Compounds which bind to toxins associated with enteric bacterial infection, compositions including the compounds, methods for the neutralization of toxins in a patient, and methods for the diagnosis of bacterial and viral infections are disclosed. Toxins which can be bound by the compounds include pentameric toxins, for example SLTs, such as those from salmonella, camylobacter and other bacteria, verotoxins from E. coli, cholera toxin, clostridium difficile toxins A and B, bacterial pili from enteropathogenic E. coli (EPEC) and enterotoxigenic E. coli (ETEC) and viral lectins such as viral hemagglutinins. The compounds include a core molecule bound to a plurality of linker arms, which in turn are bound to a plurality of bridging moieties, which in turn are bound to at least one, and preferably, two or more ligands which bind to the toxin. The presence of a plurality of bridged dimers of the ligands is responsible for the increased binding affinity of the compounds relative to the ligands themselves. In one embodiment, the compounds, when administered in a timely fashion to a patient suffering from enteric E. coli infection, inhibit progression of this infection into hemolytic uremic syndrome (HUS).