Diversity and distribution of cholix toxin, a novel ADP‐ribosylating factor from Vibrio cholerae

TitleDiversity and distribution of cholix toxin, a novel ADP‐ribosylating factor from Vibrio cholerae
Publication TypeJournal Articles
Year of Publication2010
AuthorsPurdy AE, Balch D, Lizárraga‐Partida M L, Islam M S, Martinez‐Urtaza J, Huq A, Colwell RR, Bartlett DH
JournalEnvironmental Microbiology Reports
Pagination198 - 207
Date Published2010/02/08/
ISBN Number1758-2229

Non-toxigenic non-O1, non-O139 Vibrio cholerae strains isolated from both environmental and clinical settings carry a suite of virulence factors aside from cholera toxin. Among V. cholerae strains isolated from coastal waters of southern California, this includes cholix toxin, an ADP-ribosylating factor that is capable of halting protein synthesis in eukaryotic cells. The prevalence of the gene encoding cholix toxin, chxA, was assessed among a collection of 155 diverse V. cholerae strains originating from both clinical and environmental settings in Bangladesh and Mexico and other countries around the globe. The chxA gene was present in 47% of 83 non-O1, non-O139 strains and 16% of 72 O1/O139 strains screened as part of this study. A total of 86 chxA gene sequences were obtained, and phylogenetic analysis revealed that they fall into two distinct clades. These two clades were also observed in the phylogenies of several housekeeping genes, suggesting that the divergence observed in chxA extends to other regions of the V. cholerae genome, and most likely has arisen from vertical descent rather than horizontal transfer. Our results clearly indicate that ChxA is a major toxin of V. cholerae with a worldwide distribution that is preferentially associated with non-pandemic strains.