MAP Technical Reports Series No. 106 UNEP

7.2.2 Diarrhetic Shellfish Poisoning (DSP)
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Diarrhetic shellfish poisoning (DSP) has become known only in recent years as a
shellfish poisoning distinctly different from the paralytic shellfish poisoning (PSP) and neurotoxic
shellfish poisoning (NSP) in both symptomatology and etiology (Yasumoto et al., 1978). The
clinical symptomatology is of gastrointestinal type, consisting of nausea, vomiting and diarrhoea,
and unlike PSP no fatal cases have been reported (Yasumoto et al., 1978; Krogh, 1989). The
first studies on DSP were carried out in Japan and continued in Western Europe, in Italy and
Canada.
7.2.2.1 DSP producing or potentially toxic dinoflagellates
In the sea world. In Japan Dinophysis fortii has been incriminated as the organism
producing DSP toxins (Yasumoto et al., 1980). On European Atlantic coasts other dinoflagellate
species are involved in DSP intoxications: Dinophysis acuminata in Spain (Campos et al., 1982);
D. acuminata, D. sacculus, Prorocentrum lima in France (Paulmier et al., 1984; Berthomé et
al., 1986); D. acuminata, Prorocentrum redfieldii, P. micans in The Netherlands (Kat, 1979); D.
acuminata, D. norvegica, P. micans in Scandinavia (Krogh et al., 1985; Granéli et al., 1989). Until
now, eight Dinophysis sp. have been shown to be toxic (DSP): D. acuminata, D. acuta, D. fortii,
D. mitra, D. norvegica, D. rotundata, D. sacculus and D. tripos (Yasumoto, 1990; Sampayo et
al., 1990). Also other species of Dinophysis and Prorocentrum should be regarded as shellfish
contaminant that may have caused diarrhetic poisoning.
In the Mediterranean sea. Various species of the genera Dinophysis and Prorocentrum
are present in the Mediterranean sea. Many Dinophysis species are present in the Italian seas,
but never form red tides (Rampi, 1951; Solazzi and Andreoli, 1971; Innamorati et al., 1989a-b;
Honsell, 1990). Some Dinophysis species have always been encountered in the Adriatic
phytoplankton (Schroeder, 1911; Jørgensen, 1923; Ercegovic, 1936; Revelante et al., 1984).
During the DSP intoxication which occurred in 1989 (Boni et al., 1992), the presence was
noticed of D. fortii, D. tripos, D. caudata and another species similar to D. acuminata. In
phytoplankton of the Northern and Central Adriatic sea were also observed D. rotundata Clap.
et Lachm., D. acuta Ehrb., D. diegensis Kof. (Ammazzalorso et al., 1991; Boni et al., 1992,
1993; Della Loggia et al., 1993; Lassus et al., 1993). Many Dinophysis species are also present
in the Tyrrhenian sea but DSP was never detected in the local shellfish. However it is not known
whether the species D. circumsuta (Karsten) Balech, D. infundibulus Sch., D. umbosa Sch. and
some others (Innamorati et al., 1989 a-b) found in the Tyrrhenian sea are toxic or not.
In the genus Prorocentrum, P. lima (Ehr) Dodge is considered causative agent of DSP
and also of ciguatera. This dinoflagellate has been found in the Tyrrhenian sea since 1978
(Innamorati et al., 1989 a-b), and recently in the Adriatic sea, Grado-Marano Lagoon (Moro and
Andreoli, 1991) and Gulf of Trieste (Honsell, 1992).
7.2.2.2 Chemistry of the components of DSP toxins
DSP toxins biosynthesis occurs in various species of Dinophysis (Yasumoto et al.,
1980; Kat, 1983; Underdal et al., 1985; Lassus et al., 1988; Kat, 1989; Marcaillon-Le Baut and
Masselin, 1990) and in Prorocentrum lima (Murakami et al., 1982). The chemically defined
toxins, isolated from these dinoflagellates and mussels and in other bivalve shellfish fall into
three structural classes, all being lipophilic compounds. The first (acidic toxins) consisting of
okadaic acid, dinophysis toxin 1 (DTX-1) and DTX-3, the second (neutral toxins)