title: Development of an ICR mouse bioassay for toxicity evaluation in neurotoxic poisoning toxins-contaminated shellfish.
abstract: OBJECTIVE
  To develop an ICR (female) mouse bioassay (MBA) for toxicity confirmation and evaluation of neurotoxins (brevetoxins)-contaminated shellfish.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  The two ELISA analyses agree favorably (correlation coefficient, r³⋝0.96; Student's t-tests, P>0.05) with the developed bioassay.
authors.affiliation: Biotoxin Laboratory, Microbiology Division, Public Health Laboratory Services Branch, Centre for Health Protection, Department of Health, Shek Kip Mei, Kowloon, Hong Kong, China. so_phlsS@dh-gov.hk
authors.forename: Chun Kwan
authors.initials: CK
authors.lastname: Wong
authors.forename: Patricia
authors.initials: P
authors.lastname: Hung
authors.forename: Kai Man
authors.initials: KM
authors.lastname: Kam
mesh_terms: D000818:Animals; D001681:Biological Assay; D002138:Calibration; D005260:Female; D008387:Marine Toxins / Q000633:toxicity*; D051379:Mice; D008813:Mice, Inbred ICR; D035964:Oxocins / Q000633:toxicity*; D012758:Shellfish / Q000032:analysis*; D000095702:Polyether Toxins
chemical_list: D008387:Marine Toxins; D035964:Oxocins; C053342:brevetoxin; D000095702:Polyether Toxins
keywords: Antibody-based assay; Brevetoxin; ICR female mice; LD50; Mouse bioassay; Neurotoxic shellfish poisoning