Abstract Book of EAVLD2012 - eavld congress 2012

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DETECTION OF SAXITOXINE (PSP MARINE BIOTOXIN) IN MOLLUSCS BY ELISA
Miroslaw M. Michalski, Katarzyna Grądziel-Krukowska
National Veterinary Research Institute, Department of Hygiene of Food of Animal Origin, Puławy, Poland
Head of the Department: prof. Jacek Osek
Marine biotoxins, saxitoxine, Elisa, intoxication
Introduction
Marine biotoxins are a group of natural toxins that sometimes
accumulate in shellfish. Many biotoxins are produced by marine
algae (phytoplankton, including diatoms and dinoflagellates) and
can accumulate in fish or shellfish if they ingest these algae.
There are several types of illnesses, caused by marine biotoxins,
that are connected with the consumption of contaminated
shellfish. They include Paralytic Shellfish Poisoning (PSP), and
Diarrhetic Shellfish Poisoning (DSP), Amnesic Shellfish
Poisoning (ASP). Saxitoxin is a naturally produced marine
biotoxin by several gonyaulacoid or gymnodinioid dinoflagellates,
including Alexandrium, Gymnodinium, Pyrodinium, and has also
been found in freshwater cyanobacterial strains such as
Cylindrospermopsis raciborskii
The toxins responsible for PSP are heterocyclic guanidines
(saxitoxins) and there are over 21 known congeners. Substitution
at R4 results in substantial changes in toxicity. Saxitoxin (STX)
binds with a high affinity to site 1 on the voltage dependent
sodium channel, inhibiting channel opening (1, 3)
Table 1
Type of shellfish
1.Mule
Mytilus edulis
2.Oysters
Crassostrea gigas
3.Vongole
Tapes
semidecussatus
4.Scallops
Pecten spp.
Number of
samples
Number of samples:
bld 1 /pos 2 /exc 800
µg/ 3
24 5/19/0
13 3/10/0
Country of
origin
Holland,
Norway,
France
Holland,
France
12 2/10/0 Italia
10 2/7/0 Holland
Total numbers of
sam-samples
59
1 - bellow limit of detection
2 - range 50-800 µg/kg
3 – concentartion in molluscs meat more than 800 µg/kg
PSP toxic syndrome is due primarily to the consumption of
molluscs contaminated by PSP toxins as a result of filter-feeding
by toxic dinoflagellates. After intoxication of PSP, the effects are
predominantly neurological and include tingling, burning,
numbness, drowsiness, incoherent speech, and respiratory
paralysis. Symptoms of the disease develop fairly rapidly, within
0.5 to 2 hours after ingestion of the shellfish, depending on the
amount of toxin consumed. In severe cases respiratory paralysis
is common, and death may occur if respiratory support is not
provided (1, 2, 3). In the EU law a limit for PSP toxins in bivalve
molluscs is laid down at 80 g STX eq/100 g of shellfish meat (4).
Materials & methods
The RIDACSREEN ® FAST PSP SC test was used for the
determination of PSP toxins in shellfish. This assay is a direct
competitive Elisa for PSP and related algae toxins in mussels. All
reagents are contained in the test kit. Detection limit of test is 50
µg/kg of shellfish meat. A total of four different types of mussels
were used for analysis. Live shellfish samples used in this study
were collected from warehouses and markets. A total number of
59 samples were investigated. Preparation of samples and Elisa
test was performed according to the test producer instruction.
Discussion & conclusions
Fifty nine samples of shellfish meat were analysed by the Elisa
test. In 46 samples PSP biotoxins were found, expressed as
saxitoxin-HCl, in range 50-800 µg/kg. In 12 samples the
concentration of PSP toxins was bellow the limit of the detection
of the test and no sample with more than 800 µg/kg of PSP toxins
in mussels. The present experiment clearly showed that the
shellfish available on Polish marked are, as a food, safe for
consumers.
References
1. EFSA. 2009. Marine biotoxins in shellfish – Saxitoxin group.
Scientific Opinion of the Panel on Contaminants in the Food
Chain. The EFSA Journal, 2009, 1019, 1-76
2. Michalski Miroslaw. Biotoksyny morskie - występowanie i metody
analizy. Żywność.Nauka.Technologia.Jakość. 2006, 3(48), 16-22
3. Michalski Mirosław: Paralityczne toksyny morskie jako zagrożenie dla
zdrowia konsumenta. Medycyna Weterynaryjna 2007, 63(12), 1530-1533
4. Regulation (EC) No 853/2004 of The European Parliament and of the
Council of 29 April 2004 laying down specific hygiene rules for food of
animal origin.
Results
The content of saxitoxine determined by the Elisa test in the four
species of shellfish is shown in table 1.