Severe Infections in Adults Caused by Mouse-Virulent Strains ofEscherichia coli

THIS report concerns 3 cases of Escherichia coli infection in adults in which the organisms appeared to have excessive virulence not only for the patients but also experimentally for mice. Many observers have noted that certain strains of Esch. coli are associated with epidemic diarrhea in children.1 2 3 4 5 These have been labeled "enteropathogenic" organisms, and serotypes have been established.6 The strains that caused the infections described below not only did not belong to any of the known serotypes but also appeared to have significantly greater virulence for mice than the so-called enteropathogenic strains. Furthermore, they caused generalized systemic disease in adults, . . .