Molecular epidemiology of avian influenza virus and incidence of H5 and H9 virus subtypes among poultry in Egypt in 2009-2011.

Egypt has experienced outbreaks of avian influenza (AI) since 2006. A total of 3583 cloacal swabs were collected from chickens, ducks, geese and turkeys from commercial farms, backyards and local bird markets in Qena and Luxor governorates in South Egypt during 2009-2011. These samples were examined for the presence of AI virus (AIV) and positive samples were further subtyped for the H5 and H9 by real time RT-PCR. In this way, 202 (5.64%) samples were found to be AIV-positive of which 186 (92.08%) and 7 (3.46%) belonged to H5 and H9 subtypes, respectively. Higher infection rates were observed in backyard birds and birds from local bird markets in comparison to birds from commercial farms. In conclusion, the predominance of H5 infection indicates a need for continuous monitoring of AIV among avian species and the awareness against public health risk.

Phase transformation and disorder effect on optical and electrical properties of Zn3P2 thin films.

The phase transformation of zinc phosphide (Zn(3)P(2)) thin films was detected through isochronal annealing process. The effects on isochronal annealing on the internal structural, optical and electrical properties of deposited Zn(3)P(2) thin films have been discussed. The films were prepared by thermal evaporation under constant preparation conditions of vacuum 1.3×10(-5)Torr, substrate temperature (300K), rate of deposition (∼1nm/s) and film thickness (480nm). The annealing process was carried out under vacuum for 2h at different temperatures ranging from 373 to 623K. X-ray diffraction patterns showed that the as-deposited films and those annealed at temperatures less than 623K exhibit amorphous structure, while the films annealed at 623K showed tetragonal polycrystalline structure. The optical transmission and reflection spectra were measured at the wavelength range of 190-2500nm. The absorption coefficient spectra and the degree of disorder as measured from the absorption edge were determined. The indirect and direct optical energy band gaps were evaluated for indirect allowed and direct allowed transitions for amorphous and polycrystalline films, respectively. The refractive index n(o) increases with raising the annealing temperature which refers to more condensation in the material. The electrical resistivity for Zn(3)P(2) films decreases exponentially with raising the annealing temperature up to 623K as influenced by structure transformation and decreasing the degree of disorder in the films.

Cross-protection and antigen expression by chicken embryo-grown Pasteurella multocida in chickens.

The growth of Pasteurella multocida strain X-73 (serotype 1) and P-1059 (serotype 3) in vivo instead of in vitro resulted in the expression of additional antigens, as revealed by SDS-PAGE profile and western blotting of the outer membrane detergent-insoluble fraction (DIF-OM). Minor protein bands ranging from 58-138 kDa were expressed by both strains; major bands ranging from 35-64 and 35-43 kDa were expressed by X-73 and P-1059, respectively. Antigens at 35-39 kDa were dense and dominant. Treatment of DIF-OM from both strains with sodium periodate and proteinase K, but not with trypsin, reduced ELISA reactivity; this suggested that DIF-OM was composed of glycoprotein. Western blotting with heterologous antisera demonstrated antigenic cross-reactivity between strains X-73 and P-1059 grown in vivo. Inactivated vaccine prepared from X-73 grown in vivo protected chickens against challenge with X-73, P-1059 and strain P-1662 (serotype 4); a similar vaccine prepared from in-vitro culture, however, protected only against the homologous serotype. Moreover, antiserum against X-73 grown in vivo but not against the same strain grown in vitro gave considerable passive protection against challenge with the heterologous strains P-1059 and P-1662.

Pasteurella multocida infection in the chicken embryo.

Pasteurella multocida infection in embryonated chicken eggs was studied by chorio-allantoic membrane inoculation. Strain differences were demonstrated in terms of lesion severity and time to death, especially during the first 24 h post-inoculation. A strain of low virulence gave a clear dose response but more virulent strains did not. Comparable results were obtained by infecting 6-week-old chickens. The main lesions in inoculated embryos appeared as severe vascular involvement of the entire embryo and feather tracts, thickening of the chorio-allantoic membrane, and enlargement and congestion of the yolk sac. The bacteria were demonstrated by transmission electron microscopy, either extracellularly or multiplying intracellularly in hepatocytes, heart tissue, and in the hyperplastic layer of the chorio-allantoic membrane, with resulting damage to the cellular organelles, and severe tissue changes.