Gut bacteria, bacteriophages, and probiotics: Tripartite mutualism to quench the SARS-CoV2 storm.

Patients with SARS-CoV-2 infection, exhibit various clinical manifestations and severity including respiratory and enteric involvements. One of the main reasons for death among covid-19 patients is excessive immune responses directed toward cytokine storm with a low chance of recovery. Since the balanced gut microbiota could prepare health benefits by protecting against pathogens and regulating immune homeostasis, dysbiosis or disruption of gut microbiota could promote severe complications including autoimmune disorders; we surveyed the association between the imbalanced gut bacteria and the development of cytokine storm among COVID-19 patients, also the impact of probiotics and bacteriophages on the gut bacteria community to alleviate cytokine storm in COVID-19 patients. In present review, we will scrutinize the mechanism of immunological signaling pathways which may trigger a cytokine storm in SARS-CoV2 infections. Moreover, we are explaining in detail the possible immunological signaling pathway-directing by the gut bacterial community. Consequently, the specific manipulation of gut bacteria by using probiotics and bacteriophages for alleviation of the cytokine storm will be investigated. The tripartite mutualistic cooperation of gut bacteria, probiotics, and phages as a candidate prophylactic or therapeutic approach in SARS-CoV-2 cytokine storm episodes will be discussed at last.

The Effectiveness of the Anteroom (Vestibule) Area on Hospital Infection Control and Health Staff Safety: A Systematic Review.

The emergence of SARS-CoV2 in 2019 showed again that the world's healthcare system is not fully equipped and well-designed for preventing the transmission of nosocomial respiratory infections. One of the great tools for preventing the spread of infectious organisms in hospitals is the anteroom. Several articles have investigated the role of the anteroom in disease control but the lack of a comprehensive study in this field prompted us to provide more in-depth information to fill this gap. Also, this study aimed to assess the necessity to construct an anteroom area for hospital staff members at the entrance of each ward of the hospital, and specify the equipment and facilities which make the anteroom more efficient. Articles were identified through searches of Scopus, Web of Sciences, PubMed, and Embase for studies published in English until May 2020 reporting data on the effect of the anteroom (vestibule) area in controlling hospital infections. Data from eligible articles were extracted and presented according to PRISMA's evidence-based data evaluation search strategy. Also, details around the review aims and methods were registered with the PROSPERO. From the database, 209 articles were identified, of which 25 studies met the study criteria. Most studies demonstrated that an anteroom significantly enhances practical system efficiency. The results showed that the equipment such as ventilation system, high-efficiency particulate absorption filter, hand dispensers, alcohol-based disinfection, sink, mirror, transparent panel, UVC disinfection, and zone for PPE change, and parameters like temperature, door type, pressure, and size of the anteroom are factors that are effective on the safety of the hospital environment. Studies demonstrated that providing an anteroom for changing clothing and storing equipment may be useful in reducing the transmission of airborne infections in hospitals. Since the transmission route of SARS-CoV2 is common with other respiratory infectious agents, it can be concluded that a well-designed anteroom could potentially decrease the risk of SARS-CoV2 transmission during hospitalization as well.

High Seroprevalence of SARS-CoV-2 (COVID-19)-Specific Antibodies among Healthcare Workers: A Cross-Sectional Study in Guilan, Iran.

Background: This study was conducted to evaluate the anti-SARS-CoV-2 IgM and IgG antibodies among healthcare workers in Guilan. Methods: This cross-sectional study was conducted on 503 healthcare workers. Between April and May 2020, blood samples were collected from the healthcare workers of Razi Hospital in Rasht, Guilan, Iran. Enzyme-linked immunosorbent assay (ELISA) was used for the detection and quantitation of anti-SARS-CoV-2 IgM/IgG antibodies by using kits made by Pishtaz Teb Company, Tehran, Iran. Results: From a total of 503 participants, the result of the anti-SARS-CoV-2 IgM antibody test was positive in 28 subjects (5.6%) and the anti-SARS-CoV-2 IgG antibody test was positive in171 subjects (34%). Participants in the age group of 35-54 years were significantly more likely to have a positive anti-SARS-CoV-2 antibody test than the age group of 20-34 years (odds ratio = 1.53, 95% CI: 1.04-2.25, P=0.029). Also, physicians were significantly more likely to have a positive antibody test than office workers (odds ratio = 1.92, 95% CI: 1.04-3.54, P=0.037). The wide range of symptoms was significantly associated with the positive anti-SARS-CoV-2 antibody test. The most significant association was observed between fever and a positive anti-SARS-CoV-2 antibody test (odds ratio = 3.03, 95% CI: 2.06-4.44, P < 0.001). Conclusion: The results of the current study indicated that the seroprevalence of COVID-19 was high among healthcare workers of Guilan Province. It seems that this finding was due to the earlier exposure to COVID-19 and the lack of awareness and preparedness to deal with the pandemic in Iran, compared to other countries.

Persistence of SARS-CoV-2 RNA in the nasopharyngeal, blood, urine, and stool samples of patients with COVID-19: a hospital-based longitudinal study.

BACKGROUND: The persistence of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) RNA in the body fluids of patients with the novel coronavirus disease 2019 (COVID-19) may increase the potential risk of viral transmission. There is still uncertainty on whether the recommended quarantine duration is sufficient to reduce the risk of transmission. This study aimed to investigate the persistence of SARS-CoV-2 RNA in the nasopharyngeal, blood, urine, and stool samples of patients with COVID-19. METHODS: In this hospital-based longitudinal study, 100 confirmed cases of COVID-19 were recruited between March 2020 and August 2020 in Guilan Province, north of Iran. Nasopharyngeal, blood, urine, and stool samples were obtained from each participant at the time of hospital admission, upon discharge, 1 week after discharge, and every 2 weeks until all samples were negative for SARS-CoV-2 RNA by reverse transcription-polymerase chain reaction (RT-PCR) assay. A survival analysis was also performed to identify the duration of viral persistence. RESULTS: The median duration of viral RNA persistence in the nasopharyngeal samples was 8 days from the first positive RT-PCR result upon admission (95% CI 6.91-9.09); the maximum duration of viral shedding was 25 days from admission. Positive blood, urine, and stool RT-PCR results were detected in 24%, 7%, and 6% of the patients, respectively. The median duration of viral persistence in the blood, urine, and stool samples was 7 days (95% CI 6.07-7.93), 6 days (95% CI 4.16-8.41), and 13 days (95% CI 6.96-19.4), respectively. Also, the maximum duration of viral persistence in the blood, urine, and stool samples was 17, 11, and 42 days from admission, respectively. CONCLUSION: According to the present results, immediately after the hospitalized patients were discharged, no evidence of viral genetic materials was found. Therefore, appropriate treatments were selected for the patients at this hospital. However, we recommend further investigations on a larger sample size in multi-center and prospective randomized controlled trials (RCTs) to evaluate the effects of different drugs on the shedding of the virus through body secretions.

Functional and Structural Characterization of SARS-Cov-2 Spike Protein: An In Silico Study.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of the global outbreak of coronavirus disease 2019 (Covid-19), which has been considered as a pandemic by WHO. SARS-CoV-2 encodes four major structural proteins, among which spike protein has always been a main target for new vaccine studies. This in silico study aimed to investigate some physicochemical, functional, immunological, and structural features of spike protein using several bioinformatics tools. METHOD: We retrieved all SARS-CoV-2 spike protein sequences from different countries registered in NCBI GenBank. CLC Sequence Viewer was employed to translate and align the sequences, and several programs were utilized to predict B-cell epitopes. Modification sites such as phosphorylation, glycosylation, and disulfide bonds were defined. Secondary and tertiary structures of all sequences were further computed. RESULTS: Some mutations were determined, where only one (D614G) had a high prevalence. The mutations did not impact the B-cell and physicochemical properties of the spike protein. Seven disulfide bonds were specified and also predicted in several N-link glycosylation and phosphorylation sites. The results also indicated that spike protein is a non-allergen. CONCLUSION: In summary, our findings provided a deep understanding of spike protein, which can be valuable for future studies on SARS-CoV-2 infections and design of new vaccines.