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Background and Purpose: Neutrophil overstimulation plays a crucial role in tissue damage during severe infections. Because pathogen-derived neuraminidase (NEU) stimulates neutrophils, we investigated whether host NEU can be targeted to regulate the neutrophil dysregulation observed in severe infections., Experimental Approach: The effects of NEU inhibitors on lipopolysaccharide (LPS)-stimulated neutrophils from healthy donors or COVID-19 patients were determined by evaluating the shedding of surface sialic acids, cell activation, and reactive oxygen species (ROS) production. Re-analysis of single-cell RNA sequencing of respiratory tract samples from COVID-19 patients also was carried out. The effects of oseltamivir on sepsis and betacoronavirus-induced acute lung injury were evaluated in murine models., Key Results: Oseltamivir and zanamivir constrained host NEU activity, surface sialic acid release, cell activation, and ROS production by LPS-activated human neutrophils. Mechanistically, LPS increased the interaction of NEU1 with matrix metalloproteinase 9 (MMP-9). Inhibition of MMP-9 prevented LPS-induced NEU activity and neutrophil response. In vivo, treatment with oseltamivir fine-tuned neutrophil migration and improved infection control as well as host survival in peritonitis and pneumonia sepsis. NEU1 also is highly expressed in neutrophils from COVID-19 patients, and treatment of whole-blood samples from these patients with either oseltamivir or zanamivir reduced neutrophil overactivation. Oseltamivir treatment of intranasally infected mice with the mouse hepatitis coronavirus 3 (MHV-3) decreased lung neutrophil infiltration, viral load, and tissue damage., Conclusion and Implications: These findings suggest that interplay of NEU1-MMP-9 induces neutrophil overactivation. In vivo, NEU may serve as a host-directed target to dampen neutrophil dysfunction during severe infections., (© 2022 British Pharmacological Society.)

The impacts of the recent coronavirus pandemic on Brazilian society revealed a scenario that goes beyond a health crisis. This article sets out to present the causes and consequences of a systemic crisis in the neoliberal economic order based on the prominence of markets and social exclusion, while the role of the State - as the guardian of social rights - is neglected. The methodology adopted follows a critical interdisciplinary perspective from the fields of political economy and social sciences, located in socioeconomic reports referred to in this analysis. It is argued that the neoliberal rationale guiding government policies, which is deep rooted in the social environment, has contributed to the increase in structural inequalities in Brazil, thus creating favorable conditions for exacerbating the impacts caused by the pandemic in society, particularly among the most vulnerable social groups.

(1) Background: COVID-19 vaccination in Brazil has been performed mostly with CoronaVac (Sinovac), ChAdOx1-S (AstraZeneca-University of Oxford) and BNT162b2 (Pfizer-BioNTech) vaccines. The titers of IgG antibodies reactive to the SARS-CoV-2 spike protein correlate with vaccine efficacy. Studies comparing vaccine immunogenicity in a real-world scenario are lacking. (2) Methods: We performed a population-based study to analyze the immunoglobulin G response to different COVID-19 vaccines. Citizens older than 18 years (n = 2376) provided personal data, a self-declaration of any previous COVID-19 positive tests and information regarding COVID-19 vaccination: the vaccine popular name and the date of each dose. Blood samples were collected and the levels of IgG reactive to SARS-CoV-2 antigens were determined and compared between different vaccine groups. (3) Results: The seroconversion for anti-spike IgG achieved > 95% by February 2022 and maintained stable until June 2022. Higher anti-spike IgG titers were detected in individuals vaccinated with BNT162b2, followed by ChAdOx1-S and CoronaVac. The anti-spike IgG response was negatively correlated with age and interval after the second dose for the BNT162b2 vaccine. Natural infections boosted anti-spike IgG in those individuals who completed primary vaccination with ChAdOx1-S and CoronaVac, but not with BNT162b2. The levels of anti-spike IgG increased with the number of vaccine doses administered. The application of BNT162b2 as a 3rd booster dose resulted in high anti-spike IgG antibody titers, despite the type of vaccine used during primary vaccination. (4) Conclusions: Our data confirmed the effectiveness of the Brazilian vaccination program. Of the vaccines used in Brazil, BNT162b2 performed better to elicit anti-spike protein IgG after primary vaccination and as a booster dose and thus should be recommended as a booster whenever available. A continuous COVID-19 vaccination program will be required to sustain anti-spike IgG antibodies in the population.

Immunological assays to detect SARS-CoV-2 Spike Receptor Binding Domain (RBD) antigen seroconversion in humans are important tools to monitor the levels of protecting antibodies in the population in response to infection and/or immunization. Here we describe a simple, low cost, and high throughput Ni 2+ magnetic bead immunoassay to detect human IgG reactive to Spike S1 RBD Receptor Binding Domain produced in Escherichia coli. A 6xHis-tagged Spike S1 RBD was expressed in E. coli and purified by affinity chromatography. The protein was mobilized on the surface of Ni 2+ magnetic beads and used to investigate the presence of reactive IgG in the serum obtained from pre-pandemic and COVID-19 confirmed cases. The method was validated with a cohort of 290 samples and an area under the receiver operating characteristic curve of 0.94 was obtained. The method was operated with > 82% sensitivity at 98% specificity and was also able to track human IgG raised in response to vaccination with Comirnaty at > 85% sensitivity. The IgG signal obtained with the described method was well-correlated with the signal obtained when pre fusion Spike produced in HEK cell lines was used as antigen. This novel low-cost and high throughput immunoassay may act as an important tool to investigate protecting IgG antibodies against SARS-CoV-2 in the human population., (© 2022. The Author(s) under exclusive licence to Sociedade Brasileira de Microbiologia.)

The investigation of antibodies raised against different severe acute respiratory syndrome coronavirus (SARS-CoV-2) antigens can help to determine the extent of previous SARS-CoV-2 infections in the population and track the humoral response to vaccination. Therefore, serological surveys can provide key information to better manage the pandemic and/or to implement the most effective vaccination program. Here we describe a time series anti-nucleocapsid, anti-spike IgG serological survey analysis in the city of Matinhos, PR, Brazil during the year of 2021. Seroconversion rates to the nucleocapsid antigen were not influenced by gender or age. The serological data support that the coronavirus disease 2019 (COVID-19) infection rate is ~50% higher than official numbers. Furthermore, by applying serological data, the corrected infection fatality rate was estimated to be lower than 2.4% in contrast with the official estimative of 3.6%. The rates of IgG reactive to spike antigen resembled the curve of the fraction the population that had taken the second vaccine dose. Up to 82% of spike seroconversion was detected in the end of 2021, confirming the effectiveness of the COVID-19 vaccination program in the city. This SARS-CoV-2 serological study unraveled the SARS-CoV-2 infection rates and the response to vaccination in the city of Matinhos. IMPORTANCE The investigation of antibodies raised against SARS-CoV-2 can help to determine the extent of previous SARS-CoV-2 infections and track the humoral response to vaccination. Here we describe a time series anti-nucleocapsid, anti-spike IgG serological survey in the city of Matinhos, PR, Brazil during the year of 2021. The data depicted the progression of SARS-CoV-2 infections in the city allowing the correction of the number of citizens who experienced COVID-19 and the disease fatality rate. The seroconversion rates to the spike antigen resembled the curve of the fraction of the population that had taken the second vaccine dose, thereby confirming the effectiveness of the COVID-19 vaccination program in the city.

The mangrove is an ecosystem bounded by the line of the largest tide in size that occurs in climatic and subtropical regions. In this environment, microorganisms and their enzymes are involved in a series of transformations and nutrient cycling. To evaluate the biotechnological potential of fungi from a mangrove ecosystem, samples from mangrove trees were collected at the Paranaguá Estuarine Complex in Brazil and 40 fungal isolates were obtained, cultivated, and screened for hydrolytic and ligninolytic enzymes production, adaptation to salinity and genetic diversity. The results showed a predominance of hydrolytic enzymes and fungal tolerance to ≤ 50 g L -1 sodium chloride (NaCl) concentration, a sign of adaptive halophilia. Through morphological and molecular analyses, the isolates were identified as: Trichoderma atroveride, Microsphaeropsis arundinis, Epicoccum sp., Trichoderma sp., Gliocladium sp., Geotrichum sp. and Cryphonectria sp. The ligninolytic enzymatic potential of the fungi was evaluated in liquid cultures in the presence and absence of seawater and the highest activity of laccase among isolates was observed in the presence of seawater with M. arundinis (LB07), which produced 1,037 U L -1 . Enzymatic extracts of M. arundinis fixed at 100 U L -1 of laccase partially decolorized a real textile effluent in a reaction without pH adjustment and chemical mediators. Considering that mangrove fungi are still few explored, the results bring an important contribution to the knowledge about these microorganisms, as their ability to adapt to saline conditions, biodegradation of pollutants, and enzymatic potential, which make them promising candidates in biotechnological processes., (Copyright © 2021 Elsevier GmbH. All rights reserved.)

To monitor the levels of protecting antibodies raised in the population in response to infection and/or to immunization with SARS-CoV-2, we need a technique that allows high throughput and low-cost quantitative analysis of human IgG antibodies reactive against viral antigens. Here we describe an ultra-fast, high throughput and inexpensive assay to detect SARS-CoV-2 seroconversion in humans. The assay is based on Ni 2+ magnetic particles coated with His tagged SARS-CoV-2 antigens. A simple and inexpensive 96 well plate magnetic extraction/homogenization process is described which allows the simultaneous analysis of 96 samples and delivers results in 7 min with high accuracy., (Copyright © 2021 Elsevier Inc. All rights reserved.)