ANTIBIOTIC PRESSURE AND RESISTANCE SELECTION IN THE HOSPITAL ENVIRONMENT

A worldwide problem : The development of bacterial resistance to antib iotics is a worldwide problem. The hospital environment is favorable t o the spread of resistance. The role of overuse or misuse of antibioti cs and several factors leading to the emergence and spread of resistan ce genes must be analyzed in order to better understand the phenomenon described as << Selective pressure of antibiotics >>. Recognized mech anisms : The concept of selective pressure of antibiotics is not new, it was recognized early that antibiotics favored the selection of resi stant clones among a susceptible population. The underlying mechanisms are better understood today. A full session was devoted to this topic at the CIPI meeting in May 1998. The aims of the presentations as rep orted in this series of articles were as followed : i) in vitro and in vivo methods for evaluation of resistance selection; ii) mechanisms o f resistance among quinolones; iii) risk factors in the hospital envir onment that contribute to spread of resistant strains and measures for control of dissemination of resistant bacteria;iv) the role of fecal flora in selection of resistant strains and, as an example, the impact of beta-lactams in selective pressure in the gut flora. Fight against multiresistance : The second part of this series of discussions on an tibiotic selective pressure is devoted to several examples which illus trate some current problems of multiresistance and strategies of contr ol and prevention. Several approaches to fight against bacterial multi resistance are discussed.