Resistance to Salmonella gallinarum, S. pullorum, and S. enteritidis in inbred lines of chickens.

Chickens of six inbred lines were inoculated intramuscularly with a range of doses of either Salmonella gallinarum, S. pullorum, or S. enteritidis, and levels of mortality were compared. For each serotype, large differences in mean lethal doses were observed for the different lines: Lines that had previously been shown to be resistant to S. typhimurium were also found to be resistant to S. gallinarum, S. pullorum, and S. enteritidis, and lines susceptible to S. typhimurium were also more susceptible to the other serotypes. These results suggest that there may be a general mechanism of resistance that may apply to all serotypes of Salmonella in chickens.