52 research outputs found

    Geographic distribution of methyltransferases of Helicobacter pylori: evidence of human host population isolation and migration

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    Background: Helicobacter pylori colonizes the human stomach and is associated with gastritis, peptic ulcer, and gastric cancer. This ubiquitous association between H. pylori and humans is thought to be present since the origin of modern humans. The H. pylori genome encodes for an exceptional number of restriction and modifications (R-M) systems. To evaluate if R-M systems are an adequate tool to determine the geographic distribution of H. pylori strains, we typed 221 strains from Africa, America, Asia, and Europe, and evaluated the expression of different 29 methyltransferases. Results: Independence tests and logistic regression models revealed that ten R-M systems correlate with geographical localization. The distribution pattern of these methyltransferases may have been originated by co-divergence of regional H. pylori after its human host migrated out of Africa. The expression of specific methyltransferases in the H. pylori population may also reflect the genetic and cultural background of its human host. Methyltransferases common to all strains, M. HhaI and M. NaeI, are likely conserved in H. pylori, and may have been present in the bacteria genome since the human diaspora out of Africa. Conclusion: This study indicates that some methyltransferases are useful geomarkers, which allow discrimination of bacterial populations, and that can be added to our tools to investigate human migrations.. - New England Biolabs, Inc. (USA). - We thank Lurdes Monteiro and Sebastian Suerbaum for the H. pylori strains, Patricia Fonseca and Rui Moreira for critical review of the manuscript, and Afonso Cavaco, Antonio Belo and Dinis Pestana for helping on the logistic regression analysis. This work was partially supported by New England Biolabs, Inc. (USA)

    Glutaredoxin: Discovery, redox defense and much more

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    Glutaredoxin, Grx, is a small protein containing an active site cysteine pair and was discovered in 1976 by Arne Holmgren. The Grx system, comprised of Grx, glutathione, glutathione reductase, and NADPH, was first described as an electron donor for Ribonucleotide Reductase but, from the first discovery in E.coli, the Grx family has impressively grown, particularly in the last two decades. Several isoforms have been described in different organisms (from bacteria to humans) and with different functions. The unique characteristic of Grxs is their ability to catalyse glutathione-dependent redox regulation via glutathionylation, the conjugation of glutathione to a substrate, and its reverse reaction, deglutathionylation. Grxs have also recently been enrolled in iron sulphur cluster formation. These functions have been implied in various physiological and pathological conditions, from immune defense to neurodegeneration and cancer development thus making Grx a possible drug target. This review aims to give an overview on Grxs, starting by a phylogenetic analysis of vertebrate Grxs, followed by an analysis of the mechanisms of action, the specific characteristics of the different human isoforms and a discussion on aspects related to human physiology and diseases.LC, FTO and VB would like to dedicate this work to the memory of Professor Arne Holmgren, discoverer of glutaredoxin, a reference in redox research, a great mentor and storyteller. It was a privilege to work and learn from him. The authors want to thank also all the excellent scientists with whom Arne worked for their contribution to increases the knowledge about glutaredoxins. The authors thank Dr Colin Miller for proofreading the manuscript. LC was supported by the Swedish Cancer Society (961), the Swedish Research Council Medicine (13X-3529) and a grant from the Swedish Fulbright Commission (2020). VB and FFV are supported by iMed.ULisboa’s strategic project (UIDP/04138/2020; UIDB/04138/2020), financed by national funds from Fundação para a Ciência e Tecnologia, Portugal (FCT; www.fct.pt). VB is financed by national funds via Fundação para a Ciência e Tecnologia through Norma Transitória - DL57/2016/CP1376/CT002. FFV is financed by Fundação para a Ciência e Tecnologia through Assistant Researcher grant CEECIND/03023/2017.info:eu-repo/semantics/publishedVersio

    Bacteriophages of Helicobacter pylori

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    The bacterium Helicobacter pylori colonize the stomach in approximately half of the world’s population. Infection with this bacterium is associated with gastritis, peptic ulcer, adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Besides being a pathogen with worldwide prevalence, H. pylori show increasingly high antibiotic resistance rates, making the development of new therapeutic strategies against this bacterium challenging. Furthermore, H. pylori is a genetically diverse bacterium, which may be influenced by the presence of mobile genomic elements, including prophages. In this review, we analyze these issues and summarize various reports and findings related to phages and H. pylori, discussing the relationship between the presence of these elements and the genomic diversity, virulence, and fitness of this bacterium. We also analyze the state of the knowledge on the potential utility of bacteriophages as a therapeutic strategy for H. pylori.This work was supported by the following sources: AM is a recipient of a scholarship from the Centro de Estudios Interdisciplinarios Básicos y Aplicados (CEIBA Foundation), Colombia. AM, JS, and AT are recipients of a project grant (120380763025/2018) from the Departamento Administrativo de Ciencia, Tecnología e Innovación de Colombia (Colciencias) and a project grant (PPTA_7676) from Research Vice-Rectory, Pontificia Universidad Javeriana. FV is the recipient of a project grant (PTDC/BTM-SAL/28978/2017) from the Fundação para a Ciência e a Tecnologia (FCT).info:eu-repo/semantics/publishedVersio

    Draft Genome Sequences of 29 Helicobacter pylori Strains Isolated from Colombia

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    Here, we present the draft genome sequences of 29 Colombian Helicobacter pylori strains. These strains were isolated in Bogotá, Colombia, from patients diagnosed with chronic gastritis. The genomic characterization of these strains will provide more information on the genetic composition of H. pylori strains from Colombia.We thank the entities that financially supported the development of this work. A.B.M. is a recipient of a scholarship from the Centro de Estudios Interdisciplinarios Básicos y Aplicados (CEIBA) Foundation, Colombia; and A.B.M., C.A., J.S., and A.A.T.-R. are recipients of a project grant (120380763025/2018) from MinCiencias, Colombia. The work is partially supported by Research Vice-Rectory, Pontificia Universidad Javeriana (PPTA_7676) and F.P.I.T. BanRepCultural (project 3956). F.F.V. is financed by national funds from the Fundação para a Ciência e a Tecnologia (FCT) through an assistant researcher grant (CEECIND/03023/2017), a project grant (PTDC/BTM-SAL/28978/2017), and projects UIDB/04138/2020 and UIDP/04138/2020; these funds partially supported this work. The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.info:eu-repo/semantics/publishedVersio

    Genome Sequencing of 10 Helicobacter pylori Pediatric Strains from Patients with Nonulcer Dyspepsia and Peptic Ulcer Disease

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    We present draft genome sequences of 10 Helicobacter pylori clinical strains isolated from children. This will be important for future studies of comparative genomics in order to better understand the virulence determinants underlying peptic ulcer disease.This work was supported by the FCT-PTDC/BIM-MEC/1051/2012 grant from the Fundação para a Ciência e a Tecnologia (FCT) (to M.O.). A.N. and F.F.V. are recipients of postdoctoral fellowships (SFRH/BPD/75295/2010 and SFRH/BPD/95125/2013, respectively) from FCT, and R.R. is a recipient of a fellowship (BRJ-DDI/2012) from the National Institute of Health

    Antimicrobial activity of prophage endolysins against critical Enterobacteriaceae antibiotic-resistant bacteria

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    Enterobacteriaceae species are part of the 2017 World Health Organization antibiotic-resistant priority pathogens list for development of novel medicines. Multidrug-resistant Klebsiella pneumoniae is an increasing threat to public health and has become a relevant human pathogen involved in life-threatening infections. Phage therapy involves the use of phages or their lytic endolysins as bioagents for the treatment of bacterial infectious diseases. Gram-negative bacteria have an outer membrane, making difficult the access of endolysins to the peptidoglycan. Here, three endolysins from prophages infecting three distinct Enterobacterales species, Kp2948-Lys from K. pneumoniae, Ps3418-Lys from Providencia stuartii, and Kaer26608-Lys from Klebsiella aerogenes, were purified and exhibited antibacterial activity against their specific bacterium species verified by zymogram assays. These three endolysins were successfully associated to liposomes composed of dimyristoyl phosphatidyl choline (DMPC), dioleoyl phosphatidyl ethanolamine (DOPE) and cholesteryl hemisuccinate (CHEMS) at a molar ratio (4:4:2), with an encapsulation efficiency ranging from 24 to 27%. Endolysins encapsulated in liposomes resulted in higher antibacterial activity compared to the respective endolysin in the free form, suggesting that the liposome-mediated delivery system enhances fusion with outer membrane and delivery of endolysins to the target peptidoglycan. Obtained results suggest that Kp2948-Lys appears to be specific for K. pneumoniae, while Ps3418-Lys and Kaer26608-Lys appear to have a broader antibacterial spectrum. Endolysins incorporated in liposomes constitute a promising weapon, applicable in the several dimensions (human, animals and environment) of the One Health approach, against multidrug-resistant Enterobacteriaceae.F.F.V. was funded by Fundação para a Ciência e a Tecnologia (FCT) through a project grant (PTDC/BTM-SAL/28978/2017) that supported this work. The work is partially supported by National funds from FCT, projects UIDB/04138/2020, UIDP/04138/2020, UIDB/00211/2020 and UIDB/04046/2020 (DOI https://doi.org/10.54499/UIDB/0404 6/2020)info:eu-repo/semantics/publishedVersio

    Cryptic Prophages Contribution for Campylobacter jejuni and Campylobacter coli Introgression

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    This article belongs to the Special Issue Bacteriophage Genomics.Campylobacter coli and C. jejuni, the causing agents of campylobacteriosis, are described to be undergoing introgression events, i.e., the transference of genetic material between different species, with some isolates sharing almost a quarter of its genome. The participation of phages in introgression events and consequent impact on host ecology and evolution remain elusive. Three distinct prophages, named C. jejuni integrated elements 1, 2, and 4 (CJIE1, CJIE2, and CJIE4), are described in C. jejuni. Here, we identified two unreported prophages, Campylobacter coli integrated elements 1 and 2 (CCIE1 and CCIE2 prophages), which are C. coli homologues of CJIE1 and CJIE2, respectively. No induction was achieved for both prophages. Conversely, induction assays on CJIE1 and CJIE2 point towards the inducibility of these prophages. CCIE2-, CJIE1-, and CJIE4-like prophages were identified in a Campylobacter spp. population of 840 genomes, and phylogenetic analysis revealed clustering in three major groups: CJIE1-CCIE1, CJIE2-CCIE2, and CJIE4, clearly segregating prophages from C. jejuni and C. coli, but not from human- and nonhuman-derived isolates, corroborating the flowing between animals and humans in the agricultural context. Punctual bacteriophage host-jumps were observed in the context of C. jejuni and C. coli, and although random chance cannot be fully discarded, these observations seem to implicate prophages in evolutionary introgression events that are modulating the hybridization of C. jejuni and C. coli species.F.F.V. is funded by Fundação para a Ciência e a Tecnologia (FCT) through an Assis tant Researcher grant CEECIND/03023/2017, and a project grant (PTDC/BTM-SAL/28978/2017) that supported this work. The work is partially supported by Na-tional funds from FCT, projects UIDB/04138/2020 and UIDP/04138/2020. Campylobacter strains were sequenced under the GenomePT project (POCI-01-0145-FEDER-022184), supported by COMPETE 2020—Operational Programme for Competitiveness and Internationalization (POCI), Lisboa Portugal Regional Operational Programme (Lisboa2020), Algarve Portugal Regional Oper-ational Programme (CRESC Algarve2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF), and by FCT. This work was also supported by Fundos FEDER through the Programa Op eracional Factores de Competitivida-de—COMPETE and by Fundos Nacionais through the FCT within the scope of the project UID/BIM/00009/2019 (Centre for Toxicogenomics and Human Health-ToxOmics).info:eu-repo/semantics/publishedVersio

    Repeated out-of-Africa expansions of Helicobacter pylori driven by replacement of deleterious mutations

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    Erratum in: Nat Commun. 2023 Mar 20;14(1):1539. doi: 10.1038/s41467-023-37302-5.Helicobacter pylori lives in the human stomach and has a population structure resembling that of its host. However, H. pylori fromEurope and the Middle East trace substantially more ancestry from modern African populations than the humans that carry them. Here, we use a collection of Afro-Eurasian H. pylori genomes to show that this African ancestry is due to at least three distinct admixture events. H. pylori from East Asia, which have undergone little admixture, have accumulated many more non-synonymous mutations than African strains. European and Middle Eastern bacteria have elevated African ancestry at the sites of these mutations, implying selection to remove them during admixture. Simulations show that population fitness can be restored after bottlenecks bymigration and subsequent admixture of small numbers of bacteria from non-bottlenecked populations. We conclude that recent spread of African DNA has been driven by deleterious mutations accumulated during the original out-of-Africa bottleneck.This work was supported by Sequencing Grants-in-aid for Scientific Research from the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) of Japan (221S0002, 18KK0266, 19H03473, 21H00346 and 22H02871) to Y.Y. F.F.V. is financed by FCT through Assistant Researcher grant CEECIND/03023/2017 and a project grant PTDC/BTM-TEC/3238/ 2020. I.K. studentship was funded by the National Strategic Reference Framework Operational Program “Competitiveness, Entrepreneurship and Innovation” (NSRF 2014-2020, project No. MIS5002486) and sequencing of strains was supported by the InfeNeutra Project (NSRF 2007-2013, project no. MIS450598) of the Ministry of Culture and Edu- cation, Greece. K.T. and the sequencing of KI isolates was supported by Erik Philip-Sörensen Foundation grant G2016-08, and Swedish Society for Medical research (SSMF). All primary bioinformatics and parts of the comparative genomics were performed on resources provided by Swedish National Infrastructure for Computing (SNIC) through Uppsala Multidisciplinary Center for Advanced Computational Science (UPPMAX) under projects snic2018-8-24 and uppstore2017270. Work by S.S. was supported by the German Research Foundation (DFG, project number 158 989 968–SFB 900/A1) and by the Bavarian Ministry of Sci- ence and the Arts in the framework of the Bavarian Research Network “New Strategies Against Multi-Resistant Pathogens by Means of Digital Networking—bayresq.net”. D.F. was supported by Shanghai Municipal Science and Technology Major Project No. 2019SHZDZX02.info:eu-repo/semantics/publishedVersio

    A 500-year tale of co-evolution, adaptation, and virulence: Helicobacter pylori in the Americas

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    Helicobacter pylori is a common component of the human stomach microbiota, possibly dating back to the speciation of Homo sapiens. A history of pathogen evolution in allopatry has led to the development of genetically distinct H. pylori subpopulations, associated with different human populations, and more recent admixture among H. pylori subpopulations can provide information about human migrations. However, little is known about the degree to which some H. pylori genes are conserved in the face of admixture, potentially indicating host adaptation, or how virulence genes spread among different populations. We analyzed H. pylori genomes from 14 countries in the Americas, strains from the Iberian Peninsula, and public genomes from Europe, Africa, and Asia, to investigate how admixture varies across different regions and gene families. Whole-genome analyses of 723 H. pylori strains from around the world showed evidence of frequent admixture in the American strains with a complex mosaic of contributions from H. pylori populations originating in the Americas as well as other continents. Despite the complex admixture, distinctive genomic fingerprints were identified for each region, revealing novel American H. pylori subpopulations. A pan-genome Fst analysis showed that variation in virulence genes had the strongest fixation in America, compared with non-American populations, and that much of the variation constituted non-synonymous substitutions in functional domains. Network analyses suggest that these virulence genes have followed unique evolutionary paths in the American populations, spreading into different genetic backgrounds, potentially contributing to the high risk of gastric cancer in the region.Fil: Muñoz Ramirez, Zilia Y.. INSTITUTO POLITÉCNICO NACIONAL (IPN);Fil: Pascoe, Ben. University of Bath; Reino UnidoFil: Mendez Tenorio, Alfonso. INSTITUTO POLITÉCNICO NACIONAL (IPN);Fil: Mourkas, Evangelos. University of Bath; Reino UnidoFil: Sandoval Motta, Santiago. Consejo Nacional de Ciencia y Tecnología; MéxicoFil: Perez Perez, Guillermo. New York University Langone Medical Center; Estados UnidosFil: Morgan, Douglas R.. University of Alabama at Birmingahm; Estados UnidosFil: Dominguez, Ricardo Leonel. Western Honduras Gastric Cancer Prevention Initiative Hospital de Occidente Santa Rosa de Copan; HondurasFil: Ortiz Princz, Diana. No especifíca;Fil: Cavazza, Maria Eugenia. No especifíca;Fil: Rocha, Gifone. Universidade Federal de Minas Gerais; BrasilFil: Queiroz, Dulcienne. Universidade Federal de Minas Gerais; BrasilFil: Catalano, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Zerbetto de Palma, Gerardo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Goldman, Cinthia Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Venegas, Alejandro. Universidad Diego Portales; ChileFil: Alarcon, Teresa. Universidad Autónoma de Madrid; EspañaFil: Oleastro, Monica. Universidade Nova de Lisboa; PortugalFil: Vale, Filipa F.. Universidade Nova de Lisboa; PortugalFil: Goodman, Karen J.. University of Alberta; CanadáFil: Torres, Roberto C.. Instituto Mexicano del Seguro Social; MéxicoFil: Berthenet, Elvire. Swansea University Medical School; Reino UnidoFil: Hitchings, Matthew D.. Swansea University Medical School; Reino UnidoFil: Blaser, Martin J.. Rutgers University; Estados UnidosFil: Sheppard, Samuel K.. University of Bath; Reino UnidoFil: Thorell, Kaisa. University of Gothenburg; SueciaFil: Torres, Javier. Instituto Mexicano del Seguro Social; Méxic
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