FIG. 4.

Distribution of four mutS-rpoS region sequences among ECOR strains. The schematic shows the genetic organization of the E. coli chromosome from 61 to 62 min. The bold arrows show the length and direction of the coding regions of the genes indicated. The UR of E. coli O157:H7 and corresponding region in E. coli K-12 are shown, with their sizes given in parentheses. The four probes employed in colony hybridization studies are indicated in ovals and are positioned to show their relative locations on the chromosome. The presence (+) or absence (−) of a sequences is given below each probe for 72 ECOR strains, E. coli O157:H7 and K-12, and S. dysenteriae type 1. The asterisk marks a weakly positive reaction. The map is scaled in 2,000-bp increments based on sequence coordinates of the E. coli K-12 sequence contig Ecu29579, available in GenBank.