Use of polymerase chain reaction (PCR) for the detection of vaccine contamination by infectious laryngotracheitis virus

Quality control of biologicals for veterinary use includes certification of freedom from extraneous agents. Contamination of vaccines may originate fr om various materials used for production and during manufacturing process. Requirements for avian virus vaccines to demonstrate freedom of adventitiou s agents are stated in the European Pharmacopoeia and include monitoring fo r infectious laryngotracheitis virus (ILTV). ILTV is an avian herpesvirus b elonging to the alphaherpesvirus subfamily causing acute respiratory diseas e. To date the methods to detect ILTV contaminating biologicals consist of demonstration of antibody induction in chicken after immunization or virus cultivation in embryonated eggs. These methods are time consuming and labor ious. Therefore, a specific, simple and sensitive in vitro polymerase chain reaction (PCR) for the detection of ILTV contamination in avian virus vacc ines was developed. Primers were designed to amplify part of the p32 gene. Four different ILTV vaccine strains could be unequivocally detected. The id entity of the amplified fragment was confirmed by restriction endonuclease analysis. (C) 1999 Elsevier Science Ltd. All rights reserved.