Fig 1.
Chromosomal positions of loci under study and bioluminescent typing assay of congenic S. aureus strains. (A) Chromosomal positions in NCTC 8325 of the native agr locus and SaPI-1 and ϕ11 attachment sites. The ϕ11 attB site is identical to the integration site of phage NM1 in Newman (5), and the indicated sites are located at analogous distances in the Newman chromosome. (B, C) Bioluminescent plate assay. Congenic strains with the indicated agr allele are streaked radially. The reporter strains (RN9688, RN9689, RN9690, and RN9691 [77]), each carrying an allele-specific AgrCA two-component signaling pair plus a agrp3-lux fusion, are patched alongside the congenic strains, each of which activates one of the reporters according to the specificity of its AIP. Reporters are identified by roman numerals designating their specificity group. Bioluminescence was detected with a Hamamatsu charge-coupled-device camera and is presented as a pseudocolor image, with the color bar indicating the signal intensity in counts.