An emerging theme in molecular and cellular microbiology has been the ability of many pathogens to usurp the host cell and eventually colonize the host. This interaction between bacteria and host is not unidirectional - both pathogens and host cells engage in a signalling cross-talk. Research focused on this cross-talk and discussed in this volume, reveals not only novel aspects of bacterial pathogenesis, but also key information about epithelial biology with broader implications in the prevention and treatment of infectious diseases. Written by leading researchers in this field, this book provides a valuable overview of the host-bacterial interactions that occur at mucosal surfaces including the gastrointestinal, respiratory, and urogenital tracts. It will therefore be a valuable resource for graduate students and researchers working on these systems or in the fields of molecular and cellular microbiology or infectious disease medicine.