rifamycin | - bind to DdRp wit higher affinity than human enzyme

DNA synthesis inhibitors

- fluoroquinolones - target topoisomerase - Cipro

agents that damage DNA

- nitroimidazoles - form toxic free radicals - Metronidazole

VanA locus

- constitutive resistance - all resistant or all susceptible when it burns out - constant expression of D-Ala-D-lac

Van B locus

- inducible resistance - more of a spectrum of values for susceptibility - temporary expression of D-Ala-D-lac

which costs more in terms of fitness - inducible or constitutive?

- constitutive

inhibit peptidoglycan synthesiis

- phosphomycin - cycloserine - bacitracin - glycopeptides - beta lactams PROFESSOR CREWS GOES BEYOND BOARDS

agents that act on mycobacterial cell walls

- isoniazid | - ethambutol

isoniazid

- inhibits mycolic acid synthesis

ethambutol

- inhibits arabinotransferases

lipopeptides

- disrupt cell membrane of G+ bacteria - poke holes in it - daptomycin