Evidences of exopolysaccharide production by Helicobacter pylori submitted to hydrodynamic stress

Helicobacter pylori is a widespread Gram-negative bacterium that infects the stomach of humans leading to the onset of several gastric disorders, such as gastritis, gastric ulcers, and cancers. The transmission of H. pylori remains unclear but two different pathways have been suggested: faecal-oral and oraloral. It has been reported that H. pylori has the ability to incorporate in biofilms formed on water-exposed surfaces thus providing a route of infection. On the other hand, a polysaccharide-containing biofilm has been observed at the air-liquid interface when H. pylori is grown in a glass fermenter1. Because exopolysaccharides (EPS) play a determinant role in bacterial adhesion by conferring protection against adverse conditions such as starvation and environmental aggressions, EPS production would be expected to be higher if the bacterium is exposed to water. In this work the capability of H. pylori to produce EPS when exposed to water and under hydrodynamic stress has been evaluated. H. pylori was inoculated in autoclaved distilled water and allowed to stand under gentle stirring at room temperature. The significant and continuous increase in the sugar content 192 hours after inoculation suggests the production of exopolysaccharides. This evidence is reinforced by epiflourescence microscopical observation of the bacteria stained with DAPI (4,6-diamidino-2-phenylindole) that revealed the presence of bacterial aggregates 318 hours after inoculation

Identification of cell-surface mannans in a virulent Helicobacter pylori strain

With the intent of contributing to a carbohydrate-based vaccine against the gastroduodenal pathogen, Helicobacter pylori, we report here the structure of cell-surface mannans obtained from a virulent strain. Unlike other wild-type strains, this strain was found to express in good quantities this polysaccharide in vitro. Structural analysis revealed a branched mannan formed by a backbone of α-(1→6)-linked mannopyranosyl residues with approximately 80% branching at the O-2 position. The branches were composed of O-2-linked Man residues in both α- and β-configurations: (image) In addition, this strain also expressed cell-surface emblematic H. pylori lipopolysaccharides (LPS) containing partially fucosylated polyLacNAc O-chains. Affinity assays with polymyxin-B and concanavalin A revealed no association between the mannan and the LPS. The described mannans may be implicated in the mediation of host–microbial interactions and immunological modulation.This work was supported by Fundacao para a Ciencia e Tecnologia (FCT) through project Pylori E&LPS POCI/QUI/56393/2004, PhD grant SFRH/BD/19929/2004, by the Natural Sciences and Engineering Research Council of Canada (NSERC), and by the European Network of Research Infrastructures within the 6th Framework Programme of the EC (Contract # RII3-026145, EU-NMR). The authors further thank Dr. Adrien Favier (RALF-NMR facility, Grenoble - France) for conducting NMR experiments

Bioaccumulation of amylose-like glycans by Helicobacter pylori

Background: Helicobacter pylori cell surface is composed of lipopolysaccharides (LPSs) yielding structures homologous to mammalian Lewis O-chains blood group antigens. These structures are key mediators in the definition of host-microbial interactions and known to change their expression pattern in response to environmental pressure. Aims:  The present work is focused on the identification of new H. pylori cell-surface glycosides. Special attention is further devoted to provide insights on the impact of in vitro subcultivation on H. pylori cell-surface phenotypes. Methods:  Cell-surface glycans from H. pylori NCTC 11637 and two clinical isolates were recovered from the aqueous phase resulting from phenol:water extraction of intact bacteria. They were evaluated in relation to their sugars and glycosidic-linkages composition by CG-MS, size-exclusion chromatography, NMR, and Mass Spectrometry. H. pylori glycan profile was also monitored during subcultivation in vitro in agar and F12 liquid medium. Results:  All three studied strains produce LPS expressing Lewis epitopes and express bioaccumulate amylose-like glycans. Bioaccumulation of amylose was found to be enhanced with the subcultivation of the bacterium on agar medium and accompanied by a decrease in the expression of LPS O-chains. In contrast, during exponential growth in F12 liquid medium, an opposite behavior is observed, that is, there is an increase in the overall amount of LPS and decrease in amylose content. Conclusions:  This work shows that under specific environmental conditions, H. pylori expresses a phase-variable cell-surface α-(1→4)-glucose moiety

Trophic position of dolphins tracks recent changes in the pelagic ecosystem of the Macaronesian region (NE Atlantic)

14 pages, 6 figures, 1 table.-- Open accessDolphins play a key role in marine food webs as predators of mid-trophic-level consumers. Because of their mobility and relatively long life span, they can be used as indicators oflarge-scale changes in the ecosystem. In this study, we calculated the trophic position (TP) of 5 dolphin species from the Canary, Madeira and Azores Islands using bulk and compound-specific stable isotope ratios from muscle tissue to assess trophic adaptations to recent changes in the availability of feeding resources. Dolphin TP values were then compared with those of 7 other species of cetaceans from this region. Analysis of stable nitrogen isotopes in amino acids of the common dolphin indicated non-significant effects of changes in the basal resources of the food web and thus supported the use of bulk samples for TP estimations. Dolphins occupied an intermediate TP (mean: 3.91 to 4.20) between fin (3.25) and sperm whales (4.95). Species-specific TP were equivalent among islands. However, TP increased for the common dolphin and decreased for the bottlenose dolphin (the latter also becoming more oceanic) between 2000 and 2018 in the Canary Islands. These results suggest different impacts of recent changes in the oceanography and in the pelagic food web of the Macaronesian region on the trophic ecology of dolphin speciesThis study was supported in part by the projects QLOCKS (PID2020-115620RB-I00), funded by MCIN/AEI/10.13039/501100011033 (Spain), MISTIC SEAS 2 (‘Applyinga subregional coherent and coordinated approach to the monitoring and assessment of marine biodiversity in Macaronesia for the second cycle of the MSFD’), funded by the Directorate General Environment of the European Commission (Grant Agreement No. 11.0661/2017/750679/SUB/ENV.C2), MISTIC SEAS 3 (‘Developing a coordinated approach for assessing Descriptor 4 via its linkages with D1 and other relevant descriptors in the Macaronesian subregion’), funded by the Directorate General Environment of the European Commission (Grant Agreement No. 110661/2018/794676/SUB/ENV.C2), RACAM (Rede de Arrojamentos de Cetáceos do Arquipélago da Madeira), implemented by the Madeira Whale Museum and funded by the Machico Municipality and projects MARCET (MAC/1.1b/149) and MARCET II (MAC/2.6c/392), both co-financed by EU Programme INTERREG MAC 2014−2020, and through the Commission (28-5307) for ‘Technical scientific advice for the protection of the marine environment: assessment and monitoring of marine strategies, monitoring of marine protected areas of state competence (2018−2021)’ of the Spanish Ministry of Economy and Competitiveness Demographic Challenge (MITECO). Data collection in the Azores was supported by FCT and FRCT through TRACE-PTDC/MAR/74071/2006, MAPCET-M2.1.2/F/012/2011, IF/00943/2013/CP1199/CT0001 (FEDER, COMPETE, QREN, POPH, ESF, Portuguese Ministry for Science and Education, Azores 2020 Operational Programme). M.A.S. was funded by SUMMEREU-H2020 GA 817806. M.A.S. and R.P. were funded by OP AZORES 2020, through the EU Fund 01-0145-FEDER-000140. Okeanos is funded by FCT (UIDB/05634/2020) and by the Regional Government of the Azores (M1.1.A/REEQ.CIENTÍFICO UI&D/2021/010). J.G. was supported by the Spanish National Programme Juan de la Cierva-Formación (MCIN/AEI/10.13039/501100011033 FJC2019-040016-I). This work acknowledges the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S) to the Institute of Marine Science (ICM-CSIC)Peer reviewe

Marine algal flora of Santa Maria Island, Azores

Este artículo contiene 41 páginas, 4 tablas, 15 figuras.Background The algal flora of the Island of Santa Maria (eastern group of the Azores archipelago) has attracted interest of researchers on past occasions (Drouët 1866, Agardh 1870, Trelease 1897, Schmidt 1931, Ardré et al. 1974, Fralick and Hehre 1990, Neto et al. 1991, Morton and Britton 2000, Amen et al. 2005, Wallenstein and Neto 2006, Tittley et al. 2009,Wallenstein et al. 2009a, Wallenstein et al. 2010, Botelho et al. 2010, Torres et al. 2010, León-Cisneros et al. 2011, Martins et al. 2014, Micael et al. 2014, Rebelo et al. 2014, Ávila et al. 2015, Ávila et al. 2016, Machín-Sánchez et al. 2016, Uchman et al. 2016, Johnson et al. 2017, Parente et al. 2018). Nevertheless, the Island macroalgal flora is not well-known as published information reflects limited collections obtained in short-term visits by scientists. To overcome this, a thorough investigation, encompassing collections and presence data recording, was undertaken at both the littoral and sublittoral levels down to a depth of approximately 40 m, covering an area of approximately 64 km . The resultant taxonomic records are listed in the present paper which also provides information on species ecology and occurrence around the Island, improving, thereby, the knowledge of the Azorean macroalgal flora at both local and regional scales. New information A total of 2329 specimens (including some taxa identified only to genus level) belonging to 261 taxa of macroalgae are registered, comprising 152 Rhodophyta, 43 Chlorophyta and 66 Ochrophyta (Phaeophyceae). Of these, 174 were identified to species level (102 Rhodophyta, 29 Chlorophyta and 43 Ochrophyta), encompassing 52 new records for the Island (30 Rhodophyta, 9 Chlorophyta and 13 Ochrophyta), 2 Macaronesian endemics (Laurencia viridis Gil-Rodríguez & Haroun; and Millerella tinerfensis (Seoane-Camba) S.M.Boo & J.M.Rico), 10 introduced (the Rhodophyta Acrothamnion preissii (Sonder) E.M.Wollaston, Antithamnion hubbsii E.Y.Dawson, Asparagopsis armata Harvey, Bonnemaisonia hamifera Hariot, Melanothamnus harveyi (Bailey) Díaz-Tapia & Maggs, Scinaia acuta M.J.Wynne and Symphyocladia marchantioides (Harvey) Falkenberg; the Chlorophyta Codium fragile subsp. fragile (Suringar) Hariot; and the Ochrophyta Hydroclathrus tilesii (Endlicher) Santiañez & M.J.Wynne, and Papenfussiella kuromo (Yendo) Inagaki) and 18 species of uncertain status (11 Rhodophyta, 3 Chlorophyta and 4 Ochrophyta).This research was supported by several projects, expeditions and campaigns (see Funding above) and lately by the project “ACORES-01-0145-FEDER-000072” funded the Operational Programme Azores 2020 (85% ERDF and 15% regional funds).Manuela I. Parente was supported by a postdoctoral grant (SFRH/BPD/34246/2006) awarded by Fundação para a Ciência e a Tecnologia (FCT). Eva Cacabelos was supported by a postdoctoral grant (Project M1420-09-5369-FSE-000001) from ARDITI (Regional Agency for Development of Research, Technology and Innovation of Madeira). Afonso C.L. Prestes was supported by a PhD grant (M3.1.a/F/083/2015) awarded by Fundo Regional da Ciência e Tecnologia (FRCT). Rita F. Patarra was supported by a Science and Technology Management Fellowship grant (SFRH/BGCT/135478/2018) awarded by Fundação para a Ciência e a Tecnologia, IP.Peer reviewe

Marine algal flora of São Miguel Island, Azores

Este artículo contiene 52 páginas, 4 tablas, 15 figuras.Background The macroalgal flora of the Island of São Miguel (eastern group of the Azores Archipelago) has attracted the interest of many researchers in the past, the first publications going back to the nineteenth century. Initial studies were mainly taxonomic, resulting in the publication of a checklist of the Azorean benthic marine algae. Later, the establishment of the University of the Azores on the Island permitted the logistic conditions to develop both temporal studies and long-term research and this resulted in a significant increase on research directed at the benthic marine algae and littoral communities of the Island and consequent publications. Prior to the present paper, the known macroalgal flora of São Miguel Island comprised around 260 species. Despite this richness, a significant amount of the research was never made public, notably Masters and PhD theses encompassing information regarding presence data recorded at littoral and sublittoral levels down to a depth of approximately 40 m around the Island and the many collections made, which resulted in vouchers deposited in the AZB Herbarium Ruy Telles Palhinha and the LSM- Molecular Systematics Laboratory at the Faculty of Sciences and Technology of the University of the Azores. The present publication lists the macroalgal taxonomic records, together with information on their ecology and occurrence around São Miguel Island, improving the knowledge of the Azorean macroalgal flora at local and regional scales. New information A total of 12,781 specimens (including some identified only to genus) belonging to 431 taxa of macroalgae are registered, comprising 284 Rhodophyta, 59 Chlorophyta and 88 Ochrophyta (Phaeophyceae). Of these, 323 were identified to species level (212 Rhodophyta, 48 Chlorophyta and 63 Ochrophyta), of which 61 are new records for the Island (42 Rhodophyta, 9 Chlorophyta and 10 Ochrophyta), one an Azorean endemic (Predaea feldmannii subsp. azorica Gabriel), five are Macaronesian endemisms (the red algae Botryocladia macaronesica Afonso-Carrillo, Sobrino, Tittley & Neto, Laurencia viridis Gil-Rodríguez & Haroun, Millerella tinerfensis (Seoane-Camba) S.M.Boo & J.M.Rico, Phyllophora gelidioides P.Crouan & H.Crouan ex Karsakoff and the green alga Codium elisabethiae O.C.Schmidt), 19 are introduced species (15 Rhodophyta, two Chlorophyta and two Ochrophyta) and 32 are of uncertain status (21 Rhodophyta, five Chlorophyta and six Ochrophyta).This research was supported by several projects, expeditions and campaigns (see Funding above) and lately by the project “ACORES-01-0145-FEDER-000072” funded the Operational Programme Azores 2020 (85% ERDF and 15% regional funds). Thanks are due to the campaign teams for their critical involvement in this project (Abel Sentíes, Aina del Alcázar, Ana Alfaya, Ana Belén Villalba Lapeña, Ana Santos, Ana Sofia Carreiro, André Amaral, Andrea Tracana, Ane Laborda, Anna Lloveras Armengol, António Brigos Plafon, Berta Solé Nadal, Camille Fontaine, Carlos Rius, Carles Mir, Caroline Terral, Catarina Santos, Cláudia Hipólito, Daniela Gabriel, Edward Hehre, Emanuel Xavier, Eduardo García, Enrique Almira, Esteban Belles, Eunice Nogueira, Fátima Vaz Pinto, Francisco Wallenstein, Gustavo M Martins, Heather Baldwin, Isadora Moniz, Jana Verdura, Joana Pombo, João Brum, João Faria Santos, João Ferreira, Laura Busquier, Marco Enoch, Maria Ana Dionísio, Maria Machín-Sánchez, Maria Vale, Marlene Terra, Mónica Martínez, Mutue Toyota Fujii, Patrícia Madeira, Pedro Raposeiro, Richard Fralick, Richard Thompson, Rocío Sánchez, Ruben Couto, Rubén Mosquera, Rui Sousa, Sara Peres, Tarso Costa, Tito Silva, Valeria Cassano, Virginie Leyendecker). Edgar Rosas Alquicira and Karla León Cisneros were supported by the Programme AlBan, the European Union Programme of High Level Scholarships for Latin America (through scholarships E05D060221MX and E05D060520MX), “Consejo Nacional de Ciencia y Tecnología” (doctoral scholarships 176162 and 157904) and the UNAMUNO Programme of PhD Scholarships for Europe. Eva Cacabelos was supported by a postdoctoral grant (Project M1420-09-5369-FSE-000002) from ARDITI (Regional Agency for Development of Research, Technology and Innovation of Madeira). Andrea Z. Botelho was supported by a PhD grant (M3.1.a/F/083/2015), awarded by Fundo Regional da Ciência e Tecnologia (FRCT). Afonso C.L. Prestes was supported by a PhD grant (M3.1.a/F/083/2015), awarded by Fundo Regional da Ciência e Tecnologia (FRCT). Rita F. Patarra was supported by a Science and Technology Management Fellowship grant (SFRH/BGCT/135478/2018), awarded by Fundação para a Ciência e a Tecnologia (FCT I.P.). Manuela I. Parente was supported by a Postdoc grant (SFRH/BPD/34246/2006), awarded by Fundação para a Ciência e a Tecnologia (FCT).Peer reviewe

HIV-2 interaction with cell coreceptors: amino acids within the V1/V2 region of viral envelope are determinant for CCR8, CCR5 and CXCR4 usage

© 2014 Santos-Costa et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background: Human immunodeficiency virus 1 and 2 (HIV-1 and HIV-2) use cellular receptors in distinct ways. Besides a more promiscuous usage of coreceptors by HIV-2 and a more frequent detection of CD4-independent HIV-2 isolates, we have previously identified two HIV-2 isolates (HIV-2MIC97 and HIV-2MJC97) that do not use the two major HIV coreceptors: CCR5 and CXCR4. All these features suggest that in HIV-2 the Env glycoprotein subunits may have a different structural organization enabling distinct - although probably less efficient - interactions with cellular receptors. Results: By infectivity assays using GHOST cell line expressing CD4 and CCR8 and blocking experiments using CCR8-specific ligand, I-309, we show that efficient replication of HIV-2MIC97 and HIV-2MJC97 requires the presence of CCR8 at plasma cell membrane. Additionally, we disclosed the determinants of chemokine receptor usage at the molecular level, and deciphered the amino acids involved in the usage of CCR8 (R8 phenotype) and in the switch from CCR8 to CCR5 or to CCR5/CXCR4 usage (R5 or R5X4 phenotype). The data obtained from site-directed mutagenesis clearly indicates that the main genetic determinants of coreceptor tropism are located within the V1/V2 region of Env surface glycoprotein of these two viruses. Conclusions: We conclude that a viral population able to use CCR8 and unable to infect CCR5 or CXCR4-positive cells, may exist in some HIV-2 infected individuals during an undefined time period, in the course of the asymptomatic stage of infection. This suggests that in vivo alternate molecules might contribute to HIV infection of natural target cells, at least under certain circumstances. Furthermore we provide direct and unequivocal evidence that the usage of CCR8 and the switch from R8 to R5 or R5X4 phenotype is determined by amino acids located in the base and tip of V1 and V2 loops of HIV-2 Env surface glycoprotein.This work was supported by grants from: Fundação para a Ciência e Tecnologia (FCT; PPCDT/SAU-IMI/55726/2004); Fundação para a Ciência e Tecnologia and Ministério da Saúde de Portugal (VIH/SAU/0006/2011); and from Gilead Sciences Portugal (Programa Gilead Génese).info:eu-repo/semantics/publishedVersio

May Measurement Month 2018: a pragmatic global screening campaign to raise awareness of blood pressure by the International Society of Hypertension

Aims Raised blood pressure (BP) is the biggest contributor to mortality and disease burden worldwide and fewer than half of those with hypertension are aware of it. May Measurement Month (MMM) is a global campaign set up in 2017, to raise awareness of high BP and as a pragmatic solution to a lack of formal screening worldwide. The 2018 campaign was expanded, aiming to include more participants and countries. Methods and results Eighty-nine countries participated in MMM 2018. Volunteers (≥18 years) were recruited through opportunistic sampling at a variety of screening sites. Each participant had three BP measurements and completed a questionnaire on demographic, lifestyle, and environmental factors. Hypertension was defined as a systolic BP ≥140 mmHg or diastolic BP ≥90 mmHg, or taking antihypertensive medication. In total, 74.9% of screenees provided three BP readings. Multiple imputation using chained equations was used to impute missing readings. 1 504 963 individuals (mean age 45.3 years; 52.4% female) were screened. After multiple imputation, 502 079 (33.4%) individuals had hypertension, of whom 59.5% were aware of their diagnosis and 55.3% were taking antihypertensive medication. Of those on medication, 60.0% were controlled and of all hypertensives, 33.2% were controlled. We detected 224 285 individuals with untreated hypertension and 111 214 individuals with inadequately treated (systolic BP ≥ 140 mmHg or diastolic BP ≥ 90 mmHg) hypertension. Conclusion May Measurement Month expanded significantly compared with 2017, including more participants in more countries. The campaign identified over 335 000 adults with untreated or inadequately treated hypertension. In the absence of systematic screening programmes, MMM was effective at raising awareness at least among these individuals at risk

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016