RT Journal Article SR Electronic(1) A1 Old, D. C. A1 Payne, Sheila B.YR 1971 T1 Antigens Of The Type-2 Fimbriae Of Salmonellae: “Cross-Reacting Material” (Crm) Of Type-1 Fimbriae JF Journal of Medical Microbiology, VO 4 IS 2 SP 215 OP 225 DO https://doi.org/10.1099/00222615-4-2-215 PB Microbiology Society, SN 1473-5644, AB SUMMARY Antisera were prepared against the type-1 fimbriae of three strains of Salmonella paratyphi B and against the type-2 fimbriae of two strains of S. paratyphi B and one strain of S. pullorum. The anti-type-1 and anti-type-2 sera agglutinated fimbriate-phase bacteria possessing either type-1 or type-2 fimbriae. Neither antiserum agglutinated non-fimbriate-phase bacteria of the same strains. Mirror absorption tests were performed and in each case the fimbrial agglutinin content of the serum of either type was absorbed by bacteria with fimbriae of the other type. The results showed that the type-1 and type-2 fimbriae of S. paratyphi B contain the same fimbrial antigens. It is suggested that the type-2 fimbriae of S. paratyphi B are mutational CRM forms of the type-1 fimbriae, because they are antigenically similar to type-1 fimbriae though they lack the “ functional” adhesive properties of the latter type. A mutational origin of type-2 from type-1 bacteria is suggested by the observation that some strains of S. paratyphi B with type-2 fimbriae gave rise to mutants with type-1 fimbriae both spontaneously and after treatment with mutagens. The absence of a distinctive antigen corresponding to the haemagglutinin in the type-1 fimbriae suggests that the haemagglutinin occupies only a small proportion of the surface of the fimbriae, possibly only on their tips. The type-2 fimbriae of S. pullorum cross-reacted in agglutination and agglutinin-absorption tests with both the type-1 and the type-2 fimbriae of S. paratyphi B. No type-1 fimbriae have been found in any strain of S. pullorum, and it is thought that the type-2 strains have arisen by mutation from a parental S. pullorurn-like organism with type-1 fimbriae that is now extinct., UL https://www.microbiologyresearch.org/content/journal/jmm/10.1099/00222615-4-2-215