pathogen infection antibiotic matching Flashcards
how can you identify whether a pathogen is gram positive or gram negative?
in gram positive the cell wall is made of peptidoglycan and therefore it stains purple. The inner cell wall is protected and therefore stains pink. The cell membrane is made of bilayer and therefore stains pink - staining classifys them
how do you identify a rod/cocci gram positive or negative?
gram stain positive - cocci or rods. Rods are clostridium, bacillus, corynebacteria or listeria. To identify cocci do the catylase test which if positive is stapylococcus - aureus or epidermis and if negative is streptococcus - pneumoniae or pyogenes. For gram negative the cocci are neisseria and the rods are E coli, pseudomonas etc
what is cocci shape?
they are in pairs, groups or chains
what is a rod shape?
groups, chains or solo
what is pencillin?
it is an antibiotic that is a beta lactam ring. All beta lactam rings work in a similar fashion by inhibiting cell wall synthesis - they are the oldest and most useful, safest antibiotic
what else can be targeted?
bacterial translation and protein synthesis - translation is mRNA to AA to protein - can exploit this because the bacteria and human ribosome are different
what types of bacteria translation and protein synthesis antibiotics are there?
chloramphenicol - used for conjunctivitis as eyedrops and tetracyclins
what does RNA synthesis and DNA replication get used for?
target for antibiotics as DNA to mRNA in transcription is different in different bacteria and so is DNA bacteria.
what is needed to make nucleotides?
Folate is the basic thing needed to make constituents in DNA in nucleotide synthesis
what types of antibiotics target cell wall?
penicillins, carbapenems, cephalosporins and glycopeptides
what antibiotics are used in translation?
tetracyclin, macrolides, chloramphenicol or aminoglycosides
what type of antibiotic are used in RNA synthesis?
rifamycin
what types of antibiotics are used in DNA replication?
antifolates - trimethporin and slfadrugs, quinolones and metronidazole
how would you test antibiotic resistance?
spread bacteria out of a dish and put on antibiotic discs - look at the zone of inhibition and it may take up to 6 weeks to fully wipe out bacteria
what should be done in the situation of a mutation?
change AB to avoid further resistance - can mutate and become resistant in a short amount of time
what are the four mechanisms of drug resistance?
altered target or binding site, alteration of metabolic pathways, reduced drug accumulation and drug inactivation or modification
how can drug inactivation work?
enzymes in bacteria such as E coli and carbapenemase and staph aureus with penicillinase
how can alteration of target work?
MRSA - bacteria will evolve the binding site so that AB cannot bind or staph aureus - alteration of penicillin binding protein
how can the alteration of metabolic pathway work?
sulfa resistant bugs can use preformed folic acid
how can reduced drug accumulation result?
with quinolones treatment can develop an efflux pump
why is co-amoxiclav used?
it is a component of amoxicillin (beta lactam) and clavulanic acid - acid inhibits B lactamase that often breaks down the ring in AB and then prevents amoxicillin from being degraded
what is a similar concept to coamoxiclav?
tazocin - penicillin and tazobactam
how have gram negative rods adapted?
they have B lactamase that cleaves the amoxicillin in hald
if MRSA is resistant to methicillin then what else will it be resistant to?
cyclosporin and penicillin
