scholarly journals Ferric hydroxamate uptake system contributes to Edwardsiella ictaluri virulence

2016 ◽  
Vol 100 ◽  
pp. 195-200 ◽  
Author(s):  
Hossam Abdelhamed ◽  
Jingjun Lu ◽  
Mark L. Lawrence ◽  
Attila Karsi
Keyword(s):  
Edwardsiella Ictaluri ◽  
Uptake System ◽  
Ferric Hydroxamate

scholarly journals Fur-Regulated Iron Uptake System of Edwardsiella ictaluri and Its Influence on Pathogenesis and Immunogenicity in the Catfish Host

2012 ◽  
Vol 80 (8) ◽  
pp. 2689-2703 ◽  
Author(s):  
Javier Santander ◽  
Greg Golden ◽  
Soo-Young Wanda ◽  
Roy Curtiss
Keyword(s):  
Ictalurus Punctatus ◽  
Iron Uptake ◽  
Bacterial Pathogens ◽  
Oral Vaccine ◽  
Edwardsiella Ictaluri ◽  
Uptake System ◽  
Content Type ◽  
Iron Uptake System ◽  
Fur Protein

ABSTRACTThe ability of bacterial pathogens to take up iron from the host during infection is necessary for their multiplication within the host. However, host high-affinity iron binding proteins limit levels of free iron in fluids and tissues. To overcome this deficiency of iron during infection, bacterial pathogens have developed iron uptake systems that are upregulated in the absence of iron, typically tightly controlled by the ferric uptake regulator (Fur) protein. The iron uptake system ofEdwardsiella ictaluri, a host-restricted pathogen of channel catfish (Ictalurus punctatus) and the main pathogen of this fish in aquaculture, is unknown. Here we describe theE. ictaluriFur protein, the iron uptake machinery controlled by Fur, and the effects offurgene deletion on virulence and immunogenicity in the fish host. Analysis of theE. ictaluriFur protein shows that it lacks the N-terminal region found in the majority of pathogen-encoded Fur proteins. However, it is fully functional in regulated genes encoding iron uptake proteins.E. ictalurigrown under iron-limited conditions upregulates an outer membrane protein (HemR) that shows heme-hemoglobin transport activity and is tightly regulated by Fur.In vivostudies showed that anE. ictaluriΔfurmutant is attenuated and immune protective in zebrafish (Danio rerio) and catfish (Ictalurus punctatus), triggering systemic immunity. We conclude that anE. ictaluriΔfurmutant could be an effective component of an immersion-oral vaccine for the catfish industry.

scholarly journals IN SILICO ANALYSIS AND FUNCTIONAL CHARACTERIZATION OF FHUB, A COMPONENT OF ERWINIA MALLOTIVORA FERRIC HYDROXAMATE UPTAKE SYSTEM

2020 ◽  
Vol 82 (3) ◽  
Author(s):  
Nor Mustaiqazah Juri ◽  
Aimera Farhana Samsuddin ◽  
Abdul Munir Abd Murad ◽  
Amin Asyraf Tamizi ◽  
Mohd Azhar Hassan ◽  
...  
Keyword(s):  
In Silico ◽  
Pathogenic Bacteria ◽  
Iron Acquisition ◽  
Functional Characterization ◽  
Membrane Topology ◽  
Transport Systems ◽  
Critical Element ◽  
Uptake System ◽  
Dieback Disease ◽  
Ferric Hydroxamate

Iron is a critical element for bacterial growth as most pathogenic bacteria relies on their host for iron supply. However, iron sources are bounded to the host iron binding protein and specific iron acquisition mechanism is required to chelate and transport the iron to the bacteria. Ferric hydroxamate uptake system or fhu is one of the transport systems that import iron in the form of ferric hydroxamate/ ferrichrome from the extracellular environment into the bacterial cytosol. In this present study, a detailed in silico structural analysis was conducted on an important component of fhu transport member from Erwinia mallotivora named as fhuB. This provide us the structural properties of the protein which includes the domain and 3D model, phylogenetic analysis and the membrane topology. For functional analysis, a knockout mutant of fhuB gene strain was generated to evaluate the effect of silencing this gene during E. mallotivora infection in papaya. When compared to the wild E. mallotivora strain, fhuB mutant strain of E. mallotivora loss its virulence in causing dieback disease symptom in papaya. The result of this study has revealed the significant role of iron acquisition and metabolism during E. mallotivora pathogenesis. This highlights fhuB role and importance as the target gene; to inhibit iron uptake in E. mallotivora for future study and as a part of future consideration for dieback disease management strategy in papaya.

scholarly journals Validation of Edwardsiella ictaluri oral vaccination platform in experimental pond trials

2019 ◽  
Vol 51 (2) ◽  
pp. 346-363 ◽  
Author(s):  
David J. Wise ◽  
Terrence E. Greenway ◽  
Todd S. Byars ◽  
Ganesh Kumar ◽  
Matt J. Griffin ◽  
...  
Keyword(s):  
Edwardsiella Ictaluri ◽  
Oral Vaccination ◽  
Experimental Pond

scholarly journals IncA/C Plasmid-Mediated Florfenicol Resistance in the Catfish Pathogen Edwardsiella ictaluri

2008 ◽  
Vol 53 (2) ◽  
pp. 845-846 ◽  
Author(s):  
Timothy J. Welch ◽  
David G. White ◽  
Matt Griffin ◽  
Jason Evenhuis ◽  
Patrick F. McDermott ◽  
...  
Keyword(s):  
Edwardsiella Ictaluri

Role of nuclear receptors and hepatocyte-enriched transcription factors for Ntcp repression in biliary obstruction in mouse liver

2005 ◽  
Vol 289 (5) ◽  
pp. G798-G805 ◽  
Author(s):  
Gernot Zollner ◽  
Martin Wagner ◽  
Peter Fickert ◽  
Andreas Geier ◽  
Andrea Fuchsbichler ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Bile Acid ◽  
Dna Binding ◽  
Nuclear Receptors ◽  
Farnesoid X Receptor ◽  
Acid Uptake ◽  
Mrna Levels ◽  
Uptake System ◽  
Duct Ligation

Expression of the main hepatic bile acid uptake system, the Na+-taurocholate cotransporter (Ntcp), is downregulated during cholestasis. Bile acid-induced, farnesoid X receptor (FXR)-mediated induction of the nuclear repressor short heterodimer partner (SHP) has been proposed as a key mechanism reducing Ntcp expression. However, the role of FXR and SHP or other nuclear receptors and hepatocyte-enriched transcription factors in mediating Ntcp repression in obstructive cholestasis is unclear. FXR knockout (FXR−/−) and wild-type (FXR+/+) mice were subjected to common bile duct ligation (CBDL). Cholic acid (CA)-fed and LPS-treated FXR−/− and FXR+/+ mice were studied for comparison. mRNA levels of Ntcp and SHP and nuclear protein levels of hepatocyte nuclear factor (HNF)-1α, HNF-3β, HNF-4α, retinoid X receptor (RXR)-α, and retinoic acid receptor (RAR)-α and their DNA binding were assessed. Hepatic cytokine mRNA levels were also measured. CBDL and CA led to Ntcp repression in FXR+/+, but not FXR−/−, mice, whereas LPS reduced Ntcp expression in both genotypes. CBDL and LPS but not CA induced cytokine expression and reduced levels of HNF-1α, HNF-3β, HNF-4α, RXRα, and RARα to similar extents in FXR+/+ and FXR−/−. DNA binding of these transactivators was unaffected by CA in FXR+/+ mice but was markedly reduced in FXR−/− mice. In conclusion, Ntcp repression by CBDL and CA is mediated by accumulating bile acids via FXR and does not depend on cytokines, whereas Ntcp repression by LPS is independent of FXR. Reduced levels of HNF-1α, RXRα, and RARα in CBDL FXR−/− mice and reduced DNA binding in CA-fed FXR−/− mice, despite unchanged Ntcp levels, indicate that these factors may have a minor role in regulation of mouse Ntcp during cholestasis.

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