Invasion of human fallopian tube epithelium by Escherichia coli expressing combinations of a gonococcal porin, opacity-associated protein, and chimeric lipo-oligosaccharide

The transepithelial migration of Escherichia coli that expressed all possible combinations of a plasmid-encoded gonococcal porin (Por), opacity-associated protein (Opa), and 3F11 lipooligosaccharide (LOS) epitope was investigated. Surface expression of Por mediated selective changes in E. coli antibiotic susceptibility, and coexpression of Opa and the 3F11 LOS epitope mediated bacterial clumping (P<.01). In the human fallopian tube organ-culture model, Opa-producing variants attached up to 44-fold better than control bacteria (P<.01), and Por-producing variants exceeded submucosal invasion of control bacteria by 500-fold (P<.01). Opa and Por each facilitated intracellular invasion 20-40-fold (P<.01). In dual expresser variants, the 3F11 LOS epitope markedly reduced attachment and invasion mediated by Opa or Por. The LOS inhibitory effect was curbed when all 3 factors were expressed, which suggests an additional interaction of the 3 factors at the bacterial surface. Por, Opa, and LOS play important roles in Neisseria gonorrhoeae trafficking across human fallopian tube epithelium.