title: Genotyping of infectious laryngotracheitis virus using allelic variations from multiple genomic regions.
abstract: Live attenuated vaccines are extensively used worldwide to control the outbreak of infectious laryngotracheitis. Virulent field strains showing close genetic relationship with the infectious laryngotracheitis virus (ILTV) vaccines of chicken embryo origin have been detected in the poultry industry. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis, a reliable molecular epidemiological method, of multiple genomic regions was performed. The PCR-RFLP is a time-consuming method that requires considerable amount of intact viral genomic DNA to amplify genomic regions greater than 4 kb. In this study, six variable genomic regions were selected and amplified for sequencing. The multi-allelic PCR-sequence genotyping showed better discrimination power than that of previous PCR-sequencing schemes using single or two target regions. The allelic variation patterns yielded 16 strains of ILTV classified into 14 different genotypes. Three Korean field strains, 550/05/Ko, 0010/05/Ko and 40032/08/Ko, were found to have the same genotype as the commercial vaccine strain, Laryngo Vac (Zoetis, Florham Park, NJ, USA). Three other Korean field strains, 40798/10/Ko, 12/07/Ko, and 30678/14/Ko, showed recombined allelic patterns. The multi-allelic PCR-sequencing method was proved to be an efficient and practical procedure to classify the different strains of ILTV. The method could serve as an alternate diagnostic and differentiating tool for the classification of ILTV, and contribute to understanding of the epidemiology of the disease at a global level.
authors.affiliation: a College of Veterinary Medicine , Konkuk University , Seoul , Republic of Korea.
authors.forename: Eun-Jung
authors.initials: EJ
authors.lastname: Choi
authors.affiliation: a College of Veterinary Medicine , Konkuk University , Seoul , Republic of Korea.
authors.forename: Tae-Min
authors.initials: TM
authors.lastname: La
authors.affiliation: a College of Veterinary Medicine , Konkuk University , Seoul , Republic of Korea.
authors.forename: In-Soo
authors.initials: IS
authors.lastname: Choi
authors.affiliation: a College of Veterinary Medicine , Konkuk University , Seoul , Republic of Korea.
authors.forename: Chang-Seon
authors.initials: CS
authors.lastname: Song
authors.affiliation: a College of Veterinary Medicine , Konkuk University , Seoul , Republic of Korea.
authors.forename: Seung-Yong
authors.initials: SY
authors.lastname: Park
authors.affiliation: a College of Veterinary Medicine , Konkuk University , Seoul , Republic of Korea.
authors.forename: Joong-Bok
authors.initials: JB
authors.lastname: Lee
authors.affiliation: a College of Veterinary Medicine , Konkuk University , Seoul , Republic of Korea.
authors.forename: Sang-Won
authors.initials: SW
authors.lastname: Lee
mesh_terms: D000483:Alleles; D000818:Animals; D002642:Chick Embryo; D002645:Chickens / Q000821:virology*; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D005260:Female; D005838:Genotype; D006566:Herpesviridae Infections / Q000662:veterinary* / Q000821:virology; D001352:Herpesvirus 1, Gallid / Q000145:classification* / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011201:Poultry Diseases / Q000821:virology*; D017422:Sequence Analysis, DNA / Q000662:veterinary
chemical_list: D004279:DNA, Viral
keywords: Herpesvirus; PCR-sequencing; genotyping; infectious laryngotracheitis virus; molecular epidemiology