• AZA – the producing organisms – biology and trophic transfer

      Tillmann, U.; Salas, R.; Jauffrais, T.; Hess, P.; Silke, J. (CRC Press, 2014)
      Compared to the knowledge on toxin structure, detection methods, and toxicology, convincing clarification of the aetiology of AZP was seriously lacking behind for quite a long time. Based upon the seasonal and episodic accumulation of AZA toxins in suspension-feeding bivalve molluscs – a situation similar to several other marine biotoxins - a planktonic source has been suspected from the outset. Furthermore, due to their polyether structural features, AZA has been suspected to be a dinoflagellate metabolite. Thus, it was no surprise that is was a dinoflagellate species which was first claimed to be the source of AZA. The link between AZA and P. crassipes, however, remained controversial because production of AZA by P. crassipes could not be verified in spite of numerous attempts based upon field surveys and laboratory investigations of cultured and isolated cells. Moreover, in contrast to other proven producers of phycotoxins, which are all primarily phototrophic, P. crassipes is a heterotrophic dinoflagellate, known to prey upon other dinoflagellates as food. The likelihood, therefore, that another dinoflagellate may produce AZA, which then accumulates in P. crassipes through normal feeding processes, could not be neglected.
    • Development & implementation of the Phytotest project

      Kavanagh, S.; Brennan, C.; Lyons, C.; Chamberlain, T.; Salas, R.; Moran, S.; Silke, J.; Maher, M. (Marine Institute, 2008)
      Phytotest is a 3-year research and development project funded through the Marine Institute Strategic Research Programme in Advanced Technologies as part of the National Development plan 2000-2006. The project is a collaboration between the National Diagnostics Centre at NUI Galway and the MI and involves the development of real-time PCR assays for Dinophysis and Pseudo-nitzschia species that are important in Irish waters. In the current final phase of the project, the real-time PCR assays are being transferred to the MI to support the phytoplankton monitoring service.
    • The dinophycean genus Azadinium and related species – morphological and molecular characterization, biogeography, and toxins

      Tillmann, U.; Elbrächter, M.; Gottschling, M.; Gu, H.; Jeong, H.J.; Krock, B.; Nézan, E.; Potvin, E.; Salas, R.; Soehner, S. (International Society for the Study of Harmful Algae, 2014)
      Azaspiracids (AZAs) are the most recently discovered group of lipophilic marine biotoxins of microalgal origin. It took about twelve years from the first human poisoning event until a culprit for AZA production was unambiguously identified and described as a novel species, Azadinium spinosum, within a newly created genus. Since then, knowledge on the genus has increased considerably, and an update on the current circumscription of the genus is presented here including various aspects of morphology, phylogeny, biogeography, and toxin production. There are currently five described species: A. spinosum, A. obesum, A. poporum, A. caudatum, and A. polongum. As indicated by molecular sequence variation detected in field samples, there are probably more species to recognize. Moreover, Amphidoma languida has been described recently, and this species is the closest relative of Azadinium based on both molecular and morphological data. Amphidoma and Azadinium are now grouped in the family Amphidomataceae, which forms an independent lineage among other monophyletic major groups of dinophytes. Initially, azaspiracids have been detected in A. spinosum only, but AZA production within the Amphidomataceae appears complex and diverse: A new type of azaspiracid, with a number of structural variants, has been detected in A. poporum and Amphidoma languida, and AZA-2 has now been detected in Chinese strains of A. poporum.
    • Morphological and molecular characterization of the small armoured dinoflagellate Heterocapsa minima (Peridiniales, Dinophyceae)

      Salas, R.; Tillmann, U.; Kavanagh, S. (Taylor and Francis, 2014)
      The dinophycean genus Heterocapsa is of considerable interest as it contains a number of bloom-forming and/or harmful species. Fine structure of organic body scales is regarded as the most important morphological feature for species determination but currently is unknown for the species H. minima described by Pomroy 25 years ago. Availability of a culture of H. minima collected in the south-west of Ireland allowed us to provide important information for this species, including cell size, cell organelle location, thecal plate pattern, body scale fine structure and molecular phylogeny. Light microscopy revealed the presence of one reticulate chloroplast, an elongated centrally located nucleus, and the presence of one pyrenoid surrounded by a starch sheath. Scanning electron microscopy (SEM) of the thecal plate pattern indicated that Pomroy erroneously designated the narrow first cingular plate as a sulcal plate. In addition, SEM revealed as yet unreported details of the apical pore complex and uncommon ornamentations of hypothecal plates. Organic body scales of H. minima were about 400 nm in size, roundish, with a small central hole and one central, six peripheral and three radiating spines. They differ from other body scales described within this genus allowing for positive identification of H. minima. Heterocapsa minima shares gross cell morphological features (hyposome smaller than episome, elongated nucleus in the middle of the cell, one pyrenoid located in the episome on its left side) with H. arctica (both subspecies H. arctica subsp. arctica and H. arctica subsp. frigida), H. lanceolata and H. rotundata. These relationships are reflected in the phylogenetic trees based on LSU and ITS rDNA sequence data, which identified H. arctica (both subspecies), H. rotundata and H. lanceolata as close relatives of H. minima.
    • A multi-year comparison of Spirolide profiles in planktonic field samples from the North Sea and adjacent waters

      Krock, B.; Tillmann, U.; Alpermann, T.; Salas, R.; Cembella, A.D. (Alfred-Wegener-Institut für Polar- und Meeresforschung in der Helmholtz-Gemeinschaft, 2010)
      Alexandrium ostenfeldii isolates from distinct geographical locations showed almost identical profiles, primarily consisting of 20-methyl spirolide G (20-meG). Whereas the Scottish isolate produces only this variant, the Irish isolate additionally yields slight amounts of 13-desmethyl spirolide C (13-desmeC). These profiles were also reflected in the field data, where 20-meG was the most abundant spirolide throughout all samples and years.
    • Novel azaspiracids produced by Amphidomataceae

      Krock, B.; Tillmann, U.; Jeong, H.J.; Potvin, E.; Salas, R.; Kilcoyne, J.; Gu, H. (Alfred-Wegener-Institut für Polar- und Meeresforschung, 2012)
    • Nucleic acid tests for toxic phytoplankton in Irish waters-phytotest: Marine Strategic RTDI project AT/04/02/02 - research update

      Maher, M.; Kavanagh, S.; Brennan, C.; Moran, M.; Salas, R.; Lyons, J.; Silke, J. (Marine Institute, 2007)
      The Phytotest project is a 3 year collaborative project funded through the Marine Strategic Programme in Advanced Technologies as part of the National Development plan 2000-2006. The project partners include the National Diagnostics Centre at NUI Galway and MI. The overall objective of the project is the development of nucleic acid tests (molecular methods) for the identification of key toxic phytoplankton species in Irish waters. In the final year of the programme the aim is to transfer the molecular methods developed in the project into MI to support their monitoring service. Currently, the monitoring for phytoplankton species in Irish waters is performed by light microscopy which can easily identify some plankton species based on distinctive morphological traits. Other species in particular, Pseudonitzschia spp. and Alexandrium spp. cannot be identified to species level by light microscopy. Identification of these species requires more sophisticated microscopic techniques such as scanning electron microscopy (SEM) and transmission electron microscopy (TEM). These techniques cannot easily be integrated into a routine testing environment. Molecular methods utilise unique information contained within an organism’s genome in order to identify it. This genetic information can be exploited in a range of molecular test platforms enabling microorganisms to be identified to species level. Additionally, there has been a major drive towards the development of highly automated platforms to support molecular tests for high-throughput testing in routine laboratory settings.
    • Real-time PCR detection of Dinophysis species in Irish coastal waters

      Kavanagh, S.; Brennan, C.; O’Connor, L.; Moran, S.; Salas, R.; Lyons, J.; Silke, J.; Maher, M. (Springer Verlag, 2010)
      Diarrhetic shellfish toxin-producing Dinophysis species occur in Irish coastal waters throughout the year. Dinophysis acuta and Dinophysis acuminata are the most commonly occurring species and are responsible for the majority of closures of Irish mussel farms. This study describes the development of a qualitative real-time polymerase chain reaction (PCR) assay for identification of D. acuta and D. acuminata in Irish coastal waters. DNA sequence information for the D1-D2 region of the large ribosomal sub-unit (LSU) was obtained, following single-cell PCR of D. acuta and D. acuminata cells isolated from Irish coastal locations. PCR primers and hybridization probes, specific for the detection of D. acuta, were designed for real-time PCR on the LightCycler™. The LightCycler™ software melt curve analysis programme determined that D. acuta was identified by a melt-peak at 61°C, while D. acuminata cells produced a melt peak at 48°C. The limit of detection of the real-time PCR assay was determined to be one to ten plasmid copies of the LSU D1-D2 target region for both species and one to five D. acuminata cells. Lugol's preserved water samples were also tested with the assay. The real-time PCR assay identified Dinophysis species in 100% of samples found to contain Dinophysis species by light microscopy and had a greater than 90% correlation with light microscopy for identification of D. acuta and D. acuminata in the samples. The assay can identify and discriminate D. acuta and D. acuminata at low numbers in Irish waters and has the potential to add value to the Irish phytoplankton monitoring programme.
    • Review of phytoplankton monitoring 2005

      Moran, S.; Silke, J.; Salas, R.; Chamberlain, T.; Lyons, J.; Flannery, J.; Thornton, V.; Clarke, D.; Devilly, L. (Marine Institute, 2006)
      A national phytoplankton monitoring programme, has been in operation in Ireland since 1986, and fulfils requirements of the EU Council Directive 91/492/EEC. This programme provides an important part of the baseline data in the overall integrated shellfish monitoring programme. The analysis of samples received on a regular basis from a site can provide very important information in assembling a population profile for the area. This helps in crucial decisions, for example in Management Cell Decisions - conducted by representatives from the industry, MI, FSAI and DCMNR - when borderline toxin results are present. Phytoplankton monitoring is also hugely important in the Water Framework Directive, which all EU countries must follow, in developing an index of water quality in Ireland and Europe. The Irish Monitoring programme also gives valuable public health information to County Councils, Environmental Health Officer’s and the public during times of bloom events. This paper provides an overview of phytoplankton sampling, analysis and reporting in 2005. The occurrence of potentially toxic and harmful phytoplankton found in Irish coastal and shelf waters in 2005 is also reviewed and the quality scheme in operation is described.
    • Review of phytoplankton monitoring 2006

      Moran, S.; Silke, J.; Salas, R.; Chamberlain, T.; Lyons, J.; Shannon, S. (Marine Institute, 2007)
      This paper provides an overview of phytoplankton sampling, analysis and reporting in 2006. The occurrence of potentially toxic and harmful phytoplankton found in Irish coastal and shelf waters in 2006 is compared with the previous year. The succession of phytoplankton blooms in Bantry is described and environmental data that may explain the onset of toxic species is described.
    • Review of phytoplankton monitoring programme and research activities

      Salas, R.; Chamberlain, T.; Lyons, J.; Hynes, P.; Silke, J. (Marine Institute, 2008)
      This paper provides a review of the activities of the Phytoplankton Unit in the Marine Institute as part of the National Monitoring Programme for 2007 and compares the findings with those recorded during 2005 and 2006., It also presents an overview of the research activities carried out by the phytoplankton team during the year with a focus on culturing phytoplankton and the introduction of real time PCR techniques for phytoplankton identification.
    • Review of the phytoplankton monitoring programme and research activities in 2008

      Salas, R.; Lyons, J.; Hynes, P.; Chamberlain, T.; Silke, J. (Marine Institute, 2009)
      The National Monitoring programme for phytoplankton is a well established programme and this was shown through the improvement and refinement of Phytoplankton shellfish and finfish sites around the country. One important development in the last 2 years has been to increase the number of sentinel sites. A sentinel site is a designated sampling site where a total community Phytoplankton cell count and identification is carried out. The number of sentinel sites has increased from 11 in 2005 to 24 in 2008. This means a better coverage of all the bays around the country. The number of phytoplankton samples analysed in 2008 has seen an increase from the previous year.