RESUMO
Two-dimensional gel electrophoretic analysis of cell lysates suggests that stationary phase production of wild-type levels of an ortholog of the low pH dependent chaperone HdeA in Brucella abortus 2308 during growth in a minimal medium requires the presence of the RNA binding protein Hfq. Although mutational analysis demonstrated that HdeA contributes to acid resistance in this bacterium, this protein is not required for wild-type virulence in the BALB/c mouse model. These experimental findings indicate that the brucellae rely upon additional gene products to resist the acidic conditions they encounter in the phagosomal compartment of host macrophages.
Assuntos
Brucella abortus/fisiologia , Brucelose/microbiologia , Fator Proteico 1 do Hospedeiro/fisiologia , Sequência de Aminoácidos , Animais , Brucella abortus/genética , Brucella abortus/crescimento & desenvolvimento , Brucella abortus/patogenicidade , Eletroforese em Gel Bidimensional , Concentração de Íons de Hidrogênio , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Alinhamento de Sequência , VirulênciaRESUMO
Brucella abortus 2308 derivatives with mini-Tn5 insertions in purE, purL, and purD display significant attenuation in the BALB/c mouse model, while isogenic mutants with mini-Tn5 insertions in pheA, trpB, and dagA display little or no attenuation in cultured murine macrophages or mice. These experimental findings confirm the importance of the purine biosynthesis pathways for the survival and replication of the brucellae in host macrophages. In contrast to previous reports, however, these results indicate that exogenous tryptophan and phenylalanine are available for use by the brucellae in the phagosomal compartment.
