IDENTIFICATION AND PARTIAL CHARACTERIZATION OF ARKANSAS ISOLATES OF CHICKEN ANEMIA VIRUS

Chickens from both broiler and broiler breeder puller hocks experienci ng symptoms of chicken anemia virus (CAV) infection were first observe d at the poultry Health Research Laboratory at the University of Arkan sas in September 1992, Flocks had experienced higher than normal morta lity with subcutaneous hemorrhages on the wings, neck, and thorax, Pos tmortem and histopathologic evaluation revealed thymus and bursal atro phy and lesions consistent with those reported far CAV infection. Beca use this infection had not: previously been observed by Poultry Health Research Laboratory personnel in Arkansas-grown chickens, the establi shment of a definitive diagnosis was deemed important. The presence of CAV was established by infecting MSB-1 cells with pooled liver homoge nates from groups of 10 specific-pathogen-free chickens that had previ ously been inoculated in an attempt to experimentally reproduce the di sease observed in the field. Cytopathic effects in the infected MSB-1 cells were first evident following the fifth passage. Indirect fluores cent antibody technique identified infected MSB-1 cells following at l east five blind passages. To further confirm tile presence of CAV, a p olymerase chain reaction (PCR) technique was used to amplify a specifi c portion of the virus genome from infected MSB-1 cells and tissue ext racts from several submitted chickens. Sequence analysis of a 186-bp P CR amplification product revealed that the Arkansas isolate was very s imilar to the Cuxhaven-1 isolate (99.5% sequence identity).