Isolation of ESBL-producing gram-negative bacteria and in silico inhibition of ESBLs by flavonoids

AbstractObjectiveTo evaluate nosocomial accounts of 426 extended spectrum β-lactamase (ESBL)-producing strains from 705 isolates of 9 pathogenic gram-negative bacteria in vitro. We analysed the genetic divergence of ESBLs by constructing a phylogenetic tree and modelled flavonoid inhibition of ESBLs with in silico molecular docking to determine effective control options.MethodsNine ESBL-producing bacteria were isolated from urine samples and their antibiograms were determined by the disc-diffusion method. Comparative models of the 9 ESBL enzymes were generated computationally using reference sequences, and validated by Ramachandran plots. Molecular docking with 11 flavonoids was conducted against the ESBL models.ResultsIsolated strains were floridly multidrug-resistant. From the docking study, the predicted minimum energy value of amikacin was −8.108 kcal/mol against the wild type TEM-1 ESBL of Acinetobacter baumannii, while the docking value against the mutant type Escherichia coli was −7.388 kcal/mol. The docking scores obtained corroborated the in vitro results showing that the antibiotic was incapable of controlling the ESBL of the mutant strain. Among 11 flavonoids tested against the mutant ESBL of E. coli, epigallocatechin 3-gallate and eriodictyol, with docking scores of −9.448 and −8.161 kcal/mol, respectively, were the most effective, with drug-likeness scores of 0.39 and 1.37, respectively, compared to 1.03 for amikacin.ConclusionDocking scores and drug-likeness scores indicated that flavonoids are compelling alternative antimicrobial agents that could serve as complementary therapy for newly arising ESBL-producing bacteria. Phylogenetic tree analysis elucidated the genetic relationship of the 9 ESBL serotypes

In vitro antibacterial efficacy of plants used by an Indian aboriginal tribe against pathogenic bacteria isolated from clinical samples

AbstractObjectivesTo evaluate antibacterial efficacies of 21 medicinal plants used by an Indian aboriginal tribe against infectious diseases caused by bacteria isolated from clinical samples.MethodsStandard biochemical procedures were followed for identifying bacteria that were isolated from several clinical samples. All of the bacterial strains were subjected to antibiotic sensitivity tests by Kirby–Bauer's disc diffusion method. From antibiograms of isolated Gram-positive and Gram-negative bacteria, it was discernible that samples were multidrug resistant (MDR). The methanol leaf-extract of Solanum xanthocarpum was subjected to thin layer chromatography (TLC) for phytochemical analysis. Molecular docking of β-lactamase enzyme of Escherichia coli with phytochemicals of S. xanthocarpum was performed to locate effective compounds.ResultsThe most effective 5 plants, which caused the size of the zone of inhibition to range from 21 to 27 mm, were Buchanania latifolia, Careya arborea, Ocimum tenuiflorum, Senna alata and S. xanthocarpum, for MDR bacteria. S. xanthocarpum had the lowest MIC value of 0.67 mg/ml and the lowest MBC value of 1.51 mg/ml against E. coli. In the TLC study, 9 spots of methanol leaf-extract of S. xanthocarpum were recorded with two solvent systems. The phytochemicals of S. xanthocarpum, solasodine and stigmasterol glucoside had the highest docking score values, −10.868 kcal/mol and −10.439 kcal/mol, respectively, against β-lactamase.ConclusionThis study could prove in vitro antimicrobial efficacy of 5 uncommon plants against MDR pathogenic bacteria. Solasodine and stigmasterol glucoside were computationally recorded as the best controlling chemicals from the plant S. xanthocarpum

Robust Coordinated Design of PSS and TCSC using PSO Technique for Power System Stability Enhancement

Power system stability improvement by coordinated design of a Power System Stabilizer (PSS) and a Thyristor Controlled Series Compensator (TCSC) controller is addressed in this paper. Particle Swarm Optimization (PSO) technique is employed for optimization of the parameterconstrained nonlinear optimization problem implemented in a simulation environment. The proposed controllers are tested on a weakly connected power system. The non-linear simulation results are presented for wide range of loading conditions with various fault disturbances and fault clearing sequences as well as for various small disturbances. The eigenvalue analysis and simulation results show the effectiveness and robustness of proposed controllers to improve the stability performance of power system by efficient damping of low frequency oscillations under various disturbances

On Indexed Riesz Summability of an Infinite Series

Generalizing the results of Seyhan and Misra et al. a theorem on indexed-Reisz summability has been established

Role of Serum creatinine in forecasting the outcome after cardiac surgery beyond acute kidney injury-A Cross sectional Study

Objectives: Acute kidney damage (Acute kidney injury [AKI]) is defined by elevations in serum creatinine levels that occur after surgery. In cardiac surgery, creatinine is a critical determinant. This study highlights the detection of serum creatinine as an early diagnostic and predictive marker of AKI following coronary artery bypass grafting (CABG) and to estimate the serum creatinine concentrations before and at 24 and 48 h after CABG. Methods: It is a single center, Cross-sectional study. Patients from Cardiothoracic and Vascular surgery undergoing CABG in Sri Ramachandra Medical College and Research Institute were included in the study. A total of 80 cases were included in the study. The method used for measurement of serum creatinine is by modification of kinetic Jaffe reaction. Data were analyzed using Stata/SE version 16.0 and represented in terms of means, standard deviation at 95% confidence level and t’ test was performed as statistical analysis and p<0.05 indicates significance. Sigma plot software version 10.0 was used to draw the standard error mean graphs. Results: The serum creatinine values at 24 h after the surgery was statistically higher than the preoperative values at 5% significance level (p=0.04). The serum creatinine values 48 h after the surgery was also statistically higher than the preoperative values at 1% significance level (p=0.001). The serum creatinine values 48 h after surgery are highly significant (p=0.001) when compared to the serum creatinine values 24 h after surgery. Conclusion: Before an increase in serum creatinine level is detected, over 50% of renal function must be lost. It was concluded that serum creatinine is an inadequate and delayed marker of AKI

Development of a novel forward dynamic programming method for weather routing

This paper presents a novel forward dynamic programming method for weather routing to minimise ship fuel consumption during a voyage. Compared with traditional weather routing methods which only optimise the ship's heading, while the engine power or propeller rotation speed is set as a constant throughout the voyage, this new method considers both the ship power settings and heading controls. A float state technique is used to reduce the iterations required during optimisation and thus save computation time. This new method could lead to quasiglobal optimal routing in comparison with the traditional weather routing methods

Association of nitrosative and oxidative stress in young type 2 diabetic patients

Background: Nitric oxide levels play an important role in the pathogenesis of endothelial dysfunction in type 2 diabetes mellitus (DM). Aim of the study was to assess the association between serum nitric oxide levels (NOx), Oxidant load (FOX2) and total antioxidant status (FRAP) with fasting blood sugar (FBS)  in type 2 diabetic patients.Methods: Serum concentration NOx was measured by Griess method in seventy six type 2 diabetic patients with age & sex matched (aged 45-65yrs) controls. Serum total oxidant load was estimated by Ferrous oxidation product in xylenol orange version 2 (FOX2), total antioxidant status by ferric reducing capacity of serum (FRAP) .FBS was estimated by commercial kits adapted to autoanalyser.Results: Significant difference was observed in serum NO level between patients and controls (78.6+ 8.6 vs. 37.59+ 4.19μmol/L: p<0.000). Significantly high FOX 2 levels (12.4+ 2.6μmol/L vs. 4.33+ 1.7 μmol/L) and lower FRAPS level was observed in patients as compared to controls (61.37+31.64 μmol/L vs. 226.46+ 15.23 μmol/L).Conclusions: Hyperglycemia leads to nitrosative stress (increase NO level) and oxidative stress by increasing total oxidant load (FOX2), decreasing antioxidant capacity (FRAP)

Ophthalmological Manifestations of Oculocutaneous and Ocular Albinism: Current Perspectives

Albinism describes a heterogeneous group of genetically determined disorders characterized by disrupted synthesis of melanin and a range of developmental ocular abnormalities. The main ocular features common to both oculocutaneous albinism (OCA), and ocular albinism (OA) include reduced visual acuity, refractive errors, foveal hypoplasia, congenital nystagmus, iris and fundus hypopigmentation and visual pathway misrouting, but clinical signs vary and there is phenotypic overlap with other pathologies. This study reviews the prevalence, genetics and ocular manifestations of OCA and OA, including abnormal development of the optic chiasm. The role of visual electrophysiology in the detection of chiasmal dysfunction and visual pathway misrouting is emphasized, highlighting how age-associated changes in visual evoked potential (VEP) test results must be considered to enable accurate diagnosis, and illustrated further by the inclusion of novel VEP data in genetically confirmed cases. Differential diagnosis is considered in the context of suspected retinal and other disorders, including rare syndromes that may masquerade as albinism