DETECTION OF TURKEY RHINOTRACHEITIS VIRUS IN TURKEYS USING THE POLYMERASE CHAIN-REACTION

Six-week-old turkey poults were infected with the virulent UK/3B/85 st rain of TRTV. Tracheal and oesophageal swabs were made every 2 to 3 da ys from groups of five poults and the RNA extracted. The TRTV RNA was then reverse-transcribed into complementary DNA (cDNA) using an oligon ucleotide complementary to the 3' end of the fusion protein (F) mRNA. The cDNA was then used in a polymerase chain reaction (PCR) with an up stream primer to generate a product of approximately 0.5 kbp which was detected by ethidium bromide staining after electrophoresis. In this way, TRTV was detected in both types of swab for 17 to 19 days post-in fection, nearly 2 weeks after the peak titres of infectious virus. Swa bs which were allowed to dry completely before RNA extraction were as successful as swabs kept wet and extracted almost immediately, useful for when samples are collected in the field. The oligonucleotides ampl ified the 0.5 kbp product from TRTV strains isolated in six countries over a 13-year period, indicating that they might be usable as 'univer sal' oligonucleotides for TRTV detection.