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Sample records for host intestinal environment

  1. The Host Genotype and Environment Affect Strain Types of Bifidobacterium longum subsp. longum Inhabiting the Intestinal Tracts of Twins.

    Science.gov (United States)

    Zhang, Min; Hang, Xiaomin; Tan, Jing; Yang, Hong

    2015-07-01

    To investigate the influences of host genotype and environment on Bifidobacterium longum subsp. longum inhabiting human intestines at the strain level, six pairs of twins, divided into two groups (children and adults), were recruited. Each group consisted of two monozygotic (MZ) twin pairs and one dizygotic (DZ) twin pair. Child twins had been living together from birth, while adult twins had been living separately for 5 to 10 years. A total of 345 B. longum subsp. longum isolates obtained from 60 fecal samples from these twins were analyzed by multilocus sequence typing (MLST), and 35 sequence types (STs) were finally acquired. Comparison of strains within and between the twin pairs showed that no strains with identical STs were observed between unrelated individuals or within adult DZ twin pairs. Eight STs were found to be monophyletic, existing within MZ twins and child DZ twins. The similarity of strain types within child cotwins was significantly higher than that within adult cotwins, which indicated that environment was one of the important determinants in B. longum subsp. longum strain types inhabiting human intestines. However, although these differences between MZ and DZ twins were observed, it is still difficult to reach an exact conclusion about the impact of host genotype. This is mainly because of the limited number of subjects tested in the present study and the lack of strain types tracing in the same twin pairs from birth until adulthood. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  2. Host modulation by a parasite: how Leishmania infantum modifies the intestinal environment of Lutzomyia longipalpis to favor its development.

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    Vania Cristina Santos

    Full Text Available Some reports have described the interference of Leishmania on sand flies physiology, and such behavior most likely evolved to favor the development and transmission of the parasite. Most of these studies showed that Leishmania could modulate the level of proteases in the midgut after an infective blood meal, and decreased proteolytic activity is indeed beneficial for the development of promastigotes in the gut of sand flies. In the present study, we performed a detailed investigation of the intestinal pH in Lutzomyia longipalpis females naturally infected with Leishmania infantum and investigated the production of trypsin by these insects using different approaches. Our results allowed us to propose a mechanism by which these parasites interfere with the physiology of L. longipalpis to decrease the production of proteolytic enzymes. According to our hypothesis L. infantum promastigotes indirectly interfere with the production of trypsin by modulating the mechanism that controls the intestinal pH via the action of a yet non-identified substance released by promastigote forms inside the midgut. This substance is not an acid, whose action would be restrict on to release H+ to the medium, but is a substance that is able to interfere with midgut physiology through a mechanism involving pH control. According to our hypothesis, as the pH decreases, the proteolytic enzymes efficiency is also reduced, leading to a decline in the supply of amino acids to the enterocytes: this decline reduces the stimulus for protease production because it is regulated by the supply of amino acids, thus leading to a delay in digestion.

  3. Effect of Host Condition on Intestinal Parasite Load and Prevalence ...

    African Journals Online (AJOL)

    Host condition had effect on therate of infection and greater effect on intestinal parasite load in Malapterurus electricus . These vary among sex, sizes and weights of conspecific individuals. This was investigated over a period of two years.A total of 340 fishes from the lagoon were caught and dissected for intestinal helminth ...

  4. The Shigella dysenteriae serotype 1 proteome, profiled in the host intestinal environment, reveals major metabolic modifications and increased expression of invasive proteins.

    Science.gov (United States)

    Pieper, Rembert; Zhang, Quanshun; Parmar, Prashanth P; Huang, Shih-Ting; Clark, David J; Alami, Hamid; Donohue-Rolfe, Arthur; Fleischmann, Robert D; Peterson, Scott N; Tzipori, Saul

    2009-11-01

    Shigella dysenteriae serotype 1 (SD1) causes the most severe form of epidemic bacillary dysentery. We present the first comprehensive proteome analysis of this pathogen, profiling proteins from bacteria cultured in vitro and bacterial isolates from the large bowel of infected gnotobiotic piglets (in vivo). Overall, 1061 distinct gene products were identified. Differential display analysis revealed that SD1 cells switched to an anaerobic energy metabolism in vivo. High in vivo abundances of amino acid decarboxylases (GadB and AdiA) which enhance pH homeostasis in the cytoplasm and protein disaggregation chaperones (HdeA, HdeB and ClpB) were indicative of a coordinated bacterial survival response to acid stress. Several type III secretion system effectors were increased in abundance in vivo, including OspF, IpaC and IpaD. These proteins are implicated in invasion of colonocytes and subversion of the host immune response in S. flexneri. These observations likely reflect an adaptive response of SD1 to the hostile host environment. Seven proteins, among them the type III secretion system effectors OspC2 and IpaB, were detected as antigens in Western blots using piglet antisera. The outer membrane protein OmpA, the heat shock protein HtpG and OspC2 represent novel SD1 subunit vaccine candidates and drug targets.

  5. Regulation of the Intestinal Barrier Function by Host Defense Peptides.

    Science.gov (United States)

    Robinson, Kelsy; Deng, Zhuo; Hou, Yongqing; Zhang, Guolong

    2015-01-01

    Intestinal barrier function is achieved primarily through regulating the synthesis of mucins and tight junction (TJ) proteins, which are critical for maintaining optimal gut health and animal performance. An aberrant expression of TJ proteins results in increased paracellular permeability, leading to intestinal and systemic disorders. As an essential component of innate immunity, host defense peptides (HDPs) play a critical role in mucosal defense. Besides broad-spectrum antimicrobial activities, HDPs promotes inflammation resolution, endotoxin neutralization, wound healing, and the development of adaptive immune response. Accumulating evidence has also indicated an emerging role of HDPs in barrier function and intestinal homeostasis. HDP deficiency in the intestinal tract is associated with barrier dysfunction and dysbiosis. Several HDPs were recently shown to enhance mucosal barrier function by directly inducing the expression of multiple mucins and TJ proteins. Consistently, dietary supplementation of HDPs often leads to an improvement in intestinal morphology, production performance, and feed efficiency in livestock animals. This review summarizes current advances on the regulation of epithelial integrity and homeostasis by HDPs. Major signaling pathways mediating HDP-induced mucin and TJ protein synthesis are also discussed. As an alternative strategy to antibiotics, supplementation of exogenous HDPs or modulation of endogenous HDP synthesis may have potential to improve intestinal barrier function and animal health and productivity.

  6. Regulation of the intestinal barrier function by host defense peptides

    Directory of Open Access Journals (Sweden)

    Kelsy eRobinson

    2015-11-01

    Full Text Available Intestinal barrier function is achieved primarily through regulating the synthesis of mucins and tight junction proteins, which are critical for maintaining optimal gut health and animal performance. An aberrant expression of tight junction proteins results in increased paracellular permeability, leading to intestinal and systemic disorders. As an essential component of innate immunity, host defense peptides (HDPs play a critical role in mucosal defense. Besides broad-spectrum antimicrobial activities, HDPs promotes inflammation resolution, endotoxin neutralization, wound healing, and the development of adaptive immune response. Accumulating evidence has also indicated an emerging role of HDPs in barrier function and intestinal homeostasis. HDP deficiency in the intestinal tract is associated with barrier dysfunction and dysbiosis. Several HDPs were recently shown to enhance mucosal barrier function by directly inducing the expression of multiple mucins and tight junction proteins. Consistently, dietary supplementation of HDPs often leads to an improvement in intestinal morphology, production performance, and feed efficiency in livestock animals. This review summarizes current advances on the regulation of epithelial integrity and homeostasis by HDPs. Major signaling pathways mediating HDP-induced mucin and tight junction protein synthesis are also discussed. As an alternative strategy to antibiotics, supplementation of exogenous HDPs or modulation of endogenous HDP synthesis may have potential to improve intestinal barrier function and animal health and productivity.

  7. Host Gut Motility Promotes Competitive Exclusion within a Model Intestinal Microbiota.

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    Travis J Wiles

    2016-07-01

    Full Text Available The gut microbiota is a complex consortium of microorganisms with the ability to influence important aspects of host health and development. Harnessing this "microbial organ" for biomedical applications requires clarifying the degree to which host and bacterial factors act alone or in combination to govern the stability of specific lineages. To address this issue, we combined bacteriological manipulation and light sheet fluorescence microscopy to monitor the dynamics of a defined two-species microbiota within a vertebrate gut. We observed that the interplay between each population and the gut environment produces distinct spatiotemporal patterns. As a consequence, one species dominates while the other experiences sudden drops in abundance that are well fit by a stochastic mathematical model. Modeling revealed that direct bacterial competition could only partially explain the observed phenomena, suggesting that a host factor is also important in shaping the community. We hypothesized the host determinant to be gut motility, and tested this mechanism by measuring colonization in hosts with enteric nervous system dysfunction due to a mutation in the ret locus, which in humans is associated with the intestinal motility disorder known as Hirschsprung disease. In mutant hosts we found reduced gut motility and, confirming our hypothesis, robust coexistence of both bacterial species. This study provides evidence that host-mediated spatial structuring and stochastic perturbation of communities can drive bacterial population dynamics within the gut, and it reveals a new facet of the intestinal host-microbe interface by demonstrating the capacity of the enteric nervous system to influence the microbiota. Ultimately, these findings suggest that therapeutic strategies targeting the intestinal ecosystem should consider the dynamic physical nature of the gut environment.

  8. The listeriosis triangle: Pathogen, host and the environment

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    Abram Maja

    2012-01-01

    Full Text Available Listeria monocytogenes is a foodborne pathogen well known for its adaptability to diverse environment and host niches and its high fatality rate among infected immunocompromised populations. Infection in the immunocompetent host occurs but risk factors for the disease primarily points to abnormalities in cell-mediated and innate immunity as major predispositions to listeriosis. After ingestion of contaminated food, this pathogen is able to cross the intestinal, blood-brain and placental barrier and leads to gastroenteritis, meningitis and maternofetal infections which may result in abortion and spontaneous stillbirth. Despite the extensive use of this bacterium in the study of cell-mediated immunity and intracellular growth, our understanding of the host, pathogen and environmental factors that impact the pathogenesis of listeriosis is still incomplete. This review will summarize current knowledge, including our own efforts, about pathogen, host and environmental factors that influence, and contribute to the pathogenesis of Listeria monocytogenes infection.

  9. The listeriosis triangle: Pathogen, host and the environment

    Directory of Open Access Journals (Sweden)

    Abram Maja

    2012-03-01

    Full Text Available Listeria monocytogenes is a foodborne pathogen well known for its adaptability to diverse environment and host niches and its high fatality rate among infected immunocompromised populations. Infection in the immunocompetent host occurs but risk factors for the disease primarily points to abnormalities in cell-mediated and innate immunity as major predispositions to listeriosis. After ingestion of contaminated food, this pathogen is able to cross the intestinal, blood-brain and placental barrier and leads to gastroenteritis, meningitis and maternofetal infections which may result in abortion and spontaneous stillbirth. Despite the extensive use of this bacterium in the study of cell-mediated immunity and intracellular growth, our understanding of the host, pathogen and environmental factors that impact the pathogenesis of listeriosis is still incomplete. This review will summarize current knowledge, including our own efforts, about pathogen, host and environmental factors that influence, and contribute to the pathogenesis of Listeria monocytogenes infection.

  10. Pathobiology of Salmonella, intestinal microbiota, and the host innate immune response

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    Renato Lima Santos

    2014-05-01

    Full Text Available Salmonella is a relevant pathogen under a clinical and public health perspective. Therefore, there has been a significant scientific effort to learn about pathogenic determinants of this pathogen. The clinical relevance of the disease, associated with the molecular tools available to study Salmonella as well as suitable animal models for salmonellosis, have provided optimal conditions to drive the scientific community to generate a large expansion of our knowledge about the pathogenesis of Salmonella-induced enterocolitis that took place during the past two decades. This research effort has also generated a wealth of information on the host immune mechanisms that complements gaps in the fundamental research in this area. This review focus on how the interaction between Salmonella, the microbiota and intestinal innate immunity leads to disease manifestation. As a highly successful enteropathogen, Salmonella actively elicits a robust acute intestinal inflammatory response from the host, which could theoretically lead to the pathogen demise. However, Salmonella has evolved redundant molecular machineries that renders this pathogen highly adapted to the inflamed intestinal environment, in which Salmonella is capable of outcompete resident commensal organisms. The adaptation of Salmonella to the inflamed intestinal lumen associated with the massive inflammatory response that leads to diarrhea, generate perfect conditions for transmission of the pathogen. These conditions illustrate the complexity of the co-evolution and ecology of the pathogen, commensals and the host.

  11. Pathobiology of salmonella, intestinal microbiota, and the host innate immune response.

    Science.gov (United States)

    Santos, Renato Lima

    2014-01-01

    Salmonella is a relevant pathogen under a clinical and public health perspective. Therefore, there has been a significant scientific effort to learn about pathogenic determinants of this pathogen. The clinical relevance of the disease, associated with the molecular tools available to study Salmonella as well as suitable animal models for salmonellosis, have provided optimal conditions to drive the scientific community to generate a large expansion of our knowledge about the pathogenesis of Salmonella-induced enterocolitis that took place during the past two decades. This research effort has also generated a wealth of information on the host immune mechanisms that complements gaps in the fundamental research in this area. This review focus on how the interaction between Salmonella, the microbiota and intestinal innate immunity leads to disease manifestation. As a highly successful enteropathogen, Salmonella actively elicits a robust acute intestinal inflammatory response from the host, which could theoretically lead to the pathogen demise. However, Salmonella has evolved redundant molecular machineries that renders this pathogen highly adapted to the inflamed intestinal environment, in which Salmonella is capable of outcompete resident commensal organisms. The adaptation of Salmonella to the inflamed intestinal lumen associated with the massive inflammatory response that leads to diarrhea, generate perfect conditions for transmission of the pathogen. These conditions illustrate the complexity of the co-evolution and ecology of the pathogen, commensals, and the host.

  12. Reaction norms of host immunity, host fitness and parasite performance in a mouse--intestinal nematode interaction.

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    Lippens, Cédric; Guivier, Emmanuel; Faivre, Bruno; Sorci, Gabriele

    2016-02-01

    The outcome of the encounter between a host and a parasite depends on the synergistic effects of the genetics of the two partners and the environment (sensulato) where the interaction takes place. Reaction norms can depict how host and parasite traits vary across environmental ranges for different genotypes. Here, we performed a large scale experiment where three strains of laboratory mice (SJL, BALB/c and CBA) were infected with four doses of the intestinal nematode Heligmosomoides polygyrus. An increasing infective dose can be considered as a proxy for the environment-dependent risk incontracting the infection. We looked at the fitness traits of hosts and parasites, and assessed the underlying immunological functions likely to affect the observed pattern of resistance/susceptibility/tolerance. We found that the infective dose had a strong effect on both host fitness and parasite performance. Interestingly, for most traits, host genotypes did not rank consistently across the increasing infective doses and according to the expected pattern of strain-specific resistance/susceptibility/tolerance. Analyses of cytokine production allowed better understanding of the mechanistic basis underlying variations in fitness-linked traits. The infective dose affected the shape of the reaction norms of the cytokines IL-4, IL-10 and IL-6. Dose-dependent variation in cytokine production explained, moreover, the strain-specific pattern of infection cost, host resistance and parasite performance. As long as the infective dose increased, there was a marked shift towards a pro-inflammatory status in the SJL strain of mice that was positively correlated with cost of the infection and parasite performance. Overall, our study strongly suggests that the notion of host resistance is labile and depends on the environmental conditions where the interaction takes place. Moreover, integrating information on fitness-linked traits and the underlying mechanisms seems essential for a better

  13. The symbiotic intestinal ciliates and the evolution of their hosts.

    Science.gov (United States)

    Moon-van der Staay, Seung Yeo; van der Staay, Georg W M; Michalowski, Tadeusz; Jouany, Jean-Pierre; Pristas, Peter; Javorský, Peter; Kišidayová, Svetlana; Varadyova, Zora; McEwan, Neil R; Newbold, C Jamie; van Alen, Theo; de Graaf, Rob; Schmid, Markus; Huynen, Martijn A; Hackstein, Johannes H P

    2014-04-01

    The evolution of sophisticated differentiations of the gastro-intestinal tract enabled herbivorous mammals to digest dietary cellulose and hemicellulose with the aid of a complex anaerobic microbiota. Distinctive symbiotic ciliates, which are unique to this habitat, are the largest representatives of this microbial community. Analyses of a total of 484 different 18S rRNA genes show that extremely complex, but related ciliate communities can occur in the rumen of cattle, sheep, goats and red deer (301 sequences). The communities in the hindgut of equids (Equus caballus, Equus quagga), and elephants (Elephas maximus, Loxodonta africanus; 162 sequences), which are clearly distinct from the ruminant ciliate biota, exhibit a much higher diversity than anticipated on the basis of their morphology. All these ciliates from the gastro-intestinal tract constitute a monophyletic group, which consists of two major taxa, i.e. Vestibuliferida and Entodiniomorphida. The ciliates from the evolutionarily older hindgut fermenters exhibit a clustering that is specific for higher taxa of their hosts, as extant species of horse and zebra on the one hand, and Africa and Indian elephant on the other hand, share related ciliates. The evolutionary younger ruminants altogether share the various entodiniomorphs and the vestibuliferids from ruminants. Copyright © 2014 Elsevier GmbH. All rights reserved.

  14. Staphylococcus aureus pathogenesis in diverse host environments

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    Balasubramanian, Divya; Harper, Lamia; Shopsin, Bo; Torres, Victor J.

    2017-01-01

    Abstract Staphylococcus aureus is an eminent human pathogen that can colonize the human host and cause severe life-threatening illnesses. This bacterium can reside in and infect a wide range of host tissues, ranging from superficial surfaces like the skin to deeper tissues such as in the gastrointestinal tract, heart and bones. Due to its multifaceted lifestyle, S. aureus uses complex regulatory networks to sense diverse signals that enable it to adapt to different environments and modulate virulence. In this minireview, we explore well-characterized environmental and host cues that S. aureus responds to and describe how this pathogen modulates virulence in response to these signals. Lastly, we highlight therapeutic approaches undertaken by several groups to inhibit both signaling and the cognate regulators that sense and transmit these signals downstream. PMID:28104617

  15. Emerging molecular insights into the interaction between probiotics and the host intestinal mucosa

    NARCIS (Netherlands)

    Bron, P.A.; Baarlen, van P.; Kleerebezem, M.

    2012-01-01

    Probiotic bacteria can modulate immune responses in the host gastrointestinal tract to promote health. The genomics era has provided novel opportunities for the discovery and characterization of bacterial probiotic effector molecules that elicit specific responses in the intestinal system.

  16. Pilot study of lithium to restore intestinal barrier function in severe graft-versus-host disease

    NARCIS (Netherlands)

    Steinbach, G.; Hockenbery, D.M.; Huls, G.A.; Furlong, T.; Myerson, D.; Loeb, K.R.; Fann, J.R.; Castilla-Llorente, C.; McDonald, G.B.; Martin, P.J.

    2017-01-01

    Severe intestinal graft-vs-host disease (GVHD) after allogeneic hematopoietic cell transplantation (HCT) causes mucosal ulceration and induces innate and adaptive immune responses that amplify and perpetuate GVHD and the associated barrier dysfunction. Pharmacological agents to target mucosal

  17. Host responses to intestinal microbial antigens in gluten-sensitive mice.

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    Jane M Natividad

    2009-07-01

    Full Text Available Excessive uptake of commensal bacterial antigens through a permeable intestinal barrier may influence host responses to specific antigen in a genetically predisposed host. The aim of this study was to investigate whether intestinal barrier dysfunction induced by indomethacin treatment affects the host response to intestinal microbiota in gluten-sensitized HLA-DQ8/HCD4 mice.HLA-DQ8/HCD4 mice were sensitized with gluten, and gavaged with indomethacin plus gluten. Intestinal permeability was assessed by Ussing chamber; epithelial cell (EC ultra-structure by electron microscopy; RNA expression of genes coding for junctional proteins by Q-real-time PCR; immune response by in-vitro antigen-specific T-cell proliferation and cytokine analysis by cytometric bead array; intestinal microbiota by fluorescence in situ hybridization and analysis of systemic antibodies against intestinal microbiota by surface staining of live bacteria with serum followed by FACS analysis. Indomethacin led to a more pronounced increase in intestinal permeability in gluten-sensitized mice. These changes were accompanied by severe EC damage, decreased E-cadherin RNA level, elevated IFN-gamma in splenocyte culture supernatant, and production of significant IgM antibody against intestinal microbiota.Indomethacin potentiates barrier dysfunction and EC injury induced by gluten, affects systemic IFN-gamma production and the host response to intestinal microbiota antigens in HLA-DQ8/HCD4 mice. The results suggest that environmental factors that alter the intestinal barrier may predispose individuals to an increased susceptibility to gluten through a bystander immune activation to intestinal microbiota.

  18. Performance, Nutrient Utilization and Intestinal Environment of ...

    African Journals Online (AJOL)

    Measurements were live weight, live weight gain, feed intake, carcass and organ characteristics, feed cost, nutrient digestibility, gut pH and intestinal microbial population. Organic acids had no significant (P>0.05) effect on the performance of the rabbits except mortality. Formic acid supplemented diet produced the highest ...

  19. The interplay between intestinal bacteria and host metabolism in health and disease: lessons from Drosophila melanogaster

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    Adam C. N. Wong

    2016-03-01

    Full Text Available All higher organisms negotiate a truce with their commensal microbes and battle pathogenic microbes on a daily basis. Much attention has been given to the role of the innate immune system in controlling intestinal microbes and to the strategies used by intestinal microbes to overcome the host immune response. However, it is becoming increasingly clear that the metabolisms of intestinal microbes and their hosts are linked and that this interaction is equally important for host health and well-being. For instance, an individual's array of commensal microbes can influence their predisposition to chronic metabolic diseases such as diabetes and obesity. A better understanding of host–microbe metabolic interactions is important in defining the molecular bases of these disorders and could potentially lead to new therapeutic avenues. Key advances in this area have been made using Drosophila melanogaster. Here, we review studies that have explored the impact of both commensal and pathogenic intestinal microbes on Drosophila carbohydrate and lipid metabolism. These studies have helped to elucidate the metabolites produced by intestinal microbes, the intestinal receptors that sense these metabolites, and the signaling pathways through which these metabolites manipulate host metabolism. Furthermore, they suggest that targeting microbial metabolism could represent an effective therapeutic strategy for human metabolic diseases and intestinal infection.

  20. Debug your bugs-how NLRs shape intestinal host-microbe interactions

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    Philip eRosenstiel

    2013-12-01

    Full Text Available The host’s ability to discriminate friend and foe and to establish a precise homeostasis with its associated microbiota is crucial for its survival and fitness. Among the mediators of intestinal host-microbe interactions, NOD-like receptor (NLR proteins take center stage. They are present in the epithelial lining and innate immune cells that constantly monitor microbial activities at the intestinal barrier. Dysfunctional NLRs predispose to intestinal inflammation as well as sensitization to extra-intestinal immune-mediated diseases and are linked to the alteration of microbial communities. Here, we review advances in our understanding of their reciprocal relationship in the regulation of intestinal homeostasis and implications for intestinal health.

  1. Modulating the Gut Micro-Environment in the Treatment of Intestinal Parasites

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    Luis Vitetta

    2016-11-01

    Full Text Available The interactions of micro-organisms cohabitating with Homo sapiens spans millennia, with microbial communities living in a symbiotic relationship with the host. Interacting to regulate and maintain physiological functions and immunological tolerance, the microbial community is able to exert an influence on host health. An example of micro-organisms contributing to an intestinal disease state is exhibited by a biodiverse range of protozoan and bacterial species that damage the intestinal epithelia and are therefore implicated in the symptoms of diarrhea. As a contentious exemplar, Blastocystis hominis is a ubiquitous enteric protist that can adversely affect the intestines. The symptoms experienced are a consequence of the responses of the innate immune system triggered by the disruption of the intestinal barrier. The infiltration of the intestinal epithelial barrier involves a host of immune receptors, including toll like receptors and IgM/IgG/IgA antibodies as well as CD8+ T cells, macrophages, and neutrophils. Whilst the mechanisms of interactions between the intestinal microbiome and protozoan parasites remain incompletely understood, it is acknowledged that the intestinal microbiota is a key factor in the pathophysiology of parasitic infections. Modulating the intestinal environment through the administration of probiotics has been postulated as a possible therapeutic agent to control the proliferation of intestinal microbes through their capacity to induce competition for occupation of a common biotype. The ultimate goal of this mechanism is to prevent infections of the like of giardiasis and eliminate its symptoms. The differing types of probiotics (i.e., bacteria and yeast modulate immunity by stimulating the host immune system. Early animal studies support the potential benefits of probiotic administration to prevent intestinal infections, with human clinical studies showing probiotics can reduce the number of parasites and the severity

  2. Host and environmental factors affecting the intestinal microbiota in chickens

    NARCIS (Netherlands)

    Kers, Jannigje G.; Velkers, Francisca C.; Fischer, Egil A.J.; Hermes, Gerben D.A.; Stegeman, J.A.; Smidt, Hauke

    2018-01-01

    The initial development of intestinal microbiota in poultry plays an important role in production performance, overall health and resistance against microbial infections. Multiplexed sequencing of 16S ribosomal RNA gene amplicons is often used in studies, such as feed intervention or antimicrobial

  3. Intestinal Enterococcus faecium Colonization Improves Host Defense during Polymicrobial Peritonitis

    NARCIS (Netherlands)

    Leendertse, Masja; Willems, Rob J. L.; Oei, G. Anneke; Florquin, Sandrine; Bonten, Marc J. M.; van der Poll, Tom

    2009-01-01

    Background. Vancomycin-resistant (VR) Enterococcus faecium is increasingly found to colonize and infect hospitalized patients. Enterococci are frequently isolated from polymicrobial infections originating from the intestines. The impact of VR E. faecium on these infections and vice versa is not

  4. Alcohol-associated intestinal dysbiosis impairs pulmonary host defense against Klebsiella pneumoniae.

    Science.gov (United States)

    Samuelson, Derrick R; Shellito, Judd E; Maffei, Vincent J; Tague, Eric D; Campagna, Shawn R; Blanchard, Eugene E; Luo, Meng; Taylor, Christopher M; Ronis, Martin J J; Molina, Patricia E; Welsh, David A

    2017-06-01

    Chronic alcohol consumption perturbs the normal intestinal microbial communities (dysbiosis). To investigate the relationship between alcohol-mediated dysbiosis and pulmonary host defense we developed a fecal adoptive transfer model, which allows us to investigate the impact of alcohol-induced gut dysbiosis on host immune response to an infectious challenge at a distal organ, independent of prevailing alcohol use. Male C57BL/6 mice were treated with a cocktail of antibiotics (ampicillin, gentamicin, neomycin, vancomycin, and metronidazole) via daily gavage for two weeks. A separate group of animals was fed a chronic alcohol (or isocaloric dextrose pair-fed controls) liquid diet for 10 days. Microbiota-depleted mice were recolonized with intestinal microbiota from alcohol-fed or pair-fed (control) animals. Following recolonization groups of mice were sacrificed prior to and 48 hrs. post respiratory infection with Klebsiella pneumoniae. Klebsiella lung burden, lung immunology and inflammation, as well as intestinal immunology, inflammation, and barrier damage were examined. Results showed that alcohol-associated susceptibility to K. pneumoniae is, in part, mediated by gut dysbiosis, as alcohol-naïve animals recolonized with a microbiota isolated from alcohol-fed mice had an increased respiratory burden of K. pneumoniae compared to mice recolonized with a control microbiota. The increased susceptibility in alcohol-dysbiosis recolonized animals was associated with an increase in pulmonary inflammatory cytokines, and a decrease in the number of CD4+ and CD8+ T-cells in the lung following Klebsiella infection but an increase in T-cell counts in the intestinal tract following Klebsiella infection, suggesting intestinal T-cell sequestration as a factor in impaired lung host defense. Mice recolonized with an alcohol-dysbiotic microbiota also had increased intestinal damage as measured by increased levels of serum intestinal fatty acid binding protein. Collectively, these

  5. Alcohol-associated intestinal dysbiosis impairs pulmonary host defense against Klebsiella pneumoniae

    Science.gov (United States)

    Campagna, Shawn R.; Blanchard, Eugene E.; Ronis, Martin J. J.

    2017-01-01

    Chronic alcohol consumption perturbs the normal intestinal microbial communities (dysbiosis). To investigate the relationship between alcohol-mediated dysbiosis and pulmonary host defense we developed a fecal adoptive transfer model, which allows us to investigate the impact of alcohol-induced gut dysbiosis on host immune response to an infectious challenge at a distal organ, independent of prevailing alcohol use. Male C57BL/6 mice were treated with a cocktail of antibiotics (ampicillin, gentamicin, neomycin, vancomycin, and metronidazole) via daily gavage for two weeks. A separate group of animals was fed a chronic alcohol (or isocaloric dextrose pair-fed controls) liquid diet for 10 days. Microbiota-depleted mice were recolonized with intestinal microbiota from alcohol-fed or pair-fed (control) animals. Following recolonization groups of mice were sacrificed prior to and 48 hrs. post respiratory infection with Klebsiella pneumoniae. Klebsiella lung burden, lung immunology and inflammation, as well as intestinal immunology, inflammation, and barrier damage were examined. Results showed that alcohol-associated susceptibility to K. pneumoniae is, in part, mediated by gut dysbiosis, as alcohol-naïve animals recolonized with a microbiota isolated from alcohol-fed mice had an increased respiratory burden of K. pneumoniae compared to mice recolonized with a control microbiota. The increased susceptibility in alcohol-dysbiosis recolonized animals was associated with an increase in pulmonary inflammatory cytokines, and a decrease in the number of CD4+ and CD8+ T-cells in the lung following Klebsiella infection but an increase in T-cell counts in the intestinal tract following Klebsiella infection, suggesting intestinal T-cell sequestration as a factor in impaired lung host defense. Mice recolonized with an alcohol-dysbiotic microbiota also had increased intestinal damage as measured by increased levels of serum intestinal fatty acid binding protein. Collectively, these

  6. Human Intestinal Microbiota: Interaction Between Parasites and the Host Immune Response.

    Science.gov (United States)

    Partida-Rodríguez, Oswaldo; Serrano-Vázquez, Angélica; Nieves-Ramírez, Miriam E; Moran, Patricia; Rojas, Liliana; Portillo, Tobias; González, Enrique; Hernández, Eric; Finlay, B Brett; Ximenez, Cecilia

    2017-12-28

    The human gut is a highly complex ecosystem with an extensive microbial community, and the influence of the intestinal microbiota reaches the entire host organism. For example, the microbiome regulates fat storage, stimulates or renews epithelial cells, and influences the development and maturation of the brain and the immune system. Intestinal microbes can protect against infection by pathogenic bacteria, viruses, fungi and parasites. Hence, the maintenance of homeostasis between the gut microbiota and the rest of the body is crucial for health, with dysbiosis affecting disease. This review focuses on intestinal protozoa, especially those still representing a public health problem in Mexico, and their interactions with the microbiome and the host. The decrease in prevalence of intestinal helminthes in humans left a vacant ecological niche that was quickly occupied by protozoa. Although the mechanisms governing the interaction between intestinal microbiota and protozoa are poorly understood, it is known that the composition of the intestinal bacterial populations modulates the progression of protozoan infection and the outcome of parasitic disease. Most reports on the complex interactions between intestinal bacteria, protozoa and the immune system emphasize the protective role of the microbiota against protozoan infection. Insights into such protection may facilitate the manipulation of microbiota components to prevent and treat intestinal protozoan infections. Here we discuss recent findings about the immunoregulatory effect of intestinal microbiota with regards to intestinal colonization by protozoa, focusing on infections by Entamoeba histolytica, Blastocystis spp, Giardia duodenalis, Toxoplasma gondii and Cryptosporidium parvum. The possible consequences of the microbiota on parasitic, allergic and autoimmune disorders are also considered. Copyright © 2017 IMSS. Published by Elsevier Inc. All rights reserved.

  7. Alcohol-associated intestinal dysbiosis impairs pulmonary host defense against Klebsiella pneumoniae.

    OpenAIRE

    Samuelson, Derrick R.; Shellito, Judd E.; Vincent J Maffei; Tague, Eric D.; Campagna, Shawn R.; Blanchard, Eugene E.; Meng Luo; Christopher M Taylor; Ronis, Martin J. J.; Molina, Patricia E.; Welsh, David A.

    2017-01-01

    Chronic alcohol consumption perturbs the normal intestinal microbial communities (dysbiosis). To investigate the relationship between alcohol-mediated dysbiosis and pulmonary host defense we developed a fecal adoptive transfer model, which allows us to investigate the impact of alcohol-induced gut dysbiosis on host immune response to an infectious challenge at a distal organ, independent of prevailing alcohol use. Male C57BL/6 mice were treated with a cocktail of antibiotics (ampicillin, gent...

  8. Interactions between Intestinal Microbiota and Host Immune Response in Inflammatory Bowel Disease

    Science.gov (United States)

    Zhang, Ming; Sun, Kaiji; Wu, Yujun; Yang, Ying; Tso, Patrick; Wu, Zhenlong

    2017-01-01

    Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract. Although the etiology and pathogenesis of IBD remain unclear, both genetic susceptibility and environmental factors are implicated in the initiation and progression of IBD. Recent studies with experimental animal models and clinical patients indicated that the intestinal microbiota is one of the critical environmental factors that influence nutrient metabolism, immune responses, and the health of the host in various intestinal diseases, including ulcerative colitis and Crohn’s disease. The objective of this review is to highlight the crosstalk between gut microbiota and host immune response and the contribution of this interaction to the pathogenesis of IBD. In addition, potential therapeutic strategies targeting the intestinal micro-ecosystem in IBD are discussed. PMID:28855901

  9. Cohabitation in the intestine: interactions between helminth parasites, bacterial microbiota and host immunity

    Science.gov (United States)

    Reynolds, Lisa A.; Finlay, B. Brett; Maizels, Rick M.

    2015-01-01

    Both intestinal helminth parasites and certain bacterial microbiota species have been credited with strong immunomodulatory effects. Recent studies have reported that the presence of helminth infection alters the composition of the bacterial intestinal microbiota, and conversely that the presence and composition of the bacterial microbiota affects helminth colonisation and persistence within mammalian hosts. This article reviews recent findings on these reciprocal relationships, in both human populations and mouse models at the level of potential mechanistic pathways, and the implications these bear for immunomodulatory effects on allergic and autoimmune disorders. Understanding the multidirectional complex interactions between intestinal microbes, helminth parasites and the host immune system will allow for a more holistic approach when using pro-, pre-, synbiotics, antibiotics and anthelmintics, and when designing treatments for autoimmune and allergic conditions. PMID:26477048

  10. The intestinal microbiota and host immune interactions in the critically ill

    NARCIS (Netherlands)

    Schuijt, T.J.; Poll, van der T.; Vos, de W.M.; Wiersinga, W.J.

    2013-01-01

    The gastrointestinal tract harbors a complex population of microbes that play a fundamental role in the development of the immune system and human health. Besides an important local contribution in the host defense against infections, it has become increasingly clear that intestinal bacteria also

  11. Model intestinal microflora in computer simulation : A simulation and modeling package for host-microflora interactions

    NARCIS (Netherlands)

    Wilkinson, Michael H.F.

    2002-01-01

    The ecology of the human intestinal microflora and its interaction with the host are poorly understood. Though more and more data are being acquired, in part using modern molecular methods, development of a quantitative theory has not kept pace with this increase in observing power. This is in part

  12. Human mini-guts: new insights into intestinal physiology and host-pathogen interactions.

    Science.gov (United States)

    In, Julie G; Foulke-Abel, Jennifer; Estes, Mary K; Zachos, Nicholas C; Kovbasnjuk, Olga; Donowitz, Mark

    2016-11-01

    The development of indefinitely propagating human 'mini-guts' has led to a rapid advance in gastrointestinal research related to transport physiology, developmental biology, pharmacology, and pathophysiology. These mini-guts, also called enteroids or colonoids, are derived from LGR5 + intestinal stem cells isolated from the small intestine or colon. Addition of WNT3A and other growth factors promotes stemness and results in viable, physiologically functional human intestinal or colonic cultures that develop a crypt-villus axis and can be differentiated into all intestinal epithelial cell types. The success of research using human enteroids has highlighted the limitations of using animals or in vitro, cancer-derived cell lines to model transport physiology and pathophysiology. For example, curative or preventive therapies for acute enteric infections have been limited, mostly due to the lack of a physiological human intestinal model. However, the human enteroid model enables specific functional studies of secretion and absorption in each intestinal segment as well as observations of the earliest molecular events that occur during enteric infections. This Review describes studies characterizing these human mini-guts as a physiological model to investigate intestinal transport and host-pathogen interactions.

  13. Intestinal fucose as a mediator of host-microbe symbiosis.

    Science.gov (United States)

    Pickard, Joseph M; Chervonsky, Alexander V

    2015-06-15

    Fucose is an L-configuration sugar found abundantly in the mammalian gut. It has long been known to be induced there by the presence of bacteria, but only recently have some of the molecular mechanisms behind this process been uncovered. New work suggests that fucose can have a protective role in both gut-centered and systemic infection and inflammation. This review highlights recent studies showing that, in addition to acting as a food source for beneficial gut symbionts, host fucose can suppress the virulence of pathogens and pathobionts. The relevance of gut fucosylation to human diseases also is discussed. Copyright © 2015 by The American Association of Immunologists, Inc.

  14. Microarray analysis of the intestinal host response in Giardia duodenalis assemblage E infected calves.

    Science.gov (United States)

    Dreesen, Leentje; Rinaldi, Manuela; Chiers, Koen; Li, Robert; Geurden, Thomas; Van den Broeck, Wim; Goddeeris, Bruno; Vercruysse, Jozef; Claerebout, Edwin; Geldhof, Peter

    2012-01-01

    Despite Giardia duodenalis being one of the most commonly found intestinal pathogens in humans and animals, little is known about the host-parasite interactions in its natural hosts. Therefore, the objective of this study was to investigate the intestinal response in calves following a G. duodenalis infection, using a bovine high-density oligo microarray to analyze global gene expression in the small intestine. The resulting microarray data suggested a decrease in inflammation, immune response, and immune cell migration in infected animals. These findings were examined in more detail by histological analyses combined with quantitative real-time PCR on a panel of cytokines. The transcription levels of IL-6, IL-8, IL-13, IL-17, and IFN-γ showed a trend of being downregulated in the jejunum of infected animals compared to the negative controls. No immune cell recruitment could be seen after infection, and no intestinal pathologies, such as villus shortening or increased levels of apoptosis. Possible regulators of this intestinal response are the nuclear peroxisome proliferator-activated receptors alpha (PPARα), and gamma (PPARγ) and the enzyme adenosine deaminase (ADA), all for which an upregulated expression was found in the microarray and qRT-PCR analyses.

  15. Microarray analysis of the intestinal host response in Giardia duodenalis assemblage E infected calves.

    Directory of Open Access Journals (Sweden)

    Leentje Dreesen

    Full Text Available Despite Giardia duodenalis being one of the most commonly found intestinal pathogens in humans and animals, little is known about the host-parasite interactions in its natural hosts. Therefore, the objective of this study was to investigate the intestinal response in calves following a G. duodenalis infection, using a bovine high-density oligo microarray to analyze global gene expression in the small intestine. The resulting microarray data suggested a decrease in inflammation, immune response, and immune cell migration in infected animals. These findings were examined in more detail by histological analyses combined with quantitative real-time PCR on a panel of cytokines. The transcription levels of IL-6, IL-8, IL-13, IL-17, and IFN-γ showed a trend of being downregulated in the jejunum of infected animals compared to the negative controls. No immune cell recruitment could be seen after infection, and no intestinal pathologies, such as villus shortening or increased levels of apoptosis. Possible regulators of this intestinal response are the nuclear peroxisome proliferator-activated receptors alpha (PPARα, and gamma (PPARγ and the enzyme adenosine deaminase (ADA, all for which an upregulated expression was found in the microarray and qRT-PCR analyses.

  16. Alcohol-associated intestinal dysbiosis impairs pulmonary host defense against Klebsiella pneumoniae.

    Directory of Open Access Journals (Sweden)

    Derrick R Samuelson

    2017-06-01

    Full Text Available Chronic alcohol consumption perturbs the normal intestinal microbial communities (dysbiosis. To investigate the relationship between alcohol-mediated dysbiosis and pulmonary host defense we developed a fecal adoptive transfer model, which allows us to investigate the impact of alcohol-induced gut dysbiosis on host immune response to an infectious challenge at a distal organ, independent of prevailing alcohol use. Male C57BL/6 mice were treated with a cocktail of antibiotics (ampicillin, gentamicin, neomycin, vancomycin, and metronidazole via daily gavage for two weeks. A separate group of animals was fed a chronic alcohol (or isocaloric dextrose pair-fed controls liquid diet for 10 days. Microbiota-depleted mice were recolonized with intestinal microbiota from alcohol-fed or pair-fed (control animals. Following recolonization groups of mice were sacrificed prior to and 48 hrs. post respiratory infection with Klebsiella pneumoniae. Klebsiella lung burden, lung immunology and inflammation, as well as intestinal immunology, inflammation, and barrier damage were examined. Results showed that alcohol-associated susceptibility to K. pneumoniae is, in part, mediated by gut dysbiosis, as alcohol-naïve animals recolonized with a microbiota isolated from alcohol-fed mice had an increased respiratory burden of K. pneumoniae compared to mice recolonized with a control microbiota. The increased susceptibility in alcohol-dysbiosis recolonized animals was associated with an increase in pulmonary inflammatory cytokines, and a decrease in the number of CD4+ and CD8+ T-cells in the lung following Klebsiella infection but an increase in T-cell counts in the intestinal tract following Klebsiella infection, suggesting intestinal T-cell sequestration as a factor in impaired lung host defense. Mice recolonized with an alcohol-dysbiotic microbiota also had increased intestinal damage as measured by increased levels of serum intestinal fatty acid binding protein

  17. Human intestinal microbiota: cross-talk with the host and its potential role in colorectal cancer.

    Science.gov (United States)

    Candela, Marco; Guidotti, Marco; Fabbri, Alessia; Brigidi, Patrizia; Franceschi, Claudio; Fiorentini, Carla

    2011-02-01

    In this review, we discuss the multifactorial role of intestinal microbiota in colorectal cancer. The peculiar metabolism of dietary compounds of the individual microbiota complement, its overall immunostimulation and immunomodulatory activity, and eventually the production of toxins that perturb the regulation of cell growth, define the balance of positive and negative risk factors for colorectal cancer development. Moreover, shaping the composition of the human intestinal microbiota, diet has an indirect impact in determining the balance between health and disease. The integration of diet, microbial, and host factors in a system approach is mandatory to determine the overall balance of risk and protective factors for colorectal cancer onset.

  18. Assessment of acute intestinal graft versus host disease by abdominal magnetic resonance imaging at 3 Tesla

    Energy Technology Data Exchange (ETDEWEB)

    Budjan, Johannes; Michaely, Henrik J.; Attenberger, Ulrike; Haneder, Stefan; Schoenberg, Stefan O. [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim (Germany); Heidenreich, Daniela; Kreil, Sebastian; Nolte, Florian; Hofmann, Wolf-Karsten; Klein, Stefan A. [University Medical Center Mannheim, Department of Hematology and Oncology, Mannheim (Germany)

    2014-08-15

    After allogeneic stem cell transplantation (SCT), a reliable diagnosis of acute graft versus host disease (aGvHD) is essential for an early and successful treatment. It is the aim of this analysis to assess intestinal aGvHD by magnetic resonance imaging (MRI). Prior to allogeneic SCT, 64 consecutive patients underwent abdominal MRI examination on a 3 T MR system, including axial and coronal T2w sequences and a three-dimensional dynamic T1w, contrast enhanced sequence. After SCT, 20 patients with suspected aGvHD received a second MRI as well as an endoscopic examination. Nine patients suffered from histologically proven intestinal aGvHD. In eleven patients intestinal aGvHD was excluded. In all aGvHD patients typical MRI findings with long-segment bowel wall thickening - always involving the terminal ileum - with profound submucosal oedema, were detected. The bowel wall was significantly thickened in patients with intestinal aGvHD. Bowel contrast enhancement spared the submucosa while demonstrating strong mucosal hyperemia. In intestinal aGvHD, a characteristic MR-appearance can be detected. This MRI pattern might facilitate an early and non-invasive diagnosis of intestinal aGvHD. MRI might thus be used as a sensitive tool to rule out or support the clinical diagnosis of aGvHD. (orig.)

  19. Lack of host gut microbiota alters immune responses and intestinal granuloma formation during schistosomiasis.

    Science.gov (United States)

    Holzscheiter, M; Layland, L E; Loffredo-Verde, E; Mair, K; Vogelmann, R; Langer, R; Wagner, H; Prazeres da Costa, C

    2014-02-01

    Fatalities from schistosome infections arise due to granulomatous, immune-mediated responses to eggs that become trapped in host tissues. Schistosome-specific immune responses are characterized by initial T helper type 1 (Th1) responses and our previous studies demonstrated that myeloid differentiation primary response gene 88 (Myd88)-deficient mice failed to initiate such responses in vivo. Paradoxically, schistosomal antigens fail to stimulate innate cells to release proinflammatory cytokines in vitro. Since Schistosoma mansoni infection is an intestinal disease, we hypothesized that commensal bacteria could act as bystander activators of the intestinal innate immune system to instigate Th1 responses. Using a broad spectrum of orally administered antibiotics and anti-mycotics we analysed schistosome-infected mice that were simultaneously depleted of gut bacteria. After depletion there was significantly less inflammation in the intestine, which was accompanied by decreased intestinal granuloma development. In contrast, liver pathology remained unaltered. In addition, schistosome-specific immune responses were skewed and faecal egg excretion was diminished. This study demonstrates that host microbiota can act as a third partner in instigating helminth-specific immune responses. © 2013 British Society for Immunology.

  20. Intestinal microbiota-related effects on graft-versus-host disease

    Science.gov (United States)

    Shono, Yusuke; Docampo, Melissa D.; Peled, Jonathan U.; Perobelli, Suelen M.; Jenq, Robert R.

    2016-01-01

    Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an increasingly important treatment for conditions including hematopoietic malignancies and inherited hematopoietic disorders, and is considered to be the most effective form of tumor immunotherapy available to date. However, graft-versus-host disease (GVHD) remains a major source of morbidity and mortality following allo-HSCT, and understanding the mechanisms of GVHD has been highlighted as a key research priority. During development of GVHD, activation of various immune cells, especially donor T cells, leads to damage of target organs including skin, liver, hematopoietic system, and of particular clinical importance, gut. In addition to histocompatibility complex differences between the donor and recipient, pre-transplant conditioning with chemotherapy and irradiation also contributes to GVHD by damaging the gut, resulting in systemic exposure to microbial products normally confined to the intestinal lumen. The intestinal microbiota is a modulator of gastrointestinal immune homeostasis. It also promotes the maintenance of epithelial cells. Recent reports provide growing evidence of the impact of intestinal microbiota on GVHD pathophysiology. This review summarizes current knowledge of changes and effects of intestinal microbiota in the setting of allo-HSCT. We will also discuss potential future strategies of intestinal-microbiota manipulation that might be advantageous in decreasing allo-HSCT related morbidity and mortality. PMID:25812838

  1. The genome of th17 cell-inducing segmented filamentous bacteria reveals extensive auxotrophy and adaptations to the intestinal environment.

    Science.gov (United States)

    Sczesnak, Andrew; Segata, Nicola; Qin, Xiang; Gevers, Dirk; Petrosino, Joseph F; Huttenhower, Curtis; Littman, Dan R; Ivanov, Ivaylo I

    2011-09-15

    Perturbations of the composition of the symbiotic intestinal microbiota can have profound consequences for host metabolism and immunity. In mice, segmented filamentous bacteria (SFB) direct the accumulation of potentially proinflammatory Th17 cells in the intestinal lamina propria. We present the genome sequence of SFB isolated from monocolonized mice, which classifies SFB phylogenetically as a unique member of Clostridiales with a highly reduced genome. Annotation analysis demonstrates that SFB depend on their environment for amino acids and essential nutrients and may utilize host and dietary glycans for carbon, nitrogen, and energy. Comparative analyses reveal that SFB are functionally related to members of the genus Clostridium and several pathogenic or commensal "minimal" genera, including Finegoldia, Mycoplasma, Borrelia, and Phytoplasma. However, SFB are functionally distinct from all 1200 examined genomes, indicating a gene complement representing biology relatively unique to their role as a gut commensal closely tied to host metabolism and immunity. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Potential role of chitinases and chitin-binding proteins in host-microbial interactions during the development of intestinal inflammation

    Science.gov (United States)

    Tran, Hoa T.; Barnich, Nicolas; Mizoguchi, Emiko

    2011-01-01

    Summary The small and large intestines contain an abundance of luminal antigens derived from food products and enteric microorganisms. The function of intestinal epithelial cells is tightly regulated by several factors produced by enteric bacteria and the epithelial cells themselves. Epithelial cells actively participate in regulating the homeostasis of intestine, and failure of this function leads to abnormal and host-microbial interactions resulting in the development of intestinal inflammation. Major determinants of host susceptibility against luminal commensal bacteria include genes regulating mucosal immune responses, intestinal barrier function and microbial defense. Of note, it has been postulated that commensal bacterial adhesion and invasion on/into host cells may be strongly involved in the pathogenesis of inflammatory bowel disease (IBD). During the intestinal inflammation, the composition of the commensal flora is altered, with increased population of aggressive and detrimental bacteria and decreased populations of protective bacteria. In fact, some pathogenic bacteria, including Adherent Invasive Escherichia coli, Listeria monocytogenes and Vibrio cholerae are likely to initiate their adhesion to the host cells by expressing accessory molecules such as chitinases and/or chitin-binding proteins on themselves. In addition, several inducible molecules (e.g., chitinase 3-like-1, CEACAM6) are also induced on the host cells (e.g. epithelial cells, lamina proprial macrophages) under inflammatory conditions, and are actively participated in the host-microbial interactions. In this review, we will summarize and discuss the potential roles of these important molecules during the development of acute and chronic inflammatory conditions. PMID:21938682

  3. Intestinal Crosstalk between Bile Acids and Microbiota and Its Impact on Host Metabolism

    DEFF Research Database (Denmark)

    Wahlström, Annika; Sayin, Sama I; Marschall, Hanns-Ulrich

    2016-01-01

    The gut microbiota is considered a metabolic "organ" that not only facilitates harvesting of nutrients and energy from the ingested food but also produces numerous metabolites that signal through their cognate receptors to regulate host metabolism. One such class of metabolites, bile acids, is pr...... by altered microbiota composition.......The gut microbiota is considered a metabolic "organ" that not only facilitates harvesting of nutrients and energy from the ingested food but also produces numerous metabolites that signal through their cognate receptors to regulate host metabolism. One such class of metabolites, bile acids......, is produced in the liver from cholesterol and metabolized in the intestine by the gut microbiota. These bioconversions modulate the signaling properties of bile acids via the nuclear farnesoid X receptor and the G protein-coupled membrane receptor 5, which regulate numerous metabolic pathways in the host...

  4. O-antigen delays lipopolysaccharide recognition and impairs antibacterial host defense in murine intestinal epithelial cells.

    Directory of Open Access Journals (Sweden)

    Claudia U Duerr

    2009-09-01

    Full Text Available Although Toll-like receptor (TLR 4 signals from the cell surface of myeloid cells, it is restricted to an intracellular compartment and requires ligand internalization in intestinal epithelial cells (IECs. Yet, the functional consequence of cell-type specific receptor localization and uptake-dependent lipopolysaccharide (LPS recognition is unknown. Here, we demonstrate a strikingly delayed activation of IECs but not macrophages by wildtype Salmonella enterica subsp. enterica sv. (S. Typhimurium as compared to isogenic O-antigen deficient mutants. Delayed epithelial activation is associated with impaired LPS internalization and retarded TLR4-mediated immune recognition. The O-antigen-mediated evasion from early epithelial innate immune activation significantly enhances intraepithelial bacterial survival in vitro and in vivo following oral challenge. These data identify O-antigen expression as an innate immune evasion mechanism during apical intestinal epithelial invasion and illustrate the importance of early innate immune recognition for efficient host defense against invading Salmonella.

  5. Intestinal microbiota could transfer host Gut characteristics from pigs to mice.

    Science.gov (United States)

    Diao, H; Yan, H L; Xiao, Y; Yu, B; Yu, J; He, J; Zheng, P; Zeng, B H; Wei, H; Mao, X B; Chen, D W

    2016-10-11

    The present study was conducted to compare the differences in gut microbiota composition and gut-phenotypes among pig breeds, and determine whether these differences would transmit to mice colonized with fecal microbiota of different pig breeds. A total of 24 1-day-old germ-free BALB/C mice were divided into 3 groups (TFM, YFM and RFM), which were transplanted with intact fecal microbiota of Tibetan pig (TP), Yorkshire pig (YP) and Rongchang pig (RP), respectively. Results showed that different pig breeds exhibited distinct gut microbiota profile based on high-throughput pyrosequencing. YP exhibited a lower Firmicutes/Bacteroidetes ratio and apparent genera differences compared with RP and TP, and higher levels of bacteria from Spirochaetes were observed in TP compared with RP and YP (P microbiota into GF mice replicated the phenotypes of pig donors. Moreover, the three groups of donor pigs and their mice recipients exhibited different intestinal index and morphology. TP and RP had higher intestinal weight and relative CDX2 mRNA expression in ileum than YP, and longer intestine, higher villus height of duodenum and jejunum were observed in TP compared with YP and RP (P intestine weight and CDX2 mRNA expression in ileum than TFM and RFM (P intestine length in TFM was longer than that in RFM, and TFM had higher villus height in duodenum and jejunum and GLP-2 mRNA expression in ileum than the other two groups (P microbiota improved gut barrier in mice recipients. The concentration of MDA in YP was higher than that in TP and RP (P = 0.078), and the relative ZO-1 mRNA expression in ileum in TP was higher than that in YP (P microbiota composition and gut characteristics among pig breeds, and gut microbiota could partially convey host gut characteristics from pigs to mice.

  6. Environmental factors regulate Paneth cell phenotype and host susceptibility to intestinal inflammation in Irgm1-deficient mice.

    Science.gov (United States)

    Rogala, Allison R; Schoenborn, Alexi A; Fee, Brian E; Cantillana, Viviana A; Joyce, Maria J; Gharaibeh, Raad Z; Roy, Sayanty; Fodor, Anthony A; Sartor, R Balfour; Taylor, Gregory A; Gulati, Ajay S

    2017-12-22

    Crohn's disease (CD) represents a chronic inflammatory disorder of the intestinal tract. Several susceptibility genes have been linked to CD, though their precise role in the pathogenesis of this disorder remains unclear. Immunity-Related GTPase M (IRGM) is an established CD risk allele. We have shown previously that conventionally-raised (CV) mice lacking the IRGM ortholog, Irgm1, exhibit abnormal Paneth cells (PCs) and increased susceptibility to intestinal injury. In the present study, we sought to utilize this model system to determine if environmental conditions impact these phenotypes, as is thought to be the case in human CD. To accomplish this, wild-type and Irgm1-/- mice were re-derived into specific pathogen-free (SPF) and germ-free (GF) conditions. We next assessed how these differential housing environments influenced intestinal injury patterns and epithelial cell morphology and function in wild-type and Irgm1-/- mice. Remarkably, in contrast to CV mice, SPF Irgm1-/- mice showed only a slight increase in susceptibility to dextran sodium sulfate-induced inflammation. SPF Irgm1-/- mice also displayed minimal abnormalities in PC number, morphology, and antimicrobial peptide expression. Goblet cell numbers and epithelial proliferation were also unaffected by Irgm1 in SPF conditions. No microbial differences were observed between wild-type and Irgm1-/- mice, but gut bacterial communities differed profoundly between CV and SPF mice. Specifically, Helicobacter sequences were significantly increased in CV mice; however, inoculating SPF Irgm1-/- mice with H. hepaticus was not sufficient to transmit a pro-inflammatory phenotype. In summary, our findings suggest the impact of Irgm1-deficiency on susceptibility to intestinal inflammation and epithelial function is critically dependent on environmental influences. This work establishes the importance of Irgm1-/- mice as a model to elucidate host-environment interactions that regulate mucosal homeostasis and

  7. Antimicrobial growth promoters modulate host responses in mice with a defined intestinal microbiota.

    Science.gov (United States)

    Brown, Kirsty; Zaytsoff, Sarah J M; Uwiera, Richard R E; Inglis, G Douglas

    2016-12-08

    Antibiotics can promote growth in livestock (antimicrobial growth promoters, AGPs), however lack of knowledge regarding mechanisms has hampered the development of effective non-antibiotic alternatives. Antibiotics affect eukaryotic cells at therapeutic concentrations, yet effects of AGPs on host physiology are relatively understudied, partially due to the complexity of host-microorganism interactions within the gastrointestinal tract. To determine the direct effects of AGPs on the host, we generated Altered Schaedler Flora (ASF) mice, and administered chlortetracycline (CTC) and tylosin phosphate (TYL) in feed. Mice were challenged with Citrobacter rodentium to determine how AGPs alter host responses to physiological stress. Although CTC and TYL had inconsistent effects on the ASF taxa, AGPs protected mice from weight loss following C. rodentium inoculation. Mice treated with either CTC or TYL had lower expression of βd1 and Il17a in the intestine and had a robust induction of Il17a and Il10. Furthermore, AGP administration resulted in a lower hepatic expression of acute phase proteins (Saa1, Hp, and Cp) in liver tissue, and ameliorated C. rodentium-induced reductions in the expression of genes involved in lipogenesis (Hmgcl and Fabp1). Collectively, this indicates that AGPs directly affect host physiology, and highlights important considerations in the development of non-antibiotic alternatives.

  8. Carriage of λ Latent Virus Is Costly for Its Bacterial Host due to Frequent Reactivation in Monoxenic Mouse Intestine.

    Directory of Open Access Journals (Sweden)

    Marianne De Paepe

    2016-02-01

    Full Text Available Temperate phages, the bacterial viruses able to enter in a dormant prophage state in bacterial genomes, are present in the majority of bacterial strains for which the genome sequence is available. Although these prophages are generally considered to increase their hosts' fitness by bringing beneficial genes, studies demonstrating such effects in ecologically relevant environments are relatively limited to few bacterial species. Here, we investigated the impact of prophage carriage in the gastrointestinal tract of monoxenic mice. Combined with mathematical modelling, these experimental results provided a quantitative estimation of key parameters governing phage-bacteria interactions within this model ecosystem. We used wild-type and mutant strains of the best known host/phage pair, Escherichia coli and phage λ. Unexpectedly, λ prophage caused a significant fitness cost for its carrier, due to an induction rate 50-fold higher than in vitro, with 1 to 2% of the prophage being induced. However, when prophage carriers were in competition with isogenic phage susceptible bacteria, the prophage indirectly benefited its carrier by killing competitors: infection of susceptible bacteria led to phage lytic development in about 80% of cases. The remaining infected bacteria were lysogenized, resulting overall in the rapid lysogenization of the susceptible lineage. Moreover, our setup enabled to demonstrate that rare events of phage gene capture by homologous recombination occurred in the intestine of monoxenic mice. To our knowledge, this study constitutes the first quantitative characterization of temperate phage-bacteria interactions in a simplified gut environment. The high prophage induction rate detected reveals DNA damage-mediated SOS response in monoxenic mouse intestine. We propose that the mammalian gut, the most densely populated bacterial ecosystem on earth, might foster bacterial evolution through high temperate phage activity.

  9. An in vitro model of intestinal infection reveals a developmentally regulated transcriptome of Toxoplasma sporozoites and a NF-κB-like signature in infected host cells.

    Science.gov (United States)

    Guiton, Pascale S; Sagawa, Janelle M; Fritz, Heather M; Boothroyd, John C

    2017-01-01

    Toxoplasmosis is a zoonotic infection affecting approximately 30% of the world's human population. After sexual reproduction in the definitive feline host, Toxoplasma oocysts, each containing 8 sporozoites, are shed into the environment where they can go on to infect humans and other warm-blooded intermediate hosts. Here, we use an in vitro model to assess host transcriptomic changes that occur in the earliest stages of such infections. We show that infection of rat intestinal epithelial cells with mature sporozoites primarily results in higher expression of genes associated with Tumor Necrosis Factor alpha (TNFα) signaling via NF-κB. Furthermore, we find that, consistent with their biology, these mature, invaded sporozoites display a transcriptome intermediate between the previously reported day 10 oocysts and that of their tachyzoite counterparts. Thus, this study uncovers novel host and pathogen factors that may be critical for the establishment of a successful intracellular niche following sporozoite-initiated infection.

  10. An in vitro model of intestinal infection reveals a developmentally regulated transcriptome of Toxoplasma sporozoites and a NF-κB-like signature in infected host cells.

    Directory of Open Access Journals (Sweden)

    Pascale S Guiton

    Full Text Available Toxoplasmosis is a zoonotic infection affecting approximately 30% of the world's human population. After sexual reproduction in the definitive feline host, Toxoplasma oocysts, each containing 8 sporozoites, are shed into the environment where they can go on to infect humans and other warm-blooded intermediate hosts. Here, we use an in vitro model to assess host transcriptomic changes that occur in the earliest stages of such infections. We show that infection of rat intestinal epithelial cells with mature sporozoites primarily results in higher expression of genes associated with Tumor Necrosis Factor alpha (TNFα signaling via NF-κB. Furthermore, we find that, consistent with their biology, these mature, invaded sporozoites display a transcriptome intermediate between the previously reported day 10 oocysts and that of their tachyzoite counterparts. Thus, this study uncovers novel host and pathogen factors that may be critical for the establishment of a successful intracellular niche following sporozoite-initiated infection.

  11. Adaptation to the Host Environment by Plant-Pathogenic Fungi.

    Science.gov (United States)

    van der Does, H Charlotte; Rep, Martijn

    2017-08-04

    Many fungi can live both saprophytically and as endophyte or pathogen inside a living plant. In both environments, complex organic polymers are used as sources of nutrients. Propagation inside a living host also requires the ability to respond to immune responses of the host. We review current knowledge of how plant-pathogenic fungi do this. First, we look at how fungi change their global gene expression upon recognition of the host environment, leading to secretion of effectors, enzymes, and secondary metabolites; changes in metabolism; and defense against toxic compounds. Second, we look at what is known about the various cues that enable fungi to sense the presence of living plant cells. Finally, we review literature on transcription factors that participate in gene expression in planta or are suspected to be involved in that process because they are required for the ability to cause disease.

  12. Saccharomyces boulardii modifies Salmonella typhimurium traffic and host immune responses along the intestinal tract.

    Directory of Open Access Journals (Sweden)

    Rodolphe Pontier-Bres

    Full Text Available Salmonella enterica serovar Typhimurium (ST is an enteropathogenic Gram-negative bacterium that causes infection following oral ingestion. ST spreads rapidly along the gastrointestinal tract (GIT and invades the intestinal epithelium to ultimately reach internal body organs. The probiotic yeast Saccharomyces boulardii BIOCODEX (S.b-B is prescribed for prophylaxis of diarrheal infectious diseases. We previously showed that S.b-B prevents weight loss in ST-infected mice and significantly decreases bacterial translocation to the spleen and liver. This study was designed to investigate the effect of S.b-B on ST migration along the GIT and the impact of the yeast on the host's early innate immune responses. Bioluminescent imaging (BLI was used to evaluate the effect of S.b-B on the progression of luminescent Salmonella Typhimurium (ST-lux in the GIT of mice pretreated with streptomycin. Photonic emission (PE was measured in GIT extracts (stomach, small intestine, cecum and colon at various time periods post-infection (PI. PE analysis revealed that, 45 min PI, ST-lux had migrated slightly faster in the mice treated with S.b-B than in the untreated infected animals. At 90 min PI, ST-lux had reached the cecum in both groups of mice. Adhesion of ST to S.b-B was visualized in the intestines of the mice and probably accounts for (1 the faster elimination of ST-lux in the feces, and (2 reduced translocation of ST to the spleen and liver. In the early phase of infection, S.b-B also modifies the host's immune responses by (1 increasing IFN-γ gene expression and decreasing IL-10 gene expression in the small intestine, and (2 elevating both IFN-γ, and IL-10 mRNA levels in the cecum. BLI revealed that S.b-B modifies ST migration and the host immune response along the GIT. Study findings shed new light on the protective mechanisms of S.b-B during the early phase of Salmonella pathogenesis.

  13. Association between Yogurt Consumption and Intestinal Microbiota in Healthy Young Adults Differs by Host Gender

    Directory of Open Access Journals (Sweden)

    Yoshio Suzuki

    2017-05-01

    Full Text Available Human intestinal microbiota are influenced by various factors viz. diet, environment, age, gender, geographical, and socioeconomic situation, etc. among which diet has the most profound impact. However, studies investigating this impact have mostly included subjects from diverse geographic/socioeconomic backgrounds and hence the precise effects of dietary factors on gut microbiota composition remain largely confounded. Herein, with an aim to evaluate the association between dietary habits, specifically yogurt consumption, and the gut microbiota in healthy young adults sharing similar age, lifestyle routine, geographical setting, etc., we conducted a cross-sectional study wherein 293 collegiate freshmen answered a questionnaire about their frequency of yogurt consumption over the last 2 months and provided stool specimens for microbiota analysis. Fecal microbiota were analyzed by highly sensitive reverse-transcription-quantitative-PCR assays targeting bacterial 16S rRNA molecules. Fecal organic acids were measured by HPLC. Overall, the gut microbiota were predominated (97.1 ± 8.6% by Clostridium coccoides group, Clostridium leptum subgroup, Bacteroides fragilis group, Bifidobacterium and Atopobium cluster. Interestingly, after adjusting the data for yogurt consumption, females were found to have higher total bacterial (P = 0.013 and Bifidobacterium (P = 0.046 count and fecal pH (P = 0.007 and lower fecal concentration of total organic acids (P = 0.030, succinic acid (P = 0.007 and formic acid (P = 0.046 as compared to males. Altogether, yogurt consumption showed positive linear association with Lactobacillus and Lactobacillus gasseri subgroup in both male and female subjects; however, several gender-specific disparities were also detected in this yogurt-microbiota association. Yogurt consumption demonstrated a negative association with L. sakei subgroup, Enterobacteriaceae and Staphylococcus in males but shared a positive association with L

  14. Association between Yogurt Consumption and Intestinal Microbiota in Healthy Young Adults Differs by Host Gender

    Science.gov (United States)

    Suzuki, Yoshio; Ikeda, Keiichi; Sakuma, Kazuhiko; Kawai, Sachio; Sawaki, Keisuke; Asahara, Takashi; Takahashi, Takuya; Tsuji, Hirokazu; Nomoto, Koji; Nagpal, Ravinder; Wang, Chongxin; Nagata, Satoru; Yamashiro, Yuichiro

    2017-01-01

    Human intestinal microbiota are influenced by various factors viz. diet, environment, age, gender, geographical, and socioeconomic situation, etc. among which diet has the most profound impact. However, studies investigating this impact have mostly included subjects from diverse geographic/socioeconomic backgrounds and hence the precise effects of dietary factors on gut microbiota composition remain largely confounded. Herein, with an aim to evaluate the association between dietary habits, specifically yogurt consumption, and the gut microbiota in healthy young adults sharing similar age, lifestyle routine, geographical setting, etc., we conducted a cross-sectional study wherein 293 collegiate freshmen answered a questionnaire about their frequency of yogurt consumption over the last 2 months and provided stool specimens for microbiota analysis. Fecal microbiota were analyzed by highly sensitive reverse-transcription-quantitative-PCR assays targeting bacterial 16S rRNA molecules. Fecal organic acids were measured by HPLC. Overall, the gut microbiota were predominated (97.1 ± 8.6%) by Clostridium coccoides group, Clostridium leptum subgroup, Bacteroides fragilis group, Bifidobacterium and Atopobium cluster. Interestingly, after adjusting the data for yogurt consumption, females were found to have higher total bacterial (P = 0.013) and Bifidobacterium (P = 0.046) count and fecal pH (P = 0.007) and lower fecal concentration of total organic acids (P = 0.030), succinic acid (P = 0.007) and formic acid (P = 0.046) as compared to males. Altogether, yogurt consumption showed positive linear association with Lactobacillus and Lactobacillus gasseri subgroup in both male and female subjects; however, several gender-specific disparities were also detected in this yogurt-microbiota association. Yogurt consumption demonstrated a negative association with L. sakei subgroup, Enterobacteriaceae and Staphylococcus in males but shared a positive association with L. casei subgroup

  15. Pilot study of lithium to restore intestinal barrier function in severe graft-versus-host disease.

    Directory of Open Access Journals (Sweden)

    Gideon Steinbach

    Full Text Available Severe intestinal graft-vs-host disease (GVHD after allogeneic hematopoietic cell transplantation (HCT causes mucosal ulceration and induces innate and adaptive immune responses that amplify and perpetuate GVHD and the associated barrier dysfunction. Pharmacological agents to target mucosal barrier dysfunction in GVHD are needed. We hypothesized that induction of Wnt signaling by lithium, an inhibitor of glycogen synthase kinase (GSK3, would potentiate intestinal crypt proliferation and mucosal repair and that inhibition of GSK3 in inflammatory cells would attenuate the deregulated inflammatory response to mucosal injury. We conducted an observational pilot study to provide data for the potential design of a randomized study of lithium. Twenty patients with steroid refractory intestinal GVHD meeting enrollment criteria were given oral lithium carbonate. GVHD was otherwise treated per current practice, including 2 mg/kg per day of prednisone equivalent. Seventeen patients had extensive mucosal denudation (extreme endoscopic grade 3 in the duodenum or colon. We observed that 8 of 12 patients (67% had a complete remission (CR of GVHD and survived more than 1 year (median 5 years when lithium administration was started promptly within 3 days of endoscopic diagnosis of denuded mucosa. When lithium was started promptly and less than 7 days from salvage therapy for refractory GVHD, 8 of 10 patients (80% had a CR and survived more than 1 year. In perspective, a review of 1447 consecutive adult HCT patients in the preceding 6 years at our cancer center showed 0% one-year survival in 27 patients with stage 3-4 intestinal GVHD and grade 3 endoscopic appearance in the duodenum or colon. Toxicities included fatigue, somnolence, confusion or blunted affect in 50% of the patients. The favorable outcomes in patients who received prompt lithium therapy appear to support the future conduct of a randomized study of lithium for management of severe GVHD with

  16. Location, location, location. Salmonella senses ethanolamine to gauge distinct host environments and coordinate gene expression

    Directory of Open Access Journals (Sweden)

    Christopher J. Anderson

    2016-01-01

    Full Text Available Chemical and nutrient signaling mediate all cellular processes, ensuring survival in response to changing environmental conditions. Ethanolamine is a component of phosphatidylethanolamine, a major phospholipid of mammalian and bacterial cell membranes. Ethanolamine is abundant in the gastrointestinal (GI tract from dietary sources as well as from the normal turnover of intestinal epithelial and bacterial cells in the gut. Additionally, mammalian cells maintain intracellular ethanolamine concentrations through low and high-affinity uptake systems and the internal recycling of phosphatidylethanolamine; therefore, ethanolamine is ubiquitous throughout the mammalian host. Although ethanolamine has profound signaling activity within mammalian cells by modulating inflammatory responses and intestinal physiology, ethanolamine is best appreciated as a nutrient for bacteria that supports growth. In our recent work (Anderson, et al. PLoS Pathog (2015, 11: e1005278, we demonstrated that Salmonella enterica serovar Typhimurium (Salmonella exploits ethanolamine signaling to adapt to distinct host environments to precisely coordinate expression of genes encoding metabolism and virulence, which ultimately enhances disease progression.

  17. Exploring the potential of host-environment relationship in the control of schistosomiasis in Africa

    NARCIS (Netherlands)

    Monde, C.; Syampungani, S.; Brink, van den P.J.

    2015-01-01

    A number of human disease prevalences are supported by host-parasite-environment interactions. One such disease is schistosomiasis. Schistosoma parasites are transmitted between the snail intermediate hosts and mammalian definitive hosts in an aquatic environment. This host-environment link

  18. Occurrence, Diversity, and Host Association of Intestinal Campylobacter, Arcobacter, and Helicobacter in Reptiles

    Science.gov (United States)

    Gilbert, Maarten J.; Kik, Marja; Timmerman, Arjen J.; Severs, Tim T.; Kusters, Johannes G.; Duim, Birgitta; Wagenaar, Jaap A.

    2014-01-01

    Campylobacter, Arcobacter, and Helicobacter species have been isolated from many vertebrate hosts, including birds, mammals, and reptiles. Multiple studies have focused on the prevalence of these Epsilonproteobacteria genera in avian and mammalian species. However, little focus has been given to the presence within reptiles, and their potential zoonotic and pathogenic roles. In this study, occurrence, diversity, and host association of intestinal Epsilonproteobacteria were determined for a large variety of reptiles. From 2011 to 2013, 444 cloacal swabs and fecal samples originating from 417 predominantly captive-held reptiles were screened for Epsilonproteobacteria. Campylobacter, Arcobacter, and Helicobacter genus specific PCRs were performed directly on all samples. All samples were also cultured on selective media and screened for the presence of Epsilonproteobacteria. Using a tiered approach of AFLP, atpA, and 16S rRNA sequencing, 432 Epsilonproteobacteria isolates were characterized at the species level. Based on PCR, Campylobacter, Arcobacter, and Helicobacter were detected in 69.3% of the reptiles; 82.5% of the chelonians, 63.8% of the lizards, and 58.0% of the snakes were positive for one or more of these genera. Epsilonproteobacteria were isolated from 22.1% of the reptiles and were isolated most frequently from chelonians (37.0%), followed by lizards (19.6%) and snakes (3.0%). The most commonly isolated taxa were Arcobacter butzleri, Arcobacter skirrowii, reptile-associated Campylobacter fetus subsp. testudinum, and a putative novel Campylobacter taxon. Furthermore, a clade of seven related putative novel Helicobacter taxa was isolated from lizards and chelonians. This study shows that reptiles carry various intestinal Epsilonproteobacteria taxa, including several putative novel taxa. PMID:24988130

  19. Occurrence, diversity, and host association of intestinal Campylobacter, Arcobacter, and Helicobacter in reptiles.

    Science.gov (United States)

    Gilbert, Maarten J; Kik, Marja; Timmerman, Arjen J; Severs, Tim T; Kusters, Johannes G; Duim, Birgitta; Wagenaar, Jaap A

    2014-01-01

    Campylobacter, Arcobacter, and Helicobacter species have been isolated from many vertebrate hosts, including birds, mammals, and reptiles. Multiple studies have focused on the prevalence of these Epsilonproteobacteria genera in avian and mammalian species. However, little focus has been given to the presence within reptiles, and their potential zoonotic and pathogenic roles. In this study, occurrence, diversity, and host association of intestinal Epsilonproteobacteria were determined for a large variety of reptiles. From 2011 to 2013, 444 cloacal swabs and fecal samples originating from 417 predominantly captive-held reptiles were screened for Epsilonproteobacteria. Campylobacter, Arcobacter, and Helicobacter genus specific PCRs were performed directly on all samples. All samples were also cultured on selective media and screened for the presence of Epsilonproteobacteria. Using a tiered approach of AFLP, atpA, and 16S rRNA sequencing, 432 Epsilonproteobacteria isolates were characterized at the species level. Based on PCR, Campylobacter, Arcobacter, and Helicobacter were detected in 69.3% of the reptiles; 82.5% of the chelonians, 63.8% of the lizards, and 58.0% of the snakes were positive for one or more of these genera. Epsilonproteobacteria were isolated from 22.1% of the reptiles and were isolated most frequently from chelonians (37.0%), followed by lizards (19.6%) and snakes (3.0%). The most commonly isolated taxa were Arcobacter butzleri, Arcobacter skirrowii, reptile-associated Campylobacter fetus subsp. testudinum, and a putative novel Campylobacter taxon. Furthermore, a clade of seven related putative novel Helicobacter taxa was isolated from lizards and chelonians. This study shows that reptiles carry various intestinal Epsilonproteobacteria taxa, including several putative novel taxa.

  20. Intestinal epithelial MyD88 is a sensor switching host metabolism towards obesity according to nutritional status.

    Science.gov (United States)

    Everard, Amandine; Geurts, Lucie; Caesar, Robert; Van Hul, Matthias; Matamoros, Sébastien; Duparc, Thibaut; Denis, Raphael G P; Cochez, Perrine; Pierard, Florian; Castel, Julien; Bindels, Laure B; Plovier, Hubert; Robine, Sylvie; Muccioli, Giulio G; Renauld, Jean-Christophe; Dumoutier, Laure; Delzenne, Nathalie M; Luquet, Serge; Bäckhed, Fredrik; Cani, Patrice D

    2014-12-05

    Obesity is associated with a cluster of metabolic disorders, low-grade inflammation and altered gut microbiota. Whether host metabolism is controlled by intestinal innate immune system and the gut microbiota is unknown. Here we report that inducible intestinal epithelial cell-specific deletion of MyD88 partially protects against diet-induced obesity, diabetes and inflammation. This is associated with increased energy expenditure, an improved glucose homeostasis, reduced hepatic steatosis, fat mass and inflammation. Protection is transferred following gut microbiota transplantation to germ-free recipients. We also demonstrate that intestinal epithelial MyD88 deletion increases anti-inflammatory endocannabinoids, restores antimicrobial peptides production and increases intestinal regulatory T cells during diet-induced obesity. Targeting MyD88 after the onset of obesity reduces fat mass and inflammation. Our work thus identifies intestinal epithelial MyD88 as a sensor changing host metabolism according to the nutritional status and we show that targeting intestinal epithelial MyD88 constitutes a putative therapeutic target for obesity and related disorders.

  1. Mannose-specific interactions of Lactobacillus plantarum in the intestine : bacterial genes, molecular host responses and potential probiotic effects

    NARCIS (Netherlands)

    Pretzer, G.

    2008-01-01

    One potential mechanism by which probiotic microorganisms may exert beneficial health effects to the host is the inhibition of intestinal infections by competitive exclusion of pathogenic bacteria. This concept may also be applicable for mannose-specific adhesion to the epithelial surface, which has

  2. Environment and Host Affects Arbuscular Mycorrhiza Fungi (AMF) Population.

    Science.gov (United States)

    Rahim, Norahizah Abd; Jais, Hasnah Md; Hassan, Hasnuri Mat

    2016-11-01

    The association of arbuscular mycorrhiza fungi (AMF) and roots undoubtedly gives positive advantages to the host plant. However, heavily fertilised soil such as in oil palm plantation, inhibit the growth of mycorrhiza. Thus, the aim of this research is to distinguish and quantify the availability of AMF population and propagules at different sites of an oil palm plantation by Most Probable Number (MPN) assay. In addition, root infection method was employed to observe host compatibility through the propagation of AMF using two different types of hosts, monocotyledon (Echinochloa cruss-galli) and dicotyledon (Vigna radiata). Three different locations at an oil palm plantation were chosen for sampling. Each location was represented by a distinctive soil series, and were further divided into two sites, that is canopy and midway area. Midway site had a greater population of AMF compared to canopy. The result showed that different environments affect the availability of AMF in the soil. Higher number of AMF infection observed in monocotyledon host suggests that the fibrous root system provide a better association with mycorrhiza.

  3. Activation of host constitutive immune defence by an intestinal trypanosome parasite of bumble bees.

    Science.gov (United States)

    Brown, M J F; Moret, Y; Schmid-Hempel, P

    2003-03-01

    Many parasites, including important species that affect humans and livestock, must survive the harsh environment of insect guts to complete their life-cycle. Hence, understanding how insects protect themselves against such parasites has immediate practical implications. Previously, such protection has been thought to consist mainly of mechanical structures and the action of lectins. However, recently it has become apparent that gut infections may interact with the host immune system in more complex ways. Here, using bumble bees, Bombus terrestris and their non-invasive gut trypanosome, Crithidia bombi, as a model system we investigated the effects of parasitic infection, host resources and the duration of infections on the host immune system. We found that infection doubled standing levels of immune defence in the haemolymph (the constitutive pro-phenoloxidase system), which is used as a first, general defence against parasites. However, physical separation of the parasite from the haemolymph suggests the presence of a messenger system between the gut and the genes that control the pro-phenoloxidase system. Surprisingly, we found no direct effect of host resource-stress or duration of the infection on the immune system. Our results suggest a novel and tactical response of insects to gut infections, demonstrating the complexity of such host-parasite systems.

  4. A Multi-Omic View of Host-Pathogen-Commensal Interplay in Salmonella-Mediated Intestinal Infection

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, Brooke LD; Li, Jie; Sanford, James A.; Kim, Young-Mo; Kronewitter, Scott R.; Jones, Marcus B.; Peterson, Christine; Peterson, Scott N.; Frank, Bryan C.; Purvine, Samuel O.; Brown, Joseph N.; Metz, Thomas O.; Smith, Richard D.; Heffron, Fred; Adkins, Joshua N.

    2013-06-26

    The potential for commensal microorganisms indigenous to a host (the ‘microbiome’ or ‘microbiota’) to alter infection outcome by influencing host-pathogen interplay is largely unknown. We used a multi-omics “systems” approach, incorporating proteomics, metabolomics, glycomics, and metagenomics, to explore the molecular interplay between the murine host, the pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium), and commensal gut microorganisms during intestinal infection with S. Typhimurium. We find proteomic evidence that S. Typhimurium thrives within the infected 129/SvJ mouse gut without antibiotic pre-treatment, inducing inflammation and disrupting the intestinal microbiome (e.g., suppressing Bacteroidetes and Firmicutes while promoting growth of Salmonella and Enterococcus). Alteration of the host microbiome population structure was highly correlated with gut environmental changes, including the accumulation of metabolites normally consumed by commensal microbiota. Finally, the less characterized phase of S. Typhimurium’s lifecycle was investigated, and both proteomic and glycomic evidence suggests S. Typhimurium may take advantage of increased fucose moieties to metabolize fucose while growing in the gut. The application of multiple omics measurements to Salmonella-induced intestinal inflammation provides insights into complex molecular strategies employed during pathogenesis between host, pathogen, and the microbiome.

  5. Evolutionary dynamics of bacteria in a human host environment

    DEFF Research Database (Denmark)

    Yang, Lei; Jelsbak, Lars; Marvig, Rasmus Lykke

    2011-01-01

    the evolutionary dynamics of a lineage of a clinically important opportunistic bacterial pathogen, Pseudomonas aeruginosa, as it adapts to the airways of several individual cystic fibrosis patients over 200,000 bacterial generations, and provide estimates of mutation rates of bacteria in a natural environment....... In contrast to predictions based on in vitro evolution experiments, we document limited diversification of the evolving lineage despite a highly structured and complex host environment. Notably, the lineage went through an initial period of rapid adaptation caused by a small number of mutations...... long-term in vitro evolution experiments. The evolved phenotype of the infecting bacteria further suggests that the opportunistic pathogen has transitioned to become a primary pathogen for cystic fibrosis patients....

  6. New insights into the role of the porcine intestinal yeast, Kazachstania slooffiae, in intestinal environment of weaned piglets.

    Science.gov (United States)

    Urubschurov, Vladimir; Büsing, Kirsten; Freyer, Gertraude; Herlemann, Daniel P R; Souffrant, Wolfgang-Bernhard; Zeyner, Annette

    2017-02-01

    Kazachstania slooffiae is a porcine intestinal yeast whose role in the intestinal environment is largely unexplored. Therefore, the impact of K. slooffiae on growth performance, intestinal microbial metabolites and the microbiota of weaned piglets was investigated in this study. Forty-eight German Landrace pigs were weaned at day 27 or 28 of life and grouped into one control and three treatment groups. During the 5-week experiment, piglets had ad libitum access to feed and water. On days 5, 6 and 7 post weaning, pigs were orally supplemented with either placebo or K. slooffiae cells once a day. Faecal samples collected on days 5-8, 14, 21 and 28 post weaning were used for microbiological and chemical analyses. Between groups, there were no significant differences in the incidence of diarrhoea, pH and growth performance. Total yeasts and K. slooffiae correlated positively with total short-chain fatty acids, acetic, propionic, n-butyric, i-valeric and valeric acids, and negatively with pH. Pyrosequencing of the bacterial intestinal community revealed that K. slooffiae significantly affected the composition of the microbiota. The results of this study suggest that K. slooffiae may play an important role in the porcine digestive system, especially in the critical weaning period. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. [Cell-host-parasite interactions: biodiversity, pathogenesis, environment].

    Science.gov (United States)

    Villena, I; Aubert, D; Pinon, J-M

    2006-03-01

    The apicomplexan Toxoplasma gondii, an obligate intracellular parasite, can infect humans and a wide range of vertebrates leading to toxoplasmosis. This generally benign affection can causes severe life-threatening disease, particularly in immunocompromised patients and in children with congenital toxoplasmosis. Our research team works on cell-host-parasite interactions by studying biodiversity, pathogenic mechanisms and environment. We search to identify prognostic factors of disease and markers of resistance. This project is an integral part of our Research Institute (IFR53) which receives support from the Toxoplasma Biological Resource Center for constituting a bank of well characterized toxoplasma isolates for genotyping, clinical and epidemiological data. The involvement of metalloproteinases implicated during monocytic cell invasion and identification of ABC transporter proteins in T. gondii, factors implicated in resistance, need to be explored.

  8. Neonatal environment exerts a sustained influence on the development of the intestinal microbiota and metabolic phenotype.

    Science.gov (United States)

    Merrifield, Claire A; Lewis, Marie C; Berger, Bernard; Cloarec, Olivier; Heinzmann, Silke S; Charton, Florence; Krause, Lutz; Levin, Nadine S; Duncker, Swantje; Mercenier, Annick; Holmes, Elaine; Bailey, Mick; Nicholson, Jeremy K

    2016-01-01

    The postnatal environment, including factors such as weaning and acquisition of the gut microbiota, has been causally linked to the development of later immunological diseases such as allergy and autoimmunity, and has also been associated with a predisposition to metabolic disorders. We show that the very early-life environment influences the development of both the gut microbiota and host metabolic phenotype in a porcine model of human infants. Farm piglets were nursed by their mothers for 1 day, before removal to highly controlled, individual isolators where they received formula milk until weaning at 21 days. The experiment was repeated, to create two batches, which differed only in minor environmental fluctuations during the first day. At day 1 after birth, metabolic profiling of serum by (1)H nuclear magnetic resonance spectroscopy demonstrated significant, systemic, inter-batch variation which persisted until weaning. However, the urinary metabolic profiles demonstrated that significant inter-batch effects on 3-hydroxyisovalerate, trimethylamine-N-oxide and mannitol persisted beyond weaning to at least 35 days. Batch effects were linked to significant differences in the composition of colonic microbiota at 35 days, determined by 16 S pyrosequencing. Different weaning diets modulated both the microbiota and metabolic phenotype independently of the persistent batch effects. We demonstrate that the environment during the first day of life influences development of the microbiota and metabolic phenotype and thus should be taken into account when interrogating experimental outcomes. In addition, we suggest that intervention at this early time could provide 'metabolic rescue' for at-risk infants who have undergone aberrant patterns of initial intestinal colonisation.

  9. Proteomic View of Interactions of Shiga Toxin-Producing Escherichia coli with the Intestinal Environment in Gnotobiotic Piglets.

    Science.gov (United States)

    Pieper, Rembert; Zhang, Quanshun; Clark, David J; Parmar, Prashanth P; Alami, Hamid; Suh, Moo-Jin; Kuntumalla, Srilatha; Braisted, John C; Huang, Shih-Ting; Tzipori, Saul

    2013-01-01

    Shiga toxin (Stx)-producing Escherichia coli cause severe intestinal infections involving colonization of epithelial Peyer's patches and formation of attachment/effacement (A/E) lesions. These lesions trigger leukocyte infiltration followed by inflammation and intestinal hemorrhage. Systems biology, which explores the crosstalk of Stx-producing Escherichia coli with the in vivo host environment, may elucidate novel molecular pathogenesis aspects. Enterohemorrhagic E. coli strain 86-24 produces Shiga toxin-2 and belongs to the serotype O157:H7. Bacterial cells were scrapped from stationary phase cultures (the in vitro condition) and used to infect gnotobiotic piglets via intestinal lavage. Bacterial cells isolated from the piglets' guts constituted the in vivo condition. Cell lysates were subjected to quantitative 2D gel and shotgun proteomic analyses, revealing metabolic shifts towards anaerobic energy generation, changes in carbon utilization, phosphate and ammonia starvation, and high activity of a glutamate decarboxylase acid resistance system in vivo. Increased abundance of pyridine nucleotide transhydrogenase (PntA and PntB) suggested in vivo shortage of intracellular NADPH. Abundance changes of proteins implicated in lipopolysaccharide biosynthesis (LpxC, ArnA, the predicted acyltransferase L7029) and outer membrane (OM) assembly (LptD, MlaA, MlaC) suggested bacterial cell surface modulation in response to activated host defenses. Indeed, there was evidence for interactions of innate immunity-associated proteins secreted into the intestines (GP340, REG3-γ, resistin, lithostathine, and trefoil factor 3) with the bacterial cell envelope. Proteomic analysis afforded insights into system-wide adaptations of strain 86-24 to a hostile intestinal milieu, including responses to limited nutrients and cofactor supplies, intracellular acidification, and reactive nitrogen and oxygen species-mediated stress. Protein and lipopolysaccharide compositions of the OM were

  10. Proteomic View of Interactions of Shiga Toxin-Producing Escherichia coli with the Intestinal Environment in Gnotobiotic Piglets.

    Directory of Open Access Journals (Sweden)

    Rembert Pieper

    Full Text Available Shiga toxin (Stx-producing Escherichia coli cause severe intestinal infections involving colonization of epithelial Peyer's patches and formation of attachment/effacement (A/E lesions. These lesions trigger leukocyte infiltration followed by inflammation and intestinal hemorrhage. Systems biology, which explores the crosstalk of Stx-producing Escherichia coli with the in vivo host environment, may elucidate novel molecular pathogenesis aspects.Enterohemorrhagic E. coli strain 86-24 produces Shiga toxin-2 and belongs to the serotype O157:H7. Bacterial cells were scrapped from stationary phase cultures (the in vitro condition and used to infect gnotobiotic piglets via intestinal lavage. Bacterial cells isolated from the piglets' guts constituted the in vivo condition. Cell lysates were subjected to quantitative 2D gel and shotgun proteomic analyses, revealing metabolic shifts towards anaerobic energy generation, changes in carbon utilization, phosphate and ammonia starvation, and high activity of a glutamate decarboxylase acid resistance system in vivo. Increased abundance of pyridine nucleotide transhydrogenase (PntA and PntB suggested in vivo shortage of intracellular NADPH. Abundance changes of proteins implicated in lipopolysaccharide biosynthesis (LpxC, ArnA, the predicted acyltransferase L7029 and outer membrane (OM assembly (LptD, MlaA, MlaC suggested bacterial cell surface modulation in response to activated host defenses. Indeed, there was evidence for interactions of innate immunity-associated proteins secreted into the intestines (GP340, REG3-γ, resistin, lithostathine, and trefoil factor 3 with the bacterial cell envelope.Proteomic analysis afforded insights into system-wide adaptations of strain 86-24 to a hostile intestinal milieu, including responses to limited nutrients and cofactor supplies, intracellular acidification, and reactive nitrogen and oxygen species-mediated stress. Protein and lipopolysaccharide compositions of the OM

  11. Ecotoxicoparasitology: Understanding mercury concentrations in gut contents, intestinal helminths and host tissues of Alaskan gray wolves (Canis lupus)

    Science.gov (United States)

    McGrew, Ashley K.; O'Hara, Todd M.; Stricker, Craig A.; Castellini, Margaret; Beckmen, Kimberlee B.; Salman, Mo D.; Ballweber, Lora R.

    2015-01-01

    Some gastrointestinal helminths acquire nutrients from the lumen contents in which they live; thus, they may be exposed to non-essential elements, such as mercury (Hg), during feeding. The objectives of this study were: 1) determine the total mercury concentrations ([THg]) in Gray wolves (Canis lupus) and their parasites, and 2) use stable isotopes to evaluate the trophic relationships within the host. [THg] and stable isotopes (C and N) were determined for helminths, host tissues, and lumen contents from 88 wolves. Sixty-three wolves contained grossly visible helminths (71.5%). The prevalence of taeniids and ascarids was 63.6% (56/88) and 20.5% (18/88), respectively. Nine of these 63 wolves contained both taeniids and ascarids (14.3%). All ascarids were determined to beToxascaris leonina. Taenia species present included T. krabbei and T. hydatigena. Within the GI tract, [THg] in the lumen contents of the proximal small intestine were significantly lower than in the distal small intestine. There was a significant positive association between hepatic and taeniid [THg]. Bioaccumulation factors (BAF) ranged from < 1 to 22.9 in taeniids, and 1.1 to 12.3 in T. leonina. Taeniid and ascarid BAF were significantly higher than 1, suggesting that both groups are capable of THg accumulation in their wolf host. δ13C in taeniids was significantly lower than in host liver and skeletal muscle. [THg] in helminths and host tissues, in conjunction with stable isotope (C and N) values, provides insight into food-web dynamics of the host GI tract, and aids in elucidating ecotoxicoparasitologic relationships. Variation of [THg] throughout the GI tract, and between parasitic groups, underscores the need to further evaluate the effect(s) of feeding niche, and the nutritional needs of parasites, as they relate to toxicant exposure and distribution within the host.

  12. Virtualizing access to scientific applications with the Application Hosting Environment

    Science.gov (United States)

    Zasada, S. J.; Coveney, P. V.

    2009-12-01

    The growing power and number of high performance computing resources made available through computational grids present major opportunities as well as a number of challenges to the user. At issue is how these resources can be accessed and how their power can be effectively exploited. In this paper we first present our views on the usability of contemporary high-performance computational resources. We introduce the concept of grid application virtualization as a solution to some of the problems with grid-based HPC usability. We then describe a middleware tool that we have developed to realize the virtualization of grid applications, the Application Hosting Environment (AHE), and describe the features of the new release, AHE 2.0, which provides access to a common platform of federated computational grid resources in standard and non-standard ways. Finally, we describe a case study showing how AHE supports clinical use of whole brain blood flow modelling in a routine and automated fashion. Program summaryProgram title: Application Hosting Environment 2.0 Catalogue identifier: AEEJ_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEEJ_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU Public Licence, Version 2 No. of lines in distributed program, including test data, etc.: not applicable No. of bytes in distributed program, including test data, etc.: 1 685 603 766 Distribution format: tar.gz Programming language: Perl (server), Java (Client) Computer: x86 Operating system: Linux (Server), Linux/Windows/MacOS (Client) RAM: 134 217 728 (server), 67 108 864 (client) bytes Classification: 6.5 External routines: VirtualBox (server), Java (client) Nature of problem: The middleware that makes grid computing possible has been found by many users to be too unwieldy, and presents an obstacle to use rather than providing assistance [1,2]. Such problems are compounded when one attempts to harness the

  13. Intestinal Irradiation and Fibrosis in a Th1-Deficient Environment

    Energy Technology Data Exchange (ETDEWEB)

    Linard, Christine, E-mail: christine.linard@irsn.fr [Institut de Radioprotection et de Surete Nucleaire, Fontenay-aux-Roses (France); Billiard, Fabienne; Benderitter, Marc [Institut de Radioprotection et de Surete Nucleaire, Fontenay-aux-Roses (France)

    2012-09-01

    Purpose: Changes in the Th1/Th2 immune balance may play a role in increasing the incidence of radiation-induced toxicity. This study evaluates the consequences of Th1 deficiency on intestinal response (fibrosis and T cell trafficking) to abdominal irradiation and examines in mucosa and mesenteric lymph nodes (MLN) the differential involvement of the two Th1 pathways, T-bet/STAT1 and IL-12/STAT4, in controlling this balance in mice. Methods and Materials: Using T-bet-deficient mice (T-bet{sup -/-}), we evaluated the mRNA and protein expression of the Th1 pathways (IFN-{gamma}, T-bet/STAT1, and IL-12/STAT4) and the CD4{sup +} and CD8{sup +} populations in ileal mucosa and MLN during the first 3 months after 10 Gy abdominal irradiation. Results: The T-bet-deficient mice showed an increased fibrotic response to radiation, characterized by higher TGF-{beta}1, col3a1 expression, and collagen deposition in mucosa compared with wild-type mice. This response was associated with drastically lower expression of IFN-{gamma}, the hallmark Th1 cytokine. Analysis of the Th1 expression pathways, T-bet/STAT1 and IL-12/STAT4, showed their equal involvement in the failure of Th1 polarization. A minimal IFN-{gamma} level depended on the IL-23-p19/STAT4 level. In addition, the radiation-induced deficiency in the priming of Th1 by IFN-{gamma} was related to the defective homing capacity of CD8{sup +} cells in the mucosa. Conclusion: Irradiation induces Th2 polarization, and the Th2 immune response may play a role in potentiating irradiation-induced intestinal collagen deposition.

  14. Splice variants and regulatory networks associated with host resistance to the intestinal worm Cooperia oncophora in cattle.

    Science.gov (United States)

    Li, Robert W; Wu, Sitao; Li, Cong-Jun; Li, Weizhong; Schroeder, Steven G

    2015-07-30

    To elucidate the molecular mechanism of host resistance, we characterized the jejunal transcriptome of Angus cattle selected for parasite resistance for over 20 years in response to infection caused by the intestinal worm Cooperia oncophora. The transcript abundance of 56 genes, such as that of mucin 12 (MUC12) and intestinal alkaline phosphatase (ALPI), was significantly higher in resistant cattle. Novel splicing variants, exon skipping events, and gene fusion events, were also detected. An algorithm for the reconstruction of accurate cellular networks (ARACNE) was used to infer de novo regulatory molecular networks in the interactome between the parasite and host. Under a combined cutoff of an error tolerance (ϵ = 0.10) and a stringent P-value threshold of mutual information (1.0 × 10(-5)), a total of 229,100 direct interactions controlled by 20,288 hub genes were identified. Among these hub genes, 7651 genes had ≥ 100 direct neighbors while the top 9778 hub genes controlled more than 50% of total direct interactions. Three lysozyme genes (LYZ1, LYZ2, and LYZ3), which are co-located in bovine chromosome 5 in tandem and are strongly upregulated in resistant cattle, shared a common regulatory network of 55 genes. These ancient antimicrobials were likely involved in regulating host-parasite interactions by affecting host gut microbiome. Notably, ALPI, known as a gut mucosal defense factor, controlled a molecular network consisting 410 genes, including 14 transcription factors (TF) and 10 genes that were significantly regulated in resistant cattle. Several large regulatory networks were controlled by TF, such as STAT6, SREBF1, and ELF4. Gene ontology (GO) processes significantly enriched in the regulatory network controlled by STAT6 included lipid metabolism. Our findings provide insights into the immune regulation of host-parasite interactions and the molecular mechanisms of host resistance in cattle. Published by Elsevier B.V.

  15. Ecotoxicoparasitology: Understanding mercury concentrations in gut contents, intestinal helminths and host tissues of Alaskan gray wolves (Canis lupus)

    Energy Technology Data Exchange (ETDEWEB)

    McGrew, Ashley K. [Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523-1619 (United States); O' Hara, Todd M. [Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523-1619 (United States); Wildlife Toxicology Laboratory, Department of Veterinary Medicine, University of Alaska Fairbanks, Fairbanks, AK 99775 (United States); Stricker, Craig A. [U. S. Geological Survey, Fort Collins Science Center, Denver, CO 80225 (United States); Margaret Castellini, J. [Wildlife Toxicology Laboratory, Department of Veterinary Medicine, University of Alaska Fairbanks, Fairbanks, AK 99775 (United States); Beckmen, Kimberlee B. [Alaska Department of Fish & Game, Fairbanks, AK (United States); Salman, Mo D. [Animal Population Health Institute, Department of Clinical Sciences, Colorado State University, Fort Collins, CO 80523-1644 (United States); Ballweber, Lora R. [Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523-1619 (United States)

    2015-12-01

    Some gastrointestinal helminths acquire nutrients from the lumen contents in which they live; thus, they may be exposed to non-essential elements, such as mercury (Hg), during feeding. The objectives of this study were: 1) determine the total mercury concentrations ([THg]) in Gray wolves (Canis lupus) and their parasites, and 2) use stable isotopes to evaluate the trophic relationships within the host. [THg] and stable isotopes (C and N) were determined for helminths, host tissues, and lumen contents from 88 wolves. Sixty-three wolves contained grossly visible helminths (71.5%). The prevalence of taeniids and ascarids was 63.6% (56/88) and 20.5% (18/88), respectively. Nine of these 63 wolves contained both taeniids and ascarids (14.3%). All ascarids were determined to be Toxascaris leonina. Taenia species present included T. krabbei and T. hydatigena. Within the GI tract, [THg] in the lumen contents of the proximal small intestine were significantly lower than in the distal small intestine. There was a significant positive association between hepatic and taeniid [THg]. Bioaccumulation factors (BAF) ranged from < 1 to 22.9 in taeniids, and 1.1 to 12.3 in T. leonina. Taeniid and ascarid BAF were significantly higher than 1, suggesting that both groups are capable of THg accumulation in their wolf host. δ{sup 13}C in taeniids was significantly lower than in host liver and skeletal muscle. [THg] in helminths and host tissues, in conjunction with stable isotope (C and N) values, provides insight into food-web dynamics of the host GI tract, and aids in elucidating ecotoxicoparasitologic relationships. Variation of [THg] throughout the GI tract, and between parasitic groups, underscores the need to further evaluate the effect(s) of feeding niche, and the nutritional needs of parasites, as they relate to toxicant exposure and distribution within the host. - Highlights: • [THg] and stable isotopes together provide insight on host-parasite-Hg interactions. • A

  16. Acanthamoeba spp. as a universal host for pathogenic microorganisms: One bridge from environment to host virulence.

    Science.gov (United States)

    Guimaraes, Allan J; Gomes, Kamilla Xavier; Cortines, Juliana Reis; Peralta, José Mauro; Peralta, Regina H Saramago

    2016-12-01

    Free-living amoebas (FLA) are ubiquitous environmental protists that have enormously contributed to the microbiological contamination of water sources. FLAs have displayed resistance to environmental adversities and germicides and have played important roles in the population control of microbial communities due to its predatory behavior and microbicidal activity. However, some organisms have developed resistance to the intracellular milieu of amoebas, as in the case of Acanthamoebas, which in turn, have been functioning as excellent reservoirs for amoeba-resistant microorganisms (ARMs), such as bacteria, viruses and fungi. Little is known about these relationships and interaction mechanisms, but it is speculated that the FLAs need a very broad repertoire or universal class of receptors to bind and recognize these diverse species of microorganisms. By harboring these organisms as a "Trojan Horse", the Achantamoeba has been working as an excellent vector for pathogens. Moreover, studies have demonstrated that the interaction of pathogens with Acanthamoeba results in environmental selective pressure responsible for induction and maintenance of virulence factors and increase in microbial pathogenicity. This phenomenon is correlated to the observation of higher gene number and DNA content of ARMs, when compared to their relatives which are adapted to other hosts, due to allopatric or sympatric gene transfer and acquisition, contradicting the overall genome reduction theory for intracellularly adapted pathogens. Thus, adaptation to FLAs indirectly provided a "learning" environment for pathogens to resist later to macrophages; besides the evolutionary distance, these phagocytes share similar predatory mechanisms, such as phagocytosis and phagolysossomal degradation. In this mini-review, we cover the most important aspects of Acanthamoeba biology and their interactions with endemically important human pathogens. Copyright © 2016 Elsevier GmbH. All rights reserved.

  17. Messages from the inside. The dynamic environment that favors intestinal homeostasis

    Directory of Open Access Journals (Sweden)

    Marcello eChieppa

    2013-10-01

    Full Text Available An organism is defined as an individual living thing capable of responding to stimuli, growing, reproducing, and maintaining homeostasis. Early during evolution multicellular organisms explored the advantages of a symbiotic life. Mammals harbor a complex aggregate of microorganisms (called microbiota that includes bacteria, fungi and archaea. Some of these bacteria have already defined beneficial roles for the human host that include the ability to break-down nutrients that could not otherwise be digested, preventing the growth of harmful species, as well as the ability to produce vitamins or hormones. It is intuitive that along the evolutionary path several mechanisms favored bacteria that provided advantages to the host which, in return, avoided launching an aggressive immunological response against them. The intestinal immunological response does not ignore the lumenal content, on the contrary, immune surveillance is favored by continuous antigen sampling. Some intestinal epithelial cells are crucial during the sampling process, others actively participate in the defense mechanism. In essence the epithelium acts as a traffic light, communicating to the inside world whether conditions are safe or dangerous, and thus influencing immunological response. In this review we will discuss the dynamic factors that act on the intestinal epithelial cells and how they directly or indirectly influence immune cells during states of health and disease.

  18. Magnetic resonance enterography for assessment of intestinal graft-versus-host disease after allogeneic stem cell transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Derlin, Thorsten [University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Hanover Medical School, Department of Nuclear Medicine, Hanover (Germany); Laqmani, Azien; Adam, Gerhard; Bannas, Peter [University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Veldhoen, Simon [University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); University Medical Center Wuerzburg, Department of Diagnostic and Interventional Radiology, Wuerzburg (Germany); Apostolova, Ivayla [Otto-von-Guericke University, Department of Radiology and Nuclear Medicine, Magdeburg (Germany); Ayuk, Francis; Kroeger, Nicolaus [University Medical Center Hamburg-Eppendorf, Department of Stem Cell Transplantation, Hamburg (Germany)

    2015-05-01

    To determine the diagnostic performance of MR enterography (MRE) for detection and grading of gastrointestinal graft-versus-host disease (GI GvHD) after hematopoietic stem cell transplantation (SCT). Forty-one patients with known GvHD or suspected GvHD underwent MRE and GI endoscopy with multi-level biopsies. MRE images were reviewed for presence of intestinal wall inflammation. Clinical grading of GI GvHD was performed. Histopathological evaluation (HPE) served as the reference standard. Overall, MRE demonstrated a per-patient sensitivity of 81.5 % for detection of GI GvHD. The most common findings were intestinal wall thickening (81.5 % of GvHD patients), luminal stenosis (81.5 %), mural contrast enhancement (70.4 %), and ascites (59.3 %). These findings were also observed in other conditions than GvHD. The most frequently involved intestinal segment was the sigmoid colon (63.0 %), followed by the ileum (59.3 %) and the jejeunum (51.9 %). The number of involved segments (r{sub s} =0.54, p =0.009) correlated significantly with clinical severity as determined by GvHD grading. After allogeneic stem cell transplantation, MRE may (1) contribute to detection and localization of GI GvHD, and (2) add information indicating the clinical severity of disease, but findings are unspecific. False negative results may be observed not only in low-grade GI GvHD. (orig.)

  19. The host, the parasite and their environment : how parasitism and environmental variation can maintain host genetic diversity

    NARCIS (Netherlands)

    Gsell, A.S.

    2013-01-01

    Host and parasite populations live in highly variable natural environments. This thesis explores how the population dynamics and genetic population structure of an important spring-bloom phytoplankton species, the diatom Asterionella formosa, are affected by such environmental variation and by

  20. Host galaxies and environments of compact extragalactic radio sources

    NARCIS (Netherlands)

    Labiano Ortega, Alvaro

    2006-01-01

    The main goal of this thesis is to study the interrelation of powerful radio sources with their hosts. The objects of study are GPS and CSS sources. Due to their small size, GPS/CSS sources are excellent probes of this relation. Furthermore, their young age allows us to compare them to the larger,

  1. Studies of archaeal virus-host systems in thermal environments

    DEFF Research Database (Denmark)

    Erdmann, Susanne

    features. Most of the isolated archaeal viruses infecting members of the Crenarchaeota have been characterized regarding their genome, the structure of their virions and their influence on the host viability. Only a few, SIRV a rod-shaped and STIV an icosahedrical virus, have been subjected to more...

  2. Identification of differentially expressed genes of Trichinella spiralis larvae after exposure to host intestine milieu.

    Directory of Open Access Journals (Sweden)

    Hui Jun Ren

    Full Text Available Although it has been known for many years that T. spiralis muscle larvae (ML can not invade intestinal epithelial cells unless they are exposed to the intestinal milieu and activated into intestinal infective larvae (IIL, which genes in IIL are involved in the process of invasion is still unknown. In this study, suppression subtractive hybridization (SSH was performed to identify differentially expressed genes between IIL and ML. SSH library was constructed using cDNA generated from IIL as the 'tester'. About 110 positive clones were randomly selected from the library and sequenced, of which 33 T. spiralis genes were identified. Thirty encoded proteins were annotated according to Gene Ontology Annotation in terms of molecular function, biological process, and cellular localization. Out of 30 annotated proteins, 16 proteins (53.3% had binding activity and 12 proteins (40.0% had catalytic activity. The results of real-time PCR showed that the expression of nine genes (Ts7, Ndr family protein; Ts8, serine/threonine-protein kinase polo; Ts11, proteasome subunit beta type-7; Ts17, nudix hydrolase; Ts19, ovochymase-1; Ts22, fibronectin type III domain protein; Ts23, muscle cell intermediate filament protein OV71; Ts26, neutral and basic amino acid transport protein rBAT and Ts33, FACT complex subunit SPT16 from 33 T. spiralis genes in IIL were up-regulated compared with that of ML. The present study provide a group of the potential invasion-related candidate genes and will be helpful for further studies of mechanisms by which T. spiralis infective larvae recognize and invade the intestinal epithelial cells.

  3. The role of diet on intestinal microbiota metabolism: downstream impacts on host immune function and health, and therapeutic implications.

    Science.gov (United States)

    Goldsmith, Jason R; Sartor, R Balfour

    2014-05-01

    Dietary impacts on health may be one of the oldest concepts in medicine; however, only in recent years have technical advances in mass spectroscopy, gnotobiology, and bacterial sequencing enabled our understanding of human physiology to progress to the point where we can begin to understand how individual dietary components can affect specific illnesses. This review explores the current understanding of the complex interplay between dietary factors and the host microbiome, concentrating on the downstream implications on host immune function and the pathogenesis of disease. We discuss the influence of the gut microbiome on body habitus and explore the primary and secondary effects of diet on enteric microbial community structure. We address the impact of consumption of non-digestible polysaccharides (prebiotics and fiber), choline, carnitine, iron, and fats on host health as mediated by the enteric microbiome. Disease processes emphasized include non-alcoholic fatty liver disease/non-alcoholic steatohepatitis, IBD, and cardiovascular disease/atherosclerosis. The concepts presented in this review have important clinical implications, although more work needs to be done to develop fully and validate potential therapeutic approaches. Specific dietary interventions offer exciting potential for nontoxic, physiologic ways to alter enteric microbial structure and metabolism to benefit the natural history of many intestinal and systemic disorders.

  4. Impact of Enterobius vermicularis infection and mebendazole treatment on intestinal microbiota and host immune response.

    Directory of Open Access Journals (Sweden)

    Chin-An Yang

    2017-09-01

    Full Text Available Previous studies on the association of enterobiasis and chronic inflammatory diseases have revealed contradictory results. The interaction of Enterobius vermicularis infection in particular with gut microbiota and induced immune responses has never been thoroughly examined.In order to answer the question of whether exposure to pinworm and mebendazole can shift the intestinal microbial composition and immune responses, we recruited 109 (30 pinworm-negative, 79 pinworm-infected first and fourth grade primary school children in Taichung, Taiwan, for a gut microbiome study and an intestinal cytokine and SIgA analysis. In the pinworm-infected individuals, fecal samples were collected again at 2 weeks after administration of 100 mg mebendazole. Gut microbiota diversity increased after Enterobius infection, and it peaked after administration of mebendazole. At the phylum level, pinworm infection and mebendazole deworming were associated with a decreased relative abundance of Fusobacteria and an increased proportion of Actinobacteria. At the genus level, the relative abundance of the probiotic Bifidobacterium increased after enterobiasis and mebendazole treatment. The intestinal SIgA level was found to be lower in the pinworm-infected group, and was elevated in half of the mebendazole-treated group. A higher proportion of pre-treatment Salmonella spp. was associated with a non-increase in SIgA after mebendazole deworming treatment.Childhood exposure to pinworm plus mebendazole is associated with increased bacterial diversity, an increased abundance of Actinobacteria including the probiotic Bifidobacterium, and a decreased proportion of Fusobacteria. The gut SIgA level was lower in the pinworm-infected group, and was increased in half of the individuals after mebendazole deworming treatment.

  5. Impact of Enterobius vermicularis infection and mebendazole treatment on intestinal microbiota and host immune response.

    Science.gov (United States)

    Yang, Chin-An; Liang, Chao; Lin, Chia-Li; Hsiao, Chiung-Tzu; Peng, Ching-Tien; Lin, Hung-Chih; Chang, Jan-Gowth

    2017-09-01

    Previous studies on the association of enterobiasis and chronic inflammatory diseases have revealed contradictory results. The interaction of Enterobius vermicularis infection in particular with gut microbiota and induced immune responses has never been thoroughly examined. In order to answer the question of whether exposure to pinworm and mebendazole can shift the intestinal microbial composition and immune responses, we recruited 109 (30 pinworm-negative, 79 pinworm-infected) first and fourth grade primary school children in Taichung, Taiwan, for a gut microbiome study and an intestinal cytokine and SIgA analysis. In the pinworm-infected individuals, fecal samples were collected again at 2 weeks after administration of 100 mg mebendazole. Gut microbiota diversity increased after Enterobius infection, and it peaked after administration of mebendazole. At the phylum level, pinworm infection and mebendazole deworming were associated with a decreased relative abundance of Fusobacteria and an increased proportion of Actinobacteria. At the genus level, the relative abundance of the probiotic Bifidobacterium increased after enterobiasis and mebendazole treatment. The intestinal SIgA level was found to be lower in the pinworm-infected group, and was elevated in half of the mebendazole-treated group. A higher proportion of pre-treatment Salmonella spp. was associated with a non-increase in SIgA after mebendazole deworming treatment. Childhood exposure to pinworm plus mebendazole is associated with increased bacterial diversity, an increased abundance of Actinobacteria including the probiotic Bifidobacterium, and a decreased proportion of Fusobacteria. The gut SIgA level was lower in the pinworm-infected group, and was increased in half of the individuals after mebendazole deworming treatment.

  6. Host cell-induced signaling causes Clostridium perfringens to upregulate production of toxins important for intestinal infections

    Science.gov (United States)

    Chen, Jianming; Ma, Menglin; Uzal, Francisco A; McClane, Bruce A

    2014-01-01

    Clostridium perfringens causes enteritis and enterotoxemia in humans and livestock due to prolific toxin production. In broth culture, C. perfringens uses the Agr-like quorum sensing (QS) system to regulate production of toxins important for enteritis/enterotoxemia, including beta toxin (CPB), enterotoxin, and epsilon toxin (ETX). The VirS/VirR two-component regulatory system (TCRS) also controls CPB production in broth cultures. Both the Agr-like QS and VirS/VirR systems are important when C. perfringens senses enterocyte-like Caco-2 cells and responds by upregulating CPB production; however, only the Agr-like QS system is needed for host cell-induced ETX production. These in vitro observations have pathophysiologic relevance since both the VirS/VirR and Agr-like QS signaling systems are required for C. perfringens strain CN3685 to produce CPB in vivo and to cause enteritis or enterotoxemia. Thus, apparently upon sensing its presence in the intestines, C. perfringens utilizes QS and TCRS signaling to produce toxins necessary for intestinal virulence. PMID:24061146

  7. The influence of host genotype X environment Interactions on the ...

    African Journals Online (AJOL)

    1993, 1993-1994 and 1994-1995) in three agro-ecological zones in Nigeria to study their reaction to cassava anthracnose disease (CAD), caused by Colletotrichum gloeosporioides, investigate genotype x environment (G x E) interaction ...

  8. Occurrence, diversity, and host association of intestinal Campylobacter, Arcobacter, and Helicobacter in reptiles

    NARCIS (Netherlands)

    Gilbert, Maarten J; Kik, Marja; Timmerman, Arjen J; Severs, Tim T; Kusters, Johannes G; Duim, Birgitta; Wagenaar, Jaap A

    2014-01-01

    Campylobacter, Arcobacter, and Helicobacter species have been isolated from many vertebrate hosts, including birds, mammals, and reptiles. Multiple studies have focused on the prevalence of these Epsilonproteobacteria genera in avian and mammalian species. However, little focus has been given to the

  9. Mucin utilisation and host interactions of the novel intestinal microbe Akkermansia muciniphila

    NARCIS (Netherlands)

    Derrien, M.M.N.

    2007-01-01

    Keywords .Mucin, A. muciniphila , mucin degradation, molecular techniques, host responseMucins are the major organic components of the defence barrier, known as mucus, covering epithelial cells in many organs, including the entire gastrointestinal (GI)

  10. The Ultraviolet Radiation Environment around M Dwarf Exoplanet Host Stars

    Science.gov (United States)

    France, Kevin; Froning, Cynthia S.; Linsky, Jeffrey L.; Roberge, Aki; Stocke, John T.; Tian, Feng; Bushinsky, Rachel; Desert, Jean-Michel; Mauas, Pablo; Mauas, Pablo; hide

    2013-01-01

    The spectral and temporal behavior of exoplanet host stars is a critical input to models of the chemistry and evolution of planetary atmospheres. Ultraviolet photons influence the atmospheric temperature profiles and production of potential biomarkers on Earth-like planets around these stars. At present, little observational or theoretical basis exists for understanding the ultraviolet spectra of M dwarfs, despite their critical importance to predicting and interpreting the spectra of potentially habitable planets as they are obtained in the coming decades. Using observations from the Hubble Space Telescope, we present a study of the UV radiation fields around nearby M dwarf planet hosts that covers both far-UV (FUV) and near-UV (NUV) wavelengths. The combined FUV+NUV spectra are publicly available in machine-readable format. We find that all six exoplanet host stars in our sample (GJ 581, GJ 876, GJ 436, GJ 832, GJ 667C, and GJ 1214) exhibit some level of chromospheric and transition region UV emission. No "UV-quiet" M dwarfs are observed. The bright stellar Lyman-alpha emission lines are reconstructed, and we find that the Lyman-alpha line fluxes comprise approximately 37%-75% of the total 1150-3100 A flux from most M dwarfs; approximately greater than 10(exp3) times the solar value. We develop an empirical scaling relation between Lyman-alpha and Mg II emission, to be used when interstellar H I attenuation precludes the direct observation of Lyman-alpha. The intrinsic unreddened flux ratio is F(Lyman-alpha)/F(Mg II) = 10(exp3). The F(FUV)/F(NUV) flux ratio, a driver for abiotic production of the suggested biomarkers O2 and O3, is shown to be approximately 0.5-3 for all M dwarfs in our sample, greather than 10(exp3) times the solar ratio. For the four stars with moderate signal-to-noise Cosmic Origins Spectrograph time-resolved spectra, we find UV emission line variability with amplitudes of 50%.500% on 10(exp2)-10(exp3) s timescales. This effect should be taken

  11. Induction of proliferative and destructive graft-versus-host reactions in the small intestine

    Energy Technology Data Exchange (ETDEWEB)

    Felstein, M.V.; Mowat, A.M.

    1987-01-01

    We have used the intestinal phase of a GvHR to investigate the immunological basis of enteropathies associated with CMI. The nature of the damage depends on the model of GvHR used. Adult unirradiated (CBAxBALB/cF1) mice with GvHR developed an entirely proliferative enteropathy characterized by crypt hyperplasia, increased numbers of IEL and enhanced NK cell activity, but there was no villus atrophy or CTL. Although neonatal or irradiated adult (CBAxBALB/c)F1 mice with GvHR developed a destructive enteropathy with marked villus atrophy and CTL activity, this also required an early proliferative phase identical to that found in unirradiated adult mice. Thus, we propose that proliferative enteropathy in GvHR is due to soluble mediators released by a local DTH reaction but that villus atrophy also requires activation of a further population of effector cells, which may be CTL or suppressor T cells.

  12. Immunocompetent host develops mild intestinal inflammation in acute infection with Toxoplasma gondii.

    Directory of Open Access Journals (Sweden)

    Paulo da Silva Watanabe

    Full Text Available Toxoplasma gondii (T. gondii is the causative agent of toxoplasmosis, common zoonosis among vertebrates and high incidence worldwide. During the infection, the parasite needs to transpose the intestinal barrier to spread throughout the body, which may be a trigger for an inflammatory reaction. This work evaluated the inflammatory alterations of early T. gondii infection in peripheral blood cells, in the mesenteric microcirculation, and small intestinal tissue by measurement of MPO (myeloperoxidase activity and NO (nitric oxide level in rats. Animals were randomly assigned into control group (CG that received saline orally and groups infected with 5,000 oocysts for 6 (G6, 12 (G12, 24 (G24, 48 (G48 and 72 hours (G72. Blood samples were collected for total and differential leukocyte count. Intravital microscopy was performed in the mesentery to evaluate rolling and adhesion of leukocytes. After euthanasia, 0.5cm of the duodenum, jejunum and ileum were collected for the determination of MPO activity, NO level and PCR to identify the parasite DNA and also the mesentery were collected to perform immunohistochemistry on frozen sections to quantify adhesion molecules ICAM-1, PECAM-1 and P-Selectin. The parasite DNA was identified in all infected groups and there was an increase in leukocytes in the peripheral blood and in expression of ICAM-1 and PECAM-1 in G6 and G12, however, the expression of P-selectin was reduced in G12. Leukocytes are in rolling process during the first 12 hours and they are adhered at 24 hours post-infection. The activity of MPO increased in the duodenum at 12 hours, and NO increased in the jejunum in G72 and ileum in G24, G48 and G72. Our study demonstrated that T. gondii initiates the infection precociously (at 6 hours leading to a systemic activation of innate immune response resulting in mild inflammation in a less susceptible experimental model.

  13. Immunocompetent host develops mild intestinal inflammation in acute infection with Toxoplasma gondii.

    Science.gov (United States)

    Watanabe, Paulo da Silva; Trevizan, Aline Rosa; Silva-Filho, Saulo Euclides; Góis, Marcelo Biondaro; Garcia, João Luiz; Cuman, Roberto Kenji Nakamura; Breithaupt-Faloppa, Ana Cristina; Sant Ana, Débora de Mello Gonçales; Nogueira de Melo, Gessilda de Alcantara

    2018-01-01

    Toxoplasma gondii (T. gondii) is the causative agent of toxoplasmosis, common zoonosis among vertebrates and high incidence worldwide. During the infection, the parasite needs to transpose the intestinal barrier to spread throughout the body, which may be a trigger for an inflammatory reaction. This work evaluated the inflammatory alterations of early T. gondii infection in peripheral blood cells, in the mesenteric microcirculation, and small intestinal tissue by measurement of MPO (myeloperoxidase) activity and NO (nitric oxide) level in rats. Animals were randomly assigned into control group (CG) that received saline orally and groups infected with 5,000 oocysts for 6 (G6), 12 (G12), 24 (G24), 48 (G48) and 72 hours (G72). Blood samples were collected for total and differential leukocyte count. Intravital microscopy was performed in the mesentery to evaluate rolling and adhesion of leukocytes. After euthanasia, 0.5cm of the duodenum, jejunum and ileum were collected for the determination of MPO activity, NO level and PCR to identify the parasite DNA and also the mesentery were collected to perform immunohistochemistry on frozen sections to quantify adhesion molecules ICAM-1, PECAM-1 and P-Selectin. The parasite DNA was identified in all infected groups and there was an increase in leukocytes in the peripheral blood and in expression of ICAM-1 and PECAM-1 in G6 and G12, however, the expression of P-selectin was reduced in G12. Leukocytes are in rolling process during the first 12 hours and they are adhered at 24 hours post-infection. The activity of MPO increased in the duodenum at 12 hours, and NO increased in the jejunum in G72 and ileum in G24, G48 and G72. Our study demonstrated that T. gondii initiates the infection precociously (at 6 hours) leading to a systemic activation of innate immune response resulting in mild inflammation in a less susceptible experimental model.

  14. Using PVM to host CLIPS in distributed environments

    Science.gov (United States)

    Myers, Leonard; Pohl, Kym

    1994-01-01

    It is relatively easy to enhance CLIPS (C Language Integrated Production System) to support multiple expert systems running in a distributed environment with heterogeneous machines. The task is minimized by using the PVM (Parallel Virtual Machine) code from Oak Ridge Labs to provide the distributed utility. PVM is a library of C and FORTRAN subprograms that supports distributive computing on many different UNIX platforms. A PVM deamon is easily installed on each CPU that enters the virtual machine environment. Any user with rsh or rexec access to a machine can use the one PVM deamon to obtain a generous set of distributed facilities. The ready availability of both CLIPS and PVM makes the combination of software particularly attractive for budget conscious experimentation of heterogeneous distributive computing with multiple CLIPS executables. This paper presents a design that is sufficient to provide essential message passing functions in CLIPS and enable the full range of PVM facilities.

  15. Intestinal fucose as a mediator of host-microbe symbiosis1

    Science.gov (United States)

    Pickard, Joseph M.; Chervonsky, Alexander V.

    2015-01-01

    Fucose is an L-configuration sugar found abundantly in the mammalian gut. It has long been known to be induced there by the presence of bacteria, but only recently have some of the molecular mechanisms behind this process been uncovered. New work suggests that fucose can have a protective role in both gut-centered and systemic infection and inflammation. This review highlights recent studies showing that in addition to acting as a food source for beneficial gut symbionts, host fucose can also suppress the virulence of pathogens and pathobionts. The relevance of gut fucosylation to human diseases will also be discussed. PMID:26048966

  16. The salmonella transcriptome in lettuce and cilantro soft rot reveals a niche overlap with the animal host intestine.

    Science.gov (United States)

    Goudeau, Danielle M; Parker, Craig T; Zhou, Yaguang; Sela, Shlomo; Kroupitski, Yulia; Brandl, Maria T

    2013-01-01

    Fresh vegetables have been recurrently associated with salmonellosis outbreaks, and Salmonella contamination of retail produce has been correlated positively with the presence of soft rot disease. We observed that population sizes of Salmonella enterica serovar Typhimurium SL1344 increased 56-fold when inoculated alone onto cilantro leaves, versus 2,884-fold when coinoculated with Dickeya dadantii, a prevalent pathogen that macerates plant tissue. A similar trend in S. enterica populations was observed for soft-rotted lettuce leaves. Transcriptome analysis of S. enterica cells that colonized D. dadantii-infected lettuce and cilantro leaves revealed a clear shift toward anaerobic metabolism and catabolism of substrates that are available due to the degradation of plant cells by the pectinolytic pathogen. Twenty-nine percent of the genes that were upregulated in cilantro macerates were also previously observed to have increased expression levels in the chicken intestine. Furthermore, multiple genes induced in soft rot lesions are also involved in the colonization of mouse, pig, and bovine models of host infection. Among those genes, the operons for ethanolamine and propanediol utilization as well as for the synthesis of cobalamin, a cofactor in these pathways, were the most highly upregulated genes in lettuce and cilantro lesions. In S. Typhimurium strain LT2, population sizes of mutants deficient in propanediol utilization or cobalamin synthesis were 10- and 3-fold lower, respectively, than those of the wild-type strain in macerated cilantro (P < 0.0002); in strain SL1344, such mutants behaved similarly to the parental strain. Anaerobic conditions and the utilization of nutrients in macerated plant tissue that are also present in the animal intestine indicate a niche overlap that may explain the high level of adaptation of S. enterica to soft rot lesions, a common postharvest plant disease.

  17. Large-scale determinants of intestinal schistosomiasis and intermediate host snail distribution across Africa

    DEFF Research Database (Denmark)

    Stensgaard, Anna-Sofie; Utzinger, Jürg; Vounatsou, Penelope

    2013-01-01

    to climate change. Here, we combine a growing degree day model for Schistosoma mansoni with species distribution models for the intermediate host snail (Biomphalaria spp.) to investigate large-scale environmental determinants of the distribution of the African S. mansoni-Biomphalaria system and potential...... impacts of climatic changes. Snail species distribution models included several combinations of climatic and habitat-related predictors; the latter divided into "natural" and "human-impacted" habitat variables to measure anthropogenic influence. The predictive performance of the combined snail......-parasite model was evaluated against a comprehensive compilation of historical S. mansoni parasitological survey records, and then examined for two climate change scenarios of increasing severity for 2080. Future projections indicate that while the potential S. mansoni transmission area expands, the snail ranges...

  18. Human Breast Milk and Infant Formulas Differentially Modify the Intestinal Microbiota in Human Infants and Host Physiology in Rats.

    Science.gov (United States)

    Liu, Zhenmin; Roy, Nicole C; Guo, Yanhong; Jia, Hongxin; Ryan, Leigh; Samuelsson, Linda; Thomas, Ancy; Plowman, Jeff; Clerens, Stefan; Day, Li; Young, Wayne

    2016-02-01

    In the absence of human breast milk, infant and follow-on formulas can still promote efficient growth and development. However, infant formulas can differ in their nutritional value. The objective of this study was to compare the effects of human milk (HM) and infant formulas in human infants and a weanling rat model. In a 3 wk clinical randomized controlled trial, babies (7- to 90-d-old, male-to-female ratio 1:1) were exclusively breastfed (BF), exclusively fed Synlait Pure Canterbury Stage 1 infant formula (SPCF), or fed assorted standard formulas (SFs) purchased by their parents. We also compared feeding HM or SPCF in weanling male Sprague-Dawley rats for 28 d. We examined the effects of HM and infant formulas on fecal short chain fatty acids (SCFAs) and bacterial composition in human infants, and intestinal SCFAs, the microbiota, and host physiology in weanling rats. Fecal Bifidobacterium concentrations (mean log copy number ± SEM) were higher (P = 0.003) in BF (8.17 ± 0.3) and SPCF-fed infants (8.29 ± 0.3) compared with those fed the SFs (6.94 ± 0.3). Fecal acetic acid (mean ± SEM) was also higher (P = 0.007) in the BF (5.5 ± 0.2 mg/g) and SPCF (5.3 ± 2.4 mg/g) groups compared with SF-fed babies (4.3 ± 0.2 mg/g). Colonic SCFAs did not differ between HM- and SPCF-fed rats. However, cecal acetic acid concentrations were higher (P = 0.001) in rats fed HM (42.6 ± 2.6 mg/g) than in those fed SPCF (30.6 ± 0.8 mg/g). Cecal transcriptome, proteome, and plasma metabolite analyses indicated that the growth and maturation of intestinal tissue was more highly promoted by HM than SPCF. Fecal bacterial composition and SCFA concentrations were similar in babies fed SPCF or HM. However, results from the rat study showed substantial differences in host physiology between rats fed HM and SPCF. This trial was registered at Shanghai Jiào tong University School of Medicine as XHEC-C-2012-024. © 2016 American Society for Nutrition.

  19. Loss of competition in the outside host environment generates outbreaks of environmental opportunist pathogens.

    Science.gov (United States)

    Anttila, Jani; Ruokolainen, Lasse; Kaitala, Veijo; Laakso, Jouni

    2013-01-01

    Environmentally transmitted pathogens face ecological interactions (e.g., competition, predation, parasitism) in the outside-host environment and host immune system during infection. Despite the ubiquitousness of environmental opportunist pathogens, traditional epidemiology focuses on obligatory pathogens incapable of environmental growth. Here we ask how competitive interactions in the outside-host environment affect the dynamics of an opportunist pathogen. We present a model coupling the classical SI and Lotka-Volterra competition models. In this model we compare a linear infectivity response and a sigmoidal infectivity response. An important assumption is that pathogen virulence is traded off with competitive ability in the environment. Removing this trade-off easily results in host extinction. The sigmoidal response is associated with catastrophic appearances of disease outbreaks when outside-host species richness, or overall competition pressure, decreases. This indicates that alleviating outside-host competition with antibacterial substances that also target the competitors can have unexpected outcomes by providing benefits for opportunist pathogens. These findings may help in developing alternative ways of controlling environmental opportunist pathogens.

  20. Control strategies for a stochastic model of host-parasite interaction in a seasonal environment.

    Science.gov (United States)

    Gómez-Corral, A; López García, M

    2014-08-07

    We examine a nonlinear stochastic model for the parasite load of a single host over a predetermined time interval. We use nonhomogeneous Poisson processes to model the acquisition of parasites, the parasite-induced host mortality, the natural (no parasite-induced) host mortality, and the reproduction and death of parasites within the host. Algebraic results are first obtained on the age-dependent distribution of the number of parasites infesting the host at an arbitrary time t. The interest is in control strategies based on isolation of the host and the use of an anthelmintic at a certain intervention instant t0. This means that the host is free living in a seasonal environment, and it is transferred to a uninfected area at age t0. In the uninfected area, the host does not acquire new parasites, undergoes a treatment to decrease the parasite load, and its natural and parasite-induced mortality are altered. For a suitable selection of t0, we present two control criteria that appropriately balance effectiveness and cost of intervention. Our approach is based on simple probabilistic principles, and it allows us to examine seasonal fluctuations of gastrointestinal nematode burden in growing lambs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Designing of peptides with desired half-life in intestine-like environment

    KAUST Repository

    Sharma, Arun

    2014-08-20

    Background: In past, a number of peptides have been reported to possess highly diverse properties ranging from cell penetrating, tumor homing, anticancer, anti-hypertensive, antiviral to antimicrobials. Owing to their excellent specificity, low-toxicity, rich chemical diversity and availability from natural sources, FDA has successfully approved a number of peptide-based drugs and several are in various stages of drug development. Though peptides are proven good drug candidates, their usage is still hindered mainly because of their high susceptibility towards proteases degradation. We have developed an in silico method to predict the half-life of peptides in intestine-like environment and to design better peptides having optimized physicochemical properties and half-life.Results: In this study, we have used 10mer (HL10) and 16mer (HL16) peptides dataset to develop prediction models for peptide half-life in intestine-like environment. First, SVM based models were developed on HL10 dataset which achieved maximum correlation R/R2 of 0.57/0.32, 0.68/0.46, and 0.69/0.47 using amino acid, dipeptide and tripeptide composition, respectively. Secondly, models developed on HL16 dataset showed maximum R/R2 of 0.91/0.82, 0.90/0.39, and 0.90/0.31 using amino acid, dipeptide and tripeptide composition, respectively. Furthermore, models that were developed on selected features, achieved a correlation (R) of 0.70 and 0.98 on HL10 and HL16 dataset, respectively. Preliminary analysis suggests the role of charged residue and amino acid size in peptide half-life/stability. Based on above models, we have developed a web server named HLP (Half Life Prediction), for predicting and designing peptides with desired half-life. The web server provides three facilities; i) half-life prediction, ii) physicochemical properties calculation and iii) designing mutant peptides.Conclusion: In summary, this study describes a web server \\'HLP\\' that has been developed for assisting scientific

  2. Mutation of the Enterohemorrhagic Escherichia coli Core LPS Biosynthesis Enzyme RfaD Confers Hypersusceptibility to Host Intestinal Innate Immunity In vivo.

    Science.gov (United States)

    Kuo, Cheng-Ju; Chen, Jenn-Wei; Chiu, Hao-Chieh; Teng, Ching-Hao; Hsu, Tai-I; Lu, Pei-Jung; Syu, Wan-Jr; Wang, Sin-Tian; Chou, Ting-Chen; Chen, Chang-Shi

    2016-01-01

    Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important foodborne pathogen causing severe diseases in humans worldwide. Currently, there is no specific treatment available for EHEC infection and the use of conventional antibiotics is contraindicated. Therefore, identification of potential therapeutic targets and development of effective measures to control and treat EHEC infection are needed. Lipopolysaccharides (LPS) are surface glycolipids found on the outer membrane of gram-negative bacteria, including EHEC, and LPS biosynthesis has long been considered as potential anti-bacterial target. Here, we demonstrated that the EHEC rfaD gene that functions in the biosynthesis of the LPS inner core is required for the intestinal colonization and pathogenesis of EHEC in vivo. Disruption of the EHEC rfaD confers attenuated toxicity in Caenorhabditis elegans and less bacterial colonization in the intestine of C. elegans and mouse. Moreover, rfaD is also involved in the control of susceptibility of EHEC to antimicrobial peptides and host intestinal immunity. It is worth noting that rfaD mutation did not interfere with the growth kinetics when compared to the wild-type EHEC cells. Taken together, we demonstrated that mutations of the EHEC rfaD confer hypersusceptibility to host intestinal innate immunity in vivo, and suggested that targeting the RfaD or the core LPS synthesis pathway may provide alternative therapeutic regimens for EHEC infection.

  3. Alteration of the Intestinal Environment by Lubiprostone Is Associated with Amelioration of Adenine-Induced CKD.

    Science.gov (United States)

    Mishima, Eikan; Fukuda, Shinji; Shima, Hisato; Hirayama, Akiyoshi; Akiyama, Yasutoshi; Takeuchi, Yoichi; Fukuda, Noriko N; Suzuki, Takehiro; Suzuki, Chitose; Yuri, Akinori; Kikuchi, Koichi; Tomioka, Yoshihisa; Ito, Sadayoshi; Soga, Tomoyoshi; Abe, Takaaki

    2015-08-01

    The accumulation of uremic toxins is involved in the progression of CKD. Various uremic toxins are derived from gut microbiota, and an imbalance of gut microbiota or dysbiosis is related to renal failure. However, the pathophysiologic mechanisms underlying the relationship between the gut microbiota and renal failure are still obscure. Using an adenine-induced renal failure mouse model, we evaluated the effects of the ClC-2 chloride channel activator lubiprostone (commonly used for the treatment of constipation) on CKD. Oral administration of lubiprostone (500 µg/kg per day) changed the fecal and intestinal properties in mice with renal failure. Additionally, lubiprostone treatment reduced the elevated BUN and protected against tubulointerstitial damage, renal fibrosis, and inflammation. Gut microbiome analysis of 16S rRNA genes in the renal failure mice showed that lubiprostone treatment altered their microbial composition, especially the recovery of the levels of the Lactobacillaceae family and Prevotella genus, which were significantly reduced in the renal failure mice. Furthermore, capillary electrophoresis-mass spectrometry-based metabolome analysis showed that lubiprostone treatment decreased the plasma level of uremic toxins, such as indoxyl sulfate and hippurate, which are derived from gut microbiota, and a more recently discovered uremic toxin, trans-aconitate. These results suggest that lubiprostone ameliorates the progression of CKD and the accumulation of uremic toxins by improving the gut microbiota and intestinal environment. Copyright © 2015 by the American Society of Nephrology.

  4. Characterization of the Giardia intestinalis secretome during interaction with human intestinal epithelial cells: The impact on host cells.

    Directory of Open Access Journals (Sweden)

    Showgy Y Ma'ayeh

    2017-12-01

    Full Text Available Giardia intestinalis is a non-invasive protozoan parasite that causes giardiasis in humans, the most common form of parasite-induced diarrhea. Disease mechanisms are not completely defined and very few virulence factors are known.To identify putative virulence factors and elucidate mechanistic pathways leading to disease, we have used proteomics to identify the major excretory-secretory products (ESPs when Giardia trophozoites of WB and GS isolates (assemblages A and B, respectively interact with intestinal epithelial cells (IECs in vitro.The main parts of the IEC and parasite secretomes are constitutively released proteins, the majority of which are associated with metabolism but several proteins are released in response to their interaction (87 and 41 WB and GS proteins, respectively, 76 and 45 human proteins in response to the respective isolates. In parasitized IECs, the secretome profile indicated effects on the cell actin cytoskeleton and the induction of immune responses whereas that of Giardia showed anti-oxidation, proteolysis (protease-associated and induction of encystation responses. The Giardia secretome also contained immunodominant and glycosylated proteins as well as new candidate virulence factors and assemblage-specific differences were identified. A minor part of Giardia ESPs had signal peptides (29% for both isolates and extracellular vesicles were detected in the ESPs fractions, suggesting alternative secretory pathways. Microscopic analyses showed ESPs binding to IECs and partial internalization. Parasite ESPs reduced ERK1/2 and P38 phosphorylation and NF-κB nuclear translocation. Giardia ESPs altered gene expression in IECs, with a transcriptional profile indicating recruitment of immune cells via chemokines, disturbances in glucose homeostasis, cholesterol and lipid metabolism, cell cycle and induction of apoptosis.This is the first study identifying Giardia ESPs and evaluating their effects on IECs. It highlights the

  5. Noncoding RNAs and HIV: viral manipulation of host dark matter to shape the cellular environment

    Directory of Open Access Journals (Sweden)

    Samantha eBarichievy

    2015-03-01

    Full Text Available On October 28th 1943 Winston Churchill said we shape our buildings, and afterwards our buildings shape us (Humes, 1994. Churchill was pondering how and when to rebuild the British House of Commons, which had been destroyed by enemy bombs on May 10th 1941. The old House had been small and insufficient to hold all its members, but was restored to its original form in 1950 in order to recapture the convenience and dignity that the building had shaped into its parliamentary members. The circular loop whereby buildings or dwellings are shaped and go on to shape those that reside in them is also true of pathogens and their hosts. As obligate parasites, pathogens need to alter their cellular host environments to ensure survival. Typically pathogens modify cellular transcription profiles and in doing so, the pathogen in turn is affected, thereby closing the loop. As key orchestrators of gene expression, noncoding RNAs provide a vast and extremely precise set of tools for pathogens to target in order to shape the cellular environment. This review will focus on host noncoding RNAs that are manipulated by the infamous intracellular pathogen, the Human Immunodeficiency Virus (HIV. We will briefly describe both short and long host noncoding RNAs and discuss how HIV gains control of these factors to ensure widespread dissemination throughout the host as well as the establishment of lifelong, chronic infection.

  6. The host specificity of ape malaria parasites can be broken in confined environments.

    Science.gov (United States)

    Ngoubangoye, Barthélémy; Boundenga, Larson; Arnathau, Céline; Mombo, Illich Manfred; Durand, Patrick; Tsoumbou, Thierry-Audrey; Otoro, Bertony Vacky; Sana, Rick; Okouga, Alain-Prince; Moukodoum, Nancy; Willaume, Eric; Herbert, Anaïs; Fouchet, David; Rougeron, Virginie; Bâ, Cheikh Tidiane; Ollomo, Benjamin; Paupy, Christophe; Leroy, Eric M; Renaud, François; Pontier, Dominique; Prugnolle, Franck

    2016-10-01

    Recent studies have revealed a large diversity of Plasmodium spp. among African great apes. Some of these species are related to Plasmodium falciparum, the most virulent agent of human malaria (subgenus Laverania), and others to Plasmodium ovale, Plasmodium malariae and Plasmodium vivax (subgenus Plasmodium), three other human malaria agents. Laverania parasites exhibit strict host specificity in their natural environment. Plasmodium reichenowi, Plasmodium billcollinsi, Plasmodium billbrayi and Plasmodium gaboni infect only chimpanzees, while Plasmodium praefalciparum, Plasmodium blacklocki and Plasmodium adleri are restricted to gorillas and Plasmodium falciparum is pandemic in humans. This host specificity may be due to genetic and/or environmental factors. Infrastructures hosting captive primates, such as sanctuaries and health centres, usually concentrate different primate species, thus favouring pathogen exchanges. Using molecular tools, we analysed blood samples from captive non-human primates living in Gabon to evaluate the risk of Plasmodium spp. transfers between host species. We also included blood samples from workers taking care of primates to assess whether primate-human parasite transfers occurred. We detected four transfers of Plasmodium from gorillas towards chimpanzees, one from chimpanzees to gorillas, three from humans towards chimpanzees and one from humans to mandrills. No simian Plasmodium was found in the blood samples from humans working with primates. These findings demonstrate that the genetic barrier that determines the apparent host specificity of Laverania is not completely impermeable and that parasite exchanges between gorillas and chimpanzees are possible in confined environments. Copyright © 2016 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

  7. Increase in Campylobacter jejuni invasion of intestinal epithelial cells under low-oxygen coculture conditions that reflect the in vivo environment.

    Science.gov (United States)

    Mills, Dominic C; Gundogdu, Ozan; Elmi, Abdi; Bajaj-Elliott, Mona; Taylor, Peter W; Wren, Brendan W; Dorrell, Nick

    2012-05-01

    Campylobacter jejuni infection often results in bloody, inflammatory diarrhea, indicating bacterial disruption and invasion of the intestinal epithelium. While C. jejuni infection can be reproduced in vitro using intestinal epithelial cell (IEC) lines, low numbers of bacteria invading IECs do not reflect these clinical symptoms. Performing in vitro assays under atmospheric oxygen conditions neither is optimal for microaerophilic C. jejuni nor reflects the low-oxygen environment of the intestinal lumen. A vertical diffusion chamber (VDC) model system creates microaerobic conditions at the apical surface and aerobic conditions at the basolateral surface of cultured IECs, producing an in vitro system that closely mimics in vivo conditions in the human intestine. Ninefold increases in interacting and 80-fold increases in intracellular C. jejuni 11168H wild-type strain bacteria were observed after 24-h coculture with Caco-2 IECs in VDCs under microaerobic conditions at the apical surface, compared to results under aerobic conditions. Increased bacterial interaction was matched by an enhanced and directional host innate immune response, particularly an increased basolateral secretion of the proinflammatory chemokine interleukin-8 (IL-8). Analysis of the invasive ability of a nonmotile C. jejuni 11168H rpoN mutant in the VDC model system indicates that motility is an important factor in the early stages of bacterial invasion. The first report of the use of a VDC model system for studying the interactions of an invasive bacterial pathogen with IECs demonstrates the importance of performing such experiments under conditions that represent the in vivo situation and will allow novel insights into C. jejuni pathogenic mechanisms.

  8. Parasite fitness traits under environmental variation: disentangling the roles of a chytrid's immediate host and external environment.

    Science.gov (United States)

    Van den Wyngaert, Silke; Vanholsbeeck, Olivier; Spaak, Piet; Ibelings, Bas W

    2014-10-01

    Parasite environments are heterogeneous at different levels. The first level of variability is the host itself. The second level represents the external environment for the hosts, to which parasites may be exposed during part of their life cycle. Both levels are expected to affect parasite fitness traits. We disentangle the main and interaction effects of variation in the immediate host environment, here the diatom Asterionella formosa (variables host cell volume and host condition through herbicide pre-exposure) and variation in the external environment (variables host density and acute herbicide exposure) on three fitness traits (infection success, development time and reproductive output) of a chytrid parasite. Herbicide exposure only decreased infection success in a low host density environment. This result reinforces the hypothesis that chytrid zoospores use photosynthesis-dependent chemical cues to locate its host. At high host densities, chemotaxis becomes less relevant due to increasing chance contact rates between host and parasite, thereby following the mass-action principle in epidemiology. Theoretical support for this finding is provided by an agent-based simulation model. The immediate host environment (cell volume) substantially affected parasite reproductive output and also interacted with the external herbicide exposed environment. On the contrary, changes in the immediate host environment through herbicide pre-exposure did not increase infection success, though it had subtle effects on zoospore development time and reproductive output. This study shows that both immediate host and external environment as well as their interaction have significant effects on parasite fitness. Disentangling these effects improves our understanding of the processes underlying parasite spread and disease dynamics.

  9. Pathogen transfer through environment-host contact: an agent-based queueing theoretic framework.

    Science.gov (United States)

    Chen, Shi; Lenhart, Suzanne; Day, Judy D; Lee, Chihoon; Dulin, Michael; Lanzas, Cristina

    2017-11-02

    Queueing theory studies the properties of waiting queues and has been applied to investigate direct host-to-host transmitted disease dynamics, but its potential in modelling environmentally transmitted pathogens has not been fully explored. In this study, we provide a flexible and customizable queueing theory modelling framework with three major subroutines to study the in-hospital contact processes between environments and hosts and potential nosocomial pathogen transfer, where environments are servers and hosts are customers. Two types of servers with different parameters but the same utilization are investigated. We consider various forms of transfer functions that map contact duration to the amount of pathogen transfer based on existing literature. We propose a case study of simulated in-hospital contact processes and apply stochastic queues to analyse the amount of pathogen transfer under different transfer functions, and assume that pathogen amount decreases during the inter-arrival time. Different host behaviour (feedback and non-feedback) as well as initial pathogen distribution (whether in environment and/or in hosts) are also considered and simulated. We assess pathogen transfer and circulation under these various conditions and highlight the importance of the nonlinear interactions among contact processes, transfer functions and pathogen demography during the contact process. Our modelling framework can be readily extended to more complicated queueing networks to simulate more realistic situations by adjusting parameters such as the number and type of servers and customers, and adding extra subroutines. © The authors 2017. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

  10. Cell-host, LINE and environment: Three players in search of a balance.

    Science.gov (United States)

    Del Re, Brunella; Giorgi, Gianfranco

    2013-01-01

    Long interspersed nuclear elements -1 (LINEs, L1s) are retroelements occupying almost 17% of the human genome. L1 retrotransposition can cause deleterious effects on the host-cell and it is generally inhibited by suppressive mechanisms, but it can occur in some specific cells during early development as well as in some tumor cells and in the presence of several environmental factors. In a recent publication we reported that extremely low frequency pulsed magnetic field can affect L1 retrotransposition in neuroblastoma cells. In this commentary we discuss the interaction between environment and L1 activity in the light of the new emerging paradigm of host-LINE relationship.

  11. Plastic and micro-evolutionary responses of a nematode to the host immune environment.

    Science.gov (United States)

    Guivier, Emmanuel; Lippens, Cédric; Faivre, Bruno; Sorci, Gabriele

    2017-10-01

    Parasitic organisms have to cope with the defences deployed by their hosts and this can be achieved adopting immune evasion strategies or optimal life history traits according to the prevailing pattern of immune-mediated mortality. Parasites often encounter variable immune environments both within and between hosts, promoting the evolution of plastic strategies instead of fixed responses. Here, we explored the plasticity and micro-evolutionary responses of immunomodulatory mechanisms and life history traits to the immune environment provided by the host, using the parasitic nematode Heligmosomoides polygyrus. To test if the parasite responds plastically to the immune environment, we stimulated the systemic inflammatory response of mice and we assessed i) the expression of two genes with candidate immunomodulatory functions (Hp-Tgh2 and Hp-CPI); ii) changes in the number of eggs shed in the faeces. To test if the immune environment induces a micro-evolutionary response in the parasite, we maintained the nematode in mice whose inflammatory response was up- or down-regulated during four generations. We found that H. polygyrus plastically responded to a sudden rise of pro-inflammatory cytokines, up-regulating the expression of two candidate genes involved in the process of immune modulation, and enhancing egg output. At the micro-evolutionary level, parasites maintained in hosts experiencing different levels of inflammation did not have differential expression of Hp-Tgh2 and Hp-CPI genes when infecting unmanipulated, control, mice. However, parasites maintained in mice with an up-regulated inflammation shed more eggs compared to the control line. Overall, our study shows that H. polygyrus can plastically adjust the expression of immunomodulatory genes and life history traits, and responds to selection exerted by the host immune system. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. [Effect of multicomponent environment on intestinal permeability of puerarin in biopharmaceutics classification system of Chinese materia medica].

    Science.gov (United States)

    Liu, Yang; Wang, Gang; Dong, Ling; Tang, Ming-Min; Zhu, Mei-Ling; Dong, Hong-Huant; Hou, Cheng-Bo

    2014-12-01

    The evaluation of permeability in biopharmaceutics classification system of Chinese materia medica (CMMBCS) requires multicomponent as a whole in order to conduct research, even in the study of a specific component, should also be put in the multicomponent environment. Based on this principle, the high content components in Gegen Qinlian decoction were used as multicomponent environmental impact factors in the experiment, and the relevant parameters of intestinal permeability about puerarin were measured with using in situ single-pass intestinal perfusion model, to investigate and evaluate the intestinal permeability of puerarin with other high content components. The experimental results showed that different proportions of baicalin, glycyrrhizic acid and berberine had certain influence on intestinal permeability of puerarin, and glycyrrhizic acid could significantly inhibit the intestinal absorption of puerarin, moreover, high concentration of berberine could promote the absorption of puerarin. The research results indicated that the important research ideas of permeability evaluation in biopharmaceutics classification system of Chinese materia medica with fully considering the effects of other ingredients in multicomponent environment.

  13. Toxoplasma gondii Rhoptry 16 Kinase Promotes Host Resistance to Oral Infection and Intestinal Inflammation Only in the Context of the Dense Granule Protein GRA15

    Science.gov (United States)

    Jensen, Kirk D. C.; Hu, Kenneth; Whitmarsh, Ryan J.; Hassan, Musa A.; Julien, Lindsay; Lu, Diana; Chen, Lieping; Hunter, Christopher A.

    2013-01-01

    Toxoplasma gondii transmission between intermediate hosts is dependent on the ingestion of walled cysts formed during the chronic phase of infection. Immediately following consumption, the parasite must ensure survival of the host by preventing adverse inflammatory responses and/or by limiting its own replication. Since the Toxoplasma secreted effectors rhoptry 16 kinase (ROP16) and dense granule 15 (GRA15) activate the JAK-STAT3/6 and NF-κB signaling pathways, respectively, we explored whether a particular combination of these effectors impacted intestinal inflammation and parasite survival in vivo. Here we report that expression of the STAT-activating version of ROP16 in the type II strain (strain II+ROP16I) promotes host resistance to oral infection only in the context of endogenous GRA15 expression. Protection was characterized by a lower intestinal parasite burden and dampened inflammation. Host resistance to the II+ROP16I strain occurred independently of STAT6 and the T cell coinhibitory receptors B7-DC and B7-H1, two receptors that are upregulated by ROP16. In addition, coexpression of ROP16 and GRA15 enhanced parasite susceptibility within tumor necrosis factor alpha/gamma interferon-stimulated macrophages in a STAT3/6-independent manner. Transcriptional profiling of infected STAT3- and STAT6-deficient macrophages and parasitized Peyer's patches from mice orally challenged with strain II+ROP16I suggested that ROP16 activated STAT5 to modulate host gene expression. Consistent with this supposition, the ROP16 kinase induced the sustained phosphorylation and nuclear localization of STAT5 in Toxoplasma-infected cells. In summary, only the combined expression of both GRA15 and ROP16 promoted host resistance to acute oral infection, and Toxoplasma may possibly target the STAT5 signaling pathway to generate protective immunity in the gut. PMID:23545295

  14. Protective effect of glutamine on intestinal injury and bacterial community in rats exposed to hypobaric hypoxia environment

    Science.gov (United States)

    Xu, Chun-Lan; Sun, Rui; Qiao, Xiang-Jin; Xu, Cui-Cui; Shang, Xiao-Ya; Niu, Wei-Ning

    2014-01-01

    AIM: To investigate the protective effect of glutamine (Gln) on intestinal injury and the bacterial community in rats exposed to hypobaric hypoxia environment. METHODS: Sprague-Dawley rats were divided into control, hypobaric hypoxia (HH), and hypobaric hypoxia + Gln (5.0 g/kg BW·d) (HG) groups. On the first 3 d, all rats were placed in a normal environment. After the third day, the HH and HG groups were transferred into a hypobaric chamber at a simulated elevation of 7000 m for 5 d. The rats in the HG group were given Gln by gavage daily for 8 d. The rats in the control and HH groups were treated with the same volume of saline. The intestinal morphology, serum levels of malondialdehyde (MDA), superoxide dismutase (SOD), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interferon-gamma (IFN-γ) and diamino oxidase (DAO) were examined. We also evaluated the expression levels of occludin, toll-like receptor 4 (TLR4), nuclear factor-κB p65 (NF-κB p65) and myeloid differentiation factor 88 (MyD88), and examined the bacterial community in caecal contents. RESULTS: Hypobaric hypoxia induced the enlargement of the heart, liver, lung and kidney, and caused spleen atrophy. Intestinal villi damage was also observed in the HH group. Supplementation with Gln significantly alleviated hypobaric-induced damage to main organs including the intestine, increased serum SOD (1.14 ± 0.03 vs 0.88 ± 0.04, P intestinal bacterial community. CONCLUSION: Gln treatment protects from intestinal injury and regulates the gut flora imbalance in hypoxia environment. These effects may be related to the TLR4/MyD88/NF-κB signaling pathway. PMID:24782618

  15. Parasite Fitness Traits Under Environmental Variation: Disentangling the Roles of a Chytrid's Immediate Host and External Environment

    NARCIS (Netherlands)

    van den Wyngaert, Silke; Vanholsbeeck, Olivier; Spaak, Piet; Ibelings, Bas W.

    2014-01-01

    Parasite environments are heterogeneous at different levels. The first level of variability is the host itself. The second level represents the external environment for the hosts, to which parasites may be exposed during part of their life cycle. Both levels are expected to affect parasite fitness

  16. An intestinal Trojan horse for gene delivery

    Science.gov (United States)

    Peng, Haisheng; Wang, Chao; Xu, Xiaoyang; Yu, Chenxu; Wang, Qun

    2015-02-01

    The intestinal epithelium forms an essential element of the mucosal barrier and plays a critical role in the pathophysiological response to different enteric disorders and diseases. As a major enteric dysfunction of the intestinal tract, inflammatory bowel disease is a genetic disease which results from the inappropriate and exaggerated mucosal immune response to the normal constituents in the mucosal microbiota environment. An intestine targeted drug delivery system has unique advantages in the treatment of inflammatory bowel disease. As a new concept in drug delivery, the Trojan horse system with the synergy of nanotechnology and host cells can achieve better therapeutic efficacy in specific diseases. Here, we demonstrated the feasibility of encapsulating DNA-functionalized gold nanoparticles into primary isolated intestinal stem cells to form an intestinal Trojan horse for gene regulation therapy of inflammatory bowel disease. This proof-of-concept intestinal Trojan horse will have a wide variety of applications in the diagnosis and therapy of enteric disorders and diseases.

  17. An intestinal Trojan horse for gene delivery.

    Science.gov (United States)

    Peng, Haisheng; Wang, Chao; Xu, Xiaoyang; Yu, Chenxu; Wang, Qun

    2015-03-14

    The intestinal epithelium forms an essential element of the mucosal barrier and plays a critical role in the pathophysiological response to different enteric disorders and diseases. As a major enteric dysfunction of the intestinal tract, inflammatory bowel disease is a genetic disease which results from the inappropriate and exaggerated mucosal immune response to the normal constituents in the mucosal microbiota environment. An intestine targeted drug delivery system has unique advantages in the treatment of inflammatory bowel disease. As a new concept in drug delivery, the Trojan horse system with the synergy of nanotechnology and host cells can achieve better therapeutic efficacy in specific diseases. Here, we demonstrated the feasibility of encapsulating DNA-functionalized gold nanoparticles into primary isolated intestinal stem cells to form an intestinal Trojan horse for gene regulation therapy of inflammatory bowel disease. This proof-of-concept intestinal Trojan horse will have a wide variety of applications in the diagnosis and therapy of enteric disorders and diseases.

  18. Intestinal invasion of Salmonella enterica serovar Typhimurium in the avian host is dose dependent and does not depend on motility and chemotaxis

    DEFF Research Database (Denmark)

    Olsen, John Elmerdahl; Hoegh-Andersen, Kirsten Hobolt; Rosenkrantz, Jesper Tjørnholt

    2013-01-01

    it depended on motility and chemotaxis.Wild type and previously well-characterized transposon mutants in flagella genes fliC and fljB and in chemotaxis genes cheA, cheB and cheR were used as challenge strains in intestinal loop experiments. Invasion was shown to be dose dependent, but did not require...... functional flagella or chemotaxis genes. In support of the results from intestinal loop experiments, flagella and chemotaxis genes were not significantly important to the outcome of an oral infection. The results showed that S. Typhimurium invasion in the avian host was dose dependent and was not affected...... by the loss of flagella and chemotaxis genes....

  19. Disruptions of Host Immunity and Inflammation by Giardia Duodenalis: Potential Consequences for Co-Infections in the Gastro-Intestinal Tract

    Science.gov (United States)

    Cotton, James A.; Amat, Christina B.; Buret, Andre G.

    2015-01-01

    Giardia duodenalis (syn. G. intestinalis, or G. lamblia) is a leading cause of waterborne diarrheal disease that infects hundreds of millions of people annually. Research on Giardia has greatly expanded within the last few years, and our understanding of the pathophysiology and immunology on this parasite is ever increasing. At peak infection, Giardia trophozoites induce pathophysiological responses that culminate in the development of diarrheal disease. However, human data has suggested that the intestinal mucosa of Giardia-infected individuals is devoid of signs of overt intestinal inflammation, an observation that is reproduced in animal models. Thus, our understanding of host inflammatory responses to the parasite remain incompletely understood and human studies and experimental data have produced conflicting results. It is now also apparent that certain Giardia infections contain mechanisms capable of modulating their host’s immune responses. As the oral route of Giardia infection is shared with many other gastrointestinal (GI) pathogens, co-infections may often occur, especially in places with poor sanitation and/or improper treatment of drinking water. Moreover, Giardia infections may modulate host immune responses and have been found to protect against the development of diarrheal disease in developing countries. The following review summarizes our current understanding of the immunomodulatory mechanisms of Giardia infections and their consequences for the host, and highlights areas for future research. Potential implications of these immunomodulatory effects during GI co-infection are also discussed. PMID:26569316

  20. Disruptions of Host Immunity and Inflammation by Giardia Duodenalis: Potential Consequences for Co-Infections in the Gastro-Intestinal Tract

    Directory of Open Access Journals (Sweden)

    James A. Cotton

    2015-11-01

    Full Text Available Giardia duodenalis (syn. G. intestinalis, or G. lamblia is a leading cause of waterborne diarrheal disease that infects hundreds of millions of people annually. Research on Giardia has greatly expanded within the last few years, and our understanding of the pathophysiology and immunology on this parasite is ever increasing. At peak infection, Giardia trophozoites induce pathophysiological responses that culminate in the development of diarrheal disease. However, human data has suggested that the intestinal mucosa of Giardia-infected individuals is devoid of signs of overt intestinal inflammation, an observation that is reproduced in animal models. Thus, our understanding of host inflammatory responses to the parasite remain incompletely understood and human studies and experimental data have produced conflicting results. It is now also apparent that certain Giardia infections contain mechanisms capable of modulating their host’s immune responses. As the oral route of Giardia infection is shared with many other gastrointestinal (GI pathogens, co-infections may often occur, especially in places with poor sanitation and/or improper treatment of drinking water. Moreover, Giardia infections may modulate host immune responses and have been found to protect against the development of diarrheal disease in developing countries. The following review summarizes our current understanding of the immunomodulatory mechanisms of Giardia infections and their consequences for the host, and highlights areas for future research. Potential implications of these immunomodulatory effects during GI co-infection are also discussed.

  1. Cloud hosting of the IPython Notebook to Provide Collaborative Research Environments for Big Data Analysis

    Science.gov (United States)

    Kershaw, Philip; Lawrence, Bryan; Gomez-Dans, Jose; Holt, John

    2015-04-01

    We explore how the popular IPython Notebook computing system can be hosted on a cloud platform to provide a flexible virtual research hosting environment for Earth Observation data processing and analysis and how this approach can be expanded more broadly into a generic SaaS (Software as a Service) offering for the environmental sciences. OPTIRAD (OPTImisation environment for joint retrieval of multi-sensor RADiances) is a project funded by the European Space Agency to develop a collaborative research environment for Data Assimilation of Earth Observation products for land surface applications. Data Assimilation provides a powerful means to combine multiple sources of data and derive new products for this application domain. To be most effective, it requires close collaboration between specialists in this field, land surface modellers and end users of data generated. A goal of OPTIRAD then is to develop a collaborative research environment to engender shared working. Another significant challenge is that of data volume and complexity. Study of land surface requires high spatial and temporal resolutions, a relatively large number of variables and the application of algorithms which are computationally expensive. These problems can be addressed with the application of parallel processing techniques on specialist compute clusters. However, scientific users are often deterred by the time investment required to port their codes to these environments. Even when successfully achieved, it may be difficult to readily change or update. This runs counter to the scientific process of continuous experimentation, analysis and validation. The IPython Notebook provides users with a web-based interface to multiple interactive shells for the Python programming language. Code, documentation and graphical content can be saved and shared making it directly applicable to OPTIRAD's requirements for a shared working environment. Given the web interface it can be readily made into a hosted

  2. Informing optimal environmental influenza interventions: how the host, agent, and environment alter dominant routes of transmission.

    Directory of Open Access Journals (Sweden)

    Ian H Spicknall

    Full Text Available Influenza can be transmitted through respirable (small airborne particles, inspirable (intermediate size, direct-droplet-spray, and contact modes. How these modes are affected by features of the virus strain (infectivity, survivability, transferability, or shedding profiles, host population (behavior, susceptibility, or shedding profiles, and environment (host density, surface area to volume ratios, or host movement patterns have only recently come under investigation. A discrete-event, continuous-time, stochastic transmission model was constructed to analyze the environmental processes through which a virus passes from one person to another via different transmission modes, and explore which factors increase or decrease different modes of transmission. With the exception of the inspiratory route, each route on its own can cause high transmission in isolation of other modes. Mode-specific transmission was highly sensitive to parameter values. For example, droplet and respirable transmission usually required high host density, while the contact route had no such requirement. Depending on the specific context, one or more modes may be sufficient to cause high transmission, while in other contexts no transmission may result. Because of this, when making intervention decisions that involve blocking environmental pathways, generic recommendations applied indiscriminately may be ineffective; instead intervention choice should be contextualized, depending on the specific features of people, virus strain, or venue in question.

  3. The role of viral population diversity in adaptation of bovine coronavirus to new host environments.

    Directory of Open Access Journals (Sweden)

    Monica K Borucki

    Full Text Available The high mutation rate of RNA viruses enables a diverse genetic population of viral genotypes to exist within a single infected host. In-host genetic diversity could better position the virus population to respond and adapt to a diverse array of selective pressures such as host-switching events. Multiple new coronaviruses, including SARS, have been identified in human samples just within the last ten years, demonstrating the potential of coronaviruses as emergent human pathogens. Deep sequencing was used to characterize genomic changes in coronavirus quasispecies during simulated host-switching. Three bovine nasal samples infected with bovine coronavirus were used to infect human and bovine macrophage and lung cell lines. The virus reproduced relatively well in macrophages, but the lung cell lines were not infected efficiently enough to allow passage of non lab-adapted samples. Approximately 12 kb of the genome was amplified before and after passage and sequenced at average coverages of nearly 950×(454 sequencing and 38,000×(Illumina. The consensus sequence of many of the passaged samples had a 12 nucleotide insert in the consensus sequence of the spike gene, and multiple point mutations were associated with the presence of the insert. Deep sequencing revealed that the insert was present but very rare in the unpassaged samples and could quickly shift to dominate the population when placed in a different environment. The insert coded for three arginine residues, occurred in a region associated with fusion entry into host cells, and may allow infection of new cell types via heparin sulfate binding. Analysis of the deep sequencing data indicated that two distinct genotypes circulated at different frequency levels in each sample, and support the hypothesis that the mutations present in passaged strains were "selected" from a pre-existing pool rather than through de novo mutation and subsequent population fixation.

  4. Intestinal Microbiota as Modulators of the Immune System and Neuroimmune System: Impact on the Host Health and Homeostasis

    Directory of Open Access Journals (Sweden)

    Carlos Magno da Costa Maranduba

    2015-01-01

    Full Text Available Many immune-based intestinal disorders, such as ulcerative colitis and Crohn’s disease, as well as other illnesses, may have the intestines as an initial cause or aggravator in the development of diseases, even apparently not correlating directly to the intestine. Diabetes, obesity, multiple sclerosis, depression, and anxiety are examples of other illnesses discussed in the literature. In parallel, importance of the gut microbiota in intestinal homeostasis and immunologic conflict between tolerance towards commensal microorganisms and combat of pathogens is well known. Recent researches show that the immune system, when altered by the gut microbiota, influences the state in which these diseases are presented in the patient directly and indirectly. At the present moment, a considerable number of investigations about this subject have been performed and published. However, due to difficulties on correlating information, several speculations and hypotheses are generated. Thus, the present review aims at bringing together how these interactions work—gut microbiota, immune system, and their influence in the neuroimmune system.

  5. Intestinal Microbiota as Modulators of the Immune System and Neuroimmune System: Impact on the Host Health and Homeostasis

    Science.gov (United States)

    Maranduba, Carlos Magno da Costa; De Castro, Sandra Bertelli Ribeiro; de Souza, Gustavo Torres; da Guia, Francisco Carlos; Valente, Maria Anete Santana; Rettore, João Vitor Paes; Maranduba, Claudinéia Pereira; de Souza, Camila Maurmann; do Carmo, Antônio Márcio Resende; Macedo, Gilson Costa; Silva, Fernando de Sá

    2015-01-01

    Many immune-based intestinal disorders, such as ulcerative colitis and Crohn's disease, as well as other illnesses, may have the intestines as an initial cause or aggravator in the development of diseases, even apparently not correlating directly to the intestine. Diabetes, obesity, multiple sclerosis, depression, and anxiety are examples of other illnesses discussed in the literature. In parallel, importance of the gut microbiota in intestinal homeostasis and immunologic conflict between tolerance towards commensal microorganisms and combat of pathogens is well known. Recent researches show that the immune system, when altered by the gut microbiota, influences the state in which these diseases are presented in the patient directly and indirectly. At the present moment, a considerable number of investigations about this subject have been performed and published. However, due to difficulties on correlating information, several speculations and hypotheses are generated. Thus, the present review aims at bringing together how these interactions work—gut microbiota, immune system, and their influence in the neuroimmune system. PMID:25759850

  6. Host response to Escherichia coli heat-labile enterotoxin via two microvillus membrane receptors in the rat intestine.

    Science.gov (United States)

    Zemelman, B V; Chu, S H; Walker, W A

    1989-10-01

    The responsiveness of enterocytes to Escherichia coli heat-labile enterotoxin (LT) was studied in the small intestine of 6- to 7-week-old rats. Dose-effect analysis showed the dose required for a 50% maximal LT-induced secretory response to be at 8 nM. After the well-documented glycolipid GM1 receptor was blocked with the cholera toxin B subunit, LT still activated the second messenger cascade, measured in terms of heightened cellular adenylate cyclase activity, and caused fluid to be secreted into ligated intestinal loops. Furthermore, Scatchard analysis of binding kinetics suggested that LT bound to two receptor sites on the intestinal microvillus membrane. The toxin also bound to delipidated membrane but was competitively inhibited by a galactose-specific lectin, RCA60, suggesting that the additional receptor is a galactoglycoprotein. Western blot analysis of toxin binding to membrane proteins revealed a group of binding components around 85 to 150 kilodaltons. When measured at 2.2 nM LT, approximately 70% of LT-binding activity took place through a high-affinity (Kd1, 0.38 nM) GM1 receptor and 30% of LT-binding activity took place through a low-affinity (Kd2, 3.3 nM) glycoprotein receptor. These results suggest that LT functions through two microvillus membrane receptors in the mature rat small intestine.

  7. Crowd-hosting platforms on the Internet as a method of implementation of its initiatives in the virtual environment

    OpenAIRE

    Alekseev N.

    2017-01-01

    This article designated as its subject crowd–hosting platforms on the Internet. Reflected the concept, the main features and directions of development of such phenomenon as crowdaming platform. At the same time, attention is paid to the obstacles that stand in the way of development of crowd–hosting technologies in the virtual environment of today’s Russian reality.

  8. Analysis of virus genomes from glacial environments reveals novel virus groups with unusual host interactions

    Directory of Open Access Journals (Sweden)

    Christopher Mark Bellas

    2015-07-01

    Full Text Available Microbial communities in glacial ecosystems are diverse, active, and subjected to strong viral pressures and infection rates. In this study we analyse putative virus genomes assembled from three dsDNA viromes from cryoconite hole ecosystems of Svalbard and the Greenland Ice Sheet to assess the potential hosts and functional role viruses play in these habitats. We assembled 208 million reads from the virus-size fraction and developed a procedure to select genuine virus scaffolds from cellular contamination. Our curated virus library contained 546 scaffolds up to 230 Kb in length, 54 of which were circular virus consensus genomes. Analysis of virus marker genes revealed a wide range of viruses had been assembled, including bacteriophages, cyanophages, nucleocytoplasmic large DNA viruses and a virophage, with putative hosts identified as Actinobacteria, Alphaproteobacteria, Cyanobacteria, Firmicutes, Gammaproteobacteria, eukaryotic algae and amoebae. Whole genome comparisons revealed the majority of circular genome scaffolds formed 12 novel groups, two of which contained multiple phage members with plasmid-like properties, including a group of phage-plasmids possessing plasmid-like partition genes and toxin-antitoxin addiction modules to ensure their replication and a satellite phage-plasmid group. Surprisingly we also assembled a phage that not only encoded plasmid partition genes, but a clustered regularly interspaced short palindromic repeat (CRISPR/Cas adaptive bacterial immune system. One of the spacers was an exact match for another phage in our virome, indicating that in a novel use of the system, the lysogen was potentially capable of conferring immunity on its bacterial host against other phage. Together these results suggest that highly novel and diverse groups of viruses are present in glacial environments, some of which utilise very unusual life strategies and genes to control their replication and maintain a long-term relationship with

  9. The host galaxy and environment of a bright QSO at z=7.54

    Science.gov (United States)

    Banados, Eduardo

    2017-08-01

    After almost a decade of intense search, our team has finally discovered a bright QSO well within the epoch of reionization, at z=7.54. This is by far the most distant QSO known (previous record: 7.08), at a cosmic age of 690 Myr, i.e., only 5% of our universe's current age. This is the first QSO whose spectrum shows clear evidence of an intergalactic medium that is >10% neutral and that reionization is underway. We propose deep HST ACS and WFC/IR imaging of this unique source with two main goals. (i) Unveil the rest-frame UV stellar light from the host galaxy to directly probe supermassive black hole/galaxy co-evolution at the highest accessible redshift. (ii) Search for galaxies physically associated with the QSO and test whether this object resides in one of the densest and most biased environment at the peak of the reionization epoch. HST observations are indispensable to address these topics for two reasons: (a) only HST provides the spatial resolution to separate the central bright light source from the underlying host galaxy and (b) at this record-redshift, only space-based imaging can provide the depths necessary to constrain the environment. These HST observations will provide key insights into the formation and evolution of the first super massive black holes, galaxies, and large-scale structure of the universe.

  10. Beclomethasone in Treating Patients With Graft-Versus-Host Disease of the Esophagus, Stomach, Small Intestine, or Colon

    Science.gov (United States)

    2010-03-31

    Breast Cancer; Chronic Myeloproliferative Disorders; Gestational Trophoblastic Tumor; Graft Versus Host Disease; Kidney Cancer; Leukemia; Lymphoma; Multiple Myeloma and Plasma Cell Neoplasm; Myelodysplastic Syndromes; Neuroblastoma; Ovarian Cancer; Testicular Germ Cell Tumor

  11. Extracellular Vesicles from Parasitic Helminths Contain Specific Excretory/Secretory Proteins and Are Internalized in Intestinal Host Cells

    Science.gov (United States)

    Marcilla, Antonio; Trelis, María; Cortés, Alba; Sotillo, Javier; Cantalapiedra, Fernando; Minguez, María Teresa; Valero, María Luz; Sánchez del Pino, Manuel Mateo; Muñoz-Antoli, Carla; Toledo, Rafael; Bernal, Dolores

    2012-01-01

    The study of host-parasite interactions has increased considerably in the last decades, with many studies focusing on the identification of parasite molecules (i.e. surface or excretory/secretory proteins (ESP)) as potential targets for new specific treatments and/or diagnostic tools. In parallel, in the last few years there have been significant advances in the field of extracellular vesicles research. Among these vesicles, exosomes of endocytic origin, with a characteristic size ranging from 30–100 nm, carry several atypical secreted proteins in different organisms, including parasitic protozoa. Here, we present experimental evidence for the existence of exosome-like vesicles in parasitic helminths, specifically the trematodes Echinostoma caproni and Fasciola hepatica. These microvesicles are actively released by the parasites and are taken up by host cells. Trematode extracellular vesicles contain most of the proteins previously identified as components of ESP, as confirmed by proteomic, immunogold labeling and electron microscopy studies. In addition to parasitic proteins, we also identify host proteins in these structures. The existence of extracellular vesicles explains the secretion of atypical proteins in trematodes, and the demonstration of their uptake by host cells suggests an important role for these structures in host-parasite communication, as described for other infectious agents. PMID:23029346

  12. Long-Term Intravenous Ketamine for Analgesia in a Child with Severe Chronic Intestinal Graft versus Host Disease

    Directory of Open Access Journals (Sweden)

    Jennifer Busse

    2015-01-01

    Full Text Available Ketamine is reported to be an effective adjuvant to opioids in the treatment of refractory cancer pain; however, the use of high doses of ketamine for extended periods in pediatric patients has not been described. We present a five-year-old male with grade IV intestinal GVHD whose abdominal pain required both hydromorphone and ketamine for a period of over four months. There was no evidence of hepatotoxicity, hemorrhagic cystitis, or other adverse effects. Possible withdrawal symptoms were mild and were readily mitigated by gradually weaning ketamine.

  13. Feeding high fibre diets changes luminal environment and morphology in the intestine of sows

    DEFF Research Database (Denmark)

    Serena, Anja; Hedemann, Mette Skou; Bach Knudsen, Knud Erik

    2007-01-01

    -products (sugar beet pulp, potato pulp, pectin residue, pea hull, brewer's spent grain, and seed residue). The diets were fed for a four-week period to 12 sows (4 for each diet). Sows were stunned 4 h post-feeding, and digesta and tissue samples were collected from various parts of the small and large intestines...

  14. Identification of Suitable Reference Genes for Normalization of Real-Time Quantitative Polymerase Chain Reaction in an Intestinal Graft-Versus-Host Disease Mouse Model.

    Science.gov (United States)

    Li, X; Qiao, J; Yang, N; Mi, H; Chu, P; Xia, Y; Yao, H; Liu, Y; Qi, K; Yan, Z; Zeng, L; Xu, K

    2015-01-01

    With the development of real-time quantitative polymerase chain reaction (RT-qPCR) and intensive research on acute graft-versus-host disease (GVHD), selecting the best reference gene for normalization of RT-qPCR analysis in a GVHD model becomes more and more important. In this study, we aimed to identify suitable reference genes for mRNA studies in an intestinal GVHD mouse model after bone marrow transplantation (BMT). BALB/c recipients received 7.5 Gy total body irradiation (TBI) followed by injection of 5 × 10(6) bone marrow cells, without infusion of spleen cells for BMT, with infusion of 5 × 10(5) or 2.5 × 10(6) spleen cells for mild or moderate GVHD, respectively. Healthy mice were chosen as normal control subjects. Duodenum, jejunum, ileum, colon, and small intestine were collected at days 7, 14, 21, and 28 after transplantation. Transcription levels of 9 candidate genes, B2M, SDHA, HPRT, ACTB, GAPDH, HMBS, TBP, YWHAZ, and RPLP0, in each tissue were measured with the use of RT-qPCR. Combined data from these tissues in each group were defined as all samples. The expression stability of these genes was analyzed with the use of Genorm, Normfinder, Bestkeeper, and ΔCt. Our results showed that in all samples, ACTB and HMBS displayed the highest and lowest expression levels, respectively. Genorm identified HRPT and SDHA as the most stable reference genes, whereas Normfinder and ΔCt method showed HPRT as the most stably expressed gene. Bestkeeper ranked YWHAZ and HPRT as the top 2 most suitable genes. In conclusion, HPRT was recommended as the most suitable reference gene after comprehensive ranking, suggesting that it could be used as an internal control for mRNA studies in intestinal GVHD after BMT. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Research Progress of Intestinal Microbiota in Inflammatory Bowel Diseases

    Directory of Open Access Journals (Sweden)

    Shao-shun YE

    2017-06-01

    Full Text Available Inflammatory bowel disseases (IBD are chronic recurrent diseases occurring in the gastrointestinal tract, mainly including ulcerative colitis (UC and Crohn’s disease (CD. At present, the etiological factors and mechanism of IBD are still unclear yet. However, it is widely believed that IBD is caused by immune dysfunction, genetic factors, gut barrier dysfuction and dysbacteriosis, change of dietary structure, use of antibiotics, smoking, and environment. Studies suggest that breaking the accurate balance between host and intestinal microbiota in patients with IBD can trigger immuno-inflammatory responses in genetically susceptible individuals. Therefore, regulating intestinal microbiota disturbance and recovery of intestinal homeostasis between host and intestinal microbiota become a new treatment direction for IBD. This article mainly reviewed research progress of intestinal microbiota in pathogenetic mechanism and treatment of IBD.

  16. The role of diet on intestinal microbiota metabolism: Downstream impacts on host immune function and health, and therapeutic implications

    OpenAIRE

    Goldsmith, Jason R.; Sartor, Balfour

    2014-01-01

    Dietary impacts on health may be one of the oldest concepts in medicine; however, only in recent years have technical advances in mass spectroscopy, gnotobiology, and bacterial sequencing enabled our understanding of human physiology to progress to the point where we can begin to understand how individual dietary components can affect specific illnesses. This review explores the current understanding of the complex interplay between dietary factors and the host microbiome, concentrating on th...

  17. If it transcribes, we can sequence it: mining the complexities of host-pathogen-environment interactions using RNA-seq.

    Science.gov (United States)

    Colgan, Aoife M; Cameron, Andrew Ds; Kröger, Carsten

    2017-04-01

    Host-pathogen interactions are exceedingly complex because they involve multiple host tissues, often occur in the context of normal microflora, and can span diverse microenvironments. Although decades of gene expression studies have provided detailed insights into infection processes, technical challenges have restricted experiments to single pathogenic species or host tissues. RNA-sequencing (RNA-seq) has revolutionized the study of gene expression because in addition to quantifying transcriptional output, it allows detection and characterization of all transcripts in a genome. Here, we review how refined approaches to RNA-seq are used to map the transcriptional networks that control host-pathogen interactions. These enhanced techniques include dRNA-seq and term-seq for the fine-scale mapping of transcriptional start and termination sites, and dual RNA-seq for simultaneous sequencing of host and bacterial pathogen transcriptomes. Dual RNA-seq experiments are currently limited to in vitro infection systems that do not fully reflect the complexities of the in vivo environment, thus a challenge is to develop in vivo model systems and experimental approaches that address the biological heterogeneity of host environments, followed by the integration of RNA-seq with other genome-scale datasets to identify the transcriptional networks that mediate host-pathogen interactions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Resolving the infection process reveals striking differences in the contribution of environment, genetics and phylogeny to host-parasite interactions.

    Science.gov (United States)

    Duneau, David; Luijckx, Pepijn; Ben-Ami, Frida; Laforsch, Christian; Ebert, Dieter

    2011-02-22

    Infection processes consist of a sequence of steps, each critical for the interaction between host and parasite. Studies of host-parasite interactions rarely take into account the fact that different steps might be influenced by different factors and might, therefore, make different contributions to shaping coevolution. We designed a new method using the Daphnia magna - Pasteuria ramosa system, one of the rare examples where coevolution has been documented, in order to resolve the steps of the infection and analyse the factors that influence each of them. Using the transparent Daphnia hosts and fluorescently-labelled spores of the bacterium P. ramosa, we identified a sequence of infection steps: encounter between parasite and host; activation of parasite dormant spores; attachment of spores to the host; and parasite proliferation inside the host. The chances of encounter had been shown to depend on host genotype and environment. We tested the role of genetic and environmental factors in the newly described activation and attachment steps. Hosts of different genotypes, gender and species were all able to activate endospores of all parasite clones tested in different environments; suggesting that the activation cue is phylogenetically conserved. We next established that parasite attachment occurs onto the host oesophagus independently of host species, gender and environmental conditions. In contrast to spore activation, attachment depended strongly on the combination of host and parasite genotypes. Our results show that different steps are influenced by different factors. Host-type-independent spore activation suggests that this step can be ruled out as a major factor in Daphnia-Pasteuria coevolution. On the other hand, we show that the attachment step is crucial for the pronounced genetic specificities of this system. We suggest that this one step can explain host population structure and could be a key force behind coevolutionary cycles. We discuss how different

  19. Innate immune signaling in defense against intestinal microbes

    Science.gov (United States)

    Kinnebrew, Melissa A.; Pamer, Eric G.

    2015-01-01

    Summary The gastrointestinal system is a common entry point for pathogenic microbes to access the inner environment of the body. Antimicrobial factors produced by the intestinal mucosa limit the translocation of both commensal and pathogenic microbes across the intestinal epithelial cell barrier. The regulation of these host defense mechanisms largely depends on the activation of innate immune receptors by microbial molecules. Under steady-state conditions, the microbiota provides constitutive signals to the innate immune system, which helps to maintain a healthy inflammatory tone within the intestinal mucosa and, thus, enhances resistance to infection with enteric pathogens. During an acute infection, the intestinal epithelial cell barrier is breached, and the detection of microbial molecules in the intestinal lamina propria rapidly stimulates innate immune signaling pathways that coordinate early defense mechanisms. Herein, we review how microbial molecules shed by both commensal and pathogenic microbes direct host defenses at the intestinal mucosa. We highlight the signaling pathways, effector molecules, and cell populations that are activated by microbial molecule recognition and, thereby, are involved in the maintenance of homeostatic levels of host defense and in the early response to acute enteric infection. Finally, we discuss how manipulation of these host defense pathways by stimulating innate immune receptors is a potential therapeutic strategy to prevent or alleviate intestinal disease. PMID:22168416

  20. Ability of Lactobacillus kefiri LKF01 (DSM32079) to colonize the intestinal environment and modify the gut microbiota composition of healthy individuals.

    Science.gov (United States)

    Toscano, Marco; De Grandi, Roberta; Miniello, Vito Leonardo; Mattina, Roberto; Drago, Lorenzo

    2017-03-01

    Probiotics have been observed to positively influence the host's health, but to date few data about the ability of probiotics to modify the gut microbiota composition exist. To evaluate the ability of Lactobacillus kefiri LKF01 DSM32079 (LKEF) to colonize the intestinal environment of healthy subjects and modify the gut microbiota composition. Twenty Italian healthy volunteers were randomized in pre-prandial and post-prandial groups. Changes in the gut microbiota composition were detected by using a Next Generation Sequencing technology (Ion Torrent Personal Genome Machine). L. kefiri was recovered in the feces of all volunteers after one month of probiotic administration, while it was detected only in three subjects belonging to the pre-prandial group and in two subjects belonging to the post-prandial group one month after the end of probiotic consumption. After one month of probiotic oral intake we observed a reduction of Bilophila, Butyricicomonas, Flavonifractor, Oscillibacter and Prevotella. Interestingly, after the end of probiotic administration Bacteroides, Barnesiella, Butyricicomonas, Clostridium, Haemophilus, Oscillibacter, Salmonella, Streptococcus, Subdoligranolum, and Veillonella were significantly reduced if compared to baseline samples. L. kefiri LKF01 showed a strong ability to modulate the gut microbiota composition, leading to a significant reduction of several bacterial genera directly involved in the onset of pro-inflammatory response and gastrointestinal diseases. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Recent progress in host immunity to avian coccidiosis: IL-17 family cytokines as sentinels of the intestinal mucosa.

    Science.gov (United States)

    Min, Wongi; Kim, Woo H; Lillehoj, Erik P; Lillehoj, Hyun S

    2013-11-01

    The molecular and cellular mechanisms leading to immune protection against coccidiosis are complex and include multiple aspects of innate and adaptive immunities. Innate immunity is mediated by various subpopulations of immune cells that recognize pathogen associated molecular patterns (PAMPs) through their pattern recognition receptors (PRRs) leading to the secretion of soluble factors with diverse functions. Adaptive immunity, which is important in conferring protection against subsequent reinfections, involves subtypes of T and B lymphocytes that mediate antigen-specific immune responses. Recently, global gene expression microarray analysis has been used in an attempt to dissect this complex network of immune cells and molecules during avian coccidiosis. These new studies emphasized the uniqueness of the innate immune response to Eimeria infection, and directly led to the discovery of previously uncharacterized host genes and proteins whose expression levels were modulated following parasite infection. Among these is the IL-17 family of cytokines. This review highlights recent progress in IL-17 research in the context of host immunity to avian coccidiosis. Copyright © 2013. Published by Elsevier Ltd.

  2. Interaction between Campylobacter and intestinal epithelial cells leads to a different proinflammatory response in human and porcine host.

    Science.gov (United States)

    Aguilar, Carmen; Jiménez-Marín, Ángeles; Martins, Rodrigo Prado; Garrido, Juan J

    2014-11-15

    Campylobacter jejuni and Campylobacter coli are recognized as the leading causes of human diarrheal disease throughout the development world. Unlike human beings, gastrointestinal tract of pigs are frequently colonized by Campylobacter to a high level in a commensal manner. The aim of this study was to identify the differences underlying the divergent outcome following Campylobacter challenge in porcine versus human host. In order to address this, a comparative in vitro infection model was combined with microscopy, gentamicin protection assay, ELISA and quantitative PCR techniques. Invasion assays revealed that Campylobacter invaded human cells up to 10-fold more than porcine cells (pCampylobacter in human epithelial cell at early times of infection, whereas a very reduced cytokine gene expression was detected in porcine epithelial cells. These data indicate that Campylobacter fails to invade porcine cells compared to human cells, and this leads to a lack of proinflammatory response induction, probably due to its pathogenic or commensal behavior in human and porcine host, respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. In vitro investigation of molecules involved in Lactobacillus gasseri SBT2055 adhesion to host intestinal tract components.

    Science.gov (United States)

    Arai, T; Obuchi, S; Eguchi, K; Seto, Y

    2016-06-01

    The adhesion ability of Lactobacillus gasseri SBT2055 was investigated in vitro by searching for its adhesion molecules. Lactobacillus gasseri SBT2055 showed adherence to host components, including two commercially available mucins, Caco-2 epithelial-like cells and the extracellular matrix molecule fibronectin (Fn). Its adhesion rates to host components were generally higher than those of other Lactobacillus strains. We examined sortase-dependent proteins (SDPs) anchored by a sortase enzyme encoded by srtA1. The adhesion rates of an srtA1 disruptant were lower than those of Lact. gasseri SBT2055, and the relative adherences were as follows: two mucins, 43 and 40%; Caco-2, 66% and Fn, 28%. Seven additional gene disruptants were generated to determine the precise SDPs that contribute to adhesion to each component. The adhesion ability of Lact. gasseri SBT2055 was superior to those of other Lactobacillus strains. Additionally, four adhesion molecules were newly identified from candidate SDPs. Although the contribution of SDPs to adhesion has been reported using sortase gene disruptants, this is the first report to identify the precise SDPs that act as adhesion molecules. Our results will contribute to achieving better understanding of probiotic bacterial adherence. © 2016 The Society for Applied Microbiology.

  4. Differential survival of Ichthyophonus isolates indicates parasite adaptation to its host environment

    Science.gov (United States)

    Hershberger, P.K.; Pacheco, C.A.; Gregg, J.L.; Purcell, M.K.; LaPatra, S.E.

    2008-01-01

    In vitro viability of Ichthyophonus spp. spores in seawater and freshwater corresponded with the water type of the host from which the spores were isolated. Among Ichthyophonus spp. spores from both marine and freshwater fish hosts (Pacific herring, Clupea pallasii, and rainbow trout, Oncorhynchus mykiss, respectively), viability was significantly greater (P marine host and greater freshwater tolerance of spores from the freshwater host. Prolonged aqueous survival of Ichthyophonus spp. spores in the absence of a host provides insight into routes of transmission, particularly among planktivorous fishes, and should be considered when designing strategies to dispose of infected fish carcasses and tissues.

  5. Lactobacillus reuteri I5007 Modulates Intestinal Host Defense Peptide Expression in the Model of IPEC-J2 Cells and Neonatal Piglets

    Directory of Open Access Journals (Sweden)

    Hongbin Liu

    2017-05-01

    Full Text Available Modulation of the synthesis of endogenous host defense peptides (HDPs by probiotics represents a novel antimicrobial approach for disease control and prevention, particularly against antibiotic-resistant infections in human and animals. However, the extent of HDP modulation by probiotics is species dependent and strain specific. In the present study, The porcine small intestinal epithelial cell line (IPEC-J2 cells and neonatal piglets were used as in-vitro and in-vivo models to test whether Lactobacillus reuteri I5007 could modulate intestinal HDP expression. Gene expressions of HDPs, toll-like receptors, and fatty acid receptors were determined, as well as colonic short chain fatty acid concentrations and microbiota. Exposure to 108 colony forming units (CFU/mL of L. reuteri I5007 for 6 h significantly increased the expression of porcine β-Defensin2 (PBD2, pBD3, pBD114, pBD129, and protegrins (PG 1-5 in IPEC-J2 cells. Similarly, L. reuteri I5007 administration significantly increased the expression of jejunal pBD2 as well as colonic pBD2, pBD3, pBD114, and pBD129 in neonatal piglets (p < 0.05. This was probably associated with the increase in colonic butyric acid concentration and up-regulating expression of Peroxisome Proliferator-Activated Receptor-γ (PPAR-γ and G Protein-Coupled Receptor 41 (GPR41 (p < 0.05, but not with stimulation of Pattern-Recognition Receptors. Additionally, supplementation with L. reuteri I5007 in the piglets did not affect the colonic microbiota structure. Our findings suggested that L. reuteri I5007 could modulate intestinal HDP expression and improve the gut health of neonatal piglets, probably through the increase in colonic butyric acid concentration and the up-regulation of the downstream molecules of butyric acid, PPAR-γ and GPR41, but not through modifying gut microbiota structure.

  6. Patterns of phenotypic plasticity in common and rare environments: a study of host use and color learning in the cabbage white butterfly Pieris rapae.

    Science.gov (United States)

    Snell-Rood, Emilie C; Papaj, Daniel R

    2009-05-01

    Phenotypic plasticity is adaptive in variable environments but, given its costs, may be disfavored if only one environment is commonly encountered. Yet species in relatively constant environments often adjust phenotypes successfully in rare or novel environments. Developmental biases may reduce the costs of plasticity in common environments, favoring the maintenance of plasticity. We explored this proposition by studying the flexibility of visually guided host-selection behavior in cabbage white butterflies (Pieris rapae), wherein common and rare environments consisted of green and red host types, respectively. We demonstrated in greenhouse assays that adult females display an innate bias toward green color during host search but alter that bias through learning in red-host assemblages such that, after several hours of experience, red hosts are located as efficiently as green hosts. Full-sib analyses suggested there was genetic variation in host and color choice that was more pronounced in the red-host environment. We found no evidence of genetic correlations in behavior across host environments or of fitness costs of plasticity in color choice. Our results support the idea that learning may persist in less variable environments through the evolution of innate biases that reduce operating costs in common environments.

  7. Intestinal microbiota and ulcerative colitis.

    Science.gov (United States)

    Ohkusa, Toshifumi; Koido, Shigeo

    2015-11-01

    There is a close relationship between the human host and the intestinal microbiota, which is an assortment of microorganisms, protecting the intestine against colonization by exogenous pathogens. Moreover, the intestinal microbiota play a critical role in providing nutrition and the modulation of host immune homeostasis. Recent reports indicate that some strains of intestinal bacteria are responsible for intestinal ulceration and chronic inflammation in inflammatory bowel diseases (IBD) such as ulcerative colitis (UC) and Crohn's disease (CD). Understanding the interaction of the intestinal microbiota with pathogens and the human host might provide new strategies treating patients with IBD. This review focuses on the important role that the intestinal microbiota plays in maintaining innate immunity in the pathogenesis and etiology of UC and discusses new antibiotic therapies targeting the intestinal microbiota. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  8. Cathelicidin-WA Improves Intestinal Epithelial Barrier Function and Enhances Host Defense against Enterohemorrhagic Escherichia coli O157:H7 Infection.

    Science.gov (United States)

    Yi, Hongbo; Hu, Wangyang; Chen, Shan; Lu, Zeqing; Wang, Yizhen

    2017-02-15

    Impaired epithelial barrier function disrupts immune homeostasis and increases inflammation in intestines, leading to many intestinal diseases. Cathelicidin peptides suppress intestinal inflammation and improve intestinal epithelial barrier function independently of their antimicrobial activity. In this study, we investigated the effects of Cathelicidin-WA (CWA) on intestinal epithelial barrier function, as well as the underlying mechanism, by using enterohemorrhagic Escherichia coli (EHEC)-infected mice and intestinal epithelial cells. The results showed that CWA attenuated EHEC-induced clinical symptoms and intestinal colitis, as did enrofloxacin (Enro). CWA decreased IL-6 production in the serum, jejunum, and colon of EHEC-infected mice. Additionally, CWA alleviated the EHEC-induced disruption of mucin-2 and goblet cells in the intestine. Interestingly, CWA increased the mucus layer thickness, which was associated with increasing expression of trefoil factor 3, in the jejunum of EHEC-infected mice. CWA increased the expression of tight junction proteins in the jejunum of EHEC-infected mice. Using intestinal epithelial cells and a Rac1 inhibitor in vitro, we demonstrated that the CWA-mediated increases in the tight junction proteins might depend on the Rac1 pathway. Furthermore, CWA improved the microbiota and short-chain fatty acid concentrations in the cecum of EHEC-infected mice. Although Enro and CWA had similar effects on intestinal inflammation, CWA was superior to Enro with regard to improving intestinal epithelial barrier and microbiota in the intestine. In conclusion, CWA attenuated EHEC-induced inflammation, intestinal epithelial barrier damage, and microbiota disruption in the intestine of mice, suggesting that CWA may be an effective therapy for many intestinal diseases. Copyright © 2017 by The American Association of Immunologists, Inc.

  9. A multi-colour study of the dark GRB 000210 host galaxy and its environment

    DEFF Research Database (Denmark)

    Gorosabel, J.; Christensen, Lise; Hjorth, J.

    2003-01-01

    We present UBVRIZJsHKs broad band photometry of the host galaxy of the dark gamma-ray burst (GRB) of February 10, 2000. These observations represent the most exhaustive photometry given to date of any GRB host galaxy. A grid of spectral templates have been fitted to the Spectral Energy Distribution...

  10. [Intestinal parasitic diseases in an urban environment in Sahel. A study in a district of Niamey, Niger].

    Science.gov (United States)

    Julvez, J; Badé, M A; Lamotte, M; Campagne, G; Garba, A; Gragnic, G; Bui, A; Kehren, S; Cluzel, F; Chippaux, J P

    1998-01-01

    Health and environment in Niamey, a capital in Sahel, are particularly linked owing to population growth, promiscuity and large pollution induced by human and animal excreta. One district, located in the centre of the town, was surveyed for drinking water quality (ammoniac and bacterial count) and use, as well as for the prevalence of parasites through both a random sample (fixed tools with methiolate-iodine-formaldehyde) and a systematic one (scotch-test). Water consumption was 16.5 litres/day/man from fresh water supplies (87%) and private wells (13%). Ammoniac measures were low in the wells but high in running water (pool and river). It was the same for faecal coliform bacteria. These results give evidence of biotope faecal pollution. The random sample (322 persons, male/female sex ratio 0,85, average age 20,6 years) showed a 42.1% parasitic prevalence. Amoeba was the most frequent parasite (53.6%); and Giardia (14.9%) was the most frequent pathogenic parasite. In the second sample (161 children under 10 years), 24.2% were carriers of oxyuris. This large intestinal parasitism, without any change in connection with previous data in Niger, points to an important fecal contamination of the people more by the way of "dirty hands" than consumption of drinking water. The parasites observed have a short biological cycle, not necessitating long-term maturation in the environment. Those whose ova or larvae must complete their cycle outside have no possibility of surviving in Sahel, thanks to the beneficial effect of sunlight (heat and ultraviolet light). The inhabitants of this district seem to have adapted to intestinal parasitism. But the occurrence of malnutrition linked to a new drought could lead rapidly to a very serious adverse result.

  11. Modulation of the Host Environment by Human Cytomegalovirus with Viral Interleukin 10 in Peripheral Blood.

    Science.gov (United States)

    Young, Vivian P; Mariano, Margarette C; Tu, Carolyn C; Allaire, Kathryn M; Avdic, Selmir; Slobedman, Barry; Spencer, Juliet V

    2017-03-15

    Human cytomegalovirus (HCMV) is a herpesvirus with both lytic and latent life cycles. Human cytomegalovirus encodes 2 viral cytokines that are orthologs of human cellular interleukin 10 (cIL-10). Both cytomegalovirus interleukin 10 (cmvIL-10) and Latency-associated cytomegalovirus interleukin 10 (LAcmvIL-10) (collectively vIL-10) are expressed during lytic infection and cause immunosuppressive effects that impede virus clearance. LAcmvIL-10 is also expressed during latent infection of myeloid progenitor cells and monocytes and facilitates persistence. Here, we investigated whether vIL-10 could be detected during natural infection. Plasma from healthy blood donors was tested by enzyme-linked immunosorbent assay for anti-HCMV immunoglobulin G and immunoglobulin M and for cIL-10 and vIL-10 levels using a novel vIL-10 assay that detects cmvIL-10 and LAcmvIL-10, with no cross-reactivity to cIL-10. vIL-10 was evident in HCMV+ donors (n = 19 of 26), at levels ranging 31-547 pg/mL. By comparison, cIL-10 was detected at lower levels ranging 3-69 pg/mL. There was a strong correlation between vIL-10 and cIL-10 levels (P = .01). Antibodies against vIL-10 were also detected and neutralized vIL-10 activity. vIL-10 was detected in peripheral blood of healthy blood donors. These findings suggest that vIL-10 may play a key role in sensing or modifying the host environment during latency and, therefore, may be a potential target for intervention strategies.

  12. Causes, consequences, and perspectives in the variations of intestinal density of colonization of multidrug-resistant enterobacteria

    OpenAIRE

    ETIENNE eRUPPE; Antoine eAndremont

    2013-01-01

    The intestinal microbiota is a complex environment that hosts 1013 to 1014 bacteria. Among these bacteria stand multidrug-resistant enterobacteria, which intestinal densities can substantially vary, especially according to antibiotic exposure. The intestinal density of multidrug-resistant enterobacteria and their relative abundance (i.e. the proportion between the density of multidrug-resistant enterobacteria and the density of total enterobacteria) could play a major role in the infection pr...

  13. The effects of lactoferrin on the intestinal environment of broiler chickens.

    Science.gov (United States)

    Geier, M S; Torok, V A; Guo, P; Allison, G E; Boulianne, M; Janardhana, V; Bean, A G D; Hughes, R J

    2011-10-01

    The influence of in-feed lactoferrin (Lf) on bird production, intestinal microbiota, mucosal immune system and gut microarchitecture was assessed in male Cobb 500 broiler chickens. Birds were given one of four diets from day of hatch: Control (basal diet with no additives), ZnB (basal diet + 50 mg/kg zinc bacitracin), Lf 250 mg/kg (basal diet + 250 mg/kg Lf) and Lf 500 mg/kg (basal diet + 500 mg/kg Lf); n = 24 birds/treatment. An apparent metabolisable energy study was performed between d 25-32. Lf did not affect growth rate or feed conversion in the period 0-21 d of age, nor performance or energy metabolism during the 7 d metabolism experiment which commenced at 25 d of age.The profiles of caecal microbial communities were significantly different in birds given ZnB compared with birds given a diet with no additives, or supplemented with 250 mg/kg Lf. Birds given 250 mg/kg Lf also had a different microbial profile compared with birds given 500 mg/kg Lf. In comparison to control birds, Lf treated birds showed some differences in the T cell proportions in caecal tonsil and spleen. No differences in ileal villus height, crypt depth or goblet cell proportions were observed amongst dietary treatments. Whilst Lf had little effect on the measured parameters, the use of an integrated approach to study the influence of novel feed additives may facilitate a greater understanding of the relationships between nutrition, gut health and bird performance.

  14. Developmental adaptations of trypanosome motility to the tsetse fly host environments unravel a multifaceted in vivo microswimmer system

    OpenAIRE

    Schuster, Sarah; Kr?ger, Timothy; Subota, Ines; Thusek, Sina; Rotureau, Brice; Beilhack, Andreas; Engstler, Markus

    2017-01-01

    The highly motile and versatile protozoan pathogen Trypanosoma brucei undergoes a complex life cycle in the tsetse fly. Here we introduce the host insect as an expedient model environment for microswimmer research, as it allows examination of microbial motion within a diversified, secluded and yet microscopically tractable space. During their week-long journey through the different microenvironments of the fly?s interior organs, the incessantly swimming trypanosomes cross various barriers and...

  15. Host Ranges of Listeria-Specific Bacteriophages from the Turkey Processing Plant Environment in the United States ▿

    Science.gov (United States)

    Kim, Jae-Won; Siletzky, Robin M.; Kathariou, Sophia

    2008-01-01

    Even though at least 400 Listeria phages have been isolated from various sources, limited information is available on phages from the food processing plant environment. Phages in the processing plant environment may play critical roles in determining the Listeria population that becomes established in the plant. In this study, we pursued the isolation of Listeria-specific phages from environmental samples from four turkey processing plants in the United States. These environmental samples were also utilized to isolate Listeria spp. Twelve phages were isolated and classified into three groups in terms of their host range. Of these, nine (group 1) showed a wide host range, including multiple serotypes of Listeria monocytogenes, as well as other Listeria spp. (L. innocua, L. welshimeri, L. seeligeri, and L. ivanovii). The remaining phages mostly infected L. monocytogenes serotype 4b as well as L. innocua, L. ivanovii, and/or L. welshimeri. All but one of the strains of the serotype 4b complex (4b, 4d, 4e) from the processing plant environment could be readily infected by the wide-host-range phages isolated from the environment of the processing plants. However, many strains of other serotypes (1/2a [or 3a] and 1/2b [or 3b]), which represented the majority of L. monocytogenes strains isolated from the environmental samples, were resistant to infection by these phages. Experiments with two phage-resistant strains showed reduced phage adsorption onto the host cells. These findings suggest that phage resistance may be an important component of the ecology of L. monocytogenes in the turkey processing plants. PMID:18791016

  16. Host ranges of Listeria-specific bacteriophages from the turkey processing plant environment in the United States.

    Science.gov (United States)

    Kim, Jae-Won; Siletzky, Robin M; Kathariou, Sophia

    2008-11-01

    Even though at least 400 Listeria phages have been isolated from various sources, limited information is available on phages from the food processing plant environment. Phages in the processing plant environment may play critical roles in determining the Listeria population that becomes established in the plant. In this study, we pursued the isolation of Listeria-specific phages from environmental samples from four turkey processing plants in the United States. These environmental samples were also utilized to isolate Listeria spp. Twelve phages were isolated and classified into three groups in terms of their host range. Of these, nine (group 1) showed a wide host range, including multiple serotypes of Listeria monocytogenes, as well as other Listeria spp. (L. innocua, L. welshimeri, L. seeligeri, and L. ivanovii). The remaining phages mostly infected L. monocytogenes serotype 4b as well as L. innocua, L. ivanovii, and/or L. welshimeri. All but one of the strains of the serotype 4b complex (4b, 4d, 4e) from the processing plant environment could be readily infected by the wide-host-range phages isolated from the environment of the processing plants. However, many strains of other serotypes (1/2a [or 3a] and 1/2b [or 3b]), which represented the majority of L. monocytogenes strains isolated from the environmental samples, were resistant to infection by these phages. Experiments with two phage-resistant strains showed reduced phage adsorption onto the host cells. These findings suggest that phage resistance may be an important component of the ecology of L. monocytogenes in the turkey processing plants.

  17. The intestinal microbiota, gastrointestinal environment and colorectal cancer: a putative role for probiotics in prevention of colorectal cancer?

    Science.gov (United States)

    Azcárate-Peril, M Andrea; Sikes, Michael; Bruno-Bárcena, José M

    2011-09-01

    Colorectal cancer (CRC) is the third most commonly diagnosed cancer in the United States, and, even though 5-15% of the total CRC cases can be attributed to individual genetic predisposition, environmental factors could be considered major factors in susceptibility to CRC. Lifestyle factors increasing the risks of CRC include elevated body mass index, obesity, and reduced physical activity. Additionally, a number of dietary elements have been associated with higher or lower incidence of CRC. In this context, it has been suggested that diets high in fruit and low in meat might have a protective effect, reducing the incidence of colorectal adenomas by modulating the composition of the normal nonpathogenic commensal microbiota. In addition, it has been demonstrated that changes in abundance of taxonomic groups have a profound impact on the gastrointestinal physiology, and an increasing number of studies are proposing that the microbiota mediates the generation of dietary factors triggering colon cancer. High-throughput sequencing and molecular taxonomic technologies are rapidly filling the knowledge gaps left by conventional microbiology techniques to obtain a comprehensive catalog of the human intestinal microbiota and their associated metabolic repertoire. The information provided by these studies will be essential to identify agents capable of modulating the massive amount of gut bacteria in safe noninvasive manners to prevent CRC. Probiotics, defined as "live microorganisms which, when administered in adequate amounts, confer a health benefit on the host" (219), are capable of transient modulation of the microbiota, and their beneficial effects include reinforcement of the natural defense mechanisms and protection against gastrointestinal disorders. Probiotics have been successfully used to manage infant diarrhea, food allergies, and inflammatory bowel disease; hence, the purpose of this review was to examine probiotic metabolic activities that may have an effect

  18. Factors affecting virus dynamics and microbial host-virus interactions in marine environments

    NARCIS (Netherlands)

    Mojica, K.D.A.; Brussaard, C.P.D.

    2014-01-01

    Marine microorganisms constitute the largest percentage of living biomass and serve as the major driving force behind nutrient and energy cycles. While viruses only comprise a small percentage of this biomass (i.e., 5%), they dominate in numerical abundance and genetic diversity. Through host

  19. Independent and competing disease risks : Implications for host Populations in variable environments

    NARCIS (Netherlands)

    Jolles, AE; Etienne, RS; Olff, H; Jolles, Anna E.; DeAngelis, Donald L.; Michalakis, Yannis

    Disease models usually assume disease to act independently of other mortality- and morbidity-causing factors. Alternatively, disease may function as a competing risk factor, for example, killing already moribund hosts. Using tuberculosis (TB) in African buffalo as a model system, we explore

  20. Phytoplasma adapt to the diverse environments of their plant and insect hosts by altering gene expression

    DEFF Research Database (Denmark)

    Makarova, Olga; MacLean, Allyson M.; Nicolaisen, Mogens

    2015-01-01

    Phytoplasmas are intracellular insect-transmitted phytopathogenic bacteria with small genomes. To understand how Aster Yellows phytoplasma strain witches' broom (AY-WB) adapts to their hosts, we performed qRT-PCR analysis of 179 in silico functionally annotated AY-WB genes that are likely to have...

  1. Herbicides in the environment alter infection dynamics in a microbial host-parasite system

    NARCIS (Netherlands)

    van den Wyngaert, Silke; Gsell, A.S.; Spaak, P.; Ibelings, B.W.

    2013-01-01

    Parasites play an important role in the regulation of host population growth. How these ubiquitous stressors interact with anthropogenic stressors is less often studied. In a full factorial experiment we explored the independent and combined effects of the widely used herbicide diuron and a chytrid

  2. Discordant population histories of host and its parasite: A role for ecological permeability of extreme environment?

    Science.gov (United States)

    Jirsová, Dagmar; Štefka, Jan; Jirků, Miloslav

    2017-01-01

    Biogeographical and ecological barriers strongly affect the course of micro-evolutionary processes in free living organisms. Here we assess the impact of a recently emerged barrier on populations of limnic fauna. Genetic diversity and population structure in a host-parasite system (Wenyonia virilis tapeworm, Synodontis schall catfish) are analyzed in the recently divided Turkana and Nile basins. The two basins, were repeatedly connected during the Holocene wet/dry climatic oscillations, following late Pleistocene dessication of the Turkana basin. Mitochondrial DNA sequences for cytochrome oxidase I gene (cox I) and a whole genome scanning method-amplified fragment length polymorphism (AFLP) were employed. A total of 347 cox I sequences (representing 209 haplotypes) and 716 AFLP fragments, as well as 120 cox I sequences (20 haplotypes) and 532 AFLP fragments were obtained from parasites and hosts, respectively. Although results indicate that host and parasite populations share some formative traits (bottlenecks, Nilotic origin), their population histories/patterns differ markedly. Mitochondrial analysis revealed that parasite populations evolve significantly faster and show remarkably higher genetic variability. Analyses of both markers confirmed that the parasites undergo lineage fission, forming new clusters specific for either freshwater or saline parts of Lake Turkana. In congruence with the geological history, these clusters apparently indicate multiple colonisations of Lake Turkana from the Nile. In contrast, the host population pattern indicates fusion of different colonisation waves. Although fish host populations remain connected, saline habitats in Lake Turkana (absent in the Nile), apparently pose a barrier to the gene flow in the parasite, possibly due to its multihost lifecycle, which involves freshwater annelids. Despite partially corroborating mitochondrial results, AFLP data was not sufficiently informative for analyzing populations with recently

  3. Discordant population histories of host and its parasite: A role for ecological permeability of extreme environment?

    Directory of Open Access Journals (Sweden)

    Dagmar Jirsová

    Full Text Available Biogeographical and ecological barriers strongly affect the course of micro-evolutionary processes in free living organisms. Here we assess the impact of a recently emerged barrier on populations of limnic fauna. Genetic diversity and population structure in a host-parasite system (Wenyonia virilis tapeworm, Synodontis schall catfish are analyzed in the recently divided Turkana and Nile basins. The two basins, were repeatedly connected during the Holocene wet/dry climatic oscillations, following late Pleistocene dessication of the Turkana basin. Mitochondrial DNA sequences for cytochrome oxidase I gene (cox I and a whole genome scanning method-amplified fragment length polymorphism (AFLP were employed. A total of 347 cox I sequences (representing 209 haplotypes and 716 AFLP fragments, as well as 120 cox I sequences (20 haplotypes and 532 AFLP fragments were obtained from parasites and hosts, respectively. Although results indicate that host and parasite populations share some formative traits (bottlenecks, Nilotic origin, their population histories/patterns differ markedly. Mitochondrial analysis revealed that parasite populations evolve significantly faster and show remarkably higher genetic variability. Analyses of both markers confirmed that the parasites undergo lineage fission, forming new clusters specific for either freshwater or saline parts of Lake Turkana. In congruence with the geological history, these clusters apparently indicate multiple colonisations of Lake Turkana from the Nile. In contrast, the host population pattern indicates fusion of different colonisation waves. Although fish host populations remain connected, saline habitats in Lake Turkana (absent in the Nile, apparently pose a barrier to the gene flow in the parasite, possibly due to its multihost lifecycle, which involves freshwater annelids. Despite partially corroborating mitochondrial results, AFLP data was not sufficiently informative for analyzing populations with

  4. Effects of fabrication on the mechanics, microstructure and micromechanical environment of small intestinal submucosa scaffolds for vascular tissue engineering.

    Science.gov (United States)

    Sánchez-Palencia, Diana M; D'Amore, Antonio; González-Mancera, Andrés; Wagner, William R; Briceño, Juan C

    2014-08-22

    In small intestinal submucosa scaffolds for functional tissue engineering, the impact of scaffold fabrication parameters on success rate may be related to the mechanotransductory properties of the final microstructural organization of collagen fibers. We hypothesized that two fabrication parameters, 1) preservation (P) or removal (R) of a dense collagen layer present in SIS and 2) SIS in a final dehydrated (D) or hydrated (H) state, have an effect on scaffold void area, microstructural anisotropy (fiber alignment) and mechanical anisotropy (global mechanical compliance). We further integrated our experimental measurements in a constitutive model to explore final effects on the micromechanical environment inside the scaffold volume. Our results indicated that PH scaffolds might exhibit recurrent and large force fluctuations between layers (up to 195 pN), while fluctuations in RH scaffolds might be larger (up to 256 pN) but not as recurrent. In contrast, both PD and RD groups were estimated to produce scarcer and smaller fluctuations (not larger than 50 pN). We concluded that the hydration parameter strongly affects the micromechanics of SIS and that an adequate choice of fabrication parameters, assisted by the herein developed method, might leverage the use of SIS for functional tissue engineering applications, where forces at the cellular level are of concern in the guidance of new tissue formation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Distribution and diversity of the enterococcal surface protein (esp) gene in animal hosts and the Pacific coast environment.

    Science.gov (United States)

    Layton, B A; Walters, S P; Boehm, A B

    2009-05-01

    This study sought to evaluate the distribution of the enterococcal surface protein (esp) gene in Enterococcus faecium in the Pacific coast environment as well as the distribution and diversity of the gene in Northern California animal hosts. Over 150 environmental samples from the Pacific coast environment (sand, surf zone, fresh/estuarine, groundwater, and storm drain) were screened for the esp gene marker in E. faecium, and the marker was found in 37% of the environmental samples. We examined the host specificity of the gene by screening various avian and mammalian faecal samples, and found the esp gene to be widespread in nonhuman animal faeces. DNA sequence analysis performed on esp polymerase chain reaction amplicons revealed that esp gene sequences were not divergent between hosts. Our data confirm recent findings that the E. faecium variant of the esp gene is not human-specific. Our results suggest that the use of the esp gene for microbial source tracking applications may not be appropriate at all recreational beaches.

  6. The environment-pathogen-host axis in communicable and non-communicable diseases: recent advances in experimental and clinical research.

    Science.gov (United States)

    Gilles, Stefanie; Traidl-Hoffmann, Claudia

    2014-05-01

    Allergies and autoimmune diseases are spreading worldwide. Control of infections, on the other hand, remains an issue, even in the post-antibiotic era. Chronic or poorly controlled infections occur in immune compromised individuals such as HIV patients, hospitalized patients exposed to multi-resistant bacteria, or patients on immunosuppressive treatment. They may become an even more emerging issue in an ageing population. At the same time, profound environmental changes such as global warming, urbanization, increasing environmental pollution and novel food engineering technologies may alter the abundance or aggressiveness of allergens/allergen carriers in our environment. Likewise, changes in dietary habits - and possibly also use of antibiotics - have an impact on the composition of our natural microbial flora in the gut, airways and skin, which may alter susceptibility for common diseases, among them allergies, asthma and atopic eczema. At the recently founded Institute of Environmental Medicine of the Technische Universität Munich, located in Augsburg at the UNIKA-T, experimental, clinical and translational research is focused on the complex interactions of environment, pathogen and host in expression or control of communicable and non-communicable diseases. We present our research concept and recent findings in environment - host interactions. © 2014 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

  7. Factors affecting virus dynamics and microbial host-virus interactions in marine environments.

    Science.gov (United States)

    Mojica, Kristina D A; Brussaard, Corina P D

    2014-09-01

    Marine microorganisms constitute the largest percentage of living biomass and serve as the major driving force behind nutrient and energy cycles. While viruses only comprise a small percentage of this biomass (i.e., 5%), they dominate in numerical abundance and genetic diversity. Through host infection and mortality, viruses affect microbial population dynamics, community composition, genetic evolution, and biogeochemical cycling. However, the field of marine viral ecology is currently limited by a lack of data regarding how different environmental factors regulate virus dynamics and host-virus interactions. The goal of the present minireview was to contribute to the evolution of marine viral ecology, through the assimilation of available data regarding the manner and degree to which environmental factors affect viral decay and infectivity as well as influence latent period and production. Considering the ecological importance of viruses in the marine ecosystem and the increasing pressure from anthropogenic activity and global climate change on marine systems, a synthesis of existing information provides a timely framework for future research initiatives in viral ecology. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  8. Analysis of bacterial composition in marine sponges reveals the influence of host phylogeny and environment.

    Science.gov (United States)

    Souza, Danilo T; Genuário, Diego B; Silva, Fabio Sérgio P; Pansa, Camila C; Kavamura, Vanessa N; Moraes, Fernando C; Taketani, Rodrigo G; Melo, Itamar S

    2017-01-01

    Bacterial communities associated with sponges are influenced by environmental factors; however, some degree of genetic influence of the host on the microbiome is also expected. In this work, 16S rRNA gene amplicon sequencing revealed diverse bacterial phylotypes based on the phylogenies of three tropical sponges (Aplysina fulva, Aiolochroia crassa and Chondrosia collectrix). Despite their sympatric occurrence, the studied sponges presented different bacterial compositions that differed from those observed in seawater. However, lower dissimilarities in bacterial communities were observed within sponges from the same phylogenetic group. The relationships between operational taxonomic units (OTUs) recovered from the sponges and database sequences revealed associations among sequences from unrelated sponge species and sequences retrieved from diverse environmental samples. In addition, one Proteobacteria OTU retrieved from A. fulva was identical to sequences previously reported from A. fulva specimens collected along the Brazilian coast. Based on these results, we conclude that bacterial communities associated with marine sponges are shaped by host identity, while environmental conditions seem to be less important in shaping symbiont communities. This is the first study to assess bacterial communities associated with marine sponges in the remote St. Peter and St. Paul Archipelago using amplicon sequencing of the 16S rRNA gene. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  9. Fluid spatial dynamics of West Nile virus in the USA: Rapid spread in a permissive host environment

    Science.gov (United States)

    Di Giallonardo , Francesca; Geoghegan, Jemma L.; Docherty, Douglas E.; McLean, Robert G.; Zody, Michael C.; Qu, James; Yang, Xiao; Birren, Bruce W.; Malboeuf, Christine M.; Newman, R.; Ip, Hon S.; Holmes, Edward C.

    2016-01-01

    The introduction of West Nile virus (WNV) into North America in 1999 is a classical example of viral emergence in a new environment, with its subsequent dispersion across the continent having a major impact on local bird populations. Despite the importance of this epizootic, the pattern, dynamics and determinants of WNV spread in its natural hosts remain uncertain. In particular, it is unclear whether the virus encountered major barriers to transmission, or spread in an unconstrained manner, and if specific viral lineages were favored over others indicative of intrinsic differences in fitness. To address these key questions in WNV evolution and ecology we sequenced the complete genomes of approximately 300 avian isolates sampled across the USA between 2001-2012. Phylogenetic analysis revealed a relatively ‘star-like' tree structure, indicative of explosive viral spread in US, although with some replacement of viral genotypes through time. These data are striking in that viral sequences exhibit relatively limited clustering according to geographic region, particularly for those viruses sampled from birds, and no strong phylogenetic association with well sampled avian species. The genome sequence data analysed here also contain relatively little evidence for adaptive evolution, particularly on structural proteins, suggesting that most viral lineages are of similar fitness, and that WNV is well adapted to the ecology of mosquito vectors and diverse avian hosts in the USA. In sum, the molecular evolution of WNV in North America depicts a largely unfettered expansion within a permissive host and geographic population with little evidence of major adaptive barriers.

  10. Fluid Spatial Dynamics of West Nile Virus in the United States: Rapid Spread in a Permissive Host Environment.

    Science.gov (United States)

    Di Giallonardo, Francesca; Geoghegan, Jemma L; Docherty, Douglas E; McLean, Robert G; Zody, Michael C; Qu, James; Yang, Xiao; Birren, Bruce W; Malboeuf, Christine M; Newman, Ruchi M; Ip, Hon S; Holmes, Edward C

    2015-10-28

    The introduction of West Nile virus (WNV) into North America in 1999 is a classic example of viral emergence in a new environment, with its subsequent dispersion across the continent having a major impact on local bird populations. Despite the importance of this epizootic, the pattern, dynamics, and determinants of WNV spread in its natural hosts remain uncertain. In particular, it is unclear whether the virus encountered major barriers to transmission, or spread in an unconstrained manner, and if specific viral lineages were favored over others indicative of intrinsic differences in fitness. To address these key questions in WNV evolution and ecology, we sequenced the complete genomes of approximately 300 avian isolates sampled across the United States between 2001 and 2012. Phylogenetic analysis revealed a relatively star-like tree structure, indicative of explosive viral spread in the United States, although with some replacement of viral genotypes through time. These data are striking in that viral sequences exhibit relatively limited clustering according to geographic region, particularly for those viruses sampled from birds, and no strong phylogenetic association with well-sampled avian species. The genome sequence data analyzed here also contain relatively little evidence for adaptive evolution, particularly of structural proteins, suggesting that most viral lineages are of similar fitness and that WNV is well adapted to the ecology of mosquito vectors and diverse avian hosts in the United States. In sum, the molecular evolution of WNV in North America depicts a largely unfettered expansion within a permissive host and geographic population with little evidence of major adaptive barriers. How viruses spread in new host and geographic environments is central to understanding the emergence and evolution of novel infectious diseases and for predicting their likely impact. The emergence of the vector-borne West Nile virus (WNV) in North America in 1999

  11. The Host Response to a Clinical MDR Mycobacterial Strain Cultured in a Detergent-Free Environment: A Global Transcriptomics Approach.

    Directory of Open Access Journals (Sweden)

    Gina Leisching

    Full Text Available During Mycobacterium tuberculosis (M.tb infection, the initial interactions between the pathogen and the host cell determines internalization and innate immune response events. It is established that detergents such as Tween alter the mycobacterial cell wall and solubilize various lipids and proteins. The implication of this is significant since induced changes on the cell wall affect macrophage uptake and the immune response to M.tb. Importantly, during transmission between hosts, aerosolized M.tb enters the host in its native form, i.e. in a detergent-free environment, thus in vitro and in vivo studies should mimic this as closely as possible. To this end, we have optimized a procedure for growing and processing detergent-free M.tb and assessed the response of murine macrophages (BMDM infected with multi drug-resistant M.tb (R179 Beijing 220 clinical isolate using RNAseq. We compared the effects of the host response to M.tb cultured under standard laboratory conditions (Tween 80 containing medium -R179T, or in detergent-free medium (R179NT. RNAseq comparisons reveal 2651 differentially expressed genes in BMDMs infected with R179T M.tb vs. BMDMs infected with R179NT M.tb. A range of differentially expressed genes involved in BMDM receptor interaction with M.tb (Mrc1, Ifngr1, Tlr9, Fpr1 and Itgax and pro-inflammatory cytokines/chemokines (Il6, Il1b, Tnf, Ccl5 and Cxcl14 were selected for analysis through qPCR. BMDMs infected with R179NT stimulate a robust inflammatory response. Interestingly, R179NT M.tb induce transcription of Fpr1, a receptor which detects bacterial formyl peptides and initiates a myriad of immune responses. Additionally we show that the host components Cxcl14, with an unknown role in M.tb infection, and Tlr9, an emerging role player, are only stimulated by infection with R179NT M.tb. Taken together, our results suggest that the host response differs significantly in response to Tween 80 cultured M.tb and should therefore not

  12. The nuclear properties and extended morphologies of powerful radio galaxies: the roles of host galaxy and environment

    Science.gov (United States)

    Miraghaei, H.; Best, P. N.

    2017-04-01

    Powerful radio Galaxies exist as either compact or extended sources, with the extended sources traditionally classified by their radio morphologies as Fanaroff-Riley (FR) type I and II sources. FRI/FRII and compact radio galaxies have also been classified by their optical spectra into two different types: high excitation (HERG; quasar-mode) and low excitation (LERG; jet-mode). We present a catalogue of visual morphologies for a complete sample of >1000 1.4-GHz-selected extended radio sources from the Sloan Digital Sky Survey. We study the environment and host galaxy properties of FRI/FRII and compact sources, classified into HERG/LERG types, in order to separate and distinguish the factors that drive the radio morphological variations from those responsible for the spectral properties. Comparing FRI LERGs with FRII LERGs at fixed stellar mass and radio luminosity, we show that FRIs typically reside in richer environments and are hosted by smaller galaxies with higher mass surface density; this is consistent with extrinsic effects of jet disruption driving the Fanaroff-Riley (FR) dichotomy. Using matched samples of HERGs and LERGs, we show that HERG host galaxies are more frequently star forming, with more evidence for disc-like structure than LERGs, in accordance with currently favoured models of fundamentally different fuelling mechanisms. Comparing FRI/FRII LERGs with compact LERGs, we find the primary difference is that compact objects typically harbour less massive black holes. This suggests that lower mass black holes may be less efficient at launching stable radio jets, or do so for shorter times. Finally, we investigate rarer sub-classes: wide-angle-tailed, head-tail, FR-hybrid and double-double sources.

  13. Requirements-Driven Deployment: Customizing the Requirements Model for the Host Environment

    NARCIS (Netherlands)

    Ali, Raian; Dalpiaz, Fabiano; Giorgini, Paolo

    2014-01-01

    Deployment is a main development phase which configures a software to be ready for use in a certain environment. The ultimate goal of deployment is to enable users to achieve their requirements while using the deployed software. However, requirements are not uniform and differ between deployment

  14. A walk on the tundra: Host-parasite interactions in an extreme environment

    Science.gov (United States)

    The Arctic is a vast, sparsely populated region that has captured the imagination and interest of explorers and scientists for generations. It is an environment of extremes and has been considered by many an inhospitable landscape and the last frontier to be explored. Despite the ‘hardships’ impos...

  15. Enteric Helminths Promote Salmonella Coinfection by Altering the Intestinal Metabolome.

    Science.gov (United States)

    Reynolds, Lisa A; Redpath, Stephen A; Yurist-Doutsch, Sophie; Gill, Navkiran; Brown, Eric M; van der Heijden, Joris; Brosschot, Tara P; Han, Jun; Marshall, Natalie C; Woodward, Sarah E; Valdez, Yanet; Borchers, Christoph H; Perona-Wright, Georgia; Finlay, B Brett

    2017-04-15

    Intestinal helminth infections occur predominantly in regions where exposure to enteric bacterial pathogens is also common. Helminth infections inhibit host immunity against microbial pathogens, which has largely been attributed to the induction of regulatory or type 2 (Th2) immune responses. Here we demonstrate an additional 3-way interaction in which helminth infection alters the metabolic environment of the host intestine to enhance bacterial pathogenicity. We show that an ongoing helminth infection increased colonization by Salmonella independently of T regulatory or Th2 cells. Instead, helminth infection altered the metabolic profile of the intestine, which directly enhanced bacterial expression of Salmonella pathogenicity island 1 (SPI-1) genes and increased intracellular invasion. These data reveal a novel mechanism by which a helminth-modified metabolome promotes susceptibility to bacterial coinfection. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  16. Location and Pathogenic Potential of Blastocystis in the Porcine Intestine

    Science.gov (United States)

    Wang, Wenqi; Bielefeldt-Ohmann, Helle; Traub, Rebecca J.; Cuttell, Leigh; Owen, Helen

    2014-01-01

    Blastocystis is an ubiquitous, enteric protozoan of humans and many other species. Human infection has been associated with gastrointestinal disease such as irritable bowel syndrome, however, this remains unproven. A relevant animal model is needed to investigate the pathogenesis/pathogenicity of Blastocystis. We concluded previously that pigs are likely natural hosts of Blastocystis with a potentially zoonotic, host-adapted subtype (ST), ST5, and may make suitable animal models. In this study, we aimed to characterise the host-agent interaction of Blastocystis and the pig, including localising Blastocystis in porcine intestine using microscopy, PCR and histopathological examination of tissues. Intestines from pigs in three different management systems, i.e., a commercial piggery, a small family farm and a research herd (where the animals were immunosuppressed) were examined. This design was used to determine if environment or immune status influences intestinal colonisation of Blastocystis as immunocompromised individuals may potentially be more susceptible to blastocystosis and development of associated clinical signs. Intestines from all 28 pigs were positive for Blastocystis with all pigs harbouring ST5. In addition, the farm pigs had mixed infections with STs 1 and/or 3. Blastocystis organisms/DNA were predominantly found in the large intestine but were also detected in the small intestine of the immunosuppressed and some of the farm pigs, suggesting that immunosuppression and/or husbandry factors may influence Blastocystis colonisation of the small intestine. No obvious pathology was observed in the histological sections. Blastocystis was present as vacuolar/granular forms and these were found within luminal material or in close proximity to epithelial cells, with no evidence of attachment or invasion. These results concur with most human studies, in which Blastocystis is predominantly found in the large intestine in the absence of significant organic

  17. The molecular basis for control of ETEC enterotoxin expression in response to environment and host.

    Directory of Open Access Journals (Sweden)

    James R J Haycocks

    2015-01-01

    Full Text Available Enterotoxigenic Escherichia coli (ETEC cause severe diarrhoea in humans and neonatal farm animals. Annually, 380,000 human deaths, and multi-million dollar losses in the farming industry, can be attributed to ETEC infections. Illness results from the action of enterotoxins, which disrupt signalling pathways that manage water and electrolyte homeostasis in the mammalian gut. The resulting fluid loss is treated by oral rehydration. Hence, aqueous solutions of glucose and salt are ingested by the patient. Given the central role of enterotoxins in disease, we have characterised the regulatory trigger that controls toxin production. We show that, at the molecular level, the trigger is comprised of two gene regulatory proteins, CRP and H-NS. Strikingly, this renders toxin expression sensitive to both conditions encountered on host cell attachment and the components of oral rehydration therapy. For example, enterotoxin expression is induced by salt in an H-NS dependent manner. Furthermore, depending on the toxin gene, expression is activated or repressed by glucose. The precise sensitivity of the regulatory trigger to glucose differs because of variations in the regulatory setup for each toxin encoding gene.

  18. Risk Factors in Host and Environment for Cervicitis Among Commercial Sex Workers

    Directory of Open Access Journals (Sweden)

    Nazarwin Saputra

    2017-09-01

    Full Text Available sexually transmitted infection (STI remains a major health problem in some parts of the world. This study aimed to determine the host and environmental factors the effect on the incidence of cervicitis on sex workers. The study was observational case-control design with consecutive sampling technique. Risk factor for cervicitis is a history of sexually transmitted infections (p=0,0001, have couple (boy friend different gender (p=0,014, OR=4,4; CI95%=1,3-14,3, history of oral sex/cunnilingus (p=0,003, OR=6,8;CI95%=1,9-24,8, smokers (p=0,0001, CI95%=5,6; CI95%=2,4-13,1. Condom use last sex behavior is a protective factor affecting the incidence of cervicitis (p=0,0001, OR= 0,198; CI95 %=0,07- 0,5. The conclusion of this study is to prevent servisitis at-risk groups of commercial sex workers it should avoid from exposure of agents that cause sexually transmitted infections, does not have a spouse who is not authorized (girlfriend that leads to sex behavior, avoid behaviors oral sex / cunnilingus, no smoke. At-risk behavior should use condoms for prevention servisitis

  19. Intestinal barrier function of Atlantic salmon (Salmo salar L. post smolts is reduced by common sea cage environments and suggested as a possible physiological welfare indicator

    Directory of Open Access Journals (Sweden)

    Ellis Tim

    2010-11-01

    Full Text Available Abstract Background Fish farmed under high intensity aquaculture conditions are subjected to unnatural environments that may cause stress. Therefore awareness of how to maintain good health and welfare of farmed fish is important. For Atlantic salmon held in sea cages, water flow, dissolved oxygen (DO levels and temperature will fluctuate over time and the fish can at times be exposed to detrimentally low DO levels and high temperatures. This experimental study investigates primary and secondary stress responses of Atlantic salmon post smolts to long-term exposure to reduced and fluctuating DO levels and high water temperatures, mimicking situations in the sea cages. Plasma cortisol levels and cortisol release to the water were assessed as indicators of the primary stress response and intestinal barrier integrity and physiological functions as indicators of secondary responses to changes in environmental conditions. Results Plasma cortisol levels were elevated in fish exposed to low (50% and 60% saturation DO levels and low temperature (9°C, at days 9, 29 and 48. The intestinal barrier function, measured as electrical resistance (TER and permeability of mannitol at the end of the experiment, were reduced at 50% DO, in both proximal and distal intestine. When low DO levels were combined with high temperature (16°C, plasma cortisol levels were elevated in the cyclic 1:5 h at 85%:50% DO group and fixed 50% DO group compared to the control (85% DO group at day 10 but not at later time points. The intestinal barrier function was clearly disturbed in the 50% DO group; TER was reduced in both intestinal regions concomitant with increased paracellular permeability in the distal region. Conclusions This study reveals that adverse environmental conditions (low water flow, low DO levels at low and high temperature, that can occur in sea cages, elicits primary and secondary stress responses in Atlantic salmon post smolts. The intestinal barrier function

  20. Intestinal Cancer

    Science.gov (United States)

    ... connects your stomach to your large intestine. Intestinal cancer is rare, but eating a high-fat diet ... increase your risk. Possible signs of small intestine cancer include Abdominal pain Weight loss for no reason ...

  1. Trace metal concentrations in single specimens of the intestinal broad flatworm ( Diphyllobothrium latum), compared to their fish host ( Oncorhynchus mykiss) measured by total reflection X-ray fluorescence spectrometry

    Science.gov (United States)

    Woelfl, Stefan; Mages, Margarete; Torres, Patricio

    2008-12-01

    The aim of this study was to investigate (1) whether intestine endoparasites ( Diphyllobothrium latum) accumulate trace elements related to its body size and (2) whether parasites bioconcentrate more trace elements than their host. Freshwater fish (rainbow trout Oncorhynchus mykiss) were sampled in the deep, oligotrophic and uncontaminated Lake Riñihue in Southern Chile. The element concentration of different organs (intestine, muscle, liver) and of the intestine endoparasites were analyzed using total reflection X-ray fluorescence spectrometry. The results showed that the mass fraction for Mn, Fe, Ni, Cu, and Pb decreased significantly with the body size (dry weight) of the endoparasite. Only Zn did not reveal such a relationship. Small parasites accumulated up to 80 times more Fe, Ni, Mn, Pb, and Cu than large parasites. Compared to the fish organs, small parasites accumulated in maximum 35 to 307 times more Mn, 5 to 255 times more Fe, 98 to 220 times more Ni, 3 to 175 times more Cu, and 0.4 to 12 times more Zn than the fish. Lead was only found in the endoparasite, but not in the fish organs. We conclude that (1) D. latum is a good indicator for trace element accumulation in fishes and that (2) small endoparasites are more sensitive as bioindicators because they showed higher bioconcentrations of trace metals than larger parasites.

  2. Molecular pathological epidemiology of epigenetics: emerging integrative science to analyze environment, host, and disease.

    Science.gov (United States)

    Ogino, Shuji; Lochhead, Paul; Chan, Andrew T; Nishihara, Reiko; Cho, Eunyoung; Wolpin, Brian M; Meyerhardt, Jeffrey A; Meissner, Alexander; Schernhammer, Eva S; Fuchs, Charles S; Giovannucci, Edward

    2013-04-01

    phenotype, LINE-1 (long interspersed nucleotide element-1; also called long interspersed nuclear element-1; long interspersed element-1; L1) hypomethylation, etc), and host-disease interactions. In this article, we illustrate increasing contribution of modern pathology to broader public health sciences, which attests pivotal roles of pathologists in the new integrated MPE science towards our ultimate goal of personalized medicine and prevention.

  3. HOST-MICROFLORA INTERACTION IN SYSTEMIC LUPUS-ERYTHEMATOSUS (SLE) - COLONIZATION RESISTANCE OF THE INDIGENOUS BACTERIA OF THE INTESTINAL-TRACT

    NARCIS (Netherlands)

    APPERLOORENKEMA, H.Z.; Bootsma, H.; MULDER, B.I.; Kallenberg, Cees; VANDERWAAIJ, D.

    1994-01-01

    Experimental data suggest a role for the microflora in Systemic Lupus Erythematosus (SLE). Anti-ds-DNA antibodies may be pathogenic in SLE by forming immune complexes with DNA. Foreign bacteria in the intestines could constitute the stimulus for anti-ds-DNA antibody production in SLE. Colonization

  4. The Mouse Intestinal Bacterial Collection (miBC) provides host-specific insight into cultured diversity and functional potential of the gut microbiota

    DEFF Research Database (Denmark)

    Lagkouvardos, Ilias; Pukall, Rüdiger; Abt, Birte

    2016-01-01

    Intestinal bacteria influence mammalian physiology, but many types of bacteria are still uncharacterized. Moreover, reference strains of mouse gut bacteria are not easily available, although mouse models are extensively used in medical research. These are major limitations for the investigation o...

  5. The adaptive response of bacterial food-borne pathogens in the environment, host and food: Implications for food safety.

    Science.gov (United States)

    Alvarez-Ordóñez, Avelino; Broussolle, Véronique; Colin, Pierre; Nguyen-The, Christophe; Prieto, Miguel

    2015-11-20

    Bacteria are constantly faced to stress situations in their ecological niches, the food and the host gastrointestinal tract. The capacity to detect and respond to surrounding changes is crucial for bacterial pathogens to survive or grow in changing environments. To this purpose, cells have evolved various sophisticated networks designed to protect against stressors or repair damage caused by them. Challenges can occur during production of foods when subjected to processing, and after food ingestion when confronted with host defensive barriers. Some pathogenic bacteria have shown the capacity to develop stable resistance against extreme conditions within a defined genomic context and a limited number of generations. On the other hand, bacteria can also respond to adverse conditions in a transient manner, through the so-called stress tolerance responses. Bacterial stress tolerance responses include both structural and physiological modifications in the cell and are mediated by complex genetic regulatory machinery. Major aspects in the adaptive response are the sensing mechanisms, the characterization of cell defensive systems, such as the operation of regulatory proteins (e.g. RpoS), the induction of homeostatic and repair systems, the synthesis of shock response proteins, and the modifications of cell membranes, particularly in their fatty acid composition and physical properties. This article reviews certain strategies used by food-borne bacteria to respond to particular stresses (acid, cold stress, extreme pressure) in a permanent or transient manner and discusses the implications that such adaptive responses pose for food safety. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Stage-Specific Changes in Plasmodium Metabolism Required for Differentiation and Adaptation to Different Host and Vector Environments.

    Directory of Open Access Journals (Sweden)

    Anubhav Srivastava

    2016-12-01

    Full Text Available Malaria parasites (Plasmodium spp. encounter markedly different (nutritional environments during their complex life cycles in the mosquito and human hosts. Adaptation to these different host niches is associated with a dramatic rewiring of metabolism, from a highly glycolytic metabolism in the asexual blood stages to increased dependence on tricarboxylic acid (TCA metabolism in mosquito stages. Here we have used stable isotope labelling, targeted metabolomics and reverse genetics to map stage-specific changes in Plasmodium berghei carbon metabolism and determine the functional significance of these changes on parasite survival in the blood and mosquito stages. We show that glutamine serves as the predominant input into TCA metabolism in both asexual and sexual blood stages and is important for complete male gametogenesis. Glutamine catabolism, as well as key reactions in intermediary metabolism and CoA synthesis are also essential for ookinete to oocyst transition in the mosquito. These data extend our knowledge of Plasmodium metabolism and point towards possible targets for transmission-blocking intervention strategies. Furthermore, they highlight significant metabolic differences between Plasmodium species which are not easily anticipated based on genomics or transcriptomics studies and underline the importance of integration of metabolomics data with other platforms in order to better inform drug discovery and design.

  7. Stage-Specific Changes in Plasmodium Metabolism Required for Differentiation and Adaptation to Different Host and Vector Environments.

    Science.gov (United States)

    Srivastava, Anubhav; Philip, Nisha; Hughes, Katie R; Georgiou, Konstantina; MacRae, James I; Barrett, Michael P; Creek, Darren J; McConville, Malcolm J; Waters, Andrew P

    2016-12-01

    Malaria parasites (Plasmodium spp.) encounter markedly different (nutritional) environments during their complex life cycles in the mosquito and human hosts. Adaptation to these different host niches is associated with a dramatic rewiring of metabolism, from a highly glycolytic metabolism in the asexual blood stages to increased dependence on tricarboxylic acid (TCA) metabolism in mosquito stages. Here we have used stable isotope labelling, targeted metabolomics and reverse genetics to map stage-specific changes in Plasmodium berghei carbon metabolism and determine the functional significance of these changes on parasite survival in the blood and mosquito stages. We show that glutamine serves as the predominant input into TCA metabolism in both asexual and sexual blood stages and is important for complete male gametogenesis. Glutamine catabolism, as well as key reactions in intermediary metabolism and CoA synthesis are also essential for ookinete to oocyst transition in the mosquito. These data extend our knowledge of Plasmodium metabolism and point towards possible targets for transmission-blocking intervention strategies. Furthermore, they highlight significant metabolic differences between Plasmodium species which are not easily anticipated based on genomics or transcriptomics studies and underline the importance of integration of metabolomics data with other platforms in order to better inform drug discovery and design.

  8. Modulation of the intestinal environment, innate immune response, and barrier function by dietary threonine and purified fiber during a coccidiosis challenge in broiler chicks.

    Science.gov (United States)

    Wils-Plotz, E L; Jenkins, M C; Dilger, R N

    2013-03-01

    Coccidiosis is a major contributor to economic losses in the poultry industry due to its detrimental effects on growth performance and nutrient utilization. We hypothesized that the combined effects of supplemental dietary Thr and purified fiber may modulate the intestinal environment and positively affect intestinal immune responses and barrier function in broiler chicks infected with Eimeria maxima. A Thr-deficient basal diet (3.1 g of Thr/kg of diet) was supplemented with 70 g/kg of silica sand (control) or high-methoxy pectin and 1 of 2 concentrations of Thr (1.8 or 5.3 g/kg of diet; 4 diets total), and fed to chicks from hatch to d 16 posthatch. On d 10 posthatch, chicks received 0.5 mL of distilled water or an acute dose of Eimeria maxima (1.5 × 10(3) sporulated oocytes) with 6 replicate pens of 6 chicks per each of 8 treatment combinations (4 diets and 2 inoculation states). Body weight gain, feed intake, and G:F increased (P coccidiosis, Thr supplementation had the greatest effect on intestinal immune response and maintenance of near normal growth in young broiler chicks infected with E. maxima.

  9. The Impact of Host Rock Geochemistry on Bacterial Community Structure in Oligotrophic Cave Environments.

    Directory of Open Access Journals (Sweden)

    Hazel A. Barton

    2007-07-01

    Full Text Available Despite extremely starved conditions, caves contain surprisingly diverse microbial communities. Our research is geared toward understanding what ecosystems drivers are responsible for this high diversity. To asses the effect of rock fabric and mineralogy, we carried out a comparative geomicrobiology study within Carlsbad Cavern, New Mexico, USA. Samples were collected from two different geologic locations within the cave: WF1 in the Massive Member of the Capitan Formation and sF88 in the calcareous siltstones of the Yates Formation. We examined the organic content at each location using liquid chromatography mass spectroscopy and analyzed microbial community structure using molecular phylogenetic analyses. In order to assess whether microbial activity was leading to changes in the bedrock at each location, the samples were also examined by petrology, X-ray diffraction (XRD and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX. Our results suggest that on the chemically complex Yates Formation (sF88, the microbial community was significantly more diverse than on the limestone surfaces of the Capitan (WF1, despite a higher total number of cells on the latter. Further, the broader diversity of bacterial species at sF88 reflected a larger range of potential metabolic capabilities, presumably due to opportunities to use ions within the rock as nutrients and for chemolithotrophic energy production. The use of these ions at sF88 is supported by the formation of a corrosion residue, presumably through microbial scavenging activities. Our results suggest that rock fabric and mineralogy may be an important driver of ecosystem function and should be carefully reviewed when carrying out microbial community analysis in cave environments.

  10. Living with genome instability: the adaptation of phytoplasmas todiverse environments of their insect and plant hosts

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Xiaodong; Zhang, Jianhua; Ewing, Adam; Miller, Sally A.; Radek, Agnes; Shevchenko, Dimitriy; Tsukerman, Kiryl; Walunas, Theresa; Lapidus, Alla; Campbell, John W.; Hogenhout Saskia A.

    2006-02-17

    Phytoplasmas (Candidatus Phytoplasma, Class Mollicutes) cause disease in hundreds of economically important plants, and are obligately transmitted by sap-feeding insects of the order Hemiptera, mainly leafhoppers and psyllids. The 706,569-bp chromosome and four plasmids of aster yellows phytoplasma strain witches broom (AY-WB) were sequenced and compared to the onion yellows phytoplasma strain M (OY-M) genome. The phytoplasmas have small repeat-rich genomes. The repeated DNAs are organized into large clusters, potential mobile units (PMUs), which contain tra5 insertion sequences (ISs), and specialized sigma factors and membrane proteins. So far, PMUs are unique to phytoplasmas. Compared to mycoplasmas, phytoplasmas lack several recombination and DNA modification functions, and therefore phytoplasmas probably use different mechanisms of recombination, likely involving PMUs, for the creation of variability, allowing phytoplasmas to adjust to the diverse environments of plants and insects. The irregular GC skews and presence of ISs and large repeated sequences in the AY-WB and OY-M genomes are indicative of high genomic plasticity. Nevertheless, segments of {approx}250 kb, located between genes lplA and glnQ are syntenic between the two phytoplasmas, contain the majority of the metabolic genes and no ISs. AY-WB is further along in the reductive evolution process than OY-M. The AY-WB genome is {approx}154 kb smaller than the OY-M genome, primarily as a result of fewer multicopy sequences, including PMUs. Further, AY-WB lacks genes that are truncated and are part of incomplete pathways in OY-M. This is the first comparative phytoplasma genome analysis and report of the existence of PMUs in phytoplasma genomes.

  11. Isolation and characterization of Listeria species from rodents in natural environments in China

    OpenAIRE

    Wang, Yan; Lu, Liang; Lan, Ruiting; Salazar, Joelle K; Liu, Jingli; Xu, Jianguo; Ye, Changyun

    2017-01-01

    Listeria is ubiquitous in a variety of environments and can be isolated from a wide range of animal hosts. Rodents are capable of carrying pathogenic bacteria in their intestines, such as Listeria, and can disseminate those pathogens into the natural environment and to where human activity occurs. In this study, we investigated the occurrence and antimicrobial susceptibility of List eria spp. isolated from wild rodents found in natural environments in China. We collected 341 intestinal fecal ...

  12. Developmental adaptations of trypanosome motility to the tsetse fly host environments unravel a multifaceted in vivo microswimmer system.

    Science.gov (United States)

    Schuster, Sarah; Krüger, Timothy; Subota, Ines; Thusek, Sina; Rotureau, Brice; Beilhack, Andreas; Engstler, Markus

    2017-08-15

    The highly motile and versatile protozoan pathogen Trypanosoma brucei undergoes a complex life cycle in the tsetse fly. Here we introduce the host insect as an expedient model environment for microswimmer research, as it allows examination of microbial motion within a diversified, secluded and yet microscopically tractable space. During their week-long journey through the different microenvironments of the fly´s interior organs, the incessantly swimming trypanosomes cross various barriers and confined surroundings, with concurrently occurring major changes of parasite cell architecture. Multicolour light sheet fluorescence microscopy provided information about tsetse tissue topology with unprecedented resolution and allowed the first 3D analysis of the infection process. High-speed fluorescence microscopy illuminated the versatile behaviour of trypanosome developmental stages, ranging from solitary motion and near-wall swimming to collective motility in synchronised swarms and in confinement. We correlate the microenvironments and trypanosome morphologies to high-speed motility data, which paves the way for cross-disciplinary microswimmer research in a naturally evolved environment.

  13. [Intestinal microbiota].

    Science.gov (United States)

    Perez, Horacio Joaquín; Menezes, Maria Elisabeth; d'Acâmpora, Armando José

    2014-01-01

    There is accumulative evidence on the multiple functions of the intestinal microflora in relation to the homeostasis of the host. At first considered as a simple mutualism, today this relationship proves to be essential to the health and to pathologic processes, particularly metabolic (eg, obesity) and gastrointestinal (eg, inflammatory bowel disease and functional disorders). The first studies were conducted on the microbiota from fecal material cultured anaerobically. With the advent of molecular biology, it has become possible to determine qualitative and quantitatively the dominant, subdominant and transients species. In recent years, there were advances in the understanding of the relationship betwen the microbiota and the host, as well as among the microorganisms in their respective niches. These advances result from translational integration of microbiology with specialities such as molecular biology, cell phisiology, immunology and ecology. There are few studies on the spatial distribution of the microflora in the gut. Unravelling the topography of the microflora in mammals is a way to validate new animal models for the study of microflora.

  14. Protecting intestinal epithelial integrity by galacto-oligosaccharides: Keeping it tight

    NARCIS (Netherlands)

    Akbari, P.

    2016-01-01

    The intestinal barrier serves as a first line of host defense against potentially harmful stressors from the environment ingested with food, and is primarily formed by epithelial cells connected by tight junctions. Oligosaccharides have been identified as components in milk, particularly in

  15. The Old Host-galaxy Environment of SSS17a, the First Electromagnetic Counterpart to a Gravitational-wave Source

    Science.gov (United States)

    Pan, Y.-C.; Kilpatrick, C. D.; Simon, J. D.; Xhakaj, E.; Boutsia, K.; Coulter, D. A.; Drout, M. R.; Foley, R. J.; Kasen, D.; Morrell, N.; Murguia-Berthier, A.; Osip, D.; Piro, A. L.; Prochaska, J. X.; Ramirez-Ruiz, E.; Rest, A.; Rojas-Bravo, C.; Shappee, B. J.; Siebert, M. R.

    2017-10-01

    We present an analysis of the host-galaxy environment of Swope Supernova Survey 2017a (SSS17a), the discovery of an electromagnetic counterpart to a gravitational-wave source, GW170817. SSS17a occurred 1.9 kpc (in projection; 10.″2) from the nucleus of NGC 4993, an S0 galaxy at a distance of 40 Mpc. We present a Hubble Space Telescope (HST) pre-trigger image of NGC 4993, Magellan optical spectroscopy of the nucleus of NGC 4993 and the location of SSS17a, and broadband UV-through-IR photometry of NGC 4993. The spectrum and broadband spectral-energy distribution indicate that NGC 4993 has a stellar mass of {log}(M/{M}⊙ )={10.49}-0.20+0.08 and star formation rate of 0.003 {M}⊙ yr-1, and the progenitor system of SSS17a likely had an age of >2.8 Gyr. There is no counterpart at the position of SSS17a in the HST pre-trigger image, indicating that the progenitor system had an absolute magnitude {M}V> -5.8 mag. We detect dust lanes extending out to almost the position of SSS17a and >100 likely globular clusters associated with NGC 4993. The offset of SSS17a is similar to many short gamma-ray-burst offsets, and its progenitor system was likely bound to NGC 4993. The environment of SSS17a is consistent with an old progenitor system such as a binary neutron star system. This paper includes data gathered with the 6.5 meter Magellan Telescopes located at Las Campanas Observatory, Chile.

  16. [The human gut microbiota: Interactions with the host and dysfunctions].

    Science.gov (United States)

    Lepage, P

    2017-05-12

    The human intestinal microbiota is composed of approximately 100,000 billion microorganisms with the average total number of different commensal bacterial species estimated at over 500 per individual. The human intestinal microbiota can be considered as an organ within another, which co-evolved with its host to achieve a symbiotic relationship leading to physiological homeostasis. The host provides an environment enriched in nutrients and the microbiota provides essential functions. Dysbiosis of the intestinal microbiota (changes in bacterial composition) has been associated with local dysfunctions of the gastrointestinal tract, such as inflammatory bowel disease or irritable bowel syndrome but also with obesity and metabolic diseases. However, a better understanding of the human intestinal ecosystem is still needed to understand the exact role of the microbiota in health and disease. Most intestinal bacteria are anaerobic and therefore, for the large majority, impossible to culture at present. Consequently, their function cannot be inferred from data on their composition. Today, with the help of a metagenomic approach, the bacterial genomic content of an ecosystem and the associated functions can be directly accessed from the environment without culture. Copyright © 2017 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  17. Ticks and tick-borne pathogens at the cutaneous interface: host defenses, tick countermeasures, and a suitable environment for pathogen establishment

    Directory of Open Access Journals (Sweden)

    Stephen eWikel

    2013-11-01

    Full Text Available Ticks are unique among hematophagous arthropods by continuous attachment to host skin and blood feeding for days; complexity and diversity of biologically active molecules differentially expressed in saliva of tick species; their ability to modulate the host defenses of pain and itch, hemostasis, inflammation, innate and adaptive immunity, and wound healing; and, the diverse array of infectious agents they transmit. All of these interactions occur at the cutaneous interface in a complex sequence of carefully choreographed host defense responses and tick countermeasures resulting in an environment that facilitates successful blood feeding and establishment of tick-borne infectious agents within the host. Here, we examine diverse patterns of tick attachment to host skin, blood feeding mechanisms, salivary gland transcriptomes, bioactive molecules in tick saliva, timing of pathogen transmission, and host responses to tick bite. Ticks engage and modulate cutaneous and systemic immune defenses involving keratinocytes, natural killer cells, dendritic cells, T cell subpopulations (Th1, Th2, Th17, Treg , B cells, neutrophils, mast cells, basophils, endothelial cells, cytokines, chemokines, complement, and extracellular matrix. A framework is proposed that integrates tick induced changes of skin immune effectors with their ability to respond to tick-borne pathogens. Implications of these changes are addressed. What are the consequences of tick modulation of host cutaneous defenses? Does diversity of salivary gland transcriptomes determine differential modulation of host inflammation and immune defenses and therefore, in part, the clades of pathogens effectively transmitted by different tick species? Do ticks create an immunologically modified cutaneous environment that enhances specific pathogen establishment? Can tick saliva molecules be used to develop vaccines that block pathogen transmission?

  18. In vitro activated CD4+ T cells from interferon-gamma (IFN-gamma)-deficient mice induce intestinal inflammation in immunodeficient hosts

    DEFF Research Database (Denmark)

    Bregenholt, S; Brimnes, J; Nissen, Mogens Holst

    1999-01-01

    To investigate the role of IFN-gamma in the immunopathogenesis of inflammatory bowel disease (IBD), severe combined immunodeficient (SCID) mice were transplanted with in vitro activated CD4+ T cells from either wild-type (WT) or IFN-gamma-deficient (IFN-gammaKO) BALB/c mice. In vitro, the two types...... of T cells displayed comparable proliferation rates and production of tumour necrosis factor-alpha (TNF-alpha), IL-2, IL-4 and IL-10 after concanavalin A (Con A) stimulation. When transplanted into SCID mice, WT CD4+ blasts induced a lethal IBD, whereas IFN-gammaKO blasts induced a less severe...... intestinal inflammation with moderate weight loss. Intracellular cytokine staining of lamina propria lymphocytes (LPL) revealed comparable fractions of CD4+ T cells positive for TNF-alpha, IL-2 and IL-10 in the two groups of transplanted SCID mice, whereas a two-to-three-fold increase in the fraction of IL-4...

  19. Intestinal Barrier Interactions with Specialized CD8 T Cells

    Directory of Open Access Journals (Sweden)

    Špela Konjar

    2017-10-01

    Full Text Available The trillions of microorganisms that reside in the gastrointestinal tract, essential for nutrient absorption, are kept under control by a single cell barrier and large amounts of immune cells. Intestinal epithelial cells (IECs are critical in establishing an environment supporting microbial colonization and immunological tolerance. A large population of CD8+ T cells is in direct and constant contact with the IECs and the intraepithelial lymphocytes (IELs. Due to their location, at the interphase of the intestinal lumen and external environment and the host tissues, they seem ideally positioned to balance immune tolerance and protection to preserve the fragile intestinal barrier from invasion as well as immunopathology. IELs are a heterogeneous population, with a large innate-like contribution of unknown specificity, intercalated with antigen-specific tissue-resident memory T cells. In this review, we provide a comprehensive overview of IEL physiology and how they interact with the IECs and contribute to immune surveillance to preserve intestinal homeostasis and host-microbial relationships.

  20. Effect of Caenorhabditis elegans age and genotype on horizontal gene transfer in intestinal bacteria

    Science.gov (United States)

    Portal-Celhay, Cynthia; Nehrke, Keith; Blaser, Martin J.

    2013-01-01

    Horizontal gene transfer (HGT) between bacteria occurs in the intestinal tract of their animal hosts and facilitates both virulence and antibiotic resistance. A model in which both the pathogen and the host are genetically tractable facilitates developing insight into mechanistic processes enabling or restricting the transfer of antibiotic resistance genes. Here we develop an in vivo experimental system to study HGT in bacteria using Caenorhabditis elegans as a model host. Using a thermosensitive conjugative system, we provide evidence that conjugation between two Escherichia coli strains can take place in the intestinal lumen of N2 wild-type worms at a rate of 10−3 and 10−2 per donor. We also show that C. elegans age and genotype are important determinants of the frequency of conjugation. Whereas ∼1 transconjugant for every 100 donor cells could be recovered from the intestine of N2 C. elegans, for the age-1 and tol-1 mutants, the detected rate of transconjugation (10−3 and 10−4 per donor cell, respectively) was significantly lower. This work demonstrates that increased recombination among lumenal microbial populations is a phenotype associated with host aging, and the model provides a framework to study the dynamics of bacterial horizontal gene transfer within the intestinal environment.—Portal-Celhay, C., Nehrke, K., Blaser, M. J. Effect of Caenorhabditis elegans age and genotype on horizontal gene transfer in intestinal bacteria. PMID:23085995

  1. Impacts of diarrhea on the immune system, intestinal environment, and expression of PGRPs in New Zealand rabbits

    Directory of Open Access Journals (Sweden)

    Yang Chen

    2017-11-01

    Full Text Available Diarrhea is a syndrome of digestive disorders in young rabbits and may lead to secondary infections resulting in reduced immunity and higher mortality in baby rabbits, with serious impacts on rabbit farming. In this study, we investigated the effects of diarrhea on the health of baby rabbits in terms of intestinal mucosal development, immune function, and intestinal microbial diversity. We found that the duodenal villus length and the villus/crypt ratio in rabbits with diarrhea were significantly reduced compared with those in healthy rabbits (P < 0.01. Rabbits with diarrhea had significantly lower concentrations of acetic acid (P < 0.05, higher pH levels (P < 0.05, and higher levels of ammonia nitrogen (P < 0.01 in the cecum. Moreover, diarrhea in baby rabbits led to significantly reduced levels of total serum protein (P < 0.05 and markedly increased levels of alkaline phosphatase, urea nitrogen, TNF-α, and IL-6 (P < 0.05. Transcriptional analysis of peptidoglycan recognition proteins (PGRPs, including PGLYRP-1, PGLYRP-2, and PGLYRP-3 using real-time PCR revealed that diarrhea induced the upregulation of PGRPs in the cecum and duodenum. Furthermore, through pyrosequencing of the 16S rRNA V4 region in cecum samples, we found that the total number and diversity of microbes were not significantly different between healthy rabbits and those with diarrhea, though there were noticeable differences in the prevalences of Clostridium, Roseburia, and Alistipes. Our results will contribute to a better understanding of the pathological mechanisms of diarrhea in young rabbits.

  2. Differences in performance and transcriptome-wide gene expression associated with Rhagoletis (Diptera: Tephritidae) larvae feeding in alternate host fruit environments.

    Science.gov (United States)

    Ragland, Gregory J; Almskaar, Kristin; Vertacnik, Kim L; Gough, Harlan M; Feder, Jeffrey L; Hahn, Daniel A; Schwarz, Dietmar

    2015-06-01

    Host race formation, the establishment of new populations using novel resources, is a major hypothesized mechanism of ecological speciation, especially in plant-feeding insects. The initial stages of host race formation will often involve phenotypic plasticity on the novel resource, with subsequent genetically based adaptations enhancing host-associated fitness differences. Several studies have explored the physiology of the plastic responses of insects to novel host environments. However, the mechanisms underlying evolved differences among host races and species remain poorly understood. Here, we demonstrate a reciprocal larval performance difference between two closely related species of Rhagoletis flies, R. pomonella and R. zephyria, specialized for feeding in apple and snowberry fruit, respectively. Microarray analysis of fly larvae feeding in apples versus snowberries revealed patterns of transcriptome-wide differential gene expression consistent with both plastic and evolved responses to the different fruit resources, most notably for detoxification-related genes such as cytochrome p450s. Transcripts exhibiting evolved expression differences between species tended to also demonstrate plastic responses to fruit environment. The observed pattern suggests that Rhagoletis larvae exhibit extensive plasticity in gene expression in response to novel fruit that may potentiate shifts to new hosts. Subsequent selection, particularly selection to suppress initially costly plastic responses, could account for the evolved expression differences observed between R. pomonella and R. zephyria, creating specialized races and new fly species. Thus, genetically based ecological adaptations generating new biodiversity may often evolve from initial plastic responses in gene expression to the challenges posed by novel environments. © 2015 John Wiley & Sons Ltd.

  3. A concept for the removal of microplastics from the marine environment with innovative host-guest relationships.

    Science.gov (United States)

    Herbort, Adrian Frank; Schuhen, Katrin

    2017-04-01

    Environmental pollution caused by inert anthropogenic stressors such as microplastics in aquatic media is constantly increasing. Through the proliferating use of plastic products in daily life, more and more plastic particles enter waters as primary microplastics. Even though large scale plastic items such as plastic bottles and bags represent the highest percentage of plastic waste, their degeneration also generates microparticles and nanoparticles (secondary microplastics). Modern sewage treatment plants require innovative ideas in order to deal with this man-made problem. State-of-the-art technology offers approaches to minimise the amount of microplastics in aquatic systems. These technologies, however, are either insufficient or very costly, as well as time-consuming in both cases. The conceptual idea presented here is to apply innovative inorganic-organic hybrid silica gels which provide a cost-effective and straightforward approach. Currently, the synthesis of preorganised bioinspired compounds is advancing in order to produce functionalised hybrid silica gels in a further step. These gels have the ability to remove stressors such as microplastics from waste water. By means of the sol-gel process, bioinspired silane compounds are currently being permuted to macromolecules and examined with respect to their properties as fixation and filter material in order to remove the hydrophobic anthropogenic stressors sustainably. Here, the reproduction of biological systems plays a significant role. In particular in material sciences, this approach is becoming increasingly important. Among other concepts, new biomimetic molecules form the basis for the investigation of innovative host-guest relationships for anthropogenic stressors in the environment and their implementation in technical processes.

  4. Optimizing protein and energy intake in hospitals by improving individualized meal serving, hosting and the eating environment.

    Science.gov (United States)

    Holst, Mette; Beermann, Tina; Mortensen, Marie Nerup; Skadhauge, Lotte Boa; Køhler, Marianne; Lindorff-Larsen, Karen; Rasmussen, Henrik Højgaard

    2017-02-01

    Optimizing protein and energy intake by food in nutritional risk patients is difficult. The aim of this study was to improve the ≥75% of energy and protein requirements. We would like to see nurses take on the role of hosting the nutritional-risk patients, including focusing on bringing nutrition to the forefront in the collaboration between nurses and patients. This was an interventional study that included patients admitted to the Departments of Infectious Diseases, Hematology, and Heart-Lung Surgery in a baseline and follow-up investigation. It included 24-h food intake registrations (FRs) for 3 d consecutively, a questionnaire, and a semistructured patient interview. The interventions included in this study helped to improve the eating environment and serving, integrated nutrition into the nurse-patient welcome interview, and targeted individual preferences and challenges for eating. The study comprised 76 24-h FRs at baseline and 108 FRs at follow-up. The total group had improved food intake; 75% of individual energy requirements were met by (67.6% vs. 40%; P = 0.036) and the Heart-Lung Surgery group (85.7 vs. 38.5; P = 0.036). This was not reflected for protein (NS). Energy intake improved for the entire group, albeit not significantly (P = 0.862). Patients reported being happy with the interventions regarding individualized food serving, nurse communication, and improved meal environments. Only insignificant improvements to overall energy intake were seen in two of the three departments and in the overall group, and no statistical or clinically significant improvements to protein intake were observed. The relative risk of meeting 75% of energy requirements was improved in the overall group and in patients in the Department of Heart-Lung Surgery. This did not include the meeting of protein requirements. Improvements were welcomed by patients and staff. Focus on individualized nutrition from the nursing staff also improved. Copyright © 2016 Elsevier

  5. Always one step ahead: How pathogenic bacteria use the type III secretion system to manipulate the intestinal mucosal immune system

    Directory of Open Access Journals (Sweden)

    Marchès Olivier

    2011-05-01

    Full Text Available Abstract The intestinal immune system and the epithelium are the first line of defense in the gut. Constantly exposed to microorganisms from the environment, the gut has complex defense mechanisms to prevent infections, as well as regulatory pathways to tolerate commensal bacteria and food antigens. Intestinal pathogens have developed strategies to regulate intestinal immunity and inflammation in order to establish or prolong infection. The organisms that employ a type III secretion system use a molecular syringe to deliver effector proteins into the cytoplasm of host cells. These effectors target the host cell cytoskeleton, cell organelles and signaling pathways. This review addresses the multiple mechanisms by which the type III secretion system targets the intestinal immune response, with a special focus on pathogenic E. coli.

  6. Gut microbiota - architects of small intestinal capillaries.

    Science.gov (United States)

    Khandagale, Avinash; Reinhardt, Christoph

    2018-01-01

    The commensal gut microbiota is an environmental factor that exerts manifold effects on host physiology. One obvious trait is the impact of this densely colonized ecosystem on small intestinal mucosal vascularization. At present, the microbiota-triggered signaling pathways influencing small intestinal renewal, angiogenesis, and vascular remodeling are largely unexplored. While the interplay of gut microbial communities with pattern recognition receptors, such as Toll-like receptors, in intestinal homeostasis is increasingly understood, it is unresolved how commensal microbiota affect the signaling pathways responsible for the formation of capillary networks in the intestinal mucosa. It is evident that intestinal vascular remodeling and renewal is disturbed in case of dysbiosis of this densely colonized microbial ecosystem, in particular under conditions of intestinal inflammation, but the effects of individual components of the gut microbiota are elusive. This review article provides an overview on the revealed microbiota-host interactions, influencing angiogenesis and vascular remodeling processes in the small intestine.

  7. The Inside Story of Shigella Invasion of Intestinal Epithelial Cells

    Science.gov (United States)

    Carayol, Nathalie; Tran Van Nhieu, Guy

    2013-01-01

    As opposed to other invasive pathogens that reside into host cells in a parasitic mode, Shigella, the causative agent of bacillary dysentery, invades the colonic mucosa but does not penetrate further to survive into deeper tissues. Instead, Shigella invades, replicates, and disseminates within the colonic mucosa. Bacterial invasion and spreading in intestinal epithelium lead to the elicitation of inflammatory responses responsible for the tissue destruction and shedding in the environment for further infection of other hosts. In this article, we highlight specific features of the Shigella arsenal of virulence determinants injected by a type III secretion apparatus (T3SA) that point to the targeting of intestinal epithelial cells as a discrete route of invasion during the initial event of the infectious process. PMID:24086068

  8. Monalysin, a novel ß-pore-forming toxin from the Drosophila pathogen Pseudomonas entomophila, contributes to host intestinal damage and lethality.

    Directory of Open Access Journals (Sweden)

    Onya Opota

    2011-09-01

    Full Text Available Pseudomonas entomophila is an entomopathogenic bacterium that infects and kills Drosophila. P. entomophila pathogenicity is linked to its ability to cause irreversible damages to the Drosophila gut, preventing epithelium renewal and repair. Here we report the identification of a novel pore-forming toxin (PFT, Monalysin, which contributes to the virulence of P. entomophila against Drosophila. Our data show that Monalysin requires N-terminal cleavage to become fully active, forms oligomers in vitro, and induces pore-formation in artificial lipid membranes. The prediction of the secondary structure of the membrane-spanning domain indicates that Monalysin is a PFT of the ß-type. The expression of Monalysin is regulated by both the GacS/GacA two-component system and the Pvf regulator, two signaling systems that control P. entomophila pathogenicity. In addition, AprA, a metallo-protease secreted by P. entomophila, can induce the rapid cleavage of pro-Monalysin into its active form. Reduced cell death is observed upon infection with a mutant deficient in Monalysin production showing that Monalysin plays a role in P. entomophila ability to induce intestinal cell damages, which is consistent with its activity as a PFT. Our study together with the well-established action of Bacillus thuringiensis Cry toxins suggests that production of PFTs is a common strategy of entomopathogens to disrupt insect gut homeostasis.

  9. Chronic Trichuris muris infection decreases diversity of the intestinal microbiota and concomitantly increases the abundance of lactobacilli

    DEFF Research Database (Denmark)

    Holm, Jacob Bak; Sorobetea, Daniel; Kiilerich, Pia

    2015-01-01

    The intestinal microbiota is vital for shaping the local intestinal environment as well as host immunity and metabolism. At the same time, epidemiological and experimental evidence suggest an important role for parasitic worm infections in maintaining the inflammatory and regulatory balance...... microbiota, as well as potential downstream effects on the immune system, remain largely unknown. We have assessed the influence of chronic infection with the large-intestinal nematode Trichuris muris, a close relative of the human pathogen Trichuris trichiura, on the composition of the murine intestinal...... microbiota by 16S ribosomal-RNA gene-based sequencing. Our results demonstrate that persistent T. muris infection dramatically affects the large-intestinal microbiota, most notably with a drop in the diversity of bacterial communities, as well as a marked increase in the relative abundance...

  10. Context-dependent protein folding of a virulence peptide in the bacterial and host environments: structure of an SycH–YopH chaperone–effector complex

    Energy Technology Data Exchange (ETDEWEB)

    Vujanac, Milos; Stebbins, C. Erec, E-mail: stebbins@rockefeller.edu [The Rockefeller University, New York, NY 10065 (United States)

    2013-04-01

    The structure of a SycH–YopH chaperone–effector complex from Yersinia reveals the bacterial state of a protein that adopts different folds in the host and pathogen environments. Yersinia pestis injects numerous bacterial proteins into host cells through an organic nanomachine called the type 3 secretion system. One such substrate is the tyrosine phosphatase YopH, which requires an interaction with a cognate chaperone in order to be effectively injected. Here, the first crystal structure of a SycH–YopH complex is reported, determined to 1.9 Å resolution. The structure reveals the presence of (i) a nonglobular polypeptide in YopH, (ii) a so-called β-motif in YopH and (iii) a conserved hydrophobic patch in SycH that recognizes the β-motif. Biochemical studies establish that the β-motif is critical to the stability of this complex. Finally, since previous work has shown that the N-terminal portion of YopH adopts a globular fold that is functional in the host cell, aspects of how this polypeptide adopts radically different folds in the host and in the bacterial environments are analysed.

  11. The intestinal microbiota, gastrointestinal environment and colorectal cancer: a putative role for probiotics in prevention of colorectal cancer?

    Science.gov (United States)

    Sikes, Michael; Bruno-Bárcena, José M.

    2011-01-01

    Colorectal cancer (CRC) is the third most commonly diagnosed cancer in the United States, and, even though 5–15% of the total CRC cases can be attributed to individual genetic predisposition, environmental factors could be considered major factors in susceptibility to CRC. Lifestyle factors increasing the risks of CRC include elevated body mass index, obesity, and reduced physical activity. Additionally, a number of dietary elements have been associated with higher or lower incidence of CRC. In this context, it has been suggested that diets high in fruit and low in meat might have a protective effect, reducing the incidence of colorectal adenomas by modulating the composition of the normal nonpathogenic commensal microbiota. In addition, it has been demonstrated that changes in abundance of taxonomic groups have a profound impact on the gastrointestinal physiology, and an increasing number of studies are proposing that the microbiota mediates the generation of dietary factors triggering colon cancer. High-throughput sequencing and molecular taxonomic technologies are rapidly filling the knowledge gaps left by conventional microbiology techniques to obtain a comprehensive catalog of the human intestinal microbiota and their associated metabolic repertoire. The information provided by these studies will be essential to identify agents capable of modulating the massive amount of gut bacteria in safe noninvasive manners to prevent CRC. Probiotics, defined as “live microorganisms which, when administered in adequate amounts, confer a health benefit on the host” (219), are capable of transient modulation of the microbiota, and their beneficial effects include reinforcement of the natural defense mechanisms and protection against gastrointestinal disorders. Probiotics have been successfully used to manage infant diarrhea, food allergies, and inflammatory bowel disease; hence, the purpose of this review was to examine probiotic metabolic activities that may have an

  12. Intestinal Surgery.

    Science.gov (United States)

    Desrochers, André; Anderson, David E

    2016-11-01

    A wide variety of disorders affecting the intestinal tract in cattle may require surgery. Among those disorders the more common are: intestinal volvulus, jejunal hemorrhage syndrome and more recently the duodenal sigmoid flexure volvulus. Although general principles of intestinal surgery can be applied, cattle has anatomical and behavior particularities that must be known before invading the abdomen. This article focuses on surgical techniques used to optimize outcomes and discusses specific disorders of small intestine. Diagnoses and surgical techniques presented can be applied in field conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Host-microbe interactions in the gut of Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Takayuki eKuraishi

    2013-12-01

    Full Text Available Many insect species subsist on decaying and contaminated matter and are thus exposed to large quantities of microorganisms. To control beneficial commensals and combat infectious pathogens, insects must be armed with efficient systems for microbial recognition, signaling pathways, and effector molecules. The molecular mechanisms regulating these host-microbe interactions in insects have been largely clarified in Drosophila melanogaster with its powerful genetic and genomic tools. Here we review recent advances in this field, focusing mainly on the relationships between microbes and epithelial cells in the intestinal tract where the host exposure to the external environment is most frequent.

  14. Intestinal and multivisceral transplantation.

    Science.gov (United States)

    Meira Filho, Sérgio Paiva; Guardia, Bianca Della; Evangelista, Andréia Silva; Matielo, Celso Eduardo Lourenço; Neves, Douglas Bastos; Pandullo, Fernando Luis; Felga, Guilherme Eduardo Gonçalves; Alves, Jefferson André da Silva; Curvelo, Lilian Amorim; Diaz, Luiz Gustavo Guedes; Rusi, Marcela Balbo; Viveiros, Marcelo de Melo; Almeida, Marcio Dias de; Epstein, Marina Gabrielle; Pedroso, Pamella Tung; Salvalaggio, Paolo; Meirelles Júnior, Roberto Ferreira; Rocco, Rodrigo Andrey; Almeida, Samira Scalso de; Rezende, Marcelo Bruno de

    2015-01-01

    Intestinal transplantation has shown exceptional growth over the past 10 years. At the end of the 1990's, intestinal transplantation moved out of the experimental realm to become a routine practice in treating patients with severe complications related to total parenteral nutrition and intestinal failure. In the last years, several centers reported an increasing improvement in survival outcomes (about 80%), during the first 12 months after surgery, but long-term survival is still a challenge. Several advances led to clinical application of transplants. Immunosuppression involved in intestinal and multivisceral transplantation was the biggest gain for this procedure in the past decade due to tacrolimus, and new inducing drugs, mono- and polyclonal anti-lymphocyte antibodies. Despite the advancement of rigid immunosuppression protocols, rejection is still very frequent in the first 12 months, and can result in long-term graft loss. The future of intestinal transplantation and multivisceral transplantation appears promising. The major challenge is early recognition of acute rejection in order to prevent graft loss, opportunistic infections associated to complications, post-transplant lymphoproliferative disease and graft versus host disease; and consequently, improve results in the long run.

  15. Combining Immersive Virtual Worlds and Virtual Learning Environments into an Integrated System for Hosting and Supporting Virtual Conferences

    Science.gov (United States)

    Polychronis, Nikolaos; Patrikakis, Charalampos; Voulodimos, Athanasios

    In this paper, a proposal for hosting and supporting virtual conferences based on the use of state of the art web technologies and computer mediated education software is presented. The proposed system consists of a virtual conference venue hosted in Second Life platform, targeted at hosting synchronous conference sessions, and of a web space created with the use of the e-learning platform Moodle, targeted at serving the needs of asynchronous communication, as well as user and content management. The use of Sloodle (the next generation of Moodle software incorporating virtual world supporting capabilities), which up to now has been used only in traditional education, enables the combination of the virtual conference venue and the conference supporting site into an integrated system that allows for the conduction of successful and cost-effective virtual conferences.

  16. Identification of novel esterase-active enzymes from hot environments by use of the host bacterium Thermus thermophilus

    Directory of Open Access Journals (Sweden)

    Benedikt eLeis

    2015-04-01

    Full Text Available Functional metagenomic screening strategies, which are independent of known sequence information, can lead to the identification of truly novel genes and enzymes. Since E. coli has been used exhaustively for this purpose as a host, it is important to establish alternative expression hosts and to use them for functional metagenomic screening for new enzymes. In this study we show that Thermus thermophilus HB27 is an excellent screening host and can be used as an alternative provider of truly novel biocatalysts. In a previous study we constructed the mutant strain BL03 that was no longer able to grow on defined minimal medium supplemented with tributyrin as the sole carbon source and could be used as a host to screen for metagenomic DNA fragments that could complement growth on tributyrin. Several thousand single fosmid clones from thermophilic metagenomic libraries from heated compost and hot spring water samples were subjected to a comparative screening for esterase activity in both T. thermophilus strain BL03 and E. coli EPI300. We scored a greater number of active clones in the thermophilic bacterium than in the mesophilic E. coli. From all clones functionally screened in E. coli, only two thermostable α/β-fold hydrolase enzymes with high amino acid sequence similarity to already characterized enzymes were identifiable. In contrast, five further fosmids were found that conferred lipolytic activities in T. thermophilus. Four open reading frames (ORFs were found which did not share significant similarity to known esterase enzymes. Two of the genes were expressed in both hosts and the novel thermophilic esterases, which based on their primary structures could not be assigned to known esterase or lipase families, were purified and preliminarily characterized. Our work underscores the benefit of using additional screening hosts other than E. coli for the identification of novel biocatalysts with industrial relevance.

  17. Enteric glial cells and their role in the intestinal epithelial barrier.

    Science.gov (United States)

    Yu, Yan-Bo; Li, Yan-Qing

    2014-08-28

    The intestinal epithelium constitutes a physical and functional barrier between the external environment and the host organism. It is formed by a continuous monolayer of intestinal epithelial cells maintained together by intercellular junctional complex, limiting access of pathogens, toxins and xenobiotics to host tissues. Once this barrier integrity is disrupted, inflammatory disorders and tissue injury are initiated and perpetuated. Beneath the intestinal epithelial cells lies a population of astrocyte-like cells that are known as enteric glia. The morphological characteristics and expression markers of these enteric glia cells were identical to the astrocytes of the central nervous system. In the past few years, enteric glia have been demonstrated to have a trophic and supporting relationship with intestinal epithelial cells. Enteric glia lesions and/or functional defects can be involved in the barrier dysfunction. Besides, factors secreted by enteric glia are important for the regulation of gut barrier function. Moreover, enteric glia have an important impact on epithelial cell transcriptome and induce a shift in epithelial cell phenotype towards increased cell adhesion and cell differentiation. Enteric glia can also preserve epithelial barrier against intestinal bacteria insult. In this review, we will describe the current body of evidence supporting functional roles of enteric glia on intestinal barrier.

  18. Correlation between intraluminal oxygen gradient and radial partitioning of intestinal microbiota.

    Science.gov (United States)

    Albenberg, Lindsey; Esipova, Tatiana V; Judge, Colleen P; Bittinger, Kyle; Chen, Jun; Laughlin, Alice; Grunberg, Stephanie; Baldassano, Robert N; Lewis, James D; Li, Hongzhe; Thom, Stephen R; Bushman, Frederic D; Vinogradov, Sergei A; Wu, Gary D

    2014-11-01

    The gut microbiota is a complex and densely populated community in a dynamic environment determined by host physiology. We investigated how intestinal oxygen levels affect the composition of the fecal and mucosally adherent microbiota. We used the phosphorescence quenching method and a specially designed intraluminal oxygen probe to dynamically quantify gut luminal oxygen levels in mice. 16S ribosomal RNA gene sequencing was used to characterize the microbiota in intestines of mice exposed to hyperbaric oxygen, human rectal biopsy and mucosal swab samples, and paired human stool samples. Average Po2 values in the lumen of the cecum were extremely low (intestines, we observed that oxygen diffused from intestinal tissue and established a radial gradient that extended from the tissue interface into the lumen. Increasing tissue oxygenation with hyperbaric oxygen altered the composition of the gut microbiota in mice. In human beings, 16S ribosomal RNA gene analyses showed an increased proportion of oxygen-tolerant organisms of the Proteobacteria and Actinobacteria phyla associated with rectal mucosa, compared with feces. A consortium of asaccharolytic bacteria of the Firmicute and Bacteroidetes phyla, which primarily metabolize peptones and amino acids, was associated primarily with mucus. This could be owing to the presence of proteinaceous substrates provided by mucus and the shedding of the intestinal epithelium. In an analysis of intestinal microbiota of mice and human beings, we observed a radial gradient of microbes linked to the distribution of oxygen and nutrients provided by host tissue. Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.

  19. Childhood intestinal obstruction in Northwestern Nigeria

    African Journals Online (AJOL)

    of childhood intestinal obstruction in this study agrees with those reportedis'gi m3 from other parts of the coun- try. Mortality from childhood intestinal obstruction is still high in our environment. References. 1. Otu AA. Tropical surgical abdominal emergencies: acute intestinal obstruction. Postgrad. Doctor (Afr) 1992; 14: 51. 2.

  20. Models of intestinal infection by Salmonella enterica: introduction of a new neonate mouse model [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Marc Schulte

    2016-06-01

    Full Text Available Salmonella enterica serovar Typhimurium is a foodborne pathogen causing inflammatory disease in the intestine following diarrhea and is responsible for thousands of deaths worldwide. Many in vitro investigations using cell culture models are available, but these do not represent the real natural environment present in the intestine of infected hosts. Several in vivo animal models have been used to study the host-pathogen interaction and to unravel the immune responses and cellular processes occurring during infection. An animal model for Salmonella-induced intestinal inflammation relies on the pretreatment of mice with streptomycin. This model is of great importance but still shows limitations to investigate the host-pathogen interaction in the small intestine in vivo. Here, we review the use of mouse models for Salmonella infections and focus on a new small animal model using 1-day-old neonate mice. The neonate model enables researchers to observe infection of both the small and large intestine, thereby offering perspectives for new experimental approaches, as well as to analyze the Salmonella-enterocyte interaction in the small intestine in vivo.

  1. Creche: ambiente expositor ou protetor nas infestações por parasitas intestinais em Aracaju, SE Children day care center: exposition or protection environment to intestinal parasites infestation in Aracaju, SE

    Directory of Open Access Journals (Sweden)

    Ricardo Queiroz Gurgel

    2005-05-01

    Full Text Available Para avaliar se creches são ambientes protetores ou propiciadores de infestação intestinal, foi feito exame coproparasitológico de crianças de creche e grupo controle. Creche relacionou-se à maior prevalência de parasitoses (63% x 41,4 % ; pThe work aimed to evaluate whether child daycare centers are an environment that protects against or exposes children to intestinal parasite infestation. Stool samples were analyzed from children attending such centers and a control group. It was concluded that attending daycare centers is related to intestinal parasitosis (630% vs. 41.4 %; p <0.01 and the risk of infestation is 1.5 times higher.

  2. Temporal genetic variability and host sources of Escherichia coli associated with fecal pollution from domesticated animals in the shellfish culture environment of Xiangshan Bay, East China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Fu Linglin, E-mail: full1103@yahoo.com.cn [Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310035 (China); Shuai Jiangbing [Zhejiang Entry and Exit Inspection and Quarantine Bureau, Hangzhou 310012 (China); Wang Yanbo; Ma Hongjia [Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310035 (China); Li Jianrong, E-mail: lijianrong@mail.zjgsu.edu.cn [Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310035 (China)

    2011-10-15

    This study was conducted to analyze the genetic variability of Escherichia coli from domesticated animal wastes for microbial source tracking (MST) application in fecal contaminated shellfish growing waters of Xiangshan Bay, East China Sea. (GTG){sub 5} primer was used to generate 1363 fingerprints from E. coli isolated from feces of known 9 domesticated animal sources around this shellfish culture area. Jackknife analysis of the complete (GTG){sub 5}-PCR DNA fingerprint library indicated that isolates were assigned to the correct source groups with an 84.28% average rate of correct classification. Based on one-year source tracking data, the dominant sources of E. coli were swine, chickens, ducks and cows in this water area. Moreover, annual and spatial changes of E. coli concentrations and host sources may affect the level and distribution of zoonotic pathogen species in waters. Our findings will further contribute to preventing fecal pollution in aquatic environments and quality control of shellfish. - Highlights: > The host-origin library developed by (GTG){sub 5}-PCR could be used to shellfish water MST. > Fecal pollution of Xiangshan Bay arose from multiple sources of agricultural wastes. > High level of E. coli concentration in shellfish water increases the health risk. > Annual changes of E. coli host sources affect distribution of zoonotic pathogens. - The temporal genetic variability and dominant host sources of E. coli in fecal contaminated shellfish growing waters of Xiangshan Bay was characterized.

  3. Effect of Caenorhabditis elegans age and genotype on horizontal gene transfer in intestinal bacteria.

    Science.gov (United States)

    Portal-Celhay, Cynthia; Nehrke, Keith; Blaser, Martin J

    2013-02-01

    Horizontal gene transfer (HGT) between bacteria occurs in the intestinal tract of their animal hosts and facilitates both virulence and antibiotic resistance. A model in which both the pathogen and the host are genetically tractable facilitates developing insight into mechanistic processes enabling or restricting the transfer of antibiotic resistance genes. Here we develop an in vivo experimental system to study HGT in bacteria using Caenorhabditis elegans as a model host. Using a thermosensitive conjugative system, we provide evidence that conjugation between two Escherichia coli strains can take place in the intestinal lumen of N2 wild-type worms at a rate of 10(-3) and 10(-2) per donor. We also show that C. elegans age and genotype are important determinants of the frequency of conjugation. Whereas ∼1 transconjugant for every 100 donor cells could be recovered from the intestine of N2 C. elegans, for the age-1 and tol-1 mutants, the detected rate of transconjugation (10(-3) and 10(-4) per donor cell, respectively) was significantly lower. This work demonstrates that increased recombination among lumenal microbial populations is a phenotype associated with host aging, and the model provides a framework to study the dynamics of bacterial horizontal gene transfer within the intestinal environment.

  4. Influence of Host Genetics and Environment on Nasal Carriage of Staphylococcus aureus in Danish Middle-Aged and Elderly Twins

    DEFF Research Database (Denmark)

    Andersen, Paal Skytt; Pedersen, Jacob Krabbe; Fode, Peder

    2012-01-01

    Background. Nasal carriage is a major risk factor for Staphylococcus aureus infection. Approximately, one-quarter of adults carry S. aureus. However, the role of host genetics on S. aureus nasal carriage is unknown. Methods. Nasal swabs were obtained from a national cohort of middle-aged and elde......Background. Nasal carriage is a major risk factor for Staphylococcus aureus infection. Approximately, one-quarter of adults carry S. aureus. However, the role of host genetics on S. aureus nasal carriage is unknown. Methods. Nasal swabs were obtained from a national cohort of middle...... exhibited only a modest influence on the S. aureus carrier state of middle-aged and elderly individuals....

  5. Reared Microgastrine Wasps (Hymenoptera: Braconidae) from Yanayacu Biological Station and Environs (Napo Province, Ecuador): Diversity and Host Specialization

    OpenAIRE

    Whitfield, James B.; Rodriguez, Josephine J.; Masonick, Paul K.

    2009-01-01

    The microgastrine braconid wasps recovered up through 2007 by the NSF-sponsored rearing project “Caterpillars and Parasitoids of the Eastern Andes in Ecuador” are summarized in terms of their host specialization and faunistic uniqueness. Two hundred fifty eight rearings of caterpillars resulted in records of Microgastrinae, distributed among 14 genera (Apanteles Förster, Choeras Mason, Cotesia Cameron, Diolcogaster Ashmead, Distatrix Mason, Dolichogenidea Viereck, Exix Mason, Glyptapanteles A...

  6. Tissue engineering the small intestine.

    Science.gov (United States)

    Spurrier, Ryan G; Grikscheit, Tracy C

    2013-04-01

    Short bowel syndrome (SBS) results from the loss of a highly specialized organ, the small intestine. SBS and its current treatments are associated with high morbidity and mortality. Production of tissue-engineered small intestine (TESI) from the patient's own cells could restore normal intestinal function via autologous transplantation. Improved understanding of intestinal stem cells and their niche have been coupled with advances in tissue engineering techniques. Originally described by Vacanti et al of Massachusetts General Hospital, TESI has been produced by in vivo implantation of organoid units. Organoid units are multicellular clusters of epithelium and mesenchyme that may be harvested from native intestine. These clusters are loaded onto a scaffold and implanted into the host omentum. The scaffold provides physical support that permits angiogenesis and vasculogenesis of the developing tissue. After a period of 4 weeks, histologic analyses confirm the similarity of TESI to native intestine. TESI contains a differentiated epithelium, mesenchyme, blood vessels, muscle, and nerve components. To date, similar experiments have proved successful in rat, mouse, and pig models. Additional experiments have shown clinical improvement and rescue of SBS rats after implantation of TESI. In comparison with the group that underwent massive enterectomy alone, rats that had surgical anastomosis of TESI to their shortened intestine showed improvement in postoperative weight gain and serum B12 values. Recently, organoid units have been harvested from human intestinal samples and successfully grown into TESI by using an immunodeficient mouse host. Current TESI production yields approximately 3 times the number of cells initially implanted, but improvements in the scaffold and blood supply are being developed in efforts to increase TESI size. Exciting new techniques in stem cell biology and directed cellular differentiation may generate additional sources of autologous intestinal

  7. Host species and environmental effects on bacterial communities associated with Drosophila in the laboratory and in the natural environment.

    Directory of Open Access Journals (Sweden)

    Fabian Staubach

    Full Text Available The fruit fly Drosophila is a classic model organism to study adaptation as well as the relationship between genetic variation and phenotypes. Although associated bacterial communities might be important for many aspects of Drosophila biology, knowledge about their diversity, composition, and factors shaping them is limited. We used 454-based sequencing of a variable region of the bacterial 16S ribosomal RNA gene to characterize the bacterial communities associated with wild and laboratory Drosophila isolates. In order to specifically investigate effects of food source and host species on bacterial communities, we analyzed samples from wild Drosophila melanogaster and D. simulans collected from a variety of natural substrates, as well as from adults and larvae of nine laboratory-reared Drosophila species. We find no evidence for host species effects in lab-reared flies; instead, lab of origin and stochastic effects, which could influence studies of Drosophila phenotypes, are pronounced. In contrast, the natural Drosophila-associated microbiota appears to be predominantly shaped by food substrate with an additional but smaller effect of host species identity. We identify a core member of this natural microbiota that belongs to the genus Gluconobacter and is common to all wild-caught flies in this study, but absent from the laboratory. This makes it a strong candidate for being part of what could be a natural D. melanogaster and D. simulans core microbiome. Furthermore, we were able to identify candidate pathogens in natural fly isolates.

  8. Host Species and Environmental Effects on Bacterial Communities Associated with Drosophila in the Laboratory and in the Natural Environment

    Science.gov (United States)

    Staubach, Fabian; Baines, John F.; Künzel, Sven; Bik, Elisabeth M.; Petrov, Dmitri A.

    2013-01-01

    The fruit fly Drosophila is a classic model organism to study adaptation as well as the relationship between genetic variation and phenotypes. Although associated bacterial communities might be important for many aspects of Drosophila biology, knowledge about their diversity, composition, and factors shaping them is limited. We used 454-based sequencing of a variable region of the bacterial 16S ribosomal RNA gene to characterize the bacterial communities associated with wild and laboratory Drosophila isolates. In order to specifically investigate effects of food source and host species on bacterial communities, we analyzed samples from wild Drosophila melanogaster and D. simulans collected from a variety of natural substrates, as well as from adults and larvae of nine laboratory-reared Drosophila species. We find no evidence for host species effects in lab-reared flies; instead, lab of origin and stochastic effects, which could influence studies of Drosophila phenotypes, are pronounced. In contrast, the natural Drosophila–associated microbiota appears to be predominantly shaped by food substrate with an additional but smaller effect of host species identity. We identify a core member of this natural microbiota that belongs to the genus Gluconobacter and is common to all wild-caught flies in this study, but absent from the laboratory. This makes it a strong candidate for being part of what could be a natural D. melanogaster and D. simulans core microbiome. Furthermore, we were able to identify candidate pathogens in natural fly isolates. PMID:23967097

  9. Fucose sensing regulates bacterial intestinal colonization.

    Science.gov (United States)

    Pacheco, Alline R; Curtis, Meredith M; Ritchie, Jennifer M; Munera, Diana; Waldor, Matthew K; Moreira, Cristiano G; Sperandio, Vanessa

    2012-12-06

    The mammalian gastrointestinal tract provides a complex and competitive environment for the microbiota. Successful colonization by pathogens requires scavenging nutrients, sensing chemical signals, competing with the resident bacteria and precisely regulating the expression of virulence genes. The gastrointestinal pathogen enterohaemorrhagic Escherichia coli (EHEC) relies on inter-kingdom chemical sensing systems to regulate virulence gene expression. Here we show that these systems control the expression of a novel two-component signal transduction system, named FusKR, where FusK is the histidine sensor kinase and FusR the response regulator. FusK senses fucose and controls expression of virulence and metabolic genes. This fucose-sensing system is required for robust EHEC colonization of the mammalian intestine. Fucose is highly abundant in the intestine. Bacteroides thetaiotaomicron produces multiple fucosidases that cleave fucose from host glycans, resulting in high fucose availability in the gut lumen. During growth in mucin, B. thetaiotaomicron contributes to EHEC virulence by cleaving fucose from mucin, thereby activating the FusKR signalling cascade, modulating the virulence gene expression of EHEC. Our findings suggest that EHEC uses fucose, a host-derived signal made available by the microbiota, to modulate EHEC pathogenicity and metabolism.

  10. The enteric nervous system promotes intestinal health by constraining microbiota composition.

    Directory of Open Access Journals (Sweden)

    Annah S Rolig

    2017-02-01

    Full Text Available Sustaining a balanced intestinal microbial community is critical for maintaining intestinal health and preventing chronic inflammation. The gut is a highly dynamic environment, subject to periodic waves of peristaltic activity. We hypothesized that this dynamic environment is a prerequisite for a balanced microbial community and that the enteric nervous system (ENS, a chief regulator of physiological processes within the gut, profoundly influences gut microbiota composition. We found that zebrafish lacking an ENS due to a mutation in the Hirschsprung disease gene, sox10, develop microbiota-dependent inflammation that is transmissible between hosts. Profiling microbial communities across a spectrum of inflammatory phenotypes revealed that increased levels of inflammation were linked to an overabundance of pro-inflammatory bacterial lineages and a lack of anti-inflammatory bacterial lineages. Moreover, either administering a representative anti-inflammatory strain or restoring ENS function corrected the pathology. Thus, we demonstrate that the ENS modulates gut microbiota community membership to maintain intestinal health.

  11. The enteric nervous system promotes intestinal health by constraining microbiota composition

    Science.gov (United States)

    Mittge, Erika K.; Ganz, Julia; Troll, Josh V.; Melancon, Ellie; Wiles, Travis J.; Alligood, Kristin; Stephens, W. Zac; Eisen, Judith S.; Guillemin, Karen

    2017-01-01

    Sustaining a balanced intestinal microbial community is critical for maintaining intestinal health and preventing chronic inflammation. The gut is a highly dynamic environment, subject to periodic waves of peristaltic activity. We hypothesized that this dynamic environment is a prerequisite for a balanced microbial community and that the enteric nervous system (ENS), a chief regulator of physiological processes within the gut, profoundly influences gut microbiota composition. We found that zebrafish lacking an ENS due to a mutation in the Hirschsprung disease gene, sox10, develop microbiota-dependent inflammation that is transmissible between hosts. Profiling microbial communities across a spectrum of inflammatory phenotypes revealed that increased levels of inflammation were linked to an overabundance of pro-inflammatory bacterial lineages and a lack of anti-inflammatory bacterial lineages. Moreover, either administering a representative anti-inflammatory strain or restoring ENS function corrected the pathology. Thus, we demonstrate that the ENS modulates gut microbiota community membership to maintain intestinal health. PMID:28207737

  12. The motility of Entamoeba histolytica: finding ways to understand intestinal amoebiasis.

    Science.gov (United States)

    Aguilar-Rojas, Arturo; Olivo-Marin, Jean-Christophe; Guillen, Nancy

    2016-12-01

    The pathogenic amoeba Entamoeba histolytica is able to migrate within various compartments of the human body. The present article reviews progress in understanding the mechanisms of cell motility in E. histolytica during human intestinal invasion and, in particular, how the three-dimensional characteristics of the environment regulate the parasite's behaviour. The amoeboid mode of migration that applies to E. histolytica's displacements on two-dimensional surfaces is also expected to apply to the three-dimensional environment in the human intestine although several unknown, distinct modalities may be involved. Recent advances in the field of tissue engineering have provided clues on how the construction of a human colon model could help us to understand the host's intestinal physiology and its changes following amoebic infection. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Pan-Nematoda Transcriptomic Elucidation of Essential Intestinal Functions and Therapeutic Targets With Broad Potential

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2015-09-01

    Full Text Available The nematode intestine is continuous with the outside environment, making it easily accessible to anthelmintics for parasite control, but the development of new therapeutics is impeded by limited knowledge of nematode intestinal cell biology. We established the most comprehensive nematode intestinal functional database to date by generating transcriptional data from the dissected intestines of three parasitic nematodes spanning the phylum, and integrating the results with the whole proteomes of 10 nematodes (including 9 pathogens of humans or animals and 3 host species and 2 outgroup species. We resolved 10,772 predicted nematode intestinal protein families (IntFams, and studied their presence and absence within the different lineages (births and deaths among nematodes. Conserved intestinal cell functions representing ancestral functions of evolutionary importance were delineated, and molecular features useful for selective therapeutic targeting were identified. Molecular patterns conserved among IntFam proteins demonstrated large potential as therapeutic targets to inhibit intestinal cell functions with broad applications towards treatment and control of parasitic nematodes.

  14. Pan-Nematoda Transcriptomic Elucidation of Essential Intestinal Functions and Therapeutic Targets With Broad Potential.

    Science.gov (United States)

    Wang, Qi; Rosa, Bruce A; Jasmer, Douglas P; Mitreva, Makedonka

    2015-09-01

    The nematode intestine is continuous with the outside environment, making it easily accessible to anthelmintics for parasite control, but the development of new therapeutics is impeded by limited knowledge of nematode intestinal cell biology. We established the most comprehensive nematode intestinal functional database to date by generating transcriptional data from the dissected intestines of three parasitic nematodes spanning the phylum, and integrating the results with the whole proteomes of 10 nematodes (including 9 pathogens of humans or animals) and 3 host species and 2 outgroup species. We resolved 10,772 predicted nematode intestinal protein families (IntFams), and studied their presence and absence within the different lineages (births and deaths) among nematodes. Conserved intestinal cell functions representing ancestral functions of evolutionary importance were delineated, and molecular features useful for selective therapeutic targeting were identified. Molecular patterns conserved among IntFam proteins demonstrated large potential as therapeutic targets to inhibit intestinal cell functions with broad applications towards treatment and control of parasitic nematodes.

  15. Intestinal Ischemia

    Science.gov (United States)

    ... weight loss Intestinal ischemia Symptoms & causes Diagnosis & treatment Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  16. Leishmania amazonensis promastigotes in 3D Collagen I culture: an in vitro physiological environment for the study of extracellular matrix and host cell interactions.

    Science.gov (United States)

    Petropolis, Debora B; Rodrigues, Juliany C F; Viana, Nathan B; Pontes, Bruno; Pereira, Camila F A; Silva-Filho, Fernando C

    2014-01-01

    Leishmania amazonensis is the causative agent of American cutaneous leishmaniasis, an important neglected tropical disease. Once Leishmania amazonensis is inoculated into the human host, promastigotes are exposed to the extracellular matrix (ECM) of the dermis. However, little is known about the interaction between the ECM and Leishmania promastigotes. In this study we established L. amazonensis promastigote culture in a three-dimensional (3D) environment mainly composed of Collagen I (COL I). This 3D culture recreates in vitro some aspects of the human host infection site, enabling the study of the interaction mechanisms of L. amazonensis with the host ECM. Promastigotes exhibited "freeze and run" migration in the 3D COL I matrix, which is completely different from the conventional in vitro swimming mode of migration. Moreover, L. amazonensis promastigotes were able to invade, migrate inside, and remodel the 3D COL I matrix. Promastigote trans-matrix invasion and the freeze and run migration mode were also observed when macrophages were present in the matrix. At least two classes of proteases, metallo- and cysteine proteases, are involved in the 3D COL I matrix degradation caused by Leishmania. Treatment with a mixture of protease inhibitors significantly reduced promastigote invasion and migration through this matrix. Together our results demonstrate that L. amazonensis promastigotes release proteases and actively remodel their 3D environment, facilitating their migration. This raises the possibility that promastigotes actively interact with their 3D environment during the search for their cellular "home"-macrophages. Supporting this hypothesis, promastigotes migrated faster than macrophages in a novel 3D co-culture model.

  17. Leishmania amazonensis promastigotes in 3D Collagen I culture: an in vitro physiological environment for the study of extracellular matrix and host cell interactions

    Directory of Open Access Journals (Sweden)

    Debora B. Petropolis

    2014-04-01

    Full Text Available Leishmania amazonensis is the causative agent of American cutaneous leishmaniasis, an important neglected tropical disease. Once Leishmania amazonensis is inoculated into the human host, promastigotes are exposed to the extracellular matrix (ECM of the dermis. However, little is known about the interaction between the ECM and Leishmania promastigotes. In this study we established L. amazonensis promastigote culture in a three-dimensional (3D environment mainly composed of Collagen I (COL I. This 3D culture recreates in vitro some aspects of the human host infection site, enabling the study of the interaction mechanisms of L. amazonensis with the host ECM. Promastigotes exhibited “freeze and run” migration in the 3D COL I matrix, which is completely different from the conventional in vitro swimming mode of migration. Moreover, L. amazonensis promastigotes were able to invade, migrate inside, and remodel the 3D COL I matrix. Promastigote trans-matrix invasion and the freeze and run migration mode were also observed when macrophages were present in the matrix. At least two classes of proteases, metallo- and cysteine proteases, are involved in the 3D COL I matrix degradation caused by Leishmania. Treatment with a mixture of protease inhibitors significantly reduced promastigote invasion and migration through this matrix. Together our results demonstrate that L. amazonensis promastigotes release proteases and actively remodel their 3D environment, facilitating their migration. This raises the possibility that promastigotes actively interact with their 3D environment during the search for their cellular “home”—macrophages. Supporting this hypothesis, promastigotes migrated faster than macrophages in a novel 3D co-culture model.

  18. Leishmania amazonensis promastigotes in 3D Collagen I culture: an in vitro physiological environment for the study of extracellular matrix and host cell interactions

    Science.gov (United States)

    Rodrigues, Juliany C.F.; Viana, Nathan B.; Pontes, Bruno; Pereira, Camila F.A.; Silva-Filho, Fernando C.

    2014-01-01

    Leishmania amazonensis is the causative agent of American cutaneous leishmaniasis, an important neglected tropical disease. Once Leishmania amazonensis is inoculated into the human host, promastigotes are exposed to the extracellular matrix (ECM) of the dermis. However, little is known about the interaction between the ECM and Leishmania promastigotes. In this study we established L. amazonensis promastigote culture in a three-dimensional (3D) environment mainly composed of Collagen I (COL I). This 3D culture recreates in vitro some aspects of the human host infection site, enabling the study of the interaction mechanisms of L. amazonensis with the host ECM. Promastigotes exhibited “freeze and run” migration in the 3D COL I matrix, which is completely different from the conventional in vitro swimming mode of migration. Moreover, L. amazonensis promastigotes were able to invade, migrate inside, and remodel the 3D COL I matrix. Promastigote trans-matrix invasion and the freeze and run migration mode were also observed when macrophages were present in the matrix. At least two classes of proteases, metallo- and cysteine proteases, are involved in the 3D COL I matrix degradation caused by Leishmania. Treatment with a mixture of protease inhibitors significantly reduced promastigote invasion and migration through this matrix. Together our results demonstrate that L. amazonensis promastigotes release proteases and actively remodel their 3D environment, facilitating their migration. This raises the possibility that promastigotes actively interact with their 3D environment during the search for their cellular “home”—macrophages. Supporting this hypothesis, promastigotes migrated faster than macrophages in a novel 3D co-culture model. PMID:24765565

  19. Deletion and acquisition of genomic content during early stage adaptation of Pseudomonas aeruginosa to a human host environment

    DEFF Research Database (Denmark)

    Rau, Martin H.; Marvig, Rasmus Lykke; Ehrlich, Garth D.

    2012-01-01

    Adaptation of bacterial pathogens to a permanently host‐associated lifestyle by means of deletion or acquisition of genetic material is usually examined through comparison of present‐day isolates to a distant theoretical ancestor. This limits the resolution of the adaptation process. We conducted...... of the change in genetic content during the early stage of host adaptation by this P. aeruginosa strain as it adapts to the cystic fibrosis (CF) lung of several patients. Considerable genome reduction is detected predominantly through the deletion of large genomic regions, and up to 8% of the genome is deleted...

  20. History of myeloid derived suppressor cells (MDSCs) in the macro- and micro-environment of tumour-bearing hosts

    Science.gov (United States)

    Talmadge, James E.; Gabrilovich, Dmitry I.

    2015-01-01

    Tumour-induced granulocytic hyperplasia is associated with tumour vasculogenesis and escape from immunity via T-cell suppression. Initially, these myeloid cells were identified as granulocytes or monocytes; however, recent studies revealed that this hyperplasia was associated with populations of multi-potent progenitor cells identified as myeloid-derived suppressor cells (MDSCs). The discovery and study of MDSCs have provided a wealth of information regarding tumour pathobiology, extended our understanding of neoplastic progression, and modified our approaches to immune adjuvant therapy. In this perspective, we discuss the history of MDSCs, their influence on tumour progression and metastasis, and the crosstalk between tumour cells, MDSCs, and the host macroenvironment. PMID:24060865

  1. Host Ranges of Listeria-Specific Bacteriophages from the Turkey Processing Plant Environment in the United States ▿

    OpenAIRE

    Kim, Jae-Won; Siletzky, Robin M.; Kathariou, Sophia

    2008-01-01

    Even though at least 400 Listeria phages have been isolated from various sources, limited information is available on phages from the food processing plant environment. Phages in the processing plant environment may play critical roles in determining the Listeria population that becomes established in the plant. In this study, we pursued the isolation of Listeria-specific phages from environmental samples from four turkey processing plants in the United States. These environmental samples wer...

  2. Milk products and intestinal health

    NARCIS (Netherlands)

    Van der Meer, R; Bovee-Oudenhoven, IMJ; Sesink, ALA; Kleibeuker, JH

    Milk products may improve intestinal health by means of the cytoprotective effects of their high calcium phosphate (CaPi) content. We hypothesized that this cytoprotection may increase host defenses against bacterial infections as well as decrease colon cancer risk. This paper summarizes our studies

  3. Intestinal homeostasis and its breakdown in inflammatory bowel disease.

    Science.gov (United States)

    Maloy, Kevin J; Powrie, Fiona

    2011-06-15

    Intestinal homeostasis depends on complex interactions between the microbiota, the intestinal epithelium and the host immune system. Diverse regulatory mechanisms cooperate to maintain intestinal homeostasis, and a breakdown in these pathways may precipitate the chronic inflammatory pathology found in inflammatory bowel disease. It is now evident that immune effector modules that drive intestinal inflammation are conserved across innate and adaptive leukocytes and can be controlled by host regulatory cells. Recent evidence suggests that several factors may tip the balance between homeostasis and intestinal inflammation, presenting future challenges for the development of new therapies for inflammatory bowel disease.

  4. The host of the Type I SLSN 2017egm. A young, sub-solar metallicity environment in a massive spiral galaxy

    Science.gov (United States)

    Izzo, L.; Thöne, C. C.; García-Benito, R.; de Ugarte Postigo, A.; Cano, Z.; Kann, D. A.; Bensch, K.; Della Valle, M.; Galadí-Enríquez, D.; Hedrosa, R. P.

    2018-02-01

    Context. Type I superluminous supernova (SLSN) host galaxies are predominantly low-metallicity, highly star-forming (SF) dwarfs. One of the current key questions is whether Type I SLSNe can only occur in such environments and hosts. Aims: Here we present an integral-field study of the massive, high-metallicity spiral NGC 3191, the host of SN 2017egm, the closest Type I SLSN known to date. We use data from PMAS/CAHA and the public MaNGA survey to shed light on the properties of the SLSN site and the origin of star formation in this non-starburst spiral galaxy. Methods: We map the physical properties of different H II regions throughout the galaxy and characterise their stellar populations using the STARLIGHT fitting code. Kinematical information allows us to study a possible interaction with its neighbouring galaxy as the origin of recent star formation activity which could have caused the SLSN. Results: NGC 3191 shows intense star formation in the western part with three large SF regions of low metallicity. Taking only the properties of emitting gas, the central regions of the host have a higher metallicity, a lower specific star formation rate, and lower ionisation. Modelling the stellar populations gives a different picture: the SLSN region has two dominant stellar populations with different ages, the younger one with an age of 2-10 Myr and lower metallicity, likely the population from which the SN progenitor originated. Emission line kinematics of NGC 3191 show indications of interaction with its neighbour MCG+08-19-017 at 45 kpc, which might be responsible for the recent starburst. In fact, this galaxy pair has hosted a total of four SNe, 1988B (Type Ia), SN 2003ds (Type Ic in MCG+08-19-017), PTF10bgl (Type II), and 2017egm, underlying the enhanced SF in both galaxies due to interaction. Conclusions: Our study shows that care should be taken when interpreting global host and even gas properties without looking at the stellar population history of the region

  5. The Use of Virtual Learning Environment (VLE) and Social Network Site (SNS) Hosted Forums in Higher Education: A Preliminary Examination

    Science.gov (United States)

    Hollyhead, Andrew; Edwards, David J.; Holt, Gary D.

    2012-01-01

    Grounded theory is used to examine the role and application of both educator-led and student-led forums within a virtual learning environment (VLE) of a higher education institution (HEI). The study reports experiences and perceptions of academics in two faculties (business and technology) in the HEI who use both asynchronous VLE forums and social…

  6. Role of intestinal dysbiosis on gut colonization by bacterial pathogens

    OpenAIRE

    DJUKOVIC, ANA

    2017-01-01

    The intestinal tract of virtually any metazoan, including mammals, is colonized with a complex microbial community to which we refer as intestinal or gut microbiota. One of the roles of the healthy intestinal microbiota is to protect the host against gut colonization with pathogenic bacteria through a phenomenon known as colonization resistance (CR). Dysbiosis of the intestinal microbiota, usually as a result of an antibiotic treatment, may lead to the disruption of the CR, and subsequent col...

  7. Intestinal, segmented, filamentous bacteria.

    Science.gov (United States)

    Klaasen, H L; Koopman, J P; Poelma, F G; Beynen, A C

    1992-06-01

    Segmented, filamentous bacteria (SFBs) are autochthonous, apathogenic bacteria, occurring in the ileum of mice and rats. Although the application of formal taxonomic criteria is impossible due to the lack of an in vitro technique to culture SFBs, microbes with a similar morphology, found in the intestine of a wide range of vertebrate and invertebrate host species, are considered to be related. SFBs are firmly attached to the epithelial cells of the distal ileal mucosa, their preferential ecological niche being the epithelium covering the Peyer's patches. Electron microscopic studies have demonstrated a considerable morphological diversity of SFBs, which may relate to different stages of a life cycle. Determinants of SFB colonization in vivo are host species, genotypical and phenotypical characteristics of the host, diet composition, environmental stress and antimicrobial drugs. SFBs can survive in vitro incubation, but do not multiply. On the basis of their apathogenic character and intimate relationship with the host, it is suggested that SFBs contribute to development and/or maintenance of host resistance to enteropathogens.

  8. Espiroquetosis intestinal

    OpenAIRE

    Vera Sempere, Francisco José

    2017-01-01

    El término “espiroquetosis intestinal” fue introducido por Harland y Lee en 1967 -en una breve comunicación publicada en el British Medical Journal- para describir una infección intestinal que morfológicamente se manifiesta en la biopsia de colon/recto por la presencia de una banda de microorganismos, adheridos a la superficie del epitelio de la mucosa intestinal y que fueron identificados al microscopio electrónico como espiroquetas. La definición por lo tanto de este pr...

  9. Human Enteroids/Colonoids and Intestinal Organoids Functionally Recapitulate Normal Intestinal Physiology and Pathophysiology.

    Science.gov (United States)

    Zachos, Nicholas C; Kovbasnjuk, Olga; Foulke-Abel, Jennifer; In, Julie; Blutt, Sarah E; de Jonge, Hugo R; Estes, Mary K; Donowitz, Mark

    2016-02-19

    Identification of Lgr5 as the intestinal stem cell marker as well as the growth factors necessary to replicate adult intestinal stem cell division has led to the establishment of the methods to generate "indefinite" ex vivo primary intestinal epithelial cultures, termed "mini-intestines." Primary cultures developed from isolated intestinal crypts or stem cells (termed enteroids/colonoids) and from inducible pluripotent stem cells (termed intestinal organoids) are being applied to study human intestinal physiology and pathophysiology with great expectations for translational applications, including regenerative medicine. Here we discuss the physiologic properties of these cultures, their current use in understanding diarrhea-causing host-pathogen interactions, and potential future applications. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. Regulation of intestinal permeability: The role of proteases.

    Science.gov (United States)

    Van Spaendonk, Hanne; Ceuleers, Hannah; Witters, Leonie; Patteet, Eveline; Joossens, Jurgen; Augustyns, Koen; Lambeir, Anne-Marie; De Meester, Ingrid; De Man, Joris G; De Winter, Benedicte Y

    2017-03-28

    The gastrointestinal barrier is - with approximately 400 m 2 - the human body's largest surface separating the external environment from the internal milieu. This barrier serves a dual function: permitting the absorption of nutrients, water and electrolytes on the one hand, while limiting host contact with noxious luminal antigens on the other hand. To maintain this selective barrier, junction protein complexes seal the intercellular space between adjacent epithelial cells and regulate the paracellular transport. Increased intestinal permeability is associated with and suggested as a player in the pathophysiology of various gastrointestinal and extra-intestinal diseases such as inflammatory bowel disease, celiac disease and type 1 diabetes. The gastrointestinal tract is exposed to high levels of endogenous and exogenous proteases, both in the lumen and in the mucosa. There is increasing evidence to suggest that a dysregulation of the protease/antiprotease balance in the gut contributes to epithelial damage and increased permeability. Excessive proteolysis leads to direct cleavage of intercellular junction proteins, or to opening of the junction proteins via activation of protease activated receptors. In addition, proteases regulate the activity and availability of cytokines and growth factors, which are also known modulators of intestinal permeability. This review aims at outlining the mechanisms by which proteases alter the intestinal permeability. More knowledge on the role of proteases in mucosal homeostasis and gastrointestinal barrier function will definitely contribute to the identification of new therapeutic targets for permeability-related diseases.

  11. The intestinal microbiota and obesity.

    Science.gov (United States)

    Kallus, Samuel J; Brandt, Lawrence J

    2012-01-01

    Obesity has been and continues to be an epidemic in the United States. Obesity has been addressed in multiple health initiatives, including Healthy People 2010, with no state meeting the proposed goal of a prevalence of obesity fad diets, incentive-based exercise programs, and gastric bypass surgery; none of which have been optimal. In a murine model, it was shown that the majority of the intestinal microbiome consists of two bacterial phyla, the Bacteroidetes and the Firmicutes, and that the relative abundance of these two phyla differs among lean and obese mice; the obese mouse had a higher proportion of Firmicutes to Bacteroidetes (50% greater) than the lean mouse. The same results were appreciated in obese humans compared to lean subjects. The postulated explanation for this finding is that Firmicutes produce more complete metabolism of a given energy source than do Bacteroidetes, thus promoting more efficient absorption of calories and subsequent weight gain. Researchers were able to demonstrate that colonizing germ-free mice with the intestinal microbiome from obese mice led to an increased total body fat in the recipient mice despite a lack of change in diet. The converse, that, colonizing germ-free obese mice with the intestinal microbiome of thin mice causing a decreased total body fat in the recipient mice, has not yet been done. Other possible mechanisms by which the intestinal microbiome affects host obesity include induction of low-grade inflammation with lipopolysaccharide, regulation of host genes responsible for energy expenditure and storage, and hormonal communication between the intestinal microbiome and the host. The following review discusses the microbiome-obesity relationship and proposed mechanisms by which the intestinal microbiota is hypothesized to influence weight gain.

  12. Comparative genome analysis of rice-pathogenic Burkholderia provides insight into capacity to adapt to different environments and hosts.

    Science.gov (United States)

    Seo, Young-Su; Lim, Jae Yun; Park, Jungwook; Kim, Sunyoung; Lee, Hyun-Hee; Cheong, Hoon; Kim, Sang-Mok; Moon, Jae Sun; Hwang, Ingyu

    2015-05-06

    In addition to human and animal diseases, bacteria of the genus Burkholderia can cause plant diseases. The representative species of rice-pathogenic Burkholderia are Burkholderia glumae, B. gladioli, and B. plantarii, which primarily cause grain rot, sheath rot, and seedling blight, respectively, resulting in severe reductions in rice production. Though Burkholderia rice pathogens cause problems in rice-growing countries, comprehensive studies of these rice-pathogenic species aiming to control Burkholderia-mediated diseases are only in the early stages. We first sequenced the complete genome of B. plantarii ATCC 43733T. Second, we conducted comparative analysis of the newly sequenced B. plantarii ATCC 43733T genome with eleven complete or draft genomes of B. glumae and B. gladioli strains. Furthermore, we compared the genome of three rice Burkholderia pathogens with those of other Burkholderia species such as those found in environmental habitats and those known as animal/human pathogens. These B. glumae, B. gladioli, and B. plantarii strains have unique genes involved in toxoflavin or tropolone toxin production and the clustered regularly interspaced short palindromic repeats (CRISPR)-mediated bacterial immune system. Although the genome of B. plantarii ATCC 43733T has many common features with those of B. glumae and B. gladioli, this B. plantarii strain has several unique features, including quorum sensing and CRISPR/CRISPR-associated protein (Cas) systems. The complete genome sequence of B. plantarii ATCC 43733T and publicly available genomes of B. glumae BGR1 and B. gladioli BSR3 enabled comprehensive comparative genome analyses among three rice-pathogenic Burkholderia species responsible for tissue rotting and seedling blight. Our results suggest that B. glumae has evolved rapidly, or has undergone rapid genome rearrangements or deletions, in response to the hosts. It also, clarifies the unique features of rice pathogenic Burkholderia species relative to other

  13. Environment

    DEFF Research Database (Denmark)

    Valentini, Chiara

    2017-01-01

    The term environment refers to the internal and external context in which organizations operate. For some scholars, environment is defined as an arrangement of political, economic, social and cultural factors existing in a given context that have an impact on organizational processes and structures....... For others, environment is a generic term describing a large variety of stakeholders and how these interact and act upon organizations. Organizations and their environment are mutually interdependent and organizational communications are highly affected by the environment. This entry examines the origin...... and development of organization-environment interdependence, the nature of the concept of environment and its relevance for communication scholarships and activities....

  14. Dietary Gut Microbial Metabolites, Short-chain Fatty Acids, and Host Metabolic Regulation

    Directory of Open Access Journals (Sweden)

    Mayu Kasubuchi

    2015-04-01

    Full Text Available During feeding, the gut microbiota contributes to the host energy acquisition and metabolic regulation thereby influencing the development of metabolic disorders such as obesity and diabetes. Short-chain fatty acids (SCFAs such as acetate, butyrate, and propionate, which are produced by gut microbial fermentation of dietary fiber, are recognized as essential host energy sources and act as signal transduction molecules via G-protein coupled receptors (FFAR2, FFAR3, OLFR78, GPR109A and as epigenetic regulators of gene expression by the inhibition of histone deacetylase (HDAC. Recent evidence suggests that dietary fiber and the gut microbial-derived SCFAs exert multiple beneficial effects on the host energy metabolism not only by improving the intestinal environment, but also by directly affecting various host peripheral tissues. In this review, we summarize the roles of gut microbial SCFAs in the host energy regulation and present an overview of the current understanding of its physiological functions.

  15. Symbiotic bacteria associated with a bobtail squid reproductive system are detectable in the environment, and stable in the host and developing eggs.

    Science.gov (United States)

    Kerwin, Allison H; Nyholm, Spencer V

    2017-04-01

    Female Hawaiian bobtail squid, Euprymna scolopes, have an accessory nidamental gland (ANG) housing a bacterial consortium that is hypothesized to be environmentally transmitted and to function in the protection of eggs from fouling and infection. The composition, stability, and variability of the ANG and egg jelly coat (JC) communities were characterized and compared to the bacterial community composition of the surrounding environment using Illumina sequencing and transmission electron microscopy. The ANG bacterial community was conserved throughout hosts collected from the wild and was not affected by maintaining animals in the laboratory. The core symbiotic community was composed of Alphaproteobacteria and Opitutae (a class of Verrucomicrobia). Operational taxonomic units representing 94.5% of the average ANG abundance were found in either the seawater or sediment, which is consistent with the hypothesis of environmental transmission between generations. The bacterial composition of the JC was stable during development and mirrored that of the ANG. Bacterial communities from individual egg clutches also grouped with the ANG of the female that produced them. Collectively, these data suggest a conserved role of the ANG/JC community in host reproduction. Future directions will focus on determining the function of this symbiotic community, and how it may change during ANG development. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  16. From the environment to the host: re-wiring of the transcriptome of Pseudomonas aeruginosa from 22°C to 37°C.

    Directory of Open Access Journals (Sweden)

    Mariette Barbier

    Full Text Available Pseudomonas aeruginosa is a highly versatile opportunistic pathogen capable of colonizing multiple ecological niches. This bacterium is responsible for a wide range of both acute and chronic infections in a variety of hosts. The success of this microorganism relies on its ability to adapt to environmental changes and re-program its regulatory and metabolic networks. The study of P. aeruginosa adaptation to temperature is crucial to understanding the pathogenesis upon infection of its mammalian host. We examined the effects of growth temperature on the transcriptome of the P. aeruginosa PAO1. Microarray analysis of PAO1 grown in Lysogeny broth at mid-exponential phase at 22°C and 37°C revealed that temperature changes are responsible for the differential transcriptional regulation of 6.4% of the genome. Major alterations were observed in bacterial metabolism, replication, and nutrient acquisition. Quorum-sensing and exoproteins secreted by type I, II, and III secretion systems, involved in the adaptation of P. aeruginosa to the mammalian host during infection, were up-regulated at 37°C compared to 22°C. Genes encoding arginine degradation enzymes were highly up-regulated at 22°C, together with the genes involved in the synthesis of pyoverdine. However, genes involved in pyochelin biosynthesis were up-regulated at 37°C. We observed that the changes in expression of P. aeruginosa siderophores correlated to an overall increase in Fe²⁺ extracellular concentration at 37°C and a peak in Fe³⁺ extracellular concentration at 22°C. This suggests a distinct change in iron acquisition strategies when the bacterium switches from the external environment to the host. Our work identifies global changes in bacterial metabolism and nutrient acquisition induced by growth at different temperatures. Overall, this study identifies factors that are regulated in genome-wide adaptation processes and discusses how this life-threatening pathogen responds to

  17. Intestinal flora, probiotics, and cirrhosis.

    Science.gov (United States)

    Guerrero Hernández, Ignacio; Torre Delgadillo, Aldo; Vargas Vorackova, Florencia; Uribe, Misael

    2008-01-01

    Intestinal microflora constitutes a symbiotic ecosystem in permanent equilibrium, composed mainly of anaerobic bacteria. However, such equilibrium may be altered by daily conditions as drug use or pathologies interfering with intestinal physiology, generating an unfavorable environment for the organism. Besides, there are factors which may cause alterations in the intestinal wall, creating the conditions for translocation or permeation of substances or bacteria. In cirrhotic patients, there are many conditions that combine to alter the amount and populations of intestinal bacteria, as well as the functional capacity of the intestinal wall to prevent the permeation of substances and bacteria. Nowadays, numerous complications associated with cirrhosis have been identified, where such mechanisms could play an important role. There is evidence that some probiotic microorganisms could restore the microbiologic and immunologic equilibrium in the intestinal wall in cirrhotic patients and help in the treatment of complications due to cirrhosis. This article has the objective to review the interactions between intestinal flora, gut permeability, and the actual role of probiotics in the field of cirrhotic patients.

  18. Abomasal lymph node responses to Haemonchus contortus intestinal antigens established in kid goats by infection or immunization with intestinal antigens.

    Science.gov (United States)

    Jasmer, Douglas P; Karanu, Francis; Davis, William C; McGuire, Travis S

    2003-02-01

    Immune responses to Haemonchus contortus intestinal antigens were evaluated using abomasal lymph node (ALN) lymphocytes from kid goats protected against challenge infection by immunization with parasite intestinal antigen, and from kids that were challenged after immunization with ovalbumin. ALN lymphocytes from the intestinal antigen-immunized group produced significantly higher antibody levels against intestinal antigens than the ovalbumin group, supporting the theory that immunization contributed to that ALN response. In contrast, intestinal lysates and membrane enriched preparations from intestinal cells stimulated significant proliferation of ALN lymphocytes in both groups. The proliferation was antigen-dependent, since intestinal antigens failed to stimulate proliferation in ALN lymphocytes from unimmunized and uninfected kids. For both the intestinal antigen and ovalbumin immunized groups, CD4+ T lymphocytes predominated in ALN lymphocytes that were stimulated to proliferate by intestinal antigens. The results indicate that H. contortus infection alone can induce ALN lymphocyte responses to intestinal antigens. In contrast to ALN lymphocyte responses, serum antibody against intestinal antigens was generally low to undetectable in ovalbumin-immunized kids following infection. Abomasal mucus from an H. contortus infected lamb was probed with a monoclonal antibody that binds to a periodate sensitive determinant on numerous H. contortus intestinal membrane and secreted proteins. Numerous bands of reactivity were detected, indicating that multiple parasite intestinal antigens were released into abomasal mucus during infection. The results, challenge the general concept that H. contortus intestinal antigens are 'hidden' from the host immune system during an infection. On the contrary, parasite intestinal proteins may be relatively abundant antigens presented to the host during infection. In addition, ALN T lymphocytes appear to provide a more sensitive measure

  19. The gut microbiota and host innate immunity: Regulators of host metabolism and metablic diseases in poultry?

    Science.gov (United States)

    The gut microbiota represents the multitudes of microbes residing in the intestine and is integral in multiple physiological processes of the host. The endogenous intestinal microflora together with other environmental factors, such as diet, play a central role in immune homeostasis. Moreover, the...

  20. Impact of high-fat diet on the intestinal microbiota and small intestinal physiology before and after the onset of obesity.

    Science.gov (United States)

    Araújo, João Ricardo; Tomas, Julie; Brenner, Christiane; Sansonetti, Philippe J

    2017-10-01

    The modulation of the intestinal microbiota by high-fat diet (HFD) has a major impact on both immunological and metabolic functions of the host. Taking this into consideration, the aim of this contribution is to review the impact of HFD on microbiota profile and small intestinal physiology before and after the onset of obesity and its metabolic complications. Evidence from animal studies suggest that before the onset of obesity and its metabolic complications, HFD induces intestinal dysbiosis - encompassing changes in composition balance and massive redistribution with bacteria occupying intervillous spaces and crypts - associated with early physiopathological changes, predominantly in the ileum, such as low-grade inflammation, decreased antimicrobial peptides expression, impaired mucus production, secretion and layer's thickness, and decreased expression of tight junction proteins. With time, major inflammatory signals (e.g. toll-like receptor-4 dependent) become activated, thereby stimulating proinflammatory cytokines secretion in the small intestine. This inflammatory state might subsequently exacerbate disruption of the mucus layer barrier and increase epithelial permeability of the small intestine, thereby creating an environment that facilitates the passage of bacterial components (e.g. lipopolysaccharide, peptidoglycan and flagellin) and metabolites from the intestinal lumen (e.g. secondary bile acids) to the circulation and peripheral tissues (i.e. leaky gut), eventually promoting the development of systemic inflammation, obesity, adiposity, insulin resistance and glucose intolerance preceding hyperglycemia. Although the mechanisms are still not completely understood, prebiotics, probiotics, polyphenols, peroxisome proliferator-activated receptor-γ agonists (such as rosiglitazone) and exercise have been shown to reverse HFD-induced intestinal phenotype and to attenuate the severity of obesity and its associated metabolic complications. Copyright © 2017

  1. A Dynamic WNT/β-CATENIN Signaling Environment Leads to WNT-Independent and WNT-Dependent Proliferation of Embryonic Intestinal Progenitor Cells

    Directory of Open Access Journals (Sweden)

    Alana M. Chin

    2016-11-01

    Full Text Available Much of our understanding about how intestinal stem and progenitor cells are regulated comes from studying the late fetal stages of development and the adult intestine. In this light, little is known about intestine development prior to the formation of stereotypical villus structures with columnar epithelium, a stage when the epithelium is pseudostratified and appears to be a relatively uniform population of progenitor cells with high proliferative capacity. Here, we investigated a role for WNT/β-CATENIN signaling during the pseudostratified stages of development (E13.5, E14.5 and following villus formation (E15.5 in mice. In contrast to the well-described role for WNT/β-CATENIN signaling as a regulator of stem/progenitor cells in the late fetal and adult gut, conditional epithelial deletion of β-catenin or the Frizzled co-receptors Lrp5 and Lrp6 had no effect on epithelial progenitor cell proliferation in the pseudostratified epithelium. Mutant embryos displayed obvious developmental defects, including loss of proliferation and disruptions in villus formation starting only at E15.5. Mechanistically, our data suggest that WNT signaling-mediated proliferation at the time of villus formation is driven by mesenchymal, but not epithelial, WNT ligand secretion.

  2. Interactions Between Bacteria and the Gut Mucosa: Do Enteric Neurotransmitters Acting on the Mucosal Epithelium Influence Intestinal Colonization or Infection?

    Science.gov (United States)

    Green, Benedict T; Brown, David R

    2016-01-01

    The intestinal epithelium is a critical barrier between the internal and external milieux of the mammalian host. Epithelial interactions between these two host environments have been shown to be modulated by several different, cross-communicating cell types residing in the gut mucosa. These include enteric neurons, whose activity is influenced by bacterial pathogens, and their secreted products. Neurotransmitters appear to influence epithelial associations with bacteria in the intestinal lumen. For example, internalization of Salmonella enterica and Escherichia coli O157:H7 into the Peyer's patch mucosa of the small intestine is altered after the inhibition of neural activity with saxitoxin, a neuronal sodium channel blocker. Catecholamine neurotransmitters, such as dopamine and norepinephrine, also alter bacterial internalization in Peyer's patches. In the large intestine, norepinephrine increases the mucosal adherence of E. coli. These neurotransmitter actions are mediated by well-defined catecholamine receptors situated on the basolateral membranes of epithelial cells rather than through direct interactions with luminal bacteria. Investigations of the involvement of neuroepithelial communication in the regulation of interactions between the intestinal mucosa and luminal bacteria will provide novel insights into the mechanisms underlying bacterial colonization and pathogenesis at mucosal surfaces.

  3. Salmonella enterica Serovar Typhimurium Strategies for Host Adaptation

    Directory of Open Access Journals (Sweden)

    Christopher J. Anderson

    2017-10-01

    Full Text Available Bacterial pathogens must sense and respond to newly encountered host environments to regulate the expression of critical virulence factors that allow for niche adaptation and successful colonization. Among bacterial pathogens, non-typhoidal serovars of Salmonella enterica, such as serovar Typhimurium (S. Tm, are a primary cause of foodborne illnesses that lead to hospitalizations and deaths worldwide. S. Tm causes acute inflammatory diarrhea that can progress to invasive systemic disease in susceptible patients. The gastrointestinal tract and intramacrophage environments are two critically important niches during S. Tm infection, and each presents unique challenges to limit S. Tm growth. The intestinal tract is home to billions of commensal microbes, termed the microbiota, which limits the amount of available nutrients for invading pathogens such as S. Tm. Therefore, S. Tm encodes strategies to manipulate the commensal population and side-step this nutritional competition. During subsequent stages of disease, S. Tm resists host immune cell mechanisms of killing. Host cells use antimicrobial peptides, acidification of vacuoles, and nutrient limitation to kill phagocytosed microbes, and yet S. Tm is able to subvert these defense systems. In this review, we discuss recently described molecular mechanisms that S. Tm uses to outcompete the resident microbiota within the gastrointestinal tract. S. Tm directly eliminates close competitors via bacterial cell-to-cell contact as well as by stimulating a host immune response to eliminate specific members of the microbiota. Additionally, S. Tm tightly regulates the expression of key virulence factors that enable S. Tm to withstand host immune defenses within macrophages. Additionally, we highlight the chemical and physical signals that S. Tm senses as cues to adapt to each of these environments. These strategies ultimately allow S. Tm to successfully adapt to these two disparate host environments. It is

  4. Intestinal myiasis

    Directory of Open Access Journals (Sweden)

    U S Udgaonkar

    2012-01-01

    Full Text Available Purpose: Intestinal myiasis is a condition when the fly larvae inhabit the gastrointestinal tract and are passed out in faeces. This type of infestation results when eggs or larvae of the fly, deposited on food are inadvertently taken by man. They survive the unfavourable conditions within the gastrointestinal tract and produce disturbances, which may vary from mild to severe. The condition is not uncommon and is often misdiagnosed as pinworm infestation. Correct diagnosis by the clinical microbiologist is important to avoid unnecessary treatment. Materials and Methods: We had 7 cases of intestinal myiasis. In 2 cases the larvae were reared to adult fly in modified meat and sand medium (developed by Udgaonkar. This medium is simple and can be easily prepared in the laboratory. Results: Of the 7 larvae, 5 were Sarcophaga haemorrhoidalis, 1 Megaselia species and 1 was identified as Muscina stabulans. Conclusions: S. haemorrhoidalis was the commonest maggot involved. A high index of suspicion is required for clinical diagnosis when the patient complains of passing wriggling worms in faeces for a long period without any response to antihelminthics. The reason for long duration of illness and recurrence of infestation is baffling. The nearest to cure was colonic wash. We feel prevention is of utmost importance, which is to avoid eating food articles with easy access to flies.

  5. An examination of electronic file transfer between host and microcomputers for the AMPMODNET/AIMNET (Army Material Plan Modernization Network/Acquisition Information Management Network) classified network environment

    Energy Technology Data Exchange (ETDEWEB)

    Hake, K.A.

    1990-11-01

    This report presents the results of investigation and testing conducted by Oak Ridge National Laboratory (ORNL) for the Project Manager -- Acquisition Information Management (PM-AIM), and the United States Army Materiel Command Headquarters (HQ-AMC). It concerns the establishment of file transfer capabilities on the Army Materiel Plan Modernization (AMPMOD) classified computer system. The discussion provides a general context for micro-to-mainframe connectivity and focuses specifically upon two possible solutions for file transfer capabilities. The second section of this report contains a statement of the problem to be examined, a brief description of the institutional setting of the investigation, and a concise declaration of purpose. The third section lays a conceptual foundation for micro-to-mainframe connectivity and provides a more detailed description of the AMPMOD computing environment. It gives emphasis to the generalized International Business Machines, Inc. (IBM) standard of connectivity because of the predominance of this vendor in the AMPMOD computing environment. The fourth section discusses two test cases as possible solutions for file transfer. The first solution used is the IBM 3270 Control Program telecommunications and terminal emulation software. A version of this software was available on all the IBM Tempest Personal Computer 3s. The second solution used is Distributed Office Support System host electronic mail software with Personal Services/Personal Computer microcomputer e-mail software running with IBM 3270 Workstation Program for terminal emulation. Test conditions and results are presented for both test cases. The fifth section provides a summary of findings for the two possible solutions tested for AMPMOD file transfer. The report concludes with observations on current AMPMOD understanding of file transfer and includes recommendations for future consideration by the sponsor.

  6. HmuY is an important virulence factor for Porphyromonas gingivalis growth in the heme-limited host environment and infection of macrophages.

    Science.gov (United States)

    Olczak, Teresa; Sosicka, Paulina; Olczak, Mariusz

    2015-11-27

    Porphyromonas gingivalis, the main etiologic agent and key pathogen responsible for initiation and progression of chronic periodontitis, is a haem auxotroph, and the uptake of this compound is essential for its survival and the ability to establish an infection. The aim of this study was to examine the role of a hemophore-like HmuY protein in P. gingivalis growth and infection of macrophages. Inactivation of the hmuY gene caused reduced P. gingivalis growth in vitro in the presence of serum as a heme sole source, as well as in vivo co-cultures with THP-1-derived macrophages. This resulted in diminished invasion efficiency of macrophages by live bacteria lacking functional hmuY gene. Both features were partially restored after addition of the purified HmuY protein, which was internalized when added either together with the hmuY mutant strain or alone to macrophage cultures. We conclude that HmuY is an important virulence factor of P. gingivalis for infection of macrophages in a heme-limited host environment. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Regulation of Intestinal Homeostasis by Innate Immune Cells

    OpenAIRE

    Kayama, Hisako; Nishimura, Junichi; Takeda, Kiyoshi

    2013-01-01

    The intestinal immune system has an ability to distinguish between the microbiota and pathogenic bacteria, and then activate pro-inflammatory pathways against pathogens for host defense while remaining unresponsive to the microbiota and dietary antigens. In the intestine, abnormal activation of innate immunity causes development of several inflammatory disorders such as inflammatory bowel diseases (IBD). Thus, activity of innate immunity is finely regulated in the intestine. To date, multiple...

  8. Intestinal microbiota in inflammatory bowel disease: Friend of foe

    National Research Council Canada - National Science Library

    Francesca Fava Silvio Danese

    2011-01-01

    Inflammatory bowel disease (IBD) arises from disruption of immune tolerance to the gut commensal microbiota, leading to chronic intestinal inflammation and mucosal damage in genetically predisposed hosts...

  9. Bacterial diversity in the intestinal tract of the fungus- cultivating ...

    African Journals Online (AJOL)

    GREGO

    2007-03-19

    Mar 19, 2007 ... Macrotermes gilvus provides further support for the hypothesis that microorganisms in intestinal tracts of termites ... with their hosts. Key words: Fungus-cultivating termites, bacterial diversity, intestinal tract, 16S rRNA gene, RFLP. ..... Functions of symbiotic fungus gardens in higher termites of the genus.

  10. The gills of reef fish support a distinct microbiome influenced by host-specific factors.

    Science.gov (United States)

    Pratte, Zoe A; Besson, Marc; Hollman, Rebecca D; Stewart, Frank J

    2018-02-16

    Teleost fish represent the most diverse of the vertebrate groups and play important roles in food webs, as ecosystem engineers, and as vectors for microorganisms. However, the microbial ecology of fishes remains underexplored for most host taxa, and for certain niches on the fish body. This is particularly true for the gills, the key sites for respiration and waste exchange in fishes. Here, we provide a comprehensive analysis of the gill microbiome. We focus on ecologically diverse taxa from coral reefs around Moorea, sampling the gill and intestines of adults and juveniles representing 15 families. Gill microbiome composition differed significantly from that of the gut in both adults and juveniles, with fish-associated niches having lower alpha diversity and higher beta diversity compared to seawater, sediment, and algae-associated microbiomes. Of ∼45,000 operational taxonomic units (OTUs) detected across all samples, 11% and 13% were detected only in the gill and intestine, respectively. OTUs most enriched in the gill included members of the gammaproteobacterial genus Shewanella and family Endozoicimonaceae. In adult fish, both gill and intestinal microbiomes varied significantly among host species grouped by diet category. Gill and intestinal microbiomes from the same individual were more similar to one another compared to gill and intestinal microbiomes from different individuals. These results demonstrate that distinct body sites are jointly influenced by host-specific organizing factors operating at the level of the host individual. The results also identify taxonomic signatures unique to the gill and intestine, confirming fish-associated niches as distinct reservoirs of marine microbial diversity. Importance Fish breath and excrete waste through their gills. The gills are also potential sites of pathogen invasion and colonization by other microbes. However, we know little about the microbial communities that live on the gill and the factors shaping their

  11. Host Genetic and Environmental Effects on Mouse Cecum Microbiota

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, James H [ORNL; Foster, Carmen M [ORNL; Vishnivetskaya, Tatiana A [ORNL; Campbell, Alisha G [ORNL; Yang, Zamin Koo [ORNL; Wymore, Ann [ORNL; Palumbo, Anthony Vito [ORNL; Podar, Mircea [ORNL

    2012-01-01

    The mammalian gut harbors complex and variable microbial communities, across both host phylogenetic space and conspecific individuals. A synergy of host genetic and environmental factors shape these communities and account for their variability, but their individual contributions and the selective pressures involved are still not well understood. We employed barcoded pyrosequencing of V1-2 and V4 regions of bacterial small subunit ribosomal RNA genes to characterize the effects of host genetics and environment on cecum assemblages in 10 genetically distinct, inbred mouse strains. Eight of these strains are the foundation of the Collaborative Cross (CC), a panel of mice derived from a genetically diverse set of inbred founder strains, designed specifically for complex trait analysis. Diversity of gut microbiota was characterized by complementing phylogenetic and distance-based, sequence-clustering approaches. Significant correlations were found between the mouse strains and their gut microbiota, reflected by distinct bacterial communities. Cohabitation and litter had a reduced, although detectable effect, and the microbiota response to these factors varied by strain. We identified bacterial phylotypes that appear to be discriminative and strain-specific to each mouse line used. Cohabitation of different strains of mice revealed an interaction of host genetic and environmental factors in shaping gut bacterial consortia, in which bacterial communities became more similar but retained strain specificity. This study provides a baseline analysis of intestinal bacterial communities in the eight CC progenitor strains and will be linked to integrated host genotype, phenotype and microbiota research on the resulting CC panel.

  12. Lectin Activation in Giardia lamblia by Host Protease: A Novel Host-Parasite Interaction

    Science.gov (United States)

    Lev, Boaz; Ward, Honorine; Keusch, Gerald T.; Pereira, Miercio E. A.

    1986-04-01

    A lectin in Giardia lamblia was activated by secretions from the human duodenum, the environment where the parasite lives. Incubation of the secretions with trypsin inhibitors prevented the appearance of lectin activity, implicating proteases as the activating agent. Accordingly, lectin activation was also produced by crystalline trypsin and Pronase; other proteases tested were ineffective. When activated, the lectin agglutinated intestinal cells to which the parasite adheres in vivo. The lectin was most specific to mannose-6-phosphate and apparently was bound to the plasma membrane. Activation of a parasite lectin by a host protease represents a novel mechanism of hostparasite interaction and may contribute to the affinity of Giardia lamblia to the infection site.

  13. Acidic Conditions in the NHE2-/- Mouse Intestine Result in an Altered Mucosa-Associated Bacterial Population with Changes in Mucus Oligosaccharides

    Directory of Open Access Journals (Sweden)

    Melinda A. Engevik

    2013-12-01

    Full Text Available Background: The mechanisms bacteria use to proliferate and alter the normal bacterial composition remain unknown. The ability to link changes in the intestinal micro-environment, such as ion composition and pH, to bacterial proliferation is clinically advantageous for diseases that involve an altered gut microbiota, such as Inflammatory Bowel Disease, obesity and diabetes. In human and mouse intestine, the apical Na+/H+ exchangers NHE2 and NHE3 affect luminal Na+, water, and pH. Loss of NHE2 results in acidic luminal pH. Since acid resistance systems in gram-positive bacteria are well documented, we hypothesize that gram-positive bacteria would increase in representation in the acidic NHE2-/- intestine. Methods: Intestinal ion composition was measured by fame photometry and chloridometry and pH measured electrochemically. DNA extracted from intestinal flushes or from mucosal scrapings was analyzed by qRT-PCR to examine luminal and mucosa-associated bacterial populations. Epithelial mucus oligosaccharide patterns were examined by histology with FIT-C labeled lectins. Results: Although total luminal and mucosa-associated bacteria were unchanged in NHE2-/- intestine, gram-positive bacterial phyla were increased in the mucosa-associated bacterial population in a region-specific manner. The genera Clostridium and Lactobacillus were increased in the cecum and colon which corresponded to changes in NHE2-/- mucus oligosaccharide composition of mannose, N-acetyglucosamine, N-acetygalactosamine and galactose. Conclusions: Together these data indicate that changes in ion transport induce region-specific bacterial changes, which alter host mucus oligosaccharide patterns. These host-bacterial interactions provide a possible mechanism of niche-development and shed insight on how certain groups proliferate in changing environments and maintain their proliferation by altering the host.

  14. Acidic conditions in the NHE2(-/-) mouse intestine result in an altered mucosa-associated bacterial population with changes in mucus oligosaccharides.

    Science.gov (United States)

    Engevik, Melinda A; Hickerson, Annelies; Shull, Gary E; Worrell, Roger T

    2013-01-01

    The mechanisms bacteria use to proliferate and alter the normal bacterial composition remain unknown. The ability to link changes in the intestinal micro-environment, such as ion composition and pH, to bacterial proliferation is clinically advantageous for diseases that involve an altered gut microbiota, such as Inflammatory Bowel Disease, obesity and diabetes. In human and mouse intestine, the apical Na(+)/H(+) exchangers NHE2 and NHE3 affect luminal Na(+), water, and pH. Loss of NHE2 results in acidic luminal pH. Since acid resistance systems in gram-positive bacteria are well documented, we hypothesize that gram-positive bacteria would increase in representation in the acidic NHE2(-/-) intestine. Intestinal ion composition was measured by fame photometry and chloridometry and pH measured electrochemically. DNA extracted from intestinal flushes or from mucosal scrapings was analyzed by qRT-PCR to examine luminal and mucosa-associated bacterial populations. Epithelial mucus oligosaccharide patterns were examined by histology with FIT-C labeled lectins . Although total luminal and mucosa-associated bacteria were unchanged in NHE2(-/-) intestine, gram-positive bacterial phyla were increased in the mucosa-associated bacterial population in a region-specific manner. The genera Clostridium and Lactobacillus were increased in the cecum and colon which corresponded to changes in NHE2(-/-) mucus oligosaccharide composition of mannose, N-acetyglucosamine, N-acetygalactosamine and galactose. Together these data indicate that changes in ion transport induce region-specific bacterial changes, which alter host mucus oligosaccharide patterns. These host-bacterial interactions provide a possible mechanism of niche-development and shed insight on how certain groups proliferate in changing environments and maintain their proliferation by altering the host. © 2014 S. Karger AG, Basel.

  15. Intestinal microbiota and HIV-1 infection

    Directory of Open Access Journals (Sweden)

    E. B. S. M. Trindade

    2007-01-01

    Full Text Available The intestinal microbiota consists of a qualitatively and quantitatively diverse range of microorganisms dynamically interacting with the host. It is remarkably stable with regard to the presence of microorganisms and their roles which, however, can be altered due to pathological conditions, diet composition, gastrointestinal disturbances and/or drug ingestion. The present review aimed at contributing to the discussion about changes in the intestinal microbiota due to HIV-1 infection, focusing on the triad infection-microbiota-nutrition as factors that promote intestinal bacterial imbalance. Intestinal microbiota alterations can be due to the HIV-1 infection as a primary factor or the pharmacotherapy employed, or they can be one of the consequences of the disease.

  16. New insights into the impact of Lactobacillus population on host-bacteria metabolic interplay.

    Science.gov (United States)

    Le Roy, Caroline I; Štšepetova, Jelena; Sepp, Epp; Songisepp, Epp; Claus, Sandrine P; Mikelsaar, Marika

    2015-10-13

    We aimed at evaluating the association between intestinal Lactobacillus sp. composition and their metabolic activity with the host metabolism in adult and elderly individuals. Faecal and plasma metabolites were measured and correlated to the Lactobacillus species distribution in healthy Estonian cohorts of adult (n = 16; 65 y). Total cholesterol, LDL, C-reactive protein and glycated hemoglobin were statistically higher in elderly, while platelets, white blood cells and urinary creatinine were higher in adults. Aging was associated with the presence of L. paracasei and L. plantarum and the absence of L. salivarius and L. helveticus. High levels of intestinal Lactobacillus sp. were positively associated with increased concentrations of faecal short chain fatty acids, lactate and essential amino acids. In adults, high red blood cell distribution width was positively associated with presence of L. helveticus and absence of L. ruminis. L. helveticus was correlated to lactate and butyrate in faecal waters. This indicates a strong relationship between the composition of the gut Lactobacillus sp. and host metabolism. Our results confirm that aging is associated with modulations of blood biomarkers and intestinal Lactobacillus species composition. We identified specific Lactobacillus contributions to gut metabolic environment and related those to blood biomarkers. Such associations may prove useful to decipher the biological mechanisms underlying host-gut microbial metabolic interactions in an ageing population.

  17. Ehrlichia chaffeensis infection in the reservoir host (white-tailed deer and in an incidental host (dog is impacted by its prior growth in macrophage and tick cell environments.

    Directory of Open Access Journals (Sweden)

    Arathy D S Nair

    Full Text Available Ehrlichia chaffeensis, transmitted from Amblyomma americanum ticks, causes human monocytic ehrlichiosis. It also infects white-tailed deer, dogs and several other vertebrates. Deer are its reservoir hosts, while humans and dogs are incidental hosts. E. chaffeensis protein expression is influenced by its growth in macrophages and tick cells. We report here infection progression in deer or dogs infected intravenously with macrophage- or tick cell-grown E. chaffeensis or by tick transmission in deer. Deer and dogs developed mild fever and persistent rickettsemia; the infection was detected more frequently in the blood of infected animals with macrophage inoculum compared to tick cell inoculum or tick transmission. Tick cell inoculum and tick transmission caused a drop in tick infection acquisition rates compared to infection rates in ticks fed on deer receiving macrophage inoculum. Independent of deer or dogs, IgG antibody response was higher in animals receiving macrophage inoculum against macrophage-derived Ehrlichia antigens, while it was significantly lower in the same animals against tick cell-derived Ehrlichia antigens. Deer infected with tick cell inoculum and tick transmission caused a higher antibody response to tick cell cultured bacterial antigens compared to the antibody response for macrophage cultured antigens for the same animals. The data demonstrate that the host cell-specific E. chaffeensis protein expression influences rickettsemia in a host and its acquisition by ticks. The data also reveal that tick cell-derived inoculum is similar to tick transmission with reduced rickettsemia, IgG response and tick acquisition of E. chaffeensis.

  18. Paneth cells: the hub for sensing and regulating intestinal flora.

    Science.gov (United States)

    Zhang, Zheng; Liu, Zhihua

    2016-05-01

    The complex interplay between symbiotic bacteria and host immunity plays a key role in shaping intestinal homeostasis and maintaining host health. Paneth cells, as one of the major producers of antimicrobial peptides in the intestine under steady-state conditions, play a vital role in regulating intestinal flora. Many studies on inflammatory bowel disease (IBD)-associated genes have put Paneth cells at the center of IBD pathogenesis. In this perspective, we focus on mechanistic studies of different cellular processes in Paneth cells that are regulated by various IBD-associated susceptibility genes, and we discuss the hypothesis that Paneth cells function as the central hub for sensing and regulating intestinal flora in the maintenance of intestinal homeostasis.

  19. Drosophila as a model for intestinal dysbiosis and chronic inflammatory diseases.

    Science.gov (United States)

    Lee, Kyung-Ah; Lee, Won-Jae

    2014-01-01

    The association between deregulated intestinal microbial consortia and host diseases has been recognized since the birth of microbiology over a century ago. Intestinal dysbiosis refers to a state where living metazoans harbor harmful intestinal microflora. However, there is still an issue of whether causality arises from the host or the microbe because it is unclear whether deregulation of the gut microbiota community is the consequence or cause of the host disease. Recent studies using Drosophila and its simple microbiota have provided a valuable model system for dissecting the molecular mechanisms of intestinal dysbiosis. In this review, we examine recent exciting observations in Drosophila gut-microbiota interactions, particularly the links among the host immune genotype, the microbial community structure, and the host inflammatory phenotype. Future genetic analyses using Drosophila model system will provide a valuable outcome for understanding the evolutionarily conserved mechanisms that underlie intestinal dysbiosis and chronic inflammatory diseases. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Microbiota Diurnal Rhythmicity Programs Host Transcriptome Oscillations.

    Science.gov (United States)

    Thaiss, Christoph A; Levy, Maayan; Korem, Tal; Dohnalová, Lenka; Shapiro, Hagit; Jaitin, Diego A; David, Eyal; Winter, Deborah R; Gury-BenAri, Meital; Tatirovsky, Evgeny; Tuganbaev, Timur; Federici, Sara; Zmora, Niv; Zeevi, David; Dori-Bachash, Mally; Pevsner-Fischer, Meirav; Kartvelishvily, Elena; Brandis, Alexander; Harmelin, Alon; Shibolet, Oren; Halpern, Zamir; Honda, Kenya; Amit, Ido; Segal, Eran; Elinav, Eran

    2016-12-01

    The intestinal microbiota undergoes diurnal compositional and functional oscillations that affect metabolic homeostasis, but the mechanisms by which the rhythmic microbiota influences host circadian activity remain elusive. Using integrated multi-omics and imaging approaches, we demonstrate that the gut microbiota features oscillating biogeographical localization and metabolome patterns that determine the rhythmic exposure of the intestinal epithelium to different bacterial species and their metabolites over the course of a day. This diurnal microbial behavior drives, in turn, the global programming of the host circadian transcriptional, epigenetic, and metabolite oscillations. Surprisingly, disruption of homeostatic microbiome rhythmicity not only abrogates normal chromatin and transcriptional oscillations of the host, but also incites genome-wide de novo oscillations in both intestine and liver, thereby impacting diurnal fluctuations of host physiology and disease susceptibility. As such, the rhythmic biogeography and metabolome of the intestinal microbiota regulates the temporal organization and functional outcome of host transcriptional and epigenetic programs. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Intestinal microbiome landscaping

    NARCIS (Netherlands)

    Shetty, Sudarshan A.; Hugenholtz, Floor; Lahti, Leo; Smidt, Hauke; Vos, de Willem M.

    2017-01-01

    High individuality, large complexity and limited understanding of the mechanisms underlying human intestinal microbiome function remain the major challenges for designing beneficial modulation strategies. Exemplified by the analysis of intestinal bacteria in a thousand Western adults, we discuss

  2. Vasoactive intestinal peptide test

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003508.htm Vasoactive intestinal peptide test To use the sharing features on this page, please enable JavaScript. Vasoactive intestinal peptide (VIP) is a test that measures the amount ...

  3. Intestinal ischemia and infarction

    Science.gov (United States)

    ... ency/article/001151.htm Small intestinal ischemia and infarction To use the sharing features on this page, please enable JavaScript. Intestinal ischemia and infarction occurs when there is a narrowing or blockage ...

  4. Enteric bacterial invasion of intestinal epithelial cells in vitro is dramatically enhanced using a vertical diffusion chamber model.

    Science.gov (United States)

    Naz, Neveda; Mills, Dominic C; Wren, Brendan W; Dorrell, Nick

    2013-10-22

    The interactions of bacterial pathogens with host cells have been investigated extensively using in vitro cell culture methods. However as such cell culture assays are performed under aerobic conditions, these in vitro models may not accurately represent the in vivo environment in which the host-pathogen interactions take place. We have developed an in vitro model of infection that permits the coculture of bacteria and host cells under different medium and gas conditions. The Vertical Diffusion Chamber (VDC) model mimics the conditions in the human intestine where bacteria will be under conditions of very low oxygen whilst tissue will be supplied with oxygen from the blood stream. Placing polarized intestinal epithelial cell (IEC) monolayers grown in Snapwell inserts into a VDC creates separate apical and basolateral compartments. The basolateral compartment is filled with cell culture medium, sealed and perfused with oxygen whilst the apical compartment is filled with broth, kept open and incubated under microaerobic conditions. Both Caco-2 and T84 IECs can be maintained in the VDC under these conditions without any apparent detrimental effects on cell survival or monolayer integrity. Coculturing experiments performed with different C. jejuni wild-type strains and different IEC lines in the VDC model with microaerobic conditions in the apical compartment reproducibly result in an increase in the number of interacting (almost 10-fold) and intracellular (almost 100-fold) bacteria compared to aerobic culture conditions. The environment created in the VDC model more closely mimics the environment encountered by C. jejuni in the human intestine and highlights the importance of performing in vitro infection assays under conditions that more closely mimic the in vivo reality. We propose that use of the VDC model will allow new interpretations of the interactions between bacterial pathogens and host cells.

  5. Salmonella enterica serovar Typhimurium exploits inflammation to modify swine intestinal microbiota.

    Directory of Open Access Journals (Sweden)

    Rosanna eDrumo

    2016-01-01

    Full Text Available Salmonella enterica serovar Typhimurium is an important zoonotic gastrointestinal pathogen responsible for foodborne disease worldwide. It is a successful enteric pathogen because it has developed virulence strategies allowing it to survive in a highly inflamed intestinal environment exploiting inflammation to overcome colonization resistance provided by intestinal microbiota. In this study, we used piglets featuring an intact microbiota, which naturally develop gastroenteritis, as model for salmonellosis. We compared the effects on the intestinal microbiota induced by a wild type and an attenuated S. Typhimurium in order to evaluate whether the modifications are correlated with the virulence of the strain. This study showed that Salmonella alters microbiota in a virulence-dependent manner. We found that the wild type S. Typhimurium induced inflammation and a reduction of specific protecting microbiota species (SCFA-producing bacteria normally involved in providing a barrier against pathogens. Both these effects could contribute to impair colonization resistance, increasing the host susceptibility to wild type S. Typhimurium colonization. In contrast, the attenuated S. Typhimurium, which is characterized by a reduced ability to colonize the intestine, and by a very mild inflammatory response, was unable to successfully sustain competition with the microbiota.

  6. Phylogenetic evidence for lateral gene transfer in the intestine of marine iguanas.

    Directory of Open Access Journals (Sweden)

    David M Nelson

    Full Text Available BACKGROUND: Lateral gene transfer (LGT appears to promote genotypic and phenotypic variation in microbial communities in a range of environments, including the mammalian intestine. However, the extent and mechanisms of LGT in intestinal microbial communities of non-mammalian hosts remains poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: We sequenced two fosmid inserts obtained from a genomic DNA library derived from an agar-degrading enrichment culture of marine iguana fecal material. The inserts harbored 16S rRNA genes that place the organism from which they originated within Clostridium cluster IV, a well documented group that habitats the mammalian intestinal tract. However, sequence analysis indicates that 52% of the protein-coding genes on the fosmids have top BLASTX hits to bacterial species that are not members of Clostridium cluster IV, and phylogenetic analysis suggests that at least 10 of 44 coding genes on the fosmids may have been transferred from Clostridium cluster XIVa to cluster IV. The fosmids encoded four transposase-encoding genes and an integrase-encoding gene, suggesting their involvement in LGT. In addition, several coding genes likely involved in sugar transport were probably acquired through LGT. CONCLUSION: Our phylogenetic evidence suggests that LGT may be common among phylogenetically distinct members of the phylum Firmicutes inhabiting the intestinal tract of marine iguanas.

  7. Pathways and Functions of Gut Microbiota Metabolism Impacting Host Physiology

    OpenAIRE

    Krishnan, Smitha; Alden, Nicholas; Lee, Kyongbum

    2015-01-01

    The bacterial populations in the human intestine impact host physiological functions through their metabolic activity. In addition to performing essential catabolic and biotransformation functions, the gut microbiota produces bioactive small molecules that mediate interactions with the host and contribute to the neurohumoral axes connecting the intestine with other parts of the body. This review discusses recent progress in characterizing the metabolic products of the gut microbiota and their...

  8. Treg cell-IgA axis in maintenance of host immune homeostasis with microbiota

    OpenAIRE

    Feng, Ting; Elson, Charles O.; Cong, Yingzi

    2010-01-01

    The intestine is the home to a vast diversity of microbiota and a complex of mucosal immune system. Multiple regulatory mechanisms control host immune responses to microbiota and maintain intestinal immune homeostasis. This mini review will provide evidence indicating a Treg cell-IgA axis and such axis playing a major role in maintenance of intestinal homeostasis.

  9. Intestinal lymphangiectasia in adults

    OpenAIRE

    Freeman, Hugh James; Nimmo, Michael

    2011-01-01

    Intestinal lymphangiectasia in the adult may be characterized as a disorder with dilated intestinal lacteals causing loss of lymph into the lumen of the small intestine and resultant hypoproteinemia, hypogammaglobulinemia, hypoalbuminemia and reduced number of circulating lymphocytes or lymphopenia. Most often, intestinal lymphangiectasia has been recorded in children, often in neonates, usually with other congenital abnormalities but initial definition in adults including the elderly has bec...

  10. Pathogen invasion changes the intestinal microbiota composition and induces innate immune responses in the zebrafish intestine.

    Science.gov (United States)

    Yang, Hui-Ting; Zou, Song-Song; Zhai, Li-Juan; Wang, Yao; Zhang, Fu-Miao; An, Li-Guo; Yang, Gui-Wen

    2017-12-01

    Numerous bacteria are harbored in the animal digestive tract and are impacted by several factors. Intestinal microbiota homeostasis is critical for maintaining the health of an organism. However, how pathogen invasion affects the microbiota composition has not been fully clarified. The mechanisms for preventing invasion by pathogenic microorganisms are yet to be elucidated. Zebrafish is a useful model for developmental biology, and studies in this organism have gradually become focused on intestinal immunity. In this study, we analyzed the microbiota of normal cultivated and infected zebrafish intestines, the aquarium water and feed samples. We found that the predominant bacteria in the zebrafish intestine belonged to Gammaproteobacteria (67%) and that feed and environment merely influenced intestinal microbiota composition only partially. Intestinal microbiota changed after a pathogenic bacterial challenge. At the genus level, the abundance of some pathogenic intestinal bacteria increased, and these genera included Halomonas (50%), Pelagibacterium (3.6%), Aeromonas (2.6%), Nesterenkonia (1%), Chryseobacterium (3.4‰), Mesorhizobium (1.4‰), Vibrio (1‰), Mycoplasma (0.7‰) and Methylobacterium (0.6‰) in IAh group. However, the abundance of some beneficial intestinal bacteria decreased, and these genera included Nitratireductor (0.8‰), Enterococcus (0.8‰), Brevundimonas (0.7‰), Lactococcus (0.7‰) and Lactobacillus (0.4‰). Additionally, we investigated the innate immune responses after infection. ROS levels in intestine increased in the early stages after a challenge and recovered subsequently. The mRNA levels of antimicrobial peptide genes lectin, hepcidin and defensin1, were upregulated in the intestine after pathogen infection. These results suggested that the invasion of pathogen could change the intestinal microbiota composition and induce intestinal innate immune responses in zebrafish. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Gas inflow and outflow in an interacting high-redshift galaxy. The remarkable host environment of GRB 080810 at z = 3.35

    Science.gov (United States)

    Wiseman, P.; Perley, D. A.; Schady, P.; Prochaska, J. X.; de Ugarte Postigo, A.; Krühler, T.; Yates, R. M.; Greiner, J.

    2017-11-01

    We reveal multiple components of an interacting galaxy system at z ≈ 3.35 through a detailed analysis of the exquisite high-resolution Keck/HIRES spectrum of the afterglow of a gamma-ray burst (GRB). Through Voigt-profile fitting of absorption lines from the Lyman series, we constrain the neutral hydrogen column density to NH I ≤ 1018.35 cm-2 for the densest of four distinct systems at the host redshift of GRB 080810, which is among the lowest NH I ever observed in a GRB host, even though the line of sight passes within a projected 5 kpc of the galaxy centres. By detailed analysis of the corresponding metal absorption lines, we derive chemical, ionic, and kinematic properties of the individual absorbing systems, and thus build a picture of the host as a whole. Striking differences between the systems imply that the line of sight passes through several phases of gas: the star-forming regions of the GRB host; enriched material in the form of a galactic outflow; the hot and ionised halo of a second interacting galaxy falling towards the host at a line-of-sight velocity of 700 km s-1; and a cool metal-poor cloud that may represent one of the best candidates yet for the inflow of metal-poor gas from the intergalactic medium. The reduced spectrum is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/607/A107

  12. The role of intestinal epithelium in inflammatory bowel disease and inflammation related intestinal cancer

    NARCIS (Netherlands)

    J.J. Deuring (Jasper)

    2013-01-01

    textabstractThe intestinal epithelial cells(IEC) are indispensable factors in the host protection against the harmful luminal content. In this thesis we aimed to gain further insight in the role of IEC in the Inflammatory Bowel Disease(IBD) aetiology, since it is an important mediator between the

  13. Modelling parasite transmission in a grazing system: the importance of host behaviour and immunity.

    Directory of Open Access Journals (Sweden)

    Naomi J Fox

    Full Text Available Parasitic helminths present one of the most pervasive challenges to grazing herbivores. Many macro-parasite transmission models focus on host physiological defence strategies, omitting more complex interactions between hosts and their environments. This work represents the first model that integrates both the behavioural and physiological elements of gastro-intestinal nematode transmission dynamics in a managed grazing system. A spatially explicit, individual-based, stochastic model is developed, that incorporates both the hosts' immunological responses to parasitism, and key grazing behaviours including faecal avoidance. The results demonstrate that grazing behaviour affects both the timing and intensity of parasite outbreaks, through generating spatial heterogeneity in parasite risk and nutritional resources, and changing the timing of exposure to the parasites' free-living stages. The influence of grazing behaviour varies with the host-parasite combination, dependent on the development times of different parasite species and variations in host immune response. Our outputs include the counterintuitive finding that under certain conditions perceived parasite avoidance behaviours (faecal avoidance can increase parasite risk, for certain host-parasite combinations. Through incorporating the two-way interaction between infection dynamics and grazing behaviour, the potential benefits of parasite-induced anorexia are also demonstrated. Hosts with phenotypic plasticity in grazing behaviour, that make grazing decisions dependent on current parasite burden, can reduce infection with minimal loss of intake over the grazing season. This paper explores how both host behaviours and immunity influence macro-parasite transmission in a spatially and temporally heterogeneous environment. The magnitude and timing of parasite outbreaks is influenced by host immunity and behaviour, and the interactions between them; the incorporation of both regulatory processes

  14. Intestinal, extra-intestinal and systemic sequelae of Toxoplasma gondii induced acute ileitis in mice harboring a human gut microbiota.

    Science.gov (United States)

    von Klitzing, Eliane; Ekmekciu, Ira; Kühl, Anja A; Bereswill, Stefan; Heimesaat, Markus M

    2017-01-01

    following peroral high dose T. gondii infection. Thus, hma mice constitute a suitable model to further dissect the interactions between pathogens, human microbiota and vertebrate host immunity during acute intestinal inflammation.

  15. Intestinal, extra-intestinal and systemic sequelae of Toxoplasma gondii induced acute ileitis in mice harboring a human gut microbiota.

    Directory of Open Access Journals (Sweden)

    Eliane von Klitzing

    acute ileitis following peroral high dose T. gondii infection. Thus, hma mice constitute a suitable model to further dissect the interactions between pathogens, human microbiota and vertebrate host immunity during acute intestinal inflammation.

  16. Latest concepts on the association between nonsteroidal anti-inflammatory drug-induced small intestinal injury and intestinal bacterial flora.

    Science.gov (United States)

    Fujimori, Shunji; Sakamoto, Choitsu

    2013-10-01

    Luminal bacteria, one of the main aggressive factors of nonsteroidal anti-inflammatory drugs (NSAIDs), induce small intestinal mucosal injury. Because most bacteria invading from the mouth are eliminated by the highly acidic gastric environment, the upper small intestine contains relatively low numbers of microorganisms. With decreased peristalsis, decreased acidity, and lower oxidation-reduction potential, the ileum maintains a more diverse microflora and a higher bacterial population. As NSAID-induced small intestinal ulcerations tend to localize in the small intestinal distal part, as viewed by capsule endoscopy, the ulcers are in contact with a large amount of luminal bacteria. Recently, it was reported that proton-pump inhibitors (PPIs) exacerbate NSAID-induced small intestinal injury in rats. The study showed that PPIs impair the ability to disinfect due to the PPI-induced low acidic gastric environment, and this resulted in transubstantiation of intestinal flora which exacerbated NSAID-induced small intestinal injury. If it is true that PPIs exacerbate small intestinal injury, the methods of preventing NSAID-induced gastroduodenal injury to defend PPI-induced small intestinal injury should be reconsidered. Following several studies, there may be a possibility that probiotics and prebiotics are useful treatments for the prevention of NSAID-induced small intestinal injury. A method of determining bacterial flora maintenance including alteration of the environment and the administration of various drugs is required.

  17. Medium-chain triglyceride as an alternative of in-feed colistin sulfate to improve growth performance and intestinal microbial environment in newly weaned pigs.

    Science.gov (United States)

    Yen, Hung-Che; Lai, Wei-Kang; Lin, Chuan-Shun; Chiang, Shu-Hsing

    2015-01-01

    Five hundred and twenty-eight newly weaned pigs were given four treatments, with eight replicates per treatment. Sixteen to 18 pigs were assigned per replicate and were fed diets supplemented with 0 or 3% medium-chain triglyceride (MCT) and 0 or 40 ppm colistin sulfate (CS) in a 2 × 2 factorial arrangement for 2 weeks. The results showed that dietary supplementation with MCT improved the gain-to-feed ratio during days 3-7 and in the overall period (P environment and the feed utilization efficiency of newly weaned pigs. © 2014 Japanese Society of Animal Science.

  18. Exon level transcriptomic profiling of HIV-1-infected CD4(+ T cells reveals virus-induced genes and host environment favorable for viral replication.

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    Michaël Imbeault

    Full Text Available HIV-1 is extremely specialized since, even amongst CD4(+ T lymphocytes (its major natural reservoir in peripheral blood, the virus productively infects only a small proportion of cells under an activated state. As the percentage of HIV-1-infected cells is very low, most studies have so far failed to capture the precise transcriptomic profile at the whole-genome scale of cells highly susceptible to virus infection. Using Affymetrix Exon array technology and a reporter virus allowing the magnetic isolation of HIV-1-infected cells, we describe the host cell factors most favorable for virus establishment and replication along with an overview of virus-induced changes in host gene expression occurring exclusively in target cells productively infected with HIV-1. We also establish that within a population of activated CD4(+ T cells, HIV-1 has no detectable effect on the transcriptome of uninfected bystander cells at early time points following infection. The data gathered in this study provides unique insights into the biology of HIV-1-infected CD4(+ T cells and identifies genes thought to play a determinant role in the interplay between the virus and its host. Furthermore, it provides the first catalogue of alternative splicing events found in primary human CD4(+ T cells productively infected with HIV-1.

  19. γδ T cells in homeostasis and host defence of epithelial barrier tissues.

    Science.gov (United States)

    Nielsen, Morten M; Witherden, Deborah A; Havran, Wendy L

    2017-12-01

    Epithelial surfaces line the body and provide a crucial interface between the body and the external environment. Tissue-resident epithelial γδ T cells represent a major T cell population in the epithelial tissues and are ideally positioned to carry out barrier surveillance and aid in tissue homeostasis and repair. In this Review, we focus on the intraepithelial γδ T cell compartment of the two largest epithelial tissues in the body - namely, the epidermis and the intestine - and provide a comprehensive overview of the crucial contributions of intraepithelial γδ T cells to tissue integrity and repair, host homeostasis and protection in the context of the symbiotic relationship with the microbiome and during pathogen clearance. Finally, we describe epithelium-specific butyrophilin-like molecules and briefly review their emerging role in selectively shaping and regulating epidermal and intestinal γδ T cell repertoires.

  20. Intestinal barrier in inflammatory bowel disease.

    Science.gov (United States)

    Antoni, Lena; Nuding, Sabine; Wehkamp, Jan; Stange, Eduard F

    2014-02-07

    A complex mucosal barrier protects as the first line of defense the surface of the healthy intestinal tract from adhesion and invasion by luminal microorganisms. In this review, we provide an overview about the major components of this protective system as for example an intact epithelium, the synthesis of various antimicrobial peptides (AMPs) and the formation of the mucus layer. We highlight the crucial importance of their correct functioning for the maintenance of a proper intestinal function and the prevention of dysbiosis and disease. Barrier disturbances including a defective production of AMPs, alterations in thickness or composition of the intestinal mucus layer, alterations of pattern-recognition receptors, defects in the process of autophagy as well as unresolved endoplasmic reticulum stress result in an inadequate host protection and are thought to play a crucial role in the pathogenesis of the inflammatory bowel diseases Crohn's disease and ulcerative colitis.

  1. Morfometria da mucosa duodenal em frangos de corte submetidos à temperatura ambiente cíclica elevada Intestinal morphometry of the duodenal mucosa in broiler chickens underwent to high cyclic environment temperature

    Directory of Open Access Journals (Sweden)

    C.F.P. Marchini

    2009-04-01

    days of age (P<0.01. Cyclic high environment temperature had harmful effect on intestinal structure of broiler from hatching to four weeks of age and on body weigh at the end of the productive cycle.

  2. Changes in intestinal microbiota composition and metabolism coincide with increased intestinal permeability in young adults under prolonged physiological stress.

    Science.gov (United States)

    Karl, J Philip; Margolis, Lee M; Madslien, Elisabeth H; Murphy, Nancy E; Castellani, John W; Gundersen, Yngvar; Hoke, Allison V; Levangie, Michael W; Kumar, Raina; Chakraborty, Nabarun; Gautam, Aarti; Hammamieh, Rasha; Martini, Svein; Montain, Scott J; Pasiakos, Stefan M

    2017-06-01

    The magnitude, temporal dynamics, and physiological effects of intestinal microbiome responses to physiological stress are poorly characterized. This study used a systems biology approach and a multiple-stressor military training environment to determine the effects of physiological stress on intestinal microbiota composition and metabolic activity, as well as intestinal permeability (IP). Soldiers ( n = 73) were provided three rations per day with or without protein- or carbohydrate-based supplements during a 4-day cross-country ski-march (STRESS). IP was measured before and during STRESS. Blood and stool samples were collected before and after STRESS to measure inflammation, stool microbiota, and stool and plasma global metabolite profiles. IP increased 62 ± 57% (mean ± SD, P microbiota responses were characterized by increased α-diversity and changes in the relative abundance of >50% of identified genera, including increased abundance of less dominant taxa at the expense of more dominant taxa such as Bacteroides Changes in intestinal microbiota composition were linked to 23% of metabolites that were significantly altered in stool after STRESS. Together, pre-STRESS Actinobacteria relative abundance and changes in serum IL-6 and stool cysteine concentrations accounted for 84% of the variability in the change in IP. Findings demonstrate that a multiple-stressor military training environment induced increases in IP that were associated with alterations in markers of inflammation and with intestinal microbiota composition and metabolism. Associations between IP, the pre-STRESS microbiota, and microbiota metabolites suggest that targeting the intestinal microbiota could provide novel strategies for preserving IP during physiological stress. NEW & NOTEWORTHY Military training, a unique model for studying temporal dynamics of intestinal barrier and intestinal microbiota responses to stress, resulted in increased intestinal permeability concomitant with changes in

  3. Entamoeba histolytica: Host parasite interactions at the colonic epithelium

    Science.gov (United States)

    Cornick, Steve; Chadee, Kris

    2017-01-01

    ABSTRACT Entamoeba histolytica (Eh) is the protozoan parasite responsible for intestinal amebiasis and interacts dynamically with the host intestinal epithelium during disease pathogenesis. A multifaceted pathogenesis profile accounts for why 90% of individuals infected with Eh are largely asymptomatic. For 100 millions individuals that are infected each year, key interactions within the intestinal mucosa dictate disease susceptibility. The ability for Eh to induce amebic colitis and disseminate into extraintestinal organs depends on the parasite competing with indigenous bacteria and overcoming the mucus barrier, binding to host cells inducing their cell death, invasion through the mucosa and outsmarting the immune system. In this review we summarize how Eh interacts with the intestinal epithelium and subverts host defense mechanisms in disease pathogenesis. PMID:28452682

  4. Functional and phylogenetic characterization of proteins detected in various nematode intestinal compartments.

    Science.gov (United States)

    Rosa, Bruce A; Townsend, Reid; Jasmer, Douglas P; Mitreva, Makedonka

    2015-04-01

    The parasitic nematode intestine is responsible for nutrient digestion and absorption, and many other processes essential for reproduction and survival, making it a valuable target for anthelmintic drug treatment. However, nematodes display extreme biological diversity (including occupying distinct trophic habitats), resulting in limited knowledge of intestinal cell/protein functions of fundamental or adaptive significance. We developed a perfusion model for isolating intestinal proteins in Ascaris suum (a parasite of humans and swine), allowing for the identification of over 1000 intestinal A. suum proteins (using mass spectrometry), which were assigned to several different intestinal cell compartments (intestinal tissue, the integral and peripheral intestinal membranes, and the intestinal lumen). A multi-omics analysis approach identified a large diversity of biological functions across intestinal compartments, based on both functional enrichment analysis (identifying terms related to detoxification, proteolysis, and host-parasite interactions) and regulatory binding sequence analysis to identify putatively active compartment-specific transcription factors (identifying many related to intestinal sex differentiation or lifespan regulation). Orthologs of A. suum proteins in 15 other nematodes species, five host species, and two outgroups were identified and analyzed. Different cellular compartments demonstrated markedly different levels of protein conservation; e.g. integral intestinal membrane proteins were the most conserved among nematodes (up to 96% conservation), whereas intestinal lumen proteins were the most diverse (only 6% conservation across all nematodes, and 71% with no host orthologs). Finally, this integrated multi-omics analysis identified conserved nematode-specific intestinal proteins likely performing essential functions (including V-type ATPases and ABC transporters), which may serve as promising anthelmintic drug or vaccine targets in future

  5. Functional and Phylogenetic Characterization of Proteins Detected in Various Nematode Intestinal Compartments*

    Science.gov (United States)

    Rosa, Bruce A.; Townsend, Reid; Jasmer, Douglas P.; Mitreva, Makedonka

    2015-01-01

    The parasitic nematode intestine is responsible for nutrient digestion and absorption, and many other processes essential for reproduction and survival, making it a valuable target for anthelmintic drug treatment. However, nematodes display extreme biological diversity (including occupying distinct trophic habitats), resulting in limited knowledge of intestinal cell/protein functions of fundamental or adaptive significance. We developed a perfusion model for isolating intestinal proteins in Ascaris suum (a parasite of humans and swine), allowing for the identification of over 1000 intestinal A. suum proteins (using mass spectrometry), which were assigned to several different intestinal cell compartments (intestinal tissue, the integral and peripheral intestinal membranes, and the intestinal lumen). A multi-omics analysis approach identified a large diversity of biological functions across intestinal compartments, based on both functional enrichment analysis (identifying terms related to detoxification, proteolysis, and host-parasite interactions) and regulatory binding sequence analysis to identify putatively active compartment-specific transcription factors (identifying many related to intestinal sex differentiation or lifespan regulation). Orthologs of A. suum proteins in 15 other nematodes species, five host species, and two outgroups were identified and analyzed. Different cellular compartments demonstrated markedly different levels of protein conservation; e.g. integral intestinal membrane proteins were the most conserved among nematodes (up to 96% conservation), whereas intestinal lumen proteins were the most diverse (only 6% conservation across all nematodes, and 71% with no host orthologs). Finally, this integrated multi-omics analysis identified conserved nematode-specific intestinal proteins likely performing essential functions (including V-type ATPases and ABC transporters), which may serve as promising anthelmintic drug or vaccine targets in future

  6. Host-pathogen interactions: A cholera surveillance system

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Aaron T.

    2016-02-22

    Bacterial pathogen-secreted proteases may play a key role in inhibiting a potentially widespread host-pathogen interaction. Activity-based protein profiling enabled the identification of a major Vibrio cholerae serine protease that limits the ability of a host-derived intestinal lectin to bind to the bacterial pathogen in vivo.

  7. INTESTINAL VIROME AND NORMAL MICROFLORA OF HUMAN: FEATURES OF INTERACTION

    Directory of Open Access Journals (Sweden)

    Bobyr V.V.

    2015-05-01

    Full Text Available Summary: Intestinal bacteria defend the host organism and narrow pathogenic bacterial colonization. However, the microbiome effect to enteric viruses is unexplored largely as well as role of microbiota in the pathogenesis of viral infections in general. This review focuses on precisely these issues. Keywords: microbiome, virome, normal microflora, enteric viruses, contagiousness. In this review article, facts about viral persistence in the human gut are summarized. It is described the role of viral populations during health and diseases. After analyzing of the literary facts it was concluded that the gastrointestinal tract is an environment for one from the most complex microbial ecosystems, which requires of more deeper study of its composition, role in physiological processes, as well as the dynamics of changes under influence of the environment. Normal microflora performs a different important functions providing the physiological homeostasis of the human body, including, in particular, an important role in the human metabolic processes, supporting of homeostasis, limiting of colonization by infectious bacteria. The multifactorial significance of the normal gastrointestinal microflora can be divided into immunological, structural and metabolic functions. At the same time, interaction between intestinal microflora and enteric viruses has not been studied largely. In recent years, much attention is paid to study of viruses-bacteria associations, and it is possible, obtained results should change our understanding of microbiota role in the systematic pathogenesis of the diseases with viral etiology. In contrast to the well-known benefits of normal microflora to the host, the viruses can use intestinal microflora as a trigger for replication at the optimal region. Recent studies give a reason for assumption that depletion of normal microflora with antibiotics can determining the antiviral effect. Thus, the role of commensal bacteria in viral

  8. Proteinaceous Molecules Mediating Bifidobacterium-Host Interactions

    Science.gov (United States)

    Ruiz, Lorena; Delgado, Susana; Ruas-Madiedo, Patricia; Margolles, Abelardo; Sánchez, Borja

    2016-01-01

    Bifidobacteria are commensal microoganisms found in the gastrointestinal tract. Several strains have been attributed beneficial traits at local and systemic levels, through pathogen exclusion or immune modulation, among other benefits. This has promoted a growing industrial and scientific interest in bifidobacteria as probiotic supplements. However, the molecular mechanisms mediating this cross-talk with the human host remain unknown. High-throughput technologies, from functional genomics to transcriptomics, proteomics, and interactomics coupled to the development of both in vitro and in vivo models to study the dynamics of the intestinal microbiota and their effects on host cells, have eased the identification of key molecules in these interactions. Numerous secreted or surface-associated proteins or peptides have been identified as potential mediators of bifidobacteria-host interactions and molecular cross-talk, directly participating in sensing environmental factors, promoting intestinal colonization, or mediating a dialogue with mucosa-associated immune cells. On the other hand, bifidobacteria induce the production of proteins in the intestine, by epithelial or immune cells, and other gut bacteria, which are key elements in orchestrating interactions among bifidobacteria, gut microbiota, and host cells. This review aims to give a comprehensive overview on proteinaceous molecules described and characterized to date, as mediators of the dynamic interplay between bifidobacteria and the human host, providing a framework to identify knowledge gaps and future research needs. PMID:27536282

  9. The role of the intestinal microbiota in pneumonia and sepsis

    OpenAIRE

    Lankelma, J.M.

    2017-01-01

    Humans carry with them trillions of bacteria, viruses and fungi that are collectively called the human microbiota. The intestinal microbiota fulfills essential functions in human physiology and has recently been suggested as a potential therapeutic target for several diseases. This thesis focuses on the role of the intestinal microbiota in pneumonia and sepsis. Our main hypothesis was that the gut microbiota plays a protective role in innate host defenses against systemic bacterial infections...

  10. Salmonella infection inhibits intestinal biotin transport: cellular and molecular mechanisms

    OpenAIRE

    Ghosal, Abhisek; Jellbauer, Stefan; Kapadia, Rubina; Raffatellu, Manuela; Said, Hamid M.

    2015-01-01

    Infection with the nontyphoidal Salmonella is a common cause of food-borne disease that leads to acute gastroenteritis/diarrhea. Severe/prolonged cases of Salmonella infection could also impact host nutritional status, but little is known about its effect on intestinal absorption of vitamins, including biotin. We examined the effect of Salmonella enterica serovar Typhimurium (S. typhimurium) infection on intestinal biotin uptake using in vivo (streptomycin-pretreated mice) and in vitro [mouse...

  11. Innate Immune Activation in Intestinal Homeostasis

    OpenAIRE

    Harrison, Oliver J.; Maloy, Kevin J.

    2011-01-01

    Loss of intestinal immune regulation leading to aberrant immune responses to the commensal microbiota are believed to precipitate the chronic inflammation observed in the gastrointestinal tract of patients with inflammatory bowel diseases (IBD), Crohn's disease and ulcerative colitis. Innate immune receptors that recognize conserved components derived from the microbiota are widely expressed by both epithelial cells and leucocytes of the gastrointestinal tract and play a key role in host prot...

  12. Common intestinal parasites

    National Research Council Canada - National Science Library

    Kucik, Corry Jeb; Martin, Gary L; Sortor, Brett V

    2004-01-01

    Intestinal parasites cause significant morbidity and mortality. Diseases caused by Enterobius vermicularis, Giardia lamblia, Ancylostoma duodenale, Necator americanus, and Entamoeba histolytica occur in the United States. E...

  13. Intestinal parasites and pregnancy.

    Science.gov (United States)

    D'Alauro, F; Lee, R V; Pao-In, K; Khairallah, M

    1985-11-01

    Intestinal parasites and pregnancy commonly coexist. Environmental, nutritional, and immunologic factors influence the clinical manifestations and determine the need for treatment of intestinal parasitism during pregnancy. No serious medical or obstetric problems attributable to intestinal parasites developed among 147 parasitized pregnant refugees living and delivering in a refugee camp in Southeast Thailand. These patients received adequate nutrition, careful prenatal monitoring, and no antiparasitic drug therapy. During pregnancy chemotherapy for intestinal parasites should not be used unless required for appropriate clinical and public health reasons.

  14. Intestinal parasites and tuberculosis

    Directory of Open Access Journals (Sweden)

    Anuar Alonso Cedeño-Burbano

    2017-10-01

    Conclusions: The available evidence was insufficient to affirm that intestinal parasites predispose to developing tuberculous. The studies carried out so far have found statistically insignificant results.

  15. Potential Role of Probiotics in Mechanism of Intestinal Immunity

    Directory of Open Access Journals (Sweden)

    Imran Rashid Rajput and Wei Fen Li*

    2012-06-01

    Full Text Available Probiotics are nonpathogenic bacteria exert a constructive influence on health or physiology of the host. Effect of probiotics in the intestinal defense against variety of diseases is well known. The probiotics are involved in the mechanism of intestinal defense, support as antagonist against pathogens, improve intestinal epithelial layer and boost the innate as well as adaptive immunity. However these responses are also exerted by intestinal components. The intestinal components as well as probiotics play a reciprocal role to enhance the immune response of the individual. The possibilities of mechanism of action include the stimulation of epithelial cells, activation of dendritic cells via toll-like receptors (TLRs, conversely produce cytokines. These observations reviewed together advocate that specific immunomodulatory properties of probiotic bacteria should be focusing on mechanism of action via antigen presenting cells (APC.

  16. Microbial contact during pregnancy, intestinal colonization and human disease.

    Science.gov (United States)

    Rautava, Samuli; Luoto, Raakel; Salminen, Seppo; Isolauri, Erika

    2012-10-01

    Interaction with colonizing intestinal bacteria is essential for healthy intestinal and immunological development in infancy. Advances in understanding early host-microbe interactions indicate that this early microbial programming begins in utero and is substantially modulated by mode of birth, perinatal antibiotics and breastfeeding. Furthermore, it has become evident that this stepwise microbial colonization process, as well as immune and metabolic programming by the microbiota, might have a long-lasting influence on the risk of not only gastrointestinal disease, but also allergic, autoimmune and metabolic disease, in later life. Modulating early host-microbe interaction by maternal probiotic intervention during pregnancy and breastfeeding offers a promising novel tool to reduce the risk of disease. In this Review, we describe the current body of knowledge regarding perinatal microbial contact, initial intestinal colonization and its association with human disease, as well as means of modulating early host-microbe interaction to reduce the risk of disease in the child.

  17. The Intestinal Microbiota in Metabolic Disease

    Directory of Open Access Journals (Sweden)

    Anni Woting

    2016-04-01

    Full Text Available Gut bacteria exert beneficial and harmful effects in metabolic diseases as deduced from the comparison of germfree and conventional mice and from fecal transplantation studies. Compositional microbial changes in diseased subjects have been linked to adiposity, type 2 diabetes and dyslipidemia. Promotion of an increased expression of intestinal nutrient transporters or a modified lipid and bile acid metabolism by the intestinal microbiota could result in an increased nutrient absorption by the host. The degradation of dietary fiber and the subsequent fermentation of monosaccharides to short-chain fatty acids (SCFA is one of the most controversially discussed mechanisms of how gut bacteria impact host physiology. Fibers reduce the energy density of the diet, and the resulting SCFA promote intestinal gluconeogenesis, incretin formation and subsequently satiety. However, SCFA also deliver energy to the host and support liponeogenesis. Thus far, there is little knowledge on bacterial species that promote or prevent metabolic disease. Clostridium ramosum and Enterococcus cloacae were demonstrated to promote obesity in gnotobiotic mouse models, whereas bifidobacteria and Akkermansia muciniphila were associated with favorable phenotypes in conventional mice, especially when oligofructose was fed. How diet modulates the gut microbiota towards a beneficial or harmful composition needs further research. Gnotobiotic animals are a valuable tool to elucidate mechanisms underlying diet–host–microbe interactions.

  18. The Intestinal Microbiota in Metabolic Disease

    Science.gov (United States)

    Woting, Anni; Blaut, Michael

    2016-01-01

    Gut bacteria exert beneficial and harmful effects in metabolic diseases as deduced from the comparison of germfree and conventional mice and from fecal transplantation studies. Compositional microbial changes in diseased subjects have been linked to adiposity, type 2 diabetes and dyslipidemia. Promotion of an increased expression of intestinal nutrient transporters or a modified lipid and bile acid metabolism by the intestinal microbiota could result in an increased nutrient absorption by the host. The degradation of dietary fiber and the subsequent fermentation of monosaccharides to short-chain fatty acids (SCFA) is one of the most controversially discussed mechanisms of how gut bacteria impact host physiology. Fibers reduce the energy density of the diet, and the resulting SCFA promote intestinal gluconeogenesis, incretin formation and subsequently satiety. However, SCFA also deliver energy to the host and support liponeogenesis. Thus far, there is little knowledge on bacterial species that promote or prevent metabolic disease. Clostridium ramosum and Enterococcus cloacae were demonstrated to promote obesity in gnotobiotic mouse models, whereas bifidobacteria and Akkermansia muciniphila were associated with favorable phenotypes in conventional mice, especially when oligofructose was fed. How diet modulates the gut microbiota towards a beneficial or harmful composition needs further research. Gnotobiotic animals are a valuable tool to elucidate mechanisms underlying diet–host–microbe interactions. PMID:27058556

  19. Intestinal microbiota is a plastic factor responding to environmental changes.

    Science.gov (United States)

    Candela, Marco; Biagi, Elena; Maccaferri, Simone; Turroni, Silvia; Brigidi, Patrizia

    2012-08-01

    Traditionally regarded as stable through the entire lifespan, the intestinal microbiota has now emerged as an extremely plastic entity, capable of being reconfigured in response to different environmental factors. In a mutualistic context, these microbiome fluctuations allow the host to rapidly adjust its metabolic and immunologic performances in response to environmental changes. Several circumstances can disturb this homeostatic equilibrium, inducing the intestinal microbiota to shift from a mutualistic configuration to a disease-associated profile. A mechanistic comprehension of the dynamics involved in this process is needed to deal more rationally with the role of the human intestinal microbiota in health and disease. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Geochemistry of host rocks in the Howards Pass district, Yukon-Northwest Territories, Canada: implications for sedimentary environments of Zn-Pb and phosphate mineralization

    Science.gov (United States)

    Slack, John F.; Falck, Hendrik; Kelley, Karen D.; Xue, Gabriel G.

    2017-01-01

    Detailed lithogeochemical data are reported here on early Paleozoic sedimentary rocks that host the large Howards Pass stratiform Zn-Pb deposits in Yukon-Northwest Territories. Redox-sensitive trace elements (Mo, Re, V, U) and Ce anomalies in members of the Duo Lake Formation record significant environmental changes. During the deposition of lower footwall units (Pyritic siliceous and Calcareous mudstone members), bottom waters were anoxic and sulphidic, respectively; these members formed in a marginal basin that may have become increasingly restricted with time. Relative to lower members, a major environmental change is proposed for deposition of the overlying Lower cherty mudstone member, which contains phosphorite beds up to ∼0.8 m thick in the upper part, near the base of the Zn-Pb deposits. The presence of these beds, together with models for modern phosphorite formation, suggests P input from an upwelling system and phosphorite deposition in an upper slope or outer shelf setting. The overlying Active mudstone member contains stratabound to stratiform Zn-Pb deposits within black mudstone and gray calcareous mudstone. Data for unmineralized black mudstone in this member indicate deposition under diverse redox conditions from suboxic to sulphidic. Especially distinctive in this member are uniformly low ratios of light to heavy rare earth elements that are unique within the Duo Lake Formation, attributed here to the dissolution of sedimentary apatite by downward-percolating acidic metalliferous brines. Strata that overlie the Active member (Upper siliceous mudstone member) consist mainly of black mudstone with thin (0.5–1.5 cm) laminae of fine-grained apatite, recording continued deposition on an upper slope or outer shelf under predominantly suboxic bottom waters. Results of this study suggest that exploration for similar stratiform sediment-hosted Zn-Pb deposits should include the outer parts of ancient continental margins, especially at and near

  1. Intestinal cytochromes P450 regulating the intestinal microbiota and its probiotic profile

    Directory of Open Access Journals (Sweden)

    Eugenia Elefterios Venizelos Bezirtzoglou

    2012-09-01

    Full Text Available Cytochromes P450 (CYPs enzymes metabolize a large variety of xenobiotic substances. In this vein, a plethora of studies were conducted to investigate their role, as cytochromes are located in both liver and intestinal tissues. The P450 profile of the human intestine has not been fully characterized. Human intestine serves primarily as an absorptive organ for nutrients, although it has also the ability to metabolize drugs. CYPs are responsible for the majority of phase I drug metabolism reactions. CYP3A represents the major intestinal CYP (80% followed by CYP2C9. CYP1A is expressed at high level in the duodenum, together with less abundant levels of CYP2C8-10 and CYP2D6. Cytochromes present a genetic polymorphism intra- or interindividual and intra- or interethnic. Changes in the pharmacokinetic profile of the drug are associated with increased toxicity due to reduced metabolism, altered efficacy of the drug, increased production of toxic metabolites, and adverse drug interaction. The high metabolic capacity of the intestinal flora is due to its enormous pool of enzymes, which catalyzes reactions in phase I and phase II drug metabolism. Compromised intestinal barrier conditions, when rupture of the intestinal integrity occurs, could increase passive paracellular absorption. It is clear that high microbial intestinal charge following intestinal disturbances, ageing, environment, or food-associated ailments leads to the microbial metabolism of a drug before absorption. The effect of certain bacteria having a benefic action on the intestinal ecosystem has been largely discussed during the past few years by many authors. The aim of the probiotic approach is to repair the deficiencies in the gut flora and establish a protective effect. There is a tentative multifactorial association of the CYP (P450 cytochrome role in the different diseases states, environmental toxic effects or chemical exposures and nutritional status.

  2. Giardia Colonizes and Encysts in High-Density Foci in the Murine Small Intestine

    Science.gov (United States)

    Barash, N. R.; Nosala, C.; Pham, J. K.; McInally, S. G.; Gourguechon, S.; McCarthy-Sinclair, B.

    2017-01-01

    ABSTRACT Giardia lamblia is a highly prevalent yet understudied protistan parasite causing significant diarrheal disease worldwide. Hosts ingest Giardia cysts from contaminated sources. In the gastrointestinal tract, cysts excyst to become motile trophozoites, colonizing and attaching to the gut epithelium. Trophozoites later differentiate into infectious cysts that are excreted and contaminate the environment. Due to the limited accessibility of the gut, the temporospatial dynamics of giardiasis in the host are largely inferred from laboratory culture and thus may not mirror Giardia physiology in the host. Here, we have developed bioluminescent imaging (BLI) to directly interrogate and quantify the in vivo temporospatial dynamics of Giardia infection, thereby providing an improved murine model to evaluate anti-Giardia drugs. Using BLI, we determined that parasites primarily colonize the proximal small intestine nonuniformly in high-density foci. By imaging encystation-specific bioreporters, we show that encystation initiates shortly after inoculation and continues throughout the duration of infection. Encystation also initiates in high-density foci in the proximal small intestine, and high density contributes to the initiation of encystation in laboratory culture. We suggest that these high-density in vivo foci of colonizing and encysting Giardia likely result in localized disruption to the epithelium. This more accurate visualization of giardiasis redefines the dynamics of the in vivo Giardia life cycle, paving the way for future mechanistic studies of density-dependent parasitic processes in the host. IMPORTANCE Giardia is a single-celled parasite causing significant diarrheal disease in several hundred million people worldwide. Due to limited access to the site of infection in the gastrointestinal tract, our understanding of the dynamics of Giardia infections in the host has remained limited and largely inferred from laboratory culture. To better understand

  3. adhesive intestinal obstruction

    African Journals Online (AJOL)

    2006-06-01

    Jun 1, 2006 ... ABSTRACT. Background: Adhesions after abdominal and pelvic surgery are a major cause of intestinal obstruction in the western world and the pathology is steadily gaining prominence in our practice. Objective: To determine the magnitude of adhesive intestinal obstruction; to determine the types.

  4. Neuromodulation of intestinal inflammation

    NARCIS (Netherlands)

    Costes, L.M.M.

    2015-01-01

    Interactions between the central nervous system and the immune system have been shown to exert a crucial role in the tight regulation of the immune response in the intestine. In particular, the vagus nerve was recently unraveled as an important player in this neuromodulation of intestinal

  5. [Malaria and intestinal protozoa].

    Science.gov (United States)

    Rojo-Marcos, Gerardo; Cuadros-González, Juan

    2016-03-01

    Malaria is life threatening and requires urgent diagnosis and treatment. Incidence and mortality are being reduced in endemic areas. Clinical features are unspecific so in imported cases it is vital the history of staying in a malarious area. The first line treatments for Plasmodium falciparum are artemisinin combination therapies, chloroquine in most non-falciparum and intravenous artesunate if any severity criteria. Human infections with intestinal protozoa are distributed worldwide with a high global morbid-mortality. They cause diarrhea and sometimes invasive disease, although most are asymptomatic. In our environment populations at higher risk are children, including adopted abroad, immune-suppressed, travelers, immigrants, people in contact with animals or who engage in oral-anal sex. Diagnostic microscopic examination has low sensitivity improving with antigen detection or molecular methods. Antiparasitic resistances are emerging lately. Copyright © 2016 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  6. Congenital intestinal lymphangiectasia

    Directory of Open Access Journals (Sweden)

    Popović Dušan Đ.

    2011-01-01

    Full Text Available Background. Congenital intestinal lymphangiectasia is a disease which leads to protein losing enteropathy. Tortous, dilated lymphatic vessels in the intestinal wall and mesenterium are typical features of the disease. Clinical manifestations include malabsorption, diarrhea, steatorrhea, edema and effusions. Specific diet and medication are required for disease control. Case report. A 19-year old male patient was hospitalized due to diarrhea, abdominal swelling, weariness and fatigue. Physical examination revealed growth impairment, ascites, and lymphedema of the right hand and forearm. Laboratory assessment indicated iron deficiency anaemia, lymphopenia, malabsorption, inflammatory syndrome, and urinary infection. Enteroscopy and video capsule endoscopy demonstrated dilated lymphatic vessels in the small intestine. The diagnosis was confirmed by intestinal biopsy. The patient was put on high-protein diet containing medium-chain fatty acids, somatotropin and suportive therapy. Conclusion. Congenital intestinal lymphangiectasia is a rare disease, usually diagnosed in childhood. Early recognition of the disease and adequate treatment can prevent development of various complications.

  7. Epidemiological assessment of intestinal parasitic infections in dogs at animal shelter in Veracruz, Mexico

    Directory of Open Access Journals (Sweden)

    Cosme Alvarado-Esquivel

    2015-01-01

    Conclusions: A high prevalence of intestinal parasites was found in the dogs studied. This suggests that the environment is highly contaminated with intestinal parasites. Preventive and therapeutic measures should be taken against infection with intestinal parasites in dogs in this region.

  8. Childhood intestinal obstruction in Northwestern Nigeria | Uba ...

    African Journals Online (AJOL)

    West African Journal of Medicine ... The aim of this paper was to assess the pattern and the outcome of mangement of intestinal obstruction in Nigerian children. ... Their management is associated with high mortality in our environment, especially when there are associated anomalies or the presentation is late. Key Words: ...

  9. The Drenchwater deposit, Alaska: An example of a natural low pH environment resulting from weathering of an undisturbed shale-hosted Zn-Pb-Ag deposit

    Science.gov (United States)

    Graham, G.E.; Kelley, K.D.

    2009-01-01

    The Drenchwater shale-hosted Zn-Pb-Ag deposit and the immediate vicinity, on the northern flank of the Brooks Range in north-central Alaska, is an ideal example of a naturally low pH system. The two drainages, Drenchwater and False Wager Creeks, which bound the deposit, differ in their acidity and metal contents. Moderately acidic waters with elevated concentrations of metals (pH ??? 4.3, Zn ??? 1400 ??g/L) in the Drenchwater Creek drainage basin are attributed to weathering of an exposed base-metal-rich massive sulfide occurrence. Stream sediment and water chemistry data collected from False Wager Creek suggest that an unexposed base-metal sulfide occurrence may account for the lower pH (2.7-3.1) and very metal-rich waters (up to 2600 ??g/L Zn, ??? 260 ??g/L Cu and ???89 ??g/L Tl) collected at least 2 km upstream of known mineralized exposures. These more acidic conditions produce jarosite, schwertmannite and Fe-hydroxides commonly associated with acid-mine drainage. The high metal concentrations in some water samples from both streams naturally exceed Alaska state regulatory limits for freshwater aquatic life, affirming the importance of establishing base-line conditions in the event of human land development. The studies at the Drenchwater deposit demonstrate that poor water quality can be generated through entirely natural weathering of base-metal occurrences, and, possibly unmineralized black shale.

  10. Oral-derived bacterial flora defends its domain by recognizing and killing intruders--a molecular analysis using Escherichia coli as a model intestinal bacterium.

    Science.gov (United States)

    He, Xuesong; Tian, Yan; Guo, Lihong; Lux, Renate; Zusman, David R; Shi, Wenyuan

    2010-10-01

    Within the same human gastrointestinal tract, substantial differences in the bacterial species that inhabit oral cavity and intestinal tract have been noted. Previous research primarily attributed the differences to the influences of host environments and nutritional availabilities ("host habitat" effect). Our recent study indicated that, other than the host habitat effect, an existing microbial community could impose a selective pressure on incoming foreign bacterial species independent of host-mediated selection ("community selection" effect). In this study, we employed in vitro microbial floras representing microorganisms that inhabit the oral cavities and intestinal tract of mice in combination with Escherichia coli as a model intestinal bacterium and demonstrated that E. coli displays a striking community preference. It thrived when introduced into the intestinal microbial community and survived poorly in the microbial flora of foreign origin (oral community). A more detailed examination of this phenomenon showed that the oral community produced oxygen-free radicals in the presence of wild-type E. coli while mutants deficient in lipopolysaccharides (LPS) did not trigger significant production of these cell-damaging agents. Furthermore, mutants of E. coli defective in the oxidative stress response experienced a more drastic reduction in viability when cocultivated with the oral flora, while the exogenous addition of the antioxidant vitamin C was able to rescue it. We concluded that the oral-derived microbial community senses the E. coli LPS and kills the bacterium with oxygen-free radicals. This study reveals a new mechanism of community invasion resistance employed by established microflora to defend their domains.

  11. Oral-Derived Bacterial Flora Defends Its Domain by Recognizing and Killing Intruders—A Molecular Analysis Using Escherichia coli as a Model Intestinal Bacterium

    Science.gov (United States)

    He, Xuesong; Tian, Yan; Guo, Lihong; Lux, Renate; Zusman, David R.

    2010-01-01

    Within the same human gastrointestinal tract, substantial differences in the bacterial species that inhabit oral cavity and intestinal tract have been noted. Previous research primarily attributed the differences to the influences of host environments and nutritional availabilities (“host habitat” effect). Our recent study indicated that, other than the host habitat effect, an existing microbial community could impose a selective pressure on incoming foreign bacterial species independent of host-mediated selection (“community selection” effect). In this study, we employed in vitro microbial floras representing microorganisms that inhabit the oral cavities and intestinal tract of mice in combination with Escherichia coli as a model intestinal bacterium and demonstrated that E. coli displays a striking community preference. It thrived when introduced into the intestinal microbial community and survived poorly in the microbial flora of foreign origin (oral community). A more detailed examination of this phenomenon showed that the oral community produced oxygen-free radicals in the presence of wild-type E. coli while mutants deficient in lipopolysaccharides (LPS) did not trigger significant production of these cell-damaging agents. Furthermore, mutants of E. coli defective in the oxidative stress response experienced a more drastic reduction in viability when cocultivated with the oral flora, while the exogenous addition of the antioxidant vitamin C was able to rescue it. We concluded that the oral-derived microbial community senses the E. coli LPS and kills the bacterium with oxygen-free radicals. This study reveals a new mechanism of community invasion resistance employed by established microflora to defend their domains. Electronic supplementary material The online version of this article (doi:10.1007/s00248-010-9708-4) contains supplementary material, which is available to authorized users. PMID:20625713

  12. Bacterial community characterization of water and intestine of the shrimp Litopenaeus stylirostris in a biofloc system.

    Science.gov (United States)

    Cardona, Emilie; Gueguen, Yannick; Magré, Kevin; Lorgeoux, Bénédicte; Piquemal, David; Pierrat, Fabien; Noguier, Florian; Saulnier, Denis

    2016-07-19

    Biofloc technology (BFT), a rearing method with little or no water exchange, is gaining popularity in aquaculture. In the water column, such systems develop conglomerates of microbes, algae and protozoa, together with detritus and dead organic particles. The intensive microbial community presents in these systems can be used as a pond water quality treatment system, and the microbial protein can serve as a feed additive. The current problem with BFT is the difficulty of controlling its bacterial community composition for both optimal water quality and optimal shrimp health. The main objective of the present study was to investigate microbial diversity of samples obtained from different culture environments (Biofloc technology and clear seawater) as well as from the intestines of shrimp reared in both environments through high-throughput sequencing technology. Analyses of the bacterial community identified in water from BFT and "clear seawater" (CW) systems (control) containing the shrimp Litopenaeus stylirostris revealed large differences in the frequency distribution of operational taxonomic units (OTUs). Four out of the five most dominant bacterial communities were different in both culture methods. Bacteria found in great abundance in BFT have two principal characteristics: the need for an organic substrate or nitrogen sources to grow and the capacity to attach to surfaces and co-aggregate. A correlation was found between bacteria groups and physicochemical and biological parameters measured in rearing tanks. Moreover, rearing-water bacterial communities influenced the microbiota of shrimp. Indeed, the biofloc environment modified the shrimp intestine microbiota, as the low level (27 %) of similarity between intestinal bacterial communities from the two treatments. This study provides the first information describing the complex biofloc microbial community, which can help to understand the environment-microbiota-host relationship in this rearing system.

  13. Factoring the intestinal microbiome into the pathogenesis of autoimmune hepatitis.

    Science.gov (United States)

    Czaja, Albert J

    2016-11-14

    The intestinal microbiome is a reservoir of microbial antigens and activated immune cells. The aims of this review were to describe the role of the intestinal microbiome in generating innate and adaptive immune responses, indicate how these responses contribute to the development of systemic immune-mediated diseases, and encourage investigations that improve the understanding and management of autoimmune hepatitis. Alterations in the composition of the intestinal microflora (dysbiosis) can disrupt intestinal and systemic immune tolerances for commensal bacteria. Toll-like receptors within the intestine can recognize microbe-associated molecular patterns and shape subsets of T helper lymphocytes that may cross-react with host antigens (molecular mimicry). Activated gut-derived lymphocytes can migrate to lymph nodes, and gut-derived microbial antigens can translocate to extra-intestinal sites. Inflammasomes can form within hepatocytes and hepatic stellate cells, and they can drive the pro-inflammatory, immune-mediated, and fibrotic responses. Diet, designer probiotics, vitamin supplements, re-colonization methods, antibiotics, drugs that decrease intestinal permeability, and molecular interventions that block signaling pathways may emerge as adjunctive regimens that complement conventional immunosuppressive management. In conclusion, investigations of the intestinal microbiome are warranted in autoimmune hepatitis and promise to clarify pathogenic mechanisms and suggest alternative management strategies.

  14. Original Paper Intestinal Helminthiasis among School Children in ...

    African Journals Online (AJOL)

    between water treatment and infection. Periodic ... prevalent rate and their effect on both nutritional ... with a variety of helminths, and eating habits that involve the consumption of raw vegetables, fish, ..... contaminate the environment. Intestinal ...

  15. Influence of maternal breast milk ingestion on acquisition of the intestinal microbiome in preterm infants.

    Science.gov (United States)

    Gregory, Katherine E; Samuel, Buck S; Houghteling, Pearl; Shan, Guru; Ausubel, Frederick M; Sadreyev, Ruslan I; Walker, W Allan

    2016-12-30

    The initial acquisition and early development of the intestinal microbiome during infancy are important to human health across the lifespan. Mode of birth, antibiotic administration, environment of care, and nutrition have all been shown to play a role in the assembly of the intestinal microbiome during early life. For preterm infants, who are disproportionately at risk of inflammatory intestinal disease (i.e., necrotizing enterocolitis), a unique set of clinical factors influence the establishment of the microbiome. The purpose of this study was to establish the influence of nutritional exposures on the intestinal microbiome in a cohort of preterm infants early in life. Principal component analysis of 199 samples from 30 preterm infants (<32 weeks) over the first 60 days following birth showed that the intestinal microbiome was influenced by postnatal time (p < 0.001, R (2) = 0.13), birth weight (p < 0.001, R (2) = 0.08), and nutrition (p < 0.001, R (2) = 0.21). Infants who were fed breast milk had a greater initial bacterial diversity and a more gradual acquisition of diversity compared to infants who were fed infant formula. The microbiome of infants fed breast milk were more similar regardless of birth weight (p = 0.049), in contrast to the microbiome of infants fed infant formula, which clustered differently based on birth weight (p < 0.001). By adjusting for differences in gut maturity, an ordered succession of microbial phylotypes was observed in breast milk-fed infants, which appeared to be disrupted in those fed infant formula. Supplementation with pasteurized donor human milk was partially successful in promoting a microbiome more similar to breast milk-fed infants and moderating rapid increases in bacterial diversity. The preterm infant intestinal microbiome is influenced by postnatal time, birth weight, gestational age, and nutrition. Feeding with breast milk appears to mask the influence of birth weight, suggesting a

  16. Host tissue reactions of non-demineralized autogenic and xenogenic dentin blocks implanted in a non-osteogenic environment. An experimental study in rabbits.

    Science.gov (United States)

    Al-Asfour, Adel; Farzad, Payam; Andersson, Lars; Joseph, Bobby; Dahlin, Christer

    2014-06-01

    Dentoalveolar ankylosis with osseous replacement is often seen after replantation of avulsed teeth, and this process may be used for preservation of alveolar crests after trauma. Its exact mechanisms with regard to osteoinductive properties are not yet fully understood and need to be systematically investigated. Dentin can possibly act as a slow-releasing carrier of bone morphogenic proteins (BMP), and this property of dentin has been proposed to be used as an alternative or supplement to bone grafting in the maxillofacial region. We aimed to initially asses host tissue reactions to dentin by implanting dentin blocks of autogenic and xenogenic human origin in rabbit connective tissue of the abdominal wall and femoral muscle. Animals were sacrificed after a period of 3 months, and histological processing, sectioning and examinations were carried out. Bone formation, cell counts and thickness of capsule surrounding the grafts were evaluated. Only minor signs of heterotopic bone formation were seen. There were no significant differences between autografts and xenografts or grafts implanted in connective tissue or muscle with regards to tissue reactions except for a significant difference (P = 0.018) in findings of more local inflammatory cells in relation to grafts placed in connective tissue in the autograft group. We conclude that during the time frame of this study, non-demineralized dentin, whether autogenous or xenogenic did not have the potential to induce bone formation when implanted in non-osteogenic areas such as the abdominal wall and abdominal muscle of rabbits. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. TLR2 Controls Intestinal Carcinogen Detoxication by CYP1A1

    DEFF Research Database (Denmark)

    Do, Khoa; Fink, Lisbeth Nielsen; Jensen, Thomas Elbenhardt

    2012-01-01

    of ligands for TLR2 of bacterial origin seems to be crucial for detoxication of luminal carcinogens by CYP1A1 in the intestine. This unprecedented finding indicates a complex interplay between the immune system of the host and intestinal bacteria with detoxication mechanisms. This highlights the relevance...

  18. Molecular mechanisms underlying the effects of dietary fiber in the large intestine

    NARCIS (Netherlands)

    Lange, K.

    2015-01-01

    Abstract Interactions between diet, microbiota and host response are important for intestinal health. Dietary fibers are known to promote intestinal health. Dietary fibers are edible plant-derived food components that encompass complex carbohydrates and lignin, resist the digestion

  19. Maintenance of a healthy trajectory of the intestinal microbiome during aging: A dietary approach

    NARCIS (Netherlands)

    Candela, M.; Biagi, E.; Brigidi, P.; O'Toole, P.W.; Vos, de W.M.

    2014-01-01

    Sharing an intense transgenomic metabolism with the host, the intestinal microbiota is an essential factor for several aspects of the human physiology. However, several age-related factors, such as changes diet, lifestyle, inflammation and frailty, force the deterioration of this intestinal

  20. [Design and analyze mathematical algorithms of intestinal absorption and metabolism of multicomponent drug].

    Science.gov (United States)

    Dong, Ling; Xiang, Jia-Mei; Wang, Yun; Wu, Rui-Guang; Tang, Ming-Min; Sun, Mo-Han

    2014-12-01

    Evaluation of the permeability mainly focuses on intestinal absorption in biopharmaceutics classification system (BCS). It is more complicated that the absorption and metabolism under multicomponent environment in biopharmaceutics classification system of Chinese materia medica (CMMBCS) compared with single component environment, which needs suitable mathematical models to be described. Therefore, with full consideration of existing single component mathematical algorithm combining with the characteristics of intestinal absorption and metabolism, we explored and designed a new mathematical algorithm of intestinal absorption and metabolism of multicomponent drug. Then we put forward a new coefficient, P (influence), the relative change rate of the single component's intestinal absorption and metabolism under multicomponent environment compared with single component environment, which described the influences of intestinal absorption and metabolism of the component under multicomponent environment. Moreover, P (influence) highlights the distinctive characteristics of multicomponent drug's intestinal absorption and metabolism, and lays the foundation for the construction of CMMBCS.

  1. Arginine consumption by the intestinal parasite Giardia intestinalis reduces proliferation of intestinal epithelial cells.

    Science.gov (United States)

    Stadelmann, Britta; Merino, María C; Persson, Lo; Svärd, Staffan G

    2012-01-01

    In the field of infectious diseases the multifaceted amino acid arginine has reached special attention as substrate for the hosts production of the antimicrobial agent nitric oxide (NO). A variety of infectious organisms interfere with this part of the host immune response by reducing the availability of arginine. This prompted us to further investigate additional roles of arginine during pathogen infections. As a model we used the intestinal parasite Giardia intestinalis that actively consumes arginine as main energy source and secretes an arginine-consuming enzyme, arginine deiminase (ADI). Reduced intestinal epithelial cell (IEC) proliferation is a common theme during bacterial and viral intestinal infections, but it has never been connected to arginine-consumption. Our specific question was thereby, whether the arginine-consumption by Giardia leads to reduced IEC proliferation, in addition to NO reduction. In vitro cultivation of human IEC lines in arginine-free or arginine/citrulline-complemented medium, as well as in interaction with different G. intestinalis isolates, were used to study effects on host cell replication by MTT assay. IEC proliferation was further analyzed by DNA content analysis, polyamine measurements and expressional analysis of cell cycle regulatory genes. IEC proliferation was reduced upon arginine-withdrawal and also in an arginine-dependent manner upon interaction with G. intestinalis or addition of Giardia ADI. We show that arginine-withdrawal by intestinal pathogens leads to a halt in the cell cycle in IECs through reduced polyamine levels and upregulated cell cycle inhibitory genes. This is of importance with regards to intestinal tissue homeostasis that is affected through reduced cell proliferation. Thus, the slower epithelial cell turnover helps the pathogen to maintain a more stable niche for colonization. This study also shows why supplementation therapy of diarrhea patients with arginine/citrulline is helpful and that

  2. Arginine consumption by the intestinal parasite Giardia intestinalis reduces proliferation of intestinal epithelial cells.

    Directory of Open Access Journals (Sweden)

    Britta Stadelmann

    Full Text Available In the field of infectious diseases the multifaceted amino acid arginine has reached special attention as substrate for the hosts production of the antimicrobial agent nitric oxide (NO. A variety of infectious organisms interfere with this part of the host immune response by reducing the availability of arginine. This prompted us to further investigate additional roles of arginine during pathogen infections. As a model we used the intestinal parasite Giardia intestinalis that actively consumes arginine as main energy source and secretes an arginine-consuming enzyme, arginine deiminase (ADI. Reduced intestinal epithelial cell (IEC proliferation is a common theme during bacterial and viral intestinal infections, but it has never been connected to arginine-consumption. Our specific question was thereby, whether the arginine-consumption by Giardia leads to reduced IEC proliferation, in addition to NO reduction. In vitro cultivation of human IEC lines in arginine-free or arginine/citrulline-complemented medium, as well as in interaction with different G. intestinalis isolates, were used to study effects on host cell replication by MTT assay. IEC proliferation was further analyzed by DNA content analysis, polyamine measurements and expressional analysis of cell cycle regulatory genes. IEC proliferation was reduced upon arginine-withdrawal and also in an arginine-dependent manner upon interaction with G. intestinalis or addition of Giardia ADI. We show that arginine-withdrawal by intestinal pathogens leads to a halt in the cell cycle in IECs through reduced polyamine levels and upregulated cell cycle inhibitory genes. This is of importance with regards to intestinal tissue homeostasis that is affected through reduced cell proliferation. Thus, the slower epithelial cell turnover helps the pathogen to maintain a more stable niche for colonization. This study also shows why supplementation therapy of diarrhea patients with arginine/citrulline is helpful

  3. Establishment of an In Vitro Intestinal Epithelial Cell Culture Model of Avian Origin.

    Science.gov (United States)

    Kaiser, Annette; Willer, Thomas; Steinberg, Pablo; Rautenschlein, Silke

    2017-06-01

    The role of intestinal epithelial cells (IECs) in the physiology of the gastrointestinal tract (GIT) of chickens and pathogenesis of various diseases in chickens is still poorly understood. IECs line the GIT and represent the border between the unsterile environment and the sterile internal tissues. Bacterial, viral, fungal, or parasitic pathogens are able to invade or pass IECs under certain circumstances and cause various diseases. Pathogen-host interactions in the chicken gut are poorly understood because of the lack of suitable in vitro and ex vivo models. In this context, there is a need to optimize the cell isolation and culture conditions to be able to provide reproducible IEC cultures with defined epithelial characteristics. We compared different mechanical IEC isolation protocols and cell culture media and established a reproducible primary intestinal epithelial cell culture model from specific-pathogen-free layer-type chickens. By using isolated crypts from the duodenum of 5- to 12-wk-old birds to create the starting material, we were able to culture replicating cells between 7 and 10 days. Cells built an almost closed monolayer and showed epithelial-like characteristics, such as the expression of cytokeratin and epithelial cadherin. The primary IEC cultures described in this study represent a suitable model with which to investigate in vitro pathogen-host interactions relevant to the chicken gut.

  4. Domestication and cereal feeding developed domestic pig-type intestinal microbiota in animals of suidae.

    Science.gov (United States)

    Ushida, Kazunari; Tsuchida, Sayaka; Ogura, Yoshitoshi; Toyoda, Atsushi; Maruyama, Fumito

    2016-06-01

    Intestinal microbiota are characterized by host-specific microorganisms, which have been selected through host-microbe interactions under phylogenetic evolution and transition of feeding behavior by the host. Although many studies have focused on disease-related intestinal microbiota, the origin and evolution of host-specific intestinal microbiota have not been well elucidated. Pig is the ideal mammal model to reveal the origin and evolution of host-specific intestinal microbiota because their direct wild ancestor and close phylogenetic neighbors are available for comparison. The pig has been recognized as a Lactobacillus-type animal. We analyzed the intestinal microbiota of various animals in Suidae: domestic pigs, wild boars and Red river hogs to survey the origin and evolution of Lactobacillus-dominated intestinal microbiota by metagenomic approach and following quantitative PCR confirmation. The metagenomic datasets were separated in two clusters; the wild animal cluster being characterized by a high abundance of Bifidobacterium, whereas the domesticated (or captured) animal cluster by Lactobacillus. In addition, Enterobacteriaceae were harbored as the major family only in domestic Sus scrofa. We conclude that domestication may have induced a larger Enterobacteriaceae population in pigs, and the introduction of modern feeding system further caused the development of Lactobacillus-dominated intestinal microbiota, with genetic and geographical factors possibly having a minor impact. © 2015 Japanese Society of Animal Science.

  5. [Cadaverine and its possible role in parasite and host interrelations in ascaridiasis].

    Science.gov (United States)

    Driuchenko, E A; Kulikova, M N

    1984-01-01

    A comparative study of the formation process of cadaverine in tissues of ascarides, intestine and liver of hen was conducted. Data are given on the activity, pH-optimum of lysine decarboxylase obtained from tissues of helminth and its host. The question on a toxic role of cadaverine during helminthiasis is considered. It has been concluded that the accumulation of cadaverine in the host's intestine can break the permeability of the intestine walls and favour the penetration of toxins of helminths into the host's organism.

  6. Pigs as natural hosts of Dientamoeba fragilis genotypes found in humans.

    Science.gov (United States)

    Cacciò, Simone M; Sannella, Anna Rosa; Manuali, Elisabetta; Tosini, Fabio; Sensi, Marco; Crotti, Daniele; Pozio, Edoardo

    2012-05-01

    Dientamoeba fragilis is a common intestinal parasite in humans. Transmission routes and natural host range are unknown. To determine whether pigs are hosts, we analyzed 152 fecal samples by microscopy and molecular methods. We confirmed that pigs are a natural host and harbor genotypes found in humans, suggesting zoonotic potential.

  7. MicroRNAs and the regulation of intestinal homeostasis

    Directory of Open Access Journals (Sweden)

    Marah C Runtsch

    2014-10-01

    Full Text Available The mammalian intestinal tract is a unique site in which a large portion of our immune system and the 10^14 commensal organisms that make up the microbiota reside in intimate contact with each other. Despite the potential for inflammatory immune responses, this complex interface contains host immune cells and epithelial cells interacting with the microbiota in a manner that promotes symbiosis. Due to the complexity of the cell types and microorganisms involved, this process requires elaborate regulatory mechanisms to ensure mutualism and prevent disease. While many studies have described critical roles for protein regulators of intestinal homeostasis, recent reports indicate that noncoding RNAs are also major contributors to optimal host-commensal interactions. In particular, there is emerging evidence that microRNAs (miRNAs have evolved to fine tune host gene expression networks and signaling pathways that modulate cellular physiology in the intestinal tract. Here, we review our present knowledge of the influence miRNAs have on both immune and epithelial cell biology in the mammalian intestines and the impact this has on the microbiota. We also discuss a need for further studies to decipher the functions of specific miRNAs within the gut to better understand cellular mechanisms that promote intestinal homeostasis and to identify potential molecular targets underlying diseases such as inflammatory bowel disease (IBD and colorectal cancer (CRC.

  8. Epithelial Cell Inflammasomes in Intestinal Immunity and Inflammation

    Directory of Open Access Journals (Sweden)

    Andrea C. Lei-Leston

    2017-09-01

    Full Text Available Pattern recognition receptors (PRR, such as NOD-like receptors (NLRs, sense conserved microbial signatures, and host danger signals leading to the coordination of appropriate immune responses. Upon activation, a subset of NLR initiate the assembly of a multimeric protein complex known as the inflammasome, which processes pro-inflammatory cytokines and mediates a specialized form of cell death known as pyroptosis. The identification of inflammasome-associated genes as inflammatory bowel disease susceptibility genes implicates a role for the inflammasome in intestinal inflammation. Despite the fact that the functional importance of inflammasomes within immune cells has been well established, the contribution of inflammasome expression in non-hematopoietic cells remains comparatively understudied. Given that intestinal epithelial cells (IEC act as a barrier between the host and the intestinal microbiota, inflammasome expression by these cells is likely important for intestinal immune homeostasis. Accumulating evidence suggests that the inflammasome plays a key role in shaping epithelial responses at the host–lumen interface with many inflammasome components highly expressed by IEC. Recent studies have exposed functional roles of IEC inflammasomes in mucosal immune defense, inflammation, and tumorigenesis. In this review, we present the main features of the predominant inflammasomes and their effector mechanisms contributing to intestinal homeostasis and inflammation. We also discuss existing controversies in the field and open questions related to their implications in disease. A comprehensive understanding of the molecular basis of intestinal inflammasome signaling could hold therapeutic potential for clinical translation.

  9. Transplantation of intestinal microbiota

    Directory of Open Access Journals (Sweden)

    I. Yu. Chicherin

    2013-01-01

    Full Text Available The results are presented of evaluation of the efficiency of the filtered aqueous suspension of white mice (donors feces and microorganisms of indigenous microflora in the correction of intestinal microbiocenosis of conventional white mice with antibiotic-associated dysbacteriosis with administration of suspension and microorganisms per os and per rectum. After the start of administration of suspension and microorganisms of fecal microflora to experimental animals the dynamics of the total content of microorganisms and the number of some representatives of intestinal microflora in 1 g of feces were evaluated in comparison with self-recovery of intestinal microflora in the control group animals. Results showed that the supernatant of an aqueous suspension of white mice (donors feces, containing microbial exometabolites and other biologically active compounds, has in a short time the most pronounced effect on the recovery of the normal intestinal microflora in experimental animals.

  10. Environment, interactions between Trypanosoma cruzi and its host, and health Meio-ambiente, interações entre Trypanosoma cruzi e seu hospedeiro e saúde humana

    Directory of Open Access Journals (Sweden)

    Antonio R. L. Teixeira

    2009-01-01

    Full Text Available An epidemiological chain involving Trypanosoma cruzi is discussed at the environmental level, and in terms of fine molecular interactions in invertebrate and vertebrate hosts dwelling in different ecosystems. This protozoan has a complex, genetically controlled plasticity, which confers adaptation to approximately 40 blood-sucking triatomine species and to over 1,000 mammalian species, fulfilling diverse metabolic requirements in its complex life-cycle. The Tr. cruzi infections are deeply embedded in countless ecotypes, where they are difficult to defeat using the control methods that are currently available. Many more field and laboratory studies are required to obtain data and information that may be used for the control and prevention of Tr. cruzi infections and their various disease manifestations. Emphasis should be placed on those sensitive interactions at cellular and environmental levels that could become selected targets for disease prevention. In the short term, new technologies for social mobilization should be used by people and organizations working for justice and equality through health information and promotion. A mass media directed program could deliver education, information and communication to protect the inhabitants at risk of contracting Tr. cruzi infections.Uma rede epidemiológica envolvendo o Trypanosoma cruzi foi discutida nos níveis ambientais e de interações moleculares nos hospedeiros que habitam em 19 diferentes ecossistemas. O protozoário tem uma enorme plasticidade controlada geneticamente que confere sua adaptação a cerca de quarenta espécies de triatomíneos e mais de mil espécies de mamíferos. Essas infecções estão profundamente embutidas em inúmeros ecótopos, onde elas estão inacessíveis aos métodos de controle utilizados. Muito mais estudos de campo e de laboratório são necessários à obtenção de dados e informação pertinentes ao controle e prevenção das infecções pelo Tr. cruzi e

  11. Tolerance in intestinal inflammation and cancer.

    Science.gov (United States)

    Vulcano, Marisa; Danese, Silvio; Sica, Antonio

    2008-05-01

    In the human body, mucosal surfaces of the intestinal tract are the largest and one of the most complex parts of the immune system. These surfaces are covered by a layer of epithelial cells which allows efficient absorption of nutrients but also serves to separate the intestine from an environment loaded with potential harmful agents. Discrimination between beneficial commensal bacteria, harmless antigens and pathogenic microorganisms is a central issue in the role that gut immune cells play in maintaining the balance between immune response and tolerance. However, the basis of this discrimination in the mucosal immune system, where this occurs and how it can affect both local and systemic responses is not yet well understood. Nevertheless, antigen uptake and presentation seems to be a crucial factor in this issue. In this review, we will discuss the key role of immune intestinal cells in the development of mucosal immunity, tolerance and disease.

  12. Phenology of Migration and Decline in Colony Numbers and Crop Hosts of Giant Honeybee (Apis dorsata F. in Semiarid Environment of Northwest India

    Directory of Open Access Journals (Sweden)

    Ram Chander Sihag

    2014-01-01

    Full Text Available The colonies of the giant honeybee (Apis dorsata immigrate in the semiarid environment of Northwest India in October-November with the onset of flowering on pigeon pea (Cajanus cajan/toria (Brassica campestris var. toria, stay here during the rich pollen and nectar flow period from December to mid-May, and emigrate in late May/early June when floral dearth is witnessed. This honeybee was free from any conspicuous viral, bacterial, and fungal diseases and also did not have any serious predators and enemies. However, about 20 percent of the old colonies were infested with Tropilaelaps clareae and 100 percent of the old colonies with Galleria mellonella; none of the swarm colonies had these pests. While the migration schedule of this honeybee remained similar year after year, the number of colonies immigrating in this region declined markedly over the years; the number in 2012 was even less than half of that recorded in 1984. During its stay in this region, this honeybee acted as an important pollinator of more than 30 crop plants of this region. The causes of seasonal migration and decline in the number of colonies of this honeybee and its importance in crop pollination have been discussed.

  13. Toxicity of Methylated Bismuth Compounds Produced by Intestinal Microorganisms to Bacteroides thetaiotaomicron, a Member of the Physiological Intestinal Microbiota

    Directory of Open Access Journals (Sweden)

    Beatrix Bialek

    2011-01-01

    Full Text Available Methanoarchaea have an outstanding capability to methylate numerous metal(loids therefore producing toxic and highly mobile derivatives. Here, we report that the production of methylated bismuth species by the methanoarchaeum Methanobrevibacter smithii, a common member of the human intestine, impairs the growth of members of the beneficial intestinal microbiota at low concentrations. The bacterium Bacteroides thetaiotaomicron, which is of great importance for the welfare of the host due to its versatile digestive abilities and its protective function for the intestine, is highly sensitive against methylated, but not against inorganic, bismuth species. The level of methylated bismuth species produced by the methanoarchaeum M. smithii in a coculture experiment causes a reduction of the maximum cell density of B. thetaiotaomicron. This observation suggests that the production of methylated organometal(loid species in the human intestine, caused by the activity of methanoarchaea, may affect the health of the host. The impact of the species to reduce the number of the physiological intestinal microbiota brings an additional focus on the potentially harmful role of methanoarchaea in the intestine of a higher organism.

  14. Impact of Diet on Human Intestinal Microbiota and Health

    NARCIS (Netherlands)

    Salonen, A.; Vos, de W.M.

    2014-01-01

    Our intestinal microbiota is involved in the breakdown and bioconversion of dietary and host components that are not degraded and taken up by our own digestive system. The end products generated by our microbiota fuel our enterocytes and support growth but also have signaling functions that generate

  15. Intestinal irony: how probiotic bacteria outcompete bad bugs.

    Science.gov (United States)

    Weiss, Guenter

    2013-07-17

    In this issue of Cell Host & Microbe, Deriu et al. present a mechanistic explanation underlying the benefits of certain probiotic bacteria. Intestinal bacteria compete for the essential nutrient iron, leading to replacement of pathogenic Salmonella by the probiotic Escherichia coli Nissle, which is better equipped with iron acquisition systems, and resolution of infectious colitis. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Enteric defensins are essential regulators of intestinal microbial ecology

    NARCIS (Netherlands)

    Salzman, Nita H.; Hung, Kuiechun; Haribhai, Dipica; Chu, Hiutung; Karlsson-Sjoeberg, Jenny; Amir, Elad; Teggatz, Paul; Barman, Melissa; Hayward, Michael; Eastwood, Daniel; Stoel, Maaike; Zhou, Yanjiao; Sodergren, Erica; Weinstock, George M.; Bevins, Charles L.; Williams, Calvin B.; Bos, Nicolaas A.

    Antimicrobial peptides are important effectors of innate immunity throughout the plant and animal kingdoms. In the mammalian small intestine, Paneth cell alpha-defensins are antimicrobial peptides that contribute to host defense against enteric pathogens. To determine if alpha-defensins also govern

  17. In Silico Modelling of the Human Intestinal Microflora

    NARCIS (Netherlands)

    Kamerman, Derk Jan; Wilkinson, Michael H.F.

    2002-01-01

    The ecology of the human intestinal microflora and its interaction with the host are poorly understood. Though more and more data are being acquired, in part using modern molecular methods, development of a quantitative theory has not kept pace with this development. This is in part due to the

  18. In silico modelling of the human intestinal microflora

    NARCIS (Netherlands)

    Kamerman, DJ; Wilkinson, MHF; Sloot, P; Tan, CJK; Dongarra, JJ; Hoekstra, AG

    2002-01-01

    The ecology of the human intestinal microflora and its interaction with the host are poorly understood. Though more and more data are being acquired, in part using modern molecular methods, development of a quantitative theory has not kept pace with this development. This is in part due to the

  19. Mouse models for human intestinal microbiota research: a critical evaluation

    NARCIS (Netherlands)

    Hugenholtz, Floor; de Vos, Willem M.

    2018-01-01

    Since the early days of the intestinal microbiota research, mouse models have been used frequently to study the interaction of microbes with their host. However, to translate the knowledge gained from mouse studies to a human situation, the major spatio-temporal similarities and differences between

  20. Microbiota-Produced Succinate Improves Glucose Homeostasis via Intestinal Gluconeogenesis

    DEFF Research Database (Denmark)

    De Vadder, Filipe; Kovatcheva-Datchary, Petia; Zitoun, Carine

    2016-01-01

    , no study has focused on the role of succinate on host metabolism. Here, we fed mice a fiber-rich diet and found that succinate was the most abundant carboxylic acid in the cecum. Dietary succinate was identified as a substrate for intestinal gluconeogenesis (IGN), a process that improves glucose...

  1. Liver injury from ampicillin-induced intestinal microbiota distresses ...

    African Journals Online (AJOL)

    Purpose: To investigate the effect of ampicillin on rat intestinal microflora and liver in the presence of high carbohydrate and protein ... Gut microbial flora has spatial and temporal complexity that varies from person to person, body niche, age, geographic location, health status, diet and type of host [3]. Even within the same ...

  2. A genetic model based on evapoconcentration for sediment-hosted exotic-Cu mineralization in arid environments: the case of the El Tesoro Central copper deposit, Atacama Desert, Chile

    Science.gov (United States)

    Fernández-Mort, A.; Riquelme, R.; Alonso-Zarza, A. M.; Campos, E.; Bissig, T.; Mpodozis, C.; Carretier, S.; Herrera, C.; Tapia, M.; Pizarro, H.; Muñoz, S.

    2017-12-01

    Although the formation of exotic-Cu deposits is controlled by multiple factors, the role of the sedimentary environment has not been well defined. We present a case study of the El Tesoro Central exotic-Cu deposit located in the Atacama Desert of northern Chile. This deposit consists of two mineralized bodies hosted within Late Cenozoic gravels deposited in an arid continental environment dominated by alluvial fans with sub-surficial ponded water bodies formed at the foot of these fans or within the interfan areas. Both exotic-Cu orebodies mostly consist of chrysocolla, copper wad, atacamite, paratacamite, quartz, opal, and calcite. The most commonly observed paragenesis comprises chrysocolla, silica minerals, and calcite and records a progressive increase in pH, which is notably influenced by evaporation. The results of stable isotope analyses (δ13C and δ18O) and hydrogeochemical simulations confirm that evapoconcentration is the main controlling factor in the exotic-Cu mineralization at El Tesoro Central. This conclusion complements the traditional genetic model based on the gradual neutralization of highly oversaturated Cu-bearing solutions that progressively cement the gravels and underlying bedrock regardless of the depositional environment. This study concludes that in exotic-Cu deposits formed relatively far from the source, a favorable sedimentary environment and particular hydrologic and climatic conditions are essential to trap, accumulate, evapoconcentrate, neutralize and saturate Cu-bearing solutions to trigger mineralization. Thus, detailed sedimentological studies should be incorporated when devising exploration strategies in order to discover new exotic-Cu resources, particularly if they are expected to have formed relatively far from the metal sources.

  3. Trichinella inflammatory myopathy: host or parasite strategy?

    Science.gov (United States)

    2011-01-01

    The parasitic nematode Trichinella has a special relation with muscle, because of its unique intracellular localization in the skeletal muscle cell, completely devoted in morphology and biochemistry to become the parasite protective niche, otherwise called the nurse cell. The long-lasting muscle infection of Trichinella exhibits a strong interplay with the host immune response, mainly characterized by a Th2 phenotype. The aim of this review is to illustrate the role of the Th2 host immune response at the muscle level during trichinellosis in different experimental models, such as knock-out or immuno-modulated mice. In particular, in knock-out mice a crucial role of IL-10 is evident for the regulation of inflammation intensity. The muscular host immune response to Trichinella is partially regulated by the intestinal phase of the parasite which emphasizes the intensity of the following muscle inflammation compared with animals infected by synchronized injections of newborn larvae. In eosinophil-ablated mice such as PHIL and GATA-- animals it was observed that there was an increased NOS2 expression in macrophages, driven by higher IFN-γ release, thus responsible for muscle larva damage. Besides modulation of the intestinal stage of the infection, using recombinant IL-12, increases the muscular parasite burden delaying adult worm expulsion from the intestine. Furthermore, a Th1 adjuvant of bacterial origin called Helicobacter pylori neutrophil activating protein (HP-NAP), administered during the intestinal phase of trichinellosis, alters the Th2 dependent response at muscle level. All these data from the literature delineate then a mutual adaptation between parasite and host immune response in order to achieve a strategic compromise between two evolutionary forces pointed towards the survival of both species. PMID:21429196

  4. Macrophages in intestinal homeostasis and inflammation

    Science.gov (United States)

    Bain, Calum C; Mowat, Allan McI

    2014-01-01

    The intestine contains the largest pool of macrophages in the body which are essential for maintaining mucosal homeostasis in the face of the microbiota and the constant need for epithelial renewal but are also important components of protective immunity and are involved in the pathology of inflammatory bowel disease (IBD). However, defining the biological roles of intestinal macrophages has been impeded by problems in defining the phenotype and origins of different populations of myeloid cells in the mucosa. Here, we discuss how multiple parameters can be used in combination to discriminate between functionally distinct myeloid cells and discuss the roles of macrophages during homeostasis and how these may change when inflammation ensues. We also discuss the evidence that intestinal macrophages do not fit the current paradigm that tissue-resident macrophages are derived from embryonic precursors that self-renew in situ, but require constant replenishment by blood monocytes. We describe our recent work demonstrating that classical monocytes constantly enter the intestinal mucosa and how the environment dictates their subsequent fate. We believe that understanding the factors that drive intestinal macrophage development in the steady state and how these may change in response to pathogens or inflammation could provide important insights into the treatment of IBD. PMID:24942685

  5. INTESTINAL MICROBIOTA AND USE OF PROBIOTICS IN PEDIATRIC PRACTICE: NEWS

    Directory of Open Access Journals (Sweden)

    S. G. Makarova

    2015-01-01

    Full Text Available Condition of intestinal microbiota is a key factor of a child's health. According to the latest studies, distinctness and certain stability of every person's microbiota is to a large extent determined genetically; at the same time, microbiocenosis is sensitive to external exposure, i.e. it is labile. The article presents new data on the intestinal microflora's composition and function, as well as on the nature of interaction in the microbiocenosis-host system. Intestinal microflora directly affects formation of a child's immune system, ensures protection from pathogens and takes part in all types of metabolism. The article presents modern approaches to intestinal microflora modulation and use of probiotics to prevent and treat various pathologies in pediatric practice.

  6. Antigen sampling in the fish intestine.

    Science.gov (United States)

    Løkka, Guro; Koppang, Erling Olaf

    2016-11-01

    Antigen uptake in the gastrointestinal tract may induce tolerance, lead to an immune response and also to infection. In mammals, most pathogens gain access to the host though the gastrointestinal tract, and in fish as well, this route seems to be of significant importance. The epithelial surface faces a considerable challenge, functioning both as a barrier towards the external milieu but simultaneously being the site of absorption of nutrients and fluids. The mechanisms allowing antigen uptake over the epithelial barrier play a central role for maintaining the intestinal homeostasis and regulate appropriate immune responses. Such uptake has been widely studied in mammals, but also in fish, a number of experiments have been reported, seeking to reveal cells and mechanisms involved in antigen sampling. In this paper, we review these studies in addition to addressing our current knowledge of the intestinal barrier in fish and its anatomical construction. Copyright © 2016. Published by Elsevier Ltd.

  7. Intestinal lymphangiectasia in adults.

    Science.gov (United States)

    Freeman, Hugh James; Nimmo, Michael

    2011-02-15

    Intestinal lymphangiectasia in the adult may be characterized as a disorder with dilated intestinal lacteals causing loss of lymph into the lumen of the small intestine and resultant hypoproteinemia, hypogammaglobulinemia, hypoalbuminemia and reduced number of circulating lymphocytes or lymphopenia. Most often, intestinal lymphangiectasia has been recorded in children, often in neonates, usually with other congenital abnormalities but initial definition in adults including the elderly has become increasingly more common. Shared clinical features with the pediatric population such as bilateral lower limb edema, sometimes with lymphedema, pleural effusion and chylous ascites may occur but these reflect the severe end of the clinical spectrum. In some, diarrhea occurs with steatorrhea along with increased fecal loss of protein, reflected in increased fecal alpha-1-antitrypsin levels, while others may present with iron deficiency anemia, sometimes associated with occult small intestinal bleeding. Most lymphangiectasia in adults detected in recent years, however, appears to have few or no clinical features of malabsorption. Diagnosis remains dependent on endoscopic changes confirmed by small bowel biopsy showing histological evidence of intestinal lymphangiectasia. In some, video capsule endoscopy and enteroscopy have revealed more extensive changes along the length of the small intestine. A critical diagnostic element in adults with lymphangiectasia is the exclusion of entities (e.g. malignancies including lymphoma) that might lead to obstruction of the lymphatic system and "secondary" changes in the small bowel biopsy. In addition, occult infectious (e.g. Whipple's disease from Tropheryma whipplei) or inflammatory disorders (e.g. Crohn's disease) may also present with profound changes in intestinal permeability and protein-losing enteropathy that also require exclusion. Conversely, rare B-cell type lymphomas have also been described even decades following initial

  8. Analysis of the intestinal lumen microbiota in an animal model of colorectal cancer.

    Directory of Open Access Journals (Sweden)

    Qingchao Zhu

    Full Text Available Recent reports have suggested that multiple factors such as host genetics, environment and diet can promote the progression of healthy mucosa towards sporadic colorectal carcinoma. Accumulating evidence has additionally associated intestinal bacteria with disease initiation and progression. In order to examine and analyze the composition of gut microbiota in the absence of confounding influences, we have established an animal model of 1, 2-dimethylhydrazine (DMH-induced colon cancer. Using this model, we have performed pyrosequencing of the V3 region of the 16S rRNA genes in this study to determine the diversity and breadth of the intestinal microbial species. Our findings indicate that the microbial composition of the intestinal lumen differs significantly between control and tumor groups. The abundance of Firmicutes was elevated whereas the abundance of Bacteroidetes and Spirochetes was reduced in the lumen of CRC rats. Fusobacteria was not detected in any of the healthy rats and there was no significant difference in observed Proteobacteria species when comparing the bacterial communities between our two groups. Interestingly, the abundance of Proteobacteria was higher in CRC rats. At the genus level, Bacteroides exhibited a relatively higher abundance in CRC rats compared to controls (14.92% vs. 9.22%, p<0.001. Meanwhile, Prevotella (55.22% vs. 26.19%, Lactobacillus (3.71% vs. 2.32% and Treponema (3.04% vs. 2.43%, were found to be significantly more abundant in healthy rats than CRC rats (p<0.001, respectively. We also demonstrate a significant reduction of butyrate-producing bacteria such as Roseburia and Eubacterium in the gut microbiota of CRC rats. Furthermore, a significant increase in Desulfovibrio, Erysipelotrichaceae and Fusobacterium was also observed in the tumor group. A decrease in probiotic species such as Ruminococcus and Lactobacillus was likewise observed in the tumor group. Collectively, we can conclude that a significant

  9. Maintenance of a healthy trajectory of the intestinal microbiome during aging: a dietary approach.

    Science.gov (United States)

    Candela, Marco; Biagi, Elena; Brigidi, Patrizia; O'Toole, Paul W; De Vos, Willem M

    2014-01-01

    Sharing an intense transgenomic metabolism with the host, the intestinal microbiota is an essential factor for several aspects of the human physiology. However, several age-related factors, such as changes diet, lifestyle, inflammation and frailty, force the deterioration of this intestinal microbiota-host mutualistic interaction, compromising the possibility to reach longevity. In this scenario, the NU-AGE project involves the development of dietary interventions specifically tailored to the maintenance of a healthy trajectory of the intestinal microbiome, counteracting all processes connected to the pathophysiology of the human aging. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  10. Unraveling the ties between irritable bowel syndrome and intestinal microbiota.

    Science.gov (United States)

    Hong, Sung Noh; Rhee, Poong-Lyul

    2014-03-14

    Irritable bowel syndrome (IBS) is the most prevalent functional gastrointestinal disorder. It is a multifactorial disorder. Intestinal microbiota may cause the pathogenesis of IBS by contributing to abnormal gastrointestinal motility, low-grade inflammation, visceral hypersensitivity, communication in the gut-brain axis, and so on. Previous attempts to identify the intestinal microbiota composition in IBS patients have yielded inconsistent and occasionally contradictory results. This inconsistency may be due to the differences in the molecular techniques employed, the sample collection and handling methods, use of single samples that are not linked to fluctuating symptoms, or other factors such as patients' diets and phenotypic characterizations. Despite these difficulties, previous studies found that the intestinal microbiota in some IBS patients was completely different from that in healthy controls, and there does appear to be a consistent theme of Firmicutes enrichment and reduced abundance of Bacteroides. Based on the differences in intestinal microbiota composition, many studies have addressed the roles of microbiota-targeted treatments, such as antibiotics and probiotics, in alleviating certain symptoms of IBS. This review summarizes the current knowledge of the associations between intestinal microbiota and IBS as well as the possible modes of action of intestinal microbiota in the pathogenesis of IBS. Improving the current level of understanding of host-microbiota interactions in IBS is important not only for determining the role of intestinal microbiota in IBS pathogenesis but also for therapeutic modulation of the microbiota.

  11. Role of the enteric microbiota in intestinal homeostasis and inflammation.

    Science.gov (United States)

    Koboziev, Iurii; Reinoso Webb, Cynthia; Furr, Kathryn L; Grisham, Matthew B

    2014-03-01

    The mammalian intestine encounters many more microorganisms than any other tissue in the body thus making it the largest and most complex component of the immune system. Indeed, there are greater than 100 trillion (10(14)) microbes within the healthy human intestine, and the total number of genes derived from this diverse microbiome exceeds that of the entire human genome by at least 100-fold. Our coexistence with the gut microbiota represents a dynamic and mutually beneficial relationship that is thought to be a major determinant of health and disease. Because of the potential for intestinal microorganisms to induce local and/or systemic inflammation, the intestinal immune system has developed a number of immune mechanisms to protect the host from pathogenic infections while limiting the inflammatory tissue injury that accompanies these immune responses. Failure to properly regulate intestinal mucosal immunity is thought to be responsible for the inflammatory tissue injury observed in the inflammatory bowel diseases (IBD; Crohn disease, ulcerative colitis). An accumulating body of experimental and clinical evidence strongly suggests that IBD results from a dysregulated immune response to components of the normal gut flora in genetically susceptible individuals. The objective of this review is to present our current understanding of the role that enteric microbiota play in intestinal homeostasis and pathogenesis of chronic intestinal inflammation. © 2013 Elsevier Inc. All rights reserved.

  12. Haemonchus contortus intestine: a prominent source of mucosal antigens.

    Science.gov (United States)

    Jasmer, D P; Lahmers, K K; Brown, W C

    2007-03-01

    We sought to identify antigens from Haemonchus contortus, an abomasal nematode of small ruminants, that stimulate local (abomasal lymph node, ALN) CD4+ T lymphocyte responses during a primary infection. Results led to a focus on antigens from the parasite intestine. The H. contortus intestine proved to be a major source of antigens that stimulated ALN CD4+, CD25+ T lymphocyte responses during infections in lambs. When stimulated by intestinal antigens, ALN lymphocytes from these lambs expressed IL-4 and IL-13 transcripts, and, more variably, IFN-gamma. An immunoaffinity-purified fraction, enriched for H. contortus apical intestinal membrane proteins, stimulated similar ALN responses. On further fractionation, antigens from six size classes (ranging from 30 to 200 kDa) also stimulated proliferation of ALN lymphocytes. Mass spectrometry analysis of these size classes identified several known apical intestinal membrane proteins from H. contortus. The results show that H. contortus intestinal antigens warrant investigation in strategies to induce mucosal immunity against this parasite. The specific proteins identified have value for this purpose. The results are in contrast with the now generalized idea that H. contortus intestinal antigens are 'hidden' from the host immune system, and this issue is discussed. The approach also has potential application to other gastrointestinal nematode parasites.

  13. [Acute intestinal tuberculosis].

    Science.gov (United States)

    Nguyen Duc, C; Pha Hai, B; Pham Van, T; Ton That, B; Huguier, M

    2006-05-01

    To report cases from Vietnam of intestinal tuberculosis disease, which is uncommon but did not disappear in occidental countries. Seventy-six patients were included in this retrospective study. Mean age was 40 years and sex ratio M/F was 6. Diagnosis was established on pathological examination of resected specimen or on presence of Mycobacterium tuberculosis or by polymerase chain reaction. Intestinal obstruction or subobstruction was the most usual symptom (68%), and thereafter peritoneal symptoms with pain and tenderness (17%). Five patients had intractable digestive haemorrhage. Thirty-six patients had no past history or active pulmonary tuberculosis (47%). Lesions of stenosis on barium enema and thickness of intestinal wall on CT-scan were not specific. Sixty-two patients were operated on (82%) and 14 were not. Surgical techniques differed according symptoms, site and type of lesions. Intestinal resections were performed in half of the patients, others undergoing stomies or enterolysis. There were eight postoperative deaths (13% of patients operated on), seven out of these deaths were attributable to cachexy. In the postoperative period, all the patients were medically treated and follow-up in the antituberculosis centre of Hanoi. Symptomatology and operative findings of intestinal tuberculosis are similar to those observed in Crohn's disease, and sometimes in amoeboma or lymphoma. In face of stenosis and intestinal wall thickness, probability of intestinal tuberculosis is high in endemic area, but diagnosis must be suspected in occidental countries, mainly in patients immigrated coming from these areas, patients with immuno-deficiency even if they did not have past or present pulmonary tuberculosis.

  14. Oligosaccharide binding proteins from Bifidobacterium longum subsp. infantis reveal a preference for host glycans.

    Science.gov (United States)

    Garrido, Daniel; Kim, Jae Han; German, J Bruce; Raybould, Helen E; Mills, David A

    2011-03-15

    Bifidobacterium longum subsp. infantis (B. infantis) is a common member of the infant intestinal microbiota, and it has been characterized by its foraging capacity for human milk oligosaccharides (HMO). Its genome sequence revealed an overabundance of the Family 1 of solute binding proteins (F1SBPs), part of ABC transporters and associated with the import of oligosaccharides. In this study we have used the Mammalian Glycan Array to determine the specific affinities of these proteins. This was correlated with binding protein expression induced by different prebiotics including HMO. Half of the F1SBPs in B. infantis were determined to bind mammalian oligosaccharides. Their affinities included different blood group structures and mucin oligosaccharides. Related to HMO, other proteins were specific for oligomers of lacto-N-biose (LNB) and polylactosamines with different degrees of fucosylation. Growth on HMO induced the expression of specific binding proteins that import HMO isomers, but also bind blood group and mucin oligosaccharides, suggesting coregulated transport mechanisms. The prebiotic inulin induced other family 1 binding proteins with affinity for intestinal glycans. Most of the host glycan F1SBPs in B. infantis do not have homologs in other bifidobacteria. Finally, some of these proteins were found to be adherent to intestinal epithelial cells in vitro. In conclusion, this study represents further evidence for the particular adaptations of B. infantis to the infant gut environment, and helps to understand the molecular mechanisms involved in this process.

  15. Oligosaccharide binding proteins from Bifidobacterium longum subsp. infantis reveal a preference for host glycans.

    Directory of Open Access Journals (Sweden)

    Daniel Garrido

    2011-03-01

    Full Text Available Bifidobacterium longum subsp. infantis (B. infantis is a common member of the infant intestinal microbiota, and it has been characterized by its foraging capacity for human milk oligosaccharides (HMO. Its genome sequence revealed an overabundance of the Family 1 of solute binding proteins (F1SBPs, part of ABC transporters and associated with the import of oligosaccharides. In this study we have used the Mammalian Glycan Array to determine the specific affinities of these proteins. This was correlated with binding protein expression induced by different prebiotics including HMO. Half of the F1SBPs in B. infantis were determined to bind mammalian oligosaccharides. Their affinities included different blood group structures and mucin oligosaccharides. Related to HMO, other proteins were specific for oligomers of lacto-N-biose (LNB and polylactosamines with different degrees of fucosylation. Growth on HMO induced the expression of specific binding proteins that import HMO isomers, but also bind blood group and mucin oligosaccharides, suggesting coregulated transport mechanisms. The prebiotic inulin induced other family 1 binding proteins with affinity for intestinal glycans. Most of the host glycan F1SBPs in B. infantis do not have homologs in other bifidobacteria. Finally, some of these proteins were found to be adherent to intestinal epithelial cells in vitro. In conclusion, this study represents further evidence for the particular adaptations of B. infantis to the infant gut environment, and helps to understand the molecular mechanisms involved in this process.

  16. Intestinal dendritic cells in the regulation of mucosal immunity

    DEFF Research Database (Denmark)

    Bekiaris, Vasileios; Persson, Emma K.; Agace, William Winston

    2014-01-01

    The intestine presents a huge surface area to the outside environment, a property that is of critical importance for its key functions in nutrient digestion, absorption, and waste disposal. As such, the intestine is constantly exposed to dietary and microbial-derived foreign antigens, to which im...... of the role these subsets play in the regulation of intestinal immune homeostasis and inflammation will help to define novel strategies for the treatment of intestinal pathologies and contribute to improved rational design of mucosal vaccines........ The recognition that dietary nutrients and microbial communities in the intestine influence both mucosal and systemic immune cell development and function as well as immune-mediated disease has led to an explosion of literature in mucosal immunology in recent years and a growing interest in the functionality...

  17. Genomic and functional analysis of Romboutsia ilealis CRIBT reveals adaptation to the small intestine

    Directory of Open Access Journals (Sweden)

    Jacoline Gerritsen

    2017-09-01

    Full Text Available Background The microbiota in the small intestine relies on their capacity to rapidly import and ferment available carbohydrates to survive in a complex and highly competitive ecosystem. Understanding how these communities function requires elucidating the role of its key players, the interactions among them and with their environment/host. Methods The genome of the gut bacterium Romboutsia ilealis CRIBT was sequenced with multiple technologies (Illumina paired-end, mate-pair and PacBio. The transcriptome was sequenced (Illumina HiSeq after growth on three different carbohydrate sources, and short chain fatty acids were measured via HPLC. Results We present the complete genome of Romboutsia ilealis CRIBT, a natural inhabitant and key player of the small intestine of rats. R. ilealis CRIBT possesses a circular chromosome of 2,581,778 bp and a plasmid of 6,145 bp, carrying 2,351 and eight predicted protein coding sequences, respectively. Analysis of the genome revealed limited capacity to synthesize amino acids and vitamins, whereas multiple and partially redundant pathways for the utilization of different relatively simple carbohydrates are present. Transcriptome analysis allowed identification of the key components in the degradation of glucose, L-fucose and fructo-oligosaccharides. Discussion This revealed that R. ilealis CRIBT is adapted to a nutrient-rich environment where carbohydrates, amino acids and vitamins are abundantly available.

  18. Genomic and functional analysis of Romboutsia ilealis CRIBT reveals adaptation to the small intestine.

    Science.gov (United States)

    Gerritsen, Jacoline; Hornung, Bastian; Renckens, Bernadette; van Hijum, Sacha A F T; Martins Dos Santos, Vitor A P; Rijkers, Ger T; Schaap, Peter J; de Vos, Willem M; Smidt, Hauke

    2017-01-01

    The microbiota in the small intestine relies on their capacity to rapidly import and ferment available carbohydrates to survive in a complex and highly competitive ecosystem. Understanding how these communities function requires elucidating the role of its key players, the interactions among them and with their environment/host. The genome of the gut bacterium Romboutsia ilealis CRIBT was sequenced with multiple technologies (Illumina paired-end, mate-pair and PacBio). The transcriptome was sequenced (Illumina HiSeq) after growth on three different carbohydrate sources, and short chain fatty acids were measured via HPLC. We present the complete genome of Romboutsia ilealis CRIBT, a natural inhabitant and key player of the small intestine of rats. R. ilealis CRIBT possesses a circular chromosome of 2,581,778 bp and a plasmid of 6,145 bp, carrying 2,351 and eight predicted protein coding sequences, respectively. Analysis of the genome revealed limited capacity to synthesize amino acids and vitamins, whereas multiple and partially redundant pathways for the utilization of different relatively simple carbohydrates are present. Transcriptome analysis allowed identification of the key components in the degradation of glucose, L-fucose and fructo-oligosaccharides. This revealed that R. ilealis CRIBT is adapted to a nutrient-rich environment where carbohydrates, amino acids and vitamins are abundantly available.

  19. Eating Disorders and the Intestinal Microbiota: Mechanisms of Energy Homeostasis and Behavioral Influence.

    Science.gov (United States)

    Glenny, Elaine M; Bulik-Sullivan, Emily C; Tang, Quyen; Bulik, Cynthia M; Carroll, Ian M

    2017-08-01

    We reviewed and evaluated recently published scientific studies that explored the role of the intestinal microbiota in eating disorders. Studies have demonstrated that the intestinal microbiota is a contributing factor to both host energy homeostasis and behavior-two traits commonly disrupted in patients with eating disorders. To date, intestinal microbiota research in eating disorders has focused solely on anorexia nervosa (AN). Initial studies have reported an atypical intestinal microbial composition in patients with AN compared to healthy controls. However, the impact of these AN-associated microbial communities on host metabolism and behavior remains unknown. The intriguing pattern of findings in patients with AN encourages further investigation of the intestinal microbiota in eating disorders. Elucidating the specific role(s) of these microbial communities may yield novel ideas for augmenting current clinical therapies to promote weight gain, decrease gastrointestinal distress, and even reduce psychological symptomatology.

  20. Intestinal, extra-intestinal and systemic sequelae of Toxoplasma gondii induced acute ileitis in mice harboring a human gut microbiota

    Science.gov (United States)

    von Klitzing, Eliane; Ekmekciu, Ira; Kühl, Anja A.; Bereswill, Stefan

    2017-01-01

    microbiota composition “humanized” mice display acute ileitis following peroral high dose T. gondii infection. Thus, hma mice constitute a suitable model to further dissect the interactions between pathogens, human microbiota and vertebrate host immunity during acute intestinal inflammation. PMID:28414794

  1. Intestinal microbiota and type 2 diabetes: from mechanism insights to therapeutic perspective.

    Science.gov (United States)

    Han, Jun-Ling; Lin, Hui-Ling

    2014-12-21

    The incidence of type 2 diabetes (T2DM) is rapidly increasing worldwide. However, the pathogenesis of T2DM has not yet been well explained. Recent evidence suggests that the intestinal microbiota composition is associated with obesity and T2DM. In this review, we provide an overview about the mechanisms underlying the role of intestinal microbiota in the pathogenesis of T2DM. There is clear evidence that the intestinal microbiota influences the host through its effect on body weight, bile acid metabolism, proinflammatory activity and insulin resistance, and modulation of gut hormones. Modulating gut microbiota with the use of probiotics, prebiotics, antibiotics, and fecal microbiota transplantation may have benefits for improvement in glucose metabolism and insulin resistance in the host. Further studies are required to increase our understanding of the complex interplay between intestinal microbiota and the host with T2DM. Further studies may be able to boost the development of new effective therapeutic approaches for T2DM.

  2. Vancomycin and ceftriaxone can damage intestinal microbiota and affect the development of the intestinal tract and immune system to different degrees in neonatal mice.

    Science.gov (United States)

    Cheng, Ru Yue; Li, Ming; Li, Shan Shan; He, Miao; Yu, Xiao Hong; Shi, Lei; He, Fang

    2017-11-30

    This study aimed to determine how antibiotic-driven intestinal dysbiosis impairs the development and differentiation of the digestive tract and immune organs of host animals. BALB/C neonatal mice were orally administered ceftriaxone or vancomycin from postnatal day 1 to day 21 and sacrificed on day 21. The diversity and abundance of the intestinal bacteria, morphological changes and barrier function of intestinal tract, and the splenic CD4+CD25+Foxp3+ T cells were investigated. The gut microbiota and intestinal tissue were damaged, and the numbers of Ki67-, Muc2- and ZO-1-positive cells were significantly decreased in the antibiotic treatment groups. Furthermore, the administration of ceftriaxone, but not vancomycin, led to a significant reduction in the abundance of splenic CD4+CD25+Foxp3+ T cells. Each antibiotic caused intestinal dysbiosis and characteristically influenced the regeneration of intestinal epithelial cells, formation of the intestinal mucus layer and tight junctions, and differentiation of splenic Foxp3+ Treg cells of the neonatal mice before any clinical side effects were observed. The potent ability of each antibiotic to affect the makeup of intestinal commensal microbiota may be a key determinant of the spectrum of antibiotics and influence the health of the host animal, at least partly. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. The role of the microbial environment in Drosophila post-embryonic development.

    Science.gov (United States)

    Strigini, Maura; Leulier, François

    2016-11-01

    Development, growth and maturation of animals are under genetic and environmental control. Multicellular organisms interact throughout their lives with a variety of environment- and body-associated microorganisms. It has now been appreciated that the very conspicuous and varied microbial population associated with the food and the gastro-intestinal tract is a critical factor that can influence growth. Beyond the phenomenology, the mechanisms underlying the beneficial effects of microbes on development are being revealed from studies in Drosophila melanogaster, a particularly well suited system for a mechanistic understanding of host/microbiota interactions. Association of otherwise germ-free eggs with specific bacterial strains isolated from Drosophila gut samples can accelerate growth in larvae raised on restrictive diets. We review advances made possible by the exploitation of such simplified gnotobiotic systems in the search for the genes, molecules and physiological adaptations responsible for this effect in both host and microbes. Transposon mutagenesis and gene-trait match studies in bacteria can identify the key microbial genes and metabolites required for the beneficial effect, acetic acid being one of them. In the fly, functional genomic analysis, transcriptomics and metabolomics point to the modulation of systemic insulin and steroid hormone signalling as well as the regulation of intestinal physiology, including the enhancement of intestinal protease activity, as crucial mediators of the host's response. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Chronic intestinal pseudoobstruction syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Yeon, Kyung Mo; Seo, Jeong Kee; Lee, Yong Seok [Seoul National University Children' s Hospital, Seoul (Korea, Republic of)

    1992-03-15

    Chronic intestinal pseudoobstruction syndrome is a rare clinical condition in which impaired intestinal peristalsis causes recurrent symptoms of bowel obstruction in the absence of a mechanical occlusion. This syndrome may involve variable segments of small or large bowel, and may be associated with urinary bladder retention. This study included 6 children(3 boys and 3 girls) of chronic intestinal obstruction. Four were symptomatic at birth and two were of the ages of one month and one year. All had abdominal distension and deflection difficulty. Five had urinary bladder distension. Despite parenteral nutrition and surgical intervention(ileostomy or colostomy), bowel obstruction persisted and four patients expired from sepses within one year. All had gaseous distension of small and large bowel on abdominal films. In small bowel series, consistent findings were variable degree of dilatation, decreased peristalsis(prolonged transit time) and microcolon or microrectum. This disease entity must be differentiated from congenital megacolon, ileal atresia and megacystis syndrome.

  5. Intestinal solute carriers

    DEFF Research Database (Denmark)

    Steffansen, Bente; Nielsen, Carsten Uhd; Brodin, Birger

    2004-01-01

    /or prodrugs to these carriers in order to increasing oral bioavailability and distribution. A number of absorptive intestinal transporters are described in terms of gene and protein classification, driving forces, substrate specificities and cellular localization. When targeting absorptive large capacity...... membrane transporters in the small intestine in order to increase oral bioavailabilities of drug or prodrug, the major influence on in vivo pharmacokinetics is suggested to be dose-dependent increase in bioavailability as well as prolonged blood circulation due to large capacity facilitated absorption......, and renal re-absorption, respectively. In contrast, when targeting low-capacity transporters such as vitamin transporters, dose independent saturable absorption kinetics are suggested. We thus believe that targeting drug substrates for absorptive intestinal membrane transporters could be a feasible strategy...

  6. Exploring the functionality of intestinal Bifidobacteria: a post-genomics approach

    NARCIS (Netherlands)

    Klaassens, E.S.

    2007-01-01

    Following birth, the human gastrointestinal tract is rapidly colonized by microorganisms that profoundly impact the physiology and health of the host by contributing to host nutrition and natural defense, amongst other activities. In the large intestine, bifidobacteria are especially predominant in

  7. The human intestinal microbiome: a new frontier of human biology.

    Science.gov (United States)

    Hattori, Masahira; Taylor, Todd D

    2009-02-01

    To analyze the vast number and variety of microorganisms inhabiting the human intestine, emerging metagenomic technologies are extremely powerful. The intestinal microbes are taxonomically complex and constitute an ecologically dynamic community (microbiota) that has long been believed to possess a strong impact on human physiology. Furthermore, they are heavily involved in the maturation and proliferation of human intestinal cells, helping to maintain their homeostasis and can be causative of various diseases, such as inflammatory bowel disease and obesity. A simplified animal model system has provided the mechanistic basis for the molecular interactions that occur at the interface between such microbes and host intestinal epithelia. Through metagenomic analysis, it is now possible to comprehensively explore the genetic nature of the intestinal microbiome, the mutually interacting system comprising the host cells and the residing microbial community. The human microbiome project was recently launched as an international collaborative research effort to further promote this newly developing field and to pave the way to a new frontier of human biology, which will provide new strategies for the maintenance of human health.

  8. Intestinal obstruction repair - series (image)

    Science.gov (United States)

    The most common causes of intestinal obstruction in adults are adhesions, hernias, and colon cancer. Adhesions are scars that form between loops of intestine, usually caused by prior surgery, which causes such scar formation. ...

  9. Small intestine aspirate and culture

    Science.gov (United States)

    ... ency/article/003731.htm Small intestine aspirate and culture To use the sharing features on this page, please enable JavaScript. Small intestine aspirate and culture is a lab test to check for infection ...

  10. Congenital Diseases of the Intestine

    NARCIS (Netherlands)

    D. Halim (Danny)

    2016-01-01

    markdownabstractAll research described in this dissertation is focused on understanding the pathophysiology of three rare congenital diseases of the intestine, including megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS), congenital short bowel syndrome (CSBS), and hereditary multiple

  11. Disorders of the Large Intestine

    Science.gov (United States)

    ... of Medicine, Division of Digestive Diseases; Professor of Psychology, University of North Carolina, Chapel Hill, NC, IFFGD ... Intestine Large Intestine Anorectal and Pelvic Floor Area Personal Stories Resources We provide a wide range of ...

  12. Disorders of the Small Intestine

    Science.gov (United States)

    ... of Medicine, Division of Digestive Diseases Professor of Psychology University of North Carolina, Chapel Hill, NC. Digestive ... Intestine Large Intestine Anorectal and Pelvic Floor Area Personal Stories Resources We provide a wide range of ...

  13. Genetic and epigenetic regulation of intestinal fibrosis.

    Science.gov (United States)

    Li, Chao; Kuemmerle, John F

    2016-08-01

    Crohn's disease affects those individuals with polygenic risk factors. The identified risk loci indicate that the genetic architecture of Crohn's disease involves both innate and adaptive immunity and the response to the intestinal environment including the microbiome. Genetic risk alone, however, predicts only 25% of disease, indicating that other factors, including the intestinal environment, can shape the epigenome and also confer heritable risk to patients. Patients with Crohn's disease can have purely inflammatory disease, penetrating disease or fibrostenosis. Analysis of the genetic risk combined with epigenetic marks of Crohn's disease and other disease associated with organ fibrosis reveals common events are affecting the genes and pathways key to development of fibrosis. This review will focus on what is known about the mechanisms by which genetic and epigenetic risk factors determine development of fibrosis in Crohn's disease and contrast that with other fibrotic conditions.

  14. Dynamic efficiency of the human intestinal microbiota.

    Science.gov (United States)

    Candela, Marco; Biagi, Elena; Turroni, Silvia; Maccaferri, Simone; Figini, Paolo; Brigidi, Patrizia

    2015-06-01

    The emerging dynamic dimensions of the human intestinal microbiota (IM) are challenging the traditional definition of healthy gut microbiota, principally based on the static concepts of phylogenetic and functional core. On the other hand, recent researches are revealing that the microbiota plasticity is strategic for several aspects of our biology, addressing the different immunological and metabolic needs at various ages, and adjusting the ecosystem services in response to different lifestyle, physiological states or diets. In light of these studies, we propose to revise the traditional concept of healthy human IM, including its degree of plasticity among the fundamental requisites for providing host health. In order to make a model taking into account the relative importance of IM core functions and plasticity for the maintenance of host health, we address to Economics, where the efficiency of a productive system is measured by computing static and dynamic parameters.

  15. Sarcocystis pantherophis, n. sp. from eastern rat snakes (Pantherophis alleghaniensis) definitive hosts and interferongamma gene knockout mice as experimental intermediate hosts

    Science.gov (United States)

    Here we report a new species, Sarcocystis pantherophisi with the Eastern rat snake (Pantherophis alleghaniensis) as natural definitive host and the interferon gamma gene knockout (KO) mouse as the experimental intermediate host. Sporocysts (n=15) from intestinal contents of the snake were 17.3 x 10....

  16. CT recognition of intestinal lipomatosis

    Energy Technology Data Exchange (ETDEWEB)

    Ormson, M.J.; Stephens, D.H.; Carlson, H.C.

    1985-02-01

    Lipomas are among the most common benign tumors of the small intestine. They are generally solitary lesions and asymptomatic. The extensive involvement of the small intestine with multiple lipomas is rare. The authors report a case of intestinal lipomatosis of the small bowel in which CT was specific enough to make the diagnosis without resorting to more invasive procedures.

  17. Effect of various antibiotics on modulation of intestinal microbiota and bile acid profile in mice

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Youcai; Limaye, Pallavi B.; Renaud, Helen J.; Klaassen, Curtis D., E-mail: curtisklaassenphd@gmail.com

    2014-06-01

    Antibiotic treatments have been used to modulate intestinal bacteria and investigate the role of intestinal bacteria on bile acid (BA) homeostasis. However, knowledge on which intestinal bacteria and bile acids are modified by antibiotics is limited. In the present study, mice were administered various antibiotics, 47 of the most abundant bacterial species in intestine, as well as individual BAs in plasma, liver, and intestine were quantified. Compared to the two antibiotic combinations (vancomycin + imipenem and cephalothin + neomycin), the three single antibiotics (metronidazole, ciprofloxacin and aztreonam) have less effect on intestinal bacterial profiles, and thus on host BA profiles and mRNA expression of genes that are important for BA homeostasis. The two antibiotic combinations decreased the ratio of Firmicutes to Bacteroidetes in intestine, as well as most secondary BAs in serum, liver and intestine. Additionally, the two antibiotic combinations significantly increased mRNA of the hepatic BA uptake transporters (Ntcp and Oatp1b2) and canalicular BA efflux transporters (Bsep and Mrp2), but decreased mRNA of the hepatic BA synthetic enzyme Cyp8b1, suggesting an elevated enterohepatic circulation of BAs. Interestingly, the two antibiotic combinations tended to have opposite effect on the mRNAs of most intestinal genes, which tended to be inhibited by vancomycin + imipenem but stimulated by cephalothin + neomycin. To conclude, the present study clearly shows that various antibiotics have distinct effects on modulating intestinal bacteria and host BA metabolism. - Highlights: • Various antibiotics have different effects on intestinal bacteria. • Antibiotics alter bile acid composition in mouse liver and intestine. • Antibiotics influence genes involved in bile acid homeostasis. • Clostridia appear to be important for secondary bile acid formation.

  18. adhesive intestinal obstruction

    African Journals Online (AJOL)

    2006-06-01

    Jun 1, 2006 ... obstruction. Brit. I. Surg. 1998; 85: 1071-1074. The acute abdomen: Intestinal obstruction. In: Primary surgery, Vol. 1. Edited by Maurice King et al. Oxford. Med. PubL, Oxford. 1990; 142-169. Fluids and electrolyte management. In: Essentials of pediatric surgery. Edited by Marc Rowe et al. Mosby,. St. Louis ...

  19. The Vat-AIEC protease promotes crossing of the intestinal mucus layer by Crohn's disease-associated Escherichia coli.

    Science.gov (United States)

    Gibold, Lucie; Garenaux, Estelle; Dalmasso, Guillaume; Gallucci, Camille; Cia, David; Mottet-Auselo, Benoit; Faïs, Tiphanie; Darfeuille-Michaud, Arlette; Nguyen, Hang Thi Thu; Barnich, Nicolas; Bonnet, Richard; Delmas, Julien

    2016-05-01

    The aetiology of Crohn's disease (CD) involves disorders in host genetic factors and intestinal microbiota. Adherent-invasive Escherichia coli (AIEC) are receiving increased attention because in studies of mucosa-associated microbiota, they are more prevalent in CD patients than in healthy subjects. AIEC are associated both with ileal and colonic disease phenotypes. In this study, we reported a protease called Vat-AIEC from AIEC that favours the mucosa colonization. The deletion of the Vat-AIEC-encoding gene resulted in an adhesion-impaired phenotype in vitro and affected the colonization of bacteria in contact with intestinal epithelial cells in a murine intestinal loop model, and also their gut colonization in vivo. Furthermore, unlike LF82Δvat-AIEC, wild-type AIEC reference strain LF82 was able to penetrate a mucus column extensively and promoted the degradation of mucins and a decrease in mucus viscosity. Vat-AIEC transcription was stimulated by several chemical conditions found in the ileum environment. Finally, the screening of E. coli strains isolated from CD patients revealed a preferential vat-AIEC association with AIEC strains belonging to the B2 phylogroup. Overall, this study revealed a new component of AIEC virulence that might favour their implantation in the gut of CD patients. © 2015 John Wiley & Sons Ltd.

  20. Western diet induces a shift in microbiota composition enhancing susceptibility to Adherent-Invasive E. coli infection and intestinal inflammation.

    Science.gov (United States)

    Agus, Allison; Denizot, Jérémy; Thévenot, Jonathan; Martinez-Medina, Margarita; Massier, Sébastien; Sauvanet, Pierre; Bernalier-Donadille, Annick; Denis, Sylvain; Hofman, Paul; Bonnet, Richard; Billard, Elisabeth; Barnich, Nicolas

    2016-01-08

    Recent advances have shown that the abnormal inflammatory response observed in CD involves an interplay among intestinal microbiota, host genetics and environmental factors. The escalating consumption of fat and sugar in Western countries parallels an increased incidence of CD during the latter 20(th) century. The impact of a HF/HS diet in mice was evaluated for the gut micro-inflammation, intestinal microbiota composition, function and selection of an E. coli population. The HF/HS diet created a specific inflammatory environment in the gut, correlated with intestinal mucosa dysbiosis characterized by an overgrowth of pro-inflammatory Proteobacteria such as E. coli, a decrease in protective bacteria, and a significantly decreased of SCFA concentrations. The expression of GPR43, a SCFA receptor was reduced in mice treated with a HF/HS diet and reduced in CD patients compared with controls. Interestingly, mice treated with an agonist of GPR43 were protected against DSS-induced colitis. Finally, the transplantation of feces from HF/HS treated mice to GF mice increased susceptibility to AIEC infection. Together, our results demonstrate that a Western diet could aggravate the inflammatory process and that the activation of the GPR43 receptor pathway could be used as a new strategy to treat CD patients.

  1. Western diet induces a shift in microbiota composition enhancing susceptibility to Adherent-Invasive E. coli infection and intestinal inflammation.

    Science.gov (United States)

    Agus, Allison; Denizot, Jérémy; Thévenot, Jonathan; Martinez-Medina, Margarita; Massier, Sébastien; Sauvanet, Pierre; Bernalier-Donadille, Annick; Denis, Sylvain; Hofman, Paul; Bonnet, Richard; Billard, Elisabeth; Barnich, Nicolas

    2016-01-01

    Recent advances have shown that the abnormal inflammatory response observed in CD involves an interplay among intestinal microbiota, host genetics and environmental factors. The escalating consumption of fat and sugar in Western countries parallels an increased incidence of CD during the latter 20th century. The impact of a HF/HS diet in mice was evaluated for the gut micro-inflammation, intestinal microbiota composition, function and selection of an E. coli population. The HF/HS diet created a specific inflammatory environment in the gut, correlated with intestinal mucosa dysbiosis characterized by an overgrowth of pro-inflammatory Proteobacteria such as E. coli, a decrease in protective bacteria, and a significantly decreased of SCFA concentrations. The expression of GPR43, a SCFA receptor was reduced in mice treated with a HF/HS diet and reduced in CD patients compared with controls. Interestingly, mice treated with an agonist of GPR43 were protected against DSS-induced colitis. Finally, the transplantation of feces from HF/HS treated mice to GF mice increased susceptibility to AIEC infection. Together, our results demonstrate that a Western diet could aggravate the inflammatory process and that the activation of the GPR43 receptor pathway could be used as a new strategy to treat CD patients. PMID:26742586

  2. Effect of peristalsis in balance of intestinal microbial ecosystem

    Science.gov (United States)

    Mirbagheri, Seyed Amir; Fu, Henry C.

    2017-11-01

    A balance of microbiota density in gastrointestinal tracts is necessary for health of the host. Although peristaltic flow made by intestinal muscles is constantly evacuating the lumen, bacterial density stay balanced. Some of bacteria colonize in the secreted mucus where there is no flow, but the rest resist the peristaltic flow in lumen and maintain their population. Using a coupled two-dimensional model of flow induced by large amplitude peristaltic waves, bacterial motility, reproduction, and diffusion, we address how bacterial growth and motility combined with peristaltic flow affect the balance of the intestinal microbial ecosystem.

  3. Immune defense mechanisms in the Caenorhabditis elegans intestinal epithelium.

    Science.gov (United States)

    Pukkila-Worley, Read; Ausubel, Frederick M

    2012-02-01

    Intestinal epithelial cells provide an essential line of defense for Caernohabditis elegans against ingested pathogens. Because nematodes consume microorganisms as their food source, there has presumably been selection pressure to evolve and maintain immune defense mechanisms within the intestinal epithelium. Here we review recent advances that further define the immune signaling network within these cells and suggest mechanisms used by the nematode to monitor for infection. In reviewing studies of pathogenesis that use this simple model system, we hope to illustrate some of the basic principles of epithelial immunity that may also be of relevance in higher order hosts. Copyright © 2012. Published by Elsevier Ltd.

  4. Early-life origin of intestinal inflammatory disorders.

    Science.gov (United States)

    Ley, Delphine; Desseyn, Jean-Luc; Mischke, Mona; Knol, Jan; Turck, Dominique; Gottrand, Frédéric

    2017-03-01

    A growing body of evidence supports the concept of perinatal programming through which the perinatal environment affects the development of the fetus and infant, thereby modifying the risk profile for disease later in life. Increasing attention is focusing on the role of the early environment in the development of chronic intestinal disorders. Epidemiological studies have highlighted the link between perinatal factors, such as breastfeeding, cesarean delivery, and antibiotic use, and an increased risk for inflammatory bowel disease and/or celiac disease. These links are consistent with the concept of perinatal programming of intestinal inflammatory disorders. Animal models have shown that the early-life environment affects the development of the gastrointestinal tract, but further experimental studies are needed to confirm the long-term effects of the perinatal environment on susceptibility to chronic intestinal disorders later in life. Changes in the development and composition of the intestinal microbiota as well as epigenetic changes are emerging as key mechanisms through which the perinatal environment determines susceptibility to intestinal inflammatory disorders. © The Author(s) 2017. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  5. Unbalance of intestinal microbiota in atopic children

    Directory of Open Access Journals (Sweden)

    Candela Marco

    2012-06-01

    Full Text Available Abstract Background Playing a strategic role in the host immune function, the intestinal microbiota has been recently hypothesized to be involved in the etiology of atopy. In order to investigate the gastrointestinal microbial ecology of atopic disease, here we performed a pilot comparative molecular analysis of the faecal microbiota in atopic children and healthy controls. Results Nineteen atopic children and 12 healthy controls aged 4–14 years were enrolled. Stools were collected and the faecal microbiota was characterized by means of the already developed phylogenetic microarray platform, HTF-Microbi.Array, and quantitative PCR. The intestinal microbiota of atopic children showed a significant depletion in members of the Clostridium cluster IV, Faecalibacterium prausnitzii, Akkermansia muciniphila and a corresponding increase of the relative abundance of Enterobacteriaceae. Conclusion Depleted in key immunomodulatory symbionts, the atopy-associated microbiota can represent an inflammogenic microbial consortium which can contribute to the severity of the disease. Our data open the way to the therapeutic manipulation of the intestinal microbiota in the treatment of atopy by means of pharmaceutical probiotics.

  6. B cells as a critical node in the microbiota-host immune system network.

    Science.gov (United States)

    Slack, Emma; Balmer, Maria L; Macpherson, Andrew J

    2014-07-01

    Mutualism with our intestinal microbiota is a prerequisite for healthy existence. This requires physical separation of the majority of the microbiota from the host (by secreted antimicrobials, mucus, and the intestinal epithelium) and active immune control of the low numbers of microbes that overcome these physical and chemical barriers, even in healthy individuals. In this review, we address how B-cell responses to members of the intestinal microbiota form a robust network with mucus, epithelial integrity, follicular helper T cells, innate immunity, and gut-associated lymphoid tissues to maintain host-microbiota mutualism. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Human and mouse tissue-engineered small intestine both demonstrate digestive and absorptive function

    Science.gov (United States)

    Grant, Christa N.; Mojica, Salvador Garcia; Sala, Frederic G.; Hill, J. Ryan; Levin, Daniel E.; Speer, Allison L.; Barthel, Erik R.; Shimada, Hiroyuki; Zachos, Nicholas C.

    2015-01-01

    Short bowel syndrome (SBS) is a devastating condition in which insufficient small intestinal surface area results in malnutrition and dependence on intravenous parenteral nutrition. There is an increasing incidence of SBS, particularly in premature babies and newborns with congenital intestinal anomalies. Tissue-engineered small intestine (TESI) offers a therapeutic alternative to the current standard treatment, intestinal transplantation, and has the potential to solve its biggest challenges, namely donor shortage and life-long immunosuppression. We have previously demonstrated that TESI can be generated from mouse and human small intestine and histologically replicates key components of native intestine. We hypothesized that TESI also recapitulates native small intestine function. Organoid units were generated from mouse or human donor intestine and implanted into genetically identical or immunodeficient host mice. After 4 wk, TESI was harvested and either fixed and paraffin embedded or immediately subjected to assays to illustrate function. We demonstrated that both mouse and human tissue-engineered small intestine grew into an appropriately polarized sphere of intact epithelium facing a lumen, contiguous with supporting mesenchyme, muscle, and stem/progenitor cells. The epithelium demonstrated major ultrastructural components, including tight junctions and microvilli, transporters, and functional brush-border and digestive enzymes. This study demonstrates that tissue-engineered small intestine possesses a well-differentiated epithelium with intact ion transporters/channels, functional brush-border enzymes, and similar ultrastructural components to native tissue, including progenitor cells, whether derived from mouse or human cells. PMID:25573173

  8. Breast milk, microbiota, and intestinal immune homeostasis.

    Science.gov (United States)

    Walker, W Allan; Iyengar, Rajashri Shuba

    2015-01-01

    Newborns adjust to the extrauterine environment by developing intestinal immune homeostasis. Appropriate initial bacterial colonization is necessary for adequate intestinal immune development. An environmental determinant of adequate colonization is breast milk. Although the full-term infant is developmentally capable of mounting an immune response, the effector immune component requires bacterial stimulation. Breast milk stimulates the proliferation of a well-balanced and diverse microbiota, which initially influences a switch from an intrauterine TH2 predominant to a TH1/TH2 balanced response and with activation of T-regulatory cells by breast milk-stimulated specific organisms (Bifidobacteria, Lactobacillus, and Bacteroides). As an example of its effect, oligosaccharides in breast milk are fermented by colonic bacteria producing an acid milieu for bacterial proliferation. In addition, short-chain fatty acids in breast milk activate receptors on T-reg cells and bacterial genes, which preferentially mediate intestinal tight junction expression and anti-inflammation. Other components of breast milk (defensins, lactoferrin, etc.) inhibit pathogens and further contribute to microbiota composition. The breast milk influence on initial intestinal microbiota also prevents expression of immune-mediated diseases (asthma, inflammatory bowel disease, type 1 diabetes) later in life through a balanced initial immune response, underscoring the necessity of breastfeeding as the first source of nutrition.

  9. Interaction between food components, intestinal microbiota and intestinal mucosa as a function of intestinal health

    NARCIS (Netherlands)

    Venema, K.; Sandt, H. van de

    2003-01-01

    Interaction between food components, intestinal microbiota and intestinal mucosa was studied as a function of intestinal health. A microbiota was found to be important for the onset and progression of inflammatory diseases. Studies revealed a prominent effect of micro-organisms on the gene

  10. Interactions of lactobacilli with the host immune system

    NARCIS (Netherlands)

    Meijerink, M.

    2011-01-01

    The aim of this thesis was to better understand the molecular mechanism of host res-ponses to probiotics. Probiotics can be used to stimulate or regulate immune responses in epithelial and immune cells of the intestinal mucosa and generate beneficial effects on the immune system. Carefully selected

  11. Omics approaches to study host-microbiota interactions

    NARCIS (Netherlands)

    Baarlen, van P.; Kleerebezem, M.; Wells, J.

    2013-01-01

    The intestinal microbiota has profound effects on our physiology and immune system and disturbances in the equilibrium between microbiota and host have been observed in many disorders. Here we discuss the possibilities to further our understanding of how microbiota impacts on human health and

  12. THE USE OF FK-506 FOR SMALL INTESTINE ALLOTRANSPLANTATION

    Science.gov (United States)

    Hoffman, A. L.; Makowka, L.; Banner, B.; Cai, X.; Cramer, D. V.; Pascualone, A.; Todo, S.; Starzl, T. E.

    2010-01-01

    Small intestine allotransplantation in humans is not yet feasible due to the failure of the current methods of immunosuppression. FK-506, a powerful new immunosuppressive agent that is synergistic with cyclosporine, allows long-term survival of recipients of cardiac, renal, and hepatic allografts. This study compares the effects of FK-506 and cyclosporine on host survival, graft rejection, and graft-versus-host-disease in a rat small intestine transplantation model. Transplants between strongly histoincompatible ACI and Lewis (LEW) strain rats, and their F1 progeny are performed so that graft rejection alone is genetically permitted (F1→LEW) or GVHD alone permitted (LEW→F1) or that both immunologic processes are allowed to occur simultaneously (ACI→LEW). Specific doses of FK-506 result in prolonged graft and host survival in all genetic combinations tested. Furthermore, graft rejection is prevented (ACI→LEW model) or inhibited (rejection only model) and lethal acute GVHD is eliminated. Even at very high doses, cyclosporine did not prevent graft rejection or lethal GVHD, nor did it allow long-term survival of the intestinal graft or the host. Animals receiving low doses of cyclosporine have outcomes similar to the untreated control groups. No toxicity specific to FK-506 is noted, but earlier studies by other investigators suggest otherwise. PMID:1690469

  13. A model of bacterial intestinal infections in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Nadine T Nehme

    2007-11-01

    Full Text Available Serratia marcescens is an entomopathogenic bacterium that opportunistically infects a wide range of hosts, including humans. In a model of septic injury, if directly introduced into the body cavity of Drosophila, this pathogen is insensitive to the host's systemic immune response and kills flies in a day. We find that S. marcescens resistance to the Drosophila immune deficiency (imd-mediated humoral response requires the bacterial lipopolysaccharide O-antigen. If ingested by Drosophila, bacteria cross the gut and penetrate the body cavity. During this passage, the bacteria can be observed within the cells of the intestinal epithelium. In such an oral infection model, the flies succumb to infection only after 6 days. We demonstrate that two complementary host defense mechanisms act together against such food-borne infection: an antimicrobial response in the intestine that is regulated by the imd pathway and phagocytosis by hemocytes of bacteria that have escaped into the hemolymph. Interestingly, bacteria present in the hemolymph elicit a systemic immune response only when phagocytosis is blocked. Our observations support a model wherein peptidoglycan fragments released during bacterial growth activate the imd pathway and do not back a proposed role for phagocytosis in the immune activation of the fat body. Thanks to the genetic tools available in both host and pathogen, the molecular dissection of the interactions between S. marcescens and Drosophila will provide a useful paradigm for deciphering intestinal pathogenesis.

  14. Modulation of intestinal TLR4-inflammatory signalling pathways by probiotic microorganisms: lessons learned from Lactobacillus jensenii TL2937

    OpenAIRE

    Villena, Julio Cesar; Kitazawa, Haruki

    2015-01-01

    The intestinal mucosa plays a critical role in the host?s interactions with innocuous commen- sal microbiota and invading pathogenic microorganisms. Intestinal epithelial cells (IECs) and gut associated immune cells recognize the bacterial components via pattern-recognition receptors (PRRs) and are responsible for maintaining tolerance to the large communities of resident luminal bacteria while being also able to mount inflammatory responses against pathogens. Toll-like receptors (TLRs) are a...

  15. Host response to biomaterials the impact of host response on biomaterial selection

    CERN Document Server

    Badylak, Stephen F

    2015-01-01

    Host Response to Biomaterials: The Impact of Host Response on Biomaterial Selection explains the various categories of biomaterials and their significance for clinical applications, focusing on the host response to each biomaterial. It is one of the first books to connect immunology and biomaterials with regard to host response. The text also explores the role of the immune system in host response, and covers the regulatory environment for biomaterials, along with the benefits of synthetic versus natural biomaterials, and the transition from simple to complex biomaterial solutions. Fiel

  16. Measurement of small intestinal damage.

    Science.gov (United States)

    Takeuchi, Koji; Satoh, Hiroshi

    2010-08-01

    Many animal models have been devised for investigating the pathogenesis of intestinal lesions and for screening drugs for the treatment of intestinal ulcers in humans. Recently, particular attention has been focused on NSAID-induced intestinal lesions as a result of the development of the capsule endoscope and double-balloon endoscope. Ischemic enteritis, one of the most dramatic abdominal emergencies, is known to cause severe damage to the small intestine by a significant decrease of arterial blood flow in the small intestine. In this unit, two animal models for small intestinal damage induced by NSAIDs or intestinal ischemia are described. Also included are methods for lesion induction and evaluation of the damage as well as the measurement of pathogenic functional and biochemical changes.

  17. Simulated time for host-based testing with TTCN-3

    NARCIS (Netherlands)

    Blom, Stefan; Deiß, Thomas; Ioustinova, Natalia; Kontio, Ari; van de Pol, Jan Cornelis; Rennoch, Axel; Sidorova, Natalia

    2008-01-01

    Prior to testing embedded software in a target environment, it is usually tested in a host environment used for developing the software. When a system is tested in a host environment, its real-time behaviour is affected by the use of simulators, emulation and monitoring. In this paper, the authors

  18. Activation of intestinal epithelial Stat3 orchestrates tissue defense during gastrointestinal infection.

    Science.gov (United States)

    Wittkopf, Nadine; Pickert, Geethanjali; Billmeier, Ulrike; Mahapatro, Mousumi; Wirtz, Stefan; Martini, Eva; Leppkes, Moritz; Neurath, Markus Friedrich; Becker, Christoph

    2015-01-01

    Gastrointestinal infections with EHEC and EPEC are responsible for outbreaks of diarrheal diseases and represent a global health problem. Innate first-line-defense mechanisms such as production of mucus and antimicrobial peptides by intestinal epithelial cells are of utmost importance for host control of gastrointestinal infections. For the first time, we directly demonstrate a critical role for Stat3 activation in intestinal epithelial cells upon infection of mice with Citrobacter rodentium - a murine pathogen that mimics human infections with attaching and effacing Escherichia coli. C. rodentium induced transcription of IL-6 and IL-22 in gut samples of mice and was associated with activation of the transcription factor Stat3 in intestinal epithelial cells. C. rodentium infection induced expression of several antimicrobial peptides such as RegIIIγ and Pla2g2a in the intestine which was critically dependent on Stat3 activation. Consequently, mice with specific deletion of Stat3 in intestinal epithelial cells showed increased susceptibility to C. rodentium infection as indicated by high bacterial load, severe gut inflammation, pronounced intestinal epithelial cell death and dissemination of bacteria to distant organs. Together, our data implicate an essential role for Stat3 activation in intestinal epithelial cells during C. rodentium infection. Stat3 concerts the host response to bacterial infection by controlling bacterial growth and suppression of apoptosis to maintain intestinal epithelial barrier function.

  19. Activation of intestinal epithelial Stat3 orchestrates tissue defense during gastrointestinal infection.

    Directory of Open Access Journals (Sweden)

    Nadine Wittkopf

    Full Text Available Gastrointestinal infections with EHEC and EPEC are responsible for outbreaks of diarrheal diseases and represent a global health problem. Innate first-line-defense mechanisms such as production of mucus and antimicrobial peptides by intestinal epithelial cells are of utmost importance for host control of gastrointestinal infections. For the first time, we directly demonstrate a critical role for Stat3 activation in intestinal epithelial cells upon infection of mice with Citrobacter rodentium - a murine pathogen that mimics human infections with attaching and effacing Escherichia coli. C. rodentium induced transcription of IL-6 and IL-22 in gut samples of mice and was associated with activation of the transcription factor Stat3 in intestinal epithelial cells. C. rodentium infection induced expression of several antimicrobial peptides such as RegIIIγ and Pla2g2a in the intestine which was critically dependent on Stat3 activation. Consequently, mice with specific deletion of Stat3 in intestinal epithelial cells showed increased susceptibility to C. rodentium infection as indicated by high bacterial load, severe gut inflammation, pronounced intestinal epithelial cell death and dissemination of bacteria to distant organs. Together, our data implicate an essential role for Stat3 activation in intestinal epithelial cells during C. rodentium infection. Stat3 concerts the host response to bacterial infection by controlling bacterial growth and suppression of apoptosis to maintain intestinal epithelial barrier function.

  20. [Regulation of the intestinal flora by food].

    Science.gov (United States)

    Gedek, B R

    1991-03-01

    The purpose of probiotics is to regulate the bacterial colonisation of the digestive tract. In contrast to antibiotics, with the probiotics it is not a certain metabolic product of bacteria or fungi with a known spectrum of antimicrobial activity which, for example when used as performance enhancers under the conditions permitted according to the EEC guidelines for feed additives, reduce the numbers of bacteria, which appear in the small intestines of domestic animals and compete with the host for nutrients and vitamins, but there it is rather the living micro-organisms themselves which are intended to, to help to improve the performance of domestic animals on the basis of a fundamentally different mechanism of action. Recent findings on the effect of the phenomena of bacterial competition on the processes of an infection, with penetration, adhesion, and multiplication as prerequisites for development of the parasitic mechanism of a pathogen, have shown that by controlling the processes of colonization of the intestines with micro-organisms and also their metabolic activity it is possible to at least reduce the incidence of the diarrhoeal diseases which are responsible for the the greatest economic damage. The numerical displacement of bacterial pathogens is not the only effect of the bacterial competition resulting from the orally administered micro-organisms. The fact that antagonistically acting bacteria or yeasts prevent the pathogenic species from entering the intestinal epithelial cells plays a role here. As a result of which, especially the small intestines are not colonized by pathogens (E. coli and others), the liver is largely relieved of substances accumulating in the course of bacterial protein metabolism, the absorption of fatty acids and other energy-providing compounds is increased, and not readily soluble salts are transformed into soluble compounds. Effects comparable to those obtained with small amounts of antibiotics added to the feed of farm

  1. Systems biology of the gut: the interplay of food, microbiota and host at the mucosal interface.

    Science.gov (United States)

    Martins dos Santos, Vítor; Müller, Michael; de Vos, Willem M

    2010-08-01

    Our intestinal tract is colonized since birth by complex and subject-specific microbial communities that interact with the host. The human adult microbiota has recently been characterized by deep metagenomic sequencing and several hundreds of intestinal genomes have been characterized at the sequence level. Moreover, the transcriptional response of the host and selected microbes has been identified both in animal model systems and in human. Similarly, the transcriptional response of the host to different diets has been determined in humans, germ-free and gene knockout animals. These developments bring the intestinal tract in the realm of systems biology. An integrated, modular modelling framework that cross-links top-down and bottom-up approaches for the various levels of biological organization is paramount for the understanding of intestinal function. Copyright © 2010. Published by Elsevier Ltd.

  2. Diversity of Intestinal Macrophages in Inflammatory Bowel Diseases.

    Science.gov (United States)

    Kühl, Anja A; Erben, Ulrike; Kredel, Lea I; Siegmund, Britta

    2015-01-01

    Macrophages as innate immune cells and fast responders to antigens play a central role in protecting the body from the luminal content at a huge interface. Chronic inflammation in inflammatory bowel diseases massively alters the number and the subset diversity of intestinal macrophages. We here address the diversity within the human intestinal macrophage compartment at the level of similarities and differences between homeostasis and chronic intestinal inflammation as well as between UC and CD, including the potential role of macrophage subsets for intestinal fibrosis. Hallmark of macrophages is their enormous plasticity, i.e., their capacity to integrate signals from their environment thereby changing their phenotype and functions. Tissue-resident macrophages located directly beneath the surface epithelium in gut homeostasis are mostly tolerogenic. The total number of macrophages increases with luminal contents entering the mucosa through a broken intestinal barrier in ulcerative colitis (UC) as well as in Crohn's disease (CD). Although not fully understood, the resulting mixtures of tissue-resident and tissue-infiltrating macrophages in both entities are diverse with respect to their phenotypes and their distribution. Macrophages in UC mainly act within the intestinal mucosa. In CD, macrophages can also be found in the muscularis and the mesenteric fat tissue compartment. Taken together, the present knowledge on human intestinal macrophages so far provides a good starting point to dig deeper into the similarities and differences of functional subsets and to finally use their phenotypical diversity as markers for complex local milieus in health and disease.

  3. The transcriptional repressor HIC1 regulates intestinal immune homeostasis.

    Science.gov (United States)

    Burrows, K; Antignano, F; Bramhall, M; Chenery, A; Scheer, S; Korinek, V; Underhill, T M; Zaph, C

    2017-11-01

    The intestine is a unique immune environment that must respond to infectious organisms but remain tolerant to commensal microbes and food antigens. However, the molecular mechanisms that regulate immune cell function in the intestine remain unclear. Here we identify the POK/ZBTB family transcription factor hypermethylated in cancer 1 (HIC1, ZBTB29) as a central component of immunity and inflammation in the intestine. HIC1 is specifically expressed in immune cells in the intestinal lamina propria (LP) in the steady state and mice with a T-cell-specific deletion of HIC1 have reduced numbers of T cells in the LP. HIC1 expression is regulated by the Vitamin A metabolite retinoic acid, as mice raised on a Vitamin A-deficient diet lack HIC1-positive cells in the intestine. HIC1-deficient T cells overproduce IL-17A in vitro and in vivo, and fail to induce intestinal inflammation, identifying a critical role for HIC1 in the regulation of T-cell function in the intestinal microenvironment under both homeostatic and inflammatory conditions.

  4. Host defences against Giardia lamblia.

    Science.gov (United States)

    Lopez-Romero, G; Quintero, J; Astiazarán-García, H; Velazquez, C

    2015-08-01

    Giardia spp. is a protozoan parasite that inhabits the upper small intestine of mammals and other species and is the aetiological agent of giardiasis. It has been demonstrated that nitric oxide, mast cells and dendritic cells are the first line of defence against Giardia. IL-6 and IL-17 play an important role during infection. Several cytokines possess overlapping functions in regulating innate and adaptive immune responses. IgA and CD4(+) T cells are fundamental to the process of Giardia clearance. It has been suggested that CD4(+) T cells play a double role during the anti-Giardia immune response. First, they activate and stimulate the differentiation of B cells to generate Giardia-specific antibodies. Second, they act through a B-cell-independent mechanism that is probably mediated by Th17 cells. Several Giardia proteins that stimulate humoral and cellular immune responses have been described. Variant surface proteins, α-1 giardin, and cyst wall protein 2 can induce host protective responses to future Giardia challenges. The characterization and evaluation of the protective potential of the immunogenic proteins that are associated with Giardia will offer new insights into host-parasite interactions and may aid in the development of an effective vaccine against the parasite. © 2015 John Wiley & Sons Ltd.

  5. Small Intestine Early Innate Immunity Response during Intestinal Colonization by Escherichia coli Depends on Its Extra-Intestinal Virulence Status.

    Directory of Open Access Journals (Sweden)

    Jérôme Tourret

    Full Text Available Uropathogenic Escherichia coli (UPEC strains live as commensals in the digestive tract of the host, but they can also initiate urinary tract infections. The aim of this work was to determine how a host detects the presence of a new UPEC strain in the digestive tract. Mice were orally challenged with UPEC strains 536 and CFT073, non-pathogenic strain K12 MG1655, and ΔPAI-536, an isogenic mutant of strain 536 lacking all 7 pathogenicity islands whose virulence is drastically attenuated. Intestinal colonization was measured, and cytokine expression was determined in various organs recovered from mice after oral challenge. UPEC strain 536 efficiently colonized the mouse digestive tract, and prior Enterobacteriaceae colonization was found to impact strain 536 colonization efficiency. An innate immune response, detected as the production of TNFα, IL-6 and IL-10 cytokines, was activated in the ileum 48 hours after oral challenge with strain 536, and returned to baseline within 8 days, without a drop in fecal pathogen load. Although inflammation was detected in the ileum, histology was normal at the time of cytokine peak. Comparison of cytokine secretion 48h after oral gavage with E. coli strain 536, CFT073, MG1655 or ΔPAI-536 showed that inflammation was more pronounced with UPECs than with non-pathogenic or attenuated strains. Pathogenicity islands also seemed to be involved in host detection, as IL-6 intestinal secretion was increased after administration of E. coli strain 536, but not after administration of ΔPAI-536. In conclusion, UPEC colonization of the mouse digestive tract activates acute phase inflammatory cytokine secretion but does not trigger any pathological changes, illustrating the opportunistic nature of UPECs. This digestive tract colonization model will be useful for studying the factors controlling the switch from commensalism to pathogenicity.

  6. Small Intestine Early Innate Immunity Response during Intestinal Colonization by Escherichia coli Depends on Its Extra-Intestinal Virulence Status.

    Science.gov (United States)

    Tourret, Jérôme; Willing, Benjamin P; Croxen, Matthew A; Dufour, Nicolas; Dion, Sara; Wachtel, Sarah; Denamur, Erick; Finlay, B Brett

    2016-01-01

    Uropathogenic Escherichia coli (UPEC) strains live as commensals in the digestive tract of the host, but they can also initiate urinary tract infections. The aim of this work was to determine how a host detects the presence of a new UPEC strain in the digestive tract. Mice were orally challenged with UPEC strains 536 and CFT073, non-pathogenic strain K12 MG1655, and ΔPAI-536, an isogenic mutant of strain 536 lacking all 7 pathogenicity islands whose virulence is drastically attenuated. Intestinal colonization was measured, and cytokine expression was determined in various organs recovered from mice after oral challenge. UPEC strain 536 efficiently colonized the mouse digestive tract, and prior Enterobacteriaceae colonization was found to impact strain 536 colonization efficiency. An innate immune response, detected as the production of TNFα, IL-6 and IL-10 cytokines, was activated in the ileum 48 hours after oral challenge with strain 536, and returned to baseline within 8 days, without a drop in fecal pathogen load. Although inflammation was detected in the ileum, histology was normal at the time of cytokine peak. Comparison of cytokine secretion 48h after oral gavage with E. coli strain 536, CFT073, MG1655 or ΔPAI-536 showed that inflammation was more pronounced with UPECs than with non-pathogenic or attenuated strains. Pathogenicity islands also seemed to be involved in host detection, as IL-6 intestinal secretion was increased after administration of E. coli strain 536, but not after administration of ΔPAI-536. In conclusion, UPEC colonization of the mouse digestive tract activates acute phase inflammatory cytokine secretion but does not trigger any pathological changes, illustrating the opportunistic nature of UPECs. This digestive tract colonization model will be useful for studying the factors controlling the switch from commensalism to pathogenicity.

  7. Small intestinal transplantation.

    LENUS (Irish Health Repository)

    Quigley, E M

    2012-02-03

    The past few years have witnessed a considerable shift in the clinical status of intestinal transplantation. A great deal of experience has been gained at the most active centers, and results comparable with those reported at a similar stage in the development of other solid-organ graft programs are now being achieved by these highly proficient transplant teams. Rejection and its inevitable associate, sepsis, remain ubiquitous, and new immunosuppressant regimes are urgently needed; some may already be on the near horizon. The recent success of isolated intestinal grafts, together with the mortality and morbidity attendant upon the development of advanced liver disease related to total parenteral nutrition, has prompted the bold proposal that patients at risk for this complication should be identified and should receive isolated small bowel grafts before the onset of end-stage hepatic failure. The very fact that such a suggestion has begun to emerge reflects real progress in this challenging field.

  8. Autophagy and tight junction proteins in the intestine and intestinal diseases

    Directory of Open Access Journals (Sweden)

    Chien-An A. Hu

    2015-09-01

    Full Text Available The intestinal epithelium (IE forms an indispensible barrier and interface between the intestinal interstitium and the luminal environment. The IE regulates water, ion and nutrient transport while providing a barrier against toxins, pathogens (bacteria, fungi and virus and antigens. The apical intercellular tight junctions (TJ are responsible for the paracellular barrier function and regulate trans-epithelial flux of ions and solutes between adjacent cells. Increased intestinal permeability caused by defects in the IE TJ barrier is considered an important pathogenic factor for the development of intestinal inflammation, diarrhea and malnutrition in humans and animals. In fact, defects in the IE TJ barrier allow increased antigenic penetration, resulting in an amplified inflammatory response in inflammatory bowel disease (IBD, necrotizing enterocolitis and ischemia-reperfusion injury. Conversely, the beneficial enhancement of the intestinal TJ barrier has been shown to resolve intestinal inflammation and apoptosis in both animal models of IBD and human IBD. Autophagy (self-eating mechanism is an intracellular lysosome-dependent degradation and recycling pathway essential for cell survival and homeostasis. Dysregulated autophagy has been shown to be directly associated with many pathological processes, including IBD. Importantly, the crosstalk between IE TJ and autophagy has been revealed recently. We showed that autophagy enhanced IE TJ barrier function by increasing transepithelial resistance and reducing the paracellular permeability of small solutes and ions, which is, in part, by targeting claudin-2, a cation-selective, pore-forming, transmembrane TJ protein, for lysosome (autophagy-mediated degradation. Interestingly, previous studies have shown that the inflamed intestinal mucosa in patients with active IBD has increased claudin-2 expression. In addition, inflammatory cytokines (for example, tumor necrosis factor-α, interleukin-6

  9. Modulation of immune development and function by intestinal microbiota.

    Science.gov (United States)

    Kabat, Agnieszka M; Srinivasan, Naren; Maloy, Kevin J

    2014-11-01

    The immune system must constantly monitor the gastrointestinal tract for the presence of pathogens while tolerating trillions of commensal microbiota. It is clear that intestinal microbiota actively modulate the immune system to maintain a mutually beneficial relation, but the mechanisms that maintain homeostasis are not fully understood. Recent advances have begun to shed light on the cellular and molecular factors involved, revealing that a range of microbiota derivatives can influence host immune functions by targeting various cell types, including intestinal epithelial cells, mononuclear phagocytes, innate lymphoid cells, and B and T lymphocytes. Here, we review these findings, highlighting open questions and important challenges to overcome in translating this knowledge into new therapies for intestinal and systemic immune disorders. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Impact of diet on human intestinal microbiota and health.

    Science.gov (United States)

    Salonen, Anne; de Vos, Willem M

    2014-01-01

    Our intestinal microbiota is involved in the breakdown and bioconversion of dietary and host components that are not degraded and taken up by our own digestive system. The end products generated by our microbiota fuel our enterocytes and support growth but also have signaling functions that generate systemic immune and metabolic responses. Due to the immense metabolic capacity of the intestinal microbiota and its relatively high plasticity, there is great interest in identifying dietary approaches that allow intentional and predictable modulation of the microbiota. In this article, we review the current insights on dietary influence on the human intestinal microbiota based on recent high-throughput molecular studies and interconnections with health. We focus especially on the emerging data that identify the amount and type of dietary fat as significant modulators of the colonic microbiota and its metabolic output.

  11. Intestinal microbiota during early life - impact on health and disease.

    Science.gov (United States)

    Nylund, Lotta; Satokari, Reetta; Salminen, Seppo; de Vos, Willem M

    2014-11-01

    In the first years after birth, the intestinal microbiota develops rapidly both in diversity and complexity while being relatively stable in healthy adults. Different life-style-related factors as well as medical practices have an influence on the early-life intestinal colonisation. We address the impact of some of these factors on the consecutive microbiota development and later health. An overview is presented of the microbial colonisation steps and the role of the host in that process. Moreover, new early biomarkers are discussed with examples that include the association of microbiota and atopic diseases, the correlation of colic and early development and the impact of the use of antibiotics in early life. Our understanding of the development and function of the intestinal microbiota is constantly improving but the long-term influence of early-life microbiota on later life health deserves careful clinical studies.

  12. Diet-Intestinal Microbiota Axis in Osteoarthritis: A Possible Role.

    Science.gov (United States)

    Li, Yusheng; Luo, Wei; Deng, Zhenhan; Lei, Guanghua

    2016-01-01

    Intestinal microbiota is highly involved in host physiology and pathology through activity of the microbiome and its metabolic products. Osteoarthritis (OA) is a common form of arthritis characterized by articular cartilage destruction and osteophyte formation. Although various person-level risk factors, such as age, sex, and obesity, have been proposed for the pathogenesis of OA, the underlying links between these person-level factors and OA are still enigmatic. Based on the current understanding in the crosstalk between intestinal microbiota and these risk factors, intestinal microbiota could be considered as a major hidden risk factor that provides a unifying mechanism to explain the involvement of these person-level risk factors in OA.

  13. Diet-Intestinal Microbiota Axis in Osteoarthritis: A Possible Role

    Directory of Open Access Journals (Sweden)

    Yusheng Li

    2016-01-01

    Full Text Available Intestinal microbiota is highly involved in host physiology and pathology through activity of the microbiome and its metabolic products. Osteoarthritis (OA is a common form of arthritis characterized by articular cartilage destruction and osteophyte formation. Although various person-level risk factors, such as age, sex, and obesity, have been proposed for the pathogenesis of OA, the underlying links between these person-level factors and OA are still enigmatic. Based on the current understanding in the crosstalk between intestinal microbiota and these risk factors, intestinal microbiota could be considered as a major hidden risk factor that provides a unifying mechanism to explain the involvement of these person-level risk factors in OA.

  14. Salmonella - at home in the host cell.

    Directory of Open Access Journals (Sweden)

    Preeti eMalik Kale

    2011-06-01

    Full Text Available The Gram-negative bacterium Salmonella enterica has developed an array of sophisticated tools to manipulate the host cell and establish an intracellular niche, for successful propagation as a facultative intracellular pathogen. While Salmonella exerts diverse effects on its host cell, only the cell biology of the classic trigger-mediated invasion process and the subsequent development of the Salmonella-containing vacuole have been investigated extensively. These processes are dependent on cohorts of effector proteins translocated into host cells by two type III secretion systems (T3SS, although T3SS-independent mechanisms of entry may be important for invasion of certain host cell-types. Recent studies into the intracellular lifestyle of Salmonella have provided new insights into the mechanisms used by this pathogen to modulate its intracellular environment. Here we discuss current knowledge of Salmonella-host interactions including invasion and establishment of an intracellular niche within the host.

  15. Towards finding effective indicators (diarrhoea and anaemia scores and weight gains) for the implementation of targeted selective treatment against the gastro-intestinal nematodes in lambs in a steppic environment.

    Science.gov (United States)

    Bentounsi, B; Meradi, S; Cabaret, J

    2012-06-08

    The effective application of targeted selective treatment (TST) against gastro-intestinal nematodes depends on the accurate identification of those animals in need of anthelmintic treatment. Finding cost and labour effective measures to identify such animals is paramount. This study tested the efficacy of three indicators on lambs in a farm in Eastern Algeria: anaemia score (FAMACHA(©)), diarrhoea score (DISCO) and weight gain. These were contrasted against traditional parasitological infection measures (nematode eggs per gram of faeces: EPG). Thirty lambs were used in the study; every second month they were sampled (FAMACHA(©), faecal samples for EPG and DISCO, weight gains) and two of the original 30 lambs were necropsied for adult worm counts. The main gastro-intestinal nematodes were Teladorsagia circumcincta, Marshallagia marshalli, Nematodirus helvetianus, Trichostrongylus vitrinus, and Haemonchus contortus. DISCO proved to be the most effective indicator correctly identifying 80% of the sheep in need of treatment. This was followed by FAMACHA(©) with a 50% accuracy level and finally weight gains, which were not found to be a useful indicator at all. Copyright © 2012. Published by Elsevier B.V.

  16. A critical evaluation of bifidobacterial adhesion to the host tissue

    Directory of Open Access Journals (Sweden)

    Christina Westermann

    2016-08-01

    Full Text Available Bifidobacteria are common inhabitants of the human gastrointestinal tract that, despite a long history of research, have not shown any pathogenic potential whatsoever. By contrast, some bifidobacteria are associated with a number of health-related benefits for the host. The reported beneficial effects of bifidobacteria include competitive exclusion of pathogens, alleviation of symptoms of irritable bowel syndrome and inflammatory bowel disease, and modulation of intestinal and systemic immune responses. Based on these effects, bifidobacteria are widely used as probiotics by pharmaceutical and dairy industries. In order to exert a beneficial effect bifidobacteria have to, at least transiently, colonize the host in a sufficient population size. Besides other criteria such as resistance to manufacturing processes and intestinal transit, potential probiotic bacteria are tested for adhesion to the host structures including intestinal epithelial cells (IECs, mucus and extracellular matrix (ECM components. In the present review article, we summarize the current knowledge on bifidobacterial structures that mediate adhesion to host tissue and compare these to similar structures of pathogenic bacteria. This reveals that most of the adhesive structures and mechanisms involved in adhesion of bifidobacteria to host tissue are similar or even identical to those employed by pathogens to cause disease. It is thus reasonable to assume that these structures and mechanisms are equally important for commensal or probiotic bacteria and play a similar role in the beneficial effects exerted by bifidobacteria.

  17. Suppression of intestinal immunity through silencing of TCTP by RNAi in transgenic silkworm, Bombyx mori.

    Science.gov (United States)

    Hu, Cuimei; Wang, Fei; Ma, Sanyuan; Li, Xianyang; Song, Liang; Hua, Xiaoting; Xia, Qingyou

    2015-12-10

    Intestinal immune response is a front line of host defense. The host factors that participate in intestinal immunity response remain largely unknown. We recently reported that Translationally Controlled Tumor Protein (BmTCTP) was obtained by constructing a phage display cDNA library of the silkworm midgut and carrying out high throughput screening of pathogen binding molecules. To further address the function of BmTCTP in silkworm intestinal immunity, transgenic RNAi silkworms were constructed by microinjection piggBac plasmid to Dazao embryos. The antimicrobial capacity of transgenic silkworm decreased since the expression of gut antimicrobial peptide from transgenic silkworm was not sufficiently induced during oral microbial challenge. Moreover, dynamic ERK phosphorylation from transgenic silkworm midgut was disrupted. Taken together, the innate immunity of intestinal was suppressed through disruption of dynamic ERK phosphorylation after oral microbial infection as a result of RNAi-mediated knockdown of midgut TCTP in transgenic silkworm. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Crosstalk between the intestinal microbiota and the innate immune system in intestinal homeostasis and inflammatory bowel disease.

    Science.gov (United States)

    Dupaul-Chicoine, Jeremy; Dagenais, Maryse; Saleh, Maya

    2013-09-01

    : Inflammatory bowel diseases are a set of complex and chronic disorders that arise in genetically predisposed individuals due to a lack of tolerance to the gut microflora. Although the intestinal microbiota is required for the proper development of the host and the maintenance of intestinal homeostasis, its dysbiosis is associated with inflammatory bowel diseases pathogenesis. In this review, we focus the discussion on the crosstalk between the innate immune system and the microbiota. We examine new findings from genetic and functional studies investigating the critical role of the intestinal epithelial cell layer and the processes that maintain its integrity in health and disease. We further explore the mechanisms of the mucosal innate immune system including dendritic cells, macrophages, and innate-like lymphocytes in mediating immunological tolerance at the steady state or pathogenic inflammatory responses in inflammatory bowel diseases.

  19. Epidemiology of intestinal helminthiasis among school children with emphasis on Schistosoma mansoni infection in Wolaita zone, Southern Ethiopia

    Directory of Open Access Journals (Sweden)

    Bereket Alemayehu

    2017-06-01

    Full Text Available Abstract Background Intestinal helminth infections are major parasitic diseases causing public health problems in Ethiopia. Although the epidemiology of these infections are well documented in Ethiopia, new transmission foci for schistosomiasis are being reported in different parts of the country. The objective of this study was to assess the prevalence of Schistosoma mansoni and other intestinal helminth infections among school children and determine the endemicity of schistosomiasis in Wolaita Zone, southern Ethiopia. Methods Cross-sectional parasitological and malacological surveys were conducted by collecting stool samples for microscopic examination and snails for intermediate host identification. Stool samples were collected from 503 children and processed for microscopic examination using Kato-Katz and formalin-ether concentration methods. Snails collected from aquatic environments in the study area were identified to species level and Biomphalaria pfeifferi snails, the intermediate host of S. mansoni,, were individually exposed to artificial light in order to induce cercariae shedding. Cercariae shed from snails were used to infect laboratory-bred Swiss albino mice in order to identify the schistosome to species level. Results The overall prevalence of intestinal helminth infections was 72.2% among school children. S. mansoni infection prevalence was 58.6%. The prevalence and intensity of S. mansoni infections varied among schools and sex of children. Swimming was the only factor reported to be significantly associated with S. mansoni infection (AOR = 2.954, 95% CI:1.962-4.449. Other intestinal helminth species identified were hookworms (27.6%, Ascaris lumbricoides (8.7%, E. vermicularis (2.8%, Taenia species (2.6%, T. trichiura (1.2% and H. nana (0.6%. Only B. pfeifferi snails collected from streams shed schistosome cercariae and 792 adult S. mansoni worms were harvested from mice exposed to cercariae shed from B. pfeifferi on the 6th

  20. Epidemiology of intestinal helminthiasis among school children with emphasis on Schistosoma mansoni infection in Wolaita zone, Southern Ethiopia.

    Science.gov (United States)

    Alemayehu, Bereket; Tomass, Zewdneh; Wadilo, Fiseha; Leja, Dawit; Liang, Song; Erko, Berhanu

    2017-06-20

    Intestinal helminth infections are major parasitic diseases causing public health problems in Ethiopia. Although the epidemiology of these infections are well documented in Ethiopia, new transmission foci for schistosomiasis are being reported in different parts of the country. The objective of this study was to assess the prevalence of Schistosoma mansoni and other intestinal helminth infections among school children and determine the endemicity of schistosomiasis in Wolaita Zone, southern Ethiopia. Cross-sectional parasitological and malacological surveys were conducted by collecting stool samples for microscopic examination and snails for intermediate host identification. Stool samples were collected from 503 children and processed for microscopic examination using Kato-Katz and formalin-ether concentration methods. Snails collected from aquatic environments in the study area were identified to species level and Biomphalaria pfeifferi snails, the intermediate host of S. mansoni,, were individually exposed to artificial light in order to induce cercariae shedding. Cercariae shed from snails were used to infect laboratory-bred Swiss albino mice in order to identify the schistosome to species level. The overall prevalence of intestinal helminth infections was 72.2% among school children. S. mansoni infection prevalence was 58.6%. The prevalence and intensity of S. mansoni infections varied among schools and sex of children. Swimming was the only factor reported to be significantly associated with S. mansoni infection (AOR = 2.954, 95% CI:1.962-4.449). Other intestinal helminth species identified were hookworms (27.6%), Ascaris lumbricoides (8.7%), E. vermicularis (2.8%), Taenia species (2.6%), T. trichiura (1.2%) and H. nana (0.6%). Only B. pfeifferi snails collected from streams shed schistosome cercariae and 792 adult S. mansoni worms were harvested from mice exposed to cercariae shed from B. pfeifferi on the 6th week post-exposure. The present study found high

  1. Microbiota-mediated colonization resistance against intestinal pathogens

    Science.gov (United States)

    Buffie, Charlie G.; Pamer, Eric G.

    2014-01-01

    Commensal bacteria inhabit mucosal and epidermal surfaces in mice and humans, and have effects on metabolic and immune pathways in their hosts. Recent studies indicate that the commensal microbiota can be manipulated to prevent and even to cure infections that are caused by pathogenic bacteria, particularly pathogens that are broadly resistant to antibiotics, such as vancomycin-resistant Enterococcus faecium, Gram-negative Enterobacteriaceae and Clostridium difficile. In this Review, we discuss how immune- mediated colonization resistance against antibiotic-resistant intestinal pathogens is influenced by the composition of the commensal microbiota. We also review recent advances characterizing the ability of different commensal bacterial families, genera and species to restore colonization resistance to intestinal pathogens in antibiotic-treated hosts. PMID:24096337

  2. Amniotic fluid and development of the immature intestine

    DEFF Research Database (Denmark)

    Østergaard, Mette Viberg

    the second hypothesis: “The expression of innate host defense genes and the inflammatory responses of the newborn pig intestine are associated with gestational ages of high susceptibility to NEC in preterm pigs”. Accordingly, the aim was to analyze the expression of host defense genes involved in barrier......) – to remain constant with an incidence of ~1 in 1000 live births. Nutritional interventions and feeding strategies are central for the critical care of preterm infants in general, and for the prevention and management of NEC in particular, and include parenteral nutrition (PN), minimal enteral nutrition (MEN...... gastrointestinal structure and function in preterm pigs”. Accordingly, the aim was to test the effects of enteral administration of AF as MEN during PN, as a supplement to a suboptimal enteral diet, or both in a preterm pig model of NEC. To evaluate the effects of AF, NEC sensitivity, intestinal digestive...

  3. Effects of bacterial colonization on the porcine intestinal proteome

    DEFF Research Database (Denmark)

    Danielsen, Marianne; Hornshøj, Henrik; Siggers, Richard H

    2007-01-01

    The gastrointestinal tract harbors a complex community of bacteria, of which many may be beneficial. Studies of germ-free animal models have shown that the gastrointestinal microbiota not only assists in making nutrients available for the host but also contributes to intestinal health and develop......The gastrointestinal tract harbors a complex community of bacteria, of which many may be beneficial. Studies of germ-free animal models have shown that the gastrointestinal microbiota not only assists in making nutrients available for the host but also contributes to intestinal health...... comparison of 12 animals. Our results showed that bacterial colonization differentially affected mechanisms such as proteolysis, epithelial proliferation, and lipid metabolism, which is in good agreement with previous studies of other germ-free animal models. We have also found that E. coli has a profound...

  4. Host-to-Host Transmission of the Pneumococcus-New Victims of a Toxic Relationship.

    Science.gov (United States)

    Trappetti, Claudia; Paton, James C

    2017-01-11

    Host-to-host transmission is critical for survival of the human-adapted bacterium Streptococcus pneumoniae. In this issue of Cell Host & Microbe, Zafar et al. (2017) show that transmission is dependent on nasopharyngeal inflammation elicited by the toxin pneumolysin, causing increased shedding and enhanced survival of the bacterium in the environment. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Genetic Factors in Animal Models of Intestinal Inflammation

    Directory of Open Access Journals (Sweden)

    R Balfour Sartor

    1995-01-01

    Full Text Available The critical importance of host genetic susceptibility in determining chronicity, aggressiveness and complications of intestinal inflammation is clearly demonstrated by studies of inbred rodents, transgenic rats and spontaneous mutants. Inbred Lewis rats challenged by purified bacterial cell wall polymers, indomethacin or small bowel bacterial overgrowth develop chronic granulomatous intestinal inflammation with fibrosis and extraintestinal manifestations, whereas Fischer (major histocompatibility complex identical to Lewis and Buffalo rats identically stimulated demonstrate only self-limited enterocolitis with no chronic inflammation, fibrosis, granulomas or extraintestinal inflammation. Similar differential patterns of intestinal inflammation are apparent in inbred mouse strains challenged with trinitrobenzene-sulphonic acid, Citrobacter freundii or backcrossed with T cell receptor deficient (knockout mice. The dominant role of genetic background in induction of intestinal inflammation is further documented by spontaneous colitis which develops in spontaneously mutant mice, cotton-top tamarins, human leukocyte antigen-B27/ β2 microglobulin transgenic rats and mice with targeted deletions of certain immunoregulatory cytokine and T lymphocyte genes. Identification of the immunological mechanisms of host genetic susceptibility and the genetic basis of spontaneous colitis should provide new insights into the pathogenesis of human inflammatory bowel disease.

  6. Contribution of microbiota to the intestinal physicochemical barrier.

    Science.gov (United States)

    Malago, J J

    2015-01-01

    The large number of intestinal microorganisms, which exceeds the total number of human cells by ten folds, alludes to a significant contribution to human health. This is vivid in enteric and some systemic diseases emanating from disruption of the microbiota. As life style keeps shifting towards disruption of the microbiota in most societies worldwide, interest in the contribution of the microbiota to gut health has grown enormously. Many studies have been conducted to elucidate the exact contribution of the microbiota to human health. The knowledge gained from these studies indicates that the microbiota interacts with the intestinal milieu to maintain gut health. In this review, the crosstalk of microbiota with the intestinal physicochemical barrier pivotal to the gut innate immunity is highlighted. In particular, the review focuses on the role of the microbiota on competitive exclusion of pathogens, intestinal pH, epithelial mechanical barrier integrity, apical actin cytoskeleton, antimicrobial peptides, and the mucus layer. Understanding this microbe-host relationship will provide useful insight into overcoming some diseases related to the disruption of the host microbiota.

  7. Dietary Additive Probiotics Modulation of the Intestinal Microbiota.

    Science.gov (United States)

    Hu, Shenglan; Wang, Li; Jiang, Zongyong

    2017-01-01

    The importance of the intestinal microbiota of animals is widely acknowledged because of its vital role in the health of animals. There are complex communities of microbiota, which colonize the gastrointestinal tract. Intestinal microbiota are conductive to animal health and the development of the host immune system. Probiotics are commonly used dietary additives where they provide the host with many beneficial functions, such as modulating intestinal homeostasis and promoting gut health. These beneficial effects of probiotics may accrue from the inhibiting the growth of pathogenic bacteria and promoting the growth of beneficial flora in the gastrointestinal tract. Probiotics colonization and its impact on gut microbiota members are highly species specific. Different probiotics have been shown to have dramatically different capacities of modulation physiological function. This review summarizes existing studies of the influence of dietary additive probiotics on the gut microbiota in different animals, such as humans, mice, pigs and chickens, to clarify the contribution of different kinds of probiotics to the intestinal microbiota. Moreover, the probable mechanism for the benefits of dietary supplementation with probiotics will be discussed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  8. Examining the Link between Biofilm Formation and the Ability of Pathogenic Salmonella Strains to Colonize Multiple Host Species

    Science.gov (United States)

    MacKenzie, Keith D.; Palmer, Melissa B.; Köster, Wolfgang L.; White, Aaron P.

    2017-01-01

    Salmonella are important pathogens worldwide and a predominant number of human infections are zoonotic in nature. The ability of strains to form biofilms, which is a multicellular behavior characterized by the aggregation of cells, is predicted to be a conserved strategy for increased persistence and survival. It may also contribute to the increasing number of infections caused by ingestion of contaminated fruits and vegetables. There is a correlation between biofilm formation and the ability of strains to colonize and replicate within the intestines of multiple host species. These strains predominantly cause localized gastroenteritis infections in humans. In contrast, there are salmonellae that cause systemic, disseminated infections in a select few host species; these “invasive” strains have a narrowed host range, and most are unable to form biofilms. This includes host-restricted Salmonella serovar Typhi, which are only able to infect humans, and atypical gastroenteritis strains associated with the opportunistic infection of immunocompromised patients. From the perspective of transmission, biofilm formation is advantageous for ensuring pathogen survival in the environment. However, from an infection point of view, biofilm formation may be an anti-virulence trait. We do not know if the capacity to form biofilms prevents a strain from accessing the systemic compartments within the host or if loss of the biofilm phenotype reflects a change in a strain’s interaction with the host. In this review, we examine the connections between biofilm formation, Salmonella disease states, degrees of host adaptation, and how this might relate to different transmission patterns. A better understanding of the dynamic lifecycle of Salmonella will allow us to reduce the burden of livestock and human infections caused by these important pathogens. PMID:29159172

  9. Biodegradable intestinal stents: A review

    Directory of Open Access Journals (Sweden)

    Zhanhui Wang

    2014-10-01

    Full Text Available Biodegradable stents are an attractive alternative to self-expanding metal stents in the treatment of intestinal strictures. Biodegradable stent can be made of biodegradable polymers and biodegradable metals (magnesium alloys. An overview on current biodegradable intestinal stents is presented. The future trends and perspectives in the development of biodegradable intestinal stents are proposed. For the biodegradable polymer intestinal stents, the clinical trials have shown promising results, although improved design of stents and reduced migration rate are expected. For the biodegradable magnesium intestinal stents, results of preliminary studies indicate magnesium alloys to have good biocompatibility. With many of the key fundamental and practical issues resolved and better methods for adjusting corrosion resistance and progressing biocompatibilities of magnesium alloys, it is possible to use biodegradable intestinal stents made of magnesium alloys in hospital in the not too distant future.

  10. On the Equivalence of Host Local Adaptation and Parasite Maladaptation: An Experimental Test

    OpenAIRE

    Lemoine Melissa; Doligez Blandine; Richner Heinz

    2012-01-01

    In spatiotemporally varying environments host parasite coevolution may lead to either host or parasite local adaptation. Using reciprocal infestations over 11 pairs of plots we tested local adaptation in the hen flea and its main host the great tit. Flea reproductive success (number of adults at host fledging) was lower on host individuals from the same plot compared with foreign hosts (from another plot) revealing flea local maladaptation. Host reproductive success (number of fledged young) ...

  11. Prokaryotes versus Eukaryotes: Who is hosting whom?

    Directory of Open Access Journals (Sweden)

    Guillermo eTellez

    2014-10-01

    Full Text Available Microorganisms represent the largest component of biodiversity in our world. For millions of years, prokaryotic microorganisms have functioned as a major selective force shaping eukaryotic evolution. Microbes that live inside and on animals outnumber the animals’ actual somatic and germ cells by an estimated 10-fold. Collectively, the intestinal microbiome represents a ‘forgotten organ’, functioning as an organ inside another that can execute many physiological responsibilities. The nature of primitive eukaryotes was drastically changed due to the association with symbiotic prokaryotes facilitating mutual coevolution of host and microbe. Phytophagous insects have long been used to test theories of evolutionary diversification; moreover, the diversification of a number of phytophagous insect lineages has been linked to mutualisms with microbes. From termites and honey bees to ruminants and mammals, depending on novel biochemistries provided by the prokaryotic microbiome, the association helps to metabolize several nutrients that the host cannot digest and converting these into useful end products (such as short chain fatty acids, a process which has huge impact on the biology and homeostasis of metazoans. More importantly, in a direct and/or indirect way, the intestinal microbiota influences the assembly of gut-associated lymphoid tissue, helps to educate immune system, affects the integrity of the intestinal mucosal barrier, modulates proliferation and differentiation of its epithelial lineages, regulates angiogenesis, and modifies the activity of enteric as well as the central nervous system,. Despite these important effects, the mechanisms by which the gut microbial community influences the host’s biology remains almost entirely unknown. Our aim here is to encourage empirical inquiry into the relationship between mutualism and evolutionary diversification between prokaryotes and eukaryotes which encourage us to postulate: Who is

  12. Fatty Acid Synthase Modulates Intestinal Barrier Function through Palmitoylation of Mucin 2

    OpenAIRE

    Wei, Xiaochao; Yang, Zhen; Rey, Federico E.; Ridaura, Vanessa K.; Davidson, Nicholas O.; Gordon, Jeffrey I.; Semenkovich, Clay F.

    2012-01-01

    The intestinal mucus barrier prevents pathogen invasion and maintains host-microbiota homeostasis. We show that fatty acid synthase (FAS), an insulin-responsive enzyme essential for de novo lipogenesis, helps maintain the mucus barrier by regulating Mucin 2, the dominant mucin in the colon and a central component of mucus. Inducible Cre recombinase-directed inactivation of the FAS gene in the colonic epithelium of mice is associated with disruptions in the intestinal mucus barrier as well as ...

  13. The Role of Hyaluronan in Innate Defense Responses of the Intestine

    Directory of Open Access Journals (Sweden)

    Carol A. de la Motte

    2015-01-01

    Full Text Available Hyaluronan is an abundant extracellular matrix component prevalent in the vertebrate intestinal tract. Here we discuss what is known about hyaluronan distribution during homeostasis and inflammatory diseases of the gut and discuss ways in which this glycosaminoglycan can participate in regulating innate host defense mechanisms. These natural responses include mechanisms promoting rapid leukocyte recruitment after bacterial challenge/colon tissue damage as well as promoting epithelial defense mechanisms in the intestine.

  14. Intestinal microbiota; relevance to obesity and modulation by prebiotics and probiotics

    OpenAIRE

    Sandra Tavares da Silva; Carolina Araújo dos Santos; Josefina Bressan

    2013-01-01

    Introduction: The intestinal microbiota has several beneficial functions related to host health. Studies suggest that it may be related to the presence of metabolic diseases, including obesity. Objective: A bibliographic survey was carried out upon the relationship between the intestinal microbiota and obesity and the possible impacts of the use of prebiotics and probiotics, aiming to understand this complex and promising interaction. Methods: A search was conducted in the Lilacs, PubMed, Sci...

  15. Intestinal microbiota in functional bowel disorders: a Rome foundation report

    OpenAIRE

    Simr?n, Magnus; Barbara, Giovanni; Flint, Harry J; Spiegel, Brennan M R; Spiller, Robin C; Vanner, Stephen; Verdu, Elena F; Whorwell, Peter J; Zoetendal, Erwin G

    2012-01-01

    It is increasingly perceived that gut host?microbial interactions are important elements in the pathogenesis of functional gastrointestinal disorders (FGID). The most convincing evidence to date is the finding that functional dyspepsia and irritable bowel syndrome (IBS) may develop in predisposed individuals following a bout of infectious gastroenteritis. There has been a great deal of interest in the potential clinical and therapeutic implications of small intestinal bacterial overgrowth in ...

  16. Effects of Host Phylogeny and Habitats on Gut Microbiomes of Oriental River Prawn (Macrobrachium nipponense.

    Directory of Open Access Journals (Sweden)

    Tzong-Der Tzeng

    Full Text Available The gut microbial community is one of the richest and most complex ecosystems on earth, and the intestinal microbes play an important role in host development and health. Next generation sequencing approaches, which rapidly produce millions of short reads that enable the investigation on a culture independent basis, are now popular for exploring microbial community. Currently, the gut microbiome in fresh water shrimp is unexplored. To explore gut microbiomes of the oriental river prawn (Macrobrachium nipponense and investigate the effects of host genetics and habitats on the microbial composition, 454 pyrosequencing based on the 16S rRNA gene were performed. We collected six groups of samples, including M. nipponense shrimp from two populations, rivers and lakes, and one sister species (M. asperulum as an out group. We found that Proteobacteria is the major phylum in oriental river prawn, followed by Firmicutes and Actinobacteria. Compositional analysis showed microbial divergence between the two shrimp species is higher than that between the two populations of one shrimp species collected from river and lake. Hierarchical clustering also showed that host genetics had a greater impact on the divergence of gut microbiome than host habitats. This finding was also congruent with the functional prediction from the metagenomic data implying that the two shrimp species still shared the same type of biological functions, reflecting a similar metabolic profile in their gut environments. In conclusion, this study provides the first investigation of the gut microbiome of fresh water shrimp, and supports the hypothesis of host species-specific signatures of bacterial community composition.

  17. Temperature alters host genotype-specific susceptibility to chytrid infection

    NARCIS (Netherlands)

    Gsell, A.S.; De Senerpont Domis, L.N.; Van Donk, E.; Ibelings, B.W.

    2013-01-01

    The cost of parasitism often depends on environmental conditions and host identity. Therefore, variation in the biotic and abiotic environment can have repercussions on both, species-level host-parasite interaction patterns but also on host genotype-specific susceptibility to disease. We exposed

  18. Functional metagenomics to decipher food-microbe-host crosstalk.

    Science.gov (United States)

    Larraufie, Pierre; de Wouters, Tomas; Potocki-Veronese, Gabrielle; Blottière, Hervé M; Doré, Joël

    2015-02-01

    The recent developments of metagenomics permit an extremely high-resolution molecular scan of the intestinal microbiota giving new insights and opening perspectives for clinical applications. Beyond the unprecedented vision of the intestinal microbiota given by large-scale quantitative metagenomics studies, such as the EU MetaHIT project, functional metagenomics tools allow the exploration of fine interactions between food constituents, microbiota and host, leading to the identification of signals and intimate mechanisms of crosstalk, especially between bacteria and human cells. Cloning of large genome fragments, either from complex intestinal communities or from selected bacteria, allows the screening of these biological resources for bioactivity towards complex plant polymers or functional food such as prebiotics. This permitted identification of novel carbohydrate-active enzyme families involved in dietary fibre and host glycan breakdown, and highlighted unsuspected bacterial players at the top of the intestinal microbial food chain. Similarly, exposure of fractions from genomic and metagenomic clones onto human cells engineered with reporter systems to track modulation of immune response, cell proliferation or cell metabolism has allowed the identification of bioactive clones modulating key cell signalling pathways or the induction of specific genes. This opens the possibility to decipher mechanisms by which commensal bacteria or candidate probiotics can modulate the activity of cells in the intestinal epithelium or even in distal organs such as the liver, adipose tissue or the brain. Hence, in spite of our inability to culture many of the dominant microbes of the human intestine, functional metagenomics open a new window for the exploration of food-microbe-host crosstalk.

  19. Alterations of intestinal barrier and microbiota in chronic kidney disease.

    Science.gov (United States)

    Sabatino, Alice; Regolisti, Giuseppe; Brusasco, Irene; Cabassi, Aderville; Morabito, Santo; Fiaccadori, Enrico

    2015-06-01

    Recent studies have highlighted the close relationship between the kidney and the gastrointestinal (GI) tract--frequently referred to as the kidney--gut axis--in patients with chronic kidney disease (CKD). In this regard, two important pathophysiological concepts have evolved: (i) production and accumulation of toxic end-products derived from increased bacterial fermentation of protein and other nitrogen-containing substances in the GI tract, (ii) translocation of endotoxins and live bacteria from gut lumen into the bloodstream, due to damage of the intestinal epithelial barrier and quantitative/qualitative alterations of the intestinal microbiota associated with the uraemic milieu. In both cases, these gut-centred alterations may have relevant systemic consequences in CKD patients, since they are able to trigger chronic inflammation, increase cardiovascular risk and worsen uraemic toxicity. The present review is thus focused on the kidney-gut axis in CKD, with special attention to the alterations of the intestinal barrier and the local microbiota (i.e. the collection of microorganisms living in a symbiotic coexistence with their host in the intestinal lumen) and their relationships to inflammation and uraemic toxicity in CKD. Moreover, we will summarize the most important clinical data suggesting the potential for nutritional modulation of gut-related inflammation and intestinal production of noxious by-products contributing to uraemic toxicity in CKD patients. © The Author 2014. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

  20. The Intestinal Microbiota in the Irritable Bowel Syndrome.

    Science.gov (United States)

    Collins, S M

    2016-01-01

    The irritable bowel syndrome (IBS) is a chronic abdominal symptom complex occurring in a bowel devoid of discernible relevant pathology. There is growing interest in the role of the intestinal microbiota as a basis for the intestinal and possibly behavioral manifestations of this condition. Molecular-based microbial profiling has revealed compositional changes in the microbiota of at least a subset of IBS patients but the data are often conflicting and no microbial signature for this condition has yet been defined. Animal studies in which a previously stable intestinal microbiota is perturbed, by antibiotics or dietary change, results in alterations in intestinal function reminiscent of that seen in IBS patients. These include visceral sensitivity to painful stimuli, altered motility and intestinal barrier function as well as immune activation, and low-grade inflammation. More recent studies have shown that perturbation of the microbial composition of the gut alters brain chemistry and behavior. In a step toward establishing a causal link between an altar microbiota and gut-brain manifestations of IBS, colonization of germ-free mice with microbiota from IBS patients results in an IBS-like phenotype, including alterations and behavior if the donor exhibited psychiatric comorbidity, such as high levels of anxiety. This model provides an opportunity for exploring the mechanisms underlying host-microbe interactions relevant to the pathogenesis of IBS and for developing novel therapeutic targets. © 2016 Elsevier Inc. All rights reserved.

  1. The role of intestinal microbiota and the immune system.

    Science.gov (United States)

    Purchiaroni, F; Tortora, A; Gabrielli, M; Bertucci, F; Gigante, G; Ianiro, G; Ojetti, V; Scarpellini, E; Gasbarrini, A

    2013-02-01

    The human gut is an ecosystem consisting of a great number of commensal bacteria living in symbiosis with the host. Several data confirm that gut microbiota is engaged in a dynamic interaction with the intestinal innate and adaptive immune system, affecting different aspects of its development and function. To review the immunological functions of gut microbiota and improve knowledge of its therapeutic implications for several intestinal and extra-intestinal diseases associated to dysregulation of the immune system. Significant articles were identified by literature search and selected based on content, including atopic diseases, inflammatory bowel diseases and treatment of these conditions with probiotics. Accumulating evidence indicates that intestinal microflora has protective, metabolic, trophic and immunological functions and is able to establish a "cross-talk" with the immune component of mucosal immunity, comprising cellular and soluble elements. When one or more steps in this fine interaction fail, autoimmune or auto-inflammatory diseases may occur. Furthermore, it results from the data that probiotics, used for the treatment of the diseases caused by the dysregulation of the immune system, can have a beneficial effect by different mechanisms. Gut microbiota interacts with both innate and adaptive immune system, playing a pivotal role in maintenance and disruption of gut immune quiescence. A cross talk between the mucosal immune system and endogenous microflora favours a mutual growth, survival and inflammatory control of the intestinal ecosystem. Based on these evidences, probiotics can be used as an ecological therapy in the treatment of immune diseases.  

  2. Role of intestinal flora imbalance in pathogenesis of pouchitis.

    Science.gov (United States)

    Feng, Xiao-Bo; Jiang, Jun; Li, Min; Wang, Gang; You, Jin-Wei; Zuo, Jian

    2016-08-01

    To discuss the role of intestinal flora imbalance in the pathogenesis of pouchitis. The pouchitis rat model was established and the faeces sample and the mucous membrane sample were collected regularly, in which the bacterial nucleic acids were extracted for quantitative analysis of the intestinal flora in the samples through using the real-time quantitative PCR technique and high energy sequencing technology. The disorder phenomenon of the intestinal flora appeared at the 7th day of the experiment, and the pouchitis was presented at the 21st day of the experiment. At the 31st day of the experiment, compared to control group and non-pouchitis group, the quantity of Bifidobacterium and the Lactobacillus of the pouchitis model rats in the mucous membrane sample and the faeces sample were significantly decreased (P flora in the mucous membrane of pouchitis, the bacterial diversity of non-pouchitis group and control group was significantly higher than that of the pouchitis group (P intestinal flora imbalance is one of the factors that cause the incidence of the pouchitis; this study provides a clue of the pathogenesis and treatment direction of the intestinal inflammatory disease. Copyright © 2016 Hainan Medical College. Production and hosting by Elsevier B.V. All rights reserved.

  3. Persistence and spread of gastro-intestinal infections: the case of enterotoxigenic Escherichia coli in piglets.

    Science.gov (United States)

    Boldin, Barbara

    2008-10-01

    Several gastro-intestinal infections in animal husbandry not only greatly reduce the well-being of animals, but also have the potential to cause large economical damage. Understanding of the dynamics of such diseases is thus of great importance. In this paper, we focus on within-host dynamics and present a model describing the dynamics of pathogens in the intestine of a single host. Our motivation to study the problem stems from the case of enterotoxigenic Escherichia coli in newly weaned piglets, but the models we present offer an acceptable description of within-host dynamics of several other gastro-intestinal infections. We begin by studying the case where infection is a one-time event and derive an explicit expression for the distribution of pathogens inside the intestine at an arbitrary time after the infection took place. Since farm animals often come into contact with faeces, we furthermore investigate the reinfection case, in which a fraction of the shed pathogens is reintroduced into the intestine. We find the condition that guarantees persistence of colonization in the reinfection case and determine when the microbial distribution in the intestine obeys the so called asynchronous exponential growth. We outline possibilities for infection control and point out some challenges for further research on the subject.

  4. [Experimental substantiation of the functional relationship of mineral elements of nutrition with intestinal mucus and the mucosa membrane of the intestine].

    Science.gov (United States)

    Ivanov, A A; Poliakova, E P; Ksenofontov, D A; Ksenofontova, A A

    2013-01-01

    Interaction of magnesium increased dietary level with enteral calcium metabolism through the gut wall and intestinal mucosa mechanism is described in ruminants. Magnesium excess was found in the endogenous fraction of chyme and in the intestinal mucosa and resulted in increased calcium concentration in these biological tissues. Magnesium itself did not penetrate into the internal gut environment, and calcium content in the organs and tissues was reduced. It is concluded that the interaction of minerals takes place in the gut prior to absorption, and that the intestinal mucosa is important for homeostatic balance of minerals in the digesta and in the internal body environment.

  5. Intestinal microbiota and type 2 diabetes: From mechanism insights to therapeutic perspective

    OpenAIRE

    Han, Jun-Ling; Lin, Hui-Ling

    2014-01-01

    The incidence of type 2 diabetes (T2DM) is rapidly increasing worldwide. However, the pathogenesis of T2DM has not yet been well explained. Recent evidence suggests that the intestinal microbiota composition is associated with obesity and T2DM. In this review, we provide an overview about the mechanisms underlying the role of intestinal microbiota in the pathogenesis of T2DM. There is clear evidence that the intestinal microbiota influences the host through its effect on body weight, bile aci...

  6. Non-lytic, actin-based exit of intracellular parasites from C. elegans intestinal cells.

    Directory of Open Access Journals (Sweden)

    Kathleen A Estes

    2011-09-01

    Full Text Available The intestine is a common site for invasion by intracellular pathogens, but little is known about how pathogens restructure and exit intestinal cells in vivo. The natural microsporidian parasite N. parisii invades intestinal cells of the nematode C. elegans, progresses through its life cycle, and then exits cells in a transmissible spore form. Here we show that N. parisii causes rearrangements of host actin inside intestinal cells as part of a novel parasite exit strategy. First, we show that N. parisii infection causes ectopic localization of the normally apical-restricted actin to the basolateral side of intestinal cells, where it often forms network-like structures. Soon after this actin relocalization, we find that gaps appear in the terminal web, a conserved cytoskeletal structure that could present a barrier to exit. Reducing actin expression creates terminal web gaps in the absence of infection, suggesting that infection-induced actin relocalization triggers gap formation. We show that terminal web gaps form at a distinct stage of infection, precisely timed to precede spore exit, and that all contagious animals exhibit gaps. Interestingly, we find that while perturbations in actin can create these gaps, actin is not required for infection progression or spore formation, but actin is required for spore exit. Finally, we show that despite large numbers of spores exiting intestinal cells, this exit does not cause cell lysis. These results provide insight into parasite manipulation of the host cytoskeleton and non-lytic escape from intestinal cells in vivo.

  7. Host allometry influences the evolution of parasite host-generalism: theory and meta-analysis.

    Science.gov (United States)

    Walker, Josephine G; Hurford, Amy; Cable, Jo; Ellison, Amy R; Price, Stephen J; Cressler, Clayton E

    2017-05-05

    Parasites vary widely in the diversity of hosts they infect: some parasite species are specialists-infecting just a single host species, while others are generalists, capable of infecting many. Understanding the factors that drive parasite host-generalism is of basic biological interest, but also directly relevant to predicting disease emergence in new host species, identifying parasites that are likely to have unidentified additional hosts, and assessing transmission risk. Here, we use mathematical models to investigate how variation in host body size and environmental temperature affect the evolution of parasite host-generalism. We predict that parasites are more likely to evolve a generalist strategy when hosts are large-bodied, when variation in host body size is large, and in cooler environments. We then explore these predictions using a newly updated database of over 20 000 fish-macroparasite associations. Within the database we see some evidence supporting these predictions, but also highlight mismatches between theory and data. By combining these two approaches, we establish a theoretical basis for interpreting empirical data on parasites' host specificity and identify key areas for future work that will help untangle the drivers of parasite host-generalism.This article is part of the themed issue 'Opening the black box: re-examining the ecology and evolution of parasite transmission'. © 2017 The Authors.

  8. Cytokines and intestinal inflammation.

    Science.gov (United States)

    Bamias, Giorgos; Cominelli, Fabio

    2016-11-01

    Cytokines of the intestinal microenvironment largely dictate immunological responses after mucosal insults and the dominance of homeostatic or proinflammatory pathways. This review presents important recent studies on the role of specific cytokines in the pathogenesis of intestinal inflammation. The particular mucosal effects of cytokines depend on their inherent properties but also the cellular origin, type of stimulatory antigens, intermolecular interactions, and the particular immunological milieu. Novel cytokines of the interleukin-1 (IL-1) family, including IL-33 and IL-36, have dominant roles in mucosal immunity, whereas more established ones such as IL-18 are constantly enriched with unique properties. Th17 cells are important mucosal constituents, although their profound plasticity, makes the specific set of cytokines they secrete more important than their mere numbers. Finally, various cytokines, such as tumor necrosis factor-α, IL-6, tumor necrosis factor-like cytokine 1A, and death receptor, 3 demonstrate dichotomous roles with mucosa-protective function in acute injury but proinflammatory effects during chronic inflammation. The role of cytokines in mucosal health and disease is increasingly revealed. Such information not only will advance our understanding of the pathogenesis of gut inflammation, but also set the background for development of reliable diagnostic and prognostic biomarkers and cytokine-specific therapies.

  9. Biosignatures of Pathogen and Host

    Energy Technology Data Exchange (ETDEWEB)

    Fitch, J P; Chromy, B A; Forde, C E; Garcia, E; Gardner, S N; Gu, P P; Kuczmarksi, T A; Melius, C F; McCutchen-Maloney, S L; Milanovich, F P; Motin, V L; Ott, L L; Quong, A A; Quong, J N; Rocco, J M; Slezak, T R; Sokhansanj, B A; Vitalis, E A; Zemla, A T; McCready, P M

    2002-08-27

    In information theory, a signature is characterized by the information content as well as noise statistics of the communication channel. Biosignatures have analogous properties. A biosignature can be associated with a particular attribute of a pathogen or a host. However, the signature may be lost in backgrounds of similar or even identical signals from other sources. In this paper, we highlight statistical and signal processing challenges associated with identifying good biosignatures for pathogens in host and other environments. In some cases it may be possible to identify useful signatures of pathogens through indirect but amplified signals from the host. Discovery of these signatures requires new approaches to modeling and data interpretation. For environmental biosignal collections, it is possible to use signal processing techniques from other applications (e.g., synthetic aperture radar) to track the natural progression of microbes over large areas. We also present a computer-assisted approach to identify unique nucleic-acid based microbial signatures. Finally, an understanding of host-pathogen interactions will result in better detectors as well as opportunities in vaccines and therapeutics.

  10. MDCT in blunt intestinal trauma

    Energy Technology Data Exchange (ETDEWEB)

    Romano, Stefania [Department of Diagnostic Imaging, ' A.Cardarelli' Hospital, 80131 Naples (Italy)]. E-mail: stefromano@libero.it; Scaglione, Mariano [Department of Diagnostic Imaging, ' A.Cardarelli' Hospital, 80131 Naples (Italy); Tortora, Giovanni [Department of Diagnostic Imaging, ' A.Cardarelli' Hospital, 80131 Naples (Italy); Martino, Antonio [Trauma Center, ' A.Cardarelli' Hospital, 80131 Naples (Italy); Di Pietto, Francesco [Department of Diagnostic Imaging, ' A.Cardarelli' Hospital, 80131 Naples (Italy); Romano, Luigia [Department of Diagnostic Imaging, ' A.Cardarelli' Hospital, 80131 Naples (Italy); Grassi, Roberto [Department ' Magrassi-Lanzara' , Section of Radiology, Second University of Naples, 80138 Naples (Italy)

    2006-09-15

    Injuries to the small and large intestine from blunt trauma represent a defined clinical entity, often not easy to correctly diagnose in emergency but extremely important for the therapeutic assessment of patients. This article summarizes the MDCT spectrum of findings in intestinal blunt lesions, from functional disorders to hemorrhage and perforation.

  11. Intestinal Failure (Short Bowel Syndrome)

    Science.gov (United States)

    ... or bile How is intestinal failure treated? The diet needs to be adjusted according to the intestine’s ability to absorb nutrients. TPN is usually required at the beginning to maintain nutrition and good hydration although it is hoped that the small intestine ...

  12. Hippo signalling directs intestinal fate

    DEFF Research Database (Denmark)

    le Bouteiller, Marie Catherine M; Jensen, Kim Bak

    2015-01-01

    Hippo signalling has been associated with many important tissue functions including the regulation of organ size. In the intestinal epithelium differing functions have been proposed for the effectors of Hippo signalling, YAP and TAZ1. These are now shown to have a dual role in the intestinal epit...

  13. The regulation of host defences to infection by the microbiota.

    Science.gov (United States)

    Brown, Rebecca L; Clarke, Thomas B

    2017-01-01

    The skin and mucosal epithelia of humans and other mammals are permanently colonized by large microbial communities (the microbiota). Due to this life-long association with the microbiota, these microbes have an extensive influence over the physiology of their host organism. It is now becoming apparent that nearly all tissues and organ systems, whether in direct contact with the microbiota or in deeper host sites, are under microbial influence. The immune system is perhaps the most profoundly affected, with the microbiota programming both its innate and adaptive arms. The regulation of immunity by the microbiota helps to protect the host against intestinal and extra-intestinal infection by many classes of pathogen. In this review, we will discuss the experimental evidence supporting a role for the microbiota in regulating host defences to extra-intestinal infection, draw together common mechanistic themes, including the central role of pattern recognition receptors, and outline outstanding questions that need to be answered. © 2016 The Authors. Immunology Published by John Wiley & Sons Ltd.

  14. Prohibition of antibiotic growth promoters has affected the genomic profiles of Lactobacillus salivarius inhabiting the swine intestine.

    Science.gov (United States)

    Lee, Jun-Yeong; Han, Geon Goo; Lee, Ho-Bin; Lee, Sang-Mok; Kang, Sang-Kee; Jin, Gwi-Deuk; Park, Jongbin; Chae, Byung Jo; Choi, Yo Han; Kim, Eun Bae; Choi, Yun-Jaie

    2017-01-01

    After the introduction of a ban on the use of antibiotic growth promoters (AGPs) for livestock, the feeding environment, including the composition of animal intestinal microbiota, has changed rapidly. We hypothesized that the microbial genomes have also been affected by this legal prohibition, and investigated an important member of the swine gut microbiota, Lactobacillus salivarius, with a pan-genomic approach. Here, we isolated 21 L. salivarius strains composed of 6 strains isolated before the AGP prohibition (SBPs) and 15 strains isolated after the AGP prohibition (SAPs) at an interval of a decade, and the draft genomes were generated de novo. Several genomic differences between SBPs and SAPs were identified, although the number and function of antibiotic resistance genes were not different. SBPs showed larger genome size and a higher number of orthologs, as well as lower genetic diversity, than SAPs. SBPs had genes associated with the utilization of L-rhamnose and D-tagatose for energy production. Because these sugars are also used in exopolysaccharide (EPS) synthesis, we tried to identify differences in biofilm formation-associated genes. The genes for the production of EPSs and extracellular proteins were different in terms of amino acid sequences. Indeed, SAPs formed dense biofilm and survived better than SBPs in the swine intestinal environment. These results suggest that SAPs have evolved and adapted to protect themselves from new selection pressure of the swine intestinal microenvironment by forming dense biofilms, adopting a distinct antibiotic resistance strategy. This finding is particularly important to understand the evolutionary changes in host-microbe interaction and provide detailed insight for the development of effective probiotics for livestock.

  15. Dietary Bacillus subtilis-based direct-fed microbials alleviate LPS-induced intestinal immunological stress and improve intestinal barrier gene expression in commercial broiler chickens

    Science.gov (United States)

    The present study investigated the effects of B. subtilis-based probiotics on performance, modulation of host inflammatory responses and intestinal barrier integrity of broilers subjected to LPS challenge. Birds at day 0 of age were randomly allocated to one of the 3 dietary treatments - controls, ...

  16. Intestinal dysbiosis associated with systemic lupus erythematosus.

    Science.gov (United States)

    Hevia, Arancha; Milani, Christian; López, Patricia; Cuervo, Adriana; Arboleya, Silvia; Duranti, Sabrina; Turroni, Francesca; González, Sonia; Suárez, Ana; Gueimonde, Miguel; Ventura, Marco; Sánchez, Borja; Margolles, Abelardo

    2014-09-30

    Systemic lupus erythematosus (SLE) is the prototypical systemic autoimmune disease in humans and is characterized by the presence of hyperactive immune cells and aberrant antibody responses to nuclear and cytoplasmic antigens, including characteristic anti-double-stranded DNA antibodies. We performed a cross-sectional study in order to determine if an SLE-associated gut dysbiosis exists in patients without active disease. A group of 20 SLE patients in remission, for which there was strict inclusion and exclusion criteria, was recruited, and we used an optimized Ion Torrent 16S rRNA gene-based analysis protocol to decipher the fecal microbial profiles of these patients and compare them with those of 20 age- and sex-matched healthy control subjects. We found diversity to be comparable based on Shannon's index. However, we saw a significantly lower Firmicutes/Bacteroidetes ratio in SLE individuals (median ratio, 1.97) than in healthy subjects (median ratio, 4.86; P dysbiosis is reflected, based on in silico functional inference, in an overrepresentation of oxidative phosphorylation and glycan utilization pathways in SLE patient microbiota. Growing evidence suggests that the gut microbiota might impact symptoms and progression of some autoimmune diseases. However, how and why this microbial community influences SLE remains to be elucidated. This is the first report describing an SLE-associated intestinal dysbiosis, and it contributes to the understanding of the interplay between the intestinal microbiota and the host in autoimmune disorders. Copyright © 2014 Hevia et al.

  17. Dysbiosis in intestinal inflammation: Cause or consequence.

    Science.gov (United States)

    Buttó, Ludovica F; Haller, Dirk

    2016-08-01

    The intestinal microbiota encompasses hundreds of bacterial species that constitute a relatively stable ecosystem. Alteration in the microbiota composition may arise from infections, immune defects, metabolic alterations, diet or antibiotic treatment. Dysbiosis is considered as an alteration in microbiota community structure and/or function, capable of causing/driving a detrimental distortion of microbe-host homeostasis. A variety of pathologies are associated with changes in the community structure and function of the gut microbiota, suggesting a link between dysbiosis and disease etiology. With an emphasis in this review on inflammatory bowel diseases (IBD), the non-trivial question is whether dysbiosis is the cause or consequence of inflammation. It is important to understand whether changes in microbial ecosystems are causally linked to the pathology and to what extend disease risk is predicable based on characteristic changes in community structure and/or function. Local changes in tissue integrity associated with focal areas of inflammation may result in the selection of a dysbiotic bacterial community associated with the propagation of a disease phenotype. This review outlines the role of dysbiosis in intestinal inflammation with particular focus on IBD-relevant gnotobiotic mouse models, the factors implicated in the development of dysbiosis and the means available to investigate dysbiosis in the context of human diseases. Copyright © 2016 Elsevier GmbH. All rights reserved.

  18. Prevalence of intestinal protozoan parasites in stray and domicile ...

    African Journals Online (AJOL)

    Uncontrolled population of stray and domicile dogs with intestinal protozoan in close proximity to increasing densities of human population in urban environments is a common fact in developing countries, in conjunction with the lack of veterinary attention and zoonotic awareness, increases the risks of disease transmission.

  19. Pattern of intestinal parasites at open air defecation sites in ...

    African Journals Online (AJOL)

    The poor socio-economic status of street children leads to dangerous and unhealthy living environments. Also open defecation and regular contact with dogs, flies and contaminated soil, water, faeces, foods and fomites; increase their chance of infestation by intestinal protozoa and helminths. This study intends to found out ...

  20. Modulation of Intestinal Microbiome Prevents Intestinal Ischemic Injury

    Science.gov (United States)

    Bertacco, Alessandra; Dehner, Carina A.; Caturegli, Giorgio; D'Amico, Francesco; Morotti, Raffaella; Rodriguez, Manuel I.; Mulligan, David C.; Kriegel, Martin A.; Geibel, John P.

    2017-01-01

    Background: Butyrate protects against ischemic injury to the small intestine by reducing inflammation and maintaining the structure of the intestinal barrier, but is expensive, short-lived, and cannot be administered easily due to its odor. Lactate, both economical and more palatable, can be converted into butyrate by the intestinal microbiome. This study aimed to assess in a rat model whether lactate perfusion can also protect against intestinal ischemia. Materials and Methods: Rat intestinal segments were loaded in an in vitro bowel perfusion device, and water absorption or secretion was assessed based on fluorescence of FITC-inulin, a fluorescent marker bound to a biologically inert sugar. Change in FITC concentration was used as a measure of ischemic injury, given the tendency of ischemic cells to retain water. Hematoxylin and eosin-stained sections at light level microscopy were examined to evaluate intestinal epithelium morphology. Comparisons between the data sets were paired Student t-tests or ANOVA with p < 0.05 performed on GraphPad. Results: Lactate administration resulted in a protective effect against intestinal ischemia of similar magnitude to that observed with butyrate. Both exhibited approximately 1.5 times the secretion exhibited by control sections (p = 0.03). Perfusion with lactate and methoxyacetate, a specific inhibitor of lactate-butyrate conversion, abolished this effect (p = 0.09). Antibiotic treatment also eliminated this effect, rendering lactate-perfused sections similar to control sections (p = 0.72). Perfusion with butyrate and methoxyacetate did not eliminate the observed increased secretion, which indicates that ischemic protection was mediated by microbial conversion of lactate to butyrate (p = 0.71). Conclusions: Lactate's protective effect against intestinal ischemia due to microbial conversion to butyrate suggests possible applications in the transplant setting for reducing ischemic injury and ameliorating intestinal preservation

  1. Review: Mechanisms of How the Intestinal Microbiota Alters the Effects of Drugs and Bile Acids.

    Science.gov (United States)

    Klaassen, Curtis D; Cui, Julia Yue

    2015-10-01

    Information on the intestinal microbiota has increased exponentially this century because of technical advancements in genomics and metabolomics. Although information on the synthesis of bile acids by the liver and their transformation to secondary bile acids by the intestinal microbiota was the first example of the importance of the intestinal microbiota in biotransforming chemicals, this review will discuss numerous examples of the mechanisms by which the intestinal microbiota alters the pharmacology and toxicology of drugs and other chemicals. More specifically, the altered pharmacology and toxicology of salicylazosulfapridine, digoxin, l-dopa, acetaminophen, caffeic acid, phosphatidyl choline, carnitine, sorivudine, irinotecan, nonsteroidal anti-inflammatory drugs, heterocyclic amines, melamine, nitrazepam, and lovastatin will be reviewed. In addition, recent data that the intestinal microbiota alters drug metabolism of the host, especially Cyp3a, as well as the significance and potential mechanisms of this phenomenon are summarized. The review will conclude with an update of bile acid research, emphasizing the bile acid receptors (FXR and TGR5) that regulate not only bile acid synthesis and transport but also energy metabolism. Recent data indicate that by altering the intestinal microbiota, either by diet or drugs, one may be able to minimize the adverse effects of the Western diet by altering the composition of bile acids in the intestine that are agonists or antagonists of FXR and TGR5. Therefore, it may be possible to consider the intestinal microbiota as another drug target. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

  2. A role for IL-22 in the relationship between intestinal helminths, gut microbiota and mucosal immunity.

    Science.gov (United States)

    Leung, Jacqueline M; Loke, P'ng

    2013-03-01

    The intestinal tract is home to nematodes as well as commensal bacteria (microbiota), which have coevolved with the mammalian host. The mucosal immune system must balance between an appropriate response to dangerous pathogens and an inappropriate response to commensal microbiota that may breach the epithelial barrier, in order to maintain intestinal homeostasis. IL-22 has been shown to play a critical role in maintaining barrier homeostasis against intestinal pathogens and commensal bacteria. Here we review the advances in our understanding of the role of IL-22 in helminth infections, as well as in response to commensal and pathogenic bacteria of the intestinal tract. We then consider the relationship between intestinal helminths and gut microbiota and hypothesize that this relationship may explain how helminths may improve symptoms of inflammatory bowel diseases. We propose that by inducing an immune response that includes IL-22, intestinal helminths may enhance the mucosal barrier function of the intestinal epithelium. This may restore the mucosal microbiota populations from dysbiosis associated with colitis and improve intestinal homeostasis. Copyright © 2012 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  3. Intestinal malrotation during pregnancy.

    Science.gov (United States)

    Rothstein, R D; Rombeau, J L

    1993-05-01

    Malrotation of the intestine is an uncommon anomaly most often seen in infants, but occasionally in adults. Rarely, symptoms from malrotation may occur during pregnancy. A 30-year-old woman, with a long history of abdominal pain and constipation, developed more frequent and severe symptoms in the second trimester of pregnancy. She was monitored closely and treated conservatively and went on to deliver a full-term, healthy infant. In the postpartum period, barium radiographs demonstrated a midgut malrotation. During exploratory laparotomy, obstructive peritoneal bands were noted and were transected. The mobile cecum and ascending colon were fixated to the abdominal wall. Symptoms from a malrotation may develop during pregnancy and may be nonspecific and vague. Although complications from malrotation can be life-threatening, a conservative approach with surgical intervention in the postpartum period may be appropriate in the proper clinical setting.

  4. Commensal microbiota-induced microRNA modulates intestinal epithelial permeability through the small GTPase ARF4.

    Science.gov (United States)

    Nakata, Kazuaki; Sugi, Yutaka; Narabayashi, Hikari; Kobayakawa, Tetsuro; Nakanishi, Yusuke; Tsuda, Masato; Hosono, Akira; Kaminogawa, Shuichi; Hanazawa, Shigemasa; Takahashi, Kyoko

    2017-09-15

    The intestinal tract contains many commensal bacteria that modulate various physiological host functions. Dysbiosis of commensal bacteria triggers dysfunction of the intestinal epithelial barrier, leading to the induction or aggravation of intestinal inflammation. To elucidate whether microRNA plays a role in commensal microbiome-dependent intestinal epithelial barrier regulation, we compared transcripts in intestinal epithelial cells (IECs) from conventional and germ-free mice and found that commensal bacteria induced the expression of miR-21-5p in IECs. miR-21-5p increased intestinal epithelial permeability and up-regulated ADP ribosylation factor 4 (ARF4), a small GTPase, in the IEC line Caco-2. We also found that ARF4 expression was up-regulated upon suppression of phosphatase and tensin homolog (PTEN) and programmed cell death 4 (PDCD4), which are known miR-21-5p targets, by RNAi. Furthermore, ARF4 expression in epithelial cells of the large intestine was higher in conventional mice than in germ-free mice. ARF4 suppression in the IEC line increased the expression of tight junction proteins and decreased intestinal epithelial permeability. These results indicate that commensal microbiome-dependent miR-21-5p expression in IECs regulates intestinal epithelial permeability via ARF4, which may therefore represent a target for preventing or managing dysfunction of the intestinal epithelial barrier. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  5. Multiple lethal effects induced by a benzimidazole anthelmintic in the anterior intestine of the nematode Haemonchus contortus.

    Science.gov (United States)

    Jasmer, D P; Yao, C; Rehman, A; Johnson, S

    2000-01-05

    A mechanism of benzimidazole efficacy against parasitic nematodes is postulated to involve inhibition of intestinal secretory vesicle transport via depolymerization of microtubules. We show that fenbendazole (FBZ) treatment of lambs causes pathology localized to the anterior intestine in the parasitic nematode Haemonchus contortus. The pathology included gross disintegration of the anterior intestine, DNA fragmentation in anterior intestinal nuclei with characteristics of an apoptosis-like process, and inhibition of host erythrocyte digestion. These lethal effects were associated with inhibited transport of apical secretory vesicles in the anterior intestine, and then generalized dispersal of these vesicles contents throughout the intestinal cytoplasm and worm body. Cytoplasmic accumulation of secretory vesicles and undigested erythrocytes preceded DNA fragmentation and vesicle content dispersal. Both DNA fragmentation and vesicle content dispersal were detected in disintegrated intestine and intestine that had not yet undergone disintegration. These pathologic effects in the anterior intestine appear sufficient to explain the efficacy of FBZ against adult H. contortus. The results implicate mechanisms in the anterior intestine that govern dispersal of apical secretory vesicle contents, DNA fragmentation and tissue disintegration as effectors of this pathology.

  6. Impact of the Gut Microbiota on Intestinal Immunity Mediated by Tryptophan Metabolism

    Science.gov (United States)

    Gao, Jing; Xu, Kang; Liu, Hongnan; Liu, Gang; Bai, Miaomiao; Peng, Can; Li, Tiejun; Yin, Yulong

    2018-01-01

    The gut microbiota influences the health of the host, especially with regard to gut immune homeostasis and the intestinal immune response. In addition to serving as a nutrient enhancer, L-tryptophan (Trp) plays crucial roles in the balance between intestinal immune tolerance and gut microbiota maintenance. Recent discoveries have underscored that changes in the microbiota modulate the host immune system by modulating Trp metabolism. Moreover, Trp, endogenous Trp metabolites (kynurenines, serotonin, and melatonin), and bacterial Trp metabolites (indole, indolic acid, skatole, and tryptamine) have profound effects on gut microbial composition, microbial metabolism, the host's immune system, the host-microbiome interface, and host immune system–intestinal microbiota interactions. The aryl hydrocarbon receptor (AhR) mediates the regulation of intestinal immunity by Trp metabolites (as ligands of AhR), which is beneficial for immune homeostasis. Among Trp metabolites, AhR ligands consist of endogenous metabolites, including kynurenine, kynurenic acid, xanthurenic acid, and cinnabarinic acid, and bacterial metabolites, including indole, indole propionic acid, indole acetic acid, skatole, and tryptamine. Additional factors, such as aging, stress, probiotics, and diseases (spondyloarthritis, irritable bowel syndrome, inflammatory bowel disease, colorectal cancer), which are associated with variability in Trp metabolism, can influence Trp–microbiome–immune system interactions in the gut and also play roles in regulating gut immunity. This review clarifies how the gut microbiota regulates Trp metabolism and identifies the underlying molecular mechanisms of these interactions. Increased mechanistic insight into how the microbiota modulates the intestinal immune system through Trp metabolism may allow for the identification of innovative microbiota-based diagnostics, as well as appropriate nutritional supplementation of Trp to prevent or alleviate intestinal inflammation

  7. Impact of the Gut Microbiota on Intestinal Immunity Mediated by Tryptophan Metabolism

    Directory of Open Access Journals (Sweden)

    Jing Gao

    2018-02-01

    Full Text Available The gut microbiota influences the health of the host, especially with regard to gut immune homeostasis and the intestinal immune response. In addition to serving as a nutrient enhancer, L-tryptophan (Trp plays crucial roles in the balance between intestinal immune tolerance and gut microbiota maintenance. Recent discoveries have underscored that changes in the microbiota modulate the host immune system by modulating Trp metabolism. Moreover, Trp, endogenous Trp metabolites (kynurenines, serotonin, and melatonin, and bacterial Trp metabolites (indole, indolic acid, skatole, and tryptamine have profound effects on gut microbial composition, microbial metabolism, the host's immune system, the host-microbiome interface, and host immune system–intestinal microbiota interactions. The aryl hydrocarbon receptor (AhR mediates the regulation of intestinal immunity by Trp metabolites (as ligands of AhR, which is beneficial for immune homeostasis. Among Trp metabolites, AhR ligands consist of endogenous metabolites, including kynurenine, kynurenic acid, xanthurenic acid, and cinnabarinic acid, and bacterial metabolites, including indole, indole propionic acid, indole acetic acid, skatole, and tryptamine. Additional factors, such as aging, stress, probiotics, and diseases (spondyloarthritis, irritable bowel syndrome, inflammatory bowel disease, colorectal cancer, which are associated with variability in Trp metabolism, can influence Trp–microbiome–immune system interactions in the gut and also play roles in regulating gut immunity. This review clarifies how the gut microbiota regulates Trp metabolism and identifies the underlying molecular mechanisms of these interactions. Increased mechanistic insight into how the microbiota modulates the intestinal immune system through Trp metabolism may allow for the identification of innovative microbiota-based diagnostics, as well as appropriate nutritional supplementation of Trp to prevent or alleviate

  8. Nestedness of ectoparasite-vertebrate host networks.

    Directory of Open Access Journals (Sweden)

    Sean P Graham

    2009-11-01

    Full Text Available Determining the structure of ectoparasite-host networks will enable disease ecologists to better understand and predict the spread of vector-borne diseases. If these networks have consistent properties, then studying the structure of well-understood networks could lead to extrapolation of these properties to others, including those that support emerging pathogens. Borrowing a quantitative measure of network structure from studies of mutualistic relationships between plants and their pollinators, we analyzed 29 ectoparasite-vertebrate host networks--including three derived from molecular bloodmeal analysis of mosquito feeding patterns--using measures of nestedness to identify non-random interactions among species. We found significant nestedness in ectoparasite-vertebrate host lists for habitats ranging from tropical rainforests to polar environments. These networks showed non-random patterns of nesting, and did not differ significantly from published estimates of nestedness from mutualistic networks. Mutualistic and antagonistic networks appear to be organized similarly, with generalized ectoparasites interacting with hosts that attract many ectoparasites and more specialized ectoparasites usually interacting with these same "generalized" hosts. This finding has implications for understanding the network dynamics of vector-born pathogens. We suggest that nestedness (rather than random ectoparasite-host associations can allow rapid transfer of pathogens throughout a network, and expand upon such concepts as the dilution effect, bridge vectors, and host switching in the context of nested ectoparasite-vertebrate host networks.

  9. The intestinal microbiota dysbiosis and Clostridium difficile infection: is there a relationship with inflammatory bowel disease?

    OpenAIRE

    Bien, Justyna; Palagani, Vindhya; Bozko, Przemyslaw

    2013-01-01

    Gut microbiota is a compilation of microorganisms dwelling in the entire mammalian gastrointestinal tract. They display a symbiotic relationship with the host contributing to its intestinal health and disease. Even a slight fluctuation in this equipoise may be deleterious to the host, leading to many pathological conditions like Clostridium difficile infection or inflammatory bowel disease (IBD). In this review, we focus on the role of microbial dysbiosis in initiation of C. difficile infecti...

  10. The Starting Lineup: Key Microbial Players in Intestinal Immunity and Homeostasis

    OpenAIRE

    Nicola Catherine Reading; Nicola Catherine Reading