Fig 1.

Dendrogram depicting the diversity of the chxA gene from V. cholerae non-O1/non-O139 strains. Overall, 29 different chxA subtypes were observed among 53 sequences. These strains were grouped into three sequence clusters: chxA I (n = 33), chxA II (n = 16), and chxA III (n = 4). The chxA I sequences are close to the published prototype sequence (accession no. AY876053). Letters in parentheses show the origin of the isolate: C and E, clinical and environmental, respectively. At protein level, the signal peptide in ChxA I and II is KDEL whereas ChxA III has HDEL.