• Publikační typ
• abstrakt z konference MeSH

Natural variation in the presence or the absence of STM0517-0529 genes allowing allantoin utilisation has been described in field isolates of the multidrug resistant Salmonella enterica serovar Typhimurium belonging to the phage type DT104. Interestingly, S. enterica subspecies enterica serovar Typhimurium DT104 is quite frequent in pigs and cattle, but rarely present in egg-laying hens. Taking into account the different mode of allantoin metabolism in birds and mammals, we were interested in whether the absence of STM0517-0529 genes may disable this clone in poultry colonisation. We have therefore constructed the allB (also designated as STM0523) mutants in S. enterica subspecies enterica serovar Typhimurium and S. enterica subspecies enterica serovar Enteritidis, and with these, we infected mice, newly hatched chickens and adult egg-laying hens to show that the defect in allantoin utilisation does not influence S. enterica virulence for mice or adult hens, but slightly decreases virulence of S. enterica for chickens. The decrease in virulence of the allB mutant was relatively minor as it could be observed only after a mixed infection model, consistent with a lower prevalence, but not a total absence of such clones in poultry flocks.

• MeSH
• alantoin metabolismus   MeSH
• drůbež MeSH
• kyselina močová metabolismus   MeSH
• mnohočetná bakteriální léková rezistence MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• nemoci drůbeže mikrobiologie   patologie   MeSH
• Salmonella enteritidis genetika   metabolismus   patogenita   MeSH
• Salmonella typhimurium genetika   metabolismus   patogenita   MeSH
• salmonelová infekce u zvířat mikrobiologie   patologie   MeSH
• virulence MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• Publikační typ
• abstrakt z konference MeSH

In this study we were interested in the serovars which are frequently isolated from pigs, i.e. S. Typhimurium, S. Derby and S. Infantis. First we collected different isolates of S. Infantis and S. Derby and compared them by macrorestriction analysis. In the second part of the study we infected porcine alveolar macrophages (PAMs) with representative strains of these serovars and S. Typhimurium and determined intracellular survival, cytotoxicity and cytokine response. In S. Derby, 17 different profiles in 51 isolates have been identified and in S. Infantis, 12 different profiles in 37 isolates have been identified. Four hours post-addition of bacteria to PAMs, higher numbers of intracellular S. Typhimurium than S. Derby or S. Infantis were observed. However, within next 24h, counts of S. Typhimurium did not change while S. Derby and S. Infantis increased their counts 10 and 5 times, respectively. The apparent inability of S. Typhimurium to multiply inside PAMs was caused by its higher cytotoxicity because PAMs infected with S. Typhimurium released LDH 24h post-infection to a significantly higher level than when infected with the other two serovars. The IL-1β, IL-8, IL-12p40, IL-23p19 and TNFα response to S. Derby and S. Infantis was always higher than to S. Typhimurium and the differences among the serovars were more significant at 4 than 24h post-infection. The lower cytokine signaling but higher cytotoxicity of S. Typhimurium for macrophages correlates with the higher virulence for pigs of this serotype when compared with S. Derby or S. Infantis.

• MeSH
• alveolární makrofágy mikrobiologie   MeSH
• bakteriální RNA genetika   MeSH
• cytokiny krev   MeSH
• nemoci prasat epidemiologie   imunologie   mikrobiologie   MeSH
• polymerázová řetězová reakce s reverzní transkripcí veterinární   MeSH
• prasata mikrobiologie   MeSH
• pulzní gelová elektroforéza veterinární   MeSH
• Salmonella enterica klasifikace   genetika   imunologie   MeSH
• Salmonella typhimurium MeSH
• salmonelová infekce u zvířat epidemiologie   imunologie   mikrobiologie   MeSH
• sérotypizace veterinární   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

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

Salmonella enterica serovars Typhimurium, Enteritidis, Dublin, Choleraesuis or Gallinarum can colonise liver and spleen in particular hosts while infections with serovars Infantis, Agona, Hadar, etc. are usually limited to gastrointestinal tract. Reasons for this behavior are unknown, although it has been shown that sodCI and spv genes exhibit a strict distribution between more and less virulent serovars and they influence Salmonella virulence. However to what extent the presence or absence of these genes is associated with the increased virulence of serovars which possess them has never been addressed experimentally. In this study we therefore first confirmed the exclusive association of spvB and sodCI genes with the former group of serovars. In the next step we removed these two genes from S. Enteritidis genome and compared the virulence of such a mutant with the virulence of S. Infantis, S. Agona and S. Hadar for chickens and highly sensitive Balb/C mice. Single strain infection showed that the deletion of these two genes from S. Enteritidis resulted in the reduction of its virulence for mice but not for chickens. Mixed infection further confirmed these observations and indicated that in mice but not in chickens the virulence of sodCI and spv mutant was reduced to the natural virulence of serovars Infantis, Agona and Hadar. Although sodCI and spv genes do not influence S. Enteritidis virulence for chickens directly, they may be of an indirect effect through the increased persistence of S. Enteritidis in mice and increased probability of the reintroduction of S. Enteritidis into poultry flocks.

• MeSH
• ADP-ribosatransferasy genetika   MeSH
• bakteriální adheze genetika   MeSH
• bakteriální geny MeSH
• bakteriální proteiny genetika   MeSH
• delece genu MeSH
• faktory virulence genetika   MeSH
• kur domácí MeSH
• lyasy štěpící vazby C-O genetika   MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• nemoci drůbeže mikrobiologie   MeSH
• proteiny fimbrií genetika   MeSH
• Salmonella enteritidis genetika   patogenita   MeSH
• Salmonella genetika   patogenita   MeSH
• salmonelová infekce u zvířat mikrobiologie   MeSH
• virulence MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

In Salmonella enterica, resistance to antibiotics can be caused by the presence of SGI1, transposons or conjugative plasmids. In this study we were interested in the relative contribution of these genetic elements to the antibiotic resistance of S. enterica isolates collected within a single year in the Czech Republic from animal sources. Altogether 123 antibiotic-resistant isolates belonging to 16 different S. enterica serovars were classified into 3 groups according to the presence of SGI1 and the presence of integrons. The first group consisted of 62 strains in which neither SGI1 nor class 1 integron was detected. A high diversity among serovars and resistance phenotypes was found in this group. The second group consisted of 56 strains positive for both the SGI1 and class 1 integron, out of which 55 belonged to serovar Typhimurium and one to a nonmotile serovar [4,12] which harboured the SGI1-B variant. The third group comprised five strains which were positive for class 1 integron but negative for the SGI1. Sequencing of the integrons in these isolates identified integron with sat1 and aadA1 gene cassettes in S. Sandiego and S. Pullorum, dfrA1 and aadA1 gene cassettes in S. Typhimurium integron, and aadA21 gene cassette in S. Braenderub and S. Zanzibar.

• MeSH
• antibakteriální látky farmakologie   MeSH
• bakteriální léková rezistence genetika   MeSH
• DNA bakterií genetika   chemie   MeSH
• financování organizované MeSH
• genomové ostrovy genetika   MeSH
• integrony genetika   MeSH
• mikrobiální testy citlivosti veterinární   MeSH
• mnohočetná bakteriální léková rezistence MeSH
• molekulární sekvence - údaje MeSH
• plazmidy genetika   MeSH
• počet mikrobiálních kolonií veterinární   MeSH
• polymerázová řetězová reakce veterinární   MeSH
• Salmonella enterica genetika   účinky léků   MeSH
• salmonelová infekce u zvířat farmakoterapie   mikrobiologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Geografické názvy
• Česká republika 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

• Publikační typ
• abstrakt z konference MeSH