Production of Disinfective Coating Layer to Facial Masks Supplemented with Camellia sinensis Extract.

Although usefulness of masks for protection against respiratory pathogens, accumulation of pathogens on their surface represents a source of infection spread. Here we prepared a plant extract-based disinfecting layer to be used in coating masks thus inhibiting their capacity to transmit airborne pathogens. To reach this, a polypropylene membrane base was coated with a layer of polyvinyledine difluoride polymer containing 500 µg/ml of Camellia sinensis (Black tea) methanolic extract. Direct inhibitory effects of C. sinensis were initially demonstrated against Staphylococcus aureus (respiratory bacteria), influenza A virus (enveloped virus) and adenovirus 1 (non-enveloped virus) which were directly proportional to both extract concentration and incubation time with the pathogen. This was later confirmed by the capacity of the supplemented membrane with the plant extract to block infectivity of the above mentioned pathogens, recorded % inhibition values were 61, 72 and 50 for S. aureus, influenza and adenovirus, respectively. In addition to the disinfecting capacity of the membrane its hydrophobic nature and pore size (154 nm) prevented penetration of dust particles or water droplets carrying respiratory pathogens. In summary, introducing this layer could protect users from infection and decrease infection risk upon handling contaminated masks surfaces.

Analysis of the SARS-CoV-2 nsp12 P323L/A529V mutations: coeffect in the transiently peaking lineage C.36.3 on protein structure and response to treatment in Egyptian records.

SARS-CoV-2 nsp12, the RNA-dependent RNA-polymerase plays a crucial role in virus replication. Monitoring the effect of its emerging mutants on viral replication and response to antiviral drugs is important. Nsp12 of two Egyptian isolates circulating in 2020 and 2021 were sequenced. Both isolates included P323L, one included the A529V. Tracking A529V mutant frequency, it relates to the transience peaked C.36.3 variant and its parent C.36, both peaked worldwide on February-August 2021, enlisted as high transmissible variants under investigation (VUI) on May 2021. Both Mutants were reported to originate from Egypt and showed an abrupt low frequency upon screening, we analyzed all 1104 nsp12 Egyptian sequences. A529V mutation was in 36 records with an abrupt low frequency on June 2021. As its possible reappearance might obligate actions for a candidate VUI, we analyzed the predicted co-effect of P323L and A529V mutations on protein stability and dynamics through protein structure simulations. Three available structures for drug-nsp12 interaction were used representing remdesivir, suramin and favipiravir drugs. Remdesivir and suramin showed an increase in structure stability and considerable change in flexibility while favipiravir showed an extreme interaction. Results predict a favored efficiency of the drugs except for favipiravir in case of the reported mutations.

Sensitivities of a Rapid Test Versus an ELISA Kit for Detecting Anti-SARS-CoV-2 IgM/IgG in Sera from an Egyptian Cohort.

This study aimed to compare diagnostic sensitivities of a rapid test (Rt) and an ELISA kit for detecting anti-SARS-CoV-2 IgM/IgG in virus-RT-PCR-positive (VPP) and virus-RT-PCR-unchecked (VPU) subjects in an Egyptian cohort during the first wave of SARS-CoV-2 infection. The results revealed higher sensitivity of the Rt for detecting IgM/IgG in the VPP subjects. Both the Rt and ELISA showed identical sensitivities for IgM detection in the VPU subjects. The ELISA was more sensitive for detecting IgG in the VPU subjects. Generally, within both the VPP and the VPU groups, Rt was more sensitive for detecting IgM/IgG among the symptomatic (S) compared to asymptomatic (AS) subjects than ELISA. Within the VPP group, the Rt was more sensitive for detecting both IgM/IgG among the AS subjects than ELISA. In the VPU group, the Rt was more sensitive for detecting IgM among the S subjects than ELISA. The ELISA was more sensitive for detecting IgM/IgG among AS subjects than the Rt. From these results we concluded that, despite the limitation of sample size, this study indicates suitability of the used Rt for detecting anti-SARS-CoV-2 IgM/IgG among S subjects and sheds light on possibility of relying on the used ELISA for IgG detection among AS human subjects.

Proinflammatory Cytokine Profiles in Both Mild Symptomatic and Asymptomatic SARS-CoV-2-Infected Egyptian Individuals and a Proposed Relationship to Post-COVID-19 Sequela.

Severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) infection is associated with proinflammatory cytokine release as mediators of host antiviral response to the infection. Cytokine persistent elevation leads to post-Coronavirus disease-2019 (COVID-19) post-COVID-19 sequela (PCS) reported in about 60% of patients affecting individual's normal life after recovery. This study evaluates relationship of cytokines and chemokines pattern during and postinfection to PCS events. Serum samples collected from 82 individuals with symptomatic, asymptomatic, or no SARS-CoV-2 infection were classified as recently or formerly infected groups according to levels of anti-2019nCoV Immunoglobulin G/Immunoglobulin M. Levels of interleukin (IL)-1α, IL-1ß, IL-6, IL-8, interferon alpha (IFN-α), tumor necrosis factor alpha (TNF-α), granulocyte macrophage colony-stimulating factor (GM-CSF), and monocyte chemoattractant protein-1 were assessed via ELISA for each individual. All asymptomatic groups showed nonsignificant differences in cytokines' levels than control group. Significant elevation of IFN-α, TNF-α, and GM-CSF levels were observed in recent symptomatic, while IFN-α and TNF-α levels were significant in former symptomatic groups. We observed an association between fever with IL-1α and IFN-α levels, fatigue with TNF-α and GM-CSF, dyspnea with IFN-α, TNF-α, and GM-CSF, and chest-wheezing with GM-CSF. Individuals were surveyed 12 months postsampling for PCS events. Among 35 responders to survey, 8 (22.8%) reported PCS events, 6 of which were females. Upon studying PCS events, IL-8, IFN-α, TNF-α, and GM-CSF levels showed significant elevation in active infection, that was not seen in a resolved state of infection. Cytokines patterns suggest that either a persistent elevation in levels or damage caused during infection contributes to PCS. Although with the limited sample size, our study emphasizes the importance to conduct medical approaches targeting the associated cytokines to improve the PCS symptoms.

Individual expression and processing of hepatitis C virus E1/E2 epitopes-based DNA vaccine candidate in healthy humans' peripheral blood mononuclear cells.

Purpose: The development and study of hepatitis C virus (HCV) vaccine candidates' individualized responses are of great importance. Here we report on an HCV DNA vaccine candidate based on selected envelope (E1/E2) epitopes. Besides, we assessed its expression and processing in human peripheral blood mononuclear cells (PBMCs) and in vivo cellular response in mice. Materials and Methods: HCV E1/E2 DNA construct (EC) was designed. The antigen expression of EC was assayed in PBMCs of five HCV-uninfected donors via a real-time quantitative polymerase chain reaction. Serum samples from 20 HCV antibody-positive patients were used to detect each individual PBMCs expressed antigens via enzyme-linked immunosorbent assay. Two groups, five Swiss albino mice each, were immunized with the EC or a control construct. The absolute count of lymph nodes' CD4+ and CD8+ T-lymphocytes was assessed. Results: Donors' PBMCs showed different levels of EC expression, ranging between 0.83-2.61-fold in four donors, while donor-3 showed 34.53-fold expression. The antigens expressed in PBMCs were significantly reactive to the 20 HCV antibody repertoire (all p=0.0001). All showed comparable reactivity except for donor-3 showing the lowest reactivity level. The absolute count % of the CD4+ T-cell significantly increased in four of the five EC-immunized mice compared to the control group (p=0.03). No significant difference in CD8+ T-cells % was observed (p=0.89). Conclusion: The inter-individual variation in antigen expression and processing dominance was evident, showing independence in individuals' antigen expression and reactivity levels to antibodies. The described vaccine candidate might result in a promising natural immune response with a possibility of CD4+ T-cell early priming.

Prevalence of enteric viruses in wastewater in Egypt after the COVID-19 pandemic.

People's hygienic habits greatly affect the spreading rate of enteric viruses. After the COVID-19 pandemic, many people followed announced precautions and improved their hygienic status to protect themselves from SARS-CoV-2 infection. Here, we studied if this indirectly affected the prevalence of enteric viruses in Egypt. A total of 21 samples (one sample per week) were collected from the Zenin wastewater treatment plant (WWTP) through the period between August 2021 and March 2022. Detection of adenovirus, hepatitis A virus (HAV), and rotavirus showed their presence in 66, 14.3, and 9.5% of the collected samples, respectively. Comparing those percentages to previously published data concerned with the detection of the same viruses from the same WWTP or others revealed a remarkable decrease in the prevalence of the three viruses after the COVID-19 pandemic. This allows the conclusion that safety precautions against SARS-CoV-2 lead indirectly to a reduction of adenovirus, HAV, and rotavirus prevalence rates.

Addition of Camellia sinensis extract to water to disinfect respiratory viruses accumulated over different surfaces.

New precautions have become part of our daily life since COVID-19 pandemic such as wearing masks, maintaining distance and disinfecting products bought from markets before using them which is exhausting. We aimed to test the inhibitory effect of Camellia sinensis (black tea) water extracts on respiratory viruses and the inhibition of viruses accumulated over different surface types after being soaked in water supplemented with the extracts. Two water extraction methods (extract A: maceration at 80 °C for 30 min and extract B: boiling for 40 min) were applied; extracts were analyzed by high-performance liquid chromatography to detect polyphenolic compounds. Results showed that 200 µg/ml of extract A and 50 µg/ml of extract B in water caused 100% inhibition of influenza A (enveloped virus) virus after 1.5 h and similar results were obtained for adenovirus (non-enveloped virus) but at the same concentration of extract A and at 100 µg/ml of extract B. Different surfaces (aluminum, glass, plastic or carton, vegetables of smooth (tomato) or rough (lemon) surfaces and green leaves) were inoculated with both viruses for 20 min and then soaked in the water supplemented with 200 µg/ml of extract A or 100 µg/ml of extract B for 1.5 h, and this resulted in complete inhibition of both viruses.

Multiple infections with hepatitis A virus and development of rheumatoid arthritis among waste water treatment plant workers.

INTRODUCTION: In the present work, we studied the association between multiple exposure of waste water treatment plant workers to infection with existing hepatitis A virus in waste water and development of rheumatoid arthritis, taking in consideration number of working years as an indicator for frequency of exposure to infection, compared to non waste water treatment plant workers. METHODOLOGY: A total of 105 waste water treatment plant workers and 48 NWWTPWs were included in the study. Exclusion criteria were positivity for HBV and/or HCV IgG, negativity to HAV IgG and suffering from rheumatic diseases other than rheumatoid arthritis. RESULTS: 96.2% of waste water treatment plant workers were anti-HAV-IgG positive, of whom 5 had high antibody titer indicating ongoing infection and were anti-HAV-IgM negative excluding primary infection. These 5 samples were further subjected to quantification of liver enzymes, glutamate oxaloacetate trasaminase and glutamate pyruvate transaminase and HAV-RT-PCR to check viremia and results showed increase of glutamate oxaloacetate trasaminase and glutamate pyruvate transaminase as well as viremea in all of them. Rheumatoid arthritis diagnosis was carried out by detection of C-reactive protein, rheumatoid factor and anti-cyclic citrullinated protein. Rheumatoid arthritis development was 19% in the waste water treatment plant workers with >10 working years and 8% for < 10 working years. Also, disease development started earlier (Age 30-40 years) among the waste water treatment plant workers compared to non waste water treatment plant workers (age: 40-50 years). CONCLUSIONS: Multiple exposures of waste water treatment plant workers to HAV might be one of the etiological stimuli of rheumatoid arthritis.

Cross-reaction between mouse and rat immunoglobulin G: does it matter in sandwich ELISA?

BACKGROUND: Sandwich ELISA is an ideal antigen detection and quantification assay. Recently, it was used as the basic concept for high technology diagnostics. The specificity of the assay depends on the exclusion of detection cross-reactivity which arises from using two antibodies developed in different species. Since mice and rats are the common laboratory animals used to develop antigen specific antibodies. Therefore, the questions we addressed here were (1) can one use antigen-specific antibodies raised in mice and rats in the same assay to specifically detect/quantify antigens? and (2) which antibodies of the two rodents should be placed for capturing and for detection in the antigen-detection sandwich? RESULTS: Direct ELISA assay was used to assess for the specific reaction of the HRP-conjugated antibody to the target serum. First reaction was to compare between either conjugate anti-rat IgG (homologous) or anti-mouse IgG (heterologous) for the detection of rat sera IgG. Following the dilution factor optimization, the O.D. were 0.744±0.051 and 0.604±0.05, respectively (p= .004). The difference in mean O.D. of 0.14 reflected an unaccepted non-specific reaction. The second reaction was to compare between either conjugate anti-mouse IgG (homologous) and anti-rat IgG (heterologous) for the detection of mouse sera IgG. The recorded O.D. were 0.9414±0.14 and 0.317 ±0.141, respectively (p= .0002). The improved difference in mean O.D. of 0.624 reflecting a minimized cross-reaction. CONCLUSIONS: Our results suggest that it is possible to use both Swiss albino mice and albino rats in a single sandwich ELISA, given that the captured antibody species to be from the Swiss albino mice and the detection antibody to be from the albino rat. The described working details are limited to the source of the antibodies used in the study. However, the approach stresses on the importance of such optimization steps before making any interpretations based on the antigen detection. To our knowledge, this study is the first to cover the optimal order of the capturing and the detection antibodies in a sandwich ELISA assay. In addition to addressing the possible interfering cross-reactivity that result from using mouse and rat serum antibodies in a single assay.

Impact of both socioeconomic level and occupation on antibody prevalence to SARS-CoV-2 in an Egyptian cohort: The first episode.

We studied the impact of socioeconomic level on the anti-SARS-CoV-2-antibodies prevalence in an Egyptian cohort. The low socioeconomic standard group (LSS) included 51 humans, 30 females (F) and 21 males (M). The high socioeconomic standard group (HSS) included 55 subjects, 24 F and 31 M. Of the 30 LSSF, 6 were immunoglobulin M (IgM), 21 immunoglobulin G (IgG), and 6 double positive. Of the 21 LSSM, 5 were IgM, 12 IgG, and 5 double positive. Of the 24 HSSF, 6 were IgM, 11 IgG, and 5 double positive. Of the 31 HSSM, 6 were IgM, 14 IgG, and 4 double positive. Of the 51 LSS humans, 26 were symptomatic (S) and 25 asymptomatic (AS). Of the 26 S, 20 were IgG and 8 IgM/IgG double positive. Of the 25 AS, 13 were IgG and 3 IgM/IgG double positive. Of the 55 HSS humans, 38 were S and 17 AS. Of the 38S, 24 were IgG and 11 IgM positive of whom, 9 were double positive. Of the 17 AS, one was IgG and one IgM positive. The IgM prevalence was higher among the HSS humans. The IgG prevalence was significantly higher among the LSS humans. In the two different socioeconomic standards, the prevalence of either IgM or IgG was higher among F. An inverse correlation was observed between age and the anti-SARS-CoV-2-antibodies prevalence except for LSSF-IgG and LSSM-IgM. In conclusion, socioeconomic standard, gender, and age impact humoral responses to SARS-CoV-2 with a clear heterogeneity in individualized responses to the infection in terms of symptoms.