SARS-CoV-2 surveillance in untreated wastewater: detection of viral RNA in a low-resource community in Buenos Aires, Argentina.

OBJECTIVE: To measure SARS-CoV-2 RNA in sewage in a low-resource community in order to determine if it can be considered as an estimator of changes in the prevalence of COVID-19 in the population. METHODS: In this descriptive observational study we collected samples of surface waters contaminated with sewage and optimized a method of purification of viral RNA using PEG concentration. We determined the amount of genetic material by quantitative real-time PCR using the CDC method for SARS-CoV-2 detection. RESULTS: We quantified viral RNA in surface waters contaminated with sewage of a low resource community and determined that temporal trends of SARS-CoV-2 in wastewater samples mirrored trends in COVID-19 active cases. CONCLUSIONS: Measuring of SARS-CoV-2 RNA in sewage can be applied in low-resource communities without connection to sewers as an estimator of changes in the prevalence of COVID-19.

SARS-CoV-2 surveillance in untreated wastewater: detection of viral RNA in a low-resource community in Buenos Aires, Argentina

[ABSTRACT]. Objective. To measure SARS-CoV-2 RNA in sewage in a low-resource community in order to determine if it can be considered as an estimator of changes in the prevalence of COVID-19 in the population. Methods. In this descriptive observational study we collected samples of surface waters contaminated with sewage and optimized a method of purification of viral RNA using PEG concentration. We determined the amount of genetic material by quantitative real-time PCR using the CDC method for SARS-CoV-2 detection. Results. We quantified viral RNA in surface waters contaminated with sewage of a low resource community and determined that temporal trends of SARS-CoV-2 in wastewater samples mirrored trends in COVID-19 active cases. Conclusions. Measuring of SARS-CoV-2 RNA in sewage can be applied in low-resource communities without connection to sewers as an estimator of changes in the prevalence of COVID-19.

[RESUMEN]. Objetivo. Medir el ARN del SARS-CoV-2 en las aguas residuales de una comunidad de bajos recursos para determinar si se puede considerar un estimador de cambios en la prevalencia de la COVID-19 en la población. Métodos. En este estudio descriptivo de observación se tomaron muestras de las aguas superficiales contaminadas con aguas residuales y se optimizó un método de purificación del ARN viral mediante la concentración de polietilenglicol (PEG). Se determinó la cantidad de material genético por PCR cuantitativa en tiempo real empleando el método de los CDC para la detección del SARS-CoV-2. Resultados. Se cuantificó el ARN viral de las aguas superficiales contaminadas con aguas residuales de una comunidad de bajos recursos y se determinó que las tendencias temporales del SARS-CoV-2 en las muestras de aguas residuales reflejaban las tendencias en los casos activos de COVID-19. Conclusiones. La medición del ARN del SARS-CoV-2 en aguas residuales puede aplicarse en las comunidades de bajos recursos sin conexión al alcantarillado como un estimador de los cambios en la prevalencia de la COVID-19.

[RESUMO]. Objetivo. Medir o RNA do SARS-CoV-2 nas águas residuais de uma comunidade com poucos recursos, a fim de determinar se pode ser utilizado para estimar mudanças na prevalência de COVID-19 na população. Métodos. Neste estudo observacional descritivo, coletamos amostras de águas superficiais contaminadas com dejetos e otimizamos um método de purificação de RNA viral utilizando concentração de PEG. Determinamos a quantidade de material genético por PCR quantitativo em tempo real, usando o método do CDC para detecção de SARS-CoV-2. Resultados. Quantificamos o RNA viral em águas superficiais contaminadas com dejetos de uma comunidade com poucos recursos e determinamos que as tendências temporais do SARS-CoV-2 em amostras de águas residuais refletiam tendências de casos ativos de COVID-19. Conclusões. A mensuração do RNA do SARS-CoV-2 em águas residuais pode ser aplicada em comunidades com poucos recursos, sem ligação com a rede de esgoto, para estimar mudanças na prevalência de COVID-19.

Immunomodulatory effect of baculovirus in chickens: How it modifies the immune response against infectious bursal disease virus.

Several reports have shown that baculoviruses (BVs) have strong adjuvant properties on the mammalian immune system. Recent studies of our group demonstrated the ability of BV to stimulate the innate immunity in chickens. In this investigation, we aimed to assess the potential antiviral effect of BV given both, before and after infectious bursal disease virus (IBDV). In the first case, specific pathogen free chickens were intravenously inoculated with 5 × 10(7) pfu of Autographa californica nuclear polyhedrosis virus and 3 h later were orally administered 2.5 × 10(5) egg infectious doses 50 of IBDV. In the second case, chickens received IBDV 3 h before BV inoculation. Five days later, chickens were bled and euthanized. RNA from the bursa was analyzed for cytokine production. Also, bursae were used for virus recovery, and processed for lymphocyte isolation. The results showed that the administration of BV 3 h after the inoculation with IBDV produced important changes in the effect that IBDV causes in the bursa. BV reduced the infiltration of T lymphocytes, decreased the expression pattern of IL-6 and IFN-γ and inhibited IBDV replication. The results herein presented demonstrate that this Lepidopteran virus shows antiviral activity in chickens under experimental conditions. Investigations under field conditions have to be done to probe this strategy as a valuable sanitary tool for the treatment and prevention of chicken diseases.

Infectious Bursal Disease Virus non-structural protein VP5 is not a transmembrane protein.

Infectious Bursal Disease Virus (IBDV) causes a highly relevant poultry disease that affects young chickens causing, among other effects, immunosuppression. IBDV is a bi-segmented double stranded RNA virus. The smaller ORF of larger RNA segment encodes VP5, a 17-kDa non-structural protein. Although it is an important protein for viral replication cycle, the definition of its specific role and subcellular localization remains unclear. In the present work we demonstrate, using imaging techniques, that VP5 is not a type II transmembrane protein but an intracellular membrane-associated protein. This finding might provide evidences of VP5 interaction with cellular proteins and its functions.

Immune response elicited by the oral administration of an intermediate strain of IBDV in chickens

The immune response elicited by the oral inoculation of an intermediate strain of infectious bursal disease virus was studied in chickens. A strong over expression of IL-6, IL-8, IFNα and IFNγ was observed in bursa at 3 days post inoculation together with an increase in splenic NO2 release. An influx of T-lymphocytes was also detected.

Immune response elicited by the oral administration of an intermediate strain of IBDV in chickens.

The immune response elicited by the oral inoculation of an intermediate strain of infectious bursal disease virus was studied in chickens. A strong over expression of IL-6, IL-8, IFNα and IFNγ was observed in bursa at 3 days post inoculation together with an increase in splenic NO2 release. An influx of T-lymphocytes was also detected.

Transient expression of VP2 in Nicotiana benthamiana and its use as a plant-based vaccine against infectious bursal disease virus.

Infectious Bursal Disease Virus (IBDV) is the etiological agent of an immunosuppressive and highly contagious disease that affects young birds. This disease causes important economic losses in the poultry industry worldwide. The VP2 protein has been used for the development of subunit vaccines in a variety of heterologous platforms. In this context, the aim of this study was to investigate VP2 expression and immunogenicity using an experimental plant-based vaccine against IBDV. We determined that the agroinfiltration of N. benthamiana leaves allowed the production of VP2 with no apparent change on its conformational epitopes. Chickens intramuscularly immunized in a dose/boost scheme with crude concentrated extracts developed a specific humoral response with viral neutralizing ability. Given these results, it seems plausible for a plant-based vaccine to have a niche in the veterinary field. Thus, plants can be an adequate system of choice to produce immunogens against IBDV.

Modulation of innate immunity in chickens induced by in vivo administration of baculovirus.

Baculoviruses stimulate cytokine production in mammalian cells. They induce a strong innate immune response in animals and have adjuvant properties. The purpose of this work was to study the in vivo effect of baculovirus on chicken innate immune response. SPF chickens were inoculated intravenously with Autographa californica nuclear polyhedrosis virus (BV). Three hours later, chickens were bled, euthanized and their spleen, duodenum and cecal tonsils were excised in order to take samples for RNA extraction and real time PCR, and to isolate lymphocytes, which were stained and analyzed by flow cytometry. The results obtained showed that baculovirus inoculation up-regulates the expression of IFN-γ, IL-6 and LITAF in spleen cells. This result (IFN-γ) correlated with that obtained by ELISA which showed a very strong increase of IFN-γ in chicken plasma. Flow cytometry analysis revealed that BV inoculation induced in spleen an increase in the percentage of monocyte/macrophage population together with an increase in CD3(+)CD4(+) T lymphocytes. On the other hand, BV inoculation decreased the percentage of CD3(+)CD4(+) T lymphocytes and increased the percentage of NK cells in cecal tonsils. However, intraepithelial lymphocytes of the gut did not show differences between BV and control treated animals. Even though further studies in order to understand the mechanisms by which BVs affect the avian immune response are needed, results obtained in the present work demonstrate the ability of BVs to stimulate the innate immunity in chickens, modifying the expression pattern of related genes and the profile of the immune cells involved.

Expression of a secreted version of the hemagglutinin-neuraminidase glycoprotein of Newcastle disease virus: its evaluation as a diagnostic reagent.

The hemagglutinin-neuraminidase (HN) glycoprotein of Newcastle disease virus (NDV) constitutes, together with the fusion glycoprotein, the main surface antigen of this avian pathogen, which causes a highly contagious disease, relevant economically worldwide. The purpose of this work was to obtain the HN glycoprotein as a soluble antigen in culture supernatants of recombinant baculovirus-infected Spodoptera frugiperda (Sf9) cells and to evaluate its application to the development of a recombinant enzyme-linked immunosorbent assay (rELISA) for the analysis of chicken sera. A transfer vector for baculovirus containing the sequence of a melittin signal peptide was constructed and the sequence coding for HN protein without its own signal peptide was cloned. The recombinant protein was secreted and recovered easily from the culture medium of Sf9-infected cells. The recombinant protein was evaluated as antigen for ELISA coating the plates with the recovered HN using 79 positive and 142 negative samples. The Cohen kappa value resulted 0.91, indicating excellent agreement between the rELISA and the hemagglutinin inhibition tests. The rELISA was also compared with a commercial ELISA, finding high levels of agreement between both assays. The present results show that the cloning strategy developed yielded the HN protein free in the cell culture supernatant and that the recombinant protein retained its reactivity with anti-NDV HN antibodies in chicken sera.

Activation of the immune response against Infectious Bursal Disease Virus after intramuscular inoculation of an intermediate strain.

Infectious bursal disesase is a highly contagious, wide spread immunosuppressive chicken disease caused by the Infectious Bursal Disease Virus (IBDV). IBDV is a two segmented double-strand RNA virus, member of the Birnaviridae family. In order to study the interaction between IBDV and the immune system, chickens were exposed to an intermediate IBDV strain by intramuscular route, and using Real Time PCR the expression of a panel of avian cytokines and chemokines in duodenum, spleen and bursa of Fabricius was analyzed. Also, splenic nitrite (NO2) production and the frequencies of different mononuclear cell populations were evaluated by Griess reaction and flow cytometry, respectively. Intramuscular (i.m.) IBDV inoculation promoted an over expression of proinflammatory cytokines IL-6, IL-15 and gIFN in spleen, which correlated with an increase of gIFN plasma concentration measured by ELISA, together with an increment of NO2 concentration in splenocyte supernatants at 1dpi. Results obtained in the present work showed that IBDV of intermediate virulence, given i.m., induced similar effects to those previously described for highly virulent IBDV in early innate immune responses. Considering that the i.m. route is the route of choice for the delivery of new generation vaccines, and that the use of recombinant antigens also requires the addition of adjuvants for proper immune stimulation, results presented here could contribute to identify suitable cytokines to be used or to be stimulated when utilizing subunit vaccines, for the improvement of prevention tools for avian health.

Potential use of the hemagglutinin-neuraminidase glycoprotein of Newcastle disease virus expressed in Rachiplusia nu larvae as an immunogen for chickens.

The hemagglutinin-neuraminidase glycoprotein of Newcastle disease virus (NDV) was obtained as a recombinant antigen in Rachiplusia nu larvae. When it was used as an immunogen in chickens, a solid immune response, including neutralizing antibodies, was detected, demonstrating the potential use of this simple and economic strategy in the design of recombinant anti-NDV vaccines.

Salud e intervención en lo social

Contenido: Abordaje social de la malnutrición. Vía para la construcción de capital humano y social. De la medicina al trabajo social. Introducción a la práctica basada en la evidencia. La bioética y el trabajo social. Entre soles y estrellas. La salud y el juego. Rol del trabajador social. Trabajo social e interdisciplina: la cuestión de los equipos de salud. Una experiencia de trabajo en salud sexual y reproductiva en el Bajo Flores. Procesos comunitarios que reproducen salud...