Gastrointestinal implications in COVID-19.

BACKGROUND: Coronavirus disease 2019 (COVID-19 patients mostly present with respiratory symptoms; however, gastrointestinal (GI) manifestations can also be seen either alone or along with respiratory symptoms. We aimed to evaluate the GI symptoms related to COVID-19. METHODS: This cross-sectional study retrospectively evaluated the medical files of 507 patients with confirmed or highly probable COVID-19. Based on their symptoms, patients were categorized into four groups: with GI symptoms alone (GIA), with respiratory symptoms alone (RA), with both GI and respiratory symptoms (GIR), and without GI or respiratory symptoms (WGIR). RESULTS: Of the 507 COVID-19 patients, 47.9% had at least one GI symptom; the most common was nausea and/or vomiting (31.6%). Patients in the GIA group were significantly older than those in the RA (P = 0.041) and GRI (P = 0.004) groups (54.70 ± 18.14 vs. 48.68 ± 14.67 and 46.80 ± 17.17 years, respectively). Groups were homogeneous with respect to gender. Leukopenia and lymphopenia were both less frequent in patients with GI symptoms compared to those without GI symptoms. Positive RT-PCR was significantly less frequent among patients with GI symptoms (44% vs. 100%, P < 0.001). Although mortality was lower in patients with GI symptoms (9.1%) in comparison with those without GI symptoms (13.3%), the difference was not statistically significant (P = 0.134). CONCLUSION: The typical respiratory symptoms of COVID-19 are quite commonly accompanied by GI symptoms, with nausea and/or vomiting being the most prevalent. A subgroup of COVID-19 patients may exclusively present with GI symptoms. Special attention should be paid to these patients in order to avoid misdiagnosis or delayed treatment.

Evaluation of the immune response to a multi-epitope vaccine candidate in comparison with HlaH35L, MntC, and SACOL0723 proteins against MRSA infection.

Staphylococcus aureus is an important human opportunistic pathogen that can have a major influence on public health. Here, we aimed to evaluate different aspects of the immune response to a novel multi-epitope fusion protein (HMS) based on HlaH35L, MntC, and SACOL0723 proteins in comparison to the individual antigens. For this purpose, specific total IgG, IgG1, and IgG2a isotypes and the cytokines related to Th1, Th2, and Th17 were assessed. The Bio-efficiency of the fusion protein was evaluated by opsonic killing activity. The HMS fusion protein elicited a high specific IgG level and also induced a higher level of Th1, Th2, and Th17-related cytokines which were more polarized towards the Th1 and Th17 compared to individual antigens. The HMS-specific antisera also significantly promoted phagocytosis of S. aureus COL strain by mouse macrophages. In conclusion, the fusion protein might be an effective vaccine for potential protective immunity against a lethal infection of S. aureus in mice.

Reverse vaccinology approach to design a novel multi-epitope vaccine candidate against COVID-19: an in silico study.

At present, novel Coronavirus (2019-nCoV, the causative agent of COVID-19) has caused worldwide social and economic disruption. The disturbing statistics of this infection promoted us to develop an effective vaccine candidate against the COVID-19. In this study, bioinformatics approaches were employed to design and introduce a novel multi-epitope vaccine against 2019-nCoV that can potentially trigger both CD4+ and CD8+ T-cell immune responses and investigated its biological activities by computational tools. Three known antigenic proteins (Nucleocapsid, ORF3a, and Membrane protein, hereafter called NOM) from the virus were selected and analyzed for prediction of the potential immunogenic B and T-cell epitopes and then validated using bioinformatics tools. Based on in silico analysis, we have constructed a multi-epitope vaccine candidate (NOM) with five rich-epitopes domain including highly scored T and B-cell epitopes. After predicting and evaluating of the third structure of the protein candidate, the best 3 D predicted model was applied for docking studies with Toll-like receptor 4 (TLR4) and HLA-A*11:01. In the next step, molecular dynamics (MD) simulation was used to evaluate the stability of the designed fusion protein with TLR4 and HLA-A*11:01 receptors. MD studies demonstrated that the NOM-TLR4 and NOM-HLA-A*11:01 docked models were stable during simulation time. In silico evaluation showed that the designed chimeric protein could simultaneously elicit humoral and cell-mediated immune responses. Communicated by Ramaswamy H. Sarma.

Comparative study of the immune responses to the HMS-based fusion protein and capsule-based conjugated molecules as vaccine candidates in a mouse model of Staphylococcus aureus systemic infection.

Staphylococcus aureus is a powerful pathogen that causes a wide range of infectious diseases and results in a high mortality rate in humans. Treating S. aureus-related infections is extremely difficult because of its ability to resist many antibiotics; therefore, developing an effective vaccine against this infection can be an alternative and promising approach. In this study, we evaluated the protective effects of a Hla-MntC-SACOL0723 multi-epitope protein (HMS) compared with HMS conjugated to polysaccharides 5 and 8 (CP5 and CP8) of S. aureus and CP5 and CP8 in a mouse sepsis model. To evaluate the type of induced immune response, specific IgG, and antibody isotypes (IgG1 and IgG2a) were determined using the ELISA method. The functional activity of these vaccine candidates was assessed by opsonophagocytosis. Mice were infected with S. aureus COL strain and evaluated for bacterial load in the kidney and spleen homogenates. Th1, Th2, and Th17-related cytokines in the spleen cell supernatants were assessed by flow cytometry. The therapeutic effect of specific anti-HMS protein IgG antibodies against S. aureus COL strain infection was evaluated by passive immunization. HMS recombinant protein induced a higher level of Th1, Th2, and Th17-related cytokines compared with conjugated molecules. Also, mice immunized with the HMS protein reduced the bacterial load in the kidney and spleen more than the one that received the conjugated molecules. Our study suggests that the HMS fusion protein and conjugate molecule vaccine candidates could be suitable candidates for the removal of S. aureus in the mouse sepsis model but HMS protein can be a more effective candidate.

Implementation of regional COVID-19 registry in Hormozgan (RCovidRH), Iran: Rationale and study protocol.

Background: The rapid outbreak of COVID-19 has resulted in a global pandemic in 2020. Information sources such as disease registries through accessing quality, valid, accurate, and timely data empower researchers and health authorities to study and develop appropriate actions. Our study describes the protocol for implementation of regional COVID-19 registry in Hormozgan province (RCovidRH). Methods: We followed approved phases for the development of RCovidRH to cover the population in Hormozgan. Missioned to develop and implement the protocol, the registry's steering committee was made up of 10 members from subject fields of the registry at the core and 5 subgroups. The main purpose of the registry is to provide a comprehensive information profile of demographic, clinical, laboratory, imaging, and treatment data of confirmed and probable COVID-19 patients in Hormozgan. The data is retrospectively and prospectively collected. Case report form (CRF) was mainly based on International Severe Acute Respiratory and Emerging Infection Consortium (ISARIC) CRF. A web-based, 2-language software was also developed to facilitate data collection and storage. Data analysis is to be conducted with collaboration of clinical physicians, data-mining specialists, and epidemiologists after reaching appropriate sample size. Results: We included data related to demographic and identification, onset and admission, signs and symptoms at hospital admission, admission signs and symptoms, comorbidities, pathogen testing, assessment, laboratory, imaging, complications, treatment and medication, and outcomes. We found this registry was limited by incomplete clinical data for small fraction of outpatients, incomplete or inaccurate address by referred people due to fear of social rejection, delay in data entry at the facilities due to workload. Conclusion: This registry via organizing clinical and epidemiological COVID-19 data increases the potentiality of joint studies. Recognition and coordination of a registry is highly important to solve its limitations to collect data. Other universities and provinces can apply our model to develop COVID-19 registries or data sets for this disease.