scholarly journals Update of the Planktonic Diatom Genus Pseudo-nitzschia in Aotearoa New Zealand Coastal Waters: Genetic Diversity and Toxin Production

Toxins ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 637
Author(s):  
Tomohiro Nishimura ◽  
J. Sam Murray ◽  
Michael J. Boundy ◽  
Muharrem Balci ◽  
Holly A. Bowers ◽  
...  
Keyword(s):  
New Zealand ◽  
Coastal Waters ◽  
Large Subunit ◽  
Toxin Production ◽  
Shellfish Poisoning ◽  
Aotearoa New Zealand ◽  
Amnesic Shellfish Poisoning ◽  
Liquid Chromatography Tandem Mass ◽  
Molecular Phylogenetic ◽  
Diatom Genus

Domoic acid (DA) is produced by almost half of the species belonging to the diatom genus Pseudo-nitzschia and causes amnesic shellfish poisoning (ASP). It is, therefore, important to investigate the diversity and toxin production of Pseudo-nitzschia species for ASP risk assessments. Between 2018 and 2020, seawater samples were collected from various sites around Aotearoa New Zealand, and 130 clonal isolates of Pseudo-nitzschia were established. Molecular phylogenetic analysis of partial large subunit ribosomal DNA and/or internal transcribed spacer regions revealed that the isolates were divided into 14 species (Pseudo-nitzschia americana, Pseudo-nitzschia arenysensis, Pseudo-nitzschia australis, Pseudo-nitzschia calliantha, Pseudo-nitzschia cuspidata, Pseudo-nitzschia delicatissima, Pseudo-nitzschia fraudulenta, Pseudo-nitzschia galaxiae, Pseudo-nitzschia hasleana, Pseudo-nitzschia multiseries, Pseudo-nitzschia multistriata, Pseudo-nitzschia plurisecta, Pseudo-nitzschia pungens, and Pseudo-nitzschia cf. subpacifica). The P. delicatissima and P. hasleana strains were further divided into two clades/subclades (I and II). Liquid chromatography-tandem mass spectrometry was used to assess the production of DA and DA isomers by 73 representative strains. The analyses revealed that two (P. australis and P. multiseries) of the 14 species produced DA as a primary analogue, along with several DA isomers. This study is the first geographical distribution record of P. arenysensis, P.cuspidata, P. galaxiae, and P. hasleana in New Zealand coastal waters.

scholarly journals SCREENING OF TOXIC MARINE NITZSCHIA SPECIES (BACILLARIOPHYCEAE) IN MALAYSIA

2017 ◽  
Vol 10 (1) ◽  
pp. 97
Author(s):  
Suriyanti Su Nyun Pau ◽  
Dzulhelmi Muhammad Nasir ◽  
Gires Usup
Keyword(s):  
Stationary Phase ◽  
Domoic Acid ◽  
Toxin Production ◽  
Shellfish Poisoning ◽  
Late Stationary Phase ◽  
Toxic Species ◽  
Amnesic Shellfish Poisoning ◽  
Clonal Cultures ◽  
Diatom Genus

<p>Amnesic Shellfish Poisoning (ASP) is a type of intoxication caused by the neurotoxin domoic acid (DA). The diatom genus <em>Nitzschia</em> is capable of producing this toxin. Screening for the presence of toxic <em>Nitzschia</em> spp. was carried out at various estuaries in Malaysia. <em>Nitzschia</em>-like cells were isolated and established into clonal cultures. Late stationary phase of cultures were harvested and tested for toxin production using HPLC. Toxin production and compound was verified by LC-MS. From the analyses, at least three cultures were detected with DA, while the rest of the cultures did not show detectable amounts of DA. The localities of the toxic species are Johor and Sabah. Here we conclude that toxic <em>Nitzschia</em> species are present in Malaysian water.</p><p>Keywords: diatom, estuary, intoxication, safety, toxic </p>

scholarly journals Surveillance of densoviruses and mesomycetozoans inhabiting grossly normal tissues of three Aotearoa New Zealand asteroid species

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0241026
Author(s):  
Ian Hewson ◽  
Mary A. Sewell
Keyword(s):  
New Zealand ◽  
Body Wall ◽  
Large Subunit ◽  
Small Subunit ◽  
Normal Tissues ◽  
The North ◽  
Aotearoa New Zealand ◽  
Fundamental Understanding ◽  
Host Ecology ◽  
Rna And Dna

Asteroid wasting events and mass mortality have occurred for over a century. We currently lack a fundamental understanding of the microbial ecology of asteroid disease, with disease investigations hindered by sparse information about the microorganisms associated with grossly normal specimens. We surveilled viruses and protists associated with grossly normal specimens of three asteroid species (Patiriella regularis, Stichaster australis, Coscinasterias muricata) on the North Island / Te Ika-a-Māui, Aotearoa New Zealand, using metagenomes prepared from virus and ribosome-sized material. We discovered several densovirus-like genome fragments in our RNA and DNA metagenomic libraries. Subsequent survey of their prevalence within populations by quantitative PCR (qPCR) demonstrated their occurrence in only a few (13%) specimens (n = 36). Survey of large and small subunit rRNAs in metagenomes revealed the presence of a mesomycete (most closely matching Ichthyosporea sp.). Survey of large subunit prevalence and load by qPCR revealed that it is widely detectable (80%) and present predominately in body wall tissues across all 3 species of asteroid. Our results raise interesting questions about the roles of these microbiome constituents in host ecology and pathogenesis under changing ocean conditions.

scholarly journals Phylogeny and diversity of Haploporus (Polyporaceae, Basidiomycota)

MycoKeys ◽  
2019 ◽  
Vol 54 ◽  
pp. 77-98 ◽  
Author(s):  
Meng Zhou ◽  
Li Wang ◽  
Tom W. May ◽  
Josef Vlasák ◽  
Jia-Jia Chen ◽  
...  
Keyword(s):  
New Zealand ◽  
Ribosomal Rna ◽  
Internal Transcribed Spacer ◽  
Phylogenetic Analyses ◽  
Large Subunit ◽  
Morphological Characteristics ◽  
New Combination ◽  
Ribosomal Rna Gene ◽  
Molecular Phylogenetic ◽  
The Usa

Four species of Haploporus, H.angustisporus, H.crassus, H.gilbertsonii and H.microsporus are described as new and H.pirongia is proposed as a new combination, based on morphological characteristics and molecular phylogenetic analyses inferred from internal transcribed spacer (ITS) and large subunit nuclear ribosomal RNA gene (nLSU) sequences. Haploporusangustisporus, H.crassus and H.microsporus occur in China, H.gilbertsonii occurs in the USA, and the distribution of H.pirongia is extended from New Zealand to Australia. Haploporusangustisporus is characterized by the distinct narrow oblong basidiospores measuring 10.5–13.5 × 3.9–5 µm. Haploporuscrassus is characterized by the presence of ventricose cystidioles occasionally with a simple septum, dissepimental hyphae usually with a simple septum, unique thick-walled basidia and distinctly wide oblong basidiospores measuring 13.5–16.5 × 7.5–9.5 µm. Haploporusgilbertsonii is characterized by its large pores (2–3 per mm), a dimitic hyphal structure with non-dextrinoid skeletal hyphae and wide oblong basidiospores measuring 12–15 × 6–8 µm. Haploporusmicrosporus is characterized by distinctly small pores (7–9 per mm), the presence of dendrohyphidia, and distinctly small ellipsoid basidiospores measuring 5.3–6.7 × 3–4.1 µm. Haploporuspirongia is proposed as a new combination. Haploporusamarus is shown to be a synonym of H.odorus and Pachykytosporawasseri is considered a synonym of H.subtrameteus.

scholarly journals Occurrence and Seasonal Monitoring of Domoic Acid in Three Shellfish Species from the Northern Adriatic Sea

Toxins ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 33
Author(s):  
Kristina Kvrgić ◽  
Tina Lešić ◽  
Natalija Džafić ◽  
Jelka Pleadin
Keyword(s):  
Domoic Acid ◽  
Adriatic Sea ◽  
Ultra Performance Liquid Chromatography ◽  
The Other ◽  
Shellfish Poisoning ◽  
Northern Adriatic Sea ◽  
Northern Adriatic ◽  
Amnesic Shellfish Poisoning ◽  
Aequipecten Opercularis ◽  
Liquid Chromatography Tandem Mass

As filter feeders, bivalves and ascidians can accumulate contaminants present in the environment and pass them on to higher food chain levels as vectors. The consumption of bivalves contaminated with the potent neurotoxin domoic acid (DA) can cause amnesic shellfish poisoning in humans. The aim of this study was to determine seasonal differences in occurrence and accumulation of this phycotoxin in European oysters (Ostrea edulis Linnaeus, 1758) (n = 46), Queen scallops (Aequipecten opercularis Linnaeus, 1758) (n = 53), and edible ascidians of the Microcosmus spp. (n = 107), originating from the same harvesting area in the Northern Adriatic Sea. The quantification was performed using ultra-performance liquid chromatography–tandem mass spectrometry (LC-MS/MS) preceded by derivatization with dansyl chloride. DA was found in very low concentrations throughout the year, with a maximum value of 810 μg/kg in Queen scallops. This study reveals differences in the occurrence and accumulation of DA between Queen scallops and the other two investigated species (oysters and ascidians) and the highest concentrations during the colder part of the year. Even though DA was detected in all of them, Queen scallops showed higher DA accumulation compared to the other two (p < 0.001), hence representing a sentinel species suitable for the monitoring of DA level in seafood.

scholarly journals Ciguatera Fish Poisoning: The Risk from an Aotearoa/New Zealand Perspective

Toxins ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 50 ◽  
Author(s):  
Lesley L. Rhodes ◽  
Kirsty F. Smith ◽  
J. Sam Murray ◽  
Tomohiro Nishimura ◽  
Sarah C. Finch
Keyword(s):  
New Zealand ◽  
Coastal Waters ◽  
Sampling Methods ◽  
Toxicity Tests ◽  
Aotearoa New Zealand ◽  
Ciguatera Fish Poisoning ◽  
Monitoring Strategies ◽  
Fish Poisoning ◽  
Tasman Sea ◽  
Reliable Monitoring

Gambierdiscus and Fukuyoa species have been identified in Aotearoa/New Zealand’s coastal waters and G. polynesiensis, a known producer of ciguatoxins, has been isolated from Rangitāhua/Kermadec Islands (a New Zealand territory). The warming of the Tasman Sea and the waters around New Zealand’s northern subtropical coastline heighten the risk of Gambierdiscus proliferating in New Zealand. If this occurs, the risk of ciguatera fish poisoning due to consumption of locally caught fish will increase. Research, including the development and testing of sampling methods, molecular assays, and chemical and toxicity tests, will continue. Reliable monitoring strategies are important to manage and mitigate the risk posed by this emerging threat. The research approaches that have been made, many of which will continue, are summarised in this review.

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