Genetic Analysis of Dengue Virus in Severe and Non-Severe Cases in Dhaka, Bangladesh, in 2018-2022.

Dengue virus (DENV) infections have unpredictable clinical outcomes, ranging from asymptomatic or minor febrile illness to severe and fatal disease. The severity of dengue infection is at least partly related to the replacement of circulating DENV serotypes and/or genotypes. To describe clinical profiles of patients and the viral sequence diversity corresponding to non-severe and severe cases, we collected patient samples from 2018 to 2022 at Evercare Hospital Dhaka, Bangladesh. Serotyping of 495 cases and sequencing of 179 cases showed that the dominant serotype of DENV shifted from DENV2 in 2017 and 2018 to DENV3 in 2019. DENV3 persisted as the only representative serotype until 2022. Co-circulation of clades B and C of the DENV2 cosmopolitan genotype in 2017 was replaced by circulation of clade C alone in 2018 with all clones disappearing thereafter. DENV3 genotype I was first detected in 2017 and was the only genotype in circulation until 2022. We observed a high incidence of severe cases in 2019 when the DENV3 genotype I became the only virus in circulation. Phylogenetic analysis revealed clusters of severe cases in several different subclades of DENV3 genotype I. Thus, these serotype and genotype changes in DENV may explain the large dengue outbreaks and increased severity of the disease in 2019.

Molecular Detection of Canine Parvovirus-2c (Cpv-2c) in Diseased Coyote Pups (Canis Latrans) at Northeastern Mexico

Intro: Canine parvovirus type 2 (PVC-2), Protoparvovirus genus of the Parvoviridae family, is a worldwide distribution virus that affects the Canidae family. In free-living coyotes (Canis latrans), the presence of the PCV-2a, PCV-2b and PCV-2c subtypes of PVC-2 has been reported, but there are no reports of their presence as a cause of clinical damage. The objective of this study is to report the presence of PVC-2c in an outbreak of mild gastroenteritis in three coyote pups detected in northeastern Mexico Methods: During the fall of 2019, in the suburban area of Monterrey, N.L., 3 affected coyote pups were detected with a mild gastroenteric condition consisting of mild diarrhea with loose stools, vomiting, dehydration, loss of appetite, pale mucous membranes, and low weight. Stool samples were tested for Canine Parvovirus (CPV-2), Canine Coronavirus (CCV) or Giardia antigens with a commercial kit. All samples were positive for CPV-2 and these were subsequently analyzed by PCR and sequencing of the CPV-2 VP2 gene. Using bioinformatics, the VP2 gene sequence data obtained were used to establish phylogenetic relationships with homologous sequences reported in coyotes and CPV-2 vaccines. Finding(s): The genetic sequence of VP2 obtained showed a high homology (98.1 to 100%) with CPV-2c. The sequences obtained from the pups showed 100% homology to each other. The phylogenetic tree showed that the sequences reported in coyotes are grouped in different clades and that the sequence of the VP2 gene of CPV-2c from coyote pups is grouped in a different monophyletic group. Conclusion(s): Information suggests that wild coyotes may not only act as asymptomatic reservoir hosts but may also be clinically affected by PVC-2c. It is necessary to carry out studies to know the effects of the genetic subtypes of PVC-2 in the population of coyotes and other wild canids of northeastern Mexico.Copyright © 2023

Molecular genetics and genomics of the ABO blood group system

The A and B oligosaccharide antigens of the ABO blood group system are produced from the common precursor, H substance, by enzymatic reactions catalyzed by A and B glycosyltransferases (AT and BT) encoded by functional A and B alleles at the ABO genetic locus, respectively. In 1990, my research team cloned human A, B, and O allelic cDNAs. We then demonstrated this central dogma of ABO and opened a new era of molecular genetics. We identified four amino acid substitutions between AT and BT and inactivating mutations in the O alleles, clarifying the allelic basis of ABO. We became the first to achieve successful ABO genotyping, discriminating between AA and AO genotypes and between BB and BO, which was impossible using immunohematological/serological methods. We also identified mutations in several subgroup alleles and also in the cis-AB and B(A) alleles that specify the expression of the A and B antigens by single alleles. Later, other scientists interested in the ABO system characterized many additional ABO alleles. However, the situation has changed drastically in the last decade, due to rapid advances in next-generation sequencing (NGS) technology, which has allowed the sequencing of several thousand genes and even the entire genome in individual experiments. Genome sequencing has revealed not only the exome but also transcription/translation regulatory elements. RNA sequencing determines which genes and spliced transcripts are expressed. Because more than 500,000 human genomes have been sequenced and deposited in sequence databases, bioinformaticians can retrieve and analyze this data without generating it. Now, in this era of genomics, we can harness the vast sequence information to unravel the molecular mechanisms responsible for important biological phenomena associated with the ABO polymorphism. Two examples are presented in this review: the delineation of the ABO gene evolution in a variety of species and the association of single nucleotide variant (SNV) sites in the ABO gene with diseases and biological parameters through genome-wide association studies (GWAS).Copyright © Annals of Blood. All rights reserved.

SARS-CoV-2 VARIANTS' TEMPORAL AND VL DISTRIBUTIONS IN IMMUNOCOMPROMISED PATIENTS

Background: The COVID-19 pandemic has been striking for three years and, despite the regular arise of new variants, populations are now widely immune and protected from severe symptoms. However, immunocompromised patients still have worse clinical outcomes, higher mortality and rarely develop effective immunity through vaccination or infection. Here, we studied the temporal distribution of infections, viral loads (VL) as well as the viral genetic diversity among an immunocompromised patient cohort, between January 2021 and September 2022. Method(s): Overall, 478 immunocompromised patients (solid organ transplant, HIV positive, cancer, autoimmune disease) and 234 controls (healthcare workers) from Pitie-Salpetriere and Bichat Claude-Bernard University hospitals (Paris, FRANCE) were diagnosed with SARS-CoV-2 infection by RT-qPCR. Whole genome sequencing was performed according to ARTIC protocol on Oxford Nanopore platform. All 712 full viral genomes were used to determine lineages and mapped to Wuhan-Hu-1 reference to produce a maximum likelihood phylogenetic tree (IQTree, 1000 bootstraps). Differences in temporal distributions of infections and VL were assessed using nonparametric statistical tests. Result(s): According to phylogenetic analysis, genomes from SARS-CoV- 2 infecting immunocompromised patients and those infecting healthy individuals are distributed in a similar way. No significant genetic differences can be observed between viral genomes from patients and controls within the different lineages. Temporal distribution of COVID-19 infections were also similar between immunocompromised patients and controls, with the exception of BA.2 variant for which controls were infected earlier (p< 0.001). VL were significantly lower in immunocompromised patients infected with Omicron variants (p=0.04). No differences in VL were observed for Alpha and Delta variants. Conclusion(s): At diagnosis, no intrinsic genetic divergence was observed in virus infecting immunocompromised patients compared to those circulating in the general population. Similarities in temporal distribution of infections between controls and patients suggest that these different groups become infected concomitantly. VL appeared to be lower for Omicron variants in immunocompromised patients. An earlier VL peak of Omicron and a testing of immunocompromised patients hospitalized once severe symptoms have appeared could indicate a delayed testing in these patients, once the replicative phase over. (Figure Presented).

SARS-CoV-2 INFECTION AMONG PERSONS WHO INJECT DRUGS AND THEIR PARTNERS IN KENYA

Background: Despite increased social vulnerability and barriers to care, there has been a paucity of data on SARS-CoV-2 incidence among key populations in sub-Saharan Africa. We seek to characterize active infections and define transmission dynamics of SARS-CoV-2 among people who inject drugs (PWID) and their sexual and injecting partners from Nairobi and the coastal region in Kenya. Method(s): This was a nested cross-sectional study of SARS-CoV-2 infection from April to July 2021 within a cohort study of assisted partner services for PWID in Kenya. A total of 1000 PWID and their partners (500 living with and 500 living without HIV) were recruited for SARS-CoV-2 antibody testing, of whom 440 were randomly selected to provide self-collected nasal swabs for real-time PCR testing. Whole genome sequencing (WGS) was completed on a limited subset of samples (N=23) with cycle threshold values 32.0. Phylogenetic tree construction and analysis was performed using the Nextstrain pipeline and compared with publicly available SARS-CoV-2 sequences from GenBank. Result(s): A total of 438 (99.5%) participants provided samples for SARS-CoV-2 PCR testing. Median age was 37 (IQR 32-42);128 (29.2%) were female;and 222 (50.7%) were living with HIV. The overall prevalence of SARS-CoV-2 infection identified by RT-PCR was 86 (19.6%). In univariate analyses, there was no increased relative risk of SARSCoV- 2 infection related to positive HIV status, frequenting an injection den, methadone treatment, unstable housing, report of any high-risk exposure, or having a sexual or injecting partner diagnosed with COVID-19 or who died from COVID-19 or flu-like illness. Eight samples were successfully sequenced via WGS and classified as WHO variants of concern: 3 Delta, 3 Alpha, and 2 Beta. Seven were classified into clades predominantly circulating in Kenya during 2021. Notably, two sequences were identical and matched identically to another Kenyan sequence, which is consistent with, though not indictive of, a transmission linkage. Conclusion(s): Overall, the risk of SARS-CoV-2 infection in this population of PWID and their partners was not significantly associated with risk factors related to injection drug use. At a genomic level, the SARS-CoV-2 strains in this study were consistent with contemporary Kenyan lineages circulating during the time and not unique to PWID. Prevention efforts, therefore, must also focus on marginalized groups for control given the substantial amount of mixing that likely occurs between populations.

Genetic comparison of transmissible gastroenteritis coronaviruses.

Transmissible gastroenteritis virus (TGEV) is a porcine coronavirus that threatens animal health and remains elusive despite years of research efforts. The systematical analysis of all available full-length genomes of TGEVs (a total of 43) and porcine respiratory coronaviruses PRCVs (a total of 7) showed that TGEVs fell into two independent evolutionary phylogenetic clades, GI and GII. Viruses circulating in China (until 2021) clustered with the traditional or attenuated vaccine strains within the same evolutionary clades (GI). In contrast, viruses latterly isolated in the USA fell into GII clade. The viruses circulating in China have a lower similarity with that isolated latterly in the USA all through the viral genome. In addition, at least four potential genomic recombination events were identified, three of which occurred in GI clade and one in GII clade. TGEVs circulating in China are distinct from the viruses latterly isolated in the USA at either genomic nucleotide or antigenic levels. Genomic recombination serves as a factor driving the expansion of TGEV genomic diversity.

MSClustering: A Cytoscape Tool for Multi-Level Clustering of Biological Networks.

MSClustering is an efficient software package for visualizing and analyzing complex networks in Cytoscape. Based on the distance matrix of a network that it takes as input, MSClustering automatically displays the minimum span clustering (MSC) of the network at various characteristic levels. To produce a view of the overall network structure, the app then organizes the multi-level results into an MSC tree. Here, we demonstrate the package's phylogenetic applications in studying the evolutionary relationships of complex systems, including 63 beta coronaviruses and 197 GPCRs. The validity of MSClustering for large systems has been verified by its clustering of 3481 enzymes. Through an experimental comparison, we show that MSClustering outperforms five different state-of-the-art methods in the efficiency and reliability of their clustering.

Genomic characterization and phylogenetic analysis of sars-cov-2 in libya

The COVID-19 epidemic started in Libya in March 2020 and rapidly spread. To shed some light on the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) strains circulating in Libya, viruses isolated from 10 patients in this country were sequenced, characterized at the genomic level, and compared to genomes isolated in other parts of the world. As nine genomes out of 10 belonged to the SS1 cluster and one to SS4, three datasets were built. One included only African strains and the other two contained internationally representative SS1 and SS4 genomes. Genomic analysis showed that the Libyan strains have some peculiar features in addition to those reported in other world regions. Considering the countries in which the strains are genetically more similar to the Libyan strains, SARS-CoV-2 could have entered Libya from a North African country (possibly Egypt), sub-Saharan Africa (e.g., Ghana, Mali, Nigeria), the Middle East (e.g., Saudi Arabia), or Asia (India, Bangladesh).Copyright © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Molecular Characterization of Bovine Rotaviruses and Coronaviruses in Diarrheic Calves in Egypt (2014-2019)

Bovine Rotaviruses group A (BRVA) and Bovine Coronaviruses (BCoV) are the most prevalent viral agent worldwide in diarrheic calves aged less than 6 weeks, causing economic losses due to retarded growth, increased susceptibility to other infections, treatment cost, and calf mortalities. This study aimed to detect and molecularly characterize BRVA and BCoV from diarrhetic calves. A total of 82 fecal samples were collected from calves aged less than one month from three Egyptian governorates (Alexandria, Ismailia, and Sharqia). All fecal samples were tested for BRVA and BCoV by using probe based quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Consequently, positive samples contain relatively high viral genomic load were examined by RT-PCR for amplification of viral protein 7 (VP7) and viral protein 4 (VP4) genes (G- and P- typing) for BRV and full length S1 gene for BCoV. Out of 82 of tested samples, 14 (17.1%) and 22 (26.8%) were positive by qRT-PCR for BRV and BCoV, respectively. Only three and five samples had relatively high genomic load for BRV and BCoV, respectively for further testing by RT-PCR. BRV G-type was found in two samples and P-type was detected in one sample. The sequence analysis and phylogenetic tree typed these positive samples as P11 and G10. The sequences and phylogenetic analysis of BCoV positive strains (n=5) showed closely related viruses to each other and similar to previously characterized strains in Egypt since 2014. Further studies are required to antigenically characterize the circulating BRV and BCoV in Egypt.

Computational tools for aptamer identification and optimization

Aptamers are single-stranded DNA or RNA oligonucleotides that can selectively bind to a specific target. They are generally obtained by SELEX, but the procedure is challenging and time-consuming. Moreover, the identified aptamers tend to be insufficient in stability, specificity, and affinity. Thus, only a handful of aptamers have entered the practical use stage. Recently, computational approaches have demonstrated a significant capacity to assist in the discovery of high-performance aptamers. This review discusses the advances achieved in several aspects of computational tools in this field, as well as the new progress in machine learning and deep learning, which are used in aptamer identification and optimization. To illustrate these computationally aided processes, aptamer selections against SARS-CoV-2 are discussed in detail as a case study. We hope that this review will aid and motivate researchers to develop and utilize more computational techniques to discover ideal aptamers effectively. Copyright © 2022 Elsevier B.V.

Genetic diversity of Mycobacterium tuberculosis isolates from northwest of Iran during COVID-19 era

Background: Tuberculosis (TB) is considered one of the most infectious diseases in the world. In this study, we intended to examine the epidemiology of tuberculosis by MIRU-VNTR to define the changes that occur in the transmission of tuberculosis in the region during the COVID-19 era. A total of 120 Mycobacterium tuberculosis isolates were collected from sputum samples of patients referred to East Azerbaijan Center TB from December 2020 to August 2021. Demographic information such as age, sex, place of birth, previous TB history, and relevant medical data was collected. The proportion method was performed for drug susceptibility testing, and the PCR-based MIRU-VNTR method was applied to identify molecular epidemiology relationships. Result(s): The isolates were collected from 78 male (65%) and 39 female (32.5%) Iranian patients and 3 (2.5%) Azerbaijani patients. Ninety-three distinct patterns were identified including 15 clustered patterns and 36 unique patterns. The largest cluster was composed of seven isolates. Furthermore, one cluster with 5 members, four clusters with 3 members, and nine clusters with 2 members. In MIRU-VNTR typing, 75 clusters belonged to the Tabriz region and just 3 to the Republic of Azerbaijan. All isolates were sensitive to rifampin, isoniazid, and ethambutol. Conclusion(s): Results of the current study showed COVID-19 pandemic had a direct effect on the transmission and diagnosis of tuberculosis. Less diagnosis and less clustering can indicate public controls and hygiene, and the use of masks had a direct effect on the transmission and diagnosis of tuberculosis. However, misidentification and less focus on other respiratory infections are expected during the pandemic. Studies on the co-infection of COVID-19 and tuberculosis and the role of mask and sanitization against TB are strongly recommended. Copyright © 2023, The Author(s).

Towards Privacy-Preserving Computation on Gene: Construct Covid-19 Phylogenetic Tree using Homomorphic Encryption

Constructing a phylogenetic tree is an essential method of analyzing the evolution of the covid-19 virus. In the case of multiple entities holding different coronavirus genetic data, it is simple to aggregate all data into one entity and then calculate the phylogenetic tree. However, such a method is challenging to carry out. Genetic data is susceptible and has high economic value, and it is usually impossible to copy between different entities directly. Also, the direct sharing of genetic data can lead to data leaks or even legal problems. In this paper, we propose a homomorphic-encryption-based solution to tackle this problem, where two participants, A and B, both hold a part of covid-19 genetic data and compute the gene distance matrix calculation of the overall dataset without revealing the genetic data held by both parties. After the computation, participant A can decrypt the final distance matrix from the encrypted result and then use the plain-text result to construct the covid-19 phylogenetic tree. Experiment results show that the proposed method can process the genetic data accurately in a short time, and the phylogenetic tree generated by the proposed solution has no loss of accuracy compared to plain-text calculation. In terms of engineering optimization, we propose an optimized encryption method, which can further shorten the encryption time of the entire dataset without reducing the security level. © 2022 IEEE.

TEMPO: A transformer-based mutation prediction framework for SARS-CoV-2 evolution.

The widespread of SARS-CoV-2 presents a significant threat to human society, as well as public health and economic development. Extensive efforts have been undertaken to battle against the pandemic, whereas effective approaches such as vaccination would be weakened by the continuous mutations, leading to considerable attention being attracted to the mutation prediction. However, most previous studies lack attention to phylogenetics. In this paper, we propose a novel and effective model TEMPO for predicting the mutation of SARS-CoV-2 evolution. Specifically, we design a phylogenetic tree-based sampling method to generate sequence evolution data. Then, a transformer-based model is presented for the site mutation prediction after learning the high-level representation of these sequence data. We conduct experiments to verify the effectiveness of TEMPO, leveraging a large-scale SARS-CoV- 2 dataset. Experimental results show that TEMPO is effective for mutation prediction of SARS- CoV-2 evolution and outperforms several state-of-the-art baseline methods. We further perform mutation prediction experiments of other infectious viruses, to explore the feasibility and robustness of TEMPO, and experimental results verify its superiority. The codes and datasets are freely available at https://github.com/ZJUDataIntelligence/TEMPO.

Utilizing Genomic Epidemiology to Explore SARS CoV-2 Transmission Patterns and Support Outbreak Investigations in Long Term Care Facilities, Washington State, April-October 2021

Background. In Washington State, COVID-19 cases in long-term care facilities (LTCF) have accounted for less than 3% of all cases, yet 30% of all COVID-19 deaths. Understanding transmission patterns and outbreak epidemiology informs outbreak management. From April to October 2021, two large LTCFs experienced COVID-19 outbreaks. Whole genome sequencing and phylogenetic analysis were leveraged to explore transmission patterns and complement outbreak epidemiology. Methods. Epidemiologic data was exported from the Washington Disease Reporting System. Sequences, retrieved from GISAID, were aligned to the Wuhan-1 reference genome using Nextalign version 1.11.0. Pairwise single nucleotide polymorphism (SNP) distance matrices were calculated using SNP-Dists version 0.8.2. Phylogenetic trees for each outbreak were generated using IQ-Tree multicore version 2.2.0-beta COVID-edition using the GTR+F+G4 nucleotide substitution model with 1000 bootstrap replicates. MicrobeTrace was used to visualize the phylogeny, SNP heatmap, and identify clusters among sequences. Results. Weekly, LTCF A tested 162 residents and 800 staff, and LTCF B tested 60 residents and 144 staff. Of all cases in LTCF A (n= 119), 23% (n =27) were residents and 77% (n = 92) were staff, compared to 78% (n =28) residents and 22% (n =7) staff among total LTCF B cases (n=36). In LTCF A, 34% (n=40) of the cases had highquality sequences available. Seven clusters of two or more genetically related sequences and thirteen genetically unrelated sequences were identified. Five of the clusters involved resident and staff cases, linked by unit. Two clusters and remaining unrelated sequences were among staff. In LTCF B, 40% (n=14) of the cases had high-quality sequences available. One cluster of genetically related sequences was identified, all from residents of two floors. The SNP differences between sequences from LTCF A ranged from 0 to 70, whereas SNP differences between LTCF B sequences ranged from 0 to 6. Conclusion. Phylogenetic analysis of the two outbreaks confirms differences in disease transmission patterns. Multiple independent introductions of SARS-CoV-2 were identified in LTCF A, compared to a single introduction in LTCF B. Genomic epidemiology is a valuable resource for outbreak investigation and management.

Genetic Diversity of Bovine Group A Rotavirus Strains Circulating in Korean Calves during 2014 and 2018.

The purpose of this study was to investigate annual changes in BoRVA strains by examining the VP4 and VP7 genes of rotaviruses in Korean calves. Between 2014 and 2018, 35 out of 138 samples of calf diarrhea feces collected nationwide were positive for BoRVA. Further genetic characterization of the VP7 and VP4 genes of 35 BoRVA isolates identified three different G-genotypes (G6, G8, and G10) and two different P genotypes (P[5] and P[11]). The G6 genotype was most common (94.3%) in BoRVA-positive calves, followed by the P[5] genotype (82.9%). Four genotypes comprised combinations of VP4 and VP7: 80% were G6P[5], 14.2% were G6P[11], 2.9% were G8P[5], and 2.9% were G10P[11]. Susceptibility to infection was highest in calves aged < 10 days (35%) and lowest in calves aged 30−50 days (15.4%). The data presented herein suggest that the G6P[5] genotype is the main causative agent of diarrhea in Korean calves. In addition, it is predicted that G6P[5] will continue to act as a major cause of diarrhea in Korean calves.

Isolation and Genetic Characterization of a Bovine Coronavirus KBR-1 Strain from Calf Feces in South Korea.

Bovine coronavirus (BCoV) causes severe diarrhea in neonatal calves, winter dysentery in adult cattle, and respiratory disease in feedlot cattle, resulting in economic losses. A total of 16/140 calf diarrheic feces samples collected in South Korea between 2017 and 2018 were positive for BCoV. Phylogenetic analysis of the complete spike and hemagglutinin/esterase genes revealed that the 16 Korean BCoV strains belonged to group GIIa along with Korean strains isolated after 2000, whereas Korean BCoV strains isolated before 2000 belonged to group GI. Mice and goats inoculated with an inactivated KBR-1 strain (isolated from this study) generated higher antibody titers (96 ± 13.49 and 73 ± 13.49, respectively) when mixed with the Montanide01 adjuvant than when mixed with the Carbopol or IMS1313 adjuvants. Viral antigens were detected in the large intestine, jejunum, and ileum of calves inoculated with inactivated KBR-1 vaccine (104.0 TCID50/mL) at 14 days of post-challenge (DPC). However, no viral antigens were detected in calves vaccinated with a higher dose of inactivated KBR-1 strain (106.0 TCID50/mL) at 14 DPC, and they had high antibody titers and stable diarrhea scores. Currently, the group GIIa is prevalent in cows in South Korea, and although further research is needed in the future, the recently isolated KBR-1 strain has potential value as a new vaccine candidate.

Analysis of Mutational Profiles of SARS-CoV-2 Structural and Non-Structural Proteins with Emphasis on Spike Protein Variants

SARS-CoV-2 has very recently posed a potential threat to humanity due to its very rapid rate of mutations and repairing mechanism. The spread of this virus is considered to have occurred in Wuhan, China in December 2019. Characterized by high rates of transmission, the virus is constantly evolving towards attaining higher rates of stability and transmissibility through acquiring mutations in its genome. Therefore, this study aims to analyse the mutational profiles of SARS-CoV-2 isolates. Analysis of the mutational profiles in individual SARS-CoV-2 proteins will allow us to look into the rates of mutations associated with each protein. Frequently mutated residues have been identified in this research by aligning 688 SARS-CoV-2 nucleotide sequences, which were downloaded from NCBI (National Center For Biotechnology Information) repository. Further, mutational frequencies of these mutated residues have been studied, which is instrumental in identifying the proteins that are resistant to changes, as well as the ones that have a greater proclivity towards incorporating mutations. © 2022, Walailak University. All rights reserved.

NanoCoV19: An analytical pipeline for rapid detection of severe acute respiratory syndrome coronavirus 2.

Nanopore sequencing technology (NST) has become a rapid and cost-effective method for the diagnosis and epidemiological surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the coronavirus disease 2019 (COVID-19) pandemic. Compared with short-read sequencing platforms (e.g., Illumina's), nanopore long-read sequencing platforms effectively shorten the time required to complete the detection process. However, due to the principles and data characteristics of NST, the accuracy of sequencing data has been reduced, thereby limiting monitoring and lineage analysis of SARS-CoV-2. In this study, we developed an analytical pipeline for SARS-CoV-2 rapid detection and lineage identification that integrates phylogenetic-tree and hotspot mutation analysis, which we have named NanoCoV19. This method not only can distinguish and trace the lineages contained in the alpha, beta, delta, gamma, lambda, and omicron variants of SARS-CoV-2 but is also rapid and efficient, completing overall analysis within 1 h. We hope that NanoCoV19 can be used as an auxiliary tool for rapid subtyping and lineage analysis of SARS-CoV-2 and, more importantly, that it can promote further applications of NST in public-health and -safety plans similar to those formulated to address the COVID-19 outbreak.

Propagation research of SARS-CoV-2 based on evolutionary tree and spectral clustering

RNA viruses have the characteristics of a high mutation rate. New Coronavirus (SARS-CoV-2), as a RNA virus, has been mutated to some extent since the outbreak of New Coronavirus pneumonia (COVID-19). It is of great significance to study the evolution and variation of novel coronavirus genes to analyze the source of virus infection and understand the evolution of viruses. This research is based on the Novel Coronavirus 2019 database at the National Genomics Data Center. We combined macro and micro. We used the phylogenetic tree to analyze the gene fragments of the virus, constructed an evolutionary tree with a depth of 301, searched the root node of the tree to find the source of the virus in the data set and used spectral clustering to analyze the degree of novel Coronavirus variation in each country and the clustering results were visualized to make them easier to observe. The experimental results show that the strain sample at the top of the evolutionary tree originated in New Zealand based on the existing data. In the evolutionary tree, the evolutionary process of the virus can be divided into three branches. After clustering the virus source data and constructing the visual map of the variation degree of SARS-COV-2, we found that the viruses in South Africa, New Zealand and other countries had a higher degree of variation, and the viruses in Australia, the United States and other countries have a relatively lower degree of virus variation. © 2022 IEEE.

Mutation Pattern in the Receptor Binding Motif of SARS-Cov-2 Variants and the Effect on Molecular Interactions in Docked Ligand Complexes

The spike glycoprotein of SARS-Cov-2 is a therapeutic target for Covid-19 and mutations in the Receptor Binding Motif (RBM) may alter the binding properties of ligands proposed to inhibit viral entry. This study aimed to identify the existence of a mutation pattern in the RBMs of SARS-Cov-2 variants and study the effect on ligand binding interactions. RBM sequences were obtained using NCBI BLASTP and subjected to multiple and pairwise sequence alignment analysis. Hypothetical generations were drawn from the phylogenetic tree. The effect of mutation on ligand binding was studied by docking zafirlukast on selected RBMs. Molecular dynamics simulations were conducted to explain molecular interactions. The sequences at the same phylogenetic level showed higher similarity with the observed differences defined by the crystallized chain length. 6XDG_E, a leaf node sequence was 76% similar to 7NXA_E, a branch from the root, and had the highest mutation. Differences in sequence similarity across successive generations were based on mutations and crystallized chain length and the amino acid substitution is not predictable. Different bond types and binding affinities were observed as well as varying Root Mean Square Deviation (RMSD), Root Mean Square Fluctuation (RMSF), and Region of Gyration (RoG) values for the RBMs in different variants. The RMSD, RMSF, and RoG did not differ significantly in the bound and free states of RBM from specific variants suggesting that the observed differences are attributable to amino acid substitutions. This information is crucial for drug development intended to block SARS-Cov-2 entry.