scholarly journals Regulation and Molecular Mechanism of TLR5 on Resistance to Escherichia coli F18 in Weaned Piglets

Animals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 735 ◽  
Author(s):  
Chaohui Dai ◽  
Li Yang ◽  
Jian Jin ◽  
Haifei Wang ◽  
Shenglong Wu ◽  
...  

Toll-like receptor 5 (TLR5) plays an important role in immune system. In this study, we performed transcriptome analysis of the duodenum in E. coli F18-resistant and -sensitive Sutai weaned piglets and analyzed the differential expression of TLR5. The cellular localization of TLR5 was investigated, and the effect of TLR5 expression on E. coli invasion was evaluated after pig small intestinal epithelial cell lines (IPEC-J2) were stimulated by E. coli. The results showed that TLR5 expression level in duodenum and jejunum were significantly higher in E. coli F18-sensitive than in E. coli F18-resistant piglets. TLR5 protein was mainly expressed in the cytoplasm and cell membrane. The expression of genes associated with the TLR5 signaling pathway were significantly higher in TLR5-overexpressed cells than in control cells. Bacterial adhesion was higher in TLR5-overexpressed cells than in blank cells and lower in TLR5 interference than in blank cells. The core promoter region of TLR5 included two CpG islands and 16 acting elements. The methylation of the mC-6 site in the second CpG island of the promoter region had a regulatory effect on TLR5 expression. Therefore, TLR5 plays an important regulatory role on E. coli invasion. Low expression of TLR5 inhibited the immune response and decreased cell damage, which was conducive to the resistance to E. coli stimulation. In conclusion, this study preliminarily revealed the molecular mechanism of TLR5 gene regulating the resistance of piglets to Escherichia coli, and provided a new candidate gene for screening Escherichia coli resistance markers in pigs.

2018 ◽  
Vol 19 (11) ◽  
pp. 3301 ◽  
Author(s):  
Zhengchang Wu ◽  
Haiyue Feng ◽  
Yue Cao ◽  
Yanjie Huang ◽  
Chaohui Dai ◽  
...  

Escherichia coli (E. coli) F18 is the main pathogen responsible for post-weaning diarrhea (PWD) in piglets. Resistance to E. coli F18 depends on the expression of the cognate receptors in the intestinal epithelial cells. However, the molecular mechanism of E. coli F18 resistance in weaned piglets remains unclear. Here, we performed a comparative transcriptome study of the duodenal tissue from Sutai E. coli F18 sensitive and resistant pigs by RNA-seq, and pig α(1,2) fucosyltransferase 2 (FUT2) was identified as a host differentially expressed gene controlling the E. coli F18 infection. Function analysis showed that the FUT2 expression was high in the duodenum and jejunum, with higher levels detected in sensitive individuals than in resistant individuals (p < 0.01). Expression levels of FUT2 were upregulated in IPEC-J2 cells after lipopolysaccharide (LPS)-induction or E. coli stimulation. FUT2 knockdown decreased the adhesion of E. coli F18 to IPEC-J2 cells (p < 0.05). FUT2 overexpression markedly increased the adhesion of E. coli F18 to IPEC-J2 cells (p < 0.05 or p < 0.01). Furthermore, the FUT2 mRNA levels correlated with methylation levels of the mC-22 site in the specificity protein 1 (Sp1) transcription factor (p < 0.05). Electrophoretic mobility shift assays (EMSA) showed that Sp1 interacts with the wild-type FUT2 promoter DNA, but not with methylated DNA. Our data suggested that FUT2 methylation at the mC-22 site inhibits Sp1 binding to the FUT2 promoter, thereby reducing FUT2 expression and enhancing E. coli F18 resistance in weaned piglets. These observations highlight FUT2 as a promising new target for combating E. coli F18 susceptibility in weaned piglets.


2002 ◽  
Vol 184 (9) ◽  
pp. 2533-2538 ◽  
Author(s):  
Dvora Berenstein ◽  
Kirsten Olesen ◽  
Christian Speck ◽  
Ole Skovgaard

ABSTRACT The Vibrionaceae family is distantly related to Enterobacteriaceae within the group of bacteria possessing the Dam methylase system. We have cloned, sequenced, and analyzed the dnaA gene region of Vibrio harveyi and found that although the organization of the V. harveyi dnaA region differs from that of Escherichia coli, the expression of both genes is autoregulated and ATP-DnaA binds cooperatively to ATP-DnaA boxes in the dnaA promoter region. The DnaA proteins of V. harveyi and E. coli are interchangeable and function nearly identically in controlling dnaA transcription and the initiation of chromosomal DNA replication despite the evolutionary distance between these bacteria.


Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1053
Author(s):  
Chao-Hui Dai ◽  
Fang Wang ◽  
Shi-Qin Wang ◽  
Zheng-Chang Wu ◽  
Sheng-Long Wu ◽  
...  

Previous research has revealed that miR-215 might be an important miRNA regulating weaned piglets’ resistance to Escherichia coli (E. coli) F18. In this study, target genes of miR-215 were identified by RNA-seq, bioinformatics analysis and dual luciferase detection. The relationship between target genes and E. coli infection was explored by RNAi technology, combined with E. coli stimulation and enzyme linked immunosorbent assay (ELISA) detection. Molecular regulating mechanisms of target genes expression were analyzed by methylation detection of promoter regions and dual luciferase activity assay of single nucleotide polymorphisms (SNPs) in core promoter regions. The results showed that miR-215 could target EREG, NIPAL1 and PTPRU genes. Expression levels of three genes in porcine intestinal epithelial cells (IPEC-J2) in the RNAi group were significantly lower than those in the negative control pGMLV vector (pGMLV-NC) group after E. coli F18 stimulation, while cytokines levels of TNF-α and IL-1β in the RNAi group were significantly higher than in the pGMLV-NC group. Variant sites in the promoter region of three genes could affect their promoter activities. These results suggested that miR-215 could regulate weaned piglets’ resistance to E. coli F18 by targeting EREG, NIPAL1 and PTPRU genes. This study is the first to annotate new biological functions of EREG, NIPAL1 and PTPRU genes in pigs, and provides a new experimental basis and reference for the research of piglets disease-resistance breeding.


2011 ◽  
Vol 79 (11) ◽  
pp. 4716-4729 ◽  
Author(s):  
Amin Tahoun ◽  
Gabriella Siszler ◽  
Kevin Spears ◽  
Sean McAteer ◽  
Jai Tree ◽  
...  

ABSTRACTThe EspF protein is secreted by the type III secretion system of enteropathogenic and enterohemorrhagicEscherichia coli(EPEC and EHEC, respectively). EspF sequences differ between EHEC O157:H7, EHEC O26:H11, and EPEC O127:H6 in terms of the number of SH3-binding polyproline-rich repeats and specific residues in these regions, as well as residues in the amino domain involved in cellular localization. EspFO127is important for the inhibition of phagocytosis by EPEC and also limits EPEC translocation through antigen-sampling cells (M cells). EspFO127has been shown to have effects on cellular organelle function and interacts with several host proteins, including N-WASP and sorting nexin 9 (SNX9). In this study, we compared the capacities of differentespFalleles to inhibit (i) bacterial phagocytosis by macrophages, (ii) translocation through an M-cell coculture system, and (iii) uptake by and translocation through cultured bovine epithelial cells. TheespFgene fromE. coliserotype O157 (espFO157) allele was significantly less effective at inhibiting phagocytosis and also had reduced capacity to inhibitE. colitranslocation through a human-derivedin vitroM-cell coculture system in comparison toespFO127andespFO26. In contrast,espFO157was the most effective allele at restricting bacterial uptake into and translocation through primary epithelial cells cultured from the bovine terminal rectum, the predominant colonization site of EHEC O157 in cattle and a site containing M-like cells. Although LUMIER binding assays demonstrated differences in the interactions of the EspF variants with SNX9 and N-WASP, we propose that other, as-yet-uncharacterized interactions contribute to the host-based variation in EspF activity demonstrated here.


1997 ◽  
Vol 41 (2) ◽  
pp. 374-378 ◽  
Author(s):  
M M Caniça ◽  
M Barthélémy ◽  
L Gilly ◽  
R Labia ◽  
R Krishnamoorthy ◽  
...  

IRT-14 (TEM-45) is a new mutant TEM-type beta-lactamase that was isolated from clinical Escherichia coli P37 and that confers resistance to broad-spectrum penicillins with reduced sensitivity to beta-lactamase inhibitors. The MICs of amoxicillin alone and of amoxicillin combined with 2 micrograms of clavulanic acid or 2 micrograms of tazobactam per ml were 4,096, 2,048, and 1,024 micrograms/ml, respectively. The strain was susceptible to cephalosporins, aztreonam, moxalactam, and imipenem. The enzyme was purified to homogeneity, and values of the kinetic parameters Kcat, Km, and Kcat/Km were determined for different substrates. This enzyme, with a pI of 5.2, was found to have reduced affinity for broad-spectrum penicillins and cephalosporins. The values of 50% inhibitory concentrations of clavulanic acid, sulbactam, tazobactam, and brobactam are correlated with the higher KmS for substrates. The resistance of E. coli P37 to mechanism-based inactivators results from a higher level of production of the TEM-derived enzyme due to the G-to-T substitution at position 162 (G-162-->T) in the promoter region of blaTEM and from the structural modifications resulting from the Met-69-->Leu and Arg-275-->Gln substitutions that characterize IRT-14 beta-lactamase.


2000 ◽  
Vol 182 (18) ◽  
pp. 5167-5171 ◽  
Author(s):  
Chris S. Schaumburg ◽  
Ming Tan

ABSTRACT The spacer A/T region is a positive cis-acting DNA element that was identified in the Chlamydia trachomatisrRNA promoter region. We have now demonstrated that similar sequences in other chlamydial promoters are important for transcription. Substitution of candidate spacer A/T regions in four chlamydial promoters decreased transcription by partially purified C. trachomatis RNA polymerase in an in vitro transcription assay. Addition of a spacer A/T region to the dnaK promoter, which does not contain an identifiable spacer A/T region, increased transcription 16-fold. Transcription of Escherichia colipromoters by C. trachomatis RNA polymerase also appeared to be dependent on the spacer A/T region. However, the effect of the spacer A/T region on transcription by E. coli RNA polymerase was small. In summary, the spacer A/T region is a novel DNA element that is required for high-level transcription of many promoters by chlamydial RNA polymerase.


Animals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 729 ◽  
Author(s):  
Long ◽  
Liu ◽  
Liu ◽  
Mahfuz ◽  
Piao

The aim of this study is to determine the efficiency of Forsythia suspense extract (FSE) as an antibiotics substitute on performance, nutrient digestibility, serum antioxidant capacity, fecal Escherichia coli concentration and intestinal morphology of weaned piglets. A total of 108 Duroc × (Landrace × Yorkshire) weaned piglets (28 days (d) weaned, average body weight of 8.68 ± 1.36 kg) were randomly assigned into three dietary treatments, six pens per treatment, three barrows and three gilts per pen. The treatments contained a corn-soybean meal basal diet (CTR), an antibiotic diet (basal diet + 75 mg/kg chlortetracycline; CTC), and an FSE diet (basal diet + 200 mg/kg FSE; FSE). The experiment included phase 1 (d 1 to 14), phase 2 (d 15 to 28) and phase 3 (d 29 to 35). Compared with CTR, piglets fed FSE show improved (p < 0.05) average daily gain (ADG) and average daily feed intake in phase 2, as well as enhanced (p < 0.05) ADG from day 15 to 35 and day 1 to 28. Piglets supplemented with CTC and FSE showed a reduced (p < 0.05) diarrhea rate in phase 1, while piglets fed FSE showed enhanced (p < 0.05) apparent total tract digestibility (ATTD) of dry matter, organic matter, crude protein and gross energy, as well as lower (p < 0.05) nitrogen output in phase 2 compared with CTR and CTC. The content in the form of Colony-Forming Units (CFUs) of fecal E. coli on day 14 and 28 was lower (p < 0.05) in piglets fed FSE in comparison with CTR. The contents of total antioxidant capacity, superoxide dismutase and catalase in serum are enhanced (p < 0.05) compared with CTR and CTC, whereas the concentration of malondialdehyde in serum was decreased (p < 0.05) for piglets fed FSE on day 28 compared with CTC. The villus height to crypt depth ratio in ileum was numerically higher (p < 0.05) in piglets fed FSE in comparison with CTR. In conclusion, dietary FSE supplementation could substitute CTC in improving antioxidant capacity, nutrients digestibility and reducing fecal E. coli content, so as to reduce nitrogen output and diarrhea rate, and eventually improve performance in weaned piglets.


2012 ◽  
Vol 50 (No. 7) ◽  
pp. 315-320 ◽  
Author(s):  
P. Alexa ◽  
J. Hamrik ◽  
K. Stouracova ◽  
E. Salajka

Experiments were focused on the prevention of diarrhoea in weaned piglets by means of enterotoxigenic strains of Escherichia coli (ETEC) with colonizing factors K88 (F4). The process of immunization consisted of intramuscular administration of ETEC strain bacterin one day prior to weaning and oral administration of a live culture of non-pathogenic E. coli strain containing colonizing factors (O149:K88; STa&ndash;, LT&ndash;) in 3 hours after weaning. The shedding of the K88 positive E. coli strains was monitored for 3 weeks after weaning by the culture of rectal swabs. The efficacy of such immunization protocol was tested by challenge exposure to enterotoxigenic E. coli O149:K88, LT+ strain on the third or the tenth day after weaning. Following the oral administration of non-pathogenic E. coli strain containing colonizing factors K88 to piglets, the shedding of the administered strain continued for 9 days. No or very small protection against diarrhoea following the challenge exposure to enterotoxigenic E. coli was found in immunized piglets.


2005 ◽  
Vol 49 (8) ◽  
pp. 3533-3537 ◽  
Author(s):  
Akemi Kojima ◽  
Yoshikazu Ishii ◽  
Kanako Ishihara ◽  
Hidetake Esaki ◽  
Tetsuo Asai ◽  
...  

ABSTRACT A nationwide surveillance for antimicrobial susceptibility in Escherichia coli strains isolated from food-producing animals in Japan was conducted from 1999 to 2002. Eighteen cefazolin-resistant E. coli strains were isolated from broilers. Six were CTX-M-type producing, and eight were CMY-2 producing, while eight had mutations at the ampC promoter region.


2004 ◽  
Vol 186 (16) ◽  
pp. 5410-5417 ◽  
Author(s):  
Esteban A. Roberts ◽  
Amanda Clark ◽  
Sarah McBeth ◽  
Richard L. Friedman

ABSTRACT To further understand Mycobacterium tuberculosis pathogenesis, the regulation of potential virulence genes needs to be investigated. The eis gene of M. tuberculosis H37Rv enhances the intracellular survival of Mycobacterium smegmatis, which does not contain eis, within macrophages (J. Wei, J. L. Dahl, J. W. Moulder, E. A. Roberts, P. O'Gaora, D. B. Young, and R. L. Friedman, J. Bacteriol. 182:377-384, 2000). Experiments were done to characterize the eis promoter in M. smegmatis and M. tuberculosis H37Ra. The putative −10 and −35 regions matched the Escherichia coli σ70 consensus 67 and 83%, respectively, making it a group A/SigA-like mycobacterial promoter. Expression of site-directed variants of the core promoter region, determined by flow cytometry using gfp as a reporter, showed that the putative −10 region is essential for eis expression. In addition, site-directed alteration of the eis promoter to the consensus E. coli σ70 promoter elements increased gfp transcription to levels similar to that driven by the heat shock promoter, phsp60, of Mycobacterium bovis BCG. Upstream promoter deletion analysis showed that a 200- and 412-bp region of the promoter was necessary for maximum expression of gfp in M. smegmatis and M. tuberculosis H37Ra, respectively. Random mutagenesis of the 412-bp eis promoter, using a catechol 2,3-dioxygenase screen and activity assay, defined nucleotides upstream of the core promoter region that are essential to eis expression in both M. smegmatis and M. tuberculosis H37Ra, including a region homologous to a DinR cis element.


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