Bladder surface mucin. Examination of possible mechanisms for its antibacterial effect.

We have previusly provided physiologic and histochemical data implicating the bladder surface mucin layer as an important new antibacterial defense mechanism. This mucin or its contents seems to act as an "antiadherence factor", inhibiting bacterial adherence to the bladder mucosa and thereby facilitating the removal of bacteria by the voiding process. The present study was designed to investigate three mechanisms by which the mucin might repel bacterial attachment. Our data suggest that neither IgA nor a chelating agent are anti-adherence factors. We did find, however, that pH had a significant effect on the adherence of bacteria to mucosal cells stripped of their mucin layer. This result suggest that electrochemical charge is important in bacterial adherence. We beleive that the mucin layer both provides an electrochemical coat on the bladder surface that is a poor substrate for bacterial adherence and blocks the receptor sites of the transitional cells to which the microbes might adhere.