Background: Non-ionic surfactant, Tween-80 (TW80) is commonly used for drug delivery due to its effect on the cell membrane permeation. The change in permeability can also increase viral infectivity in cells. This study was undertaken to improve upon Newcastle disease virus (NDV) titer cultivated with embryonic chicken eggs.  Methods: The toxicity of TW80 was investigated against chicken embryos at varying concentrations, and changes in the morphology and weights of the heart, liver, and spleen of 4-day old chicken embryos were analyzed. Also, the effect of non-toxic concentrations of TW80 was examined on the infectivity of NDV. The virus was titrated in the allantoic fluid, using a 50% embryo infectious dose (EID50).  Results: At high concentrations of TW80, hemorrhage-induced mortality was observed in embryos at the early stages of incubation. The embryos’ viability was not affected at low TW80 concentrations, indicating that its toxicity to the chicken embryos was dose-dependent. The infectivity titer of NDV was increased in the presence of TW80 compared to those inoculated with NDV only.  Conclusion: The data suggest that TW80 is toxic to chicken embryos at high concentrations, but it enhances cell membrane permeability for NDV particles at low concentrations without affecting the embryos’ viability.

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Ostrich-farming has been prevalent in South Africa as the main habitat of this bird since several centuries ago and the flocks of ostrich have been reared similar to other herds or tame animals and flocks of birds. It can be also possibly reared in other countries of the world. At present, whereas skin, flesh, and other organs of this bird are consumed thus farming of this bird is vitally important in the world.With respect to growing population of ostrich flocks in Tehran Province and the affiliated towns and importance of this issue in terms of providing meat and protein for the consuming market and in order to improve production yield it requires for diagnosis of and prophylaxis of the related common diseases for this animal particularly the parasitic diseases. It was tried to study by referring to 16 ostrich farming centers and visiting and sample from 55 carcasses of and or fatalities of the animal for this purpose. Then, after washing the contents of intestine of this bird and passing of those through screen (100) and staining with loop they were analyzed. Also lamella was prepared from intestinal wall and after staining the probability of existing protozoans was explored. No helminthic parasite was observed in the samples and Emeria oocyte was seen in three cases.