Antimicrobials/Vaccination Flashcards
What is bactericidal vs bacteriostatic
bactericidal- the agent kills the bacteria
Bacteriostatic- agent prevents growth of bacteria
What is a B lactam antibiotic (general) and ex
Target cell wall
- penicilin
- cepalosporins (cefazolin)
- carbapenems (ertapenem)
How do b lactams work (and what class is it considered)
binds to transpeptidase (penicilin binding pro) inactivating it ( cant form peptidoglycan cross links bw nam and nag)
Bactericidal (mostly gram positive bac)
What do vancomycins do and how they work (what class they work on)
Attaches to transpeptidase and prevents cross links in cell wall
Bactericidal (Only work on gram positive bac)
what do polymyxins target and how (+type of bac)
Target cell membrane
Bind to lipopolysaccharide altering its structure making it more fragile/ leaky
Gram neg bac
What do sulphonamides target + enzyme
Impair bacterial metabolism (by inhibiting folate by impairing dihydropteroate synthase)
Bacteriostatic
Why dont sulphpnamides affect our own cells
Bact use different enzymes/intermediates to synthesize tetrahydrafolate
What do trimethoprims work and what do they target
Bacteriostatic
Blocks folate metabolism via impairment of dihydrofolate reductase
What does fluoroquinolones do and target
impair bacterial DNA replication by targeting DNA gyrase and topoisomerases
-can break dna strands
Effective against gram pos and neg bac
What do rifamycins do and target
Blocks bacterial transcription by targeting bacterial RNA polymerase
affect gram pos and neg
What rifamycins bind to 30s subunit (2)
- Tetracycline- blocks trna(bacteriotatic)
- Aminoglycosides- causes mrna misreading(bactericidal)
what rifamycins bind to 50s subunit (3)
-all inhibit peptide bond formation
- Macrolides
- lincosamides
- chloramphenicol
What is MRSA resistent to
B lactams
What are the 3 mechanisms of antimicrobial resistence
- Enzymatic degredation of drugs
- Structural alterations (of cell wall)
- Efflux pumps etc
what does oseltamivir (tamiflu) target
Taregts influenza when trying to leave cell
Will inhibit neuramindase which usually releases virus from cell
What do nucleoside analogues do
chemically modified so when then are incorporated into growing nucleotide the replication is terminated
Why does nucleoside acylovir only work in infected cells (and what is it an analogue of)
Guanosine analogue
Only works in infected cells as it has to get one phosphate from viral enzyme
How does nucleoside reverse transcription inhibitors work (ex of what it works on)
works on HIV
adds AZT into growing DNA chain but since its chem modified it will not elongate
What do anifungals typically target
Glucan sysnthesis
Ergosterol sysnthesis
what do polyene antifungals do
Bind to ergosterol in cell membrane, which forms pores on plasma membrane
What do azoles antifungals do (+ enzyme)
inhibits enzyme used to convert lanosterol to ergosterol
lanosterol 14 a demethylase
what do allylamine antifungals do (+ enzyme)
Inhibits squalene epoxidase, one of the 1st enzymes in ergosterol biosynthesis path
What do echinocandins antifungals do
inhibit 1,3 b glucan synthase
What does metronidazole antiparasitic do
Inhibits nucleic acid synthesis
