A Sequential Histopathologic and Immunocytochemical Study of Chickens, Turkey Poults, and Broiler Breeders Experimentally Infected with Turkey Rhinotracheitis Virus

Abstract

The histopathologic changes and the distribution of turkey rhinotracheitis virus (TRTV) antigen in the respiratory and reproductive tracts of experimentally infected chickens, turkey poults, and broiler breeders is described. TRTV antigen was detected using both immunofluorescent staining of cryostat sections and immunoperoxidase staining of formalin-fixed tissues. Viral antigen was observed associated with the cilia of the epithelial cells of turbinates, trachea, and lung. No TRTV antigen and no histopathologic changes were detected in the conjunctiva of any of the sacrificed birds, or in the reproductive tract and central nervous system of broiler breeders. The main histopathologic lesions and sites of TRTV replication were observed in the ciliated epithelial cells of turbinates and lung. These findings bring forward new information about pathologic changes and TRTV antigen distribution in tissues of experimentally infected birds.

Detection and differentiation of avian pneumoviruses (metapneumoviruses)

“…Direct IF has been used successfully on both acetone-fixed cryostat sections ) and Bouin's-fixed paraffin embedded tissue . Specific staining was shown to be closely associated with the ciliated surface epithelial cells of both experimentally infected turkeys and chickens Majó et al, 1995). Similar findings have also been reported using IP staining to study respiratory tract infections in turkeys (Majó et al, 1995) and chickens (Majó et al, 1995;Catelli et al, 1998).…”

“…Specific staining was shown to be closely associated with the ciliated surface epithelial cells of both experimentally infected turkeys and chickens Majó et al, 1995). Similar findings have also been reported using IP staining to study respiratory tract infections in turkeys (Majó et al, 1995) and chickens (Majó et al, 1995;Catelli et al, 1998). Interestingly, immunochemical methods have been used to demonstrate APV-specific antigen in the female reproductive tract following experimental inoculation.…”

“…Techniques involving the use of IP Majó et al, 1995), IF Jones et al, 1986Jones et al, , 1988 and immunogold staining (O'Loan et al, 1992) have all been reported for the detection of APV in turkeys. In addition, IF and IP (Majó et al, 1995;Catelli et al, 1998) techniques have been used successfully to detect APV in chickens.…”

“…Jones et al (1988) used IF to demonstrate specific staining of the uterus of experimentally inoculated laying turkeys, while Cook et al (2000) used IP to demonstrate APV-specific staining in the oviduct of experimentally inoculated laying hens. However, the short time for which APV antigen has been detected by these methods in experimentally inoculated birds (Majó et al, 1995;Catelli et al, 1998) suggests the need for caution when using antigen detection methods to attempt to diagnose APV infection in laying birds, since a negative result may not indicate absence of infection.…”

“…Furthermore, the type of anti-APV antibody used to prepare the conjugate varies considerably. For example, Jones et al (1988) used a convalescent serum raised in APV-free turkeys, while and Majó et al (1995) used a hyperimmune rabbit antiserum and Catelli et al (1998) and Cook et al (2000) used a mouse-anti-TRT mAb. These differences also make comparisons of results between different laboratories, and therefore decisions on the optimal conditions to recommend, very difficult.…”