A more green cons resistance

A more green cons resistance

The resistors are neither more nor less than one manifestation of the adaptation process governing the evolution of species: in a hostile environment, only those individuals best equipped genetically to survive and multiply. In the world of the infinitely small, the bacterial strains did not avow defeated in the war between them with antibiotics.

 
Genetic changes can allow certain bacterial strains to evade the action of antibiotics. A classic example is the emergence of a gene responsible for producing the enzyme beta-lactamase, which inactivates certain antibiotics such as penicillin. Staphylococcus aureus Nine out of ten have adopted this defensive weapon. Fortunately, we managed to synthesize inhibitors of beta-lactamase, to thwart this resistance. However, some bacteria were again adjusted also becoming resistant to these inhibitors. Bacteria and pharmacologists and lead a chase, which the bacteria seem to always eventually win out.

The resistance: a shared secret

The mechanisms of acquisition of new genes are well known. It is either to chromosomal mutations that alter genes already present, or the integration of small circular strands of DNA (plasmid), which are transmitted from bacteria to bacteria. This phenomenon can be broken into six steps:

1-The normal bacteria (yellow) and mutant (resistant here in red) are multiplying at a very high rate.
2 and 3-L'administration antibiotic destroys most of the normal bacteria, but the mutant bacteria resistant to attack.
4-No longer in competition with normal bacteria to grow, the mutant bacteria proliferate.
5-These resistant bacteria adjust their cell structure to become invulnerable to attack the same drug.
6-These "superbugs" can even share the secret of their resistance with other bacteria, allowing the development of new resistant bacterial colonies.

One of these new genes may give the bacteria resistance to a family of antibiotics. Many host and bacteria resistant, which does not grow, because they are very few compared to other bacteria, particularly in the gastrointestinal tract, and have what is called a "barrier effect" . But just as these people ingest an antibiotic for susceptible bacteria are killed, leaving the field open to resistant bacteria. The subsequent use of the same antibiotic will be useless. Moreover, the "secret of resistance" can be shared through integration into the cytoplasm of small circular strands of DNA (plasmid), which are transmitted from bacteria to bacteria.

Resistance to antibiotics and can be regarded as an environmental problem linked, at least in part, to improper prescriptions of antibiotics, essential drugs that save many lives, but are not without drawbacks.

 

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