The mutation features and geographical distributions of the surface glycoprotein (S gene) in SARS-CoV-2 strains: A comparative analysis of the early and current strains.

The surface glycoprotein (S protein) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was used to develop coronavirus disease 2019 (COVID-19) vaccines. However, SARS-CoV-2, especially the S protein, has undergone rapid evolution and mutation, which has remained to be determined. Here, we analyzed and compared the early (12 237) and the current (more than 10 million) SARS-CoV-2 strains to identify the mutation features and geographical distribution of the S gene and S protein. Results showed that in the early strains, most of the loci were with relative low mutation frequency except S: 23403 (4486 strains), while in the current strains, there was a surge in the mutation strains and frequency, with S: 23403 constantly being the highest one, but tremendously increased to approximately 1050 times. Furthermore, D614 (S: 23403) was one of the most highly frequent mutations in the S protein of Omicron as of March 2022, and most of the mutant strains were still from the United States, and the United Kingdom. Further analysis demonstrated that in the receptor-binding domain, most of the loci with low mutation frequency in the early strains, while S: 22995 was nowadays the most prevalent loci with 3 122 491 strains in the current strains. Overall, we compare the mutation features of the S region in SARS-CoV-2 strains between the early and the current stains, providing insight into further studies in concert with emerging SARS-CoV-2 variants for COVID-19 vaccines.

Clinical characteristics of coronavirus disease (COVID-19) patients with gastrointestinal symptoms: A report of 164 cases.

Objective: To explore the clinical characteristics of Coronavirus Disease (COVID-19) patients with gastrointestinal symptoms. Methods: The clinical data of 164 COVID-19 patients with gastrointestinal symptoms were extracted and analysed retrospectively. Results: In total, 505 COVID-19 patients were divided into two groups: those with gastrointestinal symptoms (G group) and those without gastrointestinal symptoms (NG group). Common gastrointestinal symptoms included inappetence, diarrhoea, nausea, abdominal pain, and vomiting. Significantly higher proportions of patients with fever, dizziness, myalgia, and fatigue were noted in group G than in group NG. Compared with patients without fever, there was a significant difference between G group and NG group in moderate fever or above, while there was no significant difference between the two groups in low fever. The laboratory results showed that patients in the G group had significantly higher C-reactive protein, lactate dehydrogenase, and α-hydroxybutyrate dehydrogenase levels than those in the NG group. Moreover, the proportion of patients with severe pneumonia was significantly higher in the G group than in the NG group. Conclusion: In Wuhan, the proportion of COVID-19 patients who experience gastrointestinal symptoms is relatively high. Patients who experience gastrointestinal symptoms are more likely to suffer from severe pneumonia, which may help clinicians identify patients at high risk of COVID-19 and thus reduce the incidence of this condition.