The evolutionary "success" of the genus Brucella depends on the ability to persist both in the environment as well as inside of even activated macrophages of the animal host. For that, the Brucellae produce catalase and superoxide dismutase to defend against oxidative stress. Since the deletion of the mglA gene in the B. abortus S19 vaccine strain resulted not only in an increased tolerance to H2O2 but also in the induction of cytokines in macrophages, we here investigated the effect of oxidative stress (Fe2+ and H2O2) on the survival of B. abortus S19 and the isogenic B. abortus S 19 ∆mglA 3.14 deletion mutant in comparison with B. neotomae 5K33, Brucella strain 83/13, and B. microti CCM4915. These Brucellae belong to different phylogenetic clades and show characteristic differences in the mgl-operon. From the various Brucellae tested, B. abortus S19 showed the highest susceptibility to oxidative stress and the lowest ability to survive inside of murine macrophages. B. abortus S19 ∆mglA 3.14 as well as B. neotomae, which also belongs to the classical core clade of Brucella and lacks the regulators of the mgl-operon, presented the highest degree of tolerance to H2O2 but not in the survival in macrophages. The latter was most pronounced in case of an infection with B. 83/13 and B. microti CCM4915. The various Brucellae investigated here demonstrate significant differences in tolerance against oxidative stress and different survival in murine macrophages, which, however, do not correlate directly.

• Klíčová slova
• Brucella, Fe2 +, H2O2, Macrophages, Oxidative stress,
• MeSH
• adenosintrifosfát metabolismus   MeSH
• bakteriální geny MeSH
• Brucella abortus fyziologie   MeSH
• Brucella klasifikace   fyziologie   MeSH
• buněčné linie MeSH
• cytokiny metabolismus   MeSH
• druhová specificita MeSH
• makrofágy imunologie   mikrobiologie   MeSH
• mikrobiální viabilita MeSH
• mutace MeSH
• myši MeSH
• oxidační stres * MeSH
• peroxid vodíku metabolismus   MeSH
• počet mikrobiálních kolonií MeSH
• železo metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adenosintrifosfát MeSH
• cytokiny MeSH
• peroxid vodíku MeSH
• železo MeSH

Mutual interactions were investigated between intracellular parasitic bacterium Francisella tularensis (F.t.; highly virulent bacterium responsible for tularemia, replicating within the host macrophages) and murine macrophage-like cell line J774. Recombinant murine lymphokine INF-gamma and/or LPS derived from E. coli were determined to stimulate in vitro antimicrobial activity of macrophage-like J774 cell line against the live vaccine strain (LVS) of F.t. through their ability to produce proinflammatory cytokines and chemokines. F.t. infection up-regulated IL-12 p40 production and down-regulated TNF-alpha production by stimulated macrophages; on the other hand, F.t. infection did not affect the production of IL-8, IL-6, MCP-5, and RANTES by stimulated macrophages. This showed that F.t. infection modulates the cytokine synthesis by J774 macrophage cell line.

• MeSH
• buněčné linie MeSH
• chemokiny imunologie   MeSH
• cytokiny imunologie   MeSH
• Francisella tularensis imunologie   MeSH
• makrofágy imunologie   mikrobiologie   MeSH
• myši MeSH
• tularemie imunologie   mikrobiologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chemokiny MeSH
• cytokiny MeSH

The implication of the Bcg locus in the control of natural resistance to infection with a live vaccine strain (LVS) of the intracellular pathogen Francisella tularensis was studied. Analysis of phenotypic expression of natural resistance and susceptibility was performed using mouse strains congenic at the Bcg locus. Comparison of the kinetics of bacterial colonization of spleen showed that B10.A.Bcg(r) mice were extremely susceptible during early phases of primary sublethal infection, while their congenic C57BL/10N [Bcg(s)] counterparts could be classified as resistant to F. tularensis LVS infection according to the 2-log-lower bacterial CFU within the tissue as long as 5 days after infection. Different phenotypes of Bcg congenic mice were associated with differential expression of the cytokines tumor necrosis factor alpha, interleukin-10, and gamma interferon and production of reactive oxygen intermediates. These results strongly suggest that the Bcg locus, which is close or identical to the Nramp1 gene, controls natural resistance to infection by F. tularensis and that its effect is the opposite of that observed for other Bcg-controlled pathogens.

• MeSH
• cytokiny biosyntéza   MeSH
• dusitany metabolismus   MeSH
• kultivované buňky MeSH
• mapování chromozomů * MeSH
• membránové proteiny genetika   MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• přirozená imunita MeSH
• proteiny přenášející kationty * MeSH
• reaktivní formy kyslíku MeSH
• slezina mikrobiologie   MeSH
• transportní proteiny genetika   MeSH
• tularemie imunologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cytokiny MeSH
• dusitany MeSH
• membránové proteiny MeSH
• natural resistance-associated macrophage protein 1 MeSH Prohlížeč
• proteiny přenášející kationty * MeSH
• reaktivní formy kyslíku MeSH
• transportní proteiny MeSH