Hyperreactivity to Endotoxin in Mice Infected with BCG

Summary The induction of hyperreactivity to bacterial endotoxin by BCG infection was studied in germfree mice and in mice chronically infected with Salmonella typhimurium. The results showed that infection of BCG in germfree and in chronically infected animals caused a similar increase in sensitivity to endotoxin. It is concluded from these experiments that concomitant infection is not a decisive factor in the emergence of endotoxin hyperreactivity during BCG infection. The experiments also indicated that germfree mice were almost equally resistent to BCG infection as were conventional animals.