The Demonstration of Non-specific Components in Salmonella paratyphi A by Induced Variation

Abstract

Through cultivation in agglutinating serums 3 induced phases were isolated from cultures of S. paratyphi A. One of the phases was closely related to the non-specific phases of diphasic types. The other 2 bore little resemblance to the normal Salmonella antigens. Non-specific components were isolated from 12 of 16 cultures studied. These non-specific antigens were expressed as 1.5 .... and were more closely related to the non-specific phase of the Sendai type than to any of the other non-specific phases. The induced phases were stable under ordinary conditions of culture and could be reverted only by the addition of appropriate serums to the medium. The isolation of non-specific antigens from S. paratyphi A was cited as additional evidence that mono-phasic Salmonella types are derived from multiphasic types through suppression of phases.