Development of a qPCR for the detection of infectious laryngotracheitis virus (ILTV) based on the gE gene.

1. Infectious laryngotracheitis is a respiratory disease that affects the poultry industry worldwide. It is common in flocks with high-bird density, causing major economic losses. 2. In this study, a SYBR® FAST polymerase chain reaction (PCR) double-strand DNA intercalating agent assay was performed for the detection of infectious laryngotracheitis virus (ILTV) in clinical samples in comparison with a conventional nested-PCR, both based on the glycoprotein E encoding gene. This assay amplified 56 bp and was capable of detecting 1 to 1 copies of virus. 3. In total, 164 clinical samples were obtained from birds with respiratory problems from the period of 2009-2016. In the nested-PCR, there were 45.12% positive samples and 54.88% negative samples, while in the real-time PCR (qPCR), there were 81.1% positive samples and 18.9% negative samples. 4. In conclusion, qPCR from the DNA double-strand intercalating agent SYBR® GREEN FAST was useful for the diagnosis of ILTV because it detected samples that were negative in nested-PCR. This assay has advantages, such as a shortened processing-time, and no need for post-amplification processing (electrophoresis) with additional reagents, such as MgCl and agarose. Hence, qPCR proved to be useful, rapid and low cost for use with clinical samples.