SERUM BACTERICIDAL RATE - METHODOLOGICAL PROPOSAL TO PREDICT THE EFFICACY OF ANTIMICROBIAL THERAPY

Several in vitro techniques have been developed, which are able to qua ntify the bactericidal activity of a determined antibacterial drug aga inst an infective agent. The Serum Bactericidal Rate (SBR) is proposed as a complementary technique for the determination of the <<killing c urve>>, the serum bactericidal test or the minimal bactericidal concen tration. SBR takes into account the most advantageous features of both of them. SBR is based on quantifying at different times the survival of the bacterial inoculum exposed to the patient's serum. Thus, bacter icide speed is evaluated in the first hours of contact with the microo rganism (as in the <<killing curve>>), but taking into account drug co ncentrations which have been reached by the patient (as in the serum b actericidal test). Preliminary assays suggest that SBR may have greate r capacity to discriminate an infectious agent in answer to different therapeutic schemes than other determinations, although prospective st udies are required to evaluate its predictive value.