Epidemiology of antibiotic resistance in culture-positive hospitalized patients in selected hospitals in Khartoum, Sudan

Objective: To study the prevelence of antibiotic resistance and the prevalent bacterial isolates in hospitalized patients in Khartoum hospitals. Materials & Methods: A cross-sectional prevalence study was carried out during the period of April–November 2015 in Khartoum; 226 bacterial cultures were included. Identification of isolates using standard biochemical tests and antibiotic susceptibilities were determined using disc diffusion method. Results were interpreted according to the standards of the British society of antimicrobial chemotherapy. Results: Eight bacterial species were isolated: Staphylococcus aureus, Enterococcus faecalis, Streptococcus spp., Klebsiella pneumoniae, Pseudomonas spp., Escherichia coli, Proteus spp., and Acinetobacter spp. S. aureus was the most prevalent, the majority of which were resistant to methicillin/oxacillin (MRSA). Cultures in our study were mainly from urine (36.7%), blood samples (37.2%), and wound cultures (19%). More than 90% of the tested isolates were resistant to cefuroxime; 54% and 73.8% of Gram-positive and Gram-negative isolates, respectively, were resistant to ceftazidime. Furthermore, there was a high meropenem resistance among Gram-negative isolates tested. Multi-resistant Acinetobacter spp. as well as vancomycin-resistant S. aureus was isolated. Gram-negative isolates showed good susceptibilities to aminoglycosides as well as ciprofloxacin. However, the high resistance rate to these antibiotics was observed in Gram-positive isolates in these hospitals. Conclusion: Methicillin-resistant S. aureus was the most prevalent organism. Gramnegative isolates showed good susceptibilities to aminoglycosides and ciprofloxacin. There were high resistance rates to cefuroxime, ceftazidime, and meropenem. Five vancomycin-resistant S. aureus were identified

Equilibrium, Kinetic and Thermodynamic studies of adsorption of cationic dyes from aqueous solution using ZIF-8

Zeolitic imidazolate framework-8 (ZIF-8) is one type of (MOFs) that has been synthesized and characterized and detailed analysis of Crystal violet (CV) and Malachite Green (MG) adsorption behaviour. Impact of different variables on batch method as a function of solution pH, concentration of CV and MG, dose of ZIF-8, Contact time and temperature were analyzed and optimal test conditions were determined. Scanning electron microscopy (SEM) was used to measure surface alterations of the ZIF-8. The surface area and volume of the pores were found to be 495.199 m2g–1 and 0.026 cm3g−1, respectively as determined by the Brunauer-Emmett-Teller (BET) test. ZIF-8 point of zero charging (pHPZC) was calculated and was found 7.9. Adsorption data were modeled on isotherms for adsorption of Langmuir, Freundlich, Dubinin–Radushkevich and Temkin. Equilibrium data from the adsorption processes showed that the Langmuir is fitted with CV and MG adsorption. Pseudo-first order, pseudo-second order, kinetic models Weber and Morris and Elovich were used to analyze the kinetic data obtained at different initial dye concentrations. The kinetics of adsorption showed that the action in adsorption adopted the processes of pseudo-second - order kinetic model and chemisorption. The thermodynamic parameter such as ∆G, ∆S and ∆H has been determined. Study of thermodynamics for adsorption indicated the reaction was endothermal and spontaneous

Preparation of Low Molecular Weight Natural Polymers by gamma-Radiation and Their Growth Promoting Effect on Zea Maize Plants

Preparation of oligosaccharides from chitosan and Na-alginate were done using ?-rays and H2O2 as oxidizing agent. Structural and molecular weight changes of such oligosaccharides were determined by GPC, FT-IR and UV-Vis. spectroscopy. FT-IR and UV-Vis. studies revealed that during radiation degradation process, the main polysaccharide chain structure was almost remained. The effects of spraying 100 ppm of oligochitosan or oligoalginate or both of them with different ratios on the growth of zea maize plants showed an enhancement of plant growth performance and the productivity at the same time suggesting their possible use in agriculture purposes as growth promoters for plants

Strukturna i elektronska svojstva bbc selena pod visokim tlakom

Full-potential linearized augmented plane-wave method (FP-LAPW) within the density functional theory is applied to study the structural and electronic properties of selenium in the bcc phase at high pressures. We used local density approximation with and without generalized gradient correction based on exchange-correlation energy optimization. We have determined the full set of first-order elastic constants, which have not been established earlier experimentally or theoretically. The elastic moduli show linear dependence on pressure. The calculated energy allowed us to investigate several structural properties such as lattice parameter, bulk modulus and its pressure derivative. Our calculated lattice parameter is found to be in reasonable agreement with experimental result. The electronic band structure and the density of states at various pressures are also calculated to show that there is a possibility for these compounds to become metallic at high pressures. Further, we have calculated the electronic specific heat coefficient, which decreases with the increase of pressure.Primjenom metode lineariziranih proširenih ravnih valova s potpunim potencijalom, u okviru teorije funkcionala gustoće, proučavali smo strukturna i elektronska svojstva selena u bcc fazi na visokim tlakovima. Primijenili smo približenje lokalne gustoće sa i bez poopćene gradijentne popravke primjenom optimizacije energije korelacije i izmjene. Odredili smo potpun skup elestičnih konstanti prvog reda koje ranije nisu bile određene ni eksperimentalno ni teorijski. Moduli eleastičnosti pokazuju linearnu ovisnost o tlaku. Na osnovi izračunatih energija mogli smo istražiti više strukturnih svojstava, kao što su parametar rešetke, volumni modul stlačivosti i njegova derivacija po tlaku. Naš izračunat parametar rešetke je u dobrom slaganju s eksperimentalnim rezultatom. Također smo izračunali strukturu elekronskih vrpci i gustoće stanja da bismo ukazali na mogućnost da na visokim tlakovima selen u fazi bcc može postati metal. Nadalje, izračunali smo koeficijent elektronske specifične topline koji se smanjuje s porastom tlaka

The combined effect of environmental thermal drop and isotonicity on metabolic stores of the teleost, Oreochromis niloticus

AbstractFour experimental regimes were designed to test the capacity of the Nile tilapia Oreochromis niloticus to make use of the energy saved form osmoregulation in an isotonic medium in overcoming the Winter Stress Syndrome (WSS). Fish either pre- acclimated to freshwater or isotonic salinity at 25°C were transferred directly to freshwater or an isotonic medium (ca. 12‰) at 14°C. Fish were killed 3, 6, 24, 48, 72 and 168h after transfer. The mobilisation and use of lipids from perivisceral and muscle fat observed in the study seem to be a direct response to cold stress as well as the associated fasting, these effects were salinity dependent being lesser at the isotonic salinity. The energy needs of fish diminish in cold conditions when the salinity of the environment approaches the isotonicity. The absence of any significant changes in muscle and water content indicated that the changes of muscle lipid are true and lipid was the sole source of energy upon thermal drop. The changes of blood haemoglobin levels throughout the four experimental regimes may indicate that the isotonic medium acclimated tilapia showed less haematological disturbance due to cold stress. Results from this experimental study recommend that the pre-acclimation of the Egyptian strain of Nile tilapia, O. niloticus, to an environmental salinity close to the isotonicity may improve fish cold tolerance