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

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 tdhpositive 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.

Virulence Gene- and Pandemic Group-Specific Marker Profiling of Clinical Vibrio parahaemolyticus Isolates

“…While most strains and serotypes of V. parahaemolyticus are nonpathogenic, those that are pathogenic have rapidly become major etiologic agents of human gastroenteritis, wound infections, and septicemia. Since 1996, one serotype in particular, V. parahaemolyticus O3:K6 (and its clonal derivatives O4:K68, O1:K25, and O1:KUT) (7), has received increasing notoriety, as it is the first documented V. parahaemolyticus serotype to cause pandemic disease (19,24) and has recently been linked to gastroenteritis outbreaks on the Asian (6,11,24,40), North American (8,21), South American (10), European (18,31), and African (1) continents. To compound matters, serotype-based detection and surveillance efforts have been complicated by serotype transition and variation within the pandemic lineage, as additional serotypes (O1: K26 [26], O6:K18 [39], O1:K41, O4:K12 [16], O1:K56, O3:K75, O4:K8, O4:KUT, and O5:KUT [5]) from specific locales have now been identified as having been derived from the original pathogenic O3:K6 clone.…”

Biochemical Differentiation and Molecular Characterization of Biofield Treated &lt;i&gt;Vibrio parahaemolyticus&lt;/i&gt;

“…Moreover, the positive reaction of galactosidases (ONPG) indicated the identifiable characteristics feature of V. parahaemolyticus rather than sugar fermentation process i.e. sucrose [30]. Identification of V. parahaemolyticus with the help of PCR-based 16S rDNA technique is more efficient, reliable and faster in comparison with the conventional biochemical reaction pattern analysis [23].…”

Revisión y recomendaciones para el manejo de diarrea por Vibrio parahaemolyticus

“…En febrero de 1996 en Calcuta, India, se detectó por primera vez un nuevo clon de V. parahaemolyticus perteneciente al serotipo O3:K6, TDH positivo, TRH negativo, siendo responsable de un gran aumento de los casos de enfermedad diarreica en esa zona 29 . Posteriormente este clon pandémi-co 25,28,[29][30][31][32][33][34] ha sido el responsable del aumento de casos en otras regiones de Asia, llegando incluso a Norteamérica y finalmente a Chile, donde se ha detectado su presencia desde el año 1998; desde entonces ha sido el responsable de todos los grandes brotes ocurridos 35 (comunicación verbal ISP). El fundamento de la expansión de este clon permanece sin dilucidar, puesto que su nivel de producción de TDH y su susceptibilidad antimicrobiana no es distinta a la de otras cepas patógenas de V. parahaemolyticus.…”