The fate of temperature-sensitive salmonella mutants in vivo in naturally resistant and susceptible mice

Abstract

The in vivo net growth rate of salmonellae in mice is faster with virulent than with attenuated strains, and slower in resistant than in susceptible mice, the latter difference being controlled by a single host gene (Ity). Mice were injected intravenously (i.v.) with non replicating temperature-sensitive (TS) salmonellae mutants: TS mutants from virulent parents survived better in the RES than those from attenuated or non-virulent parents as if the latter were more susceptible to bactericidal mechanisms. However, a TS mutant from a virulent parent (Salmonella typhimurium C5) did not consistently survive better in susceptible Ity(r) mice, suggesting that this gene may not operate by a bacteri..