MICROBIOLOGICAL CRITERIA FOR THE CHOICE O F AN AGENT FOR ANTIBIOTIC-PROPHYLAXIS

The choice of an antibiotic for antimicrobial prophylaxis is based on microbiological, pharmacokinetic, chemical and pharmacodynamic paramet ers. The knowledge of the bacterial flora allows the identification of bacteria which could be responsible for postsurgical infections. Thes e floras are complex and their equilibrium can be modified by various factors, such as hospitalization, co-existing disease, medico-surgical procedure, administration of antibiotics, which cause the selection o f the so-called hospital-bacteria feared by therapists. The infection will develop according to the quantity of bacteria that have been intr oduced and to their virulence, which is often altered by local factors , especially the biomaterials. The knowledge of pharmacodynamic parame ters such as bactericidal activity, postantibiotic effect, activity on virulence factors (bacterial adhesion), allows the refinement of the choice of the antibiotic and the optimization of its posology.