USE OF REVERSE-TRANSCRIPTASE POLYMERASE CHAIN-REACTION FOR DETECTION OF VACCINE CONTAMINATION BY AVIAN-LEUKOSIS VIRUS

A reverse transcriptase polymerase chain reaction (RT-PCR) for avian l eukosis virus (ALV) was developed for the detection of contamination o f vaccines produced in embryonated eggs and cell cultures derived from chicken. ALV is highly pathogenic and induces a wide spectrum of dise ase in infected animals. ALV can be divided into five subgroups (A-E). The envelope glycoprotein (env gp85) is the main antigen determinant and responsible for subgroup classification. Viral RNA of all subgroup s (A-E) was isolated and amplified using three sets of primers. Subseq uently, restriction endonuclease analysis confirmed the product identi ty and discriminated between subgroups. In specific pathogen free (SPF ) eggs experimentally inoculated with ALV, viral RNA was found in alla ntoic fluids, as well as in vaccines spiked with different subgroups o f ALV. No adventitious virus was detected in commercially available pr eparations. This system provides a rapid and specific in vitro method for the detection of ALV RNA as an extraneous agent and map be applied for quality control of avian vaccines. (C) 1997 Elsevier Science B.V.