PROBLEM TO BE SOLVED : To provide an isolated antibody that specifically binds to O25b antigen of multi-drug resistant E. coli strains. SOLUTION : The invention provides : an isolated antibody that specifically binds to O25b antigen of multi-drug resistant (MDR) E. coli strains; plasmids or expression cassettes comprising nucleotide sequences encoding the antibody; host cells including the plasmids or expression cassettes; an isolated epitope recognized by the antibody; methods of identifying and preparing the antibody; and a medical or diagnostic preparation of the antibody. SELECTED DRAWING : Figure 6 COPYRIGHT : (C)2019, JPO&INPIT