Influence of antibiotics on host-parasite interactions with an emphasis on in-vivo studies

There has been considerable recent interest in the nature and importance of interactions which occur between antibiotics, microorganisms and the various cellular and humoral components of the host. The influence of antibiotics on host defense mechanisms is important because of the increasing number of compromised hosts in whom even a marginal influence on the host response may have a significant effect of the outcome. The influence of antibiotics on host/bacterial interaction reveals subtle effects on the ultrastructure of the bacterial cell, the biosynthesis of various virulence factors, the ability of microorganisms to adhere to epithelial cells and the function of polymorphonuclear leukocytes and the immune-specific response of mononuclear cells. These effects permit the proposal that at least some of the subtle effects of antibiotics on microbial pathogenicity might take place in vivo. If antibiotics can be shown definitely to enhance host-defense mechanisms, especially in compromised hosts, then more effective antibiotic therapy can be provided for these indications. Finally if antibiotics can modify the outcome of host-parasite interactions then perhaps we need to consider testing antibiotics against these parameters.