The classical surface antigens of Enterobacteriaceae: 0, K, and H antigens have been studied extensively in the past and have provided a basis for the taxonomy of this family (Kauffmann, 1966, 1975). In comparison to the vast knowledge accumulated on the structure, localization, genetic determination, and biologic effects of O and K antigens (Weinbaum et al., 1971; Orskov et al., 1977), the precise knowledge of antigens shared by various microorganisms is small. This is most probably due to the fact that the“... direction of research in the past has to a great deal been stimulated by problems and questions of taxonomy, etiology of diseases and epidemiology” (Neter and Whang, 1972).