Development and application of high?resolution melting analysisfor the classification of infectious laryngotracheitis virus strainsand detection of recombinant progeny

Abstract

AbstractLive attenuated vaccines against infectious laryngotracheitis virus (ILTV) are widely used in the poultry industry to controldisease and help prevent economic losses. Molecular epidemiological studies of currently circulating strains of ILTV withinpoultry flocks in Australia have demonstrated the presence of highly virulent viruses generated by genomic recombinationevents between vaccine strains. In this study, high-resolution melting (HRM) analysis was used to develop a tool to classifyILTV isolates and to investigate ILTV recombination. The assay was applied to plaque-purified progeny viruses generatedafter co-infection of chicken embryo kidney (CEK) monolayers with the A20 and Serva ILT vaccine strains and also toviruses isolated from field samples. The results showed that the HRM analysis is a suitable tool for the classification ofILTV isolates and can be used to detect recombination between ILTV vaccine strains in vitro. This method can be used toclassify a broad range of ILTV strains to facilitate the classification and genotyping of ILTV and help to further understandrecombination in these viruses