STUDIES ON THE SOLUBLE ANTIGENS O F

THE present method of typing Clostridium oedematiens is based on the various permutations of soluble antigens produced by different biotypes of the organism (Oakley, Warrack and Clarke, 1947; Oakley and Warrack, 1959). Oakley and his colleagues suggested that in-vitro neutralisation of the lecithovitellin reaction by specific CZ. oedematiens antisera provides an adequate practical basis for the differentiation of the species into four types. The term " lecithovitellin (LV) reaction " denotes the production of turbidity in extracts of egg-yolk emulsion after incubation with various agents; bacterial lecithinases (phospho-lipases) are frequently involved in the LV reaction and the soluble /3- and y-antigens of CZ. oedematiens have been characterised as haemolytic lecithinase-C enzymes (Macfarlane, 1948, 1950). Oakley et al. stated that the LV test can be performed in tubes with concentrated culture products of Cl. oedematiens or by a simultaneous culture and neutralisation procedure on egg-yolk agar plates. In practice it is found that strains of types B, C and D do not grow readily as surface cultures on agar media (Smith, 1955, p. 38; Willis and Hobbs