Molecular Detection and Genetic Diversity of Cytomegaloviruses and Lymphocryptoviruses in Free-Roaming and Captive African Green Monkeys (Chlorocebus sabaeus).

To date, limited information is available on cytomegalovirus (CMV) and lymphocryptovirus (LCV) from Chlorocebus monkeys. We report here high detection rates of herpesviruses in free-roaming African green monkeys (AGMs, Chlorocebus sabaeus) (26.4%, 23/87) and in captive AGMs (75%, 3/4) with respiratory disease on the Caribbean Island of St. Kitts. LCV (81.25%) was more prevalent than CMV (18.75%) in the AGMs. Applying a bigenic PCR approach (targeting DNA polymerase (DPOL) and glycoprotein B (gB) genes), long sequences were obtained from representative AGM CMV (KNA-SD6) and LCV (KNA-E4, -N6 and -R15) samples, and mixed LCV infections were identified in KNA-N6 and -R15. The nucleotide (nt) sequence (partial DPOL-intergenic region-partial gB) and partial DPOL- and gB-amino acid (aa) sequences of AGM CMV KNA-SD6 were closely related to Cytomegalovirus cercopithecinebeta5 isolates from grivet monkeys, whilst those of AGM LCV KNA-E4 and -N6 (and E4-like gB of KNA-R15) were more closely related to cognate sequences of erythrocebus patas LCV1 from patas monkey than other LCVs, corroborating the concept of cospeciation in the evolution of CMV/LCV. On the other hand, the partial DPOL aa sequence of KNA-R15, and additional gB sequences (N6-gB-2 and R15-gB-2) from samples KNA-N6 and -R15 (respectively) appeared to be distinct from those of Old World monkey LCVs, indicating LCV evolutionary patterns that were not synchronous with those of host species. The present study is the first to report the molecular prevalence and genetic diversity of CMV/LCV from free-roaming/wild and captive AGMs, and is the first report on analysis of CMV nt/deduced aa sequences from AGMs and LCV gB sequences from Chlorocebus monkeys.

ICTV virus taxonomy profile: Picobirnaviridae.

Picobirnaviridae is a family of viruses with bi-segmented (rarely unsegmented) dsRNA genomes comprising about 4.4 kbp in total, with small, non-enveloped spherical virions. The family includes one genus (Picobirnavirus) grouping three genetic clusters with high sequence variability, two defined by viruses infecting vertebrates and a third with viruses found in invertebrates. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of Picobirnaviridae, which is available at www.ictv.global/report/picobirnaviridae.

ICTV virus taxonomy profile: Birnaviridae.

Birnaviridae is a family of viruses with bi-segmented dsRNA genomes totalling about 6 kbp forming icosahedral, non-enveloped virions. The family includes four genera, members of three of which (Aquabirnavirus, Avibirnavirus and Blosnavirus) infect vertebrates (excluding mammals), whereas members of the fourth genus (Entomobirnavirus) infect insects. Each genus includes 1-3 species. Infectious pancreatic necrosis virus of salmonids and infectious bursal disease virus of poultry are two economically important birnaviruses. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of Birnaviridae, which is available at www.ictv.global/report/birnaviridae.

Evaluation of GeneXpert MTB/RIF system performances in the diagnosis of extrapulmonary tuberculosis.

BACKGROUND: Tuberculosis represents a serious public health problem and a significant diagnostic and therapeutic challenge worldwide. Molecular diagnostic techniques are crucial in the World Health Organization's new tuberculosis control strategy. This study aims to evaluate the performance of GeneXpert MTB/RIF (Cepheid Sunnyvale, CA, United States) in diagnosis of extra-pulmonary tuberculosis then compare it's performance in detecting Rifampicin resistance to GenoType MTBDRplus (HAIN Life Sciences, Nehren, Germany). METHODS: Samples from pulmonary and/or extra-pulmonary origins were analysed in a 21 months retrospective study. Samples were sent to the bacteriology laboratory for Mycobacterium tuberculosis detection using conventional bacteriological and molecular methods (GeneXpert MTB/RIF and MTBDRplus). Sensitivity and specificity were calculated for the stained smear and GeneXpert according to culture (Gold Standard) as well as for GeneXpert MTB/RIF in both negative and positive microscopy tuberculosis cases. Data's statistical analysis was performed with SPSS13.0 software. RESULTS: Seven hundred fourteen patients' samples were analysed; the average age was 47.21 ± 19.98 years with a male predominance (66.4%). Out of 714 samples: 285 were from pulmonary and 429 were from extra-pulmonary origins. The positivity rates for microscopy, GeneXpert MTB/RIF and culture were 12.88, 20.59 and 15.82%, respectively. These rates were 18.9, 23.85 and 20.35% for pulmonary samples and 9.71, 18.41 and 12.82% for extra-pulmonary samples, respectively. The sensitivity and specificity of GeneXpert MTB/RIF were almost the same in both pulmonary and extra-pulmonary samples (78.2 and 90.4%) and (79,3 and 90.3%) respectively. Rifampicin resistance rate found by GeneXpert MTB/RIF was 0.84%. Comparison of Rifampicin resistance obtained by GeneXpert MTB/RIF and Genotype MTBDRplus, showed 100% agreement between the two techniques for studied samples. CONCLUSIONS: This confirms GeneXpert MTB/RIF advantage for tuberculosis diagnosis, particularly extra-pulmonary tuberculosis with negatively stained smear. The performance of GeneXpert and Genotype MTBDRplus are similar in detection of Rifampicin resistance. However, variability of detection performance according to tuberculosis endemicity deserves more attention in the choice of screening techniques of Rifampicin resistance, hence the interest of conducting comparative studies of detection performance under low and medium endemicity on large samples of tuberculosis populations.

Classification and characterization of a laboratory chicken rotavirus strain carrying G7P[35] neutralization antigens on the genotype 4 backbone gene configuration.

The laboratory rotavirus strain, BRS/115, has been used for more than two decades to monitor rotaviruses in specific pathogen free flocks of laying hens. However, the virus strain has not been characterized in detail. Therefore we aimed at the description of molecular features of BRS115 by using random primed reverse transcription-PCR of the genomic RNA followed by massive parallel sequencing using the semiconductor sequencing technology. Over 64,000 trimmed reads mapped to reference sequences obtained from GenBank. The strain classified into the species Rotavirus A and genotyped G7-P[35]-I4-R4-C4-M4-A16-N4-T4-E11-H4 according to guidelines of the Rotavirus Classification Working Group. Phylogenetic analysis identified shared features with chicken, turkey and pigeon origin rotaviruses. This study demonstrates the robustness of next generation sequencing in the characterization of reference virus materials used in specialized laboratories.

First Report on Detection and Molecular Characterization of Astroviruses in Mongooses.

Applying a pan-astrovirus (AstV) RT-hemi-nested PCR assay, we report here high detection rates (28.3%, 15/53) of AstVs in the small Indian mongoose (Urva auropunctata) on the Caribbean Island of St. Kitts. Based on deduced amino acid (aa) identities and phylogenetic analysis of long RNA-dependent RNA polymerase (RdRp) sequences (~315 aa, partial RdRp), the AstVs detected in the mongooses (designated as Mon-AstVs) were classified into two distinct groups (deduced aa identities of 66.45-67.30% between the groups). The putative RdRps of the Mon-AstVs shared low deduced aa identities with those of AstVs from other host species (<69%, <54%, and <50% identities with reptilian/amphibian AstVs, avastroviruses, and mamastroviruses, respectively). Phylogenetically, the group-I and group-II Mon-AstVs formed two distinct clusters, near the cluster of reptilian/amphibian AstVs, and were distantly related to avastroviruses and mamastroviruses. Since the mongooses were apparently healthy during sampling, we could not establish if the Mon-AstVs infected the animal or were of dietary origin. Although we could not ascertain the true host of the Mon-AstVs, phylogenetic analysis indicated that these viruses might have originated from lower vertebrates. To our knowledge, this is the first report on the detection and molecular characterization of AstVs in mongooses, highlighting the wide host range and significant genetic diversity within the family Astroviridae.

WSV2023 - The second meeting of the world society for virology: One health - One world - One virology.

The Second International Conference of the World Society for Virology (WSV), hosted by Riga Stradins University, was held in Riga, Latvia, on June 15-17th, 2023. It prominently highlighted the recent advancements in different disciplines of virology. The conference had fourteen keynote speakers covering diverse topics, including emerging virus pseudotypes, Zika virus vaccine development, herpesvirus capsid mobility, parvovirus invasion strategies, influenza in animals and birds, West Nile virus and Marburg virus ecology, as well as the latest update in animal vaccines. Discussions further explored SARS-CoV-2 RNA replicons as vaccine candidates, SARS-CoV-2 in humans and animals, and the significance of plant viruses in the 'One Health' paradigm. The presence of the presidents from three virology societies, namely the American, Indian, and Korean Societies for Virology, highlighted the event's significance. Additionally, past president of the American Society for Virology (ASV), formally declared the partnership between ASV and WSV during the conference.

Detection and Molecular Characterization of Adenoviruses in Captive and Free-Roaming African Green Monkeys (Chlorocebus sabaeus): Evidence for Possible Recombination and Cross-Species Transmission.

In the present study, 31 samples (12 fecal, 9 nasal and 10 rectal swabs) from 28/92 (30.43%, 10 captive and 18 free-roaming African green monkeys (AGMs, Chlorocebus sabaeus)) apparently healthy AGMs in the Caribbean Island of St. Kitts tested positive for adenoviruses (AdVs) by DNA-dependent DNA polymerase (pol)-, or hexon-based screening PCR assays. Based on analysis of partial deduced amino acid sequences of Pol- and hexon- of nine AGM AdVs, at least two AdV genetic variants (group-I: seven AdVs with a Simian mastadenovirus-F (SAdV-F)/SAdV-18-like Pol and hexon, and group-II: two AdVs with a SAdV-F/SAdV-18-like Pol and a Human mastadenovirus-F (HAdV-F)/HAdV-40-like hexon) were identified, which was corroborated by analysis of the nearly complete putative Pol, complete hexon, and partial penton base sequences of a representative group-I (strain KNA-08975), and -II (KNA-S6) AdV. SAdV-F-like AdVs were reported for the first time in free-roaming non-human primates (NHPs) and after ~six decades from captive NHPs. Molecular characterization of KNA-S6 (and the other group-II AdV) indicated possible recombination and cross-species transmission events involving SAdV-F-like and HAdV-F-like viruses, corroborating the hypothesis that the evolutionary pathways of HAdVs and SAdVs are intermingled, complicated by recombination and inter-species transmission events, especially between related AdV species, such as HAdV-F and SAdV-F. To our knowledge, this is the first report on detection and molecular characterization of AdVs in AGMs.

World Society for Virology first international conference: Tackling global virus epidemics.

This communication summarizes the presentations given at the 1st international conference of the World Society for Virology (WSV) held virtually during 16-18 June 2021, under the theme of tackling global viral epidemics. The purpose of this biennial meeting is to foster international collaborations and address important viral epidemics in different hosts. The first day included two sessions exclusively on SARS-CoV-2 and COVID-19. The other two days included one plenary and three parallel sessions each. Last not least, 16 sessions covered 140 on-demand submitted talks. In total, 270 scientists from 49 countries attended the meeting, including 40 invited keynote speakers.

Novel Cyclovirus Species in Dogs with Hemorrhagic Gastroenteritis.

Nested PCRs with circovirus/cyclovirus pan-rep (replicase gene) primers detected eukaryotic circular Rep-encoding single-stranded DNA (CRESS DNA) viruses in three (samples CN9E, CN16E and CN34) of 18 canine parvovirus-2-positive fecal samples from household dogs with hemorrhagic gastroenteritis on the Caribbean island of Nevis. The complete genomes of CRESS DNA virus CN9E, CN16E and CN34 were determined by inverse nested PCRs. Based on (i) genome organization, (ii) location of the putative origin of replication, (iii) pairwise genome-wide sequence identities, (iv) the presence of conserved motifs in the putative replication-associated protein (Rep) and the arginine-rich region in the amino terminus of the putative capsid protein (Cp) and (v) a phylogenetic analysis, CN9E, CN16E and CN34 were classified as cycloviruses. Canine-associated cycloviruses CN16E and CN34 were closely related to each other and shared low genome-wide nucleotide (59.642-59.704%), deduced Rep (35.018-35.379%) and Cp (26.601%) amino acid sequence identities with CN9E. All the three canine-associated cycloviruses shared < 80% genome-wide pairwise nucleotide sequence identities with cycloviruses from other animals/environmental samples, constituting two novel species (CN9E and CN16E/34) within the genus Cyclovirus. Considering the feeding habits of dogs, we could not determine whether the cycloviruses were of dietary origin or infected the host. Interestingly, the CN9E putative Rep-encoding open reading frame was found to use the invertebrate mitochondrial genetic code with an alternative initiation codon (ATA) for translation, corroborating the hypothesis that cycloviruses are actually arthropod-infecting viruses. To our knowledge, this is the first report on the detection and complete genome analysis of cycloviruses from domestic dogs.

Molecular Investigation of Canine Parvovirus-2 (CPV-2) Outbreak in Nevis Island: Analysis of the Nearly Complete Genomes of CPV-2 Strains from the Caribbean Region.

To date, there is a dearth of information on canine parvovirus-2 (CPV-2) from the Caribbean region. During August-October 2020, the veterinary clinic on the Caribbean island of Nevis reported 64 household dogs with CPV-2-like clinical signs (hemorrhagic/non-hemorrhagic diarrhea and vomiting), of which 27 animals died. Rectal swabs/fecal samples were obtained from 43 dogs. A total of 39 of the 43 dogs tested positive for CPV-2 antigen and/or DNA, while 4 samples, negative for CPV-2 antigen, were not available for PCR. Among the 21 untested dogs, 15 had CPV-2 positive littermates. Analysis of the complete VP2 sequences of 32 strains identified new CPV-2a (CPV-2a with Ser297Ala in VP2) as the predominant CPV-2 on Nevis Island. Two nonsynonymous mutations, one rare (Asp373Asn) and the other uncommon (Ala262Thr), were observed in a few VP2 sequences. It was intriguing that new CPV-2a was associated with an outbreak of gastroenteritis on Nevis while found at low frequencies in sporadic cases of diarrhea on the neighboring island of St. Kitts. The nearly complete CPV-2 genomes (4 CPV-2 strains from St. Kitts and Nevis (SKN)) were reported for the first time from the Caribbean region. Eleven substitutions were found among the SKN genomes, which included nine synonymous substitutions, five of which have been rarely reported, and the two nonsynonymous substitutions. Phylogenetically, the SKN CPV-2 sequences formed a distinct cluster, with CPV-2b/USA/1998 strains constituting the nearest cluster. Our findings suggested that new CPV-2a is endemic in the region, with the potential to cause severe outbreaks, warranting further studies across the Caribbean Islands. Analysis of the SKN CPV-2 genomes corroborated the hypothesis that recurrent parallel evolution and reversion might play important roles in the evolution of CPV-2.

Genomic Diversity of CRESS DNA Viruses in the Eukaryotic Virome of Swine Feces.

Replication-associated protein (Rep)-encoding single-stranded DNA (CRESS DNA) viruses are a diverse group of viruses, and their persistence in the environment has been studied for over a decade. However, the persistence of CRESS DNA viruses in herds of domestic animals has, in some cases, serious economic consequence. In this study, we describe the diversity of CRESS DNA viruses identified during the metagenomics analysis of fecal samples collected from a single swine herd with apparently healthy animals. A total of nine genome sequences were assembled and classified into two different groups (CRESSV1 and CRESSV2) of the Cirlivirales order (Cressdnaviricota phylum). The novel CRESS DNA viral sequences shared 85.8-96.8% and 38.1-94.3% amino acid sequence identities for the Rep and putative capsid protein sequences compared to their respective counterparts with extant GenBank record. Data presented here show evidence for simultaneous infection of swine herds with multiple novel CRESS DNA viruses, including po-circo-like viruses and fur seal feces-associated circular DNA viruses. Given that viral genomes with similar sequence and structure have been detected in swine fecal viromes from independent studies, investigation of the association between presence of CRESS DNA viruses and swine health conditions seems to be justified.

Detection and Complete Genome Analysis of Circoviruses and Cycloviruses in the Small Indian Mongoose (Urva auropunctata): Identification of Novel Species.

Fecal samples from 76 of 83 apparently healthy small Indian mongooses (Urva auropunctata) were PCR positive with circovirus/cyclovirus pan-rep (replicase gene) primers. In this case, 30 samples yielded high quality partial rep sequences (~400 bp), of which 26 sequences shared maximum homology with cycloviruses from an arthropod, bats, humans or a sheep. Three sequences exhibited maximum identities with a bat circovirus, whilst a single sequence could not be assigned to either genus. Using inverse nested PCRs, the complete genomes of mongoose associated circoviruses (Mon-1, -29 and -66) and cycloviruses (Mon-20, -24, -32, -58, -60 and -62) were determined. Mon-1, -20, -24, -29, -32 and -66 shared <80% maximum genome-wide pairwise nucleotide sequence identities with circoviruses/cycloviruses from other animals/sources, and were assigned to novel circovirus, or cyclovirus species. Mon-58, -60 and -62 shared maximum pairwise identities of 79.90-80.20% with human and bat cycloviruses, which were borderline to the cut-off identity value for assigning novel cycloviral species. Despite high genetic diversity, the mongoose associated circoviruses/cycloviruses retained the various features that are conserved among members of the family Circoviridae, such as presence of the putative origin of replication (ori) in the 5'-intergenic region, conserved motifs in the putative replication-associated protein and an arginine rich region in the amino terminus of the putative capsid protein. Since only fecal samples were tested, and mongooses are polyphagous predators, we could not determine whether the mongoose associated circoviruses/cycloviruses were of dietary origin, or actually infected the host. To our knowledge, this is the first report on detection and complete genome analysis of circoviruses/cycloviruses in the small Indian mongoose, warranting further studies in other species of mongooses.

First Report on Detection and Molecular Characterization of Adenoviruses in the Small Indian Mongoose (Urva auropunctata).

Using a broad-range nested PCR assay targeting the DNA-dependent DNA polymerase (pol) gene, we detected adenoviruses in 17 (20.48%) out of 83 fecal samples from small Indian mongooses (Urva auropunctata) on the Caribbean island of St. Kitts. All 17 PCR amplicons were sequenced for the partial pol gene (~300 bp, hereafter referred to as Mon sequences). Fourteen of the 17 Mon sequences shared maximum homology (98.3-99.6% and 97-98.9% nucleotide (nt) and deduced amino acid (aa) sequence identities, respectively) with that of bovine adenovirus-6 (species Bovine atadenovirus E). Mongoose-associated adenovirus Mon-39 was most closely related (absolute nt and deduced aa identities) to an atadenovirus from a tropical screech owl. Mon-66 shared maximum nt and deduced aa identities of 69% and 71.4% with those of atadenoviruses from a spur-thighed tortoise and a brown anole lizard, respectively. Phylogenetically, Mon-39 and Mon-66 clustered within clades that were predominated by atadenoviruses from reptiles, indicating a reptilian origin of these viruses. Only a single mongoose-associated adenovirus, Mon-34, was related to the genus Mastadenovirus. However, phylogenetically, Mon-34 formed an isolated branch, distinct from other mastadenoviruses. Since the fecal samples were collected from apparently healthy mongooses, we could not determine whether the mongoose-associated adenoviruses infected the host. On the other hand, the phylogenetic clustering patterns of the mongoose-associated atadenoviruses pointed more towards a dietary origin of these viruses. Although the present study was based on partial pol sequences (~90 aa), sequence identities and phylogenetic analysis suggested that Mon-34, Mon-39, and Mon-66 might represent novel adenoviruses. To our knowledge, this is the first report on the detection and molecular characterization of adenoviruses from the mongoose.

Spatio-temporal and time series analysis of bluetongue outbreaks with environmental factors extracted from Google Earth Engine (GEE) in Andhra Pradesh, India.

This study describes the spatial and temporal patterns of bluetongue (BT) outbreaks with environmental factors in undivided Andhra Pradesh, India. Descriptive analysis of the reported BT outbreaks (n = 2,697) in the study period (2000-2017) revealed a higher frequency of outbreaks during monsoon and post-monsoon months. Correlation analysis of Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), rainfall and relative humidity (RH) displayed a significant positive correlation with BT outbreaks (p < .05). Retrospective unadjusted space-time, adjusted temporal and spatial analysis detected two, five and two statistically significant (p < .05) clusters, respectively. Time series distribution lag analysis examined the temporal patterns of BT outbreaks with environmental, biophysical factors and estimated that a decrease in 1 unit of rainfall (mm) was associated with 0.2% increase in the outbreak at lag 12 months. Similarly, a 1°C increase in land surface temperature (LST) was associated with 6.54% increase in the outbreaks at lag 12 months. However, an increase in 1 unit of wind speed (m/s) was associated with a 16% decrease in the outbreak at lag 10 months. The predictive model indicated that the peak of BT outbreaks were from October to December, the post-monsoon season in Andhra Pradesh region. The findings suggest that environmental factors influence BT outbreaks, and due to changes in climatic conditions, we may notice higher numbers of BT outbreaks in the coming years. The knowledge of spatial and temporal clustering of BT outbreaks may assist in adopting proper measures to prevent and control the BT spread.

SARS-CoV-2 Spike Protein Extrapolation for COVID Diagnosis and Vaccine Development.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) led to coronavirus disease 2019 (COVID-19) pandemic affecting nearly 71.2 million humans in more than 191 countries, with more than 1.6 million mortalities as of 12 December, 2020. The spike glycoprotein (S-protein), anchored onto the virus envelope, is the trimer of S-protein comprised of S1 and S2 domains which interacts with host cell receptors and facilitates virus-cell membrane fusion. The S1 domain comprises of a receptor binding domain (RBD) possessing an N-terminal domain and two subdomains (SD1 and SD2). Certain regions of S-protein of SARS-CoV-2 such as S2 domain and fragment of the RBD remain conserved despite the high selection pressure. These conserved regions of the S-protein are extrapolated as the potential target for developing molecular diagnostic techniques. Further, the S-protein acts as an antigenic target for different serological assay platforms for the diagnosis of COVID-19. Virus-specific IgM and IgG antibodies can be used to detect viral proteins in ELISA and lateral flow immunoassays. The S-protein of SARS-CoV-2 has very high sequence similarity to SARS-CoV-1, and the monoclonal antibodies (mAbs) against SARS-CoV-1 cross-react with S-protein of SARS-CoV-2 and neutralize its activity. Furthermore, in vitro studies have demonstrated that polyclonal antibodies targeted against the RBD of S-protein of SARS-CoV-1 can neutralize SARS-CoV-2 thus inhibiting its infectivity in permissive cell lines. Research on coronaviral S-proteins paves the way for the development of vaccines that may prevent SARS-CoV-2 infection and alleviate the current global coronavirus pandemic. However, specific neutralizing mAbs against SARS-CoV-2 are in clinical development. Therefore, neutralizing antibodies targeting SARS-CoV-2 S-protein are promising specific antiviral therapeutics for pre-and post-exposure prophylaxis and treatment of SARS-CoV-2 infection. We hereby review the approaches taken by researchers across the world to use spike gene and S-glycoprotein for the development of effective diagnostics, vaccines and therapeutics against SARA-CoV-2 infection the COVID-19 pandemic.

The True Host/s of Picobirnaviruses.

Picobirnaviruses (PBVs) are bisegmented double-stranded RNA viruses that have been detected in a wide variety of animal species including invertebrates and in environmental samples. Since PBVs are ubiquitous in feces/gut contents of humans and other animals with or without diarrhea, they were considered as opportunistic enteric pathogens of mammals and avian species. However, the virus remains to be propagated in animal cell cultures, or in gnotobiotic animals. Recently, the classically defined prokaryotic motif, the ribosomal binding site sequence, has been identified upstream of putative open reading frame/s in PBV and PBV-like sequences from humans, various animals, and environmental samples, suggesting that PBVs might be prokaryotic viruses. On the other hand, based on the detection of some novel PBV-like RNA-dependent RNA polymerase sequences that use the alternative mitochondrial genetic code (that of mold or invertebrates) for translation, and principal component analysis of codon usage bias for these sequences, it has been proposed that PBVs might be fungal viruses with a lifestyle reminiscent of mitoviruses. These contradicting observations warrant further studies to ascertain the true host/s of PBVs, which still remains controversial. In this minireview, we have focused on the various findings that have raised a debate on the true host/s of PBVs.

Drawing Comparisons between SARS-CoV-2 and the Animal Coronaviruses.

The COVID-19 pandemic, caused by a novel zoonotic coronavirus (CoV), SARS-CoV-2, has infected 46,182 million people, resulting in 1,197,026 deaths (as of 1 November 2020), with devastating and far-reaching impacts on economies and societies worldwide. The complex origin, extended human-to-human transmission, pathogenesis, host immune responses, and various clinical presentations of SARS-CoV-2 have presented serious challenges in understanding and combating the pandemic situation. Human CoVs gained attention only after the SARS-CoV outbreak of 2002-2003. On the other hand, animal CoVs have been studied extensively for many decades, providing a plethora of important information on their genetic diversity, transmission, tissue tropism and pathology, host immunity, and therapeutic and prophylactic strategies, some of which have striking resemblance to those seen with SARS-CoV-2. Moreover, the evolution of human CoVs, including SARS-CoV-2, is intermingled with those of animal CoVs. In this comprehensive review, attempts have been made to compare the current knowledge on evolution, transmission, pathogenesis, immunopathology, therapeutics, and prophylaxis of SARS-CoV-2 with those of various animal CoVs. Information on animal CoVs might enhance our understanding of SARS-CoV-2, and accordingly, benefit the development of effective control and prevention strategies against COVID-19.

Identification of SARS-CoV-2 Cell Entry Inhibitors by Drug Repurposing Using in silico Structure-Based Virtual Screening Approach.

The rapidly spreading, highly contagious and pathogenic SARS-coronavirus 2 (SARS-CoV-2) associated Coronavirus Disease 2019 (COVID-19) has been declared as a pandemic by the World Health Organization (WHO). The novel 2019 SARS-CoV-2 enters the host cell by binding of the viral surface spike glycoprotein (S-protein) to cellular angiotensin converting enzyme 2 (ACE2) receptor. The virus specific molecular interaction with the host cell represents a promising therapeutic target for identifying SARS-CoV-2 antiviral drugs. The repurposing of drugs can provide a rapid and potential cure toward exponentially expanding COVID-19. Thereto, high throughput virtual screening approach was used to investigate FDA approved LOPAC library drugs against both the receptor binding domain of spike protein (S-RBD) and ACE2 host cell receptor. Primary screening identified a few promising molecules for both the targets, which were further analyzed in details by their binding energy, binding modes through molecular docking, dynamics and simulations. Evidently, GR 127935 hydrochloride hydrate, GNF-5, RS504393, TNP, and eptifibatide acetate were found binding to virus binding motifs of ACE2 receptor. Additionally, KT203, BMS195614, KT185, RS504393, and GSK1838705A were identified to bind at the receptor binding site on the viral S-protein. These identified molecules may effectively assist in controlling the rapid spread of SARS-CoV-2 by not only potentially inhibiting the virus at entry step but are also hypothesized to act as anti-inflammatory agents, which could impart relief in lung inflammation. Timely identification and determination of an effective drug to combat and tranquilize the COVID-19 global crisis is the utmost need of hour. Further, prompt in vivo testing to validate the anti-SARS-CoV-2 inhibition efficiency by these molecules could save lives is justified.

Detection and Molecular Characterization of Picobirnaviruses (PBVs) in the Mongoose: Identification of a Novel PBV Using an Alternative Genetic Code.

We report high rates of detection (35.36%, 29/82) of genogroup-I (GI) picobirnaviruses (PBVs) in non-diarrheic fecal samples from the small Indian mongoose (Urva auropunctata). In addition, we identified a novel PBV-like RNA-dependent RNA polymerase (RdRp) gene sequence that uses an alternative mitochondrial genetic code (that of mold or invertebrate) for translation. The complete/nearly complete gene segment-2/RdRp gene sequences of seven mongoose PBV GI strains and the novel PBV-like strain were obtained by combining a modified non-specific primer-based amplification method with conventional RT-PCRs, facilitated by the inclusion of a new primer targeting the 3'-untranslated region (UTR) of PBV gene segment-2. The mongoose PBV and PBV-like strains retained the various features that are conserved in gene segment-2/RdRps of other PBVs. However, high genetic diversity was observed among the mongoose PBVs within and between host species. This is the first report on detection of PBVs in the mongoose. Molecular characterization of the PBV and PBV-like strains from a new animal species provided important insights into the various features and complex diversity of PBV gene segment-2/putative RdRps. The presence of the prokaryotic ribosomal binding site in the mongoose PBV genomes, and analysis of the novel PBV-like RdRp gene sequence that uses an alternative mitochondrial genetic code (especially that of mold) for translation corroborated recent speculations that PBVs may actually infect prokaryotic or fungal host cells.