SARS-CoV-2 B.1.617.2 Delta variant replication and immune evasion

Abstract: The B.1.617.2 (Delta) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first identified in the state of Maharashtra in late 2020 and spread throughout India, outcompeting pre-existing lineages including B.1.617.1 (Kappa) and B.1.1.7 (Alpha)1. In vitro, B.1.617.2 is sixfold less sensitive to serum neutralizing antibodies from recovered individuals, and eightfold less sensitive to vaccine-elicited antibodies, compared with wild-type Wuhan-1 bearing D614G. Serum neutralizing titres against B.1.617.2 were lower in ChAdOx1 vaccinees than in BNT162b2 vaccinees. B.1.617.2 spike pseudotyped viruses exhibited compromised sensitivity to monoclonal antibodies to the receptor-binding domain and the amino-terminal domain. B.1.617.2 demonstrated higher replication efficiency than B.1.1.7 in both airway organoid and human airway epithelial systems, associated with B.1.617.2 spike being in a predominantly cleaved state compared with B.1.1.7 spike. The B.1.617.2 spike protein was able to mediate highly efficient syncytium formation that was less sensitive to inhibition by neutralizing antibody, compared with that of wild-type spike. We also observed that B.1.617.2 had higher replication and spike-mediated entry than B.1.617.1, potentially explaining the B.1.617.2 dominance. In an analysis of more than 130 SARS-CoV-2-infected health care workers across three centres in India during a period of mixed lineage circulation, we observed reduced ChAdOx1 vaccine effectiveness against B.1.617.2 relative to non-B.1.617.2, with the caveat of possible residual confounding. Compromised vaccine efficacy against the highly fit and immune-evasive B.1.617.2 Delta variant warrants continued infection control measures in the post-vaccination era

Vermicompost and farmyard manure effects on biogeochemical performances of Withania somn\uedfera

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Acetylcholinesterase inhibition and antibacterial activity of Mondia whitei adventitious roots and ex vitro-grown somatic embryogenic-biomass

Mondia whitei (Hook.f.) Skeels is an important endangered medicinal and commercial plant in South Africa. In vitro propagation systems are required for biomass production and bioactivity analysis to supplement wild resources/stocks. Adventitious roots from somatic embryogenic explants using suspension culture and ex vitro-grown plants produced via somatic embryogenesis were established using different plant growth regulator treatments. The adventitious root biomass and different parts of ex vitro-grown and mother plants were used to investigate the potential for acetylcholinesterase (AChE) and antibacterial activities. Adventitious roots derived from 2.5 µM indole-3-acetic acid (IAA) treatments and ex vitro-grown plants derived from meta-topolin riboside (mTR) and IAA treatments gave the best AChE and antibacterial activities. The in vitro-established M. whitei and ex vitro biomass have comparable ability to function as inhibitors of acetylcholinesterase and antibacterial agents, and can be used as potent bioresources in traditional medicin

Spinal anaesthesia in poliomyelitis patients with scoliotic spine: A case control study

Background: There is limited data to predict the course of sub-arachnoid block in poliomyelitis patients with scoliotic spine. So we intended to study the course of intrathecal anaesthesia in these patients in comparison to patients with normal spine using 0.5% bupivacaine (heavy). Methods: In this prospective observational study, 41 poliomyelitic patients scheduled for lower limb corrective surgeries under spinal anaesthesia were enrolled. Patients were studied in two groups (Scolotic spine, n=20; Normal spine, n=21). All patients were injected 2 ml of 0.5% bupivacaine heavy intrathecally in the sitting position. The extent of block, bilateral spread, regression of sensory block and motor block were recorded. Demographic data were analysed using the unpaired t test or the chi square test as applicable. Block characteristics were analysed using the Mann Whitney U test. Results: There was statistically significant difference in bilateral spread of sensory block in between the groups. However, there was no significant difference in the maximum extent of the sensory block and the time taken for two segment regression of sensory block. There was no significant difference in time taken to reach complete motor block and for complete recovery from motor block to its preoperative value. Conclusions: Bilateral symmetrical spread of local anaesthetics through intrathecal route cannot be predicted accurately in patients with scoliotic spine. Spinal anaesthesia can be safely administered in poliomyelitis patients with scoliosis with less adverse effects