The Δ<i>fbpA</i>Δ<i>sapM</i> double knockout (DKO) strain shows enhanced lysosomal localization in mouse macrophages:

<p><i>gfpMtb</i> H37Rv or Oregon green stained mutant strains were phagocytosed into BMs, incubated, fixed 24 hrs later and stained with primary antibodies to lysosomal markers LAMP1 (IDB4), CD63 and rab7 followed by Texas red conjugated conjugates. Mycobacteria colocalizing with antibodies were scored using a Nikon fluorescence microscope and Metaview deconvolution software. <b>a</b>) Illustration that the DKO mutant colocalizes better with rab7 lysosomal marker. <b>b</b>) Percent colocalization was determined by counting 200 macrophages per well each with 1–3 mycobacteria and averaging counts from triplicate chambers (SD). One of three similar experiments is shown. Text below the bar diagram indicates the colocalization of each marker in relation to different strains (*p<0.01, t test).