阿根廷海域潜在产毒硅藻拟菱形藻属的物种出现情况及相关神经毒素软骨藻酸。

Species occurrence of the potentially toxigenic diatom genus Pseudo-nitzschia and the associated neurotoxin domoic acid in the Argentine Sea.

机构信息

División Ficología, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata. Paseo del Bosque s/n (B1900FWA), La Plata, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Rivadavia 1917, 1033 Buenos Aires, Argentina.

出版信息

Harmful Algae. 2017 Mar;63:45-55. doi: 10.1016/j.hal.2017.01.007. Epub 2017 Jan 31.

DOI:10.1016/j.hal.2017.01.007

PMID:28366399

Abstract

The marine diatom genus Pseudo-nitzschia, the major known producer of the neurotoxin domoic acid (DA) responsible for the amnesic shellfish poisoning (ASP) syndrome in humans and marine mammals, is globally distributed. The genus presents high species richness in the Argentine Sea and DA has been frequently detected in the last few years in plankton and shellfish samples, but the species identity of the producers remains unclear. In the present work, the distribution and abundance of Pseudo-nitzschia species and DA were determined from samples collected on two oceanographic cruises carried out through the Argentine Sea (∼39-47°S) during summer and spring 2013. Phytoplankton composition was analysed by light and electron microscopy while DA was determined by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The genus Pseudo-nitzschia was recorded in 71 and 86% of samples collected in summer and spring, respectively, whereas DA was detected in only 42 and 21% of samples, respectively. Microscopic analyses revealed at least five potentially toxic species (P. australis, P. brasiliana, P. fraudulenta, P. pungens, P. turgidula), plus putatively non-toxigenic P. dolorosa, P. lineola, P. turgiduloides and unidentified specimens of the P. pseudodelicatissima complex. The species P. australis showed the highest correlation with DA occurrence (r=0.55; p<0.05), suggesting its importance as a major DA producer in the Argentine Sea. In the northern area and during summer, DA was associated with the presence of P. brasiliana, a species recorded for the first time in the Argentine Sea. By contrast, high concentrations of P. fraudulenta, P. pungens and P. turgidula did not correspond with DA occurrence. This study represents the first successful attempt to link toxigenicity with Pseudo-nitzschia diversity and cell abundance in field plankton populations in the south-western Atlantic.

摘要

海洋硅藻属拟菱形藻是已知的主要产毒生物之一，它产生的软骨藻酸（DA）是导致人类和海洋哺乳动物失忆性贝类中毒（ASP）的罪魁祸首，该属在全球范围内广泛分布。该属在阿根廷海域具有丰富的物种多样性，近年来在浮游生物和贝类样本中频繁检测到 DA，但产生 DA 的物种身份仍不清楚。在本研究中，通过在 2013 年夏季和春季进行的两次海洋学考察中收集的样本，确定了阿根廷海域（~39-47°S）拟菱形藻属物种和 DA 的分布和丰度。通过光学显微镜和电子显微镜分析浮游植物组成，通过液相色谱-串联质谱（LC-MS/MS）测定 DA。在夏季和春季采集的样本中，分别有 71%和 86%记录到拟菱形藻属，而仅在 42%和 21%的样本中检测到 DA。显微镜分析显示，至少有五个潜在毒性物种（P. australis、P. brasiliana、P. fraudulenta、P. pungens、P. turgidula），外加推定非产毒物种 P. dolorosa、P. lineola、P. turgiduloides 和未鉴定的 P. pseudodelicatissima 复合体标本。P. australis 与 DA 出现的相关性最高（r=0.55；p<0.05），表明其作为阿根廷海域主要 DA 生产者的重要性。在北部地区和夏季，DA 与 P. brasiliana 的存在相关联，这是该物种首次在阿根廷海域被记录到。相比之下，高浓度的 P. fraudulenta、P. pungens 和 P. turgidula 与 DA 的出现无关。本研究首次成功将产毒性与西南大西洋浮游种群中拟菱形藻的多样性和细胞丰度联系起来。