Comparative analysis of human coronavirus-NL63 ORF3 protein homologues

It has been reported in some studies that the newly discovered human coronavirus NL-63 (HCoVNL63) is one of the most common coronaviruses associated with acute respiratory infections. HCoVNL63 was first isolated in 2004 from a 7 month old infant in Holland. The HCoV-NL63 genome encodes for one accessory protein, ORF3. This reports the computational analysis of human coronavirus NL63 ORF3 by comparing the amino acid sequences of coronavirus ORF3-homologues. The HCoV-NL63 ORF3 gene was found to encode a putative protein ~25.6 kDa in size. ORF3 was predicted to contain three potential transmembrane regions. The amino acid sequence of HCoVNL63 ORF3 was shown to be most similar to HCoV 229E ORF4 (43% identity; 62% similarity).Web of Scienc

What the latest coronavirus tells us about emerging new infections

Viruses are quick studies. They’re prolific at adapting to new environments and infecting new hosts. As a result they are able to jump the species divide from animals to humans – as the new coronavirus in China is showing. It’s estimated that 89% of one particular family of viruses, known as RNA viruses, are zoonotic in origin. This means that they started in animals and have since become established among humans. RNA viruses are notorious for being able to mutate in a range of environments. This family of viruses includes everything from Ebola and West Nile Fever to measles and the common cold. The Severe acute respiratory syndrome-related coronavirus (or SARS-CoV) that broke out in Asia in 2003 is also an RNA virus; so too is the significantly more virulent and fatal Middle East respiratory syndrome coronavirus (MERS‐CoV), first identified in Saudi Arabia in 2012. Both are zoonotic. SARS-CoV is believed – although it’s never been confirmed – to have originated in bats. Infected dromedary camels are thought to have been the source for MERS-CoV

Human coronavirus research: 20 years since the SARS-CoV outbreak

This Editorial introduces 10 articles published in a Special Issue highlighting human coronavirus (hCoV) research on the twentieth anniversary of the outbreak of severe acute respiratory syndrome (SARS) in late 2002. Only with the SARS outbreak was the pandemic potential of hCoVs acknowledged. HCoV-OC43 (Tyrrell and Bynoe, 1966), HCoV-229E (Hamre and Procknow, 1966), HCoV-NL63 (Van Der Hoek et al., 2004), and HCoV-HKU1 (Woo et al., 2005) are endemic in the human population and are mainly associated with mild, self-limiting “common cold” illnesses annually. The burden of respiratory tract infections, caused by the four “common-cold” hCoVs, is increased in patients with chronic co-morbidities or clinical risk factors including young children, the elderly and immunocompromised (Van Der Hoek, 2007). On the other hand, the three know pathogenic hCoVs, SARS-CoV (Drosten et al., 2003; Peiris et al., 2003), Middle East Respiratory Syndrome CoV (MERS-CoV) (Zaki et al., 2012), and SARS-CoV-2 (Zhou et al., 2020a,b), cause severe respiratory syndromes and result in high morbidities and mortalities, especially in the elderly (Chen et al., 2020)

The role of Severe Acute Respiratory Syndrome (SARS)-Coronavirus Accessory Proteins in Virus Pathogenesis

A respiratory disease caused by a novel coronavirus, termed the severe acute respiratory syndrome coronavirus (SARS-CoV), was first reported in China in late 2002. The subsequent efficient human-to-human transmission of this virus eventually affected more than 30 countries worldwide, resulting in a mortality rate of ~10% of infected individuals. The spread of the virus was ultimately controlled by isolation of infected individuals and there has been no infections reported since April 2004. However, the natural reservoir of the virus was never identified and it is not known if this virus will re-emerge and, therefore, research on this virus continues. The SARS-CoV genome is about 30 kb in length and is predicted to contain 14 functional open reading frames (ORFs). The genome encodes for proteins that are homologous to known coronavirus proteins, such as the replicase proteins (ORFs 1a and 1b) and the four major structural proteins: nucleocapsid (N), spike (S), membrane (M) and envelope (E). SARS-CoV also encodes for eight unique proteins, called accessory proteins, with no known homologues. This review will summarize the current knowledge on SARS-CoV accessory proteins and will include: (i) expression and processing; (ii) the effects on cellular processes; and (iii) functional studies.Web of Scienc

The characterization and phylogenetic relationship of the trichoplusia ni single capsid nuclear polyhedrosis virus polyhedrin gene

The polyhedrin gene (polh) was identified from the Trichoplusia ni (Tni) single capsid nuclear polyhedrosis virus (SNPV). An EcoRI fragment containing the truncated polyhedrin gene was detected by hybridization with an AcMNPV expression vector probe; the remaining portion of the gene was amplified by reverse PCR. An open reading frame (ORF) of 741 nucleotides (nt), encoding a putative protein of 246 amino acids (a.a) with Mr 28,780 Da was identified. The 50-noncoding region contained the putative late (TAAG) transcription initiation motif. The 30 end, downstream of the translation stop codon, lacked an obvious putative poly (A) signal. Nucleotide and amino acid homology are greater than 80% to that of Mamestra brassicae polyhedrin sequences.Results suggest that T. niSNPV is a member of the group II nuclear polyhedrosis viruses.IS

COVID-19 and HIV: so far it seems the outcome is not what was feared

Based on official figures – which may be somewhat under reported – COVID-19 has not been asdevastating in South Africa as initially feared. Back in March and April this year case numbers on the continent were still modest. But predictions and projections were sombre. There seemed to be consensus that African countries had weak public health systems and few testing facilities , and containment and social distancing were going to beproblematic in poor communities . More specifically, local and international organisations pointed to the fact that these areas typicallyhave the highest incidence of immuno-compromised individuals. Experts feared that the tens ofmillions with HIV and tuberculosis would be disproportionately affected by COVID-19

Understanding Human Coronavirus HCoV-NL63

Even though coronavirus infection of humans is not normally associated with severe diseases, the identification of the coronavirus responsible for the outbreak of severe acute respiratory syndrome showed that highly pathogenic coronaviruses can enter the human population. Shortly thereafter, in Holland in 2004, another novel human coronavirus (HCoV-NL63) was isolated from a seven-month old infant suffering from respiratory symptoms. This virus has subsequently been identified in various countries, indicating a worldwide distribution. HCoV-NL63 has been shown to infect mainly children and the immunocommpromised, who presented with either mild upper respiratory symptoms (cough, fever and rhinorrhoea) or more serious lower respiratory tract involvement such as bronchiolitis and croup, which was observed mainly in younger children. In fact, HCoV-NL63 is the aetiological agent for up to 10% of all respiratory diseases. This review summarizes recent findings of human coronavirus HCoV-NL63 infections, including isolation and identification, phylogeny and taxonomy, genome structure and transcriptional regulation, transmission and pathogenesis, and detection and diagnosis

How viruses evolve

The unusual cases of pneumonia began to appear in midwinter, in China. The cause, researchers would later learn, was a coronavirus new to science. By March, the infection began to spread to other Asian countries and overseas. People were dying, and the World Health Organization issued a global health alert But this was 2003, not 2020, and the disease was SARS, not Covid-19. By June, the outbreak was almost gone, with just 8,098 confirmed infections and 774 deaths worldwide. No cases of SARS have been reported since 2004

Human coronavirus NL63: A clinically important virus?

Respiratory tract infection is a leading cause of morbidity and mortality worldwide, especially among young children. Human coronaviruses (HCoVs) have only recently been shown to cause both lower and upper respiratory tract infections. To date, five coronaviruses (HCoV-229E, HCoV-OC43, SARS-CoV, HCoV-NL63 and HCoV HKU-1) that infect humans have been identified, four of which (HCoV-229E, HCoV-OC43, HCoV-NL63 and HCoV-HKU-1) circulate continuously in the human population. Human coronavirus NL63 (HCoV-NL63) was first isolated from the aspirate from a 7-month-old baby in early 2004. Infection with HCoV-NL63 has since been shown to be a common worldwide occurrence and has been associated with many clinical symptoms and diagnoses, including severe lower respiratory tract infection, croup and bronchiolitis. HCoV-NL63 causes disease in children, the elderly and the immunocompromised, and has been detected in 1.0–9.3% of respiratory tract infections in children. In this article, the current knowledge of human coronavirus HCoV-NL63, with special reference to the clinical features, prevalence and seasonal incidence, and coinfection with other respiratory viruses, will be discussed

South Africa and the COVID-19 vaccine

Scientists, public health experts and politicians have been telling us that, to stop Covid-19, we need to embark on a massive vaccine rollout. But do we really need to vaccinate more than 70% of our population to stop this virus? What is the science telling us