Bioassays shellfish poisons

Due to false positives, zinc may confound interpretation of the paralytic shellfish poisoning (PSP) mouse bioassay, one of the routine tests used to measure shellfish safety for human consumption. For example, mice injected intraperitoneally with extracts of healthy oyster tissues showed extreme weakness, a drop in body temperature, cyanosis, and some deaths (McCulloch et al. 1989). The threshold for a toxic PSP response corresponds to a drained tissue zinc level >900 mg/kg FW, and this overlaps the zinc concentration range of 230 to 1650 mg/kg FW (1900 to 9400 mg/kg DW) recorded in healthy oyster soft tissues (McCulloch et al. 1989). 

Mayer, F.L., Jr., and M.R. Ellersieck. 1986. Manual of acute toxicity interpretation and data base for 410 chemicals and 66 species of freshwater animals. U.S. Fish Wildl. Serv., Resour. Publ. 160. 579 pp. McCulloch, A.W., R.K. Boyd, A.S.W. de Freitas, R.A. Foxall, W.D. Jamieson, M.V. Laycock, M.A. Quilliam, J.C. Wright, V.J. Boyko, J.W. McLaren, M.R. Miedema, R. Pocklington, E. Arsenault, and D.J.A. Richard. 1989. Zinc from oyster tissue as causative factor in mouse deaths in official bioassay for paralytic shellfish poisoning. Jour. Assoc. Offic. Anal. Chem. 72 384-386. 

Jellett, J.F., et al.. Detection of paralytic shellfish poisoning (PSP) toxins in shellfish tissue using MIST Alert, a new rapid test, in parallel with the regulatory AOAC mouse bioassay, Toxicon, 40, 10, 1407, 2002. 

LEDOUX M and hall s, Proficiency testing of eight French laboratories in using the AOAC mouse bioassay for paralytic shellfish poisoning interlaboratory collaborative study , J. AOAC Int 2000 83 305-10. 

JELLET J F, MARKS L J, STEWART J E, DOREY M L, WATSON-WRIGHT W and Lawrence J F, Paralytic shellfish poison bioassays automated end-point determination and standardization of the in vitro tissue culture bioassay, and comparison with the standard mouse bioassay , Toxicon 1993 30 1143-56. 

GALLACHER S, MACKINTOSH F, SHANKS A M, O NEILL S, RIDDOCH I and Howard F G, Monitoring for paralytic shellfish poisons in Scotland and progress in research to replace the use of the mouse bioassay , J Shellfish Res, 1998 17 1647-51. 

Suzuki, T, Jin, T, Shirota, Y, Mitsuya, T, Okumura, Y, and Kamiyama, T. 2005b. Quantification of lipophilic toxins associated with diarrhetic shellfish poisoning (DSP) in Japanese bivalves by liquid chromatography-mass spectrometry (LC-MS) and comparison with mouse bioassay (MBA) as the official testing method in Japan. Fish Sci 71, 1370-1378. 

Manger, R. L., Leja, L. S., Lee, S. Y, Hungerford, J. M., Kirkpatrick, M. A., Yasumoto, T. and Wekell, M. M. Detection of paralytic shellfish poison by rapid cell bioassay antagonism of voltagegated sodium channel active toxins in vitro. J. AOAC Int., 86, 540-543 (2003). 

Combes, R.D., The mouse bioassay for diarrhetic shellfish poisoning a gross misuse of laboratory animals and scientific methodology. Alt. Lab. Anim., 31, 595, 2003. 

Usleber, E. et al.. Comparison of enzyme immnnoassay and monse bioassay for determining paralytic shellfish poisoning toxins in shellfish, FoodAddit. Contam., 14, 193, 1997. 

McFarren, E. F. Report on collaborative studies of the bioassay for paralytic shellfish poison. J. Assoc. Off. Anal Chem., 42, 263, 1959. 

Schantz, E.J. et al. Purified poison for bioassay standardisation./. A oc. Off. Anal. Chem.Al, 160, 1958. McCulloch, A.W. et al. Zinc from oyster tissue as causative factor in mouse deaths in official bioassay for paraytic shellfish poison. J. AOAC, 72,384, 1989. 

Okomura, M., Tsuzuk, H., and Tomita, B-I. A rapid detection method for paralytic shellfish poisoning toxins by cell bioassay. Toxicon, 46, 93, 2005. 

The blooms generally occur in spring, summer, and autumn and the cyanotoxins that were detected are anatoxin-a, saxitoxins, cylindrospermopsin, microcystins, and thionsulolipid. Also, paralytic shellfish poisons (PSPs) have been confirmed by mouse bioassay following analysis of... 

Due to false positives, zinc may confound interpretation of the paralytic shellfish poisoning (PSP) mouse bioassay, one of the routine tests used to measure shellfish safety for human consumption. For example, mice injected intraperitoneally with extracts of healthy oyster tissues showed extreme weakness, a drop in body temperature, cyanosis, and some... 

Truman P, Lake RJ (1996) Comparison of mouse bioassay and sodium channel cytotoxicity assay for detecting paralytic shellfish poisoning toxins in shellfish extracts. J AOAC Int... 

As described above for diarrhetic shellfish poisoning (DSP) toxins, the ether extract wash may cause the loss of not only PSP toxins, but also a part of YTXs. Nevertheless, YTXs are rather potent when injected intraperitoneally and the amoimt left on the DSP extract is sufficient to cause mouse dead within secure limits for the directive. The maximum limits for YTX are set to 1 mg of YTX equivalents (whole body or any edible part)/kg. The maximum combined limits of OA, DTXs, and PTXs (whole body or any edible part) are set to 160 pg of OA equivalents/kg. For AZAs, the maximmn limits (whole body or any edible part) are set to 160 pg of AZA equivalents/kg. Since AZA is distributed in the whole body of the mollusc, the protocol requires the use of the whole body as the test portion for the bioassay of these toxins. Therefore, whole body must be used routinely in order to include AZAs in the monitoring system. 

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