On the identity of the toxins produced by serologically different strains of Bacillus diphtheriæ / by Percival Hartley.

  • Hartley, Percival Horton-Smith, Sir, 1867-
Date:
[1923?]
Catalogue details

Licence: In copyright

Credit: On the identity of the toxins produced by serologically different strains of Bacillus diphtheriæ / by Percival Hartley. Source: Wellcome Collection.

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    ON THE IDENTITY OF THE TOXINS PRODUCED BY SEROLOGICALLY DIFFERENT STRAINS OF BACILLUS DIPHTHERIAS. By PERCIVAL HARTLEY, M.C., D.Sc. Lond. {From the Wellcome Physiological Research Laboratories.) Havens (1920) examined 206 strains of the diph¬ theria bacillus by means of a monovalent agglutinating serum and found that 169 strains (82 per cent.) were agglutinated by it in a dilution of 1/4860, and the strain used for the production of this serum was also agglutinated at this dilution. Thirty-seven strains (18 per cent.; failed to agglutinate. Accordingly a member of this smaller group was used for the produc¬ tion of a second agglutinating serum and it was found that all the members of this second group were agglutinated by this serum in a dilution of 1/4860. No evidence of cross agglutination was obtained ; the two sera were specific for their respective groups. Havens also found that whereas the toxins produced by members of group 1 were neutralised by the antitoxin in common use (which is usually made from strain Park Williams No. 8 belonging to group 1) the toxins produced by the members of group 2 required very large amounts of antitoxin for their neutralisation. As a rule 20 units of standard antitoxin protected against one minimum lethal dose of group 2 toxin, while 5 to 10 units regularly failed to protect. Some samples of antitoxin, however, required to be used in much larger doses in order to neutralise one minimum lethal dose of group 2 toxin ; in two cases 100 units were necessary, and in a third case even 1000 units failed to protect. Havens concluded from his experiments that standard anti¬ toxin contains group antitoxin which protects against the toxins from both strains of the diphtheria bacillus, and that the amount of this group antitoxin, though never very large, varies in different samples. Havens draws conclusions from his work which have a very important bearing on the preparation of diphtheria antitoxin and its practical use. He suggests that those cases which do not yield to treat¬ ment except by the use of very large amounts of antitoxin may be due to infection by organisms belonging to group 2. He also points out that, in spite of the increasing use of antitoxin and its adminis¬ tration early in the disease, the death-rate from diph¬ theria in America is still about 10 per cent., and this again may be due to infection by organisms belonging to group 2. Other procedures which, according to Havens, are affected by his results are the Schick test and active immunisation by toxin-antitoxin mixtures. As practical measures Havens recommends the inclusion of toxin from a member of group 2 in the routine preparation of antitoxin, the use of a mixture of toxins of both groups for the Schick test, and the use of mixed toxins and antitoxins for active immunisation.