Dengue virus capsid interacts with DDX3X-a potential mechanism for suppression of antiviral functions in dengue infection

Dengue virus is a pathogen of global concern and has a huge impact on public health system in low- and middle-income countries. The capsid protein of dengue virus is least conserved among related flavivirus and there is very limited information on the role of cytosolic proteins that interact with dengue virus capsid. We identified DEAD (Asp-Glu-Ala-Asp) Box Helicase 3, an X-Linked (DDX3X), cytosolic ATP-dependent RNA helicase as a dengue virus capsid-interacting protein. We show that the N-terminal region of capsid is important for interaction with DDX3X, while the N-terminal domain of DDX3X seems to be involved in interaction with dengue capsid. DDX3X was down-regulated in dengue virus infected cells at later stages of infection. Our results show that DDX3X is an antiviral protein as suppression of DDX3X expression by siRNA led to an increase in viral titers and overexpression of DDX3X led to inhibition of viral replication. Knock-down of DDX3X did not affect induction of type I interferon response upon infection suggesting that the effect of DDX3X knock-down is independent of the interferon-dependent pathways that DDX3X modulates under normal conditions. Thus, our study identifies DDX3X as a dengue virus capsid interacting protein and indicates a potential link between the antiviral functions of DDX3X and dengue capsid at later stages of dengue infection

Towards Green Computing Oriented Security: A Lightweight Postquantum Signature for IoE

[EN] Postquantum cryptography for elevating security against attacks by quantum computers in the Internet of Everything (IoE) is still in its infancy. Most postquantum based cryptosystems have longer keys and signature sizes and require more computations that span several orders of magnitude in energy consumption and computation time, hence the sizes of the keys and signature are considered as another aspect of security by green design. To address these issues, the security solutions should migrate to the advanced and potent methods for protection against quantum attacks and offer energy efficient and faster cryptocomputations. In this context, a novel security framework Lightweight Postquantum ID-based Signature (LPQS) for secure communication in the IoE environment is presented. The proposed LPQS framework incorporates a supersingular isogeny curve to present a digital signature with small key sizes which is quantum-resistant. To reduce the size of the keys, compressed curves are used and the validation of the signature depends on the commutative property of the curves. The unforgeability of LPQS under an adaptively chosen message attack is proved. Security analysis and the experimental validation of LPQS are performed under a realistic software simulation environment to assess its lightweight performance considering embedded nodes. It is evident that the size of keys and the signature of LPQS is smaller than that of existing signature-based postquantum security techniques for IoE. It is robust in the postquantum environment and efficient in terms of energy and computations.This project was funded by the Deanship of Scientific Research (DSR), King Abdulaziz University. Jeddah. under grant No. (DF-457-156-1441).Rani, R.; Kumar, S.; Kaiwartya, O.; Khasawneh, AM.; Lloret, J.; Al-Khasawneh, MA.; Mahmoud, M.... (2021). Towards Green Computing Oriented Security: A Lightweight Postquantum Signature for IoE. Sensors. 21(5):1-20. https://doi.org/10.3390/s2105188312021

Knockdown resistance mutations predict DDT resistance and pyrethroid tolerance in the visceral leishmaniasis vector Phlebotomus argentipes

BACKGROUND:Indoor residual spraying (IRS) with DDT has been the primary strategy for control of the visceral leishmaniasis (VL) vector Phlebotomus argentipes in India but efficacy may be compromised by resistance. Synthetic pyrethroids are now being introduced for IRS, but with a shared target site, the para voltage-gated sodium channel (VGSC), mutations affecting both insecticide classes could provide cross-resistance and represent a threat to sustainable IRS-based disease control. METHODOLOGY/PRINCIPAL FINDINGS:A region of the Vgsc gene was sequenced in P. argentipes from the VL hotspot of Bihar, India. Two knockdown resistance (kdr) mutations were detected at codon 1014 (L1014F and L1014S), each common in mosquitoes, but previously unknown in phlebotomines. Both kdr mutations appear largely recessive, but as homozygotes (especially 1014F/F) or as 1014F/S heterozygotes exert a strong effect on DDT resistance, and significantly predict survivorship to class II pyrethroids in short-duration bioassays. The mutations are present at high frequency in wild P. argentipes populations from Bihar, with 1014F significantly more common in higher VL areas. CONCLUSIONS/SIGNIFICANCE:The Vgsc mutations detected appear to be a primary mechanism underlying DDT resistance in P. argentipes and a contributory factor in reduced pyrethroid susceptibility, suggesting a potential impact if P. argentipes are subjected to suboptimal levels of pyrethroid exposure, or additional resistance mechanisms evolve. The assays to detect kdr frequency changes provide a sensitive, high-throughput monitoring tool to detecting spatial and temporal variation in resistance in P. argentipes

Molecular surveillance of insecticide resistance in Phlebotomus argentipes targeted by indoor residual spraying for visceral leishmaniasis elimination in India

Molecular surveillance of resistance is an increasingly important part of vector borne disease control programmes that utilise insecticides. The visceral leishmaniasis (VL) elimination programme in India uses indoor residual spraying (IRS) with the pyrethroid, alpha-cypermethrin to control Phlebotomus argentipes the vector of Leishmania donovani, the causative agent of VL. Prior long-term use of DDT may have selected for knockdown resistance (kdr) mutants (1014F and S) at the shared DDT and pyrethroid target site, which are common in India and can also cause pyrethroid cross-resistance. We monitored the frequency of these marker mutations over five years from 2017–2021 in sentinel sites in eight districts of north-eastern India covered by IRS. Frequencies varied markedly among the districts, though finer scale variation, among villages within districts, was limited. A pronounced and highly significant increase in resistance-associated genotypes occurred between 2017 and 2018, but with relative stability thereafter, and some reversion toward more susceptible genotypes in 2021. Analyses linked IRS with mutant frequencies suggesting an advantage to more resistant genotypes, especially when pyrethroid was under-sprayed in IRS. However, this advantage did not translate into sustained allele frequency changes over the study period, potentially because of a relatively greater net advantage under field conditions for a wild-type/mutant genotype than projected from laboratory studies and/or high costs of the most resistant genotype. Further work is required to improve calibration of each 1014 genotype with resistance, preferably using operationally relevant measures. The lack of change in resistance mechanism over the span of the study period, coupled with available bioassay data suggesting susceptibility, suggests that resistance has yet to emerge despite intensive IRS. Nevertheless, the advantage of resistance-associated genotypes with IRS and under spraying, suggest that measures to continue monitoring and improvement of spray quality are vital, and consideration of future alternatives to pyrethroids for IRS would be advisable

Impact of IRS: Four-years of entomological surveillance of the Indian Visceral Leishmaniases elimination programme

BACKGROUND In 2005, Bangladesh, India and Nepal agreed to eliminate visceral leishmaniasis (VL) as a public health problem. The approach to this was through improved case detection and treatment, and controlling transmission by the sand fly vector Phlebotomus argentipes, with indoor residual spraying (IRS) of insecticide. Initially, India applied DDT with stirrup pumps for IRS, however, this did not reduce transmission. After 2015 onwards, the pyrethroid alpha-cypermethrin was applied with compression pumps, and entomological surveillance was initiated in 2016. METHODS Eight sentinel sites were established in the Indian states of Bihar, Jharkhand and West Bengal. IRS coverage was monitored by household survey, quality of insecticide application was measured by HPLC, presence and abundance of the VL vector was monitored by CDC light traps, insecticide resistance was measured with WHO diagnostic assays and case incidence was determined from the VL case register KAMIS. RESULTS Complete treatment of houses with IRS increased across all sites from 57% in 2016 to 70% of houses in 2019, rising to >80% if partial house IRS coverage is included (except West Bengal). The quality of insecticide application has improved compared to previous studies, average doses of insecticide on filters papers ranged from 1.52 times the target dose of 25mg/m2 alpha-cypermethrin in 2019 to 1.67 times in 2018. Resistance to DDT has continued to increase, but the vector was not resistant to carbamates, organophosphates or pyrethroids. The annual and seasonal abundance of P. argentipes declined between 2016 to 2019 with an overall infection rate of 0.03%. This was associated with a decline in VL incidence for the blocks represented by the sentinel sites from 1.16 per 10,000 population in 2016 to 0.51 per 10,000 in 2019. CONCLUSION Through effective case detection and management reducing the infection reservoirs for P. argentipes in the human population combined with IRS keeping P. argentipes abundance and infectivity low has reduced VL transmission. This combination of effective case management and vector control has now brought India within reach of the VL elimination targets

Isolation and characterization of pink pigmented facultative methylotrophic (PPFM) bacteria from leaves of neem, Azadirachta indica

A total of twenty pink pigmented facultative methylotrophic bacteria were isolated from the leaves of neem. All isolates showed pink to orange pink pigmented, round colonies with a smooth glistening surface appearance, entire margin and convex elevation. Most of the colonies were opaque and had a butyrous consistency. Staining showed rod to coccobacilli in shape, Gram negative cells, and containing poly-β-hydroxybutyrate granules. Biochemical analysis showed they were all catalase positive majority of them citrate positive urease positive amylase negative and varied in their oxidase activity. They have the ability to grow on ammonium mineral salt (AMS) agar with methanol, glycerol peptone agar (GPA) and tryptic soy agar (TSA), with some variation in colonial morphology. Based on the observed characteristics, they can be assigned to the genus Methylobacterium.

Isolation and characterization of pink-pigmented, facultative methylotrophic (PPFM) bacteria from leaves of neem, Azadirachta indica A. Juss

A total of twenty isolates of pink-pigmented, facultative methylotrophic bacteria were obtained from the leaves of neem. All isolates exhibited pink to orange-pink pigmentation, entire margin, round colonies with a smooth glistening surface, and convex elevation. Most of the colonies were opaque with butyrous consistency. Staining revealed rod to coccobacilli shaped, Gram negative cells, containing poly-β-hydroxybutyrate granules. Biochemical analyses showed that all were catalase positive; majority of them were positive for citrate utilization, urease and oxidase activities but were negative for amylase activity. They can be cultivated on ammonium mineral salt (AMS) agar with methanol, glycerol peptone agar (GPA) and tryptic soy agar (TSA) with variations in colonial morphology. Based on the observed characteristics, the isolates obtained belong to the genus Methylobacterium

Seasonal Incidence of Diamond Back Moth in Broccoli (Brassica oleracea var. italica)

The present field experiment was conducted at entomology research field, Institute of Agriculture and Natural Sciences, Deen Dayal Upadhyaya Gorakhpur University, Gorakhpur during Rabi, 2022-23, for studying the seasonal incidence of Diamond back moth in broccoli. The broccoli planted in plot size of 3x3.15 m in three replications with spacing of 60x45 cm during first week of November. First appearance of DBM in broccoli field was started in 49th SMW 2nd week of December, the pest population reached at peak in 2nd SMW 2nd week of January. The correlation studies showed that maximum temperature, minimum temperature is significantly negatively correlated to pest population whereas morning relative humidity showed negative non- significant correlation with the pest population, rainfall had non-significant and evening relative humidity had positively significant effect on the pest population

Comparative evaluation of shear bond strength of newer resin cement (RelyX ultimate and RelyX U200) to lithium disilicate and zirconia ceramics as influenced by thermocycling

Background/Purpose: The purpose of this study was to compare the shear bond strength of high strength ceramics to cut dentine as influenced by different resin cement types after thermocycling. Materials and Methods: Shear bond strength testing was carried out for 56 sound, freshly extracted first permanent molars. Specimens were divided at random into 2 groups (n = 28) Lithium disilicate and Zirconia. Lithium disilicate and Zirconia specimens were further subdivided depending upon luting with Rely X ultimate cement bonded with single bond universal adhesive and Rely X U200 cement. Half of the specimens of each material luted with cements were subjected to thermocycling. Shear bond strength was evaluated using Universal testing machine at a crosshead speed of 5 mm/min. Results were compared and evaluated using t-test at a significance level of 0.05. The nature of bond failure was observed under a stereomicroscope for each sample. Results: The mean difference of Lithium disilicate test specimens bonded with Rely X ultimate cement bonded with single bond universal adhesive with and without thermocycling was found to be 42.95+/-17.41MPa and 120.62+/-56.46 MPa respectively. The mean difference of Zirconia test specimens with Rely X ultimate cement bonded with single bond universal adhesive, with and without thermocycling, was found to be 8.74+/-2.90 MPa and 164.28+/-43.78 MPa respectively. The mean difference of Lithium disilicate test specimens bonded with Rely X U200 with and without thermocycling was found to be 2.36+/-0.63 MPa and 36.79.62+/-17.21MPa respectively. The mean difference of Zirconia test specimens bonded with Rely X U200 with and without thermocycling was found to be 5.96+/-3.11MPa and 122.46+/-23.01MPa respectively. Conclusion: Zirconia was found to have better shear bond strength than Lithium discilicate. The use of single bond universal adhesive improves bonding to newer higher strength ceramics such as Zirconia. Cohesive failure was predominant at cement dentine interface