scholarly journals Safety of Probiotic Escherichia coli Strain Nissle 1917 Depends on Intestinal Microbiota and Adaptive Immunity of the Host

2010 ◽  
Vol 78 (7) ◽  
pp. 3036-3046 ◽  
Author(s):  
Kerstin Gronbach ◽  
Ute Eberle ◽  
Martina Müller ◽  
Tobias A. Ölschläger ◽  
Ulrich Dobrindt ◽  
...  
Keyword(s):  
T Cells ◽  
Adaptive Immunity ◽  
Intestinal Microbiota ◽  
Adaptive Immune System ◽  
Coli Strain ◽  
Oral Challenge ◽  
Clinical Effects ◽  
E Coli ◽  
Specific Pathogen ◽  
Future Work

ABSTRACT Probiotics are viable microorganisms that are increasingly used for treatment of a variety of diseases. Occasionally, however, probiotics may have adverse clinical effects, including septicemia. Here we examined the role of the intestinal microbiota and the adaptive immune system in preventing translocation of probiotics (e.g., Escherichia coli Nissle). We challenged C57BL/6J mice raised under germfree conditions (GF-raised C57BL/6J mice) and Rag1 −/− mice raised under germfree conditions (GF-raised Rag1 −/− mice) and under specific-pathogen-free conditions (SPF-raised Rag1 −/− mice) with probiotic E. coli strain Nissle 1917, strain Nissle 1917 mutants, the commensal strain E. coli mpk, or Bacteroides vulgatus mpk. Additionally, we reconstituted Rag1 −/− mice with CD4+ T cells. E. coli translocation and dissemination and the mortality of mice were assessed. In GF-raised Rag1 −/− mice, but not in SPF-raised Rag1 −/− mice or GF-raised C57BL/6J mice, oral challenge with E. coli strain Nissle 1917, but not oral challenge with E. coli mpk, resulted in translocation and dissemination. The mortality rate was significantly higher for E. coli strain Nissle 1917-challenged GF-raised Rag1 −/− mice (100%; P < 0.001) than for E. coli strain Nissle 1917-challenged SPF-raised Rag1 −/ − mice (0%) and GF-raised C57BL/6J mice (0%). Translocation of and mortality due to strain E. coli Nissle 1917 in GF-raised Rag1 −/− mice were prevented when mice were reconstituted with T cells prior to strain E. coli Nissle 1917 challenge, but not when mice were reconstituted with T cells after E. coli strain Nissle 1917 challenge. Cocolonization experiments revealed that E. coli mpk could not prevent translocation of strain E. coli Nissle 1917. Moreover, we demonstrated that neither lipopolysaccharide structure nor flagella play a role in E. coli strain Nissle 1917 translocation and dissemination. Our results suggest that if both the microbiota and adaptive immunity are defective, translocation across the intestinal epithelium and dissemination of the probiotic E. coli strain Nissle 1917 may occur and have potentially severe adverse effects. Future work should define the possibly related molecular factors that promote probiotic functions, fitness, and facultative pathogenicity.

Developing a Model to Study Commensal Translocation during IBD

2018 ◽  
Author(s):  
Kathy Yu
Keyword(s):  
Bacterial Translocation ◽  
Imaging Techniques ◽  
Coli Strain ◽  
The Body ◽  
Conjugation System ◽  
E Coli ◽  
Normal Microbiota ◽  
Bowel Diseases ◽  
Inflammatory Bowel ◽  
Future Work

Inflammatory bowel diseases (IBD) is severe inflammation of the gastrointestinal tract. This can lead to a breakdown of mucosal barriers, causing dissemination of commensal bacteria throughout the body. To better understand bacterial translocation during IBD, aim to develop a fluorescent microbiota in mice that we can interrogate using live imaging techniques.   Our preliminary experiments depleted commensals using broad-spectrum antibiotics,  and replaced these microbiota with a fluorescent E. coli strain. The length of time that E.coli stays in the mice gut were monitored. We show that E. coli can persist in the ‘germ-free’ mouse gut for at least 21 days; control mice lose all added E. coli by 8-14 days. The establishment of the E. coli colony suggests this could be a reasonable model to study bacterial translocation.  We are currently going to treat the colonized mice with DSS to induce colitis, and then to study translocation of E. coli by intravital microscopy. Considering E. coli is only a fraction of the normal microbiota and perhaps not a relevant model, future work aims at making a fluorescent microbiota consisting of multiple endogenous murine microbes. This will entail the use of a bacterial conjugation system  capable of ubiquitously transforming many microbial species.  

scholarly journals Novel ex vivo screening assay to preselect farm specific pre- and probiotics in pigs

2021 ◽  
pp. 1-16
Author(s):  
K. Zeilinger ◽  
J. Hellmich ◽  
J. Zentek ◽  
W. Vahjen
Keyword(s):  
Ex Vivo ◽  
Screening Method ◽  
Coli Strain ◽  
Screening Assay ◽  
Future Studies ◽  
E Coli ◽  
Feed Management ◽  
Specific Pathogen ◽  
On Farm ◽  
Ex Vivo Assay

A novel rapid ex vivo assay was developed as part of a concept to determine potential tailor-made combinations of pre- and probiotics for individual farms. Sow faecal slurries from 20 German pig farms were anaerobically incubated with pre- and probiotics or their combinations together with pathogenic strains that are of interest in pig production. Aliquots of these slurries were then incubated with media containing antibiotic mixtures allowing only growth of the specific pathogen. Growth was monitored and lag time was used to determine the residual fitness of the pathogenic strains. The background growth could be inhibited for an Escherichia coli- and a Clostridium difficile- but not for a Clostridium perfringens strain. The prebiotic fructo-oligosaccharides (FOS) and its combination with probiotics reduced the residual fitness of the E. coli strain in some farms. However, notable exceptions occurred in other farms where FOS increased the fitness of the E. coli strain. Generally, combinations of pre- and probiotics did not show additive effects on fitness for E. coli but displayed farm dependent differences. The effects of pre- and probiotics on the residual fitness of the C. difficile strain were less pronounced, but distinct differences between single application of prebiotics and their combination with probiotics were observed. It was concluded that the initial composition of the microbiota in the samples was more determinative for incubations with the C. difficile strain than for incubations with the E. coli strain, as the presumed fermentation of prebiotic products showed less influence on the fitness of the C. difficile strain. Farm dependent differences were pronounced for both pathogenic strains and therefore, this novel screening method offers a promising approach for pre-selecting pre- and probiotics for individual farms. However, evaluation of farm metadata (husbandry, feed, management) will be crucial in future studies to determine a tailor-made solution for combinations of pre- and probiotics for individual farms. Also, refinement of the ex vivo assay in terms of on-farm processing of samples and validation of unambiguous growth for pathogenic strains from individual farms should be addressed.

3. Adaptive immunity: a voyage of (non-)self-discovery

2017 ◽  
pp. 30-41
Author(s):  
Paul Klenerman
Keyword(s):  
T Cells ◽  
Immune System ◽  
T Lymphocytes ◽  
Adaptive Immunity ◽  
Single Unit ◽  
Adaptive Immune System ◽  
Adaptive Immune ◽  
System A ◽  
Self Discovery ◽  
B And T Lymphocytes

How does the immune system respond to such diverse threats, including viruses never encountered previously by us as a species? The inherent diversity in the immune system can be explained by examining how the adaptive immune system is built, in particular the receptors on B and T lymphocytes. ‘The adaptive immune system: a voyage of (non-)self-discovery’ describes B and T cells, receptors, and the creation of antibodies. Antibody genes are not created as a single unit but are made up from smaller parts, generating many more possible combinations. The antibodies that are created from the genetic template are further honed, becoming highly specific to their target.

scholarly journals Escherichia coli Strain Nissle 1917 Ameliorates Experimental Colitis via Toll-Like Receptor 2- and Toll-Like Receptor 4-Dependent Pathways

2006 ◽  
Vol 74 (7) ◽  
pp. 4075-4082 ◽  
Author(s):  
A. Grabig ◽  
D. Paclik ◽  
C. Guzy ◽  
A. Dankof ◽  
D. C. Baumgart ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
T Cells ◽  
Knockout Mice ◽  
Selective Reduction ◽  
Experimental Colitis ◽  
Defense Responses ◽  
Coli Strain ◽  
Cytokine Secretion ◽  
Toll Like Receptor ◽  
E Coli

ABSTRACT Toll-like receptors (TLRs) are key components of the innate immune system that trigger antimicrobial host defense responses. The aim of the present study was to analyze the effects of probiotic Escherichia coli Nissle strain 1917 in experimental colitis induced in TLR-2 and TLR-4 knockout mice. Colitis was induced in wild-type (wt), TLR-2 knockout, and TLR-4 knockout mice via administration of 5% dextran sodium sulfate (DSS). Mice were treated with either 0.9% NaCl or 107 E. coli Nissle 1917 twice daily, followed by the determination of disease activity, mucosal damage, and cytokine secretion. wt and TLR-2 knockout mice exposed to DSS developed acute colitis, whereas TLR-4 knockout mice developed significantly less inflammation. In wt mice, but not TLR-2 or TLR-4 knockout mice, E. coli Nissle 1917 ameliorated colitis and decreased proinflammatory cytokine secretion. In TLR-2 knockout mice a selective reduction of gamma interferon secretion was observed after E. coli Nissle 1917 treatment. In TLR-4 knockout mice, cytokine secretion was almost undetectable and not modulated by E. coli Nissle 1917, indicating that TLR-4 knockout mice do not develop colitis similar to the wt mice. Coculture of E. coli Nissle 1917 and human T cells increased TLR-2 and TLR-4 protein expression in T cells and increased NF-κB activity via TLR-2 and TLR-4. In conclusion, our data provide evidence that E. coli Nissle 1917 ameliorates experimental induced colitis in mice via TLR-2- and TLR-4-dependent pathways.

scholarly journals IMMUNOMODULATORY EFFECTS OF BLACK CINCAU (MESONA PALUSTRIS BL.) SUPPLEMENT ON ESCHERICHIA COLI STRAIN O157-INFECTED MICE

2017 ◽  
Vol 10 (9) ◽  
pp. 326 ◽  
Author(s):  
Tri Dewanti Widyaningsih ◽  
Erryana Martati ◽  
Diah Mustika Lukitasari
Keyword(s):  
Escherichia Coli ◽  
T Cells ◽  
Cd8 T Cells ◽  
Zingiber Officinale ◽  
Negative Control ◽  
Coli Strain ◽  
Immunomodulatory Effects ◽  
Study Objective ◽  
E Coli ◽  
Red Ginger

  Objective: This study objective was to determine the immunomodulatory effects of the black cincau (Mesona palustris BL.) supplement on Escherichia coli strain O157-infected mice.Methods: Black cincau (Mesona palustris BL.) and red ginger (Zingiber officinale var. rubrum) were extracted on a pilot plant scale. For the animal experiment, the mice were adapted for 7 days with black cincau supplement at a dose of 43.29 mg/kg b.w. (SSP I), a dose of 85.58 mg/kg b.w. (SSP II), a dose of 4.33 mg/kg b.w. of a commercial immunomodulator (SK) and buffer saline for the negative control (KN) and positive control (KP). Then, mice were infected intraperitoneally (intraperitoneally) with E. coli strain O157 1010 cfu/mL, except KN. On day 21, the cell of mouse spleen was analyzed using flow cytometry.Results: Result showed that administration of black cincau supplement up to 85.58 mg/kg b.w gave immunomodulator effects in infected mice. Immunomodulator effect can be seen through the increasing of the relative average of a cluster of differentiation (CD)4+ T cells, CD8+ T cells, CD4+ CD8+ T cells, CD4+ CD62L T cells, CD8+CD62L T cells, and CD68+interferonγ (Interferon gamma) monocytes cells. Exposure of black cincau supplement on infected mice can recover small intestine mucosa structure of mice.Conclusions: This study demonstrates that the supplement of black cincau extract can give an immunomodulatory effect on E. coli-infected mice.

The effect of a probiotic Escherichia coli strain on regulatory T-cells in six year-old children

2016 ◽  
Vol 7 (5) ◽  
pp. 639-648 ◽  
Author(s):  
J. Hrdý ◽  
I. Kocourková ◽  
R. Lodinová-Žádníková ◽  
L. Kolářová ◽  
L. Prokešová
Keyword(s):  
Escherichia Coli ◽  
T Cells ◽  
Regulatory T Cells ◽  
Beneficial Effect ◽  
Immune Function ◽  
Functional Properties ◽  
Peripheral Blood ◽  
Coli Strain ◽  
Healthy Children ◽  
E Coli

Probiotics are believed to prevent or reduce allergy development but the mechanism of their beneficial effect is still poorly understood. Immune characteristics of regulatory T cells (Tregs) in peripheral blood of perinatally probiotic-supplemented children of allergic mothers (51 children), non-supplemented children of allergic mothers (42 children), and non-supplemented children of healthy mothers (28 children) were compared at the age of 6-7 years. A first dose of a probiotic Escherichia coli strain (E. coli O83:K24:H31) was administered within 2 days after the birth and then 12 times during the first months of life and children were followed longitudinally. Proportion and functional properties of Tregs were estimated by flow cytometry in relation to the children’s allergy status. Proportion of Tregs in the peripheral blood of children suffering from allergy tends to be higher whereas median of fluorescence intensity (MFI) of FoxP3 was significantly decreased in allergic group. Intracellular presence of regulatory cytokine interleukin (IL)-10 was also lower in allergic children. Immune functions of Tregs reflected by both MFI of FoxP3 and IL-10 in the group of probiotic-supplemented children of allergic mothers were nearly comparable with children of healthy mothers while probiotic non-supplemented children of allergic mothers have decreased immune function of Tregs. Supplementation by probiotic E. coli strain decreases allergy incidence in high-risk children. In contrast to our expectation, proportion of Tregs has not been increased in probiotic supplemented children. Beneficial effect of probiotics on newborn immature immune system could be, at least partially, explained by the modulating immune function of Tregs. In summary, we detected increased proportion of Tregs in peripheral blood of allergic children, their functional properties were decreased in comparison with the Tregs of healthy children. A unifying hypothesis for these findings is that Treg numbers in allergic children are increased in order to compensate for decreased function.

Transport of escherichia coli through soil to groundwater traced by randomly amplified polymorphic DNA (RAPD)

1997 ◽  
Vol 35 (11-12) ◽  
pp. 351-357 ◽  
Author(s):  
R. Rothmaier ◽  
A. Weidenmann ◽  
K. Botzenhart
Keyword(s):  
Negative Impact ◽  
Random Amplified Polymorphic Dna ◽  
Coli Strain ◽  
Soil Samples ◽  
Test Field ◽  
Liquid Manure ◽  
E Coli ◽  
Rapd Pattern ◽  
Geological Situation ◽  
Different Strains

Isolates (50) of E. coli obtained from liquid manure (20 bovine, 20 porcine) were genotyped using random amplified polymorphic DNA (RAPD). Typing revealed 9 and 14 different strains in bovine and porcine liquid manure respectively with no strains in common. One porcine strain, showing a simple RAPD pattern, was subcultured and spread on a test field (1.5l/m2 at 1010 cfu/l) in a drinking water protection zone with loamy to sandy sediments in the Donauried area, Baden-Wurttemberg. Soil samples and groundwaters were collected at monthly intervals October 1994 – June 1995 during which 114 E. coli isolates were recovered. The first occurrence and maximum concentration of E. coli in soil samples taken from more than 20cm depth was in January 1995, declining rapidly with depth and time. All isolates from soil and only one from groundwater showed the RAPD pattern of the spread E. coli strain. The results could not demonstrate a severe negative impact of the spreading of liquid manure on the bacteriological quality of the groundwater in the given geological situation. The distinct strain patterns found in different kinds of liquid manure suggest that genotyping of E. coli by RAPD may be an adequate tool for tracing sources of faecal contamination.

Production and Preliminary In Vivo Evaluations of a Novel in silico-designed L2-based Potential HPV Vaccine

2020 ◽  
Vol 21 (4) ◽  
pp. 316-324
Author(s):  
Manica Negahdaripour ◽  
Navid Nezafat ◽  
Reza Heidari ◽  
Nasrollah Erfani ◽  
Nasim Hajighahramani ◽  
...  
Keyword(s):  
In Silico ◽  
Group Versus ◽  
Tlr Agonists ◽  
E Coli ◽  
Metal Affinity ◽  
Th1 And Th2 Cytokines ◽  
Ifn Γ ◽  
Humoral Responses ◽  
Future Work

Background: L2-based Human Papillomavirus (HPV) prophylactic vaccines, containing epitopes from HPV minor capsid proteins, are under investigation as second-generation HPV vaccines. No such vaccine has passed clinical trials yet, mainly due to the low immunogenicity of peptide vaccines; so efforts are being continued. A candidate vaccine composed of two HPV16 L2 epitopes, flagellin and a Toll-Like Receptor (TLR) 4 agonist (RS09) as adjuvants, and two universal T-helper epitopes was designed in silico in our previous researches. Methods: The designed vaccine construct was expressed in E. coli BL21 (DE3) and purified through metal affinity chromatography. Following mice vaccination, blood samples underwent ELISA and flow cytometry analyses for the detection of IgG and seven Th1 and Th2 cytokines. Results: Following immunization, Th1 (IFN-γ, IL-2) and Th2 (IL-4, IL-5, IL-10) type cytokines, as well as IgG, were induced significantly compared with the PBS group. Significant increases in IFN-γ, IL-2, and IL-5 levels were observed in the vaccinated group versus Freund’s adjuvant group. Conclusion: The obtained cytokine induction profile implied both cellular and humoral responses, with a more Th-1 favored trend. However, an analysis of specific antibodies against L2 is required to confirm humoral responses. No significant elevation in inflammatory cytokines, (IL-6 and TNF-α), suggested a lack of unwanted inflammatory side effects despite using a combination of two TLR agonists. The designed construct might be capable of inducing adaptive and innate immunity; nevertheless, comprehensive immune tests were not conducted at this stage and will be a matter of future work.

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