Résumé
Objective Clone and mutagenesis analysis of nhaA gene in Vibrio cholerae O1 and O139. Methods 40 strains of Vibrio cholerae O1 and O139 were collected. A full length nhaA gene fragment was amplified with PCR and cloned into plasmid vector pcDNA3. Homology and mutagenesis of nhaA gene in Vibrio cholerae O1 and O139 were analyzed after sequencing the nhaA gene. Results nhaA gene of Vibrio cholerae O1 and O139 were successfully amplified and cloned. Sequence analysis manifested that nhaA gene of Vibrio cholerae O1 and O139 in China share a high homology with reference sequence of wide-type Vibrio cholerae O1 in GENEBANK(99% and 96% respectively). The amino acid mutagenesis rates of nhaA gene in Vibrio cholerae O1 and O139 were 2% and 11% respectively. The important residues(Asp133,Asp163,Asp164,His225,Leu73 and Gly338 )had no mutation. But in residues 203 and 221 of nhaA gene Vibrio cholerae O1 and O139 had common mutation. Conclusions Mutagenesis of nhaA gene and NhaA protein may be the result of Vibrio cholerae adaptation to survival environment.