[Sequence analysis of the mutated genes in CTXEVC Phi and nct-CTXnew Phi genomes in Vibrio cholerae JS94484 strain].

OBJECTIVE: To analyze the sequences of the mutated genes in CTX(EVC)Phi and nct-CTX(new)Phi genomes in Vibrio cholerae JS94484 strain. METHODS: The mutated genes in CTX(EVC)Phi and nct-CTX(new)Phi genome were obtained by PCR, sequenced and analyzed. RESULTS: ig1, rstR, ig2, and ctxAB genes in CTX(EVC)Phi genome of V. cholerae strain JS94484 were highly homologous with those of standard EVC strain N16961, while ig1, rstR and ig2 genes in nct-CTX(new)Phi genome of the strain JS94484 shared low homology with those of the other 3 biotypes of V. cholerae. Considerable difference was detected in the last 60 bp of zot genes between CTX(EVC)Phi and nct-CTX(new)Phi genomes, indicating possible difference in the amino sequences of the Zot proteins encoded by these two genes. The sequence of toxin-coregulated pilus A subunit gene (tcpA) of the strain JS94484 was identical with that of strain N16961. CONCLUSION: ig1, rstR and ig2 genes of nct-CTX(new)Phigenome are of a novel type, and their functions await further investigation.