Genotyping var Gene DBL1α Domain of Severe and Non-severe Plasmodium falciparum Patients.

This study analysed the genetic diversity of DBL1α domain of Plasmodium falciparum var gene in severe and non-severe malaria patients from Delhi and Mewat in Northern India. After confirming P. falciparum infection, samples were cloned and the var gene DBL1α domain was sequenced. Out of 377 cloned DBL sequences, 194 were from severe samples and 183 from non-severe samples. Proportion of DBL1α sequences belonging to groups 1, 4 and 5 were significantly higher in severe isolates as compared to non-severe isolates-group 1 (4.1% vs 1.09%, P = 0.0333), group 4 (69.58% vs 74.31%, P < 0.0001), and group 5 (19.58% vs 10.38%, P < 0.0001). Conversely, higher proportion of group 2 was observed in non-severe isolates (0% vs 3.82%, P = 0.0350). Highest diversity was seen in PoLV4 motif of severe and non-severe isolates and like other DBL1α sequences reported from several geographical areas (Africa, Americas, Asia, and Oceania). A total of 247 DBL1α domain haplotypes were found in this study where 139 (56.27%) haplotypes are novel and not reported from India till date. These findings could aid in developing effective malaria interventions, including vaccine and drug targets, by understanding the existing antigenic diversity and vulnerabilities in the parasite's genetic makeup. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-024-01200-1.

75 years' journey of malaria publications in English: what and where?

Malaria has inflicted serious morbidity and mortality across the globe. The major brunt of the disease has been on African, South-East Asian and South American countries. Proportionally, malaria has attracted global research priorities and this is evident from the number of publications related to malaria from across the globe, irrespective of its endemicity. However, formal and exhaustive analyses of these 'malaria publications' are rarely reported. The systematic review and secondary data analyses were done to retrieve information on what has been published on malaria, where is it published, and which countries are major contributors to malaria research.The study presents malaria publications from 1945 to 2020 retrieved using three databases: Web of Science™, Embase® and Scopus®. Exported data were examined to determine the number of publications over time, their subject areas, contributions from various countries/organizations, and top publishing journals.The total number of published records on malaria ranged from 90,282 to 112,698 (due to three different databases). Based on the number of publications, USA, UK, France, and India were identified as the top four countries. Malaria Journal, American Journal of Tropical Medicine & Hygiene, and PLoS One were the most preferred journals, whereas the University of London (Institutions other than LSHTM), the National Institute of Health, the London School of Hygiene and Tropical Medicine, and the University of Oxford appeared to be the top contributing organization.A disproportional contribution to malaria research was observed with non-malaria endemic countries making the largest contribution. Databases differed in their output format and needed standardization to make the outputs comparable across databases.

Deletions of Histidine-Rich Protein 2/3 Genes in Natural Plasmodium falciparum Populations from Cameroon and India: Role of Asymptomatic and Submicroscopic Infections.

The bulk of malaria rapid diagnostic tests (RDTs) target histidine-rich protein 2 of Plasmodium falciparum, the deadliest malaria species. The WHO considers pfhrp2/3 deletions as one of the main threats to successful malaria control and/or elimination; as such, parasites that lack part or all of the pfhrp2 gene are missed by pfHRP2-targeting RDTs. Such deletions have been reported in several African and Asian countries, but little is known in Cameroon and India. Blood samples were collected from individuals living in four areas of Cameroon (Douala, Maroua, Mayo-Oulo, Pette) and India (Mewat, Raipur, Ranchi, Rourkela). Deletions in pfhrp2/3 genes were confirmed if samples 1) had ≥100 parasites/µL by quantitative polymerase chain reaction (PCR), 2) PCR negative for pfhrp2/3, and 3) PCR positive for at least two single-copy genes. The overall proportion of pfhrp2 and pfhrp3 deletions in Cameroon was 13.5% and 3.1%. In India, the overall proportion was 8% for pfhrp2 and 4% for pfhrp3. The overall proportions of samples with both gene deletions (pfhrp2-/3-) were 3.1% in Cameroon and 1.3% in India. In Cameroon, pfhrp2-/3+ and pfhrp2-/3- deletions were common in Maroua (P = 0.02), in asymptomatic parasitemia (P = 0.006) and submicroscopic parasitemia (P <0.0001). In both countries, pfhrp2/3 deletions, including pfhrp2-/3- deletions, were mainly seen in monoclonal infections. This study outlines that double deletions that result in false negative RDTs are uncommon in our settings, and highlights the importance of active molecular surveillance for pfhrp2/3 deletions in Cameroon and India.

Myco-synthesis of multi-twinned silver nanoparticles as potential antibacterial and antimalarial agents.

In recent days, biogenic and green approaches for synthesizing nanostructures have gained much attention in biological and biomedical applications. Endophytic fungi have been recognized to produce several important biomolecules for use in various fields. The present work describes the use of endophytic fungi isolated from Berberis aristata for the synthesis of multi-twinned silver nanoparticles (MT-AgNPs) and their successful applications in antimicrobial and antimalarial studies. TEM images reveal the formation of multi-twined structures in the synthesized silver nanoparticles. The synthesized MT-AgNPs have shown excellent antibacterial activities against five opportunistic bacteria, viz. Bacillus subtilis (MTCC 441), Pseudomonas aeruginosa (MTCC 424), Escherichia coli (MTCC 443), Klebsiella pneumonia (MTCC 3384), and Aeromonas salmonicida (MTCC 1522). The synthesized MT-AgNPs also exhibit interesting antimalarial activities against Plasmodium falciparum parasites (3D7 strain) by displaying 100% inhibition at a concentration of 1 µg mL-1 against the malaria parasite P. falciparum 3D7. Overall, the results describe a green method for the production of twinned-structured nanoparticles and their potential to be applied in the biomedical, pharmaceutical, food preservation, and packaging industries.

Genetic diversity and natural selection of apical membrane antigen-1 (ama-1) in Cameroonian Plasmodium falciparum isolates.

Antigenic variation associated with genetic diversity in global Plasmodium falciparum apical membrane antigen-1 (PfAMA-1) is a major impediment to designing an effective malaria vaccine. Here, we report the first study on genetic diversity and natural selection of the Pfama-1 gene in P. falciparum isolates from Cameroon. A total of 328 P. falciparum positive samples collected during 2016 and 2019 from five localities of Cameroon were analysed. The ectodomain coding fragment of Pfama-1 gene was amplified for polymorphism profiling and natural selection analysis. A total of 108 distinct haplotypes were found in 203 P. falciparum isolates with considerable nucleotide diversity (π = 0.016) and haplotype diversity (Hd = 0.976). Most amino acid substitutions detected were scattered in ectodomain-I and few specific mutations viz P145L, K148Q, K462I, L463F, N471K, S482L, E537G, K546R and I547F were seen only in Cameroonian isolates. A tendency of natural selection towards positive diversifying selection was observed (Taj-D = 2.058). Five positively selected codon sites (P145L, S283L, Q308E/K, P330S and I547F) were identified, which overlapped with predicted B-cell epitopes and red blood cell (RBC) binding sites, suggesting their potential implication in host immune pressure and parasite-RBC binding complex modulation. The Cameroonian P. falciparum populations indicated a moderate level of genetic differentiation when compared with global sequences, with few exceptions from Vietnam and Venezuela. Our findings provide baseline data on existing Pfama-1 gene polymorphisms in Cameroonian field isolates, which will be useful information for malaria vaccine design.

In vitro Propagation of Endemic Species Mahonia Jaunsarensis Ahrendt Through Callus Culture.

Mahonia jaunsarensis Ahrendt (Family Berberidaceae) an endemic species was successfully propagated in vitro. An efficient propagation protocol has been developed first time. The callus cultures were established from leaf explants on Murashige and Skoog (MS) medium supplemented with 2,4-Dichlorophenoxyacetic acid (2,4-D; 1 µM) and resulted 70% callus induction with green compact callus. When callus was transferred to MS medium containing Thidiazuron (TDZ; 0.75 µM), maximum average number of shoot (3.06) produced but shoot length (3.37 cm) and average leaf number (2.87) was increased upon transfer to MS medium containing N6-benzylaminopurine (BA; 6.0 µM) plus α-naphthalene acetic acid (NAA; 0.5 µM). In MS medium containing indole-3-butyric acid (IBA; 0.01 µM), the maximum rooting percentage (56%) and average root number (2.56) per shoot and root length (3.33 cm) were recorded. The rooted plantlets transferred in vermiculite + garden soil + farmyard manure (1:1:1) with maximum (55%) survival percentage under greenhouse condition. The phytochemical analysis of leaves obtained from tissue culture-raised plants revealed significantly higher levels of alkaloids (berberine and palmatine) than those obtained from wild plants. Similar trends were observed for antioxidant and antimutagenic activities. Results of this study offer a baseline for the conservation and sustainable utilization strategies for M. jaunsarensis.

In silico screening of chalcone derivatives as promising EGFR-TK inhibitors for the clinical treatment of cancer.

Epidermal growth factor receptor (EGFR) promotes tumorigenic characteristics and activates cancer-associated signaling pathways such as Wnt/-catenin, transforming growth factor (TGF-ß), and phosphoinositide-3-kinase (PI3K). Several inhibitors have been reported to suppress the activity of EGFR and are being used in cancer treatment. However, patients in the malignant stage of cancer show resistance to those inhibitors, opening a wide space for research to discover novel inhibitors. Therefore, we carried out machine learning and virtual screening to discover novel inhibitors with high affinity against EGFR-TK. Initially, a library of 2640 chalcones were screened out using a machine-learning model developed based on the random forest algorithm, exhibiting high sensitivity and a Receiver Operating Characteristic curve (ROC area) of 0.99. Furthermore, out of the initial 2640 screened compounds, 412 compounds exhibiting potential activity are subjected to evaluation for drug-likeness properties through different filters: Blood-brain barrier penetration, Lipinski's rule, CMC-50 like rule, Veber rule, and Ghose filter, alongside Cell Line Cytotoxicity Prediction. A total of 30 compounds that successfully pass through all these filters are selected for molecular docking. Of these, 6 compounds display substantial binding affinity and closer interaction with the conserved catalytic residues of the target EGFR-TK compared to the reference molecule (erlotinib). Furthermore, molecular dynamics simulation studies were conducted on four compounds (CID-375861, CID-375862, CID-23636403, and CID-259166) to confirm the stability of the docked complexes over a 100 ns simulation trajectory. Additionally, the binding free energy calculations by MMPBSA reveal that these four chalcone compounds exhibit strong affinity towards the EGFR-TK enzyme, with binding free energies of - 65.421 kJ/mol, - 94.266 kJ/mol, - 80.044 kJ/mol, and - 79.734 kJ/mol, respectively. The findings from this investigation highlight a set of promising chalcone compounds that have the potential to be developed into effective drugs for the treatment of various cancers. Further research and development on these compounds could pave the way for novel therapeutic interventions. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03858-8.

Screening of potential inhibitors of Leishmania major N-myristoyltransferase from Azadirachta indica phytochemicals for leishmaniasis drug discovery by molecular docking, molecular dynamics simulation and density functional theory methods.

Leishmaniasis is one of the most neglected parasitic diseases worldwide. The toxicity of current drugs used for its treatment is a major obstacle to their effectiveness, necessitating the discovery and development of new therapeutic agents for better disease control. In Leishmania parasites, N-Myristoyltransferase (NMT) has been identified as a promising target for drug development. Thus, exploring well-known medicinal plants such as Azadirachta indica and their phytochemicals can offer a diverse range of treatment options, potentially leading to disease prevention and control. To assess the therapeutic potential of these compounds, their ADMET prediction and drug-likeness properties were analyzed. The top 4 compounds were selected which had better and significantly low binding energy than the reference molecule QMI. Based on the binding energy score of the top compounds, the results show that Isonimocinolide has the highest binding affinity (-9.8 kcal/mol). In addition, a 100 ns MD simulation of the four best compounds showed that Isonimocinolide and Nimbolide have good stability with LmNMT. These compounds were then subjected to MMPBSA (last 30 ns) calculation to analyze protein-ligand stability and dynamic behavior. Nimbolide and Meldenin showed lowest binding free energy i.e. -84.301 kJ/mol and -91.937 kJ/mol respectively. DFT was employed to calculate the HOMO-LUMO energy gap, global reactivity parameters, and molecular electrostatic potential of all hit molecules. The promising results obtained from MD simulations and MMPBSA analyses provide compelling evidence for the potential use of these compounds in future drug development efforts for the treatment of leishmaniasis.Communicated by Ramaswamy H. Sarma.

Chemokines: A key driver for inflammation in protozoan infection.

Chemokines belong to the group of small proteins within the cytokine family having strong chemo-attractant properties. In most cases, the strong immuno-modulatory role of chemokines is crucial for generating the immune response against pathogens in various protozoan diseases. In this review, we have given a brief update on the classification, characterization, homeostasis, transcellular migration, and immuno-modulatory role of chemokines. Here we will evaluate the potential role of chemokines and their regulation in various protozoan diseases. There is a significant direct relationship between parasitic infection and the recruitment of effector cells of the immune response. Chemokines play an indispensable role in mediating several defense mechanisms against infection, such as leukocyte recruitment and the generation of innate and cell-mediated immunity that aids in controlling/eliminating the pathogen. This process is controlled by the chemotactic movement of chemokines induced as a primary host immune response. We have also addressed that chemokine expressions during infection are time-dependent and orchestrated in a systematic pattern that ultimately assists in generating a protective immune response. Taken together, this review provides a systematic understanding of the complexity of chemokines profiles during protozoan disease conditions and the rationale of targeting chemokines for the development of therapeutic strategies.

Abiotic factors improving fatty acid profiling of freshwater indigenous microalgae isolated from Kumaun region of Uttarakhand, India.

Microalgae have grabbed huge attention as a potential feedstock for biofuel production in response to the rise in energy consumption and the energy crisis. In the present study, indigenous microalgal strains were isolated from four freshwater lakes in the Kumaun region, Uttarakhand, India. Based on growth and lipid profiles, the four best-performing isolates were selected for further experiments. Initial identification of isolates was done by morphological observations, which were further validated by molecular identification using ITS sequencing. The screened cultures were subjected to abiotic stress conditions (varying concentrations of nitrogen and different temperatures) to monitor the biomass, lipid accumulation, and biochemical compositions (chlorophyll and carotenoids). The quantification of fatty acids was checked via gas chromatographic analysis. The strains were identified as KU_MA3 Chlamydopodium starrii, KU_MA4 Tetradesmus nygaardii, KU_MA5 Desmodesmus intermedius, and KU_MA6 Tetradesmus nygaardii. KU_MA3 Chlamydopodium starrii showed the best results in terms of growth and lipid production at 21 °C and 0.37 g/L NaNO2 concentration. The percentage of fatty acid methyl esters (FAMEs) attained >80% and met the standard for biodiesel properties. The strain has the potential to attain higher biomass and accumulate higher lipid content, and after some more studies, it can be used for upscaling processes and large-scale biodiesel production.

Comparison of SYBR green I and lactate dehydrogenase antimalarial in vitro assay in Plasmodium falciparum field isolates.

Several assay methods are in use for monitoring the drug sensitivity of malaria parasites and screening new antimalarial drugs. Plasmodium lactate dehydrogenase (pLDH) and SYBR Green I in vitro assays were used to evaluate the drug efficacy of Chloroquine, Artemisinin and Azadirachta indica silver nano particles against Plasmodium falciparum 3D7 strain. The half-maximal inhibitory concentration (IC50) of each compound was estimated with non-linear regression model - dose-response analysis. The consistency between two methods was analysed with Cohen's kappa coefficient, interclass correlation and Bland-Altman plots. No statistical difference was found between IC50 values determined by both assays (p = 0.714). The proportion of resistant isolates to chloroquine according to SYBR green I (43.48%) and pLDH (34.78%) assays were similar (z = 0.302; p = 0.762) with significant concordant between methods (k = 0.819, p < 0.001). The results of pLDH Qualisa assay was comparable with classic SYBR green I assay and can be potentially useful in antimalarial drug efficacy surveillance.

Artemisinin resistance in P. falciparum: probing the interacting partners of Kelch13 protein in parasite.

OBJECTIVES: 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. METHODS: 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. RESULTS: 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 KD 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. CONCLUSION: 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.

Design and validation of multiplex polymerase chain reaction as a diagnostic tool for Plasmodium species.

BACKGROUND & OBJECTIVES: The highly sensitive method for a true understanding of malaria prevalence is of utmost importance for India's elimination strategy. The PCR reaction type with rapid detection, cost-effectiveness, and less workforce should be preferable. Multiplex PCR type accomplishes the present requirement by saving time and resources to find true surveillance data for malaria, especially in low-parasitemia/asymptomatic groups or populations. METHODS: The present study focuses on designing multiplex PCR (mPCR) to detect simultaneously Plasmodium genus (PAN) and two common Plasmodium species found in India. It is compared to standard nested PCR on 195 clinical samples to diagnose malaria. The mPCR was designed with a minimum number of primers, leading to less clogging and effective and enhanced detection. It contains one common reverse primer and three forward primers amplifying three targeted genes corresponding to P. falciparum, P. vivax, and Plasmodium genus. RESULTS: The sensitivity and specificity for mPCR were 94.06 and 95.74, respectively. The limit of detection for mPCR was 0.1 parasites/µl. The study has shown a ROC curve area for the mPCR of 0.949 for Plasmodium genus and P. falciparum and 0.897 for P. vivax with standard nPCR. INTERPRETATION & CONCLUSION: The mPCR is rapid in detecting species together, cost-effective, and requires fewer human resources than the standard nPCR. Therefore, the mPCR can be used as an alternative technique for the higher sensitive detection of the malaria parasite. It could also become a vital tool for determining malaria prevalence, facilitating the application of the most effective measures.

Predicting phytochemical diversity of medicinal and aromatic plants (MAPs) across eco-climatic zones and elevation in Uttarakhand using Generalized Additive Model.

The present study uses a systematic approach to explore the phytochemical composition of medicinal plants from Uttarakhand, Western Himalaya. The phytochemical composition of medicinal plants was analyzed based on (i) the presence of different chemical groups and (ii) bioactive compounds. The Generalized Additive Model (GAM) analysis was used to predict the occurrence of chemical groups and active compounds across different eco-climatic zones and the elevation in Uttarakhand. A total of 789 medicinal plants represented by 144 taxonomic families were screened to explore the phytochemical diversity of the medicinal plants of Uttarakhand. These medicinal plant species are signified in different life forms such as herbs (58.86%), shrubs (18.24%), trees (17.48%), ferns (2.38%), and climbers (2.13%). The probability of occurrence of the chemical groups found in tropical, sub-tropical, and warm temperate eco-climatic zones, whereas active compounds have a high Probability towards alpine, sub-alpine, and cool temperate zones. The GAM predicted that the occurrence of species with active compounds was declining significantly (p < 0.01), while total active compounds increased across elevation (1000 m). While the occurrence of species with the chemical group increased, total chemical groups were indicated to decline with increasing elevation from 1000 m (p < 0.000). The current study is overwhelmed to predict the distribution of phytochemicals in different eco-climatic zones and elevations using secondary information, which offers to discover bioactive compounds of the species occurring in the different eco-climatic habitats of the region and setting the priority of conservation concerns. However, the study encourages the various commercial sectors, such as pharmaceutical, nutraceutical, chemical, food, and cosmetics, to utilize unexplored species. In addition, the study suggests that prioritizing eco-climatic zones and elevation based on phytochemical diversity should be a factor of concern in the Himalayan region, especially under the climate change scenario.

Phytofabrication and characterization of Alchornea cordifolia silver nanoparticles and evaluation of antiplasmodial, hemocompatibility and larvicidal potential.

Purpose: The recent emergence of Plasmodium falciparum (Pf) parasites resistant to current artemisinin-based combination therapies in Africa justifies the need to develop new strategies for successful malaria control. We synthesized, characterized and evaluated medical applications of optimized silver nanoparticles using Alchornea cordifolia (AC-AgNPs), a plant largely used in African and Asian traditional medicine. Methods: Fresh leaves of A. cordifolia were used to prepare aqueous crude extract, which was mixed with silver nitrate for AC-AgNPs synthesis and optimization. The optimized AC-AgNPs were characterized using several techniques including ultraviolet-visible spectrophotometry (UV-Vis), scanning/transmission electron microscopy (SEM/TEM), powder X-ray diffraction (PXRD), selected area electron diffraction (SAED), energy dispersive X-ray spectroscopy (EDX), Fourier transformed infrared spectroscopy (FTIR), dynamic light scattering (DLS) and Zeta potential. Thereafter, AC-AgNPs were evaluated for their hemocompatibility and antiplasmodial activity against Pf malaria strains 3D7 and RKL9. Finally, lethal activity of AC-AgNPs was assessed against mosquito larvae of Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti which are vectors of neglected diseases such as dengue, filariasis and chikungunya. Results: The AC-AgNPs were mostly spheroidal, polycrystalline (84.13%), stable and polydispersed with size of 11.77 ± 5.57 nm. FTIR revealed the presence of several peaks corresponding to functional chemical groups characteristics of alkanoids, terpenoids, flavonoids, phenols, steroids, anthraquonones and saponins. The AC-AgNPs had a high antiplasmodial activity, with IC50 of 8.05 µg/mL and 10.31 µg/mL against 3D7 and RKL9 Plasmodium falciparum strains. Likewise, high larvicidal activity of AC-AgNPs was found after 24 h- and 48 h-exposure: LC50 = 18.41 µg/mL and 8.97 µg/mL (Culex quinquefasciatus), LC50 = 16.71 µg/mL and 7.52 µg/mL (Aedes aegypti) and LC50 = 10.67 µg/mL and 5.85 µg/mL (Anopheles stephensi). The AC-AgNPs were highly hemocompatible (HC50 > 500 µg/mL). Conclusion: In worrying context of resistance of parasite and mosquitoes, green nanotechnologies using plants could be a cutting-edge alternative for drug/insecticide discovery and development.

Exploring the structural basis to develop efficient multi-epitope vaccines displaying interaction with HLA and TAP and TLR3 molecules to prevent NIPAH infection, a global threat to human health.

Nipah virus (NiV) is an emerging zoonotic virus that caused several serious outbreaks in the south asian region with high mortality rates ranging from 40 to 90% since 2001. NiV infection causes lethal encephalitis and respiratory disease with the symptom of endothelial cell-cell fusion. No specific and effective vaccine has yet been reported against NiV. To address the urgent need for a specific and effective vaccine against NiV infection, in the present study, we have designed two Multi-Epitope Vaccines (MEVs) composed of 33 Cytotoxic T lymphocyte (CTL) epitopes and 38 Helper T lymphocyte (HTL) epitopes. Out of those CTL and HTL combined 71 epitopes, 61 novel epitopes targeting nine different NiV proteins were not used before for vaccine design. Codon optimization for the cDNA of both the designed MEVs might ensure high expression potential in the human cell line as stable proteins. Both MEVs carry potential B cell linear epitope overlapping regions, B cell discontinuous epitopes as well as IFN-γ inducing epitopes. Additional criteria such as sequence consensus amongst CTL, HTL and B Cell epitopes was implemented for the design of final constructs constituting MEVs. Hence, the designed MEVs carry the potential to elicit cell-mediated as well as humoral immune response. Selected overlapping CTL and HTL epitopes were validated for their stable molecular interactions with HLA class I and II alleles and in case of CTL epitopes with human Transporter Associated with antigen Processing (TAP) cavity. The structure based epitope cross validation for interaction with TAP cavity was used as another criteria choosing final epitopes for NiV MEVs. Finally, human Beta-defensin 2 and Beta-defensin 3 were used as adjuvants to enhance the immune response of both the MEVs. Molecular dynamics simulation studies of MEVs-TLR3 ectodomain (Human Toll-Like Receptor 3) complex indicated the stable molecular interaction. We conclude that the MEVs designed and in silico validated here could be highly potential vaccine candidates to combat NiV infections, with great effectiveness, high specificity and large human population coverage worldwide.

A universal green approach for the synthesis of NPS-codoped carbon quantum dots with enhanced broad-spectrum antibacterial and antioxidant activities.

Bio-inspired quantum dots have received widespread attention in recent years due to their great potential for biological applications. Herein, we report a one pot hydrothermal synthesis of nitrogen-phosphorus-sulphur (NPS)-codoped carbon quantum dots from endophytic bacteria without using any additional doping precursor. The synthesized CQDs were thoroughly characterized and interestingly found to have a graphene like structure. The synthesized CQDs were then utilized in bactericidal activities against Gram-negative bacteria like Salmonella typhi, Pseudomonas aeruginosa and Gram-positive bacteria like the Bacillus subtilis strain. The strains were treated with different concentrations ranging from 5-100 µg ml-1. The 5 µg ml-1 concentration appeared to be the MIC (minimum inhibitory concentration) and 100 µg ml-1 is the MBC (minimum bactericidal concentration) maintaining a short incubation period of one hour. A simple, cost-effective and eco-friendly approach to synthesize multi-elemental doped CQDs would certainly cause the method to be used in future for diverse biological applications. As compared to the broadly used antibiotics, the developed CQDs have some added advantages including lower cytotoxicity, excellent photo-stability and high selectivity.

Non-falciparum species and submicroscopic infections in three epidemiological malaria facets in Cameroon.

BACKGROUND: There are growing reports on the prevalence of non-falciparum species and submicroscopic infections in sub-Saharan African countries but little information is available from Cameroon. METHODS: A hospital-based cross-sectional study was carried out in four towns (Douala, Maroua, Mayo-Oulo, and Pette) from three malaria epidemiological strata (Forest, Sahelian, and Soudanian) of Cameroon. Malaria parasites were detected by Giemsa light microscopy and polymerase chain reaction (PCR) assay. Non-falciparum isolates were characterized and their 18S gene sequences were BLASTed for confirmatory diagnosis. RESULTS: PCR assay detected malaria parasites in 82.4% (98/119) patients, among them 12.2% (12/98) were asymptomatic cases. Three Plasmodium species viz. P. falciparum, P. ovale curtisi and P. vivax, and two co-infection types (P. falciparum + P. vivax and P. falciparum + P. ovale curtisi) were found. The remaining infections were mono-infections with either P. falciparum or P. ovale curtisi. All non-falciparum infections were symptomatic and microscopic. The overall proportion of submicroscopic infections was 11.8% (14/119). Most asymptomatic and submicroscopic infection cases were self-medicated with antimalarial drugs and/or medicinal plants. On analysis, P. ovale curtisi sequences were found to be phylogenetically closer to sequences from India while P. vivax isolates appeared closer to those from Nigeria, India, and Cameroon. No G6PD-d case was found among non-falciparum infections. CONCLUSIONS: This study confirms our previous work on circulation of P. vivax and P. ovale curtisi and the absence of P. knowlesi in Cameroon. More studies are needed to address non-falciparum malaria along with submicroscopic infections for effective malaria management and control in Cameroon.

Salivary AsHPX12 influences pre-blood meal associated behavioral properties in Anopheles stephensi.

BACKGROUND & OBJECTIVES: A successful blood meal acquisition process by an adult female mosquito is accomplished through salivary glands, which releases a cocktail of proteins to counteract the vertebrate host's immune homeostasis. Here, we characterize a salivary-specific Heme peroxidase family member HPX12, originally identified from Plasmodium vivax infected salivary RNAseq data of the mosquito Anopheles stephensi. METHODS: To demonstrate we utilized a comprehensive in silico and functional genomics approach. RESULTS: Our dsRNA-mediated silencing experiments demonstrate that salivary AsHPX12 may regulate pre-blood meal-associated behavioral properties such as probing time, probing propensity, and host attraction. Altered expression of the salivary secretory and antennal proteins expression may have accounted for salivary homeostasis disruption resulting in the unusual fast release of salivary cocktail proteins and delayed acquisition of blood meal in the AsHPX12 knockdown mosquitoes. We also observed a significant parallel transcriptional modulation in response to blood feeding and P. vivax infection. INTERPRETATION & CONCLUSION: With this work, we establish a possible functional correlation of AsHPX12 role in the maintenance of salivary physiological-homeostasis, and Plasmodium sporozoites survival/transmission, though the mechanism is yet to unravel.