Comparison between a TaqMan polymerase chain reaction assay and a culture method for ctx-positive Vibrio cholerae detection.
The main objective of the present work was to evaluate a real-time polymerase chain reaction (PCR) method to detect toxigenic Vibrio cholerae in Pangasius hypophthalmus, a freshwater fish cultured mainly in South East Asia. A FDA traditional culture method and a real-time PCR method of the ctx gene were used for detection of V. cholerae in spiked samples of pangasius fish. After an overnight enrichment of samples at 37 degrees C in alkaline peptone water, 2 cfu/25 g of fish was detected with both methods. Although both methods were very sensitive, obtaining results with culture methods may take several days, while real-time PCR takes only a few hours. Furthermore, with traditional methods, complementary techniques such as serotyping, although not available for all serogroups, are needed to identify toxigenic V. cholerae. However, with real-time PCR, toxigenic serogroups are detected in only one step after overnight enrichment.
Chapela
Maria-Jose
MJ
ANFACO-CECOPESCA, Colegio Universitario, Vigo, Pontevedra, Spain. mjchapela@anfaco.es
Fajardo
Paula
P
Garrido
Alejandro
A
Cabado
Ana G
AG
Ferreira
Martina
M
Lago
Jorge
J
Vieites
Juan M
JM
D000818:Animals; D015373:Bacterial Typing Techniques; D002397:Catfishes; D018999:Charybdotoxin / Q000032:analysis / Q000235:genetics*; D046508:Culture Techniques / Q000379:methods*; D005393:Fish Diseases / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods*; D019914:Taq Polymerase / Q000032:analysis; D014734:Vibrio cholerae / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*
D018999:Charybdotoxin; D019914:Taq Polymerase