TY - JOUR T1 - Antimicrobial resistance: increasing concerns JF - British Journal of General Practice JO - Br J Gen Pract SP - 772 LP - 774 VL - 57 IS - 543 AU - Richard Wise Y1 - 2007/10/01 UR - http://bjgp.org/content/57/543/772.abstract N2 - Were Charles Darwin alive today he would rapidly understand many of the issues surrounding antimicrobial resistance. They represent ‘survival of the fittest’ at their most dynamic. Darwin drew upon examples from the Galapagos (finches and tortoises), as well as fossil records, and realised that evolution had occurred over millennia (at the least). This brought him into conflict with conservative elements in the church (with the argument still rumbling on today in the Creationist versus Evolutionist debate).In the interaction between pathogen and antimicrobial, evolution occurs over a very short period of time. As is well known, remarkably soon after the introduction of penicillin, staphylococcal resistance was reported and now resistance rates exceed 90% in Staphylococcus aureus. Similarly, staphylococcal resistance to the fluoroquinolones was reported during the pre-marketing clinical trials1 and has continued to rise.The reasons for this telescoping of time are not difficult to understand. The selection of a genetic characteristic depends upon the interplay of a number of variables. While the Galapagos tortoises were relatively few, vast numbers of bacteria are in the gastrointestinal tract and on the skin, say 1011 or 1012. Secondly, many bacteria can reproduce, double in number in 20 minutes, although the tortoise generates only few offspring in a long life. Finally, bacteria have a variety of means of passing genetic information to future generations in addition to simple division; these include conjugation (where bacteria exchange DNA via contact), bacteriophage transduction, and the direct uptake of DNA (transformation). Only the sexual method is available to tortoises. Add to this a very potent selection pressure, an antimicrobial, and resistance will readily emerge in bacteria.For example, it is possible to select for fluoroquinolone resistance in vitro by overnight exposure of a Staphylococcus or Escherichia coli to the compound. These laboratory … ER -