4.2 Interaction of Bacteria and their Products with Tissues in Organ Culture

Publisher Summary This chapter discusses the interaction of bacteria and their products with tissues in organ culture. Bacterial interactions with mucosal surfaces are thought to be critical in the pathogenesis of infectious disease. In order to colonize a mucosal surface the potential pathogen must overcome local defenses, which might include physical barriers, antibacterial substances, and resident phagocytes. Bacterial products also facilitate the colonization process by compromising mucosal defenses. Bacterial adherence involves specific interactions between structures on the bacterial surface and receptors on the mucosa, although non-specific interactions between bacteria and host cells involving charge and hydrophobicity are also likely. Further, the chapter explains the advantages of organ cultures. Organ cultures maintain the three-dimensional arrangement of folds and grooves present on some epithelial surfaces in vivo and possess a population of leukocytes, which may be important during bacterial infection, although the longevity of this cell population is limited. Organ cultures are sufficiently sensitive to discriminate between the interactions of closely related bacterial strains and hence provide a powerful tool for investigating the effects of bacterial toxins or the importance of bacterial surface structures. The number of bacteria infecting an organ culture can be estimated by culturing homogenates of tissue on agar or by radioisotope techniques. Organ cultures provide a useful method for examining complex bacterial interactions with mucosal surfaces under controlled conditions.