Emergence, evolution, and vaccine production approaches of SARS-CoV-2 virus: Benefits of getting vaccinated and common questions

From chaos to clarity: The scientometric breakthrough in COVID-19 research

BACKGROUND

The COVID-19 pandemic paralyzed the world for over three years, generating unprecedented social changes in recent human history.

AIMS

We aimed to scientometrically summarize a global and temporal overview of publications on COVID-19 in the two worst years of the pandemic and its progression in early 2022, after the start of vaccination.

METHODS

Using the Web of Science database, this review covered the period from late 2019 to March 2022 and included all publications identified using the following terms: "SARS-CoV-2", "COVID-19", "Coronavirus Disease 19", and "2019-nCoV". We retrieved 268,904 publications, with evident global spreading, demonstrating that the pandemic triggered worldwide scientific research efforts.

RESULTS

Within the dataset, 195 countries have published about Covid-19. In initial publications, a solid trend in genotyping, sequencing, and detection of the virus was evident; however, in the development of the pandemic, new knowledge and research focus gained relevance, with continental solid trends, revealed by the keywords sustainability (eastern Europe); material sciences (Asia); public and mental health (Africa); information sciences (western Europe); education (Latin America). It identified high-impact research, mainly on diagnosis and vaccines, but also equally essential topics for returning life to the new normal, such as mental health, education, and remote work. The world experienced a highly transmissible infection that proved how fragile we are regarding organization and society.

CONCLUSIONS

It is necessary to learn from such an event and establish a protocol of actions and measures to be taken and avoided in a health emergency, aiming to act differently from the chaos experienced during the pandemic. Following the One Health approach, humanity must be aware of the need for more sustainable attitudes, given the inseparability of human beings from the environment.

Human ACE2 orthologous peptide sequences show better binding affinity to SARS-CoV-2 RBD domain: Implications for drug design

Computational methods coupled with experimental validation play a critical role in the identification of novel inhibitory peptides that interact with viral antigenic determinants. The interaction between the receptor binding domain (RBD) of SARS-CoV-2 spike protein and the helical peptide of human angiotensin-converting enzyme-2 (ACE2) is a necessity for the initiation of viral infection. Herein, natural orthologs of human ACE2 helical peptide were evaluated for competitive inhibitory binding to the viral RBD by use of a computational approach, which was experimentally validated. A total of 624 natural ACE2 orthologous 32-amino acid long peptides were identified through a similarity search. Molecular docking was used to virtually screen and rank the peptides based on binding affinity metrics, benchmarked against human ACE2 peptide docked to the RBD. Molecular dynamics (MD) simulations were done for the human reference and the Nipponia nippon peptide as it exhibited the highest binding affinity (Gibbs free energy; -14 kcal/mol) predicted from the docking results. The MD simulation confirmed the stability of the assessed peptide in the complex (-12.3 kcal/mol). The top three docked-peptides (from Chitinophaga sancti, Nipponia nippon, and Mus musculus) and the human reference were experimentally validated by use of surface plasmon resonance technology. The human reference exhibited the weakest binding affinity (Kd of 318-441 pM) among the peptides tested, in agreement with the docking prediction, while the peptide from Nipponia nippon was the best, with 267-538-fold higher affinity than the reference. The validated peptides merit further investigation. This work showcases that the approach herein can aid in the identification of inhibitory biosimilar peptides for other viruses.

Improvement of German Chamomile (Matricaria recutita L.) for Mechanical Harvesting, High Flower Yield and Essential Oil Content Using Physical and Chemical Mutagenesis

Chamomile (Matricariarecutita L.) is one of the most important medicinal plants with various applications. The flowers and flower heads are the main organs inthe production of essential oil. The essential improvement goals of chamomile are considered to be high flower yield and oil content, as well asthe suitability for mechanical harvesting. The present study aimed to improve the flower yield, oil content and mechanical harvestability of German chamomile via chemical and physical mutagens. Three German chamomile populations (Fayum, Benysuif and Menia) were irradiated with 100, 200, 300 and 400 Gray doses of gamma rays, as well as chemically mutagenized using 0.001, 0.002 and 0.003 mol/mL of sodium azide for 4 h. The two mutagens produced a wide range of changes in the flowers' shape and size. At M₃ generation, 18 mutants (11 from gamma irradiation and 7 from sodium azide mutagenization) were selected and morphologically characterized. Five out of eighteen mutants were selected for morphological and chemical characterization for oil content, oil composition and oil quality in M₄ generation. Two promising mutants, F/LF5-2-1 and B/HNOF 8-4-2, were selected based on their performance in most studied traits during three generations, as well as the high percentage of cut efficiency and a homogenous flower horizon, which qualify them as suitable candidates for mechanical harvesting. The two mutants are late flowering elite mutants; the F/LF5-2-1 mutant possessed the highest oil content (1.77%) and number of flowers/plant (1595), while the second promising B/HNOF 8-4-2 mutant hada high oil content (1.29%) and chamazulene percentage (13.98%) compared to control plants. These results suggest that the B/HNOF 8-4-2 and F/LF5-2-1 mutants could be integrated as potential parents into breeding programs for a high number of flowers, high oil content, oil composition and oil color traits for German chamomile improvement.

Phylogenetic comparative analysis: Chemical and biological features of caseins (alpha-S-1, alpha-S-2, beta- and kappa-) in domestic dairy animals

Caseins determine the physicochemical, physiological, and biological characteristics of milk. Four caseins—alpha-S-1, alpha-S-2, beta, and kappa—were analyzed phylogenetically and in silico and characterized regarding chemical, antimicrobial, and antioxidant features in five dairy animals: Arabian camels, sheep, goats, cattle, and water buffalos. The sequence of full-length amino acids of the four caseins for the five species was retracted from the NCBI GenBank database. Multiple sequence alignment is used to examine further the candidate sequences for phylogenetic analysis using Clustal X and NJ-Plot tools. The results revealed that sheep and goats possess strong similarities (98.06%) because of their common ancestor. The same was observed with cattle and water buffalos (96.25%). The Arabian camel was located in a single subclade due to low similarity in casein residues and compositions with other dairy animals. Protein modeling showed that alpha-S1- and alpha-S2-caseins possess the highest number of phosphoserine residues. The in silico computed chemical properties showed that β-casein recorded highest hydrophobicity index and lowest basic amino acid content, while α-S2-casein showed the opposite. The computed biological parameters revealed that α-S2-casein presented the highest bactericidal stretches. Only Arabian camel β-casein and k-casein showed one bactericidal stretches. The analysis also revealed that β-casein, particularly in Arabian camels, possesses the highest antioxidant activity index. These results support the importance of the bioinformatics resources to determine milk casein micelles' chemical and biological activities.

Genetic and Morphological Diversity Assessment of Five Kalanchoe Genotypes by SCoT, ISSR and RAPD-PCR Markers

Determining the appropriate parents for breeding programs is the most important decision that plant breeders must make to maximize the genetic variability and produce excellent recombinant genotypes. Several methods are used to identify genotypes with desirable phenotypic features for breeding experiments. In this study, five kalanchoe genotypes were morphologically characterized by assessing plant height, number of inflorescences, number of flowers, flower length, flower diameter and number of petals. The analysis showed the distinction of yellow kalanchoe in the plant height trait, while the orange kalanchoe was distinguished in the number of inflorescences, the number of flowers and flower length traits, whereas the violet kalanchoe possessed the largest flower diameter and the highest number of petals. The molecular profiling was performed by random amplified polymorphism DNA (RAPD), inter-simple sequence repeats (ISSR) and start codon targeted (SCoT)-polymerase chain reaction (PCR) tools. Genomic DNA was extracted from young leaves and the PCR reactions were performed using ten primers for each SCoT, ISSR and RAPD marker. Only four out of ten primers showed amplicon profiles in all PCR markers. A total of 70 bands were generated by SCoT, ISSR and RAPD-PCR with 35 polymorphic bands and 35 monomorphic bands. The total number of bands of RAPD, ISSR and SCoT was 15, 17 and 38, respectively. The polymorphism percentages achieved by RAPD, ISSR and SCoT were 60.25%, 15% and 57%, respectively. The cluster analysis based on morphological data revealed two clusters. Cluster I consisted of violet and orange kalanchoe, and cluster II comprised red, yellow and purple kalanchoe. Whereas the cluster analysis based on molecular data revealed three clusters. Cluster I included only yellow kalanchoe, cluster II comprised orange and violet kalanchoe while cluster III comprised red, and purple kalanchoe. The study concluded that orange, violet and yellow kalanchoe are distinguished parents for breeding economically valued traits in kalanchoe. Also, the study concluded that SCoT and RAPD markers reproduced reliable banding patterns to assess the genetic polymorphism among kalanchoe genotypes that consider the basis stone for genetic improvements in ornamental plants.

Characterization of a cluster of COVID-19 cases linked to the Omicron variant, in Mauritania

OBJECTIVE

To describe the epidemiological and genomic profile of COVID-19 during the 4th epidemic wave in Mauritania.

METHODS

This is a cross-sectional study in Mauritania, from October 1, 2021, to February 28, 2022. Were included all people in the process of travel, performing an RT-PCR, at the level of the National Research Institute in Public Health and patients who have been sampled for sequencing by teams from the Department of Strategic Information and Epidemiological Surveillance.

RESULTS

Out of 37,574 RT-PCR tests collected on March 3, 2022, during the study period, 1,465 cases were diagnosed positive for COVID-19 (3.9%), with an average age of 39±14,6 years and a sex ratio of 2.08. Of the 112 genomic sequences performed, 75 were of the Omicron variant (66.9%). The average age was 40±15 years, with extremes of 15 to 82 years and a sex ratio of 0.97. The vaccination status was assured in 67.7% of patients and the peak of the Omicron variant was reached during the first week of January 2022.

CONCLUSION

The Omicron variant was predominant during the 4th wave in Mauritania. As part of its response plan against COVID-19, the installation of new sequencing units inside the country and the strengthening of the training of technicians in the virology laboratory will be essential.