[Isolation of thermostable direct hemolysin producing Vibrio parahaemolyticus from food using screening by PCR in food-borne outbreaks].
The producibility of thermostable direct hemolysin (TDH) is the most important pathogenic factor in Vibrio parahaemolyticus. TDH (+) V. parahaemolyticus is usually isolated from patients having V. parahaemolyticus food-borne disease. TDH (+) V. parahaemolyticus is, however, very difficult to isolate from food and environmental samples. In the 5 years from 2000 to 2004 in Tokyo, V. parahaemolyticus was isolated from food samples related to 67 of 227 V parahaemolyticus food-borne outbreaks. In these outbreaks, TDH (+) strains were also tried to isolate using PCR as the screening methods. TDH (+) V. parahaemolyticus strains were able to isolate from enrichment broth in which toxR and tdh genes become positive in PCR. TDH (+) strains of the same serotype with patients were able to be isolated from 23 food samples related to 11 outbreaks (16.4%); 3 outbreaks in 2000, 2 in 2001, 2 in 2002, 1 in 2003, and 3 in 2004. The serotypes of V. parahaemolyticus isolated from food were O3 : K6 (10 samples), O3 : K5 (6 samples), O1 : K25 (4 samples), O3 : K29 (2 samples), O4 : K 8 (1 sample), and O4 : K11 (1 sample). The isolation rate of the TDH (+) strain from enrichment broth differed with samples. In several samples TDH (+) strains were isolated easily only by examining 3 colonies, hence no TDH (+) strains were isolated in spite of the examination of 250 colonies. No correlation was seen between the number of V. parahaemolyticus and the isolation rate of TDH (+) strains in food samples. Screening using PCR is very effective method for isolating TDH (+) V. parahaemolyticus from food samples.
Obata
Hiromi
H
Department of Microbiology, Tokyo Metropolitan Institute of Public Health.
Shimojima
Yukako
Y
Konishi
Noriko
N
Monma
Chie
C
Yano
Kazuyoshi
K
Kai
Akemi
A
Morozumi
Satoshi
S
Fukuyama
Masafumi
M
D004196:Disease Outbreaks; D005516:Food Microbiology; D005517:Foodborne Diseases / Q000453:epidemiology / Q000382:microbiology*; D006460:Hemolysin Proteins / Q000096:biosynthesis*; D006358:Hot Temperature; D006801:Humans; D008828:Microbiological Techniques; D016133:Polymerase Chain Reaction; D014736:Vibrio parahaemolyticus / Q000302:isolation & purification* / Q000378:metabolism
D006460:Hemolysin Proteins