prev next front |1 |2 |3 |4 |5 |6 |7 |8 |9 |10 |11 |12 |13 |14 |15 |16 |17 |18 |19 |20 |21 |22 |23 |24 |25 |26 |27 |28 |29 |30 |31 |32 |33 |34 |35 |36 |37 |38 |review

http://www.sciam.com/1998/0398issue/0398levybox2.html

Click for large picture

Let’s review the basic science of resistance briefly.
 
How does resistance develop?  It is genetic.  Resistance genes certainly occur naturally.  (The definition of an antibiotic is a naturally produced substance which and antimicrobial activity).  There are three basic mechanisms by which resistance genes work:
1.  They encode for enzymes that degrade the antibiotic,
2.  They encode for changes in the site of action, or
3.  They encode for molecular mechanisms to prevent entry or speed exit of the antibiotic from the cell