Molecular detection and genetic characterization of infectious laryngotracheitis virus in poultry in Myanmar

Abstract

Background Avian infectious laryngotracheitis (ILT) is a highly contagious viral disease that causes severe economic losses to the poultry industry worldwide. In Southeast Asian countries, including Myanmar, poultry farming is a major industry. Although it is known that infectious respiratory pathogens like infectious laryngotracheitis virus (ILTV) are the major threat to poultry farms, there are no data currently available on the epidemiology of ILTV in Myanmar. In this study, therefore, we conducted molecular detection of ILTV in 20 poultry farms in Myanmar. Results Of the 57 tested oropharyngeal swabs, 10 were positive for ITLV by PCR of a 647 bp region of the thymidine kinase (TK) gene, giving a prevalence of ITLV of 17.5% (10/57). Further sequencing analysis of infected cell protein 4 ( ICP4 ) gene and glycoprotein B, G, and J ( gB , gG , and gJ ) genes indicated that these isolates were field strains. Phylogenetic analysis revealed that the Myanmar strains clustered together in a single branch and were closely related to other reference strains isolated from Asian countries. Conclusions This study demonstrated the presence of ILTV in poultry farms in Myanmar. The genetic characterization analysis performed provides the fundamental data for epidemiological studies monitoring circulating strains of ILTV in Myanmar.