Detection of a New Variant in Outbreak of Bovine Ephemeral Fever in Turkey, 2020

Background: In this study, partial nucleotide sequence analysis of the G gene was performed for the molecular characterization of the virus that caused the bovine ephemeral fever virus (BEFV) epidemic in Turkey in 2020. Phylogenetic analysis of these nucleotide sequences was performed with the virus nucleotide sequences of the epidemics seen in 2008 and 2012. These sequences were announced in GenBank. Phylogenetic analysis of these nucleotide sequences was performed with the virus nucleotide sequences of the epidemics seen in 2008 and 2012. Methods: The study was conducted in dairy cattle holdings located in Diyarbakır Sur, Çınar and Dicle regions in South-eastern Turkey in August-November 2020. The number of animals in the holdings consisted of 750 (n=750), 150 (n=150) and 200 (n=200) cattle, respectively. Result: Severe respiratory symptoms and high mortality in the affected animals were notable symptoms. As a result of the phylogenetic analysis, it was determined that the virus that caused the epidemic in Turkey in 2020 was formed by a new variant in the Turkey-2 group, which was similar to the Indian isolates, unlike the Turkey-1 group, which was close to the Middle East variants in 2008 and 2012 isolates.

Demographic Analysis of Mutations in Indian SARS-CoV-2 Isolates

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originally emerged from Hubei province, Wuhan, China, and has caused a worldwide pandemic with millions affected since December 2019. Since the first case of SARS-CoV-2 reported on 27th Jan 2020 in India, over 11 million people have been affected by the virus in the country in the past one year. To understand its demographic distribution, in this study we carried out the early distribution of clades and subclades state-wise based on the analysis of shared mutations in Indian SARS-CoV-2 isolates collected during the period 27th Jan – 27th May 2020. A total of 1279 mutations have been identified in 685 Indian isolates during this period. Principal component analysis on the mutational profile of Indian isolates revealed clusters corresponding to clades in Nextstrain and some state-specific clusters. Phylogenetic analysis of these isolates indicates multiple independent sources of introduction of the virus in the country. It is observed that clade 20A defining mutations C241T (ORF1ab: 5′ UTR), C3037T (ORF1ab: F924F), C14408T (ORF1ab: P4715L), and A23403G (S: D614G) are the predominant mutation set in Indian isolates during this period. Higher number of coronavirus cases were observed in certain states, viz., Delhi, Tamil Nadu, and Telangana. Genetic analysis of isolates from these states revealed a cluster with shared mutations, C6312A (ORF1ab: T2016K), C13730T (ORF1ab: A4489V), C23929T, and C28311T (N: P13L). Contact tracing led the spread of this cluster to a super spreader event, the Tablighi Jamaat religious congregation, and the efficacy of lockdown in containing it. Analysis of region-specific shared mutations carried out to understand the large number of deaths in Gujarat and Maharashtra identified shared mutations defining subclade, I/GJ-20A (C18877T, C22444T, G25563T (ORF3a: H57Q), C26735T, C28854T (N: S194L), C2836T) in Gujarat and two sets of co-occurring mutations C313T, C5700A (ORF1ab: A1812D) and A29827T, G29830T in Maharashtra. From the genetic analysis of mutation spectra of Indian isolates, the insights gained in its transmission, geographic distribution, containment, and impact are discussed.

High individual heterogeneity of neutralizing activities against the original 4 strain and 9 different variants of SARS-CoV-2

Background. Since the beginning of the COVID-19 pandemic, several SARS-CoV-2 variants have sequentially emerged. In France, most cases were due to spike D641G-harbouring viruses that descended initially from the Wuhan strain, then by variant of B.1.160 lineage we called Marseille-4 since the summer of 2020, which was followed by the alpha (UK) and beta (South African) variants in early 2021, then delta (Indian) now.Methods and Findings. We determined the neutralizing antibody (nAb) titres in sera from convalescent individuals previously infected by these 4 major local variants and from vaccine recipients to the original Wuhan strain and 9 variants, including two recent circulating delta (Indian) isolates. The results show high inter-individual heterogeneity in nAbs, especially according to the variant tested. Unexpectedly, the major variations among nAbs are based on the genotype responsible for the infection. Patients previously infected with the beta and B.1.160 variants had the lowest nAb titres. We show that this heterogeneity is well explained by spike protein mutants modelling using in silico approaches. The highest titres were observed in patients vaccinated with the Pfizer/BioNTech COVID-19 vaccine, even against the delta variant.Conclusions. Immunity acquired naturally after infection is highly dependent on the infecting variant and unexpectedly mRNA-based vaccine efficacy is shown to be often better than natural immunity in eliciting neutralizing antibodies.

Genome Sequencing and Comparative Genomics of Indian Isolates of Brucella melitensis

Brucella melitensis causes small ruminant brucellosis and a zoonotic pathogen prevalent worldwide. Whole genome phylogeny of all available B. melitensis genomes (n = 355) revealed that all Indian isolates (n = 16) clustered in the East Mediterranean lineage except the ADMAS-GI strain. Pangenome analysis indicated the presence of limited accessory genomes with few clades showing specific gene presence/absence pattern. A total of 43 virulence genes were predicted in all the Indian strains of B. melitensis except 2007BM-1 (ricA and wbkA are absent). Multilocus sequence typing (MLST) analysis indicated all except one Indian strain (ADMAS-GI) falling into sequence type (ST 8). In comparison with MLST, core genome phylogeny indicated two major clusters (>70% bootstrap support values) among Indian strains. Clusters with <70% bootstrap support values represent strains with diverse evolutionary origins present among animal and human hosts. Genetic relatedness among animal (sheep and goats) and human strains with 100% bootstrap values shows its zoonotic transfer potentiality. SNP-based analysis indicated similar clustering to that of core genome phylogeny. Among the Indian strains, the highest number of unique SNPs (112 SNPs) were shared by a node that involved three strains from Tamil Nadu. The node SNPs involved several peptidase genes like U32, M16 inactive domain protein, clp protease family protein, and M23 family protein and mostly represented non-synonymous (NS) substitutions. Vaccination has been followed in several parts of the world to prevent small ruminant brucellosis but not in India. Comparison of Indian strains with vaccine strains showed that M5 is genetically closer to most of the Indian strains than Rev.1 strain. The presence of most of the virulence genes among all Indian strains and conserved core genome compositions suggest the use of any circulating strain/genotypes for the development of a vaccine candidate for small ruminant brucellosis in India.

High individual heterogeneity of neutralizing activities against the original strain and 9 different variants of SARS-CoV-2

Since the beginning of the COVID-19 pandemic, several SARS-CoV-2 variants have sequentially emerged. In France, most cases were due to spike D641G-harbouring viruses that descended initially from the Wuhan strain, then by variant of B.1.160 lineage we called Marseille-4 since the summer of 2020, which was followed by the alpha (UK) and beta (South African) variants in early 2021. We determined the neutralizing antibody (nAb) titres in sera from convalescent individuals previously infected by these 4 major local variants and from vaccine recipients to the original Wuhan strain and 9 variants, including two recent circulating delta (Indian) isolates. The results show high interindividual heterogeneity in nAbs, especially according to the variant tested. Unexpectedly, the major variations among nAbs are based on the genotype responsible for the infection. Patients previously infected with the beta and B.1.160 variants had the lowest nAb titres. The highest titres were observed in patients vaccinated with the Pfizer/BioNTech COVID-19 vaccine, even with antibodies against the delta variant.

Identification and Characterization of novel mutants of Nsp13 Protein among Indian SARS-CoV-2 isolates.

SARS-CoV-2, the causative agent of COVID-19 has mutated rapidly which enabled them to adapt and evade the immune system of the host. Emerging SARS-CoV-2 variants with crucial mutations pose a global challenge in context of therapeutic drugs and vaccines being developed globally. There are currently no specific therapeutics or vaccines available to combat SARS-CoV-2 devastation. In view of this, the current study aimed to identify and characterize the mutations found in the Nsp13 of SARS-CoV-2 in Indian isolates. Non-structural protein, Nsp13 protein sequences from Indian isolates were analyzed by comparing with the first reported Severe acute respiratory syndrome Corona Virus-2 (SARS-CoV-2) protein sequence from Wuhan, China. Out of 825 Nsp13 protein sequences, a total of 38 mutations were observed among Indian isolates. Our data show that mutations in Nsp13 at various positions (H164Y, A237T, T214I, C309Y, S236I, P419S, V305E, G54S, H290Y, P53S, A308Y, and A308Y) have a significant impact on the protein's stability and flexibility. Also, the impact of Nsp13 mutations on the protein function were predicted based on PROVEAN score that includes 15 mutants as neutral and 23 mutants as deleterious effect. Furthermore, B-cell epitopes contributed by Nsp13 were identified using various predictive immunoinformatic tools. Immunological Parameters of Nsp13 such as antigenicity, allergenicity and toxicity were evaluated to predict the potential B-cell epitopes. The predicted peptide sequences were correlated with the observed mutants. Our predicted data showed that there are seven high rank linear epitopes as well as 18 discontinuous B-cell epitopes based on immunoinformatic tools. Moreover, it was observed that out of total 38 identified mutations among Indian SARS-CoV-2 Nsp13 protein, four mutant residues at position 142 (E142), 245 (H245), 247 (V247) and 419 (P419) are localised in the predicted B cell epitopic region. Altogether, the results of the present in-silico study might help to understand the impact of the identified mutations in Nsp13 protein on its stability, flexibility and function.

Patterns in Genotype Composition of Indian Isolates of the Bombyx mori Nucleopolyhedrovirus and Bombyx mori Bidensovirus

The mulberry silkworm, Bombyx mori (L.), is a model organism of lepidopteran insects with high economic importance. The viral diseases of the silkworm caused by Bombyx mori nucleopolyhedrovirus (BmNPV) and Bombyx mori bidensovirus (BmBDV) inflict huge economic losses and significantly impact the sericulture industry of India and other countries. To understand the distribution of Indian isolates of the BmNPV and to investigate their genetic composition, an in-depth population structure analysis was conducted using comprehensive and newly developed genomic analysis methods. The seven new Indian BmNPV isolates from Anantapur, Dehradun, Ghumarwin, Jammu, Kashmir, Mysore and Salem grouped in the BmNPV clade, and are most closely related to Autographa californica multiple nucleopolyhedrovirus and Rachiplusia ou multiple nucleopolyhedrovirus on the basis of gene sequencing and phylogenetic analyses of the partial polh, lef-8 and lef-9 gene fragments. The whole genome sequencing of three Indian BmNPV isolates from Mysore (-My), Jammu (-Ja) and Dehradun (-De) was conducted, and intra-isolate genetic variability was analyzed on the basis of variable SNP positions and the frequencies of alternative nucleotides. The results revealed that the BmNPV-De and BmNPV-Ja isolates are highly similar in their genotypic composition, whereas the population structure of BmNPV-My appeared rather pure and homogenous, with almost no or few genetic variations. The BmNPV-De and BmNPV-Ja samples further contained a significant amount of BmBDV belonging to the Bidnaviridae family. We elucidated the genotype composition within Indian BmNPV and BmBDV isolates, and the results presented have broad implications for our understanding of the genetic diversity and evolution of BmNPV and co-occurring BmBDV isolates.

Sequence phylogenetic analysis and associative genetic diversity of Sarcocystis hirsuta based on 18S rRNA gene

Background Sarcocystis hirsuta, a tissue cyst-forming coccidian parasite of cattle, is worldwide in distribution. In spite of its global presence, limited literature is available on its characterization studies. No literature is available from India on molecular aspects of S. hirsuta. The present study was designed to characterize the isolates of S. hirsuta on the 18S gene locus. A total of five isolates of S. hirsuta were characterized. PCR products were cloned, sequenced, and compared with other sequences across the world. A phylogenetic tree was constructed based on the maximum parsimony (MP) method with the tree–bisection–regrafting (TBR) algorithm. Results An appreciable genetic variability was noticed between various S. hirsuta isolates at the 18S gene locus. Sequences generated from the present study (MN121567–MN121571) represented two haplotypes with 99.74–100.00% nucleotide homology within themselves. Alongside, a nucleotide homology of 97.82–99.92% was observed between Indian isolates and isolates across the globe. The two haplotypes were markedly distinct from each other with 3 nucleotide substitutions within themselves. Overall, Indian isolates of S. hirsuta were close to those from China and Vietnam than to those from New Zealand, Brazil, and Germany. Conclusion The present communication describes the first report of phylogenetic characterization of S. hirsuta from India. The findings are very much important in delineating the evolutionary phylogenetics of S. hirsuta.