Comparative dynamic distribution of avian infectious bronchitis virus M41, H120, and SAIBK strains by quantitative real-time RT-PCR in SPF chickens.

Avian infectious bronchitis is an acute, highly contagious disease of chickens. To study the differences of dynamic distribution between nephropathogenic infectious bronchitis virus (IBV) strains such as SAIBK and other strains (the M41 and H120 strains), relative quantitative real-time reverse transcription-polymerase chain reaction was developed by housekeeping gene selection. Glyceraldehyde-3-phosphate dehydrogenase and Ubiquitin were chosen for normalization in this experimental set. Then nine tissues, the trachea, thymus, liver, spleen, lungs, kidney, pancreas, proventriculus, and bursa of Fabricius, were analyzed and compared to determine the tropism of IBV infection. In this research, the kidney and the lung were established of the most sensitive organs in IBV infection. The pancreas and the liver are candidates for antigen detection. The trachea and the spleen can be used as references for histological diagnosis, but they are not suitable for antigen detection; proventriculus might be an important target in IBV infection; the thymus and the bursa of Fabricius were not sensitive organs in IBV infection.