Detection of proteins and nucleic acids of Newcastle disease virus in Eimeria acervulina

Abstract

Ten-day-old specific pathogen free (SPF) chickens were inoculated simultaneously with Eimeria acervulina and Newcastle disease virus (NDV). By employing immunofluorescent staining and in situ hybridization techniques, we detected NDV proteins and nucleic acids in different life stages of E. acervulina. However, no NDV particle was found within E. acervulina by electron microscopy. Oocysts from E. acervulina that contained NDV proteins and nucleic acids could elicit antibodies against NDV after repeated inoculation into SPF chickens. Moreover, the proportion of oocysts from chickens infected with E. acervulina and NDV which could be induced to sporulate in vitro was lower than those from chickens infected with E. acervulina alone. These results indicate that nucleic acids and proteins of NDV can exist within E. acervulina, and stimulate an immune response against NDV in chickens, and that NDV may also interfere with the sporulation of oocysts.