Tetrodotoxin in Gastropods (Snails) Implicated in Food Poisoning in Northern Taiwan

Abstract

The toxin in the gastropods (snails) Zeuxis sufflatus and Niotha clathrata implicated in a food poisoning incident in northern Taiwan in April 2001 was studied. The symptoms exhibited by four victims were general paresthesia, paralysis of the phalanges and the extremities, paralysis, coma, vomiting, and aphasia. The remaining gastropods were assayed for toxicity in the form of tetrodotoxin (TTX). The ranges of specimen toxicity were 345 to 1,640 mouse units (MU) for Z. sufflatus and 190 to 643 MU for N. clathrata. The toxicities of the digestive gland and for other parts of the gastropod were 1,120 ± 477 MU and 497 ± 238 MU, respectively, for Z. sufflatus and 683 ± 113 MU and 289 ± 169 MU, respectively, for N. clathrata. The toxin from the methanolic extract of the gastropods was partially purified by ultrafiltration and Bio-Gel P-2 column chromatography. Cellulose acetate membrane electrophoresis, thin-layer chromatography, high-performance liquid chromatography, and gas chromatography–mass spectrometry analyses demonstrated that the toxin consisted of TTX. It was concluded that the causative agent of the food poisoning in question was TTX.