Comparison between thiosulphate-citrate-bile salt sucrose (TCBS) agar and CHROMagar Vibrio

Considering its widespread distribution in marine environments, its fast replication times and low infectious doses and the rapid spread of its strains in recent years, intensive and continuous monitoring of potentially pathogenic Vibrio parahaemolyticus is strongly recommended in order to assess the human health risk arising from shellfish consumption. The lack of epidemiological data points to the need to develop specific methods for detectingV. parahaemolyticus. In this note, the authors compare two platingmedia currently available for isolating V. parahaemolyticus in shellfish. Both approaches involve pre-enrichment of V. parahaemolyticus. One uses thiosulphate-citrate-bile salt sucrose (TCBS) as the isolation medium, while the other uses a chromogenic medium (CHROMagar Vibrio). Next, biochemical identification of isolates was performed with API 20E, followed by PCR assay aimed at the toxR gene to confirm the cultural and biochemical identification. Comparison of the two methods highlighted that CHRO-Magar Vibrio is more accurate and specific than TCBS. The analysis of data from 160 shellfish samples showed an accuracy and specificity of just 51% and 71% for TCBS compared with 88% and 95% for CAV