Tuesday, June 22, 2010

What is antibiotic resistance , how antibiotic resistance is developed , How antibiotic resistance is counteracted

What is antibiotic resistance , how antibiotic resistance is developed , How antibiotic resistance is counteracted
Antibiotics are substances which are produced by microorganisms , and are able to kill or stop growth of microorganisms completely , when they are present in minute concentrations, antibiotics posses very complex stereo chemical structures which are highly susceptible for degradation or alteration by numerous factors like enzymatic actions or effluxing out or removing out absorbed antibiotic from microbial cell , resulting in to nullification of microbicidal or microbiostatic actions of these antibiotics.
Enzymes or efflux pumps which brings about degradation or alteration or exclusion or removal of an antibiotic are mostly induced in to microbial or bacterial metabolic systems once these microbes come in contact with these antibiotic substances, this is one of the protective mechanism of microorganisms. These microorganisms then develop a resistance for a particular antibiotic with which these microorganisms were in contact , thus an antibiotic become little or less or inactive against these microorganisms.

Efflux Pumps in microorganisms:
This in an protective systems works with numerous feedback mechanisms of microorganisms, it can be defined simply as removing out any toxic substance out of microbial cell , this is a proteinaceous transport system of microorganisms , these proteins tag to a toxic substance in bacterial cell, here it is an antibiotic and remove them out of bacterial cell through active transport , which involves supplementation of energy through break down of ATP (Adenosine triphosphate ) molecule.

Numerous drugs do develop drug resistance due to the phenomenon listed above.
How antibiotic resistance is counteracted
So far there is not a single drug is available which has proved to be effective in clinical trials that it can prove to be effective as efflux modifier , and help antibiotic to cary out the desired action.

There are some enzyme inhibitors currently in use which are listed below

Beta-lactamase inhibitors:
Are the class of drugs which are given in conjugation with beta-lactam antibiotics.
These molecules do not have any antibiotic activity but they enhance the antimicrobial activity of beta-lactam antibiotics .
It is considered that beta-lactam antibiotics like penicillins and cephalosporins develop resistance as some microorganisms produce an enzyme beta-lactamase which causes breakdown of this beta lactam ring in betalactum antibiotics this betalactum ring is a piculiar characteristic of betalactum antibiotics.

1.Clavulanic acid and its slt with potassium , potassium clavulanate is formulated along with amoxicillin.

2.Sulbactam is formulated with cefoperazone and ampicillin
sulbactum binds with betalactumase irreversibly there by protecting actual antibiotics from enzymatic degradation.
3.Tazobactam is also a beta-lactamase inhibitor it is formulated with piperacillin

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