BACKGROUND: In this study we were interested in the colonisation and early immune response of Balb/C mice to infection with Salmonella Enteritidis and isogenic pathogenicity island free mutants. RESULTS: The virulence of S. Enteritidis for Balb/C mice was exclusively dependent on intact SPI-2. Infections with any of the mutants harbouring SPI-2 (including the mutant in which we left only SPI-2 but removed SPI-1, SPI-3, SPI-4 and SPI-5) resulted in fatalities, liver injures and NK cell depletion from the spleen. The infection was of minimal influence on counts of splenic CD4 CD8 T lymphocytes and gammadelta T-lymphocytes although a reduced ability of splenic lymphocytes to respond to non-specific mitogens indicated general immunosuppression in mice infected with SPI-2 positive S. Enteritidis mutants. Further investigations showed that NK cells were depleted also in blood but not in the caecal lamina propria. However, NK cell depletion was not directly associated with the presence of SPI-2 and was rather an indicator of virulence or avirulence of a particular mutant because the depletion was not observed in mice infected with other attenuated mutants such as lon and rfaL. CONCLUSIONS: The virulence of S. Enteritidis for Balb/C mice is exclusively dependent on the presence of SPI-2 in its genome, and a major hallmark of the infection in terms of early changes in lymphocyte populations is the depletion of NK cells in spleen and blood. The decrease of NK cells in circulation can be used as a marker of attenuation of S. Enteritidis mutants for Balb/C mice.

• MeSH
• antigeny CD19 imunologie   MeSH
• antigeny CD3 imunologie   MeSH
• bakteriální proteiny genetika   imunologie   MeSH
• buňky NK imunologie   MeSH
• cytokiny imunologie   MeSH
• histocytochemie MeSH
• lymfocyty cytologie   imunologie   MeSH
• membránové proteiny genetika   imunologie   MeSH
• modely nemocí na zvířatech MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• neparametrická statistika MeSH
• proliferace buněk MeSH
• Salmonella enteritidis genetika   patogenita   MeSH
• salmonelová infekce u zvířat imunologie   mikrobiologie   MeSH
• virulence MeSH
• vylučování bakterií z těla MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

If any new live Salmonella vaccine is introduced in the future, it is quite probable that detailed characterisation of its attenuation will be required. In this study we therefore compared 34 isogenic mutants of S. Enteritidis in aroA, aroD, galE, ssrA, sseA, phoP, rpoS, ompR, htrA, clpP, lon, rfaL, rfaG, rfaC, hfq, sodCI, hilA, sipA, avrA, sopB, sopA, sopE, sifA, shdA, fliC, fur, relA, spoT, rel-spoT, misL, rmbA, STM4258, STM4259 and spvBC genes for their resistance to stresses likely to be expected in the host and for their virulence and immunogenicity in Balb/C mice. We found that the cold and bile resistances essentially did not correlate with the resistances to other stress factors. Resistance to acid pH, heat, polymyxin and serum correlated with each other and also with the attenuation. When the residual virulence and immunogenicity were both considered, mutants in htrA, ompR, aroA, aroD and lon performed the best in mice. Furthermore, when a detailed comparison of polymyxin and serum sensitive mutants was performed, the serum sensitive mutants were more immunogenic.

• MeSH
• atenuované vakcíny imunologie   MeSH
• bakteriální geny MeSH
• delece genu MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• polymyxiny imunologie   MeSH
• reprodukovatelnost výsledků MeSH
• Salmonella enteritidis genetika   imunologie   patogenita   MeSH
• salmonelová infekce u zvířat imunologie   prevence a kontrola   MeSH
• salmonelové vakcíny imunologie   MeSH
• virulence MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• práce podpořená grantem MeSH
• srovnávací studie MeSH

BACKGROUND: Salmonella is a highly successful parasite of reptiles, birds and mammals. Its ability to infect and colonise such a broad range of hosts coincided with the introduction of new genetic determinants, among them 5 major pathogenicity islands (SPI1-5), into the Salmonella genome. However, only limited information is available on how each of these pathogenicity islands influences the ability of Salmonella to infect chickens. In this study, we therefore constructed Salmonella Enteritidis mutants with each SPI deleted separately, with single individual SPIs (i.e. with the remaining four deleted) and a mutant with all 5 SPIs deleted, and assessed their virulence in one-day-old chickens, together with the innate immune response of this host. RESULTS: The mutant lacking all 5 major SPIs was still capable of colonising the caecum while colonisation of the liver and spleen was dependent on the presence of both SPI-1 and SPI-2. In contrast, the absence of SPI-3, SPI-4 or SPI-5 individually did not influence virulence of S. Enteritidis for chickens, but collectively they contributed to the colonisation of the spleen. Proinflammatory signalling and heterophil infiltration was dependent on intact SPI-1 only and not on other SPIs. CONCLUSIONS: SPI-1 and SPI-2 are the two most important pathogenicity islands of Salmonella Enteritidis required for the colonisation of systemic sites in chickens.

• MeSH
• bakteriální RNA genetika   MeSH
• genomové ostrovy MeSH
• kur domácí imunologie   mikrobiologie   MeSH
• nemoci drůbeže imunologie   mikrobiologie   MeSH
• přirozená imunita MeSH
• Salmonella enteritidis genetika   patogenita   MeSH
• salmonelová infekce u zvířat imunologie   mikrobiologie   MeSH
• sekvenční delece MeSH
• virulence MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• práce podpořená grantem MeSH

In this study we characterized aro mutants of Salmonella enterica serovars Enteritidis and Typhimurium, which are frequently used as live oral vaccines. We found that the aroA, aroD, and aroC mutants were sensitive to blood serum, albumen, EDTA, and ovotransferrin, and this defect could be complemented by an appropriate aro gene cloned in a plasmid. Subsequent microarray analysis of gene expression in the aroD mutant in serovar Typhimurium indicated that the reason for this sensitivity might be the upregulation of murA. To confirm this, we artificially overexpressed murA from a multicopy plasmid, and this overexpression caused sensitivity of the strain to albumen and EDTA but not to serum and ovotransferrin. We concluded that attenuation of aro mutants is caused not only by their inability to synthesize aromatic metabolites but also by their defect in cell wall and outer membrane functions associated with decreased resistance to components of innate immune response.

• MeSH
• albuminy farmakologie   MeSH
• alkyltransferasy a aryltransferasy genetika   MeSH
• aminokyseliny aromatické biosyntéza   genetika   MeSH
• antibakteriální látky farmakologie   MeSH
• bakteriální geny MeSH
• bakteriální léková rezistence genetika   MeSH
• buněčná membrána genetika   účinky léků   MeSH
• buněčná stěna genetika   účinky léků   MeSH
• EDTA farmakologie   MeSH
• financování organizované MeSH
• fosfoenolpyruvát metabolismus   MeSH
• klonování DNA MeSH
• komplement farmakologie   MeSH
• mutace MeSH
• ovotransferin farmakologie   MeSH
• plazmidy genetika   MeSH
• Salmonella enteritidis enzymologie   genetika   účinky léků   MeSH
• Salmonella typhimurium enzymologie   genetika   účinky léků   MeSH
• sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů MeSH
• sérum MeSH
• testy genetické komplementace MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH

• Publikační typ
• abstrakt z konference MeSH

• Publikační typ
• abstrakt z konference MeSH

• Publikační typ
• abstrakt z konference MeSH

• Publikační typ
• abstrakt z konference MeSH

• Publikační typ
• abstrakt z konference MeSH

• Publikační typ
• abstrakt z konference MeSH