COLONIZATION OF THE MOUSE INTESTINE WITH ESCHERICHIA COLI

Young albino Swiss mice, of the NCS and NCS-D colonies, proved highly susceptible to the establishment of intestinal infection with an enteropathogenic strain of E. coli administered per os or by stomach tube. The period of highest susceptibility was rather short, extending from the day of birth to approximately 2 weeks of age. Adult NCS and NCS-D mice failed to become experimentally colonized with E. coli, even when large doses were administered per os on 3 consecutive days. The extent of colonization of the various parts of the gastrointestinal tract was related to the size of the infective dose. Many of the young mice died within 2 to 3 days following per os infection with large doses of enteropathogenic E. coli. However, practically all the animals which survived cleared their intestinal infection at approximately the same age. For example, in mice infected with 23 x 106 bacteria, colonization of the intestinal tract usually came to an abrupt end when the animals were 24 to 28 days old, irrespective of the age at which they had been infected. There is suggestive evidence that the acquisition of resistance with age, and the ability of adult animals to control the intestinal infection, are related to the development in the gastrointestinal tract of a microbiota which is antagonistic to E. coli.

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Effect of Escherichia Coli Infection on Metabolism of Dietary Protein in Intestine

Current Protein and Peptide Science ◽

10.2174/1389203720666191113144049 ◽

2020 ◽

Vol 21 (8) ◽

pp. 772-776

Author(s):

Xiao-Pei Peng ◽

Wei Ding ◽

Jian-Min Ma ◽

Jie Zhang ◽

Jian Sun ◽

...

Keyword(s):

Escherichia Coli ◽

Intestinal Tract ◽

Effector Proteins ◽

Physical Injury ◽

Dietary Proteins ◽

Pathogenic Role ◽

E Coli ◽

Low Protein ◽

Pathogenic Escherichia Coli ◽

Escherichia Coli Infection

Dietary proteins are linked to the pathogenic Escherichia coli (E. coli) through the intestinal tract, which is the site where both dietary proteins are metabolized and pathogenic E. coli strains play a pathogenic role. Dietary proteins are degraded by enzymes in the intestine lumen and their metabolites are transferred into enterocytes to be further metabolized. Seven diarrheagenic E. coli pathotypes have been identified, and they damage the intestinal epithelium through physical injury and effector proteins, which lead to inhibit the digestibility and absorption of dietary proteins in the intestine tract. But the increased tryptophan (Trp) content in the feed, low-protein diet or milk fractions supplementation is effective in preventing and controlling infections by pathogenic E. coli in the intestine.

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Inhibition of Escherichia coli Translocation from the Gastrointestinal Tract by Normal Cecal Flora in Gnotobiotic or Antibiotic-Decontaminated Mice

Infection and Immunity ◽

10.1128/iai.29.3.1073-1081.1980 ◽

1980 ◽

Vol 29 (3) ◽

pp. 1073-1081

Author(s):

Rodney D. Berg

Keyword(s):

Escherichia Coli ◽

Gastrointestinal Tract ◽

Lymph Nodes ◽

Bacterial Flora ◽

Specific Pathogen Free ◽

Mesenteric Lymph Nodes ◽

E Coli ◽

Mesenteric Lymph ◽

Specific Pathogen ◽

Gnotobiotic Mice

Escherichia coli C25 maintained population levels of 10 9 to 10 10 per g of cecum and translocated to 100% of the middle mesenteric lymph nodes in gnotobiotic mice monoassociated with E. coli C25. Intragastric inoculation of these mice with the cecal contents from specific-pathogen-free mice reduced the population levels of E. coli C25 to 10 6 per g of cecum and completely inhibited translocation to the mesenteric lymph nodes. Intragastric inoculation with heat-treated, Formalintreated, or filtered cecal contents did not reduce the population levels of E. coli C25 or reduce the incidence of translocation of E. coli C25 to the mesenteric lymph nodes. Thus, viable bacteria apparently are required in the cecal contents inocula to reduce the population levels and the incidence of translocation of E. coli C25. Treatment with streptomycin plus bacitracin decreased the anaerobic bacterial levels in these gnotobiotic mice, allowing increased population levels of E. coli C25 and increased translocation to the mesenteric lymph nodes. E. coli C25 also translocated to the mesenteric lymph nodes of specific-pathogen-free mice treated with streptomycin and bacitracin before colonization with E. coli C25. The high cecal population levels of E. coli C25 in these antibiotic-decontaminated specific-pathogen-free mice apparently overwhelm any barrier to translocation exerted by the immunologically developed lamina propria of the specific-pathogen-free mice. Inoculation of gnotobiotic mice with a cecal flora also reduced the population levels of an indigenous strain of E. coli with a concomitant inhibition of translocation of the indigenous E. coli to the mesenteric lymph nodes. Thus, bacterial antagonism of the gastrointestinal population levels of certain indigenous bacteria, such as E. coli , by other members of the normal bacterial flora appears to be an important defense mechanism confining bacteria to the gastrointestinal tract.

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Ability ofEscherichia coliO157:H7 isolates to colonize the intestinal tract of conventional adult CD1 mice is transient

Canadian Journal of Microbiology ◽

10.1139/w00-124 ◽

2001 ◽

Vol 47 (1) ◽

pp. 91-95 ◽

Cited By ~ 6

Author(s):

J Wayne Conlan ◽

Sonia L Bardy ◽

Rhonda KuoLee ◽

Ann Webb ◽

Malcolm B Perry

Keyword(s):

Escherichia Coli ◽

Mouse Model ◽

Intestinal Tract ◽

Vaccine Development ◽

Escherichia Coli O157 ◽

Intestinal Colonization ◽

E Coli ◽

Cd1 Mice ◽

A Current

In an attempt to improve upon a current mouse model of intestinal colonization by Escherichia coli O157:H7 used in this laboratory for vaccine development, nine clinical isolates of the pathogen were screened for their ability to persist in the intestinal tract of conventional adult CD-1 mice. None of the test isolates of E. coli O157:H7 were capable of colonizing these mice for a period of more than two weeks. Most of the isolates appeared to be benign for the experimental host, but one isolate was lethal. This virulence correlated with the ability of the latter isolate to produce large quantities of Shiga-like toxin 2 in vitro.

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Identification and Probiotic Potency Screening of Cellulolytic Bacilli Isolated from Fecal Pellets and Gastrointestinal Tract of Nypha Worm (Namalycastis rhodochorde), West Kalimantan, Indonesia

Jurnal Biologi Indonesia ◽

10.47349/jbi/17022021/189 ◽

2021 ◽

Vol 17 (2) ◽

pp. 189-195

Author(s):

TR Setyawati ◽

AH Yanti ◽

R. Kurniatuhadi

Keyword(s):

Escherichia Coli ◽

Gastrointestinal Tract ◽

Organic Acids ◽

Acid Tolerance ◽

Distilled Water ◽

Bacterial Identification ◽

Bacterial Isolates ◽

Fecal Pellets ◽

West Kalimantan ◽

E Coli

The bacterial isolates NrLtF1, NrLtF4, NrLtF5, and NrLtG2 isolated from fecal pellets and gastrointestinal tract of nypha worms (Namalycastis rhodochorde) have cellulolytic, proteolytic activity and produce organic acids. The four isolates have the potency to be developed as probiotics in nypha worm cultivation feed. This study aims to determine the probiotics potency and identify the species of NrLtF1, NrLtF4, NrLtF5, and NrLtG2 isolate based on 16srDNA sequence. The probiotic potency was carried out by the acid tolerance assays on distilled water and 0.3% acid bile media, and the antimicrobial testing against Escherichia coli (MF exp21.12). Bacterial identification was carried out by sequencing of 16sDNA sequence based on GeneBank data. The results showed that the bacterial isolates of NrLtF1, NrLtF4, NrLtF5, and NrLtG2 were able to grow on 0.3% distilled water and acid bile media. However, only the NrLtF4 and NrLtF5 inhibited E. coli (MF exp21.12) with halo zones 30 mm and 18 mm, respectively. Blasting results of the 16srDNA sequences showed that the NrLtF1, NrLtF4, NrLtF5, and NrLtG2 were closely related to Bacillus wiedmannii, Brevibacterium sediminis, Bacillus proteolyticus, and Bacillus paramycoides. The nypha worm bacterial isolates have the potency to be developed as probiotics in nypha worm culture.

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Molecular Characterization of Commensal Escherichia coli Adapted to Different Compartments of the Porcine Gastrointestinal Tract

Applied and Environmental Microbiology ◽

10.1128/aem.01688-12 ◽

2012 ◽

Vol 78 (19) ◽

pp. 6799-6803 ◽

Cited By ~ 12

Author(s):

Sam Abraham ◽

David M. Gordon ◽

James Chin ◽

Huub J. M. Brouwers ◽

Peter Njuguna ◽

...

Keyword(s):

Escherichia Coli ◽

Gastrointestinal Tract ◽

Random Amplified Polymorphic Dna ◽

Content Type ◽

E Coli ◽

Plasmid Replicon ◽

Different Strains ◽

Different Characteristics

ABSTRACTThe role ofEscherichia colias a pathogen has been the focus of considerable study, while much less is known about it as a commensal and how it adapts to and colonizes different environmental niches within the mammalian gut. In this study, we characterizeEscherichia coliorganisms (n= 146) isolated from different regions of the intestinal tracts of eight pigs (dueodenum, ileum, colon, and feces). The isolates were typed using the method of random amplified polymorphic DNA (RAPD) and screened for the presence of bacteriocin genes and plasmid replicon types. Molecular analysis of variance using the RAPD data showed thatE. coliisolates are nonrandomly distributed among different gut regions, and that gut region accounted for 25% (P< 0.001) of the observed variation among strains. Bacteriocin screening revealed that a bacteriocin gene was detected in 45% of the isolates, with 43% carrying colicin genes and 3% carrying microcin genes. Of the bacteriocins observed (H47, E3, E1, E2, E7, Ia/Ib, and B/M), the frequency with which they were detected varied with respect to gut region for the colicins E2, E7, Ia/Ib, and B/M. The plasmid replicon typing gave rise to 25 profiles from the 13 Inc types detected. Inc F types were detected most frequently, followed by Inc HI1 and N types. Of the Inc types detected, 7 were nonrandomly distributed among isolates from the different regions of the gut. The results of this study indicate that not only may the different regions of the gastrointestinal tract harbor different strains ofE. colibut also that strains from different regions have different characteristics.

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Magnesium Sensing Regulates Intestinal Colonization of Enterohemorrhagic Escherichia coli O157:H7

mBio ◽

10.1128/mbio.02470-20 ◽

2020 ◽

Vol 11 (6) ◽

Author(s):

Yutao Liu ◽

Runhua Han ◽

Junyue Wang ◽

Pan Yang ◽

Fang Wang ◽

...

Keyword(s):

Escherichia Coli ◽

Large Intestine ◽

Intestinal Tract ◽

Regulatory System ◽

Regulatory Pathway ◽

Content Type ◽

E Coli ◽

Low Magnesium ◽

Enterocyte Effacement

ABSTRACT The large intestinal pathogen enterohemorrhagic Escherichia coli (EHEC) O157:H7 detects host cues to regulate virulence gene expression during colonization and infection. However, virulence regulatory mechanisms of EHEC O157:H7 in the human large intestine are not fully understood. Herein, we identified a virulence-regulating pathway where the PhoQ/PhoP two-component regulatory system senses low magnesium levels and signals to the O island 119-encoded Z4267 (LmiA; low magnesium-induced regulator A), directly activating loci of enterocyte effacement genes to promote EHEC O157:H7 adherence in the large intestine. Disruption of this pathway significantly decreased EHEC O157:H7 adherence in the mouse intestinal tract. Moreover, feeding mice a magnesium-rich diet significantly reduced EHEC O157:H7 adherence in vivo. This LmiA-mediated virulence regulatory pathway is also conserved among several EHEC and enteropathogenic E. coli serotypes; therefore, our findings support the use of magnesium as a dietary supplement and provide greater insights into the dietary cues that can prevent enteric infections. IMPORTANCE Sensing specific gut metabolites is an important strategy for inducing crucial virulence programs by enterohemorrhagic Escherichia coli (EHEC) O157:H7 during colonization and infection. Here, we identified a virulence-regulating pathway wherein the PhoQ/PhoP two-component regulatory system signals to the O island 119-encoded low magnesium-induced regulator A (LmiA), which, in turn, activates locus of enterocyte effacement (LEE) genes to promote EHEC O157:H7 adherence in the low-magnesium conditions of the large intestine. This regulatory pathway is widely present in a range of EHEC and enteropathogenic E. coli (EPEC) serotypes. Disruption of this pathway significantly decreased EHEC O157:H7 adherence in the mouse intestinal tract. Moreover, mice fed a magnesium-rich diet showed significantly reduced EHEC O157:H7 adherence in vivo, indicating that magnesium may help in preventing EHEC and EPEC infection in humans.

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Strain Typing and the Ecological Structure of Escherichia coli

Journal of AOAC International ◽

10.1093/jaoac/93.3.974 ◽

2010 ◽

Vol 93 (3) ◽

pp. 974-984 ◽

Cited By ~ 12

Author(s):

David M Gordon

Keyword(s):

Escherichia Coli ◽

Intestinal Tract ◽

Domestic Animals ◽

Seasonal Patterns ◽

Strain Typing ◽

E Coli ◽

Hospital Acquired Infections ◽

Typing Methods ◽

The Many ◽

Hospital Acquired

Abstract Escherichia coli is a commonly encountered commensal of the lower intestinal tract of humans and other mammals. Strains of the species are responsible for a significant amount of human morbidity and mortality each year. Consequently, numerous efforts attempt to track the movement of hospital-acquired infections, determine the source of a foodborne disease outbreak, or investigate the seasonal patterns of pathogen abundance in domestic animals. All of these endeavors require that the isolates acquired be differentiated from each other in some manner. This review briefly describes some of the commonly used molecular typing methods for E. coli. However, the main aim of the review is to describe the many levels, from the species to individual strains, at which E. coli can be considered, and to contend that a hierarchical approach to strain typing may often reveal patterns that are not obvious when a typing scheme is simply designed to differentiate isolates.

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Role of Motility and the flhDC Operon in Escherichia coli MG1655 Colonization of the Mouse Intestine

Infection and Immunity ◽

10.1128/iai.00052-07 ◽

2007 ◽

Vol 75 (7) ◽

pp. 3315-3324 ◽

Cited By ~ 47

Author(s):

Eric J. Gauger ◽

Mary P. Leatham ◽

Regino Mercado-Lubo ◽

David C. Laux ◽

Tyrrell Conway ◽

...

Keyword(s):

Escherichia Coli ◽

Regulatory Region ◽

Flagellar Motor ◽

Wild Type ◽

E Coli ◽

Mouse Intestine ◽

Flagellum Biosynthesis ◽

Colonizing Ability

ABSTRACT Previously, we reported that the mouse intestine selected mutants of Escherichia coli MG1655 that have improved colonizing ability (M. P. Leatham et al., Infect. Immun. 73:8039-8049, 2005). These mutants grew 10 to 20% faster than their parent in mouse cecal mucus in vitro and 15 to 30% faster on several sugars found in the mouse intestine. The mutants were nonmotile and had deletions of various lengths beginning immediately downstream of an IS1 element located within the regulatory region of the flhDC operon, which encodes the master regulator of flagellum biosynthesis, FlhD4C2. Here we show that during intestinal colonization by wild-type E. coli strain MG1655, 45 to 50% of the cells became nonmotile by day 3 after feeding of the strain to mice and between 80 and 90% of the cells were nonmotile by day 15 after feeding. Ten nonmotile mutants isolated from mice were sequenced, and all were found to have flhDC deletions of various lengths. Despite this strong selection, 10 to 20% of the E. coli MG1655 cells remained motile over a 15-day period, suggesting that there is an as-yet-undefined intestinal niche in which motility is an advantage. The deletions appear to be selected in the intestine for two reasons. First, genes unrelated to motility that are normally either directly or indirectly repressed by FlhD4C2 but can contribute to maximum colonizing ability are released from repression. Second, energy normally used to synthesize flagella and turn the flagellar motor is redirected to growth.

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Anaerobic Respiration of Escherichia coli in the Mouse Intestine

Infection and Immunity ◽

10.1128/iai.05395-11 ◽

2011 ◽

Vol 79 (10) ◽

pp. 4218-4226 ◽

Cited By ~ 66

Author(s):

Shari A. Jones ◽

Terri Gibson ◽

Rosalie C. Maltby ◽

Fatema Z. Chowdhury ◽

Valley Stewart ◽

...

Keyword(s):

Escherichia Coli ◽

Nitrate Reductase ◽

Electron Flow ◽

Anaerobic Respiration ◽

Fumarate Reductase ◽

Treated Mouse ◽

Content Type ◽

E Coli ◽

Facultative Anaerobes ◽

Mouse Intestine

ABSTRACTThe intestine is inhabited by a large microbial community consisting primarily of anaerobes and, to a lesser extent, facultative anaerobes, such asEscherichia coli, which we have shown requires aerobic respiration to compete successfully in the mouse intestine (S. A. Jones et al., Infect. Immun. 75:4891-4899, 2007). If facultative anaerobes efficiently lower oxygen availability in the intestine, then their sustained growth must also depend on anaerobic metabolism. In support of this idea, mutants lacking nitrate reductase or fumarate reductase have extreme colonization defects. Here, we further explore the role of anaerobic respiration in colonization using the streptomycin-treated mouse model. We found that respiratory electron flow is primarily via the naphthoquinones, which pass electrons to cytochromebdoxidase and the anaerobic terminal reductases. We found thatE. coliuses nitrate and fumarate in the intestine, but not nitrite, dimethyl sulfoxide, or trimethylamineN-oxide. Competitive colonizations revealed that cytochromebdoxidase is more advantageous than nitrate reductase or fumarate reductase. Strains lacking nitrate reductase outcompeted fumarate reductase mutants once the nitrate concentration in cecal mucus reached submillimolar levels, indicating that fumarate is the more important anaerobic electron acceptor in the intestine because nitrate is limiting. Since nitrate is highest in the absence ofE. coli, we conclude thatE. coliis the only bacterium in the streptomycin-treated mouse large intestine that respires nitrate. Lastly, we demonstrated that a mutant lacking the NarXL regulator (activator of the NarG system), but not a mutant lacking the NarP-NarQ regulator, has a colonization defect, consistent with the advantage provided by NarG. The emerging picture is one in which gene regulation is tuned to balance expression of the terminal reductases thatE. coliuses to maximize its competitiveness and achieve the highest possible population in the intestine.

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Parenteral immunization with a glycoconjugate vaccine containing the O157 antigen of Escherichia coli O157:H7 elicits a systemic humoral immune response in mice, but fails to prevent colonization by the pathogen

Canadian Journal of Microbiology ◽

10.1139/w99-008 ◽

1999 ◽

Vol 45 (4) ◽

pp. 279-286

Author(s):

J Wayne Conlan ◽

Andrew D Cox ◽

Rhonda KuoLee ◽

Ann Webb ◽

Malcolm B Perry

Keyword(s):

Escherichia Coli ◽

Intestinal Tract ◽

Horse Serum ◽

Convincing Evidence ◽

Escherichia Coli O157 ◽

Intestinal Colonization ◽

E Coli ◽

Humoral Immune ◽

Parenteral Immunization ◽

Glycoconjugate Vaccine

The results of the present study show that whereas both BALB/c and C57BL/6 mice parenterally inoculated with a horse serum albumin - Escherichia coli O157 antigen conjugate vaccine develop systemic, specific antibodies to the carrier protein, only the former mice routinely develop antibodies to the carbohydrate O157 moiety. However, little convincing evidence was found to show that these antibodies transuded into the intestinal tract either naturally or in response to an oral inoculum of the pathogen. Moreover, this vaccination procedure failed to protect mice against intestinal colonization following oral challenge with the pathogen. Thus, the results of this study suggest that parenteral vaccination might be an unsuitable strategy for combatting E. coli O157:H7 organisms located in the gut.Key words: Escherichia coli, glycoconjugate vaccine, mice.

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