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

AbstractEnterotoxigenic Escherichia coli (ETEC), an essential cause of post-weaning diarrhea (PWD) in piglets, leads to significant economic losses to the pig industry. The present study aims to identify the role of ETEC total RNA in eliciting immune responses to protect animals against ETEC infection. The results showed that the total RNA isolated from pig-derived ETEC K88ac strain effectively stimulated the IL-1β secretion of porcine intestinal epithelial cells (IPEC-J2). The mouse model immunized with ETEC total RNA via intramuscular injection (IM) or oral route (OR) was used to evaluate the protective efficiency of the ETEC total RNA. The results suggested that 70 μg ETEC total RNA administered by either route significantly promoted the production of the serum IL-1β and K88ac specific immunoglobulins (IgG, IgM, and IgA). Besides, the ETEC RNA administration augmented strong mucosal immunity by elevating K88ac specific IgA level in the intestinal fluid. Intramuscularly administered RNA induced a Th1/Th2 shift toward a Th2 response, while the orally administered RNA did not. The ETEC total RNA efficiently protected the animals against the ETEC challenge either by itself or as an adjuvant. The histology characterization of the small intestines also suggested the ETEC RNA administration protected the small intestinal structure against the ETEC infection. Particularly of note was that the immunity level and protective efficacy caused by ETEC RNA were dose-dependent. These findings will help understand the role of bacterial RNA in eliciting immune responses, and benefit the development of RNA-based vaccines or adjuvants.

Download Full-text

Rapid Up-Regulation of Endothelial Nitric-Oxide Synthase in a Mouse Model of Escherichia coli Lipopolysaccharide-Induced Bladder Inflammation

Journal of Pharmacology and Experimental Therapeutics ◽

10.1124/jpet.104.066506 ◽

2004 ◽

Vol 310 (2) ◽

pp. 452-458 ◽

Cited By ~ 32

Author(s):

Walter S. Kang ◽

Frank J. Tamarkin ◽

Marcia A. Wheeler ◽

Robert M. Weiss

Keyword(s):

Nitric Oxide ◽

Escherichia Coli ◽

Nitric Oxide Synthase ◽

Mouse Model ◽

Endothelial Nitric Oxide Synthase ◽

Bladder Inflammation ◽

Oxide Synthase ◽

Endothelial Nitric Oxide ◽

Escherichia Coli Lipopolysaccharide

Download Full-text

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.

Download Full-text

Preparation of porcine enterotoxigenic Escherichia coli (ETEC) ghosts and immunogenic analysis in a mouse model

Microbial Pathogenesis ◽

10.1016/j.micpath.2018.11.015 ◽

2019 ◽

Vol 126 ◽

pp. 224-230 ◽

Cited By ~ 1

Author(s):

Xuhua Ran ◽

Xiaohong Chen ◽

Shixia Wang ◽

Chunlong Chang ◽

Xiaobo Wen ◽

...

Keyword(s):

Escherichia Coli ◽

Mouse Model ◽

Enterotoxigenic Escherichia Coli

Download Full-text

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.

Download Full-text