title: Differentiation of field isolates and vaccine strains of infectious laryngotracheitis virus by DNA sequencing.
abstract: Two different regions of the infected cell protein 4 (ICP4) gene of infectious laryngotracheitis 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 differences in nucleotide and amino acid sequences between field isolates and attenuated vaccines. The PCR-RFLP results were identical to those obtained by DNA sequencing and validated their use to differentiate ILTV strains. The approach using the sequencing of the two fragments of the ICP4 gene showed to be an efficient and practical procedure to differentiate between field isolates and vaccine strains of ILTV.
authors.affiliation: Department of Pathology, University of São Paulo, São Paulo, Brazil.
authors.forename: Jorge Luis
authors.initials: JL
authors.lastname: Chacón
authors.forename: Antonio J Piantino
authors.initials: AJ
authors.lastname: Ferreira
mesh_terms: D000818:Animals; D002642:Chick Embryo; D002645:Chickens / Q000821:virology; D004279:DNA, Viral / Q000235:genetics; D001352:Herpesvirus 1, Gallid / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D014764:Viral Proteins / Q000235:genetics*
chemical_list: D004279:DNA, Viral; C093684:ICP4 protein, infectious laryngotracheitis virus; D014764:Viral Proteins