Microcystins are emerging marine biotoxins, produced by potentially toxic cyanobacteria. Their presence has been reported in aquatic animals in Greek freshwater, while data are few in marine environments. Since the climate change induces eutrophication and harmful algal blooms in coastal marine ecosystems affecting the public health, further research on microcystins’ presence in marine waters is required. The aim of this study was to examine the potential presence of microcystins in mussels Mytilus galloprovincialis in the largest farming areas in Thermaikos gulf, in Northern Greece, and to investigate their temporal and spatial distribution, adding to the knowledge of microcystins presence in Greek Mediterranean mussels. A 4-year microcystins’ assessment was conducted from 2013 to 2016, in farmed Mediterranean mussels M. galloprovincialis, in five sampling areas in Thermaikos gulf, in northern Greece, where the 90% of the Greek mussels’ farming activities is located. The isolation of potentially toxic cyanobacteria was confirmed by molecular methods. An initial screening was performed with a qualitative and quantitative direct monoclonal (DM) ELISA and results above 1 ng g−1 were confirmed for the occurrence of the most common microcystins-RR, -LR and -YR, by Ultra High Performance Liquid Chromatography (UHPLC) coupled with a high- resolution mass spectrometer (HRMS) (Orbitrap analyzer). Microcystin-RR and microcystin-LR were detected, while the intensity of microcystin-YR was below the method detection limit. Most samples that exhibited concentrations above 1 ng g-1 were detected during the warm seasons of the year and especially in spring. Results indicated an overestimation of the ELISA method, since concentrations ranged between 0.70 ± 0.15 ng g−1 and 53.90 ± 3.18 ng g−1, while the confirmation denoted that the levels of microcystins were 6 to 22 times lower. Microcystin-RR and microcystin-LR were detected for the first time in mussel M. galloprovincialis, harvested from farms in Thermaikos gulf, in Central Macedonia, Greece. Their presence was linked to potentially toxic cyanobacteria. Bioaccumulation was observed in digestive gland, while the concentrations in muscles were found extremely low. Samples with levels above 1 ng g−1 were observed mostly during spring, confirming the seasonal distribution of microcystins. The comparison of the results by the ELISA and the LC-Orbitrap MS method indicated an overestimation of concentration by the ELISA method.

中文翻译：

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在希腊Thermaikos海湾的养殖地中海贻贝Mytilus galloprovincialis中检测到微囊藻毒素的第一份报告

微囊藻毒素是新兴的海洋生物毒素，由潜在的有毒蓝细菌产生。据报道，它们存在于希腊淡水中的水生动物中，而海洋环境中的数据很少。由于气候变化会在沿海海洋生态系统中引起富营养化和有害藻类繁殖，从而影响公共卫生，因此需要进一步研究微囊藻毒素在海水中的存在。这项研究的目的是研究希腊北部Thermaikos海湾最大的耕种地区贻贝中的微囊藻毒素的潜在存在，并调查其时空分布，从而增加了希腊地中海贻贝中微囊藻毒素存在的知识。 。从2013年到2016年，在养殖的地中海贻贝M. galloprovincialis中进行了为期4年的微囊藻毒素评估，在希腊北部Thermaikos海湾的五个采样区中，其中90％的贻贝养殖活动都位于该地区。通过分子方法证实了潜在毒性蓝细菌的分离。通过超高效液相色谱法（Quality and定量Direct Mono ELISA，DM）进行了初步筛选，结果证实了最常见的微囊藻毒素-RR，-LR和-YR的出现结果高于1 ng g-1 UHPLC）与高分辨率质谱仪（HRMS）（Orbitrap分析仪）结合使用。检测到微囊藻毒素-RR和微囊藻毒素-LR，而微囊藻毒素-YR的强度低于方法检测极限。在一年的温暖季节，特别是在春季，检测到大多数浓度高于1 ng g-1的样品。结果表明对ELISA方法的估计过高，因为其浓度范围为0.70±0.15 ng g-1至53.90±3.18 ng g-1，而确认结果表明微囊藻毒素的水平降低了6至22倍。在希腊中马其顿的Thermaikos海湾的农场收获的贻贝M. galloprovincialis中首次检测到微囊藻毒素-RR和微囊藻毒素-LR。它们的存在与潜在的毒性蓝细菌有关。在消化腺中观察到生物蓄积，而发现肌肉中的浓度极低。春季大部分观察到的样品浓度高于1 ng g-1，这证实了微囊藻毒素的季节性分布。ELISA和LC-Orbitrap MS方法的结果比较表明，ELISA方法高估了浓度。因为浓度范围在0.70±0.15 ng g-1和53.90±3.18 ng g-1之间，而确认结果表明微囊藻毒素水平降低了6到22倍。在希腊中马其顿的Thermaikos海湾的农场收获的贻贝M. galloprovincialis中首次检测到微囊藻毒素-RR和微囊藻毒素-LR。它们的存在与潜在的毒性蓝细菌有关。在消化腺中观察到生物蓄积，而发现肌肉中的浓度极低。春季大部分观察到的样品浓度高于1 ng g-1，这证实了微囊藻毒素的季节性分布。ELISA和LC-Orbitrap MS方法的结果比较表明，ELISA方法高估了浓度。因为浓度范围在0.70±0.15 ng g-1和53.90±3.18 ng g-1之间，而确认结果表明微囊藻毒素水平降低了6到22倍。在希腊中马其顿的Thermaikos海湾的农场收获的贻贝M. galloprovincialis中首次检测到微囊藻毒素-RR和微囊藻毒素-LR。它们的存在与潜在的毒性蓝细菌有关。在消化腺中观察到生物蓄积，而发现肌肉中的浓度极低。春季大部分观察到的样品浓度高于1 ng g-1，这证实了微囊藻毒素的季节性分布。ELISA和LC-Orbitrap MS方法的结果比较表明，ELISA方法高估了浓度。而确认结果表明微囊藻毒素的水平降低了6到22倍。在希腊中马其顿的Thermaikos海湾的农场收获的贻贝M. galloprovincialis中首次检测到微囊藻毒素-RR和微囊藻毒素-LR。它们的存在与潜在的毒性蓝细菌有关。在消化腺中观察到生物蓄积，而发现肌肉中的浓度极低。春季大部分观察到的样品浓度高于1 ng g-1，这证实了微囊藻毒素的季节性分布。ELISA和LC-Orbitrap MS方法的结果比较表明，ELISA方法高估了浓度。而确认结果表明微囊藻毒素的水平降低了6到22倍。在希腊中马其顿的Thermaikos海湾的农场收获的贻贝M. galloprovincialis中首次检测到微囊藻毒素-RR和微囊藻毒素-LR。它们的存在与潜在的毒性蓝细菌有关。在消化腺中观察到生物蓄积，而发现肌肉中的浓度极低。春季大部分观察到的样品浓度高于1 ng g-1，这证实了微囊藻毒素的季节性分布。ELISA和LC-Orbitrap MS方法的结果比较表明，ELISA方法高估了浓度。galloprovincialis，从希腊中马其顿的特尔马科斯海湾的农场收获。它们的存在与潜在的毒性蓝细菌有关。在消化腺中观察到生物蓄积，而发现肌肉中的浓度极低。春季大部分观察到的样品浓度高于1 ng g-1，这证实了微囊藻毒素的季节性分布。ELISA和LC-Orbitrap MS方法的结果比较表明，ELISA方法高估了浓度。galloprovincialis，从希腊中马其顿的特尔马科斯海湾的农场收获。它们的存在与潜在的毒性蓝细菌有关。在消化腺中观察到生物蓄积，而发现肌肉中的浓度极低。春季大部分观察到的样品浓度高于1 ng g-1，这证实了微囊藻毒素的季节性分布。ELISA和LC-Orbitrap MS方法的结果比较表明，ELISA方法高估了浓度。证实了微囊藻毒素的季节性分布。ELISA和LC-Orbitrap MS方法的结果比较表明，ELISA方法高估了浓度。证实了微囊藻毒素的季节性分布。ELISA和LC-Orbitrap MS方法的结果比较表明，ELISA方法高估了浓度。