CORRELATION OF SUCCINATE METABOLISM AND VIRULENCE IN SALMONELLA TYPHIMURIUM.

Herzberg, Mendel (University of Florida, Gainesville), and Mudhaffer J. Jawad, and Darrell Pratt. Succinate metabolism and virulence in Salmonella typhimurium. J. Bacteriol. 89:185-192. 1965.-A virulent, smooth strain of Salmonella typhimurium (Wild-7) grew slowly with succinate as sole carbon source (Suc-L). Old stock cultures yielded a smooth variant which grew rapidly (Suc-E). Visible colonies of Suc-E appeared in 24 hr, whereas Suc-L required 48 hr. Differences other than the response to succinate were not demonstrable between the two strains; ld(50) values of both strains were similar, but equivalent numbers of Suc-E required longer periods of time to kill mice. Recovery of bacteria from liver and spleen homogenates revealed that Suc-L remains as such in vivo, but Suc-E populations change to Suc-L. By the eighth day of infection, the organisms were 93 to 100% Suc-L; thus, mortality was due to the Suc-L population developed in vivo and not the Suc-E of the original inoculum. Animal passage of a number of stock cultures of S. typhimurium of diverse origin, all Suc-E type, invariably yielded Suc-L. Slow utilization of succinate appears to be correlated with virulence.