FIG. 4.

IS1004 fingerprinting and RFLP analyses of the various serogroup strains. (a) IS1004 fingerprints of HpaII-digested chromosomal DNAs of various V. cholerae strains. Since HpaII does not cut within IS1004, each band represents one copy of the element. (b) RFLP analysis of the smt region of chromosome II of various V. cholerae strains. The genomic DNAs were digested with SphI and hybridized simultaneously with multiple probes (smtrgn 1 to 5). The identities of the bands were deduced from their predicted sizes, based on the published V. cholerae genome sequence (22), and they were confirmed by separately hybridizing the same blot with individual probes. The sizes of the molecular weight markers (in kilobases) are indicated on the left. (c) Blot used in panel b rehybridized with an smt probe (primers M 668 and M 669). Lanes O144, O9, and O27 were omitted since they did not show any hybridizing band with this probe.