scholarly journals Control of Escherichia coli populations by a combination of indigenous clostridia and lactobacilli in gnotobiotic mice and continuous-flow cultures.

1989 ◽  
Vol 57 (2) ◽  
pp. 559-565 ◽  
Author(s):  
K Itoh ◽  
R Freter
Keyword(s):  
Escherichia Coli ◽  
Continuous Flow ◽  
Gnotobiotic Mice

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

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.

scholarly journals Pre- and Neonatal Imprinting on Immunological Homeostasis and Epithelial Barrier Integrity by Escherichia coli Nissle 1917 Prevents Allergic Poly-Sensitization in Mice

2021 ◽  
Vol 11 ◽  
Author(s):  
Priya J. Sarate ◽  
Dagmar Srutkova ◽  
Nora Geissler ◽  
Martin Schwarzer ◽  
Irma Schabussova ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Grass Pollen ◽  
Allergic Airway Inflammation ◽  
Experimental Models ◽  
Lung Epithelial Cells ◽  
Probiotic Bacteria ◽  
Allergy Prevention ◽  
Lactation Period ◽  
Gnotobiotic Mice ◽  
Immunological Homeostasis

A steady rise in the number of poly-sensitized patients has increased the demand for effective prophylactic strategies against multi-sensitivities. Probiotic bacteria have been successfully used in clinics and experimental models to prevent allergic mono-sensitization. In the present study, we have investigated whether probiotic bacteria could prevent poly-sensitization by imprinting on the immune system early in life. We used two recombinant variants of probiotic Escherichia coli Nissle 1917 (EcN): i) EcN expressing birch and grass pollen, poly-allergen chimera construct (EcN-Chim), and ii) an “empty” EcN without allergen expression (EcN-Ctrl). Conventional mice (CV) were treated with either EcN-Chim or EcN-Ctrl in the last week of the gestation and lactation period. Gnotobiotic mice received one oral dose of either EcN-Chim or EcN-Ctrl before mating. The offspring from both models underwent systemic allergic poly-sensitization and intranasal challenge with recombinant birch and grass pollen allergens (rBet v 1, rPhl p 1, and rPhl p 5). In the CV setting, the colonization of offspring via treatment of mothers reduced allergic airway inflammation (AAI) in offspring compared to poly-sensitized controls. Similarly, in a gnotobiotic model, AAI was reduced in EcN-Chim and EcN-Ctrl mono-colonized offspring. However, allergy prevention was more pronounced in the EcN-Ctrl mono-colonized offspring as compared to EcN-Chim. Mono-colonization with EcN-Ctrl was associated with a shift toward mixed Th1/Treg immune responses, increased expression of TLR2 and TLR4 in the lung, and maintained levels of zonulin-1 in lung epithelial cells as compared to GF poly-sensitized and EcN-Chim mono-colonized mice. This study is the first one to establish the model of allergic poly-sensitization in gnotobiotic mice. Using two different settings, gnotobiotic and conventional mice, we demonstrated that an early life intervention with the EcN without expressing an allergen is a powerful strategy to prevent poly-sensitization later in life.

scholarly journals The commensal Escherichia coli CEC15 reinforces intestinal defences in gnotobiotic mice and is protective in a chronic colitis mouse model

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Unai Escribano-Vazquez ◽  
Sophie Verstraeten ◽  
Rebeca Martin ◽  
Florian Chain ◽  
Philippe Langella ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Mouse Model ◽  
Chronic Colitis ◽  
Gnotobiotic Mice

Recombinant DNA transfer to Escherichia coli of human faecal origin in vitro and in digestive tract of gnotobiotic mice

1994 ◽  
Vol 15 (1-2) ◽  
pp. 79-87 ◽  
Author(s):  
Yvonne Duval-Iflah ◽  
Isabelle Gainche ◽  
Marie-France Ouriet ◽  
Marie-Claire Lett
Keyword(s):  
Escherichia Coli ◽  
Digestive Tract ◽  
Recombinant Dna ◽  
Dna Transfer ◽  
Gnotobiotic Mice

Colonization resistance against potentially pathogenic bacteria in hexaflora-associated gnotobiotic mice

1978 ◽  
Vol 24 (2) ◽  
pp. 79-83 ◽  
Author(s):  
Kunwar K. Srivastava
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Pathogenic Bacteria ◽  
Enterobacter Aerogenes ◽  
Lactobacillus Brevis ◽  
Colonization Resistance ◽  
Post Challenge ◽  
E Coli ◽  
Gnotobiotic Mice ◽  
Akr Mice

A study of colonization resistance against potentially pathogenic bacteria (Escherichia coli and Pseudomonas aeruginosa) was conducted in hexaflora-associated gnotobiotic mice. Groups of germfree AKR mice were swabbed with five bacterial and a single gastrointestinal yeast species: Streptococcus faecalis, Lactobacillus brevis, Staphylococcus epidermidis, Enterobacter aerogenes, Bacteroides fragilis var. vulgatus, and Torulopsis sp. All species became established in the gut in 8 weeks. Later these associated mice were divided and challenged by four graded doses of E. coli or P. aeruginosa. The presence of challenge organism was monitored specifically in the freshly voided fecal specimens of the challenged mice. Escherichia coli colonized the gut of each mouse at each level up to 60 days post challenge. Pseudomonas aeruginosa was completely eliminated from each mouse at each dose level after 30 days post challenge. Evidence suggests that all six species were sufficient to prevent the colonization of P. aeruginosa and not of E. coli in the gut of the gnotobiotic mice.

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