Molecular cloning of enantioselective ester hydrolase from Bacillus pumilus DBRL-191

A gene from Bacillus pumilus expressed under its native promoter was cloned in Escherichia coli. Recombinant B. pumilus esterase (BPE) affects the kinetic resolution of racemic mixtures such as unsubstituted and substituted 1-(phenyl)ethanols (E approximately 33-103), ethyl 3-hydroxy-3-phenylpropanoate (E approximately 45-71), trans-4-fluorophenyl-3-hydroxymethyl-N-methylpiperidine (E approximately 10-13) and ethyl 2-hydroxy-4-phenylbutyrate (E approximately 7). The enzyme is composed of a 34-amino acid signal peptide and a 181-amino acid mature protein corresponding to a molecular weight of approximately 19.2kD and pI approximately 9.4. 3-D the structural model of the enzyme built by homology modelling using the atomic coordinates from the crystal structure of B. subtilis lipase (LipA) showed a compact minimal alpha/beta hydrolase fold.     

Assessment of Antibacterial Activity of Solanum surrattense Against Waterborne Pathogens Isolated from Surface Drinking Water of the Potohar Region in Pakistan

People dwelling in different cities of the Potohar region, Pakistan, are mostly dependent on surface water for drinking and domestic use. In an attempt to make available potable, safe water, filtration plants were constructed along with dams in the Potohar region. Water samples from these filtration plants were collected and analyzed for total and faecal coliform bacteria as well as for total viable count. Results showed that bacterial indicators of faecal contamination were numerous and significantly greater than World Health Organization recommended guidelines. Accordingly, antibacterial activity of methanolic and aqueous extracts of different parts of Solanum surrattense were assessed in vitro against waterborne pathogens. Fruits exhibited more antibacterial activities at incubation at 37°C than shoots and roots, which showed lowest Minimum Inhibitory Concentration (MIC) and zones of inhibition. These results suggest that plants offer a great potential for purification of drinking water that needs to be explored further because fruit extract of the aforementioned plant can be of practical use against waterborne pathogens.     

Antibacterial and Cytotoxic Efficacy of Extracellular Silver Nanoparticles Biofabricated from Chromium Reducing Novel OS4 Strain of Stenotrophomonas maltophilia

Biofabricated metal nanoparticles are generally biocompatible, inexpensive, and ecofriendly, therefore, are used preferably in industries, medical and material science research. Considering the importance of biofabricated materials, we isolated, characterized and identified a novel bacterial strain OS4 of Stenotrophomonas maltophilia (GenBank: {"type":"entrez-nucleotide","attrs":{"text":"JN247637.1","term_id":"341941875","term_text":"JN247637.1"}}JN247637.1). At neutral pH, this Gram negative bacterial strain significantly reduced hexavalent chromium, an important heavy metal contaminant found in the tannery effluents and minings. Subsequently, even at room temperature the supernatant of log phase grown culture of strain OS4 also reduced silver nitrate (AgNO₃) to generate nanoparticles (AgNPs). These AgNPs were further characterized by UV–visible, Nanophox particle size analyzer, XRD, SEM and FTIR. As evident from the FTIR data, plausibly the protein components of supernatant caused the reduction of AgNO₃. The cuboid and homogenous AgNPs showed a characteristic UV-visible peak at 428 nm with average size of ∼93 nm. The XRD spectra exhibited the characteristic Bragg peaks of 111, 200, 220 and 311 facets of the face centred cubic symmetry of nanoparticles suggesting that these nanoparticles were crystalline in nature. From the nanoparticle release kinetics data, the rapid release of AgNPs was correlated with the particle size and increasing surface area of the nanoparticles. A highly significant antimicrobial activity against medically important bacteria by the biofabricated AgNPs was also revealed as decline in growth of Staphylococcus aureus (91%), Escherichia coli (69%) and Serratia marcescens (66%) substantially. Additionally, different cytotoxic assays showed no toxicity of AgNPs to liver function, RBCs, splenocytes and HeLa cells, hence these particles were safe to use. Therefore, this novel bacterial strain OS4 is likely to provide broad spectrum benefits for curing chromium polluted sites, for biofabrication of AgNPs and ultimately in the nanoparticle based drug formulation for the treatment of infectious diseases.     

Prevention of violence against women and girls: A cost-effectiveness study across 6 low- and middle-income countries

BackgroundViolence against women and girls (VAWG) is a human rights violation with social, economic, and health consequences for survivors, perpetrators, and society. Robust evidence on economic, social, and health impact, plus the cost of delivery of VAWG prevention, is critical to making the case for investment, particularly in low- and middle-income countries (LMICs) where health sector resources are highly constrained. We report on the costs and health impact of VAWG prevention in 6 countries.Methods and findingsWe conducted a trial-based cost-effectiveness analysis of VAWG prevention interventions using primary data from 5 randomised controlled trials (RCTs) in sub-Saharan Africa and 1 in South Asia. We evaluated 2 school-based interventions aimed at adolescents (11 to 14 years old) and 2 workshop-based (small group or one to one) interventions, 1 community-based intervention, and 1 combined small group and community-based programme all aimed at adult men and women (18+ years old). All interventions were delivered between 2015 and 2018 and were compared to a do-nothing scenario, except for one of the school-based interventions (government-mandated programme) and for the combined intervention (access to financial services in small groups). We computed the health burden from VAWG with disability-adjusted life year (DALY). We estimated per capita DALYs averted using statistical models that reflect each trial’s design and any baseline imbalances. We report cost-effectiveness as cost per DALY averted and characterise uncertainty in the estimates with probabilistic sensitivity analysis (PSA) and cost-effectiveness acceptability curves (CEACs), which show the probability of cost-effectiveness at different thresholds. We report a subgroup analysis of the small group component of the combined intervention and no other subgroup analysis. We also report an impact inventory to illustrate interventions’ socioeconomic impact beyond health. We use a 3% discount rate for investment costs and a 1-year time horizon, assuming no effects post the intervention period. From a health sector perspective, the cost per DALY averted varies between US$222 (2018), for an established gender attitudes and harmful social norms change community-based intervention in Ghana, to US$17,548 (2018) for a livelihoods intervention in South Africa. Taking a societal perspective and including wider economic impact improves the cost-effectiveness of some interventions but reduces others. For example, interventions with positive economic impacts, often those with explicit economic goals, offset implementation costs and achieve more favourable cost-effectiveness ratios. Results are robust to sensitivity analyses. Our DALYs include a subset of the health consequences of VAWG exposure; we assume no mortality impact from any of the health consequences included in the DALYs calculations. In both cases, we may be underestimating overall health impact. We also do not report on participants’ health costs.ConclusionsWe demonstrate that investment in established community-based VAWG prevention interventions can improve population health in LMICs, even within highly constrained health budgets. However, several VAWG prevention interventions require further modification to achieve affordability and cost-effectiveness at scale. Broadening the range of social, health, and economic outcomes captured in future cost-effectiveness assessments remains critical to justifying the investment urgently required to prevent VAWG globally.

In a cost-effectiveness study, Dr. Giulia Ferrari and colleagues examine the costs and health impact of prevention of violence against women and girls in six low- and middle-income countries.     

Influence of organic additives on the incidence of root-knot nematode,Meloidogyne javanica in roots of tomato plants

Glasshouse experiment was conducted to assess the impact of green chopped leaves of four test plants (Lantana camara, Ficus virens, Kigelia pinnata and Ficus bengalensis) and two nematicides (Phorate and Carbofuran) on the plant growth parameters of tomato cv. K25 and on the root-knot development. Results revealed that all the tested treatments significantly (p = 0.05) improved plant growth parameters and reduced root-knot development compared to control. Among the tested organic additives, chopped green leaves of Lantana camara added to soil gave the highest enhancement in plant growth parameters, including plant height, fresh and dry weight, number of fruits and fruit weight with the values of 94.2 cm, 106.8 g, 31.6 g, 7.2 and 153.3 g respectively, as well as a greater reduction of Meloidogyne javanica reproduction and development but exhibiting a lower response compared to nematicides. There was also significant reduction in root-knot development in tomato plants growing in other organic additive amended soil.     

Compensating stereochemical changes allow murein tripeptide to be accommodated in a conventional peptide-binding protein

The oligopeptide permease (Opp) of Escherichia coli is an ATP-binding cassette transporter that uses the substrate-binding protein (SBP) OppA to bind peptides and deliver them to the membrane components (OppBCDF) for transport. OppA binds conventional peptides 2-5 residues in length regardless of their sequence, but does not facilitate transport of the cell wall component murein tripeptide (Mtp, L-Ala-γ-D-Glu-meso-Dap), which contains a D-amino acid and a γ-peptide linkage. Instead, MppA, a homologous substrate-binding protein, forms a functional transporter with OppBCDF for uptake of this unusual tripeptide. Here we have purified MppA and demonstrated biochemically that it binds Mtp with high affinity (K(D) ～ 250 nM). The crystal structure of MppA in complex with Mtp has revealed that Mtp is bound in a relatively extended conformation with its three carboxylates projecting from one side of the molecule and its two amino groups projecting from the opposite face. Specificity for Mtp is conferred by charge-charge and dipole-charge interactions with ionic and polar residues of MppA. Comparison of the structure of MppA-Mtp with structures of conventional tripeptides bound to OppA, reveals that the peptide ligands superimpose remarkably closely given the profound differences in their structures. Strikingly, the effect of the D-stereochemistry, which projects the side chain of the D-Glu residue at position 2 in the direction of the main chain in a conventional tripeptide, is compensated by the formation of a γ-linkage to the amino group of diaminopimelic acid, mimicking the peptide bond between residues 2 and 3 of a conventional tripeptide.     

Accuracy checks of physical beam modifier factors algorithm used in computerized treatment planning system for a 15 MV photon beam

In order to optimize the tumour dose by using wedge filters, systematic studies were carried out to investigate the accuracy of the beam modifier algorithm in a computerized treatment planning system (Theraplan plus, version 3.8). The effect of different parameters such as beam hardening and softening coefficients on the wedge factor was also studied. A 15 MV photon beam obtained from a linear accelerator was used throughout the experiments. Normalized wedge factors were determined experimentally as well as with the Theraplan plus system as a function of field size and depth in a water phantom for 15°, 30°, 45°, and 60° wedge filters. The attenuation coefficients, beam hardening coefficient, and beam softening coefficients were also determined experimentally using the 15 MV photon beam for each wedge angle. The measured normalized wedge factor was found to increase with increasing depth and field size for the 15 MV beam. The Theraplan plus calculated normalized wedge factor was found to be in good agreement with the experimental values. This study indicated that ignoring the dependence of the wedge factor on depth and field size will result in underexposure of the tumour.