scholarly journals Heterogeneity of a Campylobacter jejuni Protein That Is Secreted through the Flagellar Filament

2007 ◽  
Vol 75 (8) ◽  
pp. 3859-3867 ◽  
Author(s):  
Frédéric Poly ◽  
Cheryl Ewing ◽  
Scarlett Goon ◽  
Thomas E. Hickey ◽  
David Rockabrand ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Virulence Factor ◽  
Promoter Analysis ◽  
Acidic Protein ◽  
Rapid Induction ◽  
Virulence Potential ◽  
Flagellar Filament ◽  
Induction Of Apoptosis ◽  
Different Strains

ABSTRACTCj0859c, or FspA, is a small, acidic protein ofCampylobacter jejunithat is expressed by a σ28promoter. Analysis of thefspAgene in 41 isolates ofC. jejunirevealed two overall variants of the predicted protein, FspA1 and FspA2. Secretion of FspA occurs in broth-grown bacteria and requires a minimum flagellar structure. The addition of recombinant FspA2, but not FspA1, to INT407 cells in vitro resulted in a rapid induction of apoptosis. These data define a novelC. jejunivirulence factor, and the observed heterogeneity amongfspAalleles suggests alternate virulence potential among different strains.

scholarly journals Pyruvate is required for catecholamine-stimulated growth of different strains of Campylobacter jejuni

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10011
Author(s):  
Meicen Liu ◽  
Mark Lyte
Keyword(s):  
Escherichia Coli ◽  
Campylobacter Jejuni ◽  
Pathogenic Bacteria ◽  
Intestinal Tract ◽  
Nerve Terminals ◽  
In Vitro Growth ◽  
Gastrointestinal Infections ◽  
Different Strains ◽  
Iron Delivery

Humans and food-producing animals are constantly exposed to and affected by stress. As a consequence of stress, the release of stress-related catecholamines, such as norepinephrine (NE) and dopamine (DA), from nerve terminals in the gastrointestinal tract potentiates both the growth and the virulence of pathogenic bacteria. This may lead to the enhancement of gastrointestinal infections in humans or food-producing animals. Compared with foodborne bacterial pathogens such as Escherichia coli and Salmonella spp., less is known about the effect of stress catecholamines on Campylobacter jejuni subsp. jejuni. The present study focuses on the effect(s) of stress catecholamines DA and NE in iron-restricted media and how they affect the growth of different C. jejuni strains NCTC 11168, 81–176, and ML2126. Results demonstrated that DA- and NE-enhanced growth of C. jejuni in iron-restricted media may involve different mechanisms that cannot be explained by current understanding which relies on catecholamine-mediated iron delivery. Specifically, we found that DA-enhanced growth requires pyruvate, whereas NE-enhanced growth does not. We further report significant strain-specific dependence of C. jejuni growth on various catecholamines in the presence or absence of pyruvate. These data provide novel insights into the effect(s) of stress catecholamines on the in vitro growth of C. jejuni in iron-restricted environments, such as the intestinal tract. They suggest a mechanism by which stress-related catecholamines affect the growth of C. jejuni in the intestinal tract of food-producing animals, which in turn may influence colonization and transmission to humans.

scholarly journals Genome Sequencing of Listeria monocytogenes “Quargel” Listeriosis Outbreak Strains Reveals Two Different Strains with Distinct In Vitro Virulence Potential

PLoS ONE ◽  
2014 ◽  
Vol 9 (2) ◽  
pp. e89964 ◽  
Author(s):  
Kathrin Rychli ◽  
Anneliese Müller ◽  
Andreas Zaiser ◽  
Dagmar Schoder ◽  
Franz Allerberger ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Genome Sequencing ◽  
Virulence Potential ◽  
Different Strains

scholarly journals Signature-Tagged Transposon Mutagenesis Studies Demonstrate the Dynamic Nature of Cecal Colonization of 2-Week-Old Chickens by Campylobacter jejuni

2005 ◽  
Vol 71 (12) ◽  
pp. 8031-8041 ◽  
Author(s):  
Andrew J. Grant ◽  
Christopher Coward ◽  
Michael A. Jones ◽  
Claire A. Woodall ◽  
Paul A. Barrow ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Hot Spots ◽  
Dynamic Nature ◽  
Transposon Insertion ◽  
Random Loss ◽  
Colonization Process ◽  
Insertion Sites ◽  
Different Strains ◽  
Constructed Plasmids

ABSTRACT We have constructed plasmids to be used for in vitro signature-tagged mutagenesis (STM) of Campylobacter jejuni and used these to generate STM libraries in three different strains. Statistical analysis of the transposon insertion sites in the C. jejuni NCTC 11168 chromosome and the plasmids of strain 81-176 indicated that their distribution was not uniform. Visual inspection of the distribution suggested that deviation from uniformity was not due to preferential integration of the transposon into a limited number of hot spots but rather that there was a bias towards insertions around the origin. We screened pools of mutants from the STM libraries for their ability to colonize the ceca of 2-week-old chickens harboring a standardized gut flora. We observed high-frequency random loss of colonization proficient mutants. When cohoused birds were individually inoculated with different tagged mutants, random loss of colonization-proficient mutants was similarly observed, as was extensive bird-to-bird transmission of mutants. This indicates that the nature of campylobacter colonization in chickens is complex and dynamic, and we hypothesize that bottlenecks in the colonization process and between-bird transmission account for these observations.

Effect of Verbascum thapsus Ethanol Extract on Induction of Apoptosis in Trichomonas vaginalis in vitro

2015 ◽  
Vol 15 (2) ◽  
pp. 125-130 ◽  
Author(s):  
Zohreh Kashan ◽  
Mohsen Arbabi ◽  
Mahdi Delavari ◽  
Hossein Hooshyar ◽  
Mohsen Taghizadeh ◽  
...  
Keyword(s):  
Trichomonas Vaginalis ◽  
Ethanol Extract ◽  
Verbascum Thapsus ◽  
Induction Of Apoptosis

scholarly journals The Olive Leaves Extract Has Anti-Tumor Effects against Neuroblastoma through Inhibition of Cell Proliferation and Induction of Apoptosis

Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2178
Author(s):  
Fabio Morandi ◽  
Veronica Bensa ◽  
Enzo Calarco ◽  
Fabio Pastorino ◽  
Patrizia Perri ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Viability ◽  
Cell Cycle Progression ◽  
Treatment Strategies ◽  
Annexin V ◽  
Dependent Manner ◽  
Induction Of Apoptosis ◽  
Dose Dependent

Neuroblastoma (NB) is the most common extra-cranial solid tumor of pediatric age. The prognosis for high-risk NB patients remains poor, and new treatment strategies are desirable. The olive leaf extract (OLE) is constituted by phenolic compounds, whose health beneficial effects were reported. Here, the anti-tumor effects of OLE were investigated in vitro on a panel of NB cell lines in terms of (i) reduction of cell viability; (ii) inhibition of cell proliferation through cell cycle arrest; (iii) induction of apoptosis; and (iv) inhibition of cell migration. Furthermore, cytotoxicity experiments, by combining OLE with the chemotherapeutic topotecan, were also performed. OLE reduced the cell viability of NB cells in a time- and dose-dependent manner in 2D and 3D models. NB cells exposed to OLE underwent inhibition of cell proliferation, which was characterized by an arrest of the cell cycle progression in G0/G1 phase and by the accumulation of cells in the sub-G0 phase, which is peculiar of apoptotic death. This was confirmed by a dose-dependent increase of Annexin V+ cells (peculiar of apoptosis) and upregulation of caspases 3 and 7 protein levels. Moreover, OLE inhibited the migration of NB cells. Finally, the anti-tumor efficacy of the chemotherapeutic topotecan, in terms of cell viability reduction, was greatly enhanced by its combination with OLE. In conclusion, OLE has anti-tumor activity against NB by inhibiting cell proliferation and migration and by inducing apoptosis.

scholarly journals The glycosyltransferase ST3GAL2 is regulated by miR-615-3p in the intestinal tract of Campylobacter jejuni infected mice

Gut Pathogens ◽  
2021 ◽  
Vol 13 (1) ◽  
Author(s):  
De Xi ◽  
Lukas Hofmann ◽  
Thomas Alter ◽  
Ralf Einspanier ◽  
Stefan Bereswill ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Regulatory Networks ◽  
In Silico Analysis ◽  
Luciferase Reporter ◽  
Colonic Tissue ◽  
Tissue Samples ◽  
Vitro Model ◽  
Pathway Analyses

Abstract Background Campylobacter jejuni (C. jejuni) infections are of increasing importance worldwide. As a typical mucosal pathogen, the interaction of C. jejuni with mucins is a prominent step in the colonisation of mucosal surfaces. Despite recent advances in understanding the interaction between bacterial pathogens and host mucins, the mechanisms of mucin glycosylation during intestinal C. jejuni infection remain largely unclear. This prompted us to identify relevant regulatory networks that are concerted by miRNAs and could play a role in the mucin modification and interaction. Results We firstly used a human intestinal in vitro model, in which we observed altered transcription of MUC2 and TFF3 upon C. jejuni NCTC 11168 infection. Using a combined approach consisting of in silico analysis together with in vitro expression analysis, we identified the conserved miRNAs miR-125a-5p and miR-615-3p associated with MUC2 and TFF3. Further pathway analyses showed that both miRNAs appear to regulate glycosyltransferases, which are related to the KEGG pathway ‘Mucin type O-glycan biosynthesis’. To validate the proposed interactions, we applied an in vivo approach utilising a well-established secondary abiotic IL-10−/− mouse model for infection with C. jejuni 81-176. In colonic tissue samples, we confirmed infection-dependent aberrant transcription of MUC2 and TFF3. Moreover, two predicted glycosyltransferases, the sialyltransferases ST3GAL1 and ST3GAL2, exhibited inversely correlated transcriptional levels compared to the expression of the identified miRNAs miR-125a-5p and miR-615-3p, respectively. In this study, we mainly focused on the interaction between miR-615-3p and ST3GAL2 and were able to demonstrate their molecular interaction using luciferase reporter assays and RNAi. Detection of ST3GAL2 in murine colonic tissue by immunofluorescence demonstrated reduced intensity after C. jejuni 81-176 infection and was thus consistent with the observations made above. Conclusions We report here for the first time the regulation of glycosyltransferases by miRNAs during murine infection with C. jejuni 81-176. Our data suggest that mucin type O-glycan biosynthesis is concerted by the interplay of miRNAs and glycosyltransferases, which could determine the shape of intestinal glycosylated proteins during infection.

H2O2 inhibits alveolar epithelial wound repair in vitro by induction of apoptosis

2004 ◽  
Vol 287 (2) ◽  
pp. L448-L453 ◽  
Author(s):  
Thomas Geiser ◽  
Masanobu Ishigaki ◽  
Coretta van Leer ◽  
Michael A. Matthay ◽  
V. Courtney Broaddus
Keyword(s):  
Acute Lung Injury ◽  
Epithelial Cells ◽  
Lung Injury ◽  
Cell Viability ◽  
Wound Repair ◽  
Wound Edge ◽  
Alveolar Epithelial ◽  
Induction Of Apoptosis

Reactive oxygen species (ROS) are released into the alveolar space and contribute to alveolar epithelial damage in patients with acute lung injury. However, the role of ROS in alveolar repair is not known. We studied the effect of ROS in our in vitro wound healing model using either human A549 alveolar epithelial cells or primary distal lung epithelial cells. We found that H2O2 inhibited alveolar epithelial repair in a concentration-dependent manner. At similar concentrations, H2O2 also induced apoptosis, an effect seen particularly at the edge of the wound, leading us to hypothesize that apoptosis contributes to H2O2-induced inhibition of wound repair. To learn the role of apoptosis, we blocked caspases with the pan-caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp (zVAD). In the presence of H2O2, zVAD inhibited apoptosis, particularly at the wound edge and, most importantly, maintained alveolar epithelial wound repair. In H2O2-exposed cells, zVAD also maintained cell viability as judged by improved cell spreading and/or migration at the wound edge and by a more normal mitochondrial potential difference compared with cells not treated with zVAD. In conclusion, H2O2 inhibits alveolar epithelial wound repair in large part by induction of apoptosis. Inhibition of apoptosis can maintain wound repair and cell viability in the face of ROS. Inhibiting apoptosis may be a promising new approach to improve repair of the alveolar epithelium in patients with acute lung injury.

scholarly journals Mutations That Affect the Tropism of DA and GDVII Strains of Theiler's Virus In Vitro Influence Sialic Acid Binding and Pathogenicity

2002 ◽  
Vol 76 (16) ◽  
pp. 8138-8147 ◽  
Author(s):  
Karima Jnaoui ◽  
Muriel Minet ◽  
Thomas Michiels
Keyword(s):  
Sialic Acid ◽  
Demyelinating Disease ◽  
Binding Capacity ◽  
Single Amino Acid ◽  
Sialic Acid Binding ◽  
Encephalomyelitis Virus ◽  
The Central Nervous System ◽  
Different Strains ◽  
Single Amino Acid Mutation

ABSTRACT Theiler's murine encephalomyelitis virus (TMEV) is a natural pathogen of the mouse. The different strains of TMEV are divided into two subgroups according to the pathology they provoke. The neurovirulent strains GDVII and FA induce an acute fatal encephalitis, while persistent strains, like DA and BeAn, cause a chronic demyelinating disease associated with viral persistence in the central nervous system. Different receptor usage was proposed to account for most of the phenotype difference between neurovirulent and persistent strains. Persistent but not neurovirulent strains were shown to bind sialic acid. We characterized DA and GDVII derivatives adapted to grow on CHO-K1 cells. Expression of glycosaminoglycans did not influence infection of CHO-K1 cells by parental and adapted viruses. Mutations resulting from adaptation of DA and GDVII to CHO-K1 cells notably mapped to the well-characterized VP1 CD and VP2 EF loops of the capsid. Adaptation of the DA virus to CHO-K1 cells correlated with decreased sialic acid usage for entry. In contrast, adaptation of the GDVII virus to CHO-K1 cells correlated with the appearance of a weak sialic acid usage for entry. The sialic acid binding capacity of the GDVII variant resulted from a single amino acid mutation (VP1-51, Asn→Ser) located out of the sialic acid binding region defined for virus DA. Mutations affecting tropism in vitro and sialic acid binding dramatically affected the persistence and neurovirulence of the viruses.

scholarly journals A σ28-Regulated Nonflagella Gene Contributes to Virulence of Campylobacter jejuni 81-176

2006 ◽  
Vol 74 (1) ◽  
pp. 769-772 ◽  
Author(s):  
Scarlett Goon ◽  
Cheryl P. Ewing ◽  
Maria Lorenzo ◽  
Dawn Pattarini ◽  
Gary Majam ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Campylobacter Jejuni ◽  
Diarrheal Disease ◽  
Intestinal Epithelial Cells ◽  
Disease Model ◽  
Intestinal Epithelial ◽  
Model Expression

ABSTRACT A Campylobacter jejuni 81-176 mutant in Cj0977 was fully motile but reduced >3 logs compared to the parent in invasion of intestinal epithelial cells in vitro. The mutant was also attenuated in a ferret diarrheal disease model. Expression of Cj0977 protein was dependent on a minimal flagella structure.

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