PREPARATION OF POLYNUCLEOTIDE COMPLEX FROM SALMONELLA TYPHOSA,

Y of Strains Derived from Salmonella Typhosa 58 ( Panama Carrier

Since the early days of immunology, it has been considered that high viru-lence and recency of isolation from pathological material were essential attributes of strains of bacteria to be used in production of superior immunizing agents. In spite of a surprising paucity of supporting factual information this concept has pesisted. Perhaps in no field of investigative immunology has the theory of ...

[Resistance of Salmonella typhosa to chloramphenicol].

Assay of typhoid vaccines with Salmonella typhosa-Salmonella typhimurium hybrids.

Salmonella typhimurium hybrids expressing the S. typhosa antigens 9, d, and Vi were constructed by genetic crosses with an S. typhosa Hfr donor. The hybrids retained the same degree of mouse virulence as their S. typhimurium parent strain, the minimum lethal dose being less than 50 organisms when tested either in C(57) black mice or Swiss white mice. Vaccination of the Swiss white mice with S. ...

Chloramphenicol-resistant strains of Salmonella typhosa.

Changes that occur in gram-positive organisms coincident to the acquisition of resistance to such antibiotics as penicillin, streptomycin, and aureomycin are well documented (Gezon, 1948; Gezon and Cryst, 1948; Gezon and Fasan, 1950; Ramsey and Padron, 1954). However, with the exception of studies with Escherichia coli (Coffey et al., 1950; Bergersen, 1953) the changes in such gram-negative ent...

Vi phage-host interaction in Salmonella typhosa.

Since their discovery by Craigie and Yen (1938), the Vi typing phages have been extensively employed in the study of the epidemiology of typhoid fever. Susceptibility to these phages is related to the presence of the Vi antigen, a component found in almost all freshly isolated typhoid cultures. The specific typing preparations, which produce confluent lysis with their homologous typhoid strains...