OmamA is required for early growth and virulence during murine infection. C57BL/6 mice were infected with a low dose aerosol of WT, omamA::tn, or omamA::tn +omamA complemented strains. Groups of four mice per strain were sacrificed at various days post infection (dpi) and bacterial burden (colony forming units, cfu) was assessed by plating from A. lung homogenates or B. spleen and liver homogenates. No significant differences were observed in the initial lung burden determined one day post infection (WT 193 +/− 10, omamA::tn 174 +/− 9 and omamA::tn +omamA 206 +/− 18). C. Groups of mice were monitored for survival. * indicates p<0.05 as compared to WT. tn indicates transposon insertion. Error bars represent standard deviation. Results are representative of two independent experiments comparing WT (MBTB178), omamA::tn (MBTB319), and omamA::tn + omamA (MBTB320).