Levels of Thermostable Direct Hemolysin Produced by Vibrio parahaemolyticus O3:K6 and Other Serovars Grown Anaerobically with the Presence of a Bile Acid

Osawa, Ro; Arakawa, Eiji; Okitsu, Tadayuki; Yamai, Shiro; Watanabe, Haruo

doi:10.1007/s00284-001-0051-3

Cited by 19 publications

(10 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Osawa et al demonstrated that production of TDH by V. parahaemolyticus was enhanced by several bile acids [35], [36]. It was also reported that bile and DC increased adherence of both KP-positive and KP-negative V. parahaemolyticus to Int-407 cells in vitro [37]. Recently, it was reported that bile modulated T3SS genes expression of non-O1/non-O139 V. cholerae [38].…”

Section: Discussionmentioning

confidence: 99%

Bile Acid-Induced Virulence Gene Expression of Vibrio parahaemolyticus Reveals a Novel Therapeutic Potential for Bile Acid Sequestrants

et al. 2010

View full text Add to dashboard Cite

Vibrio parahaemolyticus, a bacterial pathogen, causes human gastroenteritis. A type III secretion system (T3SS2) encoded in pathogenicity island (Vp-PAI) is the main contributor to enterotoxicity and expression of Vp-PAI encoded genes is regulated by two transcriptional regulators, VtrA and VtrB. However, a host-derived inducer for the Vp-PAI genes has not been identified. Here, we demonstrate that bile induces production of T3SS2-related proteins under osmotic conditions equivalent to those in the intestinal lumen. We also show that bile induces vtrA-mediated vtrB transcription. Transcriptome analysis of bile-responsive genes revealed that bile strongly induces expression of Vp-PAI genes in a vtrA-dependent manner. The inducing activity of bile was diminished by treatment with bile acid sequestrant cholestyramine. Finally, we demonstrate an in vivo protective effect of cholestyramine on enterotoxicity and show that similar protection is observed in infection with a different type of V. parahaemolyticus or with non-O1/non-O139 V. cholerae strains of vibrios carrying the same kind of T3SS. In summary, these results provide an insight into how bacteria, through the ingenious action of Vp-PAI genes, can take advantage of an otherwise hostile host environment. The results also reveal a new therapeutic potential for widely used bile acid sequestrants in enteric bacterial infections.

show abstract

Section: Discussionmentioning

confidence: 99%

Bile Acid-Induced Virulence Gene Expression of Vibrio parahaemolyticus Reveals a Novel Therapeutic Potential for Bile Acid Sequestrants

et al. 2010

View full text Add to dashboard Cite

show abstract

“…For many enteric pathogens, bile and deoxycholate are important host intraintestinal signaling molecules that serve to regulate the expression of virulence factors during infection. For example, bile can repress SPI1 T3SS-mediated invasion of Salmonella spp., and in V. parahaemolyticus, bile acids enhance the production of the thermostable direct hemolysin, which is an essential virulence factor (56,(59)(60)(61). Regulation can also occur at the protein level, and bile salts have been shown to act as environmental signals for the stable recruitment of IpaB onto the Shigella needle tip complex (74).…”

Section: Discussionmentioning

confidence: 99%

vttR _A and vttR _B Encode ToxR Family Proteins That Mediate Bile-Induced Expression of Type Three Secretion System Genes in a Non-O1/Non-O139 Vibrio cholerae Strain

et al. 2010

View full text Add to dashboard Cite

Strain AM-19226 is a pathogenic non-O1/non-O139 serogroup Vibrio cholerae strain that does not encode the toxin-coregulated pilus or cholera toxin but instead causes disease using a type three secretion system (T3SS). Two genes within the T3SS pathogenicity island, herein named vttR A (locus tag A33_1664) and vttR B (locus tag A33_1675), are predicted to encode proteins that show similarity to the transcriptional regulator ToxR, which is found in all strains of V. cholerae. Strains with a deletion of vttR A or vttR B showed attenuated colonization in vivo, indicating that the T3SS-encoded regulatory proteins play a role in virulence. lacZ transcriptional reporter fusions to intergenic regions upstream of genes encoding the T3SS structural components identified growth in the presence of bile as a condition that modulates gene expression. Under this condition, VttR A and VttR B were necessary for maximal gene expression. In contrast, growth in bile did not substantially alter the expression of a reporter fusion to the vopF gene, which encodes an effector protein. Increased vttR B reporter fusion activity was observed in a ⌬vttR B strain background, suggesting that VttR B may regulate its own expression. The collective results are consistent with the hypothesis that T3SS-encoded regulatory proteins are essential for pathogenesis and control the expression of selected T3SS genes.

show abstract

“…Bile acids play a key role in the pathogenicity of Vibrio species. Conjugated bile acids enhance production of V. parahemolyticus thermostable direct hemolysin (TDH), a virulence factor produced by strains most frequently associated with disease [245,246]. In addition, bile acids enhance the expression of other attributes associated with virulence such as Congo red binding ability, capsule production and adherence to epithelial cells [247].…”

Section: Bile and Pathogenesismentioning

confidence: 99%

The interaction between bacteria and bile

2005

View full text Add to dashboard Cite

Commensal and pathogenic microorganisms must resist the deleterious actions of bile in order to survive in the human gastrointestinal tract. Herein we review the current knowledge on the mechanisms by which Gram-positive and Gram-negative bacteria contend with bile stress. We describe the antimicrobial actions of bile, assess the variations in bile tolerance between bacterial genera and examine the interplay between bile stress and other stresses. The molecular mechanisms underlying bile tolerance are investigated and the relationship between bile and virulence is examined. Finally, the potential benefits of bile research are briefly discussed.

show abstract

Levels of Thermostable Direct Hemolysin Produced by Vibrio parahaemolyticus O3:K6 and Other Serovars Grown Anaerobically with the Presence of a Bile Acid

Cited by 19 publications

References 18 publications

Bile Acid-Induced Virulence Gene Expression of Vibrio parahaemolyticus Reveals a Novel Therapeutic Potential for Bile Acid Sequestrants

Bile Acid-Induced Virulence Gene Expression of Vibrio parahaemolyticus Reveals a Novel Therapeutic Potential for Bile Acid Sequestrants

vttR _A and vttR _B Encode ToxR Family Proteins That Mediate Bile-Induced Expression of Type Three Secretion System Genes in a Non-O1/Non-O139 Vibrio cholerae Strain

The interaction between bacteria and bile

Contact Info

Product

Resources

About

Levels of Thermostable Direct Hemolysin Produced by Vibrio parahaemolyticus O3:K6 and Other Serovars Grown Anaerobically with the Presence of a Bile Acid

Cited by 19 publications

References 18 publications

Bile Acid-Induced Virulence Gene Expression of Vibrio parahaemolyticus Reveals a Novel Therapeutic Potential for Bile Acid Sequestrants

Bile Acid-Induced Virulence Gene Expression of Vibrio parahaemolyticus Reveals a Novel Therapeutic Potential for Bile Acid Sequestrants

vttR A and vttR B Encode ToxR Family Proteins That Mediate Bile-Induced Expression of Type Three Secretion System Genes in a Non-O1/Non-O139 Vibrio cholerae Strain

The interaction between bacteria and bile

Contact Info

Product

Resources

About

vttR _A and vttR _B Encode ToxR Family Proteins That Mediate Bile-Induced Expression of Type Three Secretion System Genes in a Non-O1/Non-O139 Vibrio cholerae Strain