title: Use of chicken embryonated eggs for evaluating the virulence ofToxoplasma gondii.
abstract: The objective of the present study was to examine the virulence ofToxoplasma gondiiRH strain tachyzoites in embryonated eggs after continuous passage in Vero cell line. The firstT. gondiitachyzoites was considered low passage (no passage) and then passaged for 80 times on Vero as high passage. Groups of 9-day-old embryonated eggs with ten eggs in each group were inoculated with 102,103and 104of low or high-passageT. gondiitachyzoites, and any mortality was recorded. Suitable samples from different tissues (liver, heart, and brain) of the dead embryos were collected for histopathological study. In this study, the mortality in group 103and 104was observed, but there was no significant differences in mortality rate inT. gondiilow passage and high passage. This finding exactly correspond to previous studies that were performed in mice as animal model forT. gondiiRH strain. Thus on base of this study we could introduce the embryonated eggs as an appropriate animal model to evaluate the virulence ofT. gondiitachyzoites.
authors.affiliation: Islamic Azad University Fars Science and Research Branch, Shiraz, Iran.
authors.forename: A
authors.initials: A
authors.lastname: Setasimy
authors.affiliation: Razi Vaccine and Serum Research Institute, Shiraz, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Namavari
keywords: Chicken embryonated egg; Continuous passage; Toxoplasma gondii; Virulence