Depósito Académico

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Now showing 1 - 10 of 85
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    A novel gluconeogenic route enables efficient use of erythritol in zoonotic Brucella
    (2024) Van-Schaftingen, E. (Emile); Moriyon, I. (Ignacio); Veiga-da-Cunha, M. (Maria); Zuñiga-Ripa, A. (Amaia); Lázaro-Antón, L. (Leticia); Elizalde-Bielsa, A. (Aitor); Iriarte-Cilveti, M. (Maite); Letesson, J.J. (Jean Jacques); Conde-Alvarez, R. (Raquel); Chevalier, N. (Nathalie)
    Brucellosis is a worldwide extended zoonosis caused by pathogens of the genus Brucella. While most B. abortus, B. melitensis, and B. suis biovars grow slowly in complex media, they multiply intensely in livestock genitals and placenta indicating high metabolic capacities. Mutant analyses in vitro and in infection models emphasize that erythritol (abundant in placenta and genitals) is a preferred substrate of brucellae, and suggest hexoses, pentoses, and gluconeogenic substrates use in host cells. While Brucella sugar and erythritol catabolic pathways are known, growth on 3–4 carbon substrates persists in Fbp- and GlpX-deleted mutants, the canonical gluconeogenic fructose 1,6-bisphosphate (F1,6bP) bisphosphatases. Exploiting the prototrophic and fast-growing properties of B. suis biovar 5, we show that gluconeogenesis requires fructose-bisphosphate aldolase (Fba); the existence of a novel broad substrate bisphosphatase (Bbp) active on sedoheptulose 1,7-bisphosphate (S1,7bP), F1,6bP, and other phosphorylated substrates; that Brucella Fbp unexpectedly acts on S1,7bP and F1,6bP; and that, while active in B. abortus and B. melitensis, GlpX is disabled in B. suis biovar 5. Thus, two Fba-dependent reactions (dihydroxyacetone-phosphate + glyceraldehyde 3-phosphate ⇌ F1,6bP; and dihydroxyacetone-phosphate + erythrose 4-phosphate ⇌ S1,7bP) can, respectively, yield fructose 6-phosphate and sedoheptulose 7-phosphate for classical gluconeogenesis and the Pentose Phosphate Shunt (PPS), the latter reaction opening a new gluconeogenic route. Since erythritol generates the PPS-intermediate erythrose 4-phosphate, and the Fba/Fbp-Bbp route predicts sedoheptulose 7-phosphate generation from erythrose 4-phosphate, we re-examined the erythritol connections with PPS. Growth on erythritol required transaldolase or the Fba/Fbp-Bbp pathway, strongly suggesting that Fba/Fbp-Bbp works as a PPS entry for both erythritol and gluconeogenic substrates in Brucella. We propose that, by increasing erythritol channeling into PPS through these peculiar routes, brucellae proliferate in livestock genitals and placenta in the high numbers that cause abortion and infertility, and make brucellosis highly contagious. These findings could be the basis for developing attenuated brucellosis vaccines safer in pregnant animals.
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    Phylogenomic insights into brucellaceae: The Pseudochrobactrum algeriensis case
    (2024) Coscollá, M. (Mireia); Loperena-Barber, M. (Maite); Salvador-Bescós, M. (Miriam); Moriyon, I. (Ignacio); Bengoechea, J.A. (José A.); Pellegrini, J.M. (Joaquín Miguel); Renau-Mínguez, C. (Chantal); Zuñiga-Ripa, A. (Amaia); Ruiz-Rodríguez, P. (Paula); Gorvel, J.P. (Jean Pierre); Elizalde-Bielsa, A. (Aitor); Iriarte-Cilveti, M. (Maite); Lancaster, R. (Rebecca); Conde-Alvarez, R. (Raquel)
    The genus Pseudochrobactrum encompasses free-living bacteria phylogenetically close to Ochrobactrum opportunistic pathogens and to Brucella, facultative intracellular parasites causing brucellosis, a worldwide-extended and grave zoonosis. Recently, Pseudochrobactrum strains were isolated from Brucella natural hosts on Brucella selective media, potentially causing diagnostic confusions. Strikingly, P. algeriensis was isolated from cattle lymph nodes, organs that are inimical to bacteria. Here, we analyse P. algeriensis potential virulence factors in comparison with Ochrobactrum and Brucella. Consistent with genomic analyses, Western-Blot analyses confirmed that P. algeriensis lacks the ability to synthesize the N-formylperosamine O-polysaccharide characteristic of the lipopolysaccharide (LPS) of smooth Brucella core species. However, unlike other Pseudochrobactrum but similar to some early diverging brucellae, P. algeriensis carries genes potentially synthetizing a rhamnose-based O-polysaccharide LPS. Lipid A analysis by MALDI-TOF demonstrated that P. algeriensis LPS bears a lipid A with a reduced pathogen-associated molecular pattern, a trait shared with Ochrobactrum and Brucella that is essential to generate a highly stable outer membrane and to delay immune activation. Also, although not able to multiply intracellularly in macrophages, the analysis of P. algeriensis cell lipid envelope revealed the presence of large amounts of cationic aminolipids, which may account for the extremely high resistance of P. algeriensis to bactericidal peptides and could favor colonization of mucosae and transient survival in Brucella hosts. However, two traits critical in Brucella pathogenicity are either significantly different (T4SS [VirB]) or absent (erythritol catabolic pathway) in P. algeriensis. This work shows that, while diverging in other characteristics, lipidic envelope features relevant in Brucella pathogenicity are conserved in Brucellaceae. The constant presence of these features strongly suggests that reinforcement of the envelope integrity as an adaptive advantage in soil was maintained in Brucella because of the similarity of some environmental challenges, such as the action of cationic peptide antibiotics and host defense peptides. This information adds knowledge about the evolution of Brucellaceae, and also underlines the taxonomical differences of the three genera compared.
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    If You're Not Confused, You're Not Paying Attention: Ochrobactrum Is Not Brucella
    (2023) Bertu, W.J. (Wilson J.); Güler, L. (Leyla); Caswell, C.C. (Clayton C.); Araj, G.F. (George F.); Suárez-Esquivel, M. (Marcela); Lopez-Goñi, I. (Ignacio); Al-Dahouk, S. (Sascha); Roop, M. (Martin); Pembroke, J.T. (J. Tony); Chacon-Diaz, C. (Carlos); Middlebrook, E.A. (Edgar A.); Blasco, J.M. (José María); Loperena-Barber, M. (Maite); Keriel, A. (Anne); Salvador-Bescós, M. (Miriam); Dadar, M. (Maryam); O'Callaghan, D. (David); Moriyon, I. (Ignacio); De-Massis, F. (Frabizio); Altamirano-Silva, P. (Pamela); Barquero-Calvo, E. (Elías); Chaves-Olarte, E. (Esteban); Neubauer, H. (Heinrich); Whatmore, A.M. (Adrian M.); Wareth, G. (Gamal); De-Lima-Santos, R. (Renato); Arenas-Gamboa, A. (Ángela); Welburn, S.C. (Susan C.); Godfroid, J. (Jacques); Diaz, R. (Ramón); Splitter, G. (Gary); Garin-Bastuji, B. (B.); Gusi, A.M. (Amahyel M.); Sangari, F.J. (Félix Javier); Melzer, F. (Falk); Comerci, D.J. (Diego J.); Salcedo, S.P. (Suzana P.); Arce-Gorvel, V. (Vilma); Zuñiga-Ripa, A. (Amaia); Vizcaíno, N. (Nieves); Ruiz-Villalonos, N. (Nazaret); Erdenlig-Gürbilek, S. (Sevil); Muñoz, P. (Pilar); Tsolis, R.M. (Renee M.); Mora-Cartin, R. (Ricardo); Gorvel, J.P. (Jean Pierre); Ryan, M.P. (Michael P.); Iriarte-Cilveti, M. (Maite); Seimenis, A. (Aristarchos); Tabbaa, D. (Darem); Khames, M. (Mammar); Cravero, S. (Silvio); Celli, J. (Jean); Moran-Gilad, J. (Jacob); Bosilkovski, M. (Mile); Letesson, J.J. (Jean Jacques); Cook, E. (Elizabeth); Oñate-Landa, A.(A.); Moreno, E. (Edgardo); Ariza, J. (J.); Pandey, P. (Piyush); Escobar, G.I. (Gabriela I.); McGiven, J. (John); Guzman-Verri, C. (Caterina); Trangoni, M.D. (Marcos David); Pappas, G. (Georgios); Köhler, S. (Stephan); Foster, J.T. (Jeffrey T.); De-Boelle, X. (Xavier); Hernández-Mora, G. (Gabriela); Conde-Alvarez, R. (Raquel); Cadmus, S. (Simeon); Battelli, G. (Giorgio); Ficht, T.A. (Thomas A.); Hai, J. (Jiang); Jacob, N.R. (Nestor R.); Ocholi, R.A. (Reuben A.); Fernandez-Lago, L. (Luis)
    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 Ochrobactrum spp. in the genus Brucella. This change, founded only on global genomic analysis and the fortuitous isolation of some opportunistic Ochrobactrum spp. from medically compromised patients, has been automatically included in culture collections and databases. We argue that clinical and environmental microbiologists should not accept this nomenclature, and we advise against its use because (i) it was presented without in-depth phylogenetic analyses and did not consider alternative taxonomic solutions; (ii) it was launched without the input of experts in brucellosis or Ochrobactrum; (iii) it applies a non-consensus genus concept that disregards taxonomically relevant differences in structure, physiology, population structure, core-pangenome assemblies, genome structure, genomic traits, clinical features, treatment, prevention, diagnosis, genus description rules, and, above all, pathogenicity; and (iv) placing these two bacterial groups in the same genus creates risks for veterinarians, medical doctors, clinical laboratories, health authorities, and legislators who deal with brucellosis, a disease that is particularly relevant in low- and middle-income countries. Based on all this information, we urge microbiologists, bacterial collections, genomic databases, journals, and public health boards to keep the Brucella and Ochrobactrum genera separate to avoid further bewilderment and harm.
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    A Brucella melitensis H38ΔwbkF rough mutant protects against Brucella ovis in rams
    (2022) Salvador-Bescós, M. (Miriam); Moriyon, I. (Ignacio); Zuñiga-Ripa, A. (Amaia); Aragón-Aranda, B. (Beatriz); Vizcaíno, N. (Nieves); de-Miguel, M.J. (María Jesús); Muñoz, P. (Pilar); Andrés-Barranco, S. (Sara); Barberan, M. (Montserrat); Iriarte-Cilveti, M. (Maite); Blasco, J.M. (J. M.); Martinez-Gomez, E. (Estrella); Conde-Alvarez, R. (Raquel)
    Brucella melitensis and Brucella ovis are gram-negative pathogens of sheep that cause severe economic losses and, although B. ovis is non-zoonotic, B. melitensis is the main cause of human brucellosis. B. melitensis carries a smooth (S) lipopolysaccharide (LPS) with an N-formyl-perosamine O-polysaccharide (O-PS) that is absent in the rough LPS of B. ovis. Their control and eradication require vaccination, but B. melitensis Rev 1, the only vaccine available, triggers anti-O-PS antibodies that interfere in the S-brucellae serodiagnosis. Since eradication and serological surveillance of the zoonotic species are priorities, Rev 1 is banned once B. melitensis is eradicated or where it never existed, hampering B. ovis control and eradication. To develop a B. ovis specific vaccine, we investigated three Brucella live vaccine candidates lacking N-formyl-perosamine O-PS: Bov::CAΔwadB (CO2-independent B. ovis with truncated LPS core oligosaccharide); Rev1::wbdRΔwbkC (carrying N-acetylated O-PS); and H38ΔwbkF (B. melitensis rough mutant with intact LPS core). After confirming their attenuation and protection against B. ovis in mice, were tested in rams for efficacy. H38ΔwbkF yielded similar protection to Rev 1 against B. ovis but Bov::CAΔwadB and Rev1::wbdRΔwbkC conferred no or poor protection, respectively. All H38ΔwbkF vaccinated rams developed a protracted antibody response in ELISA and immunoprecipitation B. ovis diagnostic tests. In contrast, all remained negative in Rose Bengal and complement fixation tests used routinely for B. melitensis diagnosis, though some became positive in S-LPS ELISA owing to LPS core epitope reactivity. Thus, H38ΔwbkF is an interesting candidate for the immunoprophylaxis of B. ovis in B. melitensis-free areas.
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    Glucose Oxidation to Pyruvate Is Not Essential for Brucella suis Biovar 5 Virulence in the Mouse Model
    (2021) Moriyon, I. (Ignacio); Zuñiga-Ripa, A. (Amaia); de-Miguel, M.J. (María Jesús); Muñoz, P. (Pilar); Lázaro-Antón, L. (Leticia); Iriarte-Cilveti, M. (Maite); Letesson, J.J. (Jean Jacques); Conde-Alvarez, R. (Raquel); Barbier, T. (Thibault)
    Brucella species cause brucellosis, a worldwide extended zoonosis. The brucellae are related to free-living and plant-associated α2-Proteobacteria and, since they multiply within host cells, their metabolism probably reflects this adaptation. To investigate this, we used the rodent-associated Brucella suis biovar 5, which in contrast to the ruminant-associated Brucella abortus and Brucella melitensis and other B. suis biovars, is fast-growing and conserves the ancestral Entner-Doudoroff pathway (EDP) present in the plant-associated relatives. We constructed mutants in Edd (glucose-6-phosphate dehydratase; first EDP step), PpdK (pyruvate phosphate dikinase; phosphoenolpyruvate ⇌ pyruvate), and Pyk (pyruvate kinase; phosphoenolpyruvate → pyruvate). In a chemically defined medium with glucose as the only C source, the Edd mutant showed reduced growth rates and the triple Edd-PpdK-Pyk mutant did not grow. Moreover, the triple mutant was also unable to grow on ribose or xylose. Therefore, B. suis biovar 5 sugar catabolism proceeds through both the Pentose Phosphate shunt and EDP, and EDP absence and exclusive use of the shunt could explain at least in part the comparatively reduced growth rates of B. melitensis and B. abortus. The triple Edd-PpdK-Pyk mutant was not attenuated in mice. Thus, although an anabolic use is likely, this suggests that hexose/pentose catabolism to pyruvate is not essential for B. suis biovar 5 multiplication within host cells, a hypothesis consistent with the lack of classical glycolysis in all Brucella species and of EDP in B. melitensis and B. abortus. These results and those of previous works suggest that within cells, the brucellae use mostly 3 and 4 C substrates fed into anaplerotic pathways and only a limited supply of 5 and 6 C sugars, thus favoring the EDP loss observed in some species.
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    Disruption of pyruvate phosphate dikinase in Brucella ovis PA CO2-dependent and independent strains generates attenuation in the mouse model
    (2020) Moriyon, I. (Ignacio); Zuñiga-Ripa, A. (Amaia); Vizcaíno, N. (Nieves); Iriarte-Cilveti, M. (Maite); Pérez-Etayo, L. (Lara); Conde-Alvarez, R. (Raquel)
    Brucella ovis is a non-zoonotic rough Brucella that causes genital lesions, abortions and increased perinatal mortality in sheep and is responsible for important economic losses worldwide. Research on virulence factors of B. ovis is necessary for deciphering the mechanisms that enable this facultative intracellular pathogen to establish persistent infections and for developing a species-specific vaccine, a need in areas where the cross-protecting ovine smooth B. melitensis Rev1 vaccine is banned. Although several B. ovis virulence factors have been identified, there is little information on its metabolic abilities and their role in virulence. Here, we report that deletion of pyruvate phosphate dikinase (PpdK, catalyzing the bidirectional conversion pyruvate ⇌ phosphoenolpyruvate) in B. ovis PA (virulent and CO2-dependent) impaired growth in vitro. In cell infection experiments, although showing an initial survival higher than that of the parental strain, this ppdK mutant was unable to multiply. Moreover, when inoculated at high doses in mice, it displayed an initial spleen colonization higher than that of the parental strain followed by a marked comparative decrease, an unusual pattern of attenuation in mice. A homologous mutant was also obtained in a B. ovis PA CO2-independent construct previously proposed for developing B. ovis vaccines to solve the problem that CO2-dependence represents for large scale production. This CO2-independent ppdK mutant reproduced the growth defect in vitro and the multiplication/clearance pattern in mouse spleens, and is thus an interesting vaccine candidate for the immunoprophylaxis of B. ovis ovine brucellosis.
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    Rev1 wbdR tagged vaccines against Brucella ovis
    (2019) Salvador-Bescós, M. (Miriam); Moriyon, I. (Ignacio); Zuñiga-Ripa, A. (Amaia); Aragón-Aranda, B. (Beatriz); de-Miguel, M.J. (María Jesús); Muñoz, P. (Pilar); Iriarte-Cilveti, M. (Maite); Martinez-Gomez, E. (Estrella); Conde-Alvarez, R. (Raquel)
    Sheep brucellosis is a worldwide extended disease caused by B. melitensis and B. ovis, two species respectively carrying smooth or rough lipopolysaccharide. Vaccine B. melitensis Rev1 is used against B. melitensis and B. ovis but induces an anti-smooth-lipopolysaccharide response interfering with B. melitensis serodiagnosis, which precludes its use against B. ovis where B. melitensis is absent. In mice, Rev1 deleted in wbkC (Brucella lipopolysaccharide formyl-transferase) and carrying wbdR (E. coli acetyl-transferase) triggered antibodies that could be differentiated from those evoked by wild-type strains, was comparatively attenuated and protected against B. ovis, suggesting its potential as a B. ovis vaccine.
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    The Phospholipid N-Methyltransferase and Phosphatidylcholine Synthase Pathways and the ChoXWV Choline Uptake System Involved in Phosphatidylcholine Synthesis Are Widely Conserved in Most, but Not All Brucella Species
    (2021) Salvador-Bescós, M. (Miriam); Moriyon, I. (Ignacio); Palacios-Chaves, L. (Leyre); Sholenkamp, C. (Christian); Zuñiga-Ripa, A. (Amaia); Aragón-Aranda, B. (Beatriz); de-Miguel, M.J. (María Jesús); Muñoz, P. (Pilar); Lázaro-Antón, L. (Leticia); Iriarte-Cilveti, M. (Maite); Vences-Guzmán, M.A. (Miguel Ángel); Conde-Alvarez, R. (Raquel)
    The brucellae are facultative intracellular bacteria with a cell envelope rich in phosphatidylcholine (PC). PC is abundant in eukaryotes but rare in prokaryotes, and it has been proposed that Brucella uses PC to mimic eukaryotic-like features and avoid innate immune responses in the host. Two PC synthesis pathways are known in prokaryotes: the PmtA-catalyzed trimethylation of phosphatidylethanolamine and the direct linkage of choline to CDP-diacylglycerol catalyzed by the PC synthase Pcs. Previous studies have reported that B. abortus and B. melitensis possess non-functional PmtAs and that PC is synthesized exclusively via Pcs in these strains. A putative choline transporter ChoXWV has also been linked to PC synthesis in B. abortus. Here, we report that Pcs and Pmt pathways are active in B. suis biovar 2 and that a bioinformatics analysis of Brucella genomes suggests that PmtA is only inactivated in B. abortus and B. melitensis strains. We also show that ChoXWV is active in B. suis biovar 2 and conserved in all brucellae except B. canis and B. inopinata. Unexpectedly, the experimentally verified ChoXWV dysfunction in B. canis did not abrogate PC synthesis in a PmtA-deficient mutant, which suggests the presence of an unknown mechanism for obtaining choline for the Pcs pathway in Brucella. We also found that ChoXWV dysfunction did not cause attenuation in B. suis biovar 2. The results of these studies are discussed with respect to the proposed role of PC in Brucella virulence and how differential use of the Pmt and Pcs pathways may influence the interactions of these bacteria with their mammalian hosts.
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    Correction: Rev1 wbdR tagged vaccines against Brucella ovis
    (Springer Nature, 2020) Salvador-Bescós, M. (Miriam); Moriyon, I. (Ignacio); Zuñiga-Ripa, A. (Amaia); Aragón-Aranda, B. (Beatriz); de-Miguel, M.J. (María Jesús); Muñoz, P. (Pilar); Iriarte-Cilveti, M. (Maite); Martinez-Gomez, E. (Estrella); Conde-Alvarez, R. (Raquel)
    Correction to: Vet Res (2019) 50:95
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    Brucellosis and one health: inherited and future challenges
    (2023) Moriyon, I. (Ignacio); De-Massis, F. (Frabizio); Letesson, J.J. (Jean Jacques); Blasco, J.M. (J. M.); Moreno, E. (Edgardo)
    One Health is the collaborative efforts of multiple disciplines to attain optimal health for people, animals and the environment, a concept that historically owes much to the study of brucellosis, including recent political and ethical considerations. Brucellosis One Health actors include Public Health and Veterinary Services, microbiologists, medical and veterinary practitioners and breeders. Brucellosis awareness, and the correct use of diagnostic, epidemiological and prophylactic tools is essential. In brucellosis, One Health implementation faces inherited and new challenges, some aggravated by global warming and the intensification of breeding to meet growing food demands. In endemic scenarios, disease awareness, stakeholder sensitization/engagement and the need to build breeder trust are unresolved issues, all made difficult by the protean characteristics of this zoonosis. Extended infrastructural weaknesses, often accentuated by geography and climate, are critically important. Capacity-building faces misconceptions derived from an uncritical adoption of control/eradication strategies applied in countries with suitable means, and requires additional reference laboratories in endemic areas. Challenges for One Health implementation include the lack of research in species other than cattle and small ruminants, the need for a safer small ruminant vaccine, the need to fill in the infrastructure gap, the need for realistic capacity-building, the creation of reference laboratories in critical areas, and the stepwise implementation of measures not directly transposed from the so-called developed countries.