Sensitivity of extended-spectrum β-lactamases producing Enterobacteriaceae isolates to Annona squamosa extracts

Powdered leaves of Annona squamosa (L.) were extracted with ethanol and methanol using percolation method. The extracts were tested for antimicrobial activity against clinical isolates of confirmed extended spectrum β-lactamase producing Escherichia coli, Klebsiella pneumoniae and Proteus specie using disc diffusion method. The extracts were further subjected to phytochemical screening for the presence of secondary metabolites. Sensitivity test results showed that methanol extract of the plant was only active on E. coli at 30 μg/disc concentration with 7mm zone of inhibition but inactive against P. specie even at 60 μg/disc concentration. Ethanol extract of the plant was active against all isolates only at 60 μg/disc concentration with P. specie forming slightly wider zone of inhibition (8mm) and the remaining isolates having 7mm zone diameter. The results of phytochemical screening indicated the presence of reducing sugars, saponins and steroids in either or both extracts.Keywords: Sensitivity, ESBLs, Enterobacteriaceae, Annona squamosa, Extract

Effect of Paraquat Herbicide on Oxidative Stress Biomaker Enzyme Activities in C. Gariepinus

Toxicity assessment was conducted for 96hr exposure duration using synthetic herbicide (paraquat dichloride 276g/L) on Claris gariepinus with mean weight range of 27.2 - 29.7g and mean length 10.95 -15.5cm. They were exposed to varying herbicide concentrations of 0.0, 3.45, 6.90, 10.35 and 13.5mg/L with 5-levels exposure concentrations in a Completely Randomized Design (CRD). Liver, gills and kidney tissues were analyzed for oxidative stress enzymes activities using Solarbio science assay kit (BC1170, 0170 and 0020). Four days lethal concentration (LC50) value for 96hr was found to be 7.298mg/L. The treated fish displayed erratic swimming with irregular opercular movement, loss of reflex, mucus secretion and increased air gulping with the increasing concentration of the herbicide compared with the control fish. Antioxidant biomarkers activities revealed that Glutathione S-transferase (GST), catalase (CAT) and superoxide dismutase (SOD) activities increased significantly (P<0.05) in the gills, liver and kidney tissues at higher concentrations compared with control. It can be deduced that alterations in the oxidative stress enzyme activities in the exposed fish to paraquat exert toxic effect on the liver, gills and kidney tissues. It is therefore recommended that appropriate authorities should develop strategies on minimizing the indiscriminate use of synthetic herbicides due to their impact on aquatic biota such as fish in order to reduce its potential risk to other non-target organisms. Keywords: Clarias gariepinus, Lethal concentration, Oxidative Stress enzymes, Paraquat, Toxicity assessmen

Prevalence of extended spectrum β-lactamases (esbls) among enterobacteriaceae in murtala mohammed specialist hospital, Kano, Nigeria

Confirmed variants of enterobacteriaceae isolated from 143 patients that attended Murtala Mohammed Specialist Hospital Kano, were screened for extended spectrum β-lactamases (ESBLs) production using Clinical Laboratory Standards Institute (CLSI) breakpoint. Suspected ESBLs producers were subjected to confirmation using Disc Replacement Method (DRM). Standard discs of augmentin {AMC 30μg (Oxoid, England)}, ceftriaxone {AUF 30μg (Oxoid, England)} and ceftazidime {RP 30μg (Oxoid, England)} were used in the screening. Of the 143 isolates screened, 114 (79.72%) were Gram negative isolates belonging to the family enterobacteriaceae. Among the enterobacteriaceae isolates screened, the results of CLSI breakpoint test showed that 76 (66.7%) were ESBLs producers viz: Citrobacter spp. (3), Enterobacter spp. (2), E. coli (28), Klebsiella spp. (18), Morganella morganii (7), Proteus spp. (13), Salmonella spp. (1), Serratia spp. (1), Shigella spp. (2) and Yersinia spp (1). On subjecting the CLSI positive isolates to DRM, only 47 (41.2%) were confirmed ESBLs producers. These include; Citrobacter spp. (1), E. coli (20), Klebsiella spp. (12), Morganella morganii (4), Proteus spp. (8), Salmonella spp. (1) and Shigella spp. (1). ESBLs occur at an alarming rate among enterobacteriaceae isolates in Kano which calls for government intervention in the healthcare setting

Hepatorenal toxicity studies of sub-chronic administration of calyx aqueous extracts of hibiscus sabdariffa in albino rats

Hibiscus sabdariffa Linn has been reported to have a broad range of therapeutic effects. Subchronic effects of calyces aqueous extracts of H. Sabdariffa were studied in albino rats. Twenty four (24) albino rats were randomly divided into six (6) groups of four rats each. Group A, was fed with growers mesh and distilled water as control. Groups B to F were administered orally with the aqueous extract at 1, 2, 3, 4 and 5g /kg body weight respectively and the treatment period was 28 days. A decreased in weights of the animals were observed at all dose levels. The activities of liver maker enzymes (alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase) and direct bilirubin increased significantly (p0.05) increase in concentrations of total protein and albumin were observed in comparison to the control. The renal indices, urea, uric acid and creatinine in the treated groups were significantly increased compared to the control but a significant decrease (

Gamma ray measurements of the 1991 November 15 solar flare

The 1991 November 15 X1.5 flare was a well observed solar event. Comprehensive data from ground-based observatories and spacecraft provide the basis for a contextual interpretation of gamma-ray spectra from the Compton Gamma Ray Observatory (CGRO). In particular, spectral, spatial, and temporal data at several energies are necessary to understand the particle dynamics and the acceleration mechanism(s) within this flare. X-ray images, radio, Ca XIX data and magnetograms provide morphological information on the acceleration region [4,5], while gamma-ray spectral data provide information on the parent ion spectrum. Furthermore, time profiles in hard X-rays and gamma-rays provide valuable information on temporal characteristics of the energetic particles. We report the results of our analysis of the evolution of this flare as a function of energy (∼25 keV–2.5 MeV) and time. These results, together with other high energy data (e.g. from experiments on Yohkoh, Ulysses, and PVO) may assist in identifying and understanding the acceleration mechanism(s) taking place in this event

Extended γ‐ray emission in solar flares

During the solar flare events on 11 and 15 June 1991, COMPTEL measured extended emission in the neutron capture line for about 5 hours after the impulsive phase. The time profiles can be described by a double exponential decay with decay constants on the order of 10 min for the fast and 200 min for the slow component. Within the statistical uncertainty both flares show the same long‐term behaviour. The spectrum during the extended phase is significantly harder than during the impulsive phase and pions are not produced in significant numbers before the beginning of the extended emission. Our results with the measurements of others allow us to rule out long‐term trapping of particles in non‐turbulent loops to explain the extended emission of these two flares and our data favour models based on continued acceleration

A Numerical Algorithm for Solving Stiff Ordinary Differential Equations

An advanced method using block backward differentiation formula (BBDF) is introduced with efficient strategy in choosing the step size and order of the method. Variable step and variable order block backward differentiation formula (VSVO-BBDF) approach is applied throughout the numerical computation.The stability regions of the VSVO-BBDFmethod are investigated and presented in distinct graphs.The improved performances in terms of accuracy and computation time are presented in the numerical results with different sets of test problems. Comparisons are made between the proposed method and MATLAB’s suite of ordinary differential equations (ODEs) solvers, namely, ode15s and ode23s

Energetic proton spectra in the 11 June 1991 solar flare

The June 11, 1991 gamma-ray flare seen by the Compton Gamma-ray Observatory (CGRO) displays several features that make it a dynamic and rich event. It is a member of a class of long duration gamma-ray events with both 2.223 MeV and greater than 8 MeV emission for hours after the impulsive phase. It also contains an inter-phase between the impulsive and extended phases that presents a challenge to the standard gamma-ray line (GRL) flare picture. This phase has strong 2.223 MeV emission and relatively weak 4.44 MeV emission indicative of a very hard parent proton spectrum. However, this would indicate emission greater than 8 MeV, which is absent from this period. We present the application of new spectroscopy techniques to this phase of the flare in order to present a reasonable explanation for this seemly inconsistent picture

Green Corrosion Inhibitory Potentials of Cassava Plant (<em>Manihot esculenta</em> Crantz) Extract Nanoparticles (CPENPs) in Coatings for Oil and Gas Pipeline

Internal and external corrosion affects oil and gas pipelines and were discussed in this chapter. Corrosion inhibitors are one of the methods that can be used to achieve corrosion control and prevention. The main discussion in this chapter was the use of cassava plant (Manihot esculenta Crantz) extract nanoparticles (CPENPs) as an additive in coatings to serve as a green corrosion inhibitor for oil and gas pipeline. Trace elements, such as O, Si, Ca, K, Fe and S, which are hetero-atoms, have been identified in CPENPs. Elements like Si and Ca would also improve the strength of coatings as well as reduce corrosion rate of coated metals. It has also been revealed that CPENPs is composed of the following compounds SiO2, CaCO3, Ca2(SO4)2H2O and CaC2O4(H2O), which would help in improving the mechanical properties of alloys, composites and coatings. SiO2 if added to coatings will improve the coating hardness, while the presence of CaCO3 in coatings will form a precipitate that will serve as a protective film on the surface of the metal, thereby protecting the metal from corrosion. The nature of bond and organic compounds that exist in the CPENPs was also discussed

QSMSOR Iterative Method for the Solution of 2D Homogeneous Helmholtz Equations

In this paper, we consider the numerical solutions of homogeneous Helmholtz equations of the second order. The Quarter-Sweep Modified Successive Over-Relaxation (QSMSOR) iterative method is applied to solve linear systems generated form discretization of the second order homogeneous Helmholtz equations using quarter sweep finite difference (FD) scheme. The formulation and implementation of the method are also discussed. In addition, numerical results by solving several test problems are included and compared with the conventional iterative methods