Scanning and transmission electron microscopy of bacterial attachment to mucosal surfaces with particular reference to the human fallopian tube.

Neisseria gonorrhoeae and Chlamydia trachomatis are the common bacteria isolated from bacterial cervicitis and are the leading etiological agents for pelvic inflammatory disease. Neisseria gonorrhoeae cause infection of the mucosa of fallopian tubes in organ culture by attaching to microvilli of nonciliated cells, phagocytosis by these cells, transport across and exocytosis from the epithelial cells. In contrast the Chlamydia attach to the epithelial surface without apparent ligand binding and are taken into the cytoplasm of the epithelial cell. Exocytosis of Chlamydia is into the tubal lumen and not into the subepithelial spaces. The ciliated epithelial cells of the fallopian tube are damaged by a gonococcal toxin but chlamydia do not exhibit such activity. These observations suggest that the mechanism of attachment to and invasion of the mucosal epithelium by gonococci and chlamydia are quite different and their potential for disease production occurs by different methods.