DD Unit III Flashcards
Drugs that are no good against gram (+) cocci
Aminoglycosides (Protein Syn Inhib) and Metronidazole (DNA inhibitor)
Drugs that are no good against gram (-) rods
Penicillin, Vancomycin, Macrolides, Clindamycin, Metronidazole
What is metronidazole good for anyway?
Kicks ass against anaerobes! (C. Diff and Bacteroides fragilis)
Why don’t strep and MSSA have the same antibiotic profile?
MSSA has penicillinase
Why is MRSA resistant to methicillin anyways?
New PBP means NO beta lactams (Pens, Cephs, Carba’s) are going to work
So, what DOES work against MRSA?
Vancomycin, Macrolides, Tetracyclines, Clindamycin
Tell me about enterococcus
Enterococcus is the most intrinsically resistant gram (+) cocci (NO CEPHS), in fact, it can resist Vanco in some cases!
Tell me about enteroBACTER
Gram (-) rod, can carry AmpC on its chromosome
What is AmpC and who carries it?
Broad spectrum beta-lactamase (Pens and Cephs). Chromosomally located, can be induced (amp, cefazolin) or constitutive. Enterobacter and Pseudomonas.
How do you fuck up treating someone with enterobacter or pseudomonas infection?
(Assumes presence of AmpC) Give them any beta lactam except a carbapanem
What soothes your E. Coli/Klebsiella (ESBL) and enterobacter/pseudomonas (AmpC) problems?
Treat with carbapanems!
What two carbapenemases do we hate and who has them?
NDM-1 and KPC (like KFC, just death…) in Klebsiella and E. Coli
You got N. gonnorrhoea. Bummer. What is it, and how do you treat it?
It is a gram (+) cocci, and due to altered PBP, only drug options = cephtriaxone, macrolides, or tetracyclines
What’s the archetypical Gram (-) rod, and why doesn’t penicillin work against it?
E. Coli. Porins
What does TEM-1 mean to you?
Plasmid carried by E. Coli. Amp and Amox go away.
Tell me about ESBL
Lose pens and cephs. Carbs still work!
What are aminoglycosides good for?
Gram (-) aerobes
What two gram (-) rods have identical antibiotic spectrums, and what is the difference in their resistance?
E. Coli (TEM-1) and Klebsiella (SHV-1). These are both narrow beta-lactams, but Klebsiella has SHV-1 in its chromosome rather than a plasmid.
What’s your go-to drug list for pseudomonas?
Pip/tazo, Ceftazidime/Cefipime, Aminoglycosides (gram neg rod duh), SOME carbapanems, SOME fluoroquinolones make pseudomonas moan
What are you two C.Diff killers?
Vanco and Metronidazole (it’s an anaerobe!)
What is the benchmark for an anaerobic drug?
Can it treat Bacteroides fragilis? Can’t treat with Cephs, Vanc, Macros, AMINOGLYS, Fluoros. CAN treat with a few pens, Carbas, Tetras, Clinda, Metro
Uh oh, got Chlamydia…what to do?
Macrolides, Tetracyclines, Fluoroquinolones to the rescue!
Got walking pneumonia…what to do?
Same as chlamydia! Macrolides, Tetracyclines, Fluoroquinolones
Vancomycin is good for?
Gram + cocci and C. Diff
Tell me the names of the macrolides
“ACE”
Azithromycin, Clarithromycin, Erythromycin
Straight from lecture question: what DON’T you give to ppl with a penicillin/amox anaphylactic allergy?
Cephalosporins
Name all the damn DQ CRIMES (non-renal clearance drugs, beware drug-drug interactions, genetic polys, hepatotoxicity)
Doxycycline Quinolones Clindamycin Rifampin Isoniazid Metronidazole Erythromycin-like Sulfonamides
How do bacteria become resistant to macrolides?
modify the target: dimethylation of 23S rRNA on 50s subunit (erm gene). Confers cross-resistance to clindamycin too
What are macrolides good for again?
Just about everything except gram (-) rods, enterococus and anaerobes
Oh Shit, a bacteria’s got the erm…what’s the next important detail to know?
Is it inducible or constitutive?
How do you fuck up with antibiotic treatment of a bacteria with the erm?
Treating with clindamycin can select for mutants that constitutively express the erm-encoded methylase = not only erythromycin resistance, but sudden failure of clindamycin therapy
