Experimental infection of laying turkeys with Rhinotracheitis virus: Distribution of virus in the tissues and serological response

Abstract

SUMMARYTwenty-four laying turkey hens shown to be free of antibodies to turkey.rhinotracheitis virus were inoculated intranasally with an isolate of the virus. A mild respiratory disease developed between 5 and 9 days post infection (pi). Two birds were selected at random at intervals between days 1 and 20 pi, killed and tissues examined for the presence of virus. At autopsy between days 2 and 12 abnormalities were found in the oviducts including the deposition of inspissated albumen. Yolk material was occasionally found in the abdominal cavity and there was one instance of egg peritonitis. Eggs with abnormal shells were found in the uterus on days 3 and 9. By direct immunofluorescence (IF) staining, virus was detected in the trachea between days 1 and 7 pi and in the turbinâtes between days 2 and 5 pi. Virus could also be isolated from these sites using turkey embryo trachéal organ cultures but this method was slightly less sensitive than IF for these tissues. No virus was demonstrated in the lungs or air sacs. Viral antigens were detected by IF in the epithelium of the uterus on day 7 pi and in this and all other regions of the oviduct on day 9 pi. Virus was isolated only from middle magnum and vagina on day 9 pi. On other occasions up to 20 days pi the above tissues and spleen, ovary, liver, kidney and hypothalamus were all negative for virus. Antibodies detected by ELISA and serum neutralisation both reached, high titre by 12 days pi and were maintained at a high level (Iog2 12-15) throughout the period of observation (89 days).

Avian metapneumovirus infection of chicken and turkey tracheal organ cultures: comparison of virus–host interactions

“…Cilia may allow the virus to attach and therefore it may be suggested that polarized epithelial cells are the main target cells of aMPV (Jones et al, 1986;O'Loan & Allan, 1990;Majó et al, 1995;Jirjis et al, 2001;Zhang et al, 2002). In the present state of knowledge, the oviduct epithelium is the only other surface susceptible to aMPV, apart from respiratory epithelia (Jones et al, 1988). In addition, it has been suggested that macrophages may carry the virus and act as vectors within the host (Sharma et al, 2004).…”

Detection and differentiation of avian pneumoviruses (metapneumoviruses)

“…This may indicate the need for a larger sampling size when attempting to isolate APV. Jones et al (1988) found IF to be more sensitive than virus isolation in the case of turkeys and also to give results more quickly (Jones, 1996). Catelli et al (1998) compared virus isolation with an IP assay for the detection of APV in young, experimentally inoculated SPF chickens and found that each method detected the virus in nasal turbinate tissue for a similar period of time.…”

“…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.…”

“…Interestingly, immunochemical methods have been used to demonstrate APV-specific antigen in the female reproductive tract following experimental inoculation. 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.…”