Principles of Bacterial Adhesion

Abstract

Certain fundamental aspects of bacterial adhesion have been known for years (reviewed in Marshall, 1976; Ellwood et al., 1979; Beachey, 1980a, b; Berkeley et al., 1980; Bitton and Marshall, 1980; Beachey et al., 1982; Schlessinger, 1982; Jones and Isaacson, 1984; Marshall, 1984; Mergenhagen and Rosan, 1985; Savage and Fletcher, 1985; Lark et al., 1986). More discussions on various fundamental aspects can also be found in other selected books (Boedeker, 1984; Mirelman, 1986; Switalski et al., 1989; Doyle and Rosenberg, 1990; Hook and Switalski, 1992). During the first decade of intense research on the adhesion of microorganisms to various substrata a number of points had become clear. One, there is little doubt that the survival of microorganisms in various niches is dependent on their ability to adhere to surfaces or substrata. Second, the adhesion process involves an interaction between complementary molecules on the respective surfaces of the microbe and the substratum. Third, the expression by the organisms of the macromolecules that participate in the adhesion process is under a number of regulatory control mechanisms. During the second decade of research most of the efforts have been focused on molecular mechanisms (fine specificity and genetic control) and consequences of the adhesion phenomenon, with the premise that the process of microbial adhesion may be specifically manipulated. In this first chapter the fundamental principles that have emerged from studies performed during the last two decades are reviewed, with an emphasis on how bacteria adhere to biological substrata, the importance of adhesion in infectious processes, and the basic genetic and phenotypic variables affecting adhesion. A summary of common terms that are now widely used and have become prominent in the concepts developed in the study of bacterial adhesion is given in Table 1-1. The chapters that follow provide more in-depth discussion of the molecular nature of adhesins and their receptors. In addition, thorough reviews of the genetic regulation of adhesins are presented, along with an appraisal of the biological significance of the adhesion process. Finally, recent advances on adhesion of the most widely studied pathogens are provided.