HIGH AMOUNT OF DINOPHYSISTOXIN-3 IN Mytilus chilensis COLLECTED IN SENO DE RELONCAVI, CHILE, DURING MASSIVE HUMAN INTOXICATION ASSOCIATED WITH OUTBREAK OF Vibrio parahaemolyticus

Abstract

-This study describes the detection of high amount of 7-O-acyl-derivative dinophysistoxin-1 (Dinophysistoxin-3) in filter bivalves collected on February 2005 in the Seno de Reloncaví, Puerto Montt City, Southern Chile, in the same period of time where an intoxication episode was associated with the presence of Vibrio parahaemolyticus in shellfish.The Diarrhetic Shellfish Poisoning (DSP) mouse bioassay of mussel extract samples, performed as described for regulatory testing, were negative to DSP toxins. Therefore, the same mussel samples collected from 8 places of Seno de Reloncaví were then analyzed by the HPLC-FLD method with pre-column derivatization procedure for DSP toxins.The samples showed mainly 7-O-acyl-derivative dinophysistoxin-1 (Dinophysistoxin-3) in concentrations ranging from 190.3 ± 6.8 to 311.1 ± 4.8 ng of DSP toxin/g hepatopancreas and less amounts of Dinophysistoxin-1 ranging from 1.9 ± 1.5 to 11.7 ± 4.6 ng of DSP toxin/g hepatopancreas. After alkaline hydrolysis of the mussel extracts, 279.4 ± 7.2 ng of Dinophysistoxin-1 /g hepatopancreas (mean ± SEM, N=6) were found in mussel extracts (Zone 8). These data showed that these shellfish samples are contaminated with the ester form 7-O-acyl-derivatives of Dinophysisyoxin-1, far beyond the safe regulatory limit. This paper also shows a direct relation between lipid content in the mussel tissue extracts and the levels of Dinophysistoxin-3. The 7-O-acyl-derivative dinophysistoxin-1 ester was the only compound associated with DSP toxins detected in the shellfish samples, and in view of the fact that metabolic transformation of Dinophysistoxin-3 into Dinophysistoxin-1 in humans has recently been described in the literature, the consumption of shellfish contaminated with 7-O-acyl-derivatives dinophysistoxin-1 could be a major reason that explains the diarrhetic symptoms shown by the intoxicated patients.

First evidence of Okadaic acid acyl-derivative and Dinophysistoxin-3 in mussel samples collected in Chiloe Island, Southern Chile

“…So, DTX-3 is the most regularly DSP toxins found, being most of the time the only DSP toxin found in shellfish extracts. Some samples also showed DTX-1, but the DTX-3 amount is always prevalent and the highest one in the DSP toxin profile (García et al, 2004(García et al, , 2005(García et al, and 2006 . Therefore, after 4 years of permanently detection of DTX-3 in shellfish samples in many Chilean fjords, the presence of DTX-3 can be considered endemic and also the main DSP toxins in Chilean contaminated shellfish.…”

“…In Chile, outbreaks associated to DSP intoxications have occurred throughout Patagonian fjords since 1970 (Lagos, 1998;Muñoz et al, 1992;Uribe et al, 2001;García et al, 2003García et al, , 2004García et al, , 2005García et al, and 2006. Presently, the endemic presence of DSP toxins has been established in the three most austral Regions of Chile (X, XI and XII) (Lagos, 1998;Uribe et al, 2001;García et al, 2004García et al, , 2005García et al, and 2006.…”

“…Presently, the endemic presence of DSP toxins has been established in the three most austral Regions of Chile (X, XI and XII) (Lagos, 1998;Uribe et al, 2001;García et al, 2004García et al, , 2005García et al, and 2006.…”