Sequencing field isolates of ILTV
University of Delaware
The objective of this project is to develop new sequencing technology which will be used to determine and analyze the infectious laryngotracheitis virus (ILTV) genome. Infectious laryngotracheitis is an acute respiratory tract infection of birds. The disease spreads rapidly and is characterized by bloody mucus, gasping, and high mortality. The virus itself is classified as an alpha herpesvirus (Gallid herpesvirus 1), with a genome approximately 150,000 nucleotides in length (49). By using next-generation sequencing (Illumina) technology we have sequenced two field isolates of ILTV. The first isolate (1874C5) is a 2005 field isolate from Georgia. The second isolate (632) is a 1985 Delaware field isolate. The sequences of these two isolates were compared to show how similar the strains remain across time and geographical location. The results of sequencing for the 1874C5 strain yielded a total of 6,122,687 ILTV bases that aligned to the published reference sequence (49). For the 632 strain, a total of 432,786,937 ILTV bases were sequenced which aligned to the reference. Analysis of the 632 and 1874C5 isolates show that the two sequences are 97.6% similar with only 128 single nucleotide polymorphisms (SNPs) between them, and that the Delaware isolate contains a 3,333 base pair deletion from nucleotide 2173 to 5746.