Molecular detection and isolation of infectious laryngotracheitis virus (ILTV) in layer farms of Waset province, Iraq

Abstract

Infectious Laryngotracheitis (ILT) is an acute highly contagious respiratory disease of chickens. It has significant economic importance due to mortalities and the decrease in egg production. In this study, twenty nine samples from different layer farms were collected from the outbreaks that occurred in waset province, Iraq, at the period from November 2021 till March 2022 to detect ILTV by molecular test through real time polymerase chain reaction assay (RT-PCR) as well as isolation on embryonated chicken eggs through chorioallantoic membrane (CAM) route. The clinical signs examination of infected birds revealed extend head with expectoration of bloody mucous, gasping with weeping eye (watery eye). Gross pathological lesions examination revealed catarrhal, caseated, fibrinonecrotic, hemorrhagic tracheitis. The RT-PCR revealed amplification specific for glycoprotein G gene of ILT virus. Preparation and Inoculation of tissue samples which giving positive results with RT-PCR on embryonated chicken eggs (ECE) appeared as white pock lesions on the inoculated CAM from the second passage.