The Phase Variation of Shigella Paradysenteriae (Flexner) Type IV

[摘要] 1. 1. The observations of Boyd concerning the occurrence of a phase variation of Shigella paradysenteriae (Flexner) type IV are confirmed.2. 2. Phase A presents the characteristic type specific phase of type IV.3. 3. Some strains were found to occur only in this phase, whereas others show beside the type specific phase a second one of different behavior.4. 4. Whereas phase A may split off colonies of phase B, bacteria of phase B maintain their phase characteristics.5. 5. The phase B antigen is complex and is different from any of the known primary antigens of the Flexner species. This is particularly true of the primary antigens of the types IV (phase A), VII and VIII.6. 6. Material similar to the phase B, type IV, antigen forms part of the antigenic mosaic of the several types of the Flexner species enumerated in this paper. And it constitutes the essential part of the secondary antigens of type IV, phase A.7. 7. Anti-phase B, type IV immune serum affords some protection against infection with Flexner bacilli of types agglutinated by such sera.8. 8. The complex problems connected with these observations are discussed.

[学科分类] 生物科学（综合）