Disease relevance of VPA0257

• Calcium-dependent intestinal chloride secretion by Vibrio parahaemolyticus thermostable direct hemolysin in a rabbit model [1].
• From the results of this study, the Kanagawa hemolysis was interpreted as an expression of quantitative difference in hemolysin production, a conclusion that is clearly demonstrated on special blood agar of high salt content [2].
• Genes encoding the thermostable direct or Kanagawa phenomenon hemolysin of Vibrio parahaemolyticus were cloned in Escherichia coli [3].
• Molecular epidemiologic evidence for association of thermostable direct hemolysin (TDH) and TDH-related hemolysin of Vibrio parahaemolyticus with gastroenteritis [4].
• Vibrio parahaemolyticus strains, altered in motility or colonial morphology (opaque and translucent), and Listeria monocytogenes mutants lacking catalase, superoxide dismutase, hemolysin, and phospholipase activities were examined in winter and summer [5].

High impact information on VPA0257

• CONCLUSIONS: These data support the hypothesis that the thermostable direct hemolysin induces intestinal chloride secretion using GT1b as a putative receptor and Ca2+ as a second messenger [1].
• BACKGROUND & AIMS: Vibrio parahaemolyticus is a major agent of seafood gastroenteritis that induces intestinal secretion in the rabbit through its thermostable direct hemolysin [1].
• METHODS: Rabbit ileum was mounted in Ussing chambers, and changes in potential difference and short-circuit current were monitored after addition of hemolysin [1].
• We have demonstrated that possession of the gene for thermostable direct hemolysin-related hemolysin (trh) coincides with the presence of the urease gene among clinical Vibrio parahaemolyticus strains and that the location of the two genes are in close proximity on the chromosome [6].
• Cl(-) secretion in colonic epithelial cells induced by the vibrio parahaemolyticus hemolytic toxin related to thermostable direct hemolysin [7].

Chemical compound and disease context of VPA0257

• Effect of zinc ion on the hemolytic activity of thermostable direct hemolysin from Vibrio parahaemolyticus, streptolysin O, and Triton X-100 [8].
• Inactivation of the biological activities of the thermostable direct hemolysin of Vibrio parahaemolyticus by ganglioside Gt1 [9].
• Effect of D-tryptophan on hemolysin production in Vibrio parahaemolyticus [10].
• Selective media for Vibrio parahaemolyticus, BTB-Teepol agar and modified arabinose-ammonium sulfate-cholate agar, were modified for use in immunological detection of the thermostable direct hemolysin produced by this organism [11].
• The hemolysin of the pathogenic strains is a thermostable, cardiotoxic protein, which thus far has not been implicated in the mechanism(s) which causes human gastroenteritis [12].

Biological context of VPA0257

• However, previous studies attempting to demonstrate the contribution of the hemolysin to virulence have been inconclusive [13].
• Detection of the thermostable direct hemolysin gene and related DNA sequences in Vibrio parahaemolyticus and other vibrio species by the DNA colony hybridization test [14].
• Production of increased vascular permeability in rabbits by purified thermostable direct hemolysin from Vibrio parahaemolyticus [15].
• Vibrio parahaemolyticus thermostable direct hemolysin modulates cytoskeletal organization and calcium homeostasis in intestinal cultured cells [16].
• We previously reported the occurrence of Vibrio parahaemolyticus in patients and the environment in the Pacific Northwest. The present studies compare the biochemical characteristics, Kanagawa hemolysin reactions, and plasmid profiles of 13 patient and 221 environmental isolates of the organism [17].

Anatomical context of VPA0257

• A mutant toxin of Vibrio parahaemolyticus thermostable direct hemolysin which has lost hemolytic activity but retains ability to bind to erythrocytes [18].
• Electron micrographs of thin sections ofthe cells showed that the cytoplasm of the cells was not significantly affected by treatment with sublethal amounts of hemolysin, even when the microvilli on the cell surface were significantly affected [19].
• Cation flux studies of the lesion induced in human erythrocyte membranes by the thermostable direct hemolysin of Vibrio parahaemolyticus [20].
• The thermostable direct hemolysin produced by Vibrio parahaemolyticus showed cytotoxic activity on FL cells derived from human amniotic membrane [19].
• Microarray analysis identifies apoptosis regulatory gene expression in HCT116 cells infected with thermostable direct hemolysin-deletion mutant of Vibrio parahaemolyticus [21].

Associations of VPA0257 with chemical compounds

• Upon the addition of single amino acids to this synthetic medium, only D-tryptophan induced production of the hemolysin [22].
• In addition to its hemolytic activity, the hemolysin is cytotoxic, cardiotoxic, and rapidly lethal [23].
• In pH-stat cultures maintained at pH 6.2, higher hemolysin yields were produced irrespective of the presence or absence of mannitol [24].
• Glucose and mannose, although readily metabolized, lowered the pH below this range, inhibiting growth and hemolysin production [24].
• The modified BTB-Teepol agar and modified arabinose-ammonium sulfate-cholate agar were both found to be useful for the modified Elek test and immunohalo test with antiserum (or immunoglobulin G) against the thermostable direct hemolysin [11].

Other interactions of VPA0257

• The Maldives isolates hybridized with the DNA probe for the gene encoding the thermostable direct hemolysin (the tdh gene) under reduced stringencies [25].
• V. parahaemolyticus numbers were determined by a direct plating method involving an alkaline-phosphatase-labeled DNA probe that targets the species-specific thermolabile hemolysin gene (tlh-AP) to identify suspect isolates [26].

Analytical, diagnostic and therapeutic context of VPA0257

• Tetrameric Structure of Thermostable Direct Hemolysin from Vibrio parahaemolyticus Revealed by Ultracentrifugation, Small-angle X-ray Scattering and Electron Microscopy [27].
• All gene-positive strains produced hemolysin detectable in the enzyme-linked immunosorbent assay, although occasional strains showed weak reaction [14].
• Intravenous injection of the thermostable direct hemolysin (lethal toxin) produced by Vibrio parahaemolyticus caused rapid death of rats [28].
• The V. parahaemolyticus MTase gene was shown by PCR to be prevalent (>98%) in pandemic thermostable direct hemolysin gene-positive isolates, which suggests that VPAI may confer unique virulence traits to pandemic strains of V. parahaemolyticus [29].
• Since the Kanagawa phenomenon on Wagatsuma medium sometimes give false-positive results due to instability of the blood used in the medium, we recommend the immunological techniques described here as reproducible methods for identification of the thermostable direct hemolysin by V. parahaemolyticus [30].

References