Large-scale impact of the 2016 Marine Heatwave on the plankton-associated microbial communities of the Great Barrier Reef (Australia)

The Great Barrier Reef (GBR) is the world's largest coral ecosystem and is threatened by climate change. This study investigated the impact of the 2016 Marine Heatwave (MHW) on plankton associated microbial communities along a ∼800 km transect in the GBR. 16S rRNA gene metabarcoding of archived plankton samples collected from November 2014 to August 2016 in this region showed a significant increase in Planctomycetes and bacteria belonging to the genus Vibrio and Synechococcus during and after the heatwave. Notably, Droplet Digital PCR and targeted metagenomic analysis applied on samples collected four months after the MHW event revealed the presence of several potential pathogenic Vibrio species previously associated with diseases in aquatic animals. Overall, the 2016 MHW significantly impacted the surface picoplankton community and fostered the spread of potentially pathogenic bacteria across the GBR providing an additional threat for marine biodiversity in this area.

Metataxonomic analysis of tissue-associated microbiota in grooved carpet-shell (Ruditapes decussatus) and Manila (Ruditapes philippinarum) clams

Culture-dependent techniques only permit the study of a low percentage of the microbiota diversity in the environment. The introduction of next generation sequencing (NGS) technologies shed light into this hidden microbial world, providing a better knowledge on the general microbiota and, specifically, on the microbial populations of clams. Tissue-associated microbiota of Ruditapes decussatus and Ruditapes philippinarum (mantle, gills, gonad and hepatopancreas) was analysed in two different locations of Galicia (northwest of Spain) during Spring (April) and Autumn (October), employing a metataxonomic approach. High bacterial diversity and richness were found in all samples where a total of 22,044 OTUs were obtained. In most samples, phylum Proteobacteria was most frequently retrieved, although other phyla as Actinobacteria, Bacteroidetes, Tenericutes, Firmicutes or Chlamydiae also appeared at high relative abundances in the samples. At genus level, great variation was found across tissues and sampling periods. A Nonmetric Multidimensional Scaling (NMDS) and a hierarchical clustering analysis allowed to further analyse the factors responsible for the differences among groups of samples in the different sites. Results showed sample ordination based on tissue origin and sampling periods, pointing out that the microbiota was influenced by these factors. Indeed, predominance of certain genera was observed, such as Endozoicomonas or Methylobacterium in gills and gonads, respectively, suggesting that selection of specific bacterial taxa is likely to occur. So far, this study provided a general picture of the tissue associated microbial population structure in R. decussatus and R. philippinarum clams, which, ultimately, allowed the identification of specific tissue-related taxa.

A deep-sea bacterium related to coastal marine pathogens

Evolution of virulence traits from adaptation to environmental niches other than the host is probably a common feature of marine microbial pathogens, whose knowledge might be crucial to understand their emergence and pathogenetic potential. Here, we report genome sequence analysis of a novel marine bacterial species, Vibrio bathopelagicus sp. nov., isolated from warm bathypelagic waters (3309 m depth) of the Mediterranean Sea. Interestingly, V. bathopelagicus sp. nov. is closely related to coastal Vibrio strains pathogenic to marine bivalves. V. bathopelagicus sp. nov. genome encodes genes involved in environmental adaptation to the deep-sea but also in virulence, such as the R5.7 element, MARTX toxin cluster, Type VI secretion system and zinc-metalloprotease, previously associated with Vibrio infections in farmed oysters. The results of functional in vitro assays on immunocytes (haemocytes) of the Mediterranean mussel Mytilus galloprovincialis and the Pacific oyster Crassostrea gigas, and of the early larval development assay in Mytilus support strong toxicity of V. bathopelagicus sp. nov. towards bivalves. V. bathopelagicus sp. nov., isolated from a remote Mediterranean bathypelagic site, is an example of a planktonic marine bacterium with genotypic and phenotypic traits associated with animal pathogenicity, which might have played an evolutionary role in the origin of coastal marine pathogens.

AB0129 IL-6R GENETIC VARIANTS AS PREDICTORS OF CLINICAL RESPONSE TO TOCILIZUMAB IN RHEUMATOID ARTHRITIS PATIENTS

Background:

Rheumatoid arthritis (RA) is a chronic, systemic, inflammatory autoimmune disease of unknown etiology. Tocilizumab (TCZ) is a first-line biological disease-modifying anti-rheumatic drug (bDMARD) which inhibits Interleukin 6 (IL-6) pathway through blockade of its receptor. At present, there is a lack of evidence to recommend the treatment of one bDMARD over another.(1) Seeking for genetic biomarkers to predict response to treatment could be key towards a personalized treatment strategy in rheumatology.(2)

Objectives:

We aimed to evaluate whether functional single nucleotide polymorphisms (SNPs) in the IL6R gene could predict response and/or toxicity to TZC in Caucasian patients diagnosed with RA.

Methods:

Retrospective analytical preliminar study of a cohort of 31 patients diagnosed with RA (ACR/EULAR 2010 criteria) who received treatment with TCZ within the last 10 years. Epidemiological, clinical and laboratory data were collected. DNA was extracted from EDTA blood samples. Three SNPs in the IL-6 receptor gene (rs12083537, rs2228145, rs4329505) were genotyped by real-time PCR with TaqMan probes. The associations between polymorphisms and clinicopathological features were evaluated using parametric tests. Efficacy was assessed as the difference of DAS-28 CRP at 6 months. The toxicities recorded were hepatotoxicity, infections, hypersensibility, gastrointestinal, hematological and dyslipidemia.

Results:

The 31 DNA samples from patients included were mainly female (83.9%) and had a mean age at diagnosis of 46.8 years. The mean duration of treatment was 51.3 months and, previously to initiate TCZ, they received a mean of 2,6 csDMARD and 1,7 bDMARD.

The more frequent adverse effects were hypertransaminasemia (22.6%) and neutropenia (32.3%). Most relevant epidemiologic and clinical data is shown in Table 1.

Table 1.

Clinical characteristics. RA=Rheumatoid Arthritis. CCP= anti-Cyclic Citrullinated Peptides. RF=Rheumatoid factor. csDMARDs= conventional synthetic Disease-modifying antirheumatic drug. bDMARD= biological Disease-modifying antirheumatic drug. BMI=Body Mass Index. Sc=subcutaneous. Ev=endovenous. DAS28= Disease Activity Score in 28 joints

Sex (n=31), n (% women/men) 26/5 (83,9%/16,1%)Age at diagnosis (n=31), years +- SD 46,8+- 12,8Erosive RA (n=31), n(%) 14 (45,2%)Anti-CCP positive (n=31), n(%)UI+- SD 23 (74,2%)259,7 +- 137,3RF positive (n=31), n (%)UI+-SD 21 (67,7%)189,4+- 114Previous csDMARD (n=31), n°+-SD2,6 +-1,3Previous bDMARD (n=31), n°+- SD1,7 +- 1,4BMI (n=29), mean +- SD29,3+- 5,1Duration of treatment (n=31), months +-SD51,3 +- 36,3-Active treatment (n=12)-80,9+- 18,3-Finished treatment (n=19)-32,6+- 32,2Route of administration (n=31), n (%) sc/ev 11/20 (35,5/64,5)Basal DAS28 (n=30), mean+- SD5,3 +- 1,1DAS28 reduction at 6 months (n=28), mean+-SD2,9 +-1,1

The univariate analyses showed that the rs2228145 variant was statistically associated with differences in DAS28 reduction at 6 months (p=0.042). Regarding efficacy, we also found a trend with the SNP rs4329505 (p=0.173), which could achieve statistical significance with the projected inclusion of more patients. No associations were found regarding adverse effects.

Conclusion:

The rs2228145 polymorphisms in the IL6R gene may be considered as a pharmacogenetic biomarker of TCZ response in RA patients. More studies are required in order to investigate the clinical use of pharmacogenetic biomarkers in rheumatic diseases.

References:

[1]Smolen, Josef S., Robert B., et al. 2020. “EULAR Recommendations for the Management of Rheumatoid Arthritis with Synthetic and Biological Disease-Modifying Antirheumatic Drugs: 2019 Update.” Annals of the Rheumatic Diseases 79 (6): 685–99.

[2]Tarnowski, Maciej, Agnieszka Paradowska-Gorycka, et al. 2016. “The Effect of Gene Polymorphisms on Patient Responses to Rheumatoid Arthritis Therapy.” Expert Opinion on Drug Metabolism & Toxicology 12 (1): 41–55.

Disclosure of Interests:

None declared

Pterostilbene modifies triglyceride metabolism in hepatic steatosis induced by high-fat high-fructose feeding: a comparison with its analog resveratrol

The use of phenolic compounds as a new therapeutic approach against NAFLD has emerged recently. In the present study, we aim to study the effect of pterostilbene in the prevention of liver steatosis developed as a consequence of high-fat (saturated) high-fructose feeding, by analysing the changes induced in metabolic pathways involved in triglyceride accumulation. Interestingly, a comparison with the anti-steatotic effect of its parent compound resveratrol will be made for the first time. Rats were distributed into 5 experimental groups and fed either a standard laboratory diet or a high-fat high-fructose diet supplemented with or without pterostilbene (15 or 30 mg per kg per d) or resveratrol (30 mg per kg per d) for 8 weeks. Serum triglyceride, cholesterol, NEFA and transaminase levels were quantified. Liver histological analysis was carried out by haematoxylin-eosin staining. Different pathways involved in liver triglyceride metabolism, including fatty acid synthesis, uptake and oxidation, triglyceride assembly and triglyceride release, were studied. Pterostilbene was shown to partially prevent high-fat high-fructose feeding induced liver steatosis in rats, demonstrating a dose-response pattern. In this dietary model, it acts mainly by reducing de novo lipogenesis and increasing triglyceride assembly and release. Improvement in mitochondrial functionality was also appreciated. At the same dose, the magnitude of pterostilbene and resveratrol induced effects, as well as the involved mechanisms of action, were similar.

Insight into the microbial communities associated with first larval stages of Mytilus galloprovincialis: Possible interference by estrogenic compounds

The microbiota, the host-associated community of microbes, play important roles in health status and whole body homeostasis of all organisms, including marine species. In bivalves, the microbiota composition has been mainly investigated in adults, whereas little information is available during development. In this work, the microbiota composition of the first larval stages of Mytilus galloprovincialis was evaluated by 16S rRNA gene-based profiling, at 24 and 48 hours post fertilization in comparison with those of eggs and sperm. The main genera detected in both larvae (Vibrio, Pseudoalteromonas, Psychrobium, Colwellia) derived from eggs. However, a clear shift in microbiota was observed in developing larvae compared to eggs, both in terms of core microbiome and relative abundance of different genera. The results provide a first insight into the composition of the microbial communities associated with gametes and early larvae of mussels. Moreover, the impact on larval microbiome of estrogenic chemicals that potentially affect Mytilus early development, 17βestradiol-E₂, Bisphenol A-BPA and Bisphenol F-BPF (10 μg/L), was investigated. Exposure to estrogenic chemicals leads to changes in abundance of different genera, with distinct and common effects depending on the compound and larval stage. Both potential pathogens (Vibrio, Arcobacter, Tenacibaculum) and genera involved in xenobiotic biotransformation (Oleispira, Shewanella) were affected. The effects of estrogenic compounds on larval microbiome were not related to their developmental effects: however, the results address the importance of evaluating the impact of emerging contaminants on the microbiota of marine invertebrates, including larval stages, that are most sensitive to environmental perturbations.

Impact of nanoplastics on hemolymph immune parameters and microbiota composition in Mytilus galloprovincialis

Ocean contamination by micro- and nanoplastics represents a potential threat to marine biota, from bacterial communities to higher organisms. In this work, the effect of in vivo exposure of Mytilus galloprovincialis to amino modified nanopolystyrene (PS-NH₂) (10 μg/L, 96 h) on hemolymph immune parameters and microbiota composition were investigated. Nanoplastics significantly affected immune parameters (decreased phagocytosis, increased ROS and lysozyme activity, inhibition of NO production). These changes were associated with a shift in hemolymph microbiota composition, with increase in some genera (Arcobacter-like, Psychrobium, Vibrio), and decreases in others (Shewanella, Mycoplasma). The results indicate that exposure to nanoplastics can impact on the microbiome of marine bivalves, and suggest that downregulation of immune defences induced by PS-NH₂ may favour potentially pathogenic bacteria. These data underline how exposure to nanoplastics may represent a potential threat to the complex interplay between innate immunity and host microbiota, thus affecting the homeostatic processes involved in maintenance of organism health.

Dynamics of the Pacific oyster pathobiota during mortality episodes in Europe assessed by 16S rRNA gene profiling and a new target enrichment next-generation sequencing strategy

Infectious agents such as the bacteria Vibrio aestuarianus or Ostreid herpesvirus 1 have been repeatedly associated with dramatic disease outbreaks of Crassostrea gigas beds in Europe. Beside roles played by these pathogens, microbial infections in C. gigas may derive from the contribution of a larger number of microorganisms than previously thought, according to an emerging view supporting the polymicrobial nature of bivalve diseases. In this study, the microbial communities associated with a large number of C. gigas samples collected during recurrent mortality episodes at different European sites were investigated by real-time PCR and 16SrRNA gene-based microbial profiling. A new target enrichment next-generation sequencing protocol for selective capturing of 884 phylogenetic and virulence markers of the potential microbial pathogenic community in oyster tissue was developed allowing high taxonomic resolution analysis of the bivalve pathobiota. Comparative analysis of contrasting C. gigas samples conducted using these methods revealed that oyster experiencing mortality outbreaks displayed signs of microbiota disruption associated with the presence of previously undetected potential pathogenic microbial species mostly belonging to genus Vibrio and Arcobacter. The role of these species and their consortia should be targeted by future studies aiming to shed light on mechanisms underlying polymicrobial infections in C. gigas.

Exposure to TiO2 nanoparticles induces shifts in the microbiota composition of Mytilus galloprovincialis hemolymph

It is now recognized that host microbiome, the community of microorganisms that colonize the animal body (e.g. microbiota) and their genomes, play an important role in the health status of all organisms, from nutrient processing to protection from disease. In particular, the complex, bilateral interactions between the host innate immune system and the microbiota are crucial in maintaining whole body homeostasis. The development of nanotechnology is raising concern on the potential impact of nanoparticles-NPs on human and environmental health. Titanium dioxide-nTiO₂, one of the most widely NP in use, has been shown to affect the gut microbiota of mammals and fish, as well as to potentially alter microbial communities. In the marine bivalve Mytilus galloprovincialis, nTiO₂ has been previously shown to interact with hemolymph components, thus resulting in immunomodulation. However, no information is available on the possible impact of NPs on the microbiome of marine organisms. Bivalves host high microbial abundance and diversity, and alteration of their microbiota, in both tissues and hemolymph, in response to stressful conditions has been linked to a compromised health status and susceptibility to diseases. In this work, the effects of nTiO₂ exposure (100 μg/L, 4 days) on Mytilus hemolymph microbiota were investigated by 16S rRNA gene-based profiling. Immune parameters were also evaluated. Although hemolymph microbiota of control and nTiO₂-treated mussels revealed a similar core composition, nTiO₂ exposure affected the abundance of different genera, with decreases in some (e.g. Shewanella, Kistimonas, Vibrio) and increases in others (e.g. Stenotrophomonas). The immunomodulatory effects of nTiO₂ were confirmed by the increase in the bactericidal activity of whole hemolymph. These represent the first data on the effects of NPs on the microbiome of marine invertebrates, and suggest that the shift in hemolymph microbiome composition induced by nTiO₂ may result from the interplay between the microbiota and the immune system.

Characterization of the microbiota associated to Pecten maximus gonads using 454-pyrosequencing

A next-generation sequencing (NGS) approach was used to study the microbiota associated to Pecten maximus broodstock, applying pyrosequencing of PCR-amplified V1-V4 16S rRNA gene regions. We analysed the resident bacterial communities in female and male scallop gonads before and after spawning. DNA samples were amplified and quality-filtered reads were assigned to family and genus taxonomic levels using the Ribosomal Database Project classifier. A total of 18,520 sequences were detected, belonging to 13 phyla, including Proteobacteria (55%), Bacteroidetes (11,7%), Firmicutes (3%), Actinobacteria (2%) and Spirochaetes (1,2%), and 110 genera. The major fraction of the sequences detected corresponded to Proteobacteria, Beta- and Gammaprotebacteria being the most abundant classes. The microbiota of P. maximus gonad harbour a wide diversity, however differences on male and female samples were observed, where female gonad samples show a larger number of genera and families. The dominant bacterial genera appeared to be Delftia, Acinetobacter, Hydrotalea, Aquabacterium, Bacillus, Sediminibacterium, Sphingomonas, and Pseudomonas that were present among the four analysed samples. This next generation sequencing technique, applied for the first time in P. maximus (great scallop) gonads was useful for the study of the bacterial communities in this mollusc, unravelling the great bacterial diversity in its microbiota. [Int Microbiol 19(2): 93-99(2016)].

Genome sequence of three Psychrobacter sp. strains with potential applications in bioremediation

To date, the genus Psychrobacter consists of 37 recognized species isolated from different sources, however they are more frequently found in cold and other non-polar environments of low water activity. Some strains belonging to the genus have shown different enzymatic activities with potential applications in bioremediation or food industry. In the present study, the whole genome sequences of three Psychrobacter-like strains (C 20.9, Cmf 22.2 and Rd 27.2) isolated from reared clams in Galicia (Spain) are described. The sequenced genomes resulted in an assembly size of 3,143,782 bp for C 20.9 isolate, 3,168,467 bp for Cmf 22.2 isolate and 3,028,386 bp for Rd 27.2 isolate. Among the identified coding sequences of the genomes, mercury detoxification and biogeochemistry genes were found, as well as genes related to heavy metals and antibiotic resistance. Also virulence-related features were identified such as the siderophore vibrioferrin or an aerobactin-like siderophore. The phylogenetic analysis of the 16S rRNA gene suggested that these strains may represent novel species of the Psychrobacter genus. The genome sequences of the Psychrobacter sp. strains have been deposited at DDBJ/EMBL/GenBank under the accession numbers MRYA00000000 (Cmf 22.2), MRYB00000000 (Rd 27.2) and MRYC00000000 (C 20.9), and the sequences could be found at the site https://www.ncbi.nlm.nih.gov/bioproject/PRJNA353858.

Comparative Genomic Analysis of Two Vibrio toranzoniae Strains with Different Virulence Capacity Reveals Clues on Its Pathogenicity for Fish

Vibrio toranzoniae is a Gram-negative bacterium of the Splendidus clade within the Vibrio genus. V. toranzoniae was first isolated from healthy clams in Galicia (Spain) but recently was also identified associated to disease outbreaks of red conger eel in Chile. Experimental challenges showed that the Chilean isolates were able to produce fish mortalities but not the strains isolated from clams. The aim of the present study was to determine the differences at the genomic level between the type strain of the species (CECT 7225^T) and the strain R17, isolated from red conger eel in Chile, which could explain their different virulent capacity. The genome-based comparison showed high homology between both strains but differences were observed in certain gene clusters that include some virulence factors. Among these, we found that iron acquisition systems and capsule synthesis genes were the main differential features between both genomes that could explain the differences in the pathogenicity of the strains. Besides, the studied genomes presented genomic islands and toxins, and the R17 strain presented CRISPR sequences that are absent on the type strain. Taken together, this analysis provided important insights into virulence factors of V. toranzoniae that will lead to a better understanding of the pathogenic process.

MicroRNAs involved in the browning process of adipocytes

The present review focuses on the role of miRNAs in the control of white adipose tissue browning, a process which describes the recruitment of adipocytes showing features of brown adipocytes in white adipose tissue. MicroRNAs (miRNAs) are a class of short non-coding RNAs (19-22 nucleotides) involved in gene regulation. Although the main effect of miRNAs is the inhibition of the translational machinery, thereby preventing the production of the protein product, the activation of protein translation has also been described in the literature. In addition to modifying translation, miRNAs binding to its target mRNAs also trigger the recruitment and association of mRNA decay factors, leading to mRNA destabilization, degradation, and thus to the decrease in expression levels. Although a great number of miRNAs have been reported to potentially regulate genes that play important roles in the browning process, only a reduced number of studies have demonstrated experimentally an effect on this process associated to changes in miRNA expressions, so far. These studies have shown, by using either primary adipocyte cultures or experimental models of mice (KO mice, mice overexpressing a specific miRNA), that miR-196a, miR-26, and miR-30 are needed for browning process development. By contrast, miR-155, miR-133, miR-27b, and miR-34 act as negative regulators of this process [corrected]. Further studies are needed to fully describe the miRNA network-involved white adipose tissue browning regulation.

Potential application of non-flavonoid phenolics in diabetes: antiinflammatory effects

Polyphenols are members of a very large family of plant-derived compounds that may have beneficial effects on human health, and thus their study has become an increasingly important area of human nutrition research. Considering that it is increasingly accepted that chronic sub-acute inflammation plays an important role in the development of insulin resistance and of diabetes in animals and in humans, the aim of the present review is to compile information concerning the anti-inflammatory effects of non-flavonoid polyphenols on diabetes prevention and/or treatment. Most of these studies have been carried out with different cultured cells and using animal models displaying different types of diabetes, such as diabetes induced by streptozotocin or streptozotocin-nicotinamide, genetic diabetes or diabetes induced by high-fat feeding. In general terms, non-flavonoid polyphenols reduce the production of inflammatory mediators, such as IL-1β, IL-8, MCP-1, COX-2 or iNOS in these animal models of diabetes. This effect is accompanied in the vast majority of these studies by improved insulin action. In addition, some of the non-flavonoid polyphenols are also able to ameliorate or prevent several pathological alterations associated with the development of diabetes, such as nephropathy, cardiopathy or retinopathy. Very little information has been reported with regard to human studies to date. Thus, new studies are needed to confirm if the beneficial effects observed in preclinical studies can apply to human beings.

Vibrio tapetis isolated from vesicular skin lesions in Dover sole Solea solea

Vibrio tapetis is primarily known as the causative agent for brown ring disease in bivalves, although it has been isolated from cultivated fish during mortalities on farms. Here we describe the first isolation of V. tapetis from wild-caught and subsequently captive-held Dover sole Solea solea. Pathological features consisted of multifocal circular greyish-white skin discolourations evolving into vesicular lesions and subsequent ulcerations on the pigmented side. On the non-pigmented side, multiple circular lesions-white at the center and red at the edges-were evident. Histological examination of the vesicular lesions revealed dermal fluid-filled spaces, collagen tissue necrosis and a mixed inflammatory infiltrate, with large numbers of small rod-shaped bacteria. In the deep skin lesions, loss of scales and dermal connective tissue, with degeneration and fragmentation of the myofibres bordering the ulceration, were noted. Serotyping, DNA-DNA hybridization and REP- and ERIC-PCR techniques showed that the retrieved isolates displayed a profile similar to the representative strain of genotype/serotype O2 which originally was isolated from carpet-shell clam Venerupis decussata and to which isolates obtained from wedge sole Dicologoglossa cuneata were also closely related.

Isolation and identification of Vibrio toranzoniae associated with diseased red conger eel (Genypterus chilensis) farmed in Chile

The present study deals with the first isolation of Vibrio toranzoniae from cultured red conger eel (Genypterus chilensis). During the summer season of 2011, mortalities were observed in young red conger eel at one aquaculture experimental rearing system in Quintay, Valparaiso, Chile. The microbiological analysis of the diseased fish resulted in the isolation of three dominant and representative isolates, designated as R.17, R.18 and R.19, which were obtained from gill, fin and external lesions from three different fish, respectively. All isolates were identified as V. toranzoniae by means of a polyphasic taxonomic approach, including phenotypic characterization, sequencing of 16S rRNA and housekeeping genes, and DNA-DNA hybridization. Inoculation of a representative strain (R18) in turbot as model fish species demonstrated the pathogenic potential for fish of the Chilean isolates. Results obtained indicate that the geographical and host distribution of V. toranzoniae is wider than expected, and that this species may have negative incidence in the culture of marine organisms.

Nutritional differences between a gluten-free diet and a diet containing equivalent products with gluten

The gluten-free (GF) products market represents one of the most prosperous markets in the field of food and beverages in the immediate future. Historically, counselling for celiac disease has focused on the absence of gluten in foods, however the nutritional quality of GF foodstuffs is an important aspect to consider. The aim of the present work was to compare the nutritional composition of the 206 GF rendered products most consumed in Spain, against the composition of 289 equivalent foods with gluten, and to make a comparison between the diet including GF products and the same diet with equivalent products with gluten in a 58 adult celiac population. The results of the present collaborative study pointed out differences in calorie, macronutrient, fiber, sodium, salt and cholesterol content between GF rendered and gluten-containing foodstuffs. Thus, calorie and nutrient intake in a GF diet is different when compared to its equivalent diet with gluten. Following a diet based on GF products could suppose a nutritional imbalance for celiac patients as well as for non-celiacs who follow a diet that includes many GF rendered foodstuffs.

New Vibrio species associated to molluscan microbiota: a review

The genus Vibrio consists of more than 100 species grouped in 14 clades that are widely distributed in aquatic environments such as estuarine, coastal waters, and sediments. A large number of species of this genus are associated with marine organisms like fish, molluscs and crustaceans, in commensal or pathogenic relations. In the last decade, more than 50 new species have been described in the genus Vibrio, due to the introduction of new molecular techniques in bacterial taxonomy, such as multilocus sequence analysis or fluorescent amplified fragment length polymorphism. On the other hand, the increasing number of environmental studies has contributed to improve the knowledge about the family Vibrionaceae and its phylogeny. Vibrio crassostreae, V. breoganii, V. celticus are some of the new Vibrio species described as forming part of the molluscan microbiota. Some of them have been associated with mortalities of different molluscan species, seriously affecting their culture and causing high losses in hatcheries as well as in natural beds. For other species, ecological importance has been demonstrated being highly abundant in different marine habitats and geographical regions. The present work provides an updated overview of the recently characterized Vibrio species isolated from molluscs. In addition, their pathogenic potential and/or environmental importance is discussed.

Vibrio cortegadensis sp. nov., isolated from clams

A group of four strains isolated from clams (Venerupis decussata and Venerupis philippinarum) in Galicia (NW Spain) were subjected to a polyphasic characterization, based on the phenotypic characteristics, the analysis of chemotaxonomic features, the sequencing of the 16S rRNA and five housekeeping (atpA, pyrH, recA, rpoA and rpoD) genes, as well as DNA-DNA hybridization (DDH). The analysis of the phenotypic and chemotaxonomic characteristics and the results of a phylogenetic study, based on the 16S rRNA gene sequence analysis and multilocus sequence analysis, clearly indicated that these strains belong to the genus Vibrio and were allocated between the Splendidus and Anguillarum clades showing a close relationship with the type strains of Vibrio tapetis (98.8 %), Vibrio pomeroyi (98.0 %) and Vibrio crassostreae (97.9 %). DNA-DNA hybridization results confirmed that these isolates constitute a new species. The name Vibrio cortegadensis sp. nov. is proposed with C 16.17(T) (=CECT 7227(T)=LMG 27474(T)) as the type strain.

Dietary glycemic index/load and peripheral adipokines and inflammatory markers in elderly subjects at high cardiovascular risk

BACKGROUND AND AIMS

Epidemiological and clinical studies suggest that low-glycemic index diets could protect against weight gain. However, the relationship between these diets and adipokines or inflammatory markers is unclear. In the present study we examine how the dietary glycemic index (GI) and dietary glycemic load (GL) are associated with several adipokines and related metabolic risk markers of obesity and diabetes in a cross-sectional and longitudinal manner.

METHODS AND RESULTS

511 elderly community-dwelling men and women at high cardiovascular risk were recruited for the PREDIMED trial. Dietary data were collected at baseline and after 1 year of follow-up. The GI and GL were calculated. Plasma leptin, adiponectin and other metabolic risk markers were measured at baseline and after 1 year. At baseline, subjects in the highest quartiles of GI showed significantly higher levels of TNF and IL-6 than those in the lowest quartiles. Dietary GI index was negatively related to plasma leptin and adiponectin levels. After 1 year of follow-up, subjects with a higher increase in dietary GI or GL showed a greater reduction in leptin and adiponectin plasma levels. There was no association between GI or GL and the other metabolic markers measured.

CONCLUSION

Our results suggest that the consumption of high-GI or high-GL diets may modulate plasma concentrations of leptin and adiponectin, both adipostatic molecules implicated in energy balance and cardiometabolic risk.

The combination of resveratrol and CLA does not increase the delipidating effect of each molecule in 3T3-L1 adipocytes

INTRODUCTION

Trans-10, cis-12 conjugated linoleic acid (CLA) and resveratrol have been shown to reduce TG content in cultured 3T3-L1 adipocyte acting on different pathways. In recent years, the method of simultaneously targeting several signal transduction pathways with multiple natural products in order to achieve additive or synergistic effects has been tested. However, the combined effect of both molecules on lipid metabolism has not been described before.

OBJECTIVE

The aim of the present work was to analyze the effect of the combination of trans-10, cis-12 CLA and resveratrol on TG accumulation as well as on FAS, HSL and ATGL expression in 3T3-L1 mature adipocytes, in order to assess a potential interaction between both molecules.

METHODS

For this purpose, 3T3-L1 mature adipocytes were treated with the two molecules, both separately and combined, in 10 and 100 μM for 20 hours. TG content and FAS, ATGL and HSL expression were measured by spectrophotometry and Real Time RT-PCR respectively.

RESULTS

Both doses of CLA and 100 M resveratrol decreased TG content in mature adipocytes. The combination of both molecules reduced TG accumulation to the same extent as each one separately. No change in FAS and HSL mRNA levels after CLA and resveratrol treatment was observed. ATGL was not modified by CLA but it was increased by resveratrol and by the combination. This combination did not increase the effect caused by resveratrol on its own.

CONCLUSION

Lipolysis increase via ATGL is involved in the TG reduction induced by resveratrol and the combination of both molecules. The combination of these two molecules does not increase the efficacy of each molecule separately in mature adipocytes and thus it does not represent an advantage for obesity treatment or prevention.

Association of circulating visfatin concentrations with insulin resistance and low-grade inflammation after dietary energy restriction in Spanish obese non-diabetic women: role of body composition changes

BACKGROUND AND AIMS

To assess the influence of body composition changes on circulating serum visfatin after following 12 weeks of energy restricted diet intervention. We also examined the possible role of visfatin in glucose metabolism and in obesity-associated low-grade inflammation.

METHODS AND RESULTS

A total of 78 obese (BMI 34.0 ± 2.8 kg/m²) women aged 36.7±7 y volunteered to participate in the study. We measured by DXA body fat mass (FM) and lean mass (LM). Fasting serum visfatin, glucose, insulin, adiponectin, leptin, IL-1β, IL-6, IL-8, TNF-α and CRP concentrations were analyzed before and after the intervention and HOMA and QUIKI indexes were calculated. Mean weight loss 7.7 ± 3.0 kg and HOMA decreased in 24 ± 35%. Serum visfatin concentration change was negatively associated with LM difference (P < 0.05), whereas no significant relationship was observed with FM changes after energy restricted diet intervention. Changes in circulating serum visfatin levels were significantly and inversely associated with HOMA-IR (P < 0.01) and positively with QUICKI index (P < 0.02) after energy restricted diet intervention, regardless of achieved body weight loss. We did not find any significant association between changes in visfatin levels and IL-1β, IL-6, IL-8, TNF-α and CRP levels after dietary intervention (all P > 0.2).

CONCLUSION

Circulating visfatin concentration is associated with sensitivity improvement achieved after energy restricted diet intervention induced weight loss. Furthermore, LM changes could be an influencing factor on visfatin concentrations and consequently, on the improvement of insulin sensitivity after weight loss in obese non-diabetic women. Our findings did not provide any evidence for a role of visfatin increase on low-grade inflammation after weight loss.

Germline ATM mutational analysis in BRCA1/BRCA2 negative hereditary breast cancer families by MALDI-TOF mass spectrometry

Biallelic inactivation of ATM gene causes the rare autosomal recessive disorder Ataxia-telangiectasia (A-T). Female relatives of A-T patients have a two-fold higher risk of developing breast cancer (BC) compared with the general population. ATM mutation carrier identification is laborious and expensive, therefore, a more rapid and directed strategy for ATM mutation profiling is needed. We designed a case-control study to determine the prevalence of 32 known ATM mutations causing A-T in Spanish population in 323 BRCA1/BRCA2 negative hereditary breast cancer (HBC) cases and 625 matched Spanish controls. For the detection of the 32 ATM mutations we used the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry technique. We identified one patient carrier of the c.8264_8268delATAAG ATM mutation. This mutation was not found in the 625 controls. These results suggest a low frequency of these 32 A-T causing mutations in the HBC cases in our population. Further case-control studies analyzing the entire coding and flanking sequences of the ATM gene are warranted in Spanish BC patients to know its implication in BC predisposition.

Evaluation of the XRCC1 gene as a phenotypic modifier in BRCA1/2 mutation carriers. Results from the consortium of investigators of modifiers of BRCA1/BRCA2

BACKGROUND

Single-nucleotide polymorphisms (SNPs) in genes involved in DNA repair are good candidates to be tested as phenotypic modifiers for carriers of mutations in the high-risk susceptibility genes BRCA1 and BRCA2. The base excision repair (BER) pathway could be particularly interesting given the relation of synthetic lethality that exists between one of the components of the pathway, PARP1, and both BRCA1 and BRCA2. In this study, we have evaluated the XRCC1 gene that participates in the BER pathway, as phenotypic modifier of BRCA1 and BRCA2.

METHODS

Three common SNPs in the gene, c.-77C>T (rs3213245) p.Arg280His (rs25489) and p.Gln399Arg (rs25487) were analysed in a series of 701 BRCA1 and 576 BRCA2 mutation carriers.

RESULTS

An association was observed between p.Arg280His-rs25489 and breast cancer risk for BRCA2 mutation carriers, with rare homozygotes at increased risk relative to common homozygotes (hazard ratio: 22.3, 95% confidence interval: 14.3-34, P<0.001). This association was further tested in a second series of 4480 BRCA1 and 3016 BRCA2 mutation carriers from the Consortium of Investigators of Modifiers of BRCA1 and BRCA2.

CONCLUSIONS AND INTERPRETATION

No evidence of association was found when the larger series was analysed which lead us to conclude that none of the three SNPs are significant modifiers of breast cancer risk for mutation carriers.

Adiposity and serum parameters in hamsters fed energy restricted diets supplemented or not with trans-10,cis-12 conjugated linoleic acid

Numerous studies have demonstrated that conjugated linoleic acid (CLA) modulates body composition, reducing body fat accumulation in various mammalian species. However, very few studies have been carried out to assess the effect of CLA on previously stored body fat. The aim of the present work was to analyse the effectiveness of trans-10,cis-12 CLA in improving alterations produced by high-fat feeding in body fat and serum parameters when it was included in an energy-restricted diet. For this purpose male Syrian Golden hamsters were fed on high-fat diet for 7 weeks in order to increase their body fat content, and a further 25% energy-restricted diet supplemented or not with 0.5% trans-10,cis-12 CLA for 3 weeks. Adipose tissues, liver and gastrocnemious muscles were dissected and weighed. Adipocyte diameter and number were assessed in epididymal adipose tissue. Total cholesterol, triacylglycerols, non-esterified fatty acids and glucose were measured in serum. Three weeks of energy restriction resulted in a reduction in body weight and white adipose tissue size in all anatomical locations, without changes in liver and gastrocnemious muscle weights. Epididymal adipocyte size was reduced, but total adipocyte number remained unchanged. Serum cholesterol, triacylglycerols and glucose were significantly reduced. No differences were observed between the restricted groups (control and CLA supplemented). In conclusion, under our experimental conditions, the addition of trans-10,cis-12 CLA to the diet does not increase the benefits produced by energy restriction.

Prognostic value of minimal residual disease (MRD) in acute myeloid leukemia (AML) with favorable cytogenetics [t(8;21) and inv(16)]

Most patients with acute myeloid leukemia (AML) and t(8;21) or inv(16) have a good prognosis with current anthracycline- and cytarabine-based protocols. Tandem analysis with flow cytometry (FC) and real-time RT-PCR (RQ-PCR) was applied to 55 patients, 28 harboring a t(8;21) and 27 an inv(16), including one case with a novel CBFbeta/MYH11 transcript. A total of 31% (n=17) of CR patients relapsed: seven with t(8;21) and 10 with inv(16). The mean amount of minimal residual disease (MRD) detected by FC in relapsed and nonrelapsed patients was markedly different: 0.3 vs 0.08% (P=0.002) at the end of treatment. The mean number of fusion transcript copies/ ABL x 10(4) also differed between relapsed and non-relapsed patients: 2385 vs 122 (P=0.001) after induction, 56 vs 7.6 after intensification (P=0.0001) and 75 vs 3.3 (P=0.0001) at the end of chemotherapy. Relapses were more common in patients with FC MRD level >0.1% at the end of treatment than in patients with < or = 0.1%: cumulative incidence of relapse (CIR) was 67 and 21% (P=0.03), respectively. Likewise, using RQ-PCR, a cutoff level of >10 copies at the end of treatment correlated with a high risk of relapse: CIR was 75% for patients with RQ-PCR >10 compared to 21% for patients with RQ-PCR levels < or = 10 (P=0.04). Combined use of FC and RQ-PCR may improve MRD detection, and provide useful clinical information on relapse kinetics in AML patients.

Effects of gabapentin on the motor response to levodopa: a double-blind, placebo-controlled, crossover study in patients with complicated Parkinson disease

BACKGROUND

Motor fluctuations and dyskinesias affect many parkinsonian patients chronically treated with levodopa. Imbalance between gabaergic direct and indirect striatopallidal pathways may originate them. Manipulating GABA neurotransmission may be effective in the treatment of these patients. Gabapentin is an antiepileptic drug that increases the synthesis and release of GABA. Previous studies suggest that gabapentin may be useful in Parkinson disease (PD).

OBJECTIVE

To know the effects of gabapentin on the motor response to levodopa in PD patients with motor complications.

DESIGN

A randomized double-blind, placebo-controlled, cross-over trial with four weeks of treatment.

SETTING

A tertiary referral center.

PARTICIPANTS

Twenty subjects with PD and motor fluctuations and dyskinesias on stable antiparkinsonian treatment, took gabapentin up to a maximum dose of 2.400 mg/d in three doses and placebo.

METHODS

Three levodopa challenges were performed: at the beginning of the study and at the end of each period of treatment (4 weeks). Basal (off) and best (on) motor status were assessed by the UPDRS III. Latency to peak effect, magnitude of motor response (difference between "on" and "off" scores in the UPDRS III), duration of motor response and severity and duration of dyskinesias after each levodopa challenge were assessed. Patients' diaries were administered.

RESULTS

: Fifteen patients completed the study. A significant improvement in the basal UPDRS III resulting in a significant reduction in the magnitude of the motor response after gabapentin was obtained (P < 0.001). No other changes were observed, either on pharmacological parameters or in levodopa-induced dyskinesias. Number of daily hours spent in "on," "on with dyskinesias" and "off" also remained unchanged. Tolerance was good, dizziness being the most common side effect.

CONCLUSION

Gabapentin improved parkinsonian symptoms (basal UPDRS III and magnitude of the motor response) following levodopa. This improvement was not reflected in the daily motor situation of patients. Dyskinesias remained unchanged. Gabapentin was well tolerated. Further studies are needed to know the impact of these results in the long-term.

MEIS 1 expression is downregulated through promoter hypermethylation in AML1-ETO acute myeloid leukemias

Retroviral insertional mutagenesis in BXH2 mice commonly induces myeloid leukemias. One of the most frequently involved genes in experimental studies is Meis 1. In contrast to other genes in murine models, Meis 1 has not been affected by recurrent chromosomal translocations or point mutations in human leukemias. We found a constant downregulation of the Meis 1 gene mRNA in AML1-ETO acute myeloid leukemias and in those cases harboring in frame mutations in the bZIP domain of CEBPalpha. The absence of the Meis 1 mRNA was not caused by inactivating point mutations in the coding sequence. Promoter hypermethylation was present in more than half of the cases (9/14), including samples obtained from the widely employed Kasumi-1 cell line. Double treatment with 5-Aza-2'-deoxycytidine and trichostatin A of the Kasumi-1 cell line partially reverses Meis 1 inhibition. HoxA9 levels were also low. In a cell line model (U937 Tet AML1-ETO), AML1-ETO expression was not associated with Meis 1 suppression at 72 h. Nevertheless, Meis 1 repression is dependent on the AML1-ETO transcript levels in treated leukemic patients. Chimeric products that arise from chromosomal translocations may be associated with locus-specific epigenetic inactivation. It remains to be investigated when this methylation process is acquired and which are the basic mechanisms underlying these molecular events in AML1-ETO and CEBPalpha-mutated AML.

[Hypothesis: Parkinson's disease, reward deficiency syndrome and addictive effects of levodopa]

Since Parkinson's disease (PD) patients could suffer from a reward deficiency syndrome, they are particularly prone to develop addictive behaviours. Dopamine is involved in reward processing and in addiction. Pulsatile administration of antiparkinsonian drugs may lead to the development of dyskinesias and addictive behaviours. However, this phenomenon occurs in very few cases. Indeed, both processes share molecular mechanisms although with some differences such as the topography of the changes (it predominates in motor regions in PD with dyskinesias and in limbic regions in addictions). Nevertheless, investigations conducted to know the physiopathology of levodopa-induced dyskinesias may lead to important cues for understanding the underlying mechanisms responsible for addiction. Thus, this may have important implications for the discovery of new therapeutic strategies.

[Muscular dystrophy due to a deficit of gamma-sarcoglycan. A report of three patients with the Delta-521t mutation]

INTRODUCTION

gamma-sarcoglicanopathies, also classified as limb girdle muscular dystrophy type 2C (LGMD2C) are a group of autosomal recessive muscular dystrophies due to mutations in 13q12 and subsequent g sarcoglican deficiency. The protein is one of the components of the dystrophin associated glycoprotein complex and is thought to impart structural integrity to the myofibre. The clinical course of the disease may be heterogeneous, ranging from severe forms with onset in the first decade and rapid progression resembling Progressive Duchenne muscular dystrophy (DMD) to milder forms with later onset and slower course. Cases hitherto reported in Spain corresponds to gypsie patients, homozygous for C283Y missense mutation.

CASE REPORTS

Here, we report three new galician (Northwest Spain) patients (one male and one female sibling cases) with a severe DMD like muscular dystrophy homozygous for D 521T. In the first male familial case, initial diagnosis of DMD was made. On reevaluation fourteen years later, inmunohistochemical and molecular studies allowed for a definitive g sarcoglicanopathy diagnosis.

CONCLUSIONS

Patients with a primary sarcoglycanopathy may be clinically indistinguishable from those with the primary dystrophinopathies. Probably, the diagnosis of LGMD are underestimated and a number of male patients diagnosed as DMD really corresponds to a recessive form o muscular dystrophy. Consequently, a definitive diagnosis rests on appropriate inmunohistochemical and molecular analysis, specially in those patients showing a normal pattern of dystrophin and/or suggestive for an autosomal recessive mode of inheritance.

Distal anterior compartment myopathy: a dysferlin mutation causing a new muscular dystrophy phenotype

We report a family with a new phenotype of autosomal recessive muscle dystrophy caused by a dysferlin mutation. The onset of the illness is distal, in the muscles of the anterior compartment group. The disease is rapidly progressive, leading to severe proximal weakness. Muscle biopsy showed moderate dystrophic changes with no vacuoles. Dysferlin immunostaining was negative. Gene analysis revealed a frameshift mutation in the exon 50 (delG5966) of the DYSF gene. This phenotype further demonstrates the clinical heterogeneity of the dysferlinopathies.