Effect of Bap expression in <i>S. aureus</i> invasion into mammary glands using a murine mastitis model.

<p>A) Gp96 expression in mammary glands L4 and R4. Glands were homogenized and proteins were resolved by 10% SDS-polyacrylamide gels. Gp96 was detected using anti-Gp96 antibodies. B) Competition indexes of Δ<i>bap</i>-Wt and Δ<i>bap</i>-Δ<i>repBap</i>. Mice mammary glands were coinfected with equal numbers of the strains tested. After 18 h post-infection mammary glands were treated (intra-mammary administration) with PBS with gentamicin for 3 h. Bacterial counts (CFU) were obtained from each mammary gland. Competition indexes were calculated and statistical differences were determined with a t-test. Horizontal bars represent the means of the competition indexes. Asterisks indicate that competition indexes are significantly greater than one (**, P<0.01 [very significant]). ns, non significant differences.