RESUMO
Despite the crucial role of microbial community composition in the quality and stability of seafood, little emphasis has been given to the microbiota profile of sea urchin gonads. This study investigates the microbial quality and community composition of sea urchin gonads (Echinus esculentus) as a function of harvesting season (autumn, winter, spring, and summer) and location (one site proximal to urban activity areas while the other is located in open water close to the coastline). Significant season-dependent variations were found in psychrotrophic and aerobic plate counts, with higher counts in summer, followed by autumn, spring, and winter. H2S-producing bacteria and Pseudomonas spp. counts were unaffected by harvesting season or location. Sea urchin gonad microbial composition proved resilient and dynamic, primarily shaped by seasonal variations, and minimally influenced by location. Winter and spring samples exhibited higher diversity than autumn and summer. Key genera like Pseudomonas, Psychromonas, Vibrio, Chryseobacterium, Shewanella, and Photobacterium varied seasonally. Pseudomonas, Vibrio, and Photobacterium are crucial in assessing microbial quality and safety due to their roles as specific spoilage organisms (SSOs) and, in some cases, human pathogens. Though relative abundances differed slightly between locations, harvesting location did not notably impact microbial community shaping in gonads. However, the results suggest that harvesting locations near areas with urban activity may lead to contamination with specific bacterial species, possibly due to water quality variations. These findings emphasize the importance of considering seasonality when evaluating sea urchin gonad microbial quality. Identifying key genera enhances insights into potential SSOs and human pathogens, enhancing food safety considerations in the consumption of raw or lightly processed sea urchin gonads and guiding the development of preservation methods to extend shelf life.
Assuntos
Bactérias , Gônadas , Microbiota , Ouriços-do-Mar , Estações do Ano , Animais , Bactérias/classificação , Bactérias/isolamento & purificação , Bactérias/genética , Ouriços-do-Mar/microbiologia , Gônadas/microbiologia , Alimentos Marinhos/microbiologia , Microbiologia de AlimentosRESUMO
As grazers, sea urchins are keystone species in tropical marine ecosystems, and their loss can have important ecological ramifications. Die-offs of urchins are frequently described, but their causes are often unclear, in part because systematic examinations of animal tissues at gross and microscopic level are not done. In some areas, urchins are being employed to control invasive marine algae. Here, we describe the pathology of a mortality event in Tripneustes gratilla in Hawai`i where urchins were translocated to control invasive algae. Although we did not determine the cause of the mortality event, our investigation indicates that animals died from inflammation of the test and epidermal ulceration, followed by inability to maintain coelomic fluid volume, colonization of coelomic fluid by opportunists (diatom, algae), and inappetence. Parasites, bacteria, fungi, and viruses were not evident as a primary cause of death. Pathology was suggestive of a toxin or other environmental cause such as lack of food, possibilities that could be pursued in future investigations. These findings highlight the need for caution and additional tools to better assess health when translocating marine invertebrates to ensure maximal biosecurity.
Assuntos
Ecossistema , Ouriços-do-Mar , Animais , Ouriços-do-Mar/microbiologiaRESUMO
Animal gastrointestinal tracts harbor a microbiome that is integral to host function, yet species from diverse phyla have evolved a reduced digestive system or lost it completely. Whether such changes are associated with alterations in the diversity and/or abundance of the microbiome remains an untested hypothesis in evolutionary symbiosis. Here, using the life history transition from planktotrophy (feeding) to lecithotrophy (nonfeeding) in the sea urchin Heliocidaris, we demonstrate that the lack of a functional gut corresponds with a reduction in microbial community diversity and abundance as well as the association with a diet-specific microbiome. We also determine that the lecithotroph vertically transmits a Rickettsiales that may complement host nutrition through amino acid biosynthesis and influence host reproduction. Our results indicate that the evolutionary loss of a functional gut correlates with a reduction in the microbiome and the association with an endosymbiont. Symbiotic transitions can therefore accompany life history transitions in the evolution of developmental strategies.
Assuntos
Trato Gastrointestinal/microbiologia , Ouriços-do-Mar/microbiologia , Simbiose/genética , Adaptação Biológica/genética , Animais , Evolução Biológica , Trato Gastrointestinal/fisiologia , Microbiota/genética , Filogenia , RNA Ribossômico 16S/genética , Ouriços-do-Mar/genéticaRESUMO
We found that the extract of the body wall of the sea urchin, Pseudocentrotus depressus, agglutinate Escherichia coli and is inhibited by mannose. A mannose-binding protein of 22 kDa was purified via affinity chromatography using mannose-agarose. Amino acid sequences obtained by Edman degradation and liquid chromatography quadrupole time-of-flight mass spectrometry followed by de novo sequencing suggested that the protein is a C-type lectin. Products of PCR with a degenerate primer pair and of RACE PCR for the cDNA of the 22 kDa protein were sequenced and produced two full-length cDNA sequences encoding C-type lectins. These two lectins, named P. depressus mannose-binding C-type lectin (PdMBCL) 1 and 2 are composed of 187 and 189 amino acid residues, including signal peptides, respectively, and share 86% identity in their mature form. PdMBCLs agglutinated Lactococcus garvieae, a Gram-positive fish pathogen. Reverse transcription PCR showed that both the genes for the PdMBCLs were expressed in the body wall and in other tissues. Furthermore, the lectins were detected from a rinse of the body surface. Taken together, the present study showed that PdMBCLs function as anti-microbial agents on the body surface of P. depressus.
Assuntos
Escherichia coli/imunologia , Imunidade Inata/imunologia , Lactococcus/imunologia , Lectinas Tipo C/imunologia , Manose/imunologia , Ouriços-do-Mar/imunologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Escherichia coli/fisiologia , Expressão Gênica/imunologia , Perfilação da Expressão Gênica/métodos , Interações Hospedeiro-Patógeno/imunologia , Imunidade Inata/genética , Lactococcus/fisiologia , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Manose/metabolismo , Filogenia , Ouriços-do-Mar/genética , Ouriços-do-Mar/microbiologia , Análise de Sequência de DNA/métodos , Homologia de Sequência de AminoácidosRESUMO
This case report discusses a rare presentation of salmonella bacteremia after an oral exposure to a sand dollar in a pediatric patient. A 2-year-old Hispanic male presented to the emergency department with a chief complaint of diarrhea and fever for 8 days after a family trip to Destin beach, Florida, during the sea turtle nesting season. The symptoms began a day after the patient took a bite on a sand dollar found on the beach that caused a small wound inside his cheek. The laboratory testing done in the emergency department was remarkable for blood and stool culture testing positive for non-typhoid salmonella. The sand dollar is a type of a sea urchin commonly found on sandy beaches and consists of an anatomical filtration system to consume sandy water. It could be inferred that the increased presence of sea turtles during the time of the patient's visit to Destin beach could have led to higher levels of salmonella in the seawater and consequently in the sand dollar, possibly leading to the inoculation of salmonella in this patient. To the best of our knowledge, this is a first case report that links oral exposure of the sand dollar to invasive salmonellosis.
Assuntos
Bacteriemia/diagnóstico , Praias , Febre/microbiologia , Infecções por Salmonella/diagnóstico , Ouriços-do-Mar/microbiologia , Animais , Pré-Escolar , Florida , Humanos , Masculino , SalmonellaRESUMO
Determining the factors underlying the assembly, structure, and diversity of symbiont communities remains a focal point of animal-microbiome research. Much of these efforts focus on taxonomic variation of microbiota within or between animal populations, but rarely test the proportional impacts of ecological components that may affect animal-associated microbiota. Using larvae from the sea urchin Strongylocentrotus droebachiensis from the Atlantic and Pacific Oceans, we test the hypothesis that, under natural conditions, inter-population differences in the composition of larval-associated bacterial communities are larger than intra-population variation due to a heterogeneous feeding environment. Despite significant differences in bacterial community structure within each S. droebachiensis larval population based on food availability, development, phenotype, and time, variation in OTU membership and community composition correlated more strongly with geographic location. Moreover, 20-30% of OTUs associated with larvae were specific to a single location while less than 10% were shared. Taken together, these results suggest that inter-populational variation in symbiont communities may be more pronounced than intra-populational variation, and that this difference may suggest that broad-scale ecological variables (e.g., across ocean basins) may mask smaller scale ecological variables (e.g., food availability).
Assuntos
Alimentos , Microbiota/genética , Ouriços-do-Mar/microbiologia , Água do Mar , Animais , Oceano Atlântico , Bactérias/classificação , Bactérias/genética , Larva/microbiologia , Oceano PacíficoRESUMO
The adaptive immune response in jawed vertebrates is marked by the ability to diversify somatically specific immune receptor genes. Somatic recombination and hypermutation of gene segments are used to generate extensive repertoires of T and B cell receptors. In contrast, jawless vertebrates utilize a distinct diversification system based on copy choice to assemble their variable lymphocyte receptors. To date, very little evidence for somatic immune gene diversification has been reported in invertebrate species. Here we show that the SpTransformer (SpTrf ; formerly Sp185/333) immune effector gene family members from individual coelomocytes from purple sea urchins undergo somatic diversification by means of gene deletions, duplications, and acquisitions of single nucleotide polymorphisms. While sperm cells from an individual sea urchin have identical SpTrf gene repertoires, single cells from two distinct coelomocyte subpopulations from the same sea urchin exhibit significant variation in the SpTrf gene repertoires. Moreover, the highly diverse gene sequences derived from single coelomocytes are all in-frame, suggesting that an unknown mechanism(s) driving these somatic changes involve stringent selection or correction processes for expression of productive SpTrf transcripts. Together, our findings infer somatic immune gene diversification strategy in an invertebrate.
Assuntos
Imunidade Adaptativa/genética , Evolução Biológica , Coelomomyces/genética , Coelomomyces/imunologia , Variação Genética , Ouriços-do-Mar/microbiologia , Animais , Genes Fúngicos , Genoma Fúngico , Genômica/métodos , Genótipo , Família Multigênica , Fases de Leitura Aberta , Filogenia , Seleção GenéticaRESUMO
Sea urchins, including Tripneustes gratilla, are susceptible to a disease known as bald sea urchin disease, which has the potential to lead to economic losses in this emerging aquaculture industry in South Africa. This disease is characterized by lesions that form on sea urchin exoskeletal surfaces. This study aimed to characterize the body surface bacterial communities associated with T. gratilla, using a 16S rDNA gene metagenomics approach, to provide insight into the bacterial agents associated with this aquaculture species, as well as with this balding disease. Bacterial samples were collected from non-lesioned healthy animals obtained from natural locations along the eastern coast of South Africa, as well as from different cultured cohorts: non-lesioned healthy-, lesioned diseased- and non-lesioned stressed animals. A total of 1,067,515 individual bacterial operational taxonomic units (OTUs) were identified, belonging to 133 family-, 123 genus- and 113 species level OTU groups. Alpha diversity analyses, based on Chao1, Shannon and Simpson indices, showed that there were no statistically significant differences (ANOVA; Pâ¯>â¯0.05) between the respective cohorts, as all cohorts displayed a high degree of bacterial diversity. Similarly, beta diversity analyses (Non-metric multidimensional scaling) showed a large degree of overlapping OTUs across the four cohorts. Within each cohort, various OTUs commonly associated with marine environments were found, predominantly belonging to the families Vibrionaceae, Saprospiraceae, Flavobacteriaceae and Sphingomonadaceae. Differential abundance analysis (DESeq2) revealed that OTUs that are differentially abundant across cohorts were likely not responsible for this balding disease, suggesting that complex bacterial agents, rather than a specific pathogenic agent, are likely causing this disease. Furthermore, the putative metabolic functions assigned to the bacterial communities showed that heterotrophic bacteria appear to be responsible for tissue lysis of degrading animal matter. The results from this study, obtained through univariate and multivariate-based approaches, contributes to future management strategies of this emerging aquaculture species by providing insight into the bacterial communities associated with both natural and cultured environments.
Assuntos
Bactérias/genética , Metagenoma , Microbiota/genética , Ouriços-do-Mar/microbiologia , Animais , Aquicultura , Bactérias/classificação , África do SulRESUMO
In order to find out the seeds of antitumor agents, we focused on potential bioactive materials from marine-derived microorganisms. Marine products include a number of compounds with unique structures, some of which may exhibit unusual bioactivities. As a part of this study, we studied metabolites of a strain of Alternaria sp. OUPS-117D-1 originally derived from the sea urchin Anthocidaris crassispina, and isolated five new decalin derivatives, altercrasins A-E (1-5). The absolute stereostructure of altercrasins A (1) had been decided by chemical transformation and the modified Mosher's method. In this study, four decalin derivatives, altercrasins B-E (2-5) were purified by silica gel chromatography, and reversed phase high-performance liquid chromatography (RP HPLC), and their structures were elucidated on the basis of 1D and 2D nuclear magnetic resonance (NMR) spectroscopic analyses. The absolute configuration of them were deduced by the comparison with 1 in the NMR chemical shifts, NOESY correlations, and electronic circular dichroism (ECD) spectral analyses. As a result, we found out that compound pairs of 1/2 and 4/5 were respective stereoisomers. In addition, their cytotoxic activities using murine P388 leukemia, human HL-60 leukemia, and murine L1210 leukemia cell lines showed that 4 and 5 exhibit potent cytotoxicity, in especially, the activity of 4 was equal to that of 5-fluorouracil.
Assuntos
Alternaria/química , Antineoplásicos/isolamento & purificação , Naftalenos/isolamento & purificação , Ouriços-do-Mar/microbiologia , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Dicroísmo Circular , Ensaios de Seleção de Medicamentos Antitumorais , Fluoruracila/farmacologia , Humanos , Espectroscopia de Ressonância Magnética , Camundongos , Estrutura Molecular , Naftalenos/química , Naftalenos/farmacologia , EstereoisomerismoRESUMO
Aquaculture has been a growing sector of food production worldwide in the last decades, and now starts to include new, unconventional species from the Phylum Echinodermata, such as sea urchin (Paracentrotus lividus) and sea cucumber (Holothuria tubulosa). However, little is known in this context with regard to food safety aspects arising from toxigenic fungi. In this study, samples of feed (n = 7) and water (n = 8) or water filters (n = 4) from experimental aquaculture systems, producing sea urchin and sea cucumber, were analyzed by culture-based microbiological methods to assess fungal associations. Additionally, a search using molecular techniques for toxigenic sections within the genus Aspergillus in these materials was done. Finally, samples were analyzed for 37 mycotoxins by LC-MS/MS. In feed samples, Fusarium verticillioides and F. culmorum were detected. In water and water filter samples, Aureobasidium spp., Penicillium spp., and Cladosporium spp. were found. No genes of species from toxigenic Aspergillus sections were detected. Some feed samples were contaminated by multiple mycotoxins, namely deoxynivalenol (DON), zearalenone (ZEN), fumonisins (FBs), T-2 toxin, ochratoxin A (OTA), and mycophenolic acid (MPA). This is the first one study dealing with toxigenic fungi and mycotoxins in echinoderm-producting aquaculture. Although no clear evidence for adverse effects on the production systems could be found, the confirmed environmental association of mycotoxins and echinoderms requires further consideration. Studies on the consequences of introducing cereal-based fungi and their mycotoxins via feeds into aquaculture systems for echinoderm production seem to be advisable, to assess possible adverse effects on production and to clarify the potential impact on public health.
Assuntos
Ração Animal/análise , Aquicultura , Equinodermos/microbiologia , Microbiologia de Alimentos , Fungos/isolamento & purificação , Micotoxinas/análise , Água/análise , Animais , Cromatografia Líquida , Contaminação de Alimentos/análise , Fungos/classificação , Pepinos-do-Mar/microbiologia , Ouriços-do-Mar/microbiologia , Espectrometria de Massas em TandemRESUMO
Organisms adaptable to extreme conditions share the ability to establish protective biofilms or secrete defence toxins. The extracellular substances that are secreted may contain monosaccharides and other toxic compounds, but environmental conditions influence biofilm characteristics. Microorganisms that are present in the same environment achieve similar compositions, regardless of their phylogenetic relationships. Alternatively, cyanobacteria phylogenetically related may live in different environments, but we ignore if their physiological answers may be similar. To test this hypothesis, two strains of cyanobacteria that were both ascribed to the genus Halomicronema were isolated. H. metazoicum was isolated in marine waters off the island of Ischia (Bay of Naples, Italy), free living on leaves of Posidonia oceanica. Halomicronema sp. was isolated in adjacent thermal waters. Thus, two congeneric species adapted to different environments but diffused in the same area were polyphasically characterized by microscopy, molecular, and toxicity analyses. A variable pattern of toxicity was exhibited, in accordance with the constraints imposed by the host environments. Cyanobacteria adapted to extreme environments of thermal waters face a few competitors and exhibit a low toxicity; in contrast, congeneric strains that have adapted to stable and complex environments as seagrass meadows compete with several organisms for space and resources, and they produce toxic compounds that are constitutively secreted in the surrounding waters.
Assuntos
Alismatales/microbiologia , Cianobactérias/isolamento & purificação , Fontes Termais/microbiologia , Animais , Cianobactérias/genética , Embrião não Mamífero/microbiologia , Monitoramento Ambiental , Pradaria , Ilhas , Itália , Filogenia , Folhas de Planta/microbiologia , RNA Ribossômico 16S , Ouriços-do-Mar/microbiologia , Água do Mar/microbiologia , Especificidade da EspécieRESUMO
One new flavonoid derivative flavoside A (1), one new 5-hydroxyanthranilic acid derivative crassilin (2), along with the known angucyclinone PD116740 (3) and oxachelin (4), was isolated from the EtOAc extract of the fermentation broth of the sea urchin (Anthocidaris crassispina)-derived actinobacterium, Streptomyces sp. HD01. The structures of these compounds were established on the basis of their HR-ESI-MS and NMR spectroscopic data. All of these compounds were assessed for their antibacterial activity.
Assuntos
Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Ouriços-do-Mar/microbiologia , Streptomyces/química , Animais , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Estrutura Molecular , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
Coelomic fluid aspiration has been utilized in echinoderms in research and clinical settings. Detailed procedural descriptions for coelomic fluid sampling in sea urchins (class Echinoidea) are lacking, and samples are prone to contamination. The objectives of this study were to (1) standardize a technique for coelomic fluid collection in long-spined sea urchin Diadema antillarum that optimizes the diagnostic quality of the sample utilizing diagnostic imaging, (2) identify coelomic fluid bacterial isolates (using Biolog GEN III MicroLog and 16s rDNA sequencing), and (3) compare positive cultures to animal weight, holding time prior to sampling, water temperature, and gross fluid appearance. Seventy Diadema antillarum from the Florida Keys collected in two groups (March and September 2015) were utilized. Positive cultures for bacterial contamination were identified in 5% and 44%, respectively, of animals in the sampling groups. Vibrio spp. was the predominant genus identified. Positive cultures were more frequent in the group with smaller-sized animals, increased holding times, and elevated water temperatures. Deviation from clear-pink gross coelomic fluid appearance did not reliably predict bacterial contamination. A standardized technique for coelomocentesis was defined. The use of the proposed coelomocentesis methodology may facilitate improved health evaluations of sea urchins and may be applicable to research, conservation efforts, and disease investigations.
Assuntos
Líquidos Corporais/microbiologia , Ouriços-do-Mar/microbiologia , Animais , Bactérias/isolamento & purificação , Técnicas Bacteriológicas , Peso Corporal , Florida , Imageamento por Ressonância Magnética , RNA Ribossômico 16S , Temperatura , Tomografia Computadorizada por Raios X , Ultrassonografia , Vibrio/isolamento & purificaçãoRESUMO
The sea urchin Tripneustes gratilla (Toxopneustidae, Echinoids) is a source of protein for many islanders in the Indo-West Pacific. It was previously reported to occasionally cause ciguatera-like poisoning; however, the exact nature of the causative agent was not confirmed. In April and July 2015, ciguatera poisonings were reported following the consumption of T.gratilla in Anaho Bay (Nuku Hiva Island, Marquesas archipelago, French Polynesia). Patient symptomatology was recorded and sea urchin samples were collected from Anaho Bay in July 2015 and November 2016. Toxicity analysis using the neuroblastoma cell-based assay (CBA-N2a) detected the presence of ciguatoxins (CTXs) in T.gratilla samples. Gambierdiscus species were predominant in the benthic assemblages of Anaho Bay, and G.polynesiensis was highly prevalent in in vitro cultures according to qPCR results. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses revealed that P-CTX-3B was the major ciguatoxin congener in toxic sea urchin samples, followed by 51-OH-P-CTX-3C, P-CTX-3C, P-CTX-4A, and P-CTX-4B. Between July 2015 and November 2016, the toxin content in T.gratilla decreased, but was consistently above the safety limit allowed for human consumption. This study provides evidence of CTX bioaccumulation in T.gratilla as a cause of ciguatera-like poisoning associated with a documented symptomatology.
Assuntos
Ciguatera/etiologia , Ciguatoxinas/análise , Dinoflagellida , Ouriços-do-Mar/microbiologia , Alimentos Marinhos/toxicidade , Idoso , Animais , Baías , Bioensaio/métodos , Linhagem Celular Tumoral , Ciguatera/epidemiologia , Ciguatera/prevenção & controle , Ciguatoxinas/toxicidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polinésia/epidemiologia , Alimentos Crus/microbiologia , Alimentos Crus/toxicidade , Alimentos Marinhos/microbiologia , Testes de Toxicidade/métodosRESUMO
Four new 5-hydroxyanthranilic acid related compounds, named anthocidins Aâ»D (1â»4), two known analogues n-lauryl 5-hydroxyanthranilate (5) and isolauryl 5-hydroxyanthranilate (6), together with benzamide (7), 3-hydroxy-4-methoxycinnamamide (8), and (3S-cis)-hexahydro-3-[(3,4-dihydroxyphenyl)methyl]pyrrolo[1,2-a]pyrazine-1,4-dione (9), were isolated from the fermentation broth of the marine-derived actinomycete, Streptomyces sp. HDa1, which was isolated from the gut of a sea urchin, Anthocidaris crassispina, collected from Hainan Island, China. The structures of these secondary metabolites were elucidated on the basis of their 1D and 2D-NMR and mass spectroscopic data, and anthocidin A was confirmed by single-crystal X-ray diffraction with Cu Kα radiation. Anthocidins Aâ»D (1â»4) feature an acetyl group substitution at the amino group and varying alkyl side chains at the carboxyl group of 5-hydroxyanthranilic acid, and compound 5 was isolated as a natural product for the first time. The cytotoxic and antibacterial activity of compounds 1â»9 were evaluated.
Assuntos
Actinobacteria/patogenicidade , Antibacterianos/isolamento & purificação , Ouriços-do-Mar/microbiologia , Streptomyces/patogenicidade , ortoaminobenzoatos/isolamento & purificação , Actinobacteria/química , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular , China , Cristalografia por Raios X , Fermentação , Modelos Moleculares , Estrutura Molecular , Streptomyces/química , ortoaminobenzoatos/química , ortoaminobenzoatos/farmacologiaRESUMO
Morphological plasticity is a genotype-by-environment interaction that enables organisms to increase fitness across varying environments. Symbioses with diverse microbiota may aid in acclimating to this variation, but whether the associated bacteria community is phenotype specific remains understudied. Here we induce morphological plasticity in three species of sea urchin larvae and measure changes in the associated bacterial community. While each host species has unique bacterial communities, the expression of plasticity results in the convergence on a phenotype-specific microbiome that is, in part, driven by differential association with α- and γ-proteobacteria. Furthermore, these results suggest that phenotype-specific signatures are the product of the environment and are correlated with ingestive and digestive structures. By manipulating diet quantity over time, we also show that differentially associating with microbiota along a phenotypic continuum is bidirectional. Taken together, our data support the idea of a phenotype-specific microbial community and that phenotypic plasticity extends beyond a genotype-by-environment interaction.
Assuntos
Meio Ambiente , Interações Hospedeiro-Patógeno , Microbiota , Ouriços-do-Mar/microbiologia , Animais , Dieta , Larva/microbiologia , Larva/fisiologia , Fenótipo , Especificidade da EspécieRESUMO
In this study, successive infectious stages by diatom Cylindrotheca closterium (Bacillariophyceae) are described for the first time during the early development of sea urchin at low temperature (8°C). Diatom cell-types enclosed or not by typical theca were capable of infection. As an immune response, red spherulocytes and amoebocytes migrated towards infested areas and restrained the infection spreading over shells in 2- and 3-month old urchins. Only amoebocyte cells appeared to be involved in the immune reaction of 1-month old specimens which turned out to be a less effective fence to stop infestation. The effectiveness of the inflammatory process caused by diatoms within sea urchin spines seemed to vary as a function of urchin age, cohort's type and individual cell pool.
Assuntos
Diatomáceas , Interações Hospedeiro-Patógeno/imunologia , Ouriços-do-Mar/imunologia , Ouriços-do-Mar/microbiologia , Animais , Imunidade Celular/imunologiaRESUMO
UNLABELLED: Although little evidence existed to support that view, European countries and in particular France, have regarded echinoderms, including sea urchins, as low risk in terms of feacal contamination. It is hypothesized that the sea urchins mode of feeding, which is based on grazing and differs from bivalve molluscs, would prevent it from concentrating high levels of Escherichia coli. Here, we monitored E. coli levels in sea urchins (Paracentrotus lividus) and in filter-feeder mussels (Mytillus galloprovincialis), collected concurrently from the same natural area over a 1-year period to verify this assumption. Sea urchins were collected on the seafloor, whereas mussels were collected from the water column at a depth of 4 m. Our results showed heavy bacterial loading of sea urchins in a natural growing environment. Moreover, we highlighted that E. coli contamination of sea urchins could, in certain conditions, be higher than those detected in filter-feeding mussels collected at the same location. Finally, the results showed a significant correlation between rainfall and E. coli concentrations in sea urchins, suggesting that the bacterial safety of sea urchin could be linked to the quality of the surrounding water. SIGNIFICANCE AND IMPACT OF THE STUDY: The European regulation requires competent authorities to monitor the sanitary status of shellfish, including live echinoderms, through faecal indicator organisms. In the French Mediterranean, sea urchin production is significant. Until now, as no data showed significant E. coli contamination levels, no monitoring programs focused on this species. This study demonstrates that sea urchins are more vulnerable to faecal contamination than previously hypothesized, especially during heavy rainfall. In consequence, the European authority general approach to microbiological management of shellfish should be applied to sea urchins.
Assuntos
Bivalves/microbiologia , Escherichia coli/isolamento & purificação , Fezes/microbiologia , Ouriços-do-Mar/microbiologia , Frutos do Mar/microbiologia , Animais , França , Chuva , Poluição da Água/análiseRESUMO
Effective protection against pathogens requires the host to produce a wide range of immune effector proteins. The Sp185/333 gene family, which is expressed by the California purple sea urchin Strongylocentrotus purpuratus in response to bacterial infection, encodes a highly diverse repertoire of anti-pathogen proteins. A subset of these proteins can be isolated by affinity to metal ions based on multiple histidines, resulting in one to four bands of unique molecular weight on standard Western blots, which vary depending on the individual sea urchin. Two dimensional gel electrophoresis (2DE) of nickel-isolated protein samples followed by Western blot was employed to detect nickel-isolated Sp185/333 (Ni-Sp185/333) proteins and to evaluate protein diversity in animals before and after immune challenge with marine bacteria. Ni-Sp185/333 proteins of the same molecular weight on standard Western blots appear as a broad complex of variants that differ in pI on 2DE Western blots. The Ni-Sp185/333 protein repertoire is variable among animals, and shows a variety of changes among individual sea urchins in response to immune challenges with both the same and different species of bacteria. The extraordinary diversity of the Ni-Sp185/333 proteins may provide significant anti-pathogen capabilities for sea urchins that survive solely on innate immunity.
Assuntos
Variação Genética , Imunidade Inata , Proteínas/genética , Ouriços-do-Mar/microbiologia , Animais , Família Multigênica , Níquel/química , Proteínas/isolamento & purificação , Ouriços-do-Mar/genética , Ouriços-do-Mar/imunologia , Vibrio/imunologia , Vibrio/isolamento & purificação , Vibrioses/imunologia , Vibrioses/veterináriaRESUMO
A Gram-stain-negative, aerobic, non-motile, rod-shaped, flexirubin-producing bacterium, designated strain CC-CZW010T, was isolated from the edible sea urchin Tripneustes gratilla in Penghu Island, Taiwan. The isolate grew optimally at pH 7.0 and 30 °C in the presence of 2â% (w/v) NaCl. The most closely related strains in terms of 16S rRNA gene sequence similarity were Chryseobacterium taihuense NBRC 108747T (97.6â%) and Chryseobacterium aquaticum KCTC 12483T (96.7â%). Phylogenetic analyses based on 16S rRNA gene sequences revealed a distinct taxonomic position attained by strain CC-CZW010T with respect to other species of the genus Chryseobacterium. Strain CC-CZW010T possessed iso-C15â:â0, anteiso-C15â:â0, iso-C17â:ââ0 3-OH, summed feature 3 (comprising C16â:â1ω7c/C16â:â1ω6c) and summed feature 9 (comprising C16â:ââ0 10-methyl/iso-C17â:â1ω9c) as predominant fatty acids. The major polar lipid profile consisted of phosphatidylethanolamine, two unidentified lipids and five aminolipids. The polyamine pattern contained the major compound sym-homospermidine. Menaquinone 6 (MK-6) was the predominant respiratory quinone, and the G+C content of the genomic DNA was 36.4âmol%. According to distinct phylogenetic, phenotypic and chemotaxonomic features, strain CC-CZW010T represents a novel species of the genus Chryseobacterium, for which the name Chryseobacterium echinoideorum sp. nov. is proposed. The type strain is CC-CZW010T ( = BCRC 80786T = JCM 30470T).