When comparing the number of contributions for the proceedings of the third symposium on The Influence of Antibiotics on the Host-Parasite Relationship with those of its two predecessors, one becomes aware of the progress that has been made in this field. It is obvious that the design of experiments has substantially refined and therefore the clinical relevance of the results has gained in significance. The editors of this volume would like to thank all the colleagues who contributed to this book. It is hoped that interest in this field will develop further and that it will finally yield results which one day may be the basis for an improvement of antibiotic therapy. Bochum WOLFGANG OPFERKUCH Contents Opening Remarks P. G. Quie .... Interactions Between Antibiotics, Phagocytes, and Bacteria W. L. Hand, N. L. King-Thompson, T. H. Steinberg, and D. L. Hand. With 2 Figures and 5 Tables . . . . . . .. 4 Influence of Antibiotics on the Cell Surface of Escherichia coli H. Leying, S. Suerbaum, H.-P. Kroll, J. Gmeiner, and W. Opferkuch. With 2 Figures and 3 Tables . . . . . 17 Pseudomonas aeruginosa: Alterations Induced by Low Concentrations of 4-Quinolones M. T. Labro, A. Bryskier, C. Babin-Chevaye, and J. Hakim.

The Second International Symposium on "The Influence of Antibiotics on the Host Parasite Relationship" was held in Munich, F. R. G. , from March 28 to 30,1985. The topics of the meeting dealt with the aspects of changes in bacterial metabolism and structure which occur under the influence of antibiotics, and with the effects of such changes on the antibacterial host resistance. The influence on pathogenicity factors, changes in the outer membrane of bacteria, as well as the influence on the individual components of the defence system were analysed in detail. In addition, these studies showed that antibiotics proved to be an excellent tool for the examination of bacterial physiology, so that, 50 years after the introduction of antibiotics, additional important knowledge can be gained about the effect of these substances on bacteria. Considering the observations reported, it appears justifiable to postulate that new antibiotics should be routinely tested with respect to their possible effects on antiinfectious resistance. Of course, a consensus will have to be found on which to base methods and criteria employEUROd. The symposium documented an increasing interest of microbiologists and clini cians for this field of research. It would not have been possible to organize it without the substantial support of the Paul Ehrlich Society as well as of Squibb-Von Heyden Pharma, Inc. Particular help concerning the organization has been given by Werner Kremer of Squibb-Von Heyden Pharma.

When discussing the drug, the bug, and the host in the past, emphasis was laid mainly upon the interaction between antibiotics and bacteria or the reaction of the host to the invading organism. Today, however, standardized immunologic parameters are available for evaluating cellular and humoral responses and an increasing number of publications deal with the host reaction to the antibiotics administered. Some re searchers and clinicians felt that the time had come to bring together investigators studying the influence of antibiotics on the host-parasite relationship. The first section of this book therefore covers the influence of chemotherapy on the host defense system. Here antibody production and cellular immunity, the influence of antibiotics on the function of phagocytic cells, and immunostimulation combined with antibiotics in the treatment of infection are presented. The second section deals with the influence of antibiotics on the produc tion of extracellular and cellular virulence factors by bacteria, the adherence of bacteria being of utmost importance here. In addition, phagocytosis and serum bactericidal activity are discussed. In Prof. Opferkuch and Prof. Hahn I found two colleagues keen and knowledgeable enough to organize the First International Meeting on the Influence of Antibiotics on the Host-Parasite-Relationship. These proceedings of the meeting constitute a survey of the latest develop ments in this field, and should be of interest to clinical and researchers. Bielefeld, September 1982 Hans-Udo Eickenberg Berlin Helmut Hahn Bochum Wolfgang Opferkuch Contents Introduction H. -U."