The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Molecular cloning and characterization of pearl millet polyphenol oxidase and its role in defense against downy mildew

Polyphenol oxidase partial gene PG-PPO was cloned and characterized from Pennisetum glaucum (pearl millet) which showed 42% identity to a PPO sequence isolated from wheat at the region of Copper B with a score of 40 and e-value of 2.8. Multiple sequence alignment results revealed similarity to polyphenol oxidase (PPO) sequences from wheat, trifolium, lettuce, apricot, tobacco, tomato, pokeweed, apple, grape and poplar especially at the Copper B region of PPO. The 395 bp pearl millet PPO sequence was AT rich (53.3%) and contained the highly conserved amino acids of histidine-rich copper binding sites similar to PPO sequences from other crops. Results also indicated that PPO in pearl millet exists in multi copy. The role of the isolated PPO gene during pearl millet-downy mildew interaction was analyzed and the results showed significantly higher and rapid accumulation of PPO mRNAs in resistant pearl millet seedlings inoculated with Sclerospora graminicola in comparison to the susceptible control, demonstrating that the PPO plays a prominent role in pearl millet defense against pathogens, particularly downy mildew pathogen

V-CaHAp as a recyclable catalyst for the green multicomponent synthesis of benzochromenes

AbstractA simple and efficient one-pot method has been developed for the synthesis of benzochromenes (4a–k) using V-CaHAp as a heterogeneous catalyst by the condensation of aldehydes, β-naphthol and malononitrile in ethanol as solvent at room temperature for 20min. The reaction, with this catalyst was carried out under mild reaction conditions with very good to excellent yields (89–98%). The material can be recycled very easily and reused for at least 6 runs without substantial loss in activity, which makes this methodology environmentally benign. We achieved a feasible and cost-effective synthesis by using non-toxic materials and minimal catalyst which is easy to handle

Nanoagrosomes: Future prospects in the management of drug resistance for sustainable agriculture

Agriculture plays a crucial role in sustaining the global population with food safety and security. The inadequacy of current agrochemicals in effectively controlling microbial infestations necessitates immediate attention. The over usage of agrochemicals has posed significant threat to agriculture by hampering the crop productivity, increased disease outbreaks and spread resistant microorganisms. This review addresses the pressing issue of drug-resistant microbial pathogens and their detrimental impact on the agricultural system. The use of nanoagrosomes has gained significant attention as a potential solution for combating drug-resistant pathogens due to their unique physicochemical properties, which can be tailored to target specific activities. A diverse of nanoagrosomes is widely practiced to attenuate specific roles which has been outline in the review. It also shed light on their effectiveness in combating drug-resistant pathogens and their role in promoting agricultural sustainability by expanding scientific understanding of nanoagrosomes as a future prospect for management of drug resistance

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Not AvailableGNCH-1 a high yielding, wilt and leafhopper resistant castor hybrid was developed by Pulses and Castor Research Station, Navsari Agricultural University,Navsari, Gujarat and released byCentral Sub-Committee onCrop Standards, Notification and Release (CVRC) of Variety for Agricultural Crops in 2017 for commercial cultivation under irrigated situation of Gujarat State, India. The hybrid GNCH-1 was developed by crossing a pistillate line SKP-84 with a male line DCS-94. On an average of 18 trials conducted for five years in south and middle Gujarat, the hybrid GNCH-1 recorded a seed yield of 2545 kg/ha which is 13.8, 35.9 and 31.0 per cent higher yield over the checks GCH-7, DCH-519 and DCH-177, respectively. The hybrid had long primary spike (64.8 cm), more numbers of capsules per primary spike (78.4), matures within 110-112 days and medium height (70-80 cm) which makes it suitable for easy harvesting. The oil content of the hybrid GNCH-1 (47.0 to 48.0 %) revealed that it is at par with the checks. The hybrid screened for wilt at national wilt sick plots showed resistance reactions (< 20%) to wilt. GNCH-1 screened against leafhopper using infester row method during 2014-17 showed resistant reaction to leafhopper (hopper burn grade 0 to 1 on 0-4 scale). The hybrid demonstrated in the farmers fields for two years (2016-18) showed higher seed yield than the existing cultivars. Due to plasticity for sowing time, this new hybrid is a suitable choice for the farmers of south and middle Gujarat under irrigated condition during late kharif and rabi seasons and paddy based cropping systemNot Availabl

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