Phylogeography of Ostreopsis along West Pacific Coast, with Special Reference to a Novel Clade from Japan

BACKGROUND: A dinoflagellate genus Ostreopsis is known as a potential producer of Palytoxin derivatives. Palytoxin is the most potent non-proteinaceous compound reported so far. There has been a growing number of reports on palytoxin-like poisonings in southern areas of Japan; however, the distribution of Ostreopsis has not been investigated so far. Morphological plasticity of Ostreopsis makes reliable microscopic identification difficult so the employment of molecular tools was desirable. METHODS/PRINCIPAL FINDING: In total 223 clones were examined from samples mainly collected from southern areas of Japan. The D8-D10 region of the nuclear large subunit rDNA (D8-D10) was selected as a genetic marker and phylogenetic analyses were conducted. Although most of the clones were unable to be identified, there potentially 8 putative species established during this study. Among them, Ostreopsis sp. 1-5 did not belong to any known clade, and each of them formed its own clade. The dominant species was Ostreopsis sp. 1, which accounted for more than half of the clones and which was highly toxic and only distributed along the Japanese coast. Comparisons between the D8-D10 and the Internal Transcribed Spacer (ITS) region of the nuclear rDNA, which has widely been used for phylogenetic/phylogeographic studies in Ostreopsis, revealed that the D8-D10 was less variable than the ITS, making consistent and reliable phylogenetic reconstruction possible. CONCLUSIONS/SIGNIFICANCE: This study unveiled a surprisingly diverse and widespread distribution of Japanese Ostreopsis. Further study will be required to better understand the phylogeography of the genus. Our results posed the urgent need for the development of the early detection/warning systems for Ostreopsis, particularly for the widely distributed and strongly toxic Ostreopsis sp. 1. The D8-D10 marker will be suitable for these purposes

Inhomogeneity detection in phytoplankton time series using multivariate analyses

Phytoplankton communities have long been used as water quality indicators within environmental policies. This has fostered the development of national and international phytoplankton monitoring programs, but these networks are subject to sources of uncertainty due to laboratory issues. Nevertheless, studies regarding the interference associated with these aspects are not well-documented. Hence, a long time series (2003–2015) from the Basque continental shelf (southeastern Bay of Biscay) was analyzed to evaluate the uncertainty given by laboratory strategies when studying phytoplankton variability. Variability in phytoplankton communities was explained not only by environmental conditions but also by changes in fixatives (glutaraldehyde and acidic Lugol's solution) and laboratory staff. Based on Bray-Curtis distances, phytoplankton assemblages were found to be significantly dissimilar according to the effect of changes in the specialist handling the sample and the employed fixative. The pair-wise permutational multivariate analysis of variance (PERMANOVA) showed significant differences between the two fixatives utilized and also between the three taxonomists involved. Thus, laboratory-related effects should be considered in the study of phytoplankton time series

Origin of cryptophyte plastids in Dinophysis from Galician waters: results from field and culture experiments

Photosynthetic species of the dinoflagellate genus Dinophysis retain cryptophyte plastids from the Teleaulax/Plagioselmis/Geminigera group via their ciliate prey Mesodinium rubrum, but other cryptophyte and algal sources have occasionally been found. Identifying the specific prey of ciliates fed upon by mixotrophic Dinophysis species is a requisite to improve predictive capabilities of their bloom formation. Here we examined the origin of Dinophysis plastids from Galician waters and their transfer in cross-feeding experiments in the laboratory. Plastid 23S rDNA sequences were obtained from 60 Dinophysis specimens from the Galician Rías Baixas and shelf waters. Most sequences in Dinophysis cells were identical to Teleaulax amphioxeia. Galician shelf samples also yielded T. amphioxeia-type sequences, although one of these was closer to a freshwater cryptophyte, and a few others were related with other taxa (diatoms, red algae and proteobacteria). Mesodinium cf. major, an alternative prey to M. rubrum, was identified. Cross-feeding tests in the laboratory showed that T. amphioxeia, T. minuta, T. gracilis, and Plagioselmis prolonga sustained growth of M. rubrum. D. acuminata cultivated on a M. rubrum–T. amphioxeia system was transferred to M. rubrum fed upon T. minuta, T. gracilis and P. prolonga. After >2 mo of acclimation, T. amphioxeia plastid 23S rDNA and psbA gene sequences from D. acuminata were replaced by those of secondary cryptophytes. Here we confirm 2 cryptophytes, T. minuta and P. prolonga, as suitable prey for M. rubrum. Nevertheless, field and laboratory results show that, at least for D. acuminata, T. amphioxeia represents the main source of plastids.Versión del edito

Validation of fragility fractures in primary care electronic medical records: a population-based study

Electronic medical records databases use validated lists of ICD (or other) codes to identify fractures. These, however, are not specific enough to disentangle traumatic from fragility fractures. We report on the proportion of fragility fractures identified amongst a random sample of coded fractures in SIDIAP, both overall and after stratification by fracture site

Validation of fragility fractures in primary care electronic medical records: a population-based study

Electronic medical records databases use validated lists of ICD (or other) codes to identify fractures. These, however, are not specific enough to disentangle traumatic from fragility fractures. We report on the proportion of fragility fractures identified amongst a random sample of coded fractures in SIDIAP, both overall and after stratification by fracture site

Validation of fragility fractures in primary care electronic medical records: a population-based study

Purpose: Electronic medical records databases use pre-specified lists of diagnostic codes to identify fractures. These codes, however, are not specific enough to disentangle traumatic from fragility-related fractures. We report on the proportion of fragility fractures identified in a random sample of coded fractures in SIDIAP. Methods: Patients ≥ 50 years old with any fracture recorded in 2012 (as per pre-specified ICD-10 codes) and alive at the time of recruitment were eligible for this retrospective observational study in 6 primary care centers contributing to the SIDIAP database (www.sidiap.org). Those with previous fracture/s, non-responders, and those with dementia or a serious psychiatric disease were excluded. Data on fracture type (traumatic vs fragility), skeletal site, and basic patient characteristics were collected. Results: Of 491/616 (79.7%) patients with a registered fracture in 2012 who were contacted, 331 (349 fractures) were included. The most common fractures were forearm (82), ribs (38), and humerus (32), and 225/349 (64.5%) were fragility fractures, with higher proportions for classic osteoporotic sites: hip, 91.7%; spine, 87.7%; and major fractures, 80.5%. This proportion was higher in women, the elderly, and patients with a previously coded diagnosis of osteoporosis. Conclusions: More than 4 in 5 major fractures recorded in SIDIAP are due to fragility (non-traumatic), with higher proportions for hip (92%) and vertebral (88%) fracture, and a lower proportion for fractures other than major ones. Our data support the validity of SIDIAP for the study of the epidemiology of osteoporotic fractures. Objetivos: La historia clínica informatizada utiliza una lista de códigos diagnósticos pre-especificados para identiticar fracturas, pero estos códigos no permiten distinguir entre fracturas traumáticas y fracturas por fragilidad. Se reporta la proporción de fracturas por fragilidad identificadas en una muestra aleatorizada de fracturas codificadas en SIDIAP. Métodos: Estudio observacional retrospectivo realizado en 6 centros de atención primaria que contribuyen a la base de datos SIDIAP (www.sidiap.org). Se seleccionaron pacientes ≥ 50 años con cualquier fractura registrada en 2012 (mediante códigos CIE-10) que permanecieran vivos en el reclutamiento y excluyendo aquellos con fractura previa, contacto imposible o aquellos con demencia o trastorno mental severo. Se recogió información sobre tipo de fractura (traumática o fragilidad), localización y características descriptivas de los pacientes. Resultados: Un total de 491/616 (79,7%) de los pacientes con fractura en 2012 fueron contactados y 331 (349 fracturas) fueron incluidos. Las fracturas más comunes fueron antebrazo (82), costillas (38) y húmero (32). 225/349 (64,5%) fueron fracturas por fragilidad, con mayor proporción para las localizaciones típicas de la osteoporosis: fémur (91,7%), columna vertebral (87,7%) y fracturas principales (80,5%). La proporción fue mayor en mujeres, edad avanzada y pacientes con diagnóstico previo de osteoporosis. Conclusiones: más de 4 de cada 5 fracturas principals registradas en SIDIAP son por fragilidad, con una mayor proporción para fémur (92%) y columna verterbal (88%) y menor proporción para otras localizaciones no típicas. Nuestros datos apoyan la validación de SIDIAP para el estudio epidemiológico de las fracturas osteoporóticas

Réponses écophysiologiques d'Ostreopsis en fonction de la température: Etude de cas d'une espèce responsable d'efflorescence algale nuisible face au réchauffement des océans

International audienceReports of the benthic dinoflagellate Ostreopsis spp. have been increasing in the last decades, especially in temperate areas. In a context of global warming, evidences of the effects of increasing sea temperatures on its physiology and its distribution are still lacking and need to be investigated. In this study, the influence of temperature on growth, ecophysiology and toxicity was assessed for several strains of O. cf. siamensis from the Bay of Biscay (NE Atlantic) and O. cf. ovata from NW Mediterranean Sea. Cultures were acclimated to temperatures ranging from 14.5 ◦C to 32 ◦C in order to study the whole range of each strain-specific thermal niche. Acclimation was successful for temperatures ranging from 14.5 ◦C to 25 ◦C for O. cf. siamensis and from 19 ◦C to 32 ◦C for O. cf. ovata, with the highest growth rates measured at 22 ◦C (0.54–1.06 d-1) and 28 ◦C (0.52–0.75 d-1), respectively. The analysis of cellular content of pigments and lipids revealed some aspects of thermal acclimation processes in Ostreopsis cells. Specific capacities of O. cf. siamensis to cope with stress of cold temperatures were linked with the activation of a xanthophyll cycle based on diadinoxanthin. Lipids (neutral reserve lipids and polar ones) also revealed species-specific variations, with increases in cellular content noted under extreme temperature conditions. Variations in toxicity were assessed through the Artemia franciscana bioassay. For both species, a decrease in toxicity was observed when temperature dropped under the optimal temperature for growth. No PLTX-like compounds were detected in O. cf. siamensis strains. Thus, the main part of the lethal effect observed on A. franciscana was dependent on currently unknown compounds. From a multiclonal approach, this work allowed for defining specificities in the thermal niche and acclimation strategies of O. cf. siamensis and O. cf. ovata towards temperature. Potential impacts of climate change on the toxic risk associated with Ostreopsis blooms in both NW Mediterranean Sea and NE Atlantic coast is further discussed, taking into account variations in the geographic distribution, growth abilities and toxicity of each species

Validation of fragility fractures in primary care electronic medical records: a population-based study

Purpose: Electronic medical records databases use pre-specified lists of diagnostic codes to identify fractures. These codes, however, are not specific enough to disentangle traumatic from fragility-related fractures. We report on the proportion of fragility fractures identified in a random sample of coded fractures in SIDIAP. Methods: Patients ≥ 50 years old with any fracture recorded in 2012 (as per pre-specified ICD-10 codes) and alive at the time of recruitment were eligible for this retrospective observational study in 6 primary care centers contributing to the SIDIAP database (www.sidiap.org). Those with previous fracture/s, non-responders, and those with dementia or a serious psychiatric disease were excluded. Data on fracture type (traumatic vs fragility), skeletal site, and basic patient characteristics were collected. Results: Of 491/616 (79.7%) patients with a registered fracture in 2012 who were contacted, 331 (349 fractures) were included. The most common fractures were forearm (82), ribs (38), and humerus (32), and 225/349 (64.5%) were fragility fractures, with higher proportions for classic osteoporotic sites: hip, 91.7%; spine, 87.7%; and major fractures, 80.5%. This proportion was higher in women, the elderly, and patients with a previously coded diagnosis of osteoporosis. Conclusions: More than 4 in 5 major fractures recorded in SIDIAP are due to fragility (non-traumatic), with higher proportions for hip (92%) and vertebral (88%) fracture, and a lower proportion for fractures other than major ones. Our data support the validity of SIDIAP for the study of the epidemiology of osteoporotic fractures. Objetivos: La historia clínica informatizada utiliza una lista de códigos diagnósticos pre-especificados para identiticar fracturas, pero estos códigos no permiten distinguir entre fracturas traumáticas y fracturas por fragilidad. Se reporta la proporción de fracturas por fragilidad identificadas en una muestra aleatorizada de fracturas codificadas en SIDIAP. Métodos: Estudio observacional retrospectivo realizado en 6 centros de atención primaria que contribuyen a la base de datos SIDIAP (www.sidiap.org). Se seleccionaron pacientes ≥ 50 años con cualquier fractura registrada en 2012 (mediante códigos CIE-10) que permanecieran vivos en el reclutamiento y excluyendo aquellos con fractura previa, contacto imposible o aquellos con demencia o trastorno mental severo. Se recogió información sobre tipo de fractura (traumática o fragilidad), localización y características descriptivas de los pacientes. Resultados: Un total de 491/616 (79,7%) de los pacientes con fractura en 2012 fueron contactados y 331 (349 fracturas) fueron incluidos. Las fracturas más comunes fueron antebrazo (82), costillas (38) y húmero (32). 225/349 (64,5%) fueron fracturas por fragilidad, con mayor proporción para las localizaciones típicas de la osteoporosis: fémur (91,7%), columna vertebral (87,7%) y fracturas principales (80,5%). La proporción fue mayor en mujeres, edad avanzada y pacientes con diagnóstico previo de osteoporosis. Conclusiones: más de 4 de cada 5 fracturas principals registradas en SIDIAP son por fragilidad, con una mayor proporción para fémur (92%) y columna verterbal (88%) y menor proporción para otras localizaciones no típicas. Nuestros datos apoyan la validación de SIDIAP para el estudio epidemiológico de las fracturas osteoporóticas

Current distribution and potential expansion of the harmful benthic dinoflagellate Ostreopsis cf. siamensis towards the warming waters of the Bay of Biscay, North‐East Atlantic

In a future scenario of increasing temperatures in North‐Atlantic waters, the risk associated with the expansion of the harmful, benthic dinoflagellate Ostreopsis cf. siamensis has to be evaluated and monitored. Microscopy observations and spatio‐temporal surveys of environmental DNA (eDNA) were associated with Lagrangian particle dispersal simulations to: i) establish the current colonization of the species in the Bay of Biscay, ii) assess the spatial connectivity among sampling zones that explain this distribution, iii) identify sentinel zones to monitor future expansion. Throughout a sampling campaign carried out in August‐September 2018, microscope analysis showed that the species develops in the south‐east of the bay where optimal temperatures foster blooms. Quantitative PCR analyses revealed its presence across almost the whole bay to the western English Channel. An eDNA time‐series collected on plastic samplers showed that the species occurs in the bay from April to September. Due to the water circulation, colonization of the whole bay from the southern blooming zones is explained by inter‐site connectivity. Key areas in the middle of the bay permit continuous dispersal connectivity towards the north. These key areas are proposed as sentinel zones to monitor O. cf. siamensis invasions towards the presumably warming water of the North‐East Atlantic