Genomic characterization of non-01, non-0139 Vibrio cholerae reveals genes for a type Ill secretion system.

Non-O1, non-O139 Vibrio cholerae can cause gastroenteritis and extraintestinal infections, but, unlike 01 and 0139 strains of V. cholerae, little is known about the virulence gene content of non-O1, non-0139 strains and their phylogenetic relationship to other pathogenic V. cholerae. Comparative genomic microarray analysis of four pathogenic non-O1, non-0139 strains indicates that these strains are quite divergent from O1 and 0139 strains. Genomic sequence analysis of a non-O1, non-0139 strain (AM- 19226) that appeared particularly pathogenic in experimental animals suggests that this strain carries a type III secretion system (1755) that is related to the 17552 gene cluster found in a pandemic clone of Vibrio parahaemolyticus. The genes for this V. cholerae TTSS system appear to be present in many clinical and environ- mental non-O1, non-O139 strains, including at least one clone that is globally distributed. We hypothesize that the 1755 present in some pathogenic strains of non-O1, non-O139 V. cho!erae may be involved in the virulence and environmental fitness of these strains. [ABSTRACT FROM AUTHOR]