The Δ27735 mutant reduced intracellular survival, but intracellular trafficking was unchanged. Intracellular survival of the WT strain and the Δ27735 mutant within RAW264.7 cells was determined at 2, 8, 24 and 48 h post-infection (pi) (A). Representative images of lysosome associated membrane protein-1 (LAMP-1) -positive (yellow arrows) and -negative (white arrows) Brucella -containing vacuoles (BCVs) at 4 and 24 h pi in the WT strain and the Δ27735 mutant in RAW264.7 cells (B). Determination of LAMP-1 -positive BCVs at 4 and 24 h pi in the WT strain and the Δ27735 mutant (C). Statistical significance was determined using two-way ANOVA followed by Holm-Sidak’s multiple test. ***p < 0.001; ns: not significant (p > 0.05).