Chang F H, Anderson D M, Kulis D M, Till D G
National Institute of Water and Atmospheric Research Ltd, Kilbirnie, Wellington, New Zealand.
Toxicon. 1997 Mar;35(3):393-409. doi: 10.1016/s0041-0101(96)00168-7.
Paralytic shellfish toxins of two clonal cultures of Alexandrium minutum isolated during the 1993 toxic shellfish events in the Bay of Plenty, New Zealand, were analyzed using high-performance liquid chromatography. Toxin composition profiles of both cultures showed neosaxitoxin (> 65 mole%) as the principal toxin, with saxitoxin and gonyautoxins (GTX1-4) as minor components. Neither C-toxins (C1-4) nor GTX5-6 were detectable in the two isolates. Bay of Plenty isolates of A. minutum have a unique toxin profile not found in any other isolates of this species that have been characterized. This weakens the hypothesis that A. minutum was recently introduced to New Zealand waters by ballast water or other long-distance transport mechanisms, and argues instead that the species was endemic to the area, but not noticed in the past. The average toxicity of the cultures was 8.8 and 11.0 pg saxitoxin equiv. cell-1 with acetic acid or HCl extraction, respectively. These are at the high end of the range of toxicity reported for A. minutum strains from around the world, and on a cell volume basis are comparable to the most toxic strains of the Alexandrium tamarense group. The toxin profile of A. minutum most closely matches that of mussels and to a lesser degree tuatua harvested from the Bay during the 1993 outbreak, but is quite different from the profile measured in scallops and pipi. Plausible mechanisms for bioconversion of the ingested algal toxins within the latter two shellfish species can be proposed, but it seems more likely that either other strains of A. minutum or other saxitoxin-producing dinoflagellates were ingested by those shellfish. This study established that A. minutum from the Bay of Plenty contains saxitoxins, has a unique toxin composition compared to all other isolates of this species, and was responsible for at least part of the PSP toxicity measured in shellfish during the 1993 outbreak.
利用高效液相色谱法对1993年新西兰普伦蒂湾有毒贝类事件期间分离出的两株微小亚历山大藻克隆培养物中的麻痹性贝类毒素进行了分析。两种培养物的毒素组成谱均显示，新石房蛤毒素（>65摩尔%）为主要毒素，石房蛤毒素和膝沟藻毒素（GTX1 - 4）为次要成分。在这两个分离株中均未检测到C毒素（C1 - 4）和GTX5 - 6。普伦蒂湾分离出的微小亚历山大藻具有独特的毒素谱，在该物种其他已鉴定的分离株中未发现。这削弱了微小亚历山大藻是最近通过压舱水或其他长途运输机制引入新西兰水域的假说，相反，这表明该物种是该地区的本地物种，只是过去未被注意到。培养物的平均毒性分别为8.8和11.0皮克石房蛤毒素当量/细胞，分别采用乙酸或盐酸提取。这些处于世界各地报道的微小亚历山大藻菌株毒性范围的高端，并且按细胞体积计算，与塔玛亚历山大藻组中毒性最强的菌株相当。微小亚历山大藻的毒素谱与1993年疫情期间从该湾采集的贻贝最为匹配，与tuatua的匹配程度稍低，但与扇贝和pipi中测得的谱有很大不同。可以提出后两种贝类物种中摄入的藻毒素生物转化的合理机制，但似乎更有可能的是，这些贝类摄入了其他微小亚历山大藻菌株或其他产石房蛤毒素的甲藻。这项研究确定，普伦蒂湾的微小亚历山大藻含有石房蛤毒素，与该物种的所有其他分离株相比具有独特的毒素组成，并且是1993年疫情期间贝类中测得的至少部分麻痹性贝类中毒毒性的原因。
