STUDIES ON A NEW ENTEROVIRUS-LIKE VIRUS ISOLATED FROM CHICKENS

During investigations into an outbreak of respiratory distress in broi lers chicks, a small round virus was isolated following inoculation in to chicken embryos. The isolate, designated 612, was identified as an enterovirus-like virus on the basis of its size and morphology, resist ance to chloroform and to treatment at pH 3.0, and intracytoplasmic re plication in cell culture. The virus produced a partial cytopathic eff ect following inoculation into chick embryo kidney cell cultures and v iral antigens could be detected by immunostaining. The preferred cultu re method for 612 virus was by inoculation onto the CAM of chick embry os. Cross-immunofluorescence indicated that the virus is not antigenic ally related to five previously identified chicken enterovirus/enterov irus-like virus serogroups. Following experimental inoculation of 1-da y-old male broilers a number of which had maternal antibody to 612, gr owth retardation ranging from 9.6 to 20.4% was detected. Serological s tudies demonstrated antibody to 612 virus was widespread in commercial chicken flocks in N. Ireland.