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 18 Answers

nbme18/Block 2/Question#34 (reveal difficulty score)
25 yo woman, fatigue for 3 weeks
Greening reaction on blood agar ๐Ÿ” / ๐Ÿ“บ / ๐ŸŒณ / ๐Ÿ“–
tags:

 Login (or register) to see more


 +14  upvote downvote
submitted by โˆ—namira(39)

Mitral valve and teeth cleaning are key words for Strep viridans diagnosis. It is alpha hemolytic so it would have a greening reaction.

important mention to watch out for:

The optochin answer is incorrect because it says "inhibition BY optochin". Viridans is resistant to optochin so that answer is incorrect.

 Login (or register) to see more



 +3  upvote downvote
submitted by โˆ—laplace1(4)

"Viridans" literally means green

 Login (or register) to see more



 +1  upvote downvote
submitted by โˆ—namira(39)

Mitral valve and teeth cleaning are key words for Strep viridans diagnosis. It is alpha hemolytic so it would have a greening reaction.

important mention to watch out for:

The optochin answer is incorrect because it says "inhibition BY optochin". Viridans is resistant to optochin so that answer is incorrect.

 Login (or register) to see more



 -23  upvote downvote
submitted by โˆ—famylife(110)

This is strep pneumo, which has alpha hemolysis (green)

 Login (or register) to see more
breis  How is this differentiated from Strep Virdans which is Optochin Resistant? Because Strep Pneumo would also be inhibited by optochin* +2
mjmejora  its strep viridans. Strep viridans has a "protected chin mask" and strep pneumo is "exposed" in the sketchy. +8
rthavranek  Once again, another example of me knowing the concept but not knowing the obscure pseudonyms for common knowledge so I get the question wrong +1
dtransistor  I saw green and immediately thought of pseudomonas and crossed that answer out. Didn't know they were talking about alpha hemolysis! +



Must-See Comments from nbme18

feliperamirez on He is medically qualified to drive
anechakfspb on Tubular atrophy
aneurysmclip on Endothelial nitric oxide synthase production
azibird on 24,25-Dihydroxycholecalciferol
famylife on Increased transcription of HMG-CoA reductase
match95 on Plasmid loss
apurva on Antineoplastic
cbreland on Basement Membranes
match95 on Proximal tubule: isotonic; Macula densa: ...
sugaplum on Abnormal migration of endoderm from the ...
amirmullick3 on Myelofibrosis
merpaperple on Primary spermatocyte
wishmewell on Alpha-synuclein
namira on Greening reaction on blood agar

search for anything NEW!