Isolation and characterization of virus(es) associated with infectious enteritis (bluecomb disease) of turkeys

Abstract

The purpose of this study was to isolate and characterize the causative agent(s) of bluecomb disease, and to study the nature of the disease in gnotobiotic and conventional turkeys. Comparative studies on the infectivity titers in the lymphoid bursa and the ceca of bluecomb-infected birds revealed that the bursa had a greater concentration (10-100 times) of viruses than the intestinal tissue. The pathogenic bluecomb filtrate lost its pathogenicity when it was treated with ether, chloroform or heat at 50 C for 60 minutes. The virus(es) in the filtrate was stable at pH 3.0 but labile at pH 2.0 and 9.0. A 50 mμ (Millipore) filtrate of the bluecomb suspension was pathogenic to poults. This indicated that the minimum size of the infectious particle was approximately 40 mμ. Attempts to cultivate the virus(es) of bluecomb in primary cell cultures of turkey embryo intestinal epithelial cells and chick embryo kidney cells and a continuous cell line of African Green Monkey Kidney (VERO) cells were not successful. Fluid from in vivo infected intestinal explant cultures produced bluecomb disease when inoculated into poults, but this infectivity was due to passive transfer of the virus(es) from the tissues to the culture medium. ...