Characterization of Cell Envelope Multiple Mutants of Brucella ovis and Assessment in Mice of Their Vaccine Potential

Brucella ovis is a non-zoonotic Brucella species lacking specific vaccine. It presents a narrow host range, a unique biology relative to other Brucella species, and important distinct surface properties. To increase our knowledge on its peculiar surface and virulence features, and seeking to develop a specific vaccine, multiple mutants for nine relevant cell-envelope-related genes were investigated. Mutants lacking Omp10 plus Omp19 could not be obtained, suggesting that at least one of these lipoproteins is required for viability. A similar result was obtained for the double deletion of omp31 and omp25 that encode two major surface proteins. Conversely, the absence of major Omp25c (proved essential for internalization in HeLa cells) together with Omp25 or Omp31 was tolerated by the bacterium. Although showing important in vitro and in vivo defects, the Δomp10Δomp31Δomp25c mutant was obtained, demonstrating that B. ovis PA survives to the simultaneous absence of Omp10 and four out seven proteins of the Omp25/Omp31 family (i.e., Omp31, Omp25c, Omp25b, and Omp31b, the two latter naturally absent in B. ovis). Three multiple mutants were selected for a detailed analysis of virulence in the mouse model. The Δomp31Δcgs and Δomp10Δomp31Δomp25c mutants were highly attenuated when inoculated at 106 colony forming units/mouse but they established a persistent infection when the infection dose was increased 100-fold. The Δomp10ΔugpBΔomp31 mutant showed a similar behavior until week 3 post-infection but was then totally cleared from spleen. Accordingly, it was retained as vaccine candidate for mice protection assays. When compared to classical B. melitensis Rev1 heterologous vaccine, the triple mutant induced limited splenomegaly, a significantly higher antibody response against whole B. ovis PA cells, an equivalent memory cellular response and, according to spleen colonization measurements, better protection against a challenge with virulent B. ovis PA. Therefore, it would be a good candidate to be evaluated in the natural host as a specific vaccine against B. ovis that would avoid the drawbacks of B. melitensis Rev1. In addition, the lack in this attenuated strain of Omp31, recognized as a highly immunogenic protein during B. ovis infection, would favor the differentiation between infected and vaccinated animals using Omp31 as diagnostic target

Eina interactiva per a l'anàlisi de fraus editorials en salut

Revistes depredadores; Fraus editorials; Investigació; PublicacióPredatory magazines; Editorial frauds; Investigation; PublicationRevistas depredadoras; Fraudes editoriales; Investigación; PublicaciónINTRODUCCIÓ Es presenta una eina destinada als investigadors, elaborada a la Biblioteca de Ciències de la Salut de la UV. L’objectiu és comprovar la credibilitat de revistes potencialment fraudulentes, mitjançant l’anàlisi de la seua presència en bases de dades, recursos d’avaluacio de revistes científiques i el seu grau d’acompliment dels criteris de les associacions d’editors de publicacions mèdiques: https://airtable.com/shruAWiTvt9ubJnCn/tblRP5wUJfU83lbv5?blocks=hide MÈTODE S'ha partit d’una selecció de revistes de Salut potencialment fraudulentes de diferents fonts (Beall List, Dolos list, bibliografia especialitzada). A aquesta sel∙lecció s’ha aplicat una anàlisi sistemàtica en tres tipus de fonts: bases de dades (Medline, JCR i WoS, Scopus, MIAR, etc.), eines d’avaluació de revistes científiques (Journal Guide, Retraction Watch) i, en tercer lloc, l’acompliment o no dels requeriments d’associacions d’editor de publicacione médiques (WAME, OASPA, etc.) La informació s'ha volcat i tractat en una base de dades de l’aplicació lliure (Airtable). RESULTATS S’ofereix una potent eina interactiva que recopila més de 500 registres de revistes de Salut. L’eina ofereix la recuperación d’informació per múltiples criteris. A més, té possibilitat d’embeber‐se a Wordpress, Instagram etc., i una gran potencialitat de disseny. CONCLUSIONS Es proporciona als investigadors una eina complementària a les llistes negres de revistes depredadores, que ofereix informació objectiva i rellevant al voltant de les revistes, sense entrar en valoracions ni opinions. La seua elaboració a més ens ha dut a conèixer més en profunditat el món dels fraus editorials en Salut, i d’aquesta manera poder assessorar millor els nostres usuaris

A Brucella melitensis H38¿wbkF rough mutant protects against Brucella ovis in rams

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

Ahora / Ara

La cinquena edició del microrelatari per l’eradicació de la violència contra les dones de l’Institut Universitari d’Estudis Feministes i de Gènere «Purificación Escribano» de la Universitat Jaume I vol ser una declaració d’esperança. Aquest és el moment en el qual les dones (i els homes) hem de fer un pas endavant i eliminar la violència sistèmica contra les dones. Ara és el moment de denunciar el masclisme i els micromasclismes començant a construir una societat més igualitària. Cadascun dels relats del llibre és una denúncia i una declaració que ens encamina cap a un món millor

Biology and Genetics of the <em>Brucella</em> Outer Membrane

International audienceThe particular characteristics of the Brucella outer membrane (OM) are considered to importantly contribute to the biological properties of these bacteria that are able to survive in the hostile environment of phagocytes and cause persistent infections in diverse mammals. This contrasts with theBrucella's closest relatives in the genus Ochrobactrum which are only occasionally associated to opportunistic infections. High hydrophobicity, resistance to complement, bactericidal cationic peptides, detergents or EDTA, resistance to macrophage degradation or the protection against the host immune response are characteristics related to the Brucella OM. The O-polysaccharide chains of the smooth lipopolysaccharide (S-LPS) are a key component for the virulence of smooth strains but, since naturally rough B. canis and B. ovis that lack O-chains in the LPS are virulent in their respective natural hosts, other traits must have a significant role in virulence. Heterogeneity in LPS, OM proteins, and phospholipids draw a particular OM for each Brucellaa species (in some instances at the biovar or strain level) with a definite composition and topology. This variability leads to modifications in the antigenic and functional properties that could affect the interaction with the host and be related to the differences in pathogenicity and host tropism among the Brucellae

Evaluation in mice of Brucella ovis attenuated mutants for use as live vaccines against B. ovis infection

International audienceBrucella 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. ovis infection, but its use for this purpose has serious drawbacks. In this work, two previously characterized B. ovis attenuated mutants (Δomp25 d and Δomp22) were evaluated in mice, in comparison with B. melitensis Rev 1, as vaccines against B. ovis. Similarities, but also significant differences, were found regarding the immune response induced by the three vaccines. Mice vaccinated with the B. ovis mutants developed anti-B. ovis antibodies in serum of the IgG1, IgG2a and IgG2b subclasses and their levels were higher than those observed in Rev 1-vaccinated mice. After an antigen stimulus with B. ovis cells, splenocytes obtained from all vaccinated mice secreted similar levels of TNF-α and IL12(p40) and remarkably high amounts of IFN-γ, a crucial cytokine in protective immunity against other Brucella species. By contrast, IL-1α -an enhancer of T cell responses to antigen- was present at higher levels in mice vaccinated with the B. ovis mutants, while IL-10, an anti-inflammatory cytokine, was significantly more abundant in Rev 1-vaccinated mice. Additionally, the B. ovis mutants showed appropriate persistence, limited splenomegaly and protective efficacy against B. ovis similar to that observed with B. melitensis Rev 1. These characteristics encourage their evaluation in the natural host as homologous vaccines for the specific prophylaxis of B. ovis infection

Diseño de ejercicios de laboratorio virtual para el aprendizaje y la evaluaciónde técnicas y procesos microbiológicos de identificación y diagnóstico de microorganismos

Memoria ID-0066. Ayudas de la Universidad de Salamanca para la Innovación Docente, curso 2008-2009.Diseño y evaluación de nuevas prácticas de laboratorio virtual para el diagnóstico de enfermedades víricas y de identificación molecular de microorganismos productores de antibióticos para la enseñanza-aprendizaje de la asignatura Microbiología II del nuevo grado de Farmacia adaptado al EES