optimized polymerase chain reaction assay to identify avian virus vaccine contamination with Chicken anemia virus

• Published in: Journal of veterinary diagnostic investigation Vol. 23; no. 1; pp. 34 - 40
• Main Authors: Amer, Haitham M, Elzahed, Hanan M, Elabiare, Elham A, Badawy, Ahmed A, Yousef, Ausama A
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA SAGE Publications 2011
• Subjects: Animals; birds; Chicken anemia virus; Chicken anemia virus - chemistry; Chicken anemia virus - isolation & purification; chicken eggs; conserved sequences; cross reaction; detection limit; DNA primers; DNA, Viral - chemistry; DNA, Viral - genetics; Drug Contamination; genes; pathogens; polymerase chain reaction; Polymerase Chain Reaction - methods; Polymerase Chain Reaction - standards; Polymerase Chain Reaction - veterinary; poultry; Poultry Diseases - immunology; Poultry Diseases - prevention & control; Poultry Diseases - virology; Reproducibility of Results; Sensitivity and Specificity; tissue culture; vaccines; Viral Vaccines - analysis; Viral Vaccines - immunology; Viral Vaccines - standards; viruses; Chicken anemia virus; vaccine contamination; polymerase chain reaction
• ISSN: 1040-6387; 1943-4936
• DOI: 10.1177/104063871102300105

The use of embryonating chicken eggs in preparation of avian virus vaccines is the principle cause for contamination with Chicken anemia virus (CAV). Identification of CAV in contaminated vaccines relies on the expensive, tedious, and time-consuming practice of virus isolation in lymphoblastoid cell lines. The experience of the last 2 decades indicates that polymerase chain reaction is extending to replace most of the classic methods for detection of infectious agents. In the present report, a simple, rapid, and accurate polymerase chain reaction method for detection of CAV in poultry vaccines is described. Oligonucleotide primers homologous to highly conserved sequences of the VP1 gene were used to amplify a fragment of 676 bp. The developed assay was specific for detecting CAV from different sources, with no cross reactivity with many avian viruses. No inter- and intra-assay variations were observed. The analytical sensitivity of the test was high enough to detect 5 TCID50 (50% tissue culture infective dose) of the virus per reaction; however, different factors related to the vaccine matrix showed considerable effects on the detection limit. In conclusion, this method may represent a suitable alternative to virus isolation for identification of CAV contamination of poultry virus vaccines.