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

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

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

Environmental isotonicity improves cold tolerance of Nile tilapia, Oreochromis niloticus, in Egypt

AbstractThe limited ability of Oreochromis niloticus to tolerate low temperatures during winter in temperate and some subtropical region, such as in Egypt, is of major economic concern. The present study was aimed to improve the cold tolerance of Nile tilapia, O. niloticus, by using the well documented phenomena of saving energy consumption for osmoregulation in isotonic medium to decrease the physiological response to cold stress at winter months and may solve the Winter Stress Syndrome (WSS) and the over-wintering problems. Fish which were either pre-acclimated to freshwater or isotonic salinity at 25°C were transferred directly to freshwater or isotonic medium (12‰) at 14°C. Fish were killed 3, 6, 24, 48, 72 and 168h after transfer. In the isotonic medium pre-acclimated fish, it is shown that the effect of cold stress on the increment of plasma glucose level was much lower than that in fresh water. From the observations of Na+, K+, Mg2+-ATPase enzyme activity we conclude that less disturbance of ionic balance caused by cold tolerance was occurred in the isotonic point water than in the fresh water. The results of the acetylcholinesterase specific activity showed that, brain enzyme was inhibited by cold stress, and that the disruption of the cholinergic function induced by cold stress was much more pronounced in fresh water pre-acclimated tilapia than in isotonic point water pre-acclimated fish. Results from this study recommend that pre-acclimation of Nile tilapia, O. niloticus, to an environmental salinity close to the isotonicity, before winter onset, may improve their cold tolerance