Experimental infection of native human ureteral tissue with Neisseria gonorrhoeae: adhesion, invasion, intracellular fate, exocytosis, and passage through a stratified epithelium

Abstract

The exact mechanisms by which Neisseria gonorrhoeae invades the mucosal lining to cause local and disseminated infections are still not fully understood. The ability of gonococci to infect the human ureter and the mechanism of gonococcal infection in a stratified epithelium were investigated by using distal ureters excised from healthy adult kidney donors. In morphological terms, this tissue closely resembles parts of the urethral proximal epithelium, a site of natural gonococcal infection. Using piliated and nonpiliated variants of N. gonorrhoeae MS11, we demonstrated the importance of pili in the attachment of gonococci to native epithelial cells as well as their association with epithelial damage. By electron microscopy we elucidated the different mechanisms of colonization and invasion of a stratified epithelium, including adherence to surface cells, invasion and eventual release from infected cells, disintegration of intercellular connections followed by paracellular tissue infiltration, invasion of deeper cells, and initiation of cellular destruction and exfoliation resulting in thinning of the mucosa.