Development of an ICR mouse bioassay for toxicity evaluation in neurotoxic poisoning toxins-contaminated shellfish / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To develop an ICR (female) mouse bioassay (MBA) for toxicity confirmation and evaluation of neurotoxins (brevetoxins)-contaminated shellfish.</p><p><b>METHODS</b>Brevetoxins (BTX-B) as a causative agent of neurotoxic shellfish poisoning (NSP) under different shellfish matrices were intraperitoneally injected at different doses into mice to study their toxic effects and to differentiate the range of lethal and sublethal dosages. Their sensitivity and specificity were analyzed with 2 competitive ELISA kits for quantitative determination of standard BTX-B and dihydroBTX-B under different shellfish matrix-diluent combinations. Detection rates of MBA and two antibody-based assays for BTX-B from field NSP-positive shellfish samples were compared.</p><p><b>RESULTS</b>BTX-B could be detected in shellfish tissues at concentration of 50-400 μg/100 g under shellfish matrix-Tween-saline media, which were appropriate to identify toxic shellfish at or above the regulatory limit (80 μg/100 g shellfish tissues). The LD50 identified was 455 mg/kg for BTX-B under general shellfish matrices (excluding oyster matrices) dissolved in Tween-saline. The presence of shellfish matrices, of oyster matrices in particular, retarded the occurrence of death and toxicity presentation in mice. Two antibody-based assays, even in the presence of different shellfish matrix-diluent combinations, showed acceptable results in quantifying BTX-B and dihydroBTX-B well below the regulatory limit.</p><p><b>CONCLUSION</b>The two ELISA analyses agree favorably (correlation coefficient, r³⋝0.96; Student's t-tests, P>0.05) with the developed bioassay.</p>

Detection of shellfish toxins from scallops in Guangzhou seafood market

To evaluate scallop safety in the Guangzhou seafood market, contents of shellfish toxins in adductor muscle, mantle skirts, gills and visceral mass of scallops were examined using enzyme-linked immunosorbent assay (ELISA) and mouse unit assay. The results showed that: paralytic shellfish poisoning contents were up to 37.44 µg/100 g by ELISA and 319.99 MU/100 g by mouse unit assay, which did not exceed the limits of national standards (80 µg/100g and 400 MU/100 g); the contents of diarrhetic shellfish poisoning were 142.04 µg/100g and 0.2 MU/100 g, which exceeded the national standard limits (60 µg/100g); neurotoxic shellfish poisoning was undetectable; the contents of amnesic shellfish poisoning reached 220.12 µg/100g (no limit value could be referred to) . In addition, these poisons were present mainly in visceral mass and gills rather than adductor muscle and mantle skirts, suggesting that these toxins accumulate in a tissue-specific manner.(AU)