Bacterial Adherence to Cell Surfaces and Extracellular Matrix

An essential step in the successful colonization and production of disease by microbial pathogens is their ability to adhere to host cell surfaces and the underlying extracellular matrix. The choice of host cell substrate that a pathogen can adhere to is large. The mammalian cell surface contains many proteins, glycoproteins, glycolipids, and other carbohydrates that could potentially serve as a receptor for an adhesin. Additionally, the extracellular matrix provides a rich source of glycoproteins for adhesins to bind to and even initiate signaling, and implanted devices remain a major target for bacterial adherence. Bordetella pertussis, the causative agent of whooping cough, is a respiratory mucosal pathogen that possesses several potential adherence factors that exemplify the complexity of bacterial adherence to host cell surfaces. N. gonorrhoeae and N. meningitidis are two mucosal pathogens that have developed sophisticated and overlapping mechanisms to adhere to host cell surfaces. Two high-molecular-weight adhesins (HMW1 and HMW2) belong to the autotransporter family and mediate bacterial adherence. Adhesins play an important role in disease and represent the interface between the pathogen and the host cell. In many cases the precise role that individual adhesins play in the pathogenesis of specific diseases has been established. For example, inactivation of the gene which encodes Cna, a collagen-binding adhesin of S. aureus, results in a mutant with a considerably diminished capacity to cause septic arthritis in an animal model.