వైరాలజీ: ప్రస్తుత పరిశోధన

Infectious diseases caused by pathogens, and food contamination caused by microorganisms, are compromising human health. The efficacies of antimicrobial agents and antibiotics, which are currently being used, have been weakened by microbial resistance, while antibiotic toxicity is a known challenge. This arises the need of natural antimicrobial agents. Spices and herbs have been long used for centuries, to enhance flavour and aroma of food, and for their antimicrobial and antioxidant activities. In this study, antimicrobial activity of aqueous and ethanolic extracts of five Indian spices i.e., Black pepper, Carom, Cinnamon, Clove and Cumin, was explored against Escherichia coli and Staphylococcus aureus, by agar dilution method and disk diffusion method. For agar dilution, aqueous and ethanolic extracts, with concentrations ranging from 0.5 mg/ml-8 mg/ml, were used. Whereas for disc diffusion method, varying concentrations of the ethanolic extracts (50%, 75% and 100%) were used. The results indicated an inhibitory effect on the growth of the microbes when using higher concentration of the extract. Clove’s bud showed the best antimicrobial effect amongst all the tested spices, having Minimum Inhibitory Concentration (MIC) less than 0.5 mg/ml for aqueous extract and 6 mg/ml for ethanolic extract against both bacteria. Amongst the tested spice extracts, Clove also had the biggest zone of inhibition i.e., 21 mm, against E. coli when using 50% ethanolic extract, while Black pepper had a zone of inhibition of 20 mm against S. aureus when using 100% ethanolic extract. It was also noted that the spice extracts, in general, were more effective against S. aureus than E. coli. Therefore, spices and particularly Clove and Black pepper extracts have great potential to be further tested and developed as novel safe antimicrobial agents

Polymerase Chain Reaction (PCR) invented by Kary Mullis (1983), has become the centrepiece of molecular detection of various infectious diseases including coronavirus disease 2019 (COVID-19). Many developing countries like Nepal faces various challenges and grab many future opportunities during and after establishment of molecular PCR laboratories throughout the country. This viewpoint describes the involvement of laboratory employees, development and adoption of new protocols or framework, deliberate partnership with national and international community is very efficient for the establishment of PCR laboratories. Beside this, continued alliance and nation leadership is crucial to generate a unified and sustainable PCR laboratory network in the country like Nepal. In future the established PCR laboratories can be utilized for the diagnosis of others pandemic diseases and can be used for multipurpose like in verification of infectious diseases; Oncology; Blood test; Genetic testing.

Background: Neuropilin-1 (NRP-1) is a multifunctional transmembrane receptor for ligands that affect developmental axonal growth and angiogenesis. Beside its role in cancer, NRP-1 is a reported entrance for several viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causal agent of coronavirus disease 2019 (COVID-19).

Methods: We made Insilco docking between the spike protein and Neuropilin-1 using Cluspro 2.0 software. Therefore, Neuropilin-1 becomes host factor for SARSCoV- 2 infection. Then by using molecular docking, we test nine compounds against Neuropilin-1 for its inhibition.

Results and Conclusion: Our study revealed that some drugs and natural compounds success in inhibition of binding between the virus and its new receptor with Insilco docking data.

ACE2 is a key receptor for SARS-CoV-2 cell entry. Binding of SARS-Cov-2 to ACE2 involves the viral Spike protein. The molecular interaction between ACE2 and Spike has been resolved. Interfering with this interaction might be used in treating patients with COVID-19. Inhibition of this interaction can be attained via multiple routes: here we focus on identifying small molecules that would prevent the interaction. Specifically we focus on small molecules and peptides that have the capacity to effectively bind the ACE2: RBD contact domain to prevent and reduce SARS-CoV-2 entry into the cell. We aim to identify molecules that prevent the docking of viral spike protein (mediated by RBD) onto cells expressing ACE2, without inhibiting the activity of ACE2. We utilize the most recent ACE2-RBD crystallography resolved model (PDB-ID: 6LZG). Based on animal susceptibility data we narrowed down our interest to the location of amino acid 34 (Histidine) located on ACE2. We performed an in silico screen of a chemical library of compounds with several thousand small molecules including FDA approved compounds. All compounds were tested for binding to the proximal binding site located close to histidine 34 on ACE2. We report a list of four potential small molecules that potentially have the capacity to bind target residue: AY-NH2, a selective PAR4 receptor agonist peptide (CAS number: 352017-71-1), NAD⁺ (CAS number: 53- 84-9), Reproterol, a short-acting β₂ adrenoreceptor agonist used in the treatment of asthma (CAS number: 54063-54-6), and Thymopentin, a synthetic immune- stimulant which enhances production of thymic T cells (CAS number: 69558-55-0). The focus is on a High Throughput Screen Assay (HTSA), or in silico screen, delineating small molecules that are selectively binding/masking the crucial interface residue on ACE2 at His³⁴. Consequently, inhibiting SARS-CoV-2 binding to host ACE2 and viral entry is a potent strategy to reduce cellular entry of the virus. We suggest that this anti-viral nature of this interaction is a viable strategy for COVID19 whereas the small molecules including peptides warrant further in vitro screens.