COVID-19 is a novel coronavirus with an outbreak of unusual viral pneumonia in Wuhan, China, and then pandemic. Based on its phylogenetic relationships and genomic structures the COVID-19 belongs to genera Betacoronavirus. Human Betacoronaviruses (SARS-CoV-2, SARS-CoV, and MERS-CoV) have many similarities, but also have differences in their genomic and phenotypic structure that can influence their pathogenesis. COVID-19 is containing single-stranded (positive-sense) RNA associated with a nucleoprotein within a capsid comprised of matrix protein. A typical CoV contains at least six ORFs in its genome. All the structural and accessory proteins are translated from the sgRNAs of CoVs. Four main structural proteins are encoded by ORFs 10, 11 on the one-third of the genome near the 3'-terminus. The genetic and phenotypic structure of COVID-19 in pathogenesis is important. This article highlights the most important of these features compared to other Betacoronaviruses.

The severity of COVID-19 varies significantly among individuals. Studying the genetic factors of the host helps us figure out the answer to that difference

Cholesterol 25-hydroxylase (CH25H) and its product 25-hydroxycholesterol (25HC) showed antiviral effects against various viruses in vitro. CH25H expression is regulated in mice by pro-inflammatory cytokine interferons (IFNs) in mice but data on its possible correlation with IFNs in humans are still unclear. We examined gene expression of CH25H, IFN-α, and IFN-β and serum levels of 25HC in Iranian patients with mild and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Fifty intensive care unit (ICU) patients and outpatients with SARS-CoV-2 and 25 healthy controls were studied. Gene expression of CH25H and relevant inflammatory cytokines was quantified in peripheral blood mononuclear cells by real-time polymerase chain reaction. The expression of CH25H and serum levels of 25HC were significantly higher in ICU patients with SARS-CoV-2. Notably, IFN-α levels increased in healthy controls. However, compared to healthy controls, IFN-β was considerably higher in outpatients. Finally, statistical analysis shows that no correlation was found between CH25H and IFN-α expression; nevertheless, a lower correlation was found with IFN-β. The data revealed that CH25H and 25HC levels increase after SARS-CoV-2 infection. In other words, decreased levels of those factors in severe patients compared with mild patients may indicate the importance of their function in controlling the progression of the disease.

Objectives: The present study was conducted to assess the pattern of HBV Core/Pre-Core mutations and HBV genotype in Iraqi patients with chronic hepatitis B virus (HBV) infection. Methods: In the current cross-sectional study in an Iraqi province, we evaluated 134 patients diagnosed with HBV hepatitis. We used PCR and, subsequently, Sanger sequencing to assess HBV Core/Pre-Core mutations. Sanger sequencing reads were further used for phylogenetic analysis and multiple sequence alignment. A phylogenetic tree was generated according to the neighbor-joining method. Results: The current study revealed that 58 (45%) of the patients were male, and 72 (55%) of them were female. The mean age of the patients was 36 ± 12.7 years, and the mean duration of infection was 5.2 ± 4.8 years. The results revealed 21 nucleic acid alterations in the samples analyzed. The generated phylogenetic tree divided samples into two genotypes. Pre-core/Core mutations were significantly associated with the treatment received (P = 0.0.001) but not with laboratory parameters. Most samples were matched with the genotype D clade, while only four samples were positioned adjacent to the genotype E clade. Direct nucleic acid translation disclosed five nucleic acid variants (73T>G, 347T>G, 364A>G, 365T>C, and 366A>G) on the core protein. Conclusions: This study has detected 21 nucleotide variants and 5 amino acid alterations within the coding sequences of the C gene. This study revealed that genotype D represents the primary genotype for the identified viral infections. The current study highlights the importance of these mutations evaluation for future, more comprehensive studies.

Background: Several SARS-CoV-2 variants with distinct characteristics have emerged, with Omicron sub-variants such as BA.1 to BA.5 being predominant since late 2021. Distinguishing sub-variants using phylogenetic and molecular analyzes provides a valuable approach in the context of epidemiological research. Materials & Methods: Molecular epidemiology and sub-variants of SARS-CoV-2 omicron were investigated ...