Replication Kinetic of Infectious Laryngotracheitis Virus in Embryonic Chicken Neural Stem Cell

Background and Aims: Infectious laryngotracheitis virus (ILTV) infection causes a highly contagious respiratory disease in poultry leads to significant economic losses in the poultry industry. The genomic and antigenic characteristics between virulent and vaccine strains of ILTV are very similar. The ability of embryonated chicken neural stem (CNS) cell for differential diagnosis of ILTV strains was also evaluated. Materials and Methods: CNS cell cultures were inoculated with an ILTV vaccine stain and a virulent strain at different viral multiplicity of infections (MOI). The replication and growth kinetics of the viruses were evaluated by estimation of suitable time of infection, production of virus infectivity titers, and amplification of ICP4 gene in collected samples. Results: Based on PCR and virus titration assays, the ILTV strains were able to enter CNS cells and replicate efficiently at all MOIs used. The virus titers and tracing of ICP4 data were found to be similar, but marked cytopathic effect (CPE) was only detected in ILTV vaccine stain infection as compared to virulent strain. Conclusion: The neural stem cell had a higher growth potential and infectivity of ILTV strains, which will be of advantage in differential diagnosis.