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Author Topic: Proposal of novel test and method for antibiotic resistance detection  (Read 3057 times)

Offline marec

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I observed that in case of treatment patient with betalactam antibiotics (e.g. penicillin, amoxicillin etc.) infection caused by bacteria resistant to them, the given antibiotic usually is not present in patientís urine (usually 70-80% of the given antibiotic dose is eliminated by kidneys).

I think that it may be caused by the mechanism of resistance to betalactam antibiotic, which rely on the production of betalactamases, which destroys given antibiotic. 

I think that it would be possible to develop fast and cheap test (method?) for evaluation of antibiotic resistance based on the detection of the given antibiotic in urine. Antibiotics might be detected e.g. by immunoenzymatic strip tests.  In case of bacterial resistance antibiotic is not detected/not present in urine.

What is your opinion about such an idea? Is there any chance to develop it? Or there is only a wishful thinking?

I am sorry for some of the inappropriate phrases, I am a family doctor not a microbiologist.
Thank you in advance for your help.


 

Offline lancenti

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I'm fascinated by this and probably it is possible but there are a few things I'm not sure of.

I understand that the β-Lactam ring is easily hydrolyzed under both acidic and basic conditions. Also, after hydrolysis they don't form any particularly reactive product. β-Lactamases also end up unchanged at the end of the hydrolysis so we'll have to modify the structures to lead to a permanent change, or find some novel thing which does react with the β-Lactam ring to effect some visible change.
 

Offline marec

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Thank you for your opinion, your point of view is very valuable I appreciate it.

it is very difficult for me to answer for that question, because, as I know - or as I can imagine, there are different betalactmases which destroys (break it) betalactam ring in different places or in different ways, I do not know what is done with these metabolites (I may only imagine that these simple compounds are excreted in urine or metabolised).
Unfortunately I observed this phenomenon in my clinical activity and I did not conducted regular investigations so I do not able to tell what is the threshold for antibiotic concentration, how frequency of administration, type of antibiotic, type of infection (e.g. limited or general infection etc.) type of bacteria (G+ or G-) influences the destruction - disturbances in betalactam concentration, I observed only that betalactams are not present in urine in case of infection with bacteria resistant to them, 
I know that there are also other mechanisms of resistance e.g. efflux pomp, lack of cell wall, genomic mutations
thank you once again   


I understand that the β-Lactam ring is easily hydrolyzed under both acidic and basic conditions. Also, after hydrolysis they don't form any particularly reactive product. β-Lactamases also end up unchanged at the end of the hydrolysis so we'll have to modify the structures to lead to a permanent change, or find some novel thing which does react with the β-Lactam ring to effect some visible change
 

Offline Bored chemist

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I think some bacteria become resistant to penicilin by ignoring the stuff rather than hydrolysing it. If that's true then this proposed test wouldn't work in that case.
 

Offline marec

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The main mechanism (~90%) of antibiotic resistance to betalaclam antibiotic is based on the production of betalatamases, other mechanisms "ignoring the stuff" compares: efflux pomp (very efficient mechanism of rejecting the antibiotic from bacteria), genomic mutation, or some bacteria do not have cell wall (e.g. some of them causes pneumonia), so antibiotic can not destroy it
 

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