Bacteriological and clinical studies of the diarrheal diseases of infancy with reference to the Bacillus dysenteriae (Shiga) : from the Rockefeller Institute for Medical Research / edited by Simon Flexner and L. Emmett Holt.

Date:
1904
Catalogue details

Licence: Public Domain Mark

Credit: Bacteriological and clinical studies of the diarrheal diseases of infancy with reference to the Bacillus dysenteriae (Shiga) : from the Rockefeller Institute for Medical Research / edited by Simon Flexner and L. Emmett Holt. Source: Wellcome Collection.

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    Dysentery bacilli are subject to bacteriolysis in vitro either by ineans of fresh normal or fresh immune horses’ serum. For the purpose of studying the comparative bacteriolysis of the two types of bacilli both serums are employed. Shiga first applied the method devised by Neisser and Wechsberg to the bacteriolysis of dysentery bacilli, but his study had no reference to the differentiation of the types. A word upon the method may be in place: A fixed quantity of normal fresh horse’s serum, incapable in itself of producing bacteriolysis, will, in the presence of a definite amount of inactivated immune-serum, cause complete destruction of a given weight of dysentery (or other) bacilli. The addition of more or less immune-serum than is exactly required will allow of greater or less growth of the organisms, according as a deficiency or an excess of amboceptors is present in the mixture. An insufficiency of immune- serum prevents complete bacteriolysis by failing to supply all the ambcceptors needed to unite the complements to the bacteria; an ex- cess of immune-serum also prevents complete bacteriolysis by introduc- ing so large a number of amboceptors as to bring about their union directly with the complement (without any attachment to the bodies of the bacteria) and hence its deviation from the bacteria.* Since it is the complement that destroys the bacteria, should it become deviated from the bacteria, then no destruction takes place. Gay, while working under a grant from the Rockefeller Institute, in my laboratory at the University of Pennsylvania, found thatetne bacteriolysis of dysentery bacilli as observed under these conditions, was dependent upon the employment of bacilli and immune serum of corresponding types. Neither immune serums nor types of bacilli were mutually interchangeable in producing bacteriolysis, from which fact the conclusion that bacteriolytic variations serve to distinguish the two types of bacilli could be drawn. From the facts enumerated it will be evident that the more recent studies upon Bacillus dysenteriae have tended to establish more and more firmly the belief in the existence of “types” of the organism. Between these types the similarities are perhaps no more important than the differences; but no facts have thus far been brought forward which would indicate that one rather than the other acts pathogenetic- ally upon human beings. This last consideration is of commanding im- portance in ‘respect to the possible employment of an artificial immune serum in combating infections. with the bacilli in man. *Tt is needless to point out that the explanation of the facts of bacteriolysis under the conditions named is hypothetical.