Several nations have recently begun to relax their public health protocols, particularly regarding the use of face masks when engaging in outdoor activities. This is because there has been a general trend towards fewer cases of coronavirus disease 2019 (COVID‐19). However, new Omicron sub‐variants (designated BA.4 and BA.5) have recently emerged. These two subvariants are thought to be the cause of an increase in COVID‐19 cases in South Africa, the United States, and Europe. They have also begun to spread throughout Asia. They evolved from the Omicron lineage with characteristics that make them even more contagious and which allow them to circumvent immunity from a previous infection or vaccination. This article reviews a number of scientific considerations about these new variants, including their apparently reduced clinical severity.

The rapid spread of a novel coronavirus known as SARS-CoV-2 has compelled the entire world to seek ways to weaken this virus, prevent its spread and also eliminate it. However, no drug has been approved to treat COVID-19. Furthermore, the receptor-binding domain (RBD) on this viral spike protein, as well as several other important parts of this virus, have recently undergone mutations, resulting in new virus variants. While no treatment is currently available, a naturally derived molecule with known antiviral properties could be used as a potential treatment. Bromelain is an enzyme found in the fruit and stem of pineapples. This substance has been shown to have a broad antiviral activity. In this article, we analyse the ability of bromelain to counteract various variants of the SARS-CoV-2 by targeting bromelain binding on the side of this viral interaction with human angiotensin-converting enzyme 2 (hACE2) using molecular docking and molecular dynamics simulation approaches. We have succeeded in making three-dimensional configurations of various RBD variants using protein modelling. Bromelain exhibited good binding affinity toward various variants of RBDs and binds right at the binding site between RBDs and hACE2. This result is also presented in the modelling between Bromelain, RBD, and hACE2. The molecular dynamics (MD) simulations study revealed significant stability of the bromelain and RBD proteins separately up to 100 ns with an RMSD value of 2 Å. Furthermore, despite increases in RMSD and changes in Rog values of complexes, which are likely due to some destabilized interactions between bromelain and RBD proteins, two proteins in each complex remained bonded, and the site where the two proteins bind remained unchanged. This finding indicated that bromelain could have an inhibitory effect on different SARS-CoV-2 variants, paving the way for a new SARS-CoV-2 inhibitor drug. However, more in vitro and in vivo research on this potential mechanism of action is required.

Before entering the cell, the SARS-CoV-2 spike glycoprotein receptor-binding domain (RBD) binds to the human angiotensin-converting enzyme 2 (hACE2) receptor. Hence, this RBD is a critical target for the development of antiviral agents. Recent studies have discovered that SARS-CoV-2 variants with mutations in the RBD have spread globally. The purpose of this in silico study was to determine the potential of a fruit bromelain-derived peptide. DYGAVNEVK. to inhibit the entry of various SARS-CoV-2 variants into human cells by targeting the hACE binding site within the RBD. Molecular docking analysis revealed that DYGAVNEVK interacts with several critical RBD binding residues responsible for the adhesion of the RBD to hACE2. Moreover, 100 ns MD simulations revealed stable interactions between DYGAVNEVK and RBD variants derived from the trajectory of root-mean-square deviation (RMSD), radius of gyration (Rg), and root-mean-square fluctuation (RMSF) analysis, as well as free binding energy calculations. Overall, our computational results indicate that DYGAVNEVK warrants further investigation as a candidate for preventing SARS-CoV-2 due to its interaction with the RBD of SARS-CoV-2 variants.

The coronavirus disease 2019 (COVID-19) pandemic is still ongoing, with no signs of abatement in sight. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is the causative agent of this pandemic and has claimed over 5 million lives, is still mutating, resulting in numerous variants. One of the newest variants is Omicron, which shows an increase in its transmissibility, but also reportedly reduces hospitalization rates and shows milder symptoms, such as in those who have been vaccinated. As a result, many believe that Omicron provides a natural vaccination, which is the first step toward ending the COVID-19 pandemic. Based on published research and scientific evidence, we review and discuss how the end of this pandemic is predicted to occur as a result of Omicron variants being surpassed in the community. In light of the findings of our research, we believe that it is most likely true that the Omicron variant is a natural way of vaccinating the masses and slowing the spread of this deadly pandemic. While the mutation that causes the Omicron variant is encouraging, subsequent mutations do not guarantee that the disease it causes will be less severe. As the virus continues to evolve, humans must constantly adapt by increasing their immunity through vaccination.

Aims:This study evaluated the accuracy of three methods used in the identification of Aeromonas hydrophila, a Gramnegative bacterium found in warm aquatic environments. A. hydrophila samples from Indonesia were tested using (a) SNI 7303, developed by the Indonesian government, (b) the method of Dorsch and (c) the method of Cascón. The results obtained were compared to that of the gold standard method, which used 16S rDNA sequences. Methodology and results: Based on the Indonesian government standard identification method SNI7303, we identified 56 out of 95 samples as A. hydrophila. The samples were then screened using the PCR amplification approach developed by Dorsch and Cascón. Of the 56 samples, only 20 samples were found to be positive by either the Dorsch or Cascón methods. DNA from these 20 samples was amplified using common 16S rDNA primers and the sequences compared with available 16S rDNA sequences from the GenBank. Phylogenetic analyses on the data were performed using Clustal X and MEGA 5 software. Conclusion, significance and impact of study: Of the 56 samples positively identified as A. hydrophila using the BSN method, identity in only five samples were positively confirmed using the16S rDNA method, giving an accuracy of only 8.9%. In this connection, the Dorsch method was 31.3% accurate while the Cascón method provided 45.5% correct identification. When all three methods were used in combination, 71.4% of the samples were correctly identified. The results of the study show that methods used to identify A. hydrophila cannot be used with confidence to identify A. hydrophila from Indonesia and probably from other tropical regions as well. The genetic diversity of Aeromonas bacteria in Indonesia appears to be considerably higher than that encountered by Dorsch or Cascón. Therefore, there is a need to develop a new simple method to identify A. hydrophila from tropical regions.