The binding of Proteus mirabilis nonagglutinating fimbriae to ganglio-series asialoglycolipids and lactosyl ceramide

Proteus mirabilis is a common opportunistic Gram-negative uropathogen that infects the upper urinary tract. We have examined the role of the nonagglut inating fimbriae (NAF) of P. mirabilis in mediating bacterial adhesion to c ell surface receptors. Purified NAF of P. mirabilis were demonstrated to bi nd to a number of glycolipids, including asialo-GM1, asialo-GM2, and lactos yl ceramide (LacCer) in solid-phase binding assays and in thin layer chroma tography (TLC) overlay assays. Furthermore, preincubation of the biotinylat ed NAF (Bt-NAF) with anti-NAF monoclonal antibodies resulted in inhibition of NAF binding to immobilized asialo-GM1, asialo-GM2, and LacCer. In adhere nce assays, P. mirabilis binding to Madin-Darby canine kidney (MDCK) cells was inhibited by murine anti-asialo-GM1 monoclonal antibodies H2G10 to abou t 50% of the binding level in the absence of the antibody, specific for the terminal beta-galactopyranosyl residue of asialo-GM1 (Harrison et al. 1998 ). The results of this study suggest that NAF of P. mirabilis recognize a G alNAc beta 1-4Gal moiety present in the ganglio-series of asialoglycolipids , and that the terminal beta-galactopyranosyl -containing glycoconjugates p lay a role in NAF-mediated adherence of P. mirabilis to MDCK cells. Similar ly to other bacteria, P. mirabilis NAF was also shown to express the LacCer specificity.