Phylogenetic classification of the whole-genome sequences of SARS-CoV-2 from India & evolutionary trends

Using minor variant genomes and machine learning to study the genome biology of SARS-CoV-2 over time

In infected individuals, viruses are present as a population consisting of dominant and minor variant genomes. Most databases contain information on the dominant genome sequence. Since the emergence of SARS-CoV-2 in late 2019, variants have been selected that are more transmissible and capable of partial immune escape. Currently, models for projecting the evolution of SARS-CoV-2 are based on using dominant genome sequences to forecast whether a known mutation will be prevalent in the future. However, novel variants of SARS-CoV-2 (and other viruses) are driven by evolutionary pressure acting on minor variant genomes, which then become dominant and form a potential next wave of infection. In this study, sequencing data from 96 209 patients, sampled over a 3-year period, were used to analyse patterns of minor variant genomes. These data were used to develop unsupervised machine learning clusters to identify amino acids that had a greater potential for mutation than others in the Spike protein. Being able to identify amino acids that may be present in future variants would better inform the design of longer-lived medical countermeasures and allow a risk-based evaluation of viral properties, including assessment of transmissibility and immune escape, thus providing candidates with early warning signals for when a new variant of SARS-CoV-2 emerges.

Haplotypic Distribution of SARS-CoV-2 Variants in Cases of Intradomiciliary Infection in the State of Rondônia, Western Amazon

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has a high transmissibility profile which favors the accumulation of mutations along its genome, providing the emergence of new variants. In this context, haplotype studies have allowed mapping specific regions and combining approaches and tracking phylogenetic changes. During the COVID-19 pandemic, it was notorious that home environments favored the circulation of SARS-CoV-2, in this study we evaluated 1,407 individuals positive for SARS-CoV-2, in which we located 53 families in the period from June 2021 to February 2023. The epidemiological data were collected in E-SUS notifica and SIVEP-gripe. Then, the genetic material was extracted using the commercial kit and the viral load was evaluated and the viral genomes were sequenced using the Illumina MiSeq methodology. In addition, the circulation of 3 variants and their respective subvariants was detected. The delta variant represented the highest number of cases with 45%, the Omicron variant 43% and the lowest number with 11% of cases the Gamma variants. There were cases of families infected by different subvariants, thus showing different sources of infection. The haplotype network showed a distribution divided into 6 large clusters that were established according to the genetic characteristics observed by the algorithm and 224 Parsimony informative sites were found. In addition, 92% of subjects were symptomatic and 8% asymptomatic. The secondary attack rate of this study was 8.32%. Therefore, we can infer that the home environment favors the spread of SARS-CoV-2, so it is of paramount importance to carry out genomic surveillance in specific groups such as intradomiciliary ones.

Genomic epidemiology of severe acute respiratory syndrome coronavirus 2 from Theni, Tamil Nadu

Introduction

The coronavirus disease 2019 (COVID-19) is a viral infection characterized by respiratory and gastrointestinal symptoms. The causative agent of this infection is the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The genomic study helps in understanding the pathogenesis, epidemiology, and the development of therapeutic and preventive strategies in the combat against COVID-19.

Materials and Methods

Nasopharyngeal and oropharyngeal swab samples were collected from asymptomatic and symptomatic patients during the time period of 2021-2022 for the detection of SARS-CoV-2 by employing real-time reverse transcriptase, cDNA synthesis, whole-genome sequencing by next-genome sequencing, analysis of SARS-CoV-2 sequence data and lineage and variant of concern assignment along with phylogenetic analysis.

Results

Lineages BA.2.10 and BA.4.1.1 clustered with genomes from Senegal suggested the spread of infections. Similarly, high clustering among delta samples during the second wave showed possible importation and subsequent spread via local transmission.

Conclusions

Studies like these are important to understand the characteristics and origins of locally circulating SARS-CoV-2 diversity in order to prevent further spread.

High-throughput sequencing approaches applied to SARS-CoV-2

High-throughput sequencing is crucial for surveillance and control of viral outbreaks. During the ongoing coronavirus disease 2019 (COVID-19) pandemic, advances in the high-throughput sequencing technology resources have enhanced diagnosis, surveillance, and vaccine discovery. From the onset of the pandemic in December 2019, several genome-sequencing approaches have been developed and supported across the major sequencing platforms such as Illumina, Oxford Nanopore, PacBio, MGI DNBSEQTM and Ion Torrent. Here, we share insights from the sequencing approaches developed for sequencing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) between December 2019 and October 2022.

Using search trends to analyze web-based users' behavior profiles connected with COVID-19 in mainland China: infodemiology study based on hot words and Baidu Index

Background

Mainland China, the world's most populous region, experienced a large-scale coronavirus disease 2019 (COVID-19) outbreak in 2020 and 2021, respectively. Existing infodemiology studies have primarily concentrated on the prospective surveillance of confirmed cases or symptoms which met the criterion for investigators; nevertheless, the actual impact regarding COVID-19 on the public and subsequent attitudes of different groups towards the COVID-19 epidemic were neglected.

Methods

This study aimed to examine the public web-based search trends and behavior patterns related to COVID-19 outbreaks in mainland China by using hot words and Baidu Index (BI). The initial hot words (the high-frequency words on the Internet) and the epidemic data (2019/12/01-2021/11/30) were mined from infodemiology platforms. The final hot words table was established by two-rounds of hot words screening and double-level hot words classification. Temporal distribution and demographic portraits of COVID-19 were queried by search trends service supplied from BI to perform the correlation analysis. Further, we used the parameter estimation to quantitatively forecast the geographical distribution of COVID-19 in the future.

Results

The final English-Chinese bilingual table was established including six domains and 32 subordinate hot words. According to the temporal distribution of domains and subordinate hot words in 2020 and 2021, the peaks of searching subordinate hot words and COVID-19 outbreak periods had significant temporal correlation and the subordinate hot words in COVID-19 Related and Territory domains were reliable for COVID-19 surveillance. Gender distribution results showed that Territory domain (the male proportion: 67.69%; standard deviation (SD): 5.88%) and Symptoms/Symptom and Public Health (the female proportion: 57.95%, 56.61%; SD: 0, 9.06%) domains were searched more by male and female groups respectively. The results of age distribution of hot words showed that people aged 20-50 (middle-aged people) had a higher online search intensity, and the group of 20-29, 30-39 years old focused more on Media and Symptoms/Symptom (proportion: 45.43%, 51.66%; SD: 15.37%, 16.59%) domains respectively. Finally, based on frequency rankings of searching hot words and confirmed cases in Mainland China, the epidemic situation of provinces and Chinese administrative divisions were divided into 5 levels of early-warning regions. Central, East and South China regions would be impacted again by the COVID-19 in the future.

Lack of evidence of viability and infectivity of SARS-CoV-2 in the fecal specimens of COVID-19 patients

SARS-CoV-2 can be shed in feces and can enter sewage systems. In order to implement effective control measures and identify new channels of transmission, it is essential to identify the presence of infectious virus particles in feces and sewage. In this study, we attempt to utilize Molecular techniques, cell cultures and animal models to find out the infectivity of SARS-CoV-2 in the feces of COVID-19 patients. Our findings exclude the presence of infectious virus particles, suggesting that fecal-oral transmission may not be the main mode of transmission. Larger-scale initiatives are nevertheless required, particularly considering the emergence of new viral strains.

Evolution of the SARS-CoV-2 pandemic in India

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a bat-derived betacoronavirus, that emerged around December 2019. In spite of the lesser genomic diversity of CoVs in general, a steady accumulation of mutations spread over its genome have been noted, resulting in the emergence of several clades and lineages. Majority of these mutations are random and non-functional changes; however a few variants of concern (VOC) and variants of interest (VOI) designated by the WHO since late 2020 have implications to diagnostics, pathogenicity and immune escape. This review discusses the various nomenclatures depicting the SARS-CoV-2 evolution, the designated VOCs and VOIs and the mutations characterizing these variants. The evolution of SARS-CoV-2 in India and the implications to vaccine efficacy and breakthrough infections is also addressed.

SARS-CoV-2 Whole-Genome Sequencing by Ion S5 Technology—Challenges, Protocol Optimization and Success Rates for Different Strains

The COVID-19 pandemic demonstrated how rapidly various molecular methods can be adapted for a Public Health Emergency. Whether a need arises for whole-genome studies (next-generation sequencing), fast and high-throughput diagnostics (reverse-transcription real-time PCR) or global immunization (construction of mRNA or viral vector vaccines), the scientific community has been able to answer all these calls. In this study, we aimed at the assessment of effectiveness of the commercially available solution for full-genome SARS-CoV-2 sequencing (AmpliSeq™ SARS-CoV-2 Research Panel and Ion AmpliSeq™ Library Kit Plus, Thermo Fisher Scientific). The study is based on 634 samples obtained from patients from Poland, with varying viral load, assigned to a number of lineages. Here, we also present the results of protocol modifications implemented to obtain high-quality genomic data. We found that a modified library preparation protocol required less viral RNA input in order to obtain the optimal library quantity. Concurrently, neither concentration of cDNA nor reamplification of libraries from low-template samples improved the results of sequencing. On the basis of the amplicon success rates, we propose one amplicon to be redesigned, namely, the r1_1.15.1421280, for which less than 50 reads were produced by 44% of samples. Additionally, we found several mutations within different SARS-CoV-2 lineages that cause the neighboring amplicons to underperform. Therefore, due to constant SARS-CoV-2 evolution, we support the idea of conducting ongoing sequence-based surveillance studies to continuously validate commercially available RT-PCR and whole-genome sequencing solutions.

Clinical Profile and Outcome of Hospitalized Confirmed Cases of Omicron Variant of SARS-CoV-2 Among Children in Pune, India

Background The Omicron variant of SARS-CoV-2 infection was seen to be more infectious but less severe in children than adults with reduced hospitalization rates. There is a paucity of data on hospitalized children with confirmed Omicron variant. Objective We describe demographic, epidemiologic, clinical, radiological, laboratory features and outcomes of children with confirmed Omicron variant of SARS-CoV-2 infection admitted to a tertiary care teaching hospital in Pune, India. Methodology Children who tested positive for SARS-CoV-2 - Omicron variant and were admitted between 1st December 2021 and 28th February 2022 were included in the study. Results Out of a total of 37 Covid-positive children admitted during the study period, 16 underwent genome sequencing of which 14 were confirmed to be Omicron variant and two were Delta variant. The age range was one month to 12 years and seven (50%) were male. Common presenting features were fever (n=13, 93%), cough (n=7, 50%), seizures (n=7, 50%) and coryza (n=5, 36%). Comorbidities noted were epilepsy (n=3, 21%) and one each with Thalassemia Major, suspected inborn error of metabolism (IEM), operated anorectal malformation with hypospadias, chronic suppurative otitis media with complications (mastoiditis and facial nerve palsy), neonatal cholestasis and intracranial bleed with dural venous sinus thrombosis. Malnutrition was noted in 42%, pallor in 10 cases (71%). Severe anaemia (n=10, 71%), elevated ferritin (n=6, 43%), positive C-Reactive Protein (n=4, 28%) and deranged D-dimer (n=11, 78%) were noted. The Neutrophil to Lymphocyte ratio (NLR) was >3.3 in five (36%) children. Four (28%) had evidence of pneumonia on the chest radiograph. Oxygen therapy was needed in nine (64%) while two children (14%) required mechanical ventilation. There were two deaths (14%) in children with multiorgan dysfunction and refractory shock. Intravenous immunoglobulin and methylprednisolone were administered to one patient respectively (14%). The median hospital stay was 10 days (Interquartile range = 8). Conclusion Hospitalized children with Omicron variant of SARS-CoV-2 who have underlying comorbidities may have severe presentations needing ICU care. Mortality rates are low with appropriate ICU care.

Circulation and Evolution of SARS-CoV-2 in India: Let the Data Speak

The COVID-19 pandemic is a global challenge that impacted 200+ countries. India ranks in the second and third positions in terms of number of reported cases and deaths. Being a populous country with densely packed cities, SARS-CoV-2 spread exponentially. India sequenced ≈0.14% isolates from confirmed cases for pandemic surveillance and contributed ≈1.58% of complete genomes sequenced globally. This study was designed to map the circulating lineage diversity and to understand the evolution of SARS-CoV-2 in India using comparative genomics and population genetics approaches. Despite varied sequencing coverage across Indian States and Union Territories, isolates belonging to variants of concern (VoC) and variants of interest (VoI) circulated, persisted, and diversified during the first seventeen months of the pandemic. Delta and Kappa lineages emerged in India and spread globally. The phylogenetic tree shows lineage-wise monophyletic clusters of VoCs/VoIs and diversified tree topologies for non-VoC/VoI lineages designated as 'Others' in this study. Evolutionary dynamics analyses substantiate a lack of spatio-temporal clustering, which is indicative of multiple global and local introductions. Sites under positive selection and significant variations in spike protein corroborate with the constellation of mutations to be monitored for VoC/VoI as well as substitutions that are characteristic of functions with implications in virus-host interactions, differential glycosylation, immune evasion, and escape from neutralization.

Erratum: Phylogenetic classification of the whole-genome sequences of SARS-CoV-2 from India & evolutionary trends

[This corrects the article DOI: 10.4103/ijmr.IJMR_3418_20].

SARS-CoV-2 Spike Mutations, L452R, T478K, E484Q and P681R, in the Second Wave of COVID-19 in Maharashtra, India

As the global severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic expands, genomic epidemiology and whole genome sequencing are being used to investigate its transmission and evolution. Against the backdrop of the global emergence of "variants of concern" (VOCs) during December 2020 and an upsurge in a state in the western part of India since January 2021, whole genome sequencing and analysis of spike protein mutations using sequence and structural approaches were undertaken to identify possible new variants and gauge the fitness of the current circulating strains. Phylogenetic analysis revealed that newly identified lineages B.1.617.1 and B.1.617.2 were predominantly circulating. The signature mutations possessed by these strains were L452R, T478K, E484Q, D614G and P681R in the spike protein, including within the receptor-binding domain (RBD). Of these, the mutations at residue positions 452, 484 and 681 have been reported in other globally circulating lineages. The structural analysis of RBD mutations L452R, T478K and E484Q revealed that these may possibly result in increased ACE2 binding while P681R in the furin cleavage site could increase the rate of S1-S2 cleavage, resulting in better transmissibility. The two RBD mutations, L452R and E484Q, indicated decreased binding to select monoclonal antibodies (mAbs) and may affect their neutralization potential. Further in vitro/in vivo studies would help confirm the phenotypic changes of the mutant strains. Overall, the study revealed that the newly emerged variants were responsible for the second wave of COVID-19 in Maharashtra. Lineage B.1.617.2 has been designated as a VOC delta and B.1.617.1 as a variant of interest kappa, and they are being widely reported in the rest of the country as well as globally. Continuous monitoring of these and emerging variants in India is essential.