Submitted to: Avian Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2004
Publication Date: 6/1/2004
Citation: Malkinson, M., Banet-Noach, C., Davidson, I., Fadly, A.M., Witter, R.L. 2004. Comparison of serological and virological findings from subgroup J avian leukosis virus-infected neoplastic and non-neoplastic flocks in Israel. Avian Pathology. p. 281-287. Interpretive Summary: Subgroup J avian leukosis virus (ALV-J) is an economically important virus infection that can cause cancer-like disease and other production problems in chickens. Detection of ALV-J infection can be accomplished by one or more of established laboratory procedures. However, a comparison of the sensitivity of such procedures in identifying diseased chickens under certain circumstances is lacking. Our data show that the two most sensitive tests that differentiated between diseased and disease-free flocks were virus isolation and a DNA-based test termed polymerase chain reaction. This new information is significant and should be useful to poultry disease specialists in industry, academia and government who are interested in diagnosis and control of this important virus infection of chickens
Technical Abstract: Blood samples from nine broiler breeder flocks comprising five flocks clinically affected with myeloid leukosis tumors (ML+) and four tumor-free flocks (ML-) were compared for avian leukosis subgroup J (ALV-J) serum antibodies by ELISA, for antigenemia (group-specific antigen- GSA) by antigen-trapping ELISA and for viremia. GS antigen was detected in the sera of 58.1% of ML+ birds and 46.4% of the ML- birds (p=ns), while 41.5% of ML+ birds and 24.1% of the ML- birds had ALV-J antibodies (p=0.065). In the virus assay, 64.1% of the ML+ sera, were viremic compared with 16.7% of the ML- sera (p=0.001). Similar significant differences were found between the 2 groups of flocks when ALV-J viremia was detected by immunofluorescence using a monoclonal env antibody (p=0.004), and for proviral DNA by PCR using two different sets of env-gene primers, H5-H7 (p=0.001) and R5=F5 (p=0.001). Using the primer pair, R5-F5 the product size was approximately 1 kbp, while some heterogeneity in size among isolates was discernable.