M040: O-antigen localization with immunoelectron microscopy
in P. aeruginosa isolates from patients with cystic fibrosis using
polyclonal versus monoclonal antibodies.
A.M. Horrevorts1, G. Pool3, H. van Lee3, J.W. Mouton2, J.F.G.M.
Meis3. Dept. of Clinical Microbiology Juliana1 (The Hague) and
Sophia2 Children (Rotterdam) Hospital, University Hospital Niimegen3,
The Netherlands.
Six P. aeruginosa isolates from 6 patients with CF and five ATCC P. aeruginosa strains were each embedded in LR-White, sectioned and used for immunolabelling. O-antigens were localized by immunogold electron microscopy using a) specific rabbit polyclonal anti bodies (Difco) followed by goat-anti-rabbit gold labelling and b) monoclonal antibodies (Meiji) followed by goat-anti-mouse gold labelling. ATCC strains were used to control the specificity of the O-antisera. The results are summarized in the table.
P. aer. strain A:polyclonal ab B:monoclonal ab 128 CF 6 G, M 295 CF 6, 9 G, M 380 CF 3, 9 D, M 726 CF 3, 9, 14 D, M 591 CF 1 I, M 598 CF NT F, M ATCC 33348 1 I ATCC 33350 3 A ATCC 33351 4 F ATCC 33353 6 G ATCC 33356 9 D
Many P. aeruginosa isolates from patients with CF lack O specific side chains in their LPS. Thus core components in the OM can react with anti-core ab in polyclonal O typing sera leading to "polyagglutinability". Mlonoclonal ab M is directed against core LPS. None of the ATCC strains reacted with anti M in contrast to all CF isolates, suggesting that core components are exposed even in monoagglutinating CF isolates.