need help with your account or subscription? click here to email us (or see the contact page)
join telegramNEW! discord
jump to exam page:
search for anything ⋅ score predictor (โ€œpredict me!โ€)

NBME 16 Answers

nbme16/Block 1/Question#43 (reveal difficulty score)
A 68-year-old woman is diagnosed with ...
Substitution of d-lactate for d-alanine in peptidoglycan ๐Ÿ” / ๐Ÿ“บ / ๐ŸŒณ / ๐Ÿ“–
tags:

 Login (or register) to see more


 +1  upvote downvote
submitted by โˆ—fruitkebabs(33)
get full access to all contentpick a username

Vancomycin binds to the terminal d-Ala, d-Ala of the peptide side chain of Peptidoglycan which is normally used to cross-link Peptidoglycan strands together. Since the d-Ala, d-Ala is not available to be crosslinked when it is bound by Vancomycin, the Peptidoglycan wall cannot be crosslinked properly, thus compromising its structural rigidity. Bacteria which switch the terminal d-Ala for a d-Lac are resistant to Vancomycin. Helpful Diagram on Wiki

FA2020, p190

get full access to all contentpick a username
chaosawaits  But isn't impaired influx/increased efflux also a common method of resistance for Vancomycin? So how do you know the answer is not also "upregulation of rapid efflux pump"? +



Must-See Comments from nbme16

zincy7 on Gastrin
bingcentipede on Cerebral edema
cassdawg on Kidney
medninja on Lysosomes
cassdawg on Sildenafil
cassdawg on Feces-contaminated soil
cassdawg on Peutz-Jeghers
cassdawg on Presence of an internal ribosome entry site
hungrybox on Induction of cytochrome P450 enzymes that ...
andro on Antagonizes VLDL-cholesterol secretion
bingcentipede on Decreased function of Na+โ€“K+ ATPase
bingcentipede on Glyceraldehyde-3-phosphate dehydrogenase
cassdawg on 46,XXY
bingcentipede on Grade 4/6, holosystolic murmur heard best ...

search for anything NEW!