Publications by authors named "Luis Fernandez-Lago"

Bacteria of the genus Brucella are facultative intracellular parasites that cause brucellosis, a severe animal and human disease. Recently, a group of taxonomists merged the brucellae with the primarily free-living, phylogenetically related spp. in the genus Brucella.

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The aim of this work was to ascertain the usefulness of a new commercially-available single-assay chemiluminescence test (CHT) for the diagnosis of human tularemia (Tularaemia VIRCLIA IgG + IgM monotest, Vircell, Santa Fe, Granada, Spain). A total of 773 sera from 773 patients including 364 initial sera from patients with diagnosed tularemia, patients with suspected tularemia not confirmed (100), healthy people (152), patients with serology positive to Brucella (97), patients diagnosed with other infectious diseases (30), and patients diagnosed with autoimmune diseases (30) were included. All sera were tested by CHT, "in-house" microagglutination test (MAT), immunochromatographic test (ICT) (Virapid Tularaemia, Vircell, Santa Fe Granada, Spain), and "in-house" ELISA IgG, and ELISA IgM.

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Brucella ovis causes ram contagious epididymitis, a disease for which a specific vaccine is lacking. Attenuated Brucella melitensis Rev 1, used as vaccine against ovine and caprine brucellosis caused by B. melitensis, is also considered the best vaccine available for the prophylaxis of B.

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Brucella ovis is a rough bacterium--lacking O-polysaccharide chains in the lipopolysaccharide--that is virulent in its natural host and whose virulence mechanisms remain almost unexplored. In a search for additional traits that distinguish B. ovis from smooth Brucella, which require O-polysaccharide chains for virulence, we have analyzed the significance in B.

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Outer membrane-related properties (such as auto-agglutination and susceptibility to various compounds) of strains representative of the six classical species of the genus Brucella were assessed. The differences identified could not be fully explained based on the smooth or rough phenotype of the strain. Smooth strains of the closely related species Brucella melitensis and B.

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The establishment of infection by Brucella ovis and Brucella canis in J774.A1 macrophages was found to be dependent upon cholesterol and ganglioside GM(1), two components of lipid rafts. This process also required a class A scavenger receptor of macrophages, and was not inhibited by smooth and rough lipopolysaccharides from Brucella spp.

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Members of the Omp25/Omp31 family of surface proteins were previously shown to participate in the virulence of some Brucella species and a different distribution of the seven proteins of this family among species could be related to the difference in pathogenicity and host preference they exhibit. Accordingly, in this work we have analyzed the expression of the genes coding for the Omp25/Omp31 family in the six classical Brucella species and a set of B. ovis mutant strains with each omp gene inactivated.

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Serological diagnosis of human brucellosis is problematic in endemic brucellosis regions and with patients having a history of brucellosis. The aim of this study is to ascertain the serologic and evolutionary behavior of the tests of serum agglutination, Coombs anti-Brucella, immunocapture-agglutination, enzyme-linked immunosorbent assay (ELISA) IgG, IgA, IgM and ELISA-IgG avidity against Brucella lipopolysaccharide (S-LPS), in patients with acute brucellosis based on whether or not a history of brucellosis exists. Titers and seropositivity in all the tests assayed were higher in the patients having brucellosis history (from 90.

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The role of the outer membrane proteins of the Omp25/Omp31 family in invasiveness and intracellular survival of virulent B. ovis in phagocytes was analyzed. The absence of Omp25d or Omp22 in B.

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The genes coding for the five outer membrane proteins (OMPs) of the Omp25/Omp31 family expected to be located in the outer membrane (OM) of rough virulent Brucella ovis PA were inactivated to evaluate their role in virulence and OM properties. The OM properties of the mutant strains and of the mutants complemented with the corresponding wild-type genes were analyzed, in comparison with the parental strain and rough B. abortus RB51, in several tests: (i) binding of anti-Omp25 and anti-Omp31 monoclonal antibodies, (ii) autoagglutination of bacterial suspensions, and (iii) assessment of susceptibility to polymyxin B, sodium deoxycholate, hydrogen peroxide, and nonimmune ram serum.

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The utility of an immunocapture-agglutination (Brucellacapt, Vircell SL, Granada, Spain) test and an enzyme-linked immunosorbent assay IgG, IgA, and IgM (ELISA-IgG, ELISA-IgA, ELISA-IgM) against cytosolic proteins from Brucella melitensis B115 (R) was compared with ELISA-IgG, ELISA-IgA, and ELISA-IgM against smooth lipopolysaccharide (S-LPS) from B. melitensis 16M (S), serum agglutination test (SAT), and Coombs test in the diagnosis and follow-up for 10 months of 51 patients with acute brucellosis. The sensitivities of ELISA tests against cytosolic proteins varied from 49.

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Th1 immune responses in which gamma interferon (IFN-gamma) production predominates are associated with protective immunity against intracellular bacteria. Following infection, interleukin-18 (IL-18) may contribute, in association with IL-12, to optimal IFN-gamma production. In this study, the secretion of IL-18 following intracellular infection with virulent Brucella abortus 2308 in CD-1 cultured peritoneal macrophages and splenocyte cultures was investigated.

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Five genes homologous to the well-known omp25 and omp31 genes, that code for two major Brucella spp. outer membrane proteins (OMPs), have been detected in the genome of Brucella melitensis 16M and Brucella suis 1330. In this work we have determined the nucleotide sequence of these five genes, named omp31b, omp25b, omp25c, omp25d and omp22, in the six classical Brucella species reference strains and in representative strains of the recently proposed species Brucella cetaceae and Brucella pinnipediae that classify the Brucella strains isolated in the last years from marine mammals.

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Sequencing of bp26, the gene encoding the Brucella sp. immunogenic BP26 periplasmic protein, was performed in the reference strains of Brucella abortus, B. suis, and B.

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The secretion of interleukin-12 (IL-12) following intracellular infection with virulent Brucella abortus strain 2308 was investigated in CD-1 mice and in CD-1 cultured peritoneal macrophages. Bioactive IL-12p70 and free non-immunoactive p40 subunits (IL-12p40) were determined by enzyme-linked immunosorbent assays. In CD-1 mice, B.

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