The Permanence of the Serological Paratyphoid B Types, with Observations on the Non-specificity of Agglutination with “Rough” Variants

Abstract

1. Amoung a large number of strains belonging to the various absorption types of the paratyphoid B group and kept under observation in laboratory culture over a number of years, constancy of type has been demonstrated.2. Only two alterations in the serological nature of certain cultures have been noted; they were due (a) to the development of so-called “rough” variants, (b) to the degeneration of strains into antigenically less effective “substrains.”Though both are variations within the limits of the absorption type, the serological character of the affected strains may be so obscured that a greater variation than has actually taken place may be ascribed to them, unless the precautions indicated are observed.3. When “rough” strains are in question, agglutination results are to be mistrusted, for a marked cosmopolitanism in respect of this test has been seen to exist among such alien species as B. enteritidis Gärtner, B. paratyphosus A and B. paratyphosus B.