The prohost effect of antimicrobial agents as a predictor of clinical outcome.

Apart from their direct antimicrobial activity, some antimicrobial agents may interfere in the complex host-microorganism interplay by modulating the natural response to invading pathogens. The three main aspects of this non-antibiotic effect (alteration of bacterial virulence, synergism with/impairment of the natural host response, impact on effector cell progenitors) will be briefly reviewed here, along with their potential incidence in the clinical outcome of infectious diseases.