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Sample records for butyrate-producing colon bacteria

  1. Restricted Distribution of the Butyrate Kinase Pathway among Butyrate-Producing Bacteria from the Human Colon

    PubMed Central

    Louis, Petra; Duncan, Sylvia H.; McCrae, Sheila I.; Millar, Jacqueline; Jackson, Michelle S.; Flint, Harry J.

    2004-01-01

    The final steps in butyrate synthesis by anaerobic bacteria can occur via butyrate kinase and phosphotransbutyrylase or via butyryl-coenzyme A (CoA):acetate CoA-transferase. Degenerate PCR and enzymatic assays were used to assess the presence of butyrate kinase among 38 anaerobic butyrate-producing bacterial isolates from human feces that represent three different clostridial clusters (IV, XIVa, and XVI). Only four strains were found to possess detectable butyrate kinase activity. These were also the only strains to give PCR products (verifiable by sequencing) with degenerate primer pairs designed within the butyrate kinase gene or between the linked butyrate kinase/phosphotransbutyrylase genes. Further analysis of the butyrate kinase/phosphotransbutyrylase genes of one isolate, L2-50, revealed similar organization to that described previously from different groups of clostridia, along with differences in flanking sequences and phylogenetic relationships. Butyryl-CoA:acetate CoA-transferase activity was detected in all 38 strains examined, suggesting that it, rather than butyrate kinase, provides the dominant route for butyrate formation in the human colonic ecosystem that contains a constantly high concentration of acetate. PMID:15028695

  2. Cell-associated alpha-amylases of butyrate-producing Firmicute bacteria from the human colon.

    PubMed

    Ramsay, Alan G; Scott, Karen P; Martin, Jenny C; Rincon, Marco T; Flint, Harry J

    2006-11-01

    Selected butyrate-producing bacteria from the human colon that are related to Roseburia spp. and Butyrivibrio fibrisolvens showed a good ability to utilize a variety of starches for growth when compared with the Gram-negative amylolytic anaerobe Bacteroides thetaiotaomicron. A major cell-associated amylase of high molecular mass (140-210 kDa) was detected in each strain by SDS-PAGE zymogram analysis, and genes corresponding to these enzymes were analysed for two representative strains. Amy13B from But. fibrisolvens 16/4 is a multi-domain enzyme of 144.6 kDa that includes a family 13 glycoside hydrolase domain, and duplicated family 26 carbohydrate-binding modules. Amy13A (182.4 kDa), from Roseburia inulinivorans A2-194, also includes a family 13 domain, which is preceded by two repeat units of approximately 116 aa rich in aromatic residues, an isoamylase N-terminal domain, a pullulanase-associated domain, and an additional unidentified domain. Both Amy13A and Amy13B have N-terminal signal peptides and C-terminal cell-wall sorting signals, including a modified LPXTG motif similar to that involved in interactions with the cell surface in other Gram-positive bacteria, a hydrophobic transmembrane segment, and a basic C terminus. The overexpressed family 13 domains showed an absolute requirement for Mg2+ or Ca2+ for activity, and functioned as 1,4-alpha-glucanohydrolases (alpha-amylases; EC 3.2.1.1). These major starch-degrading enzymes thus appear to be anchored to the cell wall in this important group of human gut bacteria. PMID:17074899

  3. Prebiotic stimulation of human colonic butyrate-producing bacteria and bifidobacteria, in vitro.

    PubMed

    Scott, Karen P; Martin, Jennifer C; Duncan, Sylvia H; Flint, Harry J

    2014-01-01

    Dietary macronutrients affect the composition of the gut microbiota, and prebiotics are used to improve and maintain a healthy gut. The impact of prebiotics on dominant gut bacteria other than bifidobacteria, however, is under-researched. Here, we report carbohydrate utilisation patterns for representative butyrate-producing anaerobes, belonging to the Gram-positive Firmicutes families Lachnospiraceae and Ruminococcaceae, by comparison with selected Bacteroides and Bifidobacterium species. Growth assessments using anaerobic Hungate tubes and a new rapid microtitre plate assay were generally in good agreement. The Bacteroides strains tested showed some growth on basal medium with no added carbohydrates, utilising peptides in the growth medium. The butyrate-producing strains exhibited different growth profiles on the substrates, which included starch, inulin, fructooligosaccharides (FOS), galactooligosaccharides (GOS) and xylooligosaccharides (XOS). Eleven were able to grow on short-chain FOS, but this number decreased as the chain length of the fructan substrates increased. Long-chain inulin was utilised by Roseburia inulinivorans, but by none of the Bifidobacterium species examined here. XOS was a more selective growth substrate than FOS, with only six of the 11 Firmicutes strains able to use XOS for growth. These results illustrate the selectivity of different prebiotics and help to explain why some are butyrogenic. PMID:23909466

  4. Bifidobacteria and Butyrate-Producing Colon Bacteria: Importance and Strategies for Their Stimulation in the Human Gut.

    PubMed

    Rivière, Audrey; Selak, Marija; Lantin, David; Leroy, Frédéric; De Vuyst, Luc

    2016-01-01

    With the increasing amount of evidence linking certain disorders of the human body to a disturbed gut microbiota, there is a growing interest for compounds that positively influence its composition and activity through diet. Besides the consumption of probiotics to stimulate favorable bacterial communities in the human gastrointestinal tract, prebiotics such as inulin-type fructans (ITF) and arabinoxylan-oligosaccharides (AXOS) can be consumed to increase the number of bifidobacteria in the colon. Several functions have been attributed to bifidobacteria, encompassing degradation of non-digestible carbohydrates, protection against pathogens, production of vitamin B, antioxidants, and conjugated linoleic acids, and stimulation of the immune system. During life, the numbers of bifidobacteria decrease from up to 90% of the total colon microbiota in vaginally delivered breast-fed infants to <5% in the colon of adults and they decrease even more in that of elderly as well as in patients with certain disorders such as antibiotic-associated diarrhea, inflammatory bowel disease, irritable bowel syndrome, obesity, allergies, and regressive autism. It has been suggested that the bifidogenic effects of ITF and AXOS are the result of strain-specific yet complementary carbohydrate degradation mechanisms within cooperating bifidobacterial consortia. Except for a bifidogenic effect, ITF and AXOS also have shown to cause a butyrogenic effect in the human colon, i.e., an enhancement of colon butyrate production. Butyrate is an essential metabolite in the human colon, as it is the preferred energy source for the colon epithelial cells, contributes to the maintenance of the gut barrier functions, and has immunomodulatory and anti-inflammatory properties. It has been shown that the butyrogenic effects of ITF and AXOS are the result of cross-feeding interactions between bifidobacteria and butyrate-producing colon bacteria, such as Faecalibacterium prausnitzii (clostridial cluster IV

  5. Bifidobacteria and Butyrate-Producing Colon Bacteria: Importance and Strategies for Their Stimulation in the Human Gut

    PubMed Central

    Rivière, Audrey; Selak, Marija; Lantin, David; Leroy, Frédéric; De Vuyst, Luc

    2016-01-01

    With the increasing amount of evidence linking certain disorders of the human body to a disturbed gut microbiota, there is a growing interest for compounds that positively influence its composition and activity through diet. Besides the consumption of probiotics to stimulate favorable bacterial communities in the human gastrointestinal tract, prebiotics such as inulin-type fructans (ITF) and arabinoxylan-oligosaccharides (AXOS) can be consumed to increase the number of bifidobacteria in the colon. Several functions have been attributed to bifidobacteria, encompassing degradation of non-digestible carbohydrates, protection against pathogens, production of vitamin B, antioxidants, and conjugated linoleic acids, and stimulation of the immune system. During life, the numbers of bifidobacteria decrease from up to 90% of the total colon microbiota in vaginally delivered breast-fed infants to <5% in the colon of adults and they decrease even more in that of elderly as well as in patients with certain disorders such as antibiotic-associated diarrhea, inflammatory bowel disease, irritable bowel syndrome, obesity, allergies, and regressive autism. It has been suggested that the bifidogenic effects of ITF and AXOS are the result of strain-specific yet complementary carbohydrate degradation mechanisms within cooperating bifidobacterial consortia. Except for a bifidogenic effect, ITF and AXOS also have shown to cause a butyrogenic effect in the human colon, i.e., an enhancement of colon butyrate production. Butyrate is an essential metabolite in the human colon, as it is the preferred energy source for the colon epithelial cells, contributes to the maintenance of the gut barrier functions, and has immunomodulatory and anti-inflammatory properties. It has been shown that the butyrogenic effects of ITF and AXOS are the result of cross-feeding interactions between bifidobacteria and butyrate-producing colon bacteria, such as Faecalibacterium prausnitzii (clostridial cluster IV

  6. Swine Intestinal Tract Harbors a High Diversity of Butyrate-Producing Bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Butyrate is a preferred energy source of human colonic epithelial cells, and changes in the communities of butyrate-producing bacteria have been associated with adverse health. We hypothesize that in swine, like in humans, butyrate-producing bacteria contribute to a healthy intestinal ecosystem. T...

  7. Relationship of Enhanced Butyrate Production by Colonic Butyrate-Producing Bacteria to Immunomodulatory Effects in Normal Mice Fed an Insoluble Fraction of Brassica rapa L.

    PubMed

    Tanaka, Sachi; Yamamoto, Kana; Yamada, Kazuki; Furuya, Kanon; Uyeno, Yutaka

    2016-05-01

    This study was performed to determine the effects of feeding a fiber-rich fraction of Brassica vegetables on the immune response through changes in enteric bacteria and short-chain fatty acid (SCFA) production in normal mice. The boiled-water-insoluble fraction of Brassica rapa L. (nozawana), which consists mainly of dietary fiber, was chosen as a test material. A total of 31 male C57BL/6J mice were divided into two groups and housed in a specific-pathogen-free facility. The animals were fed either a control diet or the control diet plus the insoluble B. rapa L. fraction for 2 weeks and sacrificed to determine microbiological and SCFA profiles in lower-gut samples and immunological molecules. rRNA-based quantification indicated that the relative population of Bacteroidetes was markedly lower in the colon samples of the insoluble B. rapa L. fraction-fed group than that in the controls. Populations of the Eubacterium rectale group and Faecalibacterium prausnitzii, both of which are representative butyrate-producing bacteria, doubled after 2 weeks of fraction intake, accompanying a marginal increase in the proportion of colonic butyrate. In addition, feeding with the fraction significantly increased levels of the anti-inflammatory cytokine interleukin-10 (IL-10) and tended to increase splenic regulatory T cell numbers but significantly reduced the population of cells expressing activation markers. We demonstrated that inclusion of the boiled-water-insoluble fraction of B. rapa L. can alter the composition of the gut microbiota to decrease the numbers of Bacteroidetes and to increase the numbers of butyrate-producing bacteria, either of which may be involved in the observed shift in the production of splenic IL-10. PMID:26921420

  8. Isolation of unique butyrate-producing bacteria from swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Butyrate-producing bacteria in humans contribute to a healthy gastrointestinal tract and are known to be species from clostridial clusters IV, IX, XIVa, and XVI - with the community dominated by clusters XIVa and IV. However, the composition of the butyrate-producing bacterial community in swine is...

  9. Wheat bran promotes enrichment within the human colonic microbiota of butyrate-producing bacteria that release ferulic acid.

    PubMed

    Duncan, Sylvia H; Russell, Wendy R; Quartieri, Andrea; Rossi, Maddalena; Parkhill, Julian; Walker, Alan W; Flint, Harry J

    2016-07-01

    Cereal fibres such as wheat bran are considered to offer human health benefits via their impact on the intestinal microbiota. We show here by 16S rRNA gene-based community analysis that providing amylase-pretreated wheat bran as the sole added energy source to human intestinal microbial communities in anaerobic fermentors leads to the selective and progressive enrichment of a small number of bacterial species. In particular, OTUs corresponding to uncultured Lachnospiraceae (Firmicutes) related to Eubacterium xylanophilum and Butyrivibrio spp. were strongly enriched (by five to 160 fold) over 48 h in four independent experiments performed with different faecal inocula, while nine other Firmicutes OTUs showed > 5-fold enrichment in at least one experiment. Ferulic acid was released from the wheat bran during degradation but was rapidly converted to phenylpropionic acid derivatives via hydrogenation, demethylation and dehydroxylation to give metabolites that are detected in human faecal samples. Pure culture work using bacterial isolates related to the enriched OTUs, including several butyrate-producers, demonstrated that the strains caused substrate weight loss and released ferulic acid, but with limited further conversion. We conclude that breakdown of wheat bran involves specialist primary degraders while the conversion of released ferulic acid is likely to involve a multi-species pathway. PMID:26636660

  10. Severity of atopic disease inversely correlates with intestinal microbiota diversity and butyrate-producing bacteria.

    PubMed

    Nylund, L; Nermes, M; Isolauri, E; Salminen, S; de Vos, W M; Satokari, R

    2015-02-01

    The reports on atopic diseases and microbiota in early childhood remain contradictory, and both decreased and increased microbiota diversity have been associated with atopic eczema. In this study, the intestinal microbiota signatures associated with the severity of eczema in 6-month-old infants were characterized. Further, the changes in intestinal microbiota composition related to the improvement of this disease 3 months later were assessed. The severity of eczema correlated inversely with microbiota diversity (r = -0.54, P = 0.002) and with the abundance of butyrate-producing bacteria (r = -0.52, P = 0.005). During the 3-month follow-up, microbiota diversity increased (P < 0.001) and scoring atopic dermatitis values decreased (P < 0.001) in all infants. This decrease coincided with the increase in bacteria related to butyrate-producing Coprococcus eutactus (r = -0.59, P = 0.02). In conclusion, the high diversity of microbiota and high abundance of butyrate-producing bacteria were associated with milder eczema, thus suggesting they have a role in alleviating symptoms of atopic eczema. PMID:25413686

  11. Only fibres promoting a stable butyrate producing colonic ecosystem decrease the rate of aberrant crypt foci in rats

    PubMed Central

    Perrin, P; Pierre, F; Patry, Y; Champ, M; Berreur, M; Pradal, G; Bornet, F; Meflah, K; Menanteau, J

    2001-01-01

    BACKGROUND—Dietary fibres have been proposed as protective agents against colon cancer but results of both epidemiological and experimental studies are inconclusive.
AIMS—Hypothesising that protection against colon cancer may be restricted to butyrate producing fibres, we investigated the factors needed for long term stable butyrate production and its relation to susceptibility to colon cancer.
METHODS—A two part randomised blinded study in rats, mimicking a prospective study in humans, was performed using a low fibre control diet (CD) and three high fibre diets: starch free wheat bran (WB), type III resistant starch (RS), and short chain fructo-oligosaccharides (FOS). Using a randomised block design, 96 inbred rats were fed for two, 16, 30, or 44 days to determine the period of adaptation to the diets, fermentation profiles, and effects on the colon, including mucosal proliferation on day 44. Subsequently, 36 rats fed the same diets for 44 days were injected with azoxymethane and checked for aberrant crypt foci 30 days later.
RESULTS—After fermentation had stabilised (44 days), only RS and FOS produced large amounts of butyrate, with a trophic effect in the large intestine. No difference in mucosal proliferation between the diets was noted at this time. In the subsequent experiment one month later, fewer aberrant crypt foci were present in rats fed high butyrate producing diets (RS, p=0.022; FOS, p=0.043).
CONCLUSION—A stable butyrate producing colonic ecosystem related to selected fibres appears to be less conducive to colon carcinogenesis.


Keywords: fibre; fermentation; butyrate; colon carcinogenesis; aberrant crypt foci; rat PMID:11115823

  12. Butyrivibrio hungatei sp. nov. and Pseudobutyrivibrio xylanivorans sp. nov., butyrate-producing bacteria from the rumen.

    PubMed

    Kopecný, Jan; Zorec, Masa; Mrázek, Jakub; Kobayashi, Yasuo; Marinsek-Logar, Romana

    2003-01-01

    Two novel Gram-negative, anaerobic, non-spore-forming, butyrate-producing bacterial species, strains Mz 5T and JK 615T, were isolated from the rumen fluid of cow and sheep. Both strains were curved rods that were motile by means of single polar or subpolar flagellum and common in the rumen microbial ecosystem. Strain Mz 5T produced high xylanase, proteinase, pectin hydrolase and DNase activities; 1,4-beta-endoglucanase was also detected in the culture medium. The bacterium utilized a wide range of carbohydrates. Glucose was fermented to formate, butyrate, lactate, succinate and ethanol. The DNA G + C content was 42.1 mol%. The complete 16S rDNA sequence was obtained and phylogenetic relationships were determined. Strain Mz 5T and related isolates were located in clostridial cluster XIVa and were closely related to Pseudobutyrivibrio ruminis, Butyrivibrio crossotus, Roseburia cecicola and Eubacterium rectale. The name proposed for this novel bacterium is Pseudobutyrivibrio xylanivorans; the type strain is Mz 5T (=DSM 14809T =ATCC BAA-455T). Strain JK 615T produced no fibrolytic activity, but utilized a wide range of carbohydrates. Glucose was fermented to formate, acetate, butyrate and ethanol. The DNA G + C content was 44-8 mol%. The complete 16S rDNA sequence was obtained and phylogenetic relationships were determined. Strain JK 615T was located in clostridial cluster XIVa and was closely related to Clostridium proteoclasticum, Butyrivibrio fibrisolvens and Eubacterium halii. The name proposed for this novel bacterium is Butyrivibrio hungatei; the type strain is JK 615T (=DSM 14810T =ATCC BAA-456T). PMID:12656174

  13. Butyrate produced by commensal bacteria potentiates phorbol esters induced AP-1 response in human intestinal epithelial cells.

    PubMed

    Nepelska, Malgorzata; Cultrone, Antonietta; Béguet-Crespel, Fabienne; Le Roux, Karine; Doré, Joël; Arulampalam, Vermulugesan; Blottière, Hervé M

    2012-01-01

    The human intestine is a balanced ecosystem well suited for bacterial survival, colonization and growth, which has evolved to be beneficial both for the host and the commensal bacteria. Here, we investigated the effect of bacterial metabolites produced by commensal bacteria on AP-1 signaling pathway, which has a plethora of effects on host physiology. Using intestinal epithelial cell lines, HT-29 and Caco-2, stably transfected with AP-1-dependent luciferase reporter gene, we tested the effect of culture supernatant from 49 commensal strains. We observed that several bacteria were able to activate the AP-1 pathway and this was correlated to the amount of short chain fatty acids (SCFAs) produced. Besides being a major source of energy for epithelial cells, SCFAs have been shown to regulate several signaling pathways in these cells. We show that propionate and butyrate are potent activators of the AP-1 pathway, butyrate being the more efficient of the two. We also observed a strong synergistic activation of AP-1 pathway when using butyrate with PMA, a PKC activator. Moreover, butyrate enhanced the PMA-induced expression of c-fos and ERK1/2 phosphorylation, but not p38 and JNK. In conclusion, we showed that SCFAs especially butyrate regulate the AP-1 signaling pathway, a feature that may contribute to the physiological impact of the gut microbiota on the host. Our results provide support for the involvement of butyrate in modulating the action of PKC in colon cancer cells. PMID:23300800

  14. Diet is a major factor governing the fecal butyrate-producing community structure across Mammalia, Aves and Reptilia

    PubMed Central

    Vital, Marius; Gao, Jiarong; Rizzo, Mike; Harrison, Tara; Tiedje, James M

    2015-01-01

    Butyrate-producing bacteria have an important role in maintaining host health. They are well studied in human and medically associated animal models; however, much less is known for other Vertebrata. We investigated the butyrate-producing community in hindgut-fermenting Mammalia (n=38), Aves (n=8) and Reptilia (n=8) using a gene-targeted pyrosequencing approach of the terminal genes of the main butyrate-synthesis pathways, namely butyryl-CoA:acetate CoA-transferase (but) and butyrate kinase (buk). Most animals exhibit high gene abundances, and clear diet-specific signatures were detected with but genes significantly enriched in omnivores and herbivores compared with carnivores. But dominated the butyrate-producing community in these two groups, whereas buk was more abundant in many carnivorous animals. Clustering of protein sequences (5% cutoff) of the combined communities (but and buk) placed carnivores apart from other diet groups, except for noncarnivorous Carnivora, which clustered together with carnivores. The majority of clusters (but: 5141 and buk: 2924) did not show close relation to any reference sequences from public databases (identity <90%) demonstrating a large ‘unknown diversity'. Each diet group had abundant signature taxa, where buk genes linked to Clostridium perfringens dominated in carnivores and but genes associated with Ruminococcaceae bacterium D16 were specific for herbivores and omnivores. Whereas 16S rRNA gene analysis showed similar overall patterns, it was unable to reveal communities at the same depth and resolution as the functional gene-targeted approach. This study demonstrates that butyrate producers are abundant across vertebrates exhibiting great functional redundancy and that diet is the primary determinant governing the composition of the butyrate-producing guild. PMID:25343515

  15. Diet is a major factor governing the fecal butyrate-producing community structure across Mammalia, Aves and Reptilia.

    PubMed

    Vital, Marius; Gao, Jiarong; Rizzo, Mike; Harrison, Tara; Tiedje, James M

    2015-04-01

    Butyrate-producing bacteria have an important role in maintaining host health. They are well studied in human and medically associated animal models; however, much less is known for other Vertebrata. We investigated the butyrate-producing community in hindgut-fermenting Mammalia (n = 38), Aves (n = 8) and Reptilia (n = 8) using a gene-targeted pyrosequencing approach of the terminal genes of the main butyrate-synthesis pathways, namely butyryl-CoA:acetate CoA-transferase (but) and butyrate kinase (buk). Most animals exhibit high gene abundances, and clear diet-specific signatures were detected with but genes significantly enriched in omnivores and herbivores compared with carnivores. But dominated the butyrate-producing community in these two groups, whereas buk was more abundant in many carnivorous animals. Clustering of protein sequences (5% cutoff) of the combined communities (but and buk) placed carnivores apart from other diet groups, except for noncarnivorous Carnivora, which clustered together with carnivores. The majority of clusters (but: 5141 and buk: 2924) did not show close relation to any reference sequences from public databases (identity <90%) demonstrating a large 'unknown diversity'. Each diet group had abundant signature taxa, where buk genes linked to Clostridium perfringens dominated in carnivores and but genes associated with Ruminococcaceae bacterium D16 were specific for herbivores and omnivores. Whereas 16S rRNA gene analysis showed similar overall patterns, it was unable to reveal communities at the same depth and resolution as the functional gene-targeted approach. This study demonstrates that butyrate producers are abundant across vertebrates exhibiting great functional redundancy and that diet is the primary determinant governing the composition of the butyrate-producing guild. PMID:25343515

  16. Induction of peroxisomes by butyrate-producing probiotics.

    PubMed

    Weng, Huachun; Endo, Kosuke; Li, Jiawei; Kito, Naoko; Iwai, Naoharu

    2015-01-01

    We previously found that peroxisomal biogenesis factor 11a (Pex11a) deficiency is associated with a reduction in peroxisome abundance and impaired fatty acid metabolism in hepatocytes, and results in steatosis. In the present study, we investigated whether butyrate induces Pex11a expression and peroxisome proliferation, and studied its effect on lipid metabolism. C57BL/6 mice fed standard chow or a high-fat diet (HFD) were treated with tributyrin, 4-phelybutyrate acid (4-PBA), or the butyrate-producing probiotics (Clostridium butyricum MIYAIRI 588 [CBM]) plus inulin (dietary fiber), and the body weight, white adipose tissue, serum triglycerides, mRNA expression, and peroxisome abundance were evaluated. Tributyrin or 4-PBA treatment significantly decreased body weight and increased hepatic mRNA expression of peroxisome proliferator-activated receptor-α (PPARα) and Pex11a. In addition, 4-PBA treatment increased peroxisome abundance and the expression of genes involved in peroxisomal fatty acid β-oxidation (acyl-coenzyme A oxidase 1 and hydroxysteroid [17-beta] dehydrogenase 4). CBM and inulin administration reduced adipose tissue mass and serum triglycerides, induced Pex11a, acyl-coenzyme A oxidase 1, and hydroxysteroid (17-beta) dehydrogenase 4 genes, and increased peroxisome abundance in mice fed standard chow or an HFD. In conclusion, elevation of butyrate availability (directly through administration of butyrate or indirectly via administration of butyrate-producing probiotics plus fiber) induces PPARα and Pex11a and the genes involved in peroxisomal fatty acid β-oxidation, increases peroxisome abundance, and improves lipid metabolism. These results may provide a new therapeutic strategy against hyperlipidemia and obesity. PMID:25659146

  17. Bacteria, colonic fermentation, and gastrointestinal health.

    PubMed

    Macfarlane, George T; Macfarlane, Sandra

    2012-01-01

    The colonic microbiota plays an important role in human digestive physiology and makes a significant contribution to homeostasis in the large bowel. The microbiome probably comprises thousands of different bacterial species. The principal metabolic activities of colonic microorganisms are associated with carbohydrate and protein digestion. Nutrients of dietary and host origin support the growth of intestinal organisms. Short-chain fatty acids (SCFAs), predominantly acetate, propionate, and butyrate, are the principal metabolites generated during the catabolism of carbohydrates and proteins. In contrast, protein digestion yields a greater diversity of end products, including SCFAs, amines, phenols, indoles, thiols, CO2, H2, and H2S, many of which have toxic properties. The majority of SCFAs are absorbed from the gut and metabolized in various body tissues, making a relatively small but significant contribution to the body's daily energy requirements. Carbohydrate fermentation is, for the most part, a beneficial process in the large gut, because the growth of saccharolytic bacteria stimulates their requirements for toxic products associated with putrefaction, for incorporation into cellular proteins, thereby protecting the host. However, as digestive materials move along the gut, carbohydrates become depleted, which may be linked to the increased prevalence of colonic disease in the distal bowel. PMID:22468341

  18. Accelerated dysbiosis of gut microbiota during aggravation of DSS-induced colitis by a butyrate-producing bacterium.

    PubMed

    Zhang, Qianpeng; Wu, Yanqiu; Wang, Jing; Wu, Guojun; Long, Wenmin; Xue, Zhengsheng; Wang, Linghua; Zhang, Xiaojun; Pang, Xiaoyan; Zhao, Yufeng; Zhao, Liping; Zhang, Chenhong

    2016-01-01

    Butyrate-producing bacteria (BPB) are potential probiotic candidates for inflammatory bowel diseases as they are often depleted in the diseased gut microbiota. However, here we found that augmentation of a human-derived butyrate-producing strain, Anaerostipes hadrus BPB5, significantly aggravated colitis in dextran sulphate sodium (DSS)-treated mice while exerted no detrimental effect in healthy mice. We explored how the interaction between BPB5 and gut microbiota may contribute to this differential impact on the hosts. Butyrate production and severity of colitis were assessed in both healthy and DSS-treated mice, and gut microbiota structural changes were analysed using high-throughput sequencing. BPB5-inoculated healthy mice showed no signs of colitis, but increased butyrate content in the gut. In DSS-treated mice, BPB5 augmentation did not increase butyrate content, but induced significantly more severe disease activity index and much higher mortality. BPB5 didn't induce significant changes of gut microbiota in healthy hosts, but expedited the structural shifts 3 days earlier toward the disease phase in BPB5-augmented than DSS-treated animals. The differential response of gut microbiota in healthy and DSS-treated mice to the same potentially beneficial bacterium with drastically different health consequences suggest that animals with dysbiotic gut microbiota should also be employed for the safety assessment of probiotic candidates. PMID:27264309

  19. Accelerated dysbiosis of gut microbiota during aggravation of DSS-induced colitis by a butyrate-producing bacterium

    PubMed Central

    Zhang, Qianpeng; Wu, Yanqiu; Wang, Jing; Wu, Guojun; Long, Wenmin; Xue, Zhengsheng; Wang, Linghua; Zhang, Xiaojun; Pang, Xiaoyan; Zhao, Yufeng; Zhao, Liping; Zhang, Chenhong

    2016-01-01

    Butyrate-producing bacteria (BPB) are potential probiotic candidates for inflammatory bowel diseases as they are often depleted in the diseased gut microbiota. However, here we found that augmentation of a human-derived butyrate-producing strain, Anaerostipes hadrus BPB5, significantly aggravated colitis in dextran sulphate sodium (DSS)-treated mice while exerted no detrimental effect in healthy mice. We explored how the interaction between BPB5 and gut microbiota may contribute to this differential impact on the hosts. Butyrate production and severity of colitis were assessed in both healthy and DSS-treated mice, and gut microbiota structural changes were analysed using high-throughput sequencing. BPB5-inoculated healthy mice showed no signs of colitis, but increased butyrate content in the gut. In DSS-treated mice, BPB5 augmentation did not increase butyrate content, but induced significantly more severe disease activity index and much higher mortality. BPB5 didn’t induce significant changes of gut microbiota in healthy hosts, but expedited the structural shifts 3 days earlier toward the disease phase in BPB5-augmented than DSS-treated animals. The differential response of gut microbiota in healthy and DSS-treated mice to the same potentially beneficial bacterium with drastically different health consequences suggest that animals with dysbiotic gut microbiota should also be employed for the safety assessment of probiotic candidates. PMID:27264309

  20. Colonization of congenitally immunodeficient mice with probiotic bacteria.

    PubMed Central

    Wagner, R D; Warner, T; Roberts, L; Farmer, J; Balish, E

    1997-01-01

    We assessed the capacity of four probiotic bacteria (Lactobacillus acidophilus, Lactobacillus reuteri, Lactobacillus casei GG, and Bifidobacterium animalis) to colonize, infect, stimulate immune responses in, and affect the growth and survival of congenitally immunodeficient gnotobiotic beige-athymic (bg/bg-nu/nu) and beige-euthymic (bg/bg-nu/+) mice. The bacteria colonized and persisted, in pure culture, in the alimentary tracts of both mouse strains for the entire study period (12 weeks). Although all adult and neonatal beige-euthymic mice survived probiotic colonization, some infant mortality occurred in beige-athymic pups born to mothers colonized with pure cultures of L. reuteri or L. casei GG. The probiotic bacteria manifested different capacities to adhere to epithelial surfaces, disseminate to internal organs, affect the body weight of adult mice and the growth of neonatal mice, and stimulate immune responses. Although the probiotic species were innocuous for adults, these results suggest that caution and further studies to assess the safety of probiotic bacteria for immunodeficient hosts, especially neonates, are required. PMID:9234796

  1. Chemostat Enrichments of Human Feces with Resistant Starch Are Selective for Adherent Butyrate-Producing Clostridia at High Dilution Rates

    PubMed Central

    Sharp, Richard; Macfarlane, George T.

    2000-01-01

    Resistant starch (RS) enrichments were made using chemostats inoculated with human feces from two individuals at two dilution rates (D = 0.03 h−1 and D = 0.30 h−1) to select for slow- and fast-growing amylolytic communities. The fermentations were studied by analysis of short-chain fatty acids, amylase and α-glucosidase activities, and viable counts of the predominant culturable populations and the use of 16S rRNA-targeted oligonucleotide probes. Considerable butyrate was produced at D = 0.30 h−1, which corresponded with reduced branched-chain fatty acid formation. At both dilution rates, high levels of extracellular amylase activity were produced, while α-glucosidase was predominantly cell associated. Bacteroides and bifidobacteria predominated at the low dilution rate, whereas saccharolytic clostridia became more important at D = 0.30 h−1. Microscopic examination showed that within 48 h of inoculation, one particular bacterial morphotype predominated in RS enrichments at D = 0.30 h−1. This organism attached apically to RS granules and formed rosette-like structures which, with glycocalyx formation, agglomerated to form biofilm networks in the planktonic phase. Attempts to isolate this bacterium in pure culture were repeatedly unsuccessful, although a single colony was eventually obtained. On the basis of its 16S rDNA sequence, this RS-degrading, butyrate-producing organism was identified as being a previously unidentified group I Clostridium sp. A 16S rRNA-targeted probe was designed using this sequence and used to assess the abundance of the population in the enrichments. At 240 h, its contributions to total rRNA in the chemostats were 5 and 23% at D = 0.03 and 0.30 h−1, respectively. This study indicates that bacterial populations with significant metabolic potential can be overlooked using culture-based methodologies. This may provide a paradigm for explaining the discrepancy between the low numbers of butyrate-producing bacteria that are

  2. Microbial dysbiosis and colon carcinogenesis: could colon cancer be considered a bacteria-related disease?

    PubMed Central

    Amiot, Aurelien; Le Baleur, Yann; Levy, Michael; Auriault, Marie-Luce; Van Nhieu, Jeanne Tran; Delchier, Jean Charles

    2013-01-01

    Colorectal cancer (CRC) is posing an increasingly important burden on the health care system, with western countries seeing a growing incidence of the disease. Except for germline DNA mutations which have been attributed to less than 5% of patients, little is known about the main causes of CRC. However, environment factors such as food, lifestyle and medication are now suspected to have a major influence on inducing cancers. Today, exhaustive quantitative and qualitative evaluation of all environmental factors is not possible. Various environment-induced diseases have been characterized based on colon microflora, also called microbiota, analyses. Growing data have shown specific changes in microflora (i.e. dysbiosis) in the stools of patients with colon cancer or those adherent to the colonic mucosa. Thus, it appears that microbiota may be considered a platform offering host and environment interactions for studying CRCs. The hypothesis that colon cancer might be a bacteria-related disease is suggested and perspectives are discussed. PMID:23634186

  3. Depletion of Butyrate-Producing Clostridia from the Gut Microbiota Drives an Aerobic Luminal Expansion of Salmonella.

    PubMed

    Rivera-Chávez, Fabian; Zhang, Lillian F; Faber, Franziska; Lopez, Christopher A; Byndloss, Mariana X; Olsan, Erin E; Xu, Gege; Velazquez, Eric M; Lebrilla, Carlito B; Winter, Sebastian E; Bäumler, Andreas J

    2016-04-13

    The mammalian intestine is host to a microbial community that prevents pathogen expansion through unknown mechanisms, while antibiotic treatment can increase susceptibility to enteric pathogens. Here we show that streptomycin treatment depleted commensal, butyrate-producing Clostridia from the mouse intestinal lumen, leading to decreased butyrate levels, increased epithelial oxygenation, and aerobic expansion of Salmonella enterica serovar Typhimurium. Epithelial hypoxia and Salmonella restriction could be restored by tributyrin treatment. Clostridia depletion and aerobic Salmonella expansion were also observed in the absence of streptomycin treatment in genetically resistant mice but proceeded with slower kinetics and required the presence of functional Salmonella type III secretion systems. The Salmonella cytochrome bd-II oxidase synergized with nitrate reductases to drive luminal expansion, and both were required for fecal-oral transmission. We conclude that Salmonella virulence factors and antibiotic treatment promote pathogen expansion through the same mechanism: depletion of butyrate-producing Clostridia to elevate epithelial oxygenation, allowing aerobic Salmonella growth. PMID:27078066

  4. Colonization by aerobic bacteria in karst: Laboratory and in situ experiments

    USGS Publications Warehouse

    Personne, J.-C.; Poty, F.; Mahler, B.J.; Drogue, C.

    2004-01-01

    Experiments were carried out to investigate the potential for bacterial colonization of different substrates in karst aquifers and the nature of the colonizing bacteria. Laboratory batch experiments were performed using limestone and PVC as substrates, a natural bacterial isolate and a known laboratory strain (Escherichia coli [E. coli]) as inocula, and karst ground water and a synthetic formula as growth media. In parallel, fragments of limestone and granite were submerged in boreholes penetrating two karst aquifers for more than one year; the boreholes are periodically contaminated by enteric bacteria from waste water. Once a month, rock samples were removed and the colonizing bacteria quantified and identified. The batch experiments demonstrated that the natural isolate and E. coli both readily colonized limestone surfaces using karst ground water as the growth medium. In contrast, bacterial colonization of both the limestone and granite substrates, when submerged in the karst, was less intense. More than 300 bacterial strains were isolated over the period sampled, but no temporal pattern in colonization was seen as far as strain, and colonization by E. coli was notably absent, although strains of Salmonella and Citrobacter were each observed once. Samples suspended in boreholes penetrating highly fractured zones were less densely colonized than those in the borehole penetrating a less fractured zone. The results suggest that contamination of karst aquifers by enteric bacteria is unlikely to be persistent. We hypothesize that this may be a result of the high flow velocities found in karst conduits, and of predation of colonizing bacteria by autochthonous zooplankton.

  5. Salivary Mucins Protect Surfaces from Colonization by Cariogenic Bacteria

    PubMed Central

    Frenkel, Erica Shapiro

    2014-01-01

    Understanding how the body's natural defenses function to protect the oral cavity from the myriad of bacteria that colonize its surfaces is an ongoing topic of research that can lead to breakthroughs in treatment and prevention. One key defense mechanism on all moist epithelial linings, such as the mouth, gastrointestinal tract, and lungs, is a layer of thick, well-hydrated mucus. The main gel-forming components of mucus are mucins, large glycoproteins that play a key role in host defense. This study focuses on elucidating the connection between MUC5B salivary mucins and dental caries, one of the most common oral diseases. Dental caries is predominantly caused by Streptococcus mutans attachment and biofilm formation on the tooth surface. Once S. mutans attaches to the tooth, it produces organic acids as metabolic by-products that dissolve tooth enamel, leading to cavity formation. We utilize CFU counts and fluorescence microscopy to quantitatively show that S. mutans attachment and biofilm formation are most robust in the presence of sucrose and that aqueous solutions of purified human MUC5B protect surfaces by acting as an antibiofouling agent in the presence of sucrose. In addition, we find that MUC5B does not alter S. mutans growth and decreases surface attachment and biofilm formation by maintaining S. mutans in the planktonic form. These insights point to the importance of salivary mucins in oral health and lead to a better understanding of how MUC5B could play a role in cavity prevention or diagnosis. PMID:25344244

  6. Activation of HIF-1α and LL-37 by commensal bacteria inhibits Candida albicans colonization

    PubMed Central

    Fan, Di; Coughlin, Laura A.; Neubauer, Megan M.; Kim, Jiwoong; Kim, Minsoo; Zhan, Xiaowei; Simms-Waldrip, Tiffany R.; Xie, Yang; Hooper, Lora V.; Koh, Andrew Y.

    2015-01-01

    Candida albicans colonization is required for invasive disease1-3. Unlike humans, adult mice with mature intact gut microbiota are resistant to C. albicans gastrointestinal (GI) colonization2,4. But the factors that promote C. albicans colonization resistance are unknown. Here we demonstrate that commensal anaerobic bacteria – specifically Clostridial Firmicutes (Clusters IV and XIVa) and Bacteroidetes – are critical for maintaining C. albicans colonization resistance in mice. Using Bacteroides thetaiotamicron as a model organism, we find that HIF-1α, a transcription factor important for activating innate immune effectors, and the antimicrobial peptide LL37-CRAMP are key determinants of C. albicans colonization resistance. While antibiotic treatment enables C. albicans colonization, pharmacologic activation of colonic Hif1a induces CRAMP expression and results in a significant reduction of C. albicans GI colonization and a 50% decrease in mortality from invasive disease. In the setting of antibiotics, Hif1a and Cramp are required for B. thetaiotamicron-induced protection against CA colonization of the gut. Thus, C. albicans GI colonization modulation by activation of gut mucosal immune effectors may represent a novel therapeutic approach for preventing invasive fungal disease in humans. PMID:26053625

  7. Vancomycin-sensitive bacteria trigger development of colitis-associated colon cancer by attracting neutrophils

    PubMed Central

    Tanaka, Yuriko; Ito, Sachiko; Isobe, Ken-ichi

    2016-01-01

    Inflammatory bowel disease confers an increased risk of developing colitis-associated colon cancer (CAC). During the active colitis or developing tumor stage, commensal bacteria show dynamic translocation. However, whether alteration of the bacterial composition in the gut causes CAC is still unclear. To clarify the effect of commensal bacteria on CAC development, we employed an azoxymethane (AOM) and dextran sodium sulfate (DSS)-induced murine CAC model treated with or without antibiotics. In addition, we analyzed the effects of antibiotics on infiltration of myeloid cells, colonic inflammatory responses, and colorectal cancer formation. We found that vancomycin treatment dramatically suppressed tumor development. In addition, AOM/DSS treatment greatly induced the infiltration of Gr-1high/CD11bhigh neutrophils to the colon, which led to the production of tumor necrosis factor α and inducible nitric oxide synthase. Vancomycin treatment suppressed the infiltration of neutrophils induced by AOM/DSS. Moreover, vancomycin treatment greatly reduced the colon injury and DNA damage caused by AOM/DSS-induced NO radicals. Our results indicate that vancomycin-sensitive bacteria induced colon inflammation and DNA damage by attracting neutrophils into damaged colon tissue, thus promoting tumor formation. PMID:27050089

  8. Vancomycin-sensitive bacteria trigger development of colitis-associated colon cancer by attracting neutrophils.

    PubMed

    Tanaka, Yuriko; Ito, Sachiko; Isobe, Ken-ichi

    2016-01-01

    Inflammatory bowel disease confers an increased risk of developing colitis-associated colon cancer (CAC). During the active colitis or developing tumor stage, commensal bacteria show dynamic translocation. However, whether alteration of the bacterial composition in the gut causes CAC is still unclear. To clarify the effect of commensal bacteria on CAC development, we employed an azoxymethane (AOM) and dextran sodium sulfate (DSS)-induced murine CAC model treated with or without antibiotics. In addition, we analyzed the effects of antibiotics on infiltration of myeloid cells, colonic inflammatory responses, and colorectal cancer formation. We found that vancomycin treatment dramatically suppressed tumor development. In addition, AOM/DSS treatment greatly induced the infiltration of Gr-1(high)/CD11b(high) neutrophils to the colon, which led to the production of tumor necrosis factor α and inducible nitric oxide synthase. Vancomycin treatment suppressed the infiltration of neutrophils induced by AOM/DSS. Moreover, vancomycin treatment greatly reduced the colon injury and DNA damage caused by AOM/DSS-induced NO radicals. Our results indicate that vancomycin-sensitive bacteria induced colon inflammation and DNA damage by attracting neutrophils into damaged colon tissue, thus promoting tumor formation. PMID:27050089

  9. Zebrafish gut colonization by mCherry-labelled lactic acid bacteria.

    PubMed

    Russo, Pasquale; Iturria, Iñaki; Mohedano, Maria Luz; Caggianiello, Graziano; Rainieri, Sandra; Fiocco, Daniela; Angel Pardo, Miguel; López, Paloma; Spano, Giuseppe

    2015-04-01

    A critical feature of probiotic microorganisms is their ability to colonize the intestine of the host. Although the microbial potential to adhere to the human gut lumen has been investigated in in vitro models, there is still much to discover about their in vivo behaviour. Zebrafish is a vertebrate model that is being widely used to investigate various biological processes shared with humans. In this work, we report on the use of the zebrafish model to investigate the in vivo colonization ability of previously characterized probiotic lactic acid bacteria. Lactobacillus plantarum Lp90, L. plantarum B2 and Lactobacillus fermentum PBCC11.5 were fluorescently tagged by transfer of the pRCR12 plasmid, which encodes the mCherry protein and which was constructed in this work. The recombinant bacteria were used to infect germ-free zebrafish larvae. After removal of bacteria, the colonization ability of the strains was monitored until 3 days post-infection by using a fluorescence stereomicroscope. The results indicated differential adhesion capabilities among the strains. Interestingly, a displacement of bacteria from the medium to the posterior intestinal tract was observed as a function of time that suggested a transient colonization by probiotics. Based on fluorescence observation, L. plantarum strains exhibited a more robust adhesion capability. In conclusion, the use of pRCR12 plasmid for labelling Lactobacillus strains provides a powerful and very efficient tool to monitor the in vivo colonization in zebrafish larvae and to investigate the adhesion ability of probiotic microorganisms. PMID:25586576

  10. Bacteria from diverse habitats colonize and compete in the mouse gut

    PubMed Central

    Seedorf, Henning; Griffin, Nicholas W.; Ridaura, Vanessa K.; Reyes, Alejandro; Cheng, Jiye; Rey, Federico E.; Smith, Michelle I.; Simon, Gabriel M.; Scheffrahn, Rudolf H.; Woebken, Dagmar; Spormann, Alfred M.; Van Treuren, William; Ursell, Luke K.; Pirrung, Megan; Robbins-Pianka, Adam; Cantarel, Brandi L.; Lombard, Vincent; Henrissat, Bernard; Knight, Rob

    2014-01-01

    SUMMARY To study how microbes establish themselves in a mammalian gut environment, we colonized germ-free mice with microbial communities from human, zebrafish and termite guts, human skin and tongue, soil, and estuarine microbial mats. Bacteria from these foreign environments colonized and persisted in the mouse gut; their capacity to metabolize dietary and host carbohydrates, and bile acids, correlated with colonization success. Co-housing mice harboring these xenomicrobiota with one another, with mice harboring native gut microbiota, and germ-free ‘bystanders’ revealed the success of particular bacterial taxa in colonizing an empty gut habitat and guts with established communities. Unanticipated patterns of ecological succession were observed; for example, a soil-derived bacterium dominated even in the presence of bacteria from other gut communities (zebrafish and termite), and human-derived bacteria colonized germ-free mice before mouse-derived organisms. This approach generalizes to address a variety of mechanistic questions about succession, including succession in the context of microbiota-directed therapeutics. PMID:25284151

  11. In vitro degradation and fermentation of three dietary fiber sources by human colonic bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although clinical benefits of dietary fiber supplementation seem to depend in part on the extent of fiber degradation and fermentation by colonic bacteria, little is known about the effect of the type of supplemented fiber on bacterial metabolism. In an experiment using a non-adapted human bacterial...

  12. Colonization of plants by human pathogenic bacteria in the course of organic vegetable production

    PubMed Central

    Hofmann, Andreas; Fischer, Doreen; Hartmann, Anton; Schmid, Michael

    2014-01-01

    In recent years, increasing numbers of outbreaks caused by the consumption of vegetables contaminated with human pathogenic bacteria were reported. The application of organic fertilizers during vegetable production is one of the possible reasons for contamination with those pathogens. In this study laboratory experiments in axenic and soil systems following common practices in organic farming were conducted to identify the minimal dose needed for bacterial colonization of plants and to identify possible factors like bacterial species or serovariation, plant species or organic fertilizer types used, influencing the success of plant colonization by human pathogenic bacteria. Spinach and corn salad were chosen as model plants and were inoculated with different concentrations of Salmonella enterica sv. Weltevreden, Listeria monocytogenes sv. 4b and EGD-E sv. 1/2a either directly (axenic system) or via agricultural soil amended with spiked organic fertilizers (soil system). In addition to PCR- and culture-based detection methods, fluorescence in situ hybridization (FISH) was applied in order to localize bacteria on or in plant tissues. Our results demonstrate that shoots were colonized by the pathogenic bacteria at inoculation doses as low as 4 × 10 CFU/ml in the axenic system or 4 × 105 CFU/g in the soil system. In addition, plant species dependent effects were observed. Spinach was colonized more often and at lower inoculation doses compared to corn salad. Differential colonization sites on roots, depending on the plant species could be detected using FISH-CLSM analysis. Furthermore, the transfer of pathogenic bacteria to plants via organic fertilizers was observed more often and at lower initial inoculation doses when fertilization was performed with inoculated slurry compared to inoculated manure. Finally, it could be shown that by introducing a simple washing step, the bacterial contamination was reduced in most cases or even was removed completely in some cases

  13. Colonization of plants by human pathogenic bacteria in the course of organic vegetable production.

    PubMed

    Hofmann, Andreas; Fischer, Doreen; Hartmann, Anton; Schmid, Michael

    2014-01-01

    In recent years, increasing numbers of outbreaks caused by the consumption of vegetables contaminated with human pathogenic bacteria were reported. The application of organic fertilizers during vegetable production is one of the possible reasons for contamination with those pathogens. In this study laboratory experiments in axenic and soil systems following common practices in organic farming were conducted to identify the minimal dose needed for bacterial colonization of plants and to identify possible factors like bacterial species or serovariation, plant species or organic fertilizer types used, influencing the success of plant colonization by human pathogenic bacteria. Spinach and corn salad were chosen as model plants and were inoculated with different concentrations of Salmonella enterica sv. Weltevreden, Listeria monocytogenes sv. 4b and EGD-E sv. 1/2a either directly (axenic system) or via agricultural soil amended with spiked organic fertilizers (soil system). In addition to PCR- and culture-based detection methods, fluorescence in situ hybridization (FISH) was applied in order to localize bacteria on or in plant tissues. Our results demonstrate that shoots were colonized by the pathogenic bacteria at inoculation doses as low as 4 × 10 CFU/ml in the axenic system or 4 × 10(5) CFU/g in the soil system. In addition, plant species dependent effects were observed. Spinach was colonized more often and at lower inoculation doses compared to corn salad. Differential colonization sites on roots, depending on the plant species could be detected using FISH-CLSM analysis. Furthermore, the transfer of pathogenic bacteria to plants via organic fertilizers was observed more often and at lower initial inoculation doses when fertilization was performed with inoculated slurry compared to inoculated manure. Finally, it could be shown that by introducing a simple washing step, the bacterial contamination was reduced in most cases or even was removed completely in some

  14. Bacteria from diverse habitats colonize and compete in the mouse gut.

    PubMed

    Seedorf, Henning; Griffin, Nicholas W; Ridaura, Vanessa K; Reyes, Alejandro; Cheng, Jiye; Rey, Federico E; Smith, Michelle I; Simon, Gabriel M; Scheffrahn, Rudolf H; Woebken, Dagmar; Spormann, Alfred M; Van Treuren, William; Ursell, Luke K; Pirrung, Megan; Robbins-Pianka, Adam; Cantarel, Brandi L; Lombard, Vincent; Henrissat, Bernard; Knight, Rob; Gordon, Jeffrey I

    2014-10-01

    To study how microbes establish themselves in a mammalian gut environment, we colonized germ-free mice with microbial communities from human, zebrafish, and termite guts, human skin and tongue, soil, and estuarine microbial mats. Bacteria from these foreign environments colonized and persisted in the mouse gut; their capacity to metabolize dietary and host carbohydrates and bile acids correlated with colonization success. Cohousing mice harboring these xenomicrobiota or a mouse cecal microbiota, along with germ-free "bystanders," revealed the success of particular bacterial taxa in invading guts with established communities and empty gut habitats. Unanticipated patterns of ecological succession were observed; for example, a soil-derived bacterium dominated even in the presence of bacteria from other gut communities (zebrafish and termite), and human-derived bacteria colonized germ-free bystander mice before mouse-derived organisms. This approach can be generalized to address a variety of mechanistic questions about succession, including succession in the context of microbiota-directed therapeutics. PMID:25284151

  15. [Should we screen for colonization to control the spread of multidrug resistant bacteria?].

    PubMed

    Lepelletier, D; Perron, S; Huguenin, H; Picard, M; Bemer, P; Caillon, J; Juvin, M-E; Drugeon, H

    2003-10-01

    Should we screen for colonization to control the spread of multidrug-resistant bacteria? A multidrug-resistant bacteria surveillance program was performed in 1999 at Laënnec Hospital (Nantes, France). After a 3-year period, the results permit us to determine the strategy to strengthen their spread. In 2001, Staphylococcus aureus resistant to methicillin represented 45% of the 202 multidrug-resistant bacteria isolated. The global incidence rate per 100 admissions remained stable between 1999 and 2001 (0.42%), but those of infections acquired in our institution decreased significantly from 0.27% in 1999 to 0.18% in 2001 (P < 0.05), particularly in medical care units (P < 0.04). In spite of this surveillance program and hygiene trainings, the global incidence remained stable during the study period, even if our action contributed to decrease the incidence of S. aureus resistant to methicillin acquired in our institution. Isolation precautions and screening for colonization policy in intensive care units are not sufficient to control the spread of MRB at hospital level. They should be strengthened by procedures for the transfer of infected or colonized patients and by antibiotic use control. PMID:14568591

  16. Heat-treated colostrum feeding promotes beneficial bacteria colonization in the small intestine of neonatal calves.

    PubMed

    Malmuthuge, Nilusha; Chen, Yanhong; Liang, Guanxiang; Goonewardene, Laksiri A; Guan, Le Luo

    2015-11-01

    The present study investigated the effect of heat-treated colostrum feeding on the bacterial colonization in calf small intestine of neonatal calves within the first 12h of life. Newborn Holstein bull calves (n=32) were assigned to 3 treatment groups and fed with either fresh colostrum (FC, n=12) or heat-treated (60°C, 60 min) colostrum (HC, n=12) soon after birth, whereas the control (NC, n=8) group did not receive colostrum or water. Small intestinal tissues and contents were collected from proximal jejunum, distal jejunum, and ileum at 6 and 12h after birth, following euthanasia. Quantitative real time-PCR was used to explore the colonization of total bacteria, Lactobacillus, Bifidobacterium, and Escherichia coli. The feeding of colostrum soon after birth increased the colonization of total bacteria in calf gut within the first 12h compared with NC. In contrast, the prevalence of Lactobacillus was lower in HC and FC compared to NC. Remarkable changes in the prevalence of small intestinal tissue-attached Bifidobacterium were observed with the feeding of HC, but not that in small intestinal contents. The prevalence of Bifidobacterium was 3.2 and 5.2 fold higher in HC than FC and NC, respectively, at 6h. Although the feeding of FC did not enhance the prevalence of tissue-attached Bifidobacterium at 6h compared with NC, it displayed a gradual increase over the time that was higher than NC, but similar to that of HC at 12h. Moreover, the colonization of E. coli was drastically reduced in HC calves compared with FC and NC. Thus, the present study suggests that the feeding of HC enhances the colonization of Bifidobacterium but lessens E. coli in the calf small intestine immediately postpartum compared with that of FC and NC. The increased colonization of beneficial bacteria along with the decreased colonization of potential pathogens in calf gut may also diminish the neonatal calf diarrhea when calves are fed heat-treated colostrum soon after birth. PMID:26342981

  17. Pathogenesis of Human Enterovirulent Bacteria: Lessons from Cultured, Fully Differentiated Human Colon Cancer Cell Lines

    PubMed Central

    Liévin-Le Moal, Vanessa

    2013-01-01

    SUMMARY Hosts are protected from attack by potentially harmful enteric microorganisms, viruses, and parasites by the polarized fully differentiated epithelial cells that make up the epithelium, providing a physical and functional barrier. Enterovirulent bacteria interact with the epithelial polarized cells lining the intestinal barrier, and some invade the cells. A better understanding of the cross talk between enterovirulent bacteria and the polarized intestinal cells has resulted in the identification of essential enterovirulent bacterial structures and virulence gene products playing pivotal roles in pathogenesis. Cultured animal cell lines and cultured human nonintestinal, undifferentiated epithelial cells have been extensively used for understanding the mechanisms by which some human enterovirulent bacteria induce intestinal disorders. Human colon carcinoma cell lines which are able to express in culture the functional and structural characteristics of mature enterocytes and goblet cells have been established, mimicking structurally and functionally an intestinal epithelial barrier. Moreover, Caco-2-derived M-like cells have been established, mimicking the bacterial capture property of M cells of Peyer's patches. This review intends to analyze the cellular and molecular mechanisms of pathogenesis of human enterovirulent bacteria observed in infected cultured human colon carcinoma enterocyte-like HT-29 subpopulations, enterocyte-like Caco-2 and clone cells, the colonic T84 cell line, HT-29 mucus-secreting cell subpopulations, and Caco-2-derived M-like cells, including cell association, cell entry, intracellular lifestyle, structural lesions at the brush border, functional lesions in enterocytes and goblet cells, functional and structural lesions at the junctional domain, and host cellular defense responses. PMID:24006470

  18. Differences in Mucosal Gene Expression in the Colon of Two Inbred Mouse Strains after Colonization with Commensal Gut Bacteria

    PubMed Central

    Blaut, Michael; Loh, Gunnar

    2013-01-01

    The host genotype has been proposed to contribute to individually composed bacterial communities in the gut. To provide deeper insight into interactions between gut bacteria and host, we associated germ-free C3H and C57BL/10 mice with intestinal bacteria from a C57BL/10 donor mouse. Analysis of microbiota similarity between the animals with denaturing gradient gel electrophoresis revealed the development of a mouse strain-specific microbiota. Microarray-based gene expression analysis in the colonic mucosa identified 202 genes whose expression differed significantly by a factor of more than 2. Application of bioinformatics tools demonstrated that functional terms including signaling/secretion, lipid degradation/catabolism, guanine nucleotide/guanylate binding and immune response were significantly enriched in differentially expressed genes. We had a closer look at the 56 genes with expression differences of more than 4 and observed a higher expression in C57BL/10 mice of the genes coding for Tlr1 and Ang4 which are involved in the recognition and response to gut bacteria. A higher expression of Pla2g2a was detected in C3H mice. In addition, a number of interferon-inducible genes were higher expressed in C3H than in C57BL/10 mice including Gbp1, Mal, Oasl2, Ifi202b, Rtp4, Ly6g6c, Ifi27l2a, Usp18, Ifit1, Ifi44, and Ly6g indicating that interferons may play an essential role in microbiota regulation. However, genes coding for interferons, their receptors, factors involved in interferon expression regulation or signaling pathways were not differentially expressed between the two mouse strains. Taken together, our study confirms that the host genotype is involved in the establishment of host-specific bacterial communities in the gut. Based on expression differences after colonization with the same bacterial inoculum, we propose that Pla2g2a and interferon-dependent genes may contribute to this phenomenon. PMID:23951309

  19. The Role of Colonic Bacteria in the Metabolism of the Natural Isoflavone Daidzin to Equol

    PubMed Central

    Rafii, Fatemeh

    2015-01-01

    Isoflavones are found in leguminous plants, especially soybeans. They have a structural similarity to natural estrogens, which enables them to bind to estrogen receptors and elicit biological activities similar to natural estrogens. They have been suggested to be beneficial for the prevention and therapy of hormone-dependent diseases. After soy products are consumed, the bacteria of the intestinal microflora metabolize isoflavones to metabolites with altered absorption, bioavailability, and estrogenic characteristics. Variations in the effect of soy products have been correlated with the isoflavone metabolites found in plasma and urine samples of the individuals consuming soy products. The beneficial effects of the soy isoflavone daidzin, the glycoside of daidzein, have been reported in individuals producing equol, a reduction product of daidzein produced by specific colonic bacteria in individuals called equol producers. These individuals comprise 30% and 60% of populations consuming Western and soy-rich Asian diets, respectively. Since the higher percentage of equol producers in populations consuming soy-rich diets is correlated with a lower incidence of hormone-dependent diseases, considerable efforts have been made to detect the specific colonic bacteria involved in the metabolism of daidzein to the more estrogenic compound, equol, which should facilitate the investigation of the metabolic activities related to this compound. PMID:25594250

  20. Kinetics and strain specificity of rhizosphere and endophytic colonization by enteric bacteria on seedlings of Medicago sativa and Medicago truncatula.

    PubMed

    Dong, Yuemei; Iniguez, A Leonardo; Ahmer, Brian M M; Triplett, Eric W

    2003-03-01

    The presence of human-pathogenic, enteric bacteria on the surface and in the interior of raw produce is a significant health concern. Several aspects of the biology of the interaction between these bacteria and alfalfa (Medicago sativa) seedlings are addressed here. A collection of enteric bacteria associated with alfalfa sprout contaminations, along with Escherichia coli K-12, Salmonella enterica serotype Typhimurium strain ATCC 14028, and an endophyte of maize, Klebsiella pneumoniae 342, were labeled with green fluorescent protein, and their abilities to colonize the rhizosphere and the interior of the plant were compared. These strains differed widely in their endophytic colonization abilities, with K. pneumoniae 342 and E. coli K-12 being the best and worst colonizers, respectively. The abilities of the pathogens were between those of K. pneumoniae 342 and E. coli K-12. All Salmonella bacteria colonized the interiors of the seedlings in high numbers with an inoculum of 10(2) CFU, although infection characteristics were different for each strain. For most strains, a strong correlation between endophytic colonization and rhizosphere colonization was observed. These results show significant strain specificity for plant entry by these strains. Significant colonization of lateral root cracks was observed, suggesting that this may be the site of entry into the plant for these bacteria. At low inoculum levels, a symbiosis mutant of Medicago truncatula, dmi1, was colonized in higher numbers on the rhizosphere and in the interior by a Salmonella endophyte than was the wild-type host. Endophytic entry of M. truncatula appears to occur by a mechanism independent of the symbiotic infections by Sinorhizobium meliloti or mycorrhizal fungi. PMID:12620870

  1. Colonization and distribution of segmented filamentous bacteria (SFB) in chicken gastrointestinal tract and their relationship with host immunity.

    PubMed

    Liao, Ningbo; Yin, Yeshi; Sun, Guochang; Xiang, Charlie; Liu, Donghong; Yu, Hongwei D; Wang, Xin

    2012-08-01

    Uncultivable segmented filamentous bacteria (SFB) reside in the gastrointestinal (GI) tract of mammals and can boost the host immunity. Immunoglobulin A (IgA) from mother's milk has been previously shown to be a key factor in regulating SFB colonization. Because neonatal chicken cannot acquire IgA from maternal milk, they are a good model to examine the role of IgA in SFB colonization. Here, we used the fluorescent in situ hybridization (FISH) and quantitative PCR (qPCR) to monitor the colonization and distribution of SFB in chickens aged from 2-day-old to 6-week-old. Early SFB colonization, which primarily occurred in the ileal mucosa (< 13 days old), was IgA independent. From the age of 17-42 days, there was an increase in IgA in the gut mucosa, which was correlated with a decrease in SFB. To examine the effect of probiotics and immunosuppression on SFB colonization, we treated the chickens by feeding them Lactobacillus delbrueckii or giving them a subcutaneous injection of cyclophosphamide (CTX). Feeding lactobacilli at birth rendered SFB colonization occurring 4 days earlier, while CTX treatment increases the SFB colonization through reducing the other non-SFB bacteria. Altogether, our data suggest that early colonization of SFB in chicken occurs independently of IgA and the population of SFB in the GI tract of chicken may be manipulated from birth via probiotic or CTX treatment. PMID:22429007

  2. Effect of human isolated probiotic bacteria on preventing Campylobacter jejuni colonization of poultry.

    PubMed

    Cean, Ada; Stef, Lavinia; Simiz, Eliza; Julean, Calin; Dumitrescu, Gabi; Vasile, Aida; Pet, Elena; Drinceanu, Dan; Corcionivoschi, Nicolae

    2015-02-01

    This study was performed in order to determine whether human isolated probiotic bacteria can be effective in reducing Campylobacter jejuni infection of chicken intestinal cells, in vitro, and in decreasing its colonization abilities within the chicken gut. Our results show that the probiotic strains Lactobacillus paracasei J. R, L. rhamnosus 15b, L. lactis Y, and L. lactis FOa had a significant effect on C. jejuni invasion of chicken primary cells, with the strongest inhibitory effect detected when a combination of four was administered. In regard to the in vivo effect, using all four strains in one combination prevented mucus colonization in the duodenum and cecum. Moreover, the pathogen load in the lumen of these two compartments was significantly reduced. When probiotics were introduced during the early growth period, the presence of the pathogen in feces was increased (p>0.05), but when they were given during the last week of growth, there was no significant effect. In conclusion, our data indicate that these four new probiotic strains are able to cause modifications in the chicken intestinal mucosa and can reduce the ability of C. jejuni to invade, in vitro, and to colonize, in vivo. These probiotics are now proven to be effective even when introduced in broiler's feed 7 days before slaughter, which makes them cost-effective for the producers. PMID:25585278

  3. In vitro degradation and fermentation of three dietary fiber sources by human colonic bacteria.

    PubMed

    Bliss, Donna Z; Weimer, Paul J; Jung, Hans-Joachim G; Savik, Kay

    2013-05-15

    Although clinical benefits of dietary fiber supplementation seem to depend partially on the extent of fiber degradation and fermentation by colonic bacteria, little is known about the effect of supplemental fiber type on bacterial metabolism. In an experiment using a nonadapted human bacterial population from three normal subjects, the extent of in vitro fermentation was greater for gum arabic (GA) than for psyllium (PSY), which was greater than that for carboxymethylcellulose (CMC). In a separate experiment, in vitro incubation with feces from 52 subjects with fecal incontinence, before and after random assignment to and consumption of one of three fiber (GA, PSY, or CMC) supplements or a placebo for 20-21 days, indicated that prior consumption of a specific fiber source did not increase its degradation by fecal bacteria. Results suggest that the colonic microbial community enriched on a particular fiber substrate can rapidly adapt to the presentation of a new fiber substrate. Clinical implications of the findings are that intake of a fiber source by humans is not expected to result in bacterial adaptation that would require continually larger and eventually intolerable amounts of fiber to achieve therapeutic benefits. PMID:23556460

  4. In Vitro Degradation and Fermentation of Three Dietary Fiber Sources by Human Colonic Bacteria

    PubMed Central

    Bliss, Donna Z.; Weimer, Paul J.; Jung, Hans-Joachim G.; Savik, Kay

    2013-01-01

    Although clinical benefits of dietary fiber supplementation seem to depend partially on the extent of fiber degradation and fermentation by colonic bacteria, little is known about the effect of supplemental fiber type on bacterial metabolism. In an experiment using a non-adapted human bacterial population from three normal subjects, extent of in vitro fermentation was greater for gum arabic (GA) than for psyllium (PSY), which was greater than that for carboxymethylcellulose (CMC). In a separate experiment, in vitro incubation with feces from 52 subjects with fecal incontinence, before and after random assignment to and consumption of one of three fiber (GA, PSY, or CMC) supplements or a placebo for 20-21d, indicated that prior consumption of a specific fiber source did not increase its degradation by fecal bacteria. Results suggest that the colonic microbial community enriched on a particular fiber substrate can rapidly adapt to the presentation of a new fiber substrate. Clinical implications of the findings are that intake of a fiber source by humans is not expected to result in bacterial adaptation that would require continually larger and eventually intolerable amounts of fiber to achieve therapeutic benefits. PMID:23556460

  5. Commensal bacteria can enter colonic epithelial cells and induce proinflammatory cytokine secretion: a possible pathogenic mechanism of ulcerative colitis.

    PubMed

    Ohkusa, Toshifumi; Yoshida, Tsutomu; Sato, Nobuhiro; Watanabe, Sumio; Tajiri, Hisao; Okayasu, Isao

    2009-05-01

    Interleukin 2 (IL-2)- and IL-10-knockout mice develop spontaneous colitis under conventional but not germ-free conditions, suggesting that commensal bacteria play an important role in the pathogenesis of colitis. However, interactions between commensal bacteria and colonic epithelial cells have not been fully investigated. We therefore assessed the ability of various commensal bacteria and probiotics to adhere to and invade colonic epithelial cells. Effects of the bacteria on production of proinflammatory cytokines were also measured. Commensal bacteria, including mucosal organisms isolated from ulcerative colitis (UC) patients, such as Fusobacterium varium, reported as a possible pathogen in UC, Bacteroides vulgatus, Escherichia coli and Clostridium clostridioforme, as well as their type strains and probiotics, were assessed for their ability to adhere to and invade colonic epithelial cells using two cell lines, SW-480 and HT-29. Our experiments employed co-incubation, a combination of scanning and transmission electron microscopy and recovery of bacteria from infected-cell lysates. F. varium and several other commensal bacteria, but not probiotics, adhered to colonic epithelial cells and invaded their cytoplasm. ELISA and real-time PCR revealed that the host cells, particularly those invaded by F. varium, showed significant increases in IL-8 and TNF-alpha concentrations in supernatants, with elevation of IL-8, TNF-alpha, MCP-1 and IL-6 mRNAs. Furthermore, IL-8 and TNF-alpha expression and nuclear phosphorylated NF-kappaB p65 expression could be immunohistochemically confirmed in inflamed epithelium with cryptitis or crypt abscess in UC patients. Certain commensal bacteria can invade colonic epithelial cells, activating early intracellular signalling systems to trigger host inflammatory reactions. PMID:19369513

  6. Isolation and characterization of endophytic colonizing bacteria from agronomic crops and prairie plants.

    PubMed

    Zinniel, Denise K; Lambrecht, Pat; Harris, N Beth; Feng, Zhengyu; Kuczmarski, Daniel; Higley, Phyllis; Ishimaru, Carol A; Arunakumari, Alahari; Barletta, Raúl G; Vidaver, Anne K

    2002-05-01

    Endophytic bacteria reside within plant hosts without causing disease symptoms. In this study, 853 endophytic strains were isolated from aerial tissues of four agronomic crop species and 27 prairie plant species. We determined several phenotypic properties and found approximately equal numbers of gram-negative and gram-positive isolates. In a greenhouse study, 28 of 86 prairie plant endophytes were found to colonize their original hosts at 42 days postinoculation at levels of 3.5 to 7.7 log(10) CFU/g (fresh weight). More comprehensive colonization studies were conducted with 373 corn and sorghum endophytes. In growth room studies, none of the isolates displayed pathogenicity, and 69 of the strains were recovered from corn or sorghum seedlings at levels of 8.3 log(10) CFU/plant or higher. Host range greenhouse studies demonstrated that 26 of 29 endophytes were recoverable from at least one host other than corn and sorghum at levels of up to 5.8 log(10) CFU/g (fresh weight). Long-range dent corn greenhouse studies and field trials with 17 wild-type strains and 14 antibiotic-resistant mutants demonstrated bacterial persistence at significant average colonization levels ranging between 3.4 and 6.1 log(10) CFU/g (fresh weight) up to 78 days postinoculation. Three prairie and three agronomic endophytes exhibiting the most promising levels of colonization and an ability to persist were identified as Cellulomonas, Clavibacter, Curtobacterium, and Microbacterium isolates by 16S rRNA gene sequence, fatty acid, and carbon source utilization analyses. This study defines for the first time the endophytic nature of Microbacterium testaceum. These microorganisms may be useful for biocontrol and other applications. PMID:11976089

  7. Use of Shotgun Metagenome Sequencing To Detect Fecal Colonization with Multidrug-Resistant Bacteria in Children.

    PubMed

    Andersen, Heidi; Connolly, Natalia; Bangar, Hansraj; Staat, Mary; Mortensen, Joel; Deburger, Barbara; Haslam, David B

    2016-07-01

    Prevention of multidrug-resistant (MDR) bacterial infections relies on accurate detection of these organisms. We investigated shotgun metagenome sequencing for the detection of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), and MDR Enterobacteriaceae Fecal metagenomes were analyzed from high-risk inpatients and compared to those of low-risk outpatients and controls with minimal risk for a MDR bacterial infection. Principal-component analysis clustered patient samples into distinct cohorts, confirming that the microbiome composition was significantly different between cohorts (P = 0.006). Microbial diversity and relative anaerobe abundance were preserved in outpatients compared to those in controls. Relative anaerobe abundance was significantly reduced in inpatients compared to that in outpatients (P = 0.006). Although the potential for MDR bacteria was increased in inpatients and outpatients compared to that in controls (P < 0.001), there was no difference between inpatients and outpatients. However, 9 (53%) inpatients had colonization with a MDR bacterium that was not identified by culture. Unlike culture, shotgun sequencing quantitatively characterizes the burdens of multiple MDR bacteria relative to all of the microbiota within the intestinal community. We propose consideration of key microbiome features, such as diversity and relative anaerobe abundance, in addition to the detection of MDR bacteria by shotgun metagenome sequencing as a novel method that might better identify patients who are at increased risk of a MDR infection. PMID:27122381

  8. Biofilm formation, communication and interactions of leaching bacteria during colonization of pyrite and sulfur surfaces.

    PubMed

    Bellenberg, Sören; Díaz, Mauricio; Noël, Nanni; Sand, Wolfgang; Poetsch, Ansgar; Guiliani, Nicolas; Vera, Mario

    2014-11-01

    Bioleaching of metal sulfides is an interfacial process where biofilm formation is considered to be important in the initial steps of this process. Among the factors regulating biofilm formation, molecular cell-to-cell communication such as quorum sensing is involved. A functional LuxIR-type I quorum sensing system is present in Acidithiobacillus ferrooxidans. However, cell-to-cell communication among different species of acidophilic mineral-oxidizing bacteria has not been studied in detail. These aspects were the scope of this study with emphasis on the effects exerted by the external addition of mixtures of synthetic N-acyl-homoserine-lactones on pure and binary cultures. Results revealed that some mixtures had inhibitory effects on pyrite leaching. Some of them correlated with changes in biofilm formation patterns on pyrite coupons. We also provide evidence that A. thiooxidans and Acidiferrobacter spp. produce N-acyl-homoserine-lactones. In addition, the observation that A. thiooxidans cells attached more readily to pyrite pre-colonized by living iron-oxidizing acidophiles than to heat-inactivated or biofilm-free pyrite grains suggests that other interactions also occur. Our experiments show that pre-cultivation conditions influence A. ferrooxidans attachment to pre-colonized pyrite surfaces. The understanding of cell-to-cell communication may consequently be used to develop attempts to influence biomining/bioremediation processes. PMID:25172572

  9. Food-grade bacteria expressing elafin protect against inflammation and restore colon homeostasis.

    PubMed

    Motta, Jean-Paul; Bermúdez-Humarán, Luis G; Deraison, Céline; Martin, Laurence; Rolland, Corinne; Rousset, Perrine; Boue, Jérôme; Dietrich, Gilles; Chapman, Kevin; Kharrat, Pascale; Vinel, Jean-Pierre; Alric, Laurent; Mas, Emmanuel; Sallenave, Jean-Michel; Langella, Philippe; Vergnolle, Nathalie

    2012-10-31

    Elafin, a natural protease inhibitor expressed in healthy intestinal mucosa, has pleiotropic anti-inflammatory properties in vitro and in animal models. We found that mucosal expression of Elafin is diminished in patients with inflammatory bowel disease (IBD). This defect is associated with increased elastolytic activity (elastase-like proteolysis) in colon tissue. We engineered two food-grade strains of lactic acid bacteria (LAB) to express and deliver Elafin to the site of inflammation in the colon to assess the potential therapeutic benefits of the Elafin-expressing LAB. In mouse models of acute and chronic colitis, oral administration of Elafin-expressing LAB decreased elastolytic activity and inflammation and restored intestinal homeostasis. Furthermore, when cultures of human intestinal epithelial cells were treated with LAB secreting Elafin, the inflamed epithelium was protected from increased intestinal permeability and from the release of cytokines and chemokines, both of which are characteristic of intestinal dysfunction associated with IBD. Together, these results suggest that oral delivery of LAB secreting Elafin may be useful for treating IBD in humans. PMID:23115353

  10. [Colonization characteristics of endophytic bacteria NJ13 in Panax ginseng and its biocontrol efficiency against Alternaria leaf spot of ginseng].

    PubMed

    Chen, Chang-Qing; Li, Tong; Li, Xin-Lian; Jiang, Yun; Tian, Lei; Xu, Peng

    2014-05-01

    To reveal the colonization characteristics in host of endophytic biocontrol bacteria NJ13 isolated from Panax ginseng, this study obtained the marked strain NJ13-R which was double antibiotic resistant to rifampicin and streptomycin through enhancing the method of inducing antibiotic. The colonization characteristics in ginseng and its biocontrol efficiency against Alternaria spot of ginseng in the field were studied. The results showed that the strain could colonize in root, stem and leaf of ginseng and the colonization amount was positive correlated with inoculation concentration. Meanwhile, the strain could infect and then transfer in different tissues of ginseng The colonization amount of strain in roots and leaves of ginseng increased first and then decreased. However, the tendency of colonization amount of strain in stems was ascend at first and then descend slowly, and was more than that in roots and leaves along with time, which had a preference to specific tissue of its host. In field experiment, the endophytic bacteria NJ13 was proved to be effective in controlling Alternaria leaf spot of ginseng. The biocontrol efficiency of fermentation broth at the concentration of 0.76 x 10(8) cfu x mL(-1) reached 75.62%, which was close to the controlling level (73.06%) of 0.67 mg x L(-1) 50% cyprodinil WG. PMID:25282882

  11. Interactions between bacteria and the intestinal mucosa: Do enteric neurotransmitters acting on epithelium cells influence mucosal colonization or infection?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mechanisms governing the ability of bacteria to adhere to and colonize human and animal hosts in health and disease are still incompletely understood. Throughout the extensive mucosal surfaces of the body that are in contact with the external environment, epithelial cells represent the first po...

  12. Effects of BV-Associated Bacteria and Sexual Intercourse on Vaginal Colonization with the Probiotic Lactobacillus crispatus CTV-05

    PubMed Central

    Ngugi, Benjamin M.; Hemmerling, Anke; Bukusi, Elizabeth A.; Kikuvi, Gideon; Gikunju, Joseph; Shiboski, Stephen; Fredricks, David N.; Cohen, Craig R.

    2011-01-01

    Objective Several fastidious bacteria have been associated with bacterial vaginosis (BV), but their role in lactobacilli recolonization failure is unknown. We studied the effect of seven BV-associated bacterial species and two Lactobacillus species on vaginal colonization with L. crispatus CTV-05 (LACTIN-V). Methods Twenty four women with BV were given a 5-day course of metronidazole vaginal gel and then randomized 3:1 to receive either LACTIN-V or placebo applied vaginally once daily for 5 initial consecutive days, followed by a weekly application over 2 weeks. Vaginal swabs for L. crispatus CTV-05 culture and 9-bacterium specific 16S rRNA gene quantitative PCR assays were analyzed on several study visits for the 18 women receiving LACTIN-V. Results Vaginal colonization with CTV-05 was achieved in 61% of the participants receiving LACTIN-V at either the day 10 or the 28 visit and 44% at day 28. Participants not colonized with CTV-05 had generally higher median concentrations of BV-associated bacteria compared to those who colonized. Between enrollment and day 28, the median concentration of Gardnerella vaginalis minimally reduced from 104.5 to 104.3 16S rRNA gene copies per swab in women who colonized with CTV-05 but increased from 105.7 to 107.3 in those who failed to colonize (p=0.19). Similarly, the median concentration of Atopobium spp. reduced from 102.7 16S rRNA gene copies per swab to below limit of detection in women who colonized with CTV-05 but increased from 102.7 to 106.6 in those who failed to colonize (p=0.04). The presence of endogenous L. crispatus at enrollment was found to be significantly associated with a reduced odds of colonization with CTV-05 on day 28 (p=0.003) and vaginal intercourse during the study significantly impaired successful CTV-05 colonization (p=0.018). Conclusion Vaginal concentration of certain BV-associated bacteria, vaginal intercourse during treatment and presence of endogenous L. crispatus at enrollment predict

  13. Adopting Bacteria in Order to Adapt to Water-How Reed Beetles Colonized the Wetlands (Coleoptera, Chrysomelidae, Donaciinae).

    PubMed

    Kleinschmidt, Birgit; Kölsch, Gregor

    2011-01-01

    The present paper reviews the biology of reed beetles (Donaciinae), presents experimental data on the role of specific symbiotic bacteria, and describes a molecular method for the detection of those bacteria. Reed beetles are herbivores living on wetland plants, each species being mono- or oligo-phagous. They lay their eggs on the host plant and the larvae live underwater in the sediment attached to its roots. The larvae pupate there in a water-tight cocoon, which they build using a secretion that is produced by symbiotic bacteria. The bacteria are located in four blind sacs at the foregut of the larvae; in (female) adults they colonize two out of the six Malpighian tubules. Tetracycline treatment of larvae reduced their pupation rate, although the bacteria could not be fully eliminated. When the small amount of bacterial mass attached to eggs was experimentally removed before hatching, symbiont free larvae resulted, showing the external transmission of the bacteria to the offspring. Specific primers were designed to detect the bacteria, and to confirm their absence in manipulated larvae. The pupation underwater enabled the reed beetles to permanently colonize the wetlands and to diversify in this habitat underexploited by herbivorous insects (adaptive radiation). PMID:26467833

  14. Multidrug-resistant gram-negative bacteria colonization of healthy US military personnel in the US and Afghanistan

    PubMed Central

    2013-01-01

    Background The US military has seen steady increases in multidrug-resistant (MDR) gram-negative bacteria (GNB) infections in casualties from Iraq and Afghanistan. This study evaluates the prevalence of MDR GNB colonization in US military personnel. Methods GNB colonization surveillance of healthy, asymptomatic military personnel (101 in the US and 100 in Afghanistan) was performed by swabbing 7 anatomical sites. US-based personnel had received no antibiotics within 30 days of specimen collection, and Afghanistan-based personnel were receiving doxycycline for malaria chemoprophylaxis at time of specimen collection. Isolates underwent genotypic and phenotypic characterization. Results The only colonizing MDR GNB recovered in both populations was Escherichia coli (p=0.01), which was seen in 2% of US-based personnel (all perirectal) and 11% of Afghanistan-based personnel (10 perirectal, 1 foot+groin). Individuals with higher off-base exposures in Afghanistan did not show a difference in overall GNB colonization or MDR E. coli colonization, compared with those with limited off-base exposures. Conclusion Healthy US- and Afghanistan-based military personnel have community onset-MDR E. coli colonization, with Afghanistan-based personnel showing a 5.5-fold higher prevalence. The association of doxycycline prophylaxis or other exposures with antimicrobial resistance and increased rates of MDR E. coli colonization needs further evaluation. PMID:23384348

  15. Interaction between plants and bacteria: glucosinolates and phyllospheric colonization of cruciferous vegetables by Enterobacter radicincitans DSM 16656.

    PubMed

    Schreiner, Monika; Krumbein, Angelika; Ruppel, Silke

    2009-01-01

    For determining interactive plant-bacterial effects between glucosinolates and phyllospheric colonization by a plant growth-promoting strain, Enterobacter radicincitans DSM 16656, in cruciferous vegetables, the extent of bacterial colonization was assessed in 5 cruciferous vegetables (Brassica juncea, Brassica campestris, Brassica oleracea var. capitata, Brassica rapa var. alboglabra, Nasturtium officinale) using a species-specific TaqMan probe and quantitative real-time PCR. Colonization ability of inoculated E. radicincitans in the phyllosphere of these species varied from inability to colonize B. rapa up to a very good colonization rate of B. campestris. In addition to morphological factors and other plant compounds, the colonization rate was affected by different individual aromatic and aliphatic glucosinolates and their concentration, revealing that both plant pathogens and plant growth-promoting bacteria were affected by glucosinolates in their colonization behavior. In contrast, after E. radicincitans inoculation neither the total nor the individual glucosinolate concentrations in the phyllosphere of the 5 cruciferous species were affected, indicating that the nonpathogenic E. radicincitans might cause only poor cell damage by metabolizing plant cell components and does not induce a plant defense response and thus subsequently an increased glucosinolate concentration in the phyllosphere. Moreover, E. radicincitans induced no stimulation of indole glucosinolate biosynthesis by additional bacterial auxin supply. PMID:19556746

  16. INFLUENCE OF ROOT COLONIZING BACTERIA ON THE DEFENSE RESPONSES OF BEAN

    EPA Science Inventory

    Colonization of plant roots by fluorescent pseudomonads has been correlated with disease suppression. ne mechanism may involve altered defense responses in the plant upon colonization. ltered defense responses were observed in bean (Phaseolus vulgaris) inoculated with fluorescent...

  17. Proteinaceous determinants of surface colonization in bacteria: bacterial adhesion and biofilm formation from a protein secretion perspective

    PubMed Central

    Chagnot, Caroline; Zorgani, Mohamed A.; Astruc, Thierry; Desvaux, Mickaël

    2013-01-01

    Bacterial colonization of biotic or abiotic surfaces results from two quite distinct physiological processes, namely bacterial adhesion and biofilm formation. Broadly speaking, a biofilm is defined as the sessile development of microbial cells. Biofilm formation arises following bacterial adhesion but not all single bacterial cells adhering reversibly or irreversibly engage inexorably into a sessile mode of growth. Among molecular determinants promoting bacterial colonization, surface proteins are the most functionally diverse active components. To be present on the bacterial cell surface, though, a protein must be secreted in the first place. Considering the close association of secreted proteins with their cognate secretion systems, the secretome (which refers both to the secretion systems and their protein substrates) is a key concept to apprehend the protein secretion and related physiological functions. The protein secretion systems are here considered in light of the differences in the cell-envelope architecture between diderm-LPS (archetypal Gram-negative), monoderm (archetypal Gram-positive) and diderm-mycolate (archetypal acid-fast) bacteria. Besides, their cognate secreted proteins engaged in the bacterial colonization process are regarded from single protein to supramolecular protein structure as well as the non-classical protein secretion. This state-of-the-art on the complement of the secretome (the secretion systems and their cognate effectors) involved in the surface colonization process in diderm-LPS and monoderm bacteria paves the way for future research directions in the field. PMID:24133488

  18. Metagenomic Analysis of Microbiome in Colon Tissue from Subjects with Inflammatory Bowel Diseases Reveals Interplay of Viruses and Bacteria

    PubMed Central

    Wang, Weiwei; Jovel, Juan; Halloran, Brendan; Wine, Eytan; Patterson, Jordan; Ford, Glenn; O'Keefe, Sandra; Meng, Bo; Song, Deyong; Zhang, Yong; Tian, Zhijian; Wasilenko, Shawn T.; Rahbari, Mandana; Reza, Salman; Mitchell, Troy; Jordan, Tracy; Carpenter, Eric; Madsen, Karen; Fedorak, Richard; Dielemann, Levinus A.; Ka-Shu Wong, Gane

    2015-01-01

    Abstract: Inflammatory bowel diseases (IBD), Crohn's disease and ulcerative colitis, are poorly understood disorders affecting the intestinal tract. The current model for disease suggests that genetically susceptible patients develop intolerance to gut microflora, and chronic inflammation develops as a result of environmental insults. Although interest has mainly focused on studying genetic variants and gut bacterial flora, little is known about the potential of viral infection to contribute to disease. Accordingly, we conducted a metagenomic analysis to document the baseline virome in colonic biopsy samples from patients with IBD in order to assess the contribution of viral infection to IBD. Libraries were generated from colon RNA to create approximately 2 GB sequence data per library. Using a bioinformatic pipeline designed to detect viral sequences, more than 1000 viral reads were derived directly from tissue without any coculture or isolation procedure. Herein, we describe the complexity and abundance of viruses, bacteria/bacteriophage, and human endogenous retroviral sequences from 10 patients with IBD and 5 healthy subjects undergoing surveillance colonoscopy. Differences in gut microflora and the abundance of mammalian viruses and human endogenous retroviruses were readily detected in the metagenomic analyses. Specifically, patients with herpesviridae sequences in their colon demonstrated increased expression of human endogenous viral sequences and differences in the diversity of their microbiome. This study provides a promising metagenomic approach to describe the colonic microbiome that can be used to better understand virus–host and phage–bacteria interactions in IBD. PMID:25939040

  19. Outcome of Transplantation Using Organs From Donors Infected or Colonized With Carbapenem-Resistant Gram-Negative Bacteria.

    PubMed

    Mularoni, A; Bertani, A; Vizzini, G; Gona, F; Campanella, M; Spada, M; Gruttadauria, S; Vitulo, P; Conaldi, P; Luca, A; Gridelli, B; Grossi, P

    2015-10-01

    Donor-derived infections due to multidrug-resistant bacteria are a growing problem in solid organ transplantation, and optimal management options are not clear. In a 2-year period, 30/214 (14%) recipients received an organ from 18/170 (10.5%) deceased donors with infection or colonization caused by a carbapenem-resistant gram-negative bacteria that was unknown at the time of transplantation. Among them, 14/30 recipients (47%) received a transplant from a donor with bacteremia or with infection/colonization of the transplanted organ and were considered at high risk of donor-derived infection transmission. The remaining 16/30 (53%) recipients received an organ from a nonbacteremic donor with colonization of a nontransplanted organ and were considered at low risk of infection transmission. Proven transmission occurred in 4 of the 14 high-risk recipients because donor infection was either not recognized, underestimated, or not communicated. These recipients received late, short or inappropriate posttransplant antibiotic therapy. Transmission did not occur in high-risk recipients who received appropriate and prompt antibiotic therapy for at least 7 days. The safe use of organs from donors with multidrug-resistant bacteria requires intra- and inter-institutional communication to allow appropriate management and prompt treatment of recipients in order to avoid transmission of infection. PMID:25981339

  20. Dominant and diet-responsive groups of bacteria within the human colonic microbiota

    PubMed Central

    Walker, Alan W; Ince, Jennifer; Duncan, Sylvia H; Webster, Lucy M; Holtrop, Grietje; Ze, Xiaolei; Brown, David; Stares, Mark D; Scott, Paul; Bergerat, Aurore; Louis, Petra; McIntosh, Freda; Johnstone, Alexandra M; Lobley, Gerald E; Parkhill, Julian; Flint, Harry J

    2011-01-01

    The populations of dominant species within the human colonic microbiota can potentially be modified by dietary intake with consequences for health. Here we examined the influence of precisely controlled diets in 14 overweight men. Volunteers were provided successively with a control diet, diets high in resistant starch (RS) or non-starch polysaccharides (NSPs) and a reduced carbohydrate weight loss (WL) diet, over 10 weeks. Analysis of 16S rRNA sequences in stool samples of six volunteers detected 320 phylotypes (defined at >98% identity) of which 26, including 19 cultured species, each accounted for >1% of sequences. Although samples clustered more strongly by individual than by diet, time courses obtained by targeted qPCR revealed that ‘blooms' in specific bacterial groups occurred rapidly after a dietary change. These were rapidly reversed by the subsequent diet. Relatives of Ruminococcus bromii (R-ruminococci) increased in most volunteers on the RS diet, accounting for a mean of 17% of total bacteria compared with 3.8% on the NSP diet, whereas the uncultured Oscillibacter group increased on the RS and WL diets. Relatives of Eubacterium rectale increased on RS (to mean 10.1%) but decreased, along with Collinsella aerofaciens, on WL. Inter-individual variation was marked, however, with >60% of RS remaining unfermented in two volunteers on the RS diet, compared to <4% in the other 12 volunteers; these two individuals also showed low numbers of R-ruminococci (<1%). Dietary non-digestible carbohydrate can produce marked changes in the gut microbiota, but these depend on the initial composition of an individual's gut microbiota. PMID:20686513

  1. Culture - colonic tissue

    MedlinePlus

    ... from the large intestine. The cause may be bacteria, fungi, or viruses. ... bacteria Cytomegalovirus Mycobacterium tuberculosis bacteria Salmonella bacteria Shigella bacteria These organisms may lead to diarrhea or infections involving the colon.

  2. Capturing One of the Human Gut Microbiome's Most Wanted: Reconstructing the Genome of a Novel Butyrate-Producing, Clostridial Scavenger from Metagenomic Sequence Data.

    PubMed

    Jeraldo, Patricio; Hernandez, Alvaro; Nielsen, Henrik B; Chen, Xianfeng; White, Bryan A; Goldenfeld, Nigel; Nelson, Heidi; Alhquist, David; Boardman, Lisa; Chia, Nicholas

    2016-01-01

    The role of the microbiome in health and disease is attracting great attention, yet we still know little about some of the most prevalent microorganisms inside our bodies. Several years ago, Human Microbiome Project (HMP) researchers generated a list of "most wanted" taxa: bacteria both prevalent among healthy volunteers and distantly related to any sequenced organisms. Unfortunately, the challenge of assembling high-quality genomes from a tangle of metagenomic reads has slowed progress in learning about these uncultured bacteria. Here, we describe how recent advances in sequencing and analysis allowed us to assemble "most wanted" genomes from metagenomic data collected from four stool samples. Using a combination of both de novo and guided assembly methods, we assembled and binned over 100 genomes from an initial data set of over 1,300 Gbp. One of these genome bins, which met HMP's criteria for a "most wanted" taxa, contained three essentially complete genomes belonging to a previously uncultivated species. This species is most closely related to Eubacterium desmolans and the clostridial cluster IV/Clostridium leptum subgroup species Butyricicoccus pullicaecorum (71-76% average nucleotide identity). Gene function analysis indicates that the species is an obligate anaerobe, forms spores, and produces the anti-inflammatory short-chain fatty acids acetate and butyrate. It also appears to take up metabolically costly molecules such as cobalamin, methionine, and branch-chained amino acids from the environment, and to lack virulence genes. Thus, the evidence is consistent with a secondary degrader that occupies a host-dependent, nutrient-scavenging niche within the gut; its ability to produce butyrate, which is thought to play an anti-inflammatory role, makes it intriguing for the study of diseases such as colon cancer and inflammatory bowel disease. In conclusion, we have assembled essentially complete genomes from stool metagenomic data, yielding valuable information

  3. Capturing One of the Human Gut Microbiome’s Most Wanted: Reconstructing the Genome of a Novel Butyrate-Producing, Clostridial Scavenger from Metagenomic Sequence Data

    PubMed Central

    Jeraldo, Patricio; Hernandez, Alvaro; Nielsen, Henrik B.; Chen, Xianfeng; White, Bryan A.; Goldenfeld, Nigel; Nelson, Heidi; Alhquist, David; Boardman, Lisa; Chia, Nicholas

    2016-01-01

    The role of the microbiome in health and disease is attracting great attention, yet we still know little about some of the most prevalent microorganisms inside our bodies. Several years ago, Human Microbiome Project (HMP) researchers generated a list of “most wanted” taxa: bacteria both prevalent among healthy volunteers and distantly related to any sequenced organisms. Unfortunately, the challenge of assembling high-quality genomes from a tangle of metagenomic reads has slowed progress in learning about these uncultured bacteria. Here, we describe how recent advances in sequencing and analysis allowed us to assemble “most wanted” genomes from metagenomic data collected from four stool samples. Using a combination of both de novo and guided assembly methods, we assembled and binned over 100 genomes from an initial data set of over 1,300 Gbp. One of these genome bins, which met HMP’s criteria for a “most wanted” taxa, contained three essentially complete genomes belonging to a previously uncultivated species. This species is most closely related to Eubacterium desmolans and the clostridial cluster IV/Clostridium leptum subgroup species Butyricicoccus pullicaecorum (71–76% average nucleotide identity). Gene function analysis indicates that the species is an obligate anaerobe, forms spores, and produces the anti-inflammatory short-chain fatty acids acetate and butyrate. It also appears to take up metabolically costly molecules such as cobalamin, methionine, and branch-chained amino acids from the environment, and to lack virulence genes. Thus, the evidence is consistent with a secondary degrader that occupies a host-dependent, nutrient-scavenging niche within the gut; its ability to produce butyrate, which is thought to play an anti-inflammatory role, makes it intriguing for the study of diseases such as colon cancer and inflammatory bowel disease. In conclusion, we have assembled essentially complete genomes from stool metagenomic data, yielding

  4. Lactic acid bacteria colonization and clinical outcome after probiotic supplementation in conventionally treated bacterial vaginosis and vulvovaginal candidiasis.

    PubMed

    Ehrström, Sophia; Daroczy, Katalin; Rylander, Eva; Samuelsson, Carolina; Johannesson, Ulrika; Anzén, Bo; Påhlson, Carl

    2010-09-01

    This randomized double-blind placebo controlled study assessed the vaginal colonization of lactic acid bacteria and clinical outcome. Vaginal capsules containing L gasseri LN40, Lactobacillus fermentum LN99, L. casei subsp. rhamnosus LN113 and P. acidilactici LN23, or placebos were administered for five days to 95 women after conventional treatment of bacterial vaginosis and/or vulvovaginal candidiasis. Vulvovaginal examinations and vaginal samplings were performed before and after administration, after the first and second menstruation, and after six months. Presence of LN strains was assessed using RAPD analysis. LN strains were present 2-3 days after administration in 89% of the women receiving LN strains (placebo: 0%, p < 0.0001). After one menstruation 53% were colonized by at least one LN strain. Nine percent were still colonized six months after administration. Ninety-three percent of the women receiving LN strains were cured 2-3 days after administration (placebo: 83%), and 78% after one menstruation (placebo: 71%) (ns). The intervention group experienced less malodorous discharge 2-3 days after administration (p = 0.03) and after the second menstruation (p = 0.04), compared with placebo. In summary, five days of vaginal administration of LN strains after conventional treatment of bacterial vaginosis and/or vulvovaginal candidiasis lead to vaginal colonization, somewhat fewer recurrences and less malodorous discharge. PMID:20472091

  5. Probiotic potential of lactic acid bacteria isolated from fermented dairy milks on antiproliferation of colon cancer cells.

    PubMed

    Thirabunyanon, Mongkol; Boonprasom, Pongphun; Niamsup, Piyanuch

    2009-04-01

    Fifty-four strains of lactic acid bacteria obtained from fermented dairy milks were investigated for possible use as probiotics and for colon cancer biological products. Five of these strains inhibited growth of eight food-borne pathogens including Helicobacter pylori, Escherichia coli, and Salmonella typhimurium. Three of these strains survived at pH 2.5 and in 0.3% bile salts. Additionally they produced no haemolysis, were resistant to kanamycin and adhered to Caco-2 cells. 16S rRNA gene sequences of probiotic strains indicated that RM11 and RM28 were Enterococcus faecium and Lactobacillus fermentum, respectively. Both the cultured medium and live whole cells from probiotic strains were tested for antiproliferation of colon cancer cells through MTT and Trypan Blue exclusion assays. The probiotic strains of E. faecium RM11 and L. fermentum RM28 also triggered antiproliferation of colon cancer cells at the rates of 21-29%, and 22-29%, respectively. This suggested that both strains could be used as potential probiotics in functional food or for colon cancer biological products. PMID:19116692

  6. Probiotic bacteria reduce salmonella typhimurium intestinal colonization by competing for iron.

    PubMed

    Deriu, Elisa; Liu, Janet Z; Pezeshki, Milad; Edwards, Robert A; Ochoa, Roxanna J; Contreras, Heidi; Libby, Stephen J; Fang, Ferric C; Raffatellu, Manuela

    2013-07-17

    Host inflammation alters the availability of nutrients such as iron to limit microbial growth. However, Salmonella enterica serovar Typhimurium thrives in the inflamed gut by scavenging for iron with siderophores. By administering Escherichia coli strain Nissle 1917, which assimilates iron by similar mechanisms, we show that this nonpathogenic bacterium can outcompete and reduce S. Typhimurium colonization in mouse models of acute colitis and chronic persistent infection. This probiotic activity depends on E. coli Nissle iron acquisition, given that mutants deficient in iron uptake colonize the intestine but do not reduce S. Typhimurium colonization. Additionally, the ability of E. coli Nissle to overcome iron restriction by the host protein lipocalin 2, which counteracts some siderophores, is essential, given that S. Typhimurium is unaffected by E. coli Nissle in lipocalin 2-deficient mice. Thus, iron availability impacts S. Typhimurium growth, and E. coli Nissle reduces S. Typhimurium intestinal colonization by competing for this limiting nutrient. PMID:23870311

  7. Prevention of Biofilm Colonization by Gram-Negative Bacteria on Minocycline-Rifampin-Impregnated Catheters Sequentially Coated with Chlorhexidine

    PubMed Central

    Jamal, Mohamed A.; Rosenblatt, Joel S.; Hachem, Ray Y.; Ying, Jiang; Pravinkumar, Egbert; Nates, Joseph L.; Chaftari, Anne-Marie P.

    2014-01-01

    Resistant Gram-negative bacteria are increasing central-line-associated bloodstream infection threats. To better combat this, chlorhexidine (CHX) was added to minocycline-rifampin (M/R) catheters. The in vitro antimicrobial activity of CHX-M/R catheters against multidrug resistant, Gram-negative Acinetobacter baumannii, Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia was tested. M/R and CHX-silver sulfadiazine (CHX/SS) catheters were used as comparators. The novel CHX-M/R catheters were significantly more effective (P < 0.0001) than CHX/SS or M/R catheters in preventing biofilm colonization and showed better antimicrobial durability. PMID:24165191

  8. Distinctive colonization of Bacillus sp. bacteria and the influence of the bacterial biofilm on electrochemical behaviors of aluminum coatings.

    PubMed

    Abdoli, Leila; Suo, Xinkun; Li, Hua

    2016-09-01

    Formation of biofilm is usually essential for the development of biofouling and crucially impacts the corrosion of marine structures. Here we report the attachment behaviors of Bacillus sp. bacteria and subsequent formation of bacterial biofilm on stainless steel and thermal sprayed aluminum coatings in artificial seawater. The colonized bacteria accelerate the corrosion of the steel plates, and markedly enhance the anti-corrosion performances of the Al coatings in early growth stage of the bacterial biofilm. After 7days incubation, the biofilm formed on the steel is heterogeneous while exhibits homogeneous feature on the Al coating. Atomic force microscopy examination discloses inception of formation of local pitting on steel plates associated with significantly roughened surface. Electrochemical testing suggests that the impact of the bacterial biofilm on the corrosion behaviors of marine structures is not decided by the biofilm alone, it is instead attributed to synergistic influence by both the biofilm and physicochemical characteristics of the substratum materials. PMID:27289310

  9. Insights into Vibrio cholerae Intestinal Colonization from Monitoring Fluorescently Labeled Bacteria

    PubMed Central

    Millet, Yves A.; Alvarez, David; Ringgaard, Simon; von Andrian, Ulrich H.; Davis, Brigid M.; Waldor, Matthew K.

    2014-01-01

    Vibrio cholerae, the agent of cholera, is a motile non-invasive pathogen that colonizes the small intestine (SI). Most of our knowledge of the processes required for V. cholerae intestinal colonization is derived from enumeration of wt and mutant V. cholerae recovered from orogastrically infected infant mice. There is limited knowledge of the distribution of V. cholerae within the SI, particularly its localization along the villous axis, or of the bacterial and host factors that account for this distribution. Here, using confocal and intravital two-photon microscopy to monitor the localization of fluorescently tagged V. cholerae strains, we uncovered unexpected and previously unrecognized features of V. cholerae intestinal colonization. Direct visualization of the pathogen within the intestine revealed that the majority of V. cholerae microcolonies attached to the intestinal epithelium arise from single cells, and that there are notable regiospecific aspects to V. cholerae localization and factors required for colonization. In the proximal SI, V. cholerae reside exclusively within the developing intestinal crypts, but they are not restricted to the crypts in the more distal SI. Unexpectedly, V. cholerae motility proved to be a regiospecific colonization factor that is critical for colonization of the proximal, but not the distal, SI. Furthermore, neither motility nor chemotaxis were required for proper V. cholerae distribution along the villous axis or in crypts, suggesting that yet undefined processes enable the pathogen to find its niches outside the intestinal lumen. Finally, our observations suggest that host mucins are a key factor limiting V. cholerae intestinal colonization, particularly in the proximal SI where there appears to be a more abundant mucus layer. Collectively, our findings demonstrate the potent capacity of direct pathogen visualization during infection to deepen our understanding of host pathogen interactions. PMID:25275396

  10. Diversity and antifungal activity of endophytic diazotrophic bacteria colonizing sugarcane in Egypt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The price of nitrogen continues to increase and is a major input in sugarcane production. Sugarcane grown in Egypt was screened for the presence of nitrogen-fixing bacteria. Nitrogen-free medium LGI-P was used to isolate bacteria from cane stalks. Among the 52 isolates subjected to acetylene redu...

  11. Lack of effect of murine norovirus infection on a mouse model of bacteria-induced colon cancer.

    PubMed

    Lencioni, Karen C; Drivdahl, Rolf; Seamons, Audrey; Treuting, Piper M; Brabb, Thea; Maggio-Price, Lillian

    2011-06-01

    Murine norovirus (MNV) is endemic in mouse research facilities in the United States and Europe, with a prevalence as high as 58% to 64%. Because of MNV's orofecal route of infection, clinically silent persistent infections in some mouse strains, and proclivity for macrophage and dendritic cells, its presence in mouse colonies has potential to alter phenotypes in experimental mouse models, particularly those involving inflammation and immunologic responses. Although MNV is subclinical, not causing overt disease in immunocompetent mice, we found that MNV infection can accelerate bacteria-induced inflammatory bowel disease (IBD) progression in Mdr1a(-/-) mice. The studies presented here examined whether MNV infection also affects the phenotype of a bacterially driven mouse model of inflammation-associated colon cancer in genetically susceptible Smad3(-/-) mice. In vitro culture of bone-marrow-derived macrophages (BMDM) was used to determine whether MNV4 influenced macrophage cytokine production. For in vivo studies, Smad3(-/-) mice were infected with MNV4 one week prior to infection with Helicobacter. Mice were monitored for 17 to 32 wk for development of IBD and colon cancer, and tissues were analyzed histopathologically. Although in vitro infection of BMDM with MNV4 led to increased inflammatory cytokine production, infection with MNV4 in vivo did not result in any statistically significant differences in survival, IBD scores, tumor incidence, or tumor phenotype in Smad3(-/-) mice. In addition, MNV infection alone did not result in IBD or colon cancer. Therefore MNV infection alone or in conjunction with Helicobacter does not alter the development or progression of IBD or colon cancer in Smad3(-/-) mice. PMID:21819691

  12. Muc2 Protects against Lethal Infectious Colitis by Disassociating Pathogenic and Commensal Bacteria from the Colonic Mucosa

    PubMed Central

    Bergstrom, Kirk S. B.; Kissoon-Singh, Vanessa; Gibson, Deanna L.; Ma, Caixia; Montero, Marinieve; Sham, Ho Pan; Ryz, Natasha; Huang, Tina; Velcich, Anna; Finlay, B. Brett; Chadee, Kris; Vallance, Bruce A.

    2010-01-01

    Despite recent advances in our understanding of the pathogenesis of attaching and effacing (A/E) Escherichia coli infections, the mechanisms by which the host defends against these microbes are unclear. The goal of this study was to determine the role of goblet cell-derived Muc2, the major intestinal secretory mucin and primary component of the mucus layer, in host protection against A/E pathogens. To assess the role of Muc2 during A/E bacterial infections, we inoculated Muc2 deficient (Muc2−/−) mice with Citrobacter rodentium, a murine A/E pathogen related to diarrheagenic A/E E. coli. Unlike wildtype (WT) mice, infected Muc2−/− mice exhibited rapid weight loss and suffered up to 90% mortality. Stool plating demonstrated 10–100 fold greater C. rodentium burdens in Muc2−/− vs. WT mice, most of which were found to be loosely adherent to the colonic mucosa. Histology of Muc2−/− mice revealed ulceration in the colon amid focal bacterial microcolonies. Metabolic labeling of secreted mucins in the large intestine demonstrated that mucin secretion was markedly increased in WT mice during infection compared to uninfected controls, suggesting that the host uses increased mucin release to flush pathogens from the mucosal surface. Muc2 also impacted host-commensal interactions during infection, as FISH analysis revealed C. rodentium microcolonies contained numerous commensal microbes, which was not observed in WT mice. Orally administered FITC-Dextran and FISH staining showed significantly worsened intestinal barrier disruption in Muc2−/− vs. WT mice, with overt pathogen and commensal translocation into the Muc2−/− colonic mucosa. Interestingly, commensal depletion enhanced C. rodentium colonization of Muc2−/− mice, although colonic pathology was not significantly altered. In conclusion, Muc2 production is critical for host protection during A/E bacterial infections, by limiting overall pathogen and commensal numbers associated with the colonic

  13. Tetracycline tethered to titanium inhibits colonization by Gram-negative bacteria.

    PubMed

    Davidson, Helen; Poon, Martin; Saunders, Ray; Shapiro, Irving M; Hickok, Noreen J; Adams, Christopher S

    2015-10-01

    As peri-prosthetic infection is one of the most devastating complications associated with implant placement, we have reasoned that such infection can be largely subverted by development of antibacterial implants. Our previous work demonstrated that covalent coupling of vancomycin to titanium alloy prevented colonization by the Gram-positive pathogens, Staphylococcus aureus and Staphylococcus epidermidis. Some orthopedic devices, including permanent prosthesis anchors, and most dental implants are transcutaneous or transmucosal and can be prone to colonization by Gram-negative pathogens. We report here the successful covalent coupling of the broad-spectrum antibiotic, tetracycline (TET), to titanium surfaces (Ti-TET) to retard Gram-negative colonization. Synthetic progress was followed by changes in water contact angle, while the presence of TET was confirmed by immunofluorescence. Ti-TET actively prevented colonization in the presence of bathing Escherichia coli, both by fluorescence microscopy and direct counting. Finally, the Ti-TET surface supported osteoblastic cell adhesion and proliferation over a 72-h period. Thus, this new surface offers a powerful means to protect transcutaneous implants from adhesion of Gram-negative pathogens, decreasing the need for replacement of this hardware. PMID:25389082

  14. Bacteriocins control chicken colonization while probiotic bacteria are ineffective at reducing Campylobacter jejuni

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Broilers chickens are widely considered an important source for human exposure to Campylobacter jejuni. We sought to intervene in C. jejuni colonization by using a probiotic approach. Isolates from chicken intestine were screened for C. jejuni inhibition. These isolates were live-fed to treat chi...

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

    PubMed

    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. PMID:26589216

  16. Gut-Colonizing Bacteria Promote C. elegans Innate Immunity by Producing Nitric Oxide.

    PubMed

    Xiao, Yi; Liu, Fang; Zhang, Zhigang; Tang, Jie; Zou, Cheng-Gang; Zhang, Ke-Qin

    2016-02-16

    Many commensal bacteria in the gut are beneficial to the host immune system, but the underlying mechanisms are largely unclear. Using culture-independent Illumina MiSeq sequencing of the bacterial 16S rRNA gene amplicons, we show that bacterial diversity in the intestine of Caenorhabditis elegans, the free-living nematode, is distinct from that in soil. Of these bacteria, Bacillus subtilis is the most prominent species in the worm gut. We demonstrate that B. subtilis confers worm resistance to infection by pathogenic bacteria, such as Pseudomonas aeruginosa, Salmonella enterica, and Enterococcus faecalis, by producing nitric oxide (NO). Deletion of the nos gene, which encodes an NO synthase, reduces the protective effect. NO promotes innate immune responses to P. aeruginosa PA14 by activating a conserved p38 mitogen protein kinase (MAPK) in C. elegans. Our work provides an example of antagonism of commensal bacteria against pathogens and illustrates the importance of commensal bacteria in host immunity. PMID:26854225

  17. Predominance of multi-resistant gram-negative bacteria colonizing chronic lower limb ulcers (CLLUs) at Bugando Medical Center

    PubMed Central

    2014-01-01

    Background Infections, trauma, malignances and poorly controlled diabetes are common causes of chronic lower limb ulcerations in developing countries. Infected wound with multi-drug resistant bacteria usually are associated with increased morbidity and mortality. We report the distribution of bacteria pathogens colonizing the chronic lower limb ulcers and their drug susceptibility pattern from Bugando Medical Centre (BMC) a tertiary hospital in Tanzania. Findings Three hundred non-repetitive wound swabs were aseptically collected from 300 patients with chronic lower limb ulcers using sterile swabs and processed following standard operative procedures. Isolates were identified using in house biochemical testing and in case of ambiguous confirmation was done using API 20NE and API 20E. Susceptibility was determined using disc diffusion test following clinical laboratory standard Institute guidelines (CLSI). Of 300 swabs from patients with chronic lower limbs ulcers, 201 (67.7%) had positive aerobic culture within 48 hours of incubation. Of 201 isolates, 180(89.6%) were gram-negative bacteria. Out of 180 gram negative bacteria, resistance was detected for ampicillin (95%, n = 171), amoxicillin/clavulanate (83.9%, n = 151), trimethoprim-sulphamethoxazole (78.9%, n = 142), ceftriaxone (46.7%, n = 84), ceftazidime (45.6%, n = 82), gentamicin (39.4%, n = 71), ciprofloxacin (17.8%, n = 32) and meropenem 28(15.6%, n = 25). A total of 41 (35%) of enterobacteriaceae were found to be extended spectrum beta-lactamases (ESBL) producers while of 18 Staphylococcus aureus, 8(44.4%) were found to be methicillin resistant Staphylococcus aureus (MRSA). Conclusion There is high prevalence of ESBL and MRSA isolates in surgical wards at BMC. We recommend infection control and antibiotic stewardship programs in these wards to minimize spread of multi-resistant organisms. PMID:24708843

  18. Impact of Gut Colonization by Antibiotic-Resistant Bacteria on the Outcomes of Allogeneic Hematopoietic Stem Cell Transplantation: A Retrospective, Single-Center Study.

    PubMed

    Bilinski, Jaroslaw; Robak, Katarzyna; Peric, Zinaida; Marchel, Halina; Karakulska-Prystupiuk, Ewa; Halaburda, Kazimierz; Rusicka, Patrycja; Swoboda-Kopec, Ewa; Wroblewska, Marta; Wiktor-Jedrzejczak, Wieslaw; Basak, Grzegorz W

    2016-06-01

    Gut colonization by antibiotic-resistant bacteria may underlie hard-to-treat systemic infections. There is also accumulating evidence on the immunomodulatory function of gut microbiota after allogeneic stem cell transplantation (alloSCT) and its impact on graft-versus-host disease (GVHD). We investigated the epidemiology and clinical impact of gut colonization after alloSCT and retrospectively analyzed data on 107 alloSCTs performed at a single transplant center. Pretransplant microbiology screening identified colonization in 31% of cases. Colonization had a negative impact on overall survival after alloSCT in univariate (34% versus 74% at 24 months, P < .001) and multivariate (hazard ratio, 3.53; 95% confidence interval, 1.71 to 7.28; P < .001) analyses. Nonrelapse mortality was significantly higher in colonized than in noncolonized patients (42% versus 11% at 24 months, P = .001). Colonized patients more frequently experienced bacteremia (48% versus 24%, P = .01), and more deaths were attributable to infectious causes in the colonized group (42% versus 11% of patients and 67% versus 29% of deaths, P < .05). We observed a significantly higher incidence of grades II to IV acute GVHD in colonized than in noncolonized patients (42% versus 23%, P < .05), especially involving the gastrointestinal system (33% versus 13.5%, P = .07). In summary, we determined that gut colonization by antibiotic-resistant bacteria decreases the overall survival of patients undergoing alloSCT by increasing nonrelapse mortality and the incidences of systemic infection and acute GVHD. PMID:26900084

  19. Taxon interactions control the distributions of cryoconite bacteria colonizing a High Arctic ice cap.

    PubMed

    Gokul, Jarishma K; Hodson, Andrew J; Saetnan, Eli R; Irvine-Fynn, Tristram D L; Westall, Philippa J; Detheridge, Andrew P; Takeuchi, Nozomu; Bussell, Jennifer; Mur, Luis A J; Edwards, Arwyn

    2016-08-01

    Microbial colonization of glacial ice surfaces incurs feedbacks which affect the melting rate of the ice surface. Ecosystems formed as microbe-mineral aggregates termed cryoconite locally reduce ice surface albedo and represent foci of biodiversity and biogeochemical cycling. Consequently, greater understanding the ecological processes in the formation of functional cryoconite ecosystems upon glacier surfaces is sought. Here, we present the first bacterial biogeography of an ice cap, evaluating the respective roles of dispersal, environmental and biotic filtration occurring at local scales in the assembly of cryoconite microbiota. 16S rRNA gene amplicon semiconductor sequencing of cryoconite colonizing a Svalbard ice cap coupled with digital elevation modelling of physical parameters reveals the bacterial community is dominated by a ubiquitous core of generalist taxa, with evidence for a moderate pairwise distance-decay relationship. While geographic position and melt season duration are prominent among environmental predictors of community structure, the core population of taxa appears highly influential in structuring the bacterial community. Taxon co-occurrence network analysis reveals a highly modular community structured by positive interactions with bottleneck taxa, predominantly Actinobacteria affiliated to isolates from soil humus. In contrast, the filamentous cyanobacterial taxon (assigned to Leptolyngbya/Phormidesmis pristleyi) which dominates the community and binds together granular cryoconite are poorly connected to other taxa. While our study targeted one ice cap, the prominent role of generalist core taxa with close environmental relatives across the global cryosphere indicate discrete roles for cosmopolitan Actinobacteria and Cyanobacteria as respective keystone taxa and ecosystem engineers of cryoconite ecosystems colonizing ice caps. PMID:27261672

  20. Diversity of endophytic bacteria from Eucalyptus species seeds and colonization of seedlings by Pantoea agglomerans.

    PubMed

    Ferreira, Anderson; Quecine, Maria Carolina; Lacava, Paulo Teixeira; Oda, Shinitiro; Azevedo, João Lúcio; Araújo, Welington Luiz

    2008-10-01

    The diversity and beneficial characteristics of endophytic microorganisms have been studied in several host plants. However, information regarding naturally occurring seed-associated endophytes and vertical transmission among different life-history stages of hosts is limited. Endophytic bacteria were isolated from seeds and seedlings of 10 Eucalyptus species and two hybrids. The results showed that endophytic bacteria, such as Bacillus, Enterococcus, Paenibacillus and Methylobacterium, are vertically transferred from seeds to seedlings. In addition, the endophytic bacterium Pantoea agglomerans was tagged with the gfp gene, inoculated into seeds and further reisolated from seedlings. These results suggested a novel approach to change the profile of the plants, where the bacterium is a delivery vehicle for desired traits. This is the first report of an endophytic bacterial community residing in Eucalyptus seeds and the transmission of these bacteria from seeds to seedlings. The bacterial species reported in this work have been described as providing benefits to host plants. Therefore, we suggest that endophytic bacteria can be transmitted vertically from seeds to seedlings, assuring the support of the bacterial community in the host plant. PMID:18710397

  1. Human milk oligosaccharides shorten rotavirus-induced diarrhea and modulate piglet mucosal immunity and colonic microbiota

    PubMed Central

    Li, Min; Monaco, Marcia H; Wang, Mei; Comstock, Sarah S; Kuhlenschmidt, Theresa B; Fahey Jr, George C; Miller, Michael J; Kuhlenschmidt, Mark S; Donovan, Sharon M

    2014-01-01

    The impact of human milk oligosaccharides (HMO) on mucosal immunity, gut microbiota and response to rotavirus (RV) infection was investigated in the piglet model. Newborn piglets were fed with formula alone (FF) or formula supplemented with 4 g l−1 HMO (HMO) or a prebiotic mixture of 9:1 short-chain galactooligosaccharides (3.6 g l−1) and long-chain fructooligosaccharides (0.4 g l−1) (PRE) (n=19–21 per group) for 15 days. Piglets (n=7–8) in each dietary group were orally infected with porcine rotavirus (RV) OSU strain on d10, and stool consistency was assessed daily. Blood, small intestine and colonic contents were collected at day 15. Serum RV-specific antibody concentrations, intestinal histomorphology, RV non-structural protein-4 (NSP4) and cytokine mRNA expression were assessed. Colonic content pH, dry matter (DM) and short-chain fatty acid concentrations were measured. Ascending colonic microbiota was analyzed by 16S rRNA gene v1-3 region pyrosequencing. HMO- and PRE-fed groups had shorter duration of diarrhea than FF piglets. Infection changed intestinal histomorphology, increased serum RV-specific antibody response and intestinal RV NSP4 expression, and modulated ileal cytokine expression. HMO enhanced T helper type 1 (interferon-gamma) and anti-inflammatory (interleukin-10) cytokines in the ileum, while prebiotics promoted RV-specific immunoglobulin M response to the infection. RV infection and HMO supplementation altered intraluminal environment and gut microbiota. HMO increased pH and lowered DM of colonic contents and enhanced the abundance of unclassified Lachnospiraceae, which contains numerous butyrate-producing bacteria. In conclusion, HMO and prebiotics did not prevent the onset of RV infection but reduced the duration of RV-induced diarrhea in piglets, in part, by modulating colonic microbiota and immune response to RV infection. PMID:24522264

  2. Successful treatment of an MTBE-impacted aquifer using a bioreactor self-colonized by native aquifer bacteria

    PubMed Central

    Hicks, Kristin A.; Nickelsen, Michael G.; Boyle, Susan L.; Baker, Jeffrey M.; Tornatore, Paul M.; Hristova, Krassimira R.; Scow, Kate M.

    2014-01-01

    A field-scale fixed bed bioreactor was used to successfully treat an MTBE-contaminated aquifer in North Hollywood, CA without requiring inoculation with introduced bacteria. Native bacteria from the MTBE-impacted aquifer rapidly colonized the bioreactor, entering the bioreactor in the contaminated groundwater pumped from the site, and biodegraded MTBE with greater than 99 % removal efficiency. DNA sequencing of the 16S rRNA gene identified MTBE-degrading bacteria Methylibium petroleiphilum in the bioreactor. Quantitative PCR showed M. petroleiphilum enriched by three orders of magnitude in the bioreactor above densities pre-existing in the groundwater. Because treatment was carried out by indigenous rather than introduced organisms, regulatory approval was obtained for implementation of a full-scale bioreactor to continue treatment of the aquifer. In addition, after confirmation of MTBE removal in the bioreactor to below maximum contaminant limit levels (MCL; MTBE = 5 μg L−1), treated water was approved for reinjection back into the aquifer rather than requiring discharge to a water treatment system. This is the first treatment system in California to be approved for reinjection of biologically treated effluent into a drinking water aquifer. This study demonstrated the potential for using native microbial communities already present in the aquifer as an inoculum for ex-situ bioreactors, circumventing the need to establish non-native, non-acclimated and potentially costly inoculants. Understanding and harnessing the metabolic potential of native organisms circumvents some of the issues associated with introducing non-native organisms into drinking water aquifers, and can provide a low-cost and efficient remediation technology that can streamline future bioremediation approval processes. PMID:23613160

  3. Moderate halophilic bacteria colonizing the phylloplane of halophytes of the subfamily Salicornioideae (Amaranthaceae).

    PubMed

    Mora-Ruiz, Merit del Rocío; Font-Verdera, Francisca; Díaz-Gil, Carlos; Urdiain, Mercedes; Rodríguez-Valdecantos, Gustavo; González, Bernardo; Orfila, Alejandro; Rosselló-Móra, Ramon

    2015-09-01

    Halophytes accumulate large amounts of salt in their tissues, and thus are susceptible to colonization by halotolerant and halophilic microorganisms that might be relevant for the growth and development of the plant. Here, the study of 814 cultured strains and 14,189 sequences obtained by 454 pyrosequencing were combined in order to evaluate the presence, abundance and diversity of halophilic, endophytic and epiphytic microorganisms in the phytosphere of leaves of members of the subfamily Salicornioideae from five locations in Spain and Chile. Cultures were screened by the tandem approach of MALDI-TOF/MS and 16S rRNA gene sequencing. In addition, differential centrifugation was used to enrich endophytes for further DNA isolation, 16S rRNA gene amplification and 454 pyrosequencing. Culturable and non-culturable data showed strong agreement with a predominance of Proteobacteria, Firmicutes and Actinobacteria. The most abundant isolates corresponded to close relatives of the species Chromohalobacter canadensis and Salinicola halophilus that comprised nearly 60% of all isolates and were present in all plants. Up to 66% of the diversity retrieved by pyrosequencing could be brought into pure cultures and the community structures were highly dependent on the compartment where the microorganisms thrived (plant surface or internal tissues). PMID:26164126

  4. Effects of roxithromycin on fecal bacteria in human volunteers and resistance to colonization in gnotobiotic mice.

    PubMed Central

    Pecquet, S; Chachaty, E; Tancrède, C; Andremont, A

    1991-01-01

    The ecological impact of roxithromycin given orally at 300 mg/day on the intestinal floras in six human volunteers was studied. The resulting fecal concentrations of active roxithromycin were in the range of 100 to 200 micrograms/g of feces. Consecutive modifications in the composition of the fecal floras were limited to a decrease in counts of total members of the family Enterobacteriaceae. The rest of the intestinal floras, including the predominant anaerobic floras, changed little. No overgrowth of Pseudomonas aeruginosa, staphylococci, fungi, or highly erythromycin-resistant strains of the family Enterobacteriaceae was observed. The strains of Enterobacteriaceae and of anaerobes isolated during treatment were not markedly more resistant to roxithromycin than those isolated before treatment started. Changes in intestinal resistance to colonization by exogenous microorganisms in gnotobiotic mice inoculated with human fecal flora were studied and were also found to be minimal. The impact of oral roxithromycin on the intestinal microbiota appears to be weaker than that previously observed with oral erythromycin, perhaps because the concentrations of roxithromycin in the feces were lower than those previously found for erythromycin. PMID:2039207

  5. Bacteria colonizing root nodules of wild legumes exhibit virulence-associated properties of mammalian pathogens.

    PubMed

    Muresu, Rosella; Maddau, Giuseppe; Delogu, Giuseppe; Cappuccinelli, Piero; Squartini, Andrea

    2010-02-01

    Bacteria not proficient in nitrogen fixing symbiosis were proven able to invade root nodules of three wild legumes of the genus Hedysarum in Algeria and to be multiplying in these in place of the natural rhizobium symbionts. The involved species featured taxa known as human pathogens including: Enterobacter cloacae, Enterobacter kobei, Escherichia vulneris, Pantoea agglomerans and Leclercia adecarboxylata. A direct screening of the phenotypic determinants of virulence using human cultured cells tested positive for the traits of cytotoxicity, vital stain exclusion and adhesion to epithelia. Antibiogram analyses revealed also a complex pattern of multiple antibiotic resistances. The data suggest that legume root nodules can be a site of survival and of active multiplication for populations of mammalian pathogens, which could thus alternate between the target animal and a number of neutral plant hosts. The worldwide distribution of as yet uninvestigated legumes raises the concern that these represent a general niche that could enhance the hazards posed by microorganisms of clinical nature. PMID:19916054

  6. Iron encrustations on filamentous algae colonized by Gallionella-related bacteria in a metal-polluted freshwater stream

    NASA Astrophysics Data System (ADS)

    Mori, J. F.; Neu, T. R.; Lu, S.; Händel, M.; Totsche, K. U.; Küsel, K.

    2015-09-01

    Filamentous macroscopic algae were observed in slightly acidic to circumneutral (pH 5.9-6.5), metal-rich stream water that leaked out from a former uranium mining district (Ronneburg, Germany). These algae differed in color and morphology and were encrusted with Fe-deposits. To elucidate their potential interaction with Fe(II)-oxidizing bacteria (FeOB), we collected algal samples at three time points during summer 2013 and studied the algae-bacteria-mineral compositions via confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectra, and a 16S and 18S rRNA gene-based bacterial and algae community analysis. Surprisingly, sequencing analysis of 18S rRNA gene regions of green and brown algae revealed high homologies with the freshwater algae Tribonema (99.9-100 %). CLSM imaging indicated a loss of active chloroplasts in the algae cells, which may be responsible for the change in color in

  7. Vertical mother-neonate transfer of maternal gut bacteria via breastfeeding.

    PubMed

    Jost, Ted; Lacroix, Christophe; Braegger, Christian P; Rochat, Florence; Chassard, Christophe

    2014-09-01

    Breast milk has recently been recognized as source of commensal and potential probiotic bacteria. The present study investigated whether viable strains of gut-associated obligate anaerobes are shared between the maternal and neonatal gut ecosystem via breastfeeding. Maternal faeces, breast milk and corresponding neonatal faeces collected from seven mothers-neonate pairs at three neonatal sampling points were analyzed by culture-independent (pyrosequencing) and culture-dependent methods (16S rRNA gene sequencing, pulsed field gel electrophoresis, random amplified polymorphic DNA and repetitive extragenic palindromic polymerase chain reaction. Pyrosequencing allowed identifying gut-associated obligate anaerobic genera, like Bifidobacterium, Bacteroides, Parabacteroides and members of the Clostridia (Blautia, Clostridium, Collinsella and Veillonella) shared between maternal faeces, breast milk and neonatal faeces. Using culture, a viable strain of Bifidobacterium breve was shown to be shared between all three ecosystems within one mother-neonate pair. Furthermore, pyrosequencing revealed that several butyrate-producing members of the Clostridia (Coprococcus, Faecalibacterium, Roseburia and Subdoligranulum) were shared between maternal faeces and breast milk. This study shows that (viable) obligate gut-associated anaerobes may be vertically transferred from mother to neonate via breastfeeding. Thus, our data support the recently suggested hypothesis of a novel way of mother-neonate communication, in which maternal gut bacteria reach breast milk via an entero-mammary pathway to influence neonatal gut colonization and maturation of the immune system. PMID:24033881

  8. Colonic inflammation accompanies an increase of β-catenin signaling and Lachnospiraceae/Streptococcaceae bacteria in the hind gut of high-fat diet-fed mice.

    PubMed

    Zeng, Huawei; Ishaq, Suzanne L; Zhao, Feng-Qi; Wright, André-Denis G

    2016-09-01

    Consumption of an obesigenic/high-fat diet (HFD) is associated with a high colon cancer risk and may alter the gut microbiota. To test the hypothesis that long-term high-fat (HF) feeding accelerates inflammatory process and changes gut microbiome composition, C57BL/6 mice were fed HFD (45% energy) or a low-fat (LF) diet (10% energy) for 36 weeks. At the end of the study, body weights in the HF group were 35% greater than those in the LF group. These changes were associated with dramatic increases in body fat composition, inflammatory cell infiltration, inducible nitric oxide synthase protein concentration and cell proliferation marker (Ki67) in ileum and colon. Similarly, β-catenin expression was increased in colon (but not ileum). Consistent with gut inflammation phenotype, we also found that plasma leptin, interleukin 6 and tumor necrosis factor α concentrations were also elevated in mice fed the HFD, indicative of chronic inflammation. Fecal DNA was extracted and the V1-V3 hypervariable region of the microbial 16S rRNA gene was amplified using primers suitable for 454 pyrosequencing. Compared to the LF group, the HF group had high proportions of bacteria from the family Lachnospiraceae/Streptococcaceae, which is known to be involved in the development of metabolic disorders, diabetes and colon cancer. Taken together, our data demonstrate, for the first time, that long-term HF consumption not only increases inflammatory status but also accompanies an increase of colonic β-catenin signaling and Lachnospiraceae/Streptococcaceae bacteria in the hind gut of C57BL/6 mice. PMID:27362974

  9. Microscopic elucidation of abundant endophytic bacteria colonizing the cell wall–plasma membrane peri-space in the shoot-tip tissue of banana

    PubMed Central

    Thomas, Pious; Reddy, Krishna M.

    2013-01-01

    This study was aimed at generating microscopic evidence of intra-tissue colonization in banana in support of the previous findings on widespread association of endophytic bacteria with the shoot tips of field-grown plants and micropropagated cultures, and to understand the extent of tissue colonization. Leaf-sheath tissue sections (∼50–100 µm) from aseptically gathered shoot tips of cv. Grand Naine were treated with Live/Dead bacterial viability kit components SYTO 9 (S9) and propidium iodide (PI) followed by epifluorescence or confocal laser scanning microscopy (CLSM). The S9, which targets live bacteria, showed abundant green-fluorescing particles along the host cell periphery in CLSM, apparently in between the plasma membrane and the cell wall. These included non-motile and occasional actively motile single bacterial cells seen in different x–y planes and z-stacks over several cell layers, with the fluorescence signal similar to that of pure cultures of banana endophytes. Propidium iodide, which stains dead bacteria, did not detect any, but post-ethanol treatment, both PI and 4′,6-diamidino-2-phenylindole detected abundant bacteria. Propidium iodide showed clear nuclear staining, as did S9 to some extent, and the fluorophores appeared to detect bacteria at the exclusion of DNA-containing plant organelles as gathered from bright-field and phase-contrast microscopy. The S9–PI staining did not work satisfactorily with formalin- or paraformaldehyde-fixed tissue. The extensive bacterial colonization in fresh tissue was further confirmed with the suckers of different cultivars, and was supported by transmission electron microscopy. This study thus provides clear microscopic evidence of the extensive endophytic bacterial inhabitation in the confined cell wall–plasma membrane peri-space in shoot tissue of banana with the organisms sharing an integral association with the host. The abundant tissue colonization suggests a possible involvement of endophytes in

  10. Differential induction of apoptosis in human colonic carcinoma cells (Caco-2) by Atopobium, and commensal, probiotic and enteropathogenic bacteria: mediation by the mitochondrial pathway.

    PubMed

    Altonsy, Mohammed O; Andrews, Simon C; Tuohy, Kieran M

    2010-02-28

    The induction of apoptosis in mammalian cells by bacteria is well reported. This process may assist infection by pathogens whereas for non-pathogens apoptosis induction within carcinoma cells protects against colon cancer. Here, apoptosis induction by a major new gut bacterium, Atopobium minutum, was compared with induction by commensal (Escherichia coli K-12 strains), probiotic (Lactobacillus rhamnosus, Bifidobacterium latis) and pathogenic (E. coli: EPEC and VTEC) gut bacteria within the colon cancer cell line, Caco-2. The results show a major apoptotic effect for the pathogens, mild effects for the probiotic strains and A. minutum, but no effect for commensal E. coli. The mild apoptotic effects observed are consistent with the beneficial roles of probotics in protection against colon cancer and suggest, for the first time, that A. minutum possesses similar advantageous, anti-cancerous activity. Although bacterial infection increased Caco-2 membrane FAS levels, caspase-8 was not activated indicating that apoptosis is FAS independent. Instead, in all cases, apoptosis was induced through the mitochondrial pathway as indicated by BAX translocation, cytochrome c release, and caspase-9 and -3 cleavage. This suggests that an intracellular stimulus initiates the observed apoptosis responses. PMID:20036023

  11. Yerba mate enhances probiotic bacteria growth in vitro but as a feed additive does not reduce Salmonella Enteritidis colonization in vivo.

    PubMed

    Gonzalez-Gil, Francisco; Diaz-Sanchez, Sandra; Pendleton, Sean; Andino, Ana; Zhang, Nan; Yard, Carrie; Crilly, Nate; Harte, Federico; Hanning, Irene

    2014-02-01

    Yerba mate (Ilex paraguariensis) is a tea known to have beneficial effects on human health and antimicrobial activity against some foodborne pathogens. Thus, the application of yerba mate as a feed additive for broiler chickens to reduce Salmonella colonization was evaluated. The first in vitro evaluation was conducted by suspending Salmonella Enteritidis and lactic acid bacteria (LAB) in yerba mate extract. The in vivo evaluations were conducted using preventative and horizontal transmission experiments. In all experiments, day-of-hatch chicks were treated with one of the following 1) no treatment (control); 2) ground yerba mate in feed; 3) probiotic treatment (Lactobacillus acidophilus and Pediococcus; 9:1 administered once on day of hatch by gavage); or 4) both yerba mate and probiotic treatments. At d 3, all chicks were challenged with Salmonella Enteritidis (preventative experiment) or 5 of 20 chicks (horizontal transmission experiment). At d 10, all birds were euthanized, weighed, and cecal contents enumerated for Salmonella. For the in vitro evaluation, antimicrobial activity was observed against Salmonella and the same treatment enhanced growth of LAB. For in vivo evaluations, none of the yerba mate treatments significantly reduced Salmonella Enteritidis colonization, whereas the probiotic treatment significantly reduced Salmonella colonization in the horizontal transmission experiment. Yerba mate decreased chicken BW and decreased the performance of the probiotic treatment when used in combination. In conclusion, yerba mate had antimicrobial activity against foodborne pathogens and enhanced the growth of LAB in vitro, but in vivo yerba mate did not decrease Salmonella Enteritidis colonization. PMID:24570466

  12. Persistence of nasal colonization with human pathogenic bacteria and associated antimicrobial resistance in the German general population.

    PubMed

    Köck, R; Werner, P; Friedrich, A W; Fegeler, C; Becker, K

    2016-01-01

    The nares represent an important bacterial reservoir for endogenous infections. This study aimed to assess the prevalence of nasal colonization by different important pathogens, the associated antimicrobial susceptibility and risk factors. We performed a prospective cohort study among 1878 nonhospitalized volunteers recruited from the general population in Germany. Participants provided nasal swabs at three time points (each separated by 4-6 months). Staphylococcus aureus, Enterobacteriaceae and important nonfermenters were cultured and subjected to susceptibility testing. Factors potentially influencing bacterial colonization patterns were assessed. The overall prevalence of S. aureus, Enterobacteriaceae and nonfermenters was 41.0, 33.4 and 3.7%, respectively. Thirteen participants (0.7%) were colonized with methicillin-resistant S. aureus. Enterobacteriaceae were mostly (>99%) susceptible against ciprofloxacin and carbapenems (100%). Extended-spectrum β-lactamase-producing isolates were not detected among Klebsiella oxytoca, Klebsiella pneumoniae and Escherichia coli. Several lifestyle- and health-related factors (e.g. household size, travel, livestock density of the residential area or occupational livestock contact, atopic dermatitis, antidepressant or anti-infective drugs) were associated with colonization by different microorganisms. This study unexpectedly demonstrated high nasal colonization rates with Enterobacteriaceae in the German general population, but rates of antibiotic resistance were low. Methicillin-resistant S. aureus carriage was rare but highly associated with occupational livestock contact. PMID:26862431

  13. Persistence of nasal colonization with human pathogenic bacteria and associated antimicrobial resistance in the German general population

    PubMed Central

    Köck, R.; Werner, P.; Friedrich, A.W.; Fegeler, C.; Becker, K.; Bindewald, O.; Bui, T.T.; Eckhoff, C.; Epping, R.; Kähmann, L.; Meurer, M.; Steger, J.; von Auenmüller, L.

    2015-01-01

    The nares represent an important bacterial reservoir for endogenous infections. This study aimed to assess the prevalence of nasal colonization by different important pathogens, the associated antimicrobial susceptibility and risk factors. We performed a prospective cohort study among 1878 nonhospitalized volunteers recruited from the general population in Germany. Participants provided nasal swabs at three time points (each separated by 4–6 months). Staphylococcus aureus, Enterobacteriaceae and important nonfermenters were cultured and subjected to susceptibility testing. Factors potentially influencing bacterial colonization patterns were assessed. The overall prevalence of S. aureus, Enterobacteriaceae and nonfermenters was 41.0, 33.4 and 3.7%, respectively. Thirteen participants (0.7%) were colonized with methicillin-resistant S. aureus. Enterobacteriaceae were mostly (>99%) susceptible against ciprofloxacin and carbapenems (100%). Extended-spectrum β-lactamase–producing isolates were not detected among Klebsiella oxytoca, Klebsiella pneumoniae and Escherichia coli. Several lifestyle- and health-related factors (e.g. household size, travel, livestock density of the residential area or occupational livestock contact, atopic dermatitis, antidepressant or anti-infective drugs) were associated with colonization by different microorganisms. This study unexpectedly demonstrated high nasal colonization rates with Enterobacteriaceae in the German general population, but rates of antibiotic resistance were low. Methicillin-resistant S. aureus carriage was rare but highly associated with occupational livestock contact. PMID:26862431

  14. A New Zebrafish Model of Oro-Intestinal Pathogen Colonization Reveals a Key Role for Adhesion in Protection by Probiotic Bacteria

    PubMed Central

    Bégaud, Evelyne; Herbomel, Philippe; Levraud, Jean-Pierre; Ghigo, Jean-Marc

    2012-01-01

    The beneficial contribution of commensal bacteria to host health and homeostasis led to the concept that exogenous non-pathogenic bacteria called probiotics could be used to limit disease caused by pathogens. However, despite recent progress using gnotobiotic mammal and invertebrate models, mechanisms underlying protection afforded by commensal and probiotic bacteria against pathogens remain poorly understood. Here we developed a zebrafish model of controlled co-infection in which germ-free zebrafish raised on axenic living protozoa enabled the study of interactions between host and commensal and pathogenic bacteria. We screened enteric fish pathogens and identified Edwardsiella ictaluri as a virulent strain inducing a strong inflammatory response and rapid mortality in zebrafish larvae infected by the natural oro-intestinal route. Using mortality induced by infection as a phenotypic read-out, we pre-colonized zebrafish larvae with 37 potential probiotic bacterial strains and screened for survival upon E. ictaluri infection. We identified 3 robustly protective strains, including Vibrio parahaemolyticus and 2 Escherichia coli strains. We showed that the observed protective effect of E. coli was not correlated with a reduced host inflammatory response, nor with the release of biocidal molecules by protective bacteria, but rather with the presence of specific adhesion factors such as F pili that promote the emergence of probiotic bacteria in zebrafish larvae. Our study therefore provides new insights into the molecular events underlying the probiotic effect and constitutes a potentially high-throughput in vivo approach to the study of the molecular basis of pathogen exclusion in a relevant model of vertebrate oro-intestinal infection. PMID:22911651

  15. CD4CD8αα Lymphocytes, A Novel Human Regulatory T Cell Subset Induced by Colonic Bacteria and Deficient in Patients with Inflammatory Bowel Disease

    PubMed Central

    Sarrabayrouse, Guillaume; Bossard, Céline; Chauvin, Joe-Marc; Jarry, Anne; Meurette, Guillaume; Quévrain, Elodie; Bridonneau, Chantal; Preisser, Laurence; Asehnoune, Karim; Labarrière, Nathalie; Altare, Frédéric; Sokol, Harry; Jotereau, Francine

    2014-01-01

    How the microbiota affects health and disease is a crucial question. In mice, gut Clostridium bacteria are potent inducers of colonic interleukin (IL)-10-producing Foxp3 regulatory T cells (Treg), which play key roles in the prevention of colitis and in systemic immunity. In humans, although gut microbiota dysbiosis is associated with immune disorders, the underlying mechanism remains unknown. In contrast with mice, the contribution of Foxp3 Treg in colitis prevention has been questioned, suggesting that other compensatory regulatory cells or mechanisms may exist. Here we addressed the regulatory role of the CD4CD8 T cells whose presence had been reported in the intestinal mucosa and blood. Using colonic lamina propria lymphocytes (LPL) and peripheral blood lymphocytes (PBL) from healthy individuals, and those with colon cancer and irritable bowel disease (IBD), we demonstrated that CD4CD8αα (DP8α) T lymphocytes expressed most of the regulatory markers and functions of Foxp3 Treg and secreted IL-10. Strikingly, DP8α LPL and PBL exhibited a highly skewed repertoire toward the recognition of Faecalibacterium prausnitzii, a major Clostridium species of the human gut microbiota, which is decreased in patients with IBD. Furthermore, the frequencies of DP8α PBL and colonic LPL were lower in patients with IBD than in healthy donors and in the healthy mucosa of patients with colon cancer, respectively. Moreover, PBL and LPL from most patients with active IBD failed to respond to F. prausnitzii in contrast to PBL and LPL from patients in remission and/or healthy donors. These data (i) uncover a Clostridium-specific IL-10-secreting Treg subset present in the human colonic LP and blood, (ii) identify F. prausnitzii as a major inducer of these Treg, (iii) argue that these cells contribute to the control or prevention of colitis, opening new diagnostic and therapeutic strategies for IBD, and (iv) provide new tools to address the systemic impact of both these Treg and the

  16. CD4CD8αα lymphocytes, a novel human regulatory T cell subset induced by colonic bacteria and deficient in patients with inflammatory bowel disease.

    PubMed

    Sarrabayrouse, Guillaume; Bossard, Céline; Chauvin, Joe-Marc; Jarry, Anne; Meurette, Guillaume; Quévrain, Elodie; Bridonneau, Chantal; Preisser, Laurence; Asehnoune, Karim; Labarrière, Nathalie; Altare, Frédéric; Sokol, Harry; Jotereau, Francine

    2014-04-01

    How the microbiota affects health and disease is a crucial question. In mice, gut Clostridium bacteria are potent inducers of colonic interleukin (IL)-10-producing Foxp3 regulatory T cells (Treg), which play key roles in the prevention of colitis and in systemic immunity. In humans, although gut microbiota dysbiosis is associated with immune disorders, the underlying mechanism remains unknown. In contrast with mice, the contribution of Foxp3 Treg in colitis prevention has been questioned, suggesting that other compensatory regulatory cells or mechanisms may exist. Here we addressed the regulatory role of the CD4CD8 T cells whose presence had been reported in the intestinal mucosa and blood. Using colonic lamina propria lymphocytes (LPL) and peripheral blood lymphocytes (PBL) from healthy individuals, and those with colon cancer and irritable bowel disease (IBD), we demonstrated that CD4CD8αα (DP8α) T lymphocytes expressed most of the regulatory markers and functions of Foxp3 Treg and secreted IL-10. Strikingly, DP8α LPL and PBL exhibited a highly skewed repertoire toward the recognition of Faecalibacterium prausnitzii, a major Clostridium species of the human gut microbiota, which is decreased in patients with IBD. Furthermore, the frequencies of DP8α PBL and colonic LPL were lower in patients with IBD than in healthy donors and in the healthy mucosa of patients with colon cancer, respectively. Moreover, PBL and LPL from most patients with active IBD failed to respond to F. prausnitzii in contrast to PBL and LPL from patients in remission and/or healthy donors. These data (i) uncover a Clostridium-specific IL-10-secreting Treg subset present in the human colonic LP and blood, (ii) identify F. prausnitzii as a major inducer of these Treg, (iii) argue that these cells contribute to the control or prevention of colitis, opening new diagnostic and therapeutic strategies for IBD, and (iv) provide new tools to address the systemic impact of both these Treg and the

  17. Isolation, characterization and colonization of 1-aminocyclopropane-1-carboxylate deaminase-producing bacteria XG32 and DP24.

    PubMed

    Wang, Mei-Xia; Liu, Jia; Chen, Shuang-Lin; Yan, Shu-Zhen

    2012-03-01

    Two 1-aminocyclopropane-1-carboxylate deaminase-producing bacterial strains (DP24 and XG32) were isolated from surface-sterilized tomato roots and rizhospere soil. The strains were identified as Pseudomonas fluorescens biovar. IV (XG2) and Erwinia herbicola (DP24) by physiological and biochemical tests, and 16S rRNA gene analysis. Both strains showed positive plant growth-promoting activity when inoculated into cucumber (Cucumis sativus), tomato (Lycopersicon esculentum), pepper (Capsicum annuum) and rapeseed (Brassica napus L.). Colonization ability and behavior of these two strains were determined by treating mutant strains with rifampicin and fluorescence in situ hybridization (FISH) assay with rRNA targeted probes, respectively. Both strains were endophytic colonizers of pepper plants. The behavior of the two strains was not identical. Strain XG32 only colonized the root and reached the max level of 27.7 × 10(7) c.f.u./g (fresh weight), after 12 days postinoculation, while strain DP24 was able to colonize the roots, stems and leaves. The max level was reached at 40.87 × 10(7) c.f.u./g (fresh weight) in the roots, 17 × 10(7) c.f.u./g in the stems after 7 days postinoculation and 44.84 × 10(7) c.f.u./g in the leaves after 12 days postinoculation. PMID:22805836

  18. Colonization of frog Rana temporaria L. urinary bladder by Gram-negative bacteria leads to decreased effect of arginine-vasotocin on water reabsorption from the urinary bladder.

    PubMed

    Fock, Ekaterina; Lavrova, Elena; Parnova, Rimma

    2013-11-01

    In frogs and toads the urinary bladder is very important for the maintenance of water balance due to its ability to store water which can be reabsorbed under the action of arginine-vasotocin (AVT). The usage of isolated bladders as a model for studying the osmotic water permeability (OWP) regulation has a disadvantage which relates to high variability of AVT effect among individuals, some showing insensitivity to the hormone. We hypothesized that the response of the bladder to AVT could depend on the colonization of the mucosal epithelium by Gram-negative bacteria. To test this, paired hemibladders of the frog Rana temporaria were used for measurement of OWP and for analysis of Gram-negative bacteria in the bladder tissue or isolated epithelial cells. Among the 206 frogs studied, 41% were infected by different Enterobacteriaceae, with prevalence of Hafnia alvei and Escherichia coli. In infected bladders the basal level of OWP was unchanged, whereas OWP stimulated by AVT was reduced (non-infected: 2.53 ± 0.13, n = 59, infected: 1.21 ± 0.17 µL min(-1)  cm(-2), n = 38, for the 15 min of AVT action, P < 0.001). In the sample, 100% of hemibladders that responded to AVT very weakly (OWP <0.5 µL min(-1)  cm(-2)) had a bacterial infection. Overnight treatment of hemibladders with mucosal lipopolysaccharide E. coli decreased OWP induced by AVT, forskolin, or IBMX lowering basal and stimulated level of cAMP. The data obtained indicate that the frog bladder epithelium could be colonized by Gram-negative bacteria, probably of cloacal origin, leading to reduction of sensitivity to AVT and to impairment of the urinary bladder to provide osmoregulation. PMID:23836531

  19. Enterotoxigenic Escherichia coli and other gram-negative bacteria of infantile diarrhea: surface antigens, hemagglutinins, colonization factor antigen, and loss of enterotoxigenicity.

    PubMed

    Bäck, E; Möllby, R; Kaijser, B; Stintzing, G; Wadström, T; Habte, D

    1980-09-01

    Heat-labile enterotoxin (LT)-producing Escherichia coli and other enteric bacteria isolated from diarrheal Ethiopian children were studied for O and K antigen, production of heat-stable enterotoxin (ST), stability of LT production, properties of mannose-resistant hemagglutination (MRHA) (indicative of adhesive properties), and colonization factor antigen (CFA). Of the E. coli strains, 33% possessed O6, O8, or O78; 93% of these were stable producers of LT, and 86% produced both Lt and ST. O78 strains possessed CFA/I, whereas O6 and O8 strains possessed CFA/II. The E. coli with O antigens other than O6, O8, or O78, as well as the non-E. coli bacteria tended to lose their ability to produce LT; only 16% produced ST, and they only occasionally showed MRHA properties. The former group of E. coli strains might be considered as true enteropathogenic bacteria (enterovirulent E. coli), which may be identified serologically, while the pathogenic significance of the diversified latter group remains less certain. PMID:7003030

  20. Symbiosome-like intracellular colonization of cereals and other crop plants by nitrogen-fixing bacteria for reduced inputs of synthetic nitrogen fertilizers.

    PubMed

    Cocking, Edward C; Stone, Philip J; Davey, Michael R

    2005-09-01

    It has been forecast that the challenge of meeting increased food demand and protecting environmental quality will be won or lost in maize, rice and wheat cropping systems, and that the problem of environmental nitrogen enrichment is most likely to be solved by substituting synthetic nitrogen fertilizers by the creation of cereal crops that are able to fix nitrogen symbiotically as legumes do. In legumes, rhizobia present intracellularly in membrane-bound vesicular compartments in the cytoplasm of nodule cells fix nitrogen endosymbiotically. Within these symbiosomes, membrane-bound vesicular compartments, rhizobia are supplied with energy derived from plant photosynthates and in return supply the plant with biologically fixed nitrogen, usually as ammonia. This minimizes or eliminates the need for inputs of synthetic nitrogen fertilizers. Recently we have demonstrated, using novel inoculation conditions with very low numbers of bacteria, that cells of root meristems of maize, rice, wheat and other major non-legume crops, such as oilseed rape and tomato, can be intracellularly colonized by the non-rhizobial, non-nodulating, nitrogen fixing bacterium,Gluconacetobacter diazotrophicus that naturally occurs in sugarcane.G. diazotrophicus expressing nitrogen fixing (nifH) genes is present in symbiosome-like compartments in the cytoplasm of cells of the root meristems of the target cereals and non-legume crop species, somewhat similar to the intracellular symbiosome colonization of legume nodule cells by rhizobia. To obtain an indication of the likelihood of adequate growth and yield, of maize for example, with reduced inputs of synthetic nitrogen fertilizers, we are currently determining the extent to which nitrogen fixation, as assessed using various methods, is correlated with the extent of systemic intracellular colonization byG. diazotrophicus, with minimal or zero inputs. PMID:20549443

  1. Symbiosome-like intracellular colonization of cereals and other crop plants by nitrogen-fixing bacteria for reduced inputs of synthetic nitrogen fertilizers.

    PubMed

    Cocking, Edward C; Stone, Philip J; Davey, Michael R

    2005-12-01

    It has been forecast that the challenge of meeting increased food demand and protecting environmental quality will be won or lost in maize, rice and wheat cropping systems, and that the problem of environmental nitrogen enrichment is most likely to be solved by substituting synthetic nitrogen fertilizers by the creation of cereal crops that are able to fix nitrogen symbiotically as legumes do. In legumes, rhizobia present intracellularly in membrane-bound vesicular compartments in the cytoplasm of nodule cells fix nitrogen endosymbiotically. Within these symbiosomes, membrane-bound vesicular compartments, rhizobia are supplied with energy derived from plant photosynthates and in return supply the plant with biologically fixed nitrogen, usually as ammonia. This minimizes or eliminates the need for inputs of synthetic nitrogen fertilizers. Recently we have demonstrated, using novel inoculation conditions with very low numbers of bacteria, that cells of root meristems of maize, rice, wheat and other major non-legume crops, such as oilseed rape and tomato, can be intracellularly colonized by the non-rhizobial, non-nodulating, nitrogen fixing bacterium, Gluconacetobacter diazotrophicus that naturally occurs in sugarcane. G. diazotrophicus expressing nitrogen fixing (nifH) genes is present in symbiosome-like compartments in the cytoplasm of cells of the root meristems of the target cereals and non-legume crop species, somewhat similar to the intracellular symbiosome colonization of legume nodule cells by rhizobia. To obtain an indication of the likelihood of adequate growth and yield, of maize for example, with reduced inputs of synthetic nitrogen fertilizers, we are currently determining the extent to which nitrogen fixation, as assessed using various methods, is correlated with the extent of systemic intracellular colonization by G. diazotrophicus, with minimal or zero inputs. PMID:16512210

  2. Iron Oxidizing and Reducing Bacteria as Contributors to Basaltic Glass Colonization and Subsequent Weathering in Active Hydrothermal Vent Systems on Loihi and Vailulu'u Seamounts

    NASA Astrophysics Data System (ADS)

    Bailey, B.; Templeton, A.; Haucke, L.; Staudigel, H.; Tebo, B. M.

    2005-12-01

    The extreme oligotrophic nature of the oceanic crust was once believed to be an inhospitable environment to support microbial life. However, numerous studies in the past two decades have revealed diverse chemolithotrophic microbial communities inhabiting the deep biosphere within the oceanic crust. Vailulu'u Seamount in American Samoa and Loihi Seamount in Hawai'i provide access to the deep biosphere environments through the study of the interaction of hydrothermal vent water, basaltic substrates and microbial communities. Both seamounts have been found to exhibit similar iron-encrusted microbial mats surrounding both high and low temperature hydrothermal vent orifices. We are targeting iron as the main electron donor/acceptor in these environments due to the relative abundance and availability in basalts. Through the use of the HURL Pisces submersibles, we exposed amended basaltic glasses of several different compositions to a host of different environments on both seamounts in order to study the colonization and biofilm characteristics of the microbial communities. A large culturing effort reveals multiple iron oxidizing and reducing bacteria as members of the microbial community responsible for the colonization and subsequent dissolution and alteration of basaltic glass. We employ an annular reactor to expose the same suite of chemically altered basaltic glasses to a sample of iron microbial mats taken from Vailulu'u to provide a laboratory complement the environmental exposure experiments. Here cell counts reveal a 90% enhanced colonization and growth on the basalt glass versus the surrounding epoxy and borosilicate glass. The ability of microbes to leach nutrients (such as iron) out of the host substrate has far reaching astrobiological implications for nutrient sources available to sustain life in a Mars or Europa biosphere.

  3. Potential probiotic lactic acid bacteria of human origin induce antiproliferation of colon cancer cells via synergic actions in adhesion to cancer cells and short-chain fatty acid bioproduction.

    PubMed

    Thirabunyanon, Mongkol; Hongwittayakorn, Penrat

    2013-01-01

    The activities and modes of probiotic action of lactic acid bacteria isolated from infant feces were investigated for alternative application in the prevention and biotherapy of colon cancer. From a total of 81 isolates of Gram-positive rod and cocci bacteria obtained from healthy infants, only 15 isolates had the probiotic criteria which included growth inhibition against eight food-borne pathogens, no blood hemolysis, and tolerance to gastrointestinal tract properties such as pH 2.5 and 0.3 % bile salt. Four probiotic bacteria showed antiproliferation of colon cancer cells with the use of MTT and Trypan blue exclusion assay at the rates of 17-35 %. Through comparison of probiotic 16S rRNA sequences, they were identified as Pediococcus pentosaceus FP3, Lactobacillus salivarius FP25, L. salivarius FP35, and Enterococcus faecium FP51. Finding the mechanism of proliferative inhibition of colon cancer cells in this study indicated synergic induction by probiotic bacteria directly adhered to these cancer cells and triggered the bioproduction of short-chain fatty acids, mainly butyric and propionic acids. This study suggested that the use of these probiotics may be suitable as an alternative bioprophylactic and biotherapeutic strategy for colon cancer. PMID:23239414

  4. In vitro anti-biofilm activity of macelignan isolated from Myristica fragrans Houtt. against oral primary colonizer bacteria.

    PubMed

    Rukayadi, Yaya; Kim, Kyu-Hoi; Hwang, Jae-Kwan

    2008-03-01

    In early dental plaque formation, oral primary colonizers such as Streptococcus mutans, Streptococcus sanguis and Actinomyces viscosus are initially attached to the pellicle-coated tooth surface to form a biofilm. The study aimed to determine the efficacy of macelignan, isolated from nutmeg (Myristica fragrans Houtt.), in removing each single oral primary biofilm in vitro on a polystyrene 96-well microtiter plate. Four biofilm growth phases (4, 12, 20 and 24 h) were evaluated in this study after treatment with macelignan at various concentrations (0.2, 2 and 10 microg/mL) and exposure times (5, 10 and 30 min). Anti-biofilm activity of macelignan was measured as the percentage of the remaining biofilm absorbance after macelignan treatment in comparison with the untreated control. At 24 h of biofilm growth, S. mutans, A. viscosus and S. sanguis biofilms were reduced by up to 30%, 30% and 38%, respectively, after treatment with 10 microg/mL macelignan for 5 min. Increasing the treatment time to 30 min resulted in a reduction of more than 50% of each of the single primary biofilms. The results indicate that macelignan is a potent natural anti-biofilm agent against oral primary colonizers. PMID:17926328

  5. Effects of adsorbed and templated nanosilver in mesoporous calcium-silicate nanoparticles on inhibition of bacteria colonization of dentin

    PubMed Central

    Fan, Wei; Wu, Daming; Tay, Franklin R; Ma, Tengjiao; Wu, Yujie; Fan, Bing

    2014-01-01

    Mesoporous calcium-silicate nanoparticles (MCSNs) are advanced biomaterials for controlled drug delivery and mineralization induction. Nanosilver-incorporated MCSNs (Ag-MCSNs) were prepared in the present study using both the adsorption and template methods. Both versions of Ag-MCSNs showed characteristic morphology of mesoporous materials and exhibited sustained release of ions over time. In antibacterial testing against planktonic Enterococcus faecalis, Ag-MCSNs showed significantly better antibacterial effects when compared with MCSNs (P<0.05). The Ag-MCSNs aggregated on the dentin surface of root canal walls and infiltrated into dentinal tubules after ultrasound activation, significantly inhibiting the adherence and colonization of E. faecalis on dentin (P<0.05). Despite this, Ag-MCSNs with templated nanosilver showed much lower cytotoxicity than Ag-MCSNs with adsorbed nanosilver (P<0.05). The results of the present study indicated that nanosilver could be incorporated into MCSNs using the template method. The templated nanosilver could release silver ions and inhibit the growth and colonization of E. faecalis both in the planktonic form and as biofilms on dentin surfaces as absorbed nanosilver. Templated Ag-MCSNs may be developed into a new intracanal disinfectant for root canal disinfection due to their antibacterial ability and low cytotoxicity, and as controlled release devices for other bioactive molecules to produce multifunctional biomaterials. PMID:25419127

  6. Evidence for colonization and destruction of hinge ligaments in cultured juvenile Pacific oysters (Crassostrea gigas) by cytophaga-like bacteria.

    PubMed Central

    Dungan, C F; Elston, R A; Schiewe, M H

    1989-01-01

    Several strains of cytophaga-like gliding bacteria (CLB) were isolated as numerically dominant or codominant components of bacterial populations associated with proteinaceous hinge ligaments of cultured juvenile Pacific oysters, Crassostrea gigas. These bacteria were morphologically similar to long, flexible bacilli occurring within degenerative lesions in oyster hinge ligaments. Among bacteria isolated from hinge ligaments, only CLB strains were capable of sustained growth with hinge ligament matrix as the sole source of organic carbon and nitrogen. In vitro incubation of cuboidal portions of ligament resilium with ligament CLB resulted in bacterial proliferation on the surfaces and penetration deep into ligament matrices. Bacterial proliferation was accompanied by loss of resilium structural and mechanical integrity, including complete liquefaction, at incubation temperatures between 10 and 20 degrees C. The morphological, distributional, and degradative characteristics of CLB isolated from oyster hinge ligaments provide compelling, albeit indirect, evidence that CLB are the agents of a degenerative disease affecting juvenile cultured oysters. The motility, metabolic, and hydrolytic characteristics of hinge ligament CLB and the low moles percent G + C values (32.4 to 32.9) determined for three representative strains indicate that they are marine Cytophaga spp. Images PMID:2757377

  7. Humus bacteria of Norway spruce stands: plant growth promoting properties and birch, red fescue and alder colonizing capacity.

    PubMed

    Elo; Maunuksela; Salkinoja-Salonen; Smolander; Haahtela

    2000-02-01

    We studied the potential of the humus layer of the Norway spruce stands to supply beneficial rhizobacteria to birch (Betula pendula), alder (Alnus incana) and fescue grass (Festuca rubra), representatives of pioneer vegetation after clear-cutting of the coniferous forest. Axenically grown seedlings of these species were inoculated with the acid spruce humus, pH 3.7-5.3. Actinorhizal propagules, capable of nodulating alder, were present in high density (10(3) g(-1)) in humus of long-term limed plots, whereas plots with nitrogen fertilization contained almost none (bacteria. In addition, nitrogen-fixing R. fascians was found in the humus. The rhizoflora and humus contained high proportions of bacteria antagonistic towards plant pathogenic Rhizoctonia sp., Botrytis cinerea and Fusarium culmorum. The antagonistic isolates also commonly produced siderophores and/or cell wall degrading enzymes. PMID:10640667

  8. Phlogistic properties of peptidoglycan-polysaccharide polymers from cell walls of pathogenic and normal-flora bacteria which colonize humans.

    PubMed Central

    Schwab, J H

    1993-01-01

    PG-PS polymers which can induce experimental chronic inflammation in joints and other tissues can be isolated from the cell walls of human pathogens, such as group A streptococci, as well as from certain indigenous bacterial species which colonize the human intestinal tract. The structural and biological properties that are required for cell wall fragments to express this remarkable activity are still not well defined, but polymer size, resistance to tissue enzymes, and capacity to sustain activation of complement, macrophages, neutrophils, and T cells are properties associated with the most active preparations. There is increasing evidence that PG-PS structures with arthropathogenic activity occur in the human intestinal lumen and that these polymers can be translocated systemically. These observations support the concept that PG-PS, derived from a variety of bacterial species, can be part of the etiology of rheumatoid arthritis and other chronic inflammatory diseases. Since the PG component provides a common element to which all individuals are exposed, it follows that susceptibility is related to efficiency of disposal of bacterial cell wall debris, as well as to cytokine networks and immune cell function (51). PMID:8406849

  9. Anti-proliferative effect of fungal taxol extracted from Cladosporium oxysporum against human pathogenic bacteria and human colon cancer cell line HCT 15

    NASA Astrophysics Data System (ADS)

    Gokul Raj, K.; Manikandan, R.; Arulvasu, C.; Pandi, M.

    2015-03-01

    Cladosporium oxysporum a new taxol producing endophytic fungus was identified and production of taxol were characterized using UV-visible spectroscopy (UV-vis), high-performance liquid chromatography (HPLC), infrared (IR) nuclear magnetic resonance spectroscopy (NMR (13C and 1H)) and liquid chromatography-mass spectrometry (LC-MS). The taxol biosynthetic gene (dbat) was evaluated for new taxol producing fungus. Antibacterial activity against six different human pathogenic bacteria was done by agar well diffusion method. The anticancer efficacy of isolated fungal taxol were also evaluated in human colon cancer cell HCT 15 by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), cytotoxicity and nuclear morphology analysis. The isolated fungal taxol showed positive towards biosynthetic gene (dbat) and effective against both Gram positive as well as Gram negative. The fungal taxol suppress growth of cancer cell line HCT 15 with an IC50 value of 3.5 μM concentration by 24 h treatment. Thus, the result reveals that C. oxysporum could be a potential alternative source for production of taxol and have antibacterial as well as anticancer properties with possible clinical applications.

  10. Identification of Rothia Bacteria as Gluten-Degrading Natural Colonizers of the Upper Gastro-Intestinal Tract

    PubMed Central

    Zamakhchari, Maram; Wei, Guoxian; Dewhirst, Floyd; Lee, Jaeseop; Schuppan, Detlef; Oppenheim, Frank G.; Helmerhorst, Eva J.

    2011-01-01

    Background Gluten proteins, prominent constituents of barley, wheat and rye, cause celiac disease in genetically predisposed subjects. Gluten is notoriously difficult to digest by mammalian proteolytic enzymes and the protease-resistant domains contain multiple immunogenic epitopes. The aim of this study was to identify novel sources of gluten-digesting microbial enzymes from the upper gastro-intestinal tract with the potential to neutralize gluten epitopes. Methodology/Principal Findings Oral microorganisms with gluten-degrading capacity were obtained by a selective plating strategy using gluten agar. Microbial speciations were carried out by 16S rDNA gene sequencing. Enzyme activities were assessed using gliadin-derived enzymatic substrates, gliadins in solution, gliadin zymography, and 33-mer α-gliadin and 26-mer γ-gliadin immunogenic peptides. Fragments of the gliadin peptides were separated by RP-HPLC and structurally characterized by mass spectrometry. Strains with high activity towards gluten were typed as Rothia mucilaginosa and Rothia aeria. Gliadins (250 µg/ml) added to Rothia cell suspensions (OD620 1.2) were degraded by 50% after ∼30 min of incubation. Importantly, the 33-mer and 26-mer immunogenic peptides were also cleaved, primarily C-terminal to Xaa-Pro-Gln (XPQ) and Xaa-Pro-Tyr (XPY). The major gliadin-degrading enzymes produced by the Rothia strains were ∼70–75 kDa in size, and the enzyme expressed by Rothia aeria was active over a wide pH range (pH 3–10). Conclusion/Significance While the human digestive enzyme system lacks the capacity to cleave immunogenic gluten, such activities are naturally present in the oral microbial enzyme repertoire. The identified bacteria may be exploited for physiologic degradation of harmful gluten peptides. PMID:21957450

  11. Colonic Polyps

    MedlinePlus

    ... Colonic polyps grow in the large intestine, or colon. Most polyps are not dangerous. However, some polyps ... member with polyps Have a family history of colon cancer Most colon polyps do not cause symptoms. ...

  12. Heat-killed probiotic bacteria differentially regulate colonic epithelial cell production of human β-defensin-2: dependence on inflammatory cytokines.

    PubMed

    Habil, N; Abate, W; Beal, J; Foey, A D

    2014-12-01

    The inducible antimicrobial peptide human β-defensin-2 (hBD-2) stimulated by pro-inflammatory cytokines and bacterial products is essential to antipathogen responses of gut epithelial cells. Commensal and probiotic bacteria can augment such mucosal defences. Probiotic use in the treatment of inflammatory bowel disease, however, may have adverse effects, boosting inflammatory responses. The aim of this investigation was to determine the effect of selected probiotic strains on hBD-2 production by epithelial cells induced by pathologically relevant pro-inflammatory cytokines and the role of cytokine modulators in controlling hBD-2. Caco-2 colonic intestinal epithelial cells were pre-incubated with heat-killed probiotics, i.e. Lactobacillus casei strain Shirota (LcS) or Lactobacillus fermentum strain MS15 (LF), followed by stimulation of hBD-2 by interleukin (IL)-1β and tumour necrosis factor alpha (TNF-α) in the absence or presence of exogenous IL-10 or anti-IL-10 neutralising antibody. Cytokines and hBD-2 mRNA and protein were analysed by real-time quantitative polymerase chain reaction and enzyme-linked immunosorbent assay. LcS augmented IL-1β-induced hBD-2, whereas LF enhanced TNF-α- and suppressed IL-1β-induced hBD-2. LF enhanced TNF-α-induced TNF-α and suppressed IL-10, whereas augmented IL-1β-induced IL-10. LcS upregulated IL-1β-induced TNF-α mRNA and suppressed IL-10. Endogenous IL-10 differentially regulated hBD-2; neutralisation of IL-10 augmented TNF-α- and suppressed IL-1β-induced hBD-2. Exogenous IL-10, however, suppressed both TNF-α- and IL-1β-induced hBD-2; LcS partially rescued suppression in TNF-α- and IL-1β-stimulation, whereas LF further suppressed IL-1β-induced hBD-2. It can be concluded that probiotic strains differentially regulate hBD-2 mRNA expression and protein secretion, modulation being dictated by inflammatory stimulus and resulting cytokine environment. PMID:25116382

  13. Colon cancer

    MedlinePlus

    Colorectal cancer; Cancer - colon; Rectal cancer; Cancer - rectum; Adenocarcinoma - colon; Colon - adenocarcinoma ... In the United States, colorectal cancer is one of the leading causes of deaths due to cancer. Early diagnosis can often lead to a complete cure. Almost ...

  14. Colonization of plant substrates at hydrothermal vents and cold seeps in the northeast Atlantic and Mediterranean and occurrence of symbiont-related bacteria.

    PubMed

    Szafranski, Kamil M; Deschamps, Philippe; Cunha, Marina R; Gaudron, Sylvie M; Duperron, Sébastien

    2015-01-01

    Reducing conditions with elevated sulfide and methane concentrations in ecosystems such as hydrothermal vents, cold seeps or organic falls, are suitable for chemosynthetic primary production. Understanding processes driving bacterial diversity, colonization and dispersal is of prime importance for deep-sea microbial ecology. This study provides a detailed characterization of bacterial assemblages colonizing plant-derived substrates using a standardized approach over a geographic area spanning the North-East Atlantic and Mediterranean. Wood and alfalfa substrates in colonization devices were deployed for different periods at 8 deep-sea chemosynthesis-based sites in four distinct geographic areas. Pyrosequencing of a fragment of the 16S rRNA-encoding gene was used to describe bacterial communities. Colonization occurred within the first 14 days. The diversity was higher in samples deployed for more than 289 days. After 289 days, no relation was observed between community richness and deployment duration, suggesting that diversity may have reached saturation sometime in between. Communities in long-term deployments were different, and their composition was mainly influenced by the geographical location where devices were deployed. Numerous sequences related to horizontally-transmitted chemosynthetic symbionts of metazoans were identified. Their potential status as free-living forms of these symbionts was evaluated based on sequence similarity with demonstrated symbionts. Results suggest that some free-living forms of metazoan symbionts or their close relatives, such as Epsilonproteobacteria associated with the shrimp Rimicaris exoculata, are efficient colonizers of plant substrates at vents and seeps. PMID:25774156

  15. Colonization of plant substrates at hydrothermal vents and cold seeps in the northeast Atlantic and Mediterranean and occurrence of symbiont-related bacteria

    PubMed Central

    Szafranski, Kamil M.; Deschamps, Philippe; Cunha, Marina R.; Gaudron, Sylvie M.; Duperron, Sébastien

    2015-01-01

    Reducing conditions with elevated sulfide and methane concentrations in ecosystems such as hydrothermal vents, cold seeps or organic falls, are suitable for chemosynthetic primary production. Understanding processes driving bacterial diversity, colonization and dispersal is of prime importance for deep-sea microbial ecology. This study provides a detailed characterization of bacterial assemblages colonizing plant-derived substrates using a standardized approach over a geographic area spanning the North-East Atlantic and Mediterranean. Wood and alfalfa substrates in colonization devices were deployed for different periods at 8 deep-sea chemosynthesis-based sites in four distinct geographic areas. Pyrosequencing of a fragment of the 16S rRNA-encoding gene was used to describe bacterial communities. Colonization occurred within the first 14 days. The diversity was higher in samples deployed for more than 289 days. After 289 days, no relation was observed between community richness and deployment duration, suggesting that diversity may have reached saturation sometime in between. Communities in long-term deployments were different, and their composition was mainly influenced by the geographical location where devices were deployed. Numerous sequences related to horizontally-transmitted chemosynthetic symbionts of metazoans were identified. Their potential status as free-living forms of these symbionts was evaluated based on sequence similarity with demonstrated symbionts. Results suggest that some free-living forms of metazoan symbionts or their close relatives, such as Epsilonproteobacteria associated with the shrimp Rimicaris exoculata, are efficient colonizers of plant substrates at vents and seeps. PMID:25774156

  16. Influence of Soil Temperature and Matric Potential on Sugar Beet Seedling Colonization and Suppression of Pythium Damping-Off by the Antagonistic Bacteria Pseudomonas fluorescens and Bacillus subtilis.

    PubMed

    Schmidt, C S; Agostini, F; Leifert, C; Killham, K; Mullins, C E

    2004-04-01

    ABSTRACT Pseudomonas fluorescens B5 and Bacillus subtilis MBI 600 colonized sugar beet seedlings at matric potentials of -7 x 10(3), -140 x 10(3), and -330 x 10(3) Pa and under five temperature regimes ranging from 7 to 35 degrees C, with diurnal fluctuations of 5 to 22 degrees C. No interaction between matric potential and temperature was observed. In situ bioluminescence indicated physiological activity of Pseudomonas fluorescens B5. Colonization of the root at >/=4 cm below the seed decreased at very low matric potential (-330 x 10(3) Pa). Total population size of Pseudomonas fluorescens B5 per seedling was significantly increased at -140 x 10(3) Pa. However, matric potential had no significant effect on the population density of Pseudomonas fluorescens per gram of root fresh weight and did not affect the distribution of the population down the root. Total population size per seedling and downward colonization by Pseudomonas fluorescens B5 were significantly reduced at high temperatures (25 to 35 degrees C). Maximum colonization down the root occurred at intermediate temperature (15 degrees C) at both matric potentials (-7 x 10(3) and -140 x 10(3) Pa). Addition of B. subtilis MBI 600 to the seed had no effect on rhizosphere populations of Pseudomonas fluorescens B5. Populations of B. subtilis MBI 600, which consisted largely of spores, were slightly reduced at lower matric potentials and were not affected by temperature. Survival and dry weight of plants in soils infested with Pythium spp. decreased with increasing soil temperature and matric potential, indicating an increase in disease pressure. However, there was no significant interaction between the two factors. At -330 x 10(3) Pa, soil dryness but not Pythium infection was the limiting factor for plant emergence. At temperatures of 7 to 25 degrees C and matric potentials of -7 x 10(3) to 120 x 10(3) Pa, treatment with Pseudomonas fluorescens B5 increased plant survival and dry weight. At 7 degrees C and

  17. A Carotenoid-Deficient Mutant in Pantoea sp. YR343, a Bacteria Isolated from the Rhizosphere of Populus deltoides, Is Defective in Root Colonization

    PubMed Central

    Bible, Amber N.; Fletcher, Sarah J.; Pelletier, Dale A.; Schadt, Christopher W.; Jawdy, Sara S.; Weston, David J.; Engle, Nancy L.; Tschaplinski, Timothy; Masyuko, Rachel; Polisetti, Sneha; Bohn, Paul W.; Coutinho, Teresa A.; Doktycz, Mitchel J.; Morrell-Falvey, Jennifer L.

    2016-01-01

    The complex interactions between plants and their microbiome can have a profound effect on the health and productivity of the plant host. A better understanding of the microbial mechanisms that promote plant health and stress tolerance will enable strategies for improving the productivity of economically important plants. Pantoea sp. YR343 is a motile, rod-shaped bacterium isolated from the roots of Populus deltoides that possesses the ability to solubilize phosphate and produce the phytohormone indole-3-acetic acid (IAA). Pantoea sp. YR343 readily colonizes plant roots and does not appear to be pathogenic when applied to the leaves or roots of selected plant hosts. To better understand the molecular mechanisms involved in plant association and rhizosphere survival by Pantoea sp. YR343, we constructed a mutant in which the crtB gene encoding phytoene synthase was deleted. Phytoene synthase is responsible for converting geranylgeranyl pyrophosphate to phytoene, an important precursor to the production of carotenoids. As predicted, the ΔcrtB mutant is defective in carotenoid production, and shows increased sensitivity to oxidative stress. Moreover, we find that the ΔcrtB mutant is impaired in biofilm formation and production of IAA. Finally we demonstrate that the ΔcrtB mutant shows reduced colonization of plant roots. Taken together, these data suggest that carotenoids are important for plant association and/or rhizosphere survival in Pantoea sp. YR343. PMID:27148182

  18. A Carotenoid-Deficient Mutant in Pantoea sp. YR343, a Bacteria Isolated from the Rhizosphere of Populus deltoides, Is Defective in Root Colonization

    DOE PAGESBeta

    Bible, Amber; Fletcher, Sarah J; Pelletier, Dale A; Schadt, Christopher Warren; Jawdy, Sara; Weston, David; Engle, Nancy L.; Tschaplinski, Timothy J.; Masyuko, Rachel; Polisetti, Sneha; et al

    2016-04-18

    The complex interactions between plants and their microbiome can have a profound effect on the health and productivity of the plant host. A better understanding of the microbial mechanisms that promote plant health and stress tolerance will enable strategies for improving the productivity of economically-important plants. Pantoea sp. YR343 is a motile, rod-shaped bacterium isolated from the roots of Populus deltoides that possesses the ability to solubilize phosphate and produce the phytohormone indole-3-acetic acid. Pantoea sp. YR343 readily colonizes plant roots and does not appear to be pathogenic when applied to the leaves or roots of selected plant hosts. Tomore » better understand the molecular mechanisms involved in plant association and rhizosphere survival by Pantoea sp. YR343, we constructed a mutant in which the crtB gene encoding phytoene synthase was deleted. Phytoene synthase is responsible for converting geranylgeranyl pyrophosphate to phytoene, an important precursor to the production of carotenoids. As predicted, the ΔcrtB mutant is defective in carotenoid production, and shows increased sensitivity to oxidative stress. Moreover, we find that the ΔcrtB mutant is impaired in biofilm formation and production of indole-3-acetic acid. Finally we demonstrate that the ΔcrtB mutant shows reduced colonization of plant roots. Taken together, these data suggest that carotenoids are important for plant association and/or rhizosphere survival in Pantoea sp. YR343.« less

  19. A Carotenoid-Deficient Mutant in Pantoea sp. YR343, a Bacteria Isolated from the Rhizosphere of Populus deltoides, Is Defective in Root Colonization.

    PubMed

    Bible, Amber N; Fletcher, Sarah J; Pelletier, Dale A; Schadt, Christopher W; Jawdy, Sara S; Weston, David J; Engle, Nancy L; Tschaplinski, Timothy; Masyuko, Rachel; Polisetti, Sneha; Bohn, Paul W; Coutinho, Teresa A; Doktycz, Mitchel J; Morrell-Falvey, Jennifer L

    2016-01-01

    The complex interactions between plants and their microbiome can have a profound effect on the health and productivity of the plant host. A better understanding of the microbial mechanisms that promote plant health and stress tolerance will enable strategies for improving the productivity of economically important plants. Pantoea sp. YR343 is a motile, rod-shaped bacterium isolated from the roots of Populus deltoides that possesses the ability to solubilize phosphate and produce the phytohormone indole-3-acetic acid (IAA). Pantoea sp. YR343 readily colonizes plant roots and does not appear to be pathogenic when applied to the leaves or roots of selected plant hosts. To better understand the molecular mechanisms involved in plant association and rhizosphere survival by Pantoea sp. YR343, we constructed a mutant in which the crtB gene encoding phytoene synthase was deleted. Phytoene synthase is responsible for converting geranylgeranyl pyrophosphate to phytoene, an important precursor to the production of carotenoids. As predicted, the ΔcrtB mutant is defective in carotenoid production, and shows increased sensitivity to oxidative stress. Moreover, we find that the ΔcrtB mutant is impaired in biofilm formation and production of IAA. Finally we demonstrate that the ΔcrtB mutant shows reduced colonization of plant roots. Taken together, these data suggest that carotenoids are important for plant association and/or rhizosphere survival in Pantoea sp. YR343. PMID:27148182

  20. Antifouling activities against colonizer marine bacteria of extracts from marine invertebrates collected in the Colombian Caribbean Sea and on the Brazilian coast (Santa Catarina).

    PubMed

    Mora-Cristancho, Jennyfer A; Arévalo-Ferro, Catalina; Ramos, Freddy A; Tello, Edisson; Duque, Carmenza; Lhullier, Cintia; Falkenberg, Miriam; Schenkel, Eloir Paulo

    2011-01-01

    The growth inhibition of 12 native marine bacteria isolated from Aplysina sponge surfaces, the shell of a bivalve, and Phytagel immersed for 48 h in sea water were used as indicator of the antifouling activity of the extracts of 39 marine organisms (octocorals, sponges, algae, and zoanthid) collected in the Colombian Caribbean Sea and on the Brazilian coast (Santa Catarina). Gram-negative bacteria represented 75% of the isolates; identified strains belonged to Oceanobacillus iheyensis, Ochrobactrum pseudogrignonense, Vibrio campbellii, Vibrio harveyi, and Bacillus megaterium species and seven strains were classified at genus level by the 16S rRNA sequencing method. The extracts of the octocorals Pseudopterogorgia elisabethae, four Eunicea octocorals, and the sponges Topsentia ophiraphidites, Agelas citrina, Neopetrosia carbonaria, Monanchora arbuscula, Cliona tenuis, Iotrochota imminuta, and Ptilocaulis walpersii were the most active, thus suggesting those species as antifoulant producers. This is the first study of natural antifoulants from marine organisms collected on the Colombian and Brazilian coasts. PMID:22191218

  1. Seagrass (Zostera marina) Colonization Promotes the Accumulation of Diazotrophic Bacteria and Alters the Relative Abundances of Specific Bacterial Lineages Involved in Benthic Carbon and Sulfur Cycling

    PubMed Central

    Sun, Feifei; Zhang, Xiaoli; Zhang, Qianqian; Liu, Fanghua

    2015-01-01

    Seagrass colonization changes the chemistry and biogeochemical cycles mediated by microbes in coastal sediments. In this study, we molecularly characterized the diazotrophic assemblages and entire bacterial community in surface sediments of a Zostera marina-colonized coastal lagoon in northern China. Higher nitrogenase gene (nifH) copy numbers were detected in the sediments from the vegetated region than in the sediments from the unvegetated region nearby. The nifH phylotypes detected were mostly affiliated with the Geobacteraceae, Desulfobulbus, Desulfocapsa, and Pseudomonas. Redundancy analysis based on terminal restriction fragment length polymorphism analysis showed that the distribution of nifH genotypes was mostly shaped by the ratio of total organic carbon to total organic nitrogen, the concentration of cadmium in the sediments, and the pH of the overlying water. High-throughput sequencing and phylogenetic analyses of bacterial 16S rRNA genes also indicated the presence of Geobacteraceae and Desulfobulbaceae phylotypes in these samples. A comparison of these results with those of previous studies suggests the prevalence and predominance of iron(III)-reducing Geobacteraceae and sulfate-reducing Desulfobulbaceae diazotrophs in coastal sedimentary environments. Although the entire bacterial community structure was not significantly different between these two niches, Desulfococcus (Deltaproteobacteria) and Anaerolineae (Chloroflexi) presented with much higher proportions in the vegetated sediments, and Flavobacteriaceae (Bacteroidetes) occurred more frequently in the bare sediments. These data suggest that the high bioavailability of organic matter (indicated by relatively lower carbon-to-nitrogen ratios) and the less-reducing anaerobic condition in vegetated sediments may favor Desulfococcus and Anaerolineae lineages, which are potentially important populations in benthic carbon and sulfur cycling in the highly productive seagrass ecosystem. PMID:26209674

  2. Seagrass (Zostera marina) Colonization Promotes the Accumulation of Diazotrophic Bacteria and Alters the Relative Abundances of Specific Bacterial Lineages Involved in Benthic Carbon and Sulfur Cycling.

    PubMed

    Sun, Feifei; Zhang, Xiaoli; Zhang, Qianqian; Liu, Fanghua; Zhang, Jianping; Gong, Jun

    2015-10-01

    Seagrass colonization changes the chemistry and biogeochemical cycles mediated by microbes in coastal sediments. In this study, we molecularly characterized the diazotrophic assemblages and entire bacterial community in surface sediments of a Zostera marina-colonized coastal lagoon in northern China. Higher nitrogenase gene (nifH) copy numbers were detected in the sediments from the vegetated region than in the sediments from the unvegetated region nearby. The nifH phylotypes detected were mostly affiliated with the Geobacteraceae, Desulfobulbus, Desulfocapsa, and Pseudomonas. Redundancy analysis based on terminal restriction fragment length polymorphism analysis showed that the distribution of nifH genotypes was mostly shaped by the ratio of total organic carbon to total organic nitrogen, the concentration of cadmium in the sediments, and the pH of the overlying water. High-throughput sequencing and phylogenetic analyses of bacterial 16S rRNA genes also indicated the presence of Geobacteraceae and Desulfobulbaceae phylotypes in these samples. A comparison of these results with those of previous studies suggests the prevalence and predominance of iron(III)-reducing Geobacteraceae and sulfate-reducing Desulfobulbaceae diazotrophs in coastal sedimentary environments. Although the entire bacterial community structure was not significantly different between these two niches, Desulfococcus (Deltaproteobacteria) and Anaerolineae (Chloroflexi) presented with much higher proportions in the vegetated sediments, and Flavobacteriaceae (Bacteroidetes) occurred more frequently in the bare sediments. These data suggest that the high bioavailability of organic matter (indicated by relatively lower carbon-to-nitrogen ratios) and the less-reducing anaerobic condition in vegetated sediments may favor Desulfococcus and Anaerolineae lineages, which are potentially important populations in benthic carbon and sulfur cycling in the highly productive seagrass ecosystem. PMID:26209674

  3. Relationship between the adhesive properties of bacteria and their transport and colonization in the subsurface environment. Final report for period September 15, 1996 - September 30, 1999

    SciTech Connect

    Madilyn Fletcher

    2000-04-06

    This research has focused on the attachment of bacteria to solid surfaces and the significance of their adhesion properties in their transport through porous media. Our work has focused on strains of Pseudomonas and a related species Burkholderia cepacia. Most of our experimental strains were isolated from subsurface environments at USDOE experimental field sites. The first portion of this project was conducted at the University of Maryland during 1994-1996, during which two graduates and one graduate student were supported by the award. The project was then continued under contract number DE-FG02-96ER62302 at the University of South Carolina, where one postdoctoral associate has been supported by the award.

  4. Resistant starch induces catabolic but suppresses immune and cell division pathways and changes the microbiome in the proximal colon of male pigs.

    PubMed

    Haenen, Daniëlle; Souza da Silva, Carol; Zhang, Jing; Koopmans, Sietse Jan; Bosch, Guido; Vervoort, Jacques; Gerrits, Walter J J; Kemp, Bas; Smidt, Hauke; Müller, Michael; Hooiveld, Guido J E J

    2013-12-01

    Consumption of resistant starch (RS) has been associated with various intestinal health benefits, but knowledge of its effects on global gene expression in the colon is limited. The main objective of the current study was to identify genes affected by RS in the proximal colon to infer which biologic pathways were modulated. Ten 17-wk-old male pigs, fitted with a cannula in the proximal colon for repeated collection of tissue biopsy samples and luminal content, were fed a digestible starch (DS) diet or a diet high in RS (34%) for 2 consecutive periods of 14 d in a crossover design. Analysis of the colonic transcriptome profiles revealed that, upon RS feeding, oxidative metabolic pathways, such as the tricarboxylic acid cycle and β-oxidation, were induced, whereas many immune response pathways, including adaptive and innate immune system, as well as cell division were suppressed. The nuclear receptor peroxisome proliferator-activated receptor γ was identified as a potential key upstream regulator. RS significantly (P < 0.05) increased the relative abundance of several butyrate-producing microbial groups, including the butyrate producers Faecalibacterium prausnitzii and Megasphaera elsdenii, and reduced the abundance of potentially pathogenic members of the genus Leptospira and the phylum Proteobacteria. Concentrations in carotid plasma of the 3 main short-chain fatty acids acetate, propionate, and butyrate were significantly higher with RS consumption compared with DS consumption. Overall, this study provides novel insights on effects of RS in proximal colon and contributes to our understanding of a healthy diet. PMID:24132577

  5. Mechanisms and Rates of Bacterial Colonization of Sinking Aggregates

    PubMed Central

    Kiørboe, Thomas; Grossart, Hans-Peter; Ploug, Helle; Tang, Kam

    2002-01-01

    Quantifying the rate at which bacteria colonize aggregates is a key to understanding microbial turnover of aggregates. We used encounter models based on random walk and advection-diffusion considerations to predict colonization rates from the bacteria's motility patterns (swimming speed, tumbling frequency, and turn angles) and the hydrodynamic environment (stationary versus sinking aggregates). We then experimentally tested the models with 10 strains of bacteria isolated from marine particles: two strains were nonmotile; the rest were swimming at 20 to 60 μm s−1 with different tumbling frequency (0 to 2 s−1). The rates at which these bacteria colonized artificial aggregates (stationary and sinking) largely agreed with model predictions. We report several findings. (i) Motile bacteria rapidly colonize aggregates, whereas nonmotile bacteria do not. (ii) Flow enhances colonization rates. (iii) Tumbling strains colonize aggregates enriched with organic substrates faster than unenriched aggregates, while a nontumbling strain did not. (iv) Once on the aggregates, the bacteria may detach and typical residence time is about 3 h. Thus, there is a rapid exchange between attached and free bacteria. (v) With the motility patterns observed, freely swimming bacteria will encounter an aggregate in <1 day at typical upper-ocean aggregate concentrations. This is faster than even starving bacteria burn up their reserves, and bacteria may therefore rely solely on aggregates for food. (vi) The net result of colonization and detachment leads to a predicted equilibrium abundance of attached bacteria as a function of aggregate size, which is markedly different from field observations. This discrepancy suggests that inter- and intraspecific interactions among bacteria and between bacteria and their predators may be more important than colonization in governing the population dynamics of bacteria on natural aggregates. PMID:12147501

  6. Colon cancer

    MedlinePlus

    ... red or processed meats Have colorectal polyps Have inflammatory bowel disease ( Crohn disease or ulcerative colitis ) Have a family history of colon cancer Have a personal history of breast cancer Some inherited diseases also increase the risk ...

  7. The Chronic Kidney Disease - Colonic Axis.

    PubMed

    Pahl, Madeleine V; Vaziri, Nosratola D

    2015-01-01

    Chronic kidney disease (CKD) has long been known to cause significant gastrointestinal and colonic pathology. Recent advances in understanding of the role of colonic bacterial microbiome and its function and composition in health and disease have revealed previously unappreciated effects of CKD-associated colonic pathology on the development of uremic complications. CKD can result in profound changes in the microbiome composition and biosynthetic pattern, and the structure and function of the colon. Increases in bacteria that produce urease, uricase, p-cresol- and indole-forming enzymes and the depletion of bacteria that possess short chain fatty acid forming enzymes have been described in human and animal models. Disruption of the colonic epithelial tight junction in different animal models of CKD has been reported and is largely due to the conversion of luminal urea to ammonia by urease possessing bacteria. Together, these changes contribute to the pathogenesis of systemic inflammation and uremic toxicity by allowing the translocation of endotoxin and microbial fragments into the circulation. Additionally, colonic bacteria are the main source of several well-known pro-inflammatory uremic toxins such as indoxyl sulfate, P-cresol sulfate. This review is intended to provide an overview of the effects of CKD on the colonic microbiome and the intestinal epithelial barrier structure and function and their role in the pathogenesis the systemic inflammation and uremic toxicity. PMID:25855516

  8. Space colonization.

    PubMed

    2002-12-01

    NASA interest in colonization encompasses space tourism; space exploration; space bases in orbit, at L1, on the Moon, or on Mars; in-situ resource utilization; and planetary terraforming. Activities progressed during 2002 in areas such as Mars colonies, hoppers, and biomass; space elevators and construction; and in-situ consumables. PMID:12506926

  9. Anaerobic bacteria

    MedlinePlus

    Anaerobic bacteria are bacteria that do not live or grow when oxygen is present. In humans, these ... Goldstein EJ. Diseases caused by non-spore forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman's ...

  10. Colon cancer - resources

    MedlinePlus

    Resources - colon cancer ... The following organizations are good resources for information on colon cancer : American Cancer Society -- www.cancer.org/cancer/colonandrectumcancer/index Colon Cancer Alliance -- www.ccalliance.org National ...

  11. Clostridium Butyricum CGMCC0313.1 Modulates Lipid Profile, Insulin Resistance and Colon Homeostasis in Obese Mice.

    PubMed

    Shang, Haixiao; Sun, Jia; Chen, Yong Q

    2016-01-01

    Obesity is associated with a cluster of metabolic disorders and systemic low-grade inflammation involving multiple organs. Recent findings have suggested that intestine is a key organ altered in response to high fat diet (HFD) feeding. Probiotics mainly lactobacillus strains have earlier been implicated in alleviating metabolic disorders. Here we aimed to examine the effects of a naturally occurring butyrate-producing probiotic clostridium butyricum CGMCC0313.1 (CB0313.1) in limiting the development of HFD-induced obesity. Mice treated with CB0313.1 exhibited reduced lipid accumulation in liver and serum, lower circulating insulin levels and improved glucose tolerance and insulin sensitivity. Furthermore, CB0313.1 administration reversed the HFD-induced colonic inflammation as evidenced by reduced tumor necrosis factor (TNF)-α level and increases the interleukin (IL)-10 and IL-22 levels in colon tissue. Additionally to colonic inflammation, CB0313.1 also reduced the colon permeability by upregulating the tight junction (TJ) proteins (claudin-1 and occludin) and contributed to a decreased circulating endotoxin level. In colon content, CB0313.1 administration restored the reduced production of butyrate and other short chain fatty acids (SCFAs) caused by HFD feeding. In adipose tissue, lower transcriptional levels of pro-inflammatory TNF-α, IL-6, IL-1β and monocyte chemotactic protein (MCP)-1 in adipose tissue were observed in CB0313.1-treated mice. Collectively, our data demonstrated that CB0313.1, targeting colon inflammation and permeability, ameliorated HFD-induced obesity, insulin resistance as well as adipose inflammation. PMID:27123997

  12. Clostridium Butyricum CGMCC0313.1 Modulates Lipid Profile, Insulin Resistance and Colon Homeostasis in Obese Mice

    PubMed Central

    Shang, Haixiao

    2016-01-01

    Obesity is associated with a cluster of metabolic disorders and systemic low-grade inflammation involving multiple organs. Recent findings have suggested that intestine is a key organ altered in response to high fat diet (HFD) feeding. Probiotics mainly lactobacillus strains have earlier been implicated in alleviating metabolic disorders. Here we aimed to examine the effects of a naturally occurring butyrate-producing probiotic clostridium butyricum CGMCC0313.1 (CB0313.1) in limiting the development of HFD-induced obesity. Mice treated with CB0313.1 exhibited reduced lipid accumulation in liver and serum, lower circulating insulin levels and improved glucose tolerance and insulin sensitivity. Furthermore, CB0313.1 administration reversed the HFD-induced colonic inflammation as evidenced by reduced tumor necrosis factor (TNF)-α level and increases the interleukin (IL)-10 and IL-22 levels in colon tissue. Additionally to colonic inflammation, CB0313.1 also reduced the colon permeability by upregulating the tight junction (TJ) proteins (claudin-1 and occludin) and contributed to a decreased circulating endotoxin level. In colon content, CB0313.1 administration restored the reduced production of butyrate and other short chain fatty acids (SCFAs) caused by HFD feeding. In adipose tissue, lower transcriptional levels of pro-inflammatory TNF-α, IL-6, IL-1β and monocyte chemotactic protein (MCP)-1 in adipose tissue were observed in CB0313.1-treated mice. Collectively, our data demonstrated that CB0313.1, targeting colon inflammation and permeability, ameliorated HFD-induced obesity, insulin resistance as well as adipose inflammation. PMID:27123997

  13. Ecology of Root Colonizing Massilia (Oxalobacteraceae)

    PubMed Central

    Ofek, Maya; Hadar, Yitzhak; Minz, Dror

    2012-01-01

    Background Ecologically meaningful classification of bacterial populations is essential for understanding the structure and function of bacterial communities. As in soils, the ecological strategy of the majority of root-colonizing bacteria is mostly unknown. Among those are Massilia (Oxalobacteraceae), a major group of rhizosphere and root colonizing bacteria of many plant species. Methodology/Principal Findings The ecology of Massilia was explored in cucumber root and seed, and compared to that of Agrobacterium population, using culture-independent tools, including DNA-based pyrosequencing, fluorescence in situ hybridization and quantitative real-time PCR. Seed- and root-colonizing Massilia were primarily affiliated with other members of the genus described in soil and rhizosphere. Massilia colonized and proliferated on the seed coat, radicle, roots, and also on hyphae of phytopathogenic Pythium aphanidermatum infecting seeds. High variation in Massilia abundance was found in relation to plant developmental stage, along with sensitivity to plant growth medium modification (amendment with organic matter) and potential competitors. Massilia absolute abundance and relative abundance (dominance) were positively related, and peaked (up to 85%) at early stages of succession of the root microbiome. In comparison, variation in abundance of Agrobacterium was moderate and their dominance increased at later stages of succession. Conclusions In accordance with contemporary models for microbial ecology classification, copiotrophic and competition-sensitive root colonization by Massilia is suggested. These bacteria exploit, in a transient way, a window of opportunity within the succession of communities within this niche. PMID:22808103

  14. Keratin 8 absence down-regulates colonocyte HMGCS2 and modulates colonic ketogenesis and energy metabolism.

    PubMed

    Helenius, Terhi O; Misiorek, Julia O; Nyström, Joel H; Fortelius, Lina E; Habtezion, Aida; Liao, Jian; Asghar, M Nadeem; Zhang, Haiyan; Azhar, Salman; Omary, M Bishr; Toivola, Diana M

    2015-06-15

    Simple-type epithelial keratins are intermediate filament proteins important for mechanical stability and stress protection. Keratin mutations predispose to human liver disorders, whereas their roles in intestinal diseases are unclear. Absence of keratin 8 (K8) in mice leads to colitis, decreased Na/Cl uptake, protein mistargeting, and longer crypts, suggesting that keratins contribute to intestinal homeostasis. We describe the rate-limiting enzyme of the ketogenic energy metabolism pathway, mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2), as a major down-regulated protein in the K8-knockout (K8(-/-)) colon. K8 absence leads to decreased quantity and activity of HMGCS2, and the down-regulation is not dependent on the inflammatory state, since HMGCS2 is not decreased in dextran sulfate sodium-induced colitis. Peroxisome proliferator-activated receptor α, a transcriptional activator of HMGCS2, is similarly down-regulated. Ketogenic conditions-starvation or ketogenic diet-increase K8(+/+) HMGCS2, whereas this response is blunted in the K8(-/-) colon. Microbiota-produced short-chain fatty acids (SCFAs), substrates in the colonic ketone body pathway, are increased in stool, which correlates with decreased levels of their main transporter, monocarboxylate transporter 1 (MCT1). Microbial populations, including the main SCFA-butyrate producers in the colon, were not altered in the K8(-/-). In summary, the regulation of the SCFA-MCT1-HMGCS2 axis is disrupted in K8(-/-) colonocytes, suggesting a role for keratins in colonocyte energy metabolism and homeostasis. PMID:25904331

  15. Keratin 8 absence down-regulates colonocyte HMGCS2 and modulates colonic ketogenesis and energy metabolism

    PubMed Central

    Helenius, Terhi O.; Misiorek, Julia O.; Nyström, Joel H.; Fortelius, Lina E.; Habtezion, Aida; Liao, Jian; Asghar, M. Nadeem; Zhang, Haiyan; Azhar, Salman; Omary, M. Bishr; Toivola, Diana M.

    2015-01-01

    Simple-type epithelial keratins are intermediate filament proteins important for mechanical stability and stress protection. Keratin mutations predispose to human liver disorders, whereas their roles in intestinal diseases are unclear. Absence of keratin 8 (K8) in mice leads to colitis, decreased Na/Cl uptake, protein mistargeting, and longer crypts, suggesting that keratins contribute to intestinal homeostasis. We describe the rate-limiting enzyme of the ketogenic energy metabolism pathway, mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2), as a major down-regulated protein in the K8-knockout (K8−/−) colon. K8 absence leads to decreased quantity and activity of HMGCS2, and the down-regulation is not dependent on the inflammatory state, since HMGCS2 is not decreased in dextran sulfate sodium-induced colitis. Peroxisome proliferator–activated receptor α, a transcriptional activator of HMGCS2, is similarly down-regulated. Ketogenic conditions—starvation or ketogenic diet—increase K8+/+ HMGCS2, whereas this response is blunted in the K8−/− colon. Microbiota-produced short-chain fatty acids (SCFAs), substrates in the colonic ketone body pathway, are increased in stool, which correlates with decreased levels of their main transporter, monocarboxylate transporter 1 (MCT1). Microbial populations, including the main SCFA-butyrate producers in the colon, were not altered in the K8−/−. In summary, the regulation of the SCFA-MCT1-HMGCS2 axis is disrupted in K8−/− colonocytes, suggesting a role for keratins in colonocyte energy metabolism and homeostasis. PMID:25904331

  16. Liver Colonization Competence Governs Colon Cancer Metastasis

    NASA Astrophysics Data System (ADS)

    Kuo, Tsong-Hong; Kubota, Tetsuro; Watanabe, Masahiko; Furukawa, Toshiharu; Teramoto, Tatuso; Ishibiki, Kyuya; Kitajima, Masaki; Rahim Moosa, A.; Penman, Sheldon; Hoffman, Robert M.

    1995-12-01

    Tumors that metastasize do so to preferred target organs. To explain this apparent specificity, Paget, >100 years ago, formulated his seed and soil hypothesis; i.e., the cells from a given tumor would "seed" only favorable "soil" offered by certain organs. The hypothesis implies that cancer cells must find a suitable "soil" in a target organ-i.e., one that supports colonization-for metastasis to occur. We demonstrate in this report that ability of human colon cancer cells to colonize liver tissue governs whether a particular colon cancer is metastatic. In the model used in this study, human colon tumors are transplanted into the nude mouse colon as intact tissue blocks by surgical orthotopic implantation. These implanted tumors closely simulate the metastatic behavior of the original human patient tumor and are clearly metastatic or nonmetastatic to the liver. Both classes of tumors were equally invasive locally into tissues and blood vessels. However, the cells from each class of tumor behave very differently when directly injected into nude mouse livers. Only cells from metastasizing tumors are competent to colonize after direct intrahepatic injection. Also, tissue blocks from metastatic tumors affixed directly to the liver resulted in colonization, whereas no colonization resulted from nonmetastatic tumor tissue blocks even though some growth occurred within the tissue block itself. Thus, local invasion (injection) and even adhesion to the metastatic target organ (blocks) are not sufficient for metastasis. The results suggest that the ability to colonize the liver is the governing step in the metastasis of human colon cancer.

  17. Colon diverticula - slideshow

    MedlinePlus

    ... this page: //medlineplus.gov/ency/presentations/100158.htm Colon diverticula - series To use the sharing features on ... 6 out of 6 Normal anatomy Overview The colon, or large intestine, is a muscular tube that ...

  18. Colon cancer - slideshow

    MedlinePlus

    ... this page: //medlineplus.gov/ency/presentations/100157.htm Colon cancer - Series To use the sharing features on ... 5 out of 5 Normal anatomy Overview The colon, or large intestine, is a muscular tube that ...

  19. Colon cancer - Series (image)

    MedlinePlus

    Colon cancer is the third most common cancer in the United States. Risk factors include a diet low ... The treatment of colon cancer depends on the stage of the disease. Stage I cancer is limited to the inner lining of the colon; ...

  20. Age-related changes in select fecal bacteria in foals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adult horses depend on the microbial community in the hindgut to produce VFAs that are utilized for energy. Microbial colonization in the gastrointestinal tract of foals is essential to develop a healthy symbiotic relationship and prevent proliferation of pathogenic bacteria. However, colonization i...

  1. SIGIRR, a negative regulator of colon tumorigenesis

    PubMed Central

    Zhao, Junjie; Zepp, Jarod; Bulek, Katarzyna; Li, Xiaoxia

    2012-01-01

    Inappropriate activation of the Toll-IL-1R (TL-IL-1) signaling by commensal bacteria contributes to the pathogenesis of inflammatory bowel diseases and colitis-associated cancer. Recent studies have identified SIGIRR as a negative regulator of TL-IL-1 signaling. It dampens intestinal inflammation and tumorigenesis in the colon. In this review, we will discuss the role of SIGIRR in different cell types and the mechanisms underlying its tumor suppressor function. PMID:22529873

  2. Stability of peptide drugs in the colon.

    PubMed

    Wang, Jie; Yadav, Vipul; Smart, Alice L; Tajiri, Shinichiro; Basit, Abdul W

    2015-10-12

    This study was the first to investigate the colonic stability of 17 peptide molecules (insulin, calcitonin, glucagon, secretin, somatostatin, desmopressin, oxytocin, Arg-vasopressin, octreotide, ciclosporin, leuprolide, nafarelin, buserelin, histrelin, [D-Ser(4)]-gonadorelin, deslorelin, and goserelin) in a model of the large intestine using mixed human faecal bacteria. Of these, the larger peptides - insulin, calcitonin, somatostatin, glucagon and secretin - were metabolized rapidly, with complete degradation observed within 5 min. In contrast, a number of the smaller peptides - Arg-vasopressin, desmopressin, oxytocin, gonadorelin, goserelin, buserelin, leuprolide, nafarelin and deslorelin - degraded more slowly, while octreotide, histrelin and ciclosporin were seen to be more stable as compared to the other small peptides under the same conditions. Peptide degradation rate was directly correlated to peptide lipophilicity (logP); those peptides with a higher logP were more stable in the colonic model (R(2)=0.94). In the absence of human faecal bacteria, all peptides were stable. This study highlights the impact of the colonic environment - in particular, the gut microbiota - on the metabolism of peptide drugs, and identifies potential peptide candidates for drug delivery to the colon. PMID:26111980

  3. Mechanisms of Bacterial Colonization of the Respiratory Tract

    PubMed Central

    Siegel, Steven J.; Weiser, Jeffrey N.

    2016-01-01

    Respiratory tract infections are an important cause of morbidity and mortality worldwide. Chief among these are infections involving the lower airways. The opportunistic bacterial pathogens responsible for most cases of pneumonia can cause a range of local and invasive infections. However, bacterial colonization (or carriage) in the upper airway is the prerequisite of all these infections. Successful colonizers must attach to the epithelial lining, grow on the nutrient-limited mucosal surface, evade the host immune response, and transmit to a susceptible host. Here, we review the molecular mechanisms underlying these conserved stages of carriage. We also examine how the demands of colonization influence progression to disease. A range of bacteria can colonize the upper airway; nevertheless, we focus on strategies shared by many respiratory tract opportunistic pathogens. Understanding colonization opens a window to the evolutionary pressures these pathogens face within their animal hosts and that have selected for attributes that contribute to virulence and pathogenesis. PMID:26488280

  4. Magnetic Bacteria.

    ERIC Educational Resources Information Center

    Nelson, Jane Bray; Nelson, Jim

    1992-01-01

    Describes the history of Richard Blakemore's discovery of magnetotaxic organisms. Discusses possible reasons why the magnetic response in bacteria developed. Proposes research experiments integrating biology and physics in which students investigate problems using cultures of magnetotaxic organisms. (MDH)

  5. Anaerobic bacteria

    MedlinePlus

    Brook I, Goldstein EJ. Diseases caused by non-spore forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 297. Stedman's Online ...

  6. Methylotrophic bacteria in sustainable agriculture.

    PubMed

    Kumar, Manish; Tomar, Rajesh Singh; Lade, Harshad; Paul, Diby

    2016-07-01

    Excessive use of chemical fertilizers to increase production from available land has resulted in deterioration of soil quality. To prevent further soil deterioration, the use of methylotrophic bacteria that have the ability to colonize different habitats, including soil, sediment, water, and both epiphytes and endophytes as host plants, has been suggested for sustainable agriculture. Methylotrophic bacteria are known to play a significant role in the biogeochemical cycle in soil ecosystems, ultimately fortifying plants and sustaining agriculture. Methylotrophs also improve air quality by using volatile organic compounds such as dichloromethane, formaldehyde, methanol, and formic acid. Additionally, methylotrophs are involved in phosphorous, nitrogen, and carbon cycling and can help reduce global warming. In this review, different aspects of the interaction between methylotrophs and host plants are discussed, including the role of methylotrophs in phosphorus acquisition, nitrogen fixation, phytohormone production, iron chelation, and plant growth promotion, and co-inoculation of these bacteria as biofertilizers for viable agriculture practices. PMID:27263015

  7. Therapeutic opportunities in colon-specific drug-delivery systems.

    PubMed

    Patel, Mayur; Shah, Tejal; Amin, Avani

    2007-01-01

    Oral colon-specific drug-delivery systems have recently gained importance for delivering a variety of therapeutic agents. The major obstacles to delivering drugs to the colon are the absorption and degradation pathways in the upper gastrointestinal tract. However, a successfully designed colon-targeted system can overcome these obstacles. Targeting drugs to the colon has proven quite valuable in a variety of disorders, and the colon has proven to be a potential site for local as well as systemic administration of drugs. Colon targeting has proven beneficial for local action in a variety of disease conditions, such as inflammatory bowel disease, irritable bowel syndrome, and colonic cancer. Aminosalicylates, corticosteroids, immunosuppressive agents, cationized antioxidant enzymes, genetically engineered bacteria to produce cytokines, nicotine, and other drugs have exhibited significantly enhanced efficacy when delivered to the colon. Targeting drugs to cancer cells through receptors and ligands have opened up new avenues in the treatment of colonic cancer. Colon targeting has also proven useful for systemic action of protein-peptide drugs such as insulin, calcitonin, and met-enkaphalin and even for other nonpeptide drugs such as cardiovascular and antiasthmatic agents. This review also presents various approaches for targeting orally administered dosage forms to the colon. The use of a prodrug approach, bioadhesive polymers, and coating with pH-sensitive and biodegradable polymers has been, to an extent, highly successful in delivering the targeted formulations to the site of action. Biodegrable hydrogels such as amylose, chondroitin sulphate, chitosan, inulin, guar gum, and pectin have also been successfully used to achieve oral colon-targeted delivery. PMID:17725524

  8. Microbes, Microbiota and Colon Cancer

    PubMed Central

    Sears, Cynthia L.; Garrett, Wendy S.

    2014-01-01

    Summary Colorectal cancer (CRC) presents a considerable disease burden worldwide. The human colon is also an anatomical location with the largest number of microbes. It is natural therefore to anticipate a role for microbes, particularly bacteria, in colorectal carcinogenesis. The increasing accessibility of microbial meta’omics is fueling a surge in our understanding of the role that microbes and the microbiota play in CRC. In this review, we will discuss recent insights into contributions of the microbiota to CRC and explore conceptual frameworks for evaluating the role of microbes in cancer causation. We also highlight new findings on candidate CRC-potentiating species and current knowledge gaps. Finally, we explore the roles of microbial metabolism as it relates to bile acids, xenobiotics, and diet in the etiology and therapeutics of CRC. PMID:24629338

  9. A Case of Sigmoid Colon Tuberculosis Mimicking Colon Cancer

    PubMed Central

    Yu, Seong-Min; Kim, Min-Dae; Lee, Hee-Ryong; Jung, Peel; Ryu, Tae-Hyun; Choi, Seung-Ho; Lee, Il-Seon

    2012-01-01

    Tuberculosis of the sigmoid colon is a rare disorder. An 80-year-old man visited Bongseng Memorial Hospital for medical examination. A colonoscopy was performed, and a lesion in the sigmoid colon that was suspected to be colon cancer was found. A biopsy was performed, and tuberculous enteritis with chronic granulomatous inflammation was diagnosed. Intestinal tuberculosis is most frequent in the ileocecal area, followed by the ascending colon, transverse colon, duodenum, stomach, and sigmoid colon, in descending order. Hence, we report a case of intestinal tuberculosis in the sigmoid colon, which is rare and almost indistinguishable from colon cancer. PMID:23185709

  10. Transmission of Nephridial Bacteria of the Earthworm Eisenia fetida

    PubMed Central

    Davidson, Seana K.; Stahl, David A.

    2006-01-01

    The lumbricid earthworms (annelid family Lumbricidae) harbor gram-negative bacteria in their excretory organs, the nephridia. Comparative 16S rRNA gene sequencing of bacteria associated with the nephridia of several earthworm species has shown that each species of worm harbors a distinct bacterial species and that the bacteria from different species form a monophyletic cluster within the genus Acidovorax, suggesting that there is a specific association resulting from radiation from a common bacterial ancestor. Previous microscopy and culture studies revealed the presence of bacteria within the egg capsules and on the surface of embryos but did not demonstrate that the bacteria within the egg capsule were the same bacteria that colonized the nephridia. We present evidence, based on curing experiments, in situ hybridizations with Acidovorax-specific probes, and 16S rRNA gene sequence analysis, that the egg capsules contain high numbers of the bacterial symbiont and that juveniles are colonized during development within the egg capsule. Studies exposing aposymbiotic hatchlings to colonized adults and their bedding material suggested that juvenile earthworms do not readily acquire bacteria from the soil after hatching but must be colonized during development by bacteria deposited in the egg capsule. Whether this is due to the developmental stage of the host or the physiological state of the symbiont remains to be investigated. PMID:16391117

  11. How bacterial pathogens colonize their hosts and invade deeper tissues.

    PubMed

    Ribet, David; Cossart, Pascale

    2015-03-01

    Bacterial pathogens have evolved a wide range of strategies to colonize and invade human organs, despite the presence of multiple host defense mechanisms. In this review, we will describe how pathogenic bacteria can adhere and multiply at the surface of host cells, how some bacteria can enter and proliferate inside these cells, and finally how pathogens may cross epithelial or endothelial host barriers and get access to internal tissues, leading to severe diseases in humans. PMID:25637951

  12. Methanotrophic bacteria.

    PubMed Central

    Hanson, R S; Hanson, T E

    1996-01-01

    Methane-utilizing bacteria (methanotrophs) are a diverse group of gram-negative bacteria that are related to other members of the Proteobacteria. These bacteria are classified into three groups based on the pathways used for assimilation of formaldehyde, the major source of cell carbon, and other physiological and morphological features. The type I and type X methanotrophs are found within the gamma subdivision of the Proteobacteria and employ the ribulose monophosphate pathway for formaldehyde assimilation, whereas type II methanotrophs, which employ the serine pathway for formaldehyde assimilation, form a coherent cluster within the beta subdivision of the Proteobacteria. Methanotrophic bacteria are ubiquitous. The growth of type II bacteria appears to be favored in environments that contain relatively high levels of methane, low levels of dissolved oxygen, and limiting concentrations of combined nitrogen and/or copper. Type I methanotrophs appear to be dominant in environments in which methane is limiting and combined nitrogen and copper levels are relatively high. These bacteria serve as biofilters for the oxidation of methane produced in anaerobic environments, and when oxygen is present in soils, atmospheric methane is oxidized. Their activities in nature are greatly influenced by agricultural practices and other human activities. Recent evidence indicates that naturally occurring, uncultured methanotrophs represent new genera. Methanotrophs that are capable of oxidizing methane at atmospheric levels exhibit methane oxidation kinetics different from those of methanotrophs available in pure cultures. A limited number of methanotrophs have the genetic capacity to synthesize a soluble methane monooxygenase which catalyzes the rapid oxidation of environmental pollutants including trichloroethylene. PMID:8801441

  13. Beta-Hemolysin Promotes Skin Colonization by Staphylococcus aureus

    PubMed Central

    Katayama, Yuki; Sekine, Miwa; Fukuda, Minoru; Hiramatsu, Keiichi

    2013-01-01

    Colonization by Staphylococcus aureus is a characteristic feature of several inflammatory skin diseases and is often followed by epidermal damage and invasive infection. In this study, we investigated the mechanism of skin colonization by a virulent community-acquired methicillin-resistant S. aureus (CA-MRSA) strain, MW2, using a murine ear colonization model. MW2 does not produce a hemolytic toxin, beta-hemolysin (Hlb), due to integration of a prophage, ϕSa3mw, inside the toxin gene (hlb). However, we found that strain MW2 bacteria that had successfully colonized murine ears included derivatives that produced Hlb. Genome sequencing of the Hlb-producing colonies revealed that precise excision of prophage ϕSa3mw occurred, leading to reconstruction of the intact hlb gene in their chromosomes. To address the question of whether Hlb is involved in skin colonization, we constructed MW2-derivative strains with and without the Hlb gene and then subjected them to colonization tests. The colonization efficiency of the Hlb-producing mutant on murine ears was more than 50-fold greater than that of the mutant without hlb. Furthermore, we also showed that Hlb toxin had elevated cytotoxicity for human primary keratinocytes. Our results indicate that S. aureus Hlb plays an important role in skin colonization by damaging keratinocytes, in addition to its well-known hemolytic activity for erythrocytes. PMID:23292775

  14. Eukaryotic and prokaryotic contributions to colonic hydrogen sulfide synthesis.

    PubMed

    Flannigan, Kyle L; McCoy, Kathy D; Wallace, John L

    2011-07-01

    Hydrogen sulfide (H(2)S) is an important modulator of many aspects of digestive function, both in health and disease. Colonic tissue H(2)S synthesis increases markedly during injury and inflammation and appears to contribute to resolution. Some of the bacteria residing in the colon can also produce H(2)S. The extent to which bacterial H(2)S synthesis contributes to what is measured as colonic H(2)S synthesis is not clear. Using conventional and germ-free mice, we have delineated the eukaryotic vs. prokaryotic contributions to colonic H(2)S synthesis, both in healthy and colitic mice. Colonic tissue H(2)S production is entirely dependent on the presence of the cofactor pyridoxal 5'-phosphate (vitamin B(6)), while bacterial H(2)S synthesis appears to occur independent of this cofactor. As expected, approximately one-half of the H(2)S produced by feces is derived from eukaryotic cells. While colonic H(2)S synthesis is markedly increased when the tissue is inflamed, and, in proportion to the extent of inflammation, fecal H(2)S synthesis does not change and tissue granulocytes do not appear to be the source of the elevated H(2)S production. Rats fed a B vitamin-deficient diet for 6 wk exhibited significantly diminished colonic H(2)S synthesis, but fecal H(2)S synthesis was not different from that of rats on the control diet. Our results demonstrate that H(2)S production by colonic bacteria does not contribute significantly to what is measured as colonic tissue H(2)S production, using the acetate trapping assay system employed in this study. PMID:21474649

  15. [Colonic microbial biocenosis in rheumatoid arthritis].

    PubMed

    Gul'neva, M Iu; Noskov, S M

    2011-01-01

    The aim of the work was to study colonic microbial biocenosis and colonizing ability of opportunistic bacteria in 32 patients with rheumatoid arthritis (RA) and 30 healthy subjects. RA was diagnosed based on the American Rheumatism Association criteria (1987). Qualitative and quantitative composition of the microflora was detected by a bacteriological method. StatSoft Statistics 6.0 was used to treat the data obtained. RA was associated with significant modification of the intestinal flora, viz. decrease in lactobacteria and significant increase of enterococci, clostridia, colibacteria showing reduced enzymatic activity, and opportunistic species. Also, symbiotic relationships between microorganisms altered. The fraction of bifidobacteria, bacteroids, and lactopositive colibacteria reduced while the abundance of opportunistic enterobacteria and staphylococci was elevated. Opportunistic Enterobacteriaceae were present in urine and nasal mucosa which suggested their translocation from the intestines. It is concluded that changes in intestinal microflora and colonization by opportunistic bacteria enhance the risk of development of co-morbid conditions in patients with RA. PMID:21932563

  16. Lactobacillus rhamnosus GG-supplemented formula expands butyrate-producing bacterial strains in food allergic infants

    DOE PAGESBeta

    Berni Canani, Roberto; Sangwan, Naseer; Stefka, Andrew T.; Nocerino, Rita; Paparo, Lorella; Aitoro, Rosita; Calignano, Antonio; Khan, Aly A.; Gilbert, Jack A.; Nagler, Cathryn R.

    2015-09-22

    Dietary intervention with extensively hydrolyzed casein formula supplemented with Lactobacillus rhamnosus GG (EHCF+LGG) accelerates tolerance acquisition in infants with cow’s milk allergy (CMA). We examined whether this effect is attributable, at least in part, to an influence on the gut microbiota. Fecal samples from healthy controls (n=20) and from CMA infants (n=19) before and after treatment with EHCF with (n=12) and without (n=7) supplementation with LGG were compared by 16S rRNA-based operational taxonomic unit clustering and oligotyping. Differential feature selection and generalized linear model fitting revealed that the CMA infants have a diverse gut microbial community structure dominated by Lachnospiraceaemore » (20.5±9.7%) and Ruminococcaceae (16.2±9.1%). Blautia, Roseburia and Coprococcus were significantly enriched following treatment with EHCF and LGG, but only one genus, Oscillospira, was significantly different between infants that became tolerant and those that remained allergic. However, most tolerant infants showed a significant increase in fecal butyrate levels, and those taxa that were significantly enriched in these samples, Blautia and Roseburia, exhibited specific strain-level demarcations between tolerant and allergic infants. As a result, our data suggest that EHCF+LGG promotes tolerance in infants with CMA, in part, by influencing the strain-level bacterial community structure of the infant gut.« less

  17. Lactobacillus rhamnosus GG-supplemented formula expands butyrate-producing bacterial strains in food allergic infants.

    PubMed

    Berni Canani, Roberto; Sangwan, Naseer; Stefka, Andrew T; Nocerino, Rita; Paparo, Lorella; Aitoro, Rosita; Calignano, Antonio; Khan, Aly A; Gilbert, Jack A; Nagler, Cathryn R

    2016-03-01

    Dietary intervention with extensively hydrolyzed casein formula supplemented with Lactobacillus rhamnosus GG (EHCF+LGG) accelerates tolerance acquisition in infants with cow's milk allergy (CMA). We examined whether this effect is attributable, at least in part, to an influence on the gut microbiota. Fecal samples from healthy controls (n=20) and from CMA infants (n=19) before and after treatment with EHCF with (n=12) and without (n=7) supplementation with LGG were compared by 16S rRNA-based operational taxonomic unit clustering and oligotyping. Differential feature selection and generalized linear model fitting revealed that the CMA infants have a diverse gut microbial community structure dominated by Lachnospiraceae (20.5±9.7%) and Ruminococcaceae (16.2±9.1%). Blautia, Roseburia and Coprococcus were significantly enriched following treatment with EHCF and LGG, but only one genus, Oscillospira, was significantly different between infants that became tolerant and those that remained allergic. However, most tolerant infants showed a significant increase in fecal butyrate levels, and those taxa that were significantly enriched in these samples, Blautia and Roseburia, exhibited specific strain-level demarcations between tolerant and allergic infants. Our data suggest that EHCF+LGG promotes tolerance in infants with CMA, in part, by influencing the strain-level bacterial community structure of the infant gut. PMID:26394008

  18. Zebrafish as a Natural Host Model for Vibrio cholerae Colonization and Transmission

    PubMed Central

    Runft, Donna L.; Mitchell, Kristie C.; Abuaita, Basel H.; Allen, Jonathan P.; Bajer, Sarah; Ginsburg, Kevin; Neely, Melody N.

    2014-01-01

    The human diarrheal disease cholera is caused by the aquatic bacterium Vibrio cholerae. V. cholerae in the environment is associated with several varieties of aquatic life, including insect egg masses, shellfish, and vertebrate fish. Here we describe a novel animal model for V. cholerae, the zebrafish. Pandemic V. cholerae strains specifically colonize the zebrafish intestinal tract after exposure in water with no manipulation of the animal required. Colonization occurs in close contact with the intestinal epithelium and mimics colonization observed in mammals. Zebrafish that are colonized by V. cholerae transmit the bacteria to naive fish, which then become colonized. Striking differences in colonization between V. cholerae classical and El Tor biotypes were apparent. The zebrafish natural habitat in Asia heavily overlaps areas where cholera is endemic, suggesting that zebrafish and V. cholerae evolved in close contact with each other. Thus, the zebrafish provides a natural host model for the study of V. cholerae colonization, transmission, and environmental survival. PMID:24375135

  19. Impact of succinate on growth of cultures of cecal bacteria from commercial broilers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beneficial bacteria in probiotics produce and utilize several organic acids that may play a role in the ability of these bacteria to inhibit colonization of poultry by enteropathogens. Since cecal contents of adult poultry contain many of these beneficial bacteria, 3 experiments were conducted to ex...

  20. Laparoscopic Colon Resection

    MedlinePlus

    ... inches to complete the procedure. What are the Advantages of Laparoscopic Colon Resection? Results may vary depending ... type of procedure and patient’s overall condition. Common advantages are: Less postoperative pain May shorten hospital stay ...

  1. Colon cancer screening

    MedlinePlus

    ... screening; Sigmoidoscopy - screening; Virtual colonoscopy - screening; Fecal immunochemical test; Stool DNA test; sDNA test ... death and complications caused by colorectal cancer. SCREENING TESTS There are several ways to screen for colon ...

  2. Transverse colon conduit diversion

    SciTech Connect

    Schmidt, J.D.; Buchsbaum, H.J.

    1986-05-01

    The versatility and other advantages of the transverse colon conduit for urinary diversion have been described and implemented in 50 patients. Because most patients considered for this procedure will be at high risk because of a history of significant pelvic irradiation, underlying malignancy, poor renal function, fistula, and so forth, the technical details of surgery and patient selection cannot be minimized. The transverse colon segment is indicated for primary supravesical diversion as well as for salvage of problems related to ileal conduits. Adenocarcinoma of the colon is an unlikely long-term complication of this form of diversion because the fecal stream is absent. Now that the transverse colon conduit has been used for more than 10 years, meaningful comparisons with ileal segments should soon be available.

  3. [Angiodysplasia of the colon].

    PubMed

    Bruni, R; Rossodivita, I; Santoro, M; La Banca, G; Rollo, R; Putti, R

    1990-01-01

    The Authors report their experience with a case of angiodysplasia of the colon. It is outlined how these lesions can be demonstrated by angiography and colonoscopy. The pathophysiology, diagnosis and management are discussed as well. PMID:2223469

  4. Role of intestinal bacteria in nutrient metabolism.

    PubMed

    Cummings, J H; Macfarlane, G T

    1997-01-01

    The human large intestine contains a microbiota, the components of which are generically complex and metabolically diverse. Its primary function is to salvage energy from carbohydrate not digested in the upper gut. This is achieved through fermentation and absorption of the major products, short chain fatty acids (SCFA), which represent 40-50% of the available energy of the carbohydrate. The principal SCFA, acetate, propionate and butyrate, are metabolized by the colonic epithelium (butyrate), liver (propionate) and muscle (acetate). Intestinal bacteria also have a role in the synthesis of vitamins B and K and the metabolism of bile acids, other sterols and xenobiotics. The colonic microflora are also responsive to diet. In the presence of fermentable carbohydrate substrates such as non-starch polysaccharides, resistant starch and oligosaccharides, bacteria grow and actively synthesize protein. The amount of protein synthesis and turnover within the large intestine is difficult to determine, but around 15 g biomass is excreted in faeces each day containing 1 g bacterial-N. Whether bacterially synthesized amino acids are ever absorbed from the colon remains unclear. Finally, individual colonic micro-organisms such as sulphate-reducing bacteria, bifidobacteria and clostridia, respond selectively to specific dietary components in a way that may be important to health. PMID:9406136

  5. Identification of Population Bottlenecks and Colonization Factors during Assembly of Bacterial Communities within the Zebrafish Intestine

    PubMed Central

    Stephens, W. Zac; Wiles, Travis J.; Martinez, Emily S.; Jemielita, Matthew; Burns, Adam R.; Parthasarathy, Raghuveer; Bohannan, Brendan J. M.

    2015-01-01

    ABSTRACT The zebrafish, Danio rerio, is a powerful model for studying bacterial colonization of the vertebrate intestine, but the genes required by commensal bacteria to colonize the zebrafish gut have not yet been interrogated on a genome-wide level. Here we apply a high-throughput transposon mutagenesis screen to Aeromonas veronii Hm21 and Vibrio sp. strain ZWU0020 during their colonization of the zebrafish intestine alone and in competition with each other, as well as in different colonization orders. We use these transposon-tagged libraries to track bacterial population sizes in different colonization regimes and to identify gene functions required during these processes. We show that intraspecific, but not interspecific, competition with a previously established bacterial population greatly reduces the ability of these two bacterial species to colonize. Further, using a simple binomial sampling model, we show that under conditions of interspecific competition, genes required for colonization cannot be identified because of the population bottleneck experienced by the second colonizer. When bacteria colonize the intestine alone or at the same time as the other species, we find shared suites of functional requirements for colonization by the two species, including a prominent role for chemotaxis and motility, regardless of the presence of another species. PMID:26507229

  6. Intestinal colonization resistance

    PubMed Central

    Lawley, Trevor D; Walker, Alan W

    2013-01-01

    Dense, complex microbial communities, collectively termed the microbiota, occupy a diverse array of niches along the length of the mammalian intestinal tract. During health and in the absence of antibiotic exposure the microbiota can effectively inhibit colonization and overgrowth by invading microbes such as pathogens. This phenomenon is called ‘colonization resistance’ and is associated with a stable and diverse microbiota in tandem with a controlled lack of inflammation, and involves specific interactions between the mucosal immune system and the microbiota. Here we overview the microbial ecology of the healthy mammalian intestinal tract and highlight the microbe–microbe and microbe–host interactions that promote colonization resistance. Emerging themes highlight immunological (T helper type 17/regulatory T-cell balance), microbiota (diverse and abundant) and metabolic (short-chain fatty acid) signatures of intestinal health and colonization resistance. Intestinal pathogens use specific virulence factors or exploit antibiotic use to subvert colonization resistance for their own benefit by triggering inflammation to disrupt the harmony of the intestinal ecosystem. A holistic view that incorporates immunological and microbiological facets of the intestinal ecosystem should facilitate the development of immunomodulatory and microbe-modulatory therapies that promote intestinal homeostasis and colonization resistance. PMID:23240815

  7. Bacteria Counter

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Science Applications, Inc.'s ATP Photometer makes a rapid and accurate count of the bacteria in a body fluid sample. Instrument provides information on the presence and quantity of bacteria by measuring the amount of light emitted by the reaction between two substances. Substances are ATP adenosine triphosphate and luciferase. The reactants are applied to a human body sample and the ATP Photometer observes the intensity of the light emitted displaying its findings in a numerical output. Total time lapse is usually less than 10 minutes, which represents a significant time savings in comparison of other techniques. Other applications are measuring organisms in fresh and ocean waters, determining bacterial contamination of foodstuffs, biological process control in the beverage industry, and in assay of activated sewage sludge.

  8. Development and preclinical evaluation of safety and immunogenicity of an oral ETEC vaccine containing inactivated E. coli bacteria overexpressing colonization factors CFA/I, CS3, CS5 and CS6 combined with a hybrid LT/CT B subunit antigen, administered alone and together with dmLT adjuvant.

    PubMed

    Holmgren, J; Bourgeois, L; Carlin, N; Clements, J; Gustafsson, B; Lundgren, A; Nygren, E; Tobias, J; Walker, R; Svennerholm, A-M

    2013-05-01

    A first-generation oral inactivated whole-cell enterotoxigenic Escherichia coli (ETEC) vaccine, comprising formalin-killed ETEC bacteria expressing different colonization factor (CF) antigens combined with cholera toxin B subunit (CTB), when tested in phase III studies did not significantly reduce overall (generally mild) ETEC diarrhea in travelers or children although it reduced more severe ETEC diarrhea in travelers by almost 80%. We have now developed a novel more immunogenic ETEC vaccine based on recombinant non-toxigenic E. coli strains engineered to express increased amounts of CF antigens, including CS6 as well as an ETEC-based B subunit protein (LCTBA), and the optional combination with a nontoxic double-mutant heat-labile toxin (LT) molecule (dmLT) as an adjuvant. Two test vaccines were prepared under GMP: (1) A prototype E. coli CFA/I-only formalin-killed whole-cell+LCTBA vaccine, and (2) A "complete" inactivated multivalent ETEC-CF (CFA/I, CS3, CS5 and CS6 antigens) whole-cell+LCTBA vaccine. These vaccines, when given intragastrically alone or together with dmLT in mice, were well tolerated and induced strong intestinal-mucosal IgA antibody responses as well as serum IgG and IgA responses to each of the vaccine CF antigens as well as to LT B subunit (LTB). Both mucosal and serum responses were further enhanced (adjuvanted) when the vaccines were co-administered with dmLT. We conclude that the new multivalent oral ETEC vaccine, both alone and especially in combination with the dmLT adjuvant, shows great promise for further testing in humans. PMID:23541621

  9. Early colonizing Escherichia coli elicits remodeling of rat colonic epithelium shifting toward a new homeostatic state

    PubMed Central

    Tomas, Julie; Reygner, Julie; Mayeur, Camille; Ducroc, Robert; Bouet, Stephan; Bridonneau, Chantal; Cavin, Jean-Baptiste; Thomas, Muriel; Langella, Philippe; Cherbuy, Claire

    2015-01-01

    We investigated the effects of early colonizing bacteria on the colonic epithelium. We isolated dominant bacteria, Escherichia coli, Enterococcus faecalis, Lactobacillus intestinalis, Clostridium innocuum and a novel Fusobacterium spp., from the intestinal contents of conventional suckling rats and transferred them in different combinations into germfree (GF) adult rats. Animals were investigated after various times up to 21 days. Proliferative cell markers (Ki67, proliferating cell nuclear antigen, phospho-histone H3, cyclin A) were higher in rats monocolonized with E. coli than in GF at all time points, but not in rats monocolonized with E. faecalis. The mucin content of goblet cells declined shortly after E. coli administration whereas the mucus layer doubled in thickness. Fluorescence in situ hybridization analyses revealed that E. coli resides in this mucus layer. The epithelial mucin content progressively returned to baseline, following an increase in KLF4 and in the cell cycle arrest-related proteins p21CIP1 and p27KIP1. Markers of colonic differentiated cells involved in electrolyte (carbonic anhydrase II and slc26A3) and water (aquaglyceroporin3 (aqp3)) transport, and secretory responses to carbachol were modulated after E. coli inoculation suggesting that ion transport dynamics were also affected. The colonic responses to simplified microbiotas differed substantially according to whether or not E. coli was combined with the other four bacteria. Thus, proliferation markers increased substantially when E. coli was in the mix, but very much less when it was absent. This work demonstrates that a pioneer strain of E. coli elicits sequential epithelial remodeling affecting the structure, mucus layer and ionic movements and suggests this can result in a microbiota-compliant state. PMID:25012905

  10. Advances in understanding colonic function.

    PubMed

    Milla, Peter J

    2009-04-01

    The colon is an organ of conservation that salvages water, electrolytes, and energy. The organization of colonic function is determined by the roles played by the luminal flora, the function of the different mucosal epithelial cell types, immunocompetent cells, and the neuromusculature. These different components of the colon interact with one another and with the colonic flora, and different areas of the colon serve different functions. In the normal adult during the course of a day the colon absorbs approximately 1.5 L of fluid, but under the influence of aldosterone increases up to 5 to 6 L. Diarrhoea occurs when secretion exceeds absorptive processes by either small intestinal secretion overwhelming colonic salvage or salvage being impaired by reduced colonic absorption or increased colonic secretion. PMID:19300122

  11. Alterations of the Ileal and Colonic Mucosal Microbiota in Canine Chronic Enteropathies

    PubMed Central

    Cassmann, Eric; White, Robin; Atherly, Todd; Wang, Chong; Sun, Yaxuan; Khoda, Samir; Mosher, Curtis; Ackermann, Mark; Jergens, Albert

    2016-01-01

    Background The intestinal microbiota is increasingly linked to the pathogenesis of chronic enteropathies (CE) in dogs. While imbalances in duodenal and fecal microbial communities have been associated with mucosal inflammation, relatively little is known about alterations in mucosal bacteria seen with CE involving the ileum and colon. Aim To investigate the composition and spatial organization of mucosal microbiota in dogs with CE and controls. Methods Tissue sections from endoscopic biopsies of the ileum and colon from 19 dogs with inflammatory bowel disease (IBD), 6 dogs with granulomatous colitis (GC), 12 dogs with intestinal neoplasia, and 15 controls were studied by fluorescence in situ hybridization (FISH) on a quantifiable basis. Results The ileal and colonic mucosa of healthy dogs and dogs with CE is predominantly colonized by bacteria localized to free and adherent mucus compartments. CE dogs harbored more (P < 0.05) mucosal bacteria belonging to the Clostridium-coccoides/Eubacterium rectale group, Bacteroides, Enterobacteriaceae, and Escherichia coli versus controls. Within the CE group, IBD dogs had increased (P < 0.05) Enterobacteriaceae and E. coli bacteria attached onto surface epithelia or invading within the intestinal mucosa. Bacterial invasion with E. coli was observed in the ileal and colonic mucosa of dogs with GC (P < 0.05). Dogs with intestinal neoplasia had increased (P < 0.05) adherent (total bacteria, Enterobacteriaceae, E. coli) and invasive (Enterobacteriaceae, E. coli, and Bacteroides) bacteria in biopsy specimens. Increased numbers of total bacteria adherent to the colonic mucosa were associated with clinical disease severity in IBD dogs (P < 0.05). Conclusion Pathogenic events in canine CE are associated with different populations of the ileal and colonic mucosal microbiota. PMID:26840462

  12. Differential Colonization Dynamics of Cucurbit Hosts by Erwinia tracheiphila.

    PubMed

    Vrisman, Cláudio M; Deblais, Loïc; Rajashekara, Gireesh; Miller, Sally A

    2016-07-01

    Bacterial wilt is one of the most destructive diseases of cucurbits in the Midwestern and Northeastern United States. Although the disease has been studied since 1900, host colonization dynamics remain unclear. Cucumis- and Cucurbita-derived strains exhibit host preference for the cucurbit genus from which they were isolated. We constructed a bioluminescent strain of Erwinia tracheiphila (TedCu10-BL#9) and colonization of different cucurbit hosts was monitored. At the second-true-leaf stage, Cucumis melo plants were inoculated with TedCu10-BL#9 via wounded leaves, stems, and roots. Daily monitoring of colonization showed bioluminescent bacteria in the inoculated leaf and petiole beginning 1 day postinoculation (DPI). The bacteria spread to roots via the stem by 2 DPI, reached the plant extremities 4 DPI, and the plant wilted 6 DPI. However, Cucurbita plants inoculated with TedCu10-BL#9 did not wilt, even at 35 DPI. Bioluminescent bacteria were detected 6 DPI in the main stem of squash and pumpkin plants, which harbored approximately 10(4) and 10(1) CFU/g, respectively, of TedCu10-BL#9 without symptoms. Although significantly less systemic plant colonization was observed in nonpreferred host Cucurbita plants compared with preferred hosts, the mechanism of tolerance of Cucurbita plants to E. tracheiphila strains from Cucumis remains unknown. PMID:26926487

  13. Disturbance opens recruitment sites for bacterial colonization in activated sludge.

    PubMed

    Vuono, David C; Munakata-Marr, Junko; Spear, John R; Drewes, Jörg E

    2016-01-01

    Little is known about the role of immigration in shaping bacterial communities or the factors that may dictate success or failure of colonization by bacteria from regional species pools. To address these knowledge gaps, the influence of bacterial colonization into an ecosystem (activated sludge bioreactor) was measured through a disturbance gradient (successive decreases in the parameter solids retention time) relative to stable operational conditions. Through a DNA sequencing approach, we show that the most abundant bacteria within the immigrant community have a greater probability of colonizing the receiving ecosystem, but mostly as low abundance community members. Only during the disturbance do some of these bacterial populations significantly increase in abundance beyond background levels and in few cases become dominant community members post-disturbance. Two mechanisms facilitate the enhanced enrichment of immigrant populations during disturbance: (i) the availability of resources left unconsumed by established species and (ii) the increased availability of niche space for colonizers to establish and displace resident populations. Thus, as a disturbance decreases local diversity, recruitment sites become available to promote colonization. This work advances our understanding of microbial resource management and diversity maintenance in complex ecosystems. PMID:25727891

  14. [Microcalorimetric investigation of two cephalosporins on colon bacteria activity].

    PubMed

    Xu, Fen; Song, Cheng-Gong; Wu, Rui-Hua; Yang, Li-Ni; Sun, Li-Xian; Zhao, Zong-Bao; Zhang, Zhi-Heng; Cao, Zhong; Zhang, Ling

    2009-10-01

    The effects of cephradinum and ceftazidime on the metabolism of Escherichia coli (E. coli) DH5alpha was determined by microcalorimetry. The microbial activity was recorded as power-time curves through an ampoule method with a TAM Air Isothermal Microcalorimeter at 37 degrees C. The parameters such as the growth rate constant (k), inhibitory ratio (I), the maximum power output (Pm) and the time (tm) corresponding to the maximum power output were calculated. The results show that the ceftazidime has a better inhibitory effect on E. coli DH5alpha than cephradinum. PMID:20055136

  15. INTRACELLULAR COLONIZATION OF SEAGRASS ROOTS BY ACETOGENIC AND SULFIDOGENIC BACTERIA

    EPA Science Inventory

    The contribution of seagrasses to the stability and fertility of estuarine ecosystems is well established. Loss of seagrasses in recent years to disease and coastal development underscores the importance of understanding the microbial ecology of seagrasses, and the possible roles...

  16. Chemotaxis signaling systems in model beneficial plant-bacteria associations.

    PubMed

    Scharf, Birgit E; Hynes, Michael F; Alexandre, Gladys M

    2016-04-01

    Beneficial plant-microbe associations play critical roles in plant health. Bacterial chemotaxis provides a competitive advantage to motile flagellated bacteria in colonization of plant root surfaces, which is a prerequisite for the establishment of beneficial associations. Chemotaxis signaling enables motile soil bacteria to sense and respond to gradients of chemical compounds released by plant roots. This process allows bacteria to actively swim towards plant roots and is thus critical for competitive root surface colonization. The complete genome sequences of several plant-associated bacterial species indicate the presence of multiple chemotaxis systems and a large number of chemoreceptors. Further, most soil bacteria are motile and capable of chemotaxis, and chemotaxis-encoding genes are enriched in the bacteria found in the rhizosphere compared to the bulk soil. This review compares the architecture and diversity of chemotaxis signaling systems in model beneficial plant-associated bacteria and discusses their relevance to the rhizosphere lifestyle. While it is unclear how controlling chemotaxis via multiple parallel chemotaxis systems provides a competitive advantage to certain bacterial species, the presence of a larger number of chemoreceptors is likely to contribute to the ability of motile bacteria to survive in the soil and to compete for root surface colonization. PMID:26797793

  17. Colonic Spirochetosis in a 60-Year-Old Immunocompetent Patient

    PubMed Central

    Ngwa, Taiwo; Peng, Jennifer L.; Choi, Euna; Tayarachakul, Sucharat; Liangpunsakul, Suthat

    2016-01-01

    Spirochetes, a genetically and morphologically distinct group of bacteria, are thin, spiral-shaped, and highly motile. They are known causes of several human diseases such as syphilis, Lyme disease, relapsing fever, and leptospirosis. We report a case of colonic spirochetosis in a healthy patient presenting for surveillance colonoscopy. The diagnosis of intestinal spirochetosis was made accidentally during the histological examination of colonic polyps, which were removed during colonoscopy. We also performed an extensive review on intestinal spirochetosis with a focus on clinical presentation and outcomes of reported cases from the past two decades. PMID:27570780

  18. Lypd8 promotes the segregation of flagellated microbiota and colonic epithelia.

    PubMed

    Okumura, Ryu; Kurakawa, Takashi; Nakano, Takashi; Kayama, Hisako; Kinoshita, Makoto; Motooka, Daisuke; Gotoh, Kazuyoshi; Kimura, Taishi; Kamiyama, Naganori; Kusu, Takashi; Ueda, Yoshiyasu; Wu, Hong; Iijima, Hideki; Barman, Soumik; Osawa, Hideki; Matsuno, Hiroshi; Nishimura, Junichi; Ohba, Yusuke; Nakamura, Shota; Iida, Tetsuya; Yamamoto, Masahiro; Umemoto, Eiji; Sano, Koichi; Takeda, Kiyoshi

    2016-04-01

    Colonic epithelial cells are covered by thick inner and outer mucus layers. The inner mucus layer is free of commensal microbiota, which contributes to the maintenance of gut homeostasis. In the small intestine, molecules critical for prevention of bacterial invasion into epithelia such as Paneth-cell-derived anti-microbial peptides and regenerating islet-derived 3 (RegIII) family proteins have been identified. Although there are mucus layers providing physical barriers against the large number of microbiota present in the large intestine, the mechanisms that separate bacteria and colonic epithelia are not fully elucidated. Here we show that Ly6/PLAUR domain containing 8 (Lypd8) protein prevents flagellated microbiota invading the colonic epithelia in mice. Lypd8, selectively expressed in epithelial cells at the uppermost layer of the large intestinal gland, was secreted into the lumen and bound flagellated bacteria including Proteus mirabilis. In the absence of Lypd8, bacteria were present in the inner mucus layer and many flagellated bacteria invaded epithelia. Lypd8(-/-) mice were highly sensitive to intestinal inflammation induced by dextran sulfate sodium (DSS). Antibiotic elimination of Gram-negative flagellated bacteria restored the bacterial-free state of the inner mucus layer and ameliorated DSS-induced intestinal inflammation in Lypd8(-/-) mice. Lypd8 bound to flagella and suppressed motility of flagellated bacteria. Thus, Lypd8 mediates segregation of intestinal bacteria and epithelial cells in the colon to preserve intestinal homeostasis. PMID:27027293

  19. Streptococcus pneumoniae biofilm formation and dispersion during colonization and disease

    PubMed Central

    Chao, Yashuan; Marks, Laura R.; Pettigrew, Melinda M.; Hakansson, Anders P.

    2015-01-01

    Streptococcus pneumoniae (the pneumococcus) is a common colonizer of the human nasopharynx. Despite a low rate of invasive disease, the high prevalence of colonization results in millions of infections and over one million deaths per year, mostly in individuals under the age of 5 and the elderly. Colonizing pneumococci form well-organized biofilm communities in the nasopharyngeal environment, but the specific role of biofilms and their interaction with the host during colonization and disease is not yet clear. Pneumococci in biofilms are highly resistant to antimicrobial agents and this phenotype can be recapitulated when pneumococci are grown on respiratory epithelial cells under conditions found in the nasopharyngeal environment. Pneumococcal biofilms display lower levels of virulence in vivo and provide an optimal environment for increased genetic exchange both in vitro and in vivo, with increased natural transformation seen during co-colonization with multiple strains. Biofilms have also been detected on mucosal surfaces during pneumonia and middle ear infection, although the role of these biofilms in the disease process is debated. Recent studies have shown that changes in the nasopharyngeal environment caused by concomitant virus infection, changes in the microflora, inflammation, or other host assaults trigger active release of pneumococci from biofilms. These dispersed bacteria have distinct phenotypic properties and transcriptional profiles different from both biofilm and broth-grown, planktonic bacteria, resulting in a significantly increased virulence in vivo. In this review we discuss the properties of pneumococcal biofilms, the role of biofilm formation during pneumococcal colonization, including their propensity for increased ability to exchange genetic material, as well as mechanisms involved in transition from asymptomatic biofilm colonization to dissemination and disease of otherwise sterile sites. Greater understanding of pneumococcal biofilm

  20. Streptococcus pneumoniae biofilm formation and dispersion during colonization and disease.

    PubMed

    Chao, Yashuan; Marks, Laura R; Pettigrew, Melinda M; Hakansson, Anders P

    2014-01-01

    Streptococcus pneumoniae (the pneumococcus) is a common colonizer of the human nasopharynx. Despite a low rate of invasive disease, the high prevalence of colonization results in millions of infections and over one million deaths per year, mostly in individuals under the age of 5 and the elderly. Colonizing pneumococci form well-organized biofilm communities in the nasopharyngeal environment, but the specific role of biofilms and their interaction with the host during colonization and disease is not yet clear. Pneumococci in biofilms are highly resistant to antimicrobial agents and this phenotype can be recapitulated when pneumococci are grown on respiratory epithelial cells under conditions found in the nasopharyngeal environment. Pneumococcal biofilms display lower levels of virulence in vivo and provide an optimal environment for increased genetic exchange both in vitro and in vivo, with increased natural transformation seen during co-colonization with multiple strains. Biofilms have also been detected on mucosal surfaces during pneumonia and middle ear infection, although the role of these biofilms in the disease process is debated. Recent studies have shown that changes in the nasopharyngeal environment caused by concomitant virus infection, changes in the microflora, inflammation, or other host assaults trigger active release of pneumococci from biofilms. These dispersed bacteria have distinct phenotypic properties and transcriptional profiles different from both biofilm and broth-grown, planktonic bacteria, resulting in a significantly increased virulence in vivo. In this review we discuss the properties of pneumococcal biofilms, the role of biofilm formation during pneumococcal colonization, including their propensity for increased ability to exchange genetic material, as well as mechanisms involved in transition from asymptomatic biofilm colonization to dissemination and disease of otherwise sterile sites. Greater understanding of pneumococcal biofilm

  1. Colonization, mouse-style

    PubMed Central

    2010-01-01

    Several recent papers, including one in BMC Evolutionary Biology, examine the colonization history of house mice. As well as background for the analysis of mouse adaptation, such studies offer a perspective on the history of movements of the humans that accidentally transported the mice. See research article: http://www.biomedcentral.com/1471-2148/10/325 PMID:20977781

  2. Serotonin and colonic motility.

    PubMed

    Kendig, D M; Grider, J R

    2015-07-01

    The role of serotonin (5-hydroxytryptamine [5-HT]) in gastrointestinal motility has been studied for over 50 years. Most of the 5-HT in the body resides in the gut wall, where it is located in subsets of mucosal cells (enterochromaffin cells) and neurons (descending interneurons). Many studies suggest that 5-HT is important to normal and dysfunctional gut motility and drugs affecting 5-HT receptors, especially 5-HT3 and 5-HT4 receptors, have been used clinically to treat motility disorders; however, cardiovascular side effects have limited the use of these drugs. Recently studies have questioned the importance and necessity of 5-HT in general and mucosal 5-HT in particular for colonic motility. Recent evidence suggests the importance of 5-HT3 and 5-HT4 receptors for initiation and generation of one of the key colonic motility patterns, the colonic migrating motor complex (CMMC), in rat. The findings suggest that 5-HT3 and 5-HT4 receptors are differentially involved in two different types of rat CMMCs: the long distance contraction (LDC) and the rhythmic propulsive motor complex (RPMC). The understanding of the role of serotonin in colonic motility has been influenced by the specific motility pattern(s) studied, the stimulus used to initiate the motility (spontaneous vs induced), and the route of administration of drugs. All of these considerations contribute to the understanding and the controversy that continues to surround the role of serotonin in the gut. PMID:26095115

  3. Colonic interposition: radiographic evaluation.

    PubMed

    Agha, F P; Orringer, M B

    1984-04-01

    This report reviews the clinical and radiographic features of 40 patients who underwent visceral esophageal substitution with colon for benign or malignant lesions of the esophagus. The incidence and radiographic identification of complications are discussed. All patients were routinely examined with barium esophagrams on postoperative day 10. If an anastomotic leak was suspected clinically before this time, studies were performed using water-soluble iodinated contrast material. Follow-up barium esophagrams were obtained 1-96 months after operation (average, 60 months) in 24 patients. Eight patients (21%) demonstrated asymptomatic "jejunization" of the colonic mucosa with no attributable clinical manifestations; this finding resolved in 1-3 months, without sequelae, and has not been reported before. The spectrum of ischemic changes in the colonic segment included mucosal edema, spasm, ulceration, loss of haustration, and frank necrosis. Radiographically detectable early postoperative complications included anastomotic leak in six (three pharyngocolic, three cervical esophagocolic) and aspiration of barium into the tracheobronchial tree due to incoordinated swallowing in eight. Late postoperative complications included anastomotic narrowing (12) malfunctioning of the colon due to impaired emptying (five), recurrent aspiration pneumonia (three), small bowel obstruction (three), transhiatal herniation of small bowel through the diaphragmatic hiatus (one), and reflux into the retained bypassed esophagus (one). PMID:6608225

  4. Flagella of a plant-growth-stimulating Pseudomonas fluorescens strain are required for colonization of potato roots.

    PubMed Central

    De Weger, L A; van der Vlugt, C I; Wijfjes, A H; Bakker, P A; Schippers, B; Lugtenberg, B

    1987-01-01

    The role of motility in the colonization of potato roots by Pseudomonas bacteria was studied. Four Tn5-induced flagella-less mutants of the plant-growth-stimulating P. fluorescens WCS374 appeared to be impaired in their ability to colonize growing potato roots. Images PMID:3294806

  5. Streptococcus Adherence and Colonization

    PubMed Central

    Nobbs, Angela H.; Lamont, Richard J.; Jenkinson, Howard F.

    2009-01-01

    Summary: Streptococci readily colonize mucosal tissues in the nasopharynx; the respiratory, gastrointestinal, and genitourinary tracts; and the skin. Each ecological niche presents a series of challenges to successful colonization with which streptococci have to contend. Some species exist in equilibrium with their host, neither stimulating nor submitting to immune defenses mounted against them. Most are either opportunistic or true pathogens responsible for diseases such as pharyngitis, tooth decay, necrotizing fasciitis, infective endocarditis, and meningitis. Part of the success of streptococci as colonizers is attributable to the spectrum of proteins expressed on their surfaces. Adhesins enable interactions with salivary, serum, and extracellular matrix components; host cells; and other microbes. This is the essential first step to colonization, the development of complex communities, and possible invasion of host tissues. The majority of streptococcal adhesins are anchored to the cell wall via a C-terminal LPxTz motif. Other proteins may be surface anchored through N-terminal lipid modifications, while the mechanism of cell wall associations for others remains unclear. Collectively, these surface-bound proteins provide Streptococcus species with a “coat of many colors,” enabling multiple intimate contacts and interplays between the bacterial cell and the host. In vitro and in vivo studies have demonstrated direct roles for many streptococcal adhesins as colonization or virulence factors, making them attractive targets for therapeutic and preventive strategies against streptococcal infections. There is, therefore, much focus on applying increasingly advanced molecular techniques to determine the precise structures and functions of these proteins, and their regulatory pathways, so that more targeted approaches can be developed. PMID:19721085

  6. Microbial colonization and lung function in adolescents with cystic fibrosis.

    PubMed

    Hector, Andreas; Kirn, Tobias; Ralhan, Anjali; Graepler-Mainka, Ute; Berenbrinker, Sina; Riethmueller, Joachim; Hogardt, Michael; Wagner, Marlies; Pfleger, Andreas; Autenrieth, Ingo; Kappler, Matthias; Griese, Matthias; Eber, Ernst; Martus, Peter; Hartl, Dominik

    2016-05-01

    With intensified antibiotic therapy and longer survival, patients with cystic fibrosis (CF) are colonized with a more complex pattern of bacteria and fungi. However, the clinical relevance of these emerging pathogens for lung function remains poorly defined. The aim of this study was to assess the association of bacterial and fungal colonization patterns with lung function in adolescent patients with CF. Microbial colonization patterns and lung function parameters were assessed in 770 adolescent European (German/Austrian) CF patients in a retrospective study (median follow-up time: 10years). Colonization with Pseudomonas aeruginosa and MRSA were most strongly associated with loss of lung function, while mainly colonization with Haemophilus influenzae was associated with preserved lung function. Aspergillus fumigatus was the only species that was associated with an increased risk for infection with P. aeruginosa. Microbial interaction analysis revealed three distinct microbial clusters within the longitudinal course of CF lung disease. Collectively, this study identified potentially protective and harmful microbial colonization patterns in adolescent CF patients. Further studies in different patient cohorts are required to evaluate these microbial patterns and to assess their clinical relevance. PMID:26856310

  7. Antibody blocks acquisition of bacterial colonization through agglutination

    PubMed Central

    Roche, A. M.; Richard, A. L.; Rahkola, J. T.; Janoff, E. N.; Weiser, J. N.

    2014-01-01

    Invasive infection often begins with asymptomatic colonization of mucosal surfaces. A murine model of bacterial colonization with Streptococcus pneumoniae was used to study the mechanism for mucosal protection by immunoglobulin. In previously colonized immune mice, bacteria were rapidly sequestered within large aggregates in the nasal lumen. To further examine the role of bacterial agglutination in protection by specific antibodies, mice were passively immunized with IgG purified from anti-pneumococcal sera or pneumococcal type-specific monoclonal human IgA (hIgA1 or hIgA2). Systemically-delivered IgG accessed the mucosal surface and blocked acquisition of colonization and transmission between littermates. Optimal protection by IgG was independent of Fc fragment and complement and, therefore, did not involve an opsonophagocytic mechanism. Enzymatic digestion or reduction of IgG prior to administration showed that protection required divalent binding that maintained its agglutinating effect. Divalent hIgA1 is cleaved by the pneumococcal member of a family of bacterial proteases that generate monovalent Fabα fragments. Thus, passive immunization with hIgA1 blocked colonization by an IgA1-protease deficient mutant (agglutinated), but not the protease-producing wild-type parent (not agglutinated), whereas protease-resistant hIgA2 agglutinated and blocked colonization by both. Our findings highlight the importance of agglutinating antibodies in mucosal defense and reveal how successful pathogens evade this effect. PMID:24962092

  8. Extensive Horizontal Gene Transfer during Staphylococcus aureus Co-colonization In Vivo

    PubMed Central

    McCarthy, Alex J.; Loeffler, Anette; Witney, Adam A.; Gould, Katherine A.; Lloyd, David H.; Lindsay, Jodi A.

    2014-01-01

    Staphylococcus aureus is a commensal and major pathogen of humans and animals. Comparative genomics of S. aureus populations suggests that colonization of different host species is associated with carriage of mobile genetic elements (MGE), particularly bacteriophages and plasmids capable of encoding virulence, resistance, and immune evasion pathways. Antimicrobial-resistant S. aureus of livestock are a potential zoonotic threat to human health if they adapt to colonize humans efficiently. We utilized the technique of experimental evolution and co-colonized gnotobiotic piglets with both human- and pig-associated variants of the lineage clonal complex 398, and investigated growth and genetic changes over 16 days using whole genome sequencing. The human isolate survived co-colonization on piglets more efficiently than in vitro. During co-colonization, transfer of MGE from the pig to the human isolate was detected within 4 h. Extensive and repeated transfer of two bacteriophages and three plasmids resulted in colonization with isolates carrying a wide variety of mobilomes. Whole genome sequencing of progeny bacteria revealed no acquisition of core genome polymorphisms, highlighting the importance of MGE. Staphylococcus aureus bacteriophage recombination and integration into novel sites was detected experimentally for the first time. During colonization, clones coexisted and diversified rather than a single variant dominating. Unexpectedly, each piglet carried unique populations of bacterial variants, suggesting limited transmission of bacteria between piglets once colonized. Our data show that horizontal gene transfer occurs at very high frequency in vivo and significantly higher than that detectable in vitro. PMID:25260585

  9. Sphingolipids in colon cancer

    PubMed Central

    García-Barros, Mónica; Coant, Nicolas; Truman, Jean-Philip; Snider, Ashley J.

    2013-01-01

    Colorectal cancer is one of the major causes of death in the western world. Despite increasing knowledge of the molecular signaling pathways implicated in colon cancer, therapeutic outcomes are still only moderately successful. Sphingolipids, a family of N-acyl linked lipids, have not only structural functions but are also implicated in important biological functions. Ceramide, sphingosine and sphingosine-1-phosphate are the most important bioactive lipids, and they regulate several key cellular functions. Accumulating evidence suggests that many cancers present alterations in sphingolipids and their metabolizing enzymes. The aim of this review is to discuss the emerging roles of sphingolipids, both endogenous and dietary, in colon cancer and the interaction of sphingolipids with WNT/β-catenin pathway, one of the most important signaling cascades that regulate development and homeostasis in intestine PMID:24060581

  10. The Vitamin D Receptor, Inflammatory Bowel Diseases, and Colon Cancer.

    PubMed

    Lu, Rong; Wu, Shaoping; Xia, Yinglin; Sun, Jun

    2012-03-01

    The nuclear receptor is an emerging therapeutic target in various human diseases. Vitamin D receptor (VDR), a nuclear receptor, mediates the biological functions of vitamin D. Classically, vitamin D is recognized as an essential contributor to mineral and bone homeostasis. Increasing evidence demonstrates that vitamin D is involved in inflammatory responses. Persistent intestinal inflammation is associated with colon cancer. This review focuses on vitamin D and VDR in inflammatory bowel diseases and colon cancer. We place emphasis on the regulatory roles of vitamin D/VDR on in inflammation, enteric bacteria, and tumorigenesis. We summarize the signaling pathways regulated by VDR in intestinal homeostasis. Finally, we discuss the potential application of the insights gleaned from these findings to personalized therapies in chronic inflammation and colon cancer. PMID:23814529

  11. Giant colon lipoma

    PubMed Central

    Yaman, İsmail; Derici, Hayrullah; Demirpolat, Gülen

    2015-01-01

    Colon lipomas are rare, non-epithelial tumors. They are generally smaller than two centimeters and asymptomatic, they are incidentally diagnosed and do not require treatment. Large and symptomatic colon lipomas are rather rare. Its differential diagnosis is generally made by histopathological examination of the resected specimen. A fifty-year-old female patient presented with the symptoms of abdominal pain, swelling in the abdomen and loss of weight. During colonoscopy, there was a submucosal mass of 8×6 cm, which almost completely obstructed the lumen in the hepatic flexure and was covered by a mucosa that was sporadically ulcerated and necrotic in nature. In magnetic resonance imaging, an ovoid mass with a diameter of 8.5 cm at its widest dimension was detected, which had signal intensity similar to that of adipose tissue. Since the patient was symptomatic and differential diagnosis could not be made, she underwent laparoscopic right hemicolectomy. A submucosal lipoma was detected on histopathological examination of the specimen. The patient was discharged without any problems on post-operative day 7. Definite diagnosis of lipomas before surgery is challenging; they may be mistaken for malignancy, especially if the lesion is large and ulcerated. For large and symptomatic colon lipomas, surgery is required to both prevent complications and rule out malignancy. PMID:26170744

  12. The gastric microbial community, Helicobacter pylori colonization, and disease

    PubMed Central

    Martin, Miriam E; Solnick, Jay V

    2014-01-01

    Long thought to be a sterile habitat, the stomach contains a diverse and unique community of bacteria. One particular inhabitant, Helicobacter pylori, colonizes half of the world’s human population and establishes a decades-long infection that can be asymptomatic, pathogenic, or even beneficial for the host. Many host and bacterial factors are known to influence an individual’s risk of gastric disease, but another potentially important determinant has recently come to light: the host microbiota. Although it is unclear to what extent H. pylori infection perturbs the established gastric microbial community, and H. pylori colonization seems generally resistant to disturbances in the host microbiota, it can modulate H. pylori pathogenicity. Interactions between H. pylori and bacteria at non-gastric sites are likely indirect—via programming of the pro-inflammatory vs. regulatory T lymphocytes—which may have a significant impact on human health. PMID:24642475

  13. Back To Bacteria.

    ERIC Educational Resources Information Center

    Flannery, Maura C.

    1997-01-01

    Explores new research about bacteria. Discusses bacterial genomes, archaea, unusual environments, evolution, pathogens, bacterial movement, biofilms, bacteria in the body, and a bacterial obsession. Contains 29 references. (JRH)

  14. Magnetic bacteria against MIC

    SciTech Connect

    Javaherdashti, R.

    1997-12-01

    In this article, it is suggested to use the sensitivity of magnetotactic bacteria to changes of magnetic field direction and the natural ability of this bacteria in rapid growth during relatively short time intervals against corrosion-enhancing bacteria and especially sulfate-reducing bacteria. If colonies of sulfate-reducing bacteria could be packed among magnetotactic bacteria, then, by applying sufficiently powerful magnetic field (about 0.5 gauss), all of these bacteria (magnetic and non-magnetic) will be oriented towards an Anti-bacteria agent (oxygen or biocide). So, Microbiologically-Influenced Corrosion in the system would be controlled to a large extent.

  15. Associations between common intestinal parasites and bacteria in humans as revealed by qPCR.

    PubMed

    O'Brien Andersen, L; Karim, A B; Roager, H M; Vigsnæs, L K; Krogfelt, K A; Licht, T R; Stensvold, C R

    2016-09-01

    Several studies have shown associations between groups of intestinal bacterial or specific ratios between bacterial groups and various disease traits. Meanwhile, little is known about interactions and associations between eukaryotic and prokaryotic microorganisms in the human gut. In this work, we set out to investigate potential associations between common single-celled parasites such as Blastocystis spp. and Dientamoeba fragilis and intestinal bacteria. Stool DNA from patients with intestinal symptoms were selected based on being Blastocystis spp.-positive (B+)/negative (B-) and D. fragilis-positive (D+)/negative (D-), and split into four groups of 21 samples (B+ D+, B+ D-, B- D+, and B- D-). Quantitative PCR targeting the six bacterial taxa Bacteroides, Prevotella, the butyrate-producing clostridial clusters IV and XIVa, the mucin-degrading Akkermansia muciniphila, and the indigenous group of Bifidobacterium was subsequently performed, and the relative abundance of these bacteria across the four groups was compared. The relative abundance of Bacteroides in B- D- samples was significantly higher compared with B+ D- and B+ D+ samples (P < 0.05 and P < 0.01, respectively), and this association was even more significant when comparing all parasite-positive samples with parasite-negative samples (P < 0.001). Additionally, our data revealed that a low abundance of Prevotella and a higher abundance of Clostridial cluster XIVa was associated with parasite-negative samples (P < 0.05 and P < 0.01, respectively). Our data support the theory that Blastocystis alone or combined with D. fragilis is associated with gut microbiota characterized by low relative abundances of Bacteroides and Clostridial cluster XIVa and high levels of Prevotella. PMID:27230509

  16. Nitrogen acquisition in Agave tequilana from degradation of endophytic bacteria.

    PubMed

    Beltran-Garcia, Miguel J; White, James F; Prado, Fernanda M; Prieto, Katia R; Yamaguchi, Lydia F; Torres, Monica S; Kato, Massuo J; Medeiros, Marisa H G; Di Mascio, Paolo

    2014-01-01

    Plants form symbiotic associations with endophytic bacteria within tissues of leaves, stems, and roots. It is unclear whether or how plants obtain nitrogen from these endophytic bacteria. Here we present evidence showing nitrogen flow from endophytic bacteria to plants in a process that appears to involve oxidative degradation of bacteria. In our experiments we employed Agave tequilana and its seed-transmitted endophyte Bacillus tequilensis to elucidate organic nitrogen transfer from (15)N-labeled bacteria to plants. Bacillus tequilensis cells grown in a minimal medium with (15)NH4Cl as the nitrogen source were watered onto plants growing in sand. We traced incorporation of (15)N into tryptophan, deoxynucleosides and pheophytin derived from chlorophyll a. Probes for hydrogen peroxide show its presence during degradation of bacteria in plant tissues, supporting involvement of reactive oxygen in the degradation process. In another experiment to assess nitrogen absorbed as a result of endophytic colonization of plants we demonstrated that endophytic bacteria potentially transfer more nitrogen to plants and stimulate greater biomass in plants than heat-killed bacteria that do not colonize plants but instead degrade in the soil. Findings presented here support the hypothesis that some plants under nutrient limitation may degrade and obtain nitrogen from endophytic microbes. PMID:25374146

  17. Nitrogen acquisition in Agave tequilana from degradation of endophytic bacteria

    PubMed Central

    Beltran-Garcia, Miguel J.; White, Jr., James F.; Prado, Fernanda M.; Prieto, Katia R.; Yamaguchi, Lydia F.; Torres, Monica S.; Kato, Massuo J.; Medeiros, Marisa H. G.; Di Mascio, Paolo

    2014-01-01

    Plants form symbiotic associations with endophytic bacteria within tissues of leaves, stems, and roots. It is unclear whether or how plants obtain nitrogen from these endophytic bacteria. Here we present evidence showing nitrogen flow from endophytic bacteria to plants in a process that appears to involve oxidative degradation of bacteria. In our experiments we employed Agave tequilana and its seed-transmitted endophyte Bacillus tequilensis to elucidate organic nitrogen transfer from 15N-labeled bacteria to plants. Bacillus tequilensis cells grown in a minimal medium with 15NH4Cl as the nitrogen source were watered onto plants growing in sand. We traced incorporation of 15N into tryptophan, deoxynucleosides and pheophytin derived from chlorophyll a. Probes for hydrogen peroxide show its presence during degradation of bacteria in plant tissues, supporting involvement of reactive oxygen in the degradation process. In another experiment to assess nitrogen absorbed as a result of endophytic colonization of plants we demonstrated that endophytic bacteria potentially transfer more nitrogen to plants and stimulate greater biomass in plants than heat-killed bacteria that do not colonize plants but instead degrade in the soil. Findings presented here support the hypothesis that some plants under nutrient limitation may degrade and obtain nitrogen from endophytic microbes. PMID:25374146

  18. Human commensals producing a novel antibiotic impair pathogen colonization.

    PubMed

    Zipperer, Alexander; Konnerth, Martin C; Laux, Claudia; Berscheid, Anne; Janek, Daniela; Weidenmaier, Christopher; Burian, Marc; Schilling, Nadine A; Slavetinsky, Christoph; Marschal, Matthias; Willmann, Matthias; Kalbacher, Hubert; Schittek, Birgit; Brötz-Oesterhelt, Heike; Grond, Stephanie; Peschel, Andreas; Krismer, Bernhard

    2016-07-28

    The vast majority of systemic bacterial infections are caused by facultative, often antibiotic-resistant, pathogens colonizing human body surfaces. Nasal carriage of Staphylococcus aureus predisposes to invasive infection, but the mechanisms that permit or interfere with pathogen colonization are largely unknown. Whereas soil microbes are known to compete by production of antibiotics, such processes have rarely been reported for human microbiota. We show that nasal Staphylococcus lugdunensis strains produce lugdunin, a novel thiazolidine-containing cyclic peptide antibiotic that prohibits colonization by S. aureus, and a rare example of a non-ribosomally synthesized bioactive compound from human-associated bacteria. Lugdunin is bactericidal against major pathogens, effective in animal models, and not prone to causing development of resistance in S. aureus. Notably, human nasal colonization by S. lugdunensis was associated with a significantly reduced S. aureus carriage rate, suggesting that lugdunin or lugdunin-producing commensal bacteria could be valuable for preventing staphylococcal infections. Moreover, human microbiota should be considered as a source for new antibiotics. PMID:27466123

  19. Bacterial Responses to a Simulated Colon Tumor Microenvironment*

    PubMed Central

    Boleij, Annemarie; Dutilh, Bas E.; Kortman, Guus A. M.; Roelofs, Rian; Laarakkers, Coby M.; Engelke, Udo F.; Tjalsma, Harold

    2012-01-01

    One of the few bacteria that have been consistently linked to colorectal cancer (CRC) is the opportunistic pathogen Streptococcus gallolyticus. Infections with this bacterium are generally regarded as an indicator for colonic malignancy, while the carriage rate of this bacterium in the healthy large intestine is relatively low. We speculated that the physiological changes accompanying the development of CRC might favor the colonization of this bacterium. To investigate whether colon tumor cells can support the survival of S. gallolyticus, this bacterium was grown in spent medium of malignant colonocytes to simulate the altered metabolic conditions in the CRC microenvironment. These in vitro simulations indicated that S. gallolyticus had a significant growth advantage in these spent media, which was not observed for other intestinal bacteria. Under these conditions, bacterial responses were profiled by proteome analysis and metabolic shifts were analyzed by 1H-NMR-spectroscopy. In silico pathway analysis of the differentially expressed proteins and metabolite analysis indicated that this advantage resulted from the increased utilization of glucose, glucose derivates, and alanine. Together, these data suggest that tumor cell metabolites facilitate the survival of S. gallolyticus, favoring its local outgrowth and providing a possible explanation for the specific association of S. gallolyticus with colonic malignancy. PMID:22713208

  20. Diffuse lymphoid follicles of the colon associated with colonic carcinoma.

    PubMed

    Bronen, R A; Glick, S N; Teplick, S K

    1984-01-01

    In four patients aged 59-75 years, colonic carcinoma was associated with diffuse lymphoid follicles in the colon. In one case, the prominence and distribution of the lymphoid follicles corresponded to the progression and regression of the tumor bulk. It is extremely unusual to demonstrate lymphoid follicles, particularly diffuse, on barium enema in patients in this age range. The colonic carcinomas and lymphoid follicles are directly related, possibly representing an immune response. PMID:6606941

  1. Spatial scales of interactions among bacteria and between bacteria and the leaf surface.

    PubMed

    Esser, Daniel S; Leveau, Johan H J; Meyer, Katrin M; Wiegand, Kerstin

    2015-03-01

    Microbial life on plant leaves is characterized by a multitude of interactions between leaf colonizers and their environment. While the existence of many of these interactions has been confirmed, their spatial scale or reach often remained unknown. In this study, we applied spatial point pattern analysis to 244 distribution patterns of Pantoea agglomerans and Pseudomonas syringae on bean leaves. The results showed that bacterial colonizers of leaves interact with their environment at different spatial scales. Interactions among bacteria were often confined to small spatial scales up to 5-20 μm, compared to interactions between bacteria and leaf surface structures such as trichomes which could be observed in excess of 100 μm. Spatial point-pattern analyses prove a comprehensive tool to determine the different spatial scales of bacterial interactions on plant leaves and will help microbiologists to better understand the interplay between these interactions. PMID:25764562

  2. Spatial scales of interactions among bacteria and between bacteria and the leaf surface

    PubMed Central

    Esser, Daniel S.; Leveau, Johan H.J.; Meyer, Katrin M.; Wiegand, Kerstin

    2014-01-01

    Microbial life on plant leaves is characterized by a multitude of interactions between leaf colonizers and their environment. While the existence of many of these interactions has been confirmed, their spatial scale or reach often remained unknown. In this study, we applied spatial point pattern analysis to 244 distribution patterns of Pantoea agglomerans and Pseudomonas syringae on bean leaves. The results showed that bacterial colonizers of leaves interact with their environment at different spatial scales. Interactions among bacteria were often confined to small spatial scales up to 5–20 μm, compared to interactions between bacteria and leaf surface structures such as trichomes which could be observed in excess of 100 μm. Spatial point-pattern analyses prove a comprehensive tool to determine the different spatial scales of bacterial interactions on plant leaves and will help microbiologists to better understand the interplay between these interactions. PMID:25764562

  3. Structure, Function, and Assembly of Adhesive Organelles by Uropathogenic Bacteria

    PubMed Central

    Chahales, Peter; Thanassi, David G.

    2015-01-01

    Bacteria assemble a wide range of adhesive proteins, termed adhesins, to mediate binding to receptors and colonization of surfaces. For pathogenic bacteria, adhesins are critical for early stages of infection, allowing the bacteria to initiate contact with host cells, colonize different tissues, and establish a foothold within the host. The adhesins expressed by a pathogen are also critical for bacterial-bacterial interactions and the formation of bacterial communities such as biofilms. The ability to adhere to host tissues is particularly important for bacteria that colonize sites such as the urinary tract, where the flow of urine functions to maintain sterility by washing away non-adherent pathogens. Adhesins vary from monomeric proteins that are directly anchored to the bacterial surface to polymeric, hairlike fibers that extend out from the cell surface. These latter fibers are termed pili or fimbriae, and were among the first identified virulence factors of uropathogenic Escherichia coli. Studies since then have identified a range of both pilus and non-pilus adhesins that contribute to bacterial colonization of the urinary tract, and have revealed molecular details of the structures, assembly pathways, and functions of these adhesive organelles. In this review, we describe the different types of adhesins expressed by both Gram-negative and Gram-positive uropathogens, what is known about their structures, how they are assembled on the bacterial surface, and the functions of specific adhesins in the pathogenesis of urinary tract infections. PMID:26542038

  4. Endophytic bacteria in potato tubers affected by zebra chip disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato zebra chip disease (ZCD) could drastically reduce quality and value of all market classes of potato, costing growers and processors millions of dollars in losses in North America. Endophytic bacteria colonize the internal tissue and could have both positive and negative effects on host plants...

  5. Fungal infection of the colon

    PubMed Central

    Praneenararat, Surat

    2014-01-01

    Fungi are pathogens that commonly infect immunocompromised patients and can affect any organs of the body, including the colon. However, the literature provides limited details on colonic infections caused by fungi. This article is an intensive review of information available on the fungi that can cause colon infections. It uses a comparative style so that its conclusions may be accessible for clinical application. PMID:25364269

  6. Colonic lymphangiomatosis associated with anemia

    PubMed Central

    Chung, Woo Chul; Kim, Hye-Kang; Yoo, Jin Young; Lee, Jeong Rok; Lee, Kang-Moon; Paik, Chang Nyol; Jang, U-Im; Yang, Jin Mo

    2008-01-01

    Lymphangioma is an uncommon malformation of lymphatic system. Multiple colonic lymphangioma named as lymphangiomatosis is considered an extremely rare disease. Although lymphangioma is a benign tumor and most colonic lymphangiomas do not cause symptoms and do not require treatment, resection of lymphangioma is necessary in the presence of symptoms such as abdominal pain, bleeding, intussusceptions. We report a case of colonic lymphangiomatosis in a man who presented with abdominal discomfort and anemia, which was diagnosed and treated with endoscopic snare polypectomy. PMID:18837097

  7. Cinnamate of inulin as a vehicle for delivery of colonic drugs.

    PubMed

    López-Molina, Dorotea; Chazarra, Soledad; How, Chee Wun; Pruidze, Nikolov; Navarro-Perán, Enma; García-Cánovas, Francisco; García-Ruiz, Pedro Antonio; Rojas-Melgarejo, Francisco; Rodríguez-López, José Neptuno

    2015-02-01

    Colon diseases are difficult to treat because oral administrated drugs are absorbed at the stomach and intestine levels and they do not reach colon; in addition, intravenous administrated drugs are eliminated from the body before reaching colon. Inulin is a naturally occurring polysaccharide found in many plants. It consists of β 2-1 linked D-fructose molecules having a glucosyl unit at the reducing end. Various inulin and dextran hydrogels have been developed that serve as potential carrier for introduction of drugs into the colon. Because inulin is not absorbed in the stomach or in the small intestine, and inulin is degraded by colonic bacteria, drugs encapsulated in inulin-coated vesicles could be specifically liberated in the colon. Therefore, the use of inulin-coated vesicles could represent an advance for the treatment of colon diseases. Here, we study the use of a cinnamoylated derivative of chicory inulin as a vehicle for the controlled delivery of colonic drugs. The encapsulation of methotrexate in inulin vesicles and its release and activity was studied in colon cancer cells in cultures. PMID:25550210

  8. Nasal Bacterial Colonization in Pediatric Epistaxis: The Role of Topical Antibacterial Treatment

    PubMed Central

    Korkmaz, Mukadder; Çetinkol, Yeliz; Korkmaz, Hakan; Batmaz, Timur

    2016-01-01

    Background: Epistaxis is a common problem in childhood. It has been shown that children with recurrent epistaxis are more likely to have nasal colonization with Staphylococcus aureus. It has been suggested that low-grade inflammation, crusting and increased vascularity due to bacterial colonization contributes to the development of epistaxis in children. Aims: This study aimed to investigate the nasal colonization and treatment outcome in pediatric epistaxis patients. Study Design: Retrospective cross-sectional study. Methods: Charts of the pediatric patients referred to our university hospital otolaryngology outpatient clinics for the evaluation of epistaxis were reviewed. The patients whose nasal cultures had been taken at the first clinical visit comprised the study group. Results: Staphylococcus aureus was the most common bacteria grown. The presence of crusting and hypervascularity was not dependent on the type of bacterial growth and there was no relation between hypervascularity and crusting of the nasal mucosa. Thirty-six patients were evaluated for the outcome analysis. Resolution of bleeding was not dependent on nasal colonization; in patients with colonization, there was no difference between topical antibacterial and non-antibacterial treatments. Conclusion: Despite the high colonization rates, topical antibacterial treatment was not found superior to non-antibacterial treatment. Our study does not support the belief that bacterial colonization results in hypervascularity of the septal mucosa causing epistaxis since no relation was found between nasal colonization, hypervascularity and crusting. The role of bacterial colonization in pediatric epistaxis need to be further investigated and treatment protocols must be determined accordingly. PMID:27403392

  9. Microbial pathways in colonic sulfur metabolism and links with health and disease

    PubMed Central

    Carbonero, Franck; Benefiel, Ann C.; Alizadeh-Ghamsari, Amir H.; Gaskins, H. Rex

    2012-01-01

    Sulfur is both crucial to life and a potential threat to health. While colonic sulfur metabolism mediated by eukaryotic cells is relatively well studied, much less is known about sulfur metabolism within gastrointestinal microbes. Sulfated compounds in the colon are either of inorganic (e.g., sulfates, sulfites) or organic (e.g., dietary amino acids and host mucins) origin. The most extensively studied of the microbes involved in colonic sulfur metabolism are the sulfate-reducing bacteria (SRB), which are common colonic inhabitants. Many other microbial pathways are likely to shape colonic sulfur metabolism as well as the composition and availability of sulfated compounds, and these interactions need to be examined in more detail. Hydrogen sulfide is the sulfur derivative that has attracted the most attention in the context of colonic health, and the extent to which it is detrimental or beneficial remains in debate. Several lines of evidence point to SRB or exogenous hydrogen sulfide as potential players in the etiology of intestinal disorders, inflammatory bowel diseases (IBDs) and colorectal cancer in particular. Generation of hydrogen sulfide via pathways other than dissimilatory sulfate reduction may be as, or more, important than those involving the SRB. We suggest here that a novel axis of research is to assess the effects of hydrogen sulfide in shaping colonic microbiome structure. Clearly, in-depth characterization of the microbial pathways involved in colonic sulfur metabolism is necessary for a better understanding of its contribution to colonic disorders and development of therapeutic strategies. PMID:23226130

  10. Sialic Acid Transport Contributes to Pneumococcal Colonization

    PubMed Central

    Marion, Carolyn; Burnaugh, Amanda M.; Woodiga, Shireen A.; King, Samantha J.

    2011-01-01

    Streptococcus pneumoniae is a major cause of pneumonia and meningitis. Airway colonization is a necessary precursor to disease, but little is known about how the bacteria establish and maintain colonization. Carbohydrates are required as a carbon source for pneumococcal growth and, therefore, for colonization. Free carbohydrates are not readily available in the naso-oropharynx; however, N- and O-linked glycans are common in the airway. Sialic acid is the most common terminal modification on N- and O-linked glycans and is likely encountered frequently by S. pneumoniae in the airway. Here we demonstrate that sialic acid supports pneumococcal growth when provided as a sole carbon source. Growth on sialic acid requires import into the bacterium. Three genetic regions have been proposed to encode pneumococcal sialic acid transporters: one sodium solute symporter and two ATP binding cassette (ABC) transporters. Data demonstrate that one of these, satABC, is required for transport of sialic acid. A satABC mutant displayed significantly reduced growth on both sialic acid and the human glycoprotein alpha-1. The importance of satABC for growth on human glycoprotein suggests that sialic acid transport may be important in vivo. Indeed, the satABC mutant was significantly reduced in colonization of the murine upper respiratory tract. This work demonstrates that S. pneumoniae is able to use sialic acid as a sole carbon source and that utilization of sialic acid is likely important during pneumococcal colonization. PMID:21189320

  11. Microbial interference and colonization of the murine gastrointestinal tract by Listeria monocytogenes.

    PubMed Central

    Zachar, Z; Savage, D C

    1979-01-01

    Two strains of Listeria monocytogenes, one that formed smooth colonies on agar surfaces and a varient of it that formed rough colonies, colonized the gastrointestinal tracts of germfree mice. Within 24 h after mice were inoculated orally with about 100 bacteria, the population levels per gram (wet weight) of tissue of both strains were 10(5) to 10(7) in the stomach and ileum and 10(8) to 10(9) in the cecum and colon, respectively. As detected in Gram-stained histological sections, in such gnotobiotes, the bacteria colonized the lumen in all areas of the tract and much of the mucus layer on the epithelial surface in the proximal colon. The strain that formed smooth colonies did not colonize the tracts of specific-pathogen-free mice, but did colonize, to the same levels as in germfree mice, the stomachs and bowels of ex-germfree mice previously associated with two members of the indigenous flora (Bacteroides and Clostridium). In the latter animals, however, the listeria did not form layers on the colonic epithelium as efficiently as they did in monoassociated gnotobiotes. Images Fig. 1 Fig. 2 PMID:106003

  12. Forever competent: deep-sea bivalves are colonized by their chemosynthetic symbionts throughout their lifetime.

    PubMed

    Wentrup, Cecilia; Wendeberg, Annelie; Schimak, Mario; Borowski, Christian; Dubilier, Nicole

    2014-12-01

    Symbiotic bivalves at hydrothermal vents and cold seeps host chemosynthetic bacteria intracellularly in gill cells. In bivalves, the gills grow continuously throughout their lifetime by forming new filaments. We examined how newly developed gill tissues are colonized in bivalves with horizontal and vertical symbiont transmission (Bathymodiolus mussels versus a vesicoymid clam) using fluorescence in situ hybridization and transmission electron microscopy. Symbiont colonization was similar in mussels and clams and was independent of the transmission modes. Symbionts were absent in the growth zones of the gills, indicating that symbionts colonize newly formed gill filaments de novo after they are formed and that gill colonization is a continuous process throughout the host's lifetime. Symbiont abundance and distribution suggested that colonization is shaped by the developmental stage of host cells. Self-infection, in which new gill cells are colonized by symbionts from ontogenetically older gill tissues, may also play a role. In mussels, symbiont infection led to changes in gill cell structure similar to those described from other epithelial cells infected by intracellular pathogens, such as the loss of microvilli. A better understanding of the factors that affect symbiont colonization of bivalve gills could provide new insights into interactions between intracellular bacteria and epithelial tissues. PMID:25142549

  13. Microbial shifts associated with necrotic enteritis.

    PubMed

    Antonissen, Gunther; Eeckhaut, Venessa; Van Driessche, Karolien; Onrust, Lonneke; Haesebrouck, Freddy; Ducatelle, Richard; Moore, Robert J; Van Immerseel, Filip

    2016-06-01

    An outbreak of necrotic enteritis (NE) is a complex process requiring one or a number of predisposing factors rather than just the presence of pathogenic Clostridium perfringens. Examples are dietary influences, such as high levels of non-starch polysaccharides and fishmeal, and factors that evoke epithelial cell damage, such as Fusarium mycotoxins in feed and Eimeria infections. Recent studies have shown that different predisposing factors induce similar shifts in the intestinal microbiota composition. Butyrate-producing-strains of the Ruminococcaceae family are decreased in abundance by both fishmeal and Eimeria. Similarly, a decreased abundance of butyrate-producing-strains belonging to the Lachnospiraceae family has been induced by fishmeal. Also shifts are observed in the lactic acid-producing bacteria, such as decreased abundance of Lactobacillus johnsonii or Weissella confusa, when broilers were fed a fishmeal-based diet or a Fusarium mycotoxin contaminated diet. Finally, the abundance of Candidatus Savagella was decreased in broilers following Eimeria challenge or feeding a fumonisins contaminated diet. The nature of the microbiota shifts indicate that immune modulatory actions of the intestinal microbiota may play a critical role in the effect on the necrosis inducing activity of C. perfringens. Indeed, colonization with butyrate-producing bacteria plays a key role in counteracting inflammation in the gut and preserving intestinal integrity, while Candidatus Savagella is involved in stimulating Th17 and immunoglobulin A responses. Lactic acid bacteria stimulate colonization of lactate-utilizing and butyrate-producing Lachnospiraceae. Future research needs to clarify the role of the microbiota changes in the pathogenesis of NE. PMID:26950294

  14. Costs and Benefits of High Mutation Rates: Adaptive Evolution of Bacteria in the Mouse Gut

    NASA Astrophysics Data System (ADS)

    Giraud, Antoine; Matic, Ivan; Tenaillon, Olivier; Clara, Antonio; Radman, Miroslav; Fons, Michel; Taddei, François

    2001-03-01

    We have shown that bacterial mutation rates change during the experimental colonization of the mouse gut. A high mutation rate was initially beneficial because it allowed faster adaptation, but this benefit disappeared once adaptation was achieved. Mutator bacteria accumulated mutations that, although neutral in the mouse gut, are often deleterious in secondary environments. Consistently, the competitiveness of mutator bacteria is reduced during transmission to and re-colonization of similar hosts. The short-term advantages and long-term disadvantages of mutator bacteria could account for their frequency in nature.

  15. Surface Changes in Mild Steel Coupons from the Action of Corrosion-Causing Bacteria

    PubMed Central

    Obuekwe, Christian O.; Westlake, Donald W. S.; Cook, Fred D.; William Costerton, J.

    1981-01-01

    Changes which occur on the surface of mild steel coupons submerged in cultures of an Fe(III)-reducing bacterium, isolated from corroded pipe systems carrying crude oil, were studied microscopically to investigate the interaction between the corrosion-causing bacterium and the corroding mild steel coupon. Under micro-aerobic conditions and in the absence of the bacteria, a dense, crystalline, amorphous coat formed on the surface of the steel coupons. In the presence of bacteria the surface coat was extensively removed, exposing the bare metal to the environment. After about 2 weeks of exposure, the removal of the surface coating was followed by colonization of the metal surface by the bacteria. Colonization was mediated by fibrous, exopolysaccharidic material formed by the bacteria. Extension of studies to other bacteria isolated from crude oil and corroded pipes reveals that the formation of exopolysaccharide fibers and possession of adherent properties are common characteristics of bacteria from crude oil systems. Images PMID:16345735

  16. Pathways to Colonization

    NASA Technical Reports Server (NTRS)

    Smitherman, David V., Jr.

    2003-01-01

    The steps required for space colonization are many to grow from our current 3-person International Space Station, now under construction, to an infrastructure that can support hundreds and eventually thousands of people in space. This paper will summarize the author's findings from numerous studies and workshops on related subjects and identify some of the critical next steps toward space colonization. Findings will be drawn from the author s previous work on space colony design, space infrastructure workshops, and various studies that addressed space policy. In conclusion, this paper will note that significant progress has been made on space facility construction through the International Space Station program, and that significant efforts are needed in the development of new reusable Earth to Orbit transportation systems. The next key steps will include reusable in space transportation systems supported by in space propellant depots, the continued development of inflatable habitat and space elevator technologies, and the resolution of policy issues that will establish a future vision for space development.

  17. Collective Motion of Spherical Bacteria

    PubMed Central

    Rabani, Amit; Ariel, Gil; Be'er, Avraham

    2013-01-01

    A large variety of motile bacterial species exhibit collective motions while inhabiting liquids or colonizing surfaces. These collective motions are often characterized by coherent dynamic clusters, where hundreds of cells move in correlated whirls and jets. Previously, all species that were known to form such motion had a rod-shaped structure, which enhances the order through steric and hydrodynamic interactions. Here we show that the spherical motile bacteria Serratia marcescens exhibit robust collective dynamics and correlated coherent motion while grown in suspensions. As cells migrate to the upper surface of a drop, they form a monolayer, and move collectively in whirls and jets. At all concentrations, the distribution of the bacterial speed was approximately Rayleigh with an average that depends on concentration in a non-monotonic way. Other dynamical parameters such as vorticity and correlation functions are also analyzed and compared to rod-shaped bacteria from the same strain. Our results demonstrate that self-propelled spherical objects do form complex ordered collective motion. This opens a door for a new perspective on the role of cell aspect ratio and alignment of cells with regards to collective motion in nature. PMID:24376741

  18. Draft Genome Sequences of Acinetobacter parvus CM11, Acinetobacter radioresistens CM38, and Stenotrophomonas maltophilia BR12, Isolated from Murine Proximal Colonic Tissue

    PubMed Central

    Saffarian, Azadeh; Mulet, Céline; Naito, Tomoaki; Bouchier, Christiane; Tichit, Magali; Ma, Laurence; Grompone, Gianfranco

    2015-01-01

    Here, we report three genome sequences of bacteria isolated from murine proximal colonic tissue and identified as Acinetobacter parvus CM11, Acinetobacter radioresistens CM38, and Stenotrophomonas maltophilia BR12. PMID:26472823

  19. Draft Genome Sequences of Acinetobacter parvus CM11, Acinetobacter radioresistens CM38, and Stenotrophomonas maltophilia BR12, Isolated from Murine Proximal Colonic Tissue.

    PubMed

    Saffarian, Azadeh; Mulet, Céline; Naito, Tomoaki; Bouchier, Christiane; Tichit, Magali; Ma, Laurence; Grompone, Gianfranco; Sansonetti, Philippe J; Pédron, Thierry

    2015-01-01

    Here, we report three genome sequences of bacteria isolated from murine proximal colonic tissue and identified as Acinetobacter parvus CM11, Acinetobacter radioresistens CM38, and Stenotrophomonas maltophilia BR12. PMID:26472823

  20. Hereditary and Familial Colon Cancer

    PubMed Central

    Jasperson, Kory W.; Tuohy, Thérèse M.; Neklason, Deborah W.; Burt, Randall W.

    2011-01-01

    Between 2% to 5% of all colon cancers arise in the setting of well defined inherited syndromes, including Lynch syndrome, familial adenomatous polyposis, MUTYH-associated polyposis, and certain hamartomatous polyposis conditions. Each is associated with a high risk of colon cancer. In addition to the syndromes, up to one-third of colon cancers exhibit increased familial risk, likely related to inheritance. A number of less penetrant, but possibly more frequent susceptibility genes have been identified for this level of inheritance. Clarification of predisposing genes allows for accurate risk assessment and more precise screening approaches. This review examines the colon cancer syndromes, their genetics and management, and also the common familial colon cancers with current genetic advances and screening guidelines. PMID:20420945

  1. Schwannoma of the sigmoid colon.

    PubMed

    Çakır, Tuğrul; Aslaner, Arif; Yaz, Müjgan; Gündüz, Umut rıza

    2015-01-01

    Colonic schwannomas are very rare gastrointestinal tumours originating from Schwann cells, which form the neural sheath. Primary schwannomas of the lower gastrointestinal tract are very rare and usually benign in nature. However, if they are not surgically removed, malign degeneration can occur. We report a case of a 79-year-old woman who presented to our clinic with rectal bleeding and constipation. She underwent a lower gastrointestinal tract endoscopy. A mass subtotally obstructing the lumen of the sigmoid colon was seen and biopsies were taken. Histopathological examination indicated a suspicion of gastrointestinal tumour and the patient underwent sigmoid colon resection after preoperative evaluation by laboratory analysis, abdominal ultrasonography and CT. Her postoperative course was uneventful and she was discharged on the fifth day for outpatient control. The histopathology report revealed schwannoma of the sigmoid colon. This was a case of schwannoma of the sigmoid colon that was successfully treated with total resection. PMID:25976197

  2. Bacteria isolated from amoebae/bacteria consortium

    DOEpatents

    Tyndall, Richard L.

    1995-01-01

    New protozoan derived microbial consortia and method for their isolation are provided. Consortia and bacteria isolated therefrom are useful for treating wastes such as trichloroethylene and trinitrotoluene. Consortia, bacteria isolated therefrom, and dispersants isolated therefrom are useful for dispersing hydrocarbons such as oil, creosote, wax, and grease.

  3. Bacteria isolated from amoebae/bacteria consortium

    DOEpatents

    Tyndall, R.L.

    1995-05-30

    New protozoan derived microbial consortia and method for their isolation are provided. Consortia and bacteria isolated therefrom are useful for treating wastes such as trichloroethylene and trinitrotoluene. Consortia, bacteria isolated therefrom, and dispersants isolated therefrom are useful for dispersing hydrocarbons such as oil, creosote, wax, and grease.

  4. Colonize, evade, flourish

    PubMed Central

    Rubin, Erica J; Trent, M Stephen

    2013-01-01

    Helicobacter pylori is an adapted gastric pathogen that colonizes the human stomach, causing severe gastritis and gastric cancer. A hallmark of infection is the ability of this organism to evade detection by the human immune system. H. pylori has evolved a number of features to achieve this, many of which involve glyco-conjugates including the lipopolysaccharide, peptidoglycan layer, glycoproteins, and glucosylated cholesterol. These major bacterial components possess unique features from those of other gram-negative organisms, including differences in structure, assembly, and modification. These defining characteristics of H. pylori glycobiology help the pathogen establish a long-lived infection by providing camouflage, modulating the host immune response, and promoting virulence mechanisms. In this way, glyco-conjugates are essential for H. pylori pathogenicity and survival, allowing it to carve out a niche in the formidable environment of the human stomach. PMID:23859890

  5. [Irritable colon and constipation].

    PubMed

    Meyenberger, C

    1993-04-20

    Irritable bowel syndrome is a very common clinical problem with a broad spectrum of severity. The management includes a combination of positive diagnosis of typical symptoms with limited investigations to exclude underlying structural or biochemical disorders. Therapeutic trials focus on the relief of predominant symptoms. Identification and modification of factors exacerbating symptoms, behavioural techniques and pharmacologic agents directed to the presumed gastrointestinal motor dysfunction are required. Psychological support by the physician is the most important part of treatment. Chronic constipation may be the predominant symptom of irritable bowel syndrome. Underlying organic disorders must be excluded by clinical examination and endoscopy. Severe chronic constipation requires further investigation of colonic motility and defecation. High fibre diet, osmotic laxatives and procinetic agents may lead to an improvement. In rare cases surgery may be indicated. PMID:8488351

  6. Colon interposition for oesophageal replacement.

    PubMed

    Thomas, Pascal A; Gilardoni, Adrian; Trousse, Delphine; D'Journo, Xavier B; Avaro, Jean-Philippe; Doddoli, Christophe; Giudicelli, Roger; Fuentes, Pierre

    2009-01-01

    The choice of the colon as an oesophageal substitute results primarily from the unavailability of the stomach. However, given its durability and function, colon interposition keeps elective indications in patients with benign or malignant oesophageal disease who are potential candidates for long survival. The choice of the colonic portion used for oesophageal reconstruction depends on the required length of the graft, and the encountered colonic vascular anatomy, the last being characterised by the near-invariability of the left colonic vessels, in contrast to the vascular pattern of the right side of the colon. Accordingly, the transverse colon with all or part of the ascending colon is the substitute of choice, positioned in the isoperistaltic direction, and supplied either from the left colic vessels for long grafts or middle colic vessels for shorter grafts. Technical key points are: full mobilisation of the entire colon, identification of the main colonic vessels and collaterals, and a prolonged clamping test to ensure the permeability of the chosen nourishing pedicle. Transposition through the posterior mediastinum in the oesophageal bed is the shortest one and thereby offers the best functional results. When the oesophageal bed is not available, the retrosternal route is the preferred alternative option. The food bolus travelling mainly by gravity makes straightness of the conduit of paramount importance. The proximal anastomosis is a single-layer hand-fashioned end-to-end anastomosis to prevent narrowing. When the stomach is available, the distal anastomosis is best performed at the posterior part of the antrum for the reasons of pedicle positioning and reflux prevention, and a gastric drainage procedure is added when the oesophagus and vagus nerves have been removed. In the other cases, a Roux-en-Y jejunal loop is preferable to prevent bile reflux into the colon. Additional procedures include re-establishment of the colonic continuity, a careful closure of

  7. Bacteria-bacteria interactions within the microbiota of the ancestral metazoan Hydra contribute to fungal resistance.

    PubMed

    Fraune, Sebastian; Anton-Erxleben, Friederike; Augustin, René; Franzenburg, Sören; Knop, Mirjam; Schröder, Katja; Willoweit-Ohl, Doris; Bosch, Thomas C G

    2015-07-01

    Epithelial surfaces of most animals are colonized by diverse microbial communities. Although it is generally agreed that commensal bacteria can serve beneficial functions, the processes involved are poorly understood. Here we report that in the basal metazoan Hydra, ectodermal epithelial cells are covered with a multilayered glycocalyx that provides a habitat for a distinctive microbial community. Removing this epithelial microbiota results in lethal infection by the filamentous fungus Fusarium sp. Restoring the complex microbiota in gnotobiotic polyps prevents pathogen infection. Although mono-associations with distinct members of the microbiota fail to provide full protection, additive and synergistic interactions of commensal bacteria are contributing to full fungal resistance. Our results highlight the importance of resident microbiota diversity as a protective factor against pathogen infections. Besides revealing insights into the in vivo function of commensal microbes in Hydra, our findings indicate that interactions among commensal bacteria are essential to inhibit pathogen infection. PMID:25514534

  8. Stimulation of epithelial cell proliferation of isolated distal colon of rats by continuous colonic infusion of ammonia or short-chain fatty acids is nonadditive.

    PubMed

    Ichikawa, H; Sakata, T

    1998-05-01

    Dietary fibers accelerate colonic epithelial cell proliferation at least in part by modulating bacterial metabolism in the large intestine. Ammonia and short-chain fatty acids (SCFA) are major metabolites of hindgut bacteria and are believed to affect epithelial cell kinetics of the colon. However, the effect of luminal ammonia itself and the possible interaction of ammonia with SCFA on colonic epithelial cell proliferation have not yet been studied. The colon of rats was surgically isolated and continuously administered infusates with saline, ammonia, SCFA or both into the isolated colon for 7 d in a two-way factorial design. On d 7, vincrystine sulfate was administered intravenously to cause metaphase arrest. The activity of epithelial cell proliferation in the distal colon was estimated by using a stathmokinetic method and by histologic examination. The crypt size was significantly larger in rats given infusates containing SCFA than in rats given infusates without SCFA. Infusion of ammonia or SCFA significantly stimulated colonic epithelial cell proliferation compared with the saline infusion. Infusion of both ammonia and SCFA resulted in accumulated mitoses per crypt that did not differ from the other three infusions although the value tended to be lower than when SCFA alone were infused. Thus, stimulation of epithelial cell proliferation by ammonia and SCFA is not additive, and the interaction between them should be considered when the effects of dietary fibers on gut epithelial proliferation are investigated. PMID:9566991

  9. Bacteria Inactivation During Lithotripsy

    NASA Astrophysics Data System (ADS)

    del Sol Quintero, María; Mora, Ulises; Gutiérrez, Jorge; Mues, Enrique; Castaño, Eduardo; Fernández, Francisco; Loske, Achim M.

    2006-09-01

    The influence of extracorporeal and intracorporeal lithotripsy on the viability of bacteria contained inside artificial kidney stones was investigated in vitro. Two different bacteria were exposed to the action of one extracorporeal shock wave generator and four intracorporeal lithotripters.

  10. Bacterial colonization and gut development in preterm neonates.

    PubMed

    Cilieborg, Malene S; Boye, Mette; Sangild, Per T

    2012-03-01

    Necrotizing enterocolitis (NEC) develops in 5-10% of preterm infants in association with enteral feeding and bacterial colonization. It remains unclear how diet and bacteria interact to protect or provoke the immature gastrointestinal tract. Understanding the factors that control bacterial colonization may provide the clue to prevent NEC, and studies in infants must be combined with animal models to understand the mechanisms of the microbiota-epithelium interactions. Analyses of infant fecal samples show that the density and distribution of bacterial species are highly variable with no consistent effects of gestational age, delivery mode, diet or probiotic administration, while low bacterial diversity and bacterial overgrowth are commonly associated with NEC. A series of recent studies in preterm pigs show that the mucosa-associated microbiota is affected by delivery method, prematurity and NEC progression and that diet has limited effects. Overgrowth of specific groups (e.g. Clostridia) appears to be a consequence of NEC, rather than the cause of NEC. Administration of probiotics either decreases or increases NEC sensitivity in preterm pigs, while in preterm infants probiotics have generally decreased NEC incidence and overall mortality. The optimal nature and amount of probiotic bacteria are unknown and host defense factors appear more important for NEC sensitivity than the nature of the gut microbiota. Host defense is improved by feeding the optimal amount of enteral diets, such as mother's colostrum or milk, that help the immature intestinal immune system to respond appropriately to the highly variable bacterial colonization. PMID:22284985

  11. CHAPTER IV-2 BACTERIA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Entomopathogenic bacteria provide an alternative to chemical pesticides used in insect control programs. Today, the principal microbial insecticides utilize spore forming bacteria or toxins produced by these bacteria as their active ingredients, either in formulations or by incorporation of toxin g...

  12. Reshuffling transcriptional circuits: how microorganisms adapt to colonize the human body

    PubMed Central

    De, Sonakshi; Pérez, J Christian

    2014-01-01

    Several hundred taxa of microorganisms—including bacteria, archaea and eukaryotes—inhabit the human body. What did it take for these species to become stable residents of humans? Recent reports illustrate how evolutionary changes in transcriptional circuits played a pivotal role in the adaptation of single-celled eukaryotes to colonize mammals. PMID:25483603

  13. Ruminococcus bromii is a keystone species for the degradation of resistant starch in the human colon

    PubMed Central

    Ze, Xiaolei; Duncan, Sylvia H; Louis, Petra; Flint, Harry J

    2012-01-01

    The release of energy from particulate substrates such as dietary fiber and resistant starch (RS) in the human colon may depend on the presence of specialist primary degraders (or ‘keystone species') within the microbial community. We have explored the roles of four dominant amylolytic bacteria found in the human colon in the degradation and utilization of resistant starches. Eubacterium rectale and Bacteroides thetaiotaomicron showed limited ability to utilize RS2- and RS3-resistant starches by comparison with Bifidobacterium adolescentis and Ruminococcus bromii. In co-culture, however, R. bromii proved unique in stimulating RS2 and RS3 utilization by the other three bacterial species, even in a medium that does not permit growth of R. bromii itself. Having previously demonstrated low RS3 fermentation in vivo in two individuals with undetectable populations of R. bromii-related bacteria, we show here that supplementation of mixed fecal bacteria from one of these volunteers with R. bromii, but not with the other three species, greatly enhanced the extent of RS3 fermentation in vitro. This argues strongly that R. bromii has a pivotal role in fermentation of RS3 in the human large intestine, and that variation in the occurrence of this species and its close relatives may be a primary cause of variable energy recovery from this important component of the diet. This work also indicates that R. bromii possesses an exceptional ability to colonize and degrade starch particles when compared with previously studied amylolytic bacteria from the human colon. PMID:22343308

  14. Comparison of bacterial communities on limnic versus coastal marine particles reveals profound differences in colonization.

    PubMed

    Bižić-Ionescu, Mina; Zeder, Michael; Ionescu, Danny; Orlić, Sandi; Fuchs, Bernhard M; Grossart, Hans-Peter; Amann, Rudolf

    2015-10-01

    Marine and limnic particles are hotspots of organic matter mineralization significantly affecting biogeochemical element cycling. Fluorescence in-situ hybridization and pyrosequencing of 16S rRNA genes were combined to investigate bacterial diversity and community composition on limnic and coastal marine particles > 5 and > 10 μm respectively. Limnic particles were more abundant (average: 1 × 10(7) l(-1)), smaller in size (average areas: 471 versus 2050 μm(2)) and more densely colonized (average densities: 7.3 versus 3.6 cells 100 μm(-2)) than marine ones. Limnic particle-associated (PA) bacteria harboured Alphaproteobacteria and Betaproteobacteria, and unlike previously suggested sizeable populations of Gammaproteobacteria, Actinobacteria and Bacteroidetes. Marine particles were colonized by Planctomycetes and Betaproteobacteria additionally to Alphaproteobacteria, Bacteroidetes and Gammaproteobacteria. Large differences in individual particle colonization could be detected. High-throughput sequencing revealed a significant overlap of PA and free-living (FL) bacteria highlighting an underestimated connectivity between both fractions. PA bacteria were in 14/21 cases more diverse than FL bacteria, reflecting a high heterogeneity in the particle microenvironment. We propose that a ratio of Chao 1 indices of PA/FL < 1 indicates the presence of rather homogeneously colonized particles. The identification of different bacterial families enriched on either limnic or marine particles demonstrates that, despite the seemingly similar ecological niches, PA communities of both environments differ substantially. PMID:24674021

  15. Quorum sensing in plant-pathogenic bacteria.

    PubMed

    Von Bodman, Susanne B; Bauer, W Dietz; Coplin, David L

    2003-01-01

    Quorum sensing (QS) allows bacteria to assess their local population density and/or physical confinement via the secretion and detection of small, diffusible signal molecules. This review describes how phytopathogenic bacteria have incorporated QS mechanisms into complex regulatory cascades that control genes for pathogenicity and colonization of host surfaces. Traits regulated by QS include the production of extracellular polysaccharides, degradative enzymes, antibiotics, siderophores, and pigments, as well as Hrp protein secretion, Ti plasmid transfer, motility, biofilm formation, and epiphytic fitness. Since QS regulatory systems are often required for pathogenesis, interference with QS signaling may offer a means of controlling bacterial diseases of plants. Several bacterial pathogens of plants that have been intensively studied and have revealed information of both fundamental and practical importance are reviewed here: Agrobacterium tumefaciens, Pantoea stewartii, Erwinia carotovora, Ralstonia solanacearum, Pseudomonas syringae, Pseudomonas aeruginosa, and Xanthomonas campestris. PMID:12730390

  16. Maternal influences on fetal microbial colonization and immune development

    PubMed Central

    Romano-Keeler, Joann; Weitkamp, Jörn-Hendrik

    2014-01-01

    While critical for normal development, the exact timing of establishment of the intestinal microbiome is unknown. For example, although preterm labor and birth have been associated with bacterial colonization of the amniotic cavity and fetal membranes for many years, the prevailing dogma of a sterile intrauterine environment during normal term pregnancies has been challenged more recently. While found to be a key contributor of evolution in the animal kingdom, maternal transmission of commensal bacteria may also constitute a critical process during healthy pregnancies in humans with yet unclear developmental importance. Metagenomic sequencing has elucidated a rich placental microbiome in normal term pregnancies likely providing important metabolic and immune contributions to the growing fetus. Conversely, an altered microbial composition during pregnancy may produce aberrant metabolites impairing fetal brain development and life-long neurological outcomes. Here we review the current understanding of microbial colonization at the feto-maternal interface and explain how normal gut colonization drives a balanced neonatal mucosal immune system, while dysbiosis contributes to aberrant immune function early in life and beyond. We discuss how maternal genetics, diet, medications, and probiotics inform the fetal microbiome in preparation for perinatal and postnatal bacterial colonization. PMID:25310759

  17. The role of the colonic flora in maintaining a healthy large bowel mucosa.

    PubMed

    Chapman, M A

    2001-03-01

    This work explores the intricate relationships between bacterial products of fermentation, the short chain fatty acids and the effect that these have on the colonic epithelium and the immune system. It confirms that butyrate is a major energy source for the colonic epithelium and there may be a minor epithelial abnormality in the metabolism of butyrate in patients with ulcerative colitis. Immunological studies suggest that butyrate has an effect on lymphocyte activation and inhibits cell proliferation. Possibly, butyrate induces anergy in lymphocytes via an effect on the TCR receptor. This may represent a mechanism whereby colonic bacteria are able to regulate the host immune response. An abnormal response to butyrate may upset the homeostasis between the gut immune system and the colonising bacteria resulting in epithelial unrest and inflammation. PMID:11320933

  18. Colon polyps and cancer.

    PubMed

    Kronborg, O

    2004-01-01

    Screening for colorectal neoplasia still is the best method of reducing the mortality due to colorectal cancer, and it is to be hoped that fecal occult blood test programs will expand in the near future and be combined with appropriate endoscopy. There are substantial problems with compliance in large programs with occult blood tests as well as endoscopy. Colonography and DNA testing in feces are not yet suitable for population screening. Diagnostic strategies in symptomatic patients are becoming more selective, in the hope of avoiding many superfluous examinations without increasing the risk of missing cancers. New results have confirmed the preventive effect of long-term aspirin use on adenoma recurrence, but the most cost-effective dosage is not clear; the mechanism of action is also uncertain, but seems to involve cyclooxygenase-2. The risk of adenomas does not appear to be associated with low consumption of folate, but with low intake of fiber. A number of biomarkers have been evaluated in polyp patients, but so far surveillance is still based on endoscopic experience, which is less than optimal. Attempts have been made to restrict the number of surveillance endoscopies and reduce the pathologist's workload. The place of argon plasma coagulation has been clearly defined in connection with piecemeal removal of large sessile adenomas. Advances have been achieved in surgery and radiotherapy for rectal cancer, and acute surgery for colonic cancer with severe obstruction will be less common after the introduction of the metal stent. PMID:14722849

  19. Effect of encapsulated Lactobacillus casei 01 along with pressurized-purple-rice drinks on colonizing the colon in the digestive model.

    PubMed

    Worametrachanon, Srivilai; Apichartsrangkoon, Arunee; Chaikham, Pittaya; Van den Abbeele, Pieter; Van de Wiele, Tom; Wirjantoro, Tri Indrarini

    2014-06-01

    The objective of the study was to examine the influence of encapsulated Lactobacillus casei 01 combining with two types of pressurized-purple-rice drinks on colonizing the colon using a simulator of the human intestinal microbial ecosystem. Subsequently, the metabolic products of colon bacteria and various microflora were determined. The finding revealed that acetate which was the predominant short-chain fatty acid (SCFA) was found in both proximal and distal colons, while the combination of encapsulated L. casei 01 and germinated-purple-rice drinks gave rise to highest formation of SCFA. Significant impact of rice drinks could be observed on reducing ammonia production. The quantitative polymerase chain reaction analysis demonstrated that encapsulated L. casei 01 and encapsulated L. casei 01 plus rice drinks markedly increased concentration of colon lactobacilli and bifidobacteria by 2 and 1 log 16S rRNA gene copies/mL, respectively. On the contrary, undesirable bacteria such as clostridia and coliforms were significantly reduced with the influence of encapsulated L. casei 01 plus purple-rice drinks. PMID:24615387

  20. Characterization of pig colonic mucins.

    PubMed Central

    Fogg, F J; Hutton, D A; Jumel, K; Pearson, J P; Harding, S E; Allen, A

    1996-01-01

    Pig colonic mucins isolated from the adherent mucus gel in the presence of proteinase inhibitors were solubilized by homogenization and the component mucins fractionated by CsC1 density-gradient centrifugation. Polymeric and reduced pig colonic mucin were both largely excluded on Sepharose CL-2B, papain-digested colonic mucin was included. The M(r) values of polymeric, reduced and digested mucins were 5.5 x 10(6), 2.1 x 10(6) and 0.6 x 10(6) respectively. This suggests that pig colonic mucin is comprised of 2-3 subunits, each subunit containing 3-4 glycosylated regions. The intrinsic viscosities of polymeric, reduced and digested mucin were 240 ml.g-1, 100 ml.g-1 and 20 ml.g-1 respectively. Polymeric pig colonic mucin comprised 16% protein per mg of glycoprotein and was rich in serine, threonine and proline (43% of total amino acids). There were approx. 150 disulphide bridges and 53 free thiol groups per mucin polymer. A seventh of the protein content was lost on reduction. This protein was particularly rich in proline and the hydrophobic amino acids. Papain-digested pig colonic mucin contained 11% protein per mg of glycoprotein and was rich in serine, threonine, glutamate and aspartate. All types of amino acids with the exception of aspartate were lost on digestion. The amino acid analysis of the proteolytically digested regions of pig colonic mucin are markedly different to the tandem repeat regions of the human mucin genes shown to be expressed in the colon. PMID:8670173

  1. Who's on First? Part II: Bacterial and fungal colonization of fresh soil minerals

    NASA Astrophysics Data System (ADS)

    Whitman, T.; Neurath, R.; Zhang, P.; Yuan, T.; Weber, P. K.; Zhou, J.; Pett-Ridge, J.; Firestone, M. K.

    2015-12-01

    Soil organic matter (SOM) stabilization by soil minerals is an important mechanism influencing soil C cycling. Microbes make up only a few percent of total SOM, but have a disproportionate impact on SOM cycling. Their direct interactions with soil minerals, however, are not well characterized. We studied colonization of fresh minerals by soil microbes in an Avena barbata (wild oat) California grassland soil microcosm. Examining quartz, ferrihydrite, kaolinite, and the heavy fraction of the native soil, we asked: (1) Do different minerals select for different communities, or do random processes drive the colonization of fresh minerals? (2) What factors influence which taxa colonize fresh minerals? After incubating mesh bags (<18 μm) of minerals buried next to actively growing plant roots for 2 months, we used high-throughput sequencing of 16S and ITS2 genes to characterize the microbial communities colonizing the minerals. We found significant differences between the microbial community composition of different minerals and soil for both bacteria and fungi. We found a higher relative abundance of arbuscular mycorrhial fungi with ferrihydrite and quartz, and nanoscale secondary ion mass spectrometry (NanoSIMS) imaging of these minerals suggests that some fungal hyphae are moving C directly from roots to mineral surfaces. The enriched presence of both nematode-associated fungi (Pochonia sp.) and bacteria (Candidatus Xiphinematobacter) in the minerals suggests that these minerals may be a habitat for nematodes. Bacteria of the family Chitinophagaceae and genus Janthinobacterium were significantly enriched on both ferrihydrite and quartz minerals, both of which may interact with colonizing fungi. These findings suggest that: (1) Microbial colonization of fresh minerals is not a fully passive or neutral process. (2) Mineral exploration by plant-associated fungi and soil fauna transport may be factors in determining the initial colonization of minerals and subsequent C

  2. Inhibition of bacterial surface colonization by immobilized silver nanoparticles depends critically on the planktonic bacterial concentration.

    PubMed

    Wirth, Stacy M; Bertuccio, Alex J; Cao, Feng; Lowry, Gregory V; Tilton, Robert D

    2016-04-01

    Immobilization of antimicrobial silver nanoparticles (AgNPs) on surfaces has been proposed as a method to inhibit biofouling or as a possible route by which incidental releases of AgNPs may interfere with biofilms in the natural environment or in wastewater treatment. This study addresses the ability of planktonic Pseudomonas fluorescens bacteria to colonize surfaces with pre-adsorbed AgNPs. The ability of the AgNP-coated surfaces to inhibit colonization was controlled by the dissolved silver in the system, with a strong dependence on the initial planktonic cell concentration in the suspension, i.e., a strong inoculum effect. This dependence was attributed to a decrease in dissolved silver ion bioavailability and toxicity caused by its binding to cells and/or cell byproducts. Therefore, when the initial cell concentration was high (∼1×10(7)CFU/mL), an excess of silver binding capacity removed most of the free silver and allowed both planktonic growth and surface colonization directly on the AgNP-coated surface. When the initial cell concentration was low (∼1×10(5)CFU/mL), 100% killing of the planktonic cell inoculum occurred and prevented colonization. When an intermediate initial inoculum concentration (∼1×10(6)CFU/mL) was sufficiently large to prevent 100% killing of planktonic cells, even with 99.97% initial killing, the planktonic population recovered and bacteria colonized the AgNP-coated surface. In some conditions, colonization of AgNP-coated surfaces was enhanced relative to silver-free controls, and the bacteria demonstrated a preferential attachment to AgNP-coated, rather than bare, surface regions. The degree to which the bacterial concentration dictates whether or not surface-immobilized AgNPs can inhibit colonization has significant implications both for the design of antimicrobial surfaces and for the potential environmental impacts of AgNPs. PMID:26771749

  3. Staphylococcus aureus skin colonization is promoted by barrier disruption and leads to local inflammation.

    PubMed

    Wanke, Ines; Skabytska, Yuliya; Kraft, Beatrice; Peschel, Andreas; Biedermann, Tilo; Schittek, Birgit

    2013-02-01

    Experimental mouse models of bacterial skin infections that have been described show that pathogenic microorganisms can readily invade the epidermis and dermis to produce localized infections. We used an epicutaneous mouse skin infection model to determine how the level of barrier disruption by tape-stripping correlates with persistence of Staphylococcus aureus skin colonization, concomitant induction of cutaneous inflammation and infection. Furthermore, we investigated how murine skin responds to S. aureus colonization in a physiologic setting by analysing proinflammatory cytokines and antimicrobial peptides in mouse skin. We show that previous cutaneous damage allows skin inflammation to develop and favours S. aureus persistence leading to cutaneous colonization, suggesting an interdependence of cutaneous bacteria and skin. Our study suggests that skin barrier defects favour S. aureus skin colonization, which is associated with profound cutaneous inflammation. PMID:23362876

  4. NSAID enteropathy and bacteria: a complicated relationship.

    PubMed

    Syer, Stephanie D; Blackler, Rory W; Martin, Rebeca; de Palma, Giada; Rossi, Laura; Verdu, Elena; Bercik, Premek; Surette, Michael G; Aucouturier, Anne; Langella, Philippe; Wallace, John L

    2015-04-01

    The clinical significance of small intestinal damage caused by nonsteroidal anti-inflammatory drugs (NSAIDs) remains under-appreciated. It occurs with greater frequency than the damage caused by these drugs in the upper gastrointestinal tract, but is much more difficult to diagnose and treat. Although the pathogenesis of NSAID enteropathy remains incompletely understood, it is clear that bacteria, bile, and the enterohepatic circulation of NSAIDs are all important factors. However, they are also interrelated with one another. Bacterial enzymes can affect the cytotoxicity of bile and are essential for enterohepatic circulation of NSAIDs. Gram-negative bacteria appear to be particularly important in the pathogenesis of NSAID enteropathy, possibly through release of endotoxin. Inhibitors of gastric acid secretion significantly aggravate NSAID enteropathy, and this effect is due to significant changes in the intestinal microbiome. Treatment with antibiotics can, in some circumstances, reduce the severity of NSAID enteropathy, but published results are inconsistent. Specific antibiotic-induced changes in the microbiota have not been causally linked to prevention of intestinal damage. Treatment with probiotics, particularly Bifidobacterium, Lactobacillus, and Faecalibacteriaum prausnitzii, has shown promising effects in animal models. Our studies suggest that these beneficial effects are due to colonization by the bacteria, rather than to products released by the bacteria. PMID:25572030

  5. Shift from widespread symbiont infection of host tissues to specific colonization of gills in juvenile deep-sea mussels.

    PubMed

    Wentrup, Cecilia; Wendeberg, Annelie; Huang, Julie Y; Borowski, Christian; Dubilier, Nicole

    2013-06-01

    The deep-sea mussel Bathymodiolus harbors chemosynthetic bacteria in its gills that provide it with nutrition. Symbiont colonization is assumed to occur in early life stages by uptake from the environment, but little is known about this process. In this study, we used fluorescence in situ hybridization to examine symbiont distribution and the specificity of the infection process in juvenile B. azoricus and B. puteoserpentis (4-21 mm). In the smallest juveniles, we observed symbionts, but no other bacteria, in a wide range of epithelial tissues. This suggests that despite the widespread distribution of symbionts in many different juvenile organs, the infection process is highly specific and limited to the symbiotic bacteria. Juveniles ≥ 9 mm only had symbionts in their gills, indicating an ontogenetic shift in symbiont colonization from indiscriminate infection of almost all epithelia in early life stages to spatially restricted colonization of gills in later developmental stages. PMID:23389105

  6. Emerging roles of immunostimulatory oral bacteria in periodontitis development

    PubMed Central

    Jiao, Yizu; Hasegawa, Mizuho; Inohara, Naohiro

    2014-01-01

    Periodontitis is a common dental disease which results in irreversible alveolar bone loss around teeth, and subsequent tooth loss. Previous studies have focused on bacteria that damage the host and the roles of commensals to facilitate their colonization. Although some immune responses targeting oral bacteria protect the host from alveolar bone loss, recent studies show that particular host defense responses to oral bacteria can induce alveolar bone loss. Host damaging and immunostimulatory oral bacteria cooperatively induce bone loss by inducing gingival damage followed by immunostimulation. In mouse models of experimental periodontitis induced by either Porphyromonas gingivalis or ligature, γ-proteobacteria accumulate and stimulate host immune responses to induce host damage. Here we review the differential roles of individual bacterial groups in promoting bone loss through the induction of host damage and immunostimulation. PMID:24433922

  7. Impacts of gut bacteria on human health and diseases.

    PubMed

    Zhang, Yu-Jie; Li, Sha; Gan, Ren-You; Zhou, Tong; Xu, Dong-Ping; Li, Hua-Bin

    2015-01-01

    Gut bacteria are an important component of the microbiota ecosystem in the human gut, which is colonized by 1014 microbes, ten times more than the human cells. Gut bacteria play an important role in human health, such as supplying essential nutrients, synthesizing vitamin K, aiding in the digestion of cellulose, and promoting angiogenesis and enteric nerve function. However, they can also be potentially harmful due to the change of their composition when the gut ecosystem undergoes abnormal changes in the light of the use of antibiotics, illness, stress, aging, bad dietary habits, and lifestyle. Dysbiosis of the gut bacteria communities can cause many chronic diseases, such as inflammatory bowel disease, obesity, cancer, and autism. This review summarizes and discusses the roles and potential mechanisms of gut bacteria in human health and diseases. PMID:25849657

  8. Impacts of Gut Bacteria on Human Health and Diseases

    PubMed Central

    Zhang, Yu-Jie; Li, Sha; Gan, Ren-You; Zhou, Tong; Xu, Dong-Ping; Li, Hua-Bin

    2015-01-01

    Gut bacteria are an important component of the microbiota ecosystem in the human gut, which is colonized by 1014 microbes, ten times more than the human cells. Gut bacteria play an important role in human health, such as supplying essential nutrients, synthesizing vitamin K, aiding in the digestion of cellulose, and promoting angiogenesis and enteric nerve function. However, they can also be potentially harmful due to the change of their composition when the gut ecosystem undergoes abnormal changes in the light of the use of antibiotics, illness, stress, aging, bad dietary habits, and lifestyle. Dysbiosis of the gut bacteria communities can cause many chronic diseases, such as inflammatory bowel disease, obesity, cancer, and autism. This review summarizes and discusses the roles and potential mechanisms of gut bacteria in human health and diseases. PMID:25849657

  9. Insects as alternative hosts for phytopathogenic bacteria.

    PubMed

    Nadarasah, Geetanchaly; Stavrinides, John

    2011-05-01

    Phytopathogens have evolved specialized pathogenicity determinants that enable them to colonize their specific plant hosts and cause disease, but their intimate associations with plants also predispose them to frequent encounters with herbivorous insects, providing these phytopathogens with ample opportunity to colonize and eventually evolve alternative associations with insects. Decades of research have revealed that these associations have resulted in the formation of bacterial-vector relationships, in which the insect mediates dissemination of the plant pathogen. Emerging research, however, has highlighted the ability of plant pathogenic bacteria to use insects as alternative hosts, exploiting them as they would their primary plant host. The identification of specific bacterial genetic determinants that mediate the interaction between bacterium and insect suggests that these interactions are not incidental, but have likely arisen following the repeated association of microorganisms with particular insects over evolutionary time. This review will address the biology and ecology of phytopathogenic bacteria that interact with insects, including the traditional role of insects as vectors, as well as the newly emerging paradigm of insects serving as alternative primary hosts. Also discussed is one case where an insect serves as both host and vector, which may represent a transitionary stage in the evolution of insect-phytopathogen associations. PMID:21251027

  10. Spatiotemporal colonization of Xyllela fastidiosa in its vector supports two types of egestion in the inoculation mechanism of foregut-borne plant pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The bacterial agent that causes Pierce’s disease of grapevine, Xylella fastidiosa, is the only known arthropod-transmitted prokaryotic plant pathogen that does not circulate in the vector’s hemolymph. Instead, bacteria are foregut-borne and semi-persistent, i.e. bacteria colonize cuticular surface...