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Discussion Starter · #1 ·
A organism resistant to ampicillin and cephalosporin but sensitive to pennicillin n sulbactum: mech of resistance production of beta lactamase
But a org resistant to ampicillin but sensitive to cephalosoprin den d mech of resistance shud be????
 

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Discussion Starter · #3 ·
yep i shud be...but it again gives d answer as production of beta lactamase. it is from nbme 15 n i answered PBP's vich was wrong. D offline answer key gives beta lactamase prod as answer...:rolleyes:
 

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Discussion Starter · #5 ·
It says young female with UTI..culture shows lactose fermenting and spot indole test positive. The organism is resistant to ampicillin but sensitive to ceftriaxone. Mech of resistance??
a. alteration of PBP
b. beta lactamase prod.
c. elaboration of new PBP
 

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anyone??? need help.
i just googled it' it says.. bacteria resistant to penicillin are relatively less resistant to cephlprin''
so' if if option a is wrong as u said ..may b its B ) same mechanism of resistance as it is to penicillin (yet less resistance) i duno i am just shooting in dark :/
 

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FA 2013 pg 178

A organism resistant to ampicillin and cephalosporin but sensitive to pennicillin n sulbactum: mech of resistance production of beta lactamase
But a org resistant to ampicillin but sensitive to cephalosoprin den d mech of resistance shud be????
While ampicillins are penicillinase sensitive, cephalosporins are resistant to penicillinase (b lactamase)
Wow i:)think i will have to eo those nbme offline too:rolleyes:
 

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Beta lactams resistance..

If I am thinking in the right way so we are talking about a g- bacterial infection lactose fermenter ... Mosly e. coli!!:notsure:
And when g neg gets the plasmid for betal lactemase encoding gene it would be resistance for both pecilline as well as the 3rd gen cephalosporins.. Because it will produce the enzyme to the periplasmic space in contrast to gram possitive which will produce an exoenzyme that would be effective in providing resistance against pencillin but not cephalosporins..
G neg get resistance to beta lactams either by alteration of their accumulation "change in outer membrane as occure with p. aerogenosa.. Or by mutant or new PBPs .. Either way it is a chromosomal mediated resistance mechanism..
Now it is a blocked end for me to choose between the new or mautant"ultered" PBP .... I WILL SAY NEW PBP:confused:
Anyone correct me and give the answer I'll be thankful:D
 

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It says young female with UTI..culture shows lactose fermenting and spot indole test positive. The organism is resistant to ampicillin but sensitive to ceftriaxone. Mech of resistance??
a. alteration of PBP
b. beta lactamase prod.
c. elaboration of new PBP
I just took NBME 15 and I had the same question.

A.Alteration of the existing PBP
D. Elaboration of a new PBP
E.beta lactamase production

My answer was A and it is not the correct answer. Do you know the correct answer?
Thanks :notsure::notsure::notsure::notsure:
 

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ampicilin resistance means that bacteria has b lactamase. however cephalosporins is more resistant beta lactamase produce by bacteria. as long as cephalosporins work than its not PBP mutation but beta lactamase mutation. so that is the answer.
 

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A organism resistant to ampicillin and cephalosporin but sensitive to pennicillin n sulbactum: mech of resistance production of beta lactamase
But a org resistant to ampicillin but sensitive to cephalosoprin den d mech of resistance shud be????
I think the answer would be change in porin structure if you are talking about a gram negative organism
 
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