Mean weight loss from Map–SA- and Map+SA-infected mice. Mice were intravenously infected with either 107 Map–SA or Map+SA. Weights were taken before infection and every 7 days after infection for 4 weeks. Data are expressed as the mean ± SE of the mean of 26 and 24 mice/group for Map–SA– and Map+SA–infected mice, respectively. *P < 0.05, Student t test.