title: Cytotoxicity and enterotoxicity of the thermostable direct hemolysin-deletion mutants of Vibrio parahaemolyticus.
abstract: The thermostable direct hemolysin (TDH) has been proposed to be a major virulence factor of Vibrio parahaemolyticus. We have recently completed the genome sequence of a TDH-producing V. parahaemolyticus strain, RIMD2210633. In this study, we constructed tdh-deletion mutants from the sequenced strain by homologous recombination and analyzed their phenotypes. Although the deletion of both copies of tdh completely abolished the hemolytic activity of the wild-type strain, the deletion did not affect the cytotoxicity to HeLa cells. Enterotoxicity, assayed by the rabbit ileal loop test, was lowered by tdh deletion, but the mutant still showed partial fluid accumulation in rabbit intestine. These results indicate that the cytotoxicity and enterotoxicity of TDH-producing V. parahaemolyticus are not explained by TDH alone, and suggest that an unknown virulence factor(s) could be involved in these pathogenic activities.
authors.affiliation: Department of Bacterial Infections, Research Institute for Microbial Diseases, Osaka University, Japan.
authors.forename: Kwon-Sam
authors.initials: KS
authors.lastname: Park
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ono
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Rokuda
authors.forename: Myoung-Ho
authors.initials: MH
authors.lastname: Jang
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Iida
authors.forename: Takeshi
authors.initials: T
authors.lastname: Honda
mesh_terms: D000818:Animals; D001427:Bacterial Toxins; D017353:Gene Deletion; D006367:HeLa Cells; D006460:Hemolysin Proteins / Q000235:genetics / Q000633:toxicity*; D006801:Humans; D007082:Ileum / Q000382:microbiology / Q000473:pathology; D011817:Rabbits; D014735:Vibrio Infections / Q000382:microbiology / Q000473:pathology; D014736:Vibrio parahaemolyticus / Q000378:metabolism / Q000472:pathogenicity*
chemical_list: D001427:Bacterial Toxins; D006460:Hemolysin Proteins; C068489:thermostable direct hemolysin