scholarly journals An Estuarine Neritid Gastropod, Clithon corona, a Potential Reservoir of Thermostable Direct Hemolysin-Producing Vibrio parahaemolyticus

2005 ◽  
Vol 67 (8) ◽  
pp. 833-835 ◽  
Author(s):  
Aiyamperumal VELAMMAL ◽  
Mina KATO ◽  
Sayaka MIYAGI ◽  
Megumi TOYOZATO ◽  
Norichika H. KUMAZAWA
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Potential Reservoir ◽  
Thermostable Direct Hemolysin

scholarly journals Contribution of Vibrio parahaemolyticus Virulence Factors to Cytotoxicity, Enterotoxicity, and Lethality in Mice

2010 ◽  
Vol 78 (4) ◽  
pp. 1772-1780 ◽  
Author(s):  
Hirotaka Hiyoshi ◽  
Toshio Kodama ◽  
Tetsuya Iida ◽  
Takeshi Honda
Keyword(s):  
Cell Lines ◽  
Virulence Factors ◽  
Vibrio Parahaemolyticus ◽  
Biological Activities ◽  
Infection Model ◽  
Cytotoxic Activities ◽  
Mutant Strains ◽  
Thermostable Direct Hemolysin ◽  
Clinical Illness ◽  
Pathogenic Vibrios

ABSTRACT Vibrio parahaemolyticus, one of the human-pathogenic vibrios, causes three major types of clinical illness: gastroenteritis, wound infections, and septicemia. Thermostable direct hemolysin (TDH) secreted by this bacterium has been considered a major virulence factor of gastroenteritis because it has biological activities, including cytotoxic and enterotoxic activities. Previous reports revealed that V. parahaemolyticus strain RIMD2210633, which contains tdh, has two sets of type III secretion system (T3SS) genes on chromosomes 1 and 2 (T3SS1 and T3SS2, respectively) and that T3SS1 is responsible for cytotoxicity and T3SS2 is involved in enterotoxicity, as well as in cytotoxic activity. However, the relative importance and contributions of TDH and the two T3SSs to V. parahaemolyticus pathogenicity are not well understood. In this study, we constructed mutant strains with nonfunctional T3SSs from the V. parahaemolyticus strain containing tdh, and then the pathogenicities of the wild-type and mutant strains were evaluated by assessing their cytotoxic activities against HeLa, Caco-2, and RAW 264 cells, their enterotoxic activities in rabbit ileal loops, and their lethality in a murine infection model. We demonstrated that T3SS1 was involved in cytotoxic activities against all cell lines used in this study, while T3SS2 and TDH had cytotoxic effects on a limited number of cell lines. T3SS2 was the major contributor to V. parahaemolyticus-induced enterotoxicity. Interestingly, we found that both T3SS1 and TDH played a significant role in lethal activity in a murine infection model. Our findings provide new indications that these virulence factors contribute to and orchestrate each distinct aspect of the pathogenicity of V. parahaemolyticus.

scholarly journals Levels of Thermostable Direct Hemolysin Production by Vibrio parahaemolyticus Strains Carrying both tdh and trh Genes

1997 ◽  
Vol 71 (12) ◽  
pp. 1221-1225 ◽  
Author(s):  
Norihiko SUZUKI ◽  
Satoru HASHIMOTO ◽  
Masanori ISHIBASHI ◽  
Yung Bu KIM ◽  
Jun OKUDA ◽  
...  
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Thermostable Direct Hemolysin

Increased Sensitivity in PCR Detection of tdh-Positive Vibrio parahaemolyticus in Seafood with Purified Template DNA

2003 ◽  
Vol 66 (9) ◽  
pp. 1675-1680 ◽  
Author(s):  
Y. HARA-KUDO ◽  
Y. KASUGA ◽  
A. KIUCHI ◽  
T. HORISAKA ◽  
T. KAWASUMI ◽  
...  
Keyword(s):  
Glass Fiber ◽  
Vibrio Parahaemolyticus ◽  
Detection Sensitivity ◽  
Sea Bream ◽  
Silica Membrane ◽  
Membrane Method ◽  
Hemolysin Gene ◽  
Thermostable Direct Hemolysin ◽  
Increased Sensitivity ◽  
Template Dna

PCR is an important method for the detection of thermostable direct hemolysin gene (tdh)–positive (pathogenichemolysin-producing) strains of Vibrio parahaemolyticus in seafood because tdh-negative (nonpathogenic) V. parahaemolyticus strains often contaminate seafood and interfere with the direct isolation of tdh-positive V. parahaemolyticus. In this study, the use of PCR to detect the tdh gene of V. parahaemolyticus in various seafoods artificially contaminated with tdh-positive V. parahaemolyticus was examined. PCR was inhibited by substances in oysters, squid, mackerel, and yellowtail but not by cod, sea bream, scallop, short-necked clam, and shrimp. To improve detection, DNA was purified by either the silica membrane method, the glass fiber method, or the magnetic separation method, and the purified DNA was used as the PCR primer template. For all samples, the use of the silica membrane method and the glass fiber method increased detection sensitivity. The results of this study demonstrate that the use of properly purified template DNA for PCR markedly increases the effectiveness of the method in detecting pathogenic tdh-positive V. parahaemolyticus in contaminated seafood.

scholarly journals Prevalence of Pandemic Thermostable Direct Hemolysin-Producing Vibrio parahaemolyticus O3:K6 in Seafood and the Coastal Environment in Japan

2003 ◽  
Vol 69 (7) ◽  
pp. 3883-3891 ◽  
Author(s):  
Yukiko Hara-Kudo ◽  
Kanji Sugiyama ◽  
Mitsuaki Nishibuchi ◽  
Ashrafuzzaman Chowdhury ◽  
Jun Yatsuyanagi ◽  
...  
Keyword(s):  
Vibrio Parahaemolyticus ◽  
The United States ◽  
Most Probable Number ◽  
Asian Countries ◽  
Probable Number ◽  
Specific Pcr ◽  
Thermostable Direct Hemolysin ◽  
Chromogenic Agar ◽  
Pcr Method ◽  
Arbitrarily Primed Pcr

ABSTRACT Although thermostable direct hemolysin (TDH)-producing Vibrio parahaemolyticus has caused many infections in Asian countries, the United States, and other countries, it has been difficult to detect the same pathogen in seafoods and other environmental samples. In this study, we detected and enumerated tdh gene-positive V. parahaemolyticus in Japanese seafoods with a tdh-specific PCR method, a chromogenic agar medium, and a most-probable-number method. The tdh gene was detected in 33 of 329 seafood samples (10.0%). The number of tdh-positive V. parahaemolyticus ranged from <3 to 93/10 g. The incidence of tdh-positive V. parahaemolyticus tended to be high in samples contaminated with relatively high levels of total V. parahaemolyticus. TDH-producing strains of V. parahaemolyticus were isolated from 11 of 33 tdh-positive samples (short-necked clam, hen clam, and rock oyster). TDH-producing strains of V. parahaemolyticus were also isolated from the sediments of rivers near the coast in Japan. Representative strains of the seafood and sediment isolates were examined for the O:K serovar and by the PCR method specific to the pandemic clone and arbitrarily primed PCR and pulsed-field gel electrophoresis techniques. The results indicated that most O3:K6 tdh-positive strains belonged to the pandemic O3:K6 clone and suggested that serovariation took place in the Japanese environment.

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