Isolation and molecular characterization of a H5N1 virus isolated from a Jungle crow (Corvus macrohynchos) in India

Area of Science:

• Veterinary Virology
• Molecular Epidemiology

Background:

• Widespread outbreaks of H5N1 avian influenza virus impacted West Bengal, Tripura, and Assam, India, in 2008.
• The virus was initially detected in Kamrup district, Assam, and rapidly spread to multiple districts.

Purpose of the Study:

• To characterize the H5N1 avian influenza virus detected in a wild crow in Assam, India.
• To understand the phylogenetic and molecular properties of the circulating H5N1 strain.

Main Methods:

• Virus isolation and detection using real-time RT-PCR and RT-PCR.
• Full-length genome sequencing of all eight viral gene segments.
• Phylogenetic and molecular analyses to determine viral characteristics.

Main Results:

• H5N1 avian influenza virus was confirmed in a dead Jungle crow (Corvus macrohynchos).
• Phylogenetic analysis placed the virus within clade 2.2, closely related to human and avian isolates from India and other countries.
• Molecular analysis revealed avian receptor specificity (alpha 2,3 sialic acid), susceptibility to antivirals, and low pathogenicity in mice.

Conclusions:

• The identified H5N1 virus in Assam belongs to clade 2.2, indicating potential regional and international spread.
• The virus possesses characteristics suggesting adaptation to avian hosts and susceptibility to common antivirals.
• Further surveillance is crucial to monitor H5N1 evolution and potential zoonotic risks.