Clostridium oedematiens antitoxin: the correlation between anti-lethal and anti-edematizing activities.

To re-evaluate the current potency tests of C. oedematiens anti-toxin that titrates only the anti-lethal activity in mice, investigations were made on neutralization of the lethal, edematizing, and hemolytic activities with different preparations of the antitoxin and on their therapeutic effects. The anti-lethal and anti-edematizing potencies of antitoxins prepared by hyperimmunization with each of crude and purified antigens were the same when titrated with either crude or purified lethal toxin as test toxin. The two antitoxins protected mice equally against the lethal and edematizing activities of crude toxin. The antitoxin prepared against highly purified hemolytic toxin contained neither anti-lethal nor anti-edematizing activity. We conclude that the lethal and edematizing activities of C. oedematiens. are borne by the same molecule and that the therapeutic effect of the antitoxin may depend entirely on the anti-lethal (or anti-edematizing) activity. The method currently used for titrating C. oedematiens antitoxin, therefore, appears to be valid.