title: Isolation and phylogenetic characterization of haemagglutinin and neuraminidase genes of H9N2 low pathogenicity avian influenza virus isolated from commercial layers in India.
abstract: Avian influenza is a highly infectious and dynamically evolving disease of birds causing high morbidity and mortality. It is caused by avian influenza virus (AIV) that belongs to the family Orthomyxoviridae. Two types of AIV have been described based on their pathogenicity viz. highly pathogenic avian influenza virus that causes severe disease with high mortality and low pathogenic avian influenza virus (LPAI) that generally causes asymptomatic infection or a mild disease. The H9N2 subtype is the widely circulated LPAI type in the world. The H9N2 subtype of was first reported from northern India in March 2003. However, systematical surveillance information for the evolution of H9N2 viruses in poultry flocks of Southern India is lacking. The present study reports the isolation and characterization of H9N2 isolates from the southern parts of the country during the period between May 2010 and September 2011. Out of the 30 poultry flocks investigated, six were found to be positive for HA activity. Further, all the six samples conformed as AIV. Partial nucleotide sequencing of the HA and NA genes revealed that all were belonging to the H9N2 subtype. Phylogenetically, the HA and NA genes of the H9N2 viruses from India clustered with those isolated from Bangladesh, Pakistan and the Middle East, although we were not able to conclude on their exact geographic origin.
authors.affiliation: Avian Diseases Section, Division of Pathology, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh 243 122 India ; Poultry Disease Diagnosis and Surveillance Laboratory, Veterinary College and Research Institute Campus, Tamil Nadu Veterinary and Animal Sciences University, Namakkal, Tamil Nadu 637 002 India.
authors.forename: Vasudevan
authors.initials: V
authors.lastname: Gowthaman
authors.affiliation: Avian Diseases Section, Division of Pathology, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh 243 122 India.
authors.forename: Shambu Dayal
authors.initials: SD
authors.lastname: Singh
authors.affiliation: Avian Diseases Section, Division of Pathology, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh 243 122 India.
authors.forename: Kuldeep
authors.initials: K
authors.lastname: Dhama
authors.affiliation: Poultry Disease Diagnosis and Surveillance Laboratory, Veterinary College and Research Institute Campus, Tamil Nadu Veterinary and Animal Sciences University, Namakkal, Tamil Nadu 637 002 India.
authors.forename: Palani
authors.initials: P
authors.lastname: Srinivasan
authors.affiliation: Poultry Disease Diagnosis and Surveillance Laboratory, Veterinary College and Research Institute Campus, Tamil Nadu Veterinary and Animal Sciences University, Namakkal, Tamil Nadu 637 002 India.
authors.forename: Sellappan
authors.initials: S
authors.lastname: Saravanan
authors.affiliation: Poultry Disease Diagnosis and Surveillance Laboratory, Veterinary College and Research Institute Campus, Tamil Nadu Veterinary and Animal Sciences University, Namakkal, Tamil Nadu 637 002 India.
authors.forename: Thippichettypalayam Ramasamy Gopala Krishna
authors.initials: TR
authors.lastname: Murthy
authors.affiliation: Department of Veterinary Microbiology, Veterinary College and Research Institute, Namakkal, Tamil Nadu 637002 India.
authors.forename: Kuppanan
authors.initials: K
authors.lastname: Sukumar
authors.affiliation: Division of Virology, Indian Veterinary Research Institute, Mukteswar, Uttarakhand 263 138 India.
authors.forename: Basavaraj
authors.initials: B
authors.lastname: Mathapati
authors.affiliation: UMR Processus Infectieux en Milieu Insulaire Tropical, INSERM U1187, CNRS 9192, Université de La Réunion, IRD 249 Saint Denis, Reunion Island, France.
authors.forename: Camille
authors.initials: C
authors.lastname: Lebarbenchon
authors.affiliation: Division of Biological Standardization, ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh 243 122 India.
authors.forename: Yashpal Singh
authors.initials: YS
authors.lastname: Malik
authors.affiliation: Division of Virology, Indian Veterinary Research Institute, Mukteswar, Uttarakhand 263 138 India.
authors.forename: Muthannan Andavar
authors.initials: MA
authors.lastname: Ramakrishnan
keywords: Characterization; Haemagglutinin; India; LPAI-H9N2; Neuraminidase