Induction of macrophage pyroptosis-related factors by pathogenic E. coli high pathogenicity island (HPI) in Yunnan Saba pigs

Abstract Background Pyroptosis plays a pivotal role in the pathogenesis of many inflammatory diseases. The molecular mechanism by which pyroptosis is induced in macrophages following infection with pathogenic E. coli high pathogenicity island (HPI) will be evaluated in our study. Results After infection with the HPI+/HPI− strains and LPS, decreased macrophage cell membrane permeability and integrity were demonstrated with propidium iodide (PI) staining and the lactate dehydrogenase (LDH) assay. HPI+/HPI−-infection was accompanied by upregulated expression levels of NLRP3, ASC, caspase-1, IL-1β, IL-18 and GSDMD, with significantly higher levels detected in the HPI+ group compared to those in the HPI− group (P < 0.01 or P < 0.05). HPI+ strain is more pathogenic than HPI− strain. Conclusion Our findings indicate that pathogenic E. coli HPI infection of Saba pigs causes pyroptosis of macrophages characterized by upregulated expression of pyroptosis key factors in the NLRP3/ASC/caspase-1 signaling pathway, direct cell membrane pore formation, and secretion of the inflammatory factor IL-1β and IL-18 downstream of NLRP3 and caspase-1 activation to enhance the inflammatory response.

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Molecular mechanism of pyroptosis of mononuclear macrophages induced by pathogenic E. coli high pathogenicity island (HPI) in Yunnan Saba pigs

10.21203/rs.2.24631/v1 ◽

2020 ◽

Author(s):

Chunlan Shan ◽

Shushu Miao ◽

Chaoying Liu ◽

Weiwei Zhao ◽

Bo Zhang ◽

...

Keyword(s):

Cell Membrane ◽

Molecular Mechanism ◽

Pathogenicity Island ◽

Control Group ◽

Tunel Staining ◽

Membrane Pore ◽

Expression Levels ◽

E Coli ◽

Caspase 1 ◽

High Pathogenicity

Abstract Background In this study we evaluated the molecular mechanism by which pyroptosis is induced in mononuclear macrophages isolated from Saba pigs following infection with pathogenic E. coli high pathogenicity island (HPI). Mononuclear macrophages were divided into four treatment groups: control, Lipopolysaccharide (LPS) + adenosine triphosphate (ATP), HPI positive (+) strain and HPI negative (-) strain. The mononuclear macrophages and their culture supernatants were collected at 0.5, 3, 6, 9, 12 and 24 h after infection. DNA changes were detected by TUNEL staining and the integrity of the cell membrane was evaluated by propidium iodide (PI) staining. Changes in mRNA expression levels of NLRP3, caspase-1, IL-1β, and IL-18 gene in mononuclear macrophages were analyzed by quantitative real-time polymerase chain reaction (RT-PCR) and caspase-1 protein expression was detected by indirect immunofluorescence. IL-1β and IL-18 concentration in the mononuclear macrophage culture supernatant were measured by ELISA. Results Compared with the control group, TUNEL and PI staining of mononuclear macrophages was significantly increased following infection with the HPI + /HPI - strains ( P < 0.01 or P < 0.05), with significantly higher levels detected in the HPI + group compared with those in the HPI - group ( P < 0.01 and P < 0.05). Compared with the control group, the expression levels of NLRP3, caspase-1, IL-1β, and IL-18 in the HPI groups were upregulated after pathogenic E. coli infection, with significantly higher levels detected in the HPI + group compared with those in the HPI - group ( P < 0.01 or P < 0.05). Conclusions These findings showed that pathogenic E. coli HPI infection of Saba pigs results induced pyroptosis of mononuclear macrophages characterized by increased expression of NLRP3, caspase-1, IL-1β and IL-18 mRNA in mononuclear macrophages, the induction of cell membrane pore formation, nuclear DNA damage, and the secretion of IL-1β and IL-18 to enhance the inflammatory response.

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Prevalence of the “High-Pathogenicity Island” of Yersinia Species among Escherichia coliStrains That Are Pathogenic to Humans

Infection and Immunity ◽

10.1128/iai.66.2.480-485.1998 ◽

1998 ◽

Vol 66 (2) ◽

pp. 480-485 ◽

Cited By ~ 257

Author(s):

S. Schubert ◽

A. Rakin ◽

H. Karch ◽

E. Carniel ◽

J. Heesemann

Keyword(s):

Gene Cluster ◽

Yersinia Pseudotuberculosis ◽

Pathogenicity Island ◽

Uptake System ◽

Highly Pathogenic ◽

E Coli ◽

Yersinia Species ◽

The Family ◽

High Pathogenicity ◽

Dna Sequence Comparison

ABSTRACT The fyuA-irp gene cluster contributes to the virulence of highly pathogenic Yersinia (Yersinia pestis,Yersinia pseudotuberculosis, and Yersinia enterocolitica 1B). The cluster encodes an iron uptake system mediated by the siderophore yersiniabactin and reveals features of a pathogenicity island. Two evolutionary lineages of this “high pathogenicity island” (HPI) can be distinguished on the basis of DNA sequence comparison: a Y. pestis group and a Y. enterocolitica group. In this study we demonstrate that the HPI of the Y. pestis evolutionary group is disseminated among species of the family Enterobacteriaceae which are pathogenic to humans. It prevails in enteroaggregativeEscherichia coli and in E. coli blood culture isolates (93 and 80%, respectively), but is rarely found in enteropathogenic E. coli, enteroinvasive E. coli, and enterotoxigenic E. coli isolates. In contrast, the HPI was absent from enterohemorrhagic E. coli, Shigella, and Salmonella entericastrains investigated. Polypeptides encoded by the fyuA,irp1, and irp2 genes located on the HPI could be detected in E. coli strains pathogenic to humans. However, these E. coli strains showed a reduced sensitivity to the bacteriocin pesticin, whose uptake is mediated by the FyuA receptor. Escherichia strains do not possess thehms gene locus thought to be a part of the HPI of Y. pestis. Deletions of the fyuA-irp gene cluster affecting solely the fyuA part of the HPI were identified in 3% of the E. coli strains tested. These results suggest horizontal transfer of the HPI between Y. pestis and some pathogenic E. coli strains.

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Chemical Composition, Antibacterial Activity, and Mechanism of Action of the Essential Oil from Amomum kravanh

Journal of Food Protection ◽

10.4315/0362-028x.jfp-14-014 ◽

2014 ◽

Vol 77 (10) ◽

pp. 1740-1746 ◽

Cited By ~ 27

Author(s):

WEN-RUI DIAO ◽

LIANG-LIANG ZHANG ◽

SAI-SAI FENG ◽

JIAN-GUO XU

Keyword(s):

Antibacterial Activity ◽

Chemical Composition ◽

Essential Oil ◽

Cell Membrane ◽

Membrane Permeability ◽

Foodborne Pathogens ◽

Cell Membrane Permeability ◽

Gas Chromatography Mass Spectrometry ◽

E Coli ◽

Transmission Electron

Amomum kravanh is widely cultivated and used as a culinary spice. In this work, the chemical composition of the essential oil obtained by hydrodistillation of A. kravanh fruits was analyzed by gas chromatography–mass spectrometry, and 34 components were identified. 1,8-Cineole (68.42%) was found to be the major component, followed by α-pinene (5.71%), α-terpinene (2.63%), and β-pinene (2.41%). The results of antibacterial tests showed that the sensitivities to the essential oil of different foodborne pathogens tested were different based on the Oxford cup method, MIC, and MBC assays, and the essential oil exhibited the best antibacterial activity against Bacillus subtilis, a gram-positive bacterium, and Escherichia coli, a gram-negative bacterium. Growth in the presence of Amomum kravanh at the MIC, as measured by monitoring optical density over time, demonstrated that the essential oil was bacteriostatic after 12 h to both B. subtilis and E. coli. Observations of cell membrane permeability, cell constituent release assay, and transmission electron microscopy indicated that this essential oil may disrupt the cell wall and cell membrane permeability, leading to leakage of intracellular constituents in both B. subtilis and E. coli.

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Allograft inflammatory factor-1 (AIF-1) induces inflammatory mediator production via NF-κB signaling and impairs bovine mammary epithelial cells via mitochondrial pathway

10.21203/rs.3.rs-32056/v1 ◽

2020 ◽

Author(s):

Danru Yang ◽

Yinghuan Wu ◽

Yanying Zhao

Keyword(s):

Mammary Gland ◽

Epithelial Cells ◽

Cell Membrane ◽

Cell Apoptosis ◽

Mammary Epithelial Cells ◽

Bovine Mastitis ◽

Mammary Epithelial ◽

Cell Membrane Permeability ◽

Inflammatory Factor ◽

Bovine Mammary Epithelial Cells

Abstract Background Bovine mastitis is the inflammatory response of the mammary gland with an utmost threat to the dairy industry worldwide. Cytokine networks fuel inflammation. The sensitive and subtle changes of the inflammatory cytokine network in healthy and mastitic bovine mammary gland may encourage the use of cytokines in the diagnosis and prognosis of bovine mastitis. Allograft inflammatory factor-1 (AIF-1) is a proinflammatory cytokine mainly secreted by immune cells and it plays a central role in the complex signaling network of inflammation activation. Therefore, we explored the possible role of bovine AIF-1 related to bovine mastitis in the present study. Results The average concentration of AIF-1 in milks suffering from mastitis was 2.5 fold of that in the healthy cows, while its value decreased in cows recovered from mastitis. Furthermore, recombinant bovine AIF-1 up-regulated TNF-α, IL-6, and monocyte chemoattractant protein 1 secretion from bovine mammary epithelial cells with NF-κB activating, then NF-κB signaling inhibitor BAY 11-7085 abolished the increase of these inflammatory cytokines secretion induced by AIF-1. Thereafter, AIF-1 impaired bovine mammary epithelial cell viability, induced cell membrane permeability and cell apoptosis with exacerbated nitric oxide and oxidative stress, activated caspase 3, decreased mitochondrial membrane potential and intracellular ATP concentration. Conclusion These results indicated that AIF-1 prompted inflammation mediator production of bovine mammary epithelial cells via NF-κB signaling. Moreover, it damaged epithelial cells by depressing cell viability, inducing cell membrane permeability and cell apoptosis, which might be related to bovine mastitis.

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Characterization of an Escherichia coli O157:H7 O-Antigen Deletion Mutant and Effect of the Deletion on Bacterial Persistence in the Mouse Intestine and Colonization at the Bovine Terminal Rectal Mucosa

Applied and Environmental Microbiology ◽

10.1128/aem.00743-08 ◽

2008 ◽

Vol 74 (16) ◽

pp. 5015-5022 ◽

Cited By ~ 39

Author(s):

Haiqing Sheng ◽

Ji Youn Lim ◽

Maryann K. Watkins ◽

Scott A. Minnich ◽

Carolyn J. Hovde

Keyword(s):

Escherichia Coli ◽

Growth Rate ◽

Cell Membrane ◽

Membrane Permeability ◽

Sodium Dodecyl ◽

Rectal Mucosa ◽

Cell Membrane Permeability ◽

Wild Type ◽

E Coli ◽

O Antigen

ABSTRACT Escherichia coli O157:H7 causes hemorrhagic colitis and the life-threatening hemolytic-uremic syndrome in humans and transiently colonizes healthy cattle at the terminal rectal mucosa. To investigate the role of the O antigen in persistence and colonization in the animal host, we generated an E. coli O157:H7 mutant defective in the synthesis of the lipopolysaccharide side chain (O antigen) by deletion of a putative perosamine synthetase gene (per) in the rfb cluster. The lack of O antigen was confirmed by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and anti-O157 antibody. The growth rate and cell membrane permeability of the Δper mutant were similar to the growth rate and cell membrane permeability of the wild type. Changes in membrane and secreted proteins were observed, but the expression of intimin, EspA, and EspB, implicated in bacterial intestinal colonization, was not altered, as determined by immunoblotting and reverse transcription-PCR. Similar to other O-antigen deletion mutants, the Δper mutant was pleiotropic for autoaggregation and motility (it was FliC negative as determined by immunoblotting and flagellum negative as determined by electron microscopy). The abilities of the mutant and the wild type to persist in the murine intestine and to colonize the bovine terminal rectal mucosa were compared. Mice fed the Δper mutant shed lower numbers of bacteria (P < 0.05) over a shorter time than mice fed the wild-type or complemented strain. After rectal application in steers, lower numbers of the Δper mutant than of the wild type colonized the rectoanal junction mucosa, and the duration of the colonization was shorter (P < 0.05). Our previous work showed that flagella do not influence E. coli O157:H7 colonization at the bovine terminal rectal mucosa, so the current findings suggest that the O antigen contributes to efficient bovine colonization.

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MP075 The High-Pathogenicity Island of E. coli strain EC31: structural and functional characterization of a mobilizable Pathogenicity Island

International Journal of Medical Microbiology Supplements ◽

10.1016/s1433-1128(03)80796-9 ◽

2003 ◽

Vol 293 ◽

pp. 291

Keyword(s):

Functional Characterization ◽

Pathogenicity Island ◽

Coli Strain ◽

E Coli ◽

High Pathogenicity

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A Genomic Island, Termed High-Pathogenicity Island, Is Present in Certain Non-O157 Shiga Toxin-Producing Escherichia coli Clonal Lineages

Infection and Immunity ◽

10.1128/iai.67.11.5994-6001.1999 ◽

1999 ◽

Vol 67 (11) ◽

pp. 5994-6001 ◽

Cited By ~ 99

Author(s):

H. Karch ◽

S. Schubert ◽

D. Zhang ◽

W. Zhang ◽

H. Schmidt ◽

...

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Wide Spectrum ◽

Pathogenicity Island ◽

Immunoblot Analysis ◽

Ecological Niches ◽

Pathogenic Potential ◽

Integrase Gene ◽

E Coli ◽

High Pathogenicity

ABSTRACT Shiga toxin-producing Escherichia coli (STEC) strains cause a wide spectrum of diseases in humans. In this study, we tested 206 STEC strains isolated from patients for potential virulence genes including stx, eae, and enterohemorrhagicE. coli hly. In addition, all strains were examined for the presence of another genetic element, the high-pathogenicity island (HPI). The HPI was first described in pathogenic Yersiniaspecies and encodes the pesticin receptor FyuA and the siderophore yersiniabactin. The HPI was found in the genome of distinct clonal lineages of STEC, including all 31 eae-positive O26:H11/H− strains and 7 of 12 eae-negative O128:H2/H− strains. In total, the HPI was found in 56 (27.2%) of 206 STEC strains. However, it was absent from the genome of all 37 O157:H7/H−, 14 O111:H−, 13 O103:H2, and 13 O145:H− STEC isolates, all of which were positive for eae. Polypeptides encoded by the fyuA gene located on the HPI could be detected by using immunoblot analysis in most of the HPI-positive STEC strains, suggesting the presence of a functional yersiniabactin system. The HPI in STEC was located next to the tRNA gene asnT. In contrast to the HPI of other pathogenic enterobacteria, the HPI of O26 STEC strains shows a deletion at its left junction, leading to a truncated integrase geneint. We conclude from this study that theYersinia HPI is disseminated among certain clonal subgroups of STEC strains. The hypothesis that the HPI in STEC contributes to the fitness of the strains in certain ecological niches rather than to their pathogenic potential is discussed.

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Study on the Bactriostasis of Nano-Silver against Four Strains of Bacteria

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1051.3 ◽

2014 ◽

Vol 1051 ◽

pp. 3-11 ◽

Cited By ~ 1

Author(s):

Lu Qiu ◽

Hai Han Yang ◽

Jia Yan Lv ◽

Shu Guo Fan ◽

Mei Hua Xie ◽

...

Keyword(s):

Cell Membrane ◽

Comparative Study ◽

Membrane Permeability ◽

Cell Membrane Permeability ◽

Bacteriostatic Effect ◽

Nano Silver ◽

E Coli ◽

Streptomycin Sulfate ◽

Better Than

Through a comparative study of the bacteriostatic effect of nanosilver of different species and concentrations against bacteria, it is found that nanosilver have significant bacteriostatic effect against bacteria. Bateriostatic effect of nanosilve 15# against B. thuringiensis is significantly better than E.coli, s. aureus and B. subtillis. The optimal concentrations of 15# for inhabiting E. coli, S. aureus, B. subtillis and B. thuringiensis respectively are: 20 mg/L, 10 mg/L, 1 mg/L, 40 mg/L. nanosilvers of 13#, 14# and 15# have no significant differences in the bacteriostatic effect against E.coli, but are all significantly better than the bacteriostats of lincomycin hydrochloride and streptomycin sulfate. Antibacterial principle of nanosilver is damaging the cell membrane permeability.

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The frequency of molecular detection of virulence genes encoding cytolysin A, high-pathogenicity island and cytolethal distending toxin of Escherichia coli in cases of sudden infant death syndrome does not differ from that in other infant deaths and healthy infants

Journal of Medical Microbiology ◽

10.1099/jmm.0.005322-0 ◽

2009 ◽

Vol 58 (3) ◽

pp. 285-289 ◽

Cited By ~ 10

Author(s):

Amanda R. Highet ◽

Anne M. Berry ◽

Karl A. Bettelheim ◽

Paul N. Goldwater

Keyword(s):

Escherichia Coli ◽

Sudden Infant Death Syndrome ◽

Infant Death ◽

Pathogenicity Island ◽

Sudden Infant Death ◽

Sudden Infant ◽

Cytolethal Distending Toxin ◽

E Coli ◽

Healthy Infants ◽

High Pathogenicity

Consistent pathological findings in sudden infant death syndrome (SIDS) are seen which display similarities to the pathogenesis of toxaemic shock and/or sepsis. A key candidate infectious agent that is possibly involved is Escherichia coli, given its universal early colonization of the intestinal tract of infants and an increased frequency of toxigenic and mouse-lethal isolates from SIDS compared with comparison infants. An explanation for these findings has yet to be identified. Using PCR, we screened E. coli isolates from 145 SIDS and 101 dead control and healthy infants for three new candidate pathogenicity-related genes: clyA (cytolysin A), irp2 [high-pathogenicity island (HPI)-specific gene] and cdt (cytolethal distending toxin). The results failed to show a positive correlation with SIDS, instead proving that clyA and irp2 genes were common to the infant intestinal E. coli. Interestingly we observed a high rate of carriage of these two potentially pathogenic genes in E. coli from healthy infants in the absence of diarrhoeal disease, and we report that in a number of cases, the detection of HPI-specific genes was predictable by serotype. Despite the lack of associations defined so far, there remains the likelihood that genetic determinants influence the interactions between E. coli and the host, so these factors may be part of the multi-factorial aspect of SIDS.

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