For almost two years, the COVID-19 pandemic has constituted a major challenge to human health, particularly due to the lack of efficient antivirals to be used against the virus during routine treatment interventions. Multiple treatment options have been investigated for their potential inhibitory effect on SARS-CoV-2. Natural products, such as plant extracts, may be a promising option, as they have shown an antiviral activity against other viruses in the past. Here, a quantified extract of Hypericum perforatum was tested and found to possess a potent antiviral activity against SARS-CoV-2. The antiviral potency of the extract could be attributed to the naphtodianthrones hypericin and pseudohypericin, in contrast to other tested ingredients of the plant material, which did not show any antiviral activity. Hypericum perforatum and its main active ingredient hypericin were also effective against different SARS-CoV-2 variants (Alpha, Beta, Delta, and Omicron). Concerning its mechanism of action, evidence was obtained that Hypericum perforatum and hypericin may hold a direct virus-blocking effect against SARS-CoV-2 virus particles. Taken together, the presented data clearly emphasize the promising antiviral activity of Hypericum perforatum and its active ingredients against SARS-CoV-2 infections.

Avian orthoavulavirus1, formerly known as avian paramyxovirus type-1 (APMV-1), infects more than 250 different species of birds. It causes a broad range of clinical diseases and results in devastating economic impact due to high morbidity and mortality in addition to trade restrictions. The ease of spread has allowed the virus to disseminate worldwide with subjective virulence, which depends on the virus strain and host species. The emergence of new virulent genotypes among global epizootics, including those from Egypt, illustrates the time-to-time genomic alterations that lead to simultaneous evolution of distinct APMV-1 genotypes at different geographic locations across the world. In Egypt, the Newcastle disease was firstly reported in 1947 and continued to occur, despite rigorous prophylactic vaccination, and remained a potential threat to commercial and backyard poultry production. Since 2005, many researchers have investigated the nature of APMV-1 in different outbreaks, as they found several APMV-1 genotypes circulating among various species. The unique intermingling of migratory, free-living, and domesticated birds besides the availability of frequently mobile wild birds in Egypt may facilitate the evolution power of APMV-1 in Egypt. Pigeons and waterfowls are of interest due to their inclusion in Egyptian poultry industry and their ability to spread the infection to other birds either by presence of different genotypes (as in pigeons) or by harboring a clinically silent disease (as in waterfowl). This review details (i) the genetic and pathobiologic features of APMV-1 infections in Egypt, (ii) the epidemiologic and evolutionary events in different avian species, and (iii) the vaccine applications and challenges in Egypt.

During 2015, duck farms (n = 27) in Sharkia Province, Egypt, experienced several disease outbreaks leading to mortality and nervous manifestations. Upon necropsy, the affected ducklings showed liver lesions, such as hemorrhage or necrosis, suggestive of duck virus hepatitis (DVH). Reverse transcription-PCR (RT-PCR), on the basis of the 3D gene, found duck livers from 21 farms to be positive for duck hepatitis A virus serotype 1 (DHAV-1). All duck breeds (Pekin, Mallard, and Muscovy) were infected. The virus was isolated in embryonated chicken eggs, which showed embryonic mortality (40%–80%) within 5–7 days, stunting or dwarfing (69.6%), and necrotic liver foci (60.9%). The VP1 gene of 11 DHAV-1 strains was characterized by RT-PCR and Sanger sequencing. All study strains were clustered in a monophyletic branch within subclade B2 of Group 4 and were separated from the Egyptian vaccine strain. Several amino acid (aa) residues, such as V129, S142 (only in four strains), L181, G184, and K217, were related to virus attenuation. However, two aa residues (N193 and E205), found in virulent DHAV-1 strains, were also observed in our strains. This study confirms the circulation of DHAV-1 (subclade B2) in Lower Egypt and elucidates the phylogenetic characters of the VP1 genes, which will be useful in following the local trends of DHAV-1 infections. Further studies are indicated to determine the correlation between these mutations and the virulence of the Egyptian DHAV-1 isolates.

Kobuviruses are small non-enveloped RNA viruses that probably cause diarrhea in cattle and swine. Since its discovery in 2003, few studies have addressed bovine kobuvirus (BKoV; a species of Aichivirus B) infections. BKoV has been reported in Europe, Asia, and South America, suggesting a worldwide distribution. To investigate the presence of BKoV in Egypt, 36 fecal specimens from diarrheic calves in two different Egyptian provinces (Cairo and Sharkia) were screened by RT-PCR and 24 (66.7%) were found positive for BKoV. RNA from one of the positive samples (BKoV/Egy-1/KY407744) was subjected to next-generation sequencing to determine the complete BKoV genome sequence. When compared to the only recorded BKoV genome sequence (BKoV/U-1/AB084788), the studied strain showed 94 amino acid (aa) substitutions through its entire polyprotein (2463 aa), one nucleotide (nt) insertion and one nt deletion in the 2B gene and 4-nt deletions in the UTRs (2 each). Additionally, five VP1 and seven 3D sequences were obtained from other samples by using RT-PCR and Sanger sequencing. A discrepancy in the phylogenetic topography of VP1 and 3D was observed, where the Egyptian VP1 sequences were classified as a distinct cluster within the proposed lineage 1 (genotype A), which also contained strains from the UK, Brazil, and Japan. While, the 3D sequences from Cairo were related to those of Chinese strains unlike Sharkia ones that were more closer to Korean strains. To the best of our knowledge, this is the first detection and genomic characterization of BKoV in Egypt or indeed Africa.

Influenza A virus (IAV), like any other virus, provokes considerable modifications of its host cell’s metabolism. This includes a substantial increase in the uptake as well as the metabolization of glucose. Although it is known for quite some time that suppression of glucose metabolism restricts virus replication, the exact molecular impact on the viral life cycle remained enigmatic so far. Using 2-deoxy-d-glucose (2-DG) we examined how well inhibition of glycolysis is tolerated by host cells and which step of the IAV life cycle is affected. We observed that effects induced by 2-DG are reversible and that cells can cope with relatively high concentrations of the inhibitor by compensating the loss of glycolytic activity by upregulating other metabolic pathways. Moreover, mass spectrometry data provided information on various metabolic modifications induced by either the virus or agents interfering with glycolysis. In the presence of 2-DG viral titers were significantly reduced in a dose-dependent manner. The supplementation of direct or indirect glycolysis metabolites led to a partial or almost complete reversion of the inhibitory effect of 2-DG on viral growth and demonstrated that indeed the inhibition of glycolysis and not of N-linked glycosylation was responsible for the observed phenotype. Importantly, we could show via conventional and strand-specific qPCR that the treatment with 2-DG led to a prolonged phase of viral mRNA synthesis while the accumulation of genomic vRNA was strongly reduced. At the same time, minigenome assays showed no signs of a general reduction of replicative capacity of the viral polymerase. Therefore, our data suggest that the significant reduction in IAV replication by glycolytic interference occurs mainly due to an impairment of the dynamic regulation of the viral polymerase which conveys the transition of the enzyme’s function from transcription to replication.