An Optimized Polymerase Chain Reaction Assay to Identify Avian Virus Vaccine Contamination with Chicken Anemia Virus

Abstract

Abstract. 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 TCID 50 (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.

Detection of Influenza A virus contamination in Newcastle Disease live virus vaccines and their pathological effects on visceral organs

“…In addition, several batches of both monovalent and combined vaccines containing strain LaSota of the same company consistently disclosed contamination with strain B-that's why our results are controversial to their work. Amer et al 2011 [17] studied that use of embryonated chicken eggs in preparation of avian virus vaccines is the principal cause for contamination with Chicken Anemia Virus (CAV). Identification of CAV in contaminated vaccines relies on the expensive, tedious, and timeconsuming practice of virus isolation in lymphoblastoid cell lines.…”