scholarly journals Commensal Escherichia coli Aggravates Acute Necrotizing Pancreatitis through Targeting of Intestinal Epithelial Cells

2019 ◽  
Vol 85 (12) ◽  
Author(s):  
Junyuan Zheng ◽  
Lihong Lou ◽  
Junjie Fan ◽  
Chunlan Huang ◽  
Qixiang Mei ◽  
...  

ABSTRACT An increase of Escherichia-Shigella was previously reported in acute necrotizing pancreatitis (ANP). We investigated whether Escherichia coli MG1655, an Escherichia commensal organism, increased intestinal injury and aggravated ANP in rats. ANP was induced by retrograde injection of 3.5% sodium taurocholate into the biliopancreatic duct. Using gut microbiota-depleted rats, we demonstrated that gut microbiota was involved in the pancreatic injury and intestinal barrier dysfunction in ANP. Using 16S rRNA gene sequencing and quantitative PCR, we found intestinal dysbiosis and a significant increase of E. coli MG1655 in ANP. Afterward, administration of E. coli MG1655 by gavage to gut microbiota-depleted rats with ANP was performed. We observed that after ANP induction, E. coli MG1655-monocolonized rats presented more severe injury in the pancreas and intestinal barrier function than gut microbiota-depleted rats. Furthermore, Toll-like receptor 4 (TLR4)/MyD88/p38 mitogen-activated protein (MAPK) and endoplasmic reticulum stress (ERS) activation in intestinal epithelial cells were also increased more significantly in the MG1655-monocolonized ANP rats. In vitro, the rat ileal epithelial cell line IEC-18 displayed aggravated tumor necrosis factor alpha-induced inflammation and loss of tight-junction proteins in coculture with E. coli MG1655, as well as TLR4, MyD88, and Bip upregulation. In conclusion, our study shows that commensal E. coli MG1655 increases TLR4/MyD88/p38 MAPK and ERS signaling-induced intestinal epithelial injury and aggravates ANP in rats. Our study also describes the harmful potential of commensal E. coli in ANP. IMPORTANCE This study describes the harmful potential of commensal E. coli in ANP, which has not been demonstrated in previous studies. Our work provides new insights into gut bacterium-ANP cross talk, suggesting that nonpathogenic commensals could also exhibit adverse effects in the context of diseases.

2020 ◽  
Vol 86 (24) ◽  
Author(s):  
Matthias Dierick ◽  
Hans Van der Weken ◽  
Joanna Rybarczyk ◽  
Daisy Vanrompay ◽  
Bert Devriendt ◽  
...  

ABSTRACT Postweaning diarrhea (PWD) is an economically important, multifactorial disease affecting pigs within the first 2 weeks after weaning. The most common agent associated with PWD is enterotoxigenic Escherichia coli (ETEC). Currently, antibiotics are used to control PWD, and this has most likely contributed to an increased prevalence of antibiotic-resistant strains. This puts pressure on veterinarians and farmers to decrease or even abandon the use of antibiotics, but these measures need to be supported by alternative strategies for controlling these infections. Naturally derived molecules, such as lactoferrin, could be potential candidates due to their antibacterial or immune-modulating activities. Here, we analyzed the ability of bovine lactoferrin (bLF), porcine lactoferrin (pLF), and ovotransferrin (ovoTF) to inhibit ETEC growth, degrade ETEC virulence factors, and inhibit adherence of these pathogens to porcine intestinal epithelial cells. Our results revealed that bLF and pLF, but not ovoTF, inhibit the growth of ETEC. Furthermore, bLF and pLF can degrade several virulence factors produced by ETEC strains, more specifically F4 fimbriae, F18 fimbriae, and flagellin. On the other hand, ovoTF degrades F18 fimbriae and flagellin but not F4 fimbriae. An in vitro adhesion assay showed that bLF, ovoTF, and pLF can decrease the number of bacteria adherent to epithelial cells. Our findings demonstrate that lactoferrin can directly affect porcine ETEC strains, which could allow lactoferrin to serve as an alternative to antimicrobials for the prevention of ETEC infections in piglets. IMPORTANCE Currently, postweaning F4+ and F18+ Escherichia coli infections in piglets are controlled by the use of antibiotics and zinc oxide, but the use of these antimicrobial agents most likely contributes to an increase in antibiotic resistance. Our work demonstrates that bovine and porcine lactoferrin can inhibit the growth of porcine enterotoxigenic E. coli strains. In addition, we also show that lactoferrin can reduce the adherence of these strains to small intestinal epithelial cells, even at a concentration that does not inhibit bacterial growth. This research could allow us to develop lactoferrin as an alternative strategy to prevent enterotoxigenic E. coli (ETEC) infections in piglets.


2019 ◽  
Vol 29 (1-6) ◽  
pp. 91-100
Author(s):  
Dorna Khoobbakht ◽  
Shohreh Zare Karizi ◽  
Mohammad Javad  Motamedi ◽  
Rouhollah Kazemi ◽  
Pooneh Roghanian ◽  
...  

Enterotoxigenic <i>Escherichia coli</i> (ETEC) is the most common agent of diarrhea morbidity in developing countries. ETEC adheres to host intestinal epithelial cells via various colonization factors. The CooD and CotD proteins play a significant role in bacteria binding to the intestinal epithelial cells as adhesin tip subunits of CS1 and CS2 pili. The purpose here was to design a new construction containing <i>cooD</i> and <i>cotD</i> genes and use several types of bioinformatics software to predict the structural and immunological properties of the designed antigen. The fusion gene was synthesized with codon bias of <i>E. coli</i> in order to increase the expression level of the protein. The amino acid sequences, protein structure, and immunogenicity properties of potential antigens were analyzed in silico. The chimeric protein was expressed in <i>E. coli</i>BL21 (DE3). The antigenicity of the recombinant proteins was verified by Western blotting and ELISA. In order to assess the induced immunity, the immunized mice were challenged with wild-type ETEC by an intraperitoneal route. Immunological analyses showed the production of a high titer of IgG serum with no sign of serum-mucosal IgA antibody response. The result of the challenge assay showed that 30% of immunized mice survived. The results of this study showed that CooD-CotD recombinant protein can stimulate immunity against ETEC. The designed chimera could be a prototype for the subunit vaccine, which is worthy of further consideration.


Digestion ◽  
2014 ◽  
Vol 89 (2) ◽  
pp. 110-118 ◽  
Author(s):  
Helen M. Becker ◽  
Aretussa Apladas ◽  
Michael Scharl ◽  
Michael Fried ◽  
Gerhard Rogler

2013 ◽  
Vol 81 (10) ◽  
pp. 3662-3671 ◽  
Author(s):  
Sandrine Tchaptchet ◽  
Ting-Jia Fan ◽  
Laura Goeser ◽  
Alexi Schoenborn ◽  
Ajay S. Gulati ◽  
...  

ABSTRACTDysregulated immune responses to commensal intestinal bacteria, includingEscherichia coli, contribute to the development of inflammatory bowel diseases (IBDs) and experimental colitis. Reciprocally,E. coliresponds to chronic intestinal inflammation by upregulating expression of stress response genes, includinggadAandgadB. GadAB encode glutamate decarboxylase and protectE. colifrom the toxic effects of low pH and fermentation acids, factors present in the intestinal lumen in patients with active IBDs. We hypothesized thatE. coliupregulatesgadABduring inflammation to enhance its survival and virulence. Using real-time PCR, we determinedgadABexpression in luminalE. colifrom ex-germfree wild-type (WT) and interleukin-10 (IL-10) knockout (KO) (IL-10−/−) mice selectively colonized with a commensalE. coliisolate (NC101) that causes colitis in KO mice in isolation or in combination with 7 other commensal intestinal bacterial strains.E. colisurvival and host inflammatory responses were measured in WT and KO mice colonized with NC101 or a mutant lacking thegadABgenes (NC101ΔgadAB). The susceptibility of NC101 and NC101ΔgadABto killing by host antimicrobial peptides and their translocation across intestinal epithelial cells were evaluated using bacterial killing assays and transwell experiments, respectively. We show that expression ofgadABin luminalE. coliincreases proportionately with intestinal inflammation in KO mice and enhances the susceptibility of NC101 to killing by the host antimicrobial peptide cryptdin-4 but decreases bacterial transmigration across intestinal epithelial cells, colonic inflammation, and mucosal immune responses. Chronic intestinal inflammation upregulates acid tolerance pathways in commensalE. coliisolates, which, contrary to our original hypothesis, limits their survival and colitogenic potential. Further investigation of microbial adaptation to immune-mediated inflammation may provide novel insights into the pathogenesis and treatment of IBDs.


2009 ◽  
Vol 75 (18) ◽  
pp. 5927-5937 ◽  
Author(s):  
Brandon A. Carlson ◽  
Kendra K. Nightingale ◽  
Gary L. Mason ◽  
John R. Ruby ◽  
W. Travis Choat ◽  
...  

ABSTRACT A longitudinal study was conducted to investigate the nature of Escherichia coli O157:H7 colonization of feedlot cattle over the final 100 to 110 days of finishing. Rectal fecal grab samples were collected from an initial sample population of 788 steers every 20 to 22 days and microbiologically analyzed to detect E. coli O157:H7. The identities of presumptive colonies were confirmed using a multiplex PCR assay that screened for gene fragments unique to E. coli O157:H7 (rfbE and fliC h7) and other key virulence genes (eae, stx 1, and stx 2). Animals were classified as having persistent shedding (PS), transient shedding (TS), or nonshedding (NS) status if they consecutively shed the same E. coli O157:H7 genotype (based on the multiplex PCR profile), exhibited variable E. coli O157 shedding, or never shed morphologically typical E. coli O157, respectively. Overall, 1.0% and 1.4% of steers were classified as PS and NS animals, respectively. Characterization of 132 E. coli O157:H7 isolates from PS and TS animals by pulsed-field gel electrophoresis (PFGE) typing yielded 32 unique PFGE types. One predominant PFGE type accounted for 53% of all isolates characterized and persisted in cattle throughout the study. Isolates belonging to this predominant and persistent PFGE type demonstrated an enhanced (P < 0.0001) ability to adhere to Caco-2 human intestinal epithelial cells compared to isolates belonging to less common PFGE types but exhibited equal virulence expression. Interestingly, the attachment efficacy decreased as the genetic divergence from the predominant and persistent subtype increased. Our data support the hypothesis that certain E. coli O157:H7 strains persist in feedlot cattle, which may be partially explained by an enhanced ability to colonize the intestinal epithelium.


2001 ◽  
Vol 69 (9) ◽  
pp. 5679-5688 ◽  
Author(s):  
Ivana Simonovic ◽  
Monique Arpin ◽  
Athanasia Koutsouris ◽  
Holly J. Falk-Krzesinski ◽  
Gail Hecht

ABSTRACT Enteropathogenic Escherichia coli (EPEC) is an important human intestinal pathogen, especially in infants. EPEC adherence to intestinal epithelial cells induces the accumulation of a number of cytoskeletal proteins beneath the bacteria, including the membrane-cytoskeleton linker ezrin. Evidence suggests that ezrin can participate in signal transduction. The aim of this study was to determine whether ezrin is activated following EPEC infection and if it is involved in the cross talk with host intestinal epithelial cells. We show here that following EPEC attachment to intestinal epithelial cells there was significant phosphorylation of ezrin, first on threonine and later on tyrosine residues. A significant increase in cytoskeleton-associated ezrin occurred following phosphorylation, suggesting activation of this molecule. Nonpathogenic E. coli and EPEC strains harboring mutations in type III secretion failed to elicit this response. Expression of dominant-negative ezrin significantly decreased the EPEC-elicited association of ezrin with the cytoskeleton and attenuated the disruption of intestinal epithelial tight junctions. These results suggest that ezrin is involved in transducing EPEC-initiated signals that ultimately affect host physiological functions.


2016 ◽  
Vol 19 (3) ◽  
pp. 619-625 ◽  
Author(s):  
C.H. Dai ◽  
L.N. Gan ◽  
W.U. Qin ◽  
C. Zi ◽  
G.Q. Zhu ◽  
...  

AbstractAn efficient and accurate method to testEscherichia coli(E. coli) adhesion to intestinal epithelial cells will contribute to the study of bacterial pathogenesis and the function of genes that encode receptors related to adhesion. This study used the quantitative real-time polymerase chain reaction (qPCR) method. qPCR primers were designed from thePILINgene ofE. coliF18ab, F18ac, and K88ac, and the pig β-ACTINgene. Total deoxyribonucleic acid (DNA) fromE. coliand intestinal epithelial cells (IPEC-J2 cells) were used as templates for qPCR. The 2−ΔΔCtformula was used to calculate the relative number of bacteria in cultures of different areas. We found that the relative numbers of F18ab, F18ac, and K88ac that adhered to IPEC-J2 cells did not differ significantly in 6-, 12-, and 24-well culture plates. This finding indicated that there was no relationship between the relative adhesion number ofE. coliand the area of cells, so the method of qPCR could accurately test the relative number ofE. coli. This study provided a convenient and reliable testing method for experiments involvingE. coliadhesion, and also provided innovative ideas for similar detection methods.


2021 ◽  
Vol 12 ◽  
Author(s):  
Mengjiao Guo ◽  
Congyue Zhang ◽  
Chengcheng Zhang ◽  
Xiaorong Zhang ◽  
Yantao Wu

Lacticaseibacillus rhamnosus is a recognized probiotic that is widely used in scientific research and clinical applications. This study found that the Lacticaseibacillus rhamnosus GG (LGG) strain can reduce the adhesion of Escherichia coli (E. coli) to primary chicken intestinal epithelial cells by 75.7% and inhibit 41.7% of the E. coli that adhere to intestinal epithelial cells. Additionally, LGG showed strong inhibitory ability on the growth of E. coli, Staphylococcus aureus, Salmonella Paratyphi B, and Salmonella Enteritidis in vitro. Furthermore, the influence of LGG on the growth performance, intestinal flora, immunity, and disease resistance of chickens was explored. Chickens fed with LGG exhibited increased average daily weight gain and concentrations of sIgA, IgG, and IgM than did controls. After 21 days of feeding, a diet with LGG increased the diversity of intestinal microbiota and maintained intestinal health. Moreover, LGG promoted immunologic barriers by upregulating cytokines and chemokines via the Toll-like receptor. The major pro-inflammatory factors, including Myd88, NF-κB, Il6, and Il8, were upregulated compared to controls. After being challenged with E. coli, the survival rate of chickens fed with LGG was significantly higher than those in the control group, and decreased numbers of E. coli were detected in the heart and lungs of the LGG group. In summary, oral administration of LGG to chickens could improve growth performance, maintain intestinal homeostasis, and enhance innate immune response and disease resistance.


Sign in / Sign up

Export Citation Format

Share Document