Decreased capacity of aged mice to produce interferon-gamma in Legionella pneumophila infection.

We investigated the difference in natural resistance to Legionella pneumophila infection between aged (18-20-month-old) and young (3-month-old) mice of ddY strain. Aged mice were more susceptible to the bacterial infection than young mice; 50% lethal doses of L. pneumophila for aged and young mice were 2.2 x 10(7) and 8.5 x 10(7) colony forming units (CFU… (More)