Neonatal calf diarrhea (NCD) is a major cause of morbidity, mortality and economic losses in the beef and dairy industries. This study was conducted to investigate the existence of enteric viruses in two Egyptian farms with a history of recurrent diarrhea. Fecal samples were collected from 25 diarrheic calves. RNA was extracted and tested by reverse transcription polymerase chain reaction (RT-PCR) for the presence of rotavirus, norovirus, astrovirus, torovirus, coronavirus and bovine viral diarrhea virus. Overall, 76 % (19/25) of samples tested positive for one or more viruses. Rota-, noro- and astroviruses were detected in 48 %, 24 % and 32 % of tested samples, respectively. About 37 % (7/19) of positive samples had two different viruses. One-month-old calves were the group most vulnerable to infections. Based on phylogenetic analysis, bovine rotaviruses were of genotypes G6 and G10, bovine noroviruses were in GIII.2, and bovine astroviruses were in the BAstV lineage 1. Astrovirus sequences showed a high level nucleotide sequence similarity with the Brazilian BAstV sequences available in GenBank. We believe this is the first report of bovine norovirus and bovine astrovirus circulating among calves in Egypt. Further epidemiological studies are recommended to investigate their presence on a wider scale, to predict their association with NCD, and to design appropriate diagnostic and control methods.
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.
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.
In recent years, avian influenza virus (AIV) and Newcastle disease virus (NDV) have caused large-scale outbreaks in many countries, including Egypt. The culling and vaccination strategies have failed to control both viruses in Egypt. In this study, we investigated the outbreaks of nervous manifestations and deaths in pigeons between 2013 and 2015. The H5N1 subtype of the highly pathogenic avian influenza virus and pigeon paramyxovirus-1, an antigenic variant of NDV, were found to be the cause; AIV and pigeon paramyxovirus-1 were isolated from 61.3% (19/31) and 67.8% (21/31) of tested pigeons, respectively. Co-infection with both viruses was detected in 51.6% of pigeons (16/31). The AIV sequences showed PQGEKRRKKR/GLF motif at the haemagglutinin gene cleavage site, which is typical of the highly pathogenic H5N1 subtype. The phylogenetic tree showed that the highly pathogenic avian influenza belonged to clade 2.2.1.2. The NDV sequences carried one of the three motifs, GKQGRL, KRQKRF or RRQKRF, at the fusion protein cleavage site and were classified as genotypes I, VI and II in NDV-class II, respectively. This indicated that different genotypes of NDV can circulate simultaneously among pigeons. Further analysis revealed the clustering of some sequences in sub-genotypes Ia and VIb.2. To the best of our knowledge, these sub-genotypes have not been previously reported from pigeons in Egypt. Our results should serve as a base for future studies on both viruses in Egypt.
Avian orthoavulavirus 1, 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.
Nonsense-mediated mRNA decay (NMD) was identified as a process to degrade flawed cellular messenger RNA (mRNA). Within the last decades it was also shown that NMD carries virus-restricting capacities and thus could be considered a part of the cellular antiviral system. As this was shown to affect primarily positive-sense single stranded RNA ((+)ssRNA) viruses there is only scarce knowledge if this also applies to negative-sense single stranded RNA ((−)ssRNA) viruses. Influenza A viruses (IAVs) harbour a segmented (−)ssRNA genome. During their replication IAVs produce numerous RNA transcripts and simultaneously impair cellular transcription and translation. The viral mRNAs hold several molecular patterns which can elicit NMD and in turn would lead to their degradation. This, in consequence, may mitigate viral propagation. Thus, we examined if a knockdown or a pharmacological inhibition of NMD key components may influence IAV replication. Additionally, we performed similar experiments with respiratory syncytial virus (RSV), another (−)ssRNA virus, but with a non-segmented genome. Although it seemed that a knockdown of up-frameshift protein 1 (UPF1), the central NMD factor, slightly increased viral mRNA and protein levels, no significant alteration of viral replication could be observed, implying that the NMD machinery may not have restricting capacities against (−)ssRNA viruses.
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