[Detection of the trh gene in Vibrio parahaemolyticus isolated from overseas travellers' diarrhea and their biochemical characteristics].
A total of 478 Vibrio parahaemolyticus strains isolated from overseas travellers' diarrhea during the last 7 years of 1989 to 1995 were examined for the production of Kanagawa hemolysin by reversed passive latex agglutination (RPLA) test. Three hundred-seventy (77.4%) out of 478 strains were positive for Kanagawa hemolysin, whereas 108 strains were weakly positive or negative. For those Kanagawa hemolysin-weakly positive or negative strains, the tdh and trh genes associated with the production of TDH (thermostable direct hemolysin) and TRH (TDH-related hemolysin), respectively, were studied by the polymerase chain reaction method. The trh gene was detected in 98 (90.7%) out of 108 strains. In 35 strains belonging to 13 serotypes such as O3: K6, O1:K33, O3:K59, the trh gene alone was detected. On the other hand, both trh and tdh genes were detected in 63 strains of 17 serotypes including O1:K69, O3:K72, O6:K46. Among the strains of 4 serotypes including O1:K56, O1:KUT, O3:KUT and O5:KUT, two types of the trh positive alone and the trh and tdh positive were observed. Of interest, all of the 98 trh-positive strains were positive for the urease hydrolysis, whereas all Kanagawa hemolysin-positive strains were not. Furthermore, the strains of serotype O6:K18 (4 strains) were positive for the fermentation of dulcitol, and the strains of serotype O1:K1 (5 strains) were indole negative. These characteristics of the strains were completely different from those of typical V. parahaemolyticus strains.
Department of Microbiology, Tokyo Metropolitan Research Laboratory of Public Health.
H
H
Obata
A
A
Kai
K
K
Sekiguchi
S
S
Matsushita
S
S
Yamada
T
T
Itoh
K
K
Ohta
Y
Y
Kudoh
D003967:Diarrhea / Q000382:microbiology*; D005798:Genes, Bacterial; D006460:Hemolysin Proteins / Q000096:biosynthesis; D006801:Humans; D016133:Polymerase Chain Reaction; D012703:Serotyping; D014195:Travel; D014510:Urease / Q000378:metabolism; D014736:Vibrio parahaemolyticus / Q000145:classification / Q000235:genetics* / Q000378:metabolism
D006460:Hemolysin Proteins; D014510:Urease