NS FL 9 BB Q 1

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mgarc805
Posts: 35
Joined: Tue Jun 25, 2019 11:23 am

NS FL 9 BB Q 1

Post by mgarc805 » Thu Aug 08, 2019 2:05 pm

Administration of S. aureus-specific antibiotics to patients in shock is meant to:

A. strengthen the mucosal barrier of the tissue.


B. decrease the translation of SEB.


C. neutralize SEB.


D. prevent binding of SEB to TcR.

I understand that antibiotics work by killing the bacteria. right off the bat A is out because the muscosal it not the bacteria. D is also out because " The antibiotic is meant to kill bacteria, not stop the binding of SEB to T cell receptors." that makes perfect sense. Now, decreased translation and neutralization of SEB both imply that the antibiotic is not trying to kill the bacteria but rather mess up some sort of bacterial machinery that would prevent the infection. Decreased translation of SEB will still lead to some protein production which is a minimal infection but not a cure. Thought, Neutralizing SEB which can still be done within the bacteria seems like will prevent any SEB from acting on the mucosa.
NS_Tutor_Mathias
Posts: 282
Joined: Sat Mar 30, 2019 8:39 pm

Re: NS FL 9 BB Q 1

Post by NS_Tutor_Mathias » Thu Aug 08, 2019 3:31 pm

You are absolutely correct, an imaginary, unspecified antibiotic can only be said to be "killing" bacteria. In reality they usually inhibit cell wall formation, inhibit ribosomal function or otherwise throw a wrench in cellular machinery that is exclusive to prokaryotes. This is exactly what makes them so effective as a drug taken by humans, as we differ significantly in key pieces of cellular machinery such as the structure of our ribosomes and the absence of cell walls. The key to an effective antibioitic is after all something that disrupts bacterial proliferation with the least possible detrimental effect to the patient.

While that microbiology background may be useful, I believe you made the correct inference: Antibiotics, as the name suggests, lead to the death of bacteria.

What you wanted to realize from here is that this precludes other methods of action - neutralizing the exotoxin alone would do nothing to stop the proliferation of bacteria itself, so it would by definition not be an antiobiotic (it may be a treatment for S. aureus infected patients in shock, but it would not be an antibiotic)


Cell death in turn leads to less translation. This is irrefutably true. As an added bonus, many antibiotics do actually target ribosomal translation directly (such as streptomycin, clindamycin, chloramphenicol, tetracycline and many more). As you can imagine, inhibited translation leads to cell death and/or failure to proliferate.

I like the approach you took in reasoning this question out by first asking what an antibiotic does and what it does not do. You only needed to follow that line of reasoning to it's conclusion (killing cells would naturally stop translation) to arrive at the only viable answer choice here.
mgarc805
Posts: 35
Joined: Tue Jun 25, 2019 11:23 am

Re: NS FL 9 BB Q 1

Post by mgarc805 » Thu Aug 08, 2019 3:43 pm

Thank you for answering my question and I feel like you hit the nail in the head by saying that neutralizing the toxin will not prevent the bacteria from reproducing which eventually will lead to the bacteria being able to overcome the treatment. definitely focusing in destroying cell machinery is key here.
NS_Tutor_Mathias
Posts: 282
Joined: Sat Mar 30, 2019 8:39 pm

Re: NS FL 9 BB Q 1

Post by NS_Tutor_Mathias » Thu Aug 08, 2019 4:05 pm

mgarc805 wrote:
Thu Aug 08, 2019 3:43 pm
Thank you for answering my question and I feel like you hit the nail in the head by saying that neutralizing the toxin will not prevent the bacteria from reproducing which eventually will lead to the bacteria being able to overcome the treatment. definitely focusing in destroying cell machinery is key here.
The key point being your definition of antibiotic. Anti = against, biotic = living things. Any mechanism of action besides killing bacteria or stopping their proliferation directly is not an antibioitic. Whether it is a viable treatment (according to other information in the passage, it very well may be!) is irrelevant. What is relevant is that it is not an antibiotic, and the question only asks you to identify the action of any antibiotic.
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