Coding-complete genome of ILTV from FTA
Infectious laryngotracheitis (ILT) is a highly contagious disease of chicken caused by the Infectious laryngotracheitis virus (ILTV) also known as the Gallid herpesvirus 1. The disease characterized by severe or mild respiratory distress, tracheitis and conjunctivitis accompanied by egg production loss. ILT causes great economic losses due to morbidity, moderate to severe mortality and reduction of egg production.ILTV belongs to the genus Iltovirus and subfamily Alphaherpesvirinae within the Orthoherpesviridae family. ILTV possess a linear 150-155 kb long double stranded DNA genome consisting of the unique long (UL) and unique short (US) sequences flanked by inverted repeats (IR) and terminal repeats (TR). Discrimination of vaccine and field ILTV strains from clinical samples is crucial for epidemiological, outbreak management, vaccine efficacy monitoring, and regulatory aspects.FTA cards are designed to stabilize and protect nucleic acids at room temperature, so they are generally used for sample and nucleic acid transportation without special conditions. Despite its simplicity transportation on FTA cards has several limitations, such as the fragmentation of nucleic acids.Organ samples from layer chickens were shipped to our lab on FTA cards from the Middle East for diagnostic purposes. The samples were positive with ILTV-specific real-time PCR, genome sequence data were needed for further typing of the virus.The complete coding sequence of the ILTV present in the diagnostic sample were determined by Illumina sequencing, and phylogenetic analysis revealed that the strain belongs to the wild-type strains, separated from the vaccine-derived and recombinant strains.