In vitro detection of Shiga toxin using porcine alveolar macrophages

Porcine alveolar macrophages were found to be highly susceptible to the cyt olytic effects of a toxin (Shiga toxin [Stx]) produced by certain strains o f Escherichia coli and sometimes associated with clinical disease in pigs a nd other animals. In comparison with the cells that are most commonly used for Stx detection and titration in vitro (namely, Vero cells), porcine alve olar macrophages appeared to be generally more sensitive and test results c ould be obtained in less time. Moreover, unlike Vero cells, porcine alveola r macrophages need not be continuously propagated to ensure immediate avail ability. They can simply be removed from a low-temperature repository, thaw ed, seeded, and shortly thereafter exposed to the sample in question. These characteristics suggest that porcine alveolar macrophages may be useful in developing a highly sensitive and timely diagnostic test for Stx.