Molecular Characterization of Thymidine Kinase and Glycoprotein G
Genes from a Possible Vaccine Induced Infectious Laryngotracheitis
Outbreak in Egypt
Abdel-Moneim A Ali1*, Shimaa MG
Mansour2, Mahmoud HA Mohamed3,4, Haythm Ali1
and Abeer Shahin3
1Department of Pathology; 2Department of Virology; 3Department of Avian and Rabbit Medicine, Faculty of
Veterinary Medicine, Zagazig University, Zagazig, Egypt; 4Department
of clinical studies, Faculty of Veterinary Medicine, King Faisal
University, 31982 Ahsaa, Kingdom of Saudi Arabia *Corresponding author:abdelmoneim.ahmedali@yahoo.com
Abstract
Infectious laryngotracheitis virus (ILTV) is a
worldwide cause of acute respiratory disease in chickens. In this study, an
outbreak of laryngotracheitis in commercial layers flock, Sharkia Province,
Egypt in 2011 was investigated by sequencing of thymidine kinase (TK) and
glycoprotein G (gG) genes. The chickens showed clinical ILTV infection,
histopathological examination revealed epithelial sloughing, development of
syncytical cells, heterophilic exudation with presence of eosinophilic
intranuclear inclusion bodies. The virus was isolated on chorioallantoic
membrane (CAM) of embryonated chicken eggs (ECE), and it induced typical pock
lesions after two passages. The obtained 647 amplicon by PCR confirmed the
presence of ILTV genome. Gene sequencing of TK and gG showed high genetic
homology between field isolate from commercial layer flock (Sharkia-11) and
vaccine strains. To our knowledge, this is the first documented ILTV outbreak
attributed to vaccination with live modified ILT vaccine in Sharkia, Egypt based
on sequence analysis of TK and gG genes.