Quantitative profiling of fowl adenoviral load in experimentally infected chicken using SYBR Green real time PCR

The present study aimed to quantify the fowl adenovirus (FAdV) load in various organs at different time intervals in experimentally infected chicken using SYBR Green based real time polymerase chain reaction (Real time PCR). The SYBR Green based real time PCR was standardized using 590 bp FAdV serotype 11 plasmid standards, and the sensitivity and specificity of the assay was validated. It was found that real time PCR was 100 times more sensitive than conventional PCR. To assess the fowl adenoviral load in different organs, experimental infection was conducted. Ninety-eight day-old specific pathogen free chicks were inoculated with field isolated, PCR confirmed and sequenced FAdV serotype 11 isolate with oral and intramuscular route at a rate of 0.5 ml of 106.5/TCID50 except control group. The infected chicks were sacrificed on days 3, 5, 7, 10, 14 and 21 after inoculation. In both the groups, high FAdV copy numbers were found in the caecal tonsil at 5 to 7 days post inoculation, followed by the bursa of Fabricius and the liver, and FAdV copy numbers were seen up to day 21 pi in all the organs, where the kidneys showed the lowest copy numbers when compared to the other organs.