Infection of Thai Influenza A Viruses Subtype H5N1 Using Tracheal Culture

Abstract

Avian influenza (AI) is caused by influenza A virus subtype H5N1. The virus causes severe disease and death in several avian and mammalian species. This study investigated the ability of swine and chicken tracheal cultures to support highly pathogenic avian influenza subtype H5N1 (HPAI-H5N1) viral replication. Three Thai HPAI-H5N1 viruses isolated from chicken (A/chicken/Thailand/CU-K2/04), duck (A/duck/Thailand/CU-328/07), and tiger (A/tiger/Thailand /CU-T7/04) were used to infect the swine and chicken tracheal cultures. Our results indicated that the chicken tracheal culture could support virus replication in contrast to the swine tracheal culture, suggesting that pig has low susceptibility to Thai HPAI-H5N1 infection. Immunohistochemical staining and histopathological study showed tracheal epithelial necrosis and exfoliation, confirming HPAI-H5N1 infection. Overall, our results suggest the possibility of using animal tracheal culture as in vitro model to study HPAI infection mechanism. The information gained from the study can be used for better understanding of the pathogenesis and prevention and control of HPAI infection in the future.