Sugarcane bagasse derived xylooligosaccharides produced by an arabinofuranosidase/xylobiohydrolase from Bifidobacterium longum in synergism with xylanases.

Arabinoxylan is a major hemicellulose in the sugarcane plant cell wall with arabinose decorations that impose steric restrictions on the activity of xylanases against this substrate. Enzymatic removal of the decorations by arabinofuranosidases can allow a more efficient arabinoxylan degradation by xylanases. Here we produced and characterized a recombinant Bifidobacterium longum arabinofuranosidase from glycoside hydrolase family 43 (BlAbf43) and applied it, together with GH10 and GH11 xylanases, to produce xylooligosaccharides (XOS) from wheat arabinoxylan and alkali pretreated sugarcane bagasse. The enzyme synergistically enhanced XOS production by GH10 and GH11 xylanases, being particularly efficient in combination with the latter family of enzymes, with a degree of synergism of 1.7. We also demonstrated that the enzyme is capable of not only removing arabinose decorations from the arabinoxylan and from the non-reducing end of the oligomeric substrates, but also hydrolyzing the xylan backbone yielding mostly xylobiose and xylose in particular cases. Structural studies of BlAbf43 shed light on the molecular basis of the substrate recognition and allowed hypothesizing on the structural reasons of its multifunctionality.

Brucella abortus triggers the differential expression of immunomodulatory lncRNAs in infected murine macrophages.

Introduction: The lncRNAs (long non-coding RNAs) are the most diverse group of non-coding RNAs and are involved in most biological processes including the immune response. While some of them have been recognized for their influence on the regulation of inflammatory activity, little is known in the context of infection by Brucella abortus, a pathogen that presents significant challenges due to its ability to manipulate and evade the host immune system. This study focuses on characterize the expression profile of LincRNA-cox2, Lethe, lincRNA-EPS, Malat1 and Gas5 during infection of macrophages by B. abortus. Methods: Using public raw RNA-seq datasets we constructed for a lncRNA expression profile in macrophages Brucella-infected. In addition, from public RNA-seq raw datasets of RAW264.7 cells infected with B. abortus we constructed a transcriptomic profile of lncRNAs in order to know the expression of the five immunomodulating lncRNAs studied here at 8 and 24 h post-infection. Finally, we performed in vitro infection assays in RAW264.7 cells and peritoneal macrophages to detect by qPCR changes in the expression of these lncRNAs at first 12 hours post infection, a key stage in the infection cycle where Brucella modulates the immune response to survive. Results: Our results demonstrate that infection of macrophages with Brucella abortus, induces significant changes in the expression of LincRNA-Cox2, Lethe, LincRNA-EPS, Gas5, and Malat1. Discussion: The change in the expression profile of these immunomodulatory lncRNAs in response to infection, suggest a potential involvement in the immune evasion strategy employed by Brucella to facilitate its intracellular survival.

Production and characterization of a chimeric antigen, based on nucleocapsid of SARS-CoV-2 fused to the extracellular domain of human CD154 in HEK-293 cells as a vaccine candidate against COVID-19.

Despite that more than one hundred vaccines against SARS-CoV-2 have been developed and that some of them were evaluated in clinical trials, the latest results revealed that these vaccines still face great challenges. Among the components of the virus, the N-protein constitutes an attractive target for a subunit vaccine because it is the most abundant, highly conserved and immunogenic protein. In the present work, a chimeric protein (N-CD protein) was constructed by the fusion of the N-protein to the extracellular domain of human CD154 as the molecular adjuvant. HEK-293 cells were transduced with lentiviral vector bearing the N-CD gene and polyclonal cell populations were obtained. The N-CD protein was purified from cell culture supernatant and further characterized by several techniques. Immunogenicity studies in mice and non-human primates showed the N-CD protein induced high IgG titers in both models after two doses. Moreover, overall health monitoring of non-human primates demonstrated that animals were healthy during 228 days after first immunization. Data obtained support further investigation in order to develop this chimeric protein as vaccine candidate against COVID-19 and other coronavirus diseases.

Unraveling the Role of the Zinc-Dependent Metalloproteinase/HTH-Xre Toxin/Antitoxin (TA) System of Brucella abortus in the Oxidative Stress Response: Insights into the Stress Response and Virulence.

Toxin/antitoxin (TA) systems have been scarcely studied in Brucella abortus, the causative agent of brucellosis, which is one of the most prevalent zoonotic diseases worldwide. In this study, the roles of a putative type II TA system composed by a Zinc-dependent metalloproteinase (ZnMP) and a transcriptional regulator HTH-Xre were evaluated. The deletion of the open reading frame (ORF) BAB1_0270, coding for ZnMP, used to produce a mutant strain, allowed us to evaluate the survival and gene expression of B. abortus 2308 under oxidative conditions. Our results showed that the B. abortus mutant strain exhibited a significantly reduced capacity to survive under hydrogen peroxide-induced oxidative stress. Furthermore, this mutant strain showed a decreased expression of genes coding for catalase (katE), alkyl hydroperoxide reductase (ahpC) and transcriptional regulators (oxyR and oxyR-like), as well as genes involved in the general stress response, phyR and rpoE1, when compared to the wild-type strain. These findings suggest that this type II ZnMP/HTH-Xre TA system is required by B. abortus to resist oxidative stress. Additionally, previous evidence has demonstrated that this ZnMP also participates in the acidic stress resistance and virulence of B. abortus 2308. Therefore, we propose a hypothetical regulatory function for this ZnMP/HTH-Xre TA system, providing insight into the stress response and its potential roles in the pathogenesis of B. abortus.

A chimeric protein-based vaccine elicits a strong IgG antibody response and confers partial protection against Shiga toxin-producing Escherichia coli in mice.

Background: Shiga toxin-producing Escherichia coli (STEC) is a foodborne pathogen that causes gastrointestinal infections, ranging from acute diarrhea and dysentery to life-threatening diseases such as Hemolytic Uremic Syndrome. Currently, a vaccine to prevent STEC infection is an unmet medical need. Results: We developed a chimeric protein-based vaccine targeting seven virulence factors of STEC, including the Stx2B subunit, Tir, Intimin, EspA, Cah, OmpT, and AggA proteins. Immunization of mice with this vaccine candidate elicited significant humoral and cellular immune responses against STEC. High levels of specific IgG antibodies were found in the serum and feces of immunized mice. However, specific IgA antibodies were not detected in either serum or feces. Furthermore, a significantly higher percentage of antigen-specific CD4+ T cells producing IFN-γ, IL-4, and IL-17 was observed in the spleens of immunized mice. Notably, the immunized mice showed decreased shedding of STEC O157:H7 and STEC O91:H21 strains and were protected against weight loss during experimental infection. Additionally, infection with the STEC O91:H21 strain resulted in kidney damage in control unimmunized mice; however, the extent of damage was slightly lower in immunized mice. Our findings suggest that IgG antibodies induced by this vaccine candidate may have a role in inhibiting bacterial adhesion and complement-mediated killing. Conclusion: This study provides evidence that IgG responses are involved in the host defense against STEC. However, our results do not rule out that other classes of antibodies also participate in the protection against this pathogen. Additional work is needed to improve the protection conferred by our vaccine candidate and to elucidate the relevant immune responses that lead to complete protection against this pathogen.

Vibrio cholerae, classification, pathogenesis, immune response, and trends in vaccine development.

Vibrio cholerae is the causative agent of cholera, a highly contagious diarrheal disease affecting millions worldwide each year. Cholera is a major public health problem, primarily in countries with poor sanitary conditions and regions affected by natural disasters, where access to safe drinking water is limited. In this narrative review, we aim to summarize the current understanding of the evolution of virulence and pathogenesis of V. cholerae as well as provide an overview of the immune response against this pathogen. We highlight that V. cholerae has a remarkable ability to adapt and evolve, which is a global concern because it increases the risk of cholera outbreaks and the spread of the disease to new regions, making its control even more challenging. Furthermore, we show that this pathogen expresses several virulence factors enabling it to efficiently colonize the human intestine and cause cholera. A cumulative body of work also shows that V. cholerae infection triggers an inflammatory response that influences the development of immune memory against cholera. Lastly, we reviewed the status of licensed cholera vaccines, those undergoing clinical evaluation, and recent progress in developing next-generation vaccines. This review offers a comprehensive view of V. cholerae and identifies knowledge gaps that must be addressed to develop more effective cholera vaccines.

Can Probiotics, Particularly Limosilactobacillus fermentum UCO-979C and Lacticaseibacillus rhamnosus UCO-25A, Be Preventive Alternatives against SARS-CoV-2?

COVID-19, an infection produced by the SARS-CoV-2 virus in humans, has rapidly spread to become a high-mortality pandemic. SARS-CoV-2 is a single-stranded RNA virus characterized by infecting epithelial cells of the intestine and lungs, binding to the ACE2 receptor present on epithelial cells. COVID-19 treatment is based on antivirals and antibiotics against symptomatology in addition to a successful preventive strategy based on vaccination. At this point, several variants of the virus have emerged, altering the effectiveness of treatments and thereby attracting attention to several alternative therapies, including immunobiotics, to cope with the problem. This review, based on articles, patents, and an in silico analysis, aims to address our present knowledge of the COVID-19 disease, its symptomatology, and the possible beneficial effects for patients if probiotics with the characteristics of immunobiotics are used to confront this disease. Moreover, two probiotic strains, L. fermentum UCO-979C and L. rhamnosus UCO-25A, with different effects demonstrated at our laboratory, are emphasized. The point of view of this review highlights the possible benefits of probiotics, particularly those associated with immunomodulation as well as the production of secondary metabolites, and their potential targets during SARS-CoV-2 infection.

The effect of the electromagnetic field on the physicochemical properties of isolated corn starch obtained of plants from irradiate seeds.

Maize grains are composed of the pericarp, endosperm, and germ. Consequently, any treatment, such as electromagnetic fields (EMF) must alter these components, which in turn alters the physicochemical properties of the grain. Since starch is a major component of corn grain, and given the great industrial importance of starch, this study investigates how EMF affects the physicochemical properties of starch. Mother seed were exposed to three different intensities 23, 70, and 118 µT for 15 days. Except for a slight porosity on the surface of the starch of the grains of plants exposed to higher EMF, the starch showed no morphological differences between the different treatments and the control (according to scanning electron microscopy). The X-ray patterns showed that the orthorhombic structure was kept constant, unaffected by the intensity of EMF. However, the pasting profile of starch was affected, and a decrease in the peak viscosity was obtained when the intensity of EMF increased. In contrast to the control plants, FTIR shows characteristic bands which can be attributed to the stretching of the CO bonds at wave number 1.711 cm-1. EMF can be considered a physical modification of starch.

Neumomediastino espontáneo en paciente con COVID-19 / Sponteneous pneumomediastinum in patient with COVID-19

Introducción: El neumomediastino espontáneo o síndrome Hamman es una complicación poco frecuente y rara. Se define como la presencia de aire o gas dentro del mediastino sin una causa identificada. Objetivo: Presentar un caso clínico con una complicación poco frecuente, neumomediastino espontáneo, en un paciente con enfermedad por COVID-2019. Caso clínico: Paciente de 86 años con cuadro clínico manifestado por fiebre de 38o C y síntomas respiratorios (tos con secreción blanquecina, disnea de moderados esfuerzos). Se realiza prueba de reacción en cadena de polimerasa para enfermedad por coronavirus 2019, esta fue positiva. Al cuarto día de su hospitalización concurre con empeoramiento clínico dentro que lo destaca tos y disnea progresiva acompañado con saturación de oxigeno menor a 91 por ciento. Se realizaron estudios imagenológicos de alta resolución (angiotomografía computarizada de tórax) en la cual se evidencia la presencia de neumomediastino. Desarrollo: La pandemia por enfermedad por coronavirus 2019 ha dado lugar a una emergencia de salud pública a nivel mundial, en la que es importante que el personal de la salud esté familiarizados con los síntomas, los resultados de imágenes y con las complicaciones de esta enfermedad, como el neumomediastino encontrado en este caso. Conclusión . El neumomediastino espontáneo es una complicación poco frecuente que se presenta en la fase inflamatoria de esta enfermedad(AU)

Introduction: Spontaneous pneumomediastinum or Hamman syndrome is a rare and infrequent complication. It is defined as the presence of air or gas within the mediastinum without an identified cause. Objective: To report a clinical case of spontaneous pneumomediastinum in a patient with COVID-2019, a disease with a rare complication. Clinical case report: We report the case of an 86-year-old patient with a clinical condicion of fever of 38o C and respiratory symptoms (cough with whitish secretions, dyspnea on moderate exertion). He underwent a polymerase chain reaction test for coronavirus disease 2019, which resulted positive. On the fourth day of his hospitalization, he his clinical condition worsened, including cough and progressive dyspnea accompanied by oxygen saturation less than 91 percent. The presence of pneumomediastinum was revealed by high-resolution imaging studies (computed tomography angiography of the chest). Discussion: The 2019 coronavirus disease pandemic has given rise to a global public health emergency, which requires health personnel to be familiar with symptoms, imaging results, and complications of this disease, such as pneumomediastinum found in this case. Conclution: Spontaneous pneumomediastinum is a rare complication that occurs in the inflammatory phase of this disease(AU)

Programa de planificación semanal para el desarrollo de la fuerza en judocas de la categoría 9-10 años / Programa semanal de planeamento para o desenvolvimento da força nos judocas da categoria dos 9-10 anos de idade / Weekly planning program for the development of strength in female judo athletes of the 9-10 years old category

RESUMEN El presente trabajo consistió en la elaboración de un programa de planificación semanal para el desarrollo de la fuerza en judocas de la categoría 9-10 años. El mismo tuvo como propósito esencial, ofertar una vía para influir positivamente en el rendimiento de los judocas pertenecientes a este grupo etario, a la vez que se dispone de un nuevo recurso para elaborar la planificación de la fuerza para esta disciplina deportiva, con lo que se contribuye, además, con el proceso de superación de los profesores deportivos que laboran en el eslabón de base. Para ello, se tuvieron en cuenta los fundamentos morfo-biomecánicos de los ejercicios de fuerza, así como las características morfo-funcionales de los niños que pertenecen a la misma. Para la obtención de información, se utilizaron como métodos la revisión de documentos, la encuesta y la observación. Al no encontrarse referentes al respecto en la bibliografía especializada que fue consultada, así como la falta de evidencia de una planificación semanal del entrenamiento de la fuerza, sustentado en los parámetros anteriormente mencionados, lo que pudo constatarse a través del diagnóstico efectuado. Los autores lograron diseñar un programa de planificación semanal para el desarrollo de la fuerza en judocas de la categoría 9-10 años, acorde con las exigencias fisiológicas de este grupo etario. De este modo, se pudo influir de forma positiva en el desarrollo de esta capacidad motora, sin daños para el organismo de estos niños.

RESUMO O presente trabalho consistiu na elaboração de um programa de planeamento semanal para o desenvolvimento da força nos judocas da categoria dos 9-10 anos de idade. O seu objectivo essencial era oferecer uma forma de influenciar positivamente o desempenho dos judocas pertencentes a esta faixa etária, tendo ao mesmo tempo um novo recurso para desenvolver o planeamento de força para esta disciplina desportiva, o que também contribui para o processo de melhoria dos professores de desporto que trabalham no elo básico. Para tal, foram tidos em conta os fundamentos morfo-biomecânicos dos exercícios de força, bem como as características morfofuncionais das crianças que a ela pertencem. A fim de obter informações, foram utilizados como métodos a revisão, o levantamento e a observação de documentos. Uma vez que não foram encontradas referências na bibliografia especializada que foi consultada, bem como a falta de provas de um planeamento semanal do treino de força, baseado nos parâmetros acima mencionados, que pôde ser verificado através do diagnóstico efetuado, os autores puderam conceber um programa de planeamento semanal para o desenvolvimento da força nos jogadores de judô da categoria dos 9-10 anos, de acordo com as exigências fisiológicas desta faixa etária. Desta forma, foi possível influenciar positivamente o desenvolvimento desta capacidade motora, sem danificar o corpo destas crianças.

ABSTRACT The present work consisted in the elaboration of a weekly planning program for the development of strength in judo female athletes of the 9-10 years old category. Its essential purpose was to offer a way to positively influence the performance of judo female athletes belonging to this age group, at the same time that a new resource is available to elaborate the planning of strength for this sport discipline, which also contributes to the process of improvement of sports teachers who work in the basic link. For this purpose, the morpho-biomechanical fundamentals of strength exercises were taken into account, as well as the morpho-functional characteristics of the children who belong to it. To obtain information, document review, survey and observation were used as methods. Since no references were found in the specialized bibliography that was consulted, as well as the lack of evidence of a weekly planning of strength training, based on the aforementioned parameters, which could be verified through the diagnosis carried out, the authors were able to design a weekly planning program for the development of strength in judo female athletes of the 9-10 years old category, according to the physiological demands of this age group. In this way, it was possible to have a positive influence on the development of this motor capacity, without harming the organism of these children.

Design of experiments driven optimization of alkaline pretreatment and saccharification for sugarcane bagasse.

To maximize the sugar release from sugarcane bagasse, a high-resolution Fractional Factorial Design (FFD) was combined with a Central Composite Orthogonal (CCO) design to simultaneously evaluate a wide range of variables for alkaline pretreatment (NaOH: 0.1-1 mol/L, temperature: 100-220 °C, and time: 20-80 min) and enzymatic saccharification (enzyme loading: 2.5-17.5%, and reaction volume: 550-850 µL). A total of 46 experimental conditions were evaluated and the maximum sugar yield (423 mg/g) was obtained after 18 h enzymatic hydrolysis under optimized conditions (0.25 mol/L NaOH at 202 °C for 40 min, with 12.5% of enzyme loading). Biomass compositional analyses showed that the pretreatments strongly removed lignin (up to 70%), silica (up to 80%) and promoted cellulose enrichment (25-110%). This robust design of experiments resulted in maximizing enzymatic hydrolysis efficiency of sugarcane bagasse and further indicated that this combined approach is versatile for other lignocellulosic biomasses.

Biomass composition of the golden tide pelagic seaweeds Sargassum fluitans and S. natans (morphotypes I and VIII) to inform valorisation pathways.

Massive strandings of the pelagic brown algae Sargassum have occurred in the Caribbean, and to a lesser extent, in western Africa, almost every year since 2011. These events have major environmental, health, and economic impacts in the affected countries. Once on the shore, Sargassum is mechanically harvested and disposed of in landfills. Existing commercial applications of other brown algae indicate that the pelagic Sargassum could constitute a valuable feedstock for potential valorisation. However, limited data on the composition of this Sargassum biomass was available to inform on possible application through pyrolysis or enzymatic fractionation of this feedstock. To fill this gap, we conducted a detailed comparative biochemical and elemental analysis of three pelagic Sargassum morphotypes identified so far as forming Atlantic blooms: Sargassum natans I (SnI), S. fluitans III (Sf), and S. natans VIII (SnVIII). Our results showed that SnVIII accumulated a lower quantity of metals and metalloids compared to SnI and Sf, but it contained higher amounts of phenolics and non-cellulosic polysaccharides. SnVIII also had more of the carbon storage compound mannitol. No differences in the content and composition of the cell wall polysaccharide alginate were identified among the three morphotypes. In addition, enzymatic saccharification of SnI produced more sugars compared to SnVIII and Sf. Due to high content of arsenic, the use of pelagic Sargassum is not recommended for nutritional purposes. In addition, low yields of alginate extracted from this biomass, compared with brown algae used for industrial production, limit its use as viable source of commercial alginates. Further work is needed to establish routes for future valorisation of pelagic Sargassum biomass.

Overcoming the trade-off between grain weight and number in wheat by the ectopic expression of expansin in developing seeds leads to increased yield potential.

Wheat is the most widely grown crop globally, providing 20% of all human calories and protein. Achieving step changes in genetic yield potential is crucial to ensure food security, but efforts are thwarted by an apparent trade-off between grain size and number. Expansins are proteins that play important roles in plant growth by enhancing stress relaxation in the cell wall, which constrains cell expansion. Here, we describe how targeted overexpression of an α-expansin in early developing wheat seeds leads to a significant increase in grain size without a negative effect on grain number, resulting in a yield boost under field conditions. The best-performing transgenic line yielded 12.3% higher average grain weight than the control, and this translated to an increase in grain yield of 11.3% in field experiments using an agronomically appropriate plant density. This targeted transgenic approach provides an opportunity to overcome a common bottleneck to yield improvement across many crops.

Aporte de la 18F-FDG PET/TC en la enfermedad de Creutzfeldt-Jakob esporádica / Contribution of the 18F-FDG PET/CT IN sporadic Creutzfeldt-Jakob disease

La enfermedad de Creutzfeldt-Jakob esporádica (ECJe) es un trastorno neurodegenerativo transmisible, extremadamente raro, caracterizado por demencia rápidamente progresiva. En la tomografía por emisión de positrones con 18F-fluoro-2-desoxi-D-glucosa (18F-FDG-PET/TC) de estos pacientes se ha descrito hipometabolismo cortical bilateral parietal, frontal y occipital, sin alteraciones en el cerebelo ni en los ganglios basales, lo que podría contribuir con el diagnóstico diferencial de demencia rápidamente progresiva. Se presenta el caso de un hombre de 75 años de edad, con antecedente de cáncer de próstata y trastorno afectivo bipolar, con cuadro de dos semanas de cambios comportamentales y anímicos, déficit cognitivo, alucinaciones visuales y auditivas y desorientación espacial con rápida progresión. Posteriormente, el paciente presenta marcha lenta, temblor en miembros inferiores y Babinski derecho. La resonancia magnética (RM) cerebral mostró restricción a la difusión en la corteza frontal y temporal bilateral y giro del cíngulo, con sospecha diagnóstica de síndrome paraneoplásico versus enfermedad por priones. La 18F-FDG-PET/TC demostró hipometabolismo en la corteza frontal bilateral y lóbulo temporal y parietal derechos. La medición de la proteína 14-3-3, proteína T-Tau y conversión de proteína priónica inducida por agitación en tiempo real (RT-QUIC) en líquido cefalorraquídeo confirmó el diagnóstico de enfermedad por priones.

Sporadic Creutzfeldt-Jakob disease (sCJD) is an extremely rare transmissible neurodegenerative disorder characterized by rapidly progressive dementia. 18F-fluoro-2-deoxy-D-glucose positron emission tomography (18F-FDG-PET/CT) in these patients has described bilateral parietal, frontal and occipital cortical hypometabolism, without alterations in the cerebellum or basal ganglia, which could contribute to the differential diagnosis of rapidly progressive dementia. We present the case of a 75-year-old man with a history of prostate cancer and bipolar affective disorder, with a two-week picture of behavioral and mood changes, cognitive deficit, visual and auditory hallucinations and spatial disorientation with rapid progression. Subsequently, the patient presented slow gait, tremor in lower limbs and right Babinski. Brain magnetic resonance imaging (MRI) showed diffusion restriction in the bilateral frontal and temporal cortex and cingulate gyrus, with diagnostic suspicion of paraneoplastic syndrome versus prion disease. 18F-FDG-PET/CT showed hypometabolism in the bilateral frontal cortex and right temporal and parietal lobe. Measurement of 14-3-3 protein, T-Tau protein and real-time shake-induced prion protein conversion (RT-QUIC) in cerebrospinal fluid confirmed the diagnosis of prion disease.

Intranasal Immunization of Mice with Multiepitope Chimeric Vaccine Candidate Based on Conserved Autotransporters SigA, Pic and Sap, Confers Protection against Shigella flexneri.

Shigellosis is a diarrheal disease and the World Health Organization prompts the development of a vaccine against Shigella flexneri. The autotransporters SigA, Pic and Sap are conserved among Shigella spp. We previously designed an in silico vaccine with immunodominat epitopes from those autotransporters, and the GroEL protein of S. typhi as an adjuvant. Here, we evaluated the immunogenicity and protective efficacy of the chimeric multiepitope protein, named rMESF, in mice against lethal infection with S. flexneri. rMESF was administered to mice alone through the intranasal (i.n.) route or accompanied with Complete Freund's adjuvant (CFA) intradermically (i.d.), subcutaneously (s.c.), and intramuscular (i.m.), as well as with Imject alum (i.m.). All immunized mice increased IgG, IgG1, IgG2a, IgA and fecal IgA titers compared to PBS+CFA and PBS+alum control groups. Furthermore, i.n. immunization of mice with rMESF alone presented the highest titers of serum and fecal IgA. Cytokine levels (IFN-γ, TNF-α, IL-4, and IL-17) and lymphocyte proliferation increased in all experimental groups, with the highest lymphoproliferative response in i.n. mice immunized with rMESF alone, which presented 100% protection against S. flexneri. In summary, this vaccine vests protective immunity and highlights the importance of mucosal immunity activation for the elimination of S. flexneri.

A Zinc-Dependent Metalloproteinase of Brucella abortus Is Required in the Intracellular Adaptation of Macrophages.

Brucella abortus is a pathogen that survives in macrophages. Several virulence factors participate in this process, including the open reading frame (ORF) BAB1_0270 codifying for a zinc-dependent metalloproteinase (ZnMP). Here, its contribution in the intracellular adaptation of B. abortus was analyzed by infecting RAW264.7 macrophages with the mutant B. abortus Δ270 strain. Results showed that this ZnMP did not participated in either the adherence or the initial intracellular traffic of B. abortus in macrophages. Nevertheless, its deletion significantly increased the co-localization of B. abortus Δ270 with phagolysosomal cathepsin D and reduced its co-localization with calnexin present in endoplasmic reticulum (RE)-derived vesicles. Although B. abortus Δ270 showed an upregulated expression of genes involved in virulence (vjbR, hutC, bvrR, virB1), it was insufficient to reach a successful intracellular replication within macrophages. Furthermore, its attenuation favored in macrophages infected the production of high levels of cytokines (TNF-α and IL-6) and co-stimulatory proteins (CD80 and CD86), signals required in T cell activation. Finally, its deletion significantly reduced the ability of B. abortus Δ270 to adapt, grow and express several virulence factors under acidic conditions. Based on these results, and considering that this ZnMP has homology with ImmA/IrrE proteases, we discuss its role in the virulence of this pathogen, concluding that ZnMP is required in the intracellular adaptation of B. abortus 2308 during the infection of macrophages.

The Role of the Flagellar Protein FlgJ in the Virulence of Brucella abortus.

Brucella abortus is a facultative intracellular pathogen that causes a zoonosis called brucellosis. This disease leads to abortion and infertility in cattle, and diverse complications in humans. B. abortus is a successful intracellular bacterium that has developed the ability to evade the host's immune system and it replicates in professional and non-professional phagocytic cells, persisting in the different tissues, and organs of its hosts. It has been described that Brucella expresses a polar flagellum under certain conditions, but its function is still unknown. In this study we evaluated the role of the FlgJ, a protein, presumably a peptidoglycan hydrolase involved in flagellum formation and in the virulence of B. abortus strain 2308. B. abortus 2308 ΔflgJ mutant and complemented strains were constructed to study the function of the FlgJ protein in the context of the virulence of this pathogen in in vitro and in vivo assays. The results showed that the elimination of the flgJ gene delays the growth rate of B. abortus in culture, reduces its intracellular survival capacity in professional and non-professional phagocytic cells, rendering it unable to escape from the endocytic route and not reaching the endoplasmic reticulum. It also negatively affects their persistence in BALB/c mice. Functionally, the B. abortus 2308 flgJ gene restored motility to an E. coli flgJ mutant gene. Furthermore, it was discovered that the production of FlgJ protein is associated with the bacterial adherence by B. abortus. Therefore, although the specific function of the polar flagellum for Brucella is unknown, the data indicates that the flagellar flgJ gene and its product are required for full virulence of B. abortus 2308, since its deletion significantly reduces the fitness of this pathogen in vitro and in vivo.

Cell wall remodeling under salt stress: Insights into changes in polysaccharides, feruloylation, lignification, and phenolic metabolism in maize.

Although cell wall polymers play important roles in the tolerance of plants to abiotic stress, the effects of salinity on cell wall composition and metabolism in grasses remain largely unexplored. Here, we conducted an in-depth study of changes in cell wall composition and phenolic metabolism induced upon salinity in maize seedlings and plants. Cell wall characterization revealed that salt stress modulated the deposition of cellulose, matrix polysaccharides and lignin in seedling roots, plant roots and stems. The extraction and analysis of arabinoxylans by size-exclusion chromatography, 2D-NMR spectroscopy and carbohydrate gel electrophoresis showed a reduction of arabinoxylan content in salt-stressed roots. Saponification and mild acid hydrolysis revealed that salinity also reduced the feruloylation of arabinoxylans in roots of seedlings and plants. Determination of lignin content and composition by nitrobenzene oxidation and 2D-NMR confirmed the increased incorporation of syringyl units in lignin of maize roots. Salt stress also induced the expression of genes and the activity of enzymes enrolled in phenylpropanoid biosynthesis. The UHPLC-MS-based metabolite profiling confirmed the modulation of phenolic profiling by salinity and the accumulation of ferulate and its derivatives 3- and 4-O-feruloyl quinate. In conclusion, we present a model for explaining cell wall remodeling in response to salinity.

Efficacy of a self-applied online program to promote resilience and coping skills in university students in four Spanish-speaking countries: study protocol for a randomized controlled trial.

BACKGROUND: There is evidence of a high prevalence of depression and anxiety in university students. Therefore, college time is a key period where prevention of mental disorders through interventions that promote resilience and mental health can be relevant. Currently, there are interventions available, but these are insufficient for those who need them. Online interventions are tools that can facilitate global accessibility and are easy for young people to use. CORE (Cultivating Our Resilience) is a self-administered online program, based on Ryff's psychological well-being model, to promote resilience and coping skills in university students at risk of developing symptoms of depression or anxiety. The objective is to evaluate the effectiveness of this intervention protocol in comparison with an active control condition targeting healthy lifestyle, and a waiting list control condition. The study will be conducted in four populations of Spanish-speaking university students (Spain, Argentina, Colombia, and Mexico). METHODS: The study design is a randomized controlled trial (RCT). At least 324 university students will be randomly assigned to three conditions: 1) CORE, a 6-week training program to improve resilience; 2) HLP, a 6-week training to promote a healthy lifestyle; and 3) WL, waiting list control condition. The primary outcome measure will be the Connor-Davidson resilience scale. Additionally, measures of anxiety, depression, quality of life and socio-demographic variables (age, sex, incomes, marital status, among others) will be collected. Participants will be evaluated at pre-treatment, after each module, 6 weeks after allocation, and at 3-month follow-up. Intention-to-treat and per-protocol analyses will be performed. DISCUSSION: The results of this study will contribute to research on Internet-administered interventions and the implementation of a protocol that includes a series of components designed to improve resilience and coping skills, increase psychological well-being, and prevent depression and anxiety disorders in Spanish-speaking university students. In addition, avenues will be opened up for new research on the effectiveness of these interventions focused on the prevention and promotion of mental health in Spanish-speaking countries. TRIAL REGISTRATION: Registered at ClinicalTrials.gov NCT03903978 on April 2, 2019.