Correlation of O-ag with BSAP-2 in B. uniformis strains. (A) ORF maps showing the two types of O-ag loci (light and dark blue) in sequenced B. uniformis strains typified by Bu8492 and BuCL03. Surrounding genes are shown, including the BSAP-2-encoding gene colored red and a distinct MACPF domain protein-encoding gene colored yellow. Percent DNA identity is graphed below the open reading frames, with regions >95% identical colored in pink. (B) Ethidium bromide (EtBr)-stained agarose gel showing amplification products from various PCRs. Upper panel, Bu8492 O-ag region-specific gene; middle panel, BuCL03 O-ag region-specific gene; bottom panel, BSAP-2 gene. (C) Silver-stained gel and Western blot of purified LPS from various B. uniformis strains. The blot was probed with the adsorbed antiserum specific to the Bu8492 O-ag. (D) Agar overlays demonstrating the sensitivity or resistance of B. uniformis strains D20 (BuD20) CL03T00C23 (BuCL03), CL06T06C18 (BuCL06), CL07T00C16 (BuCL07), and CL14T09C07 (BuCL14) to BuCL03 or the BuCL03 mutant lacking the gene encoding BSAP-2. (E) Agar overlays showing zones of inhibition produced by BuCL03 and BuCL14 against Bu8492 but not the Bu8492 O-ag mutant (Δ00969).