Surface modification of thin film composite forward osmosis membrane using graphene nanosheets for water desalination.

In this study, the main motivation of this work is desalination of water for irrigation arid area such as Sidri- Baba basins- south Sinai, Egypt. Also, the novelty of this work is modification of TFC surface membrane by mix of HA, DA and GO to get high performance of FO technique. Interfacial polymerization was employed to modify a thin-film composite (TFC) membrane for forward osmosis (FO) applications; moreover, graphene oxide (GO) nanosheets (GONs), a dopamine solution (DA), and naturally accessible humic acid (HA) were modified on a polyethersulfone (PES) substrate. The effects of the different quantities of GO, HA, and DA on the membrane surfaces, as well as their various cross-sectional morphologies and FO-desalination capabilities, were investigated. The integrated TFC membrane containing appropriate GO, HA, and DA blends outperformed the control membrane, obtaining high water flux, and high salt rejection. Furthermore,.

Microstructure of gamma-ray developed polymeric nanocomposite respecting cesium and cobalt removal from aqueous solutions.

The nanoparticles of fly ash (FA) were obtained by high energy ball milling of their parent Class C kind for subsequent synthesis of poly(acrylamide-acrylic acid)/fly ash (poly(AM-AA)/FA) nanocomposite. The gamma-radiation induced polymerization was applied to achieve this concern. Different techniques were utilized to characterize such nanocomposite. The sorption abilities of the synthesized nanocomposite toward 60Co2+ and 134Cs + radionuclides were evaluated using batch and fixed-bed column approaches. Batches were designed at constants of solution pH (6.5-7.0 ± 0.02), nanocomposite particle size and dosage (106-250 µm and 0.1 L/g, respectively). The microstructure of such nanocomposite (<100 nm) was mainly amorphous with porous rough surfaces containing homogenous distribution of the incorporated nano-FA. About 56.46 and 47.9 mg/g of Co2+ and Cs+ were sorbed at equilibrium with an ion exchange reaction mechanism. Langmuir, Freundlich and Dubinin-Radushkevich D-R isotherm model parameters were calculated indicating the favorability of all sorption processes. The spontaneous and endothermic natures of sorption were observed by the calculated ΔG° and ΔH° thermodynamic parameters, respectively. Thomas, Yoon-Nelson and Adams Bohart models were fitted to the fixed-bed column data at varied conditions. The predicted sorption capacities of Thomas were very close to those obtained experimentally. Modeling of the fixed-bed column data dominates that the external mass transfer kinetics was predominant in the initial parts of the fixed-beds. Values required for retaining 50% of the initial sorbate concentration were extended from 89.05 to 68.55 to 177.2 and 149.3 min for 60Co2+ and 134Cs + radionuclides, respectively, by increasing bed depth from 1.5 to 3.0 cm. Modification of FA to its nano-scale form with the subsequent synthesis of a nanocomposite material having sorption capabilities made a duplicate beneficial environmental concern.

Increasing 2 -Bio- (H2 and CH4) production from food waste by combining two-stage anaerobic digestion and electrodialysis for continuous volatile fatty acids removal.

A novel approach of using two stage anaerobic digestion coupled with electrodialysis technology has been investigated. This approach was used to improving bio hydrogen and methane yields from food waste while simultaneously producing a green chemical feedstock. The first digester was used for hydrogen production and the second digester was used for methane production. The first digester was combined with continuous separation of volatile fatty acids using electrodialysis. The concentrations of carbohydrates, proteins and fats in the prepared food waste were 22.7%, 5.7% and 5.2% respectively. Continuous removal of volatile fatty acids during fermentation in the hydrogen digester not only increased hydrogen yields but also increased the production rate of volatile fatty acids. As a result of continuous VFA separation, hydrogen yields increased from 17.3 mL H2/g VS fermenter to 33.68 mL H2/g VS fermenter. Methane yields also increased from 28.94 mL CH4/g VS fermenter to 43.94 mL CH4/g VS fermenter. This represents a total increase in bio-energy yields of 77.1%. COD reduced by 73% after using two stage anaerobic digestion, however, this reduction increased to 86.7% after using electrodialysis technology for separation of volatile fatty acids. Electrodialysis technology coupled with anaerobic digestion improved substrate utilization, increased bioenergy yields and looks to be promising for treating complex wastes such as food waste.

[Paraspinous Sagittal Shift (PSSS): a novel approach for transmuscular quadratus lumborum block for hip surgery analgesia - four case reports]. / Paraespinhoso Sagital (PES): nova técnica no bloqueio transmuscular do quadrado lombar para analgesia em cirurgia de quadril ­ relato de quatro casos.

BACKGROUND: Effective pain management is essential for successful rehabilitation and enhanced recovery after joint arthroplasty. The Quadratus Lumborum Block (QLB) has mostly been described for abdominal surgery, but has also recently been applied to hip surgery patients. METHODS: In the following cases series, we suggest a modification of the TQL block described as Paraspinous Sagittal Shift QL block. We hypothesize that this approach may allow better LA spread to the lumbar nerve roots. Such technique involves a craniocaudal approach of LA injection between the QL and PM muscles behind the Anterior Thoracolumbar Fascia (ATLF) at the level of L4. Cases were provided with combined GA and PSSS modification of QL block via a single shot or catheter technique. RESULTS: Sensory distribution of the block in the four patients studied was found to cover the area between the T11-12 and L4-5 dermatomes. Spread of the injectate was confirmed via an A-P fluoroscopy imaging of the lumbosacral spine after injection of a mixture of LA and a contrast in the plane between the QL and PM muscles in two cases. CONCLUSIONS: The PSSS technique for TQL block may be beneficial as a part of multimodal analgesia for hip surgeries. This technique may be a safe alternative to psoas compartment block; however, future comparative studies are recommended. The PSSS technique for TQL block also may provide an easy access for catheter insertion.

Paraspinous Sagittal Shift (PSSS): a novel approach for transmuscular quadratus lumborum block for hip surgery analgesia - four cases report / Paraespinhoso Sagital (PES): nova técnica no bloqueio transmuscular do quadrado lombar para analgesia em cirurgia de quadril - relato de quatro casos

Abstract Background: Effective pain management is essential for successful rehabilitation and enhanced recovery after joint arthroplasty. The Quadratus Lumborum Block (QLB) has mostly been described for abdominal surgery, but has also recently been applied to hip surgery patients. Methods: In the following cases series, we suggest a modification of the TQL block described as Paraspinous Sagittal Shift QL block. We hypothesize that this approach may allow better LA spread to the lumbar nerve roots. Such technique involves a craniocaudal approach of LA injection between the QL and PM muscles behind the Anterior Thoracolumbar Fascia (ATLF) at the level of L4. Cases were provided with combined GA and PSSS modification of QL block via a single shot or catheter technique. Results: Sensory distribution of the block in the four patients studied was found to cover the area between the T11-12 and L4-5 dermatomes. Spread of the injectate was confirmed via an A-P fluoroscopy imaging of the lumbosacral spine after injection of a mixture of LA and a contrast in the plane between the QL and PM muscles in two cases. Conclusions: The PSSS technique for TQL block may be beneficial as a part of multimodal analgesia for hip surgeries. This technique may be a safe alternative to psoas compartment block; however, future comparative studies are recommended. The PSSS technique for TQL block also may provide an easy access for catheter insertion.

Resumo Justificativa: O controle efetivo da dor é essencial para a reabilitação bem-sucedida e melhor recuperação após artroplastia. O bloqueio do quadrado lombar tem sido descrito principalmente para cirurgia abdominal, mas recentemente também tem sido usado para pacientes submetidos a cirurgia de quadril. Método: Na série de casos a seguir, sugerimos modificação na técnica do bloqueio transmuscular do quadrado lombar descrita como bloqueio do Quadrado Lombar Paraespinhoso Sagital (PES). Nossa hipótese é de que a técnica permitiria melhor dispersão do anestésico local para as raízes dos nervos lombares. Tal técnica envolve acesso craniocaudal para injeção do anestésico local entre os músculos quadrado lombar e psoas maior atrás da Fáscia Toracolombar Anterior (FTLA) no nível de L4. Os casos foram submetidos a anestesia geral combinada a técnica modificada PES para bloqueio do quadrado lombar via injeção única ou cateter. Resultados: Verificou-se que a distribuição sensorial do bloqueio nos quatro pacientes estudados cobriu a área entre os dermátomos T11-12 e L4-5. A dispersão do anestésico injetado foi confirmada via fluoroscopia A-P da coluna lombo-sacral após injeção, em dois casos, de solução de anestésico local e contraste no plano entre os músculos quadrado lombar e psoas maior. Conclusões: A técnica PES para bloqueio transmuscular do quadrado lombar pode ser benéfica como componente da analgesia multimodal para cirurgias de quadril. A técnica pode ser alternativa segura para bloqueio do compartimento psoas; entretanto, estudos comparativos futuros são recomendados. A técnica PES para bloqueio transmuscular do quadrado lombar pode também fornecer acesso fácil para inserção do cateter.

Erector spinae versus paravertebral plane blocks in modified radical mastectomy: Randomised comparative study of the technique success rate among novice anaesthesiologists.

BACKGROUND AND AIMS: Regional analgesia may play a role in pain management during breast surgery. Ultrasound approach to paravertebral block may be challenging. This study compared success rates of ultrasound-guided erector spinae plane block (ESPB) versus parasagittal in-plane thoracic paravertebral block among senior anaesthesia residents in modified radical mastectomy. METHODS: One hundred and two female patients undergoing modified radical mastectomy were randomly categorized into PARA group receiving sagittal in-plane paravertebral block and ESPB group receiving erector spinae plane block. The block in the 1st six cases in each group was done by an experienced consultant as a demonstration for three anaesthesia residents not experienced in either block. Primary endpoint was assessing success rate of the blocks. Secondary endpoint was the haemodynamic response to skin incision and postoperative analgesia. RESULTS: All patients were females undergoing modified radical mastectomy. Success rate among residents was 100% in ESPB versus 77.8% in PARA group (P = 0.002). Duration to perform the block was less in ESPB group (4.39 ± 1.2 min) than PARA group (8.18 ± 2.42 min) (P < 0.0001). Guidance frequency by consultants was significantly higher in PARA than ESPB group. Time to 1st analgesic requirement and morphine consumption postoperatively were insignificant between the groups. There was no significant difference regarding haemodynamics. CONCLUSION: ESPB may be a simple and safe alternative to parasagittal in-plane paravertebral block to provide postoperative analgesia in modified radical mastectomy especially in novice practitioners. It provides equivalent profile of postoperative analgesia with less time to perform the block.

Lanthanide complexes of spiropyran photoswitch and sensor: spectroscopic investigations and computational modelling.

A number of novel lanthanide (Gd3+, Sm3+, and Tb3+) complexes of the 1',3'-dihydro-8-methoxy-1',3',3'-trimethyl-6-nitrospiro[2H-1-benzopyran-2,2'-(2H)-indole] (spiropyran; SP), a widely studied molecular photoswitch, were investigated. Comparative spectroscopic (absorption and fluorescence) and kinetic investigations of the stimulated photochromic and solvatochromic behavior were carried out in different media. SP embedded in a rigid thin film of poly(methylmethacrylate) might be exploited profitably as an optical sensor for the identification of a solvent's nature. Furthermore, thermodynamic parameters, in particular, Gibbs' free energy change (ΔG°), were derived using density functional theory quantum chemical calculations with the SP and merocyanine coloured form. The model used was the B3LYP/6-31G(d,p)/SCRF = (SMD, solvent) and its time-dependent extension procedure was used to quantitatively explain the structural isomerization in response to a variety of stimuli, such as light, solvent nature, lanthanide(iii) ions, and macromolecular support. These findings might be useful for the design of photoswitchable and energy transfer materials and their related fields.

The Shikani Optical Stylet as an Alternative to Awake Fiberoptic Intubation in Patients at Risk of Secondary Cervical Spine Injury: A Randomized Controlled Trial.

BACKGROUND: Conventional intubation of the trachea and consequent prone positioning of anesthetized patients with cervical spine instability may result in secondary neurological injury. Historically, flexible fiberoptics used to be the chief choice for patients presenting with cervical spine instability surgery with difficult airway. Recently, the rigid optical stylets have shown promise in assisting difficult intubations. PURPOSE: The aim of the present study was to compare the efficacy of Shikani optical stylet (SOS) with the flexible fiberscope for awake intubation in patients with cervical spine instability. PATIENTS AND METHODS: In total, 60 adult patients diagnosed with cervical instability or at risk of secondary cervical injury, who were planned for awake intubation and/or self-positioning prone, were registered in this study and were randomly categorized into 2 equal groups (30 patients each), a fiberoptic group and an SOS group, followed by assessment of coughing and gagging during intubation, time to successful intubation, number of attempts for successful intubation, and hemodynamic parameters. RESULTS: As regards time to successful intubation, statistically significant differences were detected between the 2 studied groups, with the fiberoptic group having significantly longer intubation time than the Shikani group, whereas no statistically significant differences were recorded between the 2 groups with regard to the first-attempt success, the mean heart rate value, the mean arterial blood pressure, coughing, and occurrence of complications. CONCLUSION: This study validates the efficacy of both SOS and flexible fiberoptic bronchoscope for awake oral intubation in patients with cervical spine instability. SOS has been found to be more effective in reducing time to intubation.

Baseline evaluation for natural radioactivity level and radiological hazardous parameters associated with processing of high grade monazite.

Egyptian monazite is a promising resource and investment attractive for production of valuable metals of industrial or nuclear interest such as rare earth elements (REEs), thorium (Th) and uranium (U). The study was focused to establish a baseline framework in viewpoint of radiation protection for the workers in production of REEs from high-grade monazite treated by sodium hydroxide (NaOH) solutions. Radiological hazard indices (cancer, gonadal and other risks) were evaluated, due to emissions (α-, ß- and γ-radiations) of radium-isotopes (228Ra, 226Ra, 223Ra) and lead (210Pb). The values of the estimated radiological hazard indices were higher than the permissible safe limits, worldwide average and varied with those reported in other countries. It was found that more than 70% of radioactivity and radiological hazardous indices resulted from emissions of 228Ra, while the rest was attributed to 226Ra, 223Ra and 210Pb. Therefore, processing of the Egyptian monazite can cause a significant radiological impact on workers through external exposure from γ-radiations and/or internal exposure through inhalation or ingestion airborne contaminated by the radionuclides. Thus, the results recommended that protection rules could be considered to prevent the radiation hazards associated with the production of the REEs from the high grade monazite attacked by caustic method.

High prevalence of the PER-1 gene among carbapenem-resistant Acinetobacter baumannii in Riyadh, Saudi Arabia.

The prevalence of carbapenem-resistant Acinetobacter baumannii in Saudi Arabia and their resistance genetic mechanisms are yet to be identified. We studied the prevalence and genetic diversity of extended-spectrum beta-lactamase genes, particularly the PER-1 gene, among carbapenem-resistant A. baumannii strains from patients at a tertiary care hospital in Riyadh, Saudi Arabia between 2006 and 2014. Fresh subcultured samples were tested for antimicrobial susceptibility minimum inhibitory concentration (MIC). Total genomic DNA was extracted from each isolate and further used for polymerase chain reaction (PCR) genotyping, sequence-based typing (SBT) of PER-1 and OXA-51-like gene, and multilocus sequence typing (MLST) of positive isolates. Randomly selected clinical isolates (n = 100) were subjected to MLST. A total of 503 isolates were characterized as multidrug-resistant (MDR) using the MIC. Isolates were further PCR tested for bla -TEM and bla -PER-1 resistance genes (n = 503). The genotyping results showed that 68/503 (14 %) isolates were positive to bla TEM. The genotyping results of PER-1-like genes showed that 384/503 (76.3 %) were positive among MDR Acinetobacter isolates. Based on SBT, the majority of these isolates were clustered into three main groups including isolates harboring PER-1: AB11 (bla -PER-1), isolate AB16 (bla -PER-1), and, finally, the plasmid pAB154 (bla -PER-7). Remarkably, many isolates were concealing the PER-1 gene and harboring the TEM resistance genes as well. MLST results for selected isolates (n = 100) identified four main sequence types (STs: 2, 19, 20, and 25) and four novel isolates (ST 486-489). We report 76.3 % prevalence of the PER-1 resistance gene among Acinetobacter clinical isolates from Riyadh, Saudi Arabia. Further work is needed to explore the clinical risks and patient outcome with such resistance related to healthcare-associated infections and investigate the genetic and molecular mechanisms that confer the MDR phenotype.

Synthesis, characterization and application of titanium oxide nanocomposites for removal of radioactive cesium, cobalt and europium ions.

New nanocomposite material containing TiO2/Poly (acrylamide-styrene sodium sulfonate) [TiO2/(P (AAm-SSS)] was prepared by in-situ intercalative polymerization of poly acrylamide (PAAm) and styrene sodium sulfonate (SSS) in the presence of TiO2 nanoparticles as inorganic filler. N, N-methylene bis acrylamide (MBA) was used as a cross linker. The polymerization process was performed using γ-radiation as reaction initiator. Moreover, new nanocomposite material containing poly styrene-TiO2 (PS-TiO2) was also prepared by ionic polymerization method. Styrene was catalytically polymerized by Ti(4+) via an ionic polymerization route to produce polystyrene (PS). The structure characteristics of the nanocomposites were investigated by XRD, TGA, SEM, surface area, and FTIR. The nanoparticles and nanocomposites were investigated for removal of some metal ions from aqueous solutions. The effective key parameters on the sorption behavior of radioactive cesium (Cs(+)), cobalt (Co(2+)) and europium (Eu(3+)) were investigated using batch equilibrium technique with respect to solution pH and contact time. The obtained results revealed that the equilibrium for Cs(+), Co(2+) and Eu(3)(+) is reached at 2-3 h for all nanocomposites. The data indicated that there is no significant change in the uptake between TiO2 nanoparticles and TiO2-PS. On the contrary, the uptake process is significantly improved using TiO2/(P (AAm-SSS) nanocomposite and the maximum experimental retention capacities for Cs(+), Co(2+) and Eu(3+) were found to be 120, 100.9 and 85.7 mg/g, respectively.

Spectroscopic and structural studies of the Schiff base 3-methoxy-N-salicylidene-o-amino phenol complexes with some transition metal ions and their antibacterial, antifungal activities.

Spectroscopic (IR, Raman, NMR, UV-visible, and ESR), and structural studies of the ligand 3-methoxy-N-salicylidene-o-amino phenol (H2L) and its synthesized complexes with some transition metal ions (Mn(II), Co(II), Ni(II)), Cu(II) and Zn(II)) were recorded and analyzed. The magnetic properties and thermal gravimetric analysis (TGA and DTA) were also measured for the complexes. The metal complexes were found to have The structural formula ML⋅H2O and the metal ions Mn(II), Co(II), Ni(II)) and Zn(II) were found to form tetrahedral complexes with the ligand whereas Cu(II) formed a square planar one. Antimicrobial activity of the ligand and its complexes were also investigated and discussed.

Uranyl ions adsorption by novel metal hydroxides loaded Amberlite IR120.

In this work, Ni(OH)2-loaded Amberlite IR120 (Ni-MA) and Co(OH)2-loaded Amberlite IR120 (Co-MA) resins were prepared, characterized and applied for UO2(2+) removal from aqueous solutions. The adsorption characteristics were investigated in a batch system with respect to effect of contact time, pH, equilibrium isotherms and removal kinetics data. The results indicated that the UO2(2+) could be efficiently removed from aqueous solutions at pH = 3.5 using Ni-MA and Co-MA resins. The maximum adsorption capacities for the UO2(2+) of Ni-MA and Co-MA were found to be 439 mg/g and 451 mg/g respectively. The equilibrium data fit well with the Langmuir adsorption isotherm. Kinetics study showed that the adsorption process was fast and reached equilibrium within 60 min and the kinetics data fit well with pseudo-second order and intra-particle diffusion models for both resins. The adsorption mechanism has been proposed and discussed. It was found that both Ni-MA and Co-MA resins could be used effectively for UO2(2+) removal from aqueous solutions.

Evolution of highly pathogenic avian influenza H5N1 viruses in Egypt indicating progressive adaptation.

Highly pathogenic avian influenza (HPAI) virus of the H5N1 subtype was first diagnosed in poultry in Egypt in 2006, and since then the disease became enzootic in poultry throughout the country, affecting the poultry industry and village poultry as well as infecting humans. Vaccination has been used as a part of the control strategy to help to control the disease. Epidemiological data with sequence analysis of H5N1 viruses is important to link the mechanism of virus evolution in Egypt. This study describes the evolutionary pattern of Egyptian H5N1 viruses based on molecular characterization for the isolates collected from commercial poultry farms and village poultry from 2006 to 2011. Genetic analysis of the hemagglutinin (HA) gene was done by sequencing of the full-length H5 gene. The epidemiological pattern of disease outbreaks in Egyptian poultry farms seems to be seasonal with no specific geographic distribution across the country. The molecular epidemiological data revealed that there are two major groups of viruses: the classic group of subclade 2.2.1 and a variant group of 2.2.1.1. The classic group is prevailing mainly in village poultry and had fewer mutations compared to the originally introduced virus in 2006. Since 2009, this group has started to be transmitted back to commercial sectors. The variant group emerged by late 2007, was prevalent mainly in vaccinated commercial poultry, mutated continuously at a higher rate until 2010, and started to decline in 2011. Genetic analysis of the neuraminidase (NA) gene and the other six internal genes indicates a grouping of the Egyptian viruses similar to that obtained using the HA gene, with no obvious reassortments. The results of this study indicate that HPAI-H5N1 viruses are progressively evolving and adapting in Egypt and continue to acquire new mutations every season.

A new large - Scale synthesis of magnesium oxide nanowires: Structural and antibacterial properties.

Large-scale one-dimensional magnesium oxide (MgO) nanowires with diameters of 6 nm and lengths of 10 µm have been successfully synthesized by a new facile and simple reaction. This production was performed via a microwave hydrothermal approach at low temperature growth of 180 °C for 30 min. The structure of as synthesized MgO nanowires were investigated by means of X-ray diffraction (X-ray), Fourier Transformation Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM), Selected Area Electron Diffraction (SAED) and Energy Dispersive X-ray (EDS). The antibacterial behavior of MgO nanowires concentration in solid media against Gram negative and Gram positive for different bacteria has been tested in details. The results show that the MgO nanowires have bacteriostatic activity against Escherichia coli and Bacillus sp. The antibacterial activity increases with increasing MgO nanowires concentration. Furthermore, the presence of one-dimensional MgO nanowires has high antibacterial efficacy and damages the membrane wall of bacteria. Finally, this study offered the prospect of developing ultrafine nanoscale devices utilizing MgO nanowires and implementing their useful potential in biological control.

Utilization of different crown ethers impregnated polymeric resin for treatment of low level liquid radioactive waste by column chromatography.

The main goal of this study was to find a novel impregnated resin as an alternative for the conventional resin (KY-2 and AN-31) used for low and intermediate level liquid radioactive waste treatment. Novel impregnated ion exchangers namely, poly (acrylamide-acrylic acid-acrylonitril)-N,N'-methylenedi-acrylamide-4,4'(5')di-t-butylbenzo 18 crown 6 [P(AM-AA-AN)-DAM/DtBB18C6], poly (acrylamide-acrylic acid-acrylonitril)-N,N'-methylenediacrylamide-dibenzo 18 crown 6 [P(AM-AA-AN)-DAM/DB18C6], and poly (acrylamide-acrylic acid-acrylonitril)-N,N'-methylenediacrylamide-18 crown 6 [P(AM-AA-AN)-DAM/18C6] were prepared and their removal efficiency of some radionuclides was investigated. Preliminary batch experiments were performed in order to study the influence of the different derivatives of 18 crown 6 on the characteristic removal performance. Separation of (134)Cs, (60)Co, (65)Zn and ((152+154))Eu radionuclides from low level liquid radioactive waste was investigated by using column chromatography with P(AM-AA-AN)-DAM/DtBB18C6 and metal salt solutions traced with the corresponding radionuclides. Breakthrough data was obtained in a fixed bed column at room temperature (298K) using different bed heights and flow rates. The breakthrough capacities were found to be 94.7, 83.3, 58.7, 43.1 (mg/g) for (60)Co, (65)Zn, (134)Cs, and ((152+154))Eu, respectively. Pre-concentration and separation of all radionuclides under study have been carried out using different concentration of nitric and/or oxalic acids.

Further evidence of antigenic drift and protective efficacy afforded by a recombinant HVT-H5 vaccine against challenge with two antigenically divergent Egyptian clade 2.2.1 HPAI H5N1 strains.

In this study, we have compared the protection afforded by a recombinant turkey herpesvirus vaccine expressing the H5 gene from a clade 2.2 H5N1 strain (rHVT-H5) and a Mexican-origin H5N2 inactivated vaccine, alone or in combination, against two antigenically divergent H5N1 Egyptian strains isolated in 2007 and 2008. Our results confirm the existence of a major antigenic drift among the Egyptian H5N1 strains such that, although protection against the "classical" 2007 HPAI H5N1 Egyptian strain could be obtained with both types of vaccines, only vaccination with the rHVT-H5 vaccine protected against challenge with the "variant" 2008 HPAI H5N1 Egyptian strain.

Pathogenicity of two Egyptian H5N1 highly pathogenic avian influenza viruses in domestic ducks.

Domestic ducks have been implicated in the dissemination and evolution of H5N1 highly pathogenic avian influenza (HPAI) viruses. In this study, two H5N1 HPAI viruses belonging to clade 2.2.1 isolated in Egypt in 2007 and 2008 were analyzed for their pathogenicity in domestic Pekin ducks. Both viruses produced clinical signs and mortality, but the 2008 virus was more virulent, inducing early onset of neurological signs and killing all ducks with a mean death time (MDT) of 4.1 days. The 2007 virus killed 3/8 ducks with a MDT of 7 days. Full-genome sequencing and phylogenetic analysis were used to examine differences in the virus genes that might explain the differences observed in pathogenicity. The genomes differed in 49 amino acids, with most of the differences found in the hemagglutinin protein. This increase in pathogenicity in ducks observed with certain H5N1 HPAI viruses has implications for the control of the disease, since vaccinated ducks infected with highly virulent strains shed viruses for longer periods of time, perpetuating the virus in the environment and increasing the possibility of transmission to susceptible birds.

Isolation of highly pathogenic avian influenza H5N1 from table eggs after vaccinal break in commercial layer flock.

In May 2009, during routine monitoring of a commercial layer flock of about 87,000 birds kept in cages in 4 different houses that had been vaccinated 3 times with an inactivated H5N1 vaccine at weeks 1, 7, and 16, highly pathogenic avian influenza (HPAI) virus of subtype H5N1 was isolated and detected by real-time reverse transcriptase-polymerase chain reaction (RT-PCR) in tracheal and cloacal swabs collected from houses 3 and 4; 7 days after onset of clinical signs, there was an increase in mortality accompanied by a decrease in egg production and egg quality. In addition, using RT-PCR, the viral RNA could be detected from albumin and eggshell as well. Seven days after the onset of the clinical signs, the hemagglutination inhibition (HI) titers in the affected houses were 3.2 and 1.9 log2. In the other two houses, there were no clinical signs, and all tested samples were negative using virus isolation and real-time RT-PCR. The HI titers were 6.6 and 7.0 log2 in nonaffected houses. The isolated virus from egg albumin showed high nucleotides and amino-acid identities and clustered with viruses from recently H5N1-confirmed human infections and poultry from different places in Egypt. Moreover, several amino-acid substitutions of viral H5 protein were observed. The vaccinal break seems to be associated with immune escape mutants and/or improper vaccination. The role of contaminated eggs as a source of infection and as a vehicle for spread of the virus should be considered in area with avian influenza outbreaks.