African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5227

Full Length Research Paper

Differentiation of field isolates and vaccine strains of infectious laryngotracheitis virus by DNA sequencing

Majid Sadeghi1*, Mohammad Hasan Bozorgemehrifard2, Hadi keyvanfar3, Hassan Momtaz4, Abdolhamid Shooshtari5 and Saied Charkhkar6       
  1Islamic Azad University, Science and Research Branch, Tehran, Iran. 2Division of Poultry Disease, Islamic Azad University, Science and Research Branch, Tehran, Iran. 3Division of Microbiology, Islamic Azad University, Science and Research Branch, Tehran, Iran. 4Department of Microbiology, Faculty of Veterinary Medicine, Islamic Azad University, Shahrekord branch, Shahrekord, Iran. 5Division of Poultry Disease and Research, Razi Vaccine and Serum Research Institute, Karaj, Tehran, Iran. 6Department of Poultry Disease, Islamic Azad University, Science and Research Branch, Tehran, Iran.       
Email: [email protected].

  •  Accepted: 10 October 2011
  •  Published: 30 October 2011

Abstract

Avian infectious laryngotracheitis (ILT) is a severe clinical respiratory disease of chickens and causes the clinical symptoms of difficulty in breathing and bloody coughing and as if involves laying hens affect the egg production. Two different regions of the infected cell protein 4 (ICP4) gene of infectious laryngotrucheitis virus (ILTV) were amplified and sequenced for characterization of field isolates and tissue culture-origin (TCO) and chicken embryo-origin (CEO) vaccine strains. Phylogenetic analysis of the two regions showed no differences in nucleotide and amino acid sequences between Iranian field isolates with high morbidity and nearly 30% mortality and CEO attenuated vaccines. These findings suggest that modified-Live (ML) ILT vaccine viruses may increase in virulence after bird-to-bird passages.

 

Key words: Avian infectious laryngotracheitis, infected cell protein 4, phylogenetic analysis.