Detection of Diarrheic Shellfish Poisoning and Azaspiracids Toxins in Moroccan Mussels: Comparison of LC-MS Method with the Commercial Immunoassay Kit

Abstract

Diarrheic shellfish poisoning (DSP) is a recurrent gastrointestinal illness in Morocco, resulting from consumption of contaminated shellfish. In order to develop a rapid and reliable technique for toxins detection, we have compared the results obtained by a commercial immunoassay-"DSP-Check" kit" with those obtained by LC-MS. Both techniques are capable of detecting the toxins in the whole flesh extract which was subjected to prior alkaline hydrolysis in order to detect simultaneously the esterified and non esterified toxin forms. The LC-MS method was found to be able to detect a high level of okadaic acid (OA), low level of dinophysistoxin-2 (DTX2), and surprisingly, traces of azaspiracids 2 (AZA2) in mussels. This is the first report of a survey carried out for azaspiracid (AZP) contamination of shellfish harvested in the coastal areas of Morocco. The "DSP-Check" kit was found to detect quantitatively DSP toxins in all contaminated samples containing only OA, provided that the parent toxins were within the range of detection and was not in an ester form. A good correlation was observed between the two methods when appropriate dilutions were performed. The immunoassay kit appeared to be more sensitive, specific and faster than LC-MS for determination of DSP in total shellfish extract.

Driving factors of the potentially toxic and harmful species of Prorocentrum Ehrenberg in a semi-enclosed Mediterranean lagoon (Tunisia, SW Mediterranean)

“…However, some of the polyether toxins involved may promote stomach tumours (Suganuma et al, 1988) and thus produce serious problems in shellfish consumers. The known distribution of DSP toxins in the Mediterranean includes Italy (Draisci et al, 1995;1998), Spain (Bravo et al, 2001), Greece (Mouratidou et al, 2004;Ciminiello et al, 2006), France (Lassus et al, 1985), Morocco (Elgarch et al, 2008) and also Tunisia (Bizerte Lagoon, Turki, 2004;Kacem et al, 2010). .…”

Amphidoma languida (Amphidomatacea, Dinophyceae) with a novel azaspiracid toxin profile identified as the cause of molluscan contamination at the Atlantic coast of southern Spain

“…Noteworthy, toxins are highly concentrated in the digestive gland but not as much in other shellfish tissue (Hess et al, 2005;Jauffrais et al, 2012) and thus, such values cannot directly be compared with the EU regulatory limit. In summer 2006, low levels of AZA (up to 6 mg kg À1 edible tissue) were reported from the same area about 180 km south of Casablanca (Elgarch et al, 2008).…”

Azadinium poporum from the Argentine Continental Shelf, Southwestern Atlantic, produces azaspiracid-2 and azaspiracid-2 phosphate

“…been documented in shellfish from many coastal regions of western Europe (James et al, 2002;Brañ a Magdalena et al, 2003;Furey et al, 2003;Amzil et al, 2008), northern Africa (Taleb et al, 2006;Elgarch et al, 2008), China (Yao et al, 2010), and North America (Trainer et al, 2013). In addition, AZA have been found in Japanese sponges (Ueoka et al, 2009) and Scandinavian crabs (Torgersen et al, 2008).…”