Development of novel real-time PCR assays for detecting DNA virus infections in psittaciform birds.

Viral diseases of psittacine birds are detected presently by PCR. However, conventional PCR methods are not quantitative and the products can sometimes include non-specific products of the same size. To avoid these problems, real-time PCR assays based on the SYBR Green assay system were developed for the detection and quantitation of four virus diseases of psittacine birds: psittacine beak and feather disease, avian polyomavirus infection, psittacid herpesvirus infection, and psittacine adenovirus infection. Up to 1x10(2) copies of virus DNA were detected, indicating that these assays are as sensitive as conventional PCR assays. The assays are specific because they did not amplify any other pathogens including other viruses, bacteria, and fungi in psittacine birds. The assays measured successfully virus loads in clinical samples (blood, feathers, and tissues), showing that these specimens were suitable targets for the detection and quantitation of viral DNA in psittacine birds.