EVALUATION OF 2 ASSAY KITS FOR THERMOSTABLE DIRECT HEMOLYSIN (TDH) ASAN INDICATOR OF TDH-RELATED HEMOLYSIN (TRH) PRODUCED BY VIBRIO-PARAHAEMOLYTICUS

Reversed passive latex agglutination (RPLA) or enzyme-linked immunosor bent assay kits with beads (Bead-ELISA) are commercially available in Japan to detect the thermostable direct hemolysin (TDH) produced by Vi brio parahaemolyticus isolates. We evaluated whether these kits can be used to assay the pathogenic toxin, TDH-related hemolysin (TRH), prod uced by some so-called Kanagawa phenomenon-negative V. parahaemolyticu s strains isolated from patients with diarrhea. Our results showed tha t the two kits, RPLA and Bead-ELISA, can detect TRH, although they wer e originally developed for detection of TDH. This may be due to the us e of polyclonal anti-TDH antisera that cross react with TRH. Although the sensitivity for TDH detection by RPLA and Bead-ELISA differed tenf old, that for TRH detection was essentially equal. The minimum concent ration of TRH required for detection by the two assay kits was about 1 0 ng/ml.