Artemisinin (ART) resistance in Plasmodium is threatening the artemisinin combination therapies-the first line of defence against malaria. ART resistance has been established to be mediated by the Plasmodium Kelch13 (PfK13) protein. For the crucial role of PfK13 in multiple pathways of the Plasmodium life cycle and ART resistance, it is imperative that we investigate its interacting partners. We recombinantly expressed PfK13-p (Bric a brac/Poxvirus and zinc finger and propeller domains), generating anti-PfK13-p antibodies to perform co-immunoprecipitation assays and probed PfK13 interacting partners. Surface plasmon resonance and pull-down assays were performed to establish physical interactions of representative proteins with PfK13-p. The co-immunoprecipitation assays identified 17 proteins with distinct functions in the parasite life cycle- protein folding, cellular metabolism, and protein binding and invasion. In addition to the overlap with previously identified proteins, our study identified 10 unique proteins. Fructose-biphosphate aldolase and heat shock protein 70 demonstrated strong biophysical interaction with PfK13-p, with K_D values of 6.6 µM and 7.6 µM, respectively. Additionally, Plasmodium merozoite surface protein 1 formed a complex with PfK13-p, which is evident from the pull-down assay. This study adds to our knowledge of the PfK13 protein in mediating ART resistance by identifying new PfK13 interacting partners. Three representative proteins-fructose-biphosphate aldolase, heat shock protein 70, and merozoite surface protein 1-demonstrated clear evidence of biophysical interactions with PfK13-p. However, elucidation of the functional relevance of these physical interactions are crucial in context of PfK13 role in ART resistance.

Malaria poses several challenges to the global research community on both diagnostic and therapeutic fronts. Most prominent of them are deletion of target genes (pfhrp2/3) used in rapid diagnostic tests (RDTs) and the emergence of resistance against frontline antimalarials by the evolving parasite. Exploration of novel therapeutics for malaria in view of limited vaccine options is a promising resort for malaria control and elimination. The scope of marine-derived chemotherapeutics is exciting, with a significant number of FDA-approved drugs or therapeutic leads under clinical trials for other diseases. This review article discusses the significant antimalarial potential of marine-derived natural products extracted from diverse biota including sponges, bacteria, sea hare and algae etc. Bioassay-guided fractionation of raw extracts from marine organisms for lead identification and further structural characterization of purified compounds compose a sustainable marine-derived drug discovery pipeline; which can be particularly diverted towards the exploration of antimalarials. It is to be noted that the Indian peninsula is largely unexplored, particularly for antimalarials screening; which has a huge marine biodiversity owing to the three distinct water bodies- Bay of Bengal, Indian Ocean and Arabian sea. This review also envisions a collaborative initiative to explore the potential of marine natural products in an economically feasible manner.

Mosquito vector-borne diseases are one of the leading causes of mortality and morbidity across the globe. Current vector control strategies mainly rely on chemical insecticides, but their incessant usage has resulted in the development of resistance. Insecticidal agents of microbial origin have proven as good alternative tools for vector control of mosquito. In the present study, we examined larvicidal activities of the extracts from culture supernatants of marine bacteria (extracts) against major mosquito vectors from India. Out of 55 tested marine bacterial extracts, 12 extracts caused 90–100% mortality at 250 ppm in Anopheles stephensi larvae. Furthermore, NIO 707 and 706 were found to be significantly effective against Aedes aegypti larvae and field collected larvae of An. subpictus, respectively. Some of the extracts (NIO 701, 707 and 710) demonstrated significant reduction in egg hatching of An. stephensi; while all the tested extracts were able to significantly reduce egg hatching in An. culicifacies. Additionally, we observed that any of the effective extracts did not show any detrimental activity against malaria parasite (Plasmodium falciparum). Phylogenetic analysis revealed that most of the effective extracts belonged to Bacillus sp.; however, bacteria from Enterococcus genera was a peculiar finding of our study. Altogether, our data underscores the importance of exploration of marine bacteria from Indian peninsula for their larvicidal activities and further undertaking mechanistic approach to develop novel bio-larvicides.

The present study investigated two single nucleotide polymorphisms (SNPs)—rs479200 and rs516651 in the host EGLN1/PHD2 gene for their association with COVID-19 severity. A retrospective cohort of 158 COVID-19 patients from the Indian population (March 2020 to June 2021) was enrolled. Notably, the frequency of C allele (0.664) was twofold higher than T allele (0.336) in severe COVID-19 patients. Here, we report a novel finding that the C allele of rs479200 in the EGLN1 gene imparts a high risk of severe COVID-19 (odds ratio—6.214 (1.84–20.99) p = 0.003; 9.421 (2.019–43.957) p = 0.004), in additive inheritance model (adjusted and unadjusted, respectively).

Chemical insecticides (organophosphates and pyrethroids) in the form of IRS (Indoor Residual Sprays) and LLINs (Long Lasting insecticidal nets) are the cornerstone for vector control, globally. However, their incessant use has resulted in widespread development of resistance in mosquito vectors, warranting continuous monitoring and investigation of the underlying mechanisms of resistance. Here, we identified a previously uncharacterized- Cub and Sushi Domain containing Insecticide Resistance (CSDIR) protein and generated evidence for its role in mediating insecticide resistance in the Anopheles stephensi. A strong binding affinity of the CSDIR protein towards different classes of insecticide molecules-malathion (K_D 6.43 μM) and deltamethrin (K_D 46.7μM) were demonstrated using MD simulation studies and Surface Plasmon Resonance (SPR) experiments. Further, the recombinant CSDIR^913-1190 protein exhibited potent esterase-like activity (α-naphthyl acetate (α-NA)- 1.356±0.262 mM/min/mg and β-naphthyl acetate (β -NA)- 1.777±0.220 mM/min/mg). Interestingly, dsRNA-mediated gene silencing of the CSDIR transcripts caused >60% mortality in resistant An. stephensi upon 1-hour exposure to deltamethrin and malathion insecticides, compared to the control group. A significant reduction in the esterase-like activity was also observed against α-NA (P=0.004) and β-NA (P=0.025) in CSDIR silenced mosquitoes compared to the control group. Using computational analysis and experimental data, our results provided significant evidence of the involvement of the CSDIR protein in mediating insecticide resistance in Anopheles mosquitoes. Thereby making the CSDIR protein, a novel candidate for exploration of novel insecticide molecules. These data would also be helpful in further understanding the development of metabolic resistance by the Anopheles vector.